GB2120619A - Electric power collection apparatus for a vehicle - Google Patents

Abstract

Electric power collection apparatus for a transport vehicle running on a roadway track with a plurality of power rails comprises a collector shoe (47, 48, 49) for sliding along each power rail mounted on the vehicle via a support member (240, 242, 244) of a resilient electrically insulating material, e.g. polyurethane, having a durometer hardness of about 90, for flexibly adjusting rotational and angular position of the collector shoe as the shoe passes through power rail irregularities, e.g. at track switches. <IMAGE>

Description

SPECIFICATION Power collection apparatus for a transportation vehicle The present invention relates generally to transportation system in general and more particularly to power collection apparatus in transportation systems of the people-mover-type.

It is known in the prior art to provide a rubber tired vehicle transportation system as described in an article published in the conference record of the 28th IEEE Vehicular Technology Group in relation to a meeting in Denver in March 1978 and entitled Atlanta Airport People Mover, including a guide beam located in the center of parallel vehicle support tracks and a power distribution apparatus consisting of five rail members mounted on top of the guide beam and operative with vehicle carried collector shoes to provide desired propulsion power and control signals to the vehicle.The three top power rails couple with main collector shoes to distribute three phase AC power and the fourth and fifth signal rails provide guidance for the main power collector shoes as well as a ground connection for the vehicle system and the provision of speed command signals to control the vehicle and to detect the presence of the vehicle in each of provided track signal blocks. The vehicle track system can include a movable track switch that operates with a first track section, and includes a first movable guide beam for controlling vehicle movement in relation to a second track section and a second movable guide beam for controlling vehicle movement in relation to a third track section.

In U.S. Patent 4,168,770 there is shown a power distribution rail arrangement mounted on top of the center guide beam of a roadway track and operative with collector shoes carried by the vehicle moving along that roadway track.

In U.S. Patent 4,090,452 there is shown an example of a track switch. First and second movable guide beam sections of the track switch are movable between a first position with the first movable guide beam coextensive with the fixed guide beam of a first roadway and a second position with the second movable guide beam coextensive with the fixed guide beam of that roadway. The first movable guide beam leads to a second roadway and the second movable guide beam leads to a third roadway.The power rails are mounted above a portion of the first and second movable guide beams and the power rails are discontinued through the remainder of the track switch guide beams for providing a power rail gap to permit the vehicle wheels to pass over the guide beam as the vehicle travels between the first roadway and a selected one of the second and third roadways as determined by the track switch position. The main current collector shoes carried by the vehicle physically decouple from the power rails at the beginning of the rail gap where the power rails are discontinued in relation ro a track switch and while the vehicle is located within that track switch, and then recouple with the power rails when the power rails are again provided at the end of the rail gap near the exit end of the track switch.The vehicle can typically move through the track switch at a speed in the order of 25 miles per hour.

In the present invention, a power collection apparatus is provided for a transportation vehicle operative with a roadway track having a plurality of power rails extending along that roadway track.

The collection apparatus includes a coupling member carried by the vehicle and extending toward the power rails, with an insulator support holder for each of individual collector shoes operative with respective power rails, and which support holder includes a flexible shock absorbing member made of electrically insulating and physically resilient material having a predetermined durometer hardness characteristic and that is connected with each collector shoe to control the desired rotational and angular position of that collector shoe as it passes through rail irregularities, and to permit the shoe to be shock loaded and axially rotated as the shoe moves along misaligned rail section connections, such as can occur at a track switch point rail break, and through rail gaps and other discontinuities in relation to the vehicle moving along the roadway track including roadway track switches.

The present invention in its broad form resides in an electrical-power collection apparatus for a transit vehicle moving along a roadway track said track having at least one power rail having a longitudinal axis substantially in parallel alignment with said roadway track, with said power rail having a conductive surface which may have irregularity in its contact surface, the apparatus comprising: coupling means carried by said vehicle and extending toward the contact surface of said power rail, collector means electrically connected in sliding contact with the contact surface of the power rail, and resilient support means provided between the coupling means and the collector means, said having a predetermined resilience characteristic to permit limited movement of the collector means to pass over said irregularity and then to return to a desired self centered orientation of the collector means in relation to the longitudinal axis of the power rail as the vehicle moves along the roadway track.

