US2999716A

US2999716A - Rollover grabs

Info

Publication number: US2999716A
Application number: US629913A
Authority: US
Inventors: Robert S Elberty
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-12-21
Filing date: 1956-12-21
Publication date: 1961-09-12
Anticipated expiration: 1978-09-12
Also published as: FR1195336A; GB847410A

Description

Sept. 12, 1961 R. s. ELBERTY ROLLOVER GRABS 5 Sheets-Sheet 1 Filed Dec. 21, 1956 INVENTOR ATTORNEY5 Sept. 12, 1961 R. s. ELBERTY 2,999,716

ROLLOVER GRABS Filed Dec. 21, 1956 3 Sheets-Sheet 2 mvsmpa ATTORNEY5 ROLLOVER GRABS Filed Dec. 21, 1956 3 Sheets-Sheet 3 ATTORNEYS United States This invention relates to a grapple, and more particularly to a grapple adapted for lifting and manipulating metal coils, although it will be understood that 1t can be employed in the lifting of other objects for transferring them. from one place to another.

In manipulating objects such as metal coils, for example, it is desirable to have the grapple suspended either in a vertical or inclined postion when unloaded so that the object to be picked up, such as a coil, for example, may be readily grasped by the grapple. In the past counterweights have been employed in some instances to effect such a result, but with such an arrangement the grapple may not be supported either in a horizontal or vertical position as desired but will be supported only in one of such positions.

Also it is desirable to provide for the coil to be suspended with its axis either in a vertical or horizontal position as some times one position is required and at other times another is desirable.

According to the present invention there is provided a grapple and a bail for supporting the grapple from a crane hook or the like, the grapple being movably mounted on the bail so that it may be moved to various positions so that regardless of the center of mass of the grapple or of the grapple and weight thereon, the grapple or coil carried by the grapple may be suspended either in a vertical or horizontal position as desired. Another advantageous feature of the present invention is that of supporting the grapple upon the bail so that it may be rotated to a given position with respect to the hail, the rotation taking place about the approximate center of gravity of the coil being lifted so that the load upon the rotating mechanism will be greatly reduced, it being obvious that much less effort is required to rotate an object about its center of gravity than about a point eccentric to the center of gravity.

One object of the present invention is to provide a grapple for lifting objects such as metal coils, for example, which grapple may be rotated with respect to its supporting structure to occupy any desired position within limits.

Still another object of the invention is to provide a grapple consisting of a supporting structure and a grapple structure, the latter being carried by a quadrant supported by the bail and movable with respect to the bail so that the grapple may be supported in a desired angular position with respect to the bail.

Still another object of the invention is to provide a grapple structure comprising a bail and grapple mechanism movably carried by the bail and cooperating means on the bail and grapple structure by which the latter may be rotated about a point without the bail, which point will be approximately the center of gravity of the coil or other work carried by the grapple.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed;

In the accompanying drawings:

FIG. 1 is an end elevational view of a grapple embodying my invention;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a partial sectional view on line 3-3 of FIG. 1;

FIG. 4 is a sectional view on line 4-4 of FIG. 2;

' atent O I 2,999,716 Patented Sept. 12, I961 ICE FIG. 5 is a sectional view on line 5-5 of FIG. 3;

FIG. 6 is a sectional View on line 6-6 of FIG. 2;

FIG. 7 is a diagrammatic view showing a coil supported by the grapple with its axis in a vertical position;

FIG. 8 is a similar view but showing the position of the part when the axis of the coil is substantially horizontal;

FIG. 9 is a diagrammatic view showing automatic leveling switches applied to the grapple; and

FIG. 10 is a wiring diagram showing the operation of the leveling switches.

To illustrate a preferred embodiment of the invention there is shown in the drawings a bail structure A and a grapple mechanism B suspended from the bail structure as will be hereinafter explained.

As illustrated, the bail structure may comprise a pair of

plates

10 and 11 suitably secured together. A pin 12 is mounted at the upper ends of these plates which may be received in the hook 13 of a crane or appropriate lifting mechanism 14 so that the entire structure will be pivotally supported from this hook.

The

plates

10 and 11 are relatively wide at their upper portions, as shown in FIG. 2, but also comprise narrower depending T-shaped arms 15, each having a laterally projecting extension 1 6 at its lower end and between these extensions 16 are mounted rollers 17, one of these rollers being at each end of the extensions;

Mounted on the plate 11 is an' electric motor 19 and a gear reduction unit 20, the latter having an output shaft 21 extending through the plates of the bail A and journaled therein. Secured to the shaft 21 between the plates is a pinion 22 designed to be driven at a relatively slow speed by the motor 19.

