Patent Publication Number: US-8988229-B2

Title: Systems and methods for spraying an aerosol including a communication link

Description:
BRIEF DESCRIPTION OF THE DRAWING 
     Embodiments of the present invention will be described with reference to the drawing, wherein like designations denote like elements, the terms left and right are from the perspective of a user looking in the direction of spray, and: 
       FIG. 1  is a functional block diagram of a system for spraying according to various aspects of the present invention; 
       FIG. 2A  is a perspective plan view of a system for spraying in one implementation according to various aspects of the present invention showing the left side and front; 
       FIG. 2B  is a perspective plan view of a system for spraying in one implementation according to various aspects of the present invention showing the right side and rear; 
       FIG. 3A  is a plan view of the interior of the left half of the housing of the system of  FIGS. 2A and 2B ; 
       FIGS. 3B-3E  are partial cross section views of a spray subsystem of the system for spraying of  FIGS. 2A and 2B  with the trigger switch at rest, the trigger switch at a first position, the trigger switch at a second position, and the trigger switch at a third position, respectively; 
       FIG. 4  is a front plan view of a shuttle of the spray subsystem of  FIGS. 3B-3E ; 
       FIG. 5  is a left side view of a trigger switch of the spray subsystem of  FIGS. 3B-3E ; and 
       FIG. 6  is a graph of force vs. position of a trigger switch of the system for spraying of  FIG. 1  and the implementation of a system for spraying of  FIGS. 2A ,  2 B,  3 A- 3 E,  4 , and  5 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A system for spraying includes any apparatus that dispenses aerosol and comprises a user interface. A user may include a human operator. A user may include a robotic apparatus. A user interface includes any apparatus for initiating spraying. 
     A system for spraying, according to various aspects of the present invention, supports a canister that contains an aerosol and activates release of the aerosol from the canister in response to a range of positions of a trigger switch. In one implementation as a hand-held, hand-operated device or spray gun, a human user operates the trigger switch to cause activation and directs the aerosol. 
     According to various aspects of the present invention, a user of a system for spraying comprising a trigger switch experiences a change in the force vs. position of the trigger switch preceding activation of release of the aerosol. A possibility of unintended activation is reduced. Training on use of the system is simplified. In an implementation where the system includes circuitry for functions in addition to releasing aerosol, operation of the trigger switch up to the position where a change in force is experienced may facilitate, initiate, or perform one or more of those functions. Operation of the trigger switch may facilitate, initiate, or perform a series of functions wherein the series is determined at least in part by a series of positions of the trigger switch. 
     According to various aspects of the present invention, a system for spraying provides a user interface that includes a power switch, an arm switch, and a trigger switch. The system comprises circuitry for one or more of the following functions: with audio and/or light, warn of subsequent release of aerosol; cast light for illumination and/or direction identification before and/or during release of aerosol; log date, time, and/or location of release of aerosol; record sound; record still photographs; record video; provide notice via cellular telephone; and/or facilitate communication via cellular telephone. Operation of the power switch accomplishes initialization of the circuitry. Initialization may include facilitating operation of the system as a node of a wireless network. The arm switch in a first position mechanically interferes with operation of the trigger switch and in a second position permits unrestricted operation of the trigger switch. Before operation of the power switch or in the absence of sufficient power (e.g., no available power source, dead battery), activation of release of aerosol can be accomplished in response to operation of the trigger switch as permitted by the arm switch. 
     According to various aspects of the present invention, a system for spraying provides a user interface that includes a microphone, a speaker, a record switch, and a playback switch. The record switch initiates recording of sound via the microphone. The playback switch initiates playback of recorded sound via the speaker. In various implementations, the recorded sound may be used for one or more of the following: recording of the user&#39;s voice identifies the user of the system; recording of a system administrator&#39;s voice advises the user for the purpose of system status messages (e.g., warranty expiration date, periodic maintenance due date, initial battery capacity, initial aerosol capacity, description of installed aerosol, date of dispensing the system to the user, warnings, operating instructions directed to the user). Recorded sound, recorded via the microphone and/or prerecorded by the system administrator or system manufacturer, may be used during operation of the system (e.g., as a warning preceding activation of release of aerosol, as notice via a wireless network, as notice via cellular telephone communication). Pre-recordings may comprise data for synthesizing sounds. 
     According to various aspects of the present invention, a system for spraying provides a user interface that includes a power switch, a second switch, and circuitry including a processor and a transceiver for communication. The system, when operational, performs a method for linking in advance of communicating notice as discussed above. By linking in advance, notice is more timely transmitted. In one implementation, the method begins when the power switch enables power to the processor. The method performed by the processor from indicia of instructions read by the processor from a memory includes in any practical order: (a) detecting operation of the second switch; (b) establishing a communication link via the transceiver; (c) reducing power consumption of the system; and (d) transmitting via the link in response to the second switch. For example, the second switch may be operated or held in position by the user when the power switch is being operated or within a predefined period thereafter. In one implementation, the link supports Bluetooth™ protocol (a trademark of Telefonaktiebolaget LM Ericsson). Establishing the link comprises discovering and/or responding so as to be paired with another Bluetooth capable device (e.g., a cell phone, tablet, laptop, hotspot). Reducing power consumption may include entering a sleep mode of the processor, memory, or related circuitry, reducing the range and/or recurring rate of transmitting, reducing the sensitivity of receiving, and/or removing power from portions of the circuitry of the system. 
