US3192760A - Method of forging choker hooks - Google Patents

Description

y 6, 1955 R. E. TIMBERLAKE 3,192,760

METHOD OF FORGING CHOKER HOOKS Filed Dec. 29, 1960 5 Sheets-Sheet 1 IN V EN TOR. Rea 275 finneuox:

Arramvsg:

y 6, 1965 R. E. TIMBERLAKE 3,192,760

METHOD OF FORGING.CHOKER HOOKS Filed Dec. 29, 1960 3 Shgecs-Sheet 2 INVENTOR. Rosa-RTE finaakuxs BY 612M drrqmvers y 6, 1965 R. E. TIMBERLAKE 3,192,760

METHOD OF FORGING CHOKER Hooxs Filed Dec. 29. 1960 3 Sheets-Sheet 3 INVENTOR. ROGERTE TIMBERMKE.

Jrrakmsrs FIE.

United States Patent Office 3,192,?h Fatented July 6, 1965 3,192,760 METHOD OF FORGING CHUKER HOOKS Robert E. Timberlake, Cumberland Center, Maine, assigner to American Hoist & Derrick Company, St. Paul, Minn a corporation of Minnesota Fiied Dec. 29, 1960, Ser. No. 79,362 2 Claims. (Cl. 72-641) The present invention has relation to traveling choker hooks and more particularly to a method of making forged traveling choker hooks and an apparatus for performing this method.

Traveling choker hooks presently used in industry are generally cast due to the difficulty of obtaining the proper curvature at the upper portion of the eye of the hook to allow a cable to slide freely without getting kinks or excessive wear. These cast hooks are limited in their physical properties and in order to get sufficient strength to the hook comparatively high weight and large size is necessary. The cast hooks also do not have desirable properties for shock-loading and great variation in strength and size is common between individual hooks. Quality control of the cast hooks is also a problem as internal defects make inspection diflicult.

The present invention relates to a method of making a forged choker hook toimprove the strength and physical properties of the hook and make the product purchased by the consumer uniformly satisfactory. A novel method of obtaining the proper curvature in the upper eye of the hook is disclosed and an apparatus for performing this is also disclosed.

In performing the method according to the present invention, a choker hook blank having a solid elongated upper eye portion is forged by conventional methods. A hole .is then drilled through this elongated upper portion in the direction that the cable used with the choker hook must travel. The upper end of the choker hook is then heated and placed in a die for forming a curve in the upper wall of the eye of the hook. Punches are positioned aligning with the hole and adjacent each end of the hole drilled through the upper portion of the choker hook. The machine in which the die is placed is activated and a ram forces a cam to actuate the punches inwardly and the punches in turn engage the eye of the hook and form the upper wall of said eye against a forming block having the desired curvature. The punches are then withdrawn and the traveling choker hook has been completely formed. This final forming of the curved upper wall of the eye is done with tools that travel transversely to the initial conventional forging dies. Previously no satisfactory mass production forging method of performing this operation has been advanced and casting was the only practicable way to mass produce traveling choker hooks.

The forging process of the upper eye of the hook refines the grain structure of the steel and improves strength and toughness. The books are much more uniform in strength and size than the previous cast hooks and the forging process results in a saving of material. In addition internal defects, such as blowholes and inclusions, are eliminated thus making fewer rejects of the forged hook and more uniform quality available to the users.

It is an object of the present invention to present a method for mass producing forged choker hooks that are uniform in quality and strength and are able to withstand shock load.

It is a further object of the present invention to present a device for performing the forging of traveling choker hooks.

In the drawings:

FIG. 1 is a side elevational view of a traveling choker hook blank before the upper eye has been formed;

FIG. 2 is'an end elevational view of the device of FIG. 1 as viewed from the right end thereof;

FIG. 3 is an end elevational view of the device of FIG. 1 after a pilot hole has been drilled through the upper end portion of the hook;

.FIG. 4 is a side elevational View of a traveling choker hook after the upper eye has been forged and showing the hook, positioned on 'a cable;

FIG. 5 is an end elevational view of the device of FIG. 4 as viewed from the right end thereof;

FIG. 6 is a top plan View of an apparatus for forging an upper eye of a traveling choker hook with a choker hook positioned for forging before a work stroke has begun; and

FIG. 7 is a "top plan view of the device of FIG. 6 after the completion of the work stroke.

In the use of choker hooks having an eye with a curved upper wall a hoist cable passes through the eye hole and looped around the object to be lifted. The cable end is provided with an eye that is -placed over the hook portion of the choker hook. As the cable is hoisted it slides through the hole in the hook eye and tightens or chokes down onto the object it is lifting. In this manner the object is securely held for lifting. This method is also used for lifting piles of logs as the sliding hook allows the cable to grip the pile firmly and lift the logs as a unit.

Referring to the drawings and the numerals of reference thereon, a traveling choker hook 10 that has been formed in the blank by conventional forging methods in a three stage forging die has a hook portion 11 and an elongated eye portion 12. A hole r13 is drilled through the eye portion 12 parallel to the plane of the hook. The upper wall portion 14 of the choker hook eye is then formed in a curved shape to allow the hook to slide on a cable =15 without bending or kinking the cable.

The hole 13 is transverse to the direction of travel of the forging dies used to form the hook blank and cannot be forged at the time of making the blank.

