U.S. patent application number 10/158677 was filed with the patent office on 2003-12-04 for detonator with onboard electronics mechanically connected to ignition element.
Invention is credited to Cook, Thomas A., Forman, David M., Kwiatkowski, Bruce J., Tirmizi, Abrar A..
Application Number | 20030221578 10/158677 |
Document ID | / |
Family ID | 29582732 |
Filed Date | 2003-12-04 |
United States Patent
Application |
20030221578 |
Kind Code |
A1 |
Forman, David M. ; et
al. |
December 4, 2003 |
Detonator with onboard electronics mechanically connected to
ignition element
Abstract
A detonator with onboard electronics and an ignition element
that are mechanically connected together.
Inventors: |
Forman, David M.; (Newhall,
CA) ; Tirmizi, Abrar A.; (Simi Valley, CA) ;
Kwiatkowski, Bruce J.; (Mesa, AZ) ; Cook, Thomas
A.; (Phoenix, AZ) |
Correspondence
Address: |
Thomas J. Brindisi
Suite B
20 28th Place
Venice
CA
90291
US
|
Family ID: |
29582732 |
Appl. No.: |
10/158677 |
Filed: |
May 29, 2002 |
Current U.S.
Class: |
102/202.7 ;
102/202.12 |
Current CPC
Class: |
F42B 3/121 20130101;
F42B 3/103 20130101 |
Class at
Publication: |
102/202.7 ;
102/202.12 |
International
Class: |
F42B 003/10 |
Claims
What is claimed is:
1. An ignition subassembly for use in a detonator, comprising an
ignition element and electronics for processing an ignition signal,
said electronics being mechanically connected to said ignition
element.
2. The ignition subassembly of claim 1, wherein the mechanical
connection between said ignition element and said electronics
includes a plug and crimp connection.
3. The ignition subassembly of claim 1, wherein the mechanical
connection between said ignition element and said electronics
includes an insulation displacement connection.
4. The ignition subassembly of claim 1, wherein said electronics
include a circuit board having two ends, one of the ends of said
circuit board being mechanically connected to said ignition
element.
5. The ignition subassembly of claim 1, wherein said ignition
element includes a glass-to-metal header having a sealed
feedthrough.
6. The ignition subassembly of claim 2, further comprising two plug
and crimp connectors, wherein said ignition element includes two
electrode pins that mate with said plug and crimp connectors.
7. A detonator comprising: a) an ignition element; b) electronics
for processing an ignition signal; and, c) a mechanical connector
assembly between said ignition element and said electronics, said
connector mechanically connecting said ignition element to said
electronics.
8. The detonator of claim 7, wherein said mechanical connector
assembly includes a plug and crimp connector.
9. The detonator of claim 7, wherein said mechanical connector
assembly includes an insulation displacement connector.
10. The detonator of claim 7, wherein said ignition element
includes a glass-to-metal header having a sealed feedthrough.
11. The detonator of claim 7, wherein said electronics comprise a
circuit board that includes electronic components for processing an
ignition signal.
12. The detonator of claim 11, wherein said mechanical connector
assembly is soldered to said circuit board at one or more
through-board contacts.
13. A method of making an ignition subassembly for use in a
detonator, comprising the following steps: a) providing an ignition
element suitable for initiating the detonator; b) providing
electronics for processing an ignition signal that is intended to
trigger said ignition element; c) providing a mechanical connector
assembly comprising a male portion and a female portion; d)
incorporating or attaching said male portion of said connector
assembly to one of said ignition element or said electronics; e)
incorporating or attaching said female portion of said connector
assembly to the other of said ignition element and said
electronics; and, f) mechanically connecting together said male and
female portions of said connector assembly.
14. The method of claim 13, wherein step c) includes the step of
providing at least one plug and crimp connector.
15. The method of claim 13, wherein step c) includes the step of
providing at least one insulation displacement connector.
16. The method of claim 13, wherein step a) includes the step of
providing a glass-to-metal header having a sealed feedthrough, and
wherein step d) includes the step of providing said header with a
ground pin protruding away from said header, and the step of
sealing a center pin in said header so as to form said sealed
feedthrough and so as to protrude away from said header.
