1. Field of Invention
This invention relates to intentional burning for land and forestry management and, in particular, to an apparatus, method and system for dispensing incendiary projectiles.
2. Description of Related Art
Prescribed burning is the intentional burning of typically forested areas to meet specific land management objectives, such as to reduce flammable fuels, restore ecosystem health, recycle nutrients, or prepare an area for new trees or vegetation.
Devices for igniting prescribed fires include conventional hand-held and aerial ignition devices. Conventional aerial ignition devices are typically mounted on a helicopter; receive plastic spheres containing an incendiary material, such as potassium permanganate; inject the received spheres with a reactant, such as ethylene glycol; and then expel the injected spheres to fall from the helicopter. A delayed exothermic reaction between the incendiary material and the reactant within the spheres can produce a prescribed fire where the spheres land. The delay of the exothermic reaction is typically 25 to 30 seconds.
Conventional hand-held ignition devices typically operate by dripping or throwing flaming fuel onto flammable materials such as ground vegetation. However, such conventional hand-held devices require an operator to be present on the ground at the prescribed fire, and are not suitable for aerial use due to their restricted size and output and safety concerns.
Some conventional aerial ignition devices dispense incendiary capsules obtained from capsule belts stored in magazines. However, such conventional aerial ignition devices require the use of capsule belts of specific and restricted dimensions, and are not suitable for dispensing spheres or other free flowing projectiles. Also, the belts and magazines become unusable waste after the capsules have been removed therefrom.
Some conventional aerial ignition devices permit adjustment of the desired rate of operation of the device. However, such conventional aerial ignition devices do not regulate the rate of operation. Thus, such conventional aerial ignition devices cannot correlate the rate of operation with a desired rate of operation.
Some conventional aerial ignition devices inject varying amounts of reactant into the spheres depending on the selected desired rate of operation of the device, thereby reducing the incendiary effectiveness of the injected spheres.
Some conventional aerial ignition devices include an electrically powered fire extinguisher for extinguishing fires located within the device. However, the fire extinguishers of such conventional devices do not operate when power to the device fails or becomes otherwise disconnected.
Aerial ignition devices typically require spheres to be expelled from the device after the user has stopped the flow of received spheres, thereby requiring the user to judge when to stop the flow of received spheres in order to consequently stop spheres from being expelled at a desired time. Thus, it would be desirable in the art to minimize the number of spheres expelled from the device after the flow of received spheres has been stopped. Conventional aerial ignition devices do not minimize the number of spheres expelled from the device after the flow of received spheres has been stopped.
Aerial ignition devices typically jam and/or break spheres in the device under conditions of misalignment. Thus, it would be desirable in the art to minimize the effect of jamming and breaking of spheres within the device. Conventional aerial ignition devices do not effectively address the problem of jamming and breaking of spheres within the device.
Some conventional aerial ignition devices cannot count the number of spheres being expelled.
However, such conventional aerial ignition devices may exhibit abnormal behavior when the solenoid or similar device de-energizes as a result of a failure or other disconnection of power to the device.
Some conventional aerial ignition devices do not have a removable base, thereby hindering installation of the device on the helicopter.
Prior art projectiles lack multi-coloured exteriors, thereby hindering their visibility, and are large and bulky.
The above shortcomings may be addressed by providing, in accordance with one aspect of the invention, an apparatus for dispensing projectiles. The apparatus includes: an injector for injecting the projectiles with a reactant at a dispensing rate; and a controller operable to control the dispensing rate.
The apparatus may include a hopper for storing projectiles prior to being received by the injector; a hopper motor for agitating projectiles within the hopper; one or more dispenser gates operable to control the entry of projectiles to the injector; one or more solenoids for displacing the one or more dispenser gates; a shuttle operable to receive one or more projectiles from the hopper; a shuttle motor operable to rotate an output shaft of the shuttle motor; a shuttle cam for translating rotational motion to reciprocating motion; an injector needle for puncturing a projectile; an injector pump for supplying reactant to the injector needle; a dispenser chute operable to receive projectiles from the injector; a fire extinguisher system; a fire extinguisher system battery; one or more momentary switches; one or more user output indicators; and any combination thereof.
