U.S. patent application number 11/271699 was filed with the patent office on 2006-05-18 for touch sensor firearm safety system.
Invention is credited to David O. Matteson.
Application Number | 20060101694 11/271699 |
Document ID | / |
Family ID | 36384629 |
Filed Date | 2006-05-18 |
United States Patent
Application |
20060101694 |
Kind Code |
A1 |
Matteson; David O. |
May 18, 2006 |
Touch sensor firearm safety system
Abstract
A firearm safety system prevents an unintentional discharge of a
firearm. A touch sensor is located on a front surface of the
firearm trigger and has a conductive touch pad for sensing contact
by a user of the firearm. A touch sensing electronic circuit is
coupled to the conductive touch pad and trigger and prevents the
firearm from discharging if contact with the conductive contact pad
is not sensed. Additionally, the safety system can be configured to
conserve battery power of electronic firearms by providing a signal
to wake-up the system controller.
Inventors: |
Matteson; David O.; (Horse
Cave, KY) |
Correspondence
Address: |
WOMBLE CARLYLE SANDRIDGE & RICE, PLLC
ATTN: PATENT DOCKETING 32ND FLOOR
P.O. BOX 7037
ATLANTA
GA
30357-0037
US
|
Family ID: |
36384629 |
Appl. No.: |
11/271699 |
Filed: |
November 12, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60627636 |
Nov 12, 2004 |
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Current U.S.
Class: |
42/69.01 |
Current CPC
Class: |
F41A 17/06 20130101 |
Class at
Publication: |
042/069.01 |
International
Class: |
F41A 19/00 20060101
F41A019/00 |
Claims
1. A firearm safety system including a trigger, comprising: a
trigger bow; a touch sensor located on a surface of the trigger
bow, the touch sensor including a conductive touch pad that is
isolated electrically from the firearm; and an electronic circuit
operationally coupled to the touch sensor and activated by a user's
contact with the touch pad.
2. The firearm safety system of claim 1 wherein the electronic
circuit provides a wake-up signal to a system controller when the
touch pad is touched.
3. The firearm safety system of claim 1 wherein the electronic
circuit provides a logic signal to a system controller that is used
to determine if firing can be initiated when the trigger is
pulled.
4. A trigger safety system for a firearm comprising: a touch sensor
comprising a conductive touch pad for sensing contact by a user; an
electronic circuit coupled to the touch sensor and the trigger for
controlling activation of a firing mechanism of the firearm.
5. A firearm safety system including a touch sensor comprising: at
least one conductive touch pad to sense a touch; an electronic
circuit operationally coupled to the conductive touch pad and
activated by a user's contact with the at least one touch pad.
6. The firearm safety system of claim 5 wherein the touch pad is
located on a surface of a trigger bow.
7. The firearm safety system of claim 5 wherein the touch sensor
comprises two touch pads.
8. The firearm safety system of claim 7 wherein one conductive
touch pad is located on a surface of a trigger bow.
9. The firearm safety system of claim 7 wherein both conductive
touch pads are located on a surface of a trigger bow.
10. The firearm safety system of claim 9 wherein the conductive
touch pads are positioned side by side along a length of the
trigger bow.
11. The firearm safety system of claim 5 wherein the electronic
circuit includes a system controller.
12. The firearm safety system of claim 11 wherein the safety system
is configured to conserve battery power.
13. The firearm safety system of claim 12 wherein the battery power
is conserved by allowing the system controller to remain in a sleep
mode until the touch pad is touched.
14. The firearm safety system of claim 12 wherein energy is
conserved by not charging a bulk capacitor that is used to store
the energy needed to fire the round of ammunition until the touch
pad is touched.
15. The firearm safety system of claim 5 wherein the electronic
circuit includes a solenoid coil of that is used to block the
firing of a firearm until the solenoid is energized.
16. The firearm safety system of claim 8 wherein a second touch pad
is located on a grip area of the firearm.
17. The firearm safety system of claim 8 wherein a second touch pad
is located on either a recoil pad or butt plate of a long gun.
