Abstract:
A non-lethal projectile and a method of igniting the same are provided. A propulsion charge acts on a base portion of a casing of the projectile and is ignitible from a launcher for launching the projectile therefrom. An initiator is disposed in the casing, with a combination timing and firing mechanism that is also disposed in the casing initiating the initiator. A dispersal charge is disposed in the casing and is ignitable by the initiator. Such dispersal charge is electronic subsequent to launching the projecting and prior to the projectile reaching a target area.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a non-lethal projectile that is to be launched from a launcher, and also relates to a method of igniting such a projectile. 
     Police officers and military personnel involved in peace keeping efforts often need an effective non-lethal means for subduing a person or persons from a safe distance. With devices and methods presently known, a user is required to either hit a target directly with a ballistic, or to rely on inaccurate hand-thrown or launched area-of-effect weapons. 
     It is an object of the present invention to provide a non-lethal projectile that can be delivered with an aim-point device to subdue a person from a safe distance. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     This object, and other objects in advantages of the present invention, will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which: 
     FIG.  1 . illustrates a firearm with an aiming device and a launcher for delivering the non-lethal projectile of the present invention; 
     FIG. 2 illustrates one exemplary embodiment of the projectile of the present invention; 
     FIG. 3 illustrates one exemplary embodiment of means for providing electrical contact between an aiming device and a projectile loaded into a launcher; and 
     FIG. 4 illustrates one exemplary embodiment of the electronics package of the projectile of the present invention. 
    
    
     SUMMARY OF THE INVENTION 
     The non-lethal projectile of the present invention includes a casing, a propulsion charge that acts on the base portion of the casing and is ignitible from a launcher for launching the projectile therefrom, and initiator disposed in the casing, a combination timing and firing means disposed in the casing for initiating the initiator, and a dispersal charge disposed in the casing and ignitible by the initiator. Such a projectile is also known as a so-called semi-smart projectile. 
     Pursuant to the method of the present invention, after the projectile has been launched and prior to the time that the projectile reaches a target area, a dispersal charge in the projectile is electronically ignited. Further specific features of the present invention will be described in detail subsequently. 
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings in detail, FIG. 1 illustrates by way of example only a firearm  10  that is provided with a launcher  11 , for example a 40 mm launcher, that is utilized to launch the non-lethal projectile of the present invention, which will be described in detail subsequently. It is to be understood that the launcher  11  could also be a self-contained launcher. At any rate, an aiming device  12  is provided on the firearm  10 . The aiming device  12 , which contains a non-illustrated power pack, communicates with the launcher  11  via a cable  13 . 
     FIG.  2 . illustrates one exemplary embodiment of the inventive non-lethal projectile, which is indicated generally by the reference numeral  20  and is disposed in a standard case or firing cartridge  14  for placement in the launcher  11 , which can be embodied similar to a grenade launcher. A propulsion charge  15  is provided in the firing cartridge  14  and is designed to be fired by, for example, a percussion pin of the firearm  10  for launching the projectile  20  from the launcher  11 . The propulsion charge  15  can be a standard propulsion charge, such as combustible propellant, or could, for example, also be a blank or compressed gas. 
     The projectile  20  includes a casing  21 , which can be a one part or two part casing, and is made of a material that is capable of withstanding the shock of being fired from the launcher  11 . For example, the casing  21  can be made of a suitable polymeric material such as polyethylene, metal such as brass, and even paper. If the casing  21  is made of two parts, each part can be made of a different material. The propulsion charge  15  in the firing cartridge  14  acts upon the base portion  22  of the projectile casing  21  to propel or launch the projectile  20  out of the launcher  11 . 
     A recess  23  is provided in the projectile casing  21  for receiving an electrical contact band  24  that, in a manner to be described in detail subsequently, is connected via a portion of the launcher  11  to the cable  13  and hence to the aiming device  12  for receiving positive voltage and range and timing signals for the electronics package  25  that is disposed in the base portion  22  of the casing  21 . A ground contact  26  for the electronics package  25  is also provided on the casing  21 . 
