Journal articles: 'The drilling head'

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Król, Kazimierz, Krzysztof Olejarczyk, Marcin Wikło, Zbigniew Siemiątkowski, and Krzysztof Kołodziejczyk. "Individuality dynamic system drilling head – pipe drilling – shaft during drilling deep hole." Mechanik, no. 3 (March 2015): 190/1–190/6. http://dx.doi.org/10.17814/mechanik.2015.3.110.

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Peng, Xiaogan, Liang Li, Bo Chen, Shen Yin, Zhongwang Yin, and Yinfei Yang. "Experimental study on drilling basalt with self-vibratory drilling head." Advances in Space Research 65, no. 5 (March 2020): 1344–52. http://dx.doi.org/10.1016/j.asr.2019.12.002.

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Agzamov, Z. V. "Head-target tracking control of well drilling." Journal of Physics: Conference Series 1015 (May 2018): 032159. http://dx.doi.org/10.1088/1742-6596/1015/3/032159.

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Smith, Stephen, Thomas Fehring, and Walter Beaver. "EFFICACY OF DRILLING THE OSTEONECROTIC FEMORAL HEAD." Southern Medical Journal 86, Supplement (September 1993): 83. http://dx.doi.org/10.1097/00007611-199309001-00224.

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Hou, Yali, Changhe Li, Hongliang Ma, Yanbin Zhang, Min Yang, and Xiaowei Zhang. "An Experimental Research on Bone Drilling Temperature in Orthopaedic Surgery." Open Materials Science Journal 9, no. 1 (October 6, 2015): 178–88. http://dx.doi.org/10.2174/1874088x01509010178.

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The bone drilling temperature fields under different cutting parameters and cooling modes were experimental researched by using common twist drill, diamond punching pin, diamond bullet-like grinding head and diamond spherical grinding head. Three cooling modes were applied, namely, natural air cooling, normal saline pouring cooling and normal saline spray cooling. K-thermocouple was used to measure temperature in bone hole. Results showed that the drill shape could influence drilling temperature greatly. The maximum drilling temperature of diamond spherical grinding head is 46.31°C. The maximum drilling temperature of common twist drill is 42.1°C and that of diamond bullet-like grinding head is 38.29°C. The drilling temperatures at drill speed is under 560 r/min, 900 r/min, 1,250 r/min and 2,100 r/min are 38.84°C, 41.1°C, 43.84°C and 46.31°C. This reflects that under same of other drilling parameters, drilling temperature increases with the increase of drill speed. The maximum bone drilling temperatures of diamond punch pin under 2,100 r/min speed of mainshaft and air cooling conditions vary as feed speed increase firstly and then decrease. The normal saline spray cooling has the lowest maximum drilling temperature of (29.34°C) at same depth, following by normal saline pouring cooling of (32.45°C) and air cooling of (40.28°C) successively. The normal saline spray cooling has the best cooling effect, followed by normal saline pouring cooling and air cooling successively.

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Azuma, Nobuhiko, Ikuo Tanabe, and Hideaki Motoyama. "Heat generated by cutting ice in deep ice-core drilling." Annals of Glaciology 47 (2007): 61–67. http://dx.doi.org/10.3189/172756407786857848.

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AbstractIn order to understand and solve the ‘warm-ice problem’ in deep ice-core drilling, we applied the metal-cutting theory to ice and estimated the heat generated during ice coring taking into account the mechanical and thermal properties of the ice and cutters. We found that (1) most of the heat in cutting is generated by shear deformation at the shear plane of ice, and the heat could increase the chip temperature by several degrees; (2) the rake angle of the cutter has more influence on the temperature increase in chips than the barrel rotation speed and penetration pitch; (3) if the cutter is made of a material with larger thermal conductivity, the temperature increase in the chips can be reduced; and (4) if the density of the liquid is less than the density of ice, the cutting chips sink to the bottom and the friction heat generated by the drill head and slush can raise the ambient temperature of the drill head by several degrees.

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Gao, Xing Jun, Ping Zou, De Jun Li, and Zhi Yang Xiang. "Research on Breaking Chip and Drilling Force for High Temperature Alloy Based on Self-Vibratory Drilling Head." Advanced Materials Research 299-300 (July 2011): 1044–47. http://dx.doi.org/10.4028/www.scientific.net/amr.299-300.1044.

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Problems to evacuate chips will arise from manufacturing deep holes, especially for small diameters. Such problems induce frequent tool breakage and poor surface quality. The vibratory drilling enables the chip to be split into small elements thanks to the axial vibrations of the drill, self-maintained by the cutting energy. This research aims to improve breaking chip concerning high temperature alloy by vibraiont drilling as well as to establish a drilling technology. The development of breaking chip technology was presented. By the aid of the self-made vibrating drilling table, the axial vibration drilling was experimented on high temperature alloy with different parameter of vibration drilling. The breaking chip effect of vibration cutting was studied, and the axial drilling force and torque of vibration drilling were analyzed. The relation of each parameter and its effect on machining process was theoretically discussed. The experiment results show that vibration drilling is in favor of breaking chip, making the volume of chip small, and removing chips fluently, and the change of drilling force is relatively steady with some drilling parameters.

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Chládek, P., V. Havlas, and T. Trc. "Drilling and plombage (core decompression) of a femoral head avascular necrosis." Osteologie 19, no. 01 (2010): 36–39. http://dx.doi.org/10.1055/s-0037-1619921.

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SummaryThe treatment of femoral head necrosis of adults is still rather problematic. Conservative treatment has been reported relatively unsuccessful and surgical treatment does not show convincing results either. The most effective seems to be a surgical treatment in early stages of the disease, however, the diagnosis still remains relatively complicated. For the late stages (2B and above) the most effective treatment option is represented by core decompression and vascular grafting. However, drilling and plombage (especially when using press-fit technique) seems to be successful, although not excellent. The authors describe their own method of drilling and plombage of the necrotic zone of the femoral head in 41 patients with X-ray detected necrotic changes of the femoral head. The pain measured by VAS was seen to decrease after surgery in all patients significantly. The Jacobs score was also observed to have increased (from fair to good outcome). We have not observed any large femoral head collapse after surgery, moreover, in some cases an improvement of the round shape of the femoral head was seen. It is important to mention that in all cases femoral heads with existing necrotic changes (flattening or collapse) were treated. Although the clinical improvement after surgery was not significantly high, the method we describe is a safe and simple method of diminishing pain in attempt to prepare the femoral head for further treatment in a future, without significant restriction of the indication due to necrosis (osteochondroplasty, resurfacing, THR).

