Initiation fixture and an initiator assembly including the same
An initiator assembly (38) is factory-pre-assembled and comprises an initiation fixture (10) secured to a triggering device (40). The initiation fixture (10) comprises a unitary body, i.e., one without moving parts, and includes a bushing groove (18) to receive as an accessory an O-ring (64) to seal the device within the barrel (42) of the triggering device (40). A fuse/fixture sub-assembly (34) includes an initiation charge (30) disposed at the firing face (13a) and a signal-transmission fuse (22). The initiation fixture (110) maybe a “universal” fixture having thereon optional external threads (36) and being otherwise dimensioned and configured to be received within either an internally threaded barrel (42) of a triggering device (40) or the barrel (42) of a triggering device which utilizes a fuse-holding cap (56). The initiator assembly (38) may include a spool (66) on which the signal-transmission tube (22) is wound.
1. Field of the Invention
The present invention concerns an initiation fixture and initiator assembly including the fixture. The initiator assembly facilitates the initiation of a signal in a non-electric fuse such as a signal-transmission tube, e.g., shock tube. The initiator assembly comprises a triggering device within which the initiation fixture is received. The triggering device initiates a signal within the fuse which signal serves to initiate a detonator or other signal-transmitting or explosive device connected to the remote end of the fuse.
2. Related Art
U.S. Pat. No. 5,365,851 to Shaw, issued Nov. 22, 1994 and entitled “Initiator Device”, discloses (see
Triggering devices for use in firing initiation fixtures such as those disclosed by the above-described Shaw U.S. Pat. No. 5,365,851 (“the Shaw patent”), are usually comprised of a barrel containing at one end a trigger-operated, spring-loaded firing pin and having at the other (output) end of the barrel means for connecting the initiation fixture to the barrel. Alternatively, the triggering device may contain a percussion cap and a structure for receiving and retaining the input end of a fuse in signal-transfer proximity to the percussion cap. In such case, the output end of the barrel of the triggering device usually contains a grommet or other tube-retaining structure within or aligned with an aperture formed in a fuse-holder cap fitted over the output end of the barrel. The input end of the fuse is simply inserted into the aperture and advanced until it encounters a stop member, at which point the fuse is positioned within the barrel in signal-transfer proximity to the initiation charge of the triggering device, provided only that the user has taken care to fully insert the fuse. Such triggering devices usually employ a safety mechanism and, once the safety mechanism is placed in the armed position, the trigger of the device is operated so that the firing pin strikes and initiates the initiation charge, thereby initiating a signal in the fuse. As illustrated in the Shaw patent, the other (output) end of the fuse may be connected to a detonator; obviously, it may be connected to any other device which is operated by the signal engendered in the fuse.
Whether an initiation fixture such as that of the Shaw patent is utilized, or whether the input end of the fuse is simply inserted into a triggering device containing its own initiation charge, assembly of the initiator to the triggering device or insertion of the exposed end of the fuse is required in the field at the point of use. Such field assembly or insertion may be difficult because of weather conditions or darkness, and exposes the necessarily open input end of the fuse and the interior of the triggering device to the elements, with potential adverse consequences on reliability of initiation.
SUMMARY OF THE INVENTIONGenerally, in accordance with the present invention, there is provided an initiation fixture which is so dimensioned and configured that it may be utilized in a factory-assembled or pre-assembled initiator assembly of the invention. Such initiator assembly serves to initiate a signal in a fuse in order to detonate explosives and the like. The pre-assembled initiator assembly avoids the necessity for field assembling an initiation fixture or an exposed end of the fuse to a triggering device, as is required with the known prior art devices. Such field assembly is particularly problematic in adverse weather conditions, at night, and most particularly, in combat or clandestine use situations. Factory- or other pre-assembly of the initiator assembly facilitates a secure and weatherproof installation, and enables field use simply by operating the triggering device.
The present invention also provides a “universal” initiation fixture which may be assembled either to a triggering device having an interior thread to secure the fixture, to a triggering device using a fuse-holder cap.
Specifically, in accordance with the present invention, there is provided an initiator assembly comprising a triggering device having a barrel comprising an output end and an interior surface, the barrel having disposed therein an internal positioning member and a firing mechanism comprising a firing pin. An initiation fixture is of unitary construction so that no part thereof is movable relative to any other part thereof. The initiation fixture is secured to the triggering device and comprises: (i) a cylindrical body member having an external surface, an end face and a firing face, the body member being received within the barrel of the triggering device at the output end thereof, (ii) a longitudinal internal passage extending through the body member, (iii) an external positioning member disposed on the external surface of the body member and engaging the internal positioning member, thereby positioning the body member at a predetermined position within the barrel, and (iv) an initiation charge disposed within the longitudinal internal passage at the firing face of the body member and exposed to the firing pin of the firing mechanism; and a signal-transmission fuse secured to and extending from the body member and having an input end disposed in signal-transfer relation to the initiation charge, and an opposite output end.
In accordance with one aspect of the present invention, the internal positioning member comprises an internal stop and the external positioning member comprises a shoulder, wherein the shoulder abuts the internal stop thereby properly positioning the body member within the barrel of the triggering device.
