Two lid counterbalance mechanism

Claim 2

A combination counter balance and hinge mechanism for supporting a pair of lids on a cabinet for vertical swinging movements in opposite directions between essentially horizontal closed and essentially vertical open positions, said mechanism comprising: a stationary hinge part adapted to be fixed to said cabinet; a first movable hinge part adapted to carry a first of said lids; a second movable hinge part adapted to carry a second of said lids; means for pivotally connecting said first and second hinge parts to said stationary hinge part whereby to permit independent vertical swinging movements of said lids in opposite directions; a counter balance assembly; and means coupling opposite ends of said assembly to said first and second hinge parts, said assembly establishing first and second moments tending to counterbalance the torque effects of gravity on said first and said second lids, respectively, throughout at least a substantial portion of the vertical swinging movements thereof.

Claim 3

A mechanism according to claim 1, wherein the torque effect of gravity on said first lid is greater than on said second lid; and said assembly includes a pair of compression springs, a first of said springs establishing said first moment, and said first and second springs working in opposition establishing said second moment.

Claim 4

A mechanism for use in counterbalancing first and second lids supported for vertical swinging movements in opposite directions relative to a cabinet between essentially horizontal closed and essentially vertical open positions, said mechanism comprising: a stationary hinge part; a first movable hinge part; a second movable hinge part; hinge pin means for pivotally connecting said first and second hinge parts to said stationary hinge part whereby to permit independent vertical swinging movement thereof in opposite directions, said first and second hinge parts being coupled to said first and second lids respectively for conjunctive vertical swinging movements when said first and second hinge parts are swung relative to said stationary hinge part as aforesaid; an elongated bolt extending transversely of said hinge pin means; first means for providing a slide support for one end of said bolt while permitting relative vertical swinging movements of said one end relative to said first hinge part; second means for providing an end bearing support for another end of said bolt while permitting relative vertical swinging movements of said other end relative to said second hinge part; means carried by said bolt intermediate the ends thereof; a first compression spring disposed about said bolt to bear adjacent opposite ends thereof on said bolt carried means and said first means, whereby to continuously maintain said first compression spring in a compressed state; a second compression spring disposed about said bolt intermediate said second means and said bolt carried means and being maintained thereby in no more than a minimum state of compression; stop means positioned for engagement by said second compression spring upon vertical swinging movement of said second part from said horizontal position whereby to effect compression of said second spring intermediate said stop means and said bolt carried means, said first compression spring establishing a first moment tending to counterbalance gravity induced torque effects on said first lid during vertical swinging movements thereof, and said first and Second compression springs working in opposition establishing a second moment tending to counterbalance gravity induced torque effects on said second lid during vertical swinging movements thereof.

Claim 5

A mechanism for use in counterbalancing first and second lids supported for vertical swinging movements in opposite directions relative to a cabinet between essentially horizontal closed and essentially vertical open positions, said mechanism comprising: a stationary hinge part; a first movable hinge part; a second movable hinge part; hinge pin means for pivotally connecting said first and second hinge parts to said stationary hinge part whereby to permit independent vertical swinging movement thereof in opposite directions, said first and second hinge parts being coupled to said first and second lids respectively for conjunctive vertical swinging movements when said first and second hinge parts are swung relative to said stationary hinge part as aforesaid; an elongated bolt extending transversely of said hinge pin means; first means for providing a slide support for one end of said bolt while permitting relative vertical swinging movements of said one end relative to said first hinge part; second means for providing an end bearing support for another end of said bolt while permitting relative vertical swinging movements of said other end relative to said second hinge part; means carried by said bolt intermediate the ends thereof; a first compression spring disposed about said bolt to bear adjacent opposite ends thereof on said bolt carried means and said first means, whereby to continuously maintain said first compression spring in a compressed state; a second compression spring disposed about said bolt intermediate said second means and said bolt carried means and being maintained thereby in no more than a minimum state of compression; stop means positioned for engagement by said second compression spring upon vertical swinging movement of said second part from said horizontal position whereby to effect compression of said second spring intermediate said stop means and said bolt carried means, said first compression spring establishing a first moment tending to counterbalance gravity induced torque effects on said first lid during vertical swinging movements thereof, and said first and Second compression springs working in opposition establishing a second moment tending to counterbalance gravity induced torque effects on said second lid during vertical swinging movements thereof.

Claim 6

A mechanism according to claim 3, wherein said first and second lids are fixedly carried by said first and second movable hinge parts, and said hinge pin means is a single hinge pin.

Claim 7

A mechanism according to claim 4, wherein said second means includes a connector member forming an end bearing support for said other end of said bolt, first pivot pin means, slot means defined by said stationary hinge part, said slot means extending transversely of said hinge pin means and slideably and rotatably receiving said first pivot pin means, second pivot pin means, and link means, said first and second pivot pin means pivotally connecting opposite ends of said link means to said connector member and said second hinge part for relative vertical swinging movement.

Claim 8

A mechanism according to claim 3, wherein said bolt carried means includes first and second members, said first member being arranged in bearing engagement with said first compression spring and being threadably carried by said bolt for movement lengthwise thereof whereby to adjustably vary the compression of said first compression spring, said second member being arranged for engagement with said second compression spring and constrained by said bolt for movements lengthwise thereof towards said first member, and said second means end supports said bolt for rotation relative thereto about an axis extending lengthwise of said bolt.

Claim 9

A mechanism according to claim 6, wherein said first and second lids are fixedly carried by said first and second movable hinge parts, said hinge pin means is a single hinge pin, said second means includes a connector member forming an end bearing support for said other end of said bolt, first pivot pin means, slot means defined by said stationary hinge part, said slot means extending transversely of said hinge pin means and slidably and rotatably receiving said first pivot pin means, second pivot pin means, and link means, said first and second pivot pin means pivotally connecting opposite ends of said link means to said connector member and said second hinge part for relative vertical swinging movement.