Figure 1 shows a prior art power collection apparatus for a guided transportation vehicle; Figure 2 shows a prior art roadway track switch for a guided transportation vehicle; Figure 3 provides a more detailed showing of the prior art power collection apparatus of Figure 1, including the power supply rails and the power collector shoes that move along those rails; Figure 4 shows a side view of the prior art support apparatus for the collector shoes; Figure 5 illustrates a prior art curve in the roadway track resulting in one power rail no longer being aligned with the other power rail; Figure 6 shows a side view of the collector shoe support apparatus in accordance with an embodiment of the present invention; Figure 7 shows an end view of the collector shoe support apparatus of an embodiment of the present invention;; Figure 8 shows the connection of the vertical position control member between the power collector shoes and the lowermost collector shoe; Figure 9 shows the connection of the vertical position control member with the support coupling for the lowermost collector shoe; Figure 10 shows a collector shoe support member; Figure 11 shows a modified collector shoe support member; Figure 1 2 shows a vertical misalignment of one power rail; and Figure 1 3 shows a lateral discontinuity between two sections of a power rail that are joined together.

In Figure 1 there is shown a prior art transportation system including a roadway track 10 for a mass transportation vehicle 12 and including support tracks 14 and 16 carried by a road bed 18. Flanged guide beam 20 is positioned between the tracks 14 and 1 6 and supported by a base member 22 between the road bed 18 and the guide beam 20. The self propelled vehicle 12 includes a body 24 which moves along the roadway tracks 14 and 16 on support wheels 26 and 28 provided at each end of the vehicle 12. The vehicle 1 2 is self steering through operation of a guidance apparatus 30 including guide wheels 32 and 34 which operate on the opposite sides of the guide beam 20.The guide wheels each rotate about a vertical axle, with the upper ends of those vertical axles being fixed to the vehicle steering member 42. The guide beam top flange 21 restrains and prevents the vehicle 12 from leaving the roadway 10.

The vehicle 12 is driven by an electric propulsion motor operative with the axle 37 within the housing 38. Electric propulsion power or current is supplied to the vehicle motor by a power collection apparatus, including the energized three phase power rails 43, 44 and 45 supported by an insulated support member 46 positioned above the top flange 21 of the guide beam 20.

The power rails 43, 44 and 45 have conductive surfaces that are cooperative with three phase power collector shoes 47, 48 and 49 supported by the vehicle carried coupling or support member 50 and electrically connected with the vehicle motor. A suitable power supply 69 is coupled with the power rails 43, 44 and 45 through a three phase connection 71 , which can pass through a gap between respective ends of the sections of the guide beam 20. This gap is small enough for the conductor 71 to pass but not large enough to adversely affect the operation of the guide wheels 32 and 34. A signal rail 51 and a ground rail 53, which are interchangeable and can change respective positions in relation to the track circuit signal blocks, are provided adjacent to the top flange 31 of the guide beam 20.

In Figure 2 there is shown a prior art pivotal guide beam track switch 100 that is disclosed in greater detail in U.S. Patent 4,090,452. The pivotal guide beam track switch 100 is located at the junction of a first vehicle roadway 102, a second vehicle roadway 104 and a third vehicle roadway 106. The roadways 102, 104 and 106 have laterally spaced concrete vehicle support tracks 108 and 110 and include respective flanged guide beams 112, 14 and 115. The pivotal guide beam switch 100 controls the travel of a transportation vehicle between roadways 102 and 104 and between roadways 102 and 106. The pivotal guide beam switch 100 includes a first movable switching guide beam 11 6 movable in relation to a pivot 1 21 and a second switching guide beam 122 movable in relation to a pivot 123.The first switching guide beam 116 includes a power rail section 125 including an end ramp apparatus 127 and the second switching guide beam 1 22 includes a power rail section 129 including an end ramp apparatus 1 31. The first roadway 102 includes a fixed power rail section 11 8 supported above the guide beam 11 2. A switch point power rail break is present between the fixed power rail section 118 and one of the power rail sections 125 and 129, depending upon the positions of the track switch respective first and second switching guide beams 11 6 and 122. The second roadway 104 includes power rail section 1 20 supported above the guide beam 114 and having a tapered end ramp 119.The third roadway 106 includes power rail section 124 supported above the guide beam 11 5 and including a tapered end ramp apparatus 1 26. Each of the power rail sections 11 8, 120, 124, 125 and 129 include the power rails, signal rail and ground rail such as shown in Figure 1.

