US2048144A - Lifting sling - Google Patents

Description

July 21, 1936.

| M. SHOWERS. JR

LIFTING SLING Filed Nov. 25, 1935 5 Sheets-Sheet l INVENTOR:

/ Lawns M SIT/011151157 J1,

TTORNEYS.

& m m n L. M. SHOWERS. JR

LIFTING SLING v 5 Sheets-Sheet 2 Filed Nov. 25, 1935 TORNEYS.

IN VEN TOR:

Lani/i5 M Shamans, K,

Y B N one n I F F F- 1. I I

July 21, 1936. HQ 1 2,048,144

LIFTING SLING Filed Nov. 25, 1955 5 Sheets-Sheet 4 M FIG 11:

INVENTOR: Law/.5 M Shawargfir,

' TTORNEYS.

LIFTING SLING Filed Ndv. 25, 1935 5 Sheets-Sheet 5 WITNESSES: INVENTOR:

975 Z Lawis M Shamans, Jr,

M I BY W My Mama s.

Patented July 21, 1936 uNirE. STATES ATENT 7 Claims.

My invention is related generally to lifting slings for handling truck bodies, railway containers, or similar loads; more specifically, it is related to lifting'slings which may be adjusted to loads in which the mass is unevenly distributed. These loads will not remain level when suspended unless the point of suspension is over the center of gravity, which varies in position according to the mass distribution.

In the handling of truck bodies and railway containers, it frequently happens that the truck body or container must be lowered or lifted between .two other bodies or containers, or in a confined'space; Unless the truck body or con- 151 tainer remains level, it may become jammed just as an ordinary'desk drawer jams when pulled out or pushed in at an angle. There are many situations which require that the load remain level whensuspended and uneven loading is met with regularly.

- In many cases the center of gravity is displaced more in the direction of one of the base dimensions than in the other, in relation to the center of area of the base. Further many of these situations may-be dealt with in practice provided there is no tilting about one axis even though there be some tilting about the other axis' of the suspended load. Consequently, an adjustment which will hold a load level about either its length or its width has great practic-al value. Because of the greater moments involved, it is usually preferable to adjust for the center ofgravity in the load in the direction of the long base dimension. Other means may be resorted to in order to check a tilting in the direction of the short dimension. Accordingly, the principal object of my invention is the provision of a lifting sling which will lenditself to adjustment for unevenly distributed 40 mass in the load and offer resistance to tilting inany direction. Another object is the provision of a lifting sling which will balance the load ina level position in the direction of one of its base dimensions bythe simple moving of the point of suspensionso that it is more nearly over the center of gravity of the load. Another object of my invention is the provision of a lifting sling and suspension eye which is easily movable in adjustment and yet becomes positively fixed on the-suspension of the load. Another object of my invention is the provision of a lifting sling of rugged structure, and capable of rapid and eflicient operation-in adjustment, coupling and uncoupling.

Still further advantages will appear from the following detailed description of a preferred embodiment'of my invention, having reference to the accompanying drawings of which:

Fig. I is a side view of my lifting sling, showing the same engaged with a truck body and 5 suspended from a suspension hook.

Fig. II is an end view of the same.

Fig. III is a side view of my lifting sling showing the hook engaging members at one end of the sling in engagement with the hooks of a truck 10 body which is partially shown, and the hook engaging members at the other end of the sling before engagement with the hooks of the truck body. This view also indicates in dotted lines the operation of the lifting sling when adjusted for a center of gravity which is not over the center of the truck body.

Fig. IV is a plan view of my lifting sling.

Fig. V is a partial section, taken about the lines VV of Fig. IV.

Fig. VI is an exploded view in perspective of one corner of the frame of my lifting sling enclosed in the dot-and-dash line square in Fig. II.

Fig. VII is a fragmentary view, taken about the lines VIIVII-in Figs. IV and X, partially in section, showing the lifting shackle in engagement with the lifting span, the lifting book being indicated in dotted lines.

Fig. VIII is a view similar to Fig. VII, except that the lifting shackle is disengaged from the lifting span and the retaining pins removed from the lifting shackle; the dotted lines indicate the capacity for free movement in the direction of the length of the lifting span when the retaining pins are removed.

Fig. IX is a plan view of a segment of the liftmg span.

Fig. X is a partial section, taken about the linesX-X in Fig. VII.

. Fig. 2G is a perspective view of the engaging member of the lifting shackle.

Fig. XII is a perspective view of a locking ring which fits on top of the lifting span.

Fig. XIII is a perspectivexview of one of the stop links; and,

Fig. XIV is a perspective view of one of the connector links.

