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US3606931A - Rotary impact motor - Google Patents

Rotary impact motor Download PDF

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Publication number
US3606931A
US3606931A US45047A US3606931DA US3606931A US 3606931 A US3606931 A US 3606931A US 45047 A US45047 A US 45047A US 3606931D A US3606931D A US 3606931DA US 3606931 A US3606931 A US 3606931A
Authority
US
United States
Prior art keywords
impact
dog
cam
anvil
hammer body
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US45047A
Other languages
English (en)
Inventor
Karl Gosta Karden
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Atlas Copco AB
Original Assignee
Atlas Copco AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Atlas Copco AB filed Critical Atlas Copco AB
Application granted granted Critical
Publication of US3606931A publication Critical patent/US3606931A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
    • B25B21/02—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose with means for imparting impact to screwdriver blade or nut socket
    • B25B21/026—Impact clutches

Definitions

  • the invention relates to a rotary impact motor of the kind used in connection with fastener setting tools, impact wrenches and the like.
  • a type of rotary impact motor with impact action in both rotational directions thereof against the respective of two cam flanks on a rotatable anvil in which a hammer body is rotatably carried coaxially with respect to the axis of rotation of the anvil, and an impact dog is journalled pivotally on the hammer body about an axis spaced from but parallel with said axis of rotation for taking respectively impact and release position with respect to the cam flanks, cam surfaces cooperating with the impact dog being arranged on the anvil for pivoting the impact dog towards the impact position, and a drive element being in engagement with the impact dog for rotating the latter together with the hammer body and arranged for pivoting the impact dog towards the release position.
  • a rotary impact motor with impact action in both rotational directions thereof comprising a housing, a rotatable anvil in said housing, opposed cam flanks on said anvil, a hammer body rotatably carried in said housing coaxially with respect to the axis of rotation of said anvil and around said cam flanks thereof, an imice pact dog pivotally journalled on said hammer body about an axis spaced from but parallel with said axis of rotation for taking respectively impact and release positions with respect to said cam flanks, a recess on said impact dog facing said anvil and defining opposed portions on said impact dog respectively leading and trailing in the rotational direction thereof, the flank that meets the rotation of said impact dog during rotation of said hammer body relative to said anvil cooperating with the leading portion of said impact dog for pivoting the trailing portion thereof to impact position against that very same flank, and rotatable drive means in said housing in operative engagement with said impact dog for rotating it together with said hammer body and
  • the impact dog at the moment of impact is given an impulse to roll over the cam flank receiving the impact so that the rebound is eliminated.
  • This over-rolling produces, as a matter of fact, a reverse torque by reason of the portion of the impact dog leading in the rotational direction hitting against the anvil beyond the flank against which the impact was applied in the first place and thus delivering a torque impulse in a direction opposite to the drive direction, replacing the rebound.
  • the reverse torque is an advantage for example during threading operations in which experience shows that the reverse torque pulses cause breaking of the chips and thus are apt to improve the cutting effect.
  • FIG. 1 shows a longitudinal section through an impact tool including a rotary impact motor according to the invention.
  • FIG. 2 is a cross section on the line 2-2 in FIG. 1.
  • FIG. 3 is a partial section seen on line 3-3 in FIG. 1.
  • FIG. 4 is a cross section through the rotary impact motor in release position after the delivery of an impact and seen on the line 4-4 in FIG. 1.
  • FIGS. 5-8 show various relative positions of the parts in FIG. 4 up to an impact being delivered in the impact position shown in FIG. 8.
  • the impact tool in FIG. 1 is an impact wrench including a back piece 10 provided with a handle 11 and a front piece 12.
  • the front piece 12 encloses the rotary impact motor or impact clutch and is provided with a central forward opening 13 through which a rotatable anvil 15 projects.
  • the anvil 15 is journalled in a roller bearing 14 carried by the front piece 12
  • a rotation motor 20 preferably a reversible pneumatic or electric motor having a rotor 16 arranged therein.
  • the rotor 16 in the case of a pneumatic motor has radial grooves taking up vanes 17 and is rotated in the usual way by the vanes 17 through actuation of compressed air delivered to the motor 20 and suitably introduced through the handle 11.
  • the motor 20 is controlled by a throttle valve, not shown, and by a conventional reversing slide 18.
  • the rotor 16 is journalled in the back piece 10 in roller bearings 22 and 23 and the forward end thereof is extended through the roller bearing 22 and carries parallel axially extending splines 24, FIG. 2.
  • the rotor 16 has a forward axial bore 19 which rotatably takes up a guide pin 21.
  • the forward end of the anvil 15 carries a polygonal end portion 25 for the application of a socket wrench, not shown.
  • the anvil 15 has a cylindrical portion 26 which within the front piece 12 passes over into a radial cam 27.
  • the rear end of the anvil 15 is provided with an axial bore 28 which takes up the pin 21 with a press fit, the rear end having a cylindrical reduced portion 29 which is surrounded rotatably by a cylindrical drive element 30.
  • the drive element 30 has a partly cylindrical recess 32 at the periphery thereof and is by axial grooves 31 at a rear hub portion thereof in engagement with the splines 24, FIG. 2, of the rotor 16.
  • a hammer body 35 is coaxially rotatably journalled about the anvil and sits by way of a forward hub portion 36 rotatable on the cylindrical portion 26 of the anvil 15 behind the roller bearing 14.
  • the hammer body 35 is provided with a rotation cavity 37 coaxial with the axis of rotation thereof which cavity surrounds the radial cam 27 and permits free rotation of the latter relative to the hammer body 35 within the cavity 37.
  • a journalling cavity 38 provided by a cylinder surface and intended for an impact dog 40 which by means of a cylindrical back portion 39 along the entire length thereof is slidably supported by the cylinder surface of the journallin'g cavity 38 pivotally about an axis 33, FIG.
