US2412555A - Plate grapple - Google Patents

Description

C. E. BAKER PLATE GRAPPLE Dec. 17, 1946.

Filed Oct. 27, 1943 INVENTOR CHARLES E. BA'KER BY ATTORNEY Patented Dec. 17, 1946 UNITED STATES PATENT OFFICE PLATE GRAPPLE Charles E. Baker, Oakland, Calif.

Application October 27, 1943, Serial No. 507,807

Claims.

The invention relates to a grapple or tongs adapted for use in gripping relatively large metal and other plates for their carrying support, from a hoist line.

A general object of the invention is to provide a grapple of the type described which may be readily attached to and freed from a plate with a minimum of manual effort and a maximum of safety for an attendant.

A more specific object is to simply and efficiently accomplish the general object in a novel grapple structure which utilizes the hoist line for effecting the gripping of a plate by the grapple, or a loading or removed positioning of the grapple, optionally.

Another object is to provide a grapple of the type described which may automatically release a plate from its grip by and upon the support of the gripped plate by another means.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth or be apparent in the following description of a typical embodiment of the invention, and in the accompanying drawing, in which,

Figure 1 is a perspective View showing a present grapple as conditioned and positioned for its mounting on and gripping engagement with a vertically disposed plate.

Figure 2 is an elevation showing the grapple as conditioned and positioned for its operative engagement with a horizontally disposed plate.

Figure 3 is a side sectional elevation showing the grapple as conditioned and positioned during the hanging support of a plate thereby.

Figure 4 is a horizontal view of the grapple as conditioned and positioned in Figure 3.

Figure 5 shows a pair of the present grapples cooperatively applied in the gripping and hanging support of a plate.

The illustrated grapple l embodying my invention comprises a pair of support members 8 and 9 hingedly connected at a pivot pin 2 I and operative in a common plane generally as jaws of a tongs for the gripping and lifting of a plate element 12' through the coaction therewith of a flexible hoist line in the form of a chain l3 providing a part of the grapple assembly, said hoist line being arranged for its. control from a crane or derrick or the like. As particularly shown, the support member 8 comprises a block of uniform thickness and of generally elliptical side outline, and is provided with a transverse slot I i extending into it from What may be conveniently called its lower end whereby th slot l4 boundslaterally 2?. opposed block portions i5 and it connected by an upper block por ion and arranged to receive an edge portion of a plate element or other object for its releasable gripping therein.

In the present grapple structure, the side of the slot I4 bounding the portion it of the member 8 provides a jaw face or abutment ii for cooperation with a jaw face 13 provided by the opposed portion 59 of the member 9 to grip a plate in the slot i4 whereby the portions 15 and i9 comprise jaw portions of the members 8 and 9 respectively. In the present structure, the abutment I? is flat, while the jaw face l8 of the member S is spirally convex with respect to the pivotal axis of the member in a manner to provide a ca-mming grip against the withdrawal from the slot i l of a plate supportedly engaged between the jaws l5 and 19.

The present member 9 extends longitudinally through a slot 25 provided centrally through the portion 16 and extending between the slot face 22 opposite the abutment El and the outer edge 23 of the portion i6, except for a side-connecting part 2 remaining adjacent the free point of I the portion. The pivot pin ii is engaged transversely through the member 5] and the opposed parts of the portion 56 defining the sides of the slot 2i in such a position that, with no plate disposed in the plate-receiving slot M of the member 53, the member Q may be rocked in the slot 2! between limiting positions in which it respectively engages the abutment H or the part 24 as stops. The mem er 9 is understood to constitute a lever of the first class having its jaw portion 2| comprise one arm, while its other arm 25 ex tends beyond the edge 23 for its connection with the chain id, as at a transverse terminal eye 25 of the arm.

An arm 2? extends rigidly from the end of the member 8 opposite the slot it and in transverse relation to the plane of the abutment ll at the same side thereof as the member 9, and said arm is provided with a terminal eye 28 having its axis preferably intersecting the arc of movement permitted the eye 25 of the member 9 with respect to the member 8. A terminal link 29 of the chain I3 is pivotally engaged through the eye 26 of the member ii, and said chain extends through the eye 28 in freely slidable relation thereto whereby the present grapple is arranged for suspension from a chain portion above the eye 28 while the respective jaws i5 and IQ of the members 8 and 9 grip a load element between them or are mutually engaged when no load element is pres ent.

