US2353648A - Free-chain planetary hoist - Google Patents

Description

July 18, 1944. F. w. COFFING ET Al.`

' FREE CHAI'N PLANETARY HOIST Filed July 2o, 1940 4 sheets-sheet 2 1N VENT ORS.

July 18, 1944. F. w. col-*FING ETAL FREE CHAIN PLANETARY no rsT Filed July 2o, 1940 l1 sheets-sheet 5 www m av MM., M

July 18, 1944. F. w. coFFlNG ET AL FREE CHAIN PLANETARY HOIST Filed July 20, 1940 4 Sheeilrs-Shef-rI 4 Patented July 18, 1944 FREE-CHAIN rLANE'rAnY Hols'r Fredrick W. curling, Danville, nl., and Raymond.`

H. Johnston, Newtown, Ind., assignors to Coiing Hoist Company, a copartnership consisting of Frederick Cong and Robert R. Bookwalter Application July 20, 1940, Serial No. 346,486

19 Claims.

This invention relates to a free chain planetary type hoist. Y

This invention is an mprovement'upon that disclosed in a similarly entitled application, Serial No. 167,959, led October 8, 1937, now Patent No. 2,269,438 dated January 13, 1942.

The chief object'of the invention herein disclosed is to provide in a free chain hoist of the character illustrated, described and claimed in said patent, and more especially as illustrated in Figs. 8 to 11 thereof, a safety arrangement which is foolproof and positive, so that free chain movement, especially in the load lowering direction of chain movement, is impossible to attain as long as there is an appreciable weight on the chain, thereby preventing accidental dropping of the load if the free operation mechanism were accidentally actuated.

The chief feature of the invention resides in the load chain associated and power and chain, operable mechanism for accomplishing the foregoing object.

Other objects and features of the invention will be set forth more fully hereinafter, such as the load sustaining hook stop,-et cetera. Y

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

' In the drawings, Fig. 1 is a central sectional View through a hoist of the character described, the load chain being omitted, and same is a substantial duplicate of Fig. 1l of the beforementioned copending patent.

Fig. 2 is a side elevational View of the hoist shown in Fig. 1 and is a substantial duplicate .of Fig. 12 of said patent, said figures being included herein to facilitate an understanding of the character and operation of a hoist to Which the present invention relates.

Fig. 2A is a view similar to Fig. 2., but omits all except a small part of the operating wheel cut away to show other parts with greater clearness.

Fig. 3 is a diagrammatic side elevation of the invention, the parts being shown in the free chain position.

Fig. 4 is a similar view of the same parts in the other or lock out position wherein free chain operation is impossible.

Fig. 5 is a diagrammatic bottom plan view of the parts shown in Figs. 3 and 4, the bottom plate being removed, and the brake operating mechanism, et cetera, being intentionally omitted for clearness.

Fig. 6 is a diagrammatic side elevation of the hoist embodying the invention and illustrating the chain stop.

Fig. 7 is a view similar to Fig. 4 and of a second embodiment of the invention in locking position. i'

Fig. 8 is a View similar vto Fig. 'i and of' the same embodiment and illustrating the parts, in locking positionpreliminarytorelease. l y g Fig. 9 is a view similar toeFig. -.3- andai-the form shown in Figs. '7 and 8-and in thefreeased position corresponding to that shown in Fig'. B. Fig. l0 is an enlarged longitudinal sectional view of the ratchet Wheel engaging structureffi'n the extended position,- y

Fig. 11 is a top plan lView looking down upon the pawl shown in Figs. 7 to10 inclusive. Y, Figs. 12, 13 and 14 are views similarvrespectively to Figs. 7, 8 and 9 and of Aa third form` ,ofthe invention and in corresponding positions.'` E.

Fig. 15 is a top -plan view of pivotedcatch member illustratedinFigs. 12 to 14. i Y Fig. 16 is a top plan view of ,the tiltablefulcrum providing member shown inFigs, T12-to v14.

