Pantograph positioning system
A pantograph positioning system may include a contact strip, a main valve, a supply line, at least one feeder line, and a detection line. The contact strip may be fastened to a pantograph and equipped with a wear detection circuit supplied a fluid. The main valve may include a pilot chamber and a secondary chamber, which are separated by a membrane. The membrane may be movable between a closed position, in which the membrane blocks an outlet aperture of the secondary chamber, and an open position, in which the membrane does not block the outlet aperture, allowing evacuation of the fluid. The supply line may supply the fluid to the secondary chamber of the main valve. The at least one feeder line may feed the fluid to the pilot chamber. The detection line may extend from the pilot chamber to the wear detection circuit of the contact strip.
1 . A positioning system for a pantograph, the positioning system comprising:
a contact strip configured to be fastened to a pantograph and to contact a power line, the contact strip equipped with a wear detection circuit configured to be supplied a fluid;
a main valve including a pilot chamber and a secondary chamber, which are separated by a membrane, the main valve defining an outlet aperture fluidly connected to the secondary chamber, the membrane movable between a closed position, in which the membrane blocks the outlet aperture, and an open position, in which the membrane does not block the outlet aperture, allowing evacuation of the fluid from the main valve to the atmosphere;
a supply line configured to be fluidly connected to a fluid supply unit and to supply the fluid to the secondary chamber of the main valve;
at least one feeder line configured to be fluidly connected to the fluid supply unit and to feed the fluid to the pilot chamber of the main valve; and
a detection line that extends from the pilot chamber of the main valve to the wear detection circuit of the contact strip.
2 . The positioning system of claim 1 , wherein the membrane of the main valve lacks an aperture.
3 . The positioning system of claim 1 , further comprising a manifold comprising a monolithic body defined by layers of material that are stacked and fused together, the monolithic body defining at least a portion of the supply line and at least a portion of the at least one feeder line.
4 . The positioning system of claim 3 , wherein the monolithic body of the manifold includes a housing, a supply pipe projecting from the housing and configured for connection to the fluid supply unit, a pantograph pipe projecting from the housing and configured for connection to an expansible device mechanically connected to the pantograph, and a valve pipe projecting from the housing and configured for connection to the main valve, the housing defining a chamber configured to hold the fluid.
5 . The positioning system of claim 4 , wherein the valve pipe defines a portion of a first flow channel within the housing, the supply pipe defines a portion of a second flow channel within the housing, and the pantograph pipe defines a portion of a third flow channel within the housing, the second flow channel and the third flow channel merge within the housing into a combined flow channel, the combined flow channel extending to an outlet end configured to be fluidly attached to a distributor device mounted to the manifold.
6 . The positioning system of claim 5 , wherein the first flow channel within the housing is fluidly isolated from the second flow channel, the third flow channel, and the combined flow channel.
7 . The positioning system of claim 3 , further comprising a distributor device mounted to the manifold, the distributor device fluidly connected to the supply line and the at least one feeder line, the distributor device operable in a first distribution position and a second distribution position, the distributor device in the first distribution position configured to establish a first flow path from the fluid supply unit to one of the feeder lines for supplying the fluid to the pilot chamber of the main valve, the distributor device in the second distribution position configured to establish a second flow path from the fluid supply unit to the supply line for supplying the fluid to the secondary chamber of the main valve.
8 . The positioning system of claim 3 , wherein the layers of material that are stacked and fused together comprise at least one metal material.
9 . The positioning system of claim 1 , wherein the at least one feeder line includes a branch feed line fluidly connected to the pilot chamber of the main valve, the branch feed line including a restriction with a cross-sectional passage size that is less than a cross-sectional passage size of the supply line.
10 . The positioning system of claim 1 , wherein the positioning system is configured, in response to a leak event occurring along the wear detection circuit of the contact strip, for a pressure differential within the main valve to move the membrane to the open position and the fluid from an expansible device mechanically connected to the pantograph to be conveyed through the supply line to the secondary chamber of the main valve and out of the main valve through the outlet aperture.