Stretcher with removable pressure block

Abstract

A stretcher has two head housings, and a removable pressure block/clamp assembly which is located in the housings and positioned via hydraulic cylinders. The hydraulic cylinders raise the pressure block assembly, and the gripper hydraulic cylinders lower the pressure block assembly onto a removal fixture which moves into and out of the head housing.

1 . A stretcher with a removable pressure block assembly comprising:
 a head housing;   a pressure block assembly which is located in said housing and positioned within said housing via hydraulic cylinders; said hydraulic cylinders raise said pressure block assembly; and said hydraulic cylinders lower said pressure block assembly to move said pressure block out of said housing.   
     
     
         2 . The stretcher of  claim 1 , further comprising a window formed in a wall of said housing for accessing gripper plates within said housing for removal. 
     
     
         3 . The stretcher of  claim 2 , wherein said gripper plates comprises upper gripper plates and lower gripper plates. 
     
     
         4 . The stretcher of  claim 3 , wherein said lower gripper plates remain fixed in said housing. 
     
     
         5 . The stretcher of  claim 3 , wherein said upper gripper plates move up and down relative to said housing. 
     
     
         6 . The stretcher of  claim 3 , wherein said pressure block assembly comprises at least one piston which applies gripping force onto said lower gripping plates. 
     
     
         7 . The stretcher of  claim 6 , wherein said pressure block assembly further comprises hydraulic piping for providing hydraulic fluid to said at least one piston. 
     
     
         8 . The stretcher of  claim 1 , further comprising a removal fixture wherein said removal fixture comprises rollers for moving said removal fixture into and out of said housing. 
     
     
         9 . The stretcher of  claim 1 , wherein said hydraulic cylinders lower said pressure block assembly onto said removal fixture. 
     
     
         10 . The stretcher of  claim 9 , further comprising a mechanism to pull said pressure block assembly out of said head housing. 
     
     
         11 . A stretcher with a removable pressure block assembly comprising:
 a head housing having a window in a side wall to access gripper plates;   a pressure block assembly which is located in said housing and positioned by hydraulic cylinders which raise the pressure block assembly and lower said pressure block assembly for removing said pressure block assembly from said head housing.   
     
     
         12 . The stretcher of  claim 11 , wherein said gripper plates comprises upper gripper plates and lower gripper plates. 
     
     
         13 . The stretcher of  claim 12 , wherein said lower gripper plates remain fixed relative to said head housing. 
     
     
         14 . The stretcher of  claim 12 , wherein said upper gripper plates move up and down relative to said head housing. 
     
     
         15 . The stretcher of  claim 12 , wherein said pressure block assembly comprises at least one piston which applies gripping force through said upper gripper plates onto said lower gripping plates. 
     
     
         16 . The stretcher of  claim 15 , wherein said pressure block assembly further comprises hydraulic piping for providing hydraulic fluid to said at least one piston. 
     
     
         17 . The stretcher of  claim 11 , further comprising a removal fixture for moving said pressure block assembly out of said head housing. 
     
     
         18 . The stretcher of  claim 17 , wherein said hydraulic cylinders lower said pressure block assembly onto said removal fixture. 
     
     
         19 . The stretcher of  claim 18 , further comprising a mechanism to pull or push said pressure block assembly out of said head housing.