The general type of hoist in which .thepresent invention is incorporated is that illustrated the beforementionedcopending application and for illustrative purposes. only, Figs. l and: 2

hereof (substantial duplicates of Figs. llandgjlZ thereof) arev includedV and brief reference will 'be made to the partsv sh'ownain Figs; .-1 and.2

hereof as followst' f, g

In Figs. 1 and 2 there is illustrated thejbrake mechanism, speed control" mechanismjplanetary transmission, one-way ratchet clutch mechanism,

presentinvention applies".

` and 2` hereof'will be catalogued only and followed by a brief reference to the operation: of the same.

5I'6 indicates the hoist supporting hookpand Elli-5H the housing structure closed.by cover or end plate 548 and havingia depending communicating well'portion 540; closed-,by'cover 545.

" A main shaft 524 rotatably -supportsload Asprock- Shaft 524 is rigid `with sunggearq meshing with planetary pinionsV 588;,on4 shafts 581 carried by plate 586, keyed or oi'lllEI'Wise secured to the load sprocket shaft 554., The pinions mesh with annular internal'gearj5r99 having ratchet'teeth 582 externally thereof and engageable by vpawl 592, see Fig; 2,"constrained thereto as at 596. i j, Y

shaft 524 mounts the hub SlcofrratC-ht-plate Bill having teeth 6I I'. Rotatable-romthghub*is the power -wheel -514 which?mounts-operating chain BIB. The wheel and' chainm'ay-be guarded as at 6H, if desired. vThe "chain-fwheel'and ratchet 6H) are suitably connectedtogetheryas set forth inthe copending,applicationqfoi` rotation of shaft SZLWhich, through the planetary system, rotates load sprocket-520for-ffload elevation movement of the load chain- 1,1 s :j

The ratchety 582, see Fig.V Lannular; internal -gear 590 and portion 689 constitute an inner housing for the sun and pinion gears and is closed by plate 584. This housing is arranged to receive lubricant, as indicated at 693--694-695- 533.

The shaft 524 projects through plate 584 and operation of members 6I8-6I9 when shaft 544.1.

is actuated or rocked by the pawl mechanism for load lowering.

In load elevation, the drum 563 remains stationary because the last mentioned ratchet 684 vand multiple-offset pawl l612 arrangement actsfv.

as a one-way clutch. In load lowering, this clutch is effective to connect the drum 563 to the shaft and thus the band 564 holds or releases the load depending upon the control exercised upon kthe brake through shaft 544.

The governor is of the form shown in Fig. 6 of Patent No. 2,269,438 and, as shown herein in Figs. 1 and 2, plate 560 pivotally mounts in diametrical relation at 510 the speed control weights 512, the tails 51I of which connect to one end 511 of semi-circular shoes 561, frictioned as at 555. if desired. The other ends 568 are supported by links 569 also supported at 510. The weights are normally constrained to non-actuating position by springs 518 anchored thereto at 519 and also anchored at one end 580 to plate 563. yUni form action means such as 515--516 and weight collapsing stops 513 may also be provided if desired. Y

Upon the load-lowering movement speed ex-i L ceeding thatfor which the governor is adjusted, the shoes 561 are caused to move outwardly (substantially radially) to engage the interior adjacent face of the housing 5I0 and prevent overspeeding. The greater the excess speed of lowerw lng the greater will be the governor braking application or retarding force exerted by the governor to prevent'overspeeding and thus prevent possible damage to either the hoistV or the load.

In load lowering, et cetera, the planetary system increases the lowering speed as applied to the governor as well as to the brake which are further factors for safety, all as more fully described in the copending application, made a part hereof.

It will be observed, see Fig. 1, that below load sprocket 520 in the sprocket chamber or recess is a shaft 531 upon which is rotatably mounted a sprocket 538.

No further detailed description of operation is believed necessary fora complete understanding of this type of hoist and its general operation.

Havinglthus briefly described the construction and operation of the type of hoist to which this invention applies and which is not specifica-lf ly claimed herein and of which that illustrated herein is an operative portion, reference now is more particularly directed Vto Figs. 3, 4 and 5. In said figures, I9 indicates the housing genorally; IlV the load chain and I2 the chain chan- A hub v with corresponding decrease in load travel. Reference numerals I3 and I4 indicate alternative vload chain anchoring portion for chain end anchorage when different powers are desired.

