Practice Projectile

Abstract

A practice mortar bomb comprising a pressure vessel and an outlet valve system, the pressure vessel being arranged in use to contain compressed fluid and the outlet valve system being arranged in use to allow explosive release of the compressed fluid from the pressure vessel upon activation of the valve system by a firing pin in a mortar tube.

1 . A practice mortar bomb comprising a pressure vessel and an outlet valve system, the pressure vessel being arranged in use to contain compressed fluid and the outlet valve system being arranged in use to allow explosive release of the compressed fluid from the pressure vessel upon activation of the valve system by a firing pin in a mortar tube. 
     
     
         2 . A practice mortar bomb according to  claim 1 , further comprising an inlet valve system arranged in use to allow charging of the pressure vessel with fluid such that the fluid is compressed within the pressure vessel. 
     
     
         3 . A practice mortar bomb according to  claim 1 , where the outlet valve mechanism comprises a valve seat and valve body, the valve body being mobile such that in use a valve seat end of the valve body is engageable with the valve seat to block the flow of fluid from the pressure vessel, and is disengageable from the valve seat to allow the flow of fluid from the pressure vessel. 
     
     
         4 . A practice mortar bomb according to  claim 3 , where the outlet valve system is a pressure balance valve, arranged such that in use, compressed fluid from the interior of the pressure vessel impinges on at least two opposed surfaces of the valve body, the resulting net force being towards the valve seat until the outlet valve system is activated, whereupon the net force is away from the valve seat. 
     
     
         5 . A practice mortar bomb according to  claim 4 , where the outlet valve system further comprises a chamber arranged such that in use, compressed fluid in the chamber impinges on a head end of the valve body with sufficient force to cause engagement of the valve seat end of the valve body with the valve seat. 
     
     
         6 . A practice mortar bomb according to  claim 5 , arranged such that in use, activation of the outlet valve system leads to the release of compressed fluid from the chamber at a faster rate than it is replenished, such that the force biasing the valve body towards the valve seat is reduced and the net force on the valve body is reversed so as it is away from the valve seat. 
     
     
         7 . A practice mortar bomb according to  claim 6 , where release of the compressed fluid from the chamber is controlled by a firing valve, operated in use directly or indirectly by a firing pin in a mortar tube. 
     
     
         8 . A practice mortar bomb according to  claim 5 , where the outlet valve mechanism further comprises a cylinder and wherein the chamber is defined by the cylinder and the head end of the valve body. 
     
     
         9 . A practice mortar bomb according to  claim 8 , where the cylinder has at least one cylinder through bore arranged so that the interior of the pressure vessel is in fluid communication with the chamber, such that in use pressurised fluid passes from the pressure vessel into the chamber. 
     
     
         10 . A practice mortar bomb according to  claim 3 , where a region proximate the valve seat end of the valve body is provided with at least one rebated portion, where each rebated portion creates a cavity between the cylinder and the valve body. 
     
     
         11 . A practice mortar bomb according to  claim 10 , where the at least one rebate portion creates at least one biasing surface of the valve body, arranged such that at least a component of a force applied towards the biasing surface would act to bias the valve body away from the valve seat. 
     
     
         12 . A practice mortar bomb according to  claim 3 , where the valve body has a valve body through bore passing from the head end of the valve body to the valve seat end of the valve body. 
     
     
         13 . A practice mortar bomb according to  claim 12 , where the head end of the valve body through bore is provided with a firing valve seat. 
     
     
         14 . A practice mortar bomb according to  claim 13 , where a firing valve body is provided which, when there is compressed fluid in the chamber, is biased by the compressed fluid into engagement with the firing valve seat. 
     
     
         15 . A practice mortar bomb according to  claim 12 , where a pin of smaller diameter than the valve body through bore extends from the firing valve body through the valve body through bore. 
     
     
         16 . A practice mortar bomb according to  claim 15 , where the pin is arranged to force the firing valve away from the firing valve seat when an end of the pin is impacted by a firing pin in a mortar tube. 
     
     
         17 . A practice mortar bomb according to  claim 1 , where the bomb further comprises a hollow tail portion, the interior of the tail portion being in fluid communication with the pressure vessel when the outlet valve system is open. 
     
     
         18 . A practice mortar bomb according to  claim 17 , where the tail portion comprises at least one port allowing fluid communication between its interior and exterior. 
     
     
         19 . A practice mortar bomb according to  claim 17 , where the tail portion has a tail portion through bore arranged in use to receive at least one of the pin and, in use the firing pin of a mortar tube. 
     
     
         20 . A kit of parts comprising one or more pressure vessels for practice mortar bombs in accordance with  claim 1  and one or more of the following:
 one or more nose portions of various designs to simulate different known mortar bomb fuse types, 
 one or more tail portions, 
 one or more pumps. 
 
     
     
         21 . A method of firing a practice mortar bomb, the practice mortar bomb comprising a pressure vessel and an outlet valve system arranged upon activation to explosively release at least a portion of a compressed air reservoir in the pressure vessel, the method comprising the steps of:
 charging the pressure vessel with compressed fluid, and   dropping the mortar bomb down a mortar tube.