Patent GB-189708295-A (GB)
Title: Improvements in or relating to Electric Traction, and in Apparatus employed therein.
Inventor: VEDOVELLI EDOUARD
Filed: 1897-03-31
Granted: 1898-03-05
Abstract: 8295. Vedovelli, E. March 31 Electric railways and tramways on a road-contact or sectional-conductor system with ground or overhead conductors and electromagnetic switches. Arrangements of the switch circuits &c., and the construction of the switches, collectors, conductors, road contacts, rail bonds, &c. are described. Conductors; switches.-Figs. 1 and 3 show diagrammatically two forms of switches, in which L is the main conductor, B the road contacts, and RT the return or earth circuit. A shunt current from the collector F to earth excites the electromagnet E, Fig 1, which throws the switch and thereby connects the road contact to the main] conductor, and at the same time cuts out the previous electromagnet. In Fig. 2 the throwing of one switch cuts the main circuit instead of cutting out the magnet coil of the previous switch. A number of modifications of and additions to these switches are described to ensure that the contacts or sections passed over by the vehicle are rendered dead, to prevent the passage of excessive currents, and to obviate sparking. These include double windings on the magnet, properly balanced for the current to be used, additional cut-out switches, the interpolation of condensers and resistances, and the use of dash-pot arrangements. Arrangements are then described to ensure the cutting-out and exciting of switches in the proper direction at junctions, turnouts, and passing-places. Thus, as shown in Fig. 11, the vehicle coming in either direction causes the switch C to move so as to cut out one set of switches and to make the circuit for the other set. A metallic casing 21, Fig. 16, round each road contact B intercepts leakage currents. The switches similar to those in Figs. 1 and 2 are also applied to an overhead sectional conductor. The sections 22 may overlap or may be connected while the collector is passing by a hinged bridge-piece. Fig. 20 shows a bridging-device 31 which works with the trolley running in either direction. The construction of the road-contact block is shown in section in Fig. 21. A rectangular box 39 with a central boss supports an inverted cup 41 on which a wearing-piece 48 or a rail is mounted so as to be rubbed by the collector. The cup and box are separated by insulating-material 42. A sectional side elevation of the actual switch is shown in Fig. 37. One or more magnet coils 81, 82 lift an iron core 83 forming the end of a lever 84 pivoted at 86. Attached to a cap 101 mounted on a knife-edge 99 on this lever are two contacts which normally rest on two contacts 112. A loose piece 88 pivoted at 89 on the lever 84 is furnished with a second knife-edge 96, which lifts a second cap 100, also having two contacts, which it raises to touch the second pair of fixed contacts 119. Adjustable stops 120, 121 control the movement of the loose piece 88, and the arrangement is such that the upper contacts are brought together before the lower ones are separated, and subsequently are slid over one another to ensure good contact for the main current. To make the connections between the various conductors and the contacts in this switch, a removable bridge with contacts 130 and handle 142 is used, as shown in Fig. 45. These contacts 130 take into a series of contacts 132, Fig. 41, attached to the switch and the enclosing-box. A box for holding the switch is shown in Fig. 46. It has lugs 143, 144 for attaching the switch, a cover 147 with a double oil joint 148, 149, and an outer lid 153 supported on the casing 150. This latter may be tilted by inserting wedges under its edge. The bottom is closed by a cap 154 with passages for the conductors. Rail bonds, as shown in Fig. 26, consist of a bent rod 56 held in the rail by the piece 53 and two wedges 58. Either the piece 53 or the wedges 58 may be in one piece with the rod 56. Collectors.-The bars 61 which rub over the road contacts P overlap, and are carried by links 'as in Figs. 34 or 35. Springs 65, 68 keep these bars in their lowest position. In a modification, the collector - bar is in insulated lengths, so that different parts may have different potentials.