For the purpose of description, the preferred embodiment of my invention shown in the drawings may be regarded as comprising the following elements, each of which will be described in detail later: tubular longitudinal frame members I; tubular transverse frame members 2; corner pieces 3 joining the longitudinal and transverse frame members I, 2; span rods 4 pivotally attached to the corner pieces 3; a flexible or chainlike lifting span. 5 connected to the span rods 4; a liftingshackle 6 engaging the lifting span 5; and hook engaging members I and engaging saddles 8 attached to each corner piece 3. In the drawings there is also shown in relation to the operation of the lifting sling a truck body 9 having books I!) for the engagement of the lifting sling. A suspension hook I I is also shown in the drawings indicating the suspension means by which the lifting sling isoperatecl. p

The longitudinal and transverse frame members I, 2 are tubular in form and are joined by the corner pieces 3 forming a rectangular frame l6. I

*l'i-ftingspan 5 is thus free to bend upward but any The corner pieces 3 each have two tubulararms l! formed integrally therewith and extending at right angles to each other. These arms l'! are designed to fit snugly into the frame members i, 2, andthey are provided with shoulders t8 --to make a tight joint. The hook engaging member Tis pivotally attached to the corner piece 3 by a pin 49 to which the hook engaging member 1 is integrally attached by a rivet or pin 22. The

pins 19 at each end of the frame 16 are joined by a cross connector 26 made integral with each pin H) by a rivet 2| piercing both the cross connector'29 and the pin l9. Thus-the "hookengaging members '1 at each end of the frame I-6 are integrally attached to each other so that when one hook engaging member 1 is moved the other I hook engaging member 1 is "moved likewise. These hook engaging members 1 are each double, having two engaging eyes '25, 26 to provide'for two different sizes of truck bodies. The hook engaging member '1 is operated by anoperator using an operating hook 21in engagement with eye 28, as indicated by dotted lines in Fig. The hook engaging member! has an actuating spring 29 which holds the hookengagi-ng member 1 in the up position against corner piecej3 and also in the down position againstfll'ioo'k "I 9. This actuating spring '29 is fastened 'by a collar 39 to the frame member l, and alsoto the hook engaging member I by a l-in'k 3|. In order that the actuating spring '29 may be operable in "both up and down position of the hook engaging memher 1, the point of attachment of the link 31 to the hook engaging member '1 must be such that an imaginary line drawn be'tween'this point of attachment to the hook engaging member '7 and the point of attachment to the frame member I passes above the center of the pin l9 when the hook engaging member I is in the up position and below the pin -l 9 when the hook engaging member 1 is in thedown position. For each engagin'g eye '26 there is provided an engaging shoulder 8 formed integrally with the corner piece 3 and shaped to fit over the top and :down the back of the hook Ill on the truck body -9, thus providing a guidefor positioning the lifting sling over the truck body 9. I

The span rods 4 "are pivotally attached to the corner pieces 3 by pins 35. These span rods 4 are in pairs, one pair at each end of theframe IS. The span rods 4 of each pair extend upward and inward to connect pivotall-yby pins 31 to a joining element 36, to which the lifting=span5 is also connected. I

The lifting span 5 is composed of -a "plurality of stop links 38, connecting'links, 39, and locking rings *43. Both thestop links 38 and the connecting links 39 are formed with a square topped section 43 -providing vertical abutting faces 4! which operate against the locking ring 40, as will herein-after appear. The body of span 5 is composed of a'number of connecting links 39 joined longitudinally and transversely'by pins 44; and along each outside edgerof the span 5' is a row of stop links 38, with the separate stop links 38 of each row in transverse alignment; The stop 5 links 38 are separated in a longitudinal direction :shrunk onto the square topsections 43 of alternate transverse rows of connecting links 39. The

15 downward bending is prevented'by the locking rings between the faces 4| of adjacent stop links '38 andconnecting links 39. At each end of the lifting span 5 there is insertedrin place of one of the connecting links 39 a downwardly extending .arm B5 to which is :attached a spring #6 which in turn .is fastened to acbllar 4.1 around the transverse frame member 2; The tension .on the spring lii urgesthe arms 45 outward thereby creating a force .urging'the .lifting span 5 down ward into a straight line. The springs 46 also urge the span rods 4 downward to their :rest posi tion. This arrangement with the weight of lifting shackle 6 thus holds' the lifting span 5 in a straight line when not in suspensionand facilitates its operation.

