US2426112A - Chain hoist - Google Patents

Description

Aug. 19, 1947. E, MQQRE r 2,426,112

CHAIN HOIST Filed Nov. 24, 1943 3 Sheets-Sheet 2 wuumun Geo/- eEMoore MI M 651 @FMW Aug. 19, 1947. E, MOORE ETAL 2,426,112

CHAIN HOIST Filed Nov. 24, 1943 3 Sheets-Sheet s George/3714092 6 Patented Aug. 19, 1947 icln, assignors to Manning, Maxwell & Moore,

ind, ll/iusiregon, Mich, a corporation of New .iersey Application November 24, 1943, Serial No. 511,510

"1 Claims.

The invention relates to improvements in hand operated chain hoists and more particu" larly to portable hoists of the spur gear type adapted to be suspended from an overhead supporting structure.

One object of the invention is to provide a chain hoist of the above general character, which is accurately balanced with reference to its point of suspension yet light in weight and very compact for its lifting capacity.

The invention also resides in various structural improvements and combinations of elements which contribute to the general efficiency and convenient operation of the hoist.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawings in which: Figure 1 is a longitudinal sectional view of the hoist embodying the features of the invention, the view being taken in a horizontal plane substantially on the central axis of the housing.

Fig. 2 is a transverse sectional view taken in a vertical plane substantially on the line 2-2 of Fig. 1.

Fig. 3 is a vertical sectional View of the end cover plate and chain guide support.

Fig. 4 is a vertical sectional view of the chain guide.

Fig. 5 is a sectional view taken in a horizontal plane substantially on the line 5-5 of Fig. 4.

Fig. 6 is an exploded perspective view of the housing and associated structural elements of the hoist.

Referring to the drawings, the hoist selected to illustrate the invention comprises a main body [0, preferably annular in form, adapted to be suspended from an overhead supporting structure by a hook l l. A flexible hoist line such as a roller chain I2 is reeved over a rotatable lifting member or sprocket wheel t3 mounted in the body directly below the hook l i so that the load imposed on the chain is in vertical alinement with the hook, thus avoiding any tendency of the hoist structure to tilt or skew under load.

Rotation of the sprocket wheel [3 to raise or lower a load is effected through the medium of a chain pocket wheel M adapted to be rotated manually by the usual endless pull chain 15 and operatively connected with the sprocket wheel by suitable reduction gearing and clutch mechanism. The body It provides support for the gearing and clutch mechanism and, together with end cover members #6 and ll, forms a casing for completely enclosing such elements of.

the hoist. A housing l8 enclosing the chain wheel serves as a guard therefor and insures proper running engagement between the chain and the wheel.

In order to operate with safety and efficiency, a hoist of the type under consideration must be balanced accurately with respect to its point of suspension. The attainment of the desired balance in a compact light weight hoist presents substantial difficulties. In accordance with the present invention, accurate balance is achieved in a hoist that is well balanced, very light in weight and extremely compact for its lifting capacity by constructing a part of the casing and the major portion of the wheel housing of light weight material, as for example, sheet metal stampings. The light weight construction of such elements of the hoist is made practicable by the novel form of the main body H] which alone supports the moving elements of the hoist such as the gearing and associated parts for driving the sprocket wheel I3. The end cover members l6 and I! are thus relieved of that function and one of the covers is enabled to serve additionally as a part of the wheel housing.

Turning now to a more detailed consideration of the various elements of the exemplary hoist, the body 10, as shown in Figs. 1, 2 and 6 comprises a generally cylindrical casting open at both ends. Transverse walls 20 and 2| within the casting define a downwardly opening recess at one side of the body for the sprocket wheel l3, the recess being closed at its upper end by an arouate web 22 (Fig. 2) having an elongated sleevelike bearing supporting member 23 extending axially of the body. A second bearing supporting member 2% also in the form of an elongated sleeve disposed parallel to the member 23 is formed in the lower wall of the body. Additional strength and rigidity is imparted to the supporting members by a. transverse wall 25 which, together with the members, the walls 20 and 2| and the web 22 are preferably cast integral with the body Ill,

The hoist supporting hook H is anchored to the body It in a novel manner which materially simplifies the manufacture and assembly of the heist structure. Referring to Fig. 2, it will be be observed that the hook H is formed with a cylindrical shank 26 fitted in a hole in a nut 21 and having its end portion threaded for the reception of a nut 28 which serves to hold the hook in assembled relation with the nut. A pin 29 prevents rotation of the nut on the shank of the 3 hook when the hoist is swiveled about the axis of the hook. The body I is formed with an upwardly opening recess located directly above the sprocket I3 and threaded to receive the nut 21. A locking screw 33 holds the nut against rotation. With this construction the supporting hook and associated elements may be assembled with and removed from the hoist body quickly and with a minimum of effort.