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Boiadjiev, Tony, Rumen Kastelov, George Boiadjiev, Kamen Delchev, and Kazimir Zagurski. "Automatic bone drilling by femoral head structure detection." Biotechnology & Biotechnological Equipment 32, no. 3 (November 23, 2017): 785–94. http://dx.doi.org/10.1080/13102818.2017.1407256.

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Mousavi, S., V. Gagnol, and P. Ray. "Machining prediction of spindle–self-vibratory drilling head." Journal of Materials Processing Technology 213, no. 12 (December 2013): 2119–25. http://dx.doi.org/10.1016/j.jmatprotec.2013.06.012.

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Mei, Yu Tao, and Guang Zhen Cheng. "The Semi-Automatic Drilling Machine for Flange Processing." Applied Mechanics and Materials 345 (August 2013): 543–46. http://dx.doi.org/10.4028/www.scientific.net/amm.345.543.

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This paper designed a semi-automatic drilling machine used in flange hole processing. The drilling machine consists of rotary power head, power head straight reciprocating device, rotary indexing table, positioning clamping device. Rotary power head is driven by the motor, and realize the rotary motion through the gear driving. Power head straight reciprocating device, rotary indexing table, positioning clamping device driven by the hydraulic cylinder, to achieve the semi-automatic of the flange hole processing cooperate with the PLC sequence control function. It has short design cycle, low investment, high efficiency and smooth hydraulic actuator with the generic parts of modular machine tool. Combined with programmable controller to realize the sequence control. And it will be easy to operate, operate reliable and with high efficiency.

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Jiang, Junxia, Chen Bian, Yunbo Bi, and Yinglin Ke. "A new type of inner-side working head for automatic drilling and riveting system." Assembly Automation 39, no. 1 (February 4, 2019): 154–64. http://dx.doi.org/10.1108/aa-09-2017-107.

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PurposeThe purpose of this paper is to design, analyze and optimize a new type of inner-side working head for automatic horizontal dual-machine cooperative drilling and riveting system. The inner-side working head is the key component of automatic drilling and riveting system, and it is a challenge to design an inner-side working head which must be stiffness and stable with a compact structure to realize its functions.Design/methodology/approachAccording to the assembly structure features of large aircraft panels and riveting process requirements, a new type of inner-side working head is designed for pressure riveting. The force condition of the inner-side working head during the riveting process is analyzed and the deformation model is established. Design optimization is performed based on genetic algorithm and finite element analysis. The optimized inner-side working head is tested with automatic horizontal dual-machine cooperative drilling and riveting system.FindingsThe deformation model provides the precision compensation basis for control system. Application test results show that the automatic drilling and riveting system can realize assembly of large aircraft panel with high efficiency and quality through the inner-side working head.Research limitations/implicationsThe inner-side working head has been used in aircraft panel assembly.Practical implicationsThe inner-side working head has been used in aircraft panel assembly.Originality/valueThis paper presents the design, analysis and optimization of a new type of inner-side working head which can realize automatic riveting for aircraft panel. The research will promote the automation of aircraft panel assembly.

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Aamir, Muhammad, Shanshan Tu, Majid Tolouei-Rad, Khaled Giasin, and Ana Vafadar. "Optimization and Modeling of Process Parameters in Multi-Hole Simultaneous Drilling Using Taguchi Method and Fuzzy Logic Approach." Materials 13, no. 3 (February 3, 2020): 680. http://dx.doi.org/10.3390/ma13030680.

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In industries such as aerospace and automotive, drilling many holes is commonly required to assemble different structures where machined holes need to comply with tight geometric tolerances. Multi-spindle drilling using a poly-drill head is an industrial hole-making approach that allows drilling several holes simultaneously. Optimizing process parameters also improves machining processes. This work focuses on the optimization of drilling parameters and two drilling processes—namely, one-shot drilling and multi-hole drilling—using the Taguchi method. Analysis of variance and regression analysis was implemented to indicate the significance of drilling parameters and their impact on the measured responses i.e., surface roughness and hole size. From the Taguchi optimization, optimal drilling parameters were found to occur at a low cutting speed and feed rate using a poly-drill head. Furthermore, a fuzzy logic approach was employed to predict the surface roughness and hole size. It was found that the fuzzy measured values were in good agreement with the experimental values; therefore, the developed models can be effectively used to predict the surface roughness and hole size in multi-hole drilling. Moreover, confirmation tests were performed to validate that the Taguchi optimized levels and fuzzy developed models effectively represent the surface roughness and hole size.

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Ong, F. R., and K. Bouazza-Marouf. "Evaluation of bone strength: Correlation between measurements of bone mineral density and drilling force." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 214, no. 4 (April 1, 2000): 385–99. http://dx.doi.org/10.1243/0954411001535426.

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Bone drilling is a major part of modern orthopaedic surgery which involves the internal fixation of fractured bones. The investigation of bone drilling described in this paper demonstrates the contribution of automation technology towards the study of bone strength. The aim of this preliminary investigation is to establish a relationship between bone drilling forces and measurements of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA). A linear relationship with a high coefficient of correlation has been found between average drilling forces and BMD measurements at both the greater trochanter and the femoral head of porcine femurs when drilling in the anterior-posterior (AP) direction (i.e. the direction of the DXA scan). It has also been found that in the normal drilling direction (i.e. in the cervical axis direction), which is orthogonal to the DXA scanning direction, there are similar trends between the drilling forces and BMD levels in regions where bone density is more consistent (e.g. the femoral head). The findings of this investigation indicate that analysis of bone drilling forces has the potential to provide useful information about the strength of bone.

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Luan, Zhen Hui, and Lian Jie Cai. "Research on Cone Angle of Cutter Head for Big Diameter Shaft with Analysis of Drilling Mechanics." Applied Mechanics and Materials 252 (December 2012): 85–88. http://dx.doi.org/10.4028/www.scientific.net/amm.252.85.

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In order to get a high drilling speed of shaft of nearly 13 m diameter, the authers studied on the shape of the cutter head, particularly about the cone angle. The paper discussed the motion process of slurry of drilling shaft, analysed the forces on the cutter head, and the forces on the cuttings and the motions of the cuttings in slurry. The results show that, the cone angle of the cutter head can be minished at least 20 degree.

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Fei, Ye, Shu Yang Cong, and Bin Bian. "Hydraulic System Simulation of Heavy Horizontal Directional Drilling Head." Advanced Materials Research 287-290 (July 2011): 428–31. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.428.

