US1472081A - Grapple - Google Patents

Description

I. N. MERCER @ct, 3U H923.

GRAPPLE Filed April 10. 1922 EJI Patented Get. 3%, i923.

oirao stare IZA NELSON MERCER, O "NELLSBURG, WEST VIRGINIA.

(EB/APPLE.

Application filed April 10, 1922. Serial No. 551,245.

vide a grapple where-in shitting or acciden tal displacement of the load is prevented through the medium of clamping jaws, one of which is adapted to exert automatically a gripping but positive action commensurate with the dead weight of the load.

In lifting and transporting heavy and bulkyobjects by means of cranes or derricks it frequently happens that the load becomes disengaged from the grappling mechanism and in falling causes great. damage to prop, erty and sometimes loss of life. This is generally caused when the grapple of the hoist or derrick strikes some protruding object or is iven ayibratory movement.

oo of the objects of my invention is to provide a grapple, the jaws of which are automatically locked in a positive gripping position with respect to a load through the instrumentality of the load when the same is raised from the ground. The mechanism accomplishing this purpose is so arranged that shocks received in transporting the load will not affect the locking members. Furthermore, it sometimes occurs that in lowering a load one edge or portion may momentarily rest on some obstruction thereby causing the load to be inclined at an angle, which is generally suliicient to cause the load to slip from the retaining jaws and fall to the ground. Iovercome this difiiculty by providing a plurality of locking members some of which will positively re-.

tain their locking action until the operator of the hoist has an opportunity to again raise the load clear of the obstruction. Means are also provided for automatically holding the sliding jaw in inoperative position when the load has been released.

To these and other ends, my invention consists in the construction, arrangement and combination or". parts described herein-.

after, illustrated in the drawings, and point-.

ed opt in the claims forming a part of this specification.

One embodiment of my invention is represented by way of example in the accompanying drawings, wherein:

Figure 1. is a side elevation of the grapple assembly.

Figure 2, is an end view of the same.

Figure 3, is a front elevation of one of the clamping elements.

Figure 4, is a View at right angles to Figure 3, and

Figure 5, is a detail perspective of the lower end of one of the clamping elements. Figure 6, is a modification of the levers.

Referring to the drawings wherein like characters of reference designate like or similar parts, (1) designates a cable which is suspended from a crane or derrick (not shown). Attached to the lower terminal of the cable (1) are chains (2) the free ends o1 which are secured in sockets (3) placed on each end of a cross bar (4). The cross bar (i carries a plurality of transverse supporting arms (5) each of which is provided adjacent its extremities with grooves (6) which areadapted to seat. a bracket carrying a ring Suspended from each ring (8) by means of chains (9) are locking assemblies which for convenience will here inatter be referred to as the clamps. The clamps are identical in construction and op eration and for the sake of clarity only one will be described in detail.

The fixed clamping element of my grapple consists in a frame generally designated by (10) formed with two spaced apart, parallel side beams or uprights (1].) and (12) connected at their lower ends by a trans verse bar (13). The upper ends of the up? rights (11) and (12) are bolted or riveted between plates ('14:) formed each with a semi-circular cutaway portion to permit access therebetween. Upon the lower ends of each of the uprights (11) and (12) are integrally formed beveled teeth (15) and (16) respectively, which extend 0utwardly at right angles from the uprights for disposition beneath a load to be lifted.

The adjustable element of my grapple consists in a beam (17) arranged for sliding movement between the uprights (11) and (12). and said beam is formed with racked side faces (18) for engagement with the beveled ends of opposed levers (l9) pivotally mounted between the plates (14L). The levers (19) serve in a capacity resembling pawls engaging the rack faces of the beam (17) to move the beam downwardly. Upon the lower end of the beam (17) is formed a beveled tooth (20) for engagement with a load disposed upon the teeth (15) and (16) to positively hold the same in place. A suitable guide collar (2].) is mounted on the beam (17) to hold the beam securely i(n position between the uprights (11) and The chains (9), liereinbefore referred to, are connected with the outer extremities of the levers (19) so that the dead weight of a load engaged between the teeth (13), (16) and (20) will cause the levers to move on their axes to force the beam (17) downwardly thereby increasing the gripping action upon the load. Furthermore, a latch (22) is secured for swinging movement upon the forewardmost of the plates (1-1), and is provided with a pronged head (23) having a beveled face (24). The latch serves to hold the beam (1"?) in an inoperative position when so desired and normally it will assume a vertical position.

