Patent GB-393963-A (GB)
Title: Improved means for opening and/or closing gates, doors, and the like structures
IPC: E05F1/02
Filed: 1931-12-12
Abstract: 393,963. Gate-operating mechanism ; hinges ; fastenings. ROSS, F. and ROSS, J., Pohangina, Wellington, New Zealand. Dec. 12, 1931, No. 34483. [Classes 44, 65 (i), and 65 (ii).] Mechanism for automatically opening and closing a gate comprises a vertical rod or cylinder fixed to the gate, a member secured to the gate post and surrounding or passing through the gate member, this gatepost member having a helical slot along which a pin or pawl on the gate member moves to cause rotation of the gate member and the gate when the gate member is raised or is released after being raised, and means operable from a distance to raise the gate member. The gate fastening is released by the lifting of the gate member and gate, and the mechanism also operates a holder to hold the gate open ; the mechanism is described as operated by treadles on approach and departure of a vehicle. In Fig. 1, the gate 1 has fixed to it a rod 4 which acts as a hinge pin, bearing slidably in lugs 10 on the gate post 9, and extends downwards into a housing below the ground, where it rests on an arm 10a fixed to a shaft 11. Fixed to the post and surrounding the gate member 4 is a cylinder 5 having a helical slot, in which engages a pin 6 fixed in the rod 4, so that when the operating shaft 11 is rotated and the rod 4 is lifted this rod is forced to turn and the gate is opened, the weight of the gate causing it to close when released. The helical slot is preferably formed with a vertical portion at the .lower end, so that the commencement of the lifting movement lifts the latch 12b clear of the notch in its striking-plate without turning the gate ; the slot also has a horizontal extension at the lower end, to allow the gate to be opened by hand without lifting it. The slot and pin are preferably duplicated. The striking plate 24 of the latch may be formed with an overhanging part 26, Fig. 7, to ensure engagement with the notch when the gate closes. Rotation of the shaft 11 to raise and open the gate also retracts a bolt 30, Fig. 2, on a post 28 at the roadside, by means'of a lazy-tongs mechanism, to allow the latch 12b of the gate to engage a notch in a striking-plate 29, which may be of the same form as the plate 24 in Fig. 7, on the post 28 to hold the gate open ; when the shaft 11 is rotated in the reverse direction, the bolt 30 is raised to lift the latch out of the notch in the striking plate 29 on the holding post to allow the gate to close. The operating shaft 11 is actuated by a pair of treadles on either side of the gate ; each pair of treadles comprises a plate 49, Fig. 10, hinged at the end away from the gate and supported by a leaf spring 51, and a cranked member 46 pivoted in members fixed in the ground. The member 46 is integral with a crank 43, which is attached to a crank arm 41 on the end of the operating shaft.11 ; in the normal position the member 46 is flat on the ground, and the arm 41 is close against the underside of plate 49. An approaching vehicle is driven so as to depress the plate 49, thus rotating the arm 41 and shaft 11 to open the gate and raise the members 16 on each side ; after passing through the gate, the vehicle is driven so as to strike the member 46, which rotates the shaft 11 in the opposite direction and releases the gate from the holding post 28 to allow it to close. In a modification, Fig. 15, the gate member comprises a cylinder 78, forming a hinge socket and having a rod 80 to engage the operating arm 10a, and the gate post member is formed as a hinge pin 82 with helical slots to engage pins fixed inside the cylinder. In another modification, Fig. 18, the raising of the gate does not produce any rotation, but when the approaching vehicle releases the depression plate 49 to allow the gate to fall the gate first swings open and engages the holding post 28 and then, when the treadle member 46 is operated,to release the holding catch, swings to the closed position again. In the construction shown in Fig. 18, the gate post member 107 is mounted between lugs 89, 90 on the gate post so as to be free to slide a short distance axially ; the lower lug 90 has a toothed surface to engage with a corresponding surface on the cylinder 107, but when raised slightly the member 107 is free to rotate ; the slots 88 are shaped as shown to produce the required double movement of the gate. When the gate member is raised, the member 107 is also raised until clear of the teeth on the lower lug and is then rotated freely by the pins on the gate member engaging the slots 88, the gate remaining closed ; when the gate commences to fall, the teeth on member 107 and lug 90 engage to lock the member 107 against rotation, and the gate is thus forced to swing. In a modification of this arrangement, the member 88 is fixed, and the pins on the gate member are replaced by spring-pressed pawls, which move inside the cylinder 107 during the upward movement and engage with the slots 88 on moving downwards. In another modification, also using a fixed member 107, the pin (projecting at both ends) is carried in opposed horizontal slots in the gate member, each slot having an upturned portion at one end ; on the upward movement the pin rotates in the slots of the gate member, but in the downward movement the upturned ends of the slots engage over the pin'and the gate member is forced to rotate as the pin moves along the slots 88 in the member 107. Two gates may be coupled together by cranks and a rod to operate simultaneously, and may be arranged to open in opposite directions as so to neutralize the effect of wind pressure ; only one of the gates is then lifted to cause the swinging movement. The two gates may alternatively be supported on a single rod 10 hinged to a central post. In an installation for railway level crossings, the operating shaft 11, Fig. 1, is dispensed with and the gate member 10 is supported on a long lever on the opposite end of which rests a weight ; the weight is also supported by another lever connected to a treadle for operation by a passing train. An approaching train operates a contact which electrically releases the gate latch, and the weight then falls, raising the gate member and causing the gate to swing across the road. When the train passes, it operates the treadle to raise the weight and allow the gate to close under its own weight. The lever supporting the gate member carries at the gate end a pair of pivoted pawls which engage keepers to hold this end of the lever down while the gate is closing after the lever and weight have been operated to the normal position by the passing train ; the pawls are released by the descending gate member when the gate reaches its latched position, so that the lever is free to rise and open the gate when the latch is released by the next train.