     The electronics package  25 , which is a combination timing and firing mechanism and includes a microcontroller, is responsible for igniting the projectile  20  at a pre-programmed time after launch. The electronics package  25  is potted into the base portion  22  by means of a potting material  27 , such as silica, elastic polymer, or the like, so that the electronics package  25  can survive the launch acceleration of the projectile  20 . Although illustrated as being disposed in the base portion  22 , it is to be understood that the electronics package  25  could also be provided in another location, for example on a narrow board disposed in the central core of the projectile  20 . 
     In the illustrated embodiment, a launch detector  28 , such as a launch detection transducer, extends from the electronics package  25 . The launch detector  28  detects launch of the projectile  20 , for example by means of sensing base pressure on the projectile or by sensing sustained acceleration that is indicative of launch. 
     Disposed on that side of the electronics package  25  that is remote from the propulsion charge  15  is an initiator  30  for initiating a dispersal charge  31  of the projectile  20 . The initiator  30  is initiated by the timing and firing mechanism of the electronics package  25 . 
     The initiator  30  includes a primer  32  that is activated by the electronics package  25  and in turn activates a propellant  33 , especially a fast burning propellant, which can, for example, be smokeless powder. The propellant  33  is in the form of a center core ignitor that is disposed in a frangible tube  34 , which can be made, for example, of paper, thin plastic, wax paper, or the like. The dispersal charge  31  is then disposed about the frangible tube  34 . Such dispersal charge, which is also known as a pyrotechnic charge or flash-bang charge, and is intended as a sensory disruptive mechanism, can be a mixture of aluminum and magnesium powder or potassium chloride, and can also include micro pulverized agents, pepper, dyes and the like. The burning of the dispersal charge  31  causes a great increase in pressure within the projectile  20  and causes the casing  21  thereof to rupture and to cause a filler  36  that can be disposed about the dispersal charge  31  to be dispersed into the atmosphere. The filler  36  comprises non-lethal material, such as chemical irritant, oleo-resin capsicum, tear gas, mace, pepper, etc., or mixtures thereof, and can also be in the form of a fog or mist. The filler  36  can be in the form of micro balloons of glass or plastic that are filled with the chemical irritant or the like. Such micro balloons are then crushed by the burning of the dispersal charge  31 , allowing the contents of the micro balloons to be dispersed into the atmosphere. A moisture-proof barrier  37  may be disposed about the dispersal charge  31  between the latter and the filler  36 . Such moisture-proof barrier  37  can be made of any suitable material, such as polymeric material, wax or the like. 
     The casing  21  of the projectile  20  may also be provided with a separate nose  38 , which is made of either hard or soft material depending upon the intended application of the projectile  20 . For outside applications, the nose  38  can, for example, be made of soft rubber or a suitably soft polymeric material. The nose  38  can also be provided with an optional impact switch  39  that will disable the projectile  20  if it has failed to ignite prior to impact. Further details concerning this operation will be discussed subsequently. If, on the other hand, the projectile  20  is intended to penetrate a barrier such as a window or wall, the nose  38  can be made of a material such as aluminum or titanium. It is to be understood that for such an application where the projectile  20  is intended to penetrate a barrier no impact switch  39  would be provided. 