Wheel support members 1 28 and 130 provide roadway surfaces for a vehicle traveling between the roadways 102 and 106. Wheel support members 132 and 130 provide roadway surfaces for a vehicle traveling between the roadways 102 and 104. The tapered ramp apparatus 127 is located at the end of fhe power rail section 125 that is remote from the horizontally movable end 134 of the switching guide beam 11 6. The tapered ramp apparatus 1 31 is located at the end of the power rail section 129 that is remote from the horizontally movable end 136 of the switching guide beam 122. The tapered ramp apparatus 119 is located at the end of the power rail section 1 20 that is adjacent to the wheel support member 128. The tapered ramp apparatus 126 is located at the end of the power rail section 124 that is adjacent to the wheel support member 132.

In Figure 3 there is shown the prior art current collection apparatus of Figure 1 including the three phase power rails 43, 44 and 45 respectively operative with the collector shoe pairs 47, 48 and 49. It should be understood that each collector shoe pair includes intercoupled collector shoes, and include the top pair of intercoupled collector shoes 47, a middle pair of intercoupled collector shoes 48 and a lower pair of intercoupled collector shoes 49. There are shown two power rails 43 and 44 on the left side of the support member 46 and one power rail 45 on the right side.The collector shoe arrangement provides sliding contact with the conductive surfaces of the power rails and permits the vehicle to collect propulsion current from the illustrated power rails whether the two power rails 43 and 44 are on the left side as shown in Figure 2 or are on the right side of the support member, such that the movement of the vehicle along the roadway track will be satisfactory in each direction along that roadway track. A more detailed description of the operational and physical relationship of the power rails 43, 44 and 45 with the collector shoes 47, 48 and 49 as shown in Figure 3 is provided in U.S. Patent 4,1 68,770.

Figure 4 shows a side view of the prior art current collector support apparatus including the collector coupling or support member 50 and the collector shoes 47 and 49 operative with the respective power rails 43 and 44. The collector shoe 57 operative with and following the position of ground rail 53 is operative through collector arm 54, pivot support 56 and extended connection arm 59 to determine the movement of connection link member 58 in a direction parallel to the axis of collector support member 50 for controlling the power rail alignment positions of the collector shoes 47 and 49 through the extended connection arm 60, the pivot support 62, the collector arm 64 and the fastener channel 66.

There is disclosed in Figures 3 and 4 the provision for positionally guiding in relation to the guide beam 20 the vehicle carried power collector shoes 47, 48 and 49 through rail gaps and switch point rail breaks at track switches at the desired vehicle maximum operating speed. One of the signal rail 51 and the ground rail 53 is used for position control of the respective vehicle carried power collector shoes by linking the associated collector arms to one of the continuously guided collector shoes 55 and 57 for the signal rail 51 and ground rail 53. There is disclosed a three phase five rail power collector apparatus for fixed guideway type electrically propelled vehicles, that permits high speed operation through rail gaps and switch point rail breaks at track switches and crossovers.Each vehicle carried collector support apparatus includes power collector shoes guided through necessary interruption gaps in the three phase power rails by using the signal rail 51 and ground rail 53 as position piloting rails for the respective groups of power collector shoes, which are equidistantly located one to each side of the guide beam top flange and located below the roadway surface.The signal rail 51 and ground rail 53 are each continuous throughout the system, including track switches, and since they are fixed in position by the rail support member 46 both vertically and laterally with respect to the three phase power rails 43, 44 and 45 they provide optimum position control of the vehicle carried power collector shoes 47, 48 and 49 during the time when the vehicle carried power collector shoes are not in contact with the respective power rails 43, 44 and 45, such as disclosed in above-referenced U.S. Patent 4,168,770.Accurate vertical and lateral positioning of the vehicle carried power collector shoes in the power rail gap interval through track switches is essential for high speed operation of a vehicle through those switches, and is accomplished in the controlled space envelope by connecting through a link such as link member 58 each set of the respective power collector shoes to one of the continuously guided signal rail collector shoe and ground rail collector shoe, thereby assuring proper reentry position of the power collector shoes onto the power rails after the vehicle passes through a track switch. The disclosed geometric configuration of the three power rails in combination with duplicate sets of vehicle carried collector support apparatus and associated collectors shoes permits a vehicle to operate through crossovers and the track switches.Half of the power collector shoes which are required for the crossover capability are inactive at any given time, however they remain guided even when not in contact with the power rails.

