Weapon control and firing system

A plurality of weapons are provided with electrically operated firing devices and radio transmitting and receiving equipment which permits each weapon to be fired only when the weapon trigger is depressed and a specific command signal is received by the weapon. A master control unit permits an operator to select necessary conditions which are to be satisfied before giving the command, including numbers of groups and weapons to be employed and numbers thereof which are to be in firing position with triggers depressed. Switching and logic arrangements are disclosed to permit the selection, receive signals from the weapons, recognize satisfaction of the conditions, and give the command simultaneously to all ready weapons.

This invention relates to a weapon control system and, more particularly, 
to a system for simultaneously actuating a chosen number of weapons. 
BACKGROUND OF THE INVENTION 
The increase in recent years of illegal and highly dangerous activities by 
terrorist groups has created serious problems for law enforcement 
agencies. One of the most difficult circumstances to handle is that in 
which a group of armed individuals takes a number of victims hostage and 
attempts to use the hostages as protection and leverage to obtain 
transportation to a point of refuge. 
A typical example of such a case is presented when a group of hostage 
takers kidnaps and holds, at gunpoint, a group of hostages and demands of 
a governmental agency that they be provided with an aircraft and crew and 
be flown, together with the hostages, to some remote location at which the 
hostage takers are, or believe they are, welcome. In such case it is 
obviously important to rescue the hostages and deactivate the hostage 
takers before they enter the aircraft, and it is not always possible to 
simply refuse the demands with the hope that the hostage takers are 
bluffing. Furthermore, it is frequently the case that the demands are made 
while the hostages and hostage takers are concealed in a protected 
location near or at an airport. It therefore becomes apparent that there 
will be a very limited interval of time in which the hostage takers are 
exposed, namely, that interval in which they are passing between a 
protected position such as a hanger or other building and the aircraft. 
However, during that interval it can be expected that the hostages will be 
held at gunpoint and that any evidence of efforts to stop the proceedings 
will result in one or more of the hostages being killed or seriously 
injured, an unacceptable situation. Thus, while it would be possible to 
position groups of expert marksmen in suitable locations so that the 
hostage takers could be shot while passing between the building and the 
aircraft, there is no reliable technique for guaranteeing that all of the 
marksmen will be able to eliminate all of the hostage takers before one or 
more of the hostage takers can fire shots at the hostages. While it would 
seem possible to establish a moment in time when all of the marksmen would 
commence firing, that approach is not usually practical because it cannot 
always be predicted when the optimum exposure of the hostages will occur. 
It would also seem to be possible to equip groups of marksmen, which can 
be termed "fire teams", with radios so that a voice command to commence 
firing can be given from a central control location. There is, however, no 
reliable quick way for the person at the central control location to know 
when an adequate number of marksmen in the fire teams have good sight 
pictures of their assigned hostage takers. Thus, if the fire command is 
given when a hostage taker is not in the sights of any marksman, that 
hostage taker would be capable of inflicting severe damage on the hostages 
as soon as he is alerted by the commencement of fire against the others. 
The foregoing example is, of course, only one of many possibilities and is 
presented only to illustrate some of the difficulties and considerations 
facing a law enforcement or military group given the most difficult and 
sensitive task of accomplishing a rescue of this type. 
There are also various other situations in which simultaneous firing 
control of a number of weapons may be deemed necessary, but no effort will 
be made herein to expound on other possibilities. 
BRIEF DESCRIPTION OF THE INVENTION 
It is therefore an object of the present invention to provide a system 
including specially modified weapons, a central control unit and radio 
communication links therebetween which permits the simultaneous firing of 
a plurality of weapons only when a number of predetermined conditions is 
satisfied. 
A further object is to provide such a system which provides the maximum 
probabilities of concurrently deactivating a plurality of hostage takers 
or the like with minimum danger to individuals being held as hostages. 
