Rotary Cam Patents (Class 173/205)
  • Patent number: 6269888
    Abstract: An apparatus is provided that allows a working element to undergo either rotary or reciprocation motion in a transmission system that is very compact in terms of the amount of space it requires to convert the rotary output of the motor into either rotary or reciprocating output of an output shaft operably connected to the working element. The transmission includes input and output members between which a clutch and cam mechanism are disposed for providing a rotary/reciprocating transmission system with a compact design. When the clutch is disengaged, the cam mechanism is operable to provide the output member and thus the output shaft connected thereto with reciprocating motion. Preferably, the output member is cylindrical with the input member, clutch and cam mechanism all disposed therein to provide the rotary/reciprocating tool with a so-called “barrel cam” transmission that is small to provide significant space saving in the tool housing.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: August 7, 2001
    Assignee: Hand Tools International, LLC
    Inventors: David J. Schuda, Barbara Perozek, David Iverson
  • Publication number: 20010010268
    Abstract: In a hydraulic impulse screwdriver (1), a hammer (13) includes axial grooves (14) formed in the inner side wall thereof, and a spindle (11) includes V-shaped cam grooves (15) formed in the outer side wall thereof. A plurality of balls (16) are disposed in the space between the axial grooves and the opposing cam grooves. The screwdriver additionally includes a coil spring (17) for biasing the hammer (13) in a forward direction. The hammer is coupled to an anvil (19) by means of engaging recesses (18) of the hammer and engaging teeth (21) of the anvil so as to rotate integrally with the anvil. The anvil is firmly connected to a main body (24) of a hydraulic unit (23).
    Type: Application
    Filed: January 23, 2001
    Publication date: August 2, 2001
    Applicant: Makita Corporation
    Inventors: Manabu Tokunaga, Junichi Masuda
  • Patent number: 6250401
    Abstract: A rotary impacting apparatus is provided which comprises a housing, a rotor rotatably accommodated in the housing, a driving source for rotating the rotor about a rotation axis, a main reciprocative implement reciprocatively held by the housing, and an impact member eccentrically held by the rotor. The impact member exerts an impacting force for pressing the main reciprocative implement when the main reciprocative implement is advanced relative to the rotation axis. The main reciprocative implement is provided with a diametrically smaller portion and a diametrically greater portion connected to the diametrically smaller portion.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: June 26, 2001
    Assignee: Yamada Machinery Industrial Co., Ltd.
    Inventor: Sakuji Yamada
  • Publication number: 20010003316
    Abstract: A mechanical hammer for sculptors, comprising a body (1) suitable for being handled, a striking element (5) that slidingly engages in the body (1); a tool (6) releasably engaging with a first end of said striking element (5) accessible from the exterior of the body (1); a rotating element (10) that pivotally engages in the body (1) having a first end connected to rotating drive means located at the exterior of the body (1); cooperating means provided at the second end of the striking element (5) and of the rotating element (10), both inside the body (1), for transforming the rotating motion of the rotating element (10) into a reciprocating motion of the striking element (5) under to load through the tool (6).
    Type: Application
    Filed: December 8, 2000
    Publication date: June 14, 2001
    Inventor: Vittorio Bertolla
  • Patent number: 6223833
    Abstract: A hammer drill has a motor which drives an axially displaceable intermediate gear mounted in an intermediate gear arrangement. An impact mechanism is formed by including interacting impact cams between either the intermediate gear and the housing, or the motor armature shaft and the housing to generate a reciprocating motion on an output spindle or shaft. A spindle locking mechanism is included which causes an intermediate gear to be disengageable with respect to the output shaft, while still permitting the impact mechanism to be engaged. Such an arrangement allows the hammer drill to operate in a hammer-only or chipping mode.
    Type: Grant
    Filed: June 3, 1999
    Date of Patent: May 1, 2001
    Assignee: One World Technologies, Inc.
