Hoist line sling for lifting heavy loads

Claim 2

In a hoist line sling designed to lift and handle heavy industrial loads, and which sling comprises an elongated flexible web of substantially uniform width and thickness throughout its length, and attaching members connected with the web and by which the web may be operatively connected with a load and with a lifting hook, the improvement by which the side edge portions of the web carry no more than does the medial portion thereof of the stresses in the web that result from tension loads on the web during use of the sling, and which improvement resides in the connection between the web and each of said attaching members, said connection comprising: A. a rigid crossbar having an axis and being of a length slightly greater than the width of the web, said crossbar extending transversely of the web and having both ends thereof equally supportingly connected with the attaching member; B. parts on said crossbar and on said web in load bearing engagement; C. load concentrating means on one of said parts by which said stresses in the web during use of the sling are concentrated in the medial portion of the web as distinguished from its side portions, said load concentrating means comprising an elongated load bearing surface on said one part extending transversely across the full width of the web and being convexly curved along the length thereof, said convex curvature being substantially symmetrical to the axis of said crossbar; and D. said one part and the crossbar being sufficiently rigid to preclude deformation thereof by loads encountered during use of the sling.

Claim 3

In a hoist line sling, the structure of claim 1, wherein at lEast one of the attaching members is an eye at one end of the web, and wherein said rigid crossbar is an integral part of said eye, and said part that is on the web and has load bearing engagement with the crossbar is a loop formed in the web.

Claim 4

In a hoist line sling, the structure of claim 1, wherein said one part of the connection which has the convexly curved surface is on the web.

Claim 5

In a hoist line sling, the structure of claim 3, wherein the part of the connection which is on the web is a loop formed by a portion of the web and embracing the rigid crossbar, and wherein said one part which has the convexly curved surface is a pad on the inner surface of said loop and in load bearing engagement with the rigid crossbar.

Claim 6

In a hoist line sling, the structure of claim 1, wherein said one part of the connection which has the convexly curved surface is on the rigid crossbar.

Claim 7

The hoist line sling of claim 5, wherein said eye has divergent side members joined to the ends of the crossbar with the side members and crossbar lying in a common plane, and wherein the portions of said side members that are contiguous to the ends of the crossbar project transversely to said common plane beyond the surfaces of the crossbar to provide shoulders at the ends of the crossbar which hold the loop of the web properly positioned on the crossbar and provide ribs to protect the web from contact with possibly abrasive surfaces.

Claim 8

In a hoist line sling, the structure of claim 5, wherein said one part of the connection which has the convexly curved surface is a member separate from but embracing the rigid crossbar.

Claim 9

In a hoist line sling, the structure of claim 7, wherein the rigid crossbar is round in cross section, and wherein said member which has the convexly curved surface is a flanged and crowned spool freely rotatably mounted on the crossbar.

Claim 10

In a hoist line sling, the structure of claim 7, wherein said member which has the convexly curved surface is a saddle of substantially U-shaped cross section, straddling the rigid crossbar, the top surface of the saddle being longitudinally crowned to provide the convexly curved surface.

Claim 11

In a hoist line sling, the structure of claim 9, further characterized by pins projecting from the sides of the crossbar and loosely received in holes in the adjacent portions of the saddle to keep the saddle on the crossbar without restraining limited movement of the saddle with respect to the crossbar.

Claim 12

In a hoist line sling, the structure of claim 10, wherein the underside of the saddle is longitudinally convexly curved so that the saddle can rock on the crossbar.

Claim 13

In a hoist line sling, the structure of claim 11, wherein the crossbar is narrower than the space between the sides of the saddle, so that the saddle has some freedom to rock from side to side as well as longitudinally of the crossbar.

Claim 14

In a hoist line sling designed to lift heavy industrial loads, and which sling comprises an elongated flexible web of substantially uniform width and thickness throughout its length, and a rigid metal eye connected to each end of the web and by which the web may be operatively connected with a load and a lifting hook, the eye having spaced side arms, the improvement by which the side edge portions of the web carry no more than does the medial portion thereof of the stresses in the web that result from tension loads on the web during use of the sling, and which improvement resides in the connections between the web and the eyes, each of said connections comprising: A. a rigid crossbar which forms an integral part of the eye and has both ends thereof equally supportingly connected to the spaced arms of the eye, said crossbar having an axis; B. a loop on the web embracing the crossbar and having load bearing engagement therewith; C. load concentrating means by which said stresses in the web during use of the sling are concentrated in the medial portion of the web as distinguisheD from its side edge portions, said load concentrating means comprising an elongated load bearing surface on the rigid crossbar extending transversely across the full width of the web and with which the loop on the web has said load bearing engagement, said load bearing surface being convexly curved along the length thereof with the curvature substantially symmetrical to the axis of the crossbar; and D. said crossbar being sufficiently rigid to preclude deformation thereof by loads encountered during use of the sling.