Briefly described, the invention includes a weapon firing system for 
simultaneously firing a plurality of independently supported and aimed 
weapons comprising a plurality of weapons each having a trigger, a radio 
transmitter responsive to depression of said trigger to transmit a radio 
signal, a firing mechanism, and a radio receiver connected to said firing 
mechanism for operating said mechanism in response to reception of a 
specific fire signal along with concurrent depression of said trigger; and 
a control unit having receiver means for receiving signals transmitted by 
said transmitters in said weapons and for producing signals representative 
of radio signals indicative of depression on said weapons, a control 
transmitter for generating said specific fire signal when actuated, logic 
means responsive to the production of a predetermined number of signals 
representative of trigger depression to produce a "fire" signal, and 
circuit means for coupling said "fire" signal to said control transmitter 
to actuate said transmitter to transmit said fire signal and to thereby 
cause simultaneous actuation of said firing mechanism.

For purposes of illustration and discussion, a set of circumstances 
schematically illustrated in FIG. 1 will be assumed to exist. As shown in 
that figure, several hostages, indicated by circular symbols with the 
letter H therein and indicated generally at 10 will be assumed to be under 
the control of armed hostage takers 11, 12 and 13, the hostage takers 
being illustrated by squares containing the letter T. Concealed marksmen 
will be assumed to have been suitably located at vantage points from which 
they will be able to concentrate fire on selected hostage takers. The 
marksmen constitute fire team members illustrated by triangular symbols 
bearing the letter F. As indicated in FIG. 1, fire team members 14, 15 and 
16 have been assigned the task of disposing of hostage taker 11, fire team 
members 17, 18 and 19 are to direct fire toward hostage taker 12, and fire 
team members 20, 21 and 22 are to direct fire against hostage taker 13. 
The fire teams can, of course, be disposed in relative positions other 
than those shown and need not be grouped together, but they are so 
illustrated simply for purposes of simplicity. It will also be recognized 
that fire teams may be accompanied by other unarmed individuals having 
radio equipment to facilitate moving the fire teams into position and 
advising them of actions to be taken, but these members do not form a part 
of the present invention and are therefore not illustrated. 
Each member of each fire team is in two-way radio communication, through 
their weapons, with a master control unit 25 which can have one or more 
antennas for transmitting and receiving radio signals from and to the 
weapons carried by the fire teams. 
A typical master control unit (MCU) has a control panel one configuration 
of which is illustrated in FIG. 2. The control panel is provided with 
numerous switches and indicator lights to permit an individual in charge 
of the tactical considerations and decisions dictated by the circumstances 
to choose the conditions under which firing of the weapons will be 
permitted to occur. In FIG. 2, the switches have been positioned in 
accordance with a representative set of circumstances to permit discussion 
and explanation thereof. In the example shown, the MCU is designed to 
control the activities of five hostage taker groups which permits control 
of a situation in which there are five hostage takers to be eliminated. 
The system can, of course, accommodate a larger number, five having been 
selected for purposes of illustration. Thus, at the left-hand side of the 
panel is a vertical column numbered 1 through 5 and headed "hostage taker 
group". Since three hostage takers are involved in the present example, 
only groups 1, 2 and 3 will be used and the logic associated only with 
these groups is to be employed. The MCU itself contains the logic 
necessary to make the prescribed decisions, as will be discussed in detail 
hereinafter. 
Having selected groups 1, 2 and 3 to participate in the operation, the 
operator of the MCU moves switches 26, 27 and 28 to ON positions, thereby 
energizing the logic circuits associated with these groups and 
illuminating lamps 29, 30 and 31 indicating that the associated logic 
circuits are ready to function. 
The second column of switches will be referred to as plurality selectors, 
these switches being multiple position switches movable to any one of five 
positions, in the present example. It should be noted that the fact that 
there are five positions is not related to the fact that there are five 
possible hostage taker groups. The plurality of selector switches are used 
to select the number of individuals in each team which must be in a 
completely ready position and condition to fire at the assigned hostage 
takers in order to satisfy the logic conditions necessary to operate the 
entire system. Thus, in the case of hostage taker group 1, the operator 
has selected three fire team members for that group, and it will be 
necessary for all three of the team members in that group to have good 
sight pictures and have their triggers depressed in order for the logical 
requirements for that portion of the system to be satisfied. Similarly, 
the plurality selector associated with group 2 has been placed in the 
number three position, requiring that all three team members of that group 
have good sight pictures and have triggers depressed in order for the 
logical requirements for that group to be satisfied. 
