Impact Type Patents (Class 175/395)
  • Patent number: 8336647
    Abstract: A drill bit for core sampling includes a body having a central axis and first end having a tapered outer surface and a radius transverse to the central axis, and an insert having a cutting surface on the first end oriented at an axial angle relative to the radius to move material displaced during drilling away from the first end.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: December 25, 2012
    Assignee: Longyear TM, Inc.
    Inventor: Thomas J. Oothoudt
  • Patent number: 7984773
    Abstract: A drill bit for core sampling includes a body having a central axis and first end having a tapered outer surface and a radius transverse to the central axis, and an insert having a cutting surface on the first end oriented at an axial angle relative to the radius to move material displaced during drilling away from the first end.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: July 26, 2011
    Assignee: Longyear TM, Inc.
    Inventor: Thomas J. Oothoudt
  • Patent number: 7891444
    Abstract: A drill bit comprises a plurality of cutting blades arranged circumferentially, the cutting blades having a cutting edge formed by a connecting ridge line between a cutting face and a flank; and a tip formed by coupling radially inner ends of the cutting edges to each other at a center portion of a bit tip end, wherein at least one of the cutting blades has a first flank and a second flank, wherein the first flank has a blade tip side flank close to the cutting edge and a base end side flank formed on the base end side of the blade tip side flank, and wherein a tilt angle ?1 of the blade tip side flank 3a is smaller than a tilt angle ?2 of the base end side flank 3b which is tilted toward the axial direction.
    Type: Grant
    Filed: March 7, 2005
    Date of Patent: February 22, 2011
    Assignee: Kabushiki Kaisha Miyanaga
    Inventor: Masaaki Miyanaga
  • Patent number: 7614170
    Abstract: An excavating screw unit equipped with a hydraulic excavating auxiliary blades has developed for an auger crane, comprising: an extension unit having auxiliary excavating blade, cylinder mounting hole, built-in fluid passages in extension unit, hydraulic cylinder, piston, and extension guiding rods; an excavation column formed a hollow center of a square-shaped to mount on top of extension unit; an extension rod having an outer square-shape to fit into the excavation column, a built-in hydraulic passages in the extension rod, at top portion of the extension rod, an inlet and outlet that is bent right angle at top portion of the hydraulic passages to connect to hydraulic tubes, the extension rod is sliding to extend or retract through the excavation column. The extended excavating auxiliary blades are maintained by the pressurized fluid to prevent retracting by digging resistance during the excavating. Thus, this mechanized excavating device is easily digging a burial hole for a utility pole and underbracing.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: November 10, 2009
    Assignee: Daewon Electric Co. Ltd.
    Inventor: Sae Won Kwon
  • Publication number: 20080310930
    Abstract: The invention relates to a method for anchoring an anchor (10) in an anchoring substrate (26), for example, of concrete, to an anchor (10) suitable for the method and to a drill suitable for the method. The invention proposes using the anchor (10) as tool for at least partial preparation of the anchoring hole (28) in the anchoring substrate (26) by high-frequency oscillatory working. The anchor (10) is, for example, an undercut expansion anchor, the expansible sleeve (14) of which forms the tool and is driven into an anchoring substrate (26) by being subjected to the action of high-frequency oscillations.
    Type: Application
    Filed: June 1, 2005
    Publication date: December 18, 2008
    Inventors: Marc Schaeffer, Oliver Hacker, Diethard Fohr, Achim Hess
  • Publication number: 20080110679
    Abstract: A one-piece drilling head (4) which is to be secured, in a material-locking manner, at an end of a helical shaft of a drill, is formed of hard material and includes four radially extending, in a cross-shaped manner, legs (5) forming, respectively, two diametrically opposite main cutting edges (6) and two auxiliary cutting edges (7), with the main cutting edges (6) and the auxiliary cutting edges (7) extending proceeding from a drilling head drilling head tip (8), monotonously and strictly axially up to a radially outer edge, and with an envelope surface (9?) of the auxiliary cutting edges (7) lying completely within an envelope surface (9) of the main cutting edges (6) and contacts the same only at the drilling head tip (8).