The apparatus may be dimensioned to minimize the number of projectiles between the one or more dispenser gates and the shuttle. The injector pump may be a constant displacement pump.
The controller may be operable to control the operation of the hopper motor. The controller may be operable to control the flow of projectiles from the hopper through the hopper exit to the injector. The controller may be operable to control the opening and closing of the one or more dispenser gates. The controller may be operable to control the extension and retraction of a gate pin of the one or more dispenser gates. The controller may be operable to control the one or more solenoids. The controller may be operable to prevent manual opening of the one or more dispenser gates. The controller may be operable to permit manual closing of the one or more dispenser gates. The controller may be operable to prevent the hopper motor from starting to operate until after the one or more dispenser gates have been closed. The controller may be operable to prevent the opening of the one or more dispenser gates until after the elapse of a time delay following the start of operation of the hopper motor. The controller may be operable to control the one or more solenoids to close the one or more gates after the elapse of a time delay following an unsuccessful attempt to close the one or more gates.
The controller may be operable to control the dispensing rate by controlling an output speed of a shuttle motor of the injector. The controller may be operable to start and stop operation of the shuttle motor. The controller may be operable to receive as an input an indication of a desired output speed of the shuttle motor. The controller may be operable to receive as an input an indication of the output speed of the shuttle motor. The controller may be operable to control the output speed of the shuttle motor by closed loop feedback. The controller may be operable to prevent the shuttle motor from operating when the one or more dispensing gates are closed. The controller may be operable to prevent the shuttle motor from operating at the desired output speed until after the elapse of a time delay following the start of operation of the shuttle motor. The controller may be operable to prevent the shuttle motor from operating until after the elapse of a time delay following the opening of the one or more dispenser gates. The controller may be operable to control an output direction of the shuttle motor. The controller may be operable to detect an abnormal output speed of the shuttle motor. The controller may be operable to permit manual control of motion of the shuttle. The controller may be operable to prevent the stopping of the shuttle motor until after the elapse of a time delay following the closing of the one or more dispenser gates. The controller may be operable to prevent the stopping of the shuttle motor until after the occurrence of a specifiable number of revolutions of the shuttle motor following the closing of the one or more dispenser gates.
The controller may be operable to count the number of projectiles injected, the number of projectiles dispensed, and any combination thereof. The controller may be operable to count the number of projectiles injected, the number of projectiles dispensed, and any combination thereof, during the lifetime of the apparatus. The controller may be operable to receive as an input an indication of the number of output revolutions of the shuttle motor.
The controller may be operable to receive as input an indication of the amount of extinguishing agent in the extinguisher receptacle of the fire extinguisher system. The controller may be operable to prevent the dispensing operation from starting when the amount of extinguishing agent is insufficient.
The fire extinguisher system may be operable when power to other components of the apparatus is disconnected.
In accordance with another aspect of the invention, there is provided a method of dispensing projectiles. The method involves: injecting the projectiles with a reactant at a dispensing rate; and controlling the dispensing rate.
Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of embodiments of the invention in conjunction with the accompanying figures.
In drawings which illustrate by way of example only embodiments of the invention:
An apparatus for dispensing projectiles includes: injecting means for injecting the projectiles with a reactant at a dispensing rate; and controlling means for controlling the dispensing rate.
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The apparatus 10 shown in
The apparatus 10 may receive its main power source (not shown) from the aircraft to which the apparatus 10 is installed. Referring to
While the projectiles 14 shown in
The apparatus 10 includes a hopper 18 dimensioned to be able to contain a suitable number of the projectiles 14. For example, the hopper 18 may be dimensioned to advantageously contain as many as 950 suitably sized projectiles 14. Other dimensions for the hopper 18 are contemplated within the scope of the present invention.
A hopper lid 20 is hingedly connected to the hopper 18 near the top of the hopper 18.
