US2377733A - Ratchet and pawl mechanism - Google Patents

Description

June 5, 1945. WALLER 2,377,733

RATCHET AND PAWL MEQCHANFSMS Filed Dec. 9, 1943 ATTORNEY Patented June 5, 1945 RATcriEr AND PAWL MECHANISM Fred Waller, Huntington, N. Y., assignbrtoTh Vitarama Corporation, Longlsland a corporation of New York Application December 9. 194$.Seria1No. 513,61 I io claims. (Cl. "7j4 I This invention relates to ratchet and pawl. mechanisms. i

.It is an object of ratchet and pawl mechanism which maybe perated at high speed, accurately and Without the, invention to provide a overthrow, and which is adapted to operate satisfactorily, both for .movements of relatively small and relatively large amplitude.

Other objects and advantages of the invention will appear hereinafter. 1

A preferred embodiment of the-invention se lected for purposes of, illustration is shown. in the accompanying drawing, in which,

Figure 1 is a top plan view of the mechanism. Figure 2 is a frontelevation, and c I A Figure 3 is .a front elevation of a modified form.

Referring to Figures 1 and 2, thein ve n tion is illustratedas applied to a ratchet wheel I which is rotatably mounted ona shaft 2, andin which the ratchet teeth 3 are closelyspaced, as for example, in which the teeth are spaced at .02" or pivoted on the shaft 2, but the member li should be so mounted as to have slight frictional resistance to movement in either direction.

in any suitable manner, but in the embodiment illustrated is provided with a relatively long arm I5 which is pivotally mounted at IS. The member I3. and detent are normally held in engagement with the ratchet Wheel by the spring H.

.The pawl isalso provided with a lever arm I8 having a pin I9 mounted to cooperate with the cam surface I4. Thus, when the solenoid is enerv gized because of the slightfrictional resistance to movement oi the idler member 6, the initial forward movement of the lever arm I causes the pawl to pivot on the idlermember 6 to engage a'tooth of the ratchet wheel, and causes the lever arm I 8 to lift the member I3 and the detent I2'to'free f thecratchet wheel. Subsequent forward movenient of the lever arm 1 causes the idler member 6 The pawl is provided with a lever arm I extending substantially at right angles to the pawl,

and the lever arm is-connected in any suitable manner with suitable actuating means such as the armature 8 of the solenoid 9., The lever arm I is also connected to a spring I0 adapted to return the pawl to normal position after actuation, and. carries a pin l I positioned to engage the idler member 6 to return said member to normal position after actuation. r I

A holding detent I2 is also provided, said detent being mounted on a member l3 having acurved cam surface I 4 concentric with the toothed, rim of the ratchet wheel. The member I3 is mounted to move outwardly to release the detent. The movement of the member I3 required to release the detent is small and does not substantially alter the concentric relationship between the cam surface and the rim of the ratchet wheel, but if desired the cam surface may be formed so as to be concentric with the rim of the ratchet wheel when the member I3 is in raised positiomas it is in this position that the cam surfaceis utilized as herein.-

after explained; The member l3 may be'mounted to advance with the pawl, whichremainsin engagement with the ratchet tooth, thus advancing the ratchet wheel. At the same time, the pin I9,

riding along the concentric cam surface I4 retains the detent out of engagement with the ratchet I wheel. When the solenoid is deenergized, the initial backward movement of the lever arm I under the influence of the spring I0 causes the pawl to pivot on the idler member 6 to lift the pawl out of; engagement with the ratchet Wheel, and causes the lever arm I9 to move downwardly, allowing the member I3 and detent to move downwardlyunder theinfluence of the spring I 1 to reengage the ratchetwheel. Subsequent backward movement of the lever arm causes the pin to engage the idler member 6 to return it to its initial position. c 1 l c i It will be observed that the pawl must be fully engaged with the ratchet wheel before any advancing movement can take place. Likewise the advancing movement must have ceased before the pawl can be released from the ratchet wheel. Furthermore, the arrangement of the parts is such that on the advancing stroke the detent is not released from the ratchet wheel until the pawl is in engagement therewith, and on the return stroke the pawl is not released from the ratchet when until the detentis in engagement therewith. q c I r 3' Means may be provided to limit the amplitude of movement of the idler member, and in consequence the amplitude of movement ofthe pawl, such means comprising, in the embodimentillustrated a limit stop 20 pivoted at 2| so that it may be moved into or out of position to limit the movement. In the embodiment illustrated the limit stop is set to permit the ratchet wheel to be ad- In the embodimentillustrated in Figures 1 and 2 the mechanism is adapted for two way operation, that is, to rotate the ratchet wheel in clockwise or counter-clockwise direction. Thus, the pawl 4' and idler 6' are provided and the member I3 is extended at 13' to provide acam surface V [4. The pawl is provided with lever arms 1 and I8 and said armslare providedwith pins. l l. and I9, all of'said partsfunctioning astheir counterparts previously described. The spring in is also connected to the arm 1' so that when the arm] is moved the arm 1' serves as a fixed support for the other end of the spring andjilicef'versa.