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According to the features of heavy horizontal directional drill hydraulic system, power head hydraulic system which is the main working mechanism of the 280t horizontal directional drilling is modeled and simulated base on Amesim. On that basis, we adjust working characteristics of this model and make the point of view that feedback control parameters which is the hydraulic system of heavy drill should be adjusted according to the soil conditions. So that it can enhance the utilization rate of the machine power and drilling efficiency in different operating modes.

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Litvinenko, V. S., N. I. Vasiliev, V. Ya Lipenkov, A. N. Dmitriev, and A. V. Podoliak. "Special aspects of ice drilling and results of 5G hole drilling at Vostok station, Antarctica." Annals of Glaciology 55, no. 68 (2014): 173–78. http://dx.doi.org/10.3189/2014aog68a040.

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AbstractThis paper documents the drilling of the 5G deep hole at the Russian Vostok station, Antarctica. The hole construction is described and the specifications of the drill and surface drilling equipment are given. The peculiarities of drilling at various depths are considered. Based on the extensive experimental data collected at Vostok station, the processes occurring at the hole bottom are investigated: ice breaking and cutting, bottom cleaning and chip transport, and accumulation of the chips in the screen. The main factors affecting ice-drilling efficiency are the coarseness of ice crystals and the ice temperature. When ice crystal size exceeds 10 mm the cutting efficiency sharply decreases, and when ice temperature exceeds –5°C the chip transport from the hole bottom and the chip density in the screen are reduced. The drill advance then becomes irregular, slows down and may even be terminated in some cases. Optimal values of the basic drilling parameters (e.g. cutter head rotation rate and drilling fluid flow rate in the circulation system) have been deduced empirically. The designs of the cutter head and circulation system including screens have been significantly modified, allowing the drilling process to proceed at a normal rate even in the vicinity of the subglacial lake surface.

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Shan, Fan, and Zeping Chen. "Hydraulic Simulation Analysis of Sonic Drilling Hydraulic Vibration Head." MATEC Web of Conferences 256 (2019): 02014. http://dx.doi.org/10.1051/matecconf/201925602014.

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The hydraulic vibration head is the core component of sonic drilling rig, and the performance of its hydraulic system influences the technology of sonic drilling directly. The structure and hydraulic system of the hydraulic vibration head are designed, and the AMESim model of the hydraulic system is established in the paper. The hydraulic vibration system is simulated and analyzed to find out the influence rule of vibration frequency on the system performance. The results show that the larger the vibration frequency f is, the smaller the amplitude H is, and the displacement response of the vibrating piston approximates the sine curve.The velocity and acceleration of the vibrating piston accordingly increased, and the exciting force F of the vibrating piston increased significantly.

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Wang, Weixu, Guangchan Ma, Xiuju Yang, Tianming Zhou, Peng Zhang, Yunpeng Li, Nan Hu, and Anyi Wang. "Research on the Integration Design of Double Well Head Drilling System for Semi-submersible Drilling Platform." IOP Conference Series: Materials Science and Engineering 611 (October 24, 2019): 012065. http://dx.doi.org/10.1088/1757-899x/611/1/012065.

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Piotrowski, Andrzej. "Using of CAD/CAE systems in designing of head for thread drilling on multirate stamp press." Mechanik 91, no. 7 (July 9, 2018): 487–89. http://dx.doi.org/10.17814/mechanik.2018.7.62.

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The using of CAD/CAE systems in design of head for thread drilling and reaming on multirate stamp press was described. It was presented model of device for thread drilling with the basics calculation. Furthermore, design of special tool for rearming and cutting in one step was described.

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Bai, Shixin, Zhijian Liu, and Jin Wang. "Research on the Dynamics of Geological Drilling Rig against Drill Pipe Impact." Shock and Vibration 2021 (January 29, 2021): 1–10. http://dx.doi.org/10.1155/2021/6679169.

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With the ever-increasing demand for resources, the task of geological surveys has increased rapidly, and automated geological drilling rigs that can improve the efficiency of geological surveys have become the mainstream research direction. Automated geological drilling rigs can improve construction efficiency, reduce labor intensity, and effectively reduce construction accidents. During the construction of geological survey operations, accidents such as drill breakage, stuck drill, and equipment damage, which are easily caused by drill pipe impact, occur from time to time. Therefore, drill pipe impact dynamics is currently a hot topic in academic research, but there are few studies that combine automated geological drilling rigs with drill pipe impact. This article starts with the research on the hydraulic system of the power head of the automatic drilling rig and studies the dynamics of the damage of the power head of the drilling rig caused by the impact of the drill pipe by means of hydraulic valve torque limit and closed-loop control of the speed. The oil valve group reduces the reverse torsional impact of the drill pipe on the hydraulic motor. At the same time, the requirements for the selection and pressure setting of the relief valve in the buffer filling oil valve group are proposed. The natural frequency of the relief valve is not less than 20 Hz, and the pressure is set to the working pressure 1.25 times. The effects of shock with or without the buffer filling oil valve group and the oil supply line on the power head motor were compared. The research results of this paper can provide theoretical reference and design basis for subsequent development of automated drilling rigs.

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Ma, Jun Chao, Cheng Bin Yang, and Hong Ming Yu. "Construction Technology Research on Revolving Conical Pullout Anchor." Applied Mechanics and Materials 858 (November 2016): 10–14. http://dx.doi.org/10.4028/www.scientific.net/amm.858.10.

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To solve the anti-float problems of underground buildings (structures) more economically, environmentally and effectively. The paper putted forward a construction technology of revolving conical pullout anchors based on researching and improving to the traditional pullout measures. That was a method that the conical anchor head was installed on the drilling pipe and screwed into the stable soil under the influence of drilling pipe. When pulling the drilling pipe, the fine aggregate concrete were poured into the edge. Furthermore, prestressed anchor cable should be strained which connected with the anchor head to keep a good connect with the beam so that it could improve pullout capacity. The conundrums of long construction period and high cost had effectively solved. This technique also had provided great reference values for the congener construction.

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Ochoa, J. A., A. P. Sanders, T. W. Kiesler, D. A. Heck, J. P. Toombs, K. D. Brandt, and B. M. Hillberry. "In Vivo Observations of Hydraulic Stiffening in the Canine Femoral Head." Journal of Biomechanical Engineering 119, no. 1 (February 1, 1997): 103–8. http://dx.doi.org/10.1115/1.2796051.