In the case of group 3, however, it has been determined by the operator 
that it will be regarded as sufficient if any one of the three team 
members has a good sight picture and trigger depressed in connection with 
that particular hostage taker. Although there are three team members, the 
operator is not requiring that all three be in a ready position. This 
condition might arise, for example, where two of the hostage takers are 
equipped with automatic weapons such as submachine guns, but the third 
hostage taker is armed only with a pistol. Since the pistol is a somewhat 
less dangerous weapon, it will be more difficult for him to inflict 
serious injury, and the operator may then decide that it is sufficient to 
have one weapon trained on this individual. Each one of the plurality 
selector switches has associated with it a "plurality satisfied" indicator 
32 which is illuminated when the logic in the MCU determines that the 
selected number of marksmen has a sight picture and has his trigger 
depressed. 
The remaining columns on the control panel under the heading "Weapons 
Designated", include enable-inhibit switches 33 for each weapon. Thus, the 
weapon carried by fire team member 14 may be associated with switch 33 in 
group 1, column A, and putting that switch to the enable position permits 
that weapon to be actuated with the remainder of the system. As soon as 
the switch is moved to the enable position, the enable light in the square 
associated with that switch is illuminated. Each square also includes a 
"ready" light and a "target selected" light (abbreviated TS). The ready 
light is illuminated when signals are received by the receiver and logic 
within unit 25 indicating that the individual carrying the weapon 
associated with that square on the control panel has moved a switch on his 
weapon to the "ready" position. The individual then operates a circuit 
arming switch on his weapon, and the target selected light is illuminated 
when a trigger actuated switch on the weapon is actuated, arming the 
weapon and preparing it to be fired upon receipt of a "fire" command 
signal, as will be discussed in connection with the logic. 
Finally, at the bottom of the control panel on MCU 25 is a master override 
switch is movable to either of a "fire when ready" position or an 
"inhibit" position. While in the inhibit position, the weapons cannot be 
fired. When the switch is moved to the "fire when ready" position, the 
weapons will be fired as soon as all of the necessary logical conditions 
are satisfied. 
FIG. 3 illustrates, in block diagram form, the logic within MCU 25 which is 
associated with the switches and indicator lamps discussed with reference 
to FIG. 2. Power supplies and the like have been omitted for simplicity. 
The receiving antenna 40 of the MCU is connected to a plurality of 
receivers 41, or a multichannel receiver, capable of receiving signals 
from the individual weapons. Signals from the receivers are coupled to a 
decoder and storage unit 42 which is capable of recognizing individual 
codes associated with each of the weapons and sampling and storing the 
signals received therefrom, as necessary. In this connection, it should be 
noted that no specific receiver arrangement or transmitter arrangement is 
disclosed herein, but various suitable systems are widely available in the 
art. It is necessary for the signal from each weapon to be uniquely 
identifiable, but this can be accomplished by assigning a specific 
frequency to each weapon which is recognizable by the receivers as 
belonging to that weapon. Alternatively, or in addition to the frequency 
selection, a pulse code can be used, the complexity of the code employed 
being a matter of selecting the level of security desired for the system. 
Each weapon supplies two inputs to the MCU, one input being a signal 
indicating that the weapon is in its "ready" condition and the other 
signal being representative of the fact that a target has been selected 
and the weapon trigger has been depressed. Thus, it is only necessary to 
have two different signals from each weapon recognizable. 
Received signals can then be decoded and supplied on conductors 43 to 
weapon control logic units 44. The MCU includes one weapon control logic 
unit for each weapon, and one such logic unit will be discussed in detail 
with reference to FIG. 5. The weapon control logic units each receive the 
weapon ready and target selected signals from the receiver and decoder and 
also receive enable signals from the enable switches 26, 27, 28, . . . 
from the MCU front panel. The MCU enable switches are identified in FIG. 3 
as block 45. In addition, the weapon control logic units receive input 
signals from group control logic units 46, of which five are supplied, one 
for each of the hostage taker groups as previously discussed in connection 
with FIG. 2. The group control logic units also supply outputs to the 
plurality satisfied indicators 32 on the front panel. A group control 
logic unit will be discussed in detail with reference to FIG. 6. 