18. The firearm safety system of claim 5 further comprising a
system controller to charge a capacitor to provide a firing pulse
to discharge electronically-primed ammunition.
19. The firearm safety system of claim 5 further comprising an
actuator to release or propel a firing pin for firing of
percussion-primed ammunition.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application is a formalization of a
previously filed, co-pending provisional patent application
entitled "Touch Sensor Firearm Safety System," filed Nov. 12, 2004,
as U.S. Patent Application Ser. No. 60/627,636 by the inventor
named in this patent application. This patent application claims
the benefit of the filing date of the cited provisional patent
application according to the statutes and rules governing
provisional patent applications, particularly 35 USC .sctn.
119(e)(1) and 37 CFR .sctn..sctn. 1.78(a)(4) and (a)(5). The
specification and drawings of the provisional patent application
are specifically incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to firearm safety
devices and, more particularly, to firearm safety devices having
touch sensors for allowing actuation of the firing mechanism.
BACKGROUND OF THE INVENTION
[0003] Historically, manufacturers of firearms have developed
safety systems that help prevent unintentional discharge of
firearms. The 1911 grip safety is an example of such a safety
system. It requires the shooter to depress the grip safety
sufficiently before the firearm can be fired. Thus an unintentional
trigger pull that could occur from dropping or other mishandling of
the firearm would not allow the firearm to fire because the grip
safety would have to be depressed also. The Savage AccuTrigger is
another example of such a safety system. The AccuTrigger is
essentially a trigger within a trigger. The main trigger that fires
a round of ammunition cannot be pulled until the pre-trigger is
pulled and the main trigger is allowed to release the sear. Both of
these safety systems provide some additional protection from
unintentional discharge of the firearm; however, they are not
transparent to all shooters. In the case of the 1911 grip safety,
if the grip safety is not properly gripped, it will not be
depressed sufficiently to allow the firearm to be fired. Both
safety systems require a lever other than the trigger to be
displaced a distance before a trigger pull fires the firearm.
[0004] U.S. Pat. No. 6,694,963 describes a trigger system that uses
a touch sensor as the trigger for a paintball gun. Though this may
be an acceptable trigger system for a paintball gun it is not
acceptable for a firearm. This trigger system would cause the gun
to fire even with an unintentional touch of the trigger or when the
user is trying to find the trigger so that he can pull it.
Furthermore, the touch trigger circuit only senses initial touching
and cannot tell if the user continues to touch the trigger.
[0005] U.S. Pat. No. 4,970,819 describes using pressure sensing
grip sensors to determine if the gripping pattern matches the
pattern of an authorized user of the firearm. That is, it suggests
using the pattern of how the authorized user grips the firearm as a
means of recognizing him. U.S. Pat. Nos. 6,286,242 and 6,321,478
discuss using grip sensors as a means of sensing a user's intent to
fire a firearm. In addition, the idea of using a grip sensor to
wake up a system controller is discussed. All of these prior
inventions use pressure sensors as grip sensors. This introduces
the added complexity that different users do not necessarily apply
pressure to the same area of a firearm grip. This has been
addressed by using an array of pressure sensors to work as the grip
sensor. The array of pressure sensors adds cost and complexity to
the system. Users do not necessarily apply the same amount of
pressure to the grip when they intend to fire a firearm.
[0006] The inventive system eliminates the need for displacement of
the safety device and only requires the shooter to contact or touch
sensors to show intent to fire. The sensing area of the touch
sensors can be made sufficiently large to allow for different size
hands and styles of holding the firearm to still allow firing of
the firearm.