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Agitation of the projectiles 14 advantageously facilitates the flow of projectiles 14 in, through and/or from the hopper 18. The hopper motor 24 may be a single speed motor that agitates projectiles 14 in the hopper 18 when activated, and stops agitating projectiles 14 in the hopper 18 when de-activated.
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In addition to manual closing of the dispenser gate 42, a gate closing solenoid 68 is preferably operable to automatically urge the gate pins 46 toward their blocking positions when the gate closing solenoid 68 is energized. In the first embodiment, the gate closing solenoid 68 is operable to extend its closing solenoid output plunger 70 toward an end plate 72 attached to the feed control rod 60 at the end of the feed control rod 60 opposite the gate knob 62.
A gate locking pin 66 is preferably resiliently urged toward the feed control rod 60 and positioned to lockably fit into a corresponding notch or aperture of the feed control rod 60 when the gate pins 46 are in their blocking positions so as to lock the gate pins 46 in their blocking positions, respectively. The locking mechanism for the gate pins 46 advantageously permits the gate closing solenoid 68 to de-energize without the gate pins 46 moving from their fully blocking positions under the urging of the feed control rod spring 64.
The gate opening solenoid 74 is operable to pull the gate locking pin 66 away from the feed control rod 60, thereby unlocking the gate pins 46. The gate pins 46 return to their non-blocking positions when unlocked by the force of the feed control rod spring 64. In the first embodiment, the gate locking pin 66 is implemented as the output plunger of the gate opening solenoid 74 such that the gate locking pin 66 is resiliently urged toward the feed control rod 60 by an internal resilience of the gate opening solenoid 74. For example, the gate opening solenoid 74 may include an internal spring (not shown) for resiliently urging its output plunger toward the fully extended position.
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The structural portions of the apparatus 10 may be made of any suitable material, including aluminum, sheet metal, stainless steel metal, plastic and rubber, for example.
The shuttle motor 82 is preferably reversible such that the shuttle motor 82 is operable to reverse the direction of reciprocal motion of the shuttle 78. The shuttle motor 82 may be a direct current (DC) motor, for example. The shuttle motor 82 preferably rotates its shuttle motor output shaft 86 when activated at a rotational speed corresponding to its input power level and stops rotating when de-activated.
The shuttle motor 82 may be operable to produce one or more signals associated with the completion of a constant number or fraction of revolutions of the shuttle motor output shaft 86, the instantaneous or average rotational speed of the shuttle motor output shaft 86, the power consumption of the shuttle motor 82, the power output of the shuttle motor 82, and any combination thereof. A hand wheel 90 may be connected to the shuttle motor output shaft 86 opposite the shuttle motor 82 such that the shuttle 78 may be manually reciprocated. In some embodiments, the hand wheel 90 is indirectly connected to the shuttle motor output shaft 86 via a coupling unit and a main driveshaft, as shown in
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The reciprocating movement of the shuttle 78 permits the shuttle 78 to receive a projectile 14 at one shuttle receptacle 80 in substantial alignment with the corresponding hopper exit 28, move the received projectile 14 toward the injector needle 96 where the projectile 14 is injected with a reactant, move the received projectile away from the injector needle 96 to a position where the shuttle receptacle is in substantial alignment with its associated injector exit 98 (see
The mechanical arrangement of components described herein and shown in the Figures advantageously permits the placement of the gate pins 46 in close proximity to the shuttle receptacles 80, thereby advantageously minimizing the number of projectiles 14 between the dispenser gate 42 and the shuttle 78. Also, the apparatus 10 is advantageously dimensioned to minimize the gate-to-shuttle distance between each gate pin 46 and its corresponding shuttle receptacle 80. In the first embodiment, the gate-to-shuttle distance is preferably such that a maximum of one projectiles 14 fits between the gate pins 46 and the shuttle 78. For example, the distance between each gate pin 46 and the entry of its corresponding shuttle receptacle 80 may be ⅛ (one-eighth) of an inch less than the diameter of the projectiles 14 typically used with the apparatus 10, including being 0.875 inches.
