Closure fasteners – Bolts – Sliding
Reexamination Certificate
1999-05-24
2001-09-04
Dayoan, B. (Department: 3627)
Closure fasteners
Bolts
Sliding
C292SDIG006, C200S043010
Reexamination Certificate
active
06283514
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to enhancing the safety and security of manufacturing processes and, particularly, to simultaneously monitoring and exercising control over access to enclosed areas which house operating machinery or the like. More specifically, the present invention is directed to mechanisms which may prevent the opening of and/or monitor the state of access doors and, especially, to mechanisms of such type which are suitable for mounting on access doors so as to be operable by handles provided on such doors. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
While not limited thereto in its utility, the present invention is particularly well suited for use in manufacturing facilities having enclosed areas in which, due to safety considerations, unattended operations are performed. Such an area may, for example, house machinery or machine elements which should not be approached by plant personnel while in operation. The doors or openings through which access to such areas is obtained are customarily provided with guard locking devices which include a door status signal generator, i.e., an electrical switch, located on an interior wall of the secure area adjacent to the access door. These previous guard locking devices, which are also generally known in the art as “safety switches”, perform both of the functions of door locking and controlling the state of the status signal generator. The prior art “safety switches” have conventionally included pivotal actuators coupled to rotatable door handles. Pivotal actuators have the disadvantage that they are not suitable for use on sliding doors. Pivotal actuators also have the disadvantage that the force transmitted thereby during door handle operation is not uniform, i.e., latching of the door occurs with increasing clamping force on the fixed part of the door-locking mechanism and this non-uniform force will not reliably result in establishment of operational contact with the associated status signal generator. There has, accordingly, been a long-standing desire and need in the art for a universal monitoring/locking mechanism suitable for controlling and monitoring the state of both pivotally mounted and sliding access doors while being characterized by uniform force transmission.
SUMMARY OF THE INVENTION
The present invention overcomes the above-briefly discussed and other deficiencies and disadvantages of the prior art and, in so doing, provides a novel and improved method for locking an access door and monitoring the state of the door. The invention also encompasses apparatus which cooperates with a safety switch for implementing such method and, particularly, a door mounted actuator which is longitudinally displaceable in response to door handle rotation, the actuator including a rack section which engages a ring gear segment coupled to a rotatable pin which extends through the door.
In accordance with a preferred embodiment, the longitudinally displaceable actuator is supported in a guide mounted on the inside surface of an access door. The cooperating ring gear segment is also mounted on the door inside surface. This arrangement results in the actuator being pushed out of its retracted position, in response to manual operation of an exterior door handle coupled to the rotatable pin, with uniform force transmission. Such uniform force transmission reliably locks the door, i.e., positions the actuator for engagement by an interior wall mounted latching mechanism of a safety switch, and reliably operates an electrical switch or the like which causes a signal, which may be monitored, to change as a function of the state of the access door.
Apparatus in accordance with the invention is suitable for use on both pivoting and sliding doors and is readily adaptable for installation on doors of different thickness.
REFERENCES:
patent: 1071567 (1913-08-01), Outwater
patent: 1215286 (1917-02-01), Kollmeyer
patent: 1262435 (1918-04-01), Berg
patent: 1495820 (1924-05-01), Tierney
patent: 1720590 (1929-07-01), Evans
patent: 2160611 (1939-05-01), Alexander
patent: 3638461 (1972-02-01), Watson
patent: 4058333 (1977-11-01), Roe
patent: 4248068 (1981-02-01), Esser et al.
patent: 4333324 (1982-06-01), Dietrich et al.
patent: 4502716 (1985-03-01), Yu
patent: 4563886 (1986-01-01), Kletzmaier et al.
patent: 4685709 (1987-08-01), Kambic
patent: 4695684 (1987-09-01), Bochard
patent: 5464954 (1995-11-01), Kimura
patent: 5488207 (1996-01-01), Niwa
patent: 5496082 (1996-03-01), Zuckerman
patent: 5584378 (1996-12-01), Wecke
patent: 5609244 (1997-03-01), Reiter
patent: 5675228 (1997-10-01), O'Bryan
patent: 6013881 (2000-01-01), Hall
patent: 36 06 458 (1987-09-01), None
patent: 0367026 (1990-05-01), None
patent: 0 438 008 (1991-07-01), None
patent: 0577360 (1994-01-01), None
patent: 0 677 830 (1995-10-01), None
patent: 639 187 (1928-06-01), None
patent: WO 85/03970 (1985-09-01), None
Schmersal article entitled “Guard Locking Devices Series AZM 415”, published 1994.
Alix Yale & Ristas, LLP
Dayoan B.
Estremsky Gary
K. A. Schmersal GmbH & Co.
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