Patent GB-190514630-A (GB)
Title: Improvements in Controllers for Electrically Propelled Vehicles.
Inventor: RAWORTH JOHN SMITH
Filed: 1905-07-15
Granted: 1906-07-12
Abstract: 14,630. Raworth, J. S. July 15. Switches.-In a series-parallel controller for motors, in order to cause the sequence of operations during the forward movement to be different from that during the return movement, some of the segmental contacts are mounted separately from the rest on a ring, between which and the controller shaft is a lost-motion connexion. Fig. I is a diagram of connexions with the controller and reversing drams developed. Figs. II and; III show the construction of the "floating" ring, consisting of a sector-shaped piece 108, 109, carrying contacts 21, 22, 21<a>, 22" and loosely mounted on the shaft 102. The latter has a rigid arm 104, carrying a pin 113, fitting through a slot 112 in the sector 109. Starting from the ' on ' position where the machine is disconnected from the trolly-wire contact T, current is sent, in the first on' position, through the shunt fields SF', SF<2> in series with resistances sr<1>, sr<2>, sr<3>, sr<4>, while the armatures remain in a closed circuit with resistances r', r<2>. Movement through the second to the fifth position short circuits the shunt-field resistance step by step. At the fourth position, the brushes R', R<4> move on the contacts 21, 22, carried by the " floating " ring, which has slipped one step to the right from its position in Fig. I. At the sixth position, the armatures are connected in series to line, through resistances r', r<2>, r, with full shunt excitation. At this point, one branch of the circuit passes from the trolly-wire contact T, through contacts 1, 16, SR<5>, wires 3<d>, 5, shunt fields SF<1>, SF<2>, Wires 6, 7, 8, and reverser-barrel contacts 9, 10, 11 to earth. The other branch leads through contacts 1, 17, 18, a wire 19, contacts R<5>, 24, 22, R<4>, a wire 23, resistances r<3>, r<2>, r<1>, wires 24, 25, contacts 26, 27, 28, a wire 29, contacts 30, 31, 32, wires 33, 34, the armature wires 35, 36, contacts 37, 38, 39, a wire 40, contacts 43, 44, 42, a wire 45, contacts 46, 47, 48, and wires 49, 50, the armature wires 51, 52, contacts 53, 54, 55, a wire 56, a contact E, and a wire 99<a> to earth. From the seventh to the ninth position, the armature resistance is cut out, the last section r<3> by means of a contact 64 coming upon the "floating" ring contact 22<a>. From the tenth to the thirteenth position, resistance is reinserted into the shunt field circuit. The fourteenth position leaves all connexions the same as in the preceding position. At the fifteenth position, the armature circuit is broken. At the sixteenth position, the armatures are joined to their respective series fields F<1>, F<2> and FF<1>. FF<2>, and are placed in parallel, a resistance r<3> being also brought in, while the shunt fields retain full excitation. At the seventeenth position, the resistance r<3> is cut out. In the eighteenth and nineteenth positions, the resistances sr<4> and sr<g> are successively put into the shunt field circuit. On moving the controller drum backwards, the sequence of connexions is made in reverse order with the exception of those that depend on the " floating " ring. The four contacts 21, 22, 21<a>, 22<a> now lag one step to the left, so that they do not separate from the contacts 64, R, R<4> until the fourteenth position is reached. The armatures are thereby placed in series with resistances r', r<3>. On passing to the thirteenth position, contacts 21, 22, and 22<a> meet contacts R<5>, R<4>, and 64, respectively, and short circuit the armature resistance, which commences to be reinserted when the eighth position is reached. At the fifth position, the armatures are disconnected from the line. A braking effect i obtained in the ' ofE ' position by having contacts 68 ... 73 long enough to meet their corresponding fingers. The reverser barrel then being turned so that the right-hand set of contacts comes into use, short circuits the motors through their reversed series field windings. Specifications Nos. 3657, 3658, and 10,723, A.D. 1903, and No. 1716, A.D. 1904, are referred to.