In the exemplary hoist, the sprocket wheel I3 is formed on a shaft 3| journaled in the walls and 2| of the body Ill. The sprocket shaft is adapted to be driven in a direction to wind up the chain I2 and thus raise the load by manual rotation of the chain wheel I4 which is operatively connected with the sprocket shaft through the medium of speed reduction gearing and a clutch and brake mechanism 32.

As will be seen by reference to Fig. 1, the chain wheel I4 is fast on the projecting end of a shaft 33 journaled in the supportin sleeve or member 24. The length of the member permits wide spacing of the journal bearings within the body I0 and makes it unnecessary to provide bearing support on the end cover plate I6 through which the shaft extends. A pinion on the inner end of the shaft 33 meshes with a gear 34 mounted on an intermediate shaft 35 and forming a part of the clutch and brake mechanism 32.

The intermediate shaft 35 is journaled in widely spaced bearings carried in the elongated supporting member 23 and has a driving connection with the sprocket shaft 3|. The driving connection. in this instance, is provided by a pinion 36 fast on the shaft 35 and coacting with a gear 37 fast on the sprocket shaft 3|. Since it is desirable to space the chain wheel I4 a substantial distance from the sprocket wheel I3 to provide maximum clearance between the hand and load chains, the pinion 36 and gear 31 may be located between the sprocket wheel and the chain'wheel. The clutch and brake mechanism 32 is preferably located on the other side of the sprocket wheel thus effectually balancing the forces acting on the shaft 35. The shaft may therefore be supported solely by the sleeve 23 within the body ID.

The clutch and brake mechanism 32, as herein shown, is of a generally well-known friction type having effective load braking characteristics yet permitting the load to be quickly raised or lowered by appropriate rotation of the chain wheel I4. To this end, the gear 34 is threaded on the shaft 35 whereby relative rotation of the shaft and gear is effective to shift the gear axially of the shaft in one direction or the other. Such rotation is limited to a predetermined angle by a pin 38 (Fig. 1) projecting from one face of the gear for coaction with a lug 39 projecting radially from a nut 40 keyed to the shaft 35. The nut is held in place on the shaft by a collar 4| pinned or otherwise rigidly secured to the shaft.

Keyed to the shaft on the side of the gear 34 opposite the nut 43, is a clutch disk 42 adapted to be frictionally clutched to a ratchet 43 mounted for rotation about the axis of the shaft 35. The ratchet 43 is held against rotation in one direction by a pawl 44 (Fig. 2) pivoted on the housing body I0 and having its free end positioned for engagement with the teeth of the ratchet. The pawl is yieldably urged into blocking engagement with the ratchet teeth by means of an annular spring 45 partially encircling the clutch disk 42.

For clutching the disk 42 to the ratchet 43, a

friction washer 45 is interposed therebetween. Shifting of the ratchet wheel into or out of engagement with the friction washer is effected by the gear 34 through the medium of a thrust washer 41. The arrangement is such that rotation of the chain wheel I4 in a load lifting direction screws the gear 34 axially along the shaft to the left to clamp the ratchet 43 and friction washer 46 firmly against the disk 42. Under these conditions the pawl 44 slips over the ratchet teeth thus permitting the ratchet to rotate with the gear 34 and shaft 35 as the load is being raised.

In addition to acting as a clutch, the mechanism 32 functions as a brake to prevent descent of the load except when the chain wheel is manually rotated in the load lowering direction. Thus the force applied through the load chain to the sprocket I3 tends to rotate the shaft 35 in a direction to screw the gear 34 up tightly against the ratchet 43 and thereby effectually clamp the ratchet to the disk 42. Rotation of the ratchet is prevented. in this instance, by the action of the pawl 44, hence, the shaft 35 is frictionally held against rotation and thereby effectually prevents descent of the load.

By rotating the chain wheel I4 in the load lowering direction, the gear 34 is screwed away from the ratchet 43 thus releasing the frictional connection with the disk 42 and permitting the load to descend by reason of its weight. Such descent continues only as long as the chain wheel is turned at a rate sufficient to keep the gear 34 retracted from the ratchet. Upon interruption of the rotation of the chain wheel, the gear 34 is again screwed up against the ratchet and the load is frictionally locked against descent. When the weight on the load chain is insuflicient to run out the chain in the above manner, the intermediate shaft is turned in the load lowering direction by rotation of the chain wheel through the lost motion connection provided by the pin 38 and lug 39.

