Counterbalancing mechanism for X-ray tubeheads
AssigneePennwalt Corporation
InventorsCarl G. Nilsen, Richard A. Gabel
Life of this patent
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Abstract
An X-ray tubehead counterbalancing mechanism devoid of springs, cams and chains is disclosed. The mechanism requires only a single adjustment to precisely counterbalance objects, such as tubeheads and the like. The mechanism includes a commercially available gas spring which is used in conjunction with parallel motion linkage assembly which carries the tubehead. The piston rod end of the gas spring is adjustable upwardly or downwardly in a direction substantially normal to the axis of the piston rod by means of a single adjustment screw cooperating with a clevis which pivotally mounts the piston rod. With such adjustment capability, the present mechanism will support and counterbalance tubeheads having wide variations in weight and inertia.
Claims6
In an extensible and adjustable X-ray arm carrying an X-ray tubehead at an outer end thereof, said X-ray arm including a linkage assembly articulating successively between each of a knuckle assembly, triangle assembly, cam housing assembly, and trunnion assembly, said tubehead communicating with said trunnion assembly and having wide weight and inertia variations, the combination therewith of the improvement for precisely counterbalancing said tubehead by means of a single adjustment, said counterbalancing being achieved by a counterbalance mechanism devoid of cams, chains and springs and comprising
- a hollow structural member pivotally connected at upper end portions thereof to said cam housing assembly and trunnion assembly,
- a gas spring disposed at a lower portion of said hollow structural member, said gas spring including a cylinder and a piston rod,
- means within said hollow structural member for pivotally mounting said cylinder proximal to pivotal connection of said structural member to said trunnion assembly, and
- other means within said structural member for moving outer end of said piston rod in a direction substantially normal to axis of said gas spring for changing resisting moment arm to counterbalance said tubehead.
Dependencies are inferred from the claim text.