Improved cover mounting hinge and counter balance mechanism and method of mounting same

Claim 1

In a cover mounting combination hinge and counterbalance mechanism for hingedly mounting a cover upon an open top cabinet for vertical swinging movement between horizontally disposed closed and vertically disposed open positions, said mechanism including first and second bracket means adapted to be attached to said cover and to said cabinet, respectively, a hinge pin pivotally interconnecting said bracket means, a member movably connected to said first bracket means by pin means for movement relative to said second bracket means during swinging movements of said cover, said member having an apertured bottom portion, compression spring means bearing downwardly at its bottom end uopn said bottom portion and bearing at its upper end against an upper member, a tie rod fixed at its bottom end to a bottom plate and slideably extending through said bottom portion and said spring means and fixed at its upper end to said upper member whereby to hold the latter in a constant distance relation with said bottom plate, said bottom plate being constrained from movement by engagement with a bottom end portion of said second bracket means, whereby said spring means exerts forces acting through said member counter balancing the torque effects of gravity on said cover throughout substantially the whole of the range of its positional movements, the improvement which comprises in combination: retainer means removably insertable into a position intermediate said bottom portion and said bottom plate for releasably maintaining said bottom plate at a given distance from said pin means resulting in said spring means being releasably maintained by said retainer means in a partially compressed state, said given distance being in excess of the minimum distance between said pin means and said bottom end portion at least in one position of said cover other than said closed position whereby after said bracket means are attached said member may be swung about said pin means to position said bottom plate for engagement with said bottom end portion at least when said cover is in said one position, said bottom portion moving away from said bottom plate against the bias of said spring means to permit removal of said retainer means from between said bottom portion and said bottom plate when said bottom plate is engaged with said bottom end portion and said cover is pivoted from said one position towards said closed position, and said spring means tending to maintain said bottom plate at a distance from said pin means less than the minimum distance between said bottom end portion and said pin means for all positions of said cover.