     For example, system  100  of  FIG. 1  is a system for spraying as discussed above. A functional block diagram of system  100  includes battery  102 , power switch  104 , power supply  106 , arm switch  110 , trigger switch  112 , position sensor  114 , push-to-talk switch  116 , record switch  118 , playback switch  120 , microphone  122 , video camera  124 , shuttle  130 , canister  132 , transceiver  134 , antenna  135 , processor  136 , memory  138 , displays  142 , audio deterrent  144 , visual deterrent  146 , and visual warning  148 . Mechanical apparatus and circuitry of system  100  may be constructed of conventional materials using conventional technologies including conventional computer programming technologies in light of the disclosure herein. 
     A user interface includes switches and may further include displays. A switch includes any mechanical and/or electrical apparatus of a user interface that has than one position or state. Movement from one state to another is generally responsive to action by the user. For example, system  100  may include conventional switches (e.g., slide, toggle, push-on/push-off, normally open momentary, normally closed momentary, magnetic proximity, optical, capacitive). 
     A display provides an indication to the user. The indication may describe a configuration, a capability, a condition, a status, an operating mode, a result of an operation, and/or a warning. For example, displays of system  100  may include conventional indicators (e.g., lamps, light emitting diodes, liquid crystal displays, field emission displays, displays comprising selectively excited phosphor surfaces). 
     System  100  comprises a user interface that includes power switch  104 , arm switch  110 , trigger switch  112 , position sensor  114 , push-to-talk switch  116 , record switch  118 , playback switch  120 , and displays  142 . Trigger switch  112  performs mechanical functions with respect to shuttle  130 . Trigger switch  112  and position sensor  114  cooperate to perform electrical functions. Arm switch  110  performs mechanical functions with respect to trigger switch  112  and performs electrical functions as discussed below. 
     A power switch includes any electrical switch that has an ‘off’ position and an ‘on’ position. For example, power switch  104  selectively electrically couples battery  102  to power supply  106 . Power is supplied to power supply  106  only when power switch  104  is set to the ‘on’ position. In one implementation, power switch  104  is a two-position slide switch that is not biased into either position, and includes mechanical hysteresis to maintain its current position. 
     An arm switch includes any apparatus for mechanical and electrical functions discussed herein. For example, arm switch  110  has two positions: a ‘safety’ position; and a position away from the ‘safety’ position. The second position may correspond to the safety-off position of conventional hand guns. In one implementation, arm switch  110  is a two-position rotary switch that is not biased into either position, and includes mechanical hysteresis to maintain its current position. An arm switch includes any apparatus that further mechanically interferes with operation of a trigger switch. 
     A trigger switch includes any apparatus having a first position electrically sensed and providing movement for proportional control. For example, trigger switch  112  has a ‘rest’ position, a first range of positions that includes a ‘first deterrent’ position, and a ‘second deterrent’ range of positions that facilitate proportional release of aerosol spray. Trigger switch  112  is biased to the ‘rest’ position. Arm switch  110  in its ‘safety’ position mechanically holds trigger switch  112  in the ‘rest’ position to reduce the possibility of unintended operation of trigger switch  112 . Trigger switch  112  cooperates with position sensor  114  so that a signal of position sensor  114  in accordance with obtaining the ‘first deterrent’ position effects circuitry of system  100 . 
     A push-to-talk switch, a record switch, and a playback switch include electrical switches implemented with or without latches that maintain an output signal or mode. For example, a user&#39;s manual momentary press and release of the respective switch may initiate a talk function, a record function, or a playback function until the user&#39;s manual second press and release of the respective switch. Latching may be accomplished with circuitry and/or software using conventional technologies. Push-to-talk switch  116 , record switch  118 , and playback switch  120  may be implemented as monetary electrical switches that are biased into a ‘rest’ position and require action by the user to set each into a respective ‘active’ position. Without a latch function, the user obtains the indicated function only while holding the momentary electrical switch in its ‘active’ position. 
     System  100  can operate without current from battery  102  as follows. Arm switch  110  in ‘safety’ position mechanically blocks effective movement of trigger switch  112 . A user may at any time move arm switch  110  out of the ‘safety’ position. After arm switch  110  is no longer in the ‘safety’ position, a user may at any time operate trigger switch  112  away from the ‘rest’ position to one or more other positions. When not in the ‘rest’ position, trigger switch  112  may mechanically urge shuttle  130  against force (e.g., one or more springs biased against trigger switch  112 , one or more springs biased against shuttle  130 , one or more springs biased against canister  132 , one or more springs biased against valves normally closed to retain aerosol within canister  132 ). As shuttle  130  moves in response to movement of trigger switch  112 , valves in a spray subsystem (an example of which is discussed below) open to release aerosol from canister  132  as a spray output of system  100 . If the user does not overcome spring biasing, that biasing returns valves in spray subsystem closed to stop the release of aerosol. 
     System  100  is designed for battery-powered operation so that it can be carried and used apart from other sources of electricity. If desired, battery power may be replaced with a wired source of electricity, for example, with a sufficiently long and flexible cord to permit release of aerosol from suitable locations and in suitable directions. 
     Battery  102  provides power to system  100  when power switch  104  is set to the ‘on’ position and does not supply power when power switch  104  is set to the ‘off’ position. Battery  102  may be rechargeable in situ with conventional circuitry, not shown. Any conventional battery may be used. 
