Spring assisted barrier rams and methods of operating the same

Abstract

A barrier ram includes a frame and a barrier pivotably coupled to the frame. Two springs provide a combined torque very close to the torque provided on the barrier gate by gravity at all barrier positions relative to the frame. A method of operating such barrier is also provided.

What is claimed is: 
     
         1 . A barrier ram comprising:
 a frame;   a barrier rotatable relative to the frame about a pivot axis between a first closed position to a second open position;   a first spring rotatably coupled to the frame and the barrier; and   a second spring rotatably coupled to the frame and the barrier, wherein the first and second springs are compressed when the barrier is in the closed position, and wherein said first and second spring together provide a first torque to the barrier about the pivot axis and wherein a second torque acts on the barrier about the pivot axis due to gravity in the opposite direction from the first torque, wherein the difference between the first torque and second torque is no greater than 25% of one of the first torque and the second torque when the barrier is at any position from the closed position to the open position.   
     
     
         2 . The barrier ram of  claim 1 , wherein the difference between the first torque and second torque is no greater than 20% of one of the first torque and the second torque when the barrier is at any position from the closed position to the open position. 
     
     
         3 . The barrier ram of  claim 1 , wherein the difference between the first torque and second torque is no greater than 15% of one of the first torque and the second torque when the barrier is at any position from the closed position to the open position. 
     
     
         4 . The barrier ram of  claim 1 , wherein the difference between the first torque and second torque is no greater than 10% of one of the first torque and the second torque when the barrier is at any position from the closed position to the open position. 
     
     
         5 . The barrier ram of  claim 1 , wherein the difference between the first torque and second torque is no greater than 5% of one of the first torque and the second torque when the barrier is at any position from the closed position to the open position. 
     
     
         6 . The barrier ram of  claim 1 , wherein the second spring extends and compresses along a second spring axis, wherein the second spring axis intersects the pivot axis when the barrier is in the closed position. 
     
     
         7 . The barrier ram of  claim 6 , wherein the first spring extends and compresses along a first spring axis, and wherein the first spring axis is in a first orientation and offset 30 degrees or less from a vertical axis when the barrier is in the closed position, and the first spring axis is in a second orientation, different than the first orientation and offset 30 degrees or less from the vertical axis when the frame is mounted horizontally and the barrier is in the open position. 
     
     
         8 . The barrier ram of  claim 1 , wherein the second spring has a second spring axis, wherein when the second spring axis intersects the pivot axis it is an intersecting orientation, and wherein when the barrier is in the closed position the second spring axis is within 25 degrees of the intersecting orientation. 
     
     
         9 . The barrier ram of  claim 8 , wherein the first spring extends and compresses along a first spring axis, and wherein the first spring axis is in a first orientation and offset 30 degrees or less from a vertical axis when the barrier is in the closed position, and the first spring axis is in a second orientation, different than the first orientation and offset 30 degrees or less from the vertical axis when the frame is mounted horizontally and the barrier is in the open position. 
     
     
         10 . The barrier ram of  claim 1 , wherein the first spring is housed in a first spring keeper, wherein the second spring is housed in a second spring keeper, and wherein each spring keeper comprises,
 an outer barrel,   an inner barrel slideable within the outer barrel,   a first centerer fitted inside the outer barrel, said first centerer comprising a first base and a first projection projecting axially from the first base for being received within a first end portion of its corresponding spring, and   a second centerer fitted inside the inner barrel, said second centerer comprising a second base and a second projection projecting axially from the second base for being received within a second end portion of its corresponding spring.   
     
     
         11 . The barrier ram of  claim 1 , further comprising a layer of a wear resistant material covering the outer surface of the inner barrel that is received within the outer barrel. 
     
     
         12 . The barrier ram of  claim 11 , further comprising another layer of wear resistant material covering an inner surface of the inner barrel, said layer and another layer of wear resistant material extending beyond the inner barrel and connected to each other at a location beyond the inner barrel. 
     