    Type: Application
    Filed: November 9, 2007
    Publication date: May 15, 2008
    Inventor: Olaf Koch
  • Patent number: 7309195
    Abstract: A shank for a rotary and percussive tool has a locking groove (3) arranged between two guided regions (1a, 1b) and axially closed at its opposite ends for receiving at least one radially displaceable and axially displaceable, within predetermined limits, locking member (4) of a chuck in which the shank is received, with the guide dimension (F) of the guide region being smaller than the width (B) of the axial region (A) of the locking groove (3) and that includes the radial extent of an entrain strip (2) provided in that region (A), and greater than the thickness (D) of the axial region measured in a direction transverse to the width measurement direction.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: December 18, 2007
    Assignee: Hilti Aktiengesellschaft
    Inventors: Werner Kleine, Hans-Werner Bongers-Ambrosius, Josef Obermeier, Werner Britten
  • Patent number: 7261169
    Abstract: A shank for a working tool has at least three recesses (5) provided within the lockable region (3) and arranged in a cross-section (c-c) to the tool axis (A) at least at angles of 0°, 120°, and 240° within the radial reference dimension (R) of the shank, with at least one of the recesses (5) being axially closed toward a free end of the shank (1), and at least one protrusion (6) arranged circumferentially between two adjacent recesses (5) outside of the radial reference dimension, with the sum of central recess angles (?) of the recesses amounting to at least 150°, and a central protrusion angle (?) of the at least one protrusion (6) being smaller than a central recess angle (?).
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: August 28, 2007
    Assignee: Hilti Aktiengesellschaft
    Inventors: Werner Kleine, Werner Britten
  • Patent number: 7231992
    Abstract: A drill bit has, on its face, a combination of at least one straight cutting edge and at least two curved cutting edges arranged in a Y-shape. The cutting edges on the face of the drill bit are arranged such that they start from the axis of the drill bit or end directly adjacent thereto. The straight cutting edge is symmetrical with respect to the curved cutting edges, which are curved in opposite directions.
    Type: Grant
    Filed: October 20, 2005
    Date of Patent: June 19, 2007
    Assignee: Atlas Copco MAI GmbH
    Inventor: Herbert Papousek
  • Patent number: 7225890
    Abstract: An auxiliary cutting plate (10) for a multi-cutting plate drill bit (2) has a body (44) for fixing into a slot in the drill bit (2) and a profiled tip (46). The body (44) has a central longitudinal axis and the profiled tip (46) protrudes from one end of the body (44). The profiled tip (46) has a cutting edge (62) defined by a transition between a rake face (64) and a relief face (66). The rake face (64) and the relief face (66) each slope axially rearward from opposite sides of the cutting edge (62). The angle of inclination ? of at least a portion of the rake face (64), measured from a plane perpendicular to the longitudinal axis, decreases with increasing distance from the cutting edge (62).
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: June 5, 2007
    Assignee: Black & Decker Inc.
    Inventors: Markus Meierhofer, Rainer Eggers
  • Patent number: 7185721
    Abstract: A male portion for percussive rock drilling includes sections of reduced cross-sectional area. At least one thread for percussive rock drilling is provided at an end of the male portion. The end of the male portion comprises an abutment surface for the transfer of impact waves. The length of the portion is defined as the length of an imaginary cylinder from a plane of the impact surface to a point where the plane ceases to contact a crest of the thread, wherein the length divided by the external diameter of the cylinder lies within a range of 1–2.
    Type: Grant
    Filed: June 26, 2003
    Date of Patent: March 6, 2007
    Assignee: Sandvik Intellectual Property AB
    Inventors: Bo Carlström, Anders Brungs, Christer Lundberg, Per-Olof Liljebrand
  • Patent number: 7114584
    Abstract: A hollow auger head assembly for penetrating geological formations that utilizes drill bit assemblies to which both blades and finger bits are attached. The method of securing the individual drill bit assemblies to the auger head reduces incidents of the drill bit assembly becoming detached from the auger head during drilling operations. Additionally, a rust-resistant attachment mechanism is used attach the drill bit assemblies to the auger head, which makes the drill bit assemblies easier to remove and replace. The configuration and arrangement of the bits improves cutting efficiency, increases wear life and reduces the likelihood of the bits breaking during operation.
    Type: Grant
    Filed: August 8, 2005
    Date of Patent: October 3, 2006
    Assignee: Good Earth Tools, Inc.
