Results 121 to 130 of about 252 (179)
First stage in technological production of Stone Age animal teeth pendants: evidence from Zvejnieki (Latvia) and wider social implications. [PDF]
Archaeol Anthropol SciMacāne A +8 more
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SPE California Regional Meeting, 1961
Abstract Advancements in tools and technology for air drilling have been quite numerous. One of the more publicized tools in recent years has been the air-rotary-percussion drill. This paper is prepared to evaluate the tool performance and to indicate problem areas where the tool may be used to the greatest ...
F.W. Smith, Wink Kopczynski
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Abstract Advancements in tools and technology for air drilling have been quite numerous. One of the more publicized tools in recent years has been the air-rotary-percussion drill. This paper is prepared to evaluate the tool performance and to indicate problem areas where the tool may be used to the greatest ...
F.W. Smith, Wink Kopczynski
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Experimental investigation on drilling efficiency of a percussive ultrasonic drill
2017 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2017Drilling is an important method to obtain samples on a minor planet for deep-space exploration. Conventional drilling devices driven by electromagnetic motors usually need large weight on bit to fracture hard rocks. It is a great challenge for conventional drilling devices to drill on a minor planet which has a weak gravitational field.
Deen Bai +5 more
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Optimization of percussive mechanism in rotary-percussion drill for lunar exploration
2013 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2013Rotary-percussive Drill (RPD) has been widely employed in extraterrestrial exploration as a main drilling and sampling device. Percussive mechanism, as an inevitable part of RPD, is commonly utilized to exert percussion onto drill stem to improve drilling performance once hard rock is encountered.
Degang Jie +6 more
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A new model of percussion laser drilling
International Journal of Computer Applications in Technology, 2006Manufacturing industries in strategic and other hi-tech areas are increasingly using the percussion mode of laser drilling for component development. In this paper, the optothermal effects of laser-metal interaction are analysed from a modelling viewpoint.
N. D. Pandey, H. S. Shan, T. Mohandas
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Dry Friction Model of Percussive Drilling
Meccanica, 1999zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Krivtsov, Anton M., Wiercigroch, Marian
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2001
Commercial percussion drilling machines possess for their operation in the percussion drill mode two cam disks with some teeth. By moving the upper disk at the motor side with constant angular speed, for example, and by pressing the drill into the material, a hammering process is started that consists of a combined drill/impact motion. Machines of that
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Commercial percussion drilling machines possess for their operation in the percussion drill mode two cam disks with some teeth. By moving the upper disk at the motor side with constant angular speed, for example, and by pressing the drill into the material, a hammering process is started that consists of a combined drill/impact motion. Machines of that
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International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1971
Abstract The theoretical mechanics of the percussive drilling of rock are developed from analysis of stress-wave interactions in the drilling system. Particular attention is given to 1. (i) the efficiency of impact energy transfer from drill steel to rock, and 2. (ii) the minimum thrust force needed to ensure bit-rock contact at the beginning
W.A. Hustrulid, C. Fairhurst
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Abstract The theoretical mechanics of the percussive drilling of rock are developed from analysis of stress-wave interactions in the drilling system. Particular attention is given to 1. (i) the efficiency of impact energy transfer from drill steel to rock, and 2. (ii) the minimum thrust force needed to ensure bit-rock contact at the beginning
W.A. Hustrulid, C. Fairhurst
openaire +1 more source