US1999036A - Free chain hoist - Google Patents

Description

April 23, 1935.

F. w. coFFlNG 1,999,036

FREE CHAIN HOIST Filed July 21, 1934 44^5 27 5a 72326 l T IZ 7055536 J .6-15/35 sf y ATTOIRNEY.

Patented Apr. 23, 1935 UNITED STATES PATENT OFFICE FREE onArNnols'r i FredrickkxW. Coilng, Danville, Ill. Application July 21, 1934, serial No. 736,280

19 Claims.

This invention relates to a free chain hoist and by free-chain hoist is meant a hoist which is capable of having the load supporting chain rapidly positioned to an approximate position for associating the load therewith as distinguished from a hoist, wherein the load supporting chain must through the operation of the device, be positioned relative to a load by performing the reverse operation for lowering the chain'to the desired position for load engagement, as is required to raise it for elevating the load.

This invention is a continuation in part of that shown in the copending application, Serial No. 701,651, filed December 9, 19.33, land. allowed March 15, 1934, entitled, Free chain hoist, now Patent No. 1,973,844, dated September 18, 1934.

As set forth therein, certain dimculties are associated with the free chain operation and the aforesaid invention described and claimed in the application mentioned, discloses a solution to these difficulties. y y

The present invention is specifically directed to what may be termed, the foolproof provisions.`

By the aforesaid foolproof provisions is meant the association of certain parts embodying basically the invention set forth in the copending application, so that the load can never accidentally be dropped. 'Ihis solution is obtained by either of two constructions. The first con'- sists in utilizing, instead of spur gears, gears the teeth of which are inclined at a slight angle.

One embodiment of the invention which has proven satisfactory for normal usage, has the teeth pitched approximately 6". A greater or lesser degree of pitch, however, may be employed, and the aforesaid pitching, in effect a spiral gear arrangement, provides increased friction between the two meshing gears-that is, the pinion and the chain moving gear-so that it requires a positive force of an appreciable amount to disassociate orsecure disengagement of said gears. In certain forms of the invention, this is sufiicient to insure against dropping of the load. However, in other forms of the invention, particularly where relatively light loads are to be handled, this additional friction in the spiral gears, as distinguished from the spur gears, may not be sufficient to accomplish the purpose of preventing dropping of the load. Wherefore, an additional positive means is provided to insure meshing engagement until the desired moment when the gears are to be disengaged and which furthermore is characterized by an additional arrangement so as to insure positive engagement of the gears after they have been disengaged..

The last mentioned dual functioning positive means may, with equal facility, be applied to and utilized with the spur gear construction shown in the copending application referred to, without the requirement that spiral gears be utilized. Therefore, the present invention relates to two solutions to the light load problem and either or both may be utilized.

'Ihe present .invention also incorporates an adjustment for the brake structure, so that the 10 degree of release may be accurately determined so that the rate of lowering can be accurately controlled. 'I'his also may be applied to the copending disclosure.

'I'he full nature of the invention will be un- 15 derstood from the accompanying drawing and the following description and claims:-

In the drawing, Fig. l is a side elevational view of one embodiment of the invention broadly disclosed in the copending application, Serial No. 20 701,651, before mentioned, the cover being removed and a part of the chain moving gear being broken away to illustrate the present invention more clearly.

Fig. 2 is a sectional View through the hoist 25 shown in Fig. 1, certain parts of the invention, however, being shown in elevation.

Fig. 3 illustrates a portion o'f the positive engaging and disengaging means embodying the invention in lthe load lowering position, which is intermediate the load elevating or holding and the droppingpositions, the latter corresponding to non-meshing position.

Fig. 4 represents certain of said parts shown in Fig. 3 but in a position corresponding to the full 35 release of the brake structure and the complete disengagement of the gears.

, Fig. 5 is a side elevational view of the pinion shifting mechanism shown more particularly in Figs. 3 and 4.

