Release mechanism for back rest support

Claim 2

A body supporting device including a horizontally hinged portion, supporTing means pivotally engaging said hinged portion, at least one relatively fixed stop for holding the supporting means in a position such that the hinged portion is in an elevated position, release means movable between selected positions respectively permitting and preventing engagement of the supporting means with the stop, means normally effective for biasing said release means toward said engagement-preventing position and releasable means for overriding said biasing means and normally holding the release means in said engagementpermitting position.

Claim 3

A body supporting device according to claim 1 in which the supporting means is a strut and there are a plurality of said stops for holding the strut in a plurality of positions, and in which the release means is elongated and in said engagement-permitting position permits engagement of the strut with any selected stop and, in said engagement-preventing position, prevents engagement of the strut with all of the stops.

Claim 4

A body supporting device according to claim 1 in which there are a plurality of stops constituted by pairs of serrations in the sides of a fixed upwardly open channel, in which the release means is an elongated member longitudinally movable in said channel, and which includes cam elements in the form of lugs and grooves interconnecting said release means with said channel so that upon release of said overriding means said biasing means is effective to move said member longitudinally in a first direction to prevent the engagement of said supporting means with all of said serrations.

Claim 5

A body supporting device according to claim 3 in which the biasing means is a spring under tension.

Claim 6

A body supporting device according to claim 2 in which the biasing means is a spring under tension urging the release means toward the engagement-prevention position thereof, and the releasable means is a manually operable latch operable to hold the release means in its engagement-permitting position.

Claim 7

A body supporting device comprising a main frame, a back rest horizontally hinged to said main frame, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and a head end thereof, at least one upwardly projecting stop engageable with the strut, a bar having a generally horizontal surface movable into a position between said strut and said stop to prevent engagement of the strut with the stop, means for biasing said bar into said position and a manually releasable latch for holding the bar out of said position and selectively releasing said bar for movement into said position so that upon lowering of the position of the back rest said strut slides along said bar out of engagement with said stop.

Claim 8

A body supporting device comprising a main frame, a back rest horizontally hinged to said main frame, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and a head end thereof, at least one upwardly projecting stop engageable with the strut, a bar having a generally horizontal surface movable into a position between said strut and said stop to prevent engagement of the strut with the stop, means for biasing said bar into said position and a manually releasable latch for holding the bar out of said position and selectively releasing said bar for movement into said position so that upon lowering of the position of the back rest said strut slides along said bar out of engagement with said stop.

Claim 9

A device for supporting a body in a plurality of positions, one of said positions being generally horizontal, said device being according to claim 1, in which said supporting means is movable into a given plane defined by the hinged portion when said hinged portion is in a first position for supporting said body in said horizontal position, said supporting means in said given plane being effective to override said biasing means and condition said releasable means for overriding the biasing means upon movement of said hinged means out of said first position.

Claim 10

A body supporting device having a main frame and including a horizontally hinged back rest, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and the head end thereof, a plurality of upwardly projecting stops constituted by pairs of serrations in the sides of an upwardly open channel fixed to the head end of the main frame, said stops being engageable with the bottom of the strut and fixed to the main frame at a point corresponding with an elevated position of the back rest, release means including an elongated member longitudinally moveable in said channel, said member being moveable between positions permitting and preventing engagement of the strut with the stops, means for biasing said release means toward said engagement-preventing position, releasable means adapted to hold the release means in said engagement-permitting position, and cam elements interconnecting said release means with said channel.

Claim 11

A body supporting device having a main frame and including a horizontally hinged back rest, a downwardly extending strut pivotally engaging said back rest approximately midway between the hinge and the head end thereof, a plurality of upwardly projecting stops constituted by pairs of serrations in the sides of an upwardly open channel fixed to the head end of the main frame, said stops being engageable with the bottom of the strut and fixed to the main frame at a point corresponding with an elevated position of the back rest, release means including an elongated member longitudinally moveable in said channel, said member being moveable between positions permitting and preventing engagement of the strut with the stops, means for biasing said release means toward said engagement-preventing position, releasable means adapted to hold the release means in said engagement-permitting position, and cam elements interconnecting said release means with said channel.

Claim 12

A body supporting device according to claim 8 in which the cam elements are laterally disposed lugs and slots which are angled away from horizontal, the lugs being engaged in the slots.

Claim 13

A body supporting device according to claim 8 in which the cam elements are lugs projecting laterally from the release means and slots in the sides of the channel, the slots being angled upwardly in the direction away from the head end of the frame and the lugs being engaged in the slots.

Claim 14

A release mechanism for an arm of a back rest of a body supporting structure, said back rest being hingedly connected at one end thereof to said structure and having an opposite end facing the head of said structure, said mechanism comprising: a bar having a flat surface, said bar being movable relative to said structure into first and second positions; biasing means normally urging said bar into said first position for supporting said arm on said flat surface; a member having a series of stops and carried by said structure so as to normally interpose said stops in the path of said back rest arm for holding said head end in a raised position; means for rendering said biasing means ineffective and holding said bar in said second position so that said arm engages one of said stops and is held in said raised position; and means for releasing said holding means to enable said biasing means to be effective upon raising of the head end of the back rest so that said arm moves along said flat surface as said head end is raised or lowered with an operator''s two hands on said back rest.

Claim 15

A release mechanism for an arm of a back rest of a body supporting structure, said back rest being hingedly connected at one end thereof to said structure and having an opposite end facing the head of said structure, said mechanism comprising: a bar having a flat surface, said bar being movable relative to said structure into first and second positions; biasing means normally urging said bar into said first position for supporting said arm on said flat surface; a member having a series of stops and carried by said structure so as to normally interpose said stops in the path of said back rest arm for holding said head end in a raised position; means for rendering said biasing means ineffective and holding said bar in said second position so that said arm engages one of said stops and is held in said raised position; and means for releasing said holding means to enable said biasing means to be effective upon raising of the head end of the back rest so that said arm moves along said flat surface as said head end is raised or lowered with an operator''s two hands on said back rest.