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The role that intertrabecular contents and their boundary conditions have on the dynamic mechanical response of canine femoral heads was investigated in vivo. Femoral heads from paired intact hind limbs of canine specimens were subjected to a sinusoidal strain excitation, at physiologic frequencies, in the cranio-caudal direction. The fluid boundary conditions for the contralateral limbs were changed by predrilling through the lateral femoral cortex and into the femoral neck. The drilling procedure did not invade the head itself. This femoral head fluid boundary alteration reduced the stiffness by 19 percent for testing at 1 Hz. The results of this study demonstrate that fluid stiffening occurs in vivo as previously observed ex vivo.

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Kao, Wen Hsien, Yan Liang Su, Sun Hui Yao, H. C. Huang, and M. S. Chen. "The Study of High Speed Micro-Drilling Performance and Machining Quality of Coated Micro-Drills with Zr-C:H Coatings." Advanced Materials Research 591-593 (November 2012): 342–46. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.342.

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The Zr-C:H coatings with various C2H2 flow rate were deposited on micro-drills (a diameter of 0.2 mm) used a closed field unbalanced magnetron sputtering system. The ultrahigh speed (drilling speed of 160000 rpm) through-hole drilling printed circuit board tests used to evaluate the drilling performance of the coated micro-drills. The rejection criteria of service lives of the coated micro-drills were evaluated using two different criteria: (1) a nail head ratio greater than 1.5; (2) a drilled hole surface roughness greater than 25.4 μm. Adopting a service life criterion of a nail head ratio of 1.5, the Zr-C:H-5 coating possesses the optimal high-speed machining performance, which yields a micro-drill lifetime of above 6000 drilled holes. It represents a three-fold improvement on that of an uncoated micro-drill and it also improves machining quality.

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Wegert, R., V. Guski, H. C. Moehring, and S. Schmauder. "IN-PROCESS MEASUREMENT AND NUMERICAL DETERMINATION OF THE TEMPERATURE IN THE CONTACT ZONE DURING SINGLE LIP DEEP HOLE DRILLING." MM Science Journal 2021, no. 3 (June 30, 2021): 4556–62. http://dx.doi.org/10.17973/mmsj.2021_7_2021059.

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In this presented work, the main objective is the in-process measurement of the thermal as-is state near the drilling contact zone by means of a sensor-integrated tool for single lip deep hole drilling (SLD). Additionally, the mechanical quantities feed force and drilling torque are evaluated. The process monitoring is essential to optimize the surface quality as well as the subsurface properties such as hardness and residual stresses. These quantities are strongly dependent on the thermo-mechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. This contribution gives a project overview including the development of a sensor-integrated single lip deep hole driller for the in-process temperature measurement, the integration of sensor systems in the tool as well as the experimental investigations on the temperature, the feed force and the drilling torque during drilling of a 42CrMo4 steel. The temperature measurement at eleven positions in the driller head provides data to observe the heat generation, distribution, and flow independently from the workpiece characteristics. However, one of the greatest benefits is the non-destructive fashion of the measurement system with their sensor integrated in the tool and thus the reusability. A simulation method, which uses the experimental results as a reference, is used to predict the thermo-mechanical conditions in the contact zone of the drill head and the workpiece. The results of these thermo-mechanical process simulations and the validation of this applied FE approach using the measured quantities are presented, too. The results of this work are part of an interdisciplinary research project in the framework of the priority program "Surface Conditioning in Machining Processes" (SPP 2086) of the German Research Foundation (DFG).

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Popp, Trevor J., Steffen B. Hansen, Simon G. Sheldon, and Christian Panton. "Deep ice-core drilling performance and experience at NEEM, Greenland." Annals of Glaciology 55, no. 68 (2014): 53–64. http://dx.doi.org/10.3189/2014aog68a042.

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AbstractThe NEEM deep ice-core drilling in northwest Greenland was completed in summer 2010 after three seasons, which included establishing all drilling infrastructure. Normal drilling operations in the main borehole were declared terminated at 2537.36 m below the surface, when further penetration was stopped by a stone embedded in the ice in the path of the drill head. The design and implementation of the drilling operation strongly resembled the NGRIP drilling program. The NEEM drill was an extended version of the Hans Tausen (HT) drill, with specific modifications to optimize its use with the highly viscous Estisol-240/Coasol drill fluid used at NEEM. Modification to the drill and its performance in the new drilling fluid was largely satisfactory and successful. Throughout the drilling, special consideration was given to the way chips were transported and collected in a new chip chamber, including the consequences of drilling a larger borehole diameter than with previous drill operations that used the HT family of drills. The problems normally associated with warm ice drilling near the base of an ice sheet were largely absent at NEEM.

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Sheng, Ye, and Masayoshi Tomizuka. "Intelligent Modeling of Thrust Force in Drilling Process." Journal of Dynamic Systems, Measurement, and Control 128, no. 4 (February 4, 2006): 846–55. http://dx.doi.org/10.1115/1.2361322.

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In this paper, an intelligent modeling strategy for thrust force in drilling process is proposed. First of all, neural network (NN) models are developed to model the thrust force in drilling process. Second, drill head position information is included in the NN model to get better force prediction accuracy for entrance and exit drilling stages. Third, a fuzzy switching strategy is proposed to deal with the gain variation problem due to transitions from one drilling stage to another. Finally, gain variation due to drill wear is studied and the related modeling strategy is developed. Simulation and experimental results show that the proposed model works well over a wide operating range.

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ANISCHENKO, Vasily, and Viktor ATRUSHKEVICH. "INFLUENCE OF DRILLING RIG DESIGN ON WELL DRILLING EFFICIENCY." Sustainable Development of Mountain Territories 12, no. 3 (September 30, 2020): 383–93. http://dx.doi.org/10.21177/1998-4502-2020-12-3-383-393.

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The purpose of research in the extraction of minerals is the development of technologies that will make it possible to drill wells specially designed for the extraction of ores with a length of several kilometers and a diameter of 300 mm to 2 m. The main research method is an experiment, during which drilling of wells by alternative methods under the same conditions is compared according to a single the selected performance criterion. Drilling of wells with an average length of 1500 meters with an end diameter of 295 mm at a depth of 200 to 400 meters was carried out in soft rocky ground in two alternative ways. The productivity of a directional drilling rig is determined by the efficiency of related interconnected processes,the correlation of which is characterized by graphs, for example, the dependence of the load on the bit on the drilling speed. To calculate the load on the drill pipe, Young’s modulus and the moment of inertia of its section were used. The axial force for drilling the well is determined by calculation using experimental data. By modeling in the EXCEL program, the maximum WOB value was determined. To compare the drilling speeds of a traditional rig and a new generation rig, the speed with a 5 ton bit load and a 15 ton bit load is considered, at which, if other things are equal,the ROP increases three times. The drilling speed of wells with an inclined head of the new technology will be 167 m per day versus 105 m with traditional technology, and the operational productivity of drilling with one rig will be 71 m per day versus 51 m. Universal mobile rack rigs with automatic centering of the drill string and mast in vertical and inclined position and gearless hydraulic drive for rotation and movement of the drilling carriage ensure drilling of wells with a horizontal section length of 1500 meters and a diameter of 300 mm.