The grapple mechanism B includes a toothed quadrant 25 having teethv 2'6 thereon and, as shown in FIGS. 2 and 6, this quadrant is movaby disposed between the arms 15 of the bail. The lower edge of the quadrant rests upon the rollers 17, and the teeth 26' mesh with those of the pinion 22 so that upon energization of the motor 19 the quadrant will be moved with respect to the bail. It will be noted that the radius of the quadrant is such that its center is a considerable distance below the bail and, as will be referred to hereinafter, the center lies at substantially the center of gravity of the average sized coil to be handled by the device so that the coils when rotated will be turned substantially about the center of gravity thereof.

Secured to one end of the quadrant 25 is a substantially vertically disposed frame member 27, and to this member is secured one end of a substantially horizontal arm 28. The other end of this arm is secured to the other end of the quadrant by the

frame members

29 and 30 so that the arm 28, which carries the grapple jaws tobe hereinafter described, is rigidly connected to the quadrant 25.

As shown more especially in FIG. 4, the arm 28 comprises a pair of spaced channel-

shaped members

31 and 32, and it will be understood that the

frame members

27 and 29 may also comprise spaced parallel elements, one secured to each of these channel-shaped members. Slidably mounted on the arm 28 is a pair of cooperating jaw structures designated generally by the

numerals

33 and 34. The jaw member 33, as shown more particularly in FIGS. 3 and 4, comprises ahollow rectangular upper portion 35 slidably mounted on the arm 28 and embracing the

channel members

31 and 32. Secured to the element 35 are downwardly depending

legs

36 and 37 which are joined below the arm 28 by a transverse member 38.

Each of these arms is provided with a pair of elongated openings 39' and. 40; and slidably mounted in these openings are pins 41 and 42 which arev secured to' rearwardly extending lugs 43 on a jaw member 44 which may,

as shown in FIG. 5, present a gripping surface 45 of armate form. Springs 46 connected at one end to the pin 42 and at their upper ends to pins 47 secured in the

arms

36 and 37 normally urge the jaws 44 upwardly so that the pins 41 and 42 normally lie at the upper ends of the

slots

39 and 40. As shown in FIG. 3, the forward surface 48 of the member 38 is inclined inwardly and downwardly, and the rear face 49 of the lug 43 is complementally inclined so that when the jaw 44 moves downwardly or outwardly along the member 38, it will be cammed toward the cooperating jaw structure 34. Between the

adjacent faces

48 and 49 may be mounted a series of antifriction members such as rollers 50 to reduce the friction between these parts.-

It will be understood that the jaw structure 34 is sub stantially like the jaw structure 33 except that the depending legs, one of which is shown at 37 and the jaw member 44 are, for convenience, of shorter length than the corresponding members of the jaw structure 33.

With this construction it will be apparent that when the jaws are caused to grab a coil or other piece of work, the weight of the coil as it is lifted will cause the jaws to slide downwardly on the

inclined members

38 and 38 and, therefore, effect increased gripping pressure upon the coil.

Nonrotatably mounted in the

legs

36 and 37 of one of the

jaw members

36 and 37 of the other jaw member are nuts 51 (FIGS. 3 and 4) having threaded openings 52 therein in which are received the rightand lefthand threaded portions 53 and 54 of a shaft 55 rotatably mounted between the legs of the jaw members, as shown in FIG. 3. The outer end of this shaft has a bearing 56 in the outer end of the arm 28, and the inner end of the shaft is connected through a universal coupling 57 to the output shaft 58 of a reduction gear unit 59 driven through a belt 60 from a motor 61 mounted upon the frame member 27.

With this construction it will be apparent that when the motor 61 is actuated, the shaft 55 will be rotated and the

jaw members

44 and 44 will be caused to approach each other or to separate depending upon the direction of rotation of the shaft 55. The motor 61 will preferably be a reversing motor so that the shaft can be rotated in either direction.

In FIG. 2 of the drawing the grapple mechanism B is shown in the position it occupies when no load is supported thereon. It is noted that the quadrant 25 must be rotated in a counterclockwise direction to a slight extent so that the pinion 22 is at a short distance from the upper left-hand end of the quadrant, as shown in FIG. 2, in order that the arm 28 stand in a horizontal position and the jaws extend vertically as would be desired if the grapple is to be used to lift a coil 63, the axis of which is vertically disposed. When the parts are in the position shown in FIG. 2, the center of gravity of the mechanism B falls directly below the pin 12.

It will be understood that when the coil is gripped by the grapple, the jaw 44 will lie within the coil and the jaw 44 will grip its exterior surface. When'the coil is lifted the center of gravity of the entire load including the grapple and coil will lie to the left of the center of gravity of the grapple mechanism alone, and this would tend to tilt the structure in a counterclockwise direction so that the center of gravity would lie below the point of support at 12. In order to maintain the axis of the coil vertical, the motor 19, which is a reversible motor, will be actuated in the proper direction to rotate the quadrant in a clockwise direction to the position, for example, shown in FIG. 7 where the pinion 22 will be closer to the upper or lefthand end of the quadrant than before.

