Patent GB-946785-A (GB)
Title: Improved means of light-operated remote control
IPC: E05F15/20
Filed: 1959-12-07
Abstract: 946,785. Photo-electric control of garage doors. KINETROL Ltd., and A.R.B. NASH. Dec. 7,1960 [Dec.7, 1959; April 21, 1960],Nos. 41410/59 and 13929/60. Heading G1A. [Also in Division E2] Apparatus for opening a garage door or doors by means of a light beam from a vehicle pulsed or alternating at a frequency above 100 c.p.s., and preferably between 500 and 3000 c.p.s,comprises a photo-ceil sited to receive the light beam and an electrical circuit to amplify the pulsed or alternating component of the output from the photo-cell in conjunction with an electro-mechanical device responsive to the said amplified component to cause or permit the opening of the garage door or doors. The vehicle carries a light source associated with a parabolic mirror and two apertured shutters, Fig. 1, (not shown) one of which is rotated at a predetermined speed to provide an alternating light beam at the desired frequency. The light beam can be directed to impinge on a photo-cell 20, Fig. 2, in a hemispherical casing 21 provided with an apertured spherical shutter 23 which can be rotated to adjust the position of the aperture 24 horizontally and vertically with regard to the cell. The output of the cell is fed to an amplifier circuit comprising transformercoupled transistors 30, 32, Fig. 3, arranged to amplify the A.C. component from the cell 20, and including a relay 33 in the output circuit of the cell 32 and operating a latching device. The door or doors is/are attached to a spring biased linkage, Fig.4 (not shown), which moves the door(s) to the open position when the relay and latching device are operated. In the closed position of the door 1, Fig. 5, a catch 2 on the door 1 engages a notch in a lever 4 pivoted about a fixed pivot 5 so that the force on the door 1 in the direction A due to the spring biased linkage tends to rotate the lever 4 in a clockwise direction, such rotation being normally prevented by a dead-centre linkage comprising a link 6 pivoted at 12 to the lever 4 and pivoted at 11 to an armature rotatable about a fixed pivot 10 on an electro-magnet 8 such that the pivotal points 12,11 and 10 are all in a straight line under the action of a coil spring 14 mounted on the pivot 12. With the operation of the magnet 8 the dead-centre condition is disturbed thereby allowing the lever 4 to rotate and disengage the catch 2 and so allowing the door 1 to open under the action of the biasing spring initially to push the armature 7 closer to the magnet 8. Subsequently the lever 4 is returned to its normal position by the spring 14 which also restores the link 6 and armature 7 to the dead-centre position when the magnet 8 is de-energized. The catch 2 may be operated independently by a key to unlock the doors for automatic opening by the spring member. Alternatively, the relay 33 may operate a motor to open the doors and a push-putton within the garage may be actuated to control the motor to close the doors. In a further modification, the push-button may be replaced by a further photocell and associated circuit to operate a relay controlling a motor to open or close the doors. Conversely when leaving the garage the doors may be opened by the push-button and closed photoelectrically.