[0007] The inventive safety system is more easily implemented on a
firearm that fires electronically initiated ammunition. However,
the use of electromechanical devices such as solenoids or
piezoelectric actuators can allow the safety system to work with
systems that fire percussion primed ammunition.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to a supplemental firearm
safety system intended to prevent unintentional discharge of a
firearm. The inventive safety system can utilize one or more touch
sensors. The sensor or sensors are required to be contacted by the
shooter in order to enable the firearm to fire. The touch sensor or
sensors can be located in such a way that a shooter would normally
touch or contact the sensor or sensors when he intends to fire the
firearm. Thus, the shooter would not be required to perform any
special operations to enable the use of the firearm and the safety
system would be largely transparent to the shooter. The trigger bow
area of the firearm is a potential location for touch sensors. This
safety system can function as a secondary safety in addition to the
traditional safety button or switch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention is better understood by reading the following
detailed description of the invention in conjunction with the
accompanying drawings.
[0010] FIG. 1 illustrates an exemplary embodiment of the touch
sensor firearm safety system of the present invention.
[0011] FIG. 2 illustrates an exemplary touch sensing circuit design
that can be used in the present invention.
[0012] FIG. 3 illustrates an alternate exemplary embodiment of the
touch sensor firearm safety system of the present invention.
[0013] FIG. 4 illustrates an exemplary embodiment showing the touch
sensor(s) output signal(s) being supplied as an input, along with
other inputs, to the system controller which determines if and when
to generate a fire pulse based on the inputs.
[0014] FIG. 5 illustrates another exemplary touch sensing circuit
design that can be used in the present invention.
[0015] FIG. 6 illustrates an exemplary embodiment in which a second
touch pad is located on a butt plate of a long gun.
[0016] FIG. 7 illustrates an exemplary embodiment in which a second
touch pad is located on a grip of a firearm.
DESCRIPTION OF THE INVENTION
[0017] The following description of the invention is provided as an
enabling teaching of the invention in its best, currently known
embodiment. Those skilled in the relevant art will recognize that
many changes can be made to the embodiments described, while still
obtaining the beneficial results of the present invention. It will
also be apparent that some of the desired benefits of the present
invention can be obtained by selecting some of the features of the
present invention without utilizing other features. Accordingly,
those who work in the art will recognize that many modifications
and adaptations to the present invention are possible and may even
be desirable in certain circumstances and are a part of the present
invention. Thus, the following description is provided as
illustrative of the principles of the present invention and not in
limitation thereof, since the scope of the present invention is
defined by the claims.
[0018] As illustrated in FIG. 1, an exemplary embodiment of the
touch sensor firearm safety system includes a single touch sensor
12 located on the trigger bow 10. The touch sensor sensing area
covers most of the front surface of the trigger bow. The touch
sensor sensing area is made up of a conductive touch pad 12 that is
electronically isolated from the metal trigger 10 and connected by
wires or traces to a touch sensing circuit such as illustrated in
FIG. 2. A flex circuit with an exposed pad can offer a durable
touch sensor that could be adhesively attached to the trigger 10.
It is also possible to use conductive paint or foil tape to make a
touch pad on top of an insulating coating on the metal trigger. The
trigger 10 would not have to be made from metal and, if it was made
from a non-conductive material such as a plastic or ceramic, the
insulating layer between the trigger 10 and touch pad 12 would not
be needed. If a conductive trigger were electrically isolated from
the rest of the firearm, the trigger could act as the touch pad.
The touch sensor could be implemented on a number of different
trigger systems. It would be easiest to implement the sensor on a
Zero Displacement Trigger as disclosed in U.S. Pat. Nos. 6,668,700
and 6,651,542, because the wiring would not have to work with
moving components. However the touch sensor safety system could
also be implemented on an electronic micro-switch trigger as used
in Remington Arms Co. M/700 EtronX rifles or on a standard
mechanical trigger for a firearm that fires percussion
ammunition.
[0019] Ideally, the touch sensor firearm safety system can
immediately recognize contact from a shooter and will know if and
when the shooter releases the trigger. The touch trigger described
in U.S. Pat. No. 6,694,963 only recognizes touch but does not know
when, or if, the touch is released. The touch sensor safety system
of the present invention requires the touch sensor to sense whether
or not a shooter is simultaneously contacting the touch pad before
allowing a trigger pull to initiate firing a round of ammunition.