    Inventors: James E. Thurler, John E. Nemazi, Ralph E. Smith
  • Patent number: 6213222
    Abstract: A cam drive hammer mechanism. The drive mechanism includes a drive mechanism housing connectable to the housing of the power tool, a first cam member, a second cam member and a gear assembly for drivingly connecting the first cam member and the second cam member to the drive shaft for counter-rotation. The first cam member and the second cam member each have at least one of cam surface, the cam surfaces being oriented at a steep angle with respect to the axis of the tool element, each of the cam surfaces being complementary and engageable with one another. The second cam member includes an impacting surface for engaging the tool element to provide an impact. As the cam members counter-rotate, the cam surfaces engage so that the second cam member is axially moved in a direction relative to the first cam member.
    Type: Grant
    Filed: January 6, 2000
    Date of Patent: April 10, 2001
    Assignee: Milwaukee Electric Tool Corporation
    Inventor: Peter A. Banach
  • Patent number: 6199640
    Abstract: An electric machine tool for tools which operate by percussion, the electric machine tool having a machine housing; a rotatingly drivable work spindle seated in the machine housing; a tool receiver provided for receiving a tool and driven by the work spindle; a mechanical striking mechanism having a beater accelerated in an axial direction and actuating a shaft of the tool in the axial direction by blows; a driver unit which derives an acceleration of the beater from rotational movement, the driver unit having an axially displaceably arranged scanning member which rotates synchronously with the work spindle; two circular-shaped curved paths which guide the scanning member and are fixed in the housing, said circular-shaped curved paths having elevations and depressions, each of the elevations pointing in an axial direction of the work spindle in a direction of the scanning member.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: March 13, 2001
    Assignee: Robert Bosch GmbH
    Inventor: Joachim Hecht
  • Patent number: 6192995
    Abstract: A rotary impacting apparatus is provided that includes a housing, a rotor rotatable about an axis, a main reciprocative implement and an impact member. The impact member is arranged to exert an impacting force on the main reciprocative implement when the main receprocative implement is advanced relative to the axis. The rotor is supported by the housing via needle bearings.
    Type: Grant
    Filed: May 18, 1999
    Date of Patent: February 27, 2001
    Assignee: Yamada Machinery Industrial Co., Ltd.
    Inventor: Sakuji Yamada
  • Patent number: 6138772
    Abstract: A drill including a hammer mechanism (7) for generating axial blows to be imparted to a tool (6) receivable in a drill spindle, with the hammer mechanism (7) including a first cam disc (11) connected with the spindle (5) for joint rotation therewith, a second cam disc (12) supported in a drill housing (1) without a possibility of rotation relative thereto but with a possibility of axial displacement therein and having a projection (22) extending through the first cam disc (11) and into the spindle (5) for imparting the axial blows to the tool (6) which is received in the working spindle (5) with a possibility of a limited axial displacement relative thereto, a first spring (14) located between a surface (13) of the second cam disc (12) facing in the direction opposite to the drilling direction and a surface in the housing (1) facing in the drilling direction for biasing the second cam disc (12) into the drilling direction, a second spring (23) located between the surface (13) of the second cam disc (12) and a
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: October 31, 2000
    Assignee: Hilti Aktiengesellschaft
    Inventors: Stefan Miescher, Fritz Mark
  • Patent number: 6085850
    Abstract: A miniature impact tool in which a cam and cam follower assembly is utilized for moving a striker backward by converting rotary motion of a drive shaft to a linear motion. The striker is in contact with a spring/guide pin (plunger) assembly and is moved away from a surface to be struck during a portion of the rotation cycle of the cam. On further rotation the cam surface is cut away and spring action drives the striker forward, causing impact of a cutting tool (chisel) against a workpiece. A plurality of cam lobe surfaces provides predetermined and reproducible impact forces of the cutting tool on the workpiece, even during vibration of the tool. To minimize damage to the cam and cam follower when the tool is over speeded, an elastomeric cam or a cushioning coating or sleeve prevents adverse contact (such as metal-to-metal contact) between the cam and cam follower.
