Vehicle slide out assembly actuating mechanism and method of operation

Abstract

A slide out actuating mechanism for selectively extending and retracting a slidable section of a slide out assembly fixed to a vehicle body includes at least two double acting fluid actuated actuators. Each actuator has a cylinder and an extendible ram. Each cylinder is fixed relative to one of the vehicle body and the slidable section, and each ram is fixed relative to the other of the vehicle body and the slidable section. At least one flow divider having at least two fluid ports directs fluid to and from the cylinders. One of the fluid ports is in fluid communication with one of the cylinders and the other of the fluid ports being in fluid communication with the other of the cylinders, wherein the flow divider maintains the flow of fluid flowing through the ports at substantially equal flow rates to synchronize movement of the rams when moving the rams relative to the cylinders.

1 . A slide out actuating mechanism for selectively extending and retracting a slidable section of a slide out assembly fixed to a vehicle body, said slide out actuating mechanism comprising: 
 a first double acting fluid actuated actuator having a first cylinder and an extendible first ram, said first cylinder being fixed relative to one of said vehicle body and said slidable section, and said first ram being fixed relative to the other of said vehicle body and said slidable section;    a second double acting fluid actuated actuator having a second cylinder and an extendible second ram, said second cylinder being fixed relative to one of said vehicle body and said slidable section, and said second ram being fixed relative to the other of said vehicle body and said slidable section; and    at least one flow divider including at least two fluid ports, one of said fluid ports being in fluid communication with one end of said first cylinder to move said first extendible ram in one direction relative to said first cylinder and the other of said fluid ports being in fluid communication with one end of said second cylinder to move said second extendible ram in said one direction relative to said second cylinder, wherein said flow divider includes a pilot operated spool valve that equalizes the flow of fluid flowing through said ports at substantially equal flow rates regardless of the fluid pressure in said first and second cylinders to synchronize movement of said first and second rams when moving said rams relative to said first and second cylinders to move the slide out section relative to said vehicle body.    
   
   
       2 . The slide out actuating mechanism as in  claim 1 , in which said slide out assembly includes a first pilot operated check valve to allow fluid into said first cylinder to move said first extendible ram in said one direction, said first pilot operated check valve being operated by a first pilot line in fluid communication with another end of said first cylinder to allow fluid out of said one end of said first cylinder and past said one of said ports when moving said first extendible ram in a direction opposite said one direction.  
   
   
       3 . The slide out actuating mechanism as in  claim 2 , in which said slide out assembly includes a second pilot operated check valve to allow fluid into said second cylinder to move said second extendible ram in said one direction, said second pilot operated check valve being operated by a second pilot line in fluid communication with another end of said second cylinder to allow fluid out of said one end of said second cylinder and past the other of said ports when moving said second extendible ram in a direction opposite said one direction.  
   
   
       4 . The slide out actuating mechanism as in  claim 1 , in which said slide out assembly includes at least two outer rails fixed relative to the vehicle body and at least two inner rails, each of said inner rails slidably engaging one of said outer rail and fixed relative said slidable section, wherein said first and second double-acting actuators extend and retract said inner rails to extend and retract said slidable section.  
   
   
       5 . The slide out actuating mechanism as in  claim 1 , in which said slide out section is slidably supported above a stationary floor of said vehicle body by a rail fixed to said slide out section and engaging rollers rotatably mounted to a bracket fixed to said stationary floor.  
   
   
       6 . The slide out actuating mechanism as in  claim 5 , in which said extendible ram is connected to said rail, wherein movement of said ram slidably moves said rail relative to said stationary floor.  
   
   
       7 . The slide out actuating mechanism as in  claim 1 , in which said flow divider includes at least two spools disposed in a spool cavity formed in a flow divider body, and each of said fluid ports is in fluid communication with said spool cavity, wherein each of said spools moves in response to a pressure difference between a pressure at one of said fluid ports and a pressure at a third port forming part of said flow divider and in fluid communication with said spool cavity.  
   
   
       8 . The slide out actuating mechanism as in  claim 1 , in which the slide out actuating mechanism includes only one flow divider to synchronize movement of said first and second rams when extending and retracting said rams relative to said first and second cylinders to move the slide out section of the slide out assembly.  
   