Depending from a portion of the housing I9 is plate portion I5, see Fig. 6. Also adjacent thereto but spaced therefrom is a well portion I6 in which is mounted the brake controlling mechanism, said well portion being comparable to portion 540, see Figs. 1 and 2. Said well portion is closed by cover plate I1, see Fig. 6, which support or connector I9 includes shoulder I9c which engages both plate portions when the chain is drawn into the hoist and prevents jamming of the hoist mechanism by the load supporting hook and the like.

In Figs. 3 and 4, 2I indicates the ratchet similar to ratchet 582 in Figs. 1 and 2, and 22 the pawl similar to pawl 592 in Fig. 2. Pawl 22 is pivoted at 23 similar to pivot 593 and is constrained into ratchet engagement by spring 24 similar to spring 596. Connected to pawl 22 is member 25 which is comparable to member 683. Pawl 22 permits counterclockwise rotation (see Fig. 3) of the ratchet including teeth 2l and at all times whether ratchet seated or otherwise. When seated, however, it prevents clockwise rotation, hence is unidirectional in operation. When positively unseated and held in that position, clockwise rotation of the ratchet is permitted.

Adjacent shaft 23 is a shaft 26 comparable to shaft 544 in said Figures 1 and 2. The brake connections and operating members, not shown herein, may be connected to these shafts, as

illustrated in Figs. 3 and 5 of said copending application.

One feature of the present invention will now be set forth. Projecting upwardly into the chain channel is a curved arm 21 which at its upper end pivotally supports at 28 a chain engaging shoe 29. The arm is carried by shaft 30 that extends into and across well portion I6, as shown in Fig. 5.V The arm is adjustably mounted on shaft 30 as indicated at 3|, and a tail portion 32 0f the arm is recessed as at 33 to seat spring 34, the other end of which may be suitably seated in or upon housing Ill, thereby constraining at all times the arm 21 into position for shoe 29 engagement with the load chain I I.

Within the well I6 and secured to shaft 3D is the eyebolt or equivalent member 35, 'adjust- 'ably mounted as at 35 and providing socket 31 at its free end to receive one lateral arm 39 of U-shaped link 39, the other end 148 of which is seated in aperture 4I'of the locking member 42. Locking member 42 is mounted on shaft 26 and rocks freely thereon. It includes a stop lug 43 adapted in locking position, see Fig. 4, to prevent locking pawl 22 from moving into ratchet release position as shown in Fig. 3, which is the free chain position. v

As shown in Figs. 3 to 5 inclusive, shaft 26 adjustably mounts as at 44 an arm 45 which is moved to the position shown in Fig. 3, the pawlL 22 cannot be released, and only then if the power is sufficiently applied to permitthe pawl to clear the ratchet tooth, due to the draft relationship therebetween, as recited by the ccpending application.

Now if there be no load on the chain and the power wheel be reversed for load lowering, the parts, then, assume the position as shown in Fig. 3 and the chain can be moved freely through the hoist in either direction.

However, if there be a load upon the chain, due to the fact that the chain and loadtends to centerwith respect to the center of gravity of the arrangement, the chain I I engages and bears upon shoe 29 and tilts arm 21 and shaft 30 into the position shown in Fig. 4. This is the normal load sustaining position of the parts whether the load is being elevated, held stationary, or is being lowered. This positioning of the parts insures movement of lug 43 behind pawl 22 to lock the pawl 22 into ratchet 2| engagement in the closest tooth recess, as the ratchet is rotated incident to further hoist operation.

. Thus, as long as there be any appreciable load on the chain, the lug 43 will be held in pawl'` arm 625 on shaft 544 into engagement with pawl 6|9. When rotated counterclockwise, see Fig. 2, plunger 629 recedes to permit pawl rotation without interference. Rotation in a clockwise direction causes the pawl tooth 632 adjacent plunger 629 to engage same and tilt it and arm 625.:t'or

rocking shaft 544 for the purpose described in the ccpending application.

