US3596879A

US3596879A - Chain hoist

Info

Publication number: US3596879A
Application number: US769659A
Authority: US
Inventors: Walter C Clark
Original assignee: ALUMINUM PRODUCTS Inc
Current assignee: ALUMINUM PRODUCTS Inc
Priority date: 1968-10-22
Filing date: 1968-10-22
Publication date: 1971-08-03
Anticipated expiration: 1988-08-03

Abstract

A chain hoist mechanism including an integral chain guide and load-lift, ratchet wheel. The chain guide is U-shaped and is supportably mounted on the ratchet wheel on supporting shoulders adjacent each side of the load-lifting portion. The chain guide is easily reversible for increasing operational lifetime when certain portions become worn.

Description

W n ite States Patent Welter C. Clerk lFort Lauderdale. i le. 769,69

Oct. 22. 11968 Aug. 3, 1197 11 Aluminum Products, line. Fort Leuderdale, lFlu.

Inventor App]. No. Filed Patented Assignee cumin WORST 1 0 Clieims, 3 Drawing Figs.

US. Cl 254/190, 254/167 Hm. 1C1 186611 M36 Fieid oil Seercli 254/167,

[ 1 References Cited UNITED STATES PATENTS 365,545 6/1837 Sharp et al 254/150 2,704,201 3/1955 Robins 254/167 2,773,668 12/1956 Robins 254/167 3,047,114 7/1962 Stevens 254/167 FOREIGN PATENTS 1,232,718 1/1967 Germany 254/167 Primary Examinerl-1arvey C. Hornsby Attorney-Eugene F. Malin ABSTRACT: A chain hoist mechanism including an integral chain guide and load-lift, ratchet wheel. The chain guide is U- shaped and is supportably mounted on the ratchet wheel on supporting shoulders adjacent each side of the load-lifting portion. The chain guide is easily reversible for increasing operational lifetime when certain portions become worn.

Patented Aug. 3, E971 WA LTEQ EICLAHM ATTEIRNEY CHAIN HOIST BACKGROUND OF THE INVENTION This invention relates to a new and improved operating mechanismfor a chain hoist, and, more particularly, to an integral one-piece load-lift, ratchet wheel and reversible chain guide-stripper.

As is perhaps well known, chain hoists of this type include a plurality of complex parts and mechanisms that are not only difficult to assemble but are costly to maintain. Many such hoists are suspended by means of a hook from a suitable support in order to lift or lower a load. The chain that carries the load is wound over and supported on a drum or wheel. Cooperating holding and loading pawls regulate the lifting and lowering of the load by regulating the rotation of the drum or wheel. A stripper is usually employed to maintain the chain in proper alignment with the drum as the chainmoves off the drum and on the drum.

This type of chain hoist may be operated both for lifting or pulling a load and thereafter for lowering or releasing the load, usually in response to gravity. US Pat. No. 2,927,771, issued Mar. 8, 1960, shows this type of chain hoist. In a lifting operation, an operating lever is advanced, with the loading pawl biased into engagement with a ratchet that is linked or connected to the drum or wheel. When the drum is advanced the load is lifted or pulled. The holding pawl, biased into engagement with the ratchet, rides over the advancing ratchet, to engage each tooth, to maintain the load in the advance position.

In changing from a lifting to a lowering operation, it is customary to reverse the bias of a spring, which normally urges the loading pawl into a ratchet engaging position. The spring bias is reversed to retract the loading pawl to a normally overriding position relative to the ratchet wheel. The retracted loading pawl, which may be pivotally mounted on an operating lever, is then advanced toward the holding pawl, which normally remains engaged with the ratchet to sustain the load. As the retracted pawl is advanced, it may be designed to engage a cam which then operates to disengage the holding pawl from the ratchet while concurrently permitting the loading pawl itself to reengage a tooth of the ratchet at a point which is adjacent the tooth just vacated by the holding pawl. When the reengaged loading pawl is reversely moved, the holding pawl engages the next adjacent tooth of the ratchet and the loading pawl is retracted, thereby permitting a controlled lowering of the load for a distance equal to the spacing between two ratchet teeth.

