US1977723A - Sack lifter - Google Patents

Description

Oct. 23, 1934.

A. 1.. HALL 1,977,723

SACK LIFTER Filed July 14, 1935 INVENTOR ATTORN EY Patented Oct. '23, 1934 PATENT oF Fice sAoK Arthur L. Hall,

LIFTER e Stocktom Galif., assignor of onehalf to George Trayer, Stockton, Calif. Application July 14, 193 3, SerialNo. 680,398

1 Claim.

This invention relates to hoisting apparatus or derricks, and particularly to one of a portable manually operated character.

I have particularly in mind the lifting of filled sacks in the field onto trucks or similar vehicles moving along the field to gather up sacks; my principal object being to provide a device of this character, adapted to be mounted on the truck, and so constructed that the sacks may .10 be quickly and easily lifted from the ground and swung around and deposited on the truck,

with a minimum of physical effort and yet without the need of employing a winch or similar device in connection with the apparatus and 15: which would be relatively slow to operate.

The device is so constructed and the parts are so proportioned that while excellent lifting leverage is obtained so that a man of ordinary strength can operate the hoist and lift the sacks,

; the extent of such lift approximates the movement of the actuating lever or the length that the cable connected thereto must be taken up.

The movements of the operator are therefore relatively small while the sacks are lifted very g5- rapidly.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claim.

In the drawing similar characters of reference indicate corresponding parts in the several views:

Fig. 1 is a side elevation of my improved sack lifter showing the lifting arm in its lowest position; various other positions of the arm and connected parts being shown in dotted lines.

Fig. 2 is a fragmentary enlarged view showing the swivel mounting of the lifting arm on the mast.

Fig. 3 is a similar View showing the swivel connection between the lifting arm and the lever connected link.

Fig. 4 is a similar view showing the swivel connection between the mast and the adjacent lever link.

Referring now more particularly to the characters of reference on the drawing, the numeral 1 denotes a base plate or bracket adapted to follow the contour of and to be rigidly mounted on the bed 2 of a truck at one rear corner. A socket 3 is rigidly secured to and projects upwardly from the plate at its rear end or corner, a tubular mast 4 being turnably supported in and upstanding from the socket to a suitable height.

Projecting laterally from the mast adjacent its upper end is a trunnion 5 which turnably engages an eye 6 secured to and preferably depending from the hoisting arm '7 intermediate its ends. At one end this arm is connected to a depending cable 8 or the like which at its lower end is secured to a sack engaging grab 9 of conventional character and arranged so that with an upward pull on the cable the grab grasps the sack so that the latter is lifted.

Swivelly connected to and depending from the opposite end of the arm is a yoke 10, in which the upper circular portion 11 of a depending link 12 is turnably mounted, the axis of the portion 11 lying in a plane at right angles to the pivot of the arc. The lower end of the link is pivoted as at 13 against one side of a control lever 14 intermediate the ends of the latter, said lever being disposed to one side of the mast and arm 7 and preferably extending above said arm. The lower end of the lever is pivoted as at 15 to one end of a link 16, the axis of the pivots of the two'links being parallel to each other and horizontally disposed.

Rigid with the lower end of the link 16 is an eye 1'7 whose axis is at right angles to the pivot 15 and which freely turns on a pin 18 mounted in a clevice or bracket 19. This clevice in turn is supported by and rotates on a trunnion 20 projecting laterally from the mast 4 and disposed parallel to the trunnion 5.

In operation when the grab end of the hoisting arm is in its lowest position the links and lever are in longitudinal alinement. When the operator pulls forwardly on the cable 21 attached to the upper end of the lever 14 (and which cable extends forwardly at an outward angle to the truck), the link 12 is swung forwardly so as to approach a horizontal position, as shown in dotted lines in Fig. 1. This causes the adjacent rear end of the arm 7 to be lowered and the opposite end to be raised with the engaged sack 22. At the same time the link 16 is swung downwardly so that it finally approaches a vertical position as indicated.

When the arm 7 has lifted the sack the necessary distance to clear the bed of the truck the mast and arm are swung around to cause said sack to overhang the truck, the mast turning in the socket 3. With this movement of the mast and arm the tension on the cable 21 is maintained until it is desired to lower the arm 7 to deposit the sack on the truck. Since the end of the cable engaged by the operator is of course some distance from the structure, it is not necessary for such operator to shift his stand. Also the flexible or universal connection of the links with the arm and lever permits a certain amount of swinging movement of the hoist arm about the mast as an axis and relative to the control lever which prevents any clamping or binding of the lever and links such as would prevent the free movements of the same in an arm raising or lowering direction.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects, of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device,

still in practice such deviations from such detail ber to be lifted, an upwardly projecting actuat ing lever, a link flexibly mounted at one end on the mast toward its lower end and pivoted at its other end on the lower end of the lever, and

another link pivoted at one end on the opposite end of the arm and at its other end on the lever intermediate its ends.

ARTHUR L. HALL.

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