| 摘要 |
1,067,306. Trailer brakes. LANCIA & C FABRICA AUTOMOBILI - TORINO S.p.A. Feb. 16, 1966 [Feb. 16, 1965], No. 6746/66. Heading F2F. A vacuum-servo control 18 causes an hydraulic cylinder 14 to operate the brakes 15 of a trailer 2 simultaneously with the operation of the brakes 4, 5 of its tractor 1 by a pedal actuated master cylinder 3. The control 18 is on the trailer and comprises a pneumatic cylinder subdivided into chambers 19 and 20 by a piston 21 connected to the piston-rod 24 of the hydraulic cylinder 14 and operating against a return spring 22. A distributer valve 27 on the tractor has a pneumatic chamber similarly divided by a diaphragm (Fig. 2, not shown), into two chambers, normally interconnected, and joined by a pipe 35 to the inlet manifold of the tractor engine 11 and by way of a pipe 39 and coupling 40 to the chamber 19. The first of these chambers is also connected by way of junction 34 and coupling 37 to the chamber 20 and also to a tank 58 which makes up vacuum loss during operation. Two other pipes 53 and 54 connect an hydraulic cylinder in the distributer so as to operate alternatively (in case of failure) on a piston therein. Application of the tractor brakes causes hydraulic pressure to lift the piston in the distributer which seals off the two pneumatic chambers therein from each other and admits air to one of the chambers which is connected to the chamber 19 of the servo on the trailer, causing it to act on the piston 19 to operate the hydraulic cylinder 14 and apply the tractor brakes 15. In addition, the atmospheric pressure in the one chamber of the distributer bears on the diaphragm which is supported only by the vacuum in its other chamber thereby causing additional hydraulic pressure to be applied through the distributer piston to the tractor brakes. On release of the brake pedal 20 the resiliency of the aforesaid diaphragm and of the spring 22 assist in restoring the system to its original state. Valves in the couplings 37 and 40 and a non-return valve 25 ensure that if a pipe breaks or the couplings fail the tractor brakes are kept applied. To take them off a three-way tap 59 can be operated to admit air to the chamber 20. |