SUMMARY OF THE INVENTION This invention relates to a chain hoist mechanism including a one-piece load-lift, ratchet wheel, a noncomplex one-piece guide-stripper, operating lever movably connected to a onepiece housing, and cooperating holding and loading pawl connected to the operating lever for raising or lowering a load. The one-piece load-lift, ratchet wheel has a relatively large diameter ratchet portion at one end of the wheel, first and second load-lift shoulders adjacent one side of the ratchet portion, and a chain loadlift portion between the first and second shoulders. The one-piece, reversible, guide-stripper has a generally U-shaped guideway therein with a cylindrical opening passing through a portion of the base of the U-shaped guideway. The guidestripper is supported by the cylindrical opening. The diameter of the cylindrical opening is approximately equal to the diameter of said first and second shoulders. The guide-stripper is supported on the load-lift shoulders.

The upper ends of the guideway are generally cross-shaped in cross section. The guideway is interrupted by the opening between the entrance of the guideway and the exit from the guideway. All structural material is absent in the vicinity of the cylindrical opening that encompasses the projected path of three legs of the cross, the lower leg, the upper leg and the inside leg. Only the outside leg remains in the vicinity of the opening. The outside leg encompasses the inside surface of the base portion of the U-shaped guide-stripper. The material lying between the U-shaped guideways, adjacent the upper portion of the U-shaped guide-stripper and between the entrance to the guideway and the exit from the guideway, is utilized as a stripping device. .T his stripping device aligns the chain as it moves on to the load-lift portion and as it moves off the load-lift portion of the wheel to prevent the chain from jamming the hoist mechanism.

When assembling the integral wheel and guide-stripper, the shoulders of the load-lift, ratchet wheel are placed in the cylindrical opening of the guide-stripper with one side of the guidestripper resting against the ratchet portion. The load-lift portion, the stripper, the ratchet portion, and the guide means are assembled in a single operation.

It is an object of this invention to provide a noncomplex chain hoist.

It is another object of this invention to provide a reliable chain hoist having a minimum number of components.

Another object of this invention is to provide an integral guide and load-lift, ratchet wheel assembly.

A further object of this invention is to provide a chain hoist mechanism that may be rapidly assembled.

A further object of this invention is to provide a reversible guide-stripper.

A further object of this invention is to provide a chain hoist mechanism that may be easily disassembled to reverse the guide-stripper.

An additional object of this invention. is to provide a reliable and low-cost chain hoist mechanism.

In accordance with these and other object which will be apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1, is a front view of the chain hoist,

FIG. 2, is a front view of the one-piece load-lift, ratchet wheel, and

FIG. 3, is a perspective view of the one-piece guide-stripper.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawing, wherein an embodiment of the invention is shown, and referring, particularly, to FIG. 1, the chain hoist generally designated by numeral 2, includes a book 4 for suspending the hoist above a load, a onepiece frame 6 connected to the hook 4, and an operating lever 8 for rotating the load-lift, ratchet wheel 10 in order to lower or raise a load. The chain 112 is driven by the load-lift, ratchet wheel 10. The chain 12 moves through the chain guide stripper 14. The load-lift, ratchet wheel 10 is driven by the loading pawl 16 that is connected to the operating lever 8. The loading pawl 16 is normally biased into engagement with loadlift, ratchet wheel 10 by the biasing means 13. The biasing means 18 includes a control lever 20 connected to springs 22 that biases loading pawl 16 into an engaging or disengaged position. When the operating lever 8 is moved downwardly, with the loading pawl in engagement with the ratchet wheel, the load is raised. A holding pawl 24 is normally biased into engagement with the load-lift, ratchet wheel to hold the load in a particular raised or lowered position.

An axle 26 is connected to the one piece frame. The operating lever 18 is rotatably mounted on the ends of the axle 26. The load-lift, ratchet wheel 10 is also rotatably mounted on axle 26 between the sides of the one-piece frame 6. The guide means 14 is mounted on the load-lift, ratchet wheel 10. A pin 28 is connected to the one-piece frame to prevent the guide means 14 from rotating on the load-lift, ratchet wheel.