  • the rotation cavity 37 rearwardly thereof is terminated by an enlarged cylindrical portion 41 which rotatably takes support against the periphery of the drive element 30.
  • the radial cam 27 of the anvil 15 is single-lobed relatively narrow peripherally and is with respect to a diametrical plane symmetrically bordered by two opposed cam flanks 42, 43 which pass over into a cylindrical central cam ridge 44 with the centre of curvature in said diametrical plane.
  • the impact dog 40 is recessed somewhat similarly to turbine blade shape with internally flattened limbs and the recess thereof has on the one hand a concave cylindrical middle surface 45 with the same radius of curvature as the cam ridge 44 and coaxial with the journalling cavity 38, and on the other hand flat sides 46, 47 diverging outwardly from the middle surface 45, the sides 46, 47 and the middle surface 45 being intended for impacting against the respective cam flanks 42, 43 and the adjacent portion of the cam ridge 44.
  • the forward end of the impact dog 40 is supported pivotally in the journalling cavity 38 by a pivot portion 48, FIG. 3, projecting rearwardly from the hub portion 36 into the journalling cavity 38, the pivot portion 48 having the same radius as the middle surface 45 of the impact dog.
  • the rear end of the impact dog 40 has a central extension 49, FIG. 2, which falls into the cylindrical recess 32 of the drive element 30 and is in camming engagement therewith.
  • the rotor 16 in operation rotates the rotary impact motor and thereby the anvil 15 thereof in clockwise direction by the driving connection consisting of the splines 24 and the grooves 31 and that the polygonal end portion of the anvil 15 through a socket wrench, not shown, transmits the rotation to a threaded fastener. If the parts of the rotary impact motor are in the impact position shown in FIGS. 2 and 8, the middle surface 45 and side 46 of the impact dog recess will remain in impact position as long as the screw rotates easily and in engagement with the flank 42 of the radial cam 27 and the adjoining part of the cam ridge 44.
  • the rotation of the drive element is transmitted at the recess 32 thereof and at the extension 49 of the impact dog 40 to the impact dog 40 and thence via the radial cam 27 to the anvil 15, the socket wrench, and the fastener.
  • the impact dog 40 transmits the rotation to the radial cam 27 via the portion thereof trailing in the rotational direction, in which portion the side 46 provides the main driving surface.
  • the drive element 30 during driving strives to turn the impact dog 40 over the cam ridge 44 to the released position. This is so because the driving engagement betweeen the cylinder surface of the recess 32 and the extension 49, FIG.
  • FIG. 8 there is normally generated no reverse angular movement due to rebound of the hammer body 35 and the impact dog 40 relative to the radial cam 42 of the anvil 15.
  • the impact dog In direct sequence to the impact the impact dog, as a matter of fact, is pivoted over the ridge 44 of the radial cam 27 to the position shown in FIG. 4, and the recoil upon impact is thus transformed into an angular acceleration of the impact dog 40, the latter delivering its kinetic energy in the form of a rearwardly directed impact by means of the side 47- of the impact dog 40 leading in the rotational direction and against the cam flank 43, FIG. 4.
  • a momentary reverse torque At this instant there is generated a momentary reverse torque.
  • the symmetrical design of the rotary impact motor assures corresponding impact action at rotation in counterclockwise direction. Now the impacts are delivered by the side 43 of the impact dog 40 trailing in the rotational direction and against the flank 43, while the portion of the impact dog at the outer edge of the side 46 leading in the rotational direction causes turning of the impact dog to impact position.
  • a rotary impact motor with impact action in both rotational directions thereof comprising a housing, a rotatable anvil in said housing, opposed cam flanks on said anvil, a hammer body rotatably carried in said housing coaxially with respect to the axis of rotation of said anvil and around said cam flanks thereof, an impact dog pivotally journalled on said hammer body about an axis spaced from but parallel with said axis of rotation for taking respectively impact and release positions with respect to said cam flanks, a recess on said impact dog facing said anvil and defining opposed portions on said impact dog respectively leading and trailing in the rotational direction thereof, the flank that meets the rotation of said impact dog during rotation of said hammer body relative to said anvil cooperating with the leading portion of said impact dog for pivoting the trailing portion thereof to impact position against that very same flank, and rotatable drive means in said housing in operative engagement with said impact dog for rotating it together with said hammer body and for pivoting said impact dOg towards said release position.
  • a rotary impact motor according to claim 1 in which said cam flanks form the opposite sides of a single-lobed radial cam on said anvil, said radial cam forming a cam ridge falling concentrically into said recess of said impact dog in the impact position thereof and being symmetric with respect to a diametrical plane through the axis of rotation of said anvil and said cam ridge.
  • a rotary impact motor in which said hammer body is provided with a cylindrical rotation cavity surrounding said radial cam and a journalling cavity opening out into said rotation cavity and bordered by a cylinder surface coaxial with the pivotal axis of said impact dog, the back portion of said impact dog during pivotal movement thereof being slidably supported by said journalling cavity, and the geometrical axis of the cylinder surface of the journalling cavity being disposed within the rotation cavity and in impact position of said impact dog falling radially within said cam ridge of said radial cam.
  • a rotary impact motor according to claim 3 in which said cam ridge is cylindrical and in impact position of said impact dog is substantially coaxial with the geometrical axis of said journalling cavity, the recess of said impact dog comprising a central cylindrical middle surface coaxial with said geometrical axis of said journalling cavity and sides diverging outwardly therefrom.
  • a rotary impact motor according to claim 1 in which said drive means is a drive element in camming engagement with said impact dog radially at opposite side of the pivotal axis thereof with respect to the axis of rotation of said hammer body and anvil.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Percussive Tools And Related Accessories (AREA)
US45047A 1969-06-19 1970-06-09 Rotary impact motor Expired - Lifetime US3606931A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE08307/69A SE332397B (de) 1969-06-19 1969-06-19