Associated with the group control logic units are the plurality selectors 
and a master and plurality logic unit 47. The master logic portion thereof 
will be discussed with reference to FIG. 7 and the plurality logic will be 
discussed with reference to FIG. 8. The master and plurality logic 
receives inputs from the weapon control logic unit and also receives 
inputs from enable switches 45 as indicated in FIG. 3. The enable switches 
also provide outputs to the weapon enabled indicators on the front panel, 
these indicators being identified in FIG. 3 as unit 48. 
The weapon control logic units provide outputs to the ready indicators 49, 
there being one ready indicator for each weapon in each group, and to 
target selected indicators 50, one of which is also supplied for each 
weapon. Finally, the weapon control logic units provide fire signal 
outputs to an encoder 51 which codes the signals in a form recognizable to 
each individual weapon and supplies these to the MCU transmitter 52 which 
transmits the signals on an antenna 53. 
The MCU transmitter is also supplied with a clock 54 and a "polling" timer 
which can supply an interrogation output, typically once each second, to 
all of the weapons causing the weapons to respond with signals indicating 
the conditions of readiness or target selected. 
In order to more fully understand the overall operation of the logic units 
generally illustrated in FIG. 3, reference will be made to each of the 
units individually. As shown in FIG. 5, the weapon control logic units 
each include amplifiers and gates for recognizing and combining the 
various signals. As an example, the logic unit for weapon 2c is 
illustrated. The weapon ready signal, when received, is supplied by the 
MCU receiver to a buffer amplifier 55 from which it is coupled to one 
input of an AND gate 56. As is well recognized, a gate circuit of this 
type produces an output only when all of its inputs are "true". When 
present, the output of gate 56 is coupled through an amplifier 57 to an 
output which is connected to the ready indicator associated with weapon 2c 
on the front panel of unit 25. The weapon enabled signal from the MCU 
enable switch associated with weapon 2c is supplied to an amplifier 58 
which produces an output coupled through an amplifier 59 to the weapon 
enabled indicator associated with weapon 2c. The output of amplifier 58 is 
also coupled to the other input of AND gate 56 and to one input of an AND 
gate 60. The output of amplifier 55 is coupled to a second input of gate 
60. The target selected signal from the receiver is coupled through an 
amplifier 61 to the third input of gate circuit 60, the output of which is 
coupled through an amplifier 62 to the target selected indicator 
associated with weapon 2c, and also to one input of an AND gate circuit 
63. The output of gate 60 is also coupled to the plurality logic circuit 
shown in FIG. 8, to be discussed hereinafter. Finally, an input from the 
group control logic circuit (FIG. 6) is supplied to the other input of 
gate circuit 63, the output of which is supplied as a fire signal to the 
MCU encoder and transmitters 51 and 52, respectively. 
At this point, it will be convenient to discuss the code system which is 
employed to identify the various signals in this system. Each code begins 
with letters indicating a weapon or group, the letters HT indicating a 
weapon and the letters GRP indicating a group. These letters are followed 
by a number indicating the group, in either case, followed by a letter 
indicating which weapon in the group is involved, depending upon the 
prefix letters. Finally, there is a letter or group of letters indicating 
the nature of the signal. Thus, the output of amplifier 55, HT2CR 
indicates that the signal is a ready signal associated with the weapon 2c 
assigned to a fire team member. Similarly, HT2CS indicates a target 
selected signal from weapon 2c, and HT2CE indicates that weapon 2c has 
been enabled. 
When signals are gated together, the final letter changes, so that when 
HT2CR, S and E are gated together, the result is HT2CW, indicating a 
complete readiness in the weapon. Gating HT2CW together with GRP2F (a 
group 2 fire readiness signal) produces HT2CF, a fire signal for weapon 
2c. As will be seen, a signal such as HT2CF will not be produced for any 
one weapon unless it is simultaneously being produced for all weapons. 
The signal HT2CW from gate 60 is, as previously indicated, supplied to the 
plurality logic shown in FIG. 8, along with similar signals from the other 
24 weapon control logic circuits. As shown in FIG. 8, the plurality logic 
includes five sets of gates, each of which is designed to produce an 
output when certain combinations of conditions exist. The plurality logic 
includes an OR gate 65 which produces an output G2ONE which indicates that 
it has received an input from at least one of the weapons in hostage taker 
group 2 of the type HT2AW, HT2BW, or the like. This G2ONE signal is 
supplied to the group control logic for group 2, shown in FIG. 6, and will 
be matched with a selected number chosen by the plurality selector 
associated with hostage taker group 2. 