    Type: Grant
    Filed: October 19, 1999
    Date of Patent: July 11, 2000
    Inventor: Raymond J. Phillips
  • Patent number: 6047778
    Abstract: A compressor piston divides a first compartment into two compression chambers, while a hammer piston divides a second compartment into two drive chambers, each of the compression chambers being connected to a respective one of the drive chambers to form a closed fluid system wherein reciprocation of the compressor piston causes cyclic compression and expansion of the fluid in the compression chambers and thus in the drive chambers, to effect a cyclic impacting of the hammer piston with a bit adapter connected to the drill bit. A mud motor rotates a shaft to drive an oscillator which reciprocates the compressor piston. The oscillator can comprise roller elements in the compressor piston in engagement with canted grooves in the shaft. While drilling mud drives the motor and then passes downwardly to flush the drill bit and the borehole, the drilling mud is isolated from the closed fluid system.
    Type: Grant
    Filed: June 23, 1999
    Date of Patent: April 11, 2000
    Assignee: Dresser-Rand Company
    Inventors: James E. Coffman, Paul W. Crites, Paul B. Campbell, Ewald H. Kurt
  • Patent number: 6035947
    Abstract: A primary shaft locking device of an electromotive tool is disclosed. A plurality of braking blocks are installed with a plurality of axially projected supporting pieces and a plurality of radially projected nose portions. An output shaft is installed within the receiving hole and a cam is installed in one end of the output shaft so that the cam is rotated synchronously with the output shaft. Furthermore, a driving disk attached to a speed changing gear set is installed, the disk surface of which is installed with a plurality of convex blocks having a fan shape. These convex blocks is matched with the fixing seat, and is arranged between the two supporting pieces installed on the braking blocks. Thereby, when the rotary is driven to rotate, at first, the convex block will rotate the supporting pieces in order that the braking block release from braking condition so as to drive the output shaft, the cam and the braking block to rotate at the same time.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: March 14, 2000
    Inventor: Lee Hsin-Chih Chung
  • Patent number: 6000478
    Abstract: A sculpturing tool includes a movable member and a rotatable member respectively received in the main tube which is connected to a driving member connected to the rotatable member. The movable member is connected to blade at its first end and has a first ball rotatably and eccentrically received in its second end thereof. The rotatable member has a second ball rotatably and eccentrically received in the end opposite to the driving member so that when the rotatable member is rotated, the movable member is moved in the longitudinal direction when the second ball rolls over the first ball.
    Type: Grant
    Filed: October 8, 1998
    Date of Patent: December 14, 1999
    Assignee: We Cheer Industrial Co., Ltd.
    Inventor: Shu-Wen Hsiao
  • Patent number: 5908076
    Abstract: An impact tool driver is provided and configured for removable attachment to a drive spindle of a power tool, for example a conventional drill. A body member is removably attached to the drive spindle and includes a first impact member containing a number of radially spaced impact lugs defined thereon. Second impact member includes a number of radially spaced impact lugs in engaging and opposing contact with the impact lugs defined on the first impact member. A drive member is connected to the second impact member and is rotational mounted on the body member. The drive member includes a device for connecting a tool or working device thereto. Rotational drive of the body member and the first impact member is imparted to the second impact member and drive member through rotational impacting engagement of the impact lugs.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: June 1, 1999
    Assignee: Power Tool Holders Incorporated
    Inventors: Richard L. Marcengill, Gary L. Young
  • Patent number: 5845719
    Abstract: An elongated rod is journalled in a housing to reciprocate substantially vertical therefrom and has a cutting blade fixed on the tip of the lower end of the rod. A rotary motor is located at the upper end of the housing and is provided with an eccentric cam for converting the rotary motion into linear reciprocating motion.
