US3333412A

US3333412A - Double-clawed shortening hook

Info

Publication number: US3333412A
Application number: US310822A
Authority: US
Inventors: Rieger Werner
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-09-21
Filing date: 1963-09-23
Publication date: 1967-08-01
Anticipated expiration: 1984-08-01

Description

1967 w. RIEGER 3,333,412

DOUBLE-CLAWED SHORTENING HOOK Filed Sept. 25, 1963 3 Sheets-Sheet 1 #vmvmq WERNER RIEGER ATTORNEY 1, 1967 w. RIEGER 3,333,412

DouBLE-cLAwED SHORTENING HOOK Filed Sept. 23, 1963 5 Sheets-Sheet 2 //vv/vr0/? WERNER RIE R ATTORNEY 1967 w. RIEGER 3,333,412

DOUBLE-CLAWED SHORTENING HOOK Filed Sept. 23, 1963 5 Sheets-Sheet 3 F ig.4

lNVE/VTOR WERNER RIEGER ATTORNEY United States Patent l 3,333,412 DOUBLE-CLAWED SHORTENING HOOK Werner Rieger, House Haeselhach, Unterkochen, Wurttemherg, Germany Filed Sept. 23, 1963, Ser. No. 310,822 Claims priority, application Germany, Sept. 21, 1962, R 33,547 Claims. (Cl. 59-93) This invention relates to a forked or double-clawed hook for shortening chain strands.

To shorten chain strands, more particularly those consisting of straight links, hooks are known which, as shown e.g. by the German Patent 830,449, are characterized by two hook-shaped parts, extending parallel to each other to define a forked-claw. To prevent undesirable protrusion of the hook from the chain a definite dimensioning of the forked-claw is necessary, in particular when the shortening hook is required to work with a short-linked, so-called quality chain. Experience shows that in such cases very favorable conditions are created when the outside length of the :hook claw, measured from the underedge of the hook to the claw point, is dimensioned to the formula 1-Z2d, 2 representing the chain pitch and d the strength of the material.

Hitherto shortening hooks of the type described have been made by first forging a flat piece or blank having a suspension eye in its upper end and a forked lower end portion and finally bending back and upward by 180 the forked lower end portion to form the forked claw or parallel hook-shaped parts. This method is rather nnsatisfactory, mainly because great bending forces are required, and further because considerable dimensional tolerances and resulting inaccuracies in the shape of the forked-claw arise during the bending of the forked lower end portion of the blank.

The invention achieves its aim of abolishing these disadvantages by dropforging the hook as a single piece or blank which is symmetrical with respect to a longitudinal medial axis and which has a central portion and side portions extending from the opposite sides of the central portion and formed with hook-shaped lower parts of the desired final configuration. The forged blank is then folded about its longitudinal medial axis so as to bring the side portions into substantially parallel, spaced planes at which the pre-formed hook-shaped parts define the forked-claw of the hook. The folding operation can be simply and accurately performed in a swage, without the need of particular care or special tools.

Beyond this the invention offers the possibility of joining the claw ends to the corresponding side portions of the hook by means of integral webs so that the hook can be given a greater spread angle than hitherto without fear of the forked-claw tending to straighten out or spread under the load.

As a result of the webs closing the hook-shaped parts there is the further advantage that the links of the chain suspended in the hook can be secured against mutual displacement, such, as would be necessary to lift them from the shortening hook, by means of a bent wire, hairpinshaped locking member extended through openings of the hook-shaped parts or forked-claw past a chain link engaged by the forked claw and being resiliently stressed against the webs by the next link of the chain.

Further details of the invention are shown in the drawing, which illustrates an exemplary design, and wherein;

FIG. 1 shows a front elevational view of the novel shortening hook.

FIG. 2 is the front view of the flat drop-forged workpiece or blank from which the finished shortening hook is bent.

3,333,412 Patented Aug. 1, 1967 FIG. 3 is a side elevational view of the blank of FIG. 2.

FIG. 4 is a part top view and part sectional view of the forged blank taken along the line 4-4 on FIG. 2.

The shortening hook forming the subject of the invention consists of a central portion 5 and two

side portions

6, 7 extending forwardly from the opposite sides of central portion 5 in substantially parallel, spaced planes, and having hook-shaped

lower parts

8, 9 which define a forkedclaw. The upper parts of

side portions

6, 7 have aligned holes 15 (FIG. 2) receiving a bolt 10 (FIG. 1) so that this bolt will pass through a chain link (not shown) disposed between

portions

6, 7 for suspending the book from a chain.

In order to illustrate the action of a shortening hook of the type under

consideration chain links

11, 12, 13 are shown on FIG. 1 with the link 12 resting on the

hookshapcd parts

8, 9 and extending laterally therebetween into the slot-

like openings

16, 17, and with the next link 13 passing downwardly between hook-

shaped parts

8, 9 in a plane generally parallel to the latter.