17. The method of claim 16, wherein step e) includes the step of
attaching two plug and crimp connectors to said electronics, and
wherein step f) comprises the step of pushing said pins into said
plug and crimp connectors and crimping said plug and crimp
connectors to said pins.
18. The method of claim 13, wherein step b) comprises the step of
providing a circuit board including electronic components for
processing an ignition signal.
19. The method of claim 18, wherein step e) comprises the step of
soldering two plug and crimp connectors to said circuit board at
through-board contacts.
20. The method of claim 17, further comprising the step of
substantially encapsulating said electronics, plug and crimp
connectors, and pins.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to pyrotechnic detonators, and
more particularly, to a detonator having onboard electronics and an
ignition element that are mechanically connected to each other.
[0002] The efficient use of explosives in mining operations and the
demolition of structures often requires that many charges be placed
in a predetermined pattern and detonated in a timed sequence. In
general, timed detonation can be accomplished by detonators that
use pyrotechnic delays, sequential-type blasting machines, and
electronically programmable detonators. Some examples of detonators
that have onboard electronics, i.e., electronics contained within
the detonator itself, for processing an ignition signal from, e.g.,
a blasting machine, are described in U.S. Pat. Nos. 6,173,651,
6,085,659, 6,079,332, 5,602,360, 5,460,093, 4,869,170, 4,819,560,
4,730,558, and 4,712,477, the disclosures of which are hereby
incorporated by reference herein.
[0003] Such detonators involve soldered connections between the
ignition element of the detonator to the onboard electronics, which
presents at least the risk of damaging or detonating the ignition
element. It is believed that hitherto this problem has not been
addressed through the provision of a means to mechanically connect
the ignition element to the onboard electronics in a detonator.
SUMMARY OF THE INVENTION
[0004] It is an objective of the present invention to provide a
means to mechanically connect the ignition element in a detonator
to onboard electronics, thus eliminating the risk of making a
soldered or similar connection in immediate proximity to the
ignition element of the detonator.
BRIEF DESCRIPTION OF THE FIGURES
[0005] FIG. 1 is a top sectional view of an embodiment of the
present invention.
[0006] FIG. 2 is a partial top sectional view of the ignition
element and connection portion of the embodiment shown in FIG.
1.
[0007] FIG. 3 is side view corresponding to FIG. 2.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT.sup.1
[0008] Referring to FIGS. 1-3, a detonator utilizing an embodiment
of the present invention is shown. Referring to FIG. 1, an ignition
subassembly 8 is placed inside of a shell 40 that may contain a
primary charge 36 and a base charge 38 loaded into its closed end.
(A detonator shell is typically a metal cylinder 6 to 8 mm. in
diameter and from 60-100 mm. in length). Subassembly 8 can then be
secured in place in the shell 40, such as by placing an elastomeric
plug or the like (see elastomeric plug 46 and crimp 47 in FIGS. 5
and 6) in the open end of the shell and crimping the shell 40 to
the plug, or other suitable method. Subassembly 8 may have a body
portion formed of an encapsulation 31 and is preferably formed to
snugly fit within the shell 40, preferably with features such as
ridges or other protuberances formed to dampen vibrations to which
the detonator may be subjected, generally in accordance with the
teachings of U.S. Pat. No. 6,079,332. Some relevant teachings
regarding encapsulation are also set forth in U.S. Pat. Nos.
6,079,332 and 4,869,170. .sup.1The present description incorporates
by reference in full the disclosures of the following copending
applications filed herewith: "DETONATOR UTILIZING FEATURES OF
AUTOMOTIVE AIRBAG INITIATORS," by John J. Walsh, David M. Forman,
Abrar A. Tirmizi, and Gloria Vawter (Express Mail No.
EU124494952US), "STANDALONE IGNITION SUBASSEMBLY FOR DETONATORS,"
by John J. Walsh, David M. Forman, Abrar A. Tirmizi, and Gloria
Vawter, (Express Mail No. EU124495286US), "DETONATOR WITH AN
IGNITION ELEMENT HAVING A TRANSISTOR-TYPE SEALED FEEDTHROUGH," by
David M. Forman and John H. Oldham (Express Mail No.
EU124495272US), each of which applications is assigned to the
assignee of the present application.
