WO1979000396A1

WO1979000396A1 - Anti-fouling latched sling hook

Info

Publication number: WO1979000396A1
Application number: PCT/US1978/000219
Authority: WO
Inventors: E Crook
Original assignee: American Hoist & Derrick Co
Priority date: 1977-12-15
Filing date: 1978-12-15
Publication date: 1979-07-12
Also published as: EP0007906A1; GB2036157B; EP0007906B1; DE2857269C1; GB2036157A

Abstract

Anti-fouling sling hook (10) with latch (32) that comprises a forged hook (12) of selected design to provide a wider curved surface in the throat (48) of the hook to provide a better bearing surface for a cable, and an improved design of hook (10) and latch (32) so that the latch is of greater strength and, in closed position, straddles a projecting stub (22) on the tip (20) of the hook, which resists any outward or sidewise movement of the latch. The latch is also designed to provide a smooth contour in conjunction with the outer surface of the hook and hook tip, so as to be anti-fouling.

Description

Anti-Fouling Launched Sling Hook Background of the Invention This invention lies in the field of lifting hooks. More particularly, it concerns a design of lifting hook that has a spring-controlled latch across the throat of the hook, that is of forged construction, to provide ample strength.

Known Patent References: United States:

1,324,676 Knudsen Safety Hook 1,525,292 Greve Safety Hook 2,657,446 Roberts Safety Snap Hook 2,764,792 Mansfield Pelican Type Mooring Hook 3,261,636 Pierre Clevis and Grab Hook 3,575,458 Crook, Jr. Hook and Latch with Lock 3,653,102 Crook, Jr. Hook with Gate 3,674,301 Crook, Jr. Hook and Collar with Gate 4,007,957 Roden Hook Assembly 4,013,314 Archer Lifting Hooks

Canadian: 982,326 Crook, Jr. Safety Hook Swiss:

422,266 Iseli et al

British: 804,454 Cruse et al Improvements in or Relating to

Hoisting or the like Hooks

Description of the Prior Art

Hooks used as parts of chains, or wire rope, slings, usually have an eye or clevis-type of attachment con¬ struction. - Many times the sling consists of two or more legs in order to adequately secure the load. Slings are constructed so that the one or more legs are joined to a large ring or link. This link or ring is then the attach¬ ment point of the sling to the prime mover. It can be visualized that the sling can be used to be attached to all configurations of load by direct connection of the hook to the load, or in a choker situation. The sling will be slack at the time of attachment to the load, and keeping the hook connected to the load or in the choker configuration

t~_> reguires a latching device.

Also, in the possible mishandling of a load, the hook may inadvertently become disengaged and, therefore, there is a necessity for a positive latching device. It is also apparent that, because the sling is a very portab apparatus, it is subject to much abuse of handling and, therefore, the hook latch must be of a substantial con¬ struction, the latch must be protected, and the contour of the hook and latch must avoid discontinuities that can snag on obstacles, and cause possible failures of the hoo cable, or lifting situation.

Summary of the Invention It is a primary object of this invention to provide a latched hook of greater strength/weight ratio, with a positive spring-operated latch, whcih is hinged at the shank of the hook and, at the moving end, straddles a projecting stub on the tip of the hook, which prevents any outward or sidewise movement of the latch. The latch is designed to provide a smooth, contoured outer face to the hook tip, so as to be anti-fouling. The latch is further designed so that, when it is full opened, it straddles the hook shank, and thereby provides maximum throat opening of the hook. In open and closed positions of the latch, the latch does not project beyond the extremities of the hook and vice-versa. Thus, the latch provides good protection, and cannot be snagged on objects.

Brief Description of the Drawings These and other objects and advantages of this invention and a better understanding of the principles and details of the invention will be evident from the following description taken in conjunction with the appended drawings, in which:

FIGURE 1 represents a side elevation of the latche hook.

