Unitized railcar brake equipment

Abstract

A unitized railcar brake equipment can have a relatively small integrated air supply and can be controlled electronically. The equipment can have a brake cylinder portion and a control valve portion. The brake cylinder portion can have a brake cylinder housing a piston head with a rod end of the piston connected to a railcar brake member. A pair of air chambers communicate on opposite sides of the piston head and an air reservoir can be integral with the brake cylinder housing. Selective coupling of the air chambers and the air reservoir to each other, a source of pressure, or to the atmosphere can be controlled by appropriate valves to control the pressure in the brake cylinder.

1 . Electronic brake equipment for a railcar comprising: 
 a. a brake cylinder;    b. a piston slidably housed in said brake cylinder;    c. a first volume communicating on a face of said pistin for pressurization to move said piston in a first direction to increase braking force on said railcar;    d. a second volume communicating on a back side of said piston for pressurization to move said piston in a second direction to decrease braking force on said railcar;    f. at least one electrically controllable valve actuable to selectively connect at least one of said first and second volumes with at least one of each other, a source of pressure, and the atmosphere in order to control pressurization of said first and second volumes to regulate braking force on said railcar.    
   
   
       2 . The electronic brake equipment of  claim 1  further comprising a reservoir selectively connectable via said at least one valve with at least one of said first and second volumes and said source of pressure.  
   
   
       3 . Unitized brake equipment for a railcar comprising: 
 a. a brake cylinder;    b. a single piston having a piston head end movably housed in said brake cylinder and a piston rod end connectable to a brake member for applying braking force on said railcar,    c. a first volume communicating on at least a portion of a first side of said piston head, pressurization of said first volume causing said single piston to move in a first direction to increase braking force on said railcar;    d. a second volume communicating on at least a portion of a second side of said piston head, pressurization of said second volume tending to cause said single piston to move in a second direction to decrease braking force on said railcar; and    e. at least one valve controllable responsive to an electrical brake signal selectively coupling at least one of said first and second volumes with at least one of each other, a source of pressure, and the atmosphere to control pressure in said first and second volumes and move said single piston to control braking force on said railcar in a graduable manner.    
   
   
       4 . The unitized brake equipment of  claim 3  further comprising a reservoir connectable via said at least one value to at least one of said firt volume, said second volume, and said source of pressure.  
   
   
       5 . The unitized brake equipment of  claim 4  wherein said reservoir comprises a third volume integrally formed with said brake cylinder.  
   
   
       6 . The unitized brake equipment of  claim 4  wherein said source of pressure is a brake pipe and further comprising said at least one valve connecting said first volume to said reservoir responsive to a predetermined pressure loss in said brake pipe.  
   
   
       7 . The unitized brake equipment of  claim 4  further comprising said at least one value having a normally open state wherein said first volume is connected to atmosphere and isolating said at least one valve isolating said first volume from atmosphere when in an activated state.  
   
   
       8 . The unitized brake equipment of  claim 7  further comprising a cut-off valve connected in series with said at least one valve, said cut-off valve held normally open to atmosphere by said source of pressure, said cut-off valve isolating said first volume from atmosphere responsive to a predetermined loss of pressure in said source of pressure notwithstanding the state of said at least one valve.  
   
   
       9 . The unitized brake equipment of  claim 3  further comprising 
 a. a valve between said second volume and the atmosphere; and    b. a piston travel interlock valve between said valve and atmosphere, said piston travel interlock valve movable between first and second positions responsive to travel of said single piston, said piston travel interlock valve isolating said second volume from said valve in said first position and connecting said second volume to said valve in said second position, said second position corresponding to a predetermined amount of travel of said single piston in said first direction.    
   
   
       10 . The unitized brake equipment of  claim 3  further comprising said at least one valve controllable to connect said first and second volumes to said reservoir to effectively transfer pressure between said first and second volumes to increase said braking force.  
   
   
       11 . The unitized brake equipment of  claim 3  further comprising: 
 a. a local brake control device located on said railcar, said local brake control device controlling said control valve portion; and    b. a remotely located brake control device controlling said local brake control device via at least one of wired and wireless signals.    
   