In Figure 3, the invention is illustrated as adapted for use in connection"withzalstraight variously modified and embodied within the scope of the -subjoined claims.

I claim as my invention: 1. Ratchet mechanism comprising in combina tion, a ratchet provided with teeth movable along a fixed path, a pawl mounted upon an idler member for a first movement normal to saidteeth .forvengagementfland disengagement therewith and l for a secondimovement with ther ifidler member along a path parallel to that of the teeth for advancing the ratchet, a detent mounted for movement normal to said teeth for engagement arid disengagement therewith for holding the ratchet bar 3| having ratchet teeth 33. A feed pawl 34 is pivoted at 35 on an idler slide 36 having slots 50 allowing the desired ampl-itu'de'of longitudinal motion on the guide pins ,The motion of the slide, of course, is parallel to the mo- ;tion: :of the ratchet :sbar, :buttthe sslidesshould' :be ,so:mountedaasito :havenslight'frictionakresistance toimovement.

.Thetpawl :is provided rw-ith' awleveroarm flaextending lsubstantiallyoatrrightangles: to the pawl, zand the I lever amr is'zconnectedszinz anytsuitable .manner with wsuitable f'actuatingz meansa suchwsas the-armature -38wof i thevsolen'oid F39. JThQ! lever arm :31 :-;;isalso :connecteflzto; arspringdn za-dapted toxretum .the; pawl to :normalt position'rafterr ac- .turn the. slide.

g A: holding detent-42. isoalsolprovided, ;said fideltent being a mounted on :a member e43 iiaaving 1-2. .ca-m .-surace '44 :tparallel to the z-toothed :-:edge.-.:of

the vratchet tbar. 'I'he :mem'ber v43 zis 'slidab'ly mounted-to move-vertically tovrelease .thetdetent, .being; .provi/ded for: this purposewvitlmslotsM'Snengagin lguidel pins--46. :The'- member :flzand :de- ,tentA2 1 are normally :held :inwengagement with theratchet bar by-zthespring-Al. Y

r{The paw1..;isalso; provided with ailever arm-#48 having a pin 49 mounted :to vcooperate z'withcthe cam'surfacedd. .Thus-when thBz-SGIGHOidjYiSJG EF- ,giaed,zheoauseeoftthe slight,frictionalrresistance tolmovement'of whet-slide :36, the: initial forward movement .ofrthel lever iarmr3 1 ;causesl therpaiwlzto pivot ton the .id-le'rnslide r36 Zto=:en;gage :a tooth of the ratchetbar eandacausesfitherpin M9,";onZ lever armfllllsto alift. the rmemberifltiandttheudetentan to free tthe ratchet bar. Subsequent L'fomvard movementof tthe-rleverz arm #31 1 causes cthezisd-ler slide 36 to advance with the pawl, whichammains in engagement with -st-hel ratchetttooth thus tadvanci-ng the #ratchetobar. o-htithessazme' timetthe pin. AQ-Lr-iding along the cam :surface :64 :retains the v .cle tent o-ut f --lengagement withzthe :rratchet bar. IVhenthe solenoid is.deenergizedgtheinitial backward move-ment .of the :lever arm 3'hxrm'der the influence of -the-sspring r450 :causesc-the pawl to pivot on; the, idler--s1-ideh36 ,todittttheiqaawleout of engagement-with the "ratehetkbar causes the lever warm *4 9 :to 2 move :kiownwafidly eallowing tlie member -1t3 ;=-and;detent M2 :to -emove downwardly to reengage the ratchet bar. Subsequent back wardtmovementi of.the levenarrn'reimrns theslide 3-6: to its 1 initialt positio n.

