U.S. patent application number 10/870687 was filed with the patent office on 2004-12-23 for mechanism for gas operated gun.
Invention is credited to Carnall, Martin, Garry, Paul.
Application Number | 20040255923 10/870687 |
Document ID | / |
Family ID | 33519610 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040255923 |
Kind Code |
A1 |
Carnall, Martin ; et
al. |
December 23, 2004 |
Mechanism for gas operated gun
Abstract
The tubular bolt of a paintball gun communicates with a cylinder
through bores when in a forward, firing position, allowing
compressed gas from the cylinder to expel a paintball. In
accordance with the invention a bore whereby the cylinder
communicates with a source of compressed gas is occluded by the
bolt when the bolt is in the firing position. By this arrangement
only gas stored in the cylinder is used to fire a paintball and the
source of compressed gas is not in communication with the cylinder
except when the trigger is released and the bolt is in its
retracted position.
Inventors: |
Carnall, Martin; (Barwell,
GB) ; Garry, Paul; (Middleton, GB) |
Correspondence
Address: |
Clifford Kraft
320 Robin Hill Dr.
Naperville
IL
60540
US
|
Family ID: |
33519610 |
Appl. No.: |
10/870687 |
Filed: |
June 17, 2004 |
Current U.S.
Class: |
124/73 |
Current CPC
Class: |
F41B 11/721 20130101;
F41B 11/71 20130101; F41B 11/57 20130101; F41B 11/73 20130101 |
Class at
Publication: |
124/073 |
International
Class: |
F41B 011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2003 |
GB |
0327683.9 |
Mar 5, 2004 |
GB |
0404989.6 |
Apr 21, 2004 |
GB |
0408954.6 |
Claims
What is claimed is:
1. A mechanism for a gas operated gun having a housing and a
trigger, the mechanism comprising a sleeve fixed relative to the
housing, a hollow bolt slideable in the sleeve between a firing
position when the trigger is pulled and a retracted position when
the trigger is released and a cylinder in the sleeve surrounding
the bolt, the bolt being adapted when in the retracted position to
permit communication between the cylinder and a source of fluid
under pressure while isolating the cylinder from the interior of
the bolt and when in the firing position to isolate the cylinder
from said source while communicating the cylinder with the interior
of the bolt.
2. A mechanism as claimed in claim 1, wherein the bolt is slideable
on an air fill tube fixed relative to the housing, an O-ring seal
being provided between the tube and the bolt, the tube having one
or more radial opening rearward of said seal in communication with
said source and the bolt having one or more radial opening which
will move from one side to the other of said seal as the bolt moves
between its firing and retracted positions, the arrangement being
such that in the retracted position of the bolt the cylinder
communicates with said source through the openings in the tube and
bolt while the seal prevents communication between the cylinder and
the interior of the bolt and such that in the firing position of
the bolt the opening in the tube is occluded by the bolt and the
opening in the bolt communicates the cylinder with the interior of
the bolt.
3. A mechanism as claimed in claim 1, wherein the sleeve has a
radial opening isolated from the cylinder and in communication with
said source and the bolt has a circumferential recess positioned
and dimensioned so that only when the bolt is in its retracted
position the recess will communicate said port with the interior of
the cylinder.
4. A mechanism as claimed in claim 3, wherein said port is located
in the sleeve rearwardly of the cylinder and communicates with said
source via a passageway external to the cylinder and extending
axially thereof.
5. A mechanism as claimed in claim 1 and comprising a radial bore
in the sleeve isolated from the cylinder and in communication with
said source, the outer periphery of the bolt having an axially
elongated circumferential depression which, in the retracted
position of the bolt communicates said bore with the cylinder, the
arrangement being such that in the firing position of the bolt said
bore is occluded by the bolt while the cylinder is communicated
with the interior of the bolt.