FIGURES 1A, IB, 1C, ID, IF, 1G, 1H, and II represe cross-sectional area and contours, at various points ar the eye, the shank, and the tip of the hook.

FIGURE 2 indicates a front elevation of the hook. FIGURES 3A, 3B, 3C, and 3C represent various side end views of the hook latch.

WIP Description of the Preferred Embodiment Referring now to the drawings and, in particular, to FIGURES 1 and 2, there is^" shown a side and front elevation of the latched hook, respectively. The hook is of J-shaped construction, which is con¬ ventional in the industry. The upper portion provides a ring 13, which encloses an eye 14 or a vertical shaft 14B (see Figure 4) through which a cable or clevis can be attached for supporting the hook. There is a shank portion 16 connected to the ring 13, which -connects to the lower body portion of the hook, indicated generally by the numerals 12, which, on its inner surface 36, supports a cable or chain or other lifting device (not shown) . The J portion of the hook continues upwardly to a tip 20, leaving an open mouth to the hook, with a throat space having an internal surface 36.

The mouth of the hook is closed, in the operating condition, by a latch or catch, indicated generally by the numeral 32. This latch is hingedly supported b a pin 26 at its first end, and is urged outwardly by a spring 44, ^• which closes the mouth of the hook, between the ring portion 13 and the tip 20. Thus, a smooth contour is pro¬ vided from the top of the ring 13 along a sloping ridge 30 along the outer surface 60 of the latch and down the outer surface of the tip of the hook.

The hook is of forged manufacture and embodies a, more or less, continually varying cross-sectional shape, and area, for purposes of conserving the mechanical strength of the hook while minimizing the weight of the hook, and the amount of material required.

Inside the mouth of the hook, at the shank, there is a narrowing in the form of a ridge 24 which at its upper end has an opening 28 which supports a pin 26, about which the latch 32 can rotate. Around the hook is shown a number of cross-sections, indicated as FIGURES 1A, IB, 1C, ID, IE, IF, 1G, 1H and II. These cross-sections are taken across the corresponding planes A-A, B-B, C-C, D-D, E-E, F-F, G-G, H-H, and I-I. The cross-section in the lower portion of the hook, REAT "

OMPI ^~ which has a relatively wide throat 48, has a bearing sur face 36, which is broad and of relatively long radius of curvature. The purpose of this is to provide broad-base support for a cable that is hooked over the tip of the hook, and supported on the surface 36. The cross-sectio shown in FIGURE 1A illustrates this broad curved portion 36 having a width out to the extremities 38. The cross- section then narrows to a neck 40 and to rib 18, which extends for a substantial length of the cross-section, to provide a stiffening for the hook, so that the load pulling down on the surface 36 will not bend the tip 20 in a downward direction. The width of the portion 38-38 and the length 36-42 are of the required strength of the hook, to minimize the deformation of the hook under load This is shown by the FIGURES II, 1A and IB.

Along the shank of the hook, as illustrated by FIGU 1C and ID, the shank 16 narrows, and a rib 24 forms as previously described. Because of the small size and closed perimeter of the ring.13, a reduced cross-section area can be provided, FIGURE IE.

Above the open mouth of the hook there is a wide sh 34 of the shank so as to protect the latch. This is pro vided with sizeable fillets on the top, and a sloping ri so as to provide a non-snagging condition of the shelf 3 On the top of the tip 20 there is a short post or s extension 22. This is for the purpose of locking the la against outward movement under the urging of the spring, also, because of the construction of the latch. It also permits the latch to resist sidewise movement, which mig otherwise deform the latch, and cause it to open the mou of the hook.

Referring now to FIGURES 3A, 3B, 3C, and 3D, there shown a side elevation 3A, a top plan view 3C, an end vi 3B, and a sectional 3D, taken across the planes C-C, B-B and D-D, respectively.

