High pressure hydraulic breech mechanisms

Abstract

By providing an annular chamber 7 and a vent 11 to the radial gap between bolt 10 and high pressure cylinder 3 , located between a seal 8 and a body of fluid 13 the operating range of the seal 8 cannot be exceeded. The flow rate of fluid from reservoir 13 into annular chamber 7 is restricted by the radial gap between bolt 10 and high pressure cylinder 3 . The cross sectional area of both annular chamber 7 and vent 11 are greater than that of the radial gap between bolt 10 and high pressure cylinder 3 therefore fluid cannot enter annular chamber 7 at sufficient rate to cause a pressure rise in annular chamber 7 thus seal 8 is isolated from fluid at pressures above its safe operating range. Similar protection may be applied to any seal in the mechanism.

1 ) An annular chamber or enlargement of the clearance void between two components of a high pressure hydraulic breech mechanism, located between a body of fluid and sealing means for containing the fluid, and provided with a vent such that fluid migrating along the clearance void between two components will, on entering the annular chamber, no longer be subject to high pressures and cannot therefore subject the sealing means to high pressures.  
   
   
       2 ) An annular chamber and vent as claimed in  claim 1  wherein the vent communicates directly or indirectly with the low pressure reservoir of a hydraulic breech mechanism such that any fluid passing through the vent is returned to the low pressure reservoir.  
   
   
       3 ) An annular chamber and vent as claimed in  claim 1  wherein the vent discharges any fluid outside the envelope of the breech mechanism.  
   
   
       4 ) An annular chamber and vent as claimed in  claim 1  wherein the vent communicates with a discreet reservoir that collects any fluid discharged from the vent