    Type: Grant
    Filed: April 19, 1997
    Date of Patent: December 8, 1998
    Assignee: Kioritz Corporation
    Inventors: Isao Matsumoto, Masao Ohkanda
  • Patent number: 5836403
    Abstract: A reversible rotary wrench includes an impact mechanism for applying intermittent torque impulses to a load. The mechanism includes a rotatable shaft having an axis and adapted to be coupled to a motive source, a rotatable anvil for coupling to the load and having a pair of anvil ears, a tubular hammer substantially coaxial with the shaft and having a pair of hammer ears engageable with the anvil ears and a rotatable tubular drive coupling member substantially coaxial with the shaft. The mechanism also includes a first helical cam structure coupling the drive coupling member to the shaft, a second helical cam structure coupling the drive coupling member to the hammer, and a spring biasing the hammer axially toward the anvil to engage the hammer ears with the anvil ears.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: November 17, 1998
    Assignee: Snap-on Technologies, Inc.
    Inventors: Gordon A. Putney, Dean J. Iwinski
  • Patent number: 5820312
    Abstract: A device for transmitting impulse-like blows to a continuously rotatable tool bit (6) is formed as an axially extending adapter (1) having a first chuck for the tool bit (6) and being insertable at a trailing end into a second tool bit chuck in a manually operated tool equipped with a striking mechanism. The adapter (1) has a housing (2) containing a unit for superimposing a second blow component on the first impulse blow component produced by the striking mechanism, so that an impulse-like drilling blow can be transmitted to the drill bit (6) made up of an axially directed blow component and a torsional blow component.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: October 13, 1998
    Assignee: Hilti Aktiensellschaft
    Inventors: Maximilian Stock, Boris Koller, Martin Richter, Hans-Werner Bongers-Ambrosius
  • Patent number: 5806609
    Abstract: A manually operable tool, such as a hammer drill, for drilling and/or removing material in at least one of brittle material and low ductile material, has a continuously rotatable chuck (8) and a motor driven striking mechanism (1) for transmitting impulse-like blows to a tool bit (9) held in the chuck (8). The tool includes members (5) for transmitting impulse-like blows composed of superimposed axially-directed blows and torsional blows to the tool bit (9) in the chuck for forming drilling blows. Further, an adaptor can be provided for attachment to the hammer drill containing the members (5) for affording the superimposed blows.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: September 15, 1998
    Assignee: Hilti Aktiengesellschaft
    Inventors: Maximilian Stock, Werner Kaibach, Reinhard Schulz, Hans-Werner Bongers-Ambrosius, Ralf Ludwig, Hanspeter Schad, Edwin Schweizer
  • Patent number: 5803183
    Abstract: A miniature impact tool in which a cam is utilized for moving a striker backward by converting rotary motion of a drive shaft to a linear motion. The striker is in contact with a spring/guide pin (plunger) assembly and is moved away from a surface to be struck during a portion of the rotation cycle of the cam. On further rotation the cam surface is cut away and spring action drives the striker forward, causing impact of a cutting tool (chisel) against a workpiece. An improved mechanism utilizing a plurality of cam lobe surfaces provides predetermined and reproducible impact forces on the cutting tool. This mechanism is not adversely affected by vibration of the tool.
    Type: Grant
    Filed: May 1, 1997
    Date of Patent: September 8, 1998
    Inventor: Raymond J. Phillips
  • Patent number: 5787996
    Abstract: A drilling and/or chiseling tool includes a striking mechanism (28) driven by a swash pin (12) of a swash mechanism (25). The actuation of the swash pin (12) is effected by a single piece intermediate shaft (11) powered by a drive motor (4). The shaft (11) causes a swash ring (13) from which the swash pin (12) projects, to move due to a rolling track (15) arranged at an angle to the drilling direction of the tool. The drilling direction extends generally parallel to the axis of the intermediate shaft (11). This arrangement greatly assists in the ease of assembly and the economical fabrication of the tool.