The starting point for making a hook in accordance with the invention is the workpiece or blank shown in FIGS. 2, 3 and 4. This workpiece or blank is a single, wholly drop-forged piece, characterized by its symmetrical relation to the longitudinal medial axis 14. The forged blank has a central portion and

side portions

6, 7 which extend to the left and right from central portion 5. The upper part of each of

side portions

6, 7 has a hole 15 to accommodate the suspension bolt 10. The lower parts of the side portions form the claws or hook-

shaped parts

8, 9, which thus are forged from the beginning in their final form and disposition. Each hook-shaped part includes a bight portion extending from the related side portion -6 or 7 and terminating in a

bill

21 or 22 which is directed generally parallel to the adjacent edge of the side portion. Thus, the

openings

16, 17 of the hook-shaped parts are limited by substantially

parallel walls

18, 19, and the longitudinal axis 20 of each opening runs somewhat obliquely to the longitudinal medial axis 14 of the blank.

In a preferred embodiment of the invention the

openings

16, 17 of the hook-shaped parts do not open at the top; instead there runs between each

side portion

6 or 7 and the upper end of the bill 21 or 22 a connecting

web

23, 24. In this way the hook-

shaped parts

8, 9 are prevented, even under a heavy hook load, from tending to straighten, which in turn allows each hook-shaped part to be made with a relatively great angle between the axis 20 of its

opening

16, 17 and the longitudinal medial axis 14.

The generally fiat blank which can be forged without difiiculty in a swage is after completion simply pleated or folded about the longitudinal medial axis 14 so that the

side portions

6, 7 and the hook-

shaped parts

8, 9 thereof lie parallel to each other, as shown in FIG. 1. A simple operation produces a shortening book of very accurate shape, great accuracy of dimension and extraordinary mechanical strength, whose installation and use are absolutely simple.

In many cases it may be useful to use a locking member which renders it impossible for a chain suspended in the hook to become detached therefrom, even under unusual working conditions. The nature and the possibility of using this locking device result from the provision of the webs 23, 24 (FIG. 2), which close the upper ends of the

openings

16, 17. The locking member 25 shown in FIG. 1 can be pushed through these openings and includes a hairpin-shaped locking loop 26 which can pass either in front or in back of the link 12 and a lateral stop 27 which extends from one end of loop 26 and can be fastened e.g. to bolt 10 by a small chain or the like, 28.

The upper leg of loop 26 bears against

webs

23, 24 and the lower leg of the loop bears against the top of link 13, so that spring action of locking loop 26 prevents the

chain links

11, 12 and 13 from being displaced upwardly relative to the forked-claw of the shortening hook, thus securely locking the shortening hook to the chain.

The nature of the invention naturally does not depend on the detailed structural configuration of the hook, as shown exemplarily particularly in FIG. 2. It also fulfils the preference only when the dimensioning of the jaw of the hook accords with proportions stated at the beginning.

What I claim is:

1. A shortening hook for chains comprising a one-piece forging including a central portion and side portions extending symmetrically from opposite sides of said central portion and each having a hook-shaped lower part, said side portions being folded about the longitudinal medial line of said central portion into substantially parallel, laterally spaced planes at which said hook-shaped parts of the side portions define a forked-claw for engaging a chain link.

2. A shortening hook according to claim 1; wherein each of said side portions has a body and said hookshaped lower part includes a bight extending from said body and terminating in a bill spaced from said body; and wherein each of said side portions further has an integral web connecting the end of said bill with said body to prevent spreading of each hook-shaped part by a load applied to said forked-claw and to laterally position a chain link engaged by said claw.

3. A shortening hook according to claim 2; wherein said side portions have laterally aligned holes in upper parts thereof to receive a bolt by which the hook can be connected to a chain link disposed between said upper parts of the side portions.

4. A shortening hook according to claim 2; wherein each of said side portions has an opening defined by said hook-shaped lower part and said web; and further comprising a bent wire, hairpin-shaped locking member dimensioned to extend through said openings of the side portions past a chain link engaged by said forked claw and to be resiliently stressed between said webs and the next link of the chain.

5. A shortening hook according to claim 1; wherein said side portions have laterally aligned holes in upper parts thereof to receive a bolt by which the hook can be connected to a chain link disposed between said upper parts of the side portions.

References Cited UNITED STATES PATENTS 2,027,376 1/1936 G-rav 294- 82 2,043,460 6/1936 Young 294-78 2,179,564 11/1939 Smith S9--93 2,878,640 3/1959 Johnson 59--93 FOREIGN PATENTS 830,449 2/ 1952 Germany.

CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner.

Claims

1. A SHORTENING HOOK FOR CHAINS COMPRISING A ONE-PIECE FORGING INCLUDING A CENTRAL PORTION AND SIDE PORTIONS EXTENDING SYMMETRICALLY FROM OPPOSITE SIDES OF SAID CENTRAL PORTION AND EACH HAVING A HOOK-SHAPED LOWER PART, SAID SIDE PORTIONS BEING FOLDED ABOUT THE LONGITUDINAL MEDIAL LINE OF SAID CENTRAL PORTION INTO SUBSTANTIALLY PARALLEL, LATERALLY SPACED PLANES AT WHICH SAID HOOK-SHAPED PARTS OF THE SIDE PORTION DEFINE A FORKED-CLAW FOR ENGAGING A CHAIN LINK.