Patent GB-190828120-A (GB)
Title: Improvements in Appliances for the Electric Lighting and Heating of Vehicles.
Inventor: GROB HUGO
Filed: 1908-12-24
Granted: 1909-12-24
Abstract: 28,120. Grob, H. Jan. 2, [date applied for under Section 91 of Patents &c. Act, 1907] Switches.-A reversing-switch for the electric lighting of vehicles is set in operation by a centrifugal governor R, which, when running at a given speed, shifts an eccentric sleeve H along its axis, thereby repelling in each of its extreme positions one of the arms of a two-armed lever A B, and actuating the switch through rods Li, L2 and leaves M1, M2 loosely mounted on the switch S. One of these levers M2, Fig. 4, is coupled to the switch shaft by means of a coupling-piece P, mounted on a pivot O rigid with the shaft. The position of the coupling-piece is determined by springs T, which are connected to it and to a spring carrier V mounted on the pivot O. A lever k on the carrier V bears against a stationary cam l. When the eccentric lifts the rods L1, L2, the switch shaft is turned by the lever M2, carrying with it the spring carrier V. The lever k turns in the direction shown by the arrow in Fig. 4 until the spring carrier V snaps round into its other end position, determined by the striking of projecting bolts i against squared faces of the shaft S. The springs now tend to turn the coupling-piece P into its other position, but are prevented from doing so by a lug a on the coupling-piece, which slides along a curved plate b. On switching - off, the switch shaft is returned to the mid - position, whereupon the lug a moves in front of an opening h in the plate b, thus permitting one coupling-piece P to leave the lever M2 and engage the lever M1. The switch shaft is thereby rotated in the opposite direction on the next opening of the centrifugal weights. To switch off, the eccentric sleeve H has only to release the stop K of the lever A B by means of lugs C, the remainder of the movement being performed by gravity or by a spring F. The Specification in its original form, as open to inspection under Section 91 (3) (a), comprises also the following additional features, and refers to the train-lighting system described in Specification No. 14,059, A.D. 1907. The switching-on is effected in two stages, a stop G being provided in the stopplate D to hold the switch lever in the position to which it is raised by the first eccentric E2. After a further revolution of the eccentric, during which the current reaches its full strength, a second eccentric E raises the lever into its higest position and switches-in the lighting-circuit. During the first stage, the dynamo may be loaded with a resistance which is switched off at the second stage. This feature has been included in the divided application No. 27,937, A.D. 1909, [Abridgment Class Electric switches]. In order to avoid sparking on changing from the auxiliary to the working-circuit during the switching-on movement, the contacts are arranged as shown in Fig. 6, so that each of the two brushes D1, D2, which are mechanically independent and connected up in parallel, has to traverse a long separating insulation - piece J, while one brush completes the working - circuit before the other breaks the auxiliary circuit. In order to reverse the polarity of the generator after the direction of running has been changed, the charging-brushes n, Fig. 5, are mounted on a brush-holder m, which is pivoted at p and capable of movement between two stops q. The brush-holder is carried to one of its end positions by the friction between a disk v, carried by the sleeve H, and a stud t of carbon, which is placed in a socket piece o in the brush-holder and pressed against the disk v by a spring u. The brushes n make contact with the contact paths w on the flat disk x mounted on the switch shaft S ; when the train is at rest, the switch shaft is in the central position, in which the brushes n stand opposite a depression y in the disk x and are therefore freely movable towards the sides. The brush-holder is locked in its end positions by a spring-pressed bolt d, which is placed in a socket c in a stationary body z. The reduced front end of this bolt projects through an opening e in the brush-holder. As long as the governor is closed, the bolt rests agaiost the disk v, so that only its reduced end enters the opening e. When the governor opens, the disk v recedes, and the thicker end of the bolt passes through one hole of the opening e and locks the brush-holder against lateral movement. This subject-matter does not appear in the Complete Specification as accepted.