    Inventors: Raymond W. Burns, Anthony James Regna
  • Patent number: 7090038
    Abstract: A bedrock drilling and excavating apparatus receives power from a rotational power source to drive a drill to strike and shatter bedrock under the gravity of the apparatus and reciprocal vibrations of a pneumatic unit located on the apparatus. The apparatus includes a coupling device to couple with the rotational power source and an air intake vibration structure, a coupling sleeve which has one end coupling with the lower end of a coupling axle and a connector which further couples to the pneumatic unit, and a drill coupling to the pneumatic unit. The pneumatic unit drives the drill to vibrate up and down reciprocally to strike and shatter bedrock. The drill has a drill shell which is alterable according to the diameter of the service shaft without changing the diameter of the pneumatic unit. The drill shell has a plurality of conical drill gimlets mounted thereon in different biased angles to shatter the bedrock and improve drilling and excavating effect.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: August 15, 2006
    Assignee: Chuan Home Machinery Co., Ltd.
    Inventor: Chin-Yi Lee
  • Patent number: 7028790
    Abstract: A drill bit includes a body defining an axis and first and second cylindrical portions, a coupling adapted for connection with a rotary driver, and a depth stop adjustably secured to a first portion by a plurality of adjusting fasteners in a manner to limit penetration of the bit into a target surface. A method of drilling a hole into the surface includes locating a drilling machine fitted with a drill bit over a target location, compensating for wear on the bit by setting a depth stop to limit travel of the bit at the predetermined depth, drilling at the target location until the depth stop contacts a surface, where the primary cutting surface forms a portion of the hole defined by a first diameter and the secondary cutting surface forms a portion of the hole defined by a second diameter in a single step, and removing the drill bit from the hole.
    Type: Grant
    Filed: September 19, 2003
    Date of Patent: April 18, 2006
    Assignee: Jack Moore Associates, Inc.
    Inventor: John F. Moore
  • Publication number: 20040089476
    Abstract: A drill for boring an anchor fixing hole 72 having an expanded configuration at a nearby area of a bottom part of the hole, wherein a stopper 4 having a diameter larger than an outside diameter of the drill main body 2 is disposed at a location near a shank 3 of the drill main body 2 and a surface 41 of the stopper 4 on a leading end side of the drill is a tapered curved surface which is expanded towards the shank 3 side from the leading end side of the drill. According to the drill of the present invention for boring an anchor fixing hole, an expanded bottom anchor fixing hole can be bored without using two kinds of drills and at a low cost.
    Type: Application
    Filed: November 12, 2002
    Publication date: May 13, 2004
    Inventors: Munehito Uchino, Tugio Yanagisawa
  • Patent number: 6564887
    Abstract: The present invention relates to a core drill wherein initial drilling workability is improved through reduced frictional resistance on the segment tips, when they are seated on the surface of an article to start cutting operation, and wherein cutting scraps or sludge produced by the segment tips are smoothly discharged through the helical grooves formed on the core body so as to reduce the friction between the core body and the cutting scraps or sludge, whereby both the cooling and cutting performance of the core drill are improved. The invention proposes a core drill with a cylindrical core body with a predetermined diameter and length and with plural cutting segments provided on the lower part of a core body at a finite interval, wherein the cutting thickness surface of the cutting segment consists of inclined sharp thickness portion for decreased frictional resistance with an article to be processed.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: May 20, 2003
    Assignee: Ehwa Diamond Ind. Co., Ltd.
    Inventors: Jae Hyun Hong, Chang Hyun Lee, See Hyung Kim
  • Publication number: 20030026669
    Abstract: The invention relates to a chisel (1) or a hammer drill, in particular insertable chisel or insertable drill for power-driven drill and chisel hammers, with an insertion end (2), with a chisel shank (3) or drill shank and with a chisel head (4) or drill shank located opposite the insertion end (2). In this case, the diameter of the shank (3) increases in the direction of the chisel head (4) at least once from a first, small diameter to a second, large diameter and decreases again from this to a small diameter or forms at least one bead (8).