This eliminates unintentional discharges caused by drops or other
jarring events that might cause a perceived trigger pull. If the
same circuit described in U.S. Pat. No. 6,694,963 was used, the
best that could be done is to allow a window of time from
contacting the touch pad during which the firearm is allowed to
initiate firing when the trigger is pulled or appears to be pulled.
This would still allow for the possibility of a drop-induced
trigger pull to initiate firing of the firearm if the drop occurred
within the time window starting from when the shooter touches the
touch sensor. In addition, this system may not allow a legitimate
trigger pull to initiate firing a firearm if the shooter takes too
long (i.e., longer than the allotted window of time) to pull the
trigger.
[0020] One exemplary touch sensing circuit design that can be used
with the touch sensor firearm safety system is shown in FIG. 2. The
LM555 is a timer integrated circuit (IC) for generating accurate
time delays that is available from National Semiconductor
Corporation. This IC device is not limiting in any way, and any
suitable IC timer device could be used in its place. In the present
invention, the LM555 timer is used to generate a 30 Hz square wave
when configured as shown. The 30 Hz square wave is supplied to the
movable contact of a one megaohm potentiometer. One fixed end of
the potentiometer is attached to the CLK pin of a latch to give the
latch its required 30 Hz clock signal. The other fixed end of the
potentiometer is connected to the touch pad and D pin of the latch.
The latch used in the circuit design shown in FIG. 2 is a Texas
Instruments SN74AC74N, dual positive triggered D-type flip flop.
The use of this latch should not be considered restrictive since
those skilled in the art will realize that other devices could be
used to perform the same function.
[0021] FIG. 2 shows two separate latches that are labeled as
74AC74N. These latches are both actually half of the same part and
are only separated schematically to simplify the diagram for the
optional Touch Pad #2 and supporting electronics. If more than two
touch pads were desired, additional latches would be required. If
the touch pad is not being touched, then the signal going into the
latch D pin is high. If the touch pad is being touched then the
signal going to the latch D pin will go low. The latch will set the
latch Q pin to the same voltage level as the signal supplied to the
latch D pin at a 30 Hz frequency. The latch Q pin supplies a signal
to a system controller for use in determining if firing is
allowable when the trigger is pulled.
[0022] In addition to providing an additional safety from
unintentional discharge of a firearm, the touch sensor firearm
safety system can be used to conserve the battery life of the
battery powering the firearm electronics. This battery life savings
can be obtained in several different ways. A first way is that a
low signal to the system controller signals the system controller
and the rest of the electronic system to wake-up. A second way
would be to provide a signal to the system controller to charge the
capacitor used to provide the firing pulse needed to fire
electronically-primed ammunition, or to energize a solenoid or
other actuator used to release or propel a firing pin to initiate
percussion-primed ammunition. The former way would provide the most
battery life savings but could introduce too much of a delay before
the system would be capable of firing under some circumstances. The
latter way would provide some battery life savings but would reduce
the amount of delay before the system would be capable of firing.
This is an improvement over the wake-up feature of U.S. Pat. No.
6,286,242 because it does not wake up or charge the capacitor until
just before the user intends to fire the firearm (i.e., the user
has started to pull the trigger). It is normal for shooters to
handle firearms by the grip areas even when they have no intent of
firing the firearm. However, it is not normal, or it is at least
unsafe, to touch the trigger until intending to fire a firearm.
This could allow additional energy savings because of the
elimination of false or unneeded wake-ups.
[0023] It should be obvious that minor deviations from the above
described exemplary embodiment can be implemented without deviating
from the spirit and scope of the invention. One such contemplated
alternate exemplary embodiment is illustrated in FIG. 3. This
figure depicts a trigger 10 with a touch sensor that has two touch
pads 14, 16. In such an exemplary embodiment, it would be required
for the shooter to touch both touch pads 14, 16 simultaneously.