   
       12 . The unitized brake equipment of  claim 3  further comprising said control valve portion controllable to connect said single and second volumes to said reservoir to effectively transfer pressure between said single and second volumes to increase said braking force.  
   
   
       13 . The unitized brake equipment of  claim 12  further comprising said control valve portion controllable to connect said second volume to atmosphere to further increase said braking force.  
   
   
       14 . The unitized brake equipment of  claim 13  further comprising said control valve portion controllable to connect said single volume to atmosphere to reduce said braking force.  
   
   
       15 . The unitized brake equipment of  claim 3  wherein said control valve portion further comprises a pilot valve and a booster valve activated by said pilot valve.  
   
   
       16 . The unitized brake equipment of  claim 3  wherein said control valve portion further comprises: 
 a. a first valve controllable to connect said single volume with at least said reservoir to pressurize said single volume;    b. a second valve controllable to connect said second volume with at least said third volume to pressurize said second volume;    c. a third valve controllable to connect said single volume to the atmosphere to depressurize said single volume; and    d. a fourth valve controllable to connect said second volume to the atmosphere to depressurize said second volume.    
   
   
       17 . The unitized brake equipment of  claim 16   wherein said first through fourth valves are first through fourth electrically controlled pilot valves and further comprising: 
 a. a first booster valve associated said first pilot valve and said source of pressure providing pilot pressure;  
 b. a second booster valve associated said second pilot valve, said third volume providing pilot pressure;  
 c. a third booster valve associated said third pilot valve, said third volume providing pilot pressure; and  
 d. a fourth booster valve associated said fourth pilot valve, said source of pressure providing pilot pressure.  
   
   
   
       18 . The unitized brake equipment of  claim 17  further comprising said third booster valve connecting said single volume with atmosphere when said third pilot valve is energized and isolating said single volume from atmosphere when said third pilot valve is de-energized.  
   
   
       19 . The unitized brake equipment of  claim 18  further comprising: 
 a. said piston travel interlock valve having an operating valve stem;    b. a beveled stem having a first end projecting into said second volume and a second end abutting an end of said operating valve stem, said second end having a beveled portion; and    c. said first end of said beveled stem engageable by said piston after said predetermined amount of travel of said single piston, said beveled portion causing movement of said operating valve stem responsive to said piston moving said beveled stem, movement of said operating valve stem causing said piston travel interlock valve to move between said first and second positions.    
   
   
       20 . The unitized brake equipment of  claim 15  further comprising said first booster valve connecting said first volume to said reservoir responsive to a predetermined pressure loss in said source of pressure notwithstanding an operating condition of said third pilot valve.  
   
   
       21 . The unitized brake equipment of  claim 14  further comprising said first and second valves controllable to connect said first and second volumes to said reservoir to effectively transfer pressure between said first and second volumes to increase said braking force.  
   
   
       22 . The unitized brake equipment of  claim 17  further comprising said first booster valve connecting said single volume to said third volume responsive to a predetermined pressure loss in said source of pressure notwithstanding an operating condition of said third pilot valve.  
   
   
       23 . The unitized brake equipment of  claim 16  further comprising said first and second valves controllable to connect said single and second volumes to said third volume to effectively transfer pressure between said single and second volumes to increase said braking force.  
   
   
       24 . The unitized brake equipment of  claim 23  further comprising said third valve controllable to connect said first volume to atmosphere to reduce said braking force.  
   
   
       25 . The unitized brake equipment of  claim 24  further comprising said third valve controllable to connect said single volume to atmosphere to reduce said braking force.  
   
   
       26 . Unitized brake equipment for a railcar comprising: 
 a. a brake cylinder;    b. a single piston having a piston head movably housed in said brake cylinder and a piston rod end connectable to a brake member for applying braking force on said railcar, said single piston movable in a first direction to increase said braking force, and a second direction to decrease said braking force;    c. a single volume communicating on a first side of said piston head, such that a force is created acting on said first side solely due to pressurization of said single volume, said force urging said single piston to move in said first direction;    d. a second volume communicating on a second side of said piston head, pressurization of said second volume creating a force urging said single piston to move in said second direction;    e. a third volume connectable to a source of pressure;    f. a first electrically controllable valve to selectively couple said first single volume with at least said third volume to gradually pressurize said single volume;    g. a second electrically controllable valve to selectively couple said second volume with at least said third volume to gradually pressurize said second volume;    h. a third electrically controllable valve to selectively couple said single volume to the atmosphere to gradually depressurize said single volume; and    i. a fourth electrically controllable valve to selectively couple said second volume to the atmosphere to gradually depressurize said second volume.    
   