At the other end of the spectrum, and AND gate 66 will produce an output 
G2FIV only when it receives inputs from all of the five weapon control 
logic circuits associated with hostage taker group 2, gate 66 being an AND 
gate. Thus, an output from gate 65 indicates that a plurality one 
situation can be satisfied while an output from gate 66 indicates that a 
plurality five situation can be satisfied. 
In between these extremes, more complex logic is required to assure 
satisfaction of pluralities of two, three or four. However, the logic is 
quite straightforward, and, noting that the functions in FIG. 8 are 
abbreviated to single letters for diagram simplicity, an examination of 
the logic will reveal that the following summary of each operation exists. 
GnONE+ is generated whenever any one of the weapon W functions ae true: 
EQU GnONE=A+B+C+D+E 
GnTWO is generated whenever any two of the weapon W functions are true: 
EQU GnTWO=A.(B+C+D+E)+B.(C+D+E)+C.(D+E)+(D.E.) 
GnTRE is generated whenever any three of the weapon W functions are true: 
EQU GnTRE=A.B.(C+D+E)+A.C.(D+E)+(A.D.E)+B.C(D+E)+(B.D.E)+(C.D.E) 
GnFOR is generated whenever any four of the weapon W functions are true: 
EQU GnFOR=(A.B.C.D)+(A.B.C.E)+(B.C.D.E)+(A.B.D.E)+(A.C.D.E) 
GnFIV is generated whenver all five of the weapon W functions are true: 
EQU GnFIV=A.B.C.D.E 
The output signals thus derived are connected to the group control logic of 
which, as previously indicated, five exist in the MCU. The logic for group 
2 is shown in FIG. 6 and it will be seen that the signals developed by the 
plurality logic are connected respectively to one input of each of gates 
70, 71, 72, 73 and 74, each of these being AND gates. The plurality 
selector switch 75 for group 2 includes a movable contact which is 
connected to ground and which is movable to any one of five fixed contacts 
which are individually connected to inverting amplifiers 76-80, the 
outputs of these amplifiers being respectively connected to the other 
inputs of AND gates 70-74. As will be recognized, when the input to any 
one of these amplifiers is grounded through the movable contact of switch 
75, the output thereof is a "true" signal. In the example shown, an output 
from amplifier 78 is connected to the input of gate 72. Thus, when the 
G2TRE is provided from the plurality logic of FIG. 8, AND gate 72 provides 
an output signal. All of the outputs of gates 70-74 are connected to the 
inputs of an OR gate 81 so that when any of the AND circuits provides an 
output, gate circuit 81 provides an output to one input of an AND circuit 
82, indicating that the plurality selected by switch 75 has been 
satisfied. The other input to AND circuit 82 is provided from the enable 
switch 27 of the group 2 circuit through an amplifier 83. Thus, when the 
plurality has been satisfied and an output is provided from OR gate 81, an 
output is provided from gate 82. This output is coupled through an 
amplifier 84 to the plurality satisfied indicator 32 on the master control 
unit front panel. The output is also supplied to an AND gate 85 and to the 
master logic circuit of FIG. 7. As will be described, when the group 2 
weapons have been enabled, the master logic responds to the enabling 
signal and to the GRP2W signal from gate 82 to provide an AFIRE signal 
back to the group control logic, providing the second input to gate 85. 
Gate 85 then provides a GRP2F signal to the weapon control logic of FIG. 5 
which, when the other signals are provided thereto as previously 
discussed, sends an HT2CF signal to the MCU encoder and transmitter for 
transmission to the weapon selected. 
