Abstract
An improved safety system used to determine the present position of a car riding on railroad tracks that provides data to control signals, such as flashing lights, and crossing gates at railroad grade crossings in order to prevent accidents with vehicles or persons.
Claims
1. In a system for providing safety signals at grade crossings of electrified railroad track using a shunt assembly installed on a car riding on said railroad track to complete an electrical circuit between a rail wheel of said vehicle and said track, the improvement comprising: a conductive contact shoe; a spring, whereby the position of said contact shoe is biased by said spring so as to be in continuous contact with said rail wheel riding on said track in order to complete said electrical circuit; a rail sweep mounting bracket connected to an undercarriage of said vehicle; a wheel arm connected to said bracket; a wheel hub assembly connected to said wheel arm; rail gear having a hub connected to said wheel hub assembly; and stacked housing plates connected to said mounting bracket, whereby said conductive contact shoe contacts said hub and is connected to said stacked housing plates and said spring is positioned between said contact shoe and said stacked housing plates.
2. A shunt assembly for use in a control system for signals at electrified railroad track grade crossings comprising: a rail sweep mounting bracket connected to an undercarriage of a car riding on said railroad track; a wheel arm connected to said bracket; a wheel hub assembly connected to said wheel arm; rail gear having a hub connected to said wheel hub assembly; housing plates connected to said mounting bracket; a conductive contact shoe extending through said housing plates; and a spring positioned between said contact shoe and said housing plates, whereby said spring acts to bias the position of said contact shoe with respect to said wheel hub so that said contact shoe is in continuous contact with said wheel hub.
3. The shunt assembly of claim 2 in which the base of said conductive contact shoe is concave in form.
4. The shunt assembly of claim 2 in which said conductive contact shoe is manufactured using cast 304L stainless steel.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIGS. 1a, 1b, and 1c illustrate the prior art use of wire brushes to complete an electrical circuit between a spinning rail wheel and a control system for safety at railroad grade crossings.
(2) FIG. 2 is a perspective view of the shunt assembly of the present invention.
(3) FIG. 3 is a perspective view of an entire assembly for a rail wheel of the present invention.
(4) FIG. 4 is a perspective view of a shunt assembly of the present invention.
(5) FIG. 5a shows the preferred embodiment of a conducive contact shoe of the present invention.
(6) FIGS. 5b, 5c, and 5d show alternate embodiments of a conducive contact shore of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
(7) FIG. 2 is a perspective view of the shunt assembly 10 of the instant invention. Conductive contact shoe 11 having a concave base (as shown in FIG. 2 as the preferred embodiment, and also in FIG. 5a) is connected through grease housing plates 12 and is biased with coil spring 13 to maintain contact pressure on the hub 20 (as shown in FIG. 3) of the train wheel (which wheel is not shown in FIG. 3). Contact shoe 11 extends through plates 12 with a distal end 14 having a fastener set 15 in the form of a nut and bolt extending through said distal end 14. Grease fitting 16 is used to lubricate housing plates 12 and mounting plate 17 is used to attach shunt assembly 10 to rail sweep mounting bracket 18 as shown in FIG. 3.
(8) FIG. 3 is a perspective view of the entire assembly for a rail wheel (which wheel is not shown, but would be similar to prior art element 101 as shown in prior art FIGS. 1b and 1c) as it is connected to rail gear (not shown, but similar to prior art element 102 in prior art FIG. 1c). Visible in FIG. 3 is rail wheel hub 20 on which contact shoe 11 rides. Conductive contact shoe 11 in the preferred embodiment is manufactured from cast 304L stainless steel, a relatively soft conductive material so as to minimize wear on hub 20. Wheel arm 21 connects wheel hub assembly 20 to rail gear (not shown) by white plastic insulators 22 that electrically insulate wheel hub assembly 20 from rail gear so that the sole electrical path in the system is through shunt assembly 10.
(9) FIG. 4 is a perspective view of shunt assembly 10 showing wire 30 connected by eye ring 31 that is attached to fastener set 15 on distal end 14 of contact shoe 11 completing the electrical connection from electrified track (not shown) through the rail wheel riding on such electrified track through conductive contact shoe 11 to wire 30 which forms a shunt to complete the electrical circuit to control the gate crossing signals and gates.
(10) FIG. 5a shows the preferred embodiment of the conducive contact shoe 11, in its concave form, with coil spring 13. FIGS. 5b, 5c, and 5d show alternate embodiments of contact shoe 11 and spring 13, which alternate embodiments are to be construed to be covered by this disclosure.
