US3675726A - Rotary impact motor - Google Patents

Rotary impact motor Download PDF

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Publication number
US3675726A
US3675726A US104045A US3675726DA US3675726A US 3675726 A US3675726 A US 3675726A US 104045 A US104045 A US 104045A US 3675726D A US3675726D A US 3675726DA US 3675726 A US3675726 A US 3675726A
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US
United States
Prior art keywords
impact
groove
hammer
dog
anvil
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
US104045A
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English (en)
Inventor
Knut Christian Schoeps
Klas Johan Astrom
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 US3675726A publication Critical patent/US3675726A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L37/00—Couplings of the quick-acting type
    • F16L37/22—Couplings of the quick-acting type in which the connection is maintained by means of balls, rollers or helical springs under radial pressure between the parts
    • F16L37/23—Couplings of the quick-acting type in which the connection is maintained by means of balls, rollers or helical springs under radial pressure between the parts by means of balls
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms

Definitions

  • the impact dog is movable axially in the hammer between impact and release positions relative to the anvil.
  • the impact dog is power biased towards the release position and has a follower lug which engages the anvil groove.
  • the follower lug is forced by the cam rise to move axially against the power bias to deliver a rotational impact against an impact surface in the anvil groove.
  • This invention relates to a rotary impact motor of the type incorporating a rotatable anvil, a hammer rotatably supported in coaxial relation to the anvil, and an impact dog guided for conjoined rotation on the hammer, the impact dog being axially movably arranged relative to the hammer and the anvil for taking respectively impact and release positions therebetween under the action of respectively cam means engageable with the impact dog and a power bias acting thereon.
  • main object of the invention to provide in the aforementioned type of rotary impact motors a simplified design as to shape and combination of the main parts incorporated therein.
  • Another object of the invention is to provide in such a combination an increased rigidity in the joumalling and cooperation of the parts involved.
  • a further object is to eliminate power bias providing springs in the arrangement of the impact dog and to substitute them for a simple and dependable cam mechanism.
  • a rotary impact motor comprising a housing, an anvil rotatably supported in said housing, a hammer rotatably journalled in said housing in coaxial relation around said anvil, means in said housing for rotating said hammer, a peripheral groove on and circumferentially around said anvil, an impact surface in said groove, an impact dog axially movably but non-rotatably supported in said hammer for taking respectively impact and release positions relative to said impact surface, a radially inwardly directed follower lug on said impact dog in engagement with said groove, said groove providing an axial cam rise for moving, during relative movement between said hammer and said anvil, said follower lug to impact position against said impact surface, and means in said housing for providing an axial power bias on said impact dog for moving said impact dog to said release position.
  • FIG. 1 is a longitudinal section through the rotary impact motor according to the invention with the impact dog in the release position.
  • FIG. 2 is a section on the line 22 in FIG. 1.
  • FIG. 3 is an enlarged partial side view of the anvil in FIG. 1.
  • FIG. 4 is a view of the impact dog seen radially from the inside in FIG. 1.
  • FIG. 5 is a side view made partly in section of a driving element included in FIG. 1.
  • FIG. 6 is a fragmentary section on an enlarged scale seen on the line 6-6 in FIG. 1.
  • FIGS. 7-9 show partly in section diagrammatic functional views of the main parts of the rotary impact motor.
  • FIG. 7 shows a plane development of the hammer, the impact dog, and the driving element of the rotary impact motor at the instant of impact with the impact dog in an impact position.
  • FIG. 8 shows the details in FIG. 7 immediately after the impact with the impact dog in a released position.
  • FIG. 9 shows the details in FIG. 7 prior to impact.
  • FIGS. 10-12 show partly in section diagrammatic functional views of the main parts in a modified embodiment of the rotary impact motor according to the invention.
  • FIG. 10 shows a plane development of the hammer, the impact dog, and the driving element of the rotary impact motor at the instant of impact with the impact dog in an impact position.
  • FIG. 11 shows the details in FIG. 10 immediately after the impact with the impact dog in a released position.
  • FIG. 12 finally shows the details in FIG. 10 immediately after impact.
  • the rotary impact motor is shown as forming part of a motor driven impact tool 15, and more particularly a hand sustained impact action nut setter.
  • the impact tool 15 comprises a conventional motor, not shown in the figures, for example a reversible pneumatic vane motor which rotates a drive shaft 17.
  • the impact motor proper is mounted between the housing 16 and a front piece 18 which rotatably supports a projecting anvil 19.
  • the anvil 19 has a square end 20 intended for carrying removable tools such as, for example, a socket wrench.
  • the drive shaft 17 has a splined portion 22 which is in engagement with a cooperating inwardly splined portion 23 in a driving element 24.
  • the driving element 24 is a cylindrical body can-led by the drive shaft 17 having a bore 25 which rotatably supports a rear end pivot 26 on the anvil 19. Between the end pivot 26 and the drive shaft 17 a centering pin 27 is received in axial bores. Around the centering pin 27 a spacing washer 28 provides an abutment between the splined portion 23 and the end pivot 26.
  • the anvil 19 is supported rotatably in a joumalling sleeve 21 provided with a rear radial flange and carried by the front piece 18.
  • the anvil 19 has an enlarged middle portion 29 of equal diameter with the driving element 24.
  • a peripherally surrounding helical or screw groove 30 In the middle portion 29 is formed a peripherally surrounding helical or screw groove 30.
  • the opposite transverse end walls of the screw groove 30 are designated respectively by 31 and 32, FIGS. 3 and 9, and provide impact surfaces extending obliquely outwardly in a nearly radial direction in the middle portion 29 of the anvil 19.
  • the end portions of the screw groove 30 adjacent the impact surfaces 31, 32 are arranged in overlapping arrangement and open one into the other axially.