In accordance with another aspect of the present invention, the internal positioning member comprises internal threads in the barrel and the external positioning member comprises external threads on the firing face of the body member, wherein the external threads of the body member engage the internal threads of the triggering device to properly position the body member within the barrel of the triggering device.
In accordance with another aspect of the present invention, the triggering device is mounted on a spool on which the signal-transmission fuse is wound.
In accordance with another embodiment of the present invention, there is provided an initiation fixture dimensioned and configured to be received within a barrel of a triggering device. The initiation fixture comprises a cylindrical body member having an external surface, an end face and a firing face. The body member is dimensioned and configured to be received within a barrel of a triggering device. There is a longitudinal internal passage which extends through the body member and a positioning member disposed on the external surface of the body member dimensioned and configured to position the body member within the barrel. A well is formed in the body member at the firing face thereof and is dimensioned and configured to receive an initiation charge, the well being in signal-transfer communication with the longitudinal internal passage. The initiation fixture is of unitary construction, by which it is meant that no part thereof is movable relative to any other part thereof.
In accordance with yet another embodiment of the present invention, there is provided an initiator assembly comprising a spool having a signal-transmission fuse wound thereon, the signal-transmission fuse having an input end and an opposite, output end. A triggering device is mounted upon the spool, and has a barrel comprising an output end, the barrel having a firing mechanism disposed therein. An initiation fixture comprises a cylindrical body member received within the barrel of the triggering device at the output end thereof, a longitudinal internal passage which extends through the body member, and an initiation charge disposed within the longitudinal internal passage of the body member and exposed to the firing mechanism. The input end of the signal-transmission fuse is disposed within and secured to the initiation fixture in signal-transfer relation to the initiation charge.
Other aspects of the present invention are revealed in the following description and the appended drawings.
The term “signal” used in connection with a signal-transmission tube fuse means the detonating shock wave or deflagrating flame front transmitted along the tube interior and utilized to obtain a desired effect, such as to initiate a detonator, which may in turn initiate an explosive charge.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of an initiation fixture of the present invention is shown in
The fuses with which the fixture of this invention may be used include detonating cord (in which case a remotely actuated triggering mechanism is used) and, more usually, signal-transmission tubes. A signal-transmission tube may be any detonating or deflagrating (low velocity) signal-transmission tube or fuse which can carry a detonating signal or deflagrating signal along its interior. Such detonating signal-transmission tubes are commonly referred to as “shock tube” and may be of the type disclosed in Persson U.S. Pat. No. 3,590,739 or Thureson et al U.S. Pat. No. 4,607,573. A deflagrating signal-transmission tube may be of the type disclosed in Thureson U.S. Pat. No. 4,757,764. Such impulse transmission tubes comprise flexible hollow plastic tubes having an interior coating of a reactive material capable of carrying a detonating or deflagrating signal.
In the embodiment illustrated in
The touch hole 10b between initiation charge well 10c (
Initiation fixture 10 with initiation charge 30 and signal-transmission fuse 22 mounted therein provides a fuse/fixture sub-assembly 34. A detonator (not shown in
The fuse-holder cap 56 is mounted on the output end 42a of barrel 42 by threaded engagement with external threads (unnumbered) adjacent the output end 42a. The interior of fuse-holder cap 56 includes a conical bearing surface 60. As fuse-holder cap 56 is threaded onto barrel 42, bearing surface 60 bears against rounded shoulder 16 of fixture 10, driving fixture/fuse assembly 34 into triggering device 40. Preferably, barrel 42 of device 40 includes an internal positioning member or internal stop 62 that engages shoulder 20 (see
The fixture/fuse subassembly 34 includes an O-ring 64 retained in bushing groove 18 (
In an alternative embodiment of the invention, the initiation fixture may be configured to conform to the tapered interior bore of output end 42a of barrel 42. Specifically, as shown in
Referring now to
Referring now to
Referring now to
Flexible retaining strap 68 is secured at one end to the flange 66a of spool 66 so that upon removing or rupturing fastener 70, triggering device 40 can quickly be removed from spool 66 by moving it in the direction of the arrow D in
The initiator assembly 80 has a detonator 74 secured to an output end 22b (
In use, after severing or rupturing strap 76, connector bunch block 72 is removed from spool 66 and receptor signal-transmission tubes (not shown) are passed through bunch block 72 in signal transfer proximity to detonator 74. Flaps 75a and 75b of bunch block 72 are then closed to secure the receptor signal-transmission tubes and detonator 74 in place within connector bunch block 72. With that installation complete and bunch block 72 fixed in place, the user carries spool 66 to a remote location, playing out any required length of signal-transmission tube 22 up to the capacity of tube 22 stored on spool 66. When the user is ready to initiate the signal, triggering device 40 is removed from spool 66 by moving it in the direction shown by arrow D, any safety pin or other safety device (not shown in
When the fixture is mounted on the end of a fuse and has an initiation charge therein, the resulting combination is a fixture/fuse sub-assembly that can be easily secured into a variety of triggering devices such as U.S. Army M60 and MK54 devices.