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The injector needle 96 projects through a pump arm 104 at a needle aperture 106 of the pump arm 104. The pump arm 104 is attached to a pump piston 108. The pump arm 104 and the pump piston 108 are slidably coupled via a pump cylinder 110 to a pump manifold block 112, which is fixed to the injector 76. When the shuttle 78 is near the extreme end of its reciprocating motion, any projectile 14 in the shuttle receptacle 80 proximate the reactant pump 94 is operable to slide the pump arm 104 and the pump piston 108 toward the pump manifold block 112. The extent of movement of the pump piston 108 is determined by the stroke length of the reciprocating path of the shuttle 78 and is independent of the reciprocating speed of the shuttle 78. In this manner, the pump piston 108 slides a substantially constant distance within the pump cylinder 110 for each injection.
The pump piston 108 is in fluid communication with a reactant outlet valve 114 via a reactant channel (not visible in
The volume of reactant that flows outwardly from the reactant pump 94 is determined by the extent of movement of the pump piston 108 toward the pump manifold block 112 and the dimensions of the pump piston 108 and the pump cylinder 110, and is independent of the speed of movement of the pump piston 108. The extent of movement of the pump piston 108 is determined by the dimensions of the injector 76, including the stroke length of the shuttle 78 and the size of the projectiles 14, and is independent of the reciprocating speed of the shuttle 78. When the shuttle 78 is proximate the pump manifold block 112, the injector needle 96 is typically piercing a projectile 14 located within the proximate shuttle receptacle 80 and the reactant flowing outwardly through the injector needle 96 is injected into the projectile 14.
The pump piston 108 is in fluid communication with a reactant channel within the pump manifold block 112 such that movement of the pump piston 108 away from the pump manifold block 112 causes reactant to enter the pump manifold block 112 from the reactant inlet 100 via the reactant inlet valve 102. In this manner, reactant is stored within the pump manifold body 112 between the reactant inlet valve 102 and the reactant outlet valve 114 when the pump piston 108 is displaced from the pump manifold block 112. The stored reactant is suitable for flowing outwardly from the reactant pump 94 via the injector needle 96 when the shuttle 78 returns at the next reciprocal cycle of the shuttle 78.
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Connected to the apparatus 10 is a remote panel 150, which in the first embodiment is in electrical communication with the container assembly 36 via an electrical cable 152. Additionally or alternatively, wireless communication techniques may be used for communication between the remote panel and the remainder of the apparatus 10. The length and electrical ratings of the electrical cable 152 may be optimally selected for use of the apparatus 10 within the aircraft. The length of the electrical cable 152 may be about 4 feet (1.22 meters) and may be between 1 feet (30 cm) and 10 feet (3.0 m), for example. The remote panel 150 may be powered using the main power to the apparatus 10 or may be separately powered.
The remote panel 150 in the first embodiment includes a remote power indicator 154, a remote RUN indicator 156, a remote fault indicator 158, a remote feed gate switch 160, and a remote speed control switch 162.
In some embodiments, one or more switches of the apparatus 10 are safe guarded against unintentional actuation. For example, the apparatus 10 preferably includes a switch guard for each of one or more switches of the apparatus 10. As shown in
The display 132 is preferably a light-emitting diode (LED) display, and may be a numeric LED display comprising one or more LED segments. However, the display 132 may be a liquid crystal display (LCD) or other suitable display. Each of the power indicator 134, motor fault indicator 136, low extinguishing agent indicator 138, RUN/STOP indicator 142, remote power indicator 154, remote RUN indicator 156 and the remote fault indicator 158 may be a LED or other suitable indicator. Different indicators may be differently provided. Preferably, the remote feed gate switch 160 is a three-position momentary switch having a neutral position to which the remote feed gate switch 160 is urged towards, an open position for opening the dispenser gate 42 and a close position for closing the dispenser gate 42. In the first embodiment, when the remote feed gate switch 160 is released from either the open position or the close position, the remote feed gate switch 160 returns to its neutral position.