     A power supply includes any circuitry for converting power in one format to power in another format, each format, for example, has a characteristic (e.g., voltage amplitude; pulse period, repetition rate and duty cycle) suitable for empowering one or more functions of system  100 . For example, power from battery  102  is converted by power supply  106  to +5 volts DC and +/−12 volts DC measured with respect to system ground (e.g., circuit common). These voltages supply power as needed to other functional blocks of system  100 . 
     A processor includes any digital circuitry that performs a program stored in memory. A memory includes any conventional electronic and/or mechanical apparatus for storing digital information (e.g., RAM, ROM, Flash EPROM, disk). Memory circuits may be packaged with processor circuits as a controller, a microcontroller, a microprocessor, or a microcomputer. A processor may include input/output (I/O) circuitry for conversion of signaling technologies (e.g., analog, binary digital signals of nonstandard formats, impedance matching, latched inputs, latched outputs). 
     A transceiver includes any circuitry for sending and receiving wireless communication. Communication includes any conventional circuitry for suitable carriers, modulations, demodulation, packetization, and protocols. 
     According to various aspects of the present invention, system  100  performs a method for linking in advance of communicating notice as discussed above. By linking in advance, notice is more timely transmitted. In one implementation, the method begins when power switch  104  enables power supply  106  to energize processor  136 , memory  138 , and transceiver  134 . The method performed by processor  136  in response to reading indicia of instructions from memory  138  includes in any practical order: (a) detecting operation of push-to-talk switch  116 ; (b) establishing a communication link via transceiver  134 ; (c) reducing power consumption of the system; and (d) transmitting via the link in response to push-to-talk switch  116 . For example, push-to-talk switch  116  may be operated or held in position by the user when power switch  104  is set to the ‘on’ position or within a predefined period thereafter. In one implementation, the link supports Bluetooth™ protocol (a trademark of Telefonaktiebolaget LM Ericsson). Establishing the link comprises discovering and/or responding so as to be paired with another Bluetooth capable device (e.g., a cell phone, tablet, laptop, hotspot). Reducing power consumption may include entering conventional sleep modes of processor  136 , memory  138 , and/or related circuitry, reducing the range and/or recurring rate of transmitting, reducing the sensitivity of receiving, and/or removing power from portions of the circuitry of system  100 . 
     System  100  determines a notice that may at various times be customized and/or personalized to each user. To that end, processor  136  performs a method in accordance with indicia of instructions stored in memory  138 . After power is being supplied by power supply  106 , the user may set record switch  118  to the ‘record’ position. Speech or other audio is accepted by microphone  122  and indicia of audio is recorded in memory  138  as data for a notice. Microphone  122 , processor  136 , and/or memory  138  may include analog to digital conversion capability. Recording stops when memory capacity is filled and/or when record switch  118  is no longer in the ‘record’ position. The user may review the recorded notice by setting playback switch  120  to the ‘playback’ position. Indicia of audio, recalled from memory  138  may be formatted and directed to drive audio deterrent  144 , a conventional speaker, and/or be transmitted by transceiver  134  for review on a suitable receiver (e.g., cellular telephone, tablet, laptop computer). One purpose of the notice may be to inform an emergency assistance service as discussed below. 
     In addition to transmitting audio notice over a link as discussed above, system  100  transmits audio over a link in response to arm switch  110 , trigger switch  112 , and/or push-to-talk switch  116 . In one implementation processor  136  performs a method in accordance with instructions stored in memory  138 , after power is being supplied by power supply  106 . Processor  136  monitors the position of arm switch  110 . When arm switch  110  is no longer in the ‘safety’ position, processor  136  records sound from microphone  122  as data stored in an audio circular buffer in memory  138  that keeps about 30 seconds of recorded sound. If trigger switch  112  is moved against spring bias out of a ‘rest’ position to a ‘first deterrent’ position, processor  136 , in any practical order, activates audio deterrent  144 , activates visual deterrent  146 , activates visual warning  148 , activates video camera  124  and records video into a video circular buffer in memory  138  that keeps about 15 minutes of video, issues instructions over the link established as discussed above to a cellular phone to place a call to an emergency assistance service (e.g., a 9-1-1 service), and performs playback of the recorded notice created as discussed above to inform the emergency assistance service. If a cellular phone call has been established, then processor  136  may facilitate transmitting over the cellular phone call audio from any one (e.g., alternatingly) of the following sources: recorded sound from the audio circular buffer in memory  138 , the recorded notice, live ambient sound responsive to microphone  122 , and live speech or sound responsive to microphone  122  further in response to push-to-talk switch  116  being held at the ‘talk’ position. Processor  136  may silence audio deterrent  144  in response to push-to-talk switch  116  being held at the ‘talk’ position. 
     Inputs to processor  136  may be coupled to processor  136  in any conventional manner, represented generally by bus  126 . Various additional circuitry (not shown) may be used (e.g., discrete circuitry for each input, de-bounce circuits, sampling circuits, multiplexers, addressed I/O logic, analog to digital conversion circuitry, comparators, amplifiers, digitizers). 
     Conventional digital communication is supported by bus  128  and any conventional protocols. Video camera  124 , transceiver  134 , processor  136 , and memory  138  may read and/or write data from and to any suitable combination of these devices. Data may include status, commands, responses, acknowledgements, packets, and information to facilitate any function of system  100  as discussed herein. 