In Figure 5 there is shown a prior art curve in the roadway track. The top power rail 43 is shown following the normal curved position between the rail holder members 304 and 306. The lower power rail 44 is shown positioned along the chord between the two rail holder members 304 and 306. There can in practice be about a 2 inch difference in physical position in relation to the horizontal plane of the roadway track between the position of the power rail 43 and the position of the power rail 44.

In Figure 6 there is shown an end view of the present collector shoe support apparatus. The coupling member 50 extends down from the vehicle and includes the pivot members 204, 210, 218 and 226 and the collector support arms 200, 212, 220 and 228. The support rod 206 is connected through the resilient insulator support member 240 with the collector shoe 47. The support rod 208 is connected through the resilient insulator support member 242 with the collector shoe 48. The support rod 216 is connected through the resilient insulator support member 244 with the collector shoe 49. The collector pin 224 is connected through the insulator support member 246 with the collector shoe 57.The fastener channel 66 firmly holds one end of the each of the resilient insulator support members 240, 242 and 244 to prevent axial rotation of those insulators in relation to the respective support rods 206, 208 and 216, and which operates to control the desired self centered orientation of each collector shoe in relation to the longitudinal axis of its associated power rail for providing the desired substantially parallel alignment of the respective collector shoes 47, 48 and 49.

In Figure 7 there is shown the coupling member 50 with a first collector support arm 200 and a second collector support arm 201 that operate as a parallelogram to permit horizontal movement in the plane of the drawing of the pivot member 204 relative to the pivot member 202.

The arm 200 is pivotally coupled at ends 203 and 205 for this purpose with the respective pivot members 204 and 202. Similarly the arm 201 is pivotally coupled at ends 207 and 209 with the respective pivot members 204 and 202 for this purpose. Each of the support arm arrangements shown in Figures 6 and 7 operate in a similar manner for permitting movement of the associated collector shoe in a direction perpendicular to the respective cooperative power rail. The support rod 206 extends only part way into a first end of the insulator support member 241 and is held in position by a pin 250 as shown. A second coaxial support rod 252 extends part way into the opposite second end of the insulator support member 241 and is held in position by a pin 254.A compression spring 256 is provided between the second end of insulator support member 241 and the collector shoe 47, with a pivot end 256 holding the collector shoe 47 to permit rotation of the collector shoe 47 about the pin 256 and against the compression of the helical spring 256 for improving electrical contact in a horizontal plane with the power rail 43 regardless of normal track curve bends of that power rail 43. The link connector 240 is coupled to the support rod 200 through a ball 256 provided on the support rod 206 and a socket 260 connected with the link connector 240.

Respective compression springs 262 and 264 are provided on opposite sides of the ball 258 to permit sliding movement of the ball 258 along the support rod 206 but to determine the position of the ball 258 as shown in Figure 6.