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The processing circuit 172 is operable to receive one or more inputs and perform computational operations on the received inputs to produce one or more outputs. The processing circuit 172 is preferably a digital processing circuit comprising one or more circuit units, such as a central processing unit (CPU), operating independently or in parallel, including operating redundantly. The processing circuit 172 may be implemented by one or more integrated circuits (IC), including being implemented by a single monolithic integrated circuit (MIC). Additionally or alternatively, the processing circuit 172 may be implemented as a programmable logic controller (PLC), for example. The processing circuit 172 is preferably operable to implement multi-tasking methods involving multiple threads of executable code. The processing circuit 172 may include circuitry for storing memory, such as digital data, and may comprise the memory circuit 174.
The main circuit board 170 preferably includes a battery charger (not shown) for charging the one or more extinguisher batteries 128.
The memory circuit 174 is operable to store information, including instructions for computational operations to be performed by the processing circuit 172. The memory circuit 174 is preferably operable to store digital data, including storing digital codes directing the processing circuit 172 to perform one or more methods. The memory circuit 174 may be implemented by one or more integrated circuits (IC), including being implemented by a single monolithic integrated circuit (MIC). The memory circuit may be implemented as Random Access Memory (RAM), Read-Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory, one or more flash drives, Universal Serial Bus (USB) connected memory units, magnetic storage disks, optical disks, and any combination thereof, for example. The memory circuit 174 may be operable to store memory as volatile memory, non-volatile memory, dynamic memory, and any combination thereof.
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Initializing the controller may include performing internal data integrity and processing checks; activating all output indicators for a specified amount of time; receiving input, including receiving input from the fluid level sensor (not shown) of the extinguisher tank 122 and receiving input from apparatus 10 switches; setting memory values, including possibly memory flags, within the memory circuit 174 in accordance with values of received input; determining states associated with one or more apparatus 10 output indicators, activating selected apparatus 10 output indicators; de-activating selected apparatus 10 output indicators; producing an output to close the dispenser gate 42; producing an output to de-activate the hopper motor 24; producing an output to activate the hopper motor 24; producing an output to de-activate the shuttle motor 82; any combination thereof, for example. Activating an indicator may include illuminating a light source of the indicator, including intermittently illuminating the light source to cause the indicator to flash and steadily illuminating the light source to cause the indicator to be activated and steady.
After block 180 has been executed in the case where the RUN/STOP switch 140 is set to STOP and under normal conditions, the apparatus 10 is preferably initialized such that the hopper motor 24 is not operating, the shuttle motor 82 is not operating, the dispenser gate 42 is closed, the power indicator 134 and the remote power indicator 154 are activated and steady, the motor fault indicator 136 is de-activated, the low extinguishing agent indicator 138 is de-activated, the RUN/STOP indicator 142 is de-activated, the remote RUN indicator 156 is de-activated and the remote fault indicator 158 is de-activated.
After block 180 has been executed, block 182 then directs the processing circuit 172 to perform a method in which dispensing of any projectiles 14 present in the hopper 18 is started upon appropriate user input conditions.
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Block 188 directs the processing circuit 172 to assign a value to a hopper motor flag within the memory circuit 174, such that the hopper motor 24 remains or becomes de-activated.
Block 190 then directs the processing circuit 172 to assign value to flags in the memory circuit 174 associated with the low extinguishing agent indicator 138, the motor fault indicator 136 and the remote fault indicator 158 such that the indicators 138, 136 and 158 are activated. After block 190 is executed, the processing circuit 172 is directed to return to execute block 186.
The apparatus 10 is preferably operable to prevent the start of dispensing of projectiles 14 if the level of extinguishing agent in the fire extinguisher tank 122 is insufficient, thereby advantageously providing a safety feature. The execution of blocks 186, 188 and 190 of the first embodiment implements this safety feature. Additionally or alternatively, the method 176 may include processing steps to permit the hopper motor 24 to be activated, but prevent the shuttle motor 82 from being activated, when the fluid level of the fire extinguisher tank 122 is low. Additionally or alternatively, the method 176 may include processing steps to permit the hopper motor 24 and the shuttle motor 82 to be activated, but to close the dispenser gate 42 and prevent the dispenser gate 42 from being opened.