The construction of the latch comprises a plane bas 'portion 50 of selected length and width. There are two downwardly depending ribs 52 and 54 attached to the base and there are two upwardly rising ribs 56 and contour is a, more or less, sloping surface 60, which encloses a groove 62 between the ribs 56 and 58. On the underside there is a groove or channel 64 between the two ribs 52 and 54. The channel 64, having the ribs 52 and 54 spaced apart, are provided to swing over the rib 24 of the shank of the hook against the spring pressure 44, in order to open the mouth of the hook, This condition is shown in FIGURE 1 by the dashed outline 32*, showing a width of mouth opening indicated by the dimension 46. After a cable or ring or other fixture has been placed over the tip 20 and hangs in the throat of the hook supported by the surface 36, the spring urges the latch outwardly in the position shown in FIGURE 1, where the channel 62 encloses the stub portion 22 of the tip 20, on three sides, by the base 50 and ribs 58 and 56, respectively. This is shown clearly in FIGURE 1G. Thus, a smooth contour from the top ring 13, along the ridge 30, along the surface 60 of the latch and then along the smooth outer contour of the tip 20 is pro¬ vided. There is no portion of the hook or latch which, as shown in FIGURES 1 and 2, offer any ledge or step that might snag the hook while in use.

What has been described is an improved lifting hook that has a latch of adequate strength, which is guided in such a way as to resist side and outward forces, and which has a smooth contour with the hook, to avoid snagging.

The hook is also designed with an improved shape and cross-section in order to provide a wider bearing surface for a cable sling that might be hooked over the tip of the hook, and to provide adequate strength to resist deformation under excess load.

While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrange¬ ment of components. It is understood that the invention is not to be limited to the specific embodiments set forth herein by way of exemplifying the invention, but the invention is to be limited only by the scope of the attached claims, including the full range of equivalency

OMPI

^ r\ϋ

to which each element or step thereof is entitled. For example, although this invention has been described rel tive to an eye-hook, it is to be understood that the invention is applicable to other types of hooks; for example, shank hooks, clevis hooks, etc., the basic improvement over the prior art being the provision of a hook having a relatively clean profile, eliminating par that protrude or extend outward from the normal contour of the hook.

Claims

1. In a lifting hook having a shank portion, connected to a body portion encircling a throat, and extending up¬ wardly as a tip, defining an open mouth between said tip and said shank, said mouth adapted to be closed by a hinged latch, the improvement comprising:

(a) a stub vertical extension of reduced cross- section on the top of said tip;

(b) said latch constructed in the form of a rectangular plate having spaced apart parallel flanges on its inner side, forming a first channel, and having a second pair of spaced parallel rigs on its outer side of said plate, forming a second channel;

(c) said latch rotatable at a first end, about a pin supported on said shank; whereby when said latch is open, said first channel straddles said shank;

(d) spring means to normally maintain said latch across said mouth in a closed position, with said second channel of said latch straddling said stub extension, whereby said latch resists outward and sidewise forces.

2. In a lifting hook having a shank portion, connected to a body portion encircling a throat, and extending upwardly to a tip, defining an open mouth between said tip and said shank, said mouth adapted to be closed by a hinged latch; the improvement comprising a recessed ridge along the throat side of said shank portion; a stub vertical extension of reduced cross-section on the top of said tip; said latch constructed in the form of a rectangular plate having spaced apart parallel flanges on its inner throat side, forming a first channel, and having a second pair of spaced parallel ribs on its outer side of said plate forming a second channel; said latch rotatable at a first end about a pin supported by said inner ridge, whereby when said latch is open said first channel straddles said inner ridge so as ^■ to be at least flush with the contour of said shank portion;

3. The lifting hook, as in claim 2 , wherein said hook includes, as a part of said shank, an eye.

4. The lifting hook as in claim 3, wherein said eye comprises an upper circular half connecting to downwardl and inwardly shaped side^'s to a point of curved connectio between the two.

5. The lifting hook as in claim 2, wherein said shank portion of said hook includes a vertical shaft.

-_BURE