   
       27 . The unitized brake equipment of  claim 26  wherein said first through fourth electrically controllable valves are first through fourth electrically controllable pilot valves and further comprising: 
 a. a first booster valve associated said first pilot valve and said source of pressure providing pilot pressure;    b. a second booster valve associated said second pilot valve, said third volume providing pilot pressure;    c. a third booster valve associated said third pilot valve, said third volume providing pilot pressure; and    d. a fourth booster valve associated said fourth pilot valve, said source of pressure providing pilot pressure.    
   
   
       28 . The unitized brake equipment of  claim 27  further comprising said third booster valve connecting said single volume with atmosphere when said third pilot valve is energized and isolating said single volume from atmosphere when said third pilot valve is de-energized.  
   
   
       29 . The unitized brake equipment of  claim 28  further comprising a cut-off valve connected in series with said third booster valve, said cut-off valve held normally open to atmosphere by said source of pressure, said cut-off valve isolating said third valve from atmosphere responsive to a predetermined loss of pressure in said source of pressure.  
   
   
       30 . The unitized brake equipment of  claim 27  further comprising a piston travel interlock valve connected in series with said fourth booster valve, said piston travel interlock valve movable between first and second positions responsive to travel of said single piston, said piston travel interlock valve isolating said second volume from said fourth booster valve in said first position and connecting said second volume to said fourth booster valve in said second position, said second position corresponding to a predetermined amount of travel of said single piston in said first direction.  
   
   
       31 . The unitized brake equipment of  claim 30  further comprising: 
 a. said piston travel interlock valve having an operating valve stem;    b. a beveled stem having a first end projecting into said second volume and a second end abutting an end of said operating valve stem, said second end having a beveled portion; and    c. said first end of said beveled stem engageable by said piston after said predetermined amount of travel of said single piston, said beveled portion causing movement of said operating valve stem responsive to said piston moving said beveled stem, movement of said operating valve stem causing said piston travel interlock valve to move between said first and second positions.    
   
   
       32 . The unitized brake equipment of  claim 27  further comprising said first booster valve connecting said single volume to said third volume responsive to a predetermined pressure loss in said source of pressure notwithstanding an operating condition of said third pilot valve.  
   
   
       33 . The unitized brake equipment of  claim 26  further comprising: 
 a. a local brake control device located on said railcar, said local brake control device controlling at least one of said first through fourth valves; and    b. a remotely located brake control device controlling said local brake control device via at least one of wired and wireless signals.    
   
   
       34 . The unitized brake equipment of  claim 26  further comprising said first and second valves controllable to connect said single and second volumes to said third volume to effectively transfer pressure between said single and second volumes to increase said braking force.  
   
   
       35 . The unitized brake equipment of  claim 35  further comprising said fourth valve controllable to connect said second volume to atmosphere to further increase said braking force.  
   
   
       36 . The unitized brake equipment of  claim 35  further comprising said third valve controllable to connect said single volume to atmosphere to reduce said braking force.  
   
   
       37 . A method of controlling braking force on a railcar comprising: 
 a. controlling movement of a single piston having a piston head end slidably disposed in a brake cylinder and a rod end connectable to a brake member on said railcar such that movement of said piston in a first direction increases said braking force and movement of said piston in a second direction reduces said braking force;    b. providing a single volume acting on a first side of said piston head and a second volume acting on a second side of said piston head;    c. creating a force acting on said first side solely by pressurization of said single pressure chamber, said force urging said piston to move in said first direction;    d. pressurization of said second volume creating a force urging said single piston to move in said second direction;    e. providing a third volume selectively communicable with at least one of said single and second volumes;    f. selectively connecting at least one of said single volume and said second volume to at least one of each other, a source of pressure, said third volume, and the atmosphere to control movement of said single piston to control braking force on said rail car in a graduable manner; and    at least one of:    i. isolating said first volume from atmosphere responsive to a pressure reduction in said source of pressure, and    ii. isolating said second volume from the atmosphere while connecting said first volume to said source of pressure to increase said braking force until a predetermined amount of travel of said single piston has occurred, and thereafter selectively connecting said second volume to atmosphere to gradually reduce pressure in said second volume to further increase said braking force.    
   