In Figure 8 there is shown a side view of the collector shoe support apparatus in accordance with the present invention. A vehicle carried coupling member 50 extends vertically down from each transportation vehicle, with one such coupling member 50 being provided on each side of the insulated support member 46 for the power rails as shown in Figures 1 and 3. The coupling member 50 shown in Figure 6 is operative with both sides of the support member 46 as the vehicle moves along the roadway track. The coupling member 50 can be positioned ahead of or trailing the collector shoes 47, 48 and 49, since the collector shoe apparatus is operative bidirectionally. A collector support arm 200 is shown connected between pivot members 202 and 204.The pivot member 204 is coupled with the fastener channel 66 that connects together and controls the vertical alignment positions of the three collector shoes 47, 48 and 49. The collector shoe 47 is connected by a support rod 206 that passes through the fastener channel 66 and the pivot member 204 for coupling with the support arm 200. The collector shoe 48 is connected by a support rod 208 that passes through the fastener channel 66 and the pivot member 210 for coupling with the support arm 212 that is connected between pivot member 210 and the pivot member 214. The collector shoe 49 is connected by a support rod 216 that passes through the fastener channel 66 and the pivot member 218 for coupling with the support arm 220 that is connected between pivot member 218 and pivot member 222.The collector shoe 57 operative with ground rail 53 is connected by a support rod 224 that passes through the pivot member 226 for coupling with the support arm 228 that is connected between pivot member 226 and pivot member 230. The pivot members 202, 214, 222 and 230 are pivotally connected through respective pins 232, 234, 236 and 238 with the vehicle carried support member 50. Springs 233 and 235 are provided between a plate 237 connected with bolts 239 and 241 with the coupling member 50, and the respective pivot members 204 and 218 to pull upward on the collector shoes 47, 48 and 49, and a spring 243 is provided between the plate 237 and the pivot member 226 to pull upward on the collector shoe 57.A link connector 240 is coupled between the pivot member 204 and the pivot member 226 for controlling the vertical position of the three collector shoes 47, 48 and 49 in relation to the vertical position of the collector shoe 57 that is coupled with the continuous ground rail. Another similar collector shoe support apparatus such as generally shown in Figure 6 but modified for operation with the other side of the support member 46 is also provided and the vertical position of the three collector shoes 47, 48 and 49 of the latter collector shoe supported apparatus here involved is controlled in relation to the vertical position of the collector shoe 55 coupled with the continuous signal rail and by a link connector such as shown in Figure 6.

In Figure 9 there is shown the pivot member 226 connected through support rod 224 with the insulator support member 246 that is coupled with the collector shoe 57. A first collector support arm 228 and a second collector support arm 229 operate as a parallelogram to permit horizontal movement in the plane of the drawing of the pivot member 226 relative to the pivot member 230 shown in Figure 8. The link member 240 is coupled to support rod 224 through a sliding ball 270 provided on the support rod 224 and a socket 272 connected with the link member 240. Respective compression springs 274 and 276 are placed in relation to the ball 270 to permit movement of the ball 270 along the support rod 224 and to position the ball 270 as desired.

In Figure 10 there is illustratively shown the support rod 206 extending part way into a first end 243 of resilient insulator support member 241 and is held in that position by a pin 250 to hold the insulator 241 relative to the rod 206, as also shown in Figure 7. The support rod 252 extends part way into the second end 245 of the insulator support member 241 and is held in that position by a pin 254 to prevent rotation of the insulator support member 241 relative to the rod 252. The compression helical spring 256 is provided between the second end 245 and the connector 247 fastened to the collector shoe 47.

The connector 247 is pivotally coupled with the support rod 252 through a pin 256.

In Figure lithe first end 243 of the insulator support member 241 is shown provided with a predetermined taper of about 10 degrees to permit some desired lateral relative movement between the collector shoe 47 and the collector shoe 49 when the vehicle is traveling around a curve in the roadway track. A typical curve as shown in Figure 5 has a radius of about 75 feet with power rails held by support brackets 46 about five feet apart. When a vehicle moves around such a curve there might be required about a one half inch relative movement in the vertical plane between the collector shoes 47 and 49. The taper provided for the insulator support member 241 facilitates this movement.

In Figure 12 there is schematically shown the power rails 43 and 44 in relation to the ground rail 53, as shown in Figure 3. In the power rail 43 there is illustrated a vertical bend or misalignment out of its correct alignment position as shown by the dotted longitudinal axis 300.