In Figs. 3 to 5, shaft 26 is the same or corresponding shaft designated by 544 in Figs. l and 2.

lFor clearness, the member or arm 625 and plung-IA er 629 is omitted. This is the power for retracting pawl 22 from ratchet 2|. This pawl release, however, as previously described, can only `occur after arm 21 has retracted stop 43 from the position shown in Fig. 4 to the position shown in Figf it being noted that member 42 is merely located by shaft 26 and does not affect rotation thereof nor is aiected by rotation thereof.

Inrigs. '2 to 11, there isf11ustratedanother form of the invention and in'Figs. 12 'to 16 there is illustrated a third form of invention, The chain operable or controlled stop form of the original form of the invention has been omitted from Figs. '7 to 16.

In Figs. '7 to 16, it is observed that the structure corresponding to pawl 22 in Figs. 3 to.`,5 is of `multiple construction. In Figs. '7 to 11, numerals of the one hundred series, similar .to primarynumerals utilized in Figs. 3 to 5 designate like'or This bearing herein corresponding parts. In like manner, numerals of' 75 the Itwo hundred series in Figs. 12 to 16 designate like or corresponding parts. Numerals of the ve and six hundred lseries employed in Figs. 7 to 16 indicate parts like or similar to those having `the same numerals in Figs. 1 and 2.

In Figs. 10 and 1,1, |22 indicates the base portion of the'ratchetlocking pawl. It is apertured at |23a for'piyotal mounting on pivot |23, a shaft utilized for other purposes, see the ccpending application. This body portion |22 is bored as at |51 and slidable therein is stem |56 chambered at its inner end as at |59. In this closed chamber is spring |58 normally projecting stem |55 outwardly,

The free end supports head |54 with relieved or retractive face |55 for clearance purposes. A pair of parallel elongated vslots |53 are at opposite sides of the body portion. A pin |60 extends through stem |56 and the projecting ends ride in said slots. This pin limits relative movementbetween Vbody and head longitudinally of the body and prevents relative rotation as well. The pin at one end is extended beyond the body, see Fig. 11, and one face is relieved as at |6| for clearance purposes.

In Figs. 'Ito 9, spring |24 is connected at one end to housing 0 as at ||3 and at its opposite end to anchorage |22a on body portion |22. Spring |58 normallyprojects head |54 toward the teeth of ratchet |2| and spring |24 normally constrains the entire pawlV structure toward the ratchet. Y. 1 I

With this multiple part articulated pawl structure, it is obvious that pawl-ratchet release requires positive action to telescope the parts in addition to rocking the pawl upon its pivot.Y

Instead of member |25 being connected directly to body |22, `there is interposed a plate |50'having an elongated slot |5I therein in which is mounted pivot member |23. A pin |2511. serves as a pivotal connection 'between members |50 and |25. A spring |52 normally constrains member |50 into elevated and retracted position relative to body portion |22 as shown in Fig. 7

The forward end of member |59 has an upward extension |52 with rearwardly directed portion |63 forming a hook. The member |25 eX- tends through aperture |46 in member |45 adjustably but rigidly mounted as at |44 upon shaft 544-426 in turn roel-:able by arm 625 and plunger 629.

A spring |48 concentric with member |25 bears on the washer'retained by nut v|49 by which the force of spring |48 is adjusted. Member |25 has an enlargement |41 which limits the movement upwardly on member |25 of'member |45.