The master logic circuit (FIG. 7) includes a main AND gate 90 which 
produces the AFIRE output signal upon receipt of appropriate signals from 
five circuits including AND gates 91-95 and OR gates 96-100, and also from 
an amplifier 101. Amplifier 101 receives its input from switch 34 which is 
the master override switch on the front panel. That switch is closed when 
placed in the "fire when ready" position, and the amplifier produces the 
signal FWRDY continuously when that switch is closed. Each of the other 
circuits is associated with a specific group and provides an output when 
two input conditions are satisfied, one of the inputs being the GRP2W 
signal supplied by gate 82 in the group control logic of FIG. 6. The other 
input to each of gates 91-95 is the "enable" signal which is connected to 
its associated gate and is also connected through one of inverting 
amplifiers 102-106. Using the group 2 circuit as an example, if group 2 is 
selected, then a "true" signal is supplied to one input of AND gate 92. 
With this being the case, no output is supplied by amplifier 103, and 
there is no output from OR gate 97. Thus, regardless of what conditions 
exist at the outputs of the other OR gates 96 and 98-100, there will be no 
output from AND gate 90 until an output is supplied from AND gate 92. That 
output will appear only when the plurality selected has been satisfied and 
an output is supplied by gate 82 in the group control logic. As soon as 
that GRP2W signal is supplied, there is an output from gate 92 which is 
coupled through OR gate 97 to the input of AND gate 90. If, however, group 
2 is not selected, and its enable switch is left in the off position, 
there is no GRP2E input to gate 92 and amplifier 103 supplies a 
"substitute" input through OR gate 97 to AND gate 90 so that as soon as 
the necessary conditions are satisfied for the selected weapons, gate 90 
can supply the AFIRE output. 
Thus, it is the master logic circuit which makes sure that conditions are 
satisfied for all of the chosen weapon groups before supplying the AFIRE 
signal to all of the group control logic circuits, permitting transmission 
of a signal therefrom to the weapon control logic and, thence, to the MCU 
encoder and transmitter. In the example previously discussed with the 
switches in the positions shown in FIG. 2, enable inputs are present at 
gates 91, 92 and 93, but no enable inputs are supplied to gates 94 and 95. 
Thus, before any weapons are ready, outputs are provided from OR gates 99 
and 100 to AND gate 90. Then, when the master switch is moved to the fire 
when ready position, an output from amplifier 101 is coupled to gate 90, 
and all that remains is for the appropriate signals to appear from the OR 
gates for the selected groups, i.e., gates 96, 97 and 98. As soon as the 
weapon ready, target selected and enable conditions are satisfied by the 
weapon control logic, and the plurality logic determines that the desired 
number of weapons are appropriately trained on the hostage takers and the 
triggers thereof are depressed, the GRP1W, GRP2W and GRP3W signals are 
supplied to gates 91-93, respectively, producing outputs from gates 96-98, 
completing all of the inputs to gate 90. The AFIRE signal is then supplied 
to gate 85 (for each group control logic circuit) and GRP1F, GRP2F and 
GRP3F signals are supplied to the gates 63 of the weapon control logic 
circuits for groups 1-3, producing an HT1CF, HT2CF and HT3CF signals to 
the MCU encoder and transmitter, which signals cause simultaneous 
transmission of a "fire command" signal from the MCU transmitter to all 
weapons. All selected weapons which have their triggers depressed are then 
fired simultaneously, disabling the hostage takers. 
The remaining element of the system is the weapon itself which, obviously, 
must be modified to respond only to the signals generated by the MCU along 
with trigger depression. As shown in FIG. 4, the weapon is a specially 
modified weapon which incorporates an electrical sear release controlled 
by an electronic circuit. An electrical trigger mechanism which is usable 
in this fashion, with some modification, is manufactured and sold by 
Electronic Trigger Systems, Route 2, Box 114A, Montrose, Colorado 81401. 
This mechanism includes a special trigger housing, two switches and a sear 
release circuit which includes a small solenoid coupled to the sear 
release itself, a silicon controlled rectifier (SCR) connected to energize 
the solenoid, and a capacitor discharge circuit to trigger the SCR. A 
small battery is incorporated to charge the capacitor. Since this 
mechanism is a purchased item and is not part of the invention as such, 
most of it is only diagrammatically illustrated in FIG. 4. However, it is 
necessary to modify the device and incorporate other elements for the 
weapon to be usable in the system of the present invention. 