  • the flanks or axial sides of the screw groove 30 provide an axial cam rise in the extension of which the impact surfaces 31, 32 are disposed at the end portions of the thread groove.
  • a tubular hammer 34 is rotatably supported by the outer cylindrical surfaces of the driving element 24 and the middle portion 29 and is kept axially in place around these parts between a rear flange 35 on the driving element 24 and the radial flange of the joumalling sleeve 21.
  • the tubular hammer 34 is provided with an inner axial recess or groove 36 which in cross section has a dove-tail shape.
  • an elongated impact dog 37 which by a dove-tail shaped base portion is received in and is slidably guided by the axial groove 36.
  • the impact dog 37 has forwardly thereof a radially inwardly directed follower lug 40 which is trapeziforrn in longitudinal section and by its axial flanks 44, 45 slidably cooperates with the flanks of the screw groove 30.
  • the follower lug 40 is wedge-shaped in cross section. The impact dog 37 with the wedge flanks of the follower lug 40 can either take an impact position in engagement with one of the impact surfaces 31, 32 on the middle portion 29 or take a release position at either entrance into the screw groove 30, as for example in FIG. 8 at the rear entrance.
  • a spring for creating a power bias capable to move the impact dog 37 to a release position, may be compressed between suitable abutments on the impact dog 37 and the driving element 24. More advantageous, however, is to provide the driving element 24 with a canted groove 41 in which is received a ball 42 in its turn inserted into a semispherical recess 39 fixedly at the rear end of the impact dog 37. As a result, control of the impact dog 37 function is carried out entirely without springs.
  • the square end 20 by meanS of a socket wrench is connected to a nut to be screwed onto a fastener means having a right hand thread.
  • the bidirectionally rotatable motor of the tool 15 is set for rotation in the clockwise direction when viewed in the direction of the arrows 2-2 in FIG. 1 and upon starting the drive shah 17 will transmit rotation to the driving element 24 and the oblique groove 41 which applies the driving torque against the ball 42 and thus against the semispherical recess 39 and the impact dog 37.
  • the impact dog 37 is at the base portion thereof bound to rotate conjointly with the hammer 34 which followingly also starts rotating.
  • the frictional driving position is the one shown in FIG. 7.
  • the rotational resistance willincrease very rapidly and the anvil 19 together with the middle portion 29 thereof will be retarded and stops.
  • the impact dog 37 is driven continuously by the driving element 24 and the oblique groove 41 thereof and strives together with the hammer 34 to go on rotating. Since one wedge flank of the follower lug 40 abuts against the impact surface 31, the impact dog 37 is prevented from rotating.
  • the continued turning of the driving element 24 results in a retraction of the ball 42 in the oblique groove 41 from the position in FIG. 7 to the position illustrated in FIG.
  • the follower lug 40 During rotation in the opposite direction the follower lug 40 obviously delivers impacts against the impact surface 32 at the opposite end portion of the screw groove 30. Contrary to what was the case during rotation in the clockwise direction, the power bias applied on the impact body 37 at the oblique groove 41 and the ball 42 will be directed axially away from the driving element 24 while the screw groove 30 with the forward axial side thereof will guidingly support the forward flank 45 of the follower lug 40 and move the latter towards the driving element 24 to an impact position against the impact surface 32.
  • the screw groove 30 has been substituted for by a peripheral ring groove 46 comprising at the rear axial side or flank 55 thereof an axial cam crest 49 bordered by doublesided cam surfaces 47, 48.
  • the driving element 24 is provided with a V-shaped ball groove 50 for cooperation with the ball 42 of the impact dog 37, as a result of which the impact dog 37 always will be subjected to a power bias in the direction axially towards the driving element 24 regardless of the rotational direction.
  • the impact dog 37 has a follower lug 51 provided with a rearwardly directed cam crest 52 bordered by doublesided cam surfaces and adapted for cooperation with the flank 55 of the ring groove 46 and the cam crest 49 of the latter.
  • the ring groove 46 presents at the forward axial side or flank 56 thereof angularly spaced impact surfaces 53, 54 against which the impact dog 37 with the side flanks of the follower lug 51 is arranged to deliver impacts.
  • the cam crest 49 is disposed intermediately relative to the impact surfaces 53, 54.
  • a rotary impact motor comprising:
  • a hammer rotatably joumalled in said housing in coaxial relation around said anvil; means in said housing for rotating said hammer;
  • a rotary impact motor according to claim 1 in which said groove is a screw groove, the end portions of which open into one another axially, said end portions each being terminated by an impact surface transverse to said groove.
  • a rotary impact motor according to claim 2 in which said follower lug has opposed flank surfaces engageable with said screw groove and is wedge shaped in a direction parallel to said flank surfaces.
  • a rotary impact motor accordinG to claim 1 in which said impact dog is dove-tail shaped in cross section at the base portion thereof and wherein said hammer has a groove therein of corresponding dove-tail cross-section, said impact dog being axially slidably guided in said hammer groove.
  • a rotary impact motor according to claim 1 in which said groove is a ring groove provided with said cam rise which includes a cam crest bordered by double-sided cam surfaces.
  • a rotary impact motor according to claim 5 in which said follower lug has an axial cam follower crest bordered by dou ble-sided cam surfaces which cooperates with the cam crest of said ring groove to move said follower lug to said impact position.
  • a rotary impact motor according to claim I in which said rotating means is a driving element rotatably supported in said housing, said power bias means including a cam mechanism between said driving element and said impact dog.
  • a rotary impact motor according to claim 7 in which said cam mechanism includes an axially canted groove on said driving element and a ball carried on said impact dog for cooperative engagement with said canted groove.
  • a reversibly rotatable impact motor comprising:
  • a reversibly rotatable impact motor comprising:
  • a tubular hammer rotatably joumalled in said housing in coaxial relation around said anvil, said hammer having an internal axial groove therein;
  • an impact dog axially movably supported in said axial hammer groove for taking respectively impact and release positions relative to said impact surfaces when adjacent thereto;

