Pneumatic launcher

Abstract

A pneumatic launcher includes a number of chambers for holding a compressed gas and a valve for releasing the compressed gas into a firing chamber to fire a projectile. The firing valve may include a number of surfaces on which pressure acts to slide a sliding valve body between an open position and a closed position. The launcher may include a recess for preventing pressure from acting on one of those surfaces when the valve is in the closed position. A part of the sliding valve body may interact with adjacent parts to form a closed region ahead of the sliding valve body, in order to cushion motion of the sliding valve body. The launcher may have a breech and a breech pin shaped to create a desired gas flow within the firing chamber during firing. The breech may include a breech pin seal which seals between two faces oriented transverse to the axis of the launcher. The launcher barrel may have a number of ribs for improved stability and accuracy.

1 . A pneumatic launcher having:
 i. a firing chamber configured to hold a projectile to be fired, a wall of the firing chamber having one or more apertures therein forming a flow path;   ii. a gas chamber for holding gas under pressure, the gas chamber communicating via the flow path with the firing chamber; and   iii. a firing valve having an open position and a closed position, and being configured to block the flow path in the closed position and, in the open position, to allow gas under pressure to flow from the gas chamber via the flow path into the firing chamber, the firing valve including:
 a) a sliding valve body having one or more operating surfaces angled with respect to a movement direction of the sliding valve body, such that pressure acting on the operating surfaces tends to force the valve body to slide; and 
   iv. a recess configured to receive, when the firing valve is in the closed position, a part of the sliding valve body including at least a first operating surface such that pressure in a region outside the recess is prevented from acting on the first operating surface.   
   
   
       2 . A pneumatic launcher as claimed in  claim 1  wherein the first operating surface is situated at an end of the sliding valve body. 
   
   
       3 . A pneumatic launcher as claimed in  claim 1  including one or more seals arranged to seal the recess around the part of the sliding valve body, when the firing valve is in the closed position. 
   
   
       4 . A pneumatic launcher as claimed in  claim 3  wherein the one or more seals are positioned on the sliding valve body. 
   
   
       5 . A pneumatic launcher as claimed in  claim 1  wherein, when the firing valve is in the closed position, pressure acting on the operating surfaces except the first operating surface, maintains the firing valve in the closed position and wherein, on release of pressure from a trigger chamber, pressure acting on the operating surfaces causes the firing valve to open. 
   
   
       6 . A pneumatic launcher as claimed in  claim 1  further including a valve chamber between the firing chamber wall and an outer valve chamber wall, the valve chamber communicating via the flow path with the firing chamber and also communicating with the gas chamber, the firing valve being positioned within the valve chamber. 
   
   
       7 . A pneumatic launcher as claimed in  claim 6 , wherein the sliding valve body includes:
 a) an inner surface which engages with an outer surface of the firing chamber wall to close the flow path when the firing valve is in a closed position; and   b) a protrusion extending outwards;   
     and wherein the launcher includes a valve wall positioned to the outside of the valve body and engaging with the protrusion, such that a pressure difference can be maintained between the regions on each side of the protrusion. 
   
   
       8 . A pneumatic launcher as claimed in  claim 7  configured to enable a sudden reduction in pressure on one side of the protrusion, such that pressure acting on the operating surfaces on the other side of the protrusion moves the sliding valve member to the open position. 
   
   
       9 . A pneumatic launcher as claimed in  claim 1  wherein the sliding valve body has a range of movement and cooperates with a part of the launcher to form a substantially closed region ahead of the moving sliding valve body near an extremity of the range of movement, thereby cushioning the motion of the sliding valve body. 
   
   
       10 . A pneumatic launcher as claimed in  claim 1  wherein the firing valve is held in place by a fastening mechanism at one end of the valve and can be removed from the pneumatic launcher by releasing the fastening mechanism and sliding the firing valve from the launcher. 
   
   
       11 . A pneumatic launcher as claimed in  claim 10  wherein the fastening mechanism is a top plate which also supports a barrel. 
   