In addition to the execution of blocks 186 to 190, the apparatus 10 is preferably operable to activate and de-activate the low extinguishing agent indicator 138 in accordance with the output of the fluid level sensor (not shown), including in accordance with the value of an associated flag in the memory circuit 174. A polling method may be implemented to regulate the low extinguishing agent indicator 138, for example. Additionally or alternatively, an interrupt type method may be implemented such that the processing circuit 172 is operable to receive input from the fluid sensor (not shown) at any time the fluid sensor produces an output indicating a significant change in fluid level. The apparatus 10 is preferably operable to delay toggling activation of the low extinguishing agent level 138 after the fluid level has remained at a new level for a specifiable period of time, such as a time period in the range of 1 to 5 seconds, including a time period of 2 seconds. Such time delay advantageously reduces the effect of sloshing of fluid within the fire extinguisher tank 122 on the indication of fluid level by the low extinguishing agent level 138. The apparatus 10 is preferably operable to permit the continued dispensing of projectiles 14 when the fluid level of the fire extinguisher tank 122 is low, provided the fluid level was not low when dispensing commenced. In some embodiments, the apparatus 10 is operable to stop dispensing projectiles 14 after the fluid level of the fire extinguisher tank 122 becomes low.
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Block 192 directs the processing circuit 172 to determine whether the RUN/STOP switch 140 is set to its RUN position. If the processing circuit 172 determines that the RUN/STOP switch 140 is not set to its RUN position (i.e. set to its STOP position), then processing returns to block 186. If the processing circuit 172 determines that the RUN/STOP switch 140 is set to its RUN position, then the processing circuit 172 is directed to execute block 194. Block 194 directs the processing circuit 172 to close the dispenser gate 42.
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Block 268 then directs the processing circuit 172 to wait during the elapse of a time delay before continuing. The time delay of block 268 is preferably dependent on the dispensing rate of the apparatus 10. The processing circuit 172 may determine the time delay of block 268 from a look-up table stored in the memory circuit 174 specifying the appropriate time delay for each possible desired dispensing rate, for example.
Block 270 then directs the processing circuit 172 to assign a value to a gate closing solenoid flag within the memory circuit 174 such that the gate closing solenoid 68 is activated. The processing circuit 172 may execute block 270 similarly, analogously or identically to block 264. When sufficient time has elapsed to permit the gate pins 46 to fully extend, then the process proceeds to block 272, which directs the processing circuit 172 to assign a new value to the gate closing solenoid flag within the memory circuit 174 such that the gate closing solenoid 68 is de-activated.
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Block 196 directs the processing circuit 172 to assign a value to the hopper motor flag within the memory circuit 174, such that the hopper motor 24 is or becomes activated. Block 198 then directs the processing circuit 172 to assign values to flags associated with the RUN/STOP indicator 142 and the remote RUN indicator 156 such that these indicators 142 and 156 are activated and steady. Block 200 then directs the processing circuit 172 to wait during the elapse of a time delay before continuing. The apparatus 10 is advantageously operable to prevent the opening of the dispenser gate 42 immediately following the activation of the hopper motor 24, thereby providing sufficient time for agitating projectiles 14 in the hopper 18 to form a suitable queue of projectiles 14 available to exit the hopper 18. In this manner, the likelihood of a jammed condition within the apparatus 10 is minimized. The time delay of block 200 is preferably between 1 and 3 seconds in duration.
The blocks 194, 196, 198 and 200 may be executed in any order. The time delay of block 200 may include or exclude any processing time associated with executing blocks 194, 196 and 198. When blocks 194, 196, 198 and 200 have been executed, the processing circuit 172 is directed to return to execute block 202.
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Block 204 directs the processing circuit 172 to execute a method such that the dispenser gate 42 becomes opened.
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Block 218 directs the processing circuit 172 to receive as input a value associated with the current position of the remote speed control switch 162, and assigning that value, or an associated value calculated therefrom, to the desired dispensing rate, which is preferably stored within the memory circuit 174.