In the drawing Illindicates a housing provided with a cover II suitably secured together by screw bolts associated with the lugs or ears I 2 formed upon both housing and cover. The housing and cover jointly form a bearing I3 for the 45 hook I4 by which the hoist may be sustained or suitably supported. 'I'he complete housing is provided with'a cutout portion I5 which provides both an entrance and exit for a sprocket chain I6. The cover is provided with an anchorage I1 to 50 which the hoist end of *the chain is preferably permanently secured in any suitable manner. The load adjusting end of the chain may have any suitable load anchoring member.- However, when the device is to move extremely heavy loads, 55

ried by the anchorage I9 and the other half by the sprocket 24. may be utilized.

The cover at 2I--see Fig. 2-and the housing at 22 provide anti-friction bearings I2I and |22 for a shaft 23 which mounts a sprocket`24 that may, if desired, be formed integral with said shaft. Suitably and rigidly secured to the shaft is a gear 25. The cover is provided with a. bearing 23 andthe housing is provided with a bearing 21, the latter being closed and the former consisting of an opening through the cover. Mounted in these bearings are the anti-friction constructions 28 and 23, respectively.

Rotatably supported by said anti-friction constructions, is a shaft 30, one end of which is fully enclosed by the housing and the other end 3i of which projects beyond the hoist and herein the cover portion, and is provided with suitable power means for rotating the shaft in either direction. Herein the exposed end 3| of shaft 3U is shown provided with a wheel 32 rigidly secured to said shaft and the same carries an endless chain 33 of the transverse link type.

A suitable guide, or retainer, in the form of a U-shaped bracket 34 with the cover with which it is integral, envelops the wheel 32 and serves to prevent escapement of the chain 33 from the wheel. Any suitable means for securing the wheel 32 to the shaft may be provided, the same not being shown herein. The shaft 30 includes a shoulder 135 against which bears one end of the bearing 28 against which may bear one end of a spring 36 concentric with the shaft and telescopically mounted upon a tubular extension 31. of a pinion 38 that is slidably mounted on said shaft. In these forms of the invention wherein positive pinion engaging and disengaging means is employed, the spring may be, and preferably is, omitted. Plate retains the assembly in proper relation. Pinion 33 is adapted to be rotated by said shaft through suitable means, such as a spline connection 39. The pinion 38 normally meshes with the gear 25 but is removable therefrom.

In place of the hand wheel 32 and chain 33 there may be provided any suitable source of power, such as a unidirectional motor and in certain forms of the invention, the wheel 32 may have an internal gear with which is associated a pinion driven by an electric motor of unidirectional character and in this latter modified form of the invention, either electric or hand power may be employed as desired, but it is to be understood that the application of external power to shaft 30 is of a unidirectional character, a1- though the shaft has reverse movement for load lowering under the weight of the load or reverse movement for free chain positioning when removed from the load.

In load lowering, the endless chain 33 and the wheel 32 act as an additional load and prevents quick starting movement in the initial lowering movement of the load, because the initial effect of gravity on the load must overcome the inertia of the wheel and chain in its resistance to turning in a reverse direction from that it has Any form of load anchorage drum structure.

previously turned in load elevating or overcome the inertia in starting the hand wheel and chain to move in said reverse direction. x

' It will thus be apparent that when the shaft 30 is rotated in either direction, the sprocket will be rotated in a corresponding direction for load elevation or load lowering, if the pinion 38 is in meshing engagement with the gear 25. .1f the pinion is not engaged with the gear, then the chain 33, or other power means, is not effective, no matter how much rotated for obtaining sprocket movement.

y By reason ofthe possibility of dissociating the pinion and gear in one form of the invention, means must be provided for holding the sprocket corresponding to the desired position the load is to be held-in to permit working on the load.

Such means, herein, includes a brake drum 40- see Fig. l-and a `brake band 42 which hasone end suitably anchored to the housing at 6| and which has its other end extended as at 43.

The end 43 is connected to one end of a coil spring 45, the opposite end of which is connected to an arm 46 pivotally mounted as at 41 in an opening in a housing I0. The exposed end of the member 41 is provided with a suitable means 48, whereby from without the housing the position of the arm 45 may be clampingly associated with the housing to determine the fixed position of said arm '46. When the arm is positioned as shown in Fig. 1, the coil spring is under what may be termed normal tension and the brake band is in the drum engaging position.