In Figure 13 there is shown a joint discontinuity between two power rail sections, such as can occur at a switch point power rail break. If this were the power rail 43, the rail section 43A is coupled with the rail section 43B such that the section 43B is physically below the section 43A. For a collector shoe 47 moving from right to left, there would be physical shock imparted to the collector shoe 47 as the shoe passed over the coupling joint where the two rail sections 43A and 43B were joined together.

The power rails for the Atlanta system described in the above referenced publication are several miles in length, since there are three parallel power rails and the roadway track is about one mile in length. These power rails include isolation insulated joints provided between predetermined power distribution block sections of the power rails. A physical discontinuity or irregularity of the power rail surface as shown in Figure 13 in contact with the moving vehicle carried collector shoe can occur at each of the switch point breaks. In addition the power rails are mounted above the center guide beam and do not continue through the track switches to enable the vehicle wheels to cross over the guide beam when the vehicle is switching between roadway tracks.This results in a rail surface gap since each collector shoe operative with a power rail must physically disengage the power rail near the entrance to the track switch and travel through the track switch out of contact with the power rail until again engaging the power rail as the vehicle leaves the track switch and enters a desired roadway track.

The prior art collector shoe insulator support members were made of polyvinyl chloride or PVC material, which was rigid and brittle and would break when subjected to shock loads that resulted from passing over and through irregularities and discontinuities in the power rails. In actual practice at Atlanta the collector shoes operative with power rails having such irregularities averaged about 2,000 miles of travel per shoe because of breaking of the shoes caused by those power rail surface irregularities.

In addition there was another prior art collector shoe insulator support member problem as shown in Figure 5 and in relation to the vehicle moving through a curve in the roadway track, which curve typically has a radius of about 75 feet. When the vehicle travels around such a track curve, the collector shoe 47 coupled with the top power rail 43 can move laterally by as much as about one half inch relative to the collector shoe 49 coupled with the bottom power rail 44, and this resulted in one prior art collector shoe 47 moving away from its power rail to form an air gap where an arc could take place to damage one of the involved power rail 43 or the collector shoe 47.

A different prior art collector shoe support member problem involves a vertically bent and misaligned power rail, such as shown in Figure 12 and can occur when a maintenance person inadvertently steps on a power rail and bends it out of its original vertical alignment position relative to the other power rails. In such a situation, the prior art PVC insulator member was rigid and would frequently break when a collector shoe traveled along such a bent power rail.

A further prior art collector shoe support problem involved the collector shoe alignment with the power rails and the other collector shoes when the vehicle traveled through a provided rail gap at a track switch. The prior art PVC insulator support members were hexagonally shaped and were held in a loose U-shaped channel connecting together the three collector shoes operative with the power rails. In response to being shock loaded by the power rail irregularities such as switch point rail breaks and rail gaps, after a period of time the corners of the hexagonal insulator member would wear away to permit 10 degrees or more of collector shoe rotation.This resulted in phase to phase electrical short circuit problems between collector shoes, and a given power collector shoe was no longer properly oriented by the insulator support member after a vehicle passed through a track switch for that collector shoe to reenter the desired power rail at the exit side of the track switch, since the prior art PVC insulator support members would wear or be broken away in response to the movement of that collector shoe along the power rail irregularities such that after a few hundred miles of travel the rotational movement of the associated collector shoe would increase and become loose about the pivot connection.

The present support insulator member as shown in Figure 10 and made of a synthetic or natural rubber material, such a polyurethane of about 90 durometer hardness is resilient and provides a limited vertical and rotational movement for the supported power collector shoe. A desired shock absorbing or cushioning of the collector shoe is provided and the collector shoe will return and be self centered to its original desired orientation position with the power rail after a shock loading by a rail irregularity such as a switch point rail break. The resilient insulator support member is capable of withstanding greater shock loading without permanent deformation or rupture. This insulator support member permits vehicle travel around track curves such as shown in Figure 5, with each power collector shoe in contact with its associated power rail throughout the whole curve.