The operation is as follows: Power wheel 6|4, Figs. 1 and 2, can be rotated by chain 6|6 in veither direction. AWith load on the chain ll, see Figs. 3 and 4, free-chain'movement of said chain in load lowering'direction. is impossible. Controlled lowering rthrough Ythe planetary system, brake and governor is possible while the member 689, Fig. 1, is held by pawl 592 engaging ratchet teeth 582, see Fig. 2,-'o'r its equivalent, see the other figures. Observe 'that power from the chain wheel 5M rotates 524 and through the planetary rotates the load sprocket 526 for load elevation. In this rotation the ratchet and pawl connection within the brake drum permits load elevation kwithout speed control or brake drum rotation. For load holding pawl 502 and ratchet 582 cause the load veffort to lower by gravity to become effective upon the brake drum included pawl and ratchet connectionso that this load is then held by theA brake band.` Y

When shaft 544 is actuated yto effect load lowering, observe vthat pawl 592 is still effective through teeth 582 Vto hold part 6 89 stationary. However, pawl and ratchet connection withinthe drum is effective and thebrake drum rotates through gravity on the load and to the extent permitted by brake band release effected through shaft 545. However, should excessive lowering speed result, the speed control becomes effective -to hold the controller shoes to the hoist casing preventing excessive load lowering speed orload dropping. Y

Without load on the chain, it is obvious that the load chain can be readily pulled through the hoist, by a free-chain action, and in the load elevating direction. The only other action not described,`is free-chain movement in the load lowering direction which will now Vbe described. In 2, when member 663 is pulled down, which is only possible when there is no loadon the chain, free-chain action in load lowering direction is possible. To permit free-chain action it is required that ratchet 582 be initially rotated slightly in the load elevating direction tofrelease the draft lock between the pawl 592 and ratchet teeth 582. When so released the pawl 592 is retracted by the then extended springbetween that pawl and member 663 in opposition to spring 596.

Referring to Figs. '7 to 9, 544 is the brake release control shaft for normal load lowering as previously described. Here it also is the control shaft for free-chain operation in load lowering direction. When arm 625 is rocked counterclockwise the shaft 544-I26 follows as shown in Fig. 8, as compared to Fig. 7. In this rocking motion, the arm |45V rotates counterclockwise and applies pressure on the spring |48 which,` in turn, through the enlarged end |49 of the mem- Vber |25, pulls down on said member and lowers the member thereby extending the spring |52, as shown in Fig. 8. With no load on the chain, when shaft 544|25 is rocked counterclo'clwise, stern |25 pulls down on hook |62, see Fig. fl. In so doing hook end |63 bears on pin |90 and hence pawl |54 is pulled downward and thus released or disengaged from ratchet 2| while no load is on the ratchet, see Fig. 9L Now, when load is on the ratchet, as the stem |25 draws down the hook |62|63, but due to the load, see Fig. 8, the pawl is collapsed and hook |62- |53 is free of the pin |69 or disengaged so that hook |62|63 then cannot release the pawl |54-|22 from the ratchet |2|.

Shaft 544, Figs. 1 and '7, carries arm |45 carrying stem |25. Shaft 544 carries, see Fig. 1, arm 625, shown also in Figs. '7, 8 and 9. Wheel 6|4, when rotated counter-clockwise (Fig. 2), lifts the load by ratchet 6 0. To release the load, wheel 6 |4 is rotated clockwise and pawl tooth 632 engages plunger 629, which is carried by arm 625, so that arm 625 is thus moved counter-clockwise to depress stem |25. Ratchet |2| is not rotated by wheel 6|4 at any time.

When the parts are as illustrated in Fig. 9, the ratchet wheel is freed from the pawl or locking arrangement and free chain arrangement can be obtained because ratchet |2| is free.

In Figs. 12 to 16, numerals of the two hundred series indicate parts similar to those designated by numerals of the one hundred series and employed in Figs. 1 to 11 inclusive. The operation of the device is substantially the same as to the third form of the invention illustrated. The chief difference herein is that the member 245 is shown provided with a tail portion 245a and with an'opening 245D therein. The main portion 245 is apertured as indicated at 246 and this is of Venturi type and the pull-down member 225 is seated therein and, as shown, carries the spring lAbove the member 245 is an adjustable bearing in theform of a pair of locknuts 225b and .the lower one rides on the abutment or fulcrum 24'! on thek member 245. It will be noted that in both the last two forms of the invention the hook member is provided with an elongated aperture which receives a support 223.

