Patent GB-855813-A (GB)
Title: Improvements relating to power-operated doors
Inventor: ROLLASON STEWART ADOLPHUS
IPC: E05F15/12
Filed: 1957-08-31
Abstract: 855,813. Door operating appliances. NEWMAN & SONS Ltd., W., and ROLLASON, S. A. Nov. 28, 1958 [Aug. 31, 1957], No. 27490/57. Class 65(1). An angularly movable door is driven through a spring by a power unit and the drive connection includes rotary means having two abutments which transmit the drive to the spring during clockwise and anti-clockwise movement, respectively, of the door, the drive from the power unit to the spring, in the event of the door meeting an obstruction, being absorbed by the spring which acts to complete the movement of the door after the obstruction has been removed, and the spring, in the event of failure of the power unit, yielding to permit the door to be opened manually. The door 1, (Fig. 2) is carried by a stub-shaft 11 operatively connected through a flexible coupling 13 with a shaft 14. A sprocket 16 driven by the power unit through a chain 37 is rotatably mounted on the shaft 14 and carries a tube 17 which surrounds a torsion spring 25. The spring is anchored at its upper and lower ends, respectively, to members 24, 18 rotatably mounted on the shaft 14, the upper member 24 having a projecting pin 26 (Fig. 5) engageable with an abutment face 27 on the stepped upper edge of the tube and an abutment face 29 (Fig. 6) engageable with an abutment face 31 on a dog 30 rigid with the shaft 14, and the lower member 18 having a projecting pin 19 (Fig. 4) working in an arcuate slot 20 in the wall of the tube 17 and an abutment face 21 engageable with a pin 22 fixed to the shaft 14. When the sprocket is driven in the direction A, the end 20a of slot 20 abuts the pin 19 and drives the spring through the member 18 so that, if the door is unobstructed, the spring rotates bodily causing abutment face 29 on the member 24 to engage abutment face 31 on the dog 30 and transmit drive to the shaft 14. If the door meets an obstruction the member 18 will turn relatively to the member 24 and will wind up the spring from the lower end. When the sprocket is driven in the direction B the drive is transmitted to the member 24 through the engagement of the abutment face 27 on the tube 17 with the pin 26, and the spring drives the member 18 the face 21 of which abuts the pin 22 and transmits movement to the shaft 14. In the event of obstruction the spring is wound up from the top. The door may be opened manually when the power unit is not operating, rotation of the shaft 14 relative to the sprocket 16 being absorbed by the spring. In an alternative embodiment (Figs. 7-10, not shown) the spring is housed in a tube fixed to the door. In another embodiment (Fig. 12) the upper door-pivot 63, which is driven by a power unit located in the door frame, extends into a box-like casing 61 mounted on the door and has a portion in the form of a cam 67 provided with two parallel abutments 68, 69 engageable with grooves 70, 71 in a spring-loaded slide member 72. The strength of the spring 77 is such that, if the door is unobstructed, the thrust on the member 72 when the pivot 63 is rotated will cause the whole door to turn instead of compressing the spring. In the event of the door being obstructed the member 72 is moved by one of the abutments 68, 69, to compress the spring. The power unit may be an electric or fluid pressure motor and may be controlled by photo-electric means or by floor pads.