When the arm 46 is rotated into a lower position, an additional tension will be imposed upon coil spring 45, thus band 42 is always constrained by spring 45 into drum engagement. The band, if desired, may be provided with a facing or 1ining 49. This brake structure is adapted to hold the sprocket and load in the desired elevated position.

'I'he housing I0 at 20 is provided with threaded apertures and adjustable stops in the form of bolts 44 are mounted therein and locked in the adjustable position by the lock nut 44a. It will be noted in Fig. 1 the ends of the bolts do not contact the brake band, whereas in Fig. 3, the released position, the brake band is in contact with said adjustable stops.

Inasmuch as the brake is normally constrained toward braking operation at all times, it will be apparent that it is highly desirable that the brake structure in the load elevating movement, be relatively inoperative, and to accomplish this purpose there is provided an overruning clutch in the form of a ratchet 50 which is suitably secured to l the shaft 30 as at 5l and the teeth 52 thereof are engaged by a plurality of diametrically positioned dogs 53 normally urged into ratchet engagement by springs 54 supported as at 56 upon the brake The dogs 53 are pivotally supported as at 55 upon the brake drum structure.

With this type of construction, the brake drum, it will be apparent-#see Fig. 2-is normally stationary and shaft 30 is freely rotatable in the drum 40 for load elevation. Thus, as shaft 30 is rotated to actuate the two meshing gears to turn the sprocket 24 to elevate the load, the ratchet revolves clockwise in Fig. 1 and the pawls or dogs 53 ride over the teeth of the ratchet and set between the teeth, so that when the rotational movement is discontinued, the dogs engage the teeth and thus immediately connect the brake drum to the shaft 30 and through the pinion 38 Serve to lock the sprocket wheel 24 in that position and the load will be held elevated by the brake until such time as the force of spring 46 is opposed.

The means for releasing the brake to the desired degree, to permit the lead to. be lowered at the desired rate, consists of a lever 60 pivoted at 6| to the housing. 'Ihis pivot 6| also constitutes the anchorage for the xed end of the brake band 42. Lever 68 has one end or arm 62 engaged vwith the end 43 of the brake band 42. The opposite end of the lever 60 is provided with a link 64 that connects the same -to another lever 64a pivotally supported at 64b on the housing. 'I'he lever 64a is connected to a control cable 69 by a hook 65, on the end of a rod 66 that terminates in an eye 68 at the opposite end. Rod 66 is slidably supported inthe opening 61 in the housing I0.

When cable 69 is pulled downwardly and in its initial downward movement lever 64a is tilted counterclockwise and the same vthrough the link 64 tilts clockwise lever 60 on its pivot 6| which, through the end 62 forces the brake band upwardly in opposition to the downward tendency imposed by spring 45. This upward movement of the brake band serves to release the drum from band engagement, thereby permitting the `drum together with the shaft, meshing gears and the sprocket to reversely rotate to permit lowering of the load dueto the weight of the load. The rate of lowering may be determined bythe amount of pull exerted on cable 69 or in other words, the amount of tilting movement imparted thereby to the lever 60.

, The construction so far described, is not of a free chain character. The advantages of a freechain hoist are too numerous to mention, but have been suggested hereinbefore. Briefly, a socalled free-chain hoist permits the rapid positioning of the chain in a position adjacent to the load for connection to the load and with a relative freedom of movement, as distinguished from the progressive movement of the chain when under load during the lowering and/or the raising thereof.

The means herein provided for free-chain action consists in a means for removing the pinion from meshing engagement with the gear. It is perfectly evident, however, that when this type of disconnection is provided in the source of power applied to the sprocket, and inasmuch as the brake construction also is eiective on the sprocket only through said meshing engagement, it will be evident that some means must be provided to prevent disengagement of the gears until the weight of the load has been taken oif the chain.