    Type: Grant
    Filed: October 16, 1996
    Date of Patent: August 4, 1998
    Assignee: Hilti Aktiengesellschaft
    Inventor: Josef Funfer
  • Patent number: 5732782
    Abstract: A drilling and/or chiseling tool has a gear box housing component (2) supporting the striking mechanism (31) and an intermediate shaft (15) each having an axis with the axes arranged in parallel relation. The striking mechanism (31) and the intermediate shaft (15 are supported by a bearing plate (28) detachable connected to the gear box housing component (2).
    Type: Grant
    Filed: October 16, 1996
    Date of Patent: March 31, 1998
    Assignee: Hilti Aktiengesellschaft
    Inventor: Josef Funfer
  • Patent number: 5711379
    Abstract: A hammer drill includes a spindle supported by a housing and movable in an axial direction relative to the housing within a predetermined range, a motor for rotating the spindle, a rotary cam member fixedly mounted on the spindle, a clutch cam member which supports a weight member is axially movably mounted on the spindle, and a biasing member for normally biasing the clutch cam member and weight member toward the rotary cam member in the axial direction of the spindle. A first cam and a second cam are provided on the rotary cam member and the clutch cam member, respectively, facing each other in the axial direction of the spindle. The first cam and the second cam cause the clutch cam and weight member to repeatedly move toward and away from the rotary cam member as the spindle is rotated causing the spindle to vibrate in the axial direction. The ratio: ##EQU1## determines the intensity of vibrations transmitted to the hands of an operator.
    Type: Grant
    Filed: May 23, 1996
    Date of Patent: January 27, 1998
    Assignee: Makita Corporation
    Inventors: Kunio Amano, Akihito Hara
  • Patent number: 5669453
    Abstract: A power carving tool has a housing, a driving motor, a cam shaft engaged with the rotary shaft of the driving motor and having a cooling fan, a cam sleeve with a slanted cam surface, engaged with the cam shaft and reliably held by a ball bearing supported by the housing, and an output shaft moved reciprocatingly by bringing a contact portion provided at the rear portion thereof into contact with the cam surface thereby to maintain a stable rotation of the cam sleeve and to avoid mechanical loss.
    Type: Grant
    Filed: October 5, 1995
    Date of Patent: September 23, 1997
    Assignee: Ryobi Limited
    Inventor: Shumi Akazawa
  • Patent number: 5664634
    Abstract: A power tool is provided and includes a housing having a first longitudinal axis extending therein. An output shaft is mounted in the housing along the longitudinal axis operably connected to the working element. A motor in the housing is provided for driving the output shaft. A transmission system has cooperating portions which are movable between (1) a first state wherein the cooperating portions are disengaged from each other allowing the output shaft to reciprocate, and (2) a second state wherein the cooperating portions are engaged with each other causing the output shaft to rotate. A wobble driver is mounted to the output shaft with the wobble driver having (1) a first mode wherein the wobble driver is in driving relation to the output shaft and is capable of reciprocating with the output shaft along the first longitudinal axis, and (2) a second mode when the wobble driver is in non-driving relation to the output shaft.
    Type: Grant
    Filed: October 23, 1995
    Date of Patent: September 9, 1997
    Assignee: Waxing Corporation of America, Inc.
    Inventor: Robert E. McCracken
  • Patent number: 5513709
    Abstract: The invention provides a portable power tool which is lightweight and convenient to use by the general public in any of its various forms, as a wallpaper stripper, a paint scraper or a cold chisel up to a power spade. The tool comprises a housing (12), a drive, an electric motor (14,160) adapted to drive at least one selected tool bit (4,56,62,64,66,68) mounted on an output shaft (44) moving in a reciprocating axial manner. Conveniently the drive may be a linear motor (160) or if used with a cam device, a rotary motor (14). The cam device may be a cylinder cam (32) provided with a sinusoidal cam track (34).