    Type: Application
    Filed: July 8, 2002
    Publication date: February 6, 2003
    Inventors: Marco Lang, Franc Koljaka, Friedmar Dresig, Thomas Bernhardt
  • Publication number: 20030019667
    Abstract: A rock drill (1) for rotary hammers or the like is proposed in which a conveying helix (3) having main and secondary webs (6 to 9) is used. In this case, the convexing helix (3) is run up to the front region of the drill head (2) with the core cross section being increased or the flute depth being decreased.
    Type: Application
    Filed: September 3, 2002
    Publication date: January 30, 2003
    Inventor: Wolfgang Peetz
  • Patent number: 6328506
    Abstract: A masonry drill bit 1 having an active diameter of D, comprising a shaft 3 and a tip 5 for engaging a workpiece, the tip 5 including a central portion 11 extending ahead of an outer portion 13, wherein the central portion 11 has a width of at least 0.25D and is shaped to act as a chisel during percussion drilling, and wherein the outer portion 13 is shaped to cut a workpiece as the drill bit rotates. By virtue of the drill bit tip 5 configuration as described and claimed herein, a masonry drill bit 1 having improved performance is provided.
    Type: Grant
    Filed: July 17, 2000
    Date of Patent: December 11, 2001
    Assignee: Black & Decker Inc.
    Inventors: Geoff Turner, Rudi Birk
  • Publication number: 20010013429
    Abstract: A drill including a body having mortises (7), and a solid hard metal head (4) having a plurality of bits (3) and secured to the drill body over the end surface (5) of the head (4) and additionally secured to the drill body over portions of side surfaces (6) located in a radially outer region of the head (4), extending substantially parallel to a rotational axis (A) of the drill and extending into mortise means (7), with the side surfaces (6) including first surfaces, which are associated with at least some of the bits (3) and are subjected to pressure acting in a rotational direction of the drill during operation of the drill.
    Type: Application
    Filed: February 7, 2001
    Publication date: August 16, 2001
    Inventors: Udo Hauptmann, Josef Starkmann, Karl-Heinz Hofmann, Tim Prols
  • Patent number: 6102634
    Abstract: A masonry drill bit 1 having an active diameter of D, comprising a shaft 3 and a tip 5 for engaging a workpiece, the tip 5 including a central portion 11 extending ahead of an outer portion 13, wherein the central portion 11 has a width of at least 0.25 D and is shaped to act as a chisel during percussion drilling, and wherein the outer portion 13 is shaped to cut a workpiece as the drill bit rotates. By virtue of the drill bit tip 5 configuration as described and claimed herein, a masonry drill bit 1 having improved performance is provided.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: August 15, 2000
    Assignee: Black & Decker Inc.
    Inventors: Geoff Turner, Rudi Birk
  • Patent number: 5984596
    Abstract: A combination of an insertable tool (2), e.g. a drill or chisel, for an electrical machine for drilling and/or impact operation and a tool holder (20) for the insertable tool is disclosed. The insertable tool includes a tool shaft (11) provided with a round core cross section (1) not weakened or reduced at any point along the tool shaft (11) up to an inserted tool shaft end. The tool shaft has longitudinal struts (6) for torque transmission and axial guidance extending beyond the round core cross section (1) and the longitudinal struts (6) are shaped to merge with the core cross section in front of a cylindrical end portion (3).
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: November 16, 1999
    Assignee: Robert Bosch GmbH
    Inventors: Siegfried Fehrle, Rolf Mueller, Vinzenz Haerle, Sven Kageler
  • Patent number: 5779403
    Abstract: A percussive blow assisted rotary drill includes an axially extending shank (1) with a leading end face (3) and an axially extending outside surface (2) containing a helically extending drilled material removal groove (4, 5). At least one hard metal cutting plate (6) extends across a diameter of the shank and has a base part fixed in a continuous groove (9) in the leading end face (3) of the shank (1). The base part (10) is reinforced by an outwardly extending projection (12) in at least one of its side surfaces extending across the shank diameter. Preferably, the projections forms a part of a circle and are centered between the opposite ends of the cutting plate. The continuous groove (9) has a recess in at least one of its side surfaces shaped to coincide with the shape of the outward projection (12) on the cutting plate. Accordingly, the base part (10) is secured in a positively locked manner and preferably is centered in the leading end face of the shank.
