US2439337A

US2439337A - Impact clutch

Info

Publication number: US2439337A
Application number: US484157A
Authority: US
Inventors: Frithiof P Forss
Original assignee: Independent Pneumatic Tool Co
Current assignee: Independent Pneumatic Tool Co
Priority date: 1943-04-23
Filing date: 1943-04-23
Publication date: 1948-04-06
Anticipated expiration: 1965-04-06

Description

April 6, 1948. F. P. FORSS IIPACT CLUTCH Filed April 23, 1943 r h I 4 INVENTOR. fk/r/r/ar fans PatentEd Apr. 6, 1948 IMPACT cmrron Frithiof P. Forss, Aurora, nlqfassigliortolnde pendent Pneumatic 1 Tool 1 Company, Chloe 11]., a corporation of Delaware L Application April 23, 1943, Serial;No. 84

16 Claims. (01.19%31015)? This invention relates to portable power operated impact wrenches for screwing up and unscrewing nut andbolts by power.

The invention, while relating to tools of the character referred to, is particularly concerned with the impact clutch mechanism employed in such tools for delivering a series or succession of rapid and relatively powerful rotational hammer blows on the anvil member of the clutch to tighten the nut or bolt after it has been set or to loosen a tight nut or bolt on removing the same, the invention having among its principal objects the following:

To provide an impact clutch of the roller type,

that is. wherein the impact elements are in the form of solid, relatively long, heavy metal rollers freely mounted in recesses in the hammer member of the clutch" for movement into and out of clutching engagement with the jaw or abutments on the anvil member for imparting rotation thereto in the operation of the clutch;

To locate the roller elements wholly within the recesses and in sliding contact with the end walls thereof and provided with tapered opposite ends to prevent the extremities of the rollers striking the abutments on tilting of the roller elements in the recesses; and

To provide a flexible driving connection between the rotary driver for the clutch and the hammer member of a character whereby the impact of the roller elements on the hammer member on releasing the abutments will rotate the hammer member ahead of the driver to absorb such impacts by overcoming the inertia of the hammer member to prevent premature wear on the hammer member and the recoil of the roller elements against the anvil member.

ically operated impact wrench hich the motor section I of the toolfoccupying he upper half portion of the machiiie'is' bolted orotherwise rigidly secured in axial alinernent to the clutch containing section 2 'whicnoccupiesf the lower half portion of the toolIfThe motorfsection I has aside or other handl'eiethrpugh'which compressed air is 'suppliedtothe tool'idroperating the tool motor. The

handle 3fl'iasafltting 4 at itsouter end for connec'tioiiwithanairsupplyhose (not shown) as in tools'ofthischaracter. V The handle {mounts a throttle valve, jalsol not shown, which by a trigger '5 in thehandle Enables the operator handling the toolltofcontrolthesupply of motive fluid thereto.

1Inthe'toolshown'the motor is of the rotary shaft ecti type haviri bla deprovid ed rotor 6, the lower I 1 9 which extends into the upper endfd ,theiclutchjsection 2 for driving the hammer membe 8, f the clutch through a flexible drive to beilaterf described. p

'Thefjoutsidef casing! of the clutch section 2 houses and'niounts the'operative'mechanism of theclutch and provides a journal for the spindleflllfatj the lower end of the hollow cylindric v anvil-member l o: the clutch. The anvil member l lifreceiveaithe'hammer member 81 in concentricfrelatioii"within itsouter surrounding annulai wall l2. and which wall member is provided with a] pair" of diametrically disposed, inwardly -*extending. radial 'abutments orshoulders l3, l3.

Tiiese"abutments 13 are integral with the anvil walllzand extend axially thereof as indicatedin The invention consists further in the features I hereinafter described and claimed. In the accompanying drawings- Fig. 1 is a side elevational view with parts broken away and in longitudinal section of an impact wrench embodying a clutch construction of my invention;

dotted lines; in Fig.1. The wall member l2 between thelab utments I3 is formed with arcuate track-ways Hillier the impact roller elements 15,! def the clutch to be presently described. 'lheftrackways'ji l -am made on a radiusslightly greater thanthatpf thehammer member 8 to provide clearance spaces therebetween for centrifugalfprceftojmove the roller elements l5 into the Qtrachvvays toengage the abutments l3 as showninl igsfl and 4. This positions the roller elements "l5f or."clutching the anvil and the ham..

mer members 'for rotation in unison when running afree nutprboltjand for delivering a series or Fig. 3 is a similar sectional view taken on line 3-3 of Fig. 1 to illustrate the flexible driv between the tool motor and the hammer member of the clutch; and

Fig. 4 is a sectional view similar to that of Fig. 2 showing the roller elements in the track-ways approaching the anvil abutments.