Claim 15

In a hoist line sling designed to lift heavy industrial loads, and which sling comprises an elongated flexible web of substantially uniform width and thickness throughout its length, and a rigid metal eye connected to each end of the web and by which the web may be operatively connected with a load and a lifting hook, the eye having spaced side arms, the improvement by which the side edge portions of the web carry no more than does the medial portion thereof of the stresses in the web that result from tension loads on the web during use of the sling, and which improvement resides in the connections between the web and the eyes, each of said connections comprising: A. a rigid crossbar which forms an integral part of the eye and has both ends thereof equally supportingly connected to the spaced arms of the eye, said crossbar having an axis; B. a loop on the web embracing the crossbar and having load bearing engagement therewith; C. load concentrating means by which said stresses in the web during use of the sling are concentrated in the medial portion of the web as distinguisheD from its side edge portions, said load concentrating means comprising an elongated load bearing surface on the rigid crossbar extending transversely across the full width of the web and with which the loop on the web has said load bearing engagement, said load bearing surface being convexly curved along the length thereof with the curvature substantially symmetrical to the axis of the crossbar; and D. said crossbar being sufficiently rigid to preclude deformation thereof by loads encountered during use of the sling.

Claim 16

In a hoist line sling, the structure of claim 13, wherein said crossbar has a flat-sided slot therethrough, the flat sides of which are parallel to the general plane of the eye, and wherein said elongated load bearing surface is the top of the head of a T-shaped member having its stem received in said slot with the underside of the head of the T bearing upon the crossbar at opposite sides of the slot.

Claim 17

In a hoist line sling, the structure of claim 14, wherein the underside of the head of the T-shaped member is convexly curved longitudinally thereof so that the T-shaped member may rock lengthwise of the crossbar.

Claim 18

In a hoist line sling, the structure of claim 14, wherein the top surface of the head of the T-shaped member is transversely rounded.

Claim 19

A hoist line sling for lifting heavy industrial loads, which comprises a flexible web having parallel side edges, connected at each end to a rigid eye, characterized in that: A. each eye is substantially triangular in shape, with three connected legs, one of which forms a crossbar extending between the free ends of the other two legs; B. loops on the ends of the web embracing the crossbars of the eyes to have force transmitting engagement with the inner surfaces of the crossbars during use of the sling, said crossbars being rigid and undeformable by loads lifted with the sling, and the inner surfaces of the crossbars being convexly curved lengthwise thereof so that during use of the sling and application of tension upon the web through an eye, the portion of the web medially of its side edges is stressed before any load is placed upon the side edge portions of the web; C. a second rigid crossbar connected to and bridging said other two legs of one of the eyes in parallel spaced relation to its first mentioned crossbar, the space between the first and second crossbars and the legs to which they are connected being large enough to permit the eye at the other end of the web to be passed therethrough to enable the sling to be formed into a loop around a load to be lifted by a pull on the eye at said other end of the web, and the surface of the second crossbar which faces the first crossbar being convexly curved lengthwise thereof and transversely rounded.

Claim 20

A hoist line sling for lifting heavy industrial loads, which comprises a flexible web having parallel side edges, connected at each end to a rigid eye, characterized in that: A. each eye is substantially triangular in shape, with three connected legs, one of which forms a crossbar extending between the free ends of the other two legs; B. loops on the ends of the web embracing the crossbars of the eyes to have force transmitting engagement with the inner surfaces of the crossbars during use of the sling, said crossbars being rigid and undeformable by loads lifted with the sling, and the inner surfaces of the crossbars being convexly curved lengthwise thereof so that during use of the sling and application of tension upon the web through an eye, the portion of the web medially of its side edges is stressed before any load is placed upon the side edge portions of the web; C. a second rigid crossbar connected to and bridging said other two legs of one of the eyes in parallel spaced relation to its first mentioned crossbar, the space between the first and second crossbars and the legs to which they are connected being large enough to permit the eye at the other end of the web to be passed therethrough to enable the sling to be formed into a loop around a load to be lifted by a pull on the eye at said other end of the web, and the surface of the second crossbar which faces the first crossbar being convexly curved lengthwise thereof and transversely rounded.