Figs. 'land 12 represent the parts in normal position with the hoist under no load. Figs. 4, 8 and 14 represent the parts in Working position when the hoist is under load and free chain action is not permitted. Figs. 3 9 and 13 represent the parts in free chain position with "no load on the hoist and permitting free chain Operation.

Thesecond and third forms of the invention have the advantage of the load-locking pawl structure cushioning the ratchet (|2| or 22|) contact, spring |58 or 258, respectively, serving as the shock absorber. This is not illustrative nor present inthe first form of the invention, see Figs. 3 to 5.

One primary purpose lis making the free chain actionv positive through the connection between the arm 625 operable shaft 544 (26 in Figs. 3 to 5, |26 in Figs. 7 to 9, and 226 in Figs. 12 to 14, and member 25, |25 and 225 respectively, as previously described) It is to be noted that the chain has weight. For single chain the adjustments are made so that for any weight under approximately thirty pounds, the parts can be positioned for free chain action and pawl head extending spring |58 or 258 is strong enough to withstand a pressure of a thirty-.pound load exerted by counterclockwise movement of ratchet |2| or 22| before compressing said spring thereby allowing pin |60 or 25D to move rearwardly to free catch |60 or 260 respectively rfrom said pin, When the load sustaining pawl structure is collapsed, it, in effect, becomes a solid pawl similar to that shown in Fiss. 2 and 3 t0. 5.

Y While the invention has been illustrated and described in great detail in the foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein, as Well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is: 1. In a free chain hoist, the combination with a ratchet, a load sustaining pawl normally constrained to ratchet engagement for load holding, and a load chain operatively connected to said ratchet, of means operable by the chain, a locking Y means for retaining said pawl in ratchet engagethird mentioned means conditioning the secondV mentioned means for free chain vmovement in the lowering direction, the combination of latch means for said third mentioned means, preventing free chain movement, and means operable by the chain for operating said latch means and normally constrained to latch release when the chain is not under load and effective when the chain is under load to prevent latch release.

3. In a hoist having a chain capable of free chain movement in the load lowering direction, a locking pawl normally constrained to prevent the free chain movement, means normally constrained to one position corresponding'to that permitting the free chain movement and operable by the chain, and a movable. stop Aconnected to said means and normally constrained to free chain movable position and positionable to prevent locking pawl release for free chain movement, the first mentioned means being operable by chain movement due -to load on the chain, in opposition to the Vmeans constraint, to=prevent stop movement permitting pawl release.

4. In a chain hoist having a predetermined central plane and a load chain, said chain being movable laterally relative to the plan when under load whether of static or kinetic character, the combination of pivotally supported chain engaging means, a uni-directional lock permitting free chain movement when said lock is actuated to permit such chain movement, a movable stop for said lock, and means connecting the first mentioned chain engaging means to said stop for causing stop and lock engagement when the first mentioned chain engaging means is moved by lateral movement of said chain incident to the load thereon.

5. A device, as defined by claim 4, characterized by the pivotally supported means including a pivotally supported arm and a chain engaging shoe movable supported thereby and responsive to lateral movement of thechain for arm movement, said shoe having non-interfering engagement with the chain for linear movement thereof.

6. A device, as defined by claim 4, characterized by the pivotally supported means being normally constrained toward chain engagement.

7. A device, as defined by claim 4, characterized by the pivotally supported means being an angular arm pivoted at one end, and a chain engaging shoe pivotally supported by the arm at the .opposite end.

8. A device, as defined by claim 4, characterized by the pivotally supported first mentioned means including an arm movable therewith, and the connecting means including alink between said arm and stop,the first mentioned means being normally constrained to chain engagement.

l 9. In a free chain hoist having a main control shaft, a load chain, a load holding ratchet operatively connected to said load chain, control means operableby the control shaft for load lowering and the like including a locking pawl engaging said ratchet and yieldingly connected to the control shaft fork operation thereby and v normally constrained tol ratchet engagement, a

stop for `preventing, pawl -disengagement fromv the ratchet, and means operable4 by said chain and operatively connected to the stop and normally constrained to stop release position, and movable upon chain loading into pawl lookin position in opposition to the constraint.