As shown in FIG. 4, the trigger housing includes a trigger 110, a trigger 
guard 111, and a small housing 112 attached to the trigger guard for 
holding switches. A button switch 113 is mounted in the upper portion of 
the trigger guard forward of the trigger and is mechanically connected to 
a latching switch 114 which is coupled to the sear release circuit. Behind 
trigger 110 is a push button 115 which, upon very small motion, closes a 
switch 116 which is connected in series with a resistor 117 between a 
source of voltage and ground. An amplifier 118 is connected to the 
junction between switch 116 and 117 and provides an output signal to one 
input terminal of an AND gate 199 and also to a small radio transmitter 
120 which is mounted in the weapon, (or, if desired, separately carried by 
the marksman) and which is coupled to receiver 41 in the MCU. Button 115 
and switch 116 comprise the trigger switch and the signal generated by 
actuation of switch 116 constitutes the "target selected" signal which is 
supplied to the weapon transmitter and the MCU. An additional switch 121, 
in the nature of a "safety" is connected between a source of voltage and 
an amplifier 122, the output of which is also supplied to another input of 
gate 119 and to weapon transmitter 120, the signal from amplifier 122 
constituting the "ready" signal from the weapon. In a tactical situation, 
switch 121 would be closed by the fire team member as soon as he is in a 
position from which he can fire the weapon at his assigned hostage taker, 
letting the master operator know, by illumination of the "ready" light 
associated with this weapon that he needs only to obtain a sight picture 
and depress his trigger. Button 113 is then depressed, closing switch 114 
which activates the sear release circuit 123 to the extent of charging the 
capacitor which will fire the SCR. The weapon is now in a condition of 
readiness and needs only an input from the MCU through weapon receiver 
124, this input constituting the third input to gate 119. As soon as that 
signal is received, gate 119 produces an output which is coupled through 
an amplifier 125 and a capacitor 126 to a small amplifier circuit 
including a transistor 127 to the sear release circuit, discharging the 
capacitor into the SCR and energizing the solenoid which releases the sear 
and fires the weapon. 
It will be observed that one of the inputs to gate circuit 119 is the 
signal from trigger switch 116. Thus, the weapon team member exercises 
final control over whether or not his weapon is fired. Thus, if a hostage 
should suddenly be moved between the weapon team member and his target, he 
can release the trigger and, even if the other weapons in the system fire, 
his will not be fired. As previously discussed, if his weapon is necessary 
to satisfy the plurality, none of the weapons will be fired; but if his 
weapon is a superfluous weapon as in the case of group 3, the others can 
fire, but his will not, thereby introducing a safety factor. 
It should further be pointed out that sear release circuit 123, button 113, 
switch 114, button 115, switch 116, resistor 117 and amplifier 118 along 
with the housing, trigger guard and trigger assembly are all components of 
the purchased unit produced by the above-mentioned company. In order to 
modify this system to be operative as described, it is only necessary to 
introduce the intervening logic and amplifier circuit, a modification 
which can be accomplished by severing the interconnecting wires between 
components and making connections as shown. The modification of the weapon 
itself, to install the special trigger housing and the like, are 
accomplished in accordance with instructions supplied by Electronic 
Trigger Systems. 
It will also be observed in FIG. 4 that the weapon includes a weapon code 
selector switch 128 which can be used to select the frequency or pulse 
code unique to that weapon so that it will be responsive only to signals 
supplied by the MCU. It will also be observed that the receiver can be 
designed, as previously indicated to receive an interrogation code which 
is coupled on conductor 129 to weapon transmitter 120, providing no input 
to AND circuit 119. Upon receipt of this signal, the weapon transmitter 
can respond by indicating the presence or absence of "ready" or "target 
selected" signals for transmission to the MCU. 
Normally, the weapons used in a system of this type would be modified 
sniper-type rifles having accuracy and firepower consistent with the goals 
of the system. No effort has been made herein to exhaustively discuss the 
various tactical circumstances or considerations involved in the use of 
such a system. However, it will be readily apparent that the system 
provides a degree of safety and level of operability not previously 
available and would therefore have excellent application in firing range 
safety or live firing exercises. 
While one advantageous embodiment has been chosen to illustrate the 
invention, it will be understood by those skilled in the art that various 
changes and modifications can be made therein without departing from the 
scope of the invention as defined in the appended claims.