   
       12 . A pneumatic launcher as claimed in  claim 1  wherein the sliding valve body and the firing chamber wall are formed as substantially cylindrical coaxial elements. 
   
   
       13 . A pneumatic launcher as claimed in  claim 1  including a plurality of seals for sealing between the sliding valve body and adjacent elements to prevent undesired flow of gas. 
   
   
       14 . A pneumatic launcher as claimed in  claim 1 , including:
 i. a breech; and   ii. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher;   
     wherein the breech plug extends into the firing chamber of the launcher and is shaped so as to produce a desired gas flow profile during firing, or is adapted to support an insert shaped so as to produce a desired gas flow profile during firing. 
   
   
       15 . A pneumatic launcher as claimed in  claim 1 , including:
 i. a breech;   ii. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher; and   iii. a breech seal configured to seal between the breech and the breech plug, when inserted;   
     wherein the breech seal seals between a first face on the breech and a second face on the breech plug, the first and second faces being substantially transverse to an insertion direction of the breech plug. 
   
   
       16 . A pneumatic launcher as claimed in  claim 1 , including:
 i. a breech;   ii. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher; and   iii. a locking ring configured to rotate between a first position in which the breech plug can be removed or inserted into the breech and a second position in which the breech plug is locked into the breech for firing.   
   
   
       17 . A pneumatic launcher as claimed in  claim 1  having a barrel with one or more longitudinal ribs. 
   
   
       18 . A pneumatic launcher as claimed in  claim 1  configured to fire an avalanche-triggering projectile. 
   
   
       19 . A pneumatic launcher having:
 i. a firing chamber configured to hold a projectile to be fired, a wall of the firing chamber having one or more apertures therein forming a flow path;   ii. a valve chamber between the firing chamber wall and an outer valve chamber wall, the valve chamber communicating via the flow path with the firing chamber;   iii. a gas chamber for holding gas under pressure and communicating with the valve chamber; and   iv. a firing valve positioned within the valve chamber, the firing valve having an open position and a closed position, and being configured to block the flow path in the closed position and, in the open position, to allow gas under pressure to flow from the valve chamber via the flow path into the firing chamber, the firing valve including:
 c) a sliding valve body having:
 i. an inner surface which engages with an outer surface of the firing chamber wall to close the flow path when the firing valve is in a closed position; 
 ii. one or more operating surfaces angled with respect to a movement direction of the sliding valve body, such that pressure acting on the operating surfaces tends to force the valve body to slide; and 
 iii. a protrusion extending outwards; 
 
 d) a valve wall positioned to the outside of the valve body and engaging with the protrusion, such that a pressure difference can be maintained between the regions on each side of the protrusion. 
   
   
   
       20 . A pneumatic launcher as claimed in  claim 19  configured to enable a sudden reduction in pressure on one side of the protrusion, such that pressure acting on the operating surfaces on the other side of the protrusion moves the sliding valve member to the open position. 
   
   
       21 . A pneumatic launcher as claimed in  claim 19  wherein the sliding valve body has a range of movement and cooperates with a part of the launcher to form a substantially closed region ahead of the moving sliding valve body near an extremity of the range of movement, thereby cushioning the motion of the sliding valve body. 
   
   
       22 . A pneumatic launcher as claimed in  claim 19  wherein the firing valve is held in place by a fastening mechanism at one end of the valve and can be removed from the pneumatic launcher by releasing the fastening mechanism and sliding the firing valve from the launcher. 
   
   
       23 . A pneumatic launcher as claimed in  claim 19  wherein the sliding valve body, the valve wall and the firing chamber wall are formed as substantially cylindrical coaxial elements. 
   
   
       24 . A pneumatic launcher as claimed in  claim 19 , including:
 v. a breech; and   vi. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher;   
     wherein the breech plug extends into the firing chamber of the launcher and is shaped so as to produce a desired gas flow profile during firing, or is adapted to support an insert shaped so as to produce a desired gas flow profile during firing. 
   
