Telescoping mast assembly
AssigneeThe Will-Burt Company
InventorHarry E. Featherstone
Life of this patent
Estimating the term…
Abstract
A telescoping mast assembly includes a plurality of interconnected mast sections nested within each other for movement between a fully retracted height and a fully extended height. A novel, rigid drive assembly, disposed within the interconnected mast sections, telescopes the mast sections to any position between the fully retracted and the fully extended heights. The rigid drive assembly is constructed of two interconnected, flexible chain elements which accurately position the interconnected mast sections.
Claims14
A telescoping mast assembly comprising, a plurality of interconnected mast sections nested within each other for movement along a path between retracted and extended positions, a rigid drive assembly for displacing said mast sections along said path, said rigid drive assembly comprising first and second link chain means respectively having a plurality of first link means and a plurality of second link means, each plurality interconnected for pivotal movement about corresponding link axes, the link axes of said first link chain means being perpendicular to the link axes of said second link chain means along said path, and said link means of said first and second link chain means respectively including first and second latching means interconnecting said first and second link chain means along said path against flexure relative to said path, said first latching means including plate means on adjacent ones of said first link means and having abutting edge means providing openings therebetween transverse to said path, and said second latching means including finger means on said second link means transverse to said plate means and interengaging with said openings between said plate means to restrain displacement of said finger means from said openings transverse to said path.
A vertically extendable and retractable mast assembly comprising a plurality of tubular mast sections having a vertical axis and being telescopingly interengaged for relative displacement along said axis between extended and retracted positions, said mast section including an uppermost section and a lowermost section, first and second link chain members in said mast sections and having upper ends connected to said uppermost section, said first chain member comprising a plurality of first link members interconnected for pivotal movement about parallel first link axes, said second chain member comprising a plurality of second link members interconnected for pivotal movement about parallel second link axes, said first and second link chain members extending downwardly from said uppermost section along a path parallel to said vertical axis and with said first and second link axes perpendicular to each other along said path, each of said first link members including two parallel first link plates separated by two rollers and a latch plate affixed between said first link plates, adjacent ones of said latch plates including means providing an opening therebetween, each of said second link members including two parallel second link plates separated by two rollers and a first finger affixed to one of said second link plates and projecting therefrom toward said latch plates on said first link members, the fingers on said second link members engaging in the openings between said latch plates of said first link members to rigidly interengage said first and second chain members along said path against displacement laterally of said path to provide drive member means for displacing said mast sections between said extended and retracted positions, and means to displace said drive member means in opposite directions along said path.
A mast assembly according to calim 13, wherein said means to displace said drive member means includes means to drive one of said first and second link chain members, said fingers and openings interengaging for said one chain member to drive the other chain member.
Dependencies are inferred from the claim text.