US2360602A - Plate clamp - Google Patents

Description

Oct' 17, 1944' Y R. s. 4WALDRUP 2,360,602

PLATE CLAMP Filed Feb. 19, 1944 Patented Oct. 17, 1944 UNITED STATES PATENT OFFICE PLATE CLAMP Rodney rSv. Waldrup, Houston, Tex. l Application February 19, 1944, serial No. 523,714.7

. Claims'.

rThis invention relates to a clamp and has particular relation to that type of clamp specially designed for handling heavy metal plates and the like.

The invention herein described embodies certain improvements over that type of clamp disclosed in my copending. application filed lin the United States Patent Office on November l5, 1943 under SerialNo. 510,414.

An object of the invention is to provide a clamp composed of a frame having opposing pivotally mounted jaws for gripping the plate to be lifted with means for temporarily latching one of said jaws in inactive position to permit the release of the clamp from the plate when the plate has been landed at its destination.

A further object of the invention is to provide a clamp of the character described wherein the jaws are normally in active position ready to engage with the plate to be lifted with means for temporarily latching one of the jaws inactive when the clamp is ready to be disengaged from the load.

With the above and other objects in view the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specication and illustrated in the accompanying drawing, wherein:

Figure 1 shows a sectional View of the clamp taken on the line I -I of Figure 2.

Figure 2 shows an edge View.

Figure 3 shows a cross sectional view taken on the line 3-3 of Figure 1.

Figure 4 shows a fragmentary sectional view taken on the line I-I of Figure 2 and showing one of the clamp jaws latched inactive to permit the release of the clamp from the plate.

Referring now more particularly to the drawing wherein like numerals of reference designate similar parts in each of the figures the numerals I, I designate side plates of the frame which are anchored together by suitable cross rods as 2, 2a and 2b which space the side plates apart.

The lower ends of the side plates have thedeep slots 3, 3 to receive the edge of the plate 4 to be lifted. On one side of the slot there is ajaw 5 pivoted on thecross pin 6 and Whose upper end has a transverse arcuate slot 6a through which thebolt 2b extends.

The inner margin of this jaw extends into theslots 3 and has a series of teeth arranged in r' the same plane.

On the other side of theslots 3 there is a jaw 'I which is pivoted on the eccentric pin 8 and its operative face is arcuate and'serrated and may be swung intoy the slots to grip the plate as shown in Figure 1` or may be retracted as shown in Figure 4. A

There is a control link 9A between the plates. Outwardly of the pivot 8, the jaw 'l is4 slotted and one end of. the link 9is pivoted in this, slot on the pin I0 whichextends through saidja-w-and link. At the opposite side ofl the' frame there are the toggle levers I-I',` I'I which are pivoted, at one end, on the pin I2', connecting said plates and the other ends of which are, providedv with opposing slots as I3. A cross bolt i3d extends through said slots and through the other end of thelink 9,

A clevis I4 embraces the toggle levers and the ends of its side arms have bearings on the bolt I3a, said bolt being retained in position by the usual head on one end and nut on the other end.

Near its lower end the outer margin of the link S has a notch I5 therein and there is a latch I6 pivoted between said cross plates on the pin I'I. The latch is normally held disengaged from the notch by means of a yoke I 8, one end of which is pivoted to the upper end of the margin and whose other end is connected to one end of a pull spring I9. The other end of this pull spring is attached to ananchor 20 carried by the upper end of thejaw 5.

The latch I6 has atransverse slot 2| through which thebolt 2a extends and which limits the range of movement of said latch.

In operation thejaw 1 is free to move. A lifting cable is connected to the clevls I4. The clamp may be applied to the plate 4 which is usually, but not always, in horizontal position and an upward pull on the cable will cause a corresponding longitudinal movement of thelink 9 which will swing the jaw 'I into engagement with the plate and thejaw 5, being pivotally mounted, will adjust itself in accordance with the position of the plate so as to take a rm hold thereof. The plate will be thus securely gripped between the jaws.

When the plate is landed, at destination, and the cable is slacked olf, thelink 9 will movedownwardly carrying the notch I5 beneath theactive end 22 of the latch I6 and said latch may then .be forced inwardly into engagement with the notch to hold the jaw 'I retracted, as shown in Figure 4, so that it will not re-engage the plate when it is desired to disengage the clamp from the plate. Usually this will be done automatically for the reason that the plates are usually delivered one by one to form a stack of plates which extend vertically and as each plate is landed in position alongside the stack and is leaned against the stack, thelink 9 will move downwardly and the latch I6 will rest against the stack and be pressed inwardly until itsend 22 engages in the notch I and upon upward pull of the cable the jaw I will be held retracted and the clamp will release the plate.

When the plate is released and the clamp is swung into position to be engaged with another plate, the slack on the cable will permit the latch to be disengaged from said notch, by the pull of spring I9 thus leaving the jaw 'I free to move as before.

As herein above stated the plate to bev lifted will often lie in horizontal position while the clamp is attached thereto. If thejaw 5 is underneath the plate when an upward pull is taken on the cable, the bolt I3a will move upwardly along the slots I3 causing the toggle levers to move downwardly until they are stopped by therod 2 and the bolt I3a -will move on up along the slots I3 thus imparting a tension to thelink 9 and moving thejaw 1 into engagement with the plate. If the slots were not provided, no tension should be exerted through thelink 9 until the plate had been moved to approximately vertical position and in such case the clamp might slip-off the plate before thejaw 1 came -into action.

What I claim is:

l. A plate clamp comprising a frame, opposed jaws pivoted on the frame, each of said jaws having a plate-gripping surface, lifting means for the clamp including a link connected to one of the jaws and eiective to actuate said jaw into gripping relation with an object between the jaws upon elevation of the clamp by said means, a latch, means normally holding the latch inactive, interengaging means carried by the latch and link, respectively, adapted to be interengaged, upon movement of the linkfto release its jaw, whereby said jaw will be temporarily retained in inactive position.

2. A plate clamp comprising a frame having confronting, plate gripping, jaws, one of said jaws being pivoted to move into and out of gripping relation with an object between the jaws, a link pivoted at one end to the pivoted jaw, a toggle lever pivoted at one end to the frame and whose other end is provided with a slot, a cable attaching means movable in said slot and to which the other end of the 1ink is connected, said link being connected to the pivoted jaw at a point such that upon elevation of the clamp by the cable the pivoted jaw will be actuated into gripping relation with an object between the jaws, a latch, interengaging means carried by the latch and link, respectively, and arranged to be interengaged when said pivoted jaw is moved to inactive position to temporarily retain said pivoted jaw in said inactive position.

RODNEY S. WALDRUP.

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