Block 220 then directs the processing circuit 172 to determine and assign a value for an initial shuttle motor 82 speed in response to the desired dispensing rate. The apparatus 10 is operable to activate and supply electrical power to the shuttle motor 82 in accordance with the initial shuttle motor 82 speed value. Preferably, the initial shuttle motor 82 speed value is limited to a maximum initial value such that an initial maximum level of electrical power supplied to the shuttle motor 82 is not exceeded during an initial phase of operation of the shuttle motor 82. The apparatus 10 is preferably operable to limit the momentum attainable by the shuttle 78 immediately upon startup for a specifiable duration of time, thereby advantageously minimizing the likelihood of a jammed condition of the apparatus 10. The duration of the initial phase is preferably between 0.5 and 10 seconds, including being between 1 and 2 seconds. The duration may be 1.5 seconds, for example. Although not shown in
Block 222 then directs the processing circuit 172 to assign values to flags in the memory circuit 174 associated with the RUN/STOP indicator 142 and the remote RUN indicator 156 such that these indicators 142 and 156 are periodically activated, thereby producing the effect of flashing the indicators 142 and 156.
Block 216 may be executed before, during or after the execution of blocks 218 to 222. Block 222 may be executed before, during or after the execution of blocks 216 to 220. The time delay of block 216 may include or exclude any processing time associated with executing blocks 218 to 222. When blocks 216 to 222 have been executed, the processing circuit 172 is directed to return to execute block 224 of
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Block 228 also directs the processing circuit 172 in accordance with the first embodiment to determine whether to increment a projectile 14 counter stored in the memory circuit 174. In the first embodiment, the processing circuit 172 is operable to count the shuttle motor 82 encoder ticks and to determine therefrom whether a sufficient number of shuttle motor 82 encoder ticks have been received to indicate that an additional projectile 14 has been dispensed from the apparatus 10. The processing circuit 172 is preferably operable to increment the projectile 14 counter upon receiving and counting the appropriate number of shuttle motor 82 encoder ticks. In this manner, the apparatus 10 is preferably operable to count the number of projectiles 14 dispensed from the apparatus 10.
When block 228 has been executed, the processing circuit 172 is directed to execute block 230.
Block 230 directs the processing circuit 172 to receive as input a value associated with the current position of the remote speed control switch 162, and assigning that value, or an associated value calculated therefrom, to the desired dispensing rate, which preferably is stored within the memory circuit 174.
Block 232 then directs the processing circuit 172 to produce a shuttle motor 82 speed value in response to the shuttle motor 82 speed determined by block 228 and the desired dispensing rate determined by block 230. The processing circuit 172 preferably stores within the memory circuit 174 the shuttle motor 82 speed value. The apparatus 10 is operable to vary the power supplied to the shuttle motor 82, thereby regulating the shuttle motor 82 speed. In the first embodiment, the apparatus 10 uses pulse-width-modulation (PWM) techniques to vary the power supplied to the shuttle motor 82, however, other modulation techniques will be apparent to those of ordinary skill in the art and are contemplated within the scope of the present invention. The processing circuit 172 may be operable to compute a duty cycle for a digital signal, including possibly a digital signal produced at an output port of the processing circuit 172, associated with the shuttle motor 82 speed value. The apparatus 10, including possibly the processing circuit 172, is preferably operable to produce the digital signal such that it has a modulation frequency much greater than the frequency associated with required changes in power supplied to the shuttle motor 82. For example, the modulation frequency is preferably much greater than 100 Hz and typically is in the range of 500 Hz to 20 kHz. The modulation frequency may be about 10 kHz, for example. Rectification of the digital signal may produce a power signal that can be supplied, directly or indirectly through power amplification means, to the shuttle motor 82, for example.
In addition to the execution of block 232, the processing circuit 172 may be operable to limit the duty cycle to a specifiable limit, thereby advantageously reducing the likelihood of a jam condition of the apparatus 10 occurring and the likelihood of a projectile 14 becoming broken should a jam condition of the apparatus 10 occur.
When block 232 has been executed, the processing circuit 172 is directed to execute block 234.
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Block 236 directs the processing circuit 172 to execute steps to correct the stall condition.