     Outputs from processor  136  may be coupled to processor  136  in any conventional manner, represented generally by bus  140 . Various additional circuitry (not shown) may be used (e.g., discrete circuitry for each output, latching circuits, multiplexers, addressed I/O logic, digital to analog conversion circuitry, amplifiers). 
     An audio deterrent produces sound to frighten, distract, or debilitate a human or animal and is activated by the user for purposes of self-defense. Any conventional sound deterrent technology may be used including high volume, volume bursts, high pitch, low pitch, imitations of frightening sounds such as sirens, whistles, screams, or the ranting of attacking animals. For example, audio deterrent  144  produces an 80 dB siren howl. 
     A visual deterrent produces light to frighten, distract, or debilitate a human or animal, and is activated by the user for purposes of self-defense. Any conventional light deterrent technology may be used including temporarily blinding light, rapidly flashing light, imitations of frightening lights such as colors used exclusively by police and laser colors associated with weapon sights. For example, visual deterrent  146  emits high intensity white strobe light to cause temporary blindness and/or disorientation. 
     A visual warning may be emitted in any direction to inform other persons within a reasonable range of system  100  that deterrents including sound, light, and aerosol spray may be activated without further notice. For example, visual warning  148  may emit a suitable color (e.g., yellow, orange, red) of incoherent light to the left and to the right of system  100 . 
     According to various aspects of the present invention, system  100  responds differently to more than one position of trigger switch  112  in addition to the ‘rest’ position. As discussed above, trigger switch  112  may have a ‘first deterrent’ position and a ‘second deterrent’ range of positions. Functions of system  100  initiated by trigger switch  112  entering the ‘first deterrent’ position (regardless of how long trigger switch  112  remains in the ‘first deterrent’ position) may be as discussed above. Aerosol spray may be initiated and continued while trigger switch  112  remains in the ‘second deterrent’ range of positions. 
     A position sensor detects and reports indicia of position of an object in any conventional manner of detecting and reporting. Position may be determined directly, or determined from velocity or acceleration of the object and reported directly as position or as velocity or acceleration according to conventional position sensor technologies. A position sensor may include conventional magnetic (e.g., proximity of a magnet or magnetically permeable material) and/or optical technologies (e.g., intensity of a light source or reflection, beam break). 
     For example, position sensor  114  detects magnetic flux associated with a portion of trigger switch  112 . When magnetic flux intensity or a rate of change thereof crosses a predetermined limit value, then position sensor  114  informs (e.g., writes) or makes data available (e.g., awaits being read) to inform processor  136  to the effect that trigger switch  112  has entered the ‘first deterrent’ position. 
     A shuttle includes any mechanism that locates a canister for proper initiation of aerosol output from the canister in response to (e.g., directly, indirectly, in accordance with position of) a trigger switch. A shuttle may retain a canister. A shuttle may locate and/or retain more than one canister. A canister may comprise a valve operated in response to movement of the shuttle. A canister may comprise a vent opened in response to movement of the shuttle. A shuttle may seal a canister and operate to open the seal in response to movement of the shuttle. A vent, valve, or seal may be re-closeable or non-recloseable. 
     For example, shuttle  130  retains canister  132  and moves canister  132  so as to open a valve that may be integral to canister  132 . Movement is against spring bias in the valve so that when shuttle  130  returns to a ‘rest’ position, the valve recloses. Movement in a range of positions of shuttle  130  may facilitate proportionally opening the valve for proportionally more or less volume and/or velocity of output spray. 
     The functions discussed herein for a canister may be integrated into an aerosol-containing shuttle for an implementation that omits a separable canister. 
     System  100  in one implementation is a weapon designed to be hand-held, battery operated, and used for self-defense. Weapon  200  is not a firearm and is unlikely to be a sole cause of death or serious injury of humans. For example, as shown in  FIGS. 2-6 , weapon  200  includes features corresponding generally to the functional blocks discussed above. Functional blocks are indicated parenthetically for reference. Weapon  200  includes enclosure  202 , handle  204  (e.g. an integral portion of enclosure  202 ), base  206 , and front face  208  (e.g. an integral portion of enclosure  202 ). Weapon  200  encloses spray subsystem  300  (see  FIG. 3A ). On front face  208  are located lens  207  for a visual deterrent ( 146 ) and a video camera ( 124 ), a radiator  209  for an audio deterrent ( 144 ), visual warning ( 148 )  205 , laser sight ( 148 )  210 , and spray outlet  211 . A user interface of weapon  200  includes trigger switch ( 112 )  212 , arm switch ( 110 )  213 , power switch ( 104 )  218 , record switch ( 118 )  222 , playback switch ( 120 )  220 , push-to-talk ( 116 ) switches  214  and  216 , and displays ( 142 )  224 . For ambidextrous operation, arm switch  213  and push-to-talk switches  214  and  216  have mechanical and/or electrical equivalents positioned equivalently on both sides of weapon  200 . A circuit board (omitted for clarity of description of spray subsystem  300 ) includes circuitry for all functions discussed with reference to  FIG. 1 , namely, a power supply ( 106 ), microcontroller ( 136 ,  138 ), transceiver ( 134 ), antenna ( 135 ), circuitry for audio and visual deterrents ( 144 ,  146 ), microphone ( 122 ), and video camera ( 124 ). 