    Type: Grant
    Filed: December 9, 1996
    Date of Patent: July 14, 1998
    Assignee: Hilti Aktiengesellschaft
    Inventors: Werner Kleine, Axel Neukirchen, Werner Bongers
  • Patent number: 5553682
    Abstract: A rock drill includes an axially elongated shank with a chucking shank part (1) at one end, a drilling shank part (2) extending from the chucking shank part and having at least four drilled material conveying flutes (4, 5, 6, 7) disposed next to one another in a parallel manner, and a drilling head at the opposite end of the shank and formed of hard metal and having four removal flutes (8, 9, 10, 11) spaced apart about its outer circumferential surface. The removal flutes have transverse cross-section of different size and each of the transverse cross-sections of the removal flutes (8, 9, 10, 11) open into one of the conveying flutes (4, 5, 6, 7) of the drilling shank part.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 10, 1996
    Assignee: Hilti Aktiengesellschaft
    Inventors: Rainer Batliner, Anton Knoller, Axel Neukirchen
  • Patent number: 5382121
    Abstract: A drill bit for drilling holes in concrete and asphalt, or the like, includes a circular drill bit body having two helical grooves in its cylindrical side surface. Pressurized air is injected into the drilled hole through a passage system extending longitudinally within the drill bit. The injected air is forced out of the drilled hole through the helical grooves, such that particulates formed by the drilling process are flushed with the air out of the hole. The flushing action prevents the bit from becoming immobilized by heated asphalt sticking against the drill bit side surface.
    Type: Grant
    Filed: September 2, 1993
    Date of Patent: January 17, 1995
    Inventor: David P. Bicknell
  • Patent number: 5113626
    Abstract: An earth anchor apparatus includes a hub having a longitudinal axis and first and second axial ends, and a load-bearing helix affixed to the hub. The load-bearing helix includes a generally radially extending leading edge adjacent the first end of the hub, a generally radially extending trailing edge adjacent the second end of the hub, an inner circumferential section connected to the hub, and an outer circumferential section extending radially outward from the inner circumferential section and having an outer circumferential edge separated from the inner section. A pair of opposed surfaces extend between the inner section and the outer edge and define a thickness of the helix. The thickness of the helix at the trailing edge is greater adjacent the inner circumferential section than at the outer circumferential edge, and the thickness of the helix adjacent the inner circumferential section is greater at the trailing edge of the helix than at the leading edge.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: May 19, 1992
    Assignee: A.B. Chance Company
    Inventors: Gary L. Seider, Daniel V. Hamilton
  • Patent number: 4924953
    Abstract: A rock drill for rotary and/or percussive stress, in particular for use in percussion or hammer drilling machines, is proposed, which by its geometrical design makes improved efficiency and simplified production possible. For this purpose, the feed spiral 5 is designed alternately with horizontal feed sections 8,8' with a 0.degree. pitch, and adjoining lead sections 9,9', the respective feed sections assuming an angle of rotation of 90.degree. on the drilling tool.
    Type: Grant
    Filed: April 21, 1989
    Date of Patent: May 15, 1990
    Assignee: Hawera Probst GmbH & Co.
    Inventor: Bernhard Moser
  • Patent number: 4696355
    Abstract: A drilling tool for percussion drilling machines is proposed which has an increased endurance strength or fatigue strength when used in percussion drilling machines having a high striking speed. For this purpose, the carbide cutting tip (11) is arranged transversely to the flute runout (12, 13) so that the effective moment of resistance area in the area of the groove root (22) of the recessed groove (14) is not weakened by flute runout surfaces.
    Type: Grant
    Filed: January 6, 1986
    Date of Patent: September 29, 1987
    Assignee: Hawera Probst GmbH & Co.
    Inventor: August Haussmann
  • Patent number: 4579180
    Abstract: A drilling bit having two helical withdrawal grooves which extend from the drilling head in the direction toward the insertion or chucking end. The withdrawal grooves have least slope in the vicinity of the drilling head. In the other regions, the withdrawal grooves have a different slope. As a result, no cross-sectional jumps disposed at uniform intervals are provided on the drilling bit, so that transverse oscillations cannot be reinforced by partially constantly or continuously reflected pulses. A considerable reduction in noise is achieved. Furthermore, the central portion of the drilling bit, which is critical during drilling, receives great rigidity.
