Delayed action door holder
OwnerRichard W. Armstronginventor
Life of this patent
Estimating the term…
Abstract
Apparatus including a suction mechanism for holding open a door or similar member for a predetermined time period, whereupon the door is automatically released and is able to return to its closed position. The period of time during which the suction mechanism is active may be determined by means of an adjustable air leakage to the suction mechanism. The entire mechanism is attached to the inner surface of the door and the necessary relative motion of parts achieved by a connecting rod attached to the adjacent door jam. Spring or equivalent means are provided to protect the door and apparatus against overload by accidental movement of the door when firmly held open.
Claims19
An apparatus for retaining a member in a fixed position for a predetermined period of time, said apparatus comprising:
- a suction pad mounted on said member;
- a plate mounted on said member;
- means for providing relative motion between said suction pad and said plate as said member is moved to said fixed position, said plate contacting said suction pad to form a vacuum therebetween when the member reaches said fixed position, said vacuum retaining the member in the fixed position;
- means for controlling the duration of said vacuum.
Dependencies are inferred from the claim text.