While the invention has been described with reference to specific embodiments thereof, it will be appreciated that numerous other variations may be made to the illustrated specific embodiments which variations nonetheless lie within the spirit and the scope of the invention.
Claims
1. An initiator assembly comprising:
- (a) a triggering device having a barrel comprising an output end and an interior surface, the barrel having disposed therein an internal positioning member and a firing mechanism comprising a firing pin;
- (b) an initiation fixture is of unitary construction whereby no part thereof is movable relative to any other part thereof, and is secured to the triggering device and comprises: (i) a cylindrical body member having an external surface, an end face and a firing face, the body member being received within the barrel of the triggering device at the output end thereof, (ii) a longitudinal internal passage extending through the body member, (iii) an external positioning member disposed on the external surface of the body member and engaging the internal positioning member, thereby positioning the body member at a predetermined position within the barrel, and (iv) an initiation charge disposed within the longitudinal internal passage at the firing face of the body member and exposed to the firing pin of the firing mechanism; and
- (c) a signal-transmission fuse secured to and extending from the body member and having an input end disposed in signal-transfer relation to the initiation charge, and an opposite output end.
2. The assembly of claim 1 wherein the internal positioning member comprises an internal stop and the external positioning member comprises a shoulder which is dimensioned and configured to abut the internal stop.
3. The assembly of claim 1 wherein the internal positioning member comprises internal threads of the barrel and the external positioning member comprises external threads on the firing face of the body member, the external threads being dimensioned and configured to threadably engage the internal threads of the barrel.
4. The assembly of claim 1 wherein the initiation fixture further comprises a sealing member disposed circumferentially about the body member and dimensioned and configured to engage the interior surface of the barrel to form a seal therewith.
5. The assembly of claim 1 wherein the triggering device further comprises a fuse-holder cap disposed at the output end of the barrel and having therein an aperture through which the signal-transmission fuse passes.
6. The assembly of claim 5 wherein the end face of the body member is dimensioned and configured to be engaged by the fuse-holder cap to retain the body member within the barrel.
7. The assembly of claim 1 wherein the initiation fixture further comprises a sleeve extending from the end face of the body member and through which the signal-transmission fuse passes.
8. The assembly of claim 7 wherein the triggering device further comprises a fuse-holder cap disposed at the output end of the barrel, and having therein an aperture through which the sleeve of the initiation fixture extends.
9. The assembly of claim 1 wherein the triggering device is mounted on a spool on which the signal-transmission fuse is wound.
10. The assembly of claim 1 wherein the output end of the signal-transmission fuse is received within a detonator.
11. The assembly of claim 10 wherein the detonator is positioned within a connector block dimensioned and configured to receive a plurality of signal-transmission lines therein.
12. An initiation fixture dimensioned and configured to be received within a barrel of a triggering device, the initiation fixture comprising: (i) a cylindrical body member, having an external surface, an end face and a firing face, the body member dimensioned and configured to be received within a barrel of a triggering device, (ii) a longitudinal internal passage extending through the body member, (iii) an external positioning member disposed on the external surface of the body member and dimensioned and configured to position the body member within the barrel, and (iv) a well formed in the body member at the firing face thereof and dimensioned and configured to receive an initiation charge, the well being in signal-transfer communication with the longitudinal internal passage; and
- wherein the initiation fixture is of unitary construction whereby no part thereof is movable relative to any other part thereof.
13. The fixture of claim 12 wherein the external positioning member comprises a shoulder.
14. The fixture of claim 12 wherein the external positioning member comprises external threads on the nose portion of the body member.
15. The fixture of claim 12 further comprising a sleeve extending from the end face of the body member and through which the longitudinal internal passage extends.
16. The fixture of claim 12 further comprising a sealing member disposed circumferentially about the body member.
17. An initiator assembly comprising:
- a spool having a signal-transmission fuse wound thereon, the signal-transmission fuse having an input end and an opposite, output end;
- a triggering device mounted upon the spool, the triggering device having a barrel comprising an output end, the barrel having disposed therein a firing mechanism;
- an initiation fixture comprising: (i) a cylindrical body member being received within the barrel of the triggering device at the output end thereof, (ii) a longitudinal internal passage extending through the body member, and (iii) an initiation charge disposed within the longitudinal internal passage of the body member and exposed to the firing mechanism; and
- the input end of the signal-transmission fuse being disposed within and secured to the initiation fixture in signal-transfer relation to the initiation charge.
18. The assembly of claim 17 wherein the output end of the signal-transmission fuse is received within a detonator.
19. The assembly of claim 18 wherein the detonator is positioned within a connector block dimensioned and configured to receive therein one or more receptor signal-transmission lines.
Type: Application
Filed: Feb 14, 2003
Publication Date: Jun 16, 2005
Inventors: David Lynch (Burlington, CT), Ronald Dufrane (North Granby, CT), Jeffrey Kezerian (Simsbury, CT), Jack Cotner (Madisonville, KY)
Application Number: 10/504,612