Now referring to FIG. 2, the one-piece load-lift, ratchet wheel 10 includes a relatively large diameter ratchet portion 30 at one end, a first load-lift shoulder 32 adjacent the left side of the ratchet portion 30, a second load-lift shoulder 34 spaced to the left of the first shoulder 32, and a chain load-lift portion 36 between the first and second shoulder. When the ratchet 30 is rotated by loading pawl 16 the chain 12 engages the equally spaced chain pockets that are calibrated to the chain links to lift a load connected tothe chain 12. When the ratchet is rotated in the opposite direction, the load is lowered.

Referring now to FIG. 3, showing the one-piece reversible, guide-stripper 14 having a generally U-shaped guideway 38 with a cylindrical opening 40 passes through the base of the guide-stripper. The guide-stripper is designed so that it may be reversed when certain portions become worn. The cylindrical opening passes through the base of the U-shaped guideway 38, perpendicular to the major plane of the guide-stripper.

The guide-stripper is mounted on the load-lift, ratchet wheel. The diameter of the cylindrical opening 40 is approximately equal to the diameter of the load-

lift shoulders

32 and 34. The

shoulders

32 and 34 fit into the guide-stripper opening to support the guide-stripper in the chain hoist housing 6. A hole 42 is provided at one end of the guide-stripper, a pin 28 passes through hole 42 to prevent the guide-stripper from rotating on

shoulders

32 and 34.

The U-shaped guideway 38 is generally cross-shaped in cross section, as shown in FIG. 3. The cross-shaped guideway has four legs, an outside leg 44, a lower leg 46, an upper leg 48, and an inside leg 50. In the vicinity of the opening 40, only the outside leg 44 remains to guide the chain. The foot of the outside leg is shown at 52.

The stripper includes the material 54 lying between each leg of the U-shaped guideway. The stripper aligns the chain as it is removed from the load-lift portion of the load-lift, ratchet wheel. When the stripper becomes worn, the guide-stripper is reversed to provide a longer life for the chain hoist.

The chain hoist load-lift, ratchet wheel and guide-stripper are assembled in a single operation. The load-lift shoulders are passed into the opening in the reversible chain guide-stripper to a point where one side of the guide-stripper rests against the ratchet wheel 30.

In use, the chain hoist is operated to lift or pull a load and thereafter to lower or release the load. When used to lift a load, the operating lever 8 is advanced, with the loading pawl 16 biased by spring 22 into engagement with the ratchet wheel 30. When the ratchet wheel rotates the load-lift portion 36 rotates to pull the load. The holding pawl 24, biased into engagement with the ratchet wheel 30, rides over the advancing ratchet wheel, to engage each tooth, to maintain the load in the advance position.

In changing from a lifting to a lowering operation, it is Customary to reverse the bias of spring 22 by operating lever 20, which normally urges the loading pawl 16 into a ratchet engaging position. The spring bias is reversed to retract the loading pawl 16 to a normally overriding position relative to the ratchet wheel 30. The retracted loading pawl 16 is then advanced toward the holding pawl 24, which normally remains engaged with the ratchet wheel to sustain the load, as the retracted pawl is advanced, it is designed to engage cam 56 which then operates to disengage the holding pawl 24 from the ratchet wheel 30 while concurrently permitting the loading pawl 16 to reengage a tooth of the ratchet wheel at a point which is adjacent the tooth just vacated by the holding pawl. When the reengaged loading pawl is reversely moved, the holding pawl engages the next adjacent tooth of the ratchet and the loading pawl is retracted, thereby permitting a controlled lowering of the load on chain 12 for a distance equal to the spacing between two ratchet teeth.

The instant invention has been shown and described herein in what is considered to bev the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention. Therefore, the instant invention is not to be limited to the details discussed herein but to be accorded the full scope of the claims shownas to embrace any and all equivalent apparatus and articles.