10. In a free chain hoist, the combination with a load chain, a load holding ratchet,` a load holding pawl constrained to locking .engagement therewith, vand amain control shaft, of arm means for rocking said shaft, and a yielding connection interposed between said pawl and said shaft forshaft release of said pawl permitting free chain action when no load is on the chain, the yielding connection including a member depending from and pivotally connected to the pawl, an arm rigid with the shaft, and yielding means interposed between the member and arm and compressible upon shaft releasing movement for cushioning the arm pull uponthe pawl to permit ratchet rotation in ratcheting. direction to effect pawl clearance for pawl engagement when the arm pull exceeds the pawl constraint.

11. In a ifree chain hoist, the combination with a' load chain, a load holding ratchet, a load holding pawl constrained to locking engagement therewith, and a main control shaft,

pawl permitting free chain action when no load is'on vthe chain, the yielding connection including a member depending from and pivotally connected to the pawl, an arm rigid with the shaft, and yielding means interposed between the member and arm and ycompressible upon shaft releasing movement for cushioning the arm pull upon the pawl to permit ratchet rotation in ratcheting direction to effect pawl clearance for pawl engagement `when the arm pull exceeds the pawl constraint, the depending memberextending through an aperture n- -the arm, and the yyielding means being concentric with the vdepending member portion.

12. In a free chain hoist, the combination with a load chain, va load holding ratchet, a load holding pawl constrained to locking engagement therewith, and a main control shaft, of arm means for rocking said shaft,and a yielding connection interposed between said pawl and said-shaft for shaft release of said pawl permitting free chain action when no load is on the chain, the pawl including a pair of slidably associated members having limited sliding movement and normally constrained toward extendedrelation and when retracted forming a solid .pawl arrangement.

13. In a free chain hoist, the combination with a load chain, a load holding ratchet, a load holding pawl constrained to locking engagement therewith, and a main control shaft, of armxmeans for rocking'said shaft, and a yielding v i connection interposed between said rpawl 'and said shaft for shaft release of said pawl permitting free 'chain action when no load is on the chain, the pawl including a pair of slidably associated members having limited sliding movement and'normallyV constrained toward extended relation and when retracted in 'opposition :to the constraint forming a solid pawl arrangement, a catch member carried by and movable with one of said slidably assoload :holding .pawl constrained t'o lockinge11-v arm projectinggagement therewith, and a main control shaft, of arm means for rocking said shaft, and. a yielding connection interposed between said pawl and said shaft Vfor shaft release of said pawl permitting free chain action when no load is on the chain, the yielding connection including a member depending from and pivotally connected to the pawl, an arm rigid with .the shaft, yielding means interposed between the member and arm and compressible upon shaft releasing movement for cushioning .the arm pull upon the pawl to permit ratchet rotation in ratcheting direction to effect pawlclearance for pawl disengagement when the arm pull exceeds the pawl constraint, the pawlv includinga pair of slidably associated members having limited sliding movement and normally constrained to.- ward extended relation and when retracted in opposition to the constraint forming a solid pawl arrangement, a catch member carried by.

and movable with one -of said slidably associated members, and a latch member movably associated with the other member and normally constrained to engage the catch member when in latching position, contraction movement in the pawl arrangement conditioning the latchcatch association for separation of the latch from the cat ch, and the depending member being pivoted directly to the latch member.