Referring to Figs. 1 and 6 of the drawings, the chain wheel I4, in its preferred form, comprises a pair of generally circular sheet metal stampings 50 of the same diameter each having its peripheral edge portion shaped to form a stepped flange 5|. The flanges 5| are crimped transversely at uniformly spaced points so as to define a circumferential series of chain pockets 52 when the stampings 50 are assembled in face-to-face relation. The assembled stampings are bolted or otherwise secured to a flange 53 formed at one end of the sleeve-like hub member 54 adapted to be keyed to the shaft 33, thus providing a driving connection between the chain wheel and the shaft.

The end cover I6 cooperates with the body ID to form the gear casing and also constitutes a part of the wheel housing I8. As shown in Figs. 1, 3 and 6, the end cover comprises a relatively thin plate of steel or other suitable material of generally oval contour having a pad 55 pressed in one face for seating against the end of the body ID; Within the boundary of the pad, the plate is pressed outwardly as at 56 to form a recess for receiving the pinion 36 and gear 37. The body I0 is thus shortened in its longitudinal or axial dimension and the weight at the chain wheel end of the gear casing is correspondingly reduced.

As will be seen by reference to Figs. 1 and 6, the pad 55 extends approximately from the center of the cover plate I6 to one peripheral edge so that the plate when mounted on the body I I] is eccentric thereto. The portion of the cover plate projecting radially beyond the body is pressed into a generally dish-shaped contour to make it strong and rigid and the entire periphery of the plate is bent outwardly to form a flange 51 for seating the frame of the wheel housing IS.

The wheel housing l8 substantially encloses the chain Wheel M thus concealing unsightly parts and materially improving the appearance of the hoist. Moreover, a portion of the housing is adapted to function as a guide to prevent the chain from running off the wheel l3 and to guide the chain into operative engagement with the wheel in any position of the hoist.

Referring to Figs. 1 and 4-6, the housing 18, as herein shown, comprises a rigid frame including an inner annular side member or guide ring 60 adapted to be secured to the end cover plate It and an outer annular side member or guide ring 6! spaced from the ring 60 substantially the width of the chain wheel IA. The guide rings are yoked along their upper peripheral edges by a segmental cross member 62 and at their lower edges by a narrow cross member or brace 63. The various parts of the frame structure including the guide rings and the cross members are preferably constructed as a unitary casting thus forming a rigid frame structure for the housing and providing guide surfaces of wear resisting material.

In the exemplary hoist, the guide rings 60 and 61 are formed with an inner diameter slightly greater than the diameter of the chain wheel M and are held by the cross members 62 and 63 in parallel spaced relation with their inner edges overlying the outer edges of the chain wheel flanges 5|. The cross member 62 preferably extends around the upper end of the housing over substantially one-half the circumference of the same, thus leaving the lower onehalf of the housing open to provide entrance and exit passages for the pull chain 5. The portions of the rings adjacent the opening in the housing are flared outwardly so as to effectually guide the chain l5 into engagement with the wheel in any position of the hoist. This guiding action is assisted by the cross member 62 which merges at each end into the flared rings to provide a rounded tapering throat 64 on each side of the wheel as shown in Figs. 5 and 6.

The inner guide ring Bil of the housing frame has its inner face formed to provide an annular pad within an upstanding shoulder 65 whereby the flange 51 of the end cover plate I6 is ac.- curately guided into seating engagement with the pad. Screws 6% hold the parts in assembled relation. A similar pad encircled by a shoulder 6'! is formed on the outer face of the guide ring 6| for seating a removable end plate 68. The end plate 68 preferably comprises a generally concave stamping of light weight sheet metal or other suitable material having an inturned peripheral flange 69 adapted to seat against the pad on the ring Bl. The end plate is preferably secured to the frame by screws 10 so that it may be removed to give access to the chain wheel when required. Since the inside diameters of both the inner and outer guide rings are slightly greater than the diameter of the chain wheel, either of these elements, that is, either the wheel or the housing may be removed from the hoist without disturbing the other.

Due to the substantial reduction in the weight of the elements located at the chain wheel side of the hoist supporting hook, the hoist structure is precisely balanced without resorting to the use of counterweights. Furthermore, since the gearing and associated elements of the hoist are adequately supported by the casing body I!) no bearings are required in the end cover plate H. The cover plate may therefore be of light weight construction.

It will be apparent from the foregoing that the novel form of the casing body IO- to provide the sole support for the gearing and associated parts of the hoist in combination with the chain pocket wheel, the wheel housing and the end cover plates of light weight construction provides a hoist structure which is accurately balanced with respect to its point of suspension either with or without a load on the lifting chain, which is very light in weight and which is extremely compact for its lifting capacity.