   
       38 . The method of  claim 37  further comprising selectively connecting said single and second volumes to said third volume to equalize pressure therebetween to increase said braking force.  
   
   
       39 . The method of  claim 38  further comprising connecting said second volume to atmosphere to further increase said braking force.  
   
   
       40 . The method of  claim 38  further comprising connecting said first volume to atmosphere to decrease said braking force.  
   
   
       41 . (canceled)  
   
   
       42 . The method of  claim 37  further comprising controlling pressure in said single and second volumes using at least one electrically operated valve.  
   
   
       43 . The method of  claim 42  wherein said at least one electrically operated valve is a plurality of electrically operated valves and further comprising: 
 a. connecting said single volume with at least said third volume to pressurize said first volume using a first electrically operated valve;    b. connecting said second volume with at least said third volume to pressurize said second volume using a second electrically operated valve;    c. connecting said single volume to the atmosphere to depressurize said single volume using a third electrically operated valve; and    d. connecting said second volume to the atmosphere to depressurize said second volume using a fourth electrically operated valve.    
   
   
       44 . The method of  claim 43  wherein said first through fourth electrically operated valves are first through fourth electrically operated pilot valves, and further comprising: 
 a. controlling a first booster valve with said first pilot valve and using said source of pressure as a source of pilot pressure;    b. controlling a second booster valve with said second pilot valve and using said third volume as a source of pilot pressure;    c. controlling a third booster valve with said third pilot valve and using said third volume as a source of pilot pressure; and    d. controlling a fourth booster valve with said fourth pilot valve and using said source of pressure as a source of pilot pressure.    
   
   
       45 . The method of  claim 44  further comprising connecting said single volume with atmosphere when said third pilot valve is energized and isolating said single volume from atmosphere when said third pilot valve is de-energized.  
   
   
       46 . The method of  claim 45  further comprising: 
 a. connecting a cut-off valve in series with said third booster valve;    b. holding said cut-off valve open to connect said single volume to atmosphere using pressure from said source of pressure; and    c. closing said cut-off valve to isolate said single volume from atmosphere responsive to a predetermined loss of pressure in said source of pressure.    
   
   
       47 . The method of  claim 44  further comprising: 
 a. connecting a piston travel interlock valve in series between said fourth booster valve and said second volume, said piston travel interlock valve movable between first and second positions responsive to travel of said single piston; and    b. said piston travel interlock valve isolating said second volume from said fourth booster valve in said first position and connecting said second volume to said fourth booster valve in said second position, said second position corresponding to a predetermined amount of travel of said single piston in said first direction.    
   
   
       48 . The method of  claim 47  further comprising: 
 a. using a beveled stem to move said piston travel interlock valve between said first and second positions;    b. said piston moving said beveled stem responsive to said predetermined amount of travel of said single piston;    c. using a beveled portion of said beveled stem which abuts an end of an operating valve stem of said piston travel interlock valve to move said piston travel interlock valve between said first and second positions responsive to said travel of said single piston.    
   
   
       49 . The method of  claim 44  further comprising said first booster valve connecting said single volume to said third volume responsive to a predetermined pressure loss in said source of pressure notwithstanding an operating condition of said third pilot valve.  
   
   
       50 . The method of  claim 44  wherein said selectively transferring pressure between said single and second volumes further comprises connecting said single and second volumes to said third volume using said first and second valves to increase said braking force.  
   
   
       51 . The method of  claim 50  further comprising connecting said second volume to atmosphere using said fourth valve to further increase said braking force.  
   
   
       52 . The method of  claim 51  further comprising connecting said single volume to atmosphere using said third valve to reduce said braking force.  
   
   
       53 . The method of  claim 37  further comprising controlling pressure in said single and second volumes using a local brake control device on said railcar.  
   
