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US 4,571,775 AGranted
Counterbalance device and torsion member usable therein
AssigneeAirpot Corporation
InventorGeorge H. Leonard
Life of this patent
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AssigneeAirpot Corporation
InventorGeorge H. Leonard
Estimating the term…
A device for counterbalancing a moving part comprises an elongated torsion member surrounded by a sleeve, the sleeve being connected to the torsion member at one point and the torsion member being fixedly supported at another point spaced from said one point, the moving part and the sleeve respectively carrying cooperating elements of a cam-follower combination, the cam being shaped, taking into account the torsion characteristics of the torsion element, to produce the desired counterbalancing effect. The torsion member itself advantageously comprises a plurality of elongated narrow elements of polygonal cross-section arranged in a predetermined grouping with sides of adjacent elements engaging one another, the exposed surfaces of said elements defining at least in part a polygonal shape, operative connections to points along the length of the torsion member being effected by bodies having appropriately shaped polygonal openings into which the grouping of the narrow elements is received so as to non-rotatably engage at least some of the elements and to confine the elements so that they are maintained in that predetermined grouping. The construction of the torsion member is such that a variety of different torsion element groupings can be received within a given polygonal opening, with a still greater variation in the number of torsion elements being possible by simple modifications of those polygonal openings, so that great latitude in operating characteristics can be achieved with an essentially standardized construction.
A counterbalance device to act between first and second parts connected to one another to pivot about a first axis, comprising a pair of spaced supports adapted to be secured to said first part and spaced from one another along a second axis spaced from said first axis, socket members secured to said supports, extending toward one another, and having polygonal recesses facing one another along said second axis, a torsion member having ends non-rotatably received in said recesses and extending along said second axis, a sleeve extending between and mounted on said socket members to rotate relative to said socket members about said second axis, said torsion member being freely received within said sleeve, an anchor means inside said sleeve non-rotatably mounted on said torsion member at a point spaced from said socket members, and means operatively connecting said anchor means to said second part.
A counterbalance device to act between first and second parts articulately connected to one another, comprising a pair of spaced supports adapted to be secured to said first part, socket members secured to said supports, extending toward one another, and having facing polygonal recesses, longitudinally extending lengths of torsion member each having an end nonrotatably received in said recesses respectively, a sleeve extending between and rotatably mounted on said socket members within which said torsion member is freely received, anchor means inside said sleeve non-rotatably mounted on said lengths of torsion members at points spaced from said socket members respectively, an arm extending radially from and non-rotatably secured to said sleeve, a cam adapted to be secured to said second part radially spaced from said sleeve, cam follower means on said arm engaging said cam, and means non-rotatably connecting said sleeve and said anchor means, said torsion member exerting a rotary force on said sleeve in a direction to urge said follower against said cam.
A mechanism including a first member and a second member and a pivotal connection securing said members together for relative movement about a pivotal axis, and a torsion-spring mechanism for providing spring bias between said members about said pivotal axis, said torsion-spring mechanism including
A torsion spring device including an elongated tube, a pair of bearing members aligned with each other along the axis of the tube and cooperating with opposite ends of said tube to provide bearing support for the tube, said bearings being adapted to be secured non-rotatably to an external member, said members having respective sockets that provide cavities opening toward each other, torsion spring means comprising bundled rods of regular polygonal cross-section extending axially inside said tube and having opposite end portions received non-rotatably in the cavities of said sockets, means disposed between and spaced substantially from both of said sockets for securing said tube to said bundled rods, thereby developing two lengths of bundled rods extending between said tube and said sockets, and means secured to said tube for developing torsion in said bundled rods.
Dependencies are inferred from the claim text.