This could help further eliminate unintentional discharges
associated with accidentally pulling the trigger on a light trigger
pull gun because the finger would have to be fully in the trigger
guard in order to make contact with both touch pads. FIG. 3 shows
the two touch pads 14, 16 positioned side by side. Other relative
orientations of such devices would work but may overly restrict the
allowable positioning of the shooter's finger eliminating the
transparency of the safety system to the user.
[0024] Many alternative embodiments exist for safety systems that
have a second touch pad. The second touch pad does not have to be
located on the trigger itself, but does need to be located in
proximity to where the shooter would contact it during normal use.
Some of the alternative locations for the second touch pad include
the grip area 20 of a firearm as illustrated in FIG. 7 or the
recoil pad or butt plate 18 of a long gun as illustrated in FIG. 6.
These alternative locations for the second touch pad would be more
complicated to implement since they would require electronic
communication between the stock and the system controller.
[0025] The touch sensing circuit shown in FIG. 2 is one exemplary
circuit that could be used to create a touch sensor. Other circuits
have been contemplated but for simplicity have not been shown. The
changes to the exemplary circuit can be as simple as changing to a
higher frequency square wave than the 30 Hz square wave generated
by the timer integrated circuit chip shown in FIG. 2, or could
involve a more complex circuit design. Additionally, much of the
circuit shown in FIG. 2 could be replaced by currently available
integrated circuits. Quantum Research Group's QTouch.TM. QT220, two
channel touch sensor IC, is an example of such an integrated
circuit. Other integrated circuits are available that provide
different numbers of independent channels.
[0026] FIG. 4 shows how the touch sensor(s) output 28 is provided
as an input to a system controller 30. The system controller 30
uses this information along with information received from the
safety switch 24 and trigger pull detection system 26 to determine
if and when to provide a fire pulse 32 to fire a round of
ammunition electrically or electro-mechanically. Additionally, this
input from the touch sensor 22 can be used to wake-up the system
controller 30. The input from the touch sensor 22 could also be
used to signal the system controller 30 to perform some other
function such as charging a bulk capacitor used to store energy
needed for the fire pulse 32 that needs to be completed prior to
the firearm being ready to fire. Both of these offer a means to
conserve battery power.
[0027] The touch sensing circuit shown in FIG. 5 is an exemplary
circuit that could be used to create a touch sensor for a
percussion firearm that was not equipped with a system controller.
The circuit is very similar to the one that is shown in FIG. 2
except it is only equipped with one touch pad and the Q pin signal
of the latch is not sent to a microcontroller or system controller
but to an additional circuit. The touch sensor signal from latch
pin Q is sent through an inverter U5:A, and resistor R1 to switch
U3. When the signal from the Q pin of the latch goes from logic
high to logic low, the switch U3 switches one side of a solenoid
coil to power the solenoid so as to remove a physical block that
was preventing the firearm from being fired. Thus, when the touch
sensor senses touch to the touch pad, firing the firearm is
enabled. The inverter could be eliminated if the signal from the Q
pin was used instead of the Q pin as would be understood by those
skilled in the art.
[0028] Diode D1 is a 1N4004 diode and is connected across the
solenoid as shown to protect switch U3 from damaging voltage spikes
that occur once the switch U3 is disabled. The circuit depicts
switch U3 as an International Rectifier IRF3707 N-channel MOSFET.
Switch U3 could also be another device suitable for this purpose,
such as a bipolar transistor, an electro-mechanical relay, or a
solid state relay as will be understood by those skilled in the
art.
[0029] The corresponding structures, materials, acts and
equivalents of all means plus function elements in any of the
claims below are intended to include any structure, material, or
acts for performing the function in combination with other claim
elements as specifically claimed.
[0030] Those skilled in the art will appreciate that many
modifications to the exemplary embodiments are possible without
departing from the spirit and scope of the present invention. In
addition, it is possible to use some of the features of the present
invention without the corresponding use of the other features.
Accordingly, the foregoing description of the exemplary embodiments
is provided for the purpose of illustrating the principles of the
present invention and not in limitation thereof since the scope of
the present invention is defined solely by the appended claims.
* * * * *