Patent GB-261782-A (GB)
Title: Improvements relating to railway car braking apparatus
IPC: B61K7/08
Filed: 1926-11-20
Abstract: 261,782. General Railway Signal Co., (Assignees of Howe, W. K.). Nov. 21, 1925, [Convention date]. Arresting-grips on frictional apparatus on permanent way; electric.-Railway braking apparatus located on the track and adapted to engage the wheels ot passing vehicles comprises a plurality of brake shoes 33, Fig. 1, arranged end to end along the track, the abutting ends of the shoes being connected together by means which permit relative movement about a vertical axis whereby the shoes form a flexible braking surface. One end of each shoe is provided with a vertically-dis. posed slot in which fits a tongue; on the end of the adjoining shoe. Removable wearing blocks are attached to the shoe, by T-headed bolts 50, Fig. 9, the heads of which are passed through slots in the backing plating 46 of the block 45 and turned, the bolt then being drawn tight by a nut 51. so that a squared part of the bolt engages a square hole in the shoe 33. The backing plate 46 is cast integral with the block 45 and is perforated, so that, in casting, molten iron enters the perforations to effect a connection. The shoes beside one rail are operated by beams 17, 18, Figs. 1 and 3, connected bv links to beams 21. 22 for the other rail. The beams pass under the rails, and are adapted to be moved in opposite directions bv double angle levers 12 connected to a main operating beam 30. An adiustable spring connection and guide between the shoes and the beams comprises a lever 35, Fig. 3. pivoted to the shoe and passing through a lug 18<a> on the beam. The spacing between the shoe beams is adiusted by nuts 37 on the end of the lever 35. An initiallytensioned coil spring 40 is carried on the lever 35. its tension being adjusted bv a threaded bushing 41 and a nut 42 threaded thereon. The ends nf the beams rest on plates and are guided bv U- shaped guides 20. 23, Fig. 1. Hook-shaped slots on the rail guide blocks 3 engage similar slots on the brake, shoes in order to guide. the, shoe. The main operating beam 30 is connected to the operating motor by a pitman rod 75. a crank arm 60 mounted on a fixed pivot 63, and a connecting link 64. The Specincation as open to inspection under Sect. 91 (3) (a) describes also the movement of the brake shoes bv means of an electric motor to a number of predetermined positions under the control of a remotely-placed lever, the motor current being automatically broken when the shoes have been moved to the desired position and a brake, applied to the motor. The electric motor 90. through a universal joint and a train of reduction gearing contained in the casing 76. drives a main gear wheel cast integral with a semicircular plate, between which and the main gear wheel the pitman rod 75 is pivoted. To provide a moisture-tight housing for the slot through which the pitman rod passes, a housing 95 is pivoted by a bolt 97 to a curved flange bolted over the slot, a gasket being provided between the housing and the flange. The pitman rod passes through a journal 96 pivoted about a vertical axis in the end of the housing. A pipe supplies lubricant to the reduction gearing and prevents the lubricant rising above a predetermined level. When the braking apparatus has assumed a position corresponding to that of the electric motor control lever, current is cut off from the motor by a cutout circuit controller contained in a casing in the reduction gear casing 76 and having a shaft driven by gearing from the main gear wheel spindle. On this shaft are mounted collars provided with projecting hubs carrying cams having low, medium, and high cam portions. The position of each cam may be adjusted by concentrically-arranged holes engaging a pin, this pin also providing adjustment for the position of a second cam having a high cam portion adapted to adjust the length of the high cam portion of the combined cams. The cams engage insulated rollers mounted on pivoted spring-pressed levers connected by links to other spring-pressed levers adapted to be rocked by the cams to engage, by means of double contacts of tungsten and the like, contact buttons of carbon and the like on either side mounted on spring-pressed levers. The electric control means comprises two doublethrow electromagnetically operated contactors F. R, Fig. 19 (Cancelled). When the brake is to be applied, the forward operating contactor winding F<1> is energized through one of the right-hand contacts of the cams C<o>, C<4>, and the contact 217 is opened and the contacts 218. 219 are closed. When the brake is to be released the reverse contactor winding R<1> is energized through one of the left-hand contacts of the cams C‹ - - C<4>, and a. contact 220 is opened and contacts 221, 222 are closed. The magnet windings F<2>, R<2> are connected in multiple and directly across the armature of the motor 90, and the energization of these coils aids the return springs 223, 224 to return the contacts to normal. Operation of the remotely-placed control lever 150 is adapted to complete one of a number of circuits through a contact in the cut-out circuit controller C‹ - - C<4> and the coil F<1> of the contact F or the coil R<1> of the contact R, according to whether the brake is being applied or released. The movement of the contact 218 or 221 then completes a circuit through the motor 90 in one direction or the other. The cams of the circuit controller C‹ - - C<4> are moved to out out the circuit therethrough, the contact arm through which the circuit is made being brought to an intermediate or non-contacting position, and the contactor F or R is returned to normal. The motor is brought quickly to rest by a brake 214 held out of action electromagnetically by the current passing through the series field winding of the motor. The motor may be of the compound wound type having a shunt winding 210, always energized, which establishes a dynamic braking circuit to assist in stopping the motor, when its circuit is broken, this circuit being completed through the armature of the motor, its commutating winding 213, the contacts 220, 221, and resistances 240, 249. To accelerate the motor, resistances in its circuit may be shunted by a push button 152 mounted in the control handle which completes a circuit through the contact 219 or 222, according to whether contactor F or R is energized, and a relay H which moves a contact 243 to shortcircuit resistances 240, 241 normally contained in the motor circuit. When the contactor is deenergized, the relay circuit is broken and the contact 243 moves to break its circuit to ensure the dynamic braking circuit passing through the resistances 240, 249. The control lever 150 is adapted to operate an angle arm 165, Fig. 16 (cancelled), through a yieldable connection, this arm being held in its various positions by a pawl and ratchet. The arm 165 is pivoted on a spindle 164 in which is also pivoted a crank arm 198 engaging an arm 196 on the arm 165 by springs 195 mounted on guide pins threaded through lugs on the crank arm 193, which is connected to the lever 150 bv a link 194. One arm of the angle arm 165 is provided with an arcuate tooth portion 165‹. engaged by a roller on the end of a spring-pressed, pivoted pawl 171. The other arm carries an insulating block 166 to which is attached a channel containing two contacts electrically connected by a strap and pressed outwardly by a spring mounted on a guide, pin. One contact engages an arcuate member 186 and the other contact engages a number of contact fingers L‹ corresponding to the various braking positions. Secured in the control lever cabinet is a relay comprising a core 200, the magnetic circuit through the winding 201 of which is completed through the core, the back yoke 202, and the armature 203 whereby energization of the winding causes attraction of the armature 203 which brings contacts 205, 206 into engagement ior completing circuit for a light 161. The energizing current for the coils R<1> and F<1> flows through this relay so that the light 161 is illuminated as long as current is applied to one or other of these, contacts and indicates the response of the motor to movement of the control lever. This subject-matter does not appear in the Specification as accepted.