6. A mechanism as claimed in claim 5, wherein the cylinder has
front and rear openings to the bolt, the front opening aligning
with an opening of the bolt in the firing position of the latter
and the rear opening aligning with said depression in the retracted
position of the bolt.
7. A mechanism as claimed in claim 1, wherein the cylinder is open
to the bolt throughout its length and wherein said opening of the
bolt takes the form of a circumferential array of holes in the bolt
which will be exposed to the cylinder in the firing position of the
bolt.
8. A mechanism as claimed in claim 1, wherein means for displacing
the bolt between its firing and retracted positions surrounds the
bolt in front of or behind said cylinder.
Description
[0001] This application is related to and claims priority from U.S.
application Ser. No. 10/775,756 filed 9 Feb. 2004. It also claims
priority from the following UK patent applications: 0327683.9 filed
28 Nov. 2003, 0404989.6 filed 5 Mar. 2004 and 0408954.6 filed 21
Apr. 2004.
FIELD OF THE INVENTION
[0002] This invention relates to an improved mechanism for a gas
operated gun, by which is meant a gun of the type which fires a
projectile by means of compressed gas. Guns of this type are used
in paintball games. Balls of paint are fired at other players to
mark them.
BACKGROUND OF THE INVENTION
[0003] Conventional paint ball guns have a hollow bolt which, when
the trigger is pulled to fire the gun, is moved from a rear to a
forward position in the barrel, in the process selecting and moving
forward the lowermost paintball in a magazine above the barrel. In
the forward position of the bolt bores opening to its interior are
exposed and compressed gas in a cylinder surrounding the bolt,
causing the selected paintball to be expelled from the gun. When
the trigger is released the bolt is moved back to its rear
position, in which the bores are isolated from the cylinder.
[0004] A disadvantage of this otherwise simple arrangement is that
more gas is used every time the gun is fired than is necessary to
expel the selected paintball. Consequently the source of compressed
gas, usually an air cylinder fitted to the gun housing, has to be
replaced quite frequently, which is an expense and
inconvenience.
[0005] U.S. Pat. No. 5,613,483 seeks to address this problem by
attaching a spool valve to the rear of the bolt. A fill and a dump
chamber are positioned in the gun housing behind the bolt. In the
rear position of the bolt both chambers are filled with compressed
gas, but when the bolt moves forward the spool valve isolates the
chambers so that only the gas stored in the dump chamber escapes
through the hollow bolt to fire the selected paint ball. A drawback
of this gun is its complexity and relatively high manufacturing and
maintenance costs.
[0006] A principal object of the present invention is to provide a
simpler solution to the problem addressed by U.S. Pat. No.
5,613,483 allowing conventional paintball guns to have the
advantages of the gun of that patent as a result of a simple
modification.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention there is provided a
mechanism for a gas operated gun having a housing and a trigger,
the mechanism comprising a sleeve fixed relative to the housing, a
hollow bolt slideable in the sleeve between a firing position when
the trigger is pulled and a retracted position when the trigger is
released and a cylinder in the sleeve surrounding the bolt, the
bolt being adapted when in the retracted position to permit
communication between the cylinder and a source of fluid under
pressure while isolating the cylinder from the interior of the bolt
and when in the firing position to isolate the cylinder from said
source while communicating the cylinder with the interior of the
bolt.
[0008] The bolt may be slideable on an air fill tube fixed relative
to the housing, an O-ring seal being provided between the tube and
the bolt, the tube having one or more radial opening rearward of
said seal in communication with said source and the bolt having one
or more radial opening which will move from one side to the other
of said seal as the bolt moves between its firing and retracted
positions, the arrangement being such that in the retracted
position of the bolt the cylinder communicates with said source
through the openings in the tube and bolt while the seal prevents
communication between the cylinder and the interior of the bolt and
such that in the firing position of the bolt the opening in the
tube is occluded by the bolt and the opening in the bolt
communicates the cylinder with the interior of the bolt.