Publications (1)

Publication Number Publication Date
US3606931A true US3606931A (en) 1971-09-21

Family

ID=20275067

Family Applications (1)

Application Number Title Priority Date Filing Date
US45047A Expired - Lifetime US3606931A (en) 1969-06-19 1970-06-09 Rotary impact motor

Country Status (8)

Country Link
US (1) US3606931A (de)
JP (1) JPS4919319B1 (de)
DE (1) DE2029928A1 (de)
FR (1) FR2052795A5 (de)
GB (1) GB1276258A (de)
NL (1) NL7009013A (de)
SE (1) SE332397B (de)
ZA (1) ZA703868B (de)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4002212A (en) * 1974-10-02 1977-01-11 Atlas Copco Aktiebolag Rotary impact mechanism
US20120237295A1 (en) * 2011-03-16 2012-09-20 Central Japan Railway Company Jointing structure in vehicle travelling path joints and the like having expansion function and method of mounting elastic member therein
US20120247288A1 (en) * 2011-03-29 2012-10-04 Emerson Electric Co. Direct action powered soil pipe cutter
US9289886B2 (en) 2010-11-04 2016-03-22 Milwaukee Electric Tool Corporation Impact tool with adjustable clutch
US20190375078A1 (en) * 2018-06-12 2019-12-12 Tranmax Machinery Co., Ltd. Impact block, carrier member and impact tool using sames
US20190375085A1 (en) * 2018-06-12 2019-12-12 Tranmax Machinery Co., Ltd. Impact block, carrier member and impart tool using sames
US10974372B2 (en) * 2018-02-23 2021-04-13 Makita Corporation Impact tool
US11192223B2 (en) 2017-03-07 2021-12-07 Makita Corporation Tool holding apparatus and power tool, and impact tool
US11318589B2 (en) 2018-02-19 2022-05-03 Milwaukee Electric Tool Corporation Impact tool
US20220176523A1 (en) * 2020-12-08 2022-06-09 Snap-On Incorporated Impact mechanism for a rotary impact tool
US11484997B2 (en) * 2018-12-21 2022-11-01 Milwaukee Electric Tool Corporation High torque impact tool
US11511400B2 (en) * 2018-12-10 2022-11-29 Milwaukee Electric Tool Corporation High torque impact tool
USD971706S1 (en) 2020-03-17 2022-12-06 Milwaukee Electric Tool Corporation Rotary impact wrench
US11701759B2 (en) * 2019-09-27 2023-07-18 Makita Corporation Electric power tool
US11806855B2 (en) 2019-09-27 2023-11-07 Makita Corporation Electric power tool, and method for controlling motor of electric power tool
US12157208B2 (en) 2020-02-24 2024-12-03 Milwaukee Electric Tool Corporation Impact tool

