Patent GB-147977-A (GB)
Title: Improvements in brakes for railway trains
IPC: B61H11/02
Filed: 1919-04-16
Abstract: 147,977. Dufour, P. F. April 16, 1919. Actuated by backward pressure of tractor or relaxation of pull or push.-Brakes for railway vehicles are coupled to the buffers, when travelling forwards, or to the draw-bars, when travelling backwards, the coupling-mechanism being actuated by a compressed-air or electric motor controlled by the driver. The draw-bar 11, Fig. 4, slides in a sleeve 12 containing a spring 13 engaged by a rod 10. The buffer rod 1, Fig. 2, engages a plunger 7, carrying a spring 6 and mounted in a recess in a rod 3, which is connected by a lever 5, Fig. 6, to a rod 16. The rods 10, 16 are coupled to arms 17, 15 keyed on shafts 26, 25 mounted in the control box 14. Either of these shafts can be coupled to either of two shafts 27, 28 which are connected by arms 19, 20 and rods d, f to a retaining-sector 8 for the brake a and to a release finger 9<1> for the pawl 9, respectively. Each arm in the control box has a spring-stop for returning it normally to rest. Shafts 25, 26 each carry two disks 29, 30, Fig. 8, each disk having a notch engaged by pins 34 on the disks 31, 32 which slide on, and are rotated by, the shafts 27, 28. The motor 21, controlled by the driver, actuates an arm 22 mounted on a shaft 39 which carries a fork 36 engaging in grooves 37 formed in the hubs of the disks 31, 32 so as to move these disks into engagement with the disks 29, 30. When the fork 86 is moved to the left, the shafts 25, 28 are coupled together, and also 26, 27, so that the draw-bar applies the brakes and the buffer releases them. In the right-hand positon, the buffer applies the brakes and the draw-bar releases them, a spring being secured to the arm 22 so that the control gear is normally in this position. The box 14 has an inclined boss 40, Fig. 14, engaged by a roller 41 on the disk 32, so that when the fork is moved to the left, the disk is rotated by the boss 40 and then returned by its spring-stop; in this way, if the brakes are on when the control is reversed, the rotation of the shaft 28 will release the pawl 9 and the brakes. The disk 32, Fig. 15, may be feathered on an intermediate sleeve 42 and spaced by springs 43, or each pin 34 on the disk 32 may have lateral movement. Two control boxes may be provided on each vehicle, or all the brakeblocks of each vehicle may be connected to the same control box, the rods from the gear at either end of the vehicle having slotted connexion with arms on opposite sides of the same shafts. The sector 8 may be engaged by the pawl 9 only after a certain amount of braking has been produced, so that light brakings are not continuous, or the brakes may be rendered non-continuous by omitting the sector 8, pawl 9 and the left-hand part of box 14 with shaft 28 and disk 32. The box 14 may be modified, Fig. 17, to allow disengagement of the brakes, such as when shunting. The shaft 39 is continued across the box 14 and provided with an arm 45 having a stud 48 engaged by a pawl 47 when the arm 45 is in neutral position. A partial movement of the motor 21 will thus free the control box. The arm 45 can be released by moving it across the box, when the tail 49 of the pawl 47 will be caught by the pawl 51. The arm 45 may have a heel 67 engaging the tail 68 of the pawl 51. Rods 66, or ropes, may connect to a device on each side of the vehicle to indicate the position of the brake. The control may be freed or re-set manually by means of chains and levers connected to two bolts 53, 54. In the former case, the end of the bolt 53 engages the pawl 51, while a nose 62 on the bolt engages the arm 45. In the latter case, a nose 65 on the bolt 54 engages the arm 45, but the bolt rides clear of the pawl 51, which can thus retain the pawl 47 and allow the return of the arm 45 to normal position. For backward travel, the bolt 54 may be locked in extended position. The brake a may be a hand or segment brake, a band, core, or cord brake, or it may be a cord brake used as a relay to operate the actual brakes.