In operation my device functions as follows: When it is desired to apply my grappling mechanism to a heavy or bulky object the fixed jaws are allowed to rest on the ground with a slack in the chains The sliding jaws are each grasped at their uppermost portions and are raised until the tooth strikes the beveled face on the pronged head of the latch. This will cause the latch to be forced out of the path of the on the upper surface of the load.

"the cable (1) is raised the slack will be tooth until it is clear, when by its own weight and due to its pivotal attachmentthe' pronged head will swing beneath the tooth to hold the sliding jaw in inoperative position. When all of the sliding jaws have been raised to inoperative position the fixed jaws are forced beneath tlieload. Then bv releasing the latches the sliding jaws will of their own weight fall. to proper position hen taken up from the chains (9), and the chains being secured to the lever arms will turn the lever arms on their pivots thereby exerting a downward pressure on the beam of the sliding jaw; The tension of the chains (9) will be dependent on the weight of the load being hoisted and the force exerted upon the sliding jaws will. consequently be proportional to the weigl'u; of the load. When the grapple is to be .l1s connected from the load the sliding jaws are raised until the latches swing to operative position to retain them in the raised" position. The fixed jaws are then removed from beneath the load leaving the grappling mechanism in inoperative position and ready for attachment to another load.

The beveled faces on the teeth of the fixed jaw are to facilitate their insertion beneath a load. Occasion may arise when it will not be necessary to utilize the looking action in which event the sliding jaw may be allowed to drop until it rests on the bar (13). The beveled face on the tooth of the sliding jaw is to permit the ready application of the device when used in. this manner. r

The primary purpose of the chains (2) is to absorb shocks caused by striking obstructions when raising a load. No matter how severe a shock may be imparted to the chains (2) the locking action will not bi- If an obstacle is encountered while lowering a load the 'load will either rest upon the obstacle or be caused to tilt untilit is permitted to slip free, the latter case being the only one it becomes necessary to provide for. By providing a plurality of sets of clamps there will always be a ma-v jority of such members which will retain their locking action and thus support the load. Y

.Figure 6 shows a modification of the levers (19) in which a lever arm is loosely mounted in the engaging element.

While in the foregoing therehas been ilthoroughly acquaint one skilled in the artwith its construction and advantages, I claim 1. A grappling mechanismcomprising a cross bar, means secured to the ends of the cross bar for attaching it to a cable, a plu ality of transverse supporting arms car-- ried by the cross bar, opposed clamps flexibly suspended from each supporting arm, each of said clamps including a fixed and a movable jaw and means for automatically locking the movable jaw in gripping position when supporting a load.

2. A grapple comprising a frame formed with load engaging members, a beam mov- .ably mounted upon the frame and formed with a load engaging member, and means for automatically actuating the beam to in crease the. pressure upon the "load as the weight of the load is increased.

'3. A grapplecomprising a frame, formed.

power to move the beam to grip the load as the load is raised.

4. A grapple comprising a frame formed with load engaging members, a beam movably mounted upon the frame and formed with a load engaging member, said beam having racked faces, and levers engaging the racked faces of the beam to move the same downwardly under the weight of the load.

5. A grapple comprising a frame, a movable member carried by the frame, a catch for retaining the movable member, and means connected with the frame for ac tuating the movable member.

6. A grapple comprising a frame formed with a pair of parallel, spaced, side rails having load engaging members on their lower ends, a movable beam carried between the side rails and formed with racked faces, a pair of levers engaging the teeth formed by the racked faces, and flexible means conneoting the levers with a source of power.

7 A grapple comprising a frame formed with load engaging members, a beam movably mounted on the frame and formed with a load engaging member, a pair of levers engaging the beam to move the same to cause the load engaging member thereon to approach the first mentioned load engaging members, a supporting bar, flexible members connecting the levers with the supporting bar, and flexible members connecting the supporting bar with a source of power.

In testimony whereof I affix my signature hereto.

12A NELSON MERGER.

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