Patent GB-252155-A (GB)
Title: Improvements in and connected with mechanism for opening and closing gates, doors and the like
IPC: E05F13/04
Filed: 1926-05-07
Abstract: 252,155. Thomas, A. D. May 12, 1925, [Convention date]. Operating doors and gates by treadles and the like, and by cords, springs, and weights.- In mechanism for operating a door or gate as by the engagement of a moving vehicle with a treadle positioned on the road track, and embodying a radial member pivotally mounted on or adjacent to the gate stile and connected at its free end to the gate by a spring or equivalent device, means are provided when the radial members is displaced for maintaining the opening or closing leverage on the gate until it has been moved into alignment with the radial member. The arrangement is stated to be applicable also to the operation of signals by a vehicle passing over a rail track. Figs. 1 and 3 show the arrangement. As applied to a field gate 10 operable by the depression of a treadle 39 connected to the heel of the gate by cables 37. A radial member 19 has a pin 20 at its outer end which supports an oscillating bar 21 and shackle 22. A tension spring 23 is connected to the shackle and to a rack 24 fitted to the bottom of the gate. The bar 21 has a jaw engaging the lower part of the shackle and the movement of the bar is limited by a stop 26 on the radial member. Links 27 connect the bar 21 to a double pawl 28 pivoted to the member 19. The pivot pin 29 of the pawl is connected to the end of a slidable bar 31 secured to a lever 33 connected to a latch operating bar 35. The cables 37 pass over pulleys 42 and guide loops 41 and are attached to the radial member, as shown. In operation, when one of the treadles 39 is depressed by a wheel of an approaching vehicle a cable 37 causes a partial rotation of the radial member 19 away from the operated treadle and the spring 23 is tensioned to exert an opening force on the gate. The movement of the member 19 causes the pawl 28 to engage with one of the stops 16 on a member 15 secured to the gate post, and the movement of the pawl causes the latch to be withdrawn and the gate to swing open until the latch engages with a catch on one of the side posts 14. The engagement of the pawl and stop also retains the radial member at an angle to the gate and the tension on the spring 23 is maintained after the vehicle wheel has passed over the treadle. When the gate in its opening movement moves into line with the radial member, the pawl and stop are disengaged and the gate and radial member then move together. The crank arms 38 of thetreadle levers are provided with an arcuate guide 38, Fig. 7, to support a counterbalance weight 39<1>. which is used to return the treadle levers to their normal positions after each operation of the gate. An arrangement is also described adapted for gates or doors which are to open in one direction only. In order that a gateway be opened by a vehicle travelling at a comparatively high speed, two or more treadles may be arranged on each side and at different distances from the gate, so that the depression of the first treadle causes the radial member to engage a stop 16 to release the latch and exert an opening force on the gate, the depression of the second treadle causing fhe radial member to be rotated further until it engages a second stop and increases the force acting to open the gate. Instead of a spring acting on the gate, a weight may be connected to radial member by a cord passing over a pulley.