[0009] Alternatively the sleeve may have a radial opening isolated
from the cylinder in communication with said source and the bolt
may have a circumferential recess positioned and dimensioned so
that only when the bolt is in its retracted position the recess
will communicate said port with the interior of the cylinder.
[0010] Said port may be located in the sleeve rearwardly of the
cylinder and may communicate with said source via a passageway
external to the cylinder and extending axially thereof.
[0011] In yet another embodiment of the invention a radial bore is
provided in the sleeve isolated from the cylinder and in
communication with said source, the outer periphery of the bolt
having an axially elongated circumferential depression which in the
retracted position of the bolt communicates said bore with the
cylinder, the arrangement being such that in the firing position of
the bolt said bore is occluded by the bolt while the cylinder is
communicated with the interior of the bolt. The cylinder may have
front and rear openings to the bolt, the front opening aligning
with an opening of the bolt in the firing position of the latter
and the rear opening aligning with said depression in the retracted
position of the bolt.
[0012] Alternatively the cylinder may be open to the bolt
throughout its length and said opening of the bolt may take the
form of a circumferential array of holes in the bolt which will be
exposed to the cylinder in the firing position of the bolt.
[0013] Means for displacing the bolt between its firing and
retracted positions may surround the bolt in front of or behind
said cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates part of the mechanism of a paintball gun
according to a first embodiment of the invention showing the bolt
in its forward or firing position;
[0015] FIG. 2 illustrates the mechanism of FIG. 1 showing the bolt
in its rear or withdrawn position;
[0016] FIG. 3 illustrates part of the mechanism of a paintball gun
according to a second embodiment of the invention showing the bolt
in its rear or withdrawn position;
[0017] FIG. 4 illustrates the mechanism of FIG. 3 showing the bolt
in its forward, firing position;
[0018] FIG. 5 illustrates part of the mechanism of a paintball gun
according to a third embodiment of the invention showing the bolt
in its forward or firing position, and
[0019] FIG. 6 illustrates the mechanism of FIG. 5 showing the bolt
in its rear or withdrawn position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] Referring first to FIGS. 1 and 2, a paintball gun has a
hollow, tubular bolt 10 which is slideable on a guide 11 fixed
cantilever fashion to the rear of the gun housing (not shown) by
its head 12. Surrounding the bolt and bolt guide is a mechanism 13
which serves to move the bolt 10 forward when the trigger (not
shown) of the gun is pulled and rearward when the trigger is
released. In the example illustrated this mechanism 13 works by
placing a compressed gas canister (not shown) fitted to the gun
selectively in communication with bores 14 and 15 whereby lands on
the bolt will be driven in one direction or the other. This
arrangement is conventional and so will not be further described,
except to say that compressed gas actuation of the bolt may be
replaced by an electronic system.
[0021] Forward of the mechanism 13 a cylinder 16 surrounds the bolt
and bolt guide. The cylinder extends beyond the distal end of the
bolt guide 11 so that in the forward position of the bolt (FIG. 1)
an array of circumferentially spaced radial bores 17 of the bolt
exposes the interior of the bolt to the interior of the cylinder
16. In the withdrawn position of the bolt (FIG. 2) however the
bores 17 are between O-ring seals (not shown) in axially spaced
circumferential grooves 18 and 19 of the bolt guide 11 and
therefore occluded from the cylinder 16.
[0022] A port 20 at the rear of the cylinder 16 is in communication
with the canister via a passageway 21 external to the cylinder and
extending axially thereof. In accordance with a preferred
embodiment of the invention the port 20 takes the form of a
circumferential slot in a radial formation 22 at the rear of the
cylinder dimensioned such that it is in contact with the periphery
of the bolt 10 except when it is in register with a circumferential
recess 23 in the bolt periphery. This occurs when the bolt 10 is in
its withdrawn position (FIG. 2) and the recess 23 has a length
axially of the bolt such that it permits communication of the port
20 with the interior of the cylinder 16. Therefore so long as the
trigger of the gun is not pulled the cylinder 16 is charged with
compressed gas which cannot escape to the interior of the bolt.