    Type: Grant
    Filed: May 21, 1991
    Date of Patent: May 7, 1996
    Inventor: Hugh E. Fisher
  • Patent number: 5505271
    Abstract: A hammer mechanism (200,200') for a power tool comprises a housing (203), a chuck spindle (201) journalled for rotation in the housing and having axial freedom of movement in the housing, a rotary ratchet (204) fixed on the spindle, the ratchet having teeth (207) facing a rear end of the housing, a fixed ratchet (205) rotationally fixed in the housing but having axial freedom of movement in the housing, the fixed ratchet surrounding the spindle and having teeth (207) facing the teeth of the rotary ratchet, and a spring (213) between the fixed ratchet and housing resiliently biasing the fixed ratchet towards the rotary ratchet.A first cam (208,209) between the fixed and rotary ratchets has two positions. In a first position, the ratchets can engage one another, whereby reciprocal motion is imparted on the spindle on rotation thereof. In a second position the ratchets are prevented from inter-engagement.A second cam (224) between the fixed ratchet and housing have two positions.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: April 9, 1996
    Assignee: Black & Decker Inc.
    Inventor: Michael D. Bourner
  • Patent number: 5488997
    Abstract: A rotary impacting apparatus comprises a housing, a rotor rotated in the housing, an impact member eccentrically held by the rotor, and a main reciprocative implement held reciprocatively at a forward end portion of the housing. The rotor rotates to hit the impact member for driving the main reciprocative implement into the ground for instance. The apparatus further includes an auxiliary oscillating mechanism for transmitting an impacting force from the impact member to pull the main reciprocative implement when the housing is pulled relative to the main reciprocative implement by a predetermined distance.
    Type: Grant
    Filed: October 14, 1994
    Date of Patent: February 6, 1996
    Assignee: Yamada Juki Co., Ltd.
    Inventor: Sakuji Yamada
  • Patent number: 5449044
    Abstract: A miniature impact tool in which a cam is utilized for moving a striker backward by converting rotary motion of a drive shaft to a linear motion. The striker is in contact with a spring/plunger assembly and is moved away from a surface to be struck during a portion of the rotation cycle of the cam. On further rotation the cam surface is cut away and spring action drives the striker forward, causing impact of a cutting tool (chisel) against a workpiece. Excessive wear of the drive shaft is eliminated using a specific design of a shelf upon which the striker moves, as well as a sleeve bearing around the drive shaft in the area of possible wear. The striker is provided with a guide structure (such as a recess) into which the nose of the plunger fits in order to provide controlled guidance of the striker in its longitudinal movement. The output shaft of the tool accepts removable collets of varying shapes in order to accommodate chisel tools having different shank geometries and sizes.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: September 12, 1995
    Inventor: Raymond J. Phillips
  • Patent number: 5427188
    Abstract: The invention relates to portable power tool intended to form part of a power tool or a conversion unit adpated to be fitted to the shaft of a power tool. The tool includes a rotary cam member (6, 8) having an internal sinusoidal cam track (12) in which cam followers (26) of an output shaft (2) are received. When the cam member (6, 8) rotates, the shaft (2) is caused to partake of a lengthwise reciprocating movement suitable for application to a scraper bit or other tool kit such as a chisel. In an example of the invention, the shaft (86) passes through a fixed bearing ring (88), a slidable sleeve (96) being provided to control engagement of the shaft (86) via a key member (104) with portions of the ring (88) or the cam member (76), so as to enable the shaft (86) to partake of lengthwise movement or to be convertible to rotational movement, as selected by the operator.