     A user may perform a method of operating the system including: removing base  206 ; installing a canister  318  of aerosol spray (e.g., pepper spray); installing a battery ( 102 )  319 ; and replacing base  206 . If battery  319  is absent or not sufficiently charged, aerosol spray may be dispensed mechanically by moving arm switch  213  away from a ‘safety’ position; directing spray outlet  211  of front face  208  toward a human or animal to be sprayed; and controlling the dispensing of aerosol spray by pulling and releasing trigger switch  212 . 
     If the battery has sufficient charge to operate circuitry of system  100  including a processor and display, system  100  may respond to the user&#39;s act of sliding power switch  218  to the ‘on’ position by illuminating display  224  as notice that no communication link has been established. The processor performs a method similar in some ways to the method discussed above including detecting whether push-to-talk switch  214  or  216  is operated by the user within a limit period of time relative to operation of power switch  218 . If not, then the processor operates display  224  to provide notice to the user (e.g. red light is emitted). 
     If the battery has sufficient charge to operate circuitry of system  100  including a processor and a transceiver, the system may respond to the user&#39;s act of sliding power switch  218  to the ‘on’ position and operating push-to-talk switch  214  or  216  within a limit period of time by: (a) establishing a communication link via a transceiver of the system circuitry; and (b) reducing power consumption of the system. The processor may control the transceiver with a signal or command to reduce power consumed by the transceiver; and the processor may change to a low power mode (e.g., sleep mode) where transition out of the sleep mode may be responsive to setting arm switch  106  to an arm position. During low power mode, the communication link (e.g., pairing) is maintained ready for immediate use (e.g., without repeating steps of initializing, discovering, identifying, configuring, verifying configuration). 
     A spray subsystem, according to various aspects of the present invention, facilitates activation of a series of deterrents. For example, a series comprising one or more first deterrents followed in time by second deterrents as discussed herein. 
     A spray subsystem, according to various aspects of the present invention facilitates a series of functions of a system for spraying. For example, a system for spraying performs a series of functions including initializing a communication capability, operating a communication capability, operating an incident recording capability, and releasing aerosol spray. A spray subsystem, according to various aspects of the present invention comprises a shuttle and a trigger switch wherein the shuttle and the trigger switch cooperate with discontinuous mechanical coupling. According to various aspects of the present invention, the trigger switch may provide a discontinuity in bias against operation of the trigger switch by the user. These aspects are realized in a spray subsystem  300  of  FIGS. 3A-3E ,  4 , and  5 . 
     Spray subsystem  300  is located within enclosure  202  of weapon  200  shown in  FIGS. 2A and 2B . Spray subsystem  300  includes exit valve  302 , tube  304 , entry valve  314 , trigger switch  212 , shuttle  320 , and canister  318  having canister outlet valve  316 . In the side view of  FIG. 3A , spray subsystem  300  is located against the inside surface of left side  203  of enclosure  202 . Stop  317  maintains alignment of entry valve  314  and canister outlet valve  316 . 
     In the partial cross section views of  FIGS. 3B-3E , shuttle  320  is shown in a section identified by plane  414  in  FIG. 4 . Canister  318  is shown supported by shuttle  320  and in a section with reference to the same plane  414 . 
     A valve, as discussed herein, includes any conventional check valve for a fluid (e.g., gas, liquid, suspension, aerosol). For example, canister outlet valve  316 , entry valve  314 , and exit valve  302  may comprise duck-bill check valves that open in response to a prescribed minimum pressure and otherwise close in response to bias of the valve design. Bias may be provided by a spring or any other conventional materials or components. 
     A tube includes any structure having a passage that transports a fluid. Tube  302  may be rigid, formed of stainless steel. 
     With reference to  FIGS. 3B-E , when the user applies pressure to trigger switch  212 , trigger switch  212  pivots into abutting contact with shuttle  320 . After contact occurs, continued pressure by the user on trigger switch  212  causes trigger switch  212  to urge shuttle  320  upward. As shuttle  320  moves upward, shuttle  320  lifts canister  318 . As canister  318  is lifted, canister  318  compresses canister outlet valve  316  against entry valve  314  and thereby opens canister outlet valve  316 . Pressure of the aerosol opens entry valve  314  and exit valve  302 . When canister outlet valve  316  is open, aerosol spray travels through canister outlet valve  316 , entry valve  314 , tube  304 , exit valve  302 , and spray outlet  211  of front face  208 . 
     Operation of spray subsystem  300  will now be further described with reference to  FIGS. 3B-3E  and  FIG. 6 . In  FIG. 3B , trigger switch  212  is at the ‘rest’ position indicated as X 0  in graph  600 . In  FIG. 3C , trigger switch  212  is at a ‘first deterrent’ position indicated as X 1  in graph  600 . In  FIG. 3D , trigger switch  212  is at a beginning of a range of positions indicated as X 2 -X 3  in graph  600 . In  FIG. 3E , trigger switch  212  is at an end position X 4  of a ‘second deterrent’ range of positions indicated as X 3 -X 4  in graph  600 . 
     Spray system  300  further includes trigger bias spring  312 . Trigger bias spring  312  provides a trigger bias spring bias force that maintains trigger switch  212  in ‘rest’ position X 0  by opposing force (if any) exerted by the user of weapon  200  to move trigger switch  212  away from ‘rest’ position X 0 . As trigger switch  212  pivots at the center of reference circle  308 , trigger bias spring  312  extends, increasing this trigger bias spring bias force. 