When the trigger is pulled and the bolt 10 moves forward (FIG. 1)
the charge of compressed gas can escape from the cylinder 16
through the bores 17 to the interior of the bolt 10, but meanwhile
the port 20 is occluded by the periphery of the bolt because the
recess 23 has moved forward. As is known per se the bolt 10 as it
moves forward displaces in to the barrel of the gun the lowermost
paintball in a magazine (not shown) mounted above the gun and the
selected paintball is fired from the gun by the compressed gas
escaping from the cylinder 16. When the trigger is released and the
bolt 10 is moved back the cylinder 16 is isolated from the interior
of the bolt and is recharged with compressed gas as soon as the
recess 23 comes back into register with the port 20.
[0023] In the alternative embodiment of the invention illustrated
in FIGS. 3 and 4 like parts have like references but with the
suffix A. The arrangement is generally similar to that of 20 FIGS.
1 and 2 except that the firing mechanism is positioned behind the
bolt-moving mechanism and not in front of it.
[0024] A bolt 10A is slideable within a sleeve 13A between the
positions shown in FIGS. 3 and 4. Bores 14A and 15A alternatively
communicate with a canister of compressed air (not shown) to move
the bolt 10A forward or back.
[0025] In a rearward part of the sleeve 13A is a chamber 16A in
which compressed gas from the canister is stored when, in the
rearward position of the bolt (FIG. 3) an axially elongated
circumferential depression 23A in the periphery of the bolt
communicates a bore 20A with an opening 16B which opens from the
chamber 16A to the inner periphery of the sleeve 13A.
[0026] When the bolt is moved forward to the position of FIG. 4 the
chamber 16A is isolated from the bore 20A and an array of radial
bores 17B in the bolt comes into alignment with openings 17A of the
chamber 16A to the inner periphery of the sleeve 13A. Thus
compressed gas in the chamber 16A escapes to the interior of the
bolt 10A to fire a paintball.
[0027] A third embodiment of the invention is illustrated in FIGS.
5 and 6. The arrangement is similar to that of FIGS. 1 and 2 and
like parts have like references but with the suffix B.
[0028] A bolt 10B is slideable within a sleeve 13B between the
positions shown in FIGS. 5 and 6. Bores 14B and 15B alternatively
communicate with a canister of compressed air (not shown) to move
the bolt 10B forward or back.
[0029] The bolt 10B is slideable on a guide 11B similar to the
guide 11 of the embodiment of FIGS. 1 and 2, but in this case the
guide 11B serves as an air fill tube. It has a longitudinal bore
11C at the head 12B end communicating with the gas canister via a
radial bore 11D and near to the other end of the guide 11B
communicating with a circumferential array 100 of radial bores
which open to the periphery of the guide 11B. It will be observed
that the bores 100 open to the periphery of the guide 11B between
the O-ring seals in their respective grooves 18B and 19B. In the
firing position of the bolt 10B (FIG. 5), therefore, the bores 100
are occluded by the bolt and the cylinder 16B is isolated from the
gas canister. However in the retracted position of the bolt 10B
(FIG. 6) the bores 17B in the bolt have passed from a position in
front of to a position behind the O-ring in groove 18B and are
therefore in communication with the bores 100. Thus the cylinder
16B is placed in communication with the gas canister while at the
same time it is isolated from the interior of the bolt 10B.
[0030] In a conventional paintball gun the equivalent of the
cylinder 16, 16A or 16B is permanently in communication with the
gas canister so that gas will escape through the bolt 10, 10A or
10B for as long as the latter remains in its forward, firing
position. Such a gun can be readily modified in accordance with the
present invention to ensure that when the gun is fired only
compressed gas stored in the cylinder 16, 16A or 16B will
escape.
* * * * *