,nln the? embodiment illustrated in Figure 3 the pawl: and "detent are aligne d 'to'engage thesaine tooth ioftthe irratohet 'bar, as"tlris'arran,gerrrent' is frequently advantageous. It "will" be" understood, however, that the pawl may belocated either' in front of or behin d theidtent,"if'desired.

lt will 'be understoodithatthe invention maybe ratchet except .while it is-being advanced, and .interacting means "between said pawl and detent .fforaactuatinglthe.idetent during the first movement of the pawl,

2'. Ratc-heir mechanism comprising in combination, a ratchet provided with teeth movable along a'fixe'd path, a pawl mounted upon an idler memtimer 1 for ta firstzrmovement normal .1110 ws'aida-teth for engagement and disengagement,therewitlrsand for a 'ssecond rmoveme'nt with the idler: menrber along-r aipath:parallel'ztorthatvofi the teethi forsadwarming the: ratchetga: detent mounted for rmovement :tnormal i to tssaid zteethxfor i'engagement zand disengagement:therewith;forrholding t'he' ratchet except while :it :is sbeing raidvanced, azand interiactingr means tbet weenrsaid pawlrarrd i detent Ifor actuating the detent duringtthezfirstizmovement lof-a the :pawLosa-i'd detentactuating means lnclud- :izllgrazcaim :and rcam foll'ower having: relative "sliding movement during lthe iratchet la'dvancing m-ovementioftsaid pawl.

3. Ratchet mechanism;comprisingrin combina- .tlOILmi-L -i-atchet zh avingcan :engageable feed ele ment movable along a fixed path, a pawl mounted a ng:movementiandsaasecondtor advancing and :return zm'overnent-,:.a'etuat-ing' means connect-ed to said pawl toifirstzrengage and advaneeit anwthen ltaiseaarrd'*return itga thetent-mounted*"f-or "an en gagingzaiodzdisengaging-movementrelative tosaid ratchet tt-eth, -an d earn "and cam follower means operatively arranged"between'said "pawl and Tdetentforraismg the detent whenthe pawldsengaged, ho lding the detent raised "as Vthe,paw1 advancosadropping the-"'detentwhenfthe pawl is reengage'ii, an'd leaving "the ;detent, 'down while the-pawlreturns; .j. I r i i'l 5. Apparatus "as 'set'fforth in .claim .4,,.w icn further includes" an element ,carriedsby isaidlzpawl 'for'returnin'g said idler whenthelpavrlmeturns.

*"6..Apparatus as .sett'forthlinoclai-m l, :which iu-rtl rer includes a oreversely acting ,1 pawl ,1- idler, actuating means, and eam .and rcam follower means associatedtwith saidlrlatchet: and idetent'.

v 'Ratchetnnechanism.eomprisingdn-scombina tion,;a ratchetwheel, anlidlerrcoaxiallyimolmted alongsidethe wheel, a pawl pivoted on said idler,

an arm on said pawl extending alongside an arm of said idler, actuating means connected, to said pawl arm, a pin on said pawl arm for returning the idler with the pawl, a detent, a cam connected to the, detent, and a cam operating arm on said pawl forfirst raising and then sliding along said cam.

8. Ratchet mechanism as set forth in claim '7, which further includes a reversely acting pawl,

idler, actuating means, and cam and cam operating means associated with said ratchet and detent. i

9. Ratchet mechanism as set forth in claim 7,

which further includes a reversely acting pawl, idler, actuating means, and cam and cam oper-.

ating means associated with said ratchet and detent, said actuating means for the two pawls including oppositely disposed power devices and a common return spring, secured, between the power devices. l

10. Apparatus as set forth in claim 4 in which 10 said ratchet and idlermove rectilineally.

FRED

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