What I claim is: l. A chain hoist comprising,

frame,

an operating lever moveably connected to said frame,

cooperating holding pawl and loading pawl connected to said frame for raising and lowering loads,

a one-piece load-lift, ratchet wheel connected to said frame,

said wheel having a relatively large diameter ratchet portion at one end of said wheel,

a chain guide means reversibly and supportably coupled to said wheel,

a first load-lift shoulder adjacent one side of said ratchet portion for supporting the chain guide means,

a second load-lift shoulder spaced from said first shoulder for supporting the chain guide means, and

a chain load-lift portion between said first and second shoulder for raising and lowering a chain.

2. A chain hoist as set forth in claim 1 wherein,

a chain guide means supported on said first and second shoulder.

3. A chain hoist as set forth in claim 2 wherein,

said guide means includes a chain stripper portion.

4. A chain hoist as set forth in claim 3 wherein,

said guide means includes a U-shaped guideway.

5. A chain hoist as set forth in claim 4 wherein,

said guideway is generally cross-shaped in cross section.

6. A chain hoist comprising,

a frame,

a load-lift wheel connected to said frame said wheel having at least two symmetrical supporting shoulders,

an operating lever movably connected to said frame,

cooperating holding pawl and loading pawl connected to said frame for raising or lowering a load by rotating said load-lift wheel,

a reversible guide-stripper having a generally U-shaped guideway, said guide-stripper being symmetrically supported on said supporting shoulders of said load-lift wheel, and said guide-stripper having a stripper portion between the upper ends of the generally Ushaped guideway.

7. A chain hoist as set forth in claim 6 wherein,

an inner surface of said guide-stripper encompasses an opening in the base portion of said guide-stripper for supporting said guide-stripper on the load-lift wheel.

8. A chain hoist as set forth in claim 7 wherein,

said load-lift wheel is a one-piece load-lift, ratchet wheel having a large ratchet portion, a first and second shoulder, and said load-lift wheel between said first and second shoulder.

9. A chain hoist as set forth in claim 8 wherein,

said first and second shoulders fit against said inner surface in said guide-stripper to support said guide-stripper.

10. A chain hoist as set forth in claim 9 wherein,

said guideway in said guide-stripper is generally crossshaped in cross section.

Claims

1. A chain hoist comprising, frame, an operating lever moveably connected to said frame, cooperating holding pawl and loading pawl connected to said frame for raising and lowering loads, a one-piece load-lift, ratchet wheel connected to said frame, said wheel having a relatively large diameter ratchet portion at one end of said wheel, a chain guide means reversibly and supportably coupled to said wheel, a first load-lift shoulder adjacent one side of said ratchet portion for supporting the chain guide means, a second load-lift shoulder spaced from said first shoulder for supporting the chain guide means, and a chain load-lift portion between said first and second shoulder for raising and lowering a chain.

2. A chain hoist as set forth in claim 1 wherein, a chain guide means supported on said first and second shoulder.

3. A chain hoist as set forth in claim 2 wherein, said guide means includes a chain stripper portion.

4. A chain hoist as set forth in claim 3 wherein, said guide means includes a U-shaped guideway.

5. A chain hoist as set forth in claim 4 wherein, said guideway is generally cross-shaped in cross section.

6. A chain hoist comprising, a frame, a load-lift wheel connected to said frame said wheel having at least two symmetrical supporting shoulders, an operating lever movably connected to said frame, cooperating holding pawl and loading pawl connected to said frame for raising or lowering a load by rotating said load-lift wheel, a reversible guide-stripper having a generally U-shaped guideway, said guide-stripper being symmetrically supported on said supporting shoulders of said load-lift wheel, and said guide-stripper having a stripper portion between the upper ends of the generally U-shaped guideway.

7. A chain hoist as set forth in claim 6 wherein, an inner surface of said guide-stripper encompasses an opening in the base portion of said guide-stripper for supporting said guide-stripper on the load-lift wheel.

8. A chain hoist as set forth in claim 7 wherein, said load-lift wheel is a one-piece load-lift, ratchet wheel having a large ratchet portion, a first and second shoulder, and said load-lift wheel between said first and second shoulder.

9. A chain hoist as set forth in claim 8 wherein, said first and second shoulders fit against said inner surface in said guide-stripper to support said guide-stripper.

10. A chain hoist as set forth in claim 9 wherein, said guideway in said guide-stripper is generally cross-shaped in cross section.