Claims
- 1. A quarter point return mechanism for a manually driven revolving door having revolving door leaves extending outwardly from a central shaft and being partially enclosed between opposed curved side walls, said return mechanism comprising:
- an actuator;
- transmission means connecting said actuator to said central shaft, said transmission means transmitting rotation to said shaft when said actuator is actuated in a first direction and not transmitting rotation to said shaft when said actuator is actuated in a second direction; and
- sensing means for sensing circumferential displacement of outer-ends of said door leaves from said side walls, said actuator being actuated in said first direction when said sensing means senses said outer ends of said door leaves are in a position circumferentially displaced from said side walls,
- said return mechanism returning said door leaves to a rest position in which said door leaves are in contact with said side walls.
- 2. A mechanism as described in claim 1, wherein said transmission means includes a one-way clutch between the actuator and the central shaft.
- 3. A mechanism as described in claim 2, wherein, between the one-way clutch and the actuator, the transmission means further comprises;
- a rack arranged to be linearly displaced by said actuator;
- a pinion engaging said rack, said pinion being connected to the one-way clutch and being rotatable in opposite directions.
- 4. A mechanism as described in claim 1 or 3 further comprising, adjustable timing means located between said sensing means and said actuator, and arranged to permit said return mechanism to operate only after the revolving door leaves have remained stationary in other than said rest position for a timed interval.
- 5. A mechanism as described in claim 3, wherein, between the one-way clutch and the central shaft, the transmission means further comprises, a first pulley connected to the one way clutch, a second pulley centred on the central shaft and rotationally coupled to said first pulley, and a belt coupling said first pulley and said second pulley together.
- 6. A mechanism as described in claim 5, wherein said belt slidably engages said first and second pulleys permitting said door to be manually rotated while said return mechanism is in operation.
- 7. A mechanism as described in claim 1 or 3 wherein said sensing means includes a remote sensing switch and a plurality of trigger means, said trigger means tripping said switch upon rotation of said door.
- 8. A mechanism as described in claim 7, wherein said trigger means comprises four ferrous plugs and said sensing switch comprises an electromagnetic switch.
- 9. A quarter point return mechanism for use in a manually driven revolving door having four leaves equidistant about and extending outwardly from a central shaft, said revolving door being enclosed between two opposed curved sidewalls, each of said side walls having a length of at least one quarter of a circle of revolution defined by the outer ends of said door leaves, said return mechanism comprising an actuator, a rack arranged to be linearly displaced by said actuator, a pinion engaging said rack, a first pulley attached to said pinion, a one way clutch located between said first pulley and said pinion for transmitting drive to said pulley in response to turning of the pinion in a first direction, and a second pulley centered on and coupled to the central shaft, a belt slidably rotationally coupling said pulley and said second pulley together, means for sensing circumferential displacement of said outer end of said door leaves from said side walls, and operating said actuator when said outer ends of said door leaves are in a position circumferentially displaced from said side walls, said return mechanism returning said door leaves to a rest position in which each of said side walls is in contact with two of said outer ends of said door leaves.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of Application Ser. No. 060,198, filed June 10, 1987 now U.S. pat. No. 4,800,679 dated Jan. 31, 1989.
US Referenced Citations (12)
Foreign Referenced Citations (1)
Number |
Date |
Country |
WO8202224 |
Jul 1982 |
WOX |
Continuation in Parts (1)
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Number |
Date |
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Parent |
60198 |
Jun 1987 |
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