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Liu, Yi, Qiang Fang, and Yinglin Ke. "Hybrid Position/Force Control for Dual-Machine Drilling and Riveting System." Mathematical Problems in Engineering 2020 (August 24, 2020): 1–16. http://dx.doi.org/10.1155/2020/3493715.

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The deformation of riveting machine caused by riveting force during rivet formed makes the riveting tool out of positioning, which leads to gapping underneath the rivet manufactured head and insufficient rivet drive head. This paper proposes a hybrid position/force riveting control method for the dual-machine drilling and riveting system to eliminate the negative effects of machine deformation. The cooperative work of two-side machine tool is realized by a hybrid position/force control strategy, which compensates for the force-induced deformation error without an accurate stiffness model of the riveting system. The position of pressing foot relative to the machine which represents the deformation of skin-side machine is obtained for the compensation to the displacement of skin-side actuator. Simultaneously, the advanced force control is adopted for the stringer-side actuator. The dynamics model of the stringer-side actuator in consideration of the machine deformation is established and identified. The disturbance observer (DOB) and feedforward controller are introduced as the model-based control algorithm to achieve the high-performance force control. Also, contrast experiments are conducted to validate the effectiveness of the proposed riveting control method. The results show that the rivet manufactured head can be seated in the countersink during the forming process and the gapping under the head is eliminated. The driven head height tolerance of ±0.1 mm is achieved by accurate force control.

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Zagorodnov, V., and L. G. Thompson. "Thermal electric ice-core drills: history and new design options for intermediate-depth drilling." Annals of Glaciology 55, no. 68 (2014): 322–30. http://dx.doi.org/10.3189/2014aog68a012.

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AbstractIce coring of temperate and polythermal glaciers demonstrates some limitations of most electromechanical (EM) and thermal electric (TE) drills. Most TE drills are heavy, require a heavy power system, work slowly and cannot operate in boreholes going through the cold–temperate ice transition. Antifreeze thermal electric drills (ATED) are capable of operating in polar ice caps, polythermal and temperate glaciers, in boreholes filled with water and/or hydrophilic fluids. Performance of the ATED drill can be improved by using an open-top core barrel and low-power and narrow-kerf coring head. ATED-type drills can be modified for an open-top core barrel equipped with low-power coring head and include a new scheme for drilling-fluid circulation using two pumps. A small metering pump releases pure ethanol above the top of the drill, and a second pump enables circulation of the borehole fluid, an ethanol–water solution (EWS), above the kerf. Use of a narrow-kerf coring head reduces power requirements and makes it possible to design a lightweight drilling system that includes the EM and TE drills for shallow and intermediate-depth drilling.

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Chang, Dar Yuan, Kuo Ho Su, and Chyn Shu Deng. "Tool Wear in a Ceramic Microdrilling Processing Using Image Processing Methods." Advanced Materials Research 579 (October 2012): 227–34. http://dx.doi.org/10.4028/www.scientific.net/amr.579.227.

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A microhole array is a critical feature on a probe head for microprobe positioning in vertical probe cards. The precision of fabricating microholes affects the final positions of needle tips, and has a significant influence on the correctness of testing results. In the industry, the probe head is made of ceramic and the microhole array is mainly machined by a mechanical microdrilling process. Thus, measuring tool wear and the precision of the microhole is an important task in probe head fabrication. Only then can the functions of probe card be mastered effectively. This study presents a computer vision system that uses image processing methods to evaluate the microdrill wear. Five experiments with different drilling length and two trials of long-drilling were implemented. Wear measurements of the cutting lip and wear land discussed by image methods provide practical references for ceramic microdrilling.

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Neuhaus, Michael-Tobias, Alexander-Nicolai Zeller, Alexander K. Bartella, Anna K. Sander, Bernd Lethaus, and Rüdiger M. Zimmerer. "Accuracy of Guided Surgery and Real-Time Navigation in Temporomandibular Joint Replacement Surgery." Dentistry Journal 9, no. 8 (August 2, 2021): 87. http://dx.doi.org/10.3390/dj9080087.

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Background: Sophisticated guided surgery has not been implemented into total joint replacement-surgery (TJR) of the temporomandibular joint (TMJ) so far. Design and in-house manufacturing of a new advanced drilling guide with vector and length control for a typical TJR fossa component are described in this in vitro study, and its accuracy/utilization was evaluated and compared with those of intraoperative real-time navigation and already available standard drilling guides. Methods: Skull base segmentations of five CT-datasets from different patients were used to design drilling guides with vector and length control according to virtual surgical planning (VSP) for the TJR of the TMJ. Stereolithographic models of the skull bases were printed three times for each case. Three groups were formed to compare our newly designed advanced drilling guide with a standard drilling guide and drill-tracking by real-time navigation. The deviation of screw head position, screw length and vector in the lateral skull base have been evaluated (n = 72). Results: There was no difference in the screw head position between all three groups. The deviation of vector and length was significantly lower with the use of the advanced drilling guide compared with standard guide and navigation. However, no benefit in terms of accuracy on the lateral skull base by the use of real-time navigation could be observed. Conclusion: Since guided surgery is standard in implant dentistry and other CMF reconstructions, this new approach can be introduced into clinical practice soon, in order to increase accuracy and patient safety.

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Wu, Mark, Katherine Eisenberg, Kathryn Williams, and Donald S. Bae. "Radial Head Changes in Osteochondritis Dissecans of the Humeral Capitellum." Orthopaedic Journal of Sports Medicine 6, no. 4 (April 1, 2018): 232596711876905. http://dx.doi.org/10.1177/2325967118769059.