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
US104045A 1970-01-14 1971-01-05 Rotary impact motor Expired - Lifetime US3675726A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE00421/70A SE347685B (enrdf_load_stackoverflow) 1970-01-14 1970-01-14

Publications (1)

Publication Number Publication Date
US3675726A true US3675726A (en) 1972-07-11

Family

ID=20256546

Family Applications (1)

Application Number Title Priority Date Filing Date
US104045A Expired - Lifetime US3675726A (en) 1970-01-14 1971-01-05 Rotary impact motor

Country Status (10)

Country Link
US (1) US3675726A (enrdf_load_stackoverflow)
BE (1) BE761523A (enrdf_load_stackoverflow)
CA (1) CA929050A (enrdf_load_stackoverflow)
CH (1) CH517565A (enrdf_load_stackoverflow)
DE (1) DE2100550A1 (enrdf_load_stackoverflow)
FR (1) FR2075316A5 (enrdf_load_stackoverflow)
GB (1) GB1297591A (enrdf_load_stackoverflow)
NL (1) NL7100109A (enrdf_load_stackoverflow)
SE (1) SE347685B (enrdf_load_stackoverflow)
ZA (1) ZA7136B (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140027140A1 (en) * 2010-10-29 2014-01-30 Chuan Cheong Yew Handheld machine tool comprising a mechanical striking mechanism
US12048988B2 (en) 2020-12-08 2024-07-30 Snap-On Incorporated Impact mechanism for a rotary impact tool

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001428A (en) * 1960-02-23 1961-09-26 Master Power Corp Rotary impact wrench
US3001429A (en) * 1959-04-16 1961-09-26 Master Power Corp Rotary impact wrench
US3253662A (en) * 1961-10-20 1966-05-31 Cooper Bessemer Corp Controlled torque tool
US3272265A (en) * 1964-03-26 1966-09-13 Ingersoll Rand Co Rotary impact tool
US3331452A (en) * 1963-09-27 1967-07-18 Bosch Gmbh Robert Torque wrench

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001429A (en) * 1959-04-16 1961-09-26 Master Power Corp Rotary impact wrench
US3001428A (en) * 1960-02-23 1961-09-26 Master Power Corp Rotary impact wrench
US3253662A (en) * 1961-10-20 1966-05-31 Cooper Bessemer Corp Controlled torque tool
US3331452A (en) * 1963-09-27 1967-07-18 Bosch Gmbh Robert Torque wrench
US3272265A (en) * 1964-03-26 1966-09-13 Ingersoll Rand Co Rotary impact tool

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140027140A1 (en) * 2010-10-29 2014-01-30 Chuan Cheong Yew Handheld machine tool comprising a mechanical striking mechanism
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
ZA7136B (en) 1971-10-27
BE761523A (fr) 1971-06-16
CH517565A (de) 1972-01-15
SE347685B (enrdf_load_stackoverflow) 1972-08-14
GB1297591A (enrdf_load_stackoverflow) 1972-11-22
DE2100550A1 (de) 1971-07-22
FR2075316A5 (enrdf_load_stackoverflow) 1971-10-08
CA929050A (en) 1973-06-26
NL7100109A (enrdf_load_stackoverflow) 1971-07-16

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