The lifting shackle 6 comprises van inverted .U-' shaped casting -d8 with a separate engaging member 49 bolted in place between the ends of the inverted U bybolts 59. "Ihere are'two retaining pins fifiextending'through the Ush'aped casting '48 and these are so positioned that they'engage the top of the liftingspan 5 when the engaging InemberAS is in engagement with the underside of the lifting span 5. The function of :the re-' taining pins 55 is to support the heavy lifting shackle'B in an upright position on the span ii to receive the suspension hook ll; and as soon as the suspension hook H has engaged -the lift- 7 ing shackle 6, these pins 55 ar'e'removed to allow adjustment of the lifting shackle 6 on the span 5. The engaging'member 49 is formed with a row of upwardly projecting teeth 56 which into the spaces between adjacent c'onnectinglinks 39 and two .end teeth '51which are designed to fit in the spaces between longitudinally adjacent stop links 38 and guide the teeth 56 into proper engagement with'the' span 5. 'Thus'when'the engaging member 49 is fully engaged with the underside of lifting span '5 there can be no dis placement of the lifting shackle '6 in any direction due to a" displaced center of gravity in the truck body 9. When the lifting shackle 6 is adjusted for a displaced center of gravity theadjus'tment will be preserved during suspension because'of this positive engagement between the engaging member'49 and the undersid'e' of the lifting span 5.

' While the operation of the'lifting'sli-nghas been referred" to in the detailed description above, the following description of a complete 'cycle of its operation should'be helpful. First, the suspension hook H is engaged with the lifting shackle'6 and the pins 55 removed as explained above. The liftguides on the tops and backs of the hooks I 0, guiding the lifting sling into position over the V truck body 9.

The hook engaging members I which are in the up position are now pulled downward, overcoming the force of spring 29, by the use of an operating hook 2'! in eye 28. The spring 29 holds the hook-engaging members I in positive engagement with hooks ID. The shackle 6 is then moved along the span 5, until it is approximately over the transverse line passing through the center of gravity of the load in the truck body 9. The engaging member i9 of the shackle 6 is then engaged with the underside of the lifting span 5. The suspension hook H is then raised and the truck body 9 lifted by means of the lifting sling. As the lifting force is applied, the lifting span bends upward against the force of the springs 46 taking a position something like the showing in dotted lines in Fig. III, thus keeping the truck body 9 in a substantially level position in suspension. When the place of deposit is reached, the truck body 9 is lowered to the ground and the suspension hook is further lowered until the engaging saddles 3 of the lifting sling are resting on the tops and backs of hooks I0. The span 5 assumes a straight line under the influence of springs 46. The hook engaging members I are then snapped upward by the operating hook 21; the lifting shackle 6 moved back to a center position; and the sling is disengaged by lifting it clear of the hooks II]. If the suspension hook II is to be disengaged from the lifting shackle 6, the pins 55 are first replaced to support the lifting shackle 6 in an upright position on span 5. Thus the transfer of the truck body 9 is efficiently and quickly accomplished, preserving at all times a substantially level position of the truck body 9 in spite of a displaced center of gravity in the load. The adjustment for the displaced center of gravity in the load is easily accomplished and positive in its operation. The coupling and uncoupling by means of the operating hook is obviously a speedy process. The positioning of the lifting sling by means of the engaging saddles 8 also speeds up the entire operation.

While my invention has been described in some detail with reference to a specific embodiment, various changes in the form of apparatus used are within the contemplation of the invention and such changes should not be deemed to constitute a departure from the invention as hereinafter claimed.

Having thus described my invention, I claim:

from bending downward from the straight line of the top surface of the links without preventing a free bending upward.

3. The invention of claim 2 characterized by the further fact that the lifting shackle is formed with a toothed engaging member to fit into the spaces between adjacent links and a removable retaining pin extending above the lifting span across the opening in the shackle whereby the retaining pin holds the shackle in an upright position on the span for engagement and disengagement with a suspension means.

4. A lifting sling having a frame, hook engaging members attached to the frame, a pair of span rods pivotally attached to each end of the frame, a flexible lifting span connected to each pair of span rods where the members of each pair connect, said span being made up of stop links and connector links pivotally attached to each other, said links having abutting faces and locking rings for contacting said abutting faces to limit said pivotal action, and a movable lifting shackle engaging the underside of said span between adjacent stop links.

5. The invention of claim 4 characterized by the further fact that the links of the span and span rods are spring urged to a position in which the links lie in a straight line.

6. The invention of claim 4 characterized by the further fact that the span is urged into a straight line by a downwardly extending lever arm which is urged outward by a spring attached to said frame.

7. The invention of claim 4 characterized by the further fact that said frame is rectangular in shape and said span is of substantial width to oppose tilting in the direction of the width of the frame.

LEWIS M. SHOWERS, JR.

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