If it is desired to turn the coil to a horizontal position, the motor 19 is energized in a direction to rotate the quadrant in a counterclockwise direction and turn the quadrant and grapple mechanism B to the position shown in FIG. 8 where again the center of gravity of the entire load will lie below the point of support 12. It will be apparent, therefore, that the load may be lifted in any desired position or lifted in one position and turned to another to be deposited, if that is desired. Moreover, the turning of the grapple mechanism takes place about an axis lying within the coil and substantially at the center of the average coil to be handled so that the turning of the coil is effected with a minimum of elfort, thus reducing the load on the motor 19 and the teeth of the pinion 22 and rack 26. a

So far as previously described, the motor 19 may be manually controlled in its operation. Under some circumstances it may be desirable to provide for automatic control of the position of the grapple mechanism so that the arm 28 will be automatically maintained either in a horizontal or a vertical position, thus maintaining the axis of the coil either vertical or horizontal. I have shown in FIGS. 9 and 10 of the drawings a leveling switch mechanism by which this automatic control of the coil may be readily effected.

A switch mechanism 65 is mounted on the frame member 27 which is perpendicular to the arm 28, and a second switch member 66 is mounted on the arm 28. The member 65 is provided with a pair of

mercury switches

67 and 68. [Wires 69 and 70 lead to the upper end of the switch 67, and likewise

wires

71 and 72 lead to the lower end of the switch 68. As shown in FIG. 10 the wires 70 and 72 lead through a switch 73 to one pole 74 of a source of current, while the wire 69 leads to a pole of the motor which would actuate it in a reverse direction, while the wire 71 leads to another pole of the motor to actuate it in a forward direction. A conductor 75 leads from the motor to the other pole 76 of the current source.

Similarly the switch member 66 comprises '

mercury switches

78 and 79 under a similar arrangement to the

switches

67 and 68 except that these two switches are disposed in a substantially horizontal plane, while the

switches

67 and 68 are disposed in more nearly a vertical plane. It will be seen, therefore, that when the arm '28 is horizontal, the mercury will be at the lower ends of the

members

78 and 79, and hence will not connect the wires leading into the outer or upper ends of these switches. The switch 73 may, of course, be moved to connect the lead 74 either with the

switches

67 and 68 or with the

switches

78 and 79 depending upon whether it is desired to automatically maintain the coil with its axis in a horizontal position or in a vertical position.

'If it is desired to maintain the load with its axis in a vertical position (that is to maintain the arm 28 in a horizontal position), the switch 73 is set, as shown in full lines in FIG. 10. In this case it will be noted that both

switches

78 and 79 are open, and the motor 19 would remain at rest. However, if the arm 28 should tilt in a clockwise direction from the horizontal, the mercury would flow to the other end of the tube of the switch 79, and thus close the circuit through the wires 80 and 81, the latter leading to the motor so as to actuate the motor in the proper direction to rotate the arm 28 in a clockwise direction until it reached a level position.

If the arm 28 tipped in the other direction or counterclockwise, the switch 78 would be closed across the wires 82 and 83 which would rotate the motor in the opposite direction and turn the quadrant in a clockwise direction.

During these movements the switch mechanism 65 would, of course, be inoperative due to the fact that it was out out of the circuit by the switch 73.

However, if it is desired to maintain the axis of the coil in a horizontal direction, as shown in FIG. 8, the switch 73 is thrown to its dotted-line position, shown in FIG. 10, so that the

switches

67 and 68 become operative. If now the frame member 27 is in a vertical position, as shown in FIGS. 2 and 9, the

wires

71 and 72 of the switch 68 will be connected, thus driving the motor in a forward direction or in a direction to rotate the quadrant 25 counterclockwise so as to move the coil to the position shown in FIG. 8.

If conditions are such that the center of gravity of the load supported from the point of support 12 is such that the arm 28 is tilted in a counterclockwise direction from that shown in FIG. 8, then the switch 67 would come into operation (provided the switch 73 is in its dotted-line position), and the motor 19 would be automatically set into operation to rotate in the proper direction to move the quadrant in a clockwise direction.

It will be noted that when a coil is grasped with its axis in a vertical position, as shown in dotted lines in FIG. 2, there will be a tendency, due to the weight of the coil, for the coil to rotate in a counterclockwise direction, thus tending to urge the gripping jaw 44 downwardly and the "ripping jaw 44 upwardly. On the other hand, when a coil is grasped with its axis in a horizontal position, there will be a tendency, again due to the weight of the coil, for the coil to rotate in a clockwise direction, thus moving the gripping jaw 44 outwardly or toward the remote end of the coil and the gripping jaw 44 inwardly. It is desirably, therefore, in order to render the grapple of universal application for both jaw members to be movable and to be mounted on the rollers 50 in order that they may move freely and grip the coil or other work tightly whether it is lifted when its axis is vertical or horizontal.