The U-shaped channel 66, as shown in Figure 6 and 7, now more firmly holds the insulator support members against rotation and the end of the present insulator member does not break or wear away to prevent undesired greater rotation of the supported collector shoe.

There are several power rail irregularities that can present problems to satisfactory collector shoe operation. In Figure 1 2 there is illustrated a power rail misalignment condition, where the power rail 43 is bent out of its normal substantially parallel position in relation to the power rail 44 and the guidance ground rail 53, which can occur by someone such as a maintenance person bending the power rail. In Figure 1 3 there is illustrated a discontinuity condition such as might occur at a track switch point rail break, where a joint between rail sections 43A and 43B does not provide a continuous contact surface for the moving collector shoe 47. Further, the power rail sections are typically made in sections about 30 feet long, and a discontinuity can occur where they have to be joined together for providing the required power rail.In addition, isolation joints are provided in the power rail as required for power distribution blocks. Further, as shown in Figure 2, power rail gaps are provided in relation to track switches, where a section of each power rail several feet in length is not provided above the center guide beam to permit the vehicle wheels to travel over the guide beam for moving between the respective roadway tracks.It was found in the actual operation of passenger vehicles provided with insulator support members 240, 242 and 244 as shown in Figure 6 and which were made of a predetermined durometer hardness polyurethane or like rubber material, that sufficient collector shoe support was provided as the vehicle passed through the track switch to prevent undesired sag or droop in the respective collector shoes out of desired positional alignment with the power rails while maintaining the desired self centering orientation of those shoes with the power rails, and each collector shoe was properly oriented to more smoothly reenter the correct power rail as the vehicle left the rail gap of the track switch.

The helical spring 256 provided in relation to pivot connection 257 of a collector shoe, as shown in Figures 7 and 10, with the support rod 252 coupled with the second end 245 of the insulator support member 241 cooperates with the resilient insulator support member to prevent free rotation of the associated collector shoe about the pivot connection 257. The friction of the collector shoe moving along a power rail, having contact surface irregularity such as a pitted or roughened contact surface, creates an excessive moment about the pivot connection 257 and the spring 256 acting in conjunction with the resilience of the insulator support member operates to effect a more even wearing of the collector shoe by normalizing the shoe position.

The prior art insulator support members provided an average satisfactory collector shoe operation versus vehicle travel distance relationship of about 2,000 miles before a shoe failure occurred due to breakage. The present insulator support members provide an average satisfactory collector shoe operation versus vehicle travel distance relationship of greater than 6,000 miles while using the same power collector shoe material and before a power collector shoe wears out rather than fails by being broken.

Claims (6)

Claims

1. An electrical-power collection apparatus for a transit vehicle moving along a roadway track said track having at least one power rail having a longitudinal axis substantially in parallel alignment with said roadway track, with said power rail having a conductive surface which may have irregularity in its contact surface, the apparatus comprising:: coupling means carried by said vehicle and extending toward the contact surface of said power rail, collector means electrically connected in sliding contact with the contact surface of the power rail, and resilient support means provided between the coupling means and the collector means, said having a predetermined resilience characteristic to permit limited movement of the collector means to pass over said irregularity and then to return to a desired self centered orientation of the collector means in relation to the longitudinal axis of the power rail as the vehicle moves along the roadway track.

2. The power collection apparatus of claim 1, with the support means comprising a resilient rubber material having a predetermined durometer hardness.

3. The power collection apparatus of claim 1, with the support means comprising polyurethane material having hardness of the order of a 90 durometer measure.

4. The power collection apparatus of claim 1 with said power rail irregularity comprising a rail gap in relation to a track switch, said support means being operative to support the collector means for estabiishing the self centered orientation of the collector means as required for the collector means to electrically disconnect with the power rail as the vehicle enters the rail gap of the track switch and to electrically connect with the power rail as the vehicle leaves the rail gap of the track switch.

5. The power collection apparatus of claim 1 with said support means being operative to cushion a shock loading of the collector means as the collector means slides along the power rail and through said irregularity.

6. The power collection apparatus of claim 1, with the support means comprising electrical insulation providing electrical insulation between the couping means and the collector means.