U.S. patent application number 12/532775 was filed with the patent office on 2010-04-29 for gas operated gun mechanism.
This patent application is currently assigned to BLACK MARKET SPORTZ LIMITED. Invention is credited to Martin Carnall.
Application Number | 20100101550 12/532775 |
Document ID | / |
Family ID | 34708081 |
Filed Date | 2010-04-29 |
United States Patent
Application |
20100101550 |
Kind Code |
A1 |
Carnall; Martin |
April 29, 2010 |
GAS OPERATED GUN MECHANISM
Abstract
In a paintball gun mechanism compressed air is admitted through
passages (16) to the interior of the barrel (10) where it will move
forward a hollow bolt (11) until it can escape through the bolt
(11) to fire a paintball. The bolt (11) is then moved backward by
compressed air in a chamber (15) until a central formation (12) of
the bolt (11) enters a guide (13) to close a firing chamber (14)
behind the bolt (11). The invention provides a valve member (17)
independent of the bolt (11) which is biased by a spring (18) to
close off the firing chamber (14) from the passages (16) except
when displaced by the formation (12) of the bolt (11) during a
final part of the rearward movement of the bolt (11).
Inventors: |
Carnall; Martin; (Leicester,
GB) |
Correspondence
Address: |
CAESAR, RIVISE, BERNSTEIN,;COHEN & POKOTILOW, LTD.
11TH FLOOR, SEVEN PENN CENTER, 1635 MARKET STREET
PHILADELPHIA
PA
19103-2212
US
|
Assignee: |
BLACK MARKET SPORTZ LIMITED
Nuneaton, Warwickshire
GB
|
Family ID: |
34708081 |
Appl. No.: |
12/532775 |
Filed: |
May 12, 2006 |
PCT Filed: |
May 12, 2006 |
PCT NO: |
PCT/GB2006/001792 |
371 Date: |
September 23, 2009 |
Current U.S.
Class: |
124/76 ;
124/73 |
Current CPC
Class: |
F41B 11/73 20130101;
F41A 3/12 20130101; F41B 11/62 20130101; F41B 11/721 20130101 |
Class at
Publication: |
124/76 ;
124/73 |
International
Class: |
F41B 11/00 20060101
F41B011/00; F41B 11/32 20060101 F41B011/32 |
Foreign Application Data
Date |
Code |
Application Number |
May 13, 2005 |
GB |
0509728.2 |
Claims
1. A gas-operated gun mechanism comprising a bolt which is
reciprocable in a barrel between positions opening and closing
communication between a source of compressed gas behind the bolt
and an interior of the barrel forward of the bolt, thereby in said
open position being adapted to expel a paintball from the barrel,
communication between the source and the rear of the bolt being
through a firing chamber of the barrel behind the bolt, wherein
between said source and the rear of the bolt and not connected to
the bolt a valve is provided which is biased to a closed position
in which it closes communication between said source and the firing
chamber but which is displaced by the bolt to an open position
during a final part of a movement of the bolt to a closed position
of the bolt, thereby re-charging the firing chamber.
2. A gas-operated gun mechanism as claimed in claim 1, wherein the
valve is spring biased to the closed position.
3. A gas-operated gun mechanism as claimed in claim 1, wherein the
bolt is tubular with a coaxial formation which enters a guide
within the barrel when the bolt is retracted, said formation
leaving the guide as the bolt reaches a forward, firing position
thereby allowing compressed gas from the firing chamber to flow
through the bolt.
4. A gas-operated gun mechanism as claimed in claim 1, wherein the
bolt is moved forward to firing position by compressed gas from the
firing chamber and is retracted from the firing position by
admission of compressed gas to an annular chamber between the a
periphery of the bolt and the barrel.
5. A mechanism for a gas-operated gun having a barrel from which a
projectile is fireable, the mechanism comprising: a bolt; a sleeve
fixedly locatable in the barrel; a valve assembly; and and a
chamber located between the sleeve and the valve assembly, wherein:
(a) the bolt is reciprocable within the sleeve between a forward
firing position and a retracted position, (b) the valve is
actuatable to permit communication between a gas source and the
chamber when the bolt is in the retracted position but closed to
prevent said communication as the bolt moves to the firing
position, (c) and the bolt allows secondary communication between
the chamber and the barrel, via the sleeve, as the bolt moves to
the forward firing position, to fire the projectile located in the
barrel of the gun.
6. A mechanism according to claim 5, wherein the valve assembly
comprises a forward end which is reciprocable within the sleeve
when the bolt alternates between the forward and retracted
positions.
7. A mechanism according to claim 5, wherein the valve assembly is
spring biased to a closed position.
Description
[0001] This invention relates to an improved gas operated gun
mechanism and particularly but not exclusively to an improved
mechanism for a paintball gun. Paintball guns are used in paintball
war games in which the participants fire paintballs at one another
to mark a "hit".