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Background: Osteochondritis dissecans (OCD) of the elbow has almost exclusively been described in the humeral capitellum, with only a small number of reports describing secondary osteochondral changes in the radial head. Hypothesis: The authors hypothesized that concomitant radial head lesions (RHLs) would be seen with capitellar OCD and that patients with RHLs would present with more advanced capitellar OCD lesions and would respond better to procedures restoring articular congruity. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 86 elbows from 82 patients (39 female patients; mean ± SD age, 13.8 ± 2.2 years; age range, 9.8-23.6 years) were treated for capitellar OCD and enrolled in a prospective registry. Clinical and radiographic data were compared between those with and without RHLs, with a median follow-up of 10.8 months (interquartile range, 6.2-17.1 months). Magnetic resonance imaging was used to characterize and measure RHLs and OCD lesions. Postoperative clinical results were compared between patients who underwent drilling and those who had osteochondral autograft transplantation surgery (OATS). Results: RHLs were present in 26 (30%) elbows—17 in the dominant arm. Edema was seen in 22 elbows; 17 had involvement of the anterior third of the radial epiphysis. Cysts were present in 4 elbows: 2 in the anterior third and 2 in the middle third. Blunting of the normal concave contour of the radial epiphysis was present in 10 elbows in the anterior third. Demographic and presenting clinical features were similar between those with and without RHLs. RHLs were more commonly seen in Nelson grade 4 OCD lesions ( P = .04) as compared with elbows without RHLs. Elbows with RHLs that underwent OATS (n = 9) trended toward greater improvement in forearm range of motion ( P = .058) and fewer persistent mechanical symptoms ( P = .06) postoperatively as compared with elbows having RHLs that underwent drilling. There were no postoperative differences in elbows without RHLs that underwent OATS versus drilling. Conclusion: RHLs were seen in one-third of elbows with capitellar OCD. Lesions predominantly occurred in the anterior RH in patients with more advanced capitellar lesions. Short-term clinical follow-up suggested greater improvement in range of motion and resolution of mechanical symptoms for patients with RHLs who were treated with OATS than with drilling.

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Danilov, Boris, and Boris Smolyanitskiy. "Optimization of technical solutions for pilot hole drilling in soil." MATEC Web of Conferences 216 (2018): 03008. http://dx.doi.org/10.1051/matecconf/201821603008.

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The paper discusses approaches to improvement of equipment for borehole drilling with a predetermined trajectory in construction of underground utility systems and facilities. Piercing method allows implementing dry drilling of boreholes with small diameter using simple technical equipment. The methods used when preparing the research are analysis, generalization, and experimental research methods. Outcomes of the research include evidence that increase in performance of vibro-impact piercing is possible not only due to higher impact energy, but also due to optimization of interaction between the operating tool and soil. Combination of dynamic action by impact pulses and static forces applied to the drilling equipment enables to enhance performance of impact pulse action and increase the drilling speed. Accuracy of the borehole trajectory can be provided by using dynamic stabilizers or correcting the drilling direction due to asymmetrical tool shape in combination with the torque moment of a drilling equipment. The study formulates requirements to design of a drilling unit for directed pilot hole drilling by dynamic piercing method. The design of an improved pneumatic tool installed in front of the drill string and equipped with asymmetrical front head is described. Experimental research results are given on the process of a borehole drilling using the described tool.

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Gómez-Barrena, Enrique, Norma Padilla-Eguiluz, and REBORNE Consortium. "Implantation of autologous Expanded Mesenchymal Stromal Cells in Hip Osteonecrosis through Percutaneous Forage: Evaluation of the Operative Technique." Journal of Clinical Medicine 10, no. 4 (February 12, 2021): 743. http://dx.doi.org/10.3390/jcm10040743.

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Bone forage to treat early osteonecrosis of the femoral head (ONFH) has evolved as the channel to percutaneously deliver cell therapy into the femoral head. However, its efficacy is variable and the drivers towards higher efficacy are currently unknown. The aim of this study was to evaluate the forage technique and correlate it with the efficacy to heal ONFH in a multicentric, multinational clinical trial to implant autologous mesenchymal stromal cells expanded from bone marrow (BM-hMSCs). Methods: In the context of EudraCT 2012-002010-39, patients with small and medium-sized (mean volume = 13.3%, range: 5.4 to 32.2) ONFH stage II (Ficat, ARCO, Steinberg) C1 and C2 (Japanese Investigation Committee (JIC)) were treated with percutaneous forage and implantation of 140 million BM-hMSCs in a standardized manner. Postoperative hip radiographs (AP—anteroposterior and lateral), and MRI sections (coronal and transverse) were retrospectively evaluated in 22 patients to assess the femoral head drilling orientation in both planes, and its relation to the necrotic area. Results: Treatment efficacy was similar in C1 and C2 (coronal plane) and in anterior to posterior (transverse plane) osteonecrotic lesions. The drill crossed the sclerotic rim in all cases. The forage was placed slightly valgus, at 139.3 ± 8.4 grades (range, 125.5–159.3) with higher dispersion (f = 2.6; p = 0.034) than the anatomical cervicodiaphyseal angle. Bonferroni’s correlation between both angles was 0.50 (p = 0.028). More failures were seen with a varus drill positioning, aiming at the central area of the femoral head, outside the weight-bearing area (WBA) (p = 0.049). In the transverse plane, the anterior positioning of the drill did not result in better outcomes (p = 0.477). Conclusion: The forage drilling to deliver cells should be positioned within the WBA in the coronal plane, avoiding varus positioning, and central to anterior in the transverse plane. The efficacy of delivered MSCs to regenerate bone in ONFH could be influenced by the drilling direction. Standardization of this surgical technique is desirable.

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Beckmann, J., J. Goetz, H. Baethis, T. Kalteis, J. Grifka, and L. Perlick. "Precision of computer-assisted core decompression drilling of the femoral head." Archives of Orthopaedic and Trauma Surgery 126, no. 6 (June 1, 2006): 374–79. http://dx.doi.org/10.1007/s00402-006-0155-0.

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Chandrasekaran, Sivashankar, Dror Lindner, Timothy J. Martin, Parth Lodhia, Carlos Suarez-Ahedo, and Benjamin G. Domb. "Technique of Arthroscopically Assisted Transtrochanteric Drilling for Femoral Head Chondral Defects." Arthroscopy Techniques 4, no. 4 (August 2015): e287-e291. http://dx.doi.org/10.1016/j.eats.2015.02.007.

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Stroe, Sergiu, Constantin Onescu, and Cagri Inal. "Development of a Drilling Machine for an Asymmetric Element with Multiple Holes." Applied Mechanics and Materials 760 (May 2015): 577–82. http://dx.doi.org/10.4028/www.scientific.net/amm.760.577.

