Closure fasteners – Bolts – Sliding
Patent
1997-08-05
1999-08-03
Boucher, Darnell M.
Closure fasteners
Bolts
Sliding
292139, 292335, E05C 104
Patent
active
059315156
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a locking device for doors, intended for connection between the dead-bolt of the door and its drive means (door-frame or rotating cam, such as an electrical strike plate).
BACKGROUND OF THE INVENTION
It is important in different locking constructions that the lock has distinct positions, locked and unlocked. There is a risk when unlocking a door, for instance during emergency evacuation of premises, that a door cannot be opened although it has been unlocked in the normal manner. In critical situations this may have disastrous results. Both security and fire-protection aspects must be respected. The locked position shall be firm and unlocking shall not be made more difficult, for instance when a crowd of people are pushing towards the exit, thereby unintentionally preventing its opening.
OBJECT OF THE INVENTION
The object of the invention is a solution of these and other similar problems, and is characterized in that a hinged arm is connected to the dead-bolt or its extension, a wheel or pin being arranged at the other end of the arm and designed to tumble into a recess in a pivotable cam-disc upon turning of the cam-disc, and also to be disengageable from this recess, whereupon the cam-disc in the latter case is arranged to block the dead-bolt and upon tumbling into the recess release it, and also that the dead-bolt has an inclined surface designed, upon pressure against the dead-bolt, to assist in the opening process. The arrangement of dead-bolt and drive means normally provides reliable locking and unlocking and the inclined surface assists in ensuring opening even in emergency situations arising out of pressure against the door and thus against the dead-bolt, since a force component is obtained in opening direction of the dead-bolt.
The invention can be used on double doors by applying it on the passive door, where pressure is obtained from a door-frame. The drive means comprises a spring bolt actuated by a door-frame.
The invention can also be applied on a single door, such as a fire-door, where the pressure is obtained from a rotating cam, e.g. an electrical strike plate. An example of a lock for a single door where the invention can be applied, is shown in Swedish Priority patent application 8900988 now U.S. Pat. No. 5,195,792. The drive means is in this patent an electro-magnet, and the pressure is obtained from a rotating cam.
In a preferred embodiment the cam-disc is arranged to be turned either with or against spring force and the cam-disc is provided with a blocking protrusion, designed to cooperate in the locking position with a locking surface in the extension of the dead-bolt.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the lock;
FIG. 2 is a front view of the lock; and
FIG. 3 is a partial side view of the spring bolt.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show the lock seen from two different directions, and FIG. 3 shows a detailed view of the spring bolt.
In FIGS. 1 and 2 a lock is shown having a dead-bolt (1) designed for engagement in a door-frame and to lock the passive door in case of double doors to a door-frame. The dead-bolt (1) is shaped with a bevelled surface (3) designed so that upon pressure against the door, a force component in the opening direction is produced. The dead-bolt has an extension (5) to which an arm (6) is hinged. A wheel (7) or pin for engagement in a recess (8) in a swivel cam-disc (9) is arranged at the outer end of the arm (6). This is the open position. To achieve locking, this wheel (7) is moved out of the recess and up along the outer edge of the cam-disc so that the cam-disc is pushed inwards and a blocking surface (13) cooperates with a locking surface in the extension (14) of the dead-bolt. This is the locked position. The arm (6) on which the wheel or pin is located, is connected to one end of a link arm (11), the other end of the link arm is connected to a swivel plate (10) which can be actuated by a spring bolt 2. If the spring bolt is pushed out, the arm
REFERENCES:
patent: 3464728 (1969-09-01), Ruckel et al.
patent: 4099753 (1978-07-01), Gwozdz et al.
patent: 5195792 (1993-03-01), Stendal
patent: 5341752 (1994-08-01), Hambleton
patent: 5373716 (1994-12-01), MacNeil
Boucher Darnell M.
Stendals Elektriska AB
Walsh John B.
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