     As indicated previously, the electronics package  25  receives power from the aiming device  12  via the cable  13 . Pursuant to one specific embodiment of the present invention, power can be transferred to the projectile  20 , and hence to the electronics package  25  thereof, in the manner illustrated in FIG.  3 . In particular, FIG. 3 illustrates a retractable pin assembly  40  that is connected to the cable  13 . The pin assembly  40  is seated on a part  17  of the launcher  11  in which the projectile  20  is disposed. The pin assembly  40  includes a conductive transmission pin  41  that passes through an insulator  42  mounted on the part  17 . The transmission pin  41  applies positive pressure to the electrical contact band  24  of the projectile casing  21  by means of an elastic insulator  43 . The entire pin assembly  40  is fixed to the part or barrel  17  of the launcher  11  via a metal housing  44 . It is to be understood that alternative electrical transmission means could also be provided in place of the illustrated retractable pin assembly  40 . For example, in order to provide electrical contact with the contact band  24  of the projectile casing  21 , an annular or concentric ring could be provided in the barrel part  17  of the launcher  11 , or an inductive transmission mechanism could be provided. 
     Operation of the electronic system for the present invention will now be described in conjunction with FIG. 4, which in particular illustrates one specific embodiment of the electronics package  25 , of the projectile  20 . 
     The electronics package of the projectile  20  is built around a miniature microcontroller  25 ′, such as Microchip PIC 16C505. Actions of the microcontroller are performed through its port connections as a result of the programming placed in the memory of the microcontroller. The main functions of the microcontroller  25 ′ are to control the time to burst, to sense acceleration (i.e. launch), unchambering, impact, and to switch electrical energy through the primer  32  to fire the projectile  20 . The microcontroller  25 ′ also performs two-way electrical energy signal communication with the aiming device  12 . Communication received from the aiming device is a digital number used to create the time interval after which the projectile  20  is to be initiated in flight. Communication back from the projectile to the aiming device digitally conveys an identifying code used to describe essential characteristics of the projectile. 
     An important and novel characteristic of the communication between the projectile  20  and the aiming device  12  is that it reveals indirectly the clock rate of the microcontroller  25 ′ in the projectile. It is envisioned that for economical production of the projectile the clock speed be controlled by a simple resistor-capacitor network, rather than by a precision timing element such as a quartz crystal, although the latter is of course possible. Further, it is desirable to not require accurate calibration of the clock due to the expense of doing so and the possibility of changes in properties of the timing components with age that could decalibrate the clock. The clock in the projectile  20  is envisioned as having a timing error as great as twenty-five percent above or below the designed nominal value as a result of initial component tolerance and aging. However, proper functioning of the projectile requires fuse timing accuracy within approximately one-tenth of one percent during flight. The desired accuracy is therefore attained by determining the actual clock rate of the microcontroller  25 ′ in the projectile  20  and correcting the count contained in the command message to produce the desired initiation time. 
     The speed of the clock in the projectile  20  is measured by determining the time duration of the response signal from the projectile. This is accomplished by a microprocessor in the aiming device  12 . The microprocessor has a timer that can be programmed to accurately measure the duration of the response signal from the projectile  20 , which is directly proportional to the speed of the clock in the projectile. Having determined the clock speed of the projectile, the microprocessor of the aiming device  12  is programmed to calculate the number of clock cycles required in the projectile to produce the correct fusing time at the measured clock speed. This number is conveyed from the aiming device  12  to the projectile  20  in the command signal. The process of measuring the clock speed of the projectile is repeated during each exchange of signals between the aiming device and the projectile, which occurs approximately twenty times per second. 
     When the projectile  20  is chambered or loaded in the launcher  11 , a DC voltage of from 24 to 200 volts is present on cable  13 . In addition to the DC voltage, serial digital signals from the aiming device  12  to the projectile  20  and return signals from the projectile are present on the cable. The data/power separator (see FIG. 4) allows DC power to pass to the regulator and the power capacitor while blocking the DC power from passing to the serial digital elements, which are the serial decoder and the line driver. The serial digital signals are a form of AC current, and are blocked from being absorbed by the regulator and the power capacitor by the data/power separator. The electrical circuit return for the power and the serial digital signals is through the conductive case of the projectile  20 . Later, after launch, no power or connection is available from the aiming device  12 , so operating current for the microcontroller  25 ′ will be supplied from the power capacitor. 