[0002] A paintball gun mechanism is known in which compressed air
in a canister connected to the gun housing is communicated with the
interior of the barrel of the gun to expel a paintball therefrom
through a bolt which moves forward in the barrel to open the
communication, when the trigger of the gun is pulled, and backward
to close it. This means that for the whole time that the bolt is
not in the closed position air is escaping even after a paintball
has been fired, which represents a considerable wastage of
compressed air. Moreover the bolt moves to its closed position
against the pressurised air behind it, requiring considerable force
to move the bolt.
[0003] In an effort to solve this problem it has been proposed to
attach to the rear of the bolt a tail having an enlargement which
will fill an orifice in the path of the compressed air between the
canister and a firing chamber in the barrel behind the bolt when
the bolt is in its open position, thereby cutting off communication
between the canister and the firing chamber as a paintball is
fired. This solution, however, is far from perfect. As soon as the
bolt begins to move toward its closed position communication with
the canister is again opened so that some wastage will occur before
the bolt is fully closed. The bolt will still be working against
compressed air behind it as it moves to its closed position. Even
more seriously, the length of the tail must be at least equal to
the travel of the bolt, requiring an extension of the rear of the
gun housing which will make the gun unduly large and unweildy.
[0004] A principal object of the present invention is to resolve
these problems by replacing the tail and its enlargement with a
valve member which is independent of the bolt and which is moved to
an open position only during a final part of the movement of the
bolt to its closed position. As soon as the bolt begins to move
forward the valve closes so that during the greater part of the
movement of the bolt from its open to its closed position no
compressed air is admitted to the firing chamber to resist the
movement of the bolt. Movement of the valve member is so small that
it requires no extension of the gun housing to accommodate it.
[0005] In accordance with the present invention there is provided a
gas-operated gun mechanism of the kind in which a bolt is
reciprocable in a barrel between positions opening and closing
communication between a source of compressed gas behind the bolt
and the interior of the barrel forward of the bolt, thereby in said
open position expelling a projectile from the barrel, communication
between the source and the rear of the bolt being through a firing
chamber of the barrel behind the bolt, characterised in that
between said source and the rear of the bolt and not connected to
the latter a valve is provided which is biased to a closed position
in which it closes communication between said source and the firing
chamber but which is displaced by the bolt to an open position
during a final part of the movement of the bolt to the closed
position of the latter, thereby re-charging the firing chamber.
[0006] Preferably the valve is spring biased to its closed
position.
[0007] The bolt may be tubular with a coaxial formation which
enters a guide within the barrel when the bolt is retracted, said
formation leaving the guide as the bolt reaches a forward, firing
position thereby allowing compressed gas from the firing chamber to
flow through the bolt.
[0008] In a preferred embodiment of the invention the bolt is moved
forward to its firing position by compressed gas from the firing
chamber and is retracted from its firing position by the admission
of compressed gas to an annular chamber between the bolt periphery
and the barrel.
[0009] A preferred embodiment of the invention will now be
described by way of non-limitative example with reference to the
accompanying drawings, in which:
[0010] FIG. 1 is a sectional elevation of the mechanism of a
paintball gun in accordance with the invention, and
[0011] FIG. 2 is a similar view of the mechanism of FIG. 1 but with
the bolt in the firing position.
[0012] The barrel 10 of a paintball gun contains a tubular bolt 11
having a coaxial central formation 12. The formation 12 is
reciprocable into and out of a tubular guide 13 fixed coaxially
within the barrel 10 when the bolt 11 as a whole reciprocates in
the barrel. To the rear of the guide 13 is a firing chamber 14
within the barrel. When the bolt 11 moves backward from the
position of FIG. 1 to the position of FIG. 2 under the influence of
compressed air introduced into an annular chamber 15 around the
bolt compressed air is admitted to the firing chamber 14 from a
canister (not shown) through radial passages 16. A latch (not
shown) holds the bolt in its retracted position. When the trigger
(not shown) of the gun is pulled the latch is released and the
chamber 15 evacuated so that compressed air in the firing chamber
14 can push the bolt 11 forward from the position of FIG. 2 to the
position of FIG. 1 until the formation 12 emerges from the guide 13
so that compressed air can flow through the bolt and expel from the
barrel 10 a paintball (not shown) in front of the bolt. The way in
which a paintball is selected from a magazine to lie in front of
the bolt 11 when the latter is retracted is well known per se and
will not be described.
[0013] In accordance with the present invention an elongated valve
member 17 is provided which is urged by a compression spring 18 to
the closed position of FIG. 1 in which it shuts off communication
between the air passages 16 and the firing chamber 14. During a
final part of the rearward movement of the bolt 11 from the firing
position of FIG. 2 to the retracted position of FIG. 1 the rear end
of the formation 12 strikes the leading end of the valve member 17
and displaces the valve member to the open position of FIG. 1 so
that the firing chamber 14 is recharged with compressed air.
[0014] By this arrangement, when the bolt is in the firing position
of FIG. 2 compressed air is exhausted from the firing chamber 14
and therefore the bolt 11 is not working against compressed air
when it is retracted by pressure in the chamber 15. The travel of
the valve member 17 is so small that the housing of the gun
requires very little enlargement to accommodate it.
* * * * *