     Spray system  300  further includes shuttle bias spring  322 . Shuttle bias spring  322  provides a bias force that maintains shuttle  320  at a ‘rest’ position to assure opening of canister outlet valve  316  is intended by the user of weapon  200 . When shuttle bias spring  322  is compressed against stop  323 , shuttle  322  is urged by shuttle bias spring  322  to return to its ‘rest’ position as shown in  FIGS. 3A-3D . 
     Canister outlet valve  316  has a return spring (not shown). This return spring cooperates with shuttle bias spring  322  to provide a combined bias against force exerted by the user of weapon  200  against trigger switch  212 . According to various aspects of the present invention, the combined bias increases at a rate different (e.g., greater) than the trigger bias spring bias force discussed above. Consequently, a first increasing force exerted by the user to move trigger switch  212  in a first range of positions X 0 -X 2  is noticeably at a different rate of increase than a second increasing force exerted by the user to move trigger switch  212  in a second range of positions X 2 -X 4 . In other words, in an exemplary implementation, the respective spring constants of trigger bias spring  312 , return spring of canister outlet valve  316 , and shuttle bias spring  322  are designed to generally provide the force vs. position relationship of graph  600  where forces F 0 -F 4  represent a series of ever increasing forces matched by the user of system  100  to attain and/or leave trigger switch positions X 0 -X 4 . 
     The graph of  FIG. 6  presents a simplified linearized approximation of the reaction force F that a user of weapon  200  would experience when applying pressure against trigger switch  212  at various angular positions X 0 -X 4  measured about the center of circle  308 . A model of the actual force as a function of position X would account for nonlinear stretching of trigger bias spring  312  and nonlinear compression of shuttle bias spring  322  for values of X from X 0 -X 4 . 
     A position sensor may include a fixed portion and a moving portion. A fixed portion of position sensor  310  is mounted on a circuit board (not shown) and located on reference circle  308 . A moving portion comprises magnet  332  of trigger switch  212 . As trigger switch  212  moves into ‘first deterrent’ position X 1 , magnet  332  operates the fixed portion to indicate to circuitry that the ‘first deterrent’ position has been accomplished. The fixed portion of position sensor  310  comprises a conventional magnetic proximity switch. Circuitry including proximity switch  310  is coupled to a processor to notify the processor when trigger switch  212  is in the ‘first deterrent’ position. 
     Trigger switch  212  is coupled to shuttle  320  when surface  334  of trigger switch  212  abuts surface  313  of shuttle  320 . Opening  410  of shuttle  320  comprising surface  313  accepts a portion of trigger switch  212  comprising surface  334 . These surfaces are not mechanically coupled for cooperation when trigger switch  212  is in a first range of positions X 0 -X 2 . These surfaces are mechanically coupled for cooperation when trigger switch  212  is in a second range of positions X 2 -X 4 . Because there is no tactile feedback to the user at position X 1  of trigger switch  212 , the user learns that trigger switch  212  has achieved the ‘first deterrent’ position X 1  and is now beyond position X 1  when tactile feedback is available at position X 2 . The range of positions X 1 -X 2  accommodates manufacturing tolerances. The range of positions X 1 -X 2  when greater than about 10% of the range X 0 -X 2  makes system  100  easier to use, for instance because proper operation is less dependent on the user moving trigger switch  212  to a narrowly defined position such as X 1  itself. The range of positions X 1 -X 2  can be made greater than about 10% of the range X 0 -X 2  by conventional design techniques for the size and shape of trigger switch  212  relative to the position and size of opening  410  of shuttle  320 . 
     A shuttle may include a base for lifting a canister, and an operative surface for coupling to a trigger switch. The base and operative surface may be in fixed relationship. For example, the base and operative surface may be features of a rigid structure that forms the shuttle. In one implementation, shuttle  320  is rigid, formed of conventional plastic. 
     The operative surface of the shuttle comprises any portion of the shuttle that cooperates (e.g., abuts, impinges) with a portion of a trigger switch. The operative surface may be an inside surface of a feature (e.g., aperture, hook, L-shape, box, cup, loop). The trigger switch may, after coming into contact with the operative surface of the shuttle, form a coupling (e.g., hinge, joint, ball and socket). Mechanical coupling of the operative surface and the trigger switch may include abutting, sliding, and/or impinging. The operative surface may be located on the shuttle at a distance away from the canister. The operative surface may be located beside the canister. The operative surface may be located on the shuttle at a distance above or below the canister. 
     The base of a shuttle includes an surface capable of urging open the canister outlet valve. The base may abut a lower extremity of a canister (e.g., lift the canister by a surface of the canister abutting the shuttle when the shuttle is in a ‘rest’ position). A base may abut, grasp, and/or impinge a portion of a canister above the lower extremity (e.g., urge the canister to open the canister outlet valve by contact with a feature near the top, at a neck, and/or of a wall of the canister). 
     A spring, as used herein, includes any device that provides a mechanical force in response to a position or change of position. Spring includes any conventional spring (e.g., coil, leaf, torsion spring, flat wound, strip, cord) operative by extension, compression, bending, or twisting. A spring includes devices of conventional materials (e.g., solids, liquids, gels, gases) having resilient and/or elastic characteristics. 