     Prior to launch or removal from the aiming device  12 , the projectile  20  and the aiming device maintain communication. The command signal from the aiming device is sent to the projectile approximately 20 times per second. The microcontroller  25 ′ in the projectile  20  creates a response each time a signal is received from the aiming device  12 . The command signal information to the projectile is the number of clock cycles to be counted down after launch to determine the time to initiate the primer  32 . The command signal is sent several times per second to continually adjust the initiation time in response to measured range and other conditions at the aiming device  12 . 
     Each time the projectile  20  has received a command signal it will send a response signal back to the aiming device. The response signal is a serial binary word that encodes a number (i.e. an identification code) that describes the characteristics of the projectile. It is envisioned that several styles of projectile could be made with differing properties, such as weight and propellant strength, that would influence the flight trajectory. The response signal informs the aiming device  12  of the particular style of projectile present, so that the appropriate tables will be used to calculate the trajectory and initiation time. The microcontroller  25  in the projectile  20  sends the signal through the line driver that amplifies the power of the signal. 
     The serial digital command signal is a sequential group of electrical symbols consisting of a start symbol followed by a predetermined number of self clocking binary symbols that, when decoded, form a binary number. The self clocking form of symbol described here is intended to provide reliable serial information transfer to the projectile  20  despite poor timing accuracy of the decoder in the projectile. The self clocking binary format has two electrical pulses for each binary symbol. The first pulse is negative with respect to the idle state, and signals the start of the symbol. The second pulse may have three different values or states, and determines the meaning of the symbol being sent. If the second pulse is negative with respect to the idle state, the symbol has no binary value itself, but does signify that the next symbol will be the first of a subsequent group. If the second pulse is positive with respect to the idle state, the binary character is a one. If the second pulse is zero with respect to the idle state, the binary character is a zero. A sixteen bit serial digital command would require a sequence of seventeen symbols. These would be the start symbol followed by sixteen symbols for the binary data characters. 
     The command signal is interpreted one symbol at a time, as each is received at the projectile  20  through the serial decoder, with the result accumulated in a data memory register in the microcontroller  25 ′. When the predetermined number of symbols have been received, as counted by the microcontroller programming, the command signal is completed and the number is considered valid. Later, commencing with launching of the projectile, the microcontrollerwill decrement the number at its clock rate. When the decremented number attains zero, the microcontroller  25 ′ will produce a signal to initiate the burst. The signal opens the shunt element of the Switch/shunt and closes the series element. This causes the power capacitor to discharge through the primer  32  to initiate burst of the propellant  33  in the frangible tube  34  of the projectile  20 . 
     When power is first applied to the system, or if power should be removed from the system without there being a launch, the shunt switch element is closed and discharges the capacitor. When the microcontroller is operating under program control, the shunt is opened, allowing the capacitor to charge. 
     When the projectile is launched, the motion is detected by closure of the acceleration switch, which is part of the launch detector  28 . This provides a signal to the microcontroller  25 ′that launch has occurred and that counting down to the initiation time is to begin. If the projectile  20  is unloaded from the launcher  11  without being launched, the microcontroller  25 ′ senses the break of the power connection combined with the lack of closure of the acceleration switch and closes the shunt of the switch/shunt to discharge the power capacitor without firing the primer  32 . 
     If the projectile  20  is in flight and encounters an unintended object, the crush or impact switch  39  will be closed by the impact and signal the microcontroller  25 ′. The microcontroller would then close the shunt of the switch/shunt to discharge the power capacitor without firing the primer  32 . 
     If the projectile  20  is removed from the launcher  11 , or if it fails to initiate in flight, the power capacitor will discharge by the gradual consumption of its stored energy by idle operation of the microcontroller  25 ′. Within approximately seven seconds, the power capacitor will be so discharged that insufficient energy remains to initiate the primer  32 . The projectile  20  would then become safe for recovery and disposal. 
     The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.