The upper wall of the traveling choker hook is formed in a forming die .16. The die 16 is fastened in a machine having a bed 20 and a ram block 31 powered with a suitable ram (not shown). A choker hook lit with the drilled hole 13 is heated and placed in position on a locating nest 17 of the forming die 16. The eye portion 12 of the choker hook is adjacent a forming block 18 that is fixedly attached to the forming die and is made with a curved lower surface 19 for forming the upper wall '14 of the choker hook eye.

The forming block 18, locating nest 17 and the choker hook it) are located between a first punch 21 and a second punch 22. The punches 21 and 22 are slidable toward each other and are aligned with the hole 13 in the choker hook eye. Each of the punches is fixedly attached to a punch adapter 23 each of which is slidable in one of a pair of guides 24, 24. Each of the punch adapters has a cam follower roller 25 rotatably attached thereto. First punch 21, its associated punch adapter 23 and roller 25 are positioned to be actuated by a first cam plate 26. Second unch 22, its attached punch adapter 23 and roller 25 are positioned to be actuated by a second cam plate 27. The punches are normally urged apart by a pair of return springs 39, 349 one of which is attached to each of the punch adapters in a manner to urge the punches away from each other and from the forged choker hook.

An adjustment screw 33 is provided to adjust forming block 18 and locating nest 17 to proper position with respect to the punches 21 and 22. Also die wear can be compensated with the adjustment screw.

The cam plates 26 and 27 are attached to ram block 31 of the machine in which the die is placed and the ram block in turn is attached to a suitable source of power such as a hydraulic ram (not shown). The ram block 31 is movable in direction as shown by arrow 32.

Operation With the choker hook blank, having the hole 13 drilled therein, properly positioned in locating nest 17 and with hole 13 aligned with punches 21 and 22 the ram block is actuated by proper mechanism in direction as shown by arrow 32. v The cam plates 26 and 27 act on rollers 25 as they advance and move the respective punch adapters and punches inwardly toward each other. The punches 21 and 22 travel in a direction transverse to the direction of travel of the dies originally used to form the hook blank. As illustrated in FIG. 7, when the ram block has traveled a suflicient distance, the punches 21 and 22 will be forced into hole 13 and the upper wall 14 of the choker hook eye will be formed to the configuration of the lower surface 19 of forming block 18 and the punches 21 and 22. The ram block 31 is then withdrawn and the return springs 30, 30 pull the punch adapters and their attached punches away from the finished choker hook. The choker hook may then be removed and the upper wall will have a configuration as illustrated in FIGS. 4 and 5. With this configuration, a cable can slide easily through the choker hook eye without kinking or bending.

The uniform properties of the forged hooks makes them safer to use and more readily adaptable to quality control and modern inspection methods. There are no internal defects in the forged choker hooks such as blowholes or inclusions that are often found in cast products. The forged inner surface of the upper wall 14 of the choker hook eye is smoother than the previous cast surface and results in less wear on the cable with which the hook is used.

What is claimed is:

1. A method of forming choker hooks including the steps of: forging a choker hook blank having an elongated upper eye portion parallel to the plane of the hook, drilling a hole longitudinally through said eye portion parallel to the plane of the hook, heating said elongated eye portion, placing said eye with the upper wall thereof adjacent a curved forming block, and forcing complementary curved punches into said hole to cooperate with said forming block to form an upper wall of said eye into a longitudinally curved shape the inner wall portions defining said hole closest to said hook remaining substantially straight.

2. A method of forging traveling choker hooks including the steps of: forging a choker hook blank having an elongated eye portion parallel to the plane of the hook, drilling a hole longitudinally through said eye portion parallel to the plane of the hook, heating said elongated eye portion, placing said hook between a pair of aligned punches movable in direction toward each other and parallel to the longitudinal axis of said hole, and actuating said punches to move simultaneously toward each other and to enter said hole to deform the upper wall of said eye into a longitudinally curved shape and hold the wall portions of said eye adjacent the hook straight.

References Cited by the Examiner UNITED STATES PATENTS 1,791,035 2/3 1 Malby 29555 1,924,114 8/33 Evans 29-555 1,931,307 10/33 Taylor 153-32 X 2,027,406 1/ 3 6 Spatta 7863 2,038,165 4/36 Criley 7863 2,642,112 6/53 Schaefer 29551 X 2,917,033 12/59 Brogren 29551 X 2,992,465 7/61 Gale 24-123 X WHITMORE A. WILTZ, Primary Examiner.

HYLAND BIZOT, JOHN F. CAMPBELL, Examiners.

Claims (1)

1. A METHOD OF FORMING CHOKER HOOKS INCLUDING THE STEPS OF: FORGING A CHOKER HOOK BLANK HAVING AN ELONGATED UPPER EYE PORTION PARALLEL TO THE PLANE OF THE HOOK, DRILLING A HOLE LONGITUDINALLY THROUGH SAID EYE PORTION PARALLEL TO THE PLANE OF THE HOOK HEATING SAID ELONGATED EYE PORTION, PLACING SAID EYE WITH THE UPPER WALL THERE OF ADJACENT A CURVED FORMING BLOCK, AND FORCING COMPLEMENTARY CURVED PUNCHED INTO SAID HOLE TO COOPERATE WITH SAID FORMING BLOCK TO FORM AN UPPER WALL OF SAID EYE INTO A LONGITUDINALLY CURVED SHAPE THE INNER WALL PORTIONS DEFINING SAID HOLE CLOSEST TO SAID HOOK REMAINING SUBSTANTIALLY STRAIGHT.

Images