     
         13 . A barrier ram comprising:
 a frame;   a barrier rotatable relative to the frame about a pivot axis between a first closed position and a second open position;   a first spring rotatably coupled to the frame and the barrier, the first spring compressing and extending along a first spring axis; and   a second spring rotatably coupled to the frame and the barrier, wherein the second spring compresses and extends along a second spring axis, wherein when the second spring axis intersects the pivot axis it is an intersecting orientation, and wherein when the barrier is in the closed position the second spring axis is within 25 degrees of the intersecting orientation or intersects the pivot axis, wherein the first and second springs are compressed when the barrier is in the closed position, and wherein said two springs together provide a first torque to the barrier about the pivot axis and wherein a second torque about the pivot axis acts on the barrier due to gravity in an opposite direction from the first torque.   
     
     
         14 . The barrier ram of  claim 13 , wherein the first spring axis is in a first orientation and offset 30 degrees or less from a vertical axis when the barrier is in the closed position, and the first spring axis is in a second orientation, different than the first orientation and offset 30 degrees or less from the vertical axis when the frame is mounted horizontally and the barrier is in the closed position. 
     
     
         15 . The barrier ram of  claim 13 , wherein the first spring is housed in a first spring keeper, wherein the second spring is housed in a second spring keeper, and wherein each spring keeper comprises,
 an outer barrel,   an inner barrel slideable within the outer barrel,   a first centerer fitted inside the outer barrel, said first centerer comprising a first base and a first projection projecting axially from the first base for being received within a first end portion of its corresponding spring, and   a second centerer fitted inside the inner barrel, said second centerer comprising a second base and a second projection projecting axially from the second base for being received within a second end portion of its corresponding spring.   
     
     
         16 . The barrier ram of  claim 15 , further comprising a layer of a wear resistant material covering an outer surface of the inner barrel that is received within the outer barrel. 
     
     
         17 . The barrier ram of  claim 16 , further comprising another layer of wear resistant material covering an inner surface of the inner barrel, said layer and another layer of wear resistant material extending beyond the inner barrel and connected to each other at a location beyond the inner barrel. 
     
     
         18 . A method of operating a barrier comprising a frame and a barrier rotatable about a pivot axis between a closed position and an open position relative to the frame, a first spring, and a second spring, wherein as the barrier opens and closes and it is exposed to a torque due to gravity about the pivot axis, said method comprising:
 providing a first torque with a first spring on the barrier about the pivot axis opposite the torque provided by gravity; and   
       providing a second torque with the second spring on the barrier about the pivot axis opposite the torque provided by gravity, wherein the combined first and second torque at all positions between the open and closed positions is within 25% of the torque provided by gravity. 
     
     
         19 . The method as recited in  claim 18 , wherein the combined first and second torque at all positions between the open and closed positions is within 20% of the torque provided by gravity. 
     
     
         20 . The method as recited in  claim 18 , wherein the combined first and second torque at all positions between the open and closed positions is within 15% of the torque provided by gravity. 
     
     
         21 . The method as recited in  claim 18 , wherein the combined first and second torque at all positions between the open and closed positions is within 10% of the torque provided by gravity. 
     
     
         22 . The method as recited in  claim 18 , wherein the combined first and second torque at all positions between the open and closed positions is within 5% of the torque provided by gravity. 
     
     
         23 . A method of operating a barrier comprising a frame and a barrier rotatable about a pivot axis between a closed position and an open position relative to the frame, a first spring, and a second spring, wherein as the barrier opens and closes it is exposed to a torque about the pivot axis due to gravity:
 providing a first torque with a first spring on the barrier about the pivot axis opposite the torque provided by gravity;   
       providing a second torque with the second spring on the barrier about the pivot axis opposite the torque provided by gravity; and 
       providing a third torque using at least one actuator, said third torque being opposite the torque provided by gravity, and said third torque being not greater than 25% of the torque provided by gravity, wherein the first torque, the second torque and the third torque are sufficient for rotating the barrier toward the open position. 
     
     
         24 . The method as recited in  claim 23 , wherein said third torque is not greater than 20% of the torque provided by gravity. 
     
     
         25 . The method as recited in  claim 21 , wherein said third torque is not greater than 15% of the torque provided by gravity. 
     
     
         26 . The method as recited in  claim 21 , wherein said third torque is not greater than 10% of the torque provided by gravity. 
     
     
         27 . The method as recited in  claim 21 , wherein said third torque is not greater than 5% of the torque provided by gravity.