15. In a free chain hoist, the .combination with a load chain, aload holding ratchet, a load holding pawl constrained to locking engagement therewith, and a main control shaft,y of arm means for rockingsaid shaft, and a yielding connection interposed between said pawl and said shaft for shaft -release of said pawl permitting free chain action when no load is on the chain, the yielding connection including a member depending from and pivotally connected to the pawl, .an arm rigid-with the shaft, yielding means interposed between the member and arm and compressible upon shaft releasing movement for cushioning the arm pull upon the pawl to permit ratchet rotation in ratcheting direction to effect pawl clearance for pawl disengagement when the arm pull exceeds the pawl constraint, the depending member extending through an aperture in the arm, the yielding means being concentric with the depending member arm projecting portion, the pawl including a pair of slidably associated members having limited sliding movement and normally constrained toward extended relation and when retracted in opposition to the constraint forming a solid pawl arrangement, a catch member carried by and movable with one of said slidably associated members, and a latch member movably associated with-.the other member and normally constrained .to engage the catch member when in latchingposition, contraction lmovement in the pawl arrangement conditioning the latch-catch association for separation of the latch from the catch, and the depending member being pivoted directly to the latch member.

16, In a free chain-hoist, the .combination with a :load chain, a load holding ratchet, a load holding pawl constrained to locking engagement therewith, and a main control shaft, of arm means for rocking said shaft, .and a yielding connection interposed between said pawl and said shaft for shaft release of said pawl permitting free chain action when no load is on the chain, the yielding Yconnection including a member depending from and `pivotally connected to the pawl, an arm rigid with the shaft, yielding means interposed between the member and arm and compressible upon shaft releasing movement for cushioning the arm pull upon the pawl to permit ratchet rotation in ratcheting direction to effect pawl clearance for pawl disengagement when the arm pull exceeds the pawl constraint, the depending member extending through an aperture in the arm, the yielding means being concentric with the depending member arm projecting portion, the depending member above the arm including a bearing arrangement, and the arm adjacent thereto including a bearing engageable fulcrum.

17. In a free chain hoist, the combination with a load chain, a load holding ratchet, a load holding pawl constrained to locking engagement therewith, and a main control shaft, of arm means for rocking said shaft, and a yielding connection inter-posed between said pawl and said shaft for shaft release of said pawl permitting free chain action when no load is on the chain, the yielding connection including a member depending from and pivotally connected to the pawl, an arm rigid with the shaft, yielding means interposed between the member and arm and compressible upon shaft releasing movement for cushioning the arm pull upon the pawl to permit ratchet rotation in ratcheting direction to effect pawl clearance for pawl disengagement when the arm pull exceeds the pawl constraint, the depending member extending through an aperture in the arm, the yielding means being concentric with the depending member arm projecting portion, the depending member above the arm including a bearing arrangement, and the arm adjacent thereto including a bearing engageable fulcrum, the bearing arrangement being adiustable longitudinally of the depending member.

18. In a free chain hoist, the combination with a load chain, a load holding ratchet, a load holding pawl constrained to locking engagement therewith, and a main control shaft, of arm means for rocking said shaft, and a yielding connection interposed between said pawl and said shaft for shaft release of said pawl permitting free chain action when no load is on the chain, the yielding connection including a member depending from and pivotally connected to the pawl, an arm rigid with the shaft, yielding means interposed between the member and arm and compressible upon shaft releasing movement for cushioning the arm pull upon the pawl to permit ratchet rototion in ratcheting direction to effect pawl clearance for pawl disengagement when the arm pull exceeds the pawl constraint, the depending member extending through an aperture in the arm, the yielding means being concentric with the depending member arm projecting portion, the depending member above the arm including a bearing arrangement, the arm adjacent thereto including a bearing Aengageable fulcrum, the bearing arrangement being adjustable longitudinallyV of the depending member, the pawl including a pair of slidably associated members having limited sliding movement and normally constrained toward extended relation and when retracted in opposition to the constraint forming a solid pawl arrangement, a catch member carried by and movable with one of said slidably associated members, and a latch member movably associated with the other member and normally constrained t'o engage the catch gagement therewith, and a main control shaft, m

of arm means for rocking said shaft, a yielding connection interposed between said pawl and said shaft for shaft release of said paWl, means for locking said pawl in ratchet engaging position, and chain engaging means operably connected to the locking means and operable by said chain when the chain is under load to prevent the locking means from releasing said pawl for free chain movement in lowering direction, the chain engaging means being normally constrained to pawl release position.

FREDRICK W. COFFING. RAYMOND H. JOHNSTON.

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