While I have shown and described an embodiment of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

l. A grapple comprising an arm member, means for suspending said member, a pair of gripping jaws slidably mounted on said arm member for relative approaching and separating movements, means for actuating said jaws, each of said jaws comprising a leg member projecting from said arm in substantial parallelism and a jaw member slidably mounted on each of the leg members, the contacting surfaces of each leg member and its associated jaw member being inclined toward the gripping surface of the corresponding jaw member whereby relative movement between each jaw member and its associated leg member will efiect relative approaching or separating movements of the jaw members and spring means urging each of said jaw members in one direction along said inclined surface upon its associated leg member, said direction being that tending to separate the jaw members.

2. A grapple comprising a bail and grapple mechanism suspended by the bail, said bail comprising spaced members having rollers mounted therebetween at their lower edges, said grapple mechanism comprising a quadrant member suspended from the bail with the lower edge of said member resting on said rollers, an arm mounted within the included angle of the quadrant and rigidly connected thereto to be supported thereby, a pair of cooperating gripping jaws slidably mounted on said arm for relative approaching and separating movements, motor means carried by the quadrant, means connecting said motor means to the jaws to move the latter to open and closed positions, a motor supported by the bail, a pinion carried by the bail for rotation by said bail motor, and said quadrant provided with teeth on its upper edge for engagement by said pinion.

3. A grapple as in claim 2 wherein said arm comprises a pair of spaced members and including a threaded rod carried by said members, a pair of nuts are threadably mounted on said rod between the spaced members, and each of said nuts being connected to one of said jaws whereby rotation of the rod moves said jaws.

4. A grapple mechanism as in claim 2 wherein means are provided on the grapple mechanism to automatically maintain said arm in a predetermined position with respect to the vertical, said means being responsive to the deviation of the arm from such position and comprising a gravity-actuated switch mounted on the grapple mechanism and connected to the motor to control the same.

5. A grapple mechanism as in claim 2 wherein means are provided upon said grapple mechanism to maintain said arm in one of a plurality of predetermined positions, said means being responsive to deviation of the arm from such position and comprising a pair of gravity-actuated switches mounted on the grapple mechanism and means to connect either of these switches to the motor circuit to control energization of the motor.

6. A grapple, as in claim 2, wherein a pair of gripping jaws are slidably mounted on said arm for relative approaching and separating movements, means for actuating said jaws, each of said jaws comprising a leg member projecting from said arm in substantial parallelism and a jaw member slidably mounted on each of the leg members, the contracting surfaces of each leg member and its associated jaw member being inclined toward the grip ping surface of the corresponding jaw member, whereby relative movement between each jaw member and its associated leg member will effect relative approaching or separating movements in the jaw members and spring means urging each of said jaw members in one direction along said inclined surface upon its associated leg member, said direction being that tending to separate the jaw members.

7. A grapple comprising a bail and grapple mechanism suspended by the bail, said bail comprising spaced members having rollers mounted therebetween at their lower edges, said grapple mechanism comprising a quadrant member suspended from the bail with the lower edge of said member resting on said rollers, an arm mounted within the included angle of the quadrant and rigidly connected thereto to be supported thereby, a pair of cooperating gripping jaws slidably mounted on said arm for relative approaching and separating movements, motor means carried by the quadrant, means connecting said motor means to the jaws to move the latter to open and closed positions, a motor supported by the bail, and means connecting said bail motor to said quadrant member for rotating said quadrant member when said bail motor is energized.

References Cited in the file of this patent UNITED STATES PATENTS Re. 19,234 Hendrickson July 28, 1934 1,729,735 Chiles Oct. 1, 1929 2,337,178 Breslav Dec. 21, 1943 2,342,597 Opalek Feb. 22, 1944 2,347,361' Nelson Apr. 25, 1944 2,347,922 Nelson May 2, 1944 2,348,309 Rohr May 9, 1944 2,349,717 Graham May 23, 1944 2,399,360 Lacey Apr. 30, 1946 2,461,394 Plante Feb. 8, 1949 2,477,927 Hanson Aug. 2, 1949 2,502,167 Moore Mar. 28, 1950 2,520,252 Mutchler Aug. 29, 1950 2,530,333 Jost Nov. 14, 1950 2,630,931 Douglas Mar. 10, 1953 2,699,879 Bertram Jan. 18, 1955 2,703,252 Blackwell Mar. 1, 1955 2,718,320 Nelson et a1 Sept. 20, 1955 2,718,321 Westermeyer Septf20, 1955 2,821,318 Kendall Jan. 28, 1958 2,823,367 Huron Feb. 11, 1958 2,906,555 Heppenstall Sept. 29, 1959 2,913,276 Collings Nov. 17, 1959