    Type: Grant
    Filed: June 16, 1994
    Date of Patent: June 27, 1995
    Inventor: Hugh E. Fisher
  • Patent number: 5366025
    Abstract: A drill or impact hammer has a mechanical striking mechanism which is driven in a reciprocating manner by a drive element which is tiltable around an axle. A resilient driver member which is tiltable around the axle serves to transmit this movement to a striker. The driver member is articulated at the striker with play to protect the bearings from the reaction forces in percussion operation.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: November 22, 1994
    Assignee: Robert Bosch GmbH
    Inventors: Axel Dutschk, Joachim Hecht
  • Patent number: 5305672
    Abstract: Driving means in particular for a cutting-off device with a rotationally held cutting-off tool. In order to provide the cutting-off tool with high acceleration in a simple manner, a sledge hammer (6) is provided that cooperates with an impact surface (5) arranged on a rotationally held cutting-off tool (4). Furthermore, a cam (2) is arranged on at least one driven rotating inertial body (1) for acting upon said sledge hammer, whereby said inertial body (1) is driven at an essentially constant, optionally adjustable speed.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: April 26, 1994
    Inventor: Ludwig Balint
  • Patent number: 5287582
    Abstract: An adhering substance peeling apparatus provided with a vertically reciprocating scraping blade at the lower end of an operating rod of a proper length so that chewing gum, dirt and other adhering substances adhering to the ground surface or the like may be peeled off while the worker is standing upright.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: February 22, 1994
    Assignee: Oppama Kogyo Kabushiki Kaisha
    Inventors: Norio Kawai, Yoshiki Kitamura
  • Patent number: 5277259
    Abstract: A power tool has a tool spindle, a hammer unit, a drive including a motor having a motor driven shaft, a motion conversion gear for generating reciprocating piston movement, and a disengageable coupling located between the motor and the motion conversion gear and engaging the hammer unit. The coupling has two coupling parts which held apart, one of the coupling parts being axially fixed and another of the coupling parts being axially movable and arranged on the motor-driven shaft rotatable relative to the shaft. A gear linkage connects the another coupling part with the shaft and transmits portions of a torque of the shaft to the another coupling part in form of an axially directed closing force.
    Type: Grant
    Filed: October 29, 1991
    Date of Patent: January 11, 1994
    Assignee: Robert Bosch GmbH
    Inventors: Wolfgang Schmid, Jorg Faelchle, Walter Laubengaier
  • Patent number: 5224231
    Abstract: A brush attachment for a power tool, such as an electric drill, capable of rotating a suitable shaft including an attachment body containing a longitudinally extending chamber and an elongate shaft rotatably mounted in this body and projecting from a rear end thereof. A cam and cam follower mechanism in the chamber convert rotary motion of the shaft into a reciprocating linear motion. There is a shaft mechanism mounted in the body for sliding reciprocating movement only relative to the body and connected to the cam follower. This shaft mechanism projects from a front end of the body. A brush is attached to a front end of the shaft mechanism and reciprocates with this mechanism in the longitudinal direction thereof. The brush attachment can be mounted on the power tool so the attachment body remains stationary relative to the tool when the shaft is rotating.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: July 6, 1993
    Inventor: Ernesto Nacar
  • Patent number: 5125461
    Abstract: An electric power tool of the type which has an inserted tool bit (8), which can be operated with a rotary and a hammer action, and comprises a hammer which can be activated by axial displacement of the tool bit (8) by engagement with the work piece, also comprises a manually operable adjustment handle which can be rotated about an adjustment axis (59) between a first position in which a stop element (53) permits the axial displacement for the activation of the hammer means, and a second position in which the stop element (53) blocks the axial displacement. The stop element (53) is connected with cam surface (61, 62) which is coupled with an adjustment element (41) movement of which switches between high and low speeds of the tool. The cam surface has an arc-shaped portion (61) circular about the adjustment axis (59). Connected to one end of the arc-shaped portion(61) of the cam surface is a curved second portion (62), the distance of which from the adjustment axis (59) changes continuously.
    Type: Grant
    Filed: April 22, 1991
    Date of Patent: June 30, 1992
    Assignee: Black & Decker, Inc.
    Inventor: Jurgen Hoser