US2987792A

US2987792A - Safety latch for lift hook

Info

Publication number: US2987792A
Application number: US799946A
Authority: US
Inventors: John F O'brien
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1959-03-17
Filing date: 1959-03-17
Publication date: 1961-06-13
Anticipated expiration: 1978-06-13

Description

June 13, 1961 J. F. O'BRIEN SAFETY LATCH FOR LIFT HOOK Filed March 17, 1959 INVENTOR //JOHN E O'BRIEN m B, wflw Attorney United States Patent 2,987,792 SAFETY LATCH FOR LIFT HOOK John F. OBrien, Midlothian, 111., assignor to United States Steel Corporation, a corporation of New Jersey Filed Mar. 17, 1959, Ser. No. 799,946 2 Claims. (Cl. 24-241) The present invention relates generally to lift hooks and more particularly to an improved safety latch for lift hooks.

It is a primary object of the present invention to provide a safety latch for a lift hook which can be quickly and easily installed on presently existing lift hooks without weakening the lift hook in any manner.

Another object of the inventionis to provide a safety latch for a lift hook above which includes positive retention means for securing the safety latch in latching position.

A further object of the invention is to provide a safety latch of the character set forth in the preceding objects which can be easily and quickly removed from a lift hook when desired without impairing the hook.

These and other objects will become more apparent after referring to the following specification and attached drawings, in which:

FIGURE 1 is a side elevational view with a part broken away for clarity of a lift hook having the safety latch of the invention installed thereon;

FIGURE 2 is a plan view of the safety latch ring of the invention; and

FIGURE 3 is a view similar to FIGURE 1 showing a modified embodiment of the invention.

Referring more particularly to the drawings reference numeral 2 designates generally a lift hook having a preferred embodiment of the invention installed thereon. The hook 2 is conventional in shape and includes a shank 4, a main load-supporting body portion 6, and a bill 8. A throat is defined between and by the bill 8 and the shank 4. The bill is provided with a transverse hole 12. The hole 12 has no weakening efiect upon the hook since it is remote from the main load-supporting body portion 6 in a portion of the hook which is not affected by strain when a load is suspended therefrom.

The safety latch of the invention includes a split ring collar 16 detachably mounted on the shank 4 by nut and bolt means 18. The collar 16 is so mounted that it slants in the direction of the bill 8 for a purpose which will become apparent. An elongated substantially rectangular metal ring 20 is fitted on the shank 4 above the collar 16. The width of the ring 20 is less than the outside diameter of the collar 16 so that the collar prevents the ring from moving down the shank of the hook. The length of the ring 20 is greater than the diameters of the shank 4 and the main body portion 6 so that when the collar 16 is removed from the shank 4, the ring may be easily slid down the shank along the main body portion 6 and over the hill 8 to be removed from the hook.

One end of the ring 20 is rounded as at 22 to conform with the contour of the shank 4 and the opposite end is straight as at 24. A tongue projection 26 extends from the end 24 of the ring and is adapted to fit into the hole 12 when the safety latch is in operative position spanning the throat 10 as shown in FIGURE 1. To open the throat 10 so that a cable or other load may be removed from the hook 2, the ring 20 is moved in the direction away from the bill 8 to remove the projection 26 from the hole 12 and then turned 180.

The tilted position of the collar 16 upon which the ring 20 is supported serves to cause the tongue projection 26 to remain in the hole 12 when the hook is in upright position. In order to insure retention of the ring 20 in latching position a spring-loaded pin 28 is attached to the 2,987,792 Patented June 13, 1961 ice collar 16 in a block 30 which is welded or otherwise mounted on the portion of the collar remote from the bill 8. The pin fits loosely in a hole in the block 30 and is urged downwardly by a compression spring 31 which bears against the collar 30 at one end and the enlarged head of the pin at its other end. The upper portion of the pin is curved so as to be able to engage the end 22 of the ring 20 when the ring is in latching position, as shown in FIGURE 1. When it is desired to move the ring 20 to inoperative position the pin 28 is lifted slightly to disengage it from the ring 20 and turned at least degrees. The tension of spring 31 then pulls the pin downwardly so it is out of the way of the ring 20. The ring may then be moved away from the bill 8 to withdraw the tongue projection 26 from the hole 12 and turned to inoperative position.

In operation, the ring 20 is applied to the hook by passing it over the hill 8, the main body portion 6 and up along the shank 4. The collar 16 is then mounted on the shank 4 to support the ring 20 as described above. The ring then may be put in latching position by moving it so that the tongue projection 26 is positioned within the hole 12. After the ring is in latching position the pin 28 may be raised against the tension of spring 31 and turned to engage the end 22 of the ring and thus positively lock the ring in latching position.

FIGURE 3 illustrates a modified embodiment of my invention in which the latch member consists of a chain 32 which is welded or otherwise fixedly connected to the collar 16 by one end. The opposite end 33 of the chain 32 carries a rigid tongue projection 34 which is provided with a transverse hole 36 therethrough intermediate its ends. A flexible branch 38 of the chain extends from its end 33 adjacent the tongue projection 34. A rigid tongue projection 39 is carried by the free end of the branch 38. The bill 8 of the hook is provided with a longitudinal hole 40 which projects inwardly from the tip of the bill and intersects the transverse hole 12 to accom modate the projection 40.

In operation, the chain 32 is put into latching position by extending it across the throat 10 and inserting the tongue projection 34 into the transverse hole 12. Then the tongue 39 is inserted through the hole 40 into the hole 36 of the tongue projection 34. Thus, the chain is positively locked in latching position. To remove the chain from latching position the tongue projection 39 is removed from the holes 36 and 40 and the projection 34 is withdrawn from the transverse hole 12.

While two embodiments of my invention have been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A safety latch for a lift hook having a shank, a main load-supporting body portion, a bill, and a throat defined between and by said shank and said bill, said safety latch comprising a latch member adapted to extend across said throat between said shank and said bill, a split collar detachably secured around said shank opposite said bill and adjacent said throat, said collar being disposed with its upper surface inclined downwardly toward said bill when said hook is in upright position, said bill having a hole therethrough substantially aligned with the inclined surface of said collar, said latch member including an elongated rigid ring, said ring having two parallel sides, and a first end and a second end connecting said sides, said sides and said ends being coplanar, a tongue projecting from said first side outwardly of said ring coaxially with the longitudinal axis of said ring, said tongue being integral with said ring, said ring encompassing said shank and resting on the inclined surface of said collar at said second end, the first end of said ring being disposed in the 3 throat of said hook adjacent the hole in said bill, said tongue projecting into the hole in said bill, the width of said ring being less than the diameter of said collar and greater than the thicknesses of said shank and said body portion, respectively, in the direction normal to the plane of the hook and the length of said ring being greater than the diameters of the shank and body portion of said hook, respectively, whereby the ring can pass overtthe shank and body portion in the direction toward the bill of the hook to be removed therefrom after the collar has been removed from the shank, the length of said ring exclusive of said tongue being less than the distance from the inner side of said bill to the outer side of the portion of said shank adjacent the inclined upper surface of said collar.

2. A safety latch as defined by claim 1 in'which a pin is carried by the portion of the collar remote from the bill of the hook for movement parallel with the axis of the collar, said pin having an angular upper portion adapted to engage a portion of said ring to retain it in latching position when the ring is in latching position and said tongue is received in the hole in the bill.

References Cited in the file of this patent UNITED STATES PATENTS