Patent GB-190700293-A (GB)
Title: Improvements in Brakes.
Inventor: FREUND EDWIN
Filed: 1907-01-04
Granted: 1907-04-18
Abstract: 293. Freund, E. Jan. 4. Bra7ces.-Brakes applied by a spring or weight are retained ' on' by auxiliary means, so that the spring or weight may be brought back to its original strained position ready for the next application, without releasing the brakes. Fig. 1 shows the application of the invention to a track brake b operated by a spring d through a bell-crank c' carrying a pawl c, which gear s with a rack b<4> connected to the shoe. A pawl b<5> on the rack b<4> engages with a toothed wheel e, which is normally held stationary by a band brake e<1> held on by a spring e<3>. The pawl c is slotted and attached to a rod c<2>, connected at one end to a handlever c<3> and at the other to the brake lever e<2>. The spring d is tensioned by a winding- drum d' which is normally braked by a band d<3> held on by a spring d<5>. When the brake is to be applied, the winding-drum is released and the pawl c presses down the rack b<4>, the brakes being retained by the pawl b<5> which engages with the wheel c. To release the brakes, the lever c<3> is moved to draw the pawl c away from the rack and to release the band brake e', and the wheel e is then free to rotate under the influence of the springs b<3> which raise the brake shoe. In another arrangement, the power is stored in the spring by using the momentum of the vehicle or a motor for tensioning the spring, and auxiliary means may be provided whereby the tensioning can be done by hand. An eccentric f, Fig. 6, is keyed to the axle r of the vehicle, and the eccentric-rod f<1> carries two cranks f<2> which are loose on a shaft g. A pawl f<3>, on the end of the rod f<1>, gears with a toothed wheel g<1> keyed to the shaft g, and the motion is transmitted through a toothed wheel g<3> on the shaft and a sector j' to a shaft j<3> connected to the power spring d. Au incline g<4> on the wheel g<1> lifts the pawl f<3> out of gear with the teeth when the spring is fully wound. The shaft g is prevented from turning backwards by a pawl g<2>, Fig. 5, on the shaft, which engages a ratchet-wheel h<1> on a brake drum h loosely mounted on the shaft g and normally held by a band brake h<2> kept tight by a spring h<3>. The pawl f<3> is raised and the band h<2> is released, so that the power spring can apply the brakes, by a shoe q<1>, Fig. 6, formed on the end of a rod q and adapted to bear on the tail f<4> of the pawlf The shoe is connected by a slotted rod q<2> with the operating-lever h<5> of the band brake h'. The rod q is depressed by a lever p, operated through chains p<1> from either end of the vehicle and pivoted at p<3>, Fig. 8, to a sleeve p<3> sliding freely on the rod q. On the sleeve p<3> is mounted a sleeve q7 secured to the rod q, and springs q<6>, q<5> are placed between the sleeves q<7>, p<3> and the sleeve p<3> and a fixed bracket q<3>. By this arrangement, if the pawl f<3> is driving when the shoe q<1> descends, the springs are compressed and the pawl is not tripped until its return movement. A clutch g<5>, Fig. 5, able to slide on the shaft g but turning with it, gears with the part l<1> formed on a sleeve l, on which is pivoted a pawl l<2> engaging with a rack-wheel m<1> on a brake drum m. A pinion l<3> fixed to the sleeve l gears with a sector j<2> secured to a shaft j, on which the links d<7>, d<8> carrying the brake shoes are fixed. When the pawl f<3> is tripped by the operating-lever, the shaft g rotates the sleeve and the sector j<2>, and applies the brakes, which are retained by the pawl l<2>. To release the brakes, a lever n is moved to de-clutch the part g<5> from the sleeve l and to release, through a lost-motion device n<3>, the band m<2> from the brake drum. In order that the spring may be tensioned by hand independently of the pawl f<3>, a second ratchet-wheel and pawl, adapted to be worked by hand, may be provided. The brake shoes may be wound as electro-magnets.