   
       25 . A pneumatic launcher as claimed in  claim 19 , including:
 v. a breech;   vi. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher; and   vii. a breech seal configured to seal between the breech and the breech plug, when inserted;   
     wherein the breech seal seals between a first face on the breech and a second face on the breech plug, the first and second faces being substantially transverse to an insertion direction of the breech plug. 
   
   
       26 . A pneumatic launcher as claimed in  claim 19 , including:
 V. a breech;   vi. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher; and   vii. a locking ring configured to rotate between a first position in which the breech plug can be removed or inserted into the breech and a second position in which the breech plug is locked into the breech for firing.   
   
   
       27 . A pneumatic launcher as claimed in  claim 19  having a barrel with one or more longitudinal ribs. 
   
   
       28 . A pneumatic launcher as claimed in  claim 19  configured to fire an avalanche-triggering projectile. 
   
   
       29 . A pneumatic launcher having:
 i. a firing chamber configured to hold a projectile to be fired, a wall of the firing chamber having one or more apertures therein forming a flow path;   ii. a gas chamber for holding gas under pressure, the gas chamber communicating via the flow path with the firing chamber; and   iii. a firing valve having an open position and a closed position, and being configured to block the flow path in the closed position and, in the open position, to allow gas under pressure to flow from the gas chamber via the flow path into the firing chamber, the firing valve including:
 a) a sliding valve body having a range of movement and cooperating with a part of the launcher to form a substantially closed region ahead of the moving sliding valve body near an extremity of the range of movement, thereby cushioning the motion of the sliding valve body. 
   
   
   
       30 . A pneumatic launcher as claimed in  claim 29  wherein the sliding valve body has one or more operating surfaces angled with respect to a movement direction of the sliding valve body, such that pressure acting on the operating surfaces tends to force the valve body to slide; and wherein the launcher includes a recess configured to receive, when the firing valve is in the closed position, a part of the sliding valve body including at least a first operating surface such that pressure in a region outside the recess is prevented from acting on the first operating surface. 
   
   
       31 . A pneumatic launcher as claimed in  claim 30  wherein, when the firing valve is in the closed position, pressure acting on the operating surfaces except the first operating surface, maintains the firing valve in the closed position and wherein, on release of pressure from a trigger chamber, pressure acting on the operating surfaces causes the firing valve to open. 
   
   
       32 . A pneumatic launcher as claimed in  claim 29  wherein the sliding valve body and the firing chamber wall are formed as substantially cylindrical coaxial elements. 
   
   
       33 . A pneumatic launcher as claimed in  claim 29  configured to fire an avalanche-triggering projectile. 
   
   
       34 . A pneumatic launcher having:
 i. a firing chamber configured to hold a projectile to be fired, a wall of the firing chamber having one or more apertures therein forming a flow path;   ii. a gas chamber for holding gas under pressure, the gas chamber communicating via the flow path with the firing chamber;   iii. a firing valve having an open position and a closed position, and being configured to block the flow path in the closed position and, in the open position, to allow gas under pressure to flow from the gas chamber via the flow path into the firing chamber; and   
     wherein the firing valve is held in place by a fastening mechanism at one end of the valve and can be removed from the pneumatic launcher by releasing the fastening mechanism and sliding the firing valve from the launcher. 
   
   
       35 . A pneumatic launcher having:
 i. a breech; and   ii. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher;   
     wherein the breech plug extends into a firing chamber of the launcher and is shaped so as to produce a desired gas flow profile during firing, or is adapted to support an insert shaped so as to produce a desired gas flow profile during firing. 
   
   
       36 . A pneumatic launcher having:
 i. a breech;   ii. a breech plug configured to be inserted to close the breech during firing and to be removed from the breech to allow a projectile to be loaded into the launcher; and   iii. a breech seal configured to seal between the breech and the breech plug, when inserted;   
     wherein the breech seal seals between a first face on the breech and a second face on the breech plug, the first and second faces being substantially transverse to an insertion direction of the breech plug. 
   
   
       37 . A pneumatic launcher configured to project a projectile using gas pressure and having a barrel with one or more longitudinal ribs. 
   
   
       38 . A pneumatic launcher as claimed in  claim 37  wherein the ribs include one or more external ribs.