     A shuttle bias spring includes any device coupled to a shuttle and/or any integral portion of a shuttle that provides a force to close a canister exit valve and/or return the shuttle to a ‘rest’ position. 
     For example, shuttle  320  includes base  406 , post  408 , top  412 , and arm  402 . Base  406  and top  412  define the vertical extent of interior space  404  sized for retaining a conventional canister containing under pressure an aerosol (e.g., oleoresin capsicum, pepper spray). Arm  402  comprises opening  410 . A top portion of opening  410  is defined by surface  313  of arm  402 . In operation, canister  318  abuts base  406  at all times. When shuttle  320  is lifted by trigger switch  212 , shuttle  320  lifts canister  318  by force applied from base  406  to a lower extremity of canister  318 . Pressure of surface  234  of trigger switch  212  is communicated through arm  402  to lift base  406  and canister  318 . Post  408  confines shuttle bias spring  322  during compression of shuttle bias spring  322  against stop  323  as shuttle  320  moves away from its ‘rest’ position. Top  412  may abut a top surface of canister  318  to assure that canister outlet valve  316  is pulled away from entry valve  314  as shuttle  320  returns to its ‘rest’ position. 
     A trigger switch for operation in a spray subsystem according to various aspects of the present invention includes structure for position sensing, structure for cooperation with a trigger bias spring, and structure for cooperation with a shuttle. For example, trigger switch  212  of  FIG. 5  includes switch body  231  and magnet  232 . Switch body  231  includes features identified as mount  233 , surface  234 , aperture  235 , and finger grip  236 . 
     In one implementation, trigger switch  212  is an assembly. Switch body  231  is formed of rigid conventional plastic. Magnet  232  is pressed into position in a suitable aperture of switch body  231 . Trigger bias spring  312  may be coupled to switch body  231  in any conventional manner (e.g., threaded into mount  233 , threaded into a suitable aperture of body  231 , mounted coaxially to oppose rotation of trigger body  231  about aperture  235 ). 
     Aperture  235  supports switch body  231  on a suitable post feature of body  203 . Aperture  235  facilitates rotation of switch body  231  about a center of aperture  235  coaxial to circle  308  discussed above. 
     Finger grip  236  provides a comfortable surface for the user to operate trigger switch  212  with an index finger in a conventional manner. 
     In the implementations discussed above with reference to  FIGS. 2A ,  2 B,  3 A- 3 E,  4 , and  5  body  202  includes handle  204  at an angle from a horizontal top portion of weapon  200 . Trigger switch  212  provides rotational motion about circle  308  to open canister outlet valve  316 . Space for a canister is provided in a handle of the weapon. Other implementations are within the scope of the present invention. 
     For example, a weapon having analogous functions supports a canister substantially parallel to the direction of spray. A trigger switch in such an implementation may operate by movement along a substantially straight line instead of about an axis of rotation as discussed above. Movement of the trigger switch may be confined to a track having any suitable linear or nonlinear form. A handle may be provided at an angle to the direction of spray, substantially parallel to the direction of spray, or omitted (e.g., for use against a human user&#39;s shoulder or for use by a robotic user). 
     For example, a canister may include a canister release valve that is opened using rotational force (in contrast with linear force for canister  318  discussed above). A trigger switch and shuttle may be arranged in linear format (e.g., similar to rack (trigger) and pinion (shuttle) coupling), arranged in coaxial coupling (both trigger and shuttle rotate on the same axis), or arranged in counter rotational coupling (analogous to the way two disc-shaped gears mesh on their circumferences). 
     In all of these alternatives, movement of the trigger switch causes movement of the shuttle only after an initial range of motion of the trigger switch (e.g., after a position analogous to position X 2  of  FIG. 6 ). 
     Examples of systems for spraying and methods performed by systems for spraying, according to various aspects of the present invention, include the following. 
     As a first example, a system for spraying includes a trigger switch, a first spring, a second spring, and a canister of aerosol. The first spring is coupled to the trigger switch to oppose operation of the trigger switch. The second spring is not coupled to the trigger switch during a first range of positions of the trigger switch and is coupled to the trigger switch during a second range of positions of the trigger switch. During the second range of positions of the trigger switch, the first spring and the second spring oppose operation of the trigger switch without release of the aerosol. During a third range of positions of the trigger switch, the first spring and the second spring oppose operation of the trigger switch in a range of positions with release of the aerosol. 
     As a second example, a variation of the first example, the system further includes a shuttle operative when coupled to the trigger switch to open the canister to release the aerosol; and during the first range of positions of the trigger switch, the shuttle is not coupled to move in response to the trigger switch. 
     In a variation of the second example, the second spring is coupled to the shuttle to oppose movement of the shuttle. 
     In another variation of the second example, the system is useful for self-defense against an attacker. The system further includes circuitry and a position sensor. The circuitry provides a deterrent to aggression by the attacker. The position sensor enables the circuitry to provide the deterrent after the trigger switch is operated beyond a first portion of the first range and before the trigger switch is operated in the second range. 
     In another variation of the first example, the system is useful for self-defense against an attacker. The system further includes circuitry and a position sensor. The circuitry provides a deterrent to aggression by the attacker. The position sensor enables the circuitry to provide the deterrent after the trigger switch is operated beyond a first portion of the first range and before the trigger switch is operated in the second range. 
