Jack construction for trailers and the like

Claim 2

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner element and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises a pair of tubelike members telescoped one over the other and means securing said two members together, including indexing means for preventing relative rotation between said two tube-like members, said indexing means including side wall portions of each of said tube-like members defining mutually interfitting and rotationally interfering structures, and the innermost one of said tube-like members having a side wall portion which is generally flattened and which extends along a substantial portion of the length of said member.

Claim 3

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner eLement and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises a pair of tube-like members telescoped one over the other and means securing said two members together, including indexing means for preventing relative rotation between said two tube-like members, said indexing means including side wall portions of each of said tube-like members defining mutually interfitting and rotationally interfering structures, the said side wall portion of the outermost one of said tube-like members defining a longitudinal deformation in the wall of such member which provides a longitudinal guideway thereon, and said outer jack element including a portion projecting slideably into said guideway to guide said lengthwise movement of said inner and outer elements and prevent relative rotation therebetween.

Claim 4

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner eLement and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises a pair of tube-like members telescoped one over the other and means securing said two members together, including indexing means for preventing relative rotation between said two tube-like members, said indexing means including side wall portions of each of said tube-like members defining mutually interfitting and rotationally interfering structures, the said side wall portion of the outermost one of said tube-like members defining a longitudinal deformation in the wall of such member which provides a longitudinal guideway thereon, and said outer jack element including a portion projecting slideably into said guideway to guide said lengthwise movement of said inner and outer elements and prevent relative rotation therebetween.

Claim 5

The improvement defined in claim 2, wherein said deformation is an inward crimp in the wall of said tube-like member which extends along a substantial portion of length of said outer tube.

Claim 6

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner element and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises a pair of tube-like members telescoped one over the other and means securing said two members together, including indexing means for preventing relative rotation between said two tube-like members, said indexing means including side wall portions of each of said tube-like members defining mutually interfitting and rotationally interfering structures, the said side wall portion of the outermost one of said tube-like members defining a longitudinal deformation in the wall of such member which provides a longitudinal guideway thereon, and said side wall portion of said innermost tube-like member defining a laterally raised ridge-like portion extending along a substantial part of the length of such member.

Claim 7

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner element and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises a pair of tube-like members telescoped one over the other and means securing said two members together, including indexing means for preventing relative rotation between said two tube-like members, said indexing means including side wall portions of each of said tube-like members defining mutually interfitting and rotationally interfering structures, the said side wall portion of the outermost one of said tube-like members defining a longitudinal deformation in the wall of such member which provides a longitudinal guideway thereon, and said side wall portion of said innermost tube-like member defining a laterally raised ridge-like portion extending along a substantial part of the length of such member.

Claim 8

The improvement defined in claim 4, wherein said laterally raised ridge-like portion comprises a longitudinal flange fixed to and extending from a side of said member.

Claim 9

The improvement defined in claim 4, wherein said innermost tube-like member comprises a pair of generally channel-shaped strips each of which has flanged edges, said strips being secured together along their respective flanges in back-to-back relation to form a laterally flanged tubular member.

Claim 10

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner element and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises a pair of tube-like members telescoped one over the other and means securing said two members together, and wherein the innermost one of said tube-like members is formed with a generally polygonal cross section having corner portions spaced sufficiently apart to cause such corners to contact the interior of the outermost tube-like member.

Claim 11

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner element and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises a pair of tube-like members telescoped one over the other and means securing said two members together, and wherein the innermost one of said tube-like members is formed with a generally polygonal cross section having corner portions spaced sufficiently apart to cause such corners to contact the interior of the outermost tube-like member.

Claim 12

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner element and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises at least one relatively thin-walled tube having a circumferential wall defining undulations extending ridge-like and groove-like along the length of such tube, and wherein said outer jack element includes a portion projecting slideably into one of said groove-like undulations as a guideway to guide said lengthwise movement of said inner and outer elements and prevent relative rotation therebetween.

Claim 13

In a lengthwise-extendable jack member of the type having an outer element telescoped over an inner element and means for moving one of said elements along the length of the other, the improvement wherein said inner element comprises at least one relatively thin-walled tube having a circumferential wall defining undulations extending ridge-like and groove-like along the length of such tube, and wherein said outer jack element includes a portion projecting slideably into one of said groove-like undulations as a guideway to guide said lengthwise movement of said inner and outer elements and prevent relative rotation therebetween.