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The aim of this paper is to develop a drilling machine for 5 holes simultaneously manufactured for an asymmetric element from automotive industry. The function analysis system technique (FAST) and SADT (Structured Analysis and Design Technique) is used to identify, describe and categorize the drilling machine functions in order to propose technical solution. The paper propose an original solution with flat extruded engine for the closest 2 holes to avoid the usage of multispindle head.

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Osinde, Nahashon O., Jean B. Byiringiro, Michael M. Gichane, and Hasan Smajic. "Process Modelling of Geothermal Drilling System Using Digital Twin for Real-Time Monitoring and Control." Designs 3, no. 3 (August 17, 2019): 45. http://dx.doi.org/10.3390/designs3030045.

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Currently, Kenya supplies its energy demand predominantly through hydroelectric power, which fluctuates due to poor and unpredictable rainfall in particular years. Geothermal energy is proposed as a clean and reliable energy source in meeting Kenya’s increasing energy demand. During geothermal drilling operations, disruptions due to tool wear and breakages increases the cost of operation significantly. Some of these causes can be mitigated by real-time monitoring of the tool head during operations. This paper presents the design and implementation of a digital twin model of a drilling tool head, represented as a section of a mechatronic assembly system. The system was modelled in Siemens NX and programmed via the TIA portal using S7 1200 PLC. The digital model was programmed to exactly match the operations of the physical system using OPC (open platform communications) standards. These operations were verified through the motion study by simultaneous running of the assembly system and digital twin model. The study results substantiate that a digital twin model of a geothermal drilling operation can closely mimic the physical operation.

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Luo, You Xin, Yan Geng Li, Heng Shu Li, and Hui Jun Wen. "Research and Development of Multi-Function Excavator Drill with Hydraulic Rotary Cutting and Pneumatic Impacting." Applied Mechanics and Materials 34-35 (October 2010): 874–77. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.874.

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To solve the existing shortage of cutting drill, a multi-function excavator drill with hydraulic rotary cutting and pneumatic impact was invented on the base of market investigation, which is suitable for different rocks because of combining hydraulic rotary cutting with pneumatic impacting. If working on the soft rock, the new drill will turn off the pneumatic rock drill, replace the drill bit and only operate with the rotary power head, while on the hard rock it will operate efficiently with the rotary power head and the pneumatic rock drill. The new drill has many features, such as compact structure, the capacity of meeting a variety of drilling requirements, wider operating range, lower energy consumption, higher drilling efficiency, comfortable and flexible operation, and lower cost.

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Schwebel, D. "EXPLORATION REVIEW." APPEA Journal 43, no. 2 (2003): 93. http://dx.doi.org/10.1071/aj02066.

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Both exploration expenditure and drilling were significantly down in 2002 in comparison to 2001. This quiet phase is primarily due to the evaluation of the 2001 drilling and seismic results which should lead, in the long term, to the next cycle of prospect drilling and re-evaluation.The amount of onshore 2D seismic acquisition data gathered was similar to 2001 with most data acquired primarily in the producing basins.Offshore seismic acquisition was down markedly due the completion of a number of major 3D surveys. These data are now in the processing and interpretation phase and when completed will identify the next drilling candidates.The continued success story of the offshore Otway Basin has re-invigorated exploration interest in Australia’s southern margins with exploration continuing to ramp up in the Bight Basin. In the west, the further evaluation of the offshore Perth Basin indicates renewed interest as a result of the Cliff Head discovery.

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Zhang, Yong Jiang. "Study on Suddenly Extrusion Mechanism and Forecasting of Deep Mine Fully Mechanized Mine Head Face." Advanced Materials Research 225-226 (April 2011): 216–19. http://dx.doi.org/10.4028/www.scientific.net/amr.225-226.216.

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In view of the Huai Nan mining area deep mine Dingji mine fully mechanized mine head face low-index outburst suddenly extrusion the region gas geological feature, analysis mechanism of the suddenly extrusion frictional sliding instability. The research gain sensitive index critical value drilling bits S and depth of hole coefficient S′, drilling gas inrush initial velocity q and attenuation coefficients Cq, its innovative index S′ the forecast enhanced the rate of accuracy take the ground stress as the leading role low- index outburst. The results show that the forecasting non-outbursting risk rate is 87%, and the forecasting non-outbursting accuracy rate is 100% during 2000m tunnel driving in test area.

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Popp, Trevor J., Steffen B. Hansen, Simon G. Sheldon, Jakob Schwander, and Jay A. Johnson. "Drilling into debris-rich basal ice at the bottom of the NEEM (Greenland) borehole." Annals of Glaciology 55, no. 68 (2014): 199–206. http://dx.doi.org/10.3189/2014aog68a029.

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AbstractAfter the NEEM (Greenland) deep ice-core drilling was declared terminated with respect to developing stratigraphic climate reconstructions, efforts were turned toward collecting basal ice-sheet debris and, if possible, drilling into the bedrock itself. In 2010, several meters of banded debris-rich ice were obtained under normal ice-drilling operations with the NEEM version of the Hans Tausen (HT) drill, but further penetration was obstructed by a rock in the path of the drill head at 2537.36 m. During short campaigns in 2011 and 2012, attempts were made to penetrate further using various reinforced ice cutters mounted on the HT drill head, tailored to cut through rock. These had some success in penetrating coarse material, but produced severely damaged cutters. Additionally a 51 mm diameter diamond cutting tipped rock drill was adapted to fit the NEEM drill. With this device, several additional meters of core containing subglacial sediments, rocks and rock fragments were collected. With these tools 1.39m of additional material were obtained during the 2011 field season, and 7.1 m during 2012. Subglacial water refreezing into the newly formed borehole hindered further penetration, and the bedrock interface was not reached before final closure of the NEEM Camp.

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Moisyshyn, V. M., Ya S. Biletsky, M. V. Seniushkovych, and I. I. Vytvytsky. "INVESTIGATION OF PARAMETERS OF HYDROMONITOR JET OF A BIT." PRECARPATHIAN BULLETIN OF THE SHEVCHENKO SCIENTIFIC SOCIETY Number, no. 1(59) (January 28, 2021): 98–110. http://dx.doi.org/10.31471/2304-7399-2020-1(59)-98-110.

