Spring biased prop for a pivoted member hinged to a support member

Claim 1

A prop for use with a pivot member hinged to a support member, said prop having an inner tubular member and an outer tubular member, the inner of said tubular members fitting telescopically in a slidable relationship into the outer of said tubular members, the terminal ends of said telescopically fitting tubular members being arcuately constricted in diameter, the terminal ends of said tubular members terminating in an inturned edge to provide openings into said tubular members of a diameter less than the internal diameter of the tubular members, each tubular member having an end edge oppositely located from its said terminal end, two arm parts each including a shank terminating in an enlarged spherical end, said arm parts adapted for connection at their shank to said pivot member and support member, said shank of said one arm part extending with clearance through the terminal opening in said one tubular member with said enlarged spherical end fitting within said tubular member terminal end, said shank of said other arm part extending with clearance through the terminal opening in said other tubular member with said enlarged spherical end fitting within said tubular member terminal end, a helical compression spring positioned within and in association with said tubular members for biasing said tubular members toward an extended position, each end of said spring contacting an arcuate disk, said arcuate disk being interposed between the end of its contacting spring and the enlarged spherical end of an arm part to urge said arm part into slidable contact with the internal surface of the terminal end of the tubular member receiving said arm part, said inner tubular member having an outturned flange formed at its end edge, said flange extending to adjacent the inner surface of said outer tubular member, a slot formed in each of the terminal ends of said tubular members interrupting the said inturned edges, said slots for receiving the shanks of said arm parts to accommodate angular pivoted movement of said arm parts relative to said tubular members, a sleeve formed of a material providing a low coefficient of static friction, said sleeve being bonded to the inner surface of said outer tubular member adjacent its end edge, said sleeve having an inner end edge, said sleeve inner end edge engaging the outturned flange of said inner tubular member upon full extension of the tubular members wherein said engagement prevents separation of said tubular members, said sleeve forming a bearing surface to accommodate sliding movement of the said inner tubular member within the said outer tubular member.