Leveling sling

Claim 2

A sling for carrying a load comprising a liftable, loadbearing frame, a releasable gripper mounted on said frame, two sling legs depending from the sides of said frame opposite each other and being defined by a cable having an intermediate end portion trained across said gripper and an end doubled back and connected with said frame to form an elongated loop, said legs having free ends adapted for attachment to the load, said gripper serving to hold said frame against sliding on the intermediate end portion of the cable when under load, mechanism for releasing said gripper from the cable when under no load so that saiD gripper may be slid with said frame across the cable to lengthen one of the legs by enlarging the loop forming that leg while shortening the other leg thereby to select the general attitude at which said load is to be lifted, and means connected to the doubled back end of said cable and selectively operable to lengthen and shorten said one loop after said load is lifted to move said load into a precise attitude for carriage by said sling.

Claim 3

A sling for carrying a load comprising a liftable, load-bearing frame, a releasable gripper mounted on said frame, two sling legs depending from opposite sides of the frame and formed as elongated loops defined by a cable having an intermediate end portion trained across said gripper and end portions doubled back and connected with said frame, said loops having free ends adapted for attachment to the load, said gripper serving to hold said frame against sliding on the intermediate end portion of the cable when under load, mechanism for releasing said gripper from the cable when under no load so that said gripper may be slid with said frame across the cable to lengthen one of the legs by enlarging the loop forming that leg while shortening the other leg thereby to select the general attitude at which said load is to be lifted, and power means connected between said two loop portions and being selectively operable to lengthen one of said loops while shortening the other of said loops after said load is lifted to move said load into a precise attitude for carriage by said sling.

Claim 4

A sling for carrying a load comprising a liftable, load-bearing frame, a releasable gripper mounted on said frame, two sling legs depending from opposite sides of the frame and formed as elongated loops defined by a cable having an intermediate end portion trained across said gripper and end portions doubled back and connected with said frame, said loops having free ends adapted for attachment to the load, said gripper serving to hold said frame against sliding on the intermediate end portion of the cable when under load, mechanism for releasing said gripper from the cable when under no load so that said gripper may be slid with said frame across the cable to lengthen one of the legs by enlarging the loop forming that leg while shortening the other leg thereby to select the general attitude at which said load is to be lifted, and power means connected between said two loop portions and being selectively operable to lengthen one of said loops while shortening the other of said loops after said load is lifted to move said load into a precise attitude for carriage by said sling.

Claim 5

A sling as defined by claim 2 wherein said power means includes a motor mounted on said frame, a drive sprocket mounted on said frame vertically of said gripper and connected to said motor for selective rotation thereby, and a chain connected to and extending between the doubled back ends of said loop portions and trained across said sprocket for selective movement thereby from one side of said frame to the other side to shorten one of said loop portions while lengthening the other of said loop portions when said motor is actuated to rotate the sprocket.

Claim 6

A sling as defined by claim 3 wherein said power means further includes a power reducer mounted on said frame opposite said motor and connected between said motor and said sprocket to act as a brake and thereby prevent movement of said chain without actuation of said motor.

Claim 7

A sling as defined by claim 4 including two idler sprockets mounted on said frame vertically of said drive sprocket, said idler sprockets being spaced from each other at opposite ends of said drive sprocket, said chain being threaded around said idler sprockets to guide the chain over a predetermined length on the circumference of said drive sprocket notwithstanding differences in the included angle between said sling legs.

Claim 8

A sling as defined by claim 5 including a block and hook mounted on the looped end of each of said legs for attachment to the load and for riding within said loop portions as said legs are lengthened and shortened to adjust the attitude of said load.

Claim 9

A sling for carrying a load comprising a liftable, load-bearing frame, a releasable gripper mounted on said frame, two sling legs depending from opposite sides of the frame and formed as elongated loops defined by a cable having an intermediate end portion trained across said gripper and end portions doubled back toward said frame, and connected to each other, said loops having free ends adapted for attachment to the load, said gripper serving to hold said frame against sliding on the intermediate end portion of the cable when under load, mechanism for releasing said gripper from the cable when under no load so that said gripper may be slid with said frame across the cable to lengthen one of the legs by enlarging the loop forming that leg while shortening the other leg thereby to select the general attitude at which said load is to be lifted, power means being operable to move the connected end portions of said cable back and forth selectively to lengthen one of said loops while shortening the other of said loops after said load is lifted to move said load into a precise attitude for carriage by said sling.

Claim 10

A sling for carrying a load comprising a liftable, load-bearing frame, a releasable gripper mounted on said frame, two sling legs depending from opposite sides of the frame and formed as elongated loops defined by a cable having an intermediate end portion trained across said gripper and end portions doubled back toward said frame, and connected to each other, said loops having free ends adapted for attachment to the load, said gripper serving to hold said frame against sliding on the intermediate end portion of the cable when under load, mechanism for releasing said gripper from the cable when under no load so that said gripper may be slid with said frame across the cable to lengthen one of the legs by enlarging the loop forming that leg while shortening the other leg thereby to select the general attitude at which said load is to be lifted, power means being operable to move the connected end portions of said cable back and forth selectively to lengthen one of said loops while shortening the other of said loops after said load is lifted to move said load into a precise attitude for carriage by said sling.