By reason of the disposition of the operative hoist line portion between the eye 23 of the support member 8 and the eye 25 of the support member 9 in spaced and generally parallel relation to the plane of the abutment H, the suspended grapple will have, or tend to have, said abutment oblique :to the vertical whether the grapple is loaded or not. The general disposition of a present grapple supporting a plate l2 solely from one edge is shown in Figure 3, it being noted that the angle oi obliquity of the supported plate, and the grapple abutment ll engaged by it, is determined by the fact that the center of gravity of the freely hanging plate and grapple assembly is disposed in a vertical plane including the hoist line portion above the grapple. Figure 5 shows a pair of grapples 7 operatively applied and cooperative for supporting a relatively heavy and wide plate 8 of metal or other material from a primary hoist line 3! through a spreader assembly 32 and the hoist line chains i3 of the grapples; the line 35 may comprise a wire cable, as indicated. If but one grapple is needed for the line 3!, the chain E3 of a grapple 1 may be directly attached to the line 3! as a continuation thereof.

It will now be noted that the present grapple arrangement by which a suspension support of a loaded grapple from its hoist line disposes, or tends to dispose, the load-engaging jaw abut- Inent ll in oblique relation to the vertical, is desirable for insuring and maintaining an appropriate grip on a supported plate. But the same operative arrangement also disposes an unloaded grapple with the plane of its abutment I! even more oblique to the vertical than when the grapple is loaded, while holding its jaws mutually engaged, whereby certain practical difficulties are presented during a mounting or dismounting of the grapple with respect to a plate to be handled, particularly if the unengaged plate is substantially vertical or substantially horizontal as is most usual in stockpiles of plates. Accordingly, means are provided for facilitating a loading of a suspended present grapple by so supporting and conditioning it that its slot it may freely receive an edge of a positioned plate to be engaged without involving an otherwise required manual twisting of the supported grapple into a platereceiving positioning of the slot i l and a separation of the grapple jaws i5 and l9 for the engagement of the plate between them; both such manual operations involve certain physical efforts and dangers of injury to an attendant for the grapple.

Essentially, the aforesaid means for positioning and conditioning a suspended present grapple for freely receiving a plate for its gripping and lifting comprises the provision of special hoist line connections for a suspension of the grapple assembly in appropriate position directly through the support member 8 while the member 9 is left free for a relative opening of the jaws. In the present instance. such a positioning support of the grapple structure is arranged to be efiected from the chain it, and to that end, hooks are provided at appropriate points of the periphery of the member 8 for selective engagement by a link of the chain beyond the arm 25 of the member 9 while the chain portion between the engaged link and said arm 25 is slack and the chain portion at and above the engaged link comprises, or

5 part of, a hoist line.

The present grapple has been particularly designed for engagement with plates which are either substantially vertical or substantially horizontal, and hooks 34 and 35 are provided on the member 8 at appropriate peripheral points thereof to respectively position the slot M vertical or horizontal when the grapple is supported from a chain link in the described manner. Preferably, and as shown, the hooks 34 and 35 are provided within the generally elliptical outline of the support member 8, have the planes of their loops disposed in the central plane of the member, and are enough narrower than the member that the link which engages them need be no wider than the member.

In the present grapple structure, all but one of the links of the chain l3 are relatively short, and a longer link 36 is provided at such a point of the chain that it may supportingly engage either book while the chain extends through the eye 23 of the member 8. While the link 35 is shown in Figures 1 and 5 as comprising the terminal link of the chain 13 which engages the spreader 32, it may, of course, comprise an intermediate link of the chain is. Also, the link 36 is preferably wide enough to prevent its movement through the eye 23, and generally comprises an eye on the hoist line.