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The movement of drilling mud through hydromonitor nozzles is investigated in the work. On the basis of the theory of destruction of rocks by a liquid stream the necessary values of pressure on hydromonitor nozzles of a drilling head for concrete values of mechanical properties of the drilled breed are found. The results of the performed analytical researches were used for modeling of processes of movement of a stream of washing liquid through hydromonitor nozzles of a bit with use of the Flow Simulation CAD / CAM package of the Solid Works system. During the simulation following parameters were investigated: the location of the nozzles at different distances from the axis of the bit and from the bottom of the well, pressure distribution at the bottom of the well at the exit of the flushing fluid from each nozzle and the velocity of the jet and the wall of the well, the vorticity of the jets on the bottom and the walls of the well. According to the results of research design of the hydromonitor unit of the drilling head was improved and new tests were carried out in industrial conditions.

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Wang, Chunsheng, Yang Liu, Qiji Sun, Shan Meng, Kai Zhang, and Yufei Dong. "Investigation on a Rock-breaking Drilling Mechanism by Using a High Pressure Jet Bit." Open Petroleum Engineering Journal 10, no. 1 (January 23, 2017): 12–18. http://dx.doi.org/10.2174/1874834101701010012.

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How to effectively transfer and exert a pressure on drills in lateral drilling, and to raise the efficiency of rock-breaking and rate of penetration in a bid, is the key technology to improve the quality, speed and economic benefits of lateral drilling. Therefore, based on high pressure jet of 16-hole and 7-hole nozzles, which are suitable for lateral drilling in oilfield at the present stage, we carry out a research on the hydraulic calculation of high pressure water jet flow and the mechanism of rock-breaking. We use three-dimensional modeling software to establish models, and analyze the high pressure water jet velocity field combined with numerical simulation software. According to different injection, we calculate the local head of the two nozzles when the working fluid is pure water and the liquid-solid two phases of 4% solid content respectively, through the simulated relational expression between the local head and the injection rate to calculate the maximum speed of each hole and to ensure rock-breaking critical injection of 16-hole and 7-hole nozzles, then compare and analyze the rock-breaking effect of these two kinds of drill bits, at the same time to analyze the influence of nozzles angle on the effect of rock-breaking, so as to optimize the perfect angle of the nozzle and to provide theoretical basis for the popularization and application of lateral drilling high pressure jet rock-breaking.

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Ochoa, J. A., A. P. Sanders, D. A. Heck, and B. M. Hillberry. "Stiffening of the Femoral Head Due to Intertrabecular Fluid and Intraosseous Pressure." Journal of Biomechanical Engineering 113, no. 3 (August 1, 1991): 259–62. http://dx.doi.org/10.1115/1.2894882.

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The mechanical properties of cancellous bone, as measured from bone plug samples, have been widely documented. However, few tests have been attempted to explore the effects the intertrabecular contents may have on the load bearing capabilities. In this study, canine femoral heads were subjected to dynamic compressive strain cycles. The femoral heads were tested intact, as well as with disrupted boundary conditions of the continuous, intraosseous fluid space. A significant reduction in mechanical stiffness was observed when the fluid compartment boundary was disrupted by drilling a hole part way into the femoral neck. A finite element model of a typical femoral head showed that the stiffness change was not due to removal of material from the neck, hydraulic effects notwithstanding. Refilling the hole in the neck with saline solution and sealing the boundary restored the stiffness to the intact baseline level. However, an increase in the fluid pressure did not cause a statistically significant increase in the stiffness of the femoral head.

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Lafleur, J., F. Giroux, and M. Huot. "Field permeability of the weathered Champlain clay crust." Canadian Geotechnical Journal 24, no. 4 (November 1, 1987): 581–89. http://dx.doi.org/10.1139/t87-072.

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This paper discusses methods for evaluating the coefficient of permeability k of the weathered and fissured Champlain clay crust. This parameter is important because losses due to seepage from fluid-retaining structures are directly porportional to the value of k. The presence of fissures complicates its evaluation, and conventional techniques produce questionable results for two reasons: Clogging of fissures by the smearing of the clay on the walls of test holes during drilling and insertion of a probe leads to an underestimation of k, and conversely, hydraulic fracturing caused by the application of excessive heads leads to an overestimation of k. A new technique is presented that prevents the smearing of the clay by reaming the walls of a prebored auger hole. Falling head and constant head tests were performed with feeding devices using a large range of heads including low values. Results confirm that hydraulic fracturing occurs when a critical value of head is reached. As a result, the use of the low-head reaming permeameter described in this paper appears suitable for evaluating the coefficient of permeability of weathered Champlain clay crust. Key words: permeability, field test, hydraulic fracturing, fissured clay, smearing effect.

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Jian, Xiao Gang, Ye Feng Wang, and Peng Chun Yang. "Schematic Design and Research on Steering Mechanism of Drilling Robot." Applied Mechanics and Materials 189 (July 2012): 321–25. http://dx.doi.org/10.4028/www.scientific.net/amm.189.321.

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Through the research on drilling robot at home and abroad, this paper divides steering methods into two types: steering caused by radial motion of body parts; steering caused by deflection of the head. Based on this classification, several schematic designs of steering mechanism are proposed. Respectively, structural design and principle analysis of steering mechanisms are carried out. And steering mechanism 3 is chosen the best one through comparison from the following aspects: No. of motors in the steering mechanism, size, turning radius and control difficulty. In order to prove its feasibility theoretically, the detailed modeling and analysis are presented. The results of DOF (degree of freedom) calculation and kinematics simulation of the head point show that its motion is determined and no collision exists between the parts during the kinematical process. The relation among peak value of rollers’ trajectory H, distances from rollers to the rotation axis of the cylindrical cam r and maximum deflection angle θmax is analyzed by building the deflection model, which lays foundation for further optimization.

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Krasnopolskiy, F. "D.S.Schetkin. Tool for drilling the fetal head. (Medic. Review. 1893. No. 3)." Journal of obstetrics and women's diseases 7, no. 5 (September 22, 2020): 428–29. http://dx.doi.org/10.17816/jowd75428-429.

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Recognizing the Blot spear-shaped perforator as a rather useful tool, the author, however, on the basis of personal experience and theoretical reasoning, finds an excessive ability to open it; to destroy the contents of the skull is much more convenient with a long forceps, and to increase the opening into the skull by pushing apart into your needs, since the opening and without the mentioned act is large enough, both for removing the brain and for introducing the inner spoon of the cranioclast.

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Beckmann, Johannes, Juergen Goetz, Lars Perlick, Christian Luring, Joachim Grifka, and Markus Tingart. "Fluoroscopically based drilling of the femoral head in a model of adiposis." Computer Aided Surgery 13, no. 1 (January 2008): 55–61. http://dx.doi.org/10.3109/10929080701882564.

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Journal articles on the topic 'The drilling head'

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