We claim as our invention:

1. A pull chain hoist comprising, in combination, a rigid hollow body providing a main supporting structure open at opposite ends, a suspension hook at one side and a laterally opening recess at the opposite side, a lifting sprocket having a shaft journaled in the body with the sprocket disposed within said recess, a pull chain wheel having a shaft rotatably supported near opposite ends of said body and supporting the wheel at one end of the body with its axis spaced laterally with respect to the axis of the lifting sprocket, means providing a driving connection between said wheel and sprocket shafts, and a housing for the chain wheel having one wall constructed of light weight sheet metal and secured to the adjacent end of the body and forming a cover plate therefor, said cover plate having a clearance hole for said wheel shaft.

2. A pull chain hoist comprising, in combination, a hollow body providing a main supporting structure with openings at opposite ends, a lifting sprocket having a shaft journaled in the lower portion of the body, a suspension hook on the opposite side of the body alined with the sprocket, a pull chain wheel having a shaft journaled. in said body, means supported solely by the body providing a driving connection between said shafts, and a housing for said wheel comprising a pair of spaced chain guiding members disposed at the periphery of the wheel, said guiding members being yoked together at one side ofthe wheel, and a sheet metal stamping closing the end of the body adjacent the wheel and providing a support for the housing.

3. A pull chain hoist comprising, in combination, a hollow body providing a main supporting structure with openings at opposite ends, a lifting sprocket having a shaft journaled in the lower portion of the body, said body having a downwardly opening recess for receiving said sprocket and a suspension hook on the opposite side of the body alined with the sprocket, a pull chain wheel having a shaft journaled in said body, means supported solely within the body providing a driving connection between said shafts, guiding means for a pull chain reeved over said chain wheel comprising a pair of axially spaced rings disposed at the periphery of the wheel, said rings being yoked together at one side of the wheel, and a sheet metal stamping closing the end of the body adjacent the wheel and providing a support for said guide rings.

4. A portable chain hoist comprising, in combination, a casing including a hollow body open at one end, means for suspending said body from a supporting structure, a rotatable lifting member journaled in said body below with suspending means, a chain wheel journaled in said body and disposed forwardly of the open end thereof and in spaced relation thereto, mechanism within the body operatively connecting the chain wheel with said lifting member, a housing enclosing said chain wheel including a frame casting having spaced annular side members encircling the periphery of the wheel, a sheet metal cover plate adapted to close the open end of said body and the opening in one of said annular members, and a second cover plate for the opening in the other one of said annular members.

5. A portable chain hoist having, in combination, a gear casing including a body member in the form of a hollow casting open at one end, means for suspending said member from a supporting structure, a rotatable lifting member journaled in the body member below said supporting means, a shaft journaled in said body member and projecting from the open end thereof, a chain wheel fast on the projecting end of the shaft, a housing enclosing said chain wheel, means including spur gearing operatively connecting said shaft with said lifting member, a part of said gearing projecting beyond the open end of the body member, and a cover plate supporting said wheel housing and closing the open end of said body member, said cover plate comprising a sheet metal stamping formed to provide a recess for receiving the projecting part of said gearing.

6. A chain hoist having, in combination, a rotatable lifting member, a shaft carrying said member, a manually rotatable chain wheel, a shaft carrying said wheel, an intermediate shaft, mechanism connecting said wheel shaft with one end of said intermediate shaft, gearing connecting the other end of said intermediate shaft with said lifting member, and a casing enclosing said shafts, said mechanism and said gearing, said casing comprising a hollow body, a pair of elongated sleeves for supporting said wheel shaft and said intermediate shaft, and a pair of spaced transverse walls supporting said first shaft and said sleeves, said walls and said body being formed as a unitary casting.

7. A portable chain hoist comprising, in combination, a casing in the form of an elongated hollow casting open at both ends, means for suspending said casing from an overhead support, a lifting sprocket journaled in said casing below said suspending means, a drive shaft extending substantially through said casing and projecting at one end thereof, a hand chain wheel fast on the projecting end of said drive shaft, a chain guide for said wheel, an end cover mounted on said one end of the casing to close the same and to support said chain guide, a removable cover closing the other end of said casing, means including an intermediate shaft operatively connecting said drive shaft with said sprocket wheel, and members formed integrally with said casing supporting each of said shafts independently of said covers at two points spaced apart a substantial distance longitudinally of the shafts.

GEORGE E. MOORE. RALPH E. SMITH.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,335,571 Schroeder Nov. 30, 1943 2,246,923 Meunier June 24, 1941 1,492,581 Simpson May 6, 1924 1,143,958 Harrington et al. June 22, 1915 1,021,347 Windhoif Mar. 26, 1912 916,111 Cross Mar. 23, 1909 FOREIGN PATENTS Number Country Date 853,414 France Mar. 19, 1940 681,834 Germany Oct. 2, 1939 607,488 Germany Dec. 28, 1934 379,566 Great Britain Sept. 1, 1932 111,744 Australia Oct. 16, 1940

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