It will now be noted that the support axis of the hook 34 is so related to the member 8 that the link 35 will suspendingly and swingably support the grapple assembly below the link to dispose the plate-receiving slot i l of the member 8 in a plane parallel to that of an upright plate !2 to be engaged at its top; as illustrated in Figure 1, said plate is in vertical position. When an upright plate i2 is to be gripped by a grapple I having the hoist line link 36 supportingly engaged with its hook 3d, the line-supported grapple is lowered to receive and rest upon the plate in its slot l4 while an attendant at the grapple guides the descending grapple into plate-receiving position merely by swinging it and/or rotating it about the hoist line axis as may be needed. When the grapple rests upon the top plate edge, the hoist line is slacked off enough to permit the attendant to manually release the link 36 from the hook 34. A subsequent raising of the hoist line ellects a rocking of the camming member 9 with respect to the member 8 to efiect a preliminary gripping of the plate edge between the jaws l5 and I 9, while the continued raising of the line thereafter lifts the grapple and the engaged plate. It will be noted that the final tightening of the camming jaw l5 raises the grapple slightly with respect to the plate, the latter being shown in Figure 3 which discloses the oblique positioning of the fully suspended plate l2.

When the present grapple is to be used for lifting a plate l2 supported in prone position with an edge portion free for its gripping by the grapple, the grapple may be suspended by its hook 35 from the hoist line link 36 and with its slot it opposite said plate edge portion as is shown in Figure 2. It will be understood that the position of the hook 35 on the member 3 is such that the slot H3 is horizontal when the rapple assembly below the link 35 is supported from said link by the hook. Having the slot i4 positioned opposite the plate edge, an appropriate lateral movement of the hoist line and/or its manual swinging may engage the plate edge in the slot, after which a slacking off of the hoist line to provide for the support of the grapple on the upper plate side permits a release of the link from the hook 35. A lifting on the hoist line then operates the member 9 to grip and lift the plate. If the horizontal plate is engaged by one or more grapples I solely along one edge thereof, the plate. when lifted clear, will assume the general position shown in Figure 3. On the other hand, if a grapple l issimultaneously rendered operative at an opposite edge part of the plate, the plate may be lifted while supported in horizontal position. In any case, the hoist line pro vides the gripping action of a grapple while a plate is supported thereby.

When a present grapple I is supported by the direct connection of the member 8 to the hoist line, as at the hooks 34 or 35, the hoist line portion between the connection and lever arm 25 is slack to permit a rocking of the member 9 to dispose its jaw out of the slot I l; under the conditions of Figure 1, the hoist chain portion below the link 36 automatically accomplishes the latter by gravity. Also, when a gripped plate l2 which has been supported by a present grapple, or grapples, in upright position, is set down edgewise upon an underlying support, the resulting upward movement of the plate in the slot 14 releases the cam grip of the grapple jaw 19 and permits a gravity cam-release rocking of the member 9 to inoperative position, both by reason of its own form and the weight of the hoist chain portion then supported by it.

When a plate which has been supported horizontally is set down in horizontal position, the slacking off of the hoist line permits a manual release of the camming jaw [9 to allow the manual pushing or hoist line swinging of the grapple laterally from the plate. While the hoist line is still slack with respect to the grapple, the link 36 would be reengaged with the appropriate hook 34 or 35 whereby a subsequent raising of the hoist line will lift the freed grapple in position and condition for its gripping engagement with the. next plate to be handled.

Noting that the use of a common hoist line for supporting the present grapple in position and condition for its loading and in its plate-carrying condition is generally preferable for minimizing the amount of equipment needed, it will be understood that separate hoist lines might be provided for alternatively supporting the grapple in the different said conditions. The latter arrangement would, of course, require the provision of two separate hoist line mounts and controls with the derrick or crane utilizing a present grapple. but would eliminate any requirement for manually making or breaking the connections for the lines for the different manners of supporting the grapple.

In view of the foregoing description and discussion respecting the manipulation of the presgrappie during and preparatory to its use, it will be understood that the required manual handling of the grapple assembly, which may Weigh ninety pounds more or less, in mounting and lifting and releasing a load require a minimum of muscular effort by an attendant and involve a minimum risk of personal injury, particularly since all usually required operations are performed While the hoist line is slack.