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4002212A (en) * 1974-10-02 1977-01-11 Atlas Copco Aktiebolag Rotary impact mechanism
US9289886B2 (en) 2010-11-04 2016-03-22 Milwaukee Electric Tool Corporation Impact tool with adjustable clutch
US20120237295A1 (en) * 2011-03-16 2012-09-20 Central Japan Railway Company Jointing structure in vehicle travelling path joints and the like having expansion function and method of mounting elastic member therein
US8602678B2 (en) * 2011-03-16 2013-12-10 Central Japan Railway Company Jointing structure of vehicle traveling path joints having expansion function and method of mounting elastic member therein
US20120247288A1 (en) * 2011-03-29 2012-10-04 Emerson Electric Co. Direct action powered soil pipe cutter
US9192995B2 (en) * 2011-03-29 2015-11-24 Emerson Electric Co. Direct action powered soil pipe cutter
US12064853B2 (en) 2017-03-07 2024-08-20 Makita Corporation Impact tool
US11192223B2 (en) 2017-03-07 2021-12-07 Makita Corporation Tool holding apparatus and power tool, and impact tool
US11318589B2 (en) 2018-02-19 2022-05-03 Milwaukee Electric Tool Corporation Impact tool
US11964368B2 (en) * 2018-02-19 2024-04-23 Milwaukee Electric Tool Corporation Impact tool
US20220250216A1 (en) * 2018-02-19 2022-08-11 Milwaukee Electric Tool Corporation Impact tool
US10974372B2 (en) * 2018-02-23 2021-04-13 Makita Corporation Impact tool
US20190375085A1 (en) * 2018-06-12 2019-12-12 Tranmax Machinery Co., Ltd. Impact block, carrier member and impart tool using sames
EP3581334A1 (de) * 2018-06-12 2019-12-18 Tranmax Machinery Co., Ltd. Schlagblock, trägerelement und schlagwerkzeug mit verwendung davon
US20190375078A1 (en) * 2018-06-12 2019-12-12 Tranmax Machinery Co., Ltd. Impact block, carrier member and impact tool using sames
EP3581333A1 (de) * 2018-06-12 2019-12-18 Tranmax Machinery Co., Ltd. Schlagblock, trägerelement und schlagwerkzeug damit
US11511400B2 (en) * 2018-12-10 2022-11-29 Milwaukee Electric Tool Corporation High torque impact tool
US11597061B2 (en) * 2018-12-10 2023-03-07 Milwaukee Electric Tool Corporation High torque impact tool
US11938594B2 (en) * 2018-12-21 2024-03-26 Milwaukee Electric Tool Corporation High torque impact tool
US11484997B2 (en) * 2018-12-21 2022-11-01 Milwaukee Electric Tool Corporation High torque impact tool
US20230080957A1 (en) * 2018-12-21 2023-03-16 Milwaukee Electric Tool Corporation High torque impact tool
US20240227131A1 (en) * 2018-12-21 2024-07-11 Milwaukee Electric Tool Corporation High torque impact tool
US11806855B2 (en) 2019-09-27 2023-11-07 Makita Corporation Electric power tool, and method for controlling motor of electric power tool
US11701759B2 (en) * 2019-09-27 2023-07-18 Makita Corporation Electric power tool
US12157208B2 (en) 2020-02-24 2024-12-03 Milwaukee Electric Tool Corporation Impact tool
USD971706S1 (en) 2020-03-17 2022-12-06 Milwaukee Electric Tool Corporation Rotary impact wrench
AU2021269384B2 (en) * 2020-12-08 2023-11-30 Snap-On Incorporated Impact mechanism for a rotary impact tool
US20220176523A1 (en) * 2020-12-08 2022-06-09 Snap-On Incorporated Impact mechanism for a rotary impact tool
US12048988B2 (en) * 2020-12-08 2024-07-30 Snap-On Incorporated Impact mechanism for a rotary impact tool

Also Published As

Publication number Publication date
FR2052795A5 (de) 1971-04-09
JPS4919319B1 (de) 1974-05-16
DE2029928A1 (de) 1971-02-25
ZA703868B (en) 1971-01-27
NL7009013A (de) 1970-12-22
GB1276258A (en) 1972-06-01
SE332397B (de) 1971-02-01

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