'I'he means for securing non-meshing engagement of the pinion l38 to the gear 25 includes a yoke member having arms that straddle the shaft 36 and ride in an annular groove 10a in the tubular extension of the pinion 38 and directed oppositely from the extension 31 thereof.

It will be recalled that in one form of the invention, spring 36 normally urges gear 38 into .meshing engagement and normally maintains the same in meshing engagement. When spring 36 is not utilized, spring 45 through lever 60, pin 85 and link 83, actuates lever 1| to insure pinion and gear meshing and to maintain said engagement. When spring 36 is utilized therewith, it is merely cumulative `in its` action and it is not necessary. 'I'he yoke member 1| through the arms 10 and groove 10a is adapted to disengage the pinion from gear 25 in opposition to the spring 36 when the member 1| is actuated. A Member 1| is pivotally supported at 12 on a bracket 13 secured to the housing, as at 14. Lever 1|, therefore, constitutes a yoke shifter. The other end of the member 1| at 15 has a ball and socket or universal connection with one arm 16 of a bell crank lever, pivoted at 11 to the'housing. Herein ypivot 11 is coaxial with the bracket mounting 14. The other arm 18 is connected to one end of a spring 80, said spring at its opposite end being associated with a hook 8| that has an eye portion 8| a`that encircles the rod 66.

'I'he arm 18 of the bell crank lever-see Fig. 4-is also connected, and herein said connection coincides with that of a spring 88, to a link or strap 83 which has an elongated slot 82 therein and at its lower end a pin 85, carried by lever 60, rides in said slot.

The pinion and gear in this form of the invention, are of spiral character. The angle or pitch of the spiraling may be approximately from 6 to 12.

'I'he connection between the yoke shifter 1| and the rod 66 and/or the employment of spiral gears in place of spur gears and the adjustable stops for limiting the position of the brake band when released, constitute broadly the departures from the disclosure'in the allowed copending application, herein before mentioned.

The purpose of the'stops is to limit the released position and, therefore, the rate of lowering when the band is fully released.

'I'he connection between the yoke shifter 1| and the control rod 66 is of gdual character and is for dual purposes. The slotted link and pin connection 82-83-85 is to insure positive engagement of the pinion and gear so that the same are in meshing engagement for load elevation. 'Ihe spring and hook connection 8I- 8|a80 between the bell crank lever and the rod 66 is for the purpose of securing the disengagement of the pinion fromthe gear but only upon the actuation of the control rod 66 beyond that necessary to secure load lowering or partial release of the brake.

Continued movement of the control rod downwardly, after the load has been deposited in lowered position, insures full release of the brake from the drum and then and thereupon continued movement of the rod 66 downwardly secures actuation of the yoke shifter 1| to secure the disengagement of the pinion from the gear to permit free-chain positioning in the lowering direction, as broadly disclosed in the before mentioned application. Following free-chain posi-l tioning, control rod 66 is released and upon said release, the spring 80 land spring 45 cooperate together with the pin and the link slot to secure positive meshing engagement.

'I'he employment of spiral gears, as before mentioned, insures additional frictional contact between the gears and prevents disengagement of the pinion from the gear in the lowering of relatively light loads and is one means for insuring against dropping relatively light loads. With heavy loads, dropping is relatively impossible, because of the weight of the load being transmit-4 ted through the gear tooth face to the pinion tooth face and which will hold the two in contact and prevent lateral movement of the pinion into a non-meshing position. Just the substitution of spiral gears for the spur gears, shown in the copending application, is one solution to the problem of preventing dropping of light loads in load-lowering, in the invention shown in the co- Cil Cil

pending application and in the present invention.'

The delayed action or lost motion connection obtained through the eye 8Ia and rod 66 and lever 64a insures positive disengagement only after the load is fully lowered or the brake band is fully released.

If and when. spiral gears are employed, the lateral friction between the faces may be such that positive engagement may be quite diicult and for that reason, a positive engaging means or connection is provided and this is obtained through the slotted link and the pin connection.