   
       54 . The method of  claim 53  further comprising remotely controlling said local brake control device via at least one of wired and wireless signals from a remotely located brake control device.  
   
   
       55 . A method of controlling braking force on a railcar comprising: 
 a. controlling movement of a piston having a piston head end slidably disposed in a brake cylinder and a rod end connectable to a brake member on said railcar such that movement of said piston in a first direction increases said braking force and movement of said piston in a second direction reduces said braking force;    b. providing a single pressure chamber acting on a first side of said piston head;    c. creating a force acting on said first side solely by pressurization of said single pressure chamber, said force urging said piston to move in said first direction;    d. providing a second pressure chamber acting on a second side of said piston head;    e. providing a third pressure chamber integral with said brake cylinder;    f. selectively connecting at least one of said single pressure chamber and said second pressure chamber to at least one of each other, a source of pressure, said third pressure chamber, and the atmosphere to control said braking force; and    g. isolating said second volume from said third volume and connecting said second volume to atmosphere responsive to piston travel a certain distance in said first direction and a predetermined reduction in pressure at said pressure source.    
   
   
       56 . The method of  claim 55  further comprising isolating said first pressure chamber from atmosphere and connecting said first pressure chamber to said third pressure chamber responsive to a predetermined reduction in pressure at said pressure source.  
   
   
       57 . A method of controlling braking force on a railcar comprising: 
 a. controlling movement of a piston having a piston head end slidably disposed in a brake cylinder and a rod end connectable to a brake member on said railcar such that movement of said piston in a first direction increases said braking force and movement of said piston in a second direction reduces said braking force;    b. providing a single application chamber acting on a first side of said piston head, a single release chamber acting on a second side of said piston head, and a reservoir;    c. creating a force acting on said first side solely by pressurization of said single application chamber, said force urging said piston to move in said first direction;    d. sealing said piston head against said brake cylinder at a single location such that said application and release chambers are separated using a single seal; and    e. selectively connecting at least one of said first and second pressure chambers to at least one of each other, a source of pressure, said reservoir, and the atmosphere to move said piston in said first and second directions to control said braking force.    
   
   
       58 . The method of  claim 57  further comprising isolating said release chamber from said reservoir and connecting said release chamber to atmosphere responsive to piston travel a certain distance in said first direction and a predetermined reduction in pressure at said pressure source.  
   
   
       59 . The method of  claim 58  further comprising isolating said application chamber from atmosphere and connecting said application chamber to said reservoir responsive to a predetermined reduction in pressure at said pressure source.  
   
   
       60 . The method of  claim 58  further comprising forming said reservoir surrounding at least a portion of said release chamber.  
   
   
       61 . A method of controlling braking force on a railcar comprising: 
 a. controlling movement of a piston having a piston head end slidably disposed in a brake cylinder and a rod end connectable to a brake member on said railcar such that movement of said piston in a first direction increases said braking force and movement of said piston in a second direction reduces said braking force;    b. providing first, second, and third volumes in said brake cylinder, said first volume acting on a first side of said piston head and said second volume acting on a second side of said piston head;    c. forming said third volume as an annular chamber which circumscribes at least a portion of both said first and second volumes; and    d. selectively connecting at least one of said first volume and said second volume to at least one of each other, a source of pressure, said third volume, and the atmosphere to control said braking force.    
   
   
       62 . Unitized brake equipment for a railcar comprising: 
 a. a brake cylinder;    b. a piston having a piston head end movably housed in said brake cylinder and a piston rod end connectable to a brake member for applying braking force on said railcar;    c. a single pressure chamber communicating on a first side of said piston head, pressurization of said single pressurization chamber solely responsible for urging said piston to move in a first direction to increase said braking force;    d. a second pressure chamber communicating on a second side of said piston head, pressurization of said second pressure chamber tending to cause said piston to move in a second direction to reduce said braking force;    e. an annular reservoir formed integrally with said brake cylinder, said annular reservoir circumscribing at least a portion of both said first and second pressure chambers; and    f. a control valve portion controllable responsive to an electrical brake signal to selectively connect at least one of said single pressure chamber and said second pressure chamber with at least one of each other, said reservoir, a source of pressure, and the atmosphere to move said piston and control said braking force in a graduable manner.