In the accompanying drawings. I have shown a uccessions: rotational hammer blows on the abutments wl'ieiith'e "anvil member is held against rotationby thenut'orbolt. i

Th toner-elements li engage and/or strike ag instjtn*dppdsite sme edges is, .Il6a of the side edg'es being on arcs of the v s the roller elements. Inthese rek "is'poii'itd out that the tool motor 6 is of the reversible type, the roller elements l5 I strike against the side edges of the abutments as fOr example at the points A in Fig. 2, the

lugs

39, 40 of the drive are in solid driving engagement as will be apparent from Fig. 3 wherein the arrow a indicates the direction 01' rotation. The resultant action of this impact of the roller elements on the abutments forces the roller. elements towards the opposed leading side walls 4| of the recesses I9 along a line indicated by the arrowB in Fig. 2. The roller elements l5 would strike with considerable force against the leading side walls 4| at the points 6 if the hammer member at this moment were directly conwould also rebound from these solid blows and strike against the abutments on the surfaces Ill as at points D causing wear. With the spacing between the

lugs

39, 40, the impacts at 0 force the hammer member ahead of the driver 35 and these impacts are absorbed in overcoming the inertiaof the hammer member in throwing it ahead of the driver. Hence, the roller elements may be madeto strike relatively powerful blows and respond quickly to the speed of the motor as the lugs close into driving engagement.

The machine shown and described has been designed tohave the minimum number of parts for the striking mechanism, large striking surfaces for the rollers with no adjustments required. The parts are all of a heavy metal construction and are rigidly clamped together providing an effective impact tool.

The details of construction and arrangement of parts shown and described may be variously changed and modified without departing from the spirit and-scope of my invention, except as pointed out in the annexed claims.

I claim as my invention:

1. An impact clutch of the character described comprising, relatively rotatable hammer and anvil members, the anvil member having a wall surrounding the hammer member and provided with internal abutments and track-ways there'- between, roller elements carried by the hammer member in recesses therein and movable by centrifugal force into the track-ways for delivering a series of rotational hammer blows on the abutments in the rotation of the hammer member relatively to the anvil, said hammer member providing side and end walls for the recesses for retaining the roller elements in operative position therein, said roller elements fitting wholly between the end walls of the recesses and having their opposite ends in sliding contact therewith, and means for rotating the hammer member.

2. An impact clutch of the character described comprising, relatively rotatable hammer and anvil members, the anvil member having a wall surrounding the hammer member and provided with internal abutments and track-ways therebetween, roller elements carried by the hammer member in recesses therein and movable by centrifugal force into the track-ways for delivering a series of rotational hammer blows on the abutments in the rotation of the hammer member relatively to the anvil, said hammer member provlding side and end walls for the recesses for retaining the roller elements in operative position therein, said roller elements fitting wholly between the end walls of the recesses and having their opposite ends flattened and in sliding contact therewith, and means for rotating the hammer member.

3. An impact clutch of the character described nected with the driver 35 causing premature wear 'at the points of impact. The roller elements .7 r comprising, relatively rotatable hammer and anvil members, the anvil member having a wall surrounding the hammer member and provided with internal abutments and track-ways therebetween, roller elements carried by the hammer member within recesses therein and movable by centrifugal force outwardly of the recesses into the track ways for delivering a. series of rotational hammer blows onthe abutments in the rotation of the hammer member relatively to the anvil, said hammer member providing the recesses with divergent side walls and end walls for anvil members, the anvil member having a wall surrounding the hammer member and Provided with internal abutments and track-ways therebetween, roller elements carried by the hammer member in recesses therein and movable by centrifugal force into the track-ways for delivering a series of rotational hammer blows on the abutments in the rotation of the hammer member relatively tothe anvil, said trackways being in arcuate form on a radius slightly greater than the radius of the hammer member and said abutments having blow receiving surfaces on the opposite sides thereof to receive impacts from the roller elements in either direction of rotation of the hammer member, said hammer member providing side and end walls for the recesses for -re-- taining the roller elements. in operative position therein, said roller elements fitting wholly between the end walls of the recesses and having their opposite ends in sliding contact therewith, and means. .for reversely rotating the hammer member.