By the aforesaid, it is not to be implied that the slotted link and pin connection cannot be employed with the invention shown broadly in the copending application but it is affirmatively asserted that the same can be associated therewith.

To facilitate a specific understanding of the operation of the last mentioned mechanism, the same is briefly set forth as follows:-

Upon the initial downward pull of. the cable 69 from the position shown in Fig. 1 to a position intermediate between that and the one shown in Fig. 3, the brake band will be released to a partial degree so that the rate of load lowering can be regulated. This is normal operation and the position of parts will be maintained until the load is lowered. If no regulation is desired, the cable 69 may be pulled until the rod 6B causes lever 64a and lever 80 to assume the position illustrated in Fig. 3 which constitutes the full release position for the brake band. Under relatively light loads, this position will probably be the normal operating position.

After the load has been lowered to the desired elevation and is suitably supported, then continued pulling upon cable 69 causes lever 64a to engage the eye Bla of the member 8l and the same is pulled downwardly, the brake band having been permitted to move to the full release position, remains in that position. In this movement of the member 8 I, the spring 80 is extended. and tends to tilt the arm 'I8 counterclockwisesee Fig. 5--which tilts the arm 'I6 in the same direction and through the universal connection 'l5 tilts the yoke shifter 'Il to move the pinion in*o disengaged position in opposition to spring 36.

In this continued downward movement of the lever 60, the pin 85 cannot engage the lower end of the slot 82 in the link member 83 and positively disengage the gear. This is to insure against a single strong pull on-rod 66 successively but almost in immediate succession releasing the brake and disengaging the gears. Thus accidental dropping due to acidental gear disengagement is prevented.

When the device is to be reconditioned for load elevation, cable 65 is released and immediately the spring 45 (as well as spring 36 if utilized) tends to tilt the yoke shifter 1I in a reverse direction by tilting lever 60 so that the pin 85 on the end of said lever engages the upper end of the slot 82 in the member 83 to tilt the bell crank lever 18-16 in a direction opposite to which it has been previously tilted to cause gear engagement. The effective constraint imposed by the spring 80 is removed. The spring 45 then also becomes operative to insure brake band engagement with the drum. The device is then operative for load elevation.

It will, of course, be apparent that free-chain movement corresponding to load elevating movement is possible without operating the control rod 66, because the gear 25, pinion 3B, shaft 30 and ratchet 50 will al1 freely rotate to permit such movement. However, lf the chain is heavy and thereis considerable friction inherent in the structure and this may be true in relatively large capacity hoists, the cable 69 may be .actuated and rod 66 fully lowered into the position shown in Fig. 4, which will immediately free the gear from pinion engagement and thus only the gear, the sprocket and the chain need be moved.

The device, therefore, is a free-cham hoist, capable of free-chain movement in either direction. It is fool-proof for load dropping is prevented and conditioning forl load elevation, that is pinion and gear meshing is positively assured.

The invention claimed is:-

1. In a free chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movementl into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, and means normally preventing gear disengagement under light load lowering, comprising biased teeth on said gears.

2. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure includinga pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constrainingmeans, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, and means normally preventing gear disengagement under light load lowering including a lost motion connection between said single control member and the gear moving means.

3. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a oneway clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagementin opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear forfree-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, and a lost motion connection between said control member and the gear moving means for positively engaging said gears following gear disengagement.

4. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, a lost motion connection between said control member and the gear moving means for positively engaging said gears following gear disengagement, and means normally preventing gear disengagement under light load lowering.

5. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being .operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for Vmoving the slidable gear out of gear engagement in opposition to the last mentioned con-o straining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load. lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement,` a lost motion connection between said control member and the gear moving -means for positivelyengaging said gears following gear disengagement, and means normally preventing gear disengagement under light load/lowering, comprising biased teeth on said gears.-

6.v In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out .of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means `for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, a lost motion connection between said control member and the gear moving means for positively engaging said gears following gear disengagement, and means normally preventing gear disengagement under light load lowering, including a lost motion connection.

7. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for ro tating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a

one-way clutch between the brake structure and l the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing` said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said memberwhereby brake actuation for load lowering occurs previous to gear disengagement, a lost motion connection between said control member and the gear moving means for positively engaging said gears following gear disengagement, and means normally preventing gear disengagement under light load lowering, and the teeth of said gears having a biased relation.

8. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating vthe same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, anti other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a. single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement,4

means normally preventing gear disengagement under light load lowering including a lost motion connection between said single control member and the gear moving means, and a parallel yielding connection.

9. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure, to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, a lost motion connection between said control member and the gear moving means for positively engaging said gears following'gear disengagement, means normally preventing gear disengagement under light load lowering, including a lost motion connection, and a parallel yielding connection.

10. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means tc said member whereby brake actuation for load lowering occurs previous to gear disengagement,

means normally preventing gear disengagement under light load lowering, comprising biased teeth onsaid gears, and a lost motion connection.

11. In a free-chain hoist, the combination with a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket-for rotating the same, the vother gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structureand the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, comprising biased teeth on said gears, a lost motion connection, and a yielding connection in multiple with the lost motion connection.

12. In a free-chain hoist, the combination with a housing, a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other geartoward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, and means carried by the housing and operatively associated with the brake structure for limiting the full release position thereof.

13. In a free-chain hoist, the combination with a housing, a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshingengagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby vious to gear disengagement, means normally preventing gear disengagement under light load lowering, and mea-ns carried by the housing and operatively associated with the. brake structure for limiting the full release position thereof, said preventing means comprising biased teeth on said gears.

14. In a free-chain hoist, the combination with 4a housing, a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear havinga slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of asingle control member for releasing said brake structure and disengaging said gear for freechain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, and means carried by the housing and operatively associated with the brake structure for limiting the full release position thereof, said preventing means including a lost motion connection.

15. In a free-chain hoist, the combination with a housing, a chain engaging sprocket, -a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining saidl other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for freechain movement in the load lowering direction,

means operatively connecting the brake structure y and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, and means carried by the housing and operatively associated with the brake structure for limiting the full release position thereof, said preventing means including a lost motion connection and the teeth on said gears having a biased arrangement.

16. In a free-chain hoist, the combination with a housing, a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidablel connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure vand the shaft, means normally constraining the brake structure to braking' operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slid-` able gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free chain movement in the load lowering direction, means operatively connectingthe brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, means carried by the housing and operatively associated with the brake structure for hunting the full release position thereof, and means operable by said member for positive engagement of the gears.

17. In a free-chain hoist, the combination with al housing, a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft formovement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition'to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gear for free-chain movement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, means carried by the housing and operatively associated with the brake structure for limiting the full release position thereof, said preventing. means comprising biased teeth on said gears, and means operable by said member for positive engagement of the gears.

18. In a free-chain hoist, the combination with a housing, a chain engaging sprocket, a shaft, means' for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a slidable connection with the shaft for movement into and out of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normallyf "gear moving means to said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, means carried by the housing and operatively associated with the brake structure for limiting the full release position thereof, said preventing means including a lost motion connection, and means operable by said member for positive engagement of the gears.

19. In a free-chain hoist, the combination with a housing, a chain engaging sprocket, a shaft, means for rotating the shaft, a meshing gear structure including a pair of gears, one of said gears being operatively connected with the sprocket for rotating the same, the other gear having a,siidab1e connection with-the shaft for movement into andout of meshing engagement, a brake structure, a one-way clutch between the brake structure and the shaft, means normally constraining the brake structure to braking operation for restricting free rotation of the shaft in the load lowering direction, means normally constraining said other gear toward meshing engagement, and other means for moving the slidable gear out of gear engagement in opposition to the last mentioned constraining means, of a single control member for releasing said brake structure and disengaging said gearforfree-chainnovement in the load lowering direction, means operatively connecting the brake structure and the gear moving means to' said member whereby brake actuation for load lowering occurs previous to gear disengagement, means normally preventing gear disengagement under light load lowering, means carmeans operable by said member for positive en- FREDRICK W. COIE'FING.

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