Description TECHNICAL FIELD The present invention relates generally to lifting devices, such as cranes or the like, and more particularly to a boom assembly comprised of a plurality of telescoping boom sections and corresponding interchangeable wear pads for reducing the friction during the relative telescoping movement. Typically, the boom assembly includes a plurality of nested tubular sections, with each outer section having a larger cross-sectional size than the next-adjacent inner section to permit the desired relative telescoping movement. In the typical arrangement, the proximal end of the outermost boom section is pivotally mounted on a turntable, and the distal end of the innermost section carries one or more sheaves or equivalent structures for supporting the hoisting cable or the like. A basic example of such an arrangement is shown in Kidde's U.
Telescoping boom assembly with rounded profile sections and interchangeable wear pads
German Patents in International Class B21B45/04
SUBSTANCE: method comprises steps of multiple elastic-plastic sign-variable lengthwise bending of strip and simultaneous crosswise bending of it due to increased bending of edge along strip width portions in comparison with mean portion of strip; providing bending value of edge portions more than that bending value of its mean portion at first bending operation and at each next bending operation providing bending value of edge portions less than that of previous bending operation; successively reducing values of lengthwise bending along straightening process direction from predetermined value to zero. For editing using special roller machine, in which the alternating elastic-plastic buckling of moving metal, such as strip steel. Sheet profiles with recurrent corrugations profiles high rigidity is made by cold local deformation; corrugated strip before cutting to length is subjected to the edit on the right machines, containing rollers with grooves for the passage of the corrugations, as the edit is only performed on a flat Migatronic areas of these bands. Known way to edit the sheet metal, mainly maraboutage, multi-roll belt machine with asymmetric location of the sectional support rollers along the length of the barrel of the working rollers see U. CL , No.
US3213573A - Extensible and retractable member - Google Patents
Bohr, Sparta, and Walter 0. Borcherdt, Mountain Lakes, N. As is well known, extensible members have useful application in many different arts as: antennae in communications; supports for platforms used in the harvesting of fruit and in the inspection or servicing of machinery; as elevators for fire hoses, loading of supplies, etc. Usually such extensible or retractable members are of the telescopic type which involves related problems of length of span and span strength, their support or reinforcing by adjacent spans, and number of spans to effect a desired amount of extensionall of which have to be reconciled with practical considerations such as the support of the member in both the extended or retracted position and particularly its bulk in the latter position.
Leroy, Rockford, Application October 15, , Serial No. The screen, when straightened in this way can be out safely, there being no longer any danger of a loose cut end springing upwardly and putting out an eye or doing other serious injury to a workman Such injuries were very common when this material was handled the old way, which consisted in merely rolling the roll to unwind a given length lying on the ground and then cutting off the length thus unwound. The springback in the unstraightened material, taken together with the sharpness of the freshly cut ends on the wires, made a treacherous combination hard to cope with. Transversely extending supports are also provided between the roll and crimping roller to engage the loose end portion of the screen from below so as to prevent downward buckling and retain the end portion between the guard or bumper and the transverse support.