5. An impact clutch of the character described comprising, relatively rotatable hammer and anvil members, the anvil member having a wall surrounding the hammer member and provided with internal abutments and track-Ways therebetween, roller elements carried by the hammer member in recesses therein and movable by centrifugal force into the track-ways for delivering a series of rotational hammer blows on the abutments in the rotation of the hammer member relatively to the anvil, said hammer member providing side and end wallsfor the recesses for retaining the roller elements in operative position I ments interposed therebetween for clutching and I declutching said members, said roller elements being Slidably mounted at their ends in recesses in one of said members,said roller elements hav-' ing their opposite ends tapered to prevent their 7 dun t lr edlllfll. fornnpuflngmhfluntn llninpletdulflnotthednnetermibed relatively rotatable III-nerand mmmmcab mwnmmemuun memfiu'. meets for m the driver.

emmmdmurmemmed mm withinmmllghufmmtsendhut-nmithere- 11.. Anhnpmtdutehofitherhermfierdesrribed rehflwelymhhflehnmmer and mshoulders mm; lateral mmm mmm sur'-- 15 faces extending mummy from said track-ways,

rdler demm'ls remhbly carried W the hammermemba'mradialrmmtheremandmwam In response to emh'flml force mm the hack-nus inmm: a series of rotatinnml ,lnmmerhbwsmthemmwematfihehteral tbnotthehammernmherremflivelywflm mllnmbe andmelnsfm-mmrmgthehammermunber.

' lzhnnnpeetclutchoflfiechmranterdescnm mll'lslngrellflmlyrdlhhrehammerandi arm-- wfl members, the vmmvim member having a walm the hnmmermmber and provided. with internal Mill-Hilts and track-ways there:-

mmmmmmwmmmm mmmmgmmmmmm mmumywm munbuinmthudnmflmnhlebyemmm shuulders having lateral impact: receiving mines extending mm from the track-wag, roller elemmfs xewomhly carried by the: hammer member in radial recesses and mmbre:

wm imdelivering a series @fi mtati'nnar hammerbhwsomthesmuwersmtzthehflerallimpletremiwingmmmesflmrmfimfiherotafiom of the hammer member w the anvil. 5 member, mid hammer mm and means re-- nimble therewith pruwmmg and end walls; furaidmforniainmgfihemfler dementia inoperativepmiiilntliereimsmidmner elements: mgwhollybewemtheemilwmflsorthew thehnnmn-munhanllmfwmthe driver.

I. Inanmmctlnoldthemdenalbed mm 5. vi] when, the anvil .w

faces at! end 11%, and means Eur rotating me ham, met member. v

13. An Imp-at clutch of the character described 7.1a 2L wall surrumdingthe hammer member and provided with internal abwnemrs amfll track-ms slid ahlflmentts relatively ahrumxtr shuulders lmwirng lateral impact; receiving: sur- "1:. mnrdilly firum said trunk-ways aheeddfllemM-h-Mtbemhmmin: the inertia! the-hem number.

openflvepasiziomthamsardmfler eiemerrts fltflnewholwmwemtheendwmflsofthem- "mandhavmgtheiromasiteendsrelatiwely elnnetoummdwalmsfmslidablemmem;

" therewith, Mannheim-infirm; the member.

m Idem, xemsflrm. Me hamfilflncmfidgleempmzlwm emedhnbdwemthednlw-lndthemu'eimm hmrmbermd pact receiving surfaces thereof in either direction of rotation of. the hammer member relatively to the anvil member, and means for rotating the hammer member in either direction.

15. An impact clutch of the character described comprising, hammer and anvil members relatively rotatable about a common axis, said anvil member having relatively abrupt impact receiving surfaces, elongated roller elements rotatable with the hammer member and centrifugally urged into impacting relation with said impact receiving surfaces on rotation of the hammer member, said hammer member having driving surfacesfor driving the roller elements, said driving and impact receiving surfaces being substantially co-extensive in length with the peripheral portions of the roller elements driven by the hammer member against the impact receiving surfaces in the rotation of the hammer member relatively to the anvil for imparting rotational hammer blows thereto, and means for rotating the hammer member.

16. An impact clutch of the character described comprising, hammer and anvil members relatively rotatable about a common axis, said anvil member having relatively abrupt impact receiving surfaces, elongated roller elements revolvably carried by the hammer member in radial recesses therein and centrifugally urged into impacting relation with the impact receiving surfaces on the rotation of the hammer member, said recesses receiving the whole of the roller elements and having wall portions forming driving surfaces for the roller elements, said driving and impact surfaces being substantially coextensive in length with each other and with said roller elements and engageable with the peripheral portions thereof for the major portion of their'length for imparting rotational hammer V blows against the anvil men her for rotating the same on the rotation of the hammer member relative to the anvil member, and means to rotating the hammer member.

FRITHIOF P. FORSSf REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATEN'I S Shafl! -,.-Q Mar. 7, 1944 I