   
       9 . The slide out actuating mechanism as in  claim 1 , in which said fluid is allowed past said ports by flowing through said ports.  
   
   
       10 . The slide out actuating mechanism as in  claim 1 , in which said fluid is allowed past said ports by bypassing said ports.  
   
   
       11 . A method of operating a slide out assembly forming part of a vehicle, wherein the slide out assembly includes an actuating mechanism including at least two hydraulic actuators, each of said hydraulic actuators having an extendible ram extendible from a cylinder, said extendible rams being fixed to at least one of a stationary floor and a slide out section, and said cylinders being fixed to the other of said stationary floor and said slide out section, said method comprising: 
 maintaining a substantially equal flow of fluid flowing into each of said cylinders when extending and retracting said rams regardless of the fluid pressure in each of said cylinders to synchronize movement of said rams, wherein the flow of fluid into each of said cylinders when moving each of said rams in one direction is maintained substantially equal by a flow divider upstream of said cylinders, and the flow of fluid out of said cylinders past said flow divider is blocked by a pilot operated check valve that opens when fluid is pumped into said cylinders to move said rams in a direction opposite said one direction.    
   
   
       12 . The method as in  claim 11 , in which said flow of fluid into each of said cylinders is controlled by at least one flow divider.  
   
   
       13 . The method as in  claim 12 , in which said flow divider includes a pilot operated spool valve.  
   
   
       14 . The method as in  claim 11 , in which said fluid flows past said flow divider when said check valves are opened by flowing around said flow divider.  
   
   
       15 . The method as in  claim 11 , in which said fluid flows past said flow divider when said check valves are opened by flowing through said flow divider.  
   
   
       16 . A slide out assembly for selectively extending and retracting a slidable portion of a vehicle relative to a stationary portion of the vehicle, said slide out assembly comprising: 
 a first support member supported by and movable relative to the stationary portion of the vehicle and secured to the slidable portion of the vehicle to extend and retract with the slidable portion of the vehicle, said first support member being extendible and retractable by a first double acting fluid actuated actuator having a first cylinder and an extendible and retractable first ram, said first cylinder being fixed relative to one of said stationary portion and said first support member, and said first ram being fixed relative to the other of said stationary portion and said first support member;    a second support member supported by and movable relative to the stationary portion of the vehicle and secured to the slidable portion of the vehicle to extend and retract with the slidable portion of the vehicle, said second support member being extendible and retractable by a second double acting fluid actuated actuator having a second cylinder and an extendible and retractable second ram, said second cylinder being fixed relative to one of said stationary portion and said second support member, and said second ram being fixed relative to the other of said stationary portion and said second support member;    at least one flow divider including at least two fluid ports, one of said fluid ports being in fluid communication with one of said first and second cylinders and the other of said fluid ports being in communication with the other of said first and second ports, wherein said flow divider is responsive to pressures within said cylinders to equalize the flow of fluid flowing through said ports in response to pressures in said cylinders so as to synchronize movement of said first and second support members when moving said slide out portion of said vehicle;    a first pilot operated check valve interposed between said one of said fluid ports and said one end of said first cylinder to allow fluid into said first cylinder to move said first extendible ram in one direction, said first pilot operated check valve being operated by a first pilot line in fluid communication with another end of said first cylinder to allow fluid out of said one end of said first cylinder and through said one of said fluid ports when moving said first extendible ram in a direction opposite said one direction; and    a second pilot operated check valve interposed between said other of said fluid ports and said one end of said second cylinder to allow fluid into said second cylinder to move said second extendible ram, said second pilot operated check valve being operated by a second pilot line in fluid communication with another end of said second cylinder to allow fluid out of said one end of second cylinder and through the other of said fluid ports when moving said second extendible ram in a direction opposite said one direction.    
   
   
       17 . The slide out actuating mechanism as in  claim 16  in which the slide out actuating mechanism includes only one flow divider to synchronize movement of said first and second rams when extending and retracting said rams relative to said first and second cylinders to move the slide out section of the slide out assembly.