US1221693A - Unloading-sling for derricks. - Google Patents

Description

0. CROSBY. UNLOADING .SLING FOR DERRICKS.

APPLlCATlON HLED NOV. 14. 1912.

Patented Apr. 3,1917.

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UNITED r TATFfi NT FFIQE.

OLIVER CROSBY, OF ST. PAUL, MINNESOTA, ASSIGNOR T0 AMERICAN HOIST & DERRICK COMPANY, OF ST. PAUL, MINNESOTA, A CORPORATION OF MINNESOTA.

UNLOADING-SLING FOR DERRIGKS.

Specification of Letters Patent.

Patented Apr. 3, 1917.

Application filed November 14, 1912. Serial No. 731,249.

To all whom it may concern:

Be it known that I, OLIVER CROSBY, a citizen of the United States, residing at St. Paul, Ramsey county, Minnesota, have invented new and useful Improvements in Unloading-Slings for Derricks, of which the following is a specification.

This invention relates to unloading slings for derricks, etc., and particularly to the tripping beam or spreader which is suspended from the lifting hook of the derrick, and to which the chains of the sling are attached.

The object of the invention is to provide a device of the character described to which the cane slings may be rapidly and securely attached and from which they may all be simultaneously released by the operation of a single tripping member to discharge the entire load as a unit.

With the above obj eot in view my invention consists of the construction hereinafter described and shown in the accompanying drawings, it being understood however that my invention is'not limited to the mechanism shown and described, but that the construction of the same may be widely varied without departing from the spirit of my in vention or the scope of the appended claims.

In the said drawings Figure 1 shows my approved tripping beam in side elevation, with portions of the sling chains depending therefrom in the position they assume when the sling is loaded;

Fig. 2 is an end view of the beam looking from the right of Fig. 1; and

Fig. 3 is a detail view partly in section of the tripping mechanism viewed from the Referring now to the drawings, in which like reference characters represent like parts throughout the several views, 1 indicates the beam proper here shown as consisting of two pieces of channel iron riveted together with shouldered rivets as shown in Fig. 2, to provide a space between the channel irons for the reception of the hanger 2 and the tripping mechanism as will belater described. The hanger 2 is provided with a suitable link 3 for attachment to the derrick cable 4 in the usual manner. The beam shown in the drawing is of a length to accommodate three sling chains 5, but it will of course be understood that a greater or smaller number of chains may be employed if desired. At suitable intervals along the under side of the beam depending hangers or bearings 6 for a shaft 7 are arranged in pairs spaced slightly apart and loosely mounted on the shaft between the bearings are hooks 8 for one end of the chains.

Adjacent each of the hooks 8 is a hook 9 fast to the shaft 7 and so shaped that when the weight of the load comes on the chains, the shaft 7, unless prevented by a suitable mechanism will be turned in its bearings to a position such that the end of the chain slips off the hook. To prevent such rotation of the shaft 7 during the lifting of the load I provide a trip latch 10 mounted to slide vertically between the channel irons of the beam 1, and held down by a spring 11 in the path of a dog 12 fastened to the shaft in such a position that when the dog is held by the latch the hooks 9 are held in position to support the load as shown by full lines in Fig. 2. The latch 10 is provided with a laterally projecting pin 13, (see Fig. 3), by means of which it may be lifted against the tension of the spring 11 to release the dog 12. For operating the latch I provide a lever 14. pivotally mounted on a suitable stud between the channel irons of the beam and having its inner end proj ecting under the pin 13. The outer end of the lever 1-1 projects beyond the end of the beam and is provided with an eye to which is attached a rope 15 by means of which the trip may be operated. The end of the lever 14 is guided between two upwardly projccting guide members 16 attached to the end of the beam 1; and a pin 18 is provided at the upper end of the guide members to prevent the lever 14 swinging beyond its normal operating position. For turning thev shaft 7 to its operative position after the latch 10 has been released, I provide a handle 18 in the projecting end of the shaft adjacent the latch. A stop 19, shown in Fig. 2 is also provided to engage the dog 12 and prevent excessive movement of the shaft 7.

In operation the chains, which are provided with a ring at each end, are laid across the floor of the wagon or car on which the material, for instance sugar cane, is loaded. When the wagon comes under the derrick at the mill or other unloading point, the tripping beam is lowered to a position immediately above the load and the rings in the ends of the chains which project from under each side of the load are attached to the hooks 8 and 9 in the manner shown in full lines on Fig. 2, the shaft 7 being locked by the latch 10 in the position 7 shown.- The'derrick is then'operated to lift the load, and when the load is swung into proper position for unloading the rope I is pulled or jerked by the operator thereby,

through the medium of the lever 1a and'pin 13, raising the latch 10 from engagement with the dog 12 and permitting the shaft 7 V to turn under the weight of the load and release the chains held by the hooks 9. As the hooks 8 are loose on the shaft 7fthey are not affected by the operation of the latch butcontinue to hold the opposite ends of the chains so that as the load drops the derrick draws the chains out from underit.

The advantages of my improved tripping V beam Wlll,'1t is thought, be obvious from the ent is:

1. Inan unloading sling, the combination of a beam, means for suspending the same from a suitable hoisting mechanism, a shaft extending longitudinally of said beam, and a plurality of hooks loosely mounted on said shaft, a plurality of hooks attached to said shaft and adjacent said loosely mounted hooks, a dog attached to said shaft, a latch engaging said dog to hold said second mentioned hooks in a load-carrying position and a manually-operated trip for shifting said latch to release said dog, said attached hooks being shaped to free the sling when said shaft holding means is released.

In a device of the class described, the combination of a beam, a shaft extending longitudinally of said beam, a plurality of hooks loosely mounted on said shaft and adapted to support a load when depending directly from said shaft, a plurality of hooks fixed to said shaft, said hooks being adapted to support a load and shaped to release said load when depending directly from said shaft, means for locking said shaft with said last mentioned hooks in a load supporting position, and a manually operatable device for releasing said lock.

In witness whereof I have hereunto set my hand at the city of St. Paul, county of Ramsey and State of Minnesota, this sixth day of November, 1912.

OLIVER CROSBY.

lVitnesses:

Rosn A. CUMMINGS, OLIVER W. MORTON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, I). G.

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