GB190927086A - A Mechanical Brake-controlling Device, especially applicable to Tram Cars having Hand-operated Brakes. - Google Patents

Abstract

27,086. Elorza, A. Nov. 22. Actuated by running axle; force - transmitting mechanism-In brake apparatus applicable generally, but especially adapted for use with the ordinary hand - operated brakes of tramcars, and of the type comprising rack-and-pinion mechanism which is operated in steps through ratchet gearing by means of a lever oscillated by a cam secured on an axle or other rotating part, the ratchet gearing comprises a disk having bevelled edges engaged by forked pawls which act thereon by a wedging action, and is provided with a regulator device which allows the intensity of the breaking action to be varied or maintained constant. The hand-operated shafts I, I<1>, Fig. 2, of a tramcar, which are connected to the brakes in the usual manner by a chain i<3> and lever i<1>, are provided with additional connexions h attached to ratchet controlling-mechanism c, which may be operated to bring a lever k<1> into the line of action of an eccentric n on the axle, whereupon the brakes are applied by means of a rack l connected to the lever i<1>. The mechanism c comprises a pinion a, Figs. 3 and 4, which engages the rack l and is mounted on a spindle a<2> and secured to or formed integrally with a bevelled ratchet disk a ; a ratchet lever or pawl j<1> which has a wedging engagement with the periphery of the disk a and is controlled by a spring j<4> and oscillated by the lever k<1> so as to rotate the disk a in the direction of the arrow x ; a second pawl m, pivoted at f and having a wedging engagement with the disk a so as to prevent rotation opposite to the direction of the arrow x; and a regulator device g, which rotates loosely on the spindle a<2> and is attached by rods g<6>, g<7> to the connexions h and provided with a controlling-spring g<5> and projections g<1>, g<2>, g<3>. Figs. 3 and 6 show the position of the parts when the brakes are released, the lever k' being held out of engagement with the cam n by means of the pin g<3> on the regulator g, while the pawls j<1>, mare held out of engagement with the disk a by the projections g', g<2> respectively. To apply the brakes, the handle I is moved to the position shown in Fig. 9, whereupon the regulator g is turned by the spring g<5> so as to bring the lever k<1> into contact with the cam n and the pawls j<1>, m into gear with the disk a. The oscillations of the lever k<1> caused by the cam n are imparted to the pawl j<1>, which produces a step-bystep rotation of the disk a and pinion a', the brakes being locked on by the pawl m. An inclined stop c<4> disengages the pawl j<1> from the disk a at the end of its forward stroke. When the brakes have been sufficiently applied, the parts are moved back to the position shown in Fig. 7 so that the pawl j<1> is held clear of the disk a by the projection g<1> while the pawl m still operates to maintain the brakes on. A further application of the brakes, but with less rapidity than when the parts are in the position shown in Fig. 9, may be obtained by moving the apparatus to a position intermediate those shown in Figs. 7 and 9, so that the pawl j' is effective only during one-half of its stroke. Full release of the brakes is obtained by bringing the parts to the position shown in Fig. 6 ; or, if a part release is required, the apparatus is moved forwards again to the position shown in Fig. 7, when the required amount of release has been obtained.