     As a third example, a system for spraying includes a canister, a tube, a trigger switch, a first spring, and a second spring. The canister comprises an outlet valve biased closed. The tube comprises an entry valve and an exit valve. The first spring is biased to return the trigger switch to a rest position. The second spring is biased to return the canister to a rest position. Movement of the trigger by a user of the system when opposed by only the first spring does not open the outlet valve. Movement of the trigger by a user of the system when opposed by only the first spring and the second spring does not open the outlet valve. Movement of the trigger by a user of the system when opposed by the first spring, the second spring, and the bias of the outlet valve opens the outlet valve to form a spray comprising contents of the canister. 
     As a fourth example, a system for spraying includes a canister of aerosol, a circuit, and a trigger switch. The trigger switch provides a force as a function of position, the force opposing operation of the trigger switch by a user. The force increases at a first average rate in a first range from a rest position of the trigger switch to a tactile feedback position of the trigger switch. The force increases at a second average rate greater than the first average rate in a second range from the tactile feedback position to a maximum position of the trigger switch. The circuit is enabled to output an audio deterrent at a position within the first range spaced respectively from each extreme of the first range. The canister is opened to release aerosol in a portion of the second range that is less than the entire second range. 
     As a fifth example, a spray subsystem comprises a shuttle and a trigger switch. The shuttle and the trigger switch cooperate with discontinuous mechanical coupling. The trigger switch provides a discontinuity in bias against operation of the trigger switch by the user. 
     As a sixth example, a spray subsystem includes a shuttle and a trigger switch. The trigger switch moves in a first range of positions before abutting the shuttle. The trigger switch moves in a second range of positions while abutting the shuttle to move the shuttle. Movement of the trigger switch is opposed by a first spring. Movement of the shuttle is opposed by a second spring. 
     In a variation of the sixth example, a portion of the trigger switch passes through an opening of the shuttle before the trigger switch abuts the shuttle. 
     As a seventh example, a trigger switch for operation in a spray subsystem, includes a portion of a position sensor (e.g., a sensor, a characteristic capable of being sensed), a mount, and a surface. The position sensor senses the position of the trigger switch as operated by a user of the spray subsystem. The mount accepts a spring to oppose movement of the trigger by the user of the trigger switch. The surface mechanically cooperates with a provided canister to release a spray from the canister. 
     In a variation of the seventh example, the portion of the position sensor includes a magnet. 
     As an eighth example, a system for spraying for self-defense against an attacker includes a power switch, an arm switch, a trigger switch, circuitry, and a canister. The circuitry provides a notice via a wireless link and for recording audio and video of the attacker. The canister contains aerosol. The circuitry, in response to operation of the power switch, enables operation of the system as a node of a wireless network. The circuitry, in response to operation of the arm switch, records audio and video of the attacker. The notice is provided via the wireless link in response to operation of the trigger switch. The aerosol is released toward the attacker in response to operation of the trigger switch. 
     As a ninth example, a method is performed by a processor that reads indicia of instructions for the method from a memory. The processor and memory are part of a system operated by a user. The system further comprises a power switch, a second switch, and a transceiver. The method is performed when the power switch couples power to the processor and the memory. The method includes in any practical order, the steps of (a) detecting a first operation by the user of a second switch; (b) in response to detecting, establishing a communication link via the transceiver and reducing power consumption of the system; and (c) transmitting via the link in response to a second operation by the user of the second switch. 
     In a variation of the ninth example, the first operation of the second switch is detected if the second switch is held in position by the user within a predefined period after power is coupled to the processor. 
     In another variation of the ninth example, establishing the link comprises responding so as to be paired with a node of a network. 
     In another variation of the ninth example, reducing power consumption comprises entering a sleep mode of at least one of the processor and the memory. 
     In another variation of the ninth example, reducing power consumption comprises reducing a recurring rate of transmitting by the transceiver. 
     In another variation of the ninth example, reducing power consumption comprises reducing the sensitivity of receiving by the transceiver. 
     As a tenth example, a method is performed by a system for spraying. The system is operated by a user. The method includes in any practical order, the steps of (a) initializing a communication capability of the system in response to operation by the user of a first switch of the system; (b) operating a communication capability in response to operation by the user of a second switch; (c) operating an incident recording capability in response to operation by the user of a third switch; and (d) releasing aerosol spray in response to operation by the user of a fourth switch. 
     The foregoing description discusses preferred embodiments of the present invention, which may be changed or modified without departing from the scope of the present invention as defined in the claims. As used herein, the term ‘coupled’ is used for explaining cooperation (e.g., electrical communication, mechanical communication) that may be direct or indirect (e.g., through intervening mechanical, through intervening electrical components). As used herein, the term ‘generally’ is used for explaining a component or process in an implementation where in other implementations of the present invention each of the narrower terms ‘substantially’, ‘primarily’, and ‘exclusively’ is specifically intended to be disclosed and to apply. These relationships correspond to relative effectiveness of the component or process such as generally about 50% effective, substantially about 80% effective, primarily about 95% effective, and exclusively meaning 100% effective. The term ‘about’ means a factor of +/−15%. The examples listed in parentheses may be alternative or combined in any manner. The invention includes any practical combination of the structures and methods disclosed. As used in the specification and claims, the words ‘having’ and ‘including’ in all grammatical variants are open-ended and synonymous with ‘comprising’ and its grammatical variants. While for the sake of clarity of description several specifics embodiments of the invention have been described, the scope of the invention is intended to be measured by the claims as set forth below.