Safety side mechanism

Claim 1

For hospital beds, a safety side mechanism comprising: a base member; at least one telescoping side rail member substantially parallel to said base member; a pair of side members pivotally attached to said base and said rail member; said base, said side rail and said side members forming a trapezoid; said side members being biased toward an extended position with respect to said base member; a pair of push arm members connected between respective side members and said base member and biasing means connected between the lower ends of said push arm members for urging said trapezoid into said extended position; said base member including slots in which said lower ends of said push arm members reciprocally move as said safety side mechanism is moved from the extended to the collapsed positions; said biasing means comprising a pair of parallel spaced apart overlapping puss-pull bars, a connecting means connecting adjacent ends of said push-pull bars for permitting equal and opposite movement between said push-pull bars and a spring means connecting the intermediate portions of said push-pull bars for permitting equal and opposite movement between said push-pull bars and a spring means connecting the intermediate portions of said push-pull bars tending to urge said push-pull bars toward each other so that said safety side mechanism isurged toward the extended position; and pivotal attachment means for pivotally attaching said mechanism to a frame member of said hospital bed adapted to be pivoted alongside said frame member when said trapezoid is in a collapsed position defined by said side, rail and base members being substantially parallel so that said mechanism in said collapsed position does not substantially extend beyond the normal width of said bed.