Door latch
AssigneePhiladelphia Tramrail Company
InventorA. Henry Schwab
Life of this patent
Estimating the term…
Abstract
A door latch arrangement is disclosed to prevent a door from popping open when the door is subjected to pressure from the inside. Means are provided to restrain movement of the door latch until the door and latch have moved partially open, thereafter the door is free to manipulated to a fully open position.
Claims13
An apparatus comprising a housing having an opening, a door movably supported by said housing for movement from a position wherein it closes said opening to a position wherein the opening is unobstructed, latch means for controlling the initial opening movement of said door so that the door does not pop open, said latch means including a latch movably supported by the housing and overlying a portion of the door and a cam follower movably supported by the door, said latch having a cam surface cooperating with said cam follower to block opening movement of the door, means connected to the cam follower and selectively operable for moving the cam follower along the cam surface and in a direction away from the door until the cam follower is out of the path of movement of the cam surface on said latch whereby the latch and door are thereafter movable to an open disposition.
Apparatus comprising a housing having an opening, a door pivotably supported by the housing for closing said opening and for moving to an open disposition wherein the said opening is unobstructed, latch means for controlling the initial opening movement of said door so that the door does not pop open, said latch means including a latch pivotably supported by the housing and overlying a portion of the door and in contact with the door so that internal biasing forces on the door are transmitted to the latch, said latch means including a latch retainer for controllably restraining the pivotable movement of the latch in a direction away from the door until the door has pivoted toward an open disposition through an arc of at least 5.degree. and not more than about 25.degree., and said latch being out of contact with said latch retainer after said door has pivoted through said arc whereby the latch and door are freely pivotable to open dispositions.
Apparatus comprising a housing having an opening, a door pivotably supported by said housing for movement between a closed position and an open position with respect to said opening, latch means for controlling the initial opening movement of said door so that said door does not pop open, said latch means including a latch pivotably supported by one of said housing and door, said latch means including a latch retainer supported by the other of said housing and door, said latch retainer including a movable cam follower, said latch retainer cooperating with said latch to restrain movement of the latch in a direction corresponding to the direction of movement of the door toward its open position, said latch having a cam surface in contact with said cam follower, said cam surface being at an acute angle with respect to the plane of the outer surface of said door, and said latch retainer including means connected to the cam follower for selectively moving the cam follower along said cam surface and in a direction away from the door while the door moves toward an open position for a sufficient distance to relief internal pressure on it and then cause the cam follower to lose contact with said cam surface whereby said latch and door are then freely movable to an open disposition.
Apparatus comprising a housing having an opening, a door pivotably supported by said housing along one side of said opening for movement between a closed position and an open position with respect to said opening, latch means for controlling the initial opening movement to said door so that said door does not pop open, said latch means including a latch pivotably supported by said housing along an opposite side of said opening, said latch means including a latch retainer supported by said door, said latch retainer including a cam follower, said latch retainer cooperating with said latch to restrain movement of the latch in a direction corresponding to the direction of movement of the door toward its open position, said latch having a cam surface in contact with said cam follower, said cam surface being at an acute angle with respect to the plane of the outer surface of said door, said door contacting said latch at a location between said cam surface and the pivotal axis of said latch, and said latch retainer including an arm connected to the cam follower for selectively moving the cam follower along said cam surface and in a direction away from the door while the door moves toward an open position for a sufficient distance to relieve internal pressure on it and then causes the cam follower to lose contact with said cam surface whereby said latch and door are then freely movable in opposite directions to an open disposition, said latch retainer including a gear rotatable with said arm, a worm connected to said gear for driving said gear and a handle connected to said worm for rotating said worm about an axis perpendicular to said door.
Dependencies are inferred from the claim text.