Apparatus for supporting a load in a dynamically balanced condition

Claim 1

Apparatus for adjustably supporting a load of determinable weight, said apparatus comprising lever means for engaging and supporting said load for multi-dimensional adjustment to a selected spatial position, first gravitational control means for engaging said lever means and counteracting the weight of said load with a force in excess of that necessary to balance said load, and second gravitational control means engaging said lever means and counteracting said force with a force such that the weight of said load in conjunction with the force of said second gravitational control means counterbalances the force of the first gravitational control means to provide a substantially neutral gravitational condition whereby the load will remain in any spatial position to which displaced and whereby displacement of the load can be effected in substantially effortless manner; said apparatus further comprising an anchor means for clamping on to a supporting structure, said second control means being mounted on said anchor means and pivotally supporting said lever means, said first control means being extensible and being coupled between said anchor means and lever means; said first control means being a piston and cylinder combination having a gas filled chamber and being adapted to support a weight in excess of that of said load; said second control means including first and second relatively rotatable members, a friction member between said rotatable members, and adjustable spring means for controllably urging the rotatable members together to entrap the friction member with controllable force; said spring means including first and second concentric helical springs, said lever means being attached to said first rotatable member, said first and second rotatable members having disc-like portions entrapping the friction member therebetween, said first rotatable member including inner and outer concentric cylindrical parts defining a cylindrical chamber in which said helical springs are accommodated, said adjustable spring means including a plate having a spline-like coupling with said outer cylindrical part, said plate compressing said springs against the disc-like portion of the first rotatable member to compress the same against said friction member.