[0009] A header-based, or automotive airbag initiator-style,
ignition element 28 is shown in the embodiment depicted in the
Figures, but a detonator according to the present invention may
include any kind of suitable ignition element (e.g.,
matchhead-type). U.S. Pat. Nos. 6,274,252, 5,709,724, 5,639,986,
5,602,359, 5,596,163, 5,404,263, 5,140,906, and 3,971,320 are also
hereby incorporated by reference herein for their disclosure
concerning the construction of ignition elements based on a
glass-to-metal sealed header feedthrough, including the types of
pins commonly used.
[0010] As shown in FIG. 2, ignition element 28 includes a header
assembly with a sealed electrical feedthrough, comprising an eyelet
10 (preferably stainless steel), insulator glass 14 (preferably a
glass such as a sodasilicate, e.g., 9010, that is chosen to form a
compression seal with the eyelet and center pin, or less preferably
a matched seal), a center pin 18 (preferably iron/nickel alloy), a
ground pin 20, and an igniter wire 12 (preferably a low energy
igniter wire with a diameter of 10 to 20 microns). The ignition
element 28 further preferably includes a charge can 26 that is
preferably metallic and hermetically sealed to the eyelet at
circumferential through-weld 16, with an ignition charge 30
contained between the can 26 and upper surface of the header, in
tight contact with igniter wire 12. An insulator cup 27 may
preferably be attached around the can 26 so that, except for female
connectors 52 that protrude from the input end of the subassembly,
the entire outer surface of ignition subassembly 8 consists of
insulating material, thus providing electrical isolation and
vibration and environmental protection to the components within
until such time as the subassembly is placed in the detonator
shell.
[0011] Turning again to FIG. 1, it can be seen that a circuit board
24 and electronic components 25 are provided within ignition
subassembly 8, to provide a means of triggering ignition of the
ignition element based on the processing of an electrical ignition
signal from a blasting machine or the like that supplies power and
commands to the detonator. Such electronic components are
well-known and preferably include means for imparting a
programmable period of delay to the ignition, means for ESD and RF
protection, et cetera. (Another preferred alternative is the use of
an application-specific integrated circuit). Circuit board 24 and
electronic components 25 are preferably encapsulated together in
encapsulation 31, and connected to female connectors 52 and to plug
and crimp connectors 50 at contacts 22 through soldering or other
suitable connection.
[0012] Suitable plug and crimp connectors 50 that may be purchased
off the shelf are suitable for use in an embodiment of the present
invention like that depicted. Thus, after the plug and crimp
connectors 50 are attached to the circuit board 24 (or other
electronics), pins 18 and 20 of ignition subassembly 28 are
inserted within the openings of connectors 50, and a crimping tool
is used to securely crimp the connectors 50 to pins 18 and 20.
Virtually any contact pin (of appropriate size) designed for use
with a header is suitable for use with connectors 50. After the
plug and crimp connection has been made, ignition subassembly 8 can
be completed by the provision of encapsulation 31 around the
circuit board, electronics, plug and crimp connectors, pins, and
bottom of the ignition subassemblies.
[0013] Alternately to a plug and crimp connection, a standard
off-the-shelf "Insulation Displacement Connection" (IDC) can be
made, with or without insulation sheathing on the pins. IDCs may be
soldered during circuit board assembly in conventional fashion. The
pins 18 and 20 of ignition subassembly 28 can then be inserted into
an IDC and secured.
[0014] It should be noted that although the Figures depict
embodiments including electronic components that receive, process,
and deliver an ignition signal, such an ignition signal may
alternately be received, processed, and delivered by a number of
other well-known non-electronic or partly-electronic means, such as
through the use of a shock tube to deliver an ignition signal to a
piezoelectric device, column fuse delays, et cetera. It is noted
that this detailed description of certain embodiments herein does
not imply that such alternate embodiments are not within the scope
of the invention.
[0015] A preferred embodiment of a detonator having an ignition
element and onboard electronics that are mechanically connected
together, and many of its attendant advantages, has thus been
disclosed. It will be apparent, however, that various changes may
be made in the form, construction, and arrangement of the parts
without departing from the spirit and scope of the invention, the
form hereinbefore described being merely a preferred or exemplary
embodiment thereof. Therefore, the invention is not to be
restricted or limited except in accordance with the following
claims.
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