    Type: Grant
    Filed: May 16, 1984
    Date of Patent: April 1, 1986
    Assignee: Hawera Probst GmbH and Co.
    Inventors: Wolfgang Peetz, Siegried Klaissle, Bernhard Moser, August Hausmann
  • Patent number: 4548281
    Abstract: A well casing to be installed in the ground is resonantly driven at a sonic frequency by means of an orbiting mass oscillator. A wedging probe member is optionally attached to the end of the casing and is driven by the vibratory energy to facilitate the penetration of the earthen material ahead of the casing. A closure wall is fitted to the bottom of the casing, this closure wall having jet nozzles formed therein. While the casing member and probe member are being vibratorily driven by the sonic energy, pulsating jets of water are emitted through the jet nozzles to aid in the cutting of the earthen formation along with the sonic vibratory energy, the sonic energy markedly enhancing the hydraulic jet action by virtue of the pulsating force it imposes on the hydraulic jets.
    Type: Grant
    Filed: April 13, 1984
    Date of Patent: October 22, 1985
    Inventor: Albert G. Bodine
  • Patent number: 4286677
    Abstract: The bit for drilling stone for use in a hammer drill or an electric hammer comprises a body defining recesses which, in axial section, have a profile at least approximately in the form of an arc of a circle with a radius of between approximately 8 mm and 15 mm. The ratio of the surface area of guide lips each located between two of the recesses in the body of the bit and of the outer cylindrical surface defined by the bit is less than 5%, and preferably of the order of 1 to 2%. The diameter of a tip of the bit, which is provided with a plate of hard metal is equal to the diameter of said cylindrical surface in the vicinity of the plate.
    Type: Grant
    Filed: September 27, 1979
    Date of Patent: September 1, 1981
    Assignee: Guex and Fils S.A.
    Inventor: Raymond Guex
  • Patent number: 4262762
    Abstract: Rib structure for an impact type rock drilling bit, spirally oriented on the external surface of the bit to move particulate matter forwardly relative to the bit when it be turned in its normal drilling direction, to aid the process of extraction of the bit from a drilled hole.
    Type: Grant
    Filed: October 9, 1979
    Date of Patent: April 21, 1981
    Inventor: Robert P. Potratz
  • Patent number: 4202420
    Abstract: A rock drill for rotary blow drilling with a drilling head arranged at the free end of the drill shaft, which at least partially consists of hard metal. The drilling head the end face of which is circular disc shaped or circular ring shaped includes a formed piece of solid hard metal. Cutting bodies are machined out of the end of this piece of hard metal which cutting bodies have the shape of pyramids or truncated pyramids and taper with increasing distance from the drill shank.
    Type: Grant
    Filed: July 31, 1978
    Date of Patent: May 13, 1980
    Assignee: Hawera Probst GmbH & Co.
    Inventors: Wolfgang Peetz, Siegfried Klaissle, Bernhard Moser
  • Patent number: 4091884
    Abstract: A rotary air percussion bit has a cylindrically shaped sidewall, a body portion with a flat or recessed face on one end and a shank attached to the remaining end. A plurality of inserts of wear resistant material is mounted in the face and extending outwardly therefrom. A plurality of chip cutting grooves is formed in the face and extending radially from the axis of the body outwardly to the sidewalls. In order to improve the chip removal from the bit a plurality of chip clearance grooves is formed in the sidewall of the body extending from the terminus of the face chip cutting grooves and spiraling from the face to the shank end. The angle of the spiral with respect to the face is less than 45.degree..
    Type: Grant
    Filed: November 15, 1976
    Date of Patent: May 30, 1978
    Assignee: Smith International, Inc.
    Inventor: Robert D. Thomas
  • Patent number: 4047722
    Abstract: In a drilling device, especially a hammer drill, a tool is coupled to a tool receiving means by co-operating male and female coupling elements which ensure uniform rotational motion of the tool in relation to the tool receiving means; additional transition and guiding surfaces being provided for inserting or removing the tool single-handed.
    Type: Grant
    Filed: August 19, 1975
    Date of Patent: September 13, 1977
    Assignee: H. Reinholdt A/S
    Inventors: Mogens B. Nielsen, Niels Halfdan Boa, Jimmy Jensen