GB498588A - Improvements in band brakes - Google Patents

Abstract

498,588. Band brakes. CHAMPNEYS, F. C. (Bojesen, P. L.) April 10, 1937, No. 10289. [Class 103 (i)] A brake for an epicyclic gear or other purpose comprises a brake band wound in a coil around the drum in a self-servoing direction from one end to the other, sliding guides for the ends of the band to constrain them to move coaxially with the drum, means for applying a gradually increasing force to one end of the band and means such as a spring for permitting consequential displacement of the other end of the band against a gradually increasing resistance. A coil b wound on a drum a which may be part of the planet cage of an epicyclic gear is connected at one end b<2> to the rod d of a spring plunger the cylinder of which is pivoted at d<3> to a fixed part. The other end b3 of the coil is attached by link c to the piston c<1> of a hydraulic cylinder. A casing b<1> surrounds the coil and the pins b<2>, b<3> at the ends of the coil are mounted in guides b<4>, b<5> free to move circumferentially about the casing bl. The drum rotates in the direction of the arrows. Initial movement of the piston c<1> under the fluid pressure applies the coil to the drum and further movement results in corresponding displacement of the end b<2> against the action of the spring d<4> and increasing braking action which in the case of an epicyclic gear, results in a gradual reduction and increase of speed respectively of the planet cage and the driven shaft. The pressure liquid may be supplied to the cylinder through a non-return valve another valve being opened to release the brake. There may be a pair of brake coils wound in opposite directions around the drum so that the forces which they transmit to the journal of the shaft a<1> are balanced.