From the foregoing description, taken in connection with the accompanying drawing, the d vantages of the construction and use of the present grapple will be readily understood by those skilled in the art to which the invention appertains. While I have described the features and use of an arrangement which I now consider to be a preferred embodiment of my invention, I desire to have it understood that the showing is primarily illustrative, and that such indicated and other changes may be made, when desired, as fall within the scope of the following claims.

I claim:

1. In a plate-lifting grapple or the like for support from a hoist line. a unitary support member providing an abutment against which a plate to be lifted may be pressed and providing an eye spaced from the plane of the abutment having its plane transverse to the abutment plane, a second support member pivoted to the first member at a point thereof opposite the abutment and comprising a lever-providing a head for plate-gripping coaction with the abutment and providing an operating arm arranged for its connection to a hoist line extending slidably through the eye for efiecting a gripping and support by the grapple assembly of a plate or the like disposed between the abutment and head thereof upon a tensing and raising of the line, and plural hoist line connection means provided by the first member in fixed relation thereto for selective'use and so located on the member that the unloaded grapple supported on a hoist line from said connection means will have its abutment disposed in the same angular relation to the vertical as that of a plate to be gripped and lifted by the grapple, support of the unloaded grapple from the different said means being arranged to dispose the abutment in mutually difierent relations to the vertical.

2. In a plate-lifting grapple or the like for support from a hoist line, a unitary support member providing an abutment against which a plate to be lifted may be pressed and providing an eye spaced from the plane of the abutment, a second support member pivoted to the first member and providing a camming head for plate-gripping coaction with the abutment. an arm connected with the camming head member for actuating the same and arranged for its connection to a hoist line extending slidably through the eye for effecting a gripping and support by the grapple assembly of a plate disposed between the abutment and camming head upon a tensing and raising of the line, and means on the first member providing a plurality of hoist line connections at different points of the member for effecting the direct support of th unloaded grapple assembly from a selected said connection point, support of the unloaded grapple from the different said points being arranged to dispose the abutment in mutually different relations to the vertical.

3. In a plate-lifting grapple, a unitary support member providing an abutwent against which a plate to be lifted may be grippedly pressed and an eye spaced from the plane of the abutment, a second support member hinged to the first at a point thereof opposite the abutment and comprising a lever providing an operating arm and a head for plate-gripping coaction with the abutment, flexible hoist line comprising a link chain extending from the arm of the second member and slidably through said eye of the first member for effecting a gripping and support of a plate engaged between the abutment and head upon its ten'sing and raising, and a hook on the memher for engaging a link of the hoist line for the support from the hoist line of the unloaded grapple independently of the second member and to dispose the abutment of the line-supported grapple in a different and predetermined angular relation to the vertical than that assumed by the abutment while the suspended grapple supports a plate.

4. In a plate-lifting grapple or the like, a unitary support member providing an abutment against which a plate to be lifted may be grippedly pressed and providing an eye spaced from the lane of the abutment, a second support member pivoted to the first and providing a camming head for plate-gripping coaction With the abutment. an arm connected with the camming head member for actuating the same, a hoist line comprising a link chain extending from the arm and slidably through the eye for efiecting a gripping and support by the grapple assembly of a plate disposed between the abutment and camming head upon a tensing and raising of the line, and a hook on the first member engageable with a link of the hoist line to directly and releasably connect the member and line for the support of the grapple from the line independently of the second member, support of the unloaded grapple by the hoist line from the second member or from said connections on the first member beingarranged to dispose the abutment in mutually different relations to the vertical.

5. .In a plate-lifting grapple or the like for support from a hoist line, a unitary support member providing an abutment against which a plate to be lifted may be pressed and providing an eye spaced from the plane of the abutment, a second support member pivoted to the first member and c providing a camming head for plate-gripping 00- action with the abutment, an arm connected with the camming head member for actuating the same and arranged for its connection to a hoist line extending slidably through the eye for effecting a gripping and support by the grapple assembly of a plate disposed between the abutment and eamming head upon a tensing and raising of the

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