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Block 242 directs the processing circuit 172 to produce and assign values to variables in the memory circuit 174 associated with the shuttle motor 82 speed value such that the shuttle motor 82 becomes stopped; then execute a time delay to provide sufficient time for mechanical components of the apparatus 10 to come to a complete rest; and then produce and assign values to variables in the memory circuit 174 associated with the shuttle motor 82 speed value and the shuttle motor 82 direction, such that the shuttle motor 82 is caused to reverse its direction of rotation and is supplied with power to rotate in the reverse direction at a reverse rotation speed. The time delay executed when stopping the shuttle motor 82 is preferably between 0.1 and 2 seconds, and may be 350 milliseconds, for example. The reverse rotation speed is preferably a substantially constant speed, and may be substantially equal to the maximum initial speed (albeit in the reverse direction), for example.
Block 244 then directs the processing circuit 172 to execute a time delay during which the shuttle motor 82 is operating in the reverse direction. The time delay is preferably between 0.1 and 5 seconds, and may be about 2 seconds, for example. Additionally or alternatively, the processing circuit 172 may be operable to determine whether a specifiable number of shuttle motor 82 encoder ticks have been received such that the shuttle motor 82 has operated in the reverse direction for a sufficient number of revolutions, and/or fractional portion thereof.
Block 246 then directs the processing circuit 172 to assign values to flags in the memory circuit 174 associated with the motor fault indicator 136 and the remote fault indicator 158 such that these indicators 136 and 158 are de-activated.
Block 248 then directs the processing circuit 172 to receive as input a value associated with the current position of the remote speed control switch 162, and assigning that value, or an associated value calculated therefrom, to the desired dispensing rate, which is preferably stored within the memory circuit 174.
Block 250 then directs the processing circuit 172 to produce and assign values to variables in the memory circuit 174 associated with the shuttle motor 82 speed value such that the shuttle motor 82 becomes stopped; then execute a time delay to provide sufficient time for mechanical components of the apparatus 10 to come to a complete rest; and then determine and assign a value for an initial shuttle motor 82 speed in response to the desired dispensing rate, such that the shuttle motor 82 is caused to resume operation in the forward direction in accordance with the desired dispensing rate. The time delay executed when stopping the shuttle motor 82 is preferably between 0.1 and 2 seconds, and may be 350 milliseconds, for example. Portions of block 250 may be executed similarly, analogously or identically to the execution of block 220 (
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Block 252 directs the processing circuit 172 to determine whether the RUN/STOP switch 140 is set to its STOP position. If the processing circuit 172 determines that the RUN/STOP switch 140 is not set to its STOP position (i.e. set to its RUN position), then the processing circuit is directed to execute block 254.
Block 254 directs the processing circuit 172 to determine whether the remote feed gate switch 160 is being set to its CLOSED position. If the processing circuit 172 determines that the remote feed gate switch 160 is not being set to its CLOSED position, the processing circuit is directed to execute block 228.
Blocks 228 to 254 form a loop whose execution is iterated until either the RUN/STOP switch 140 is removed from its RUN position or the remote feed gate switch 160 is removed from its OPEN position. Additionally or alternatively, the apparatus 10 may be operable to detect a change in the status of a switch, including detecting the removal of the RUN/STOP switch 140 from its RUN position and/or the removal of the remote feed gate switch 160 from its OPEN position, at any time the processing circuit 172 is executing code. Such detection may occur by executing an interrupt service routine or other event handler in response to the reception, including the asynchronous detection, of an interrupt request or other detection of a change in switch status, including detecting by polling, for example.
During iterations of the loop formed by blocks 228 to 254, the shuttle motor speed value is adjusted in response to changes in shuttle motor speed and the desired dispensing rate. In this manner, the apparatus 10 is operable to compensate for changes in load and other factors such that differences between the shuttle motor speed and that required to meet the desired dispensing rate are minimized. For example, the apparatus 10 is preferably operable to increase the power supplied to the shuttle motor 82 in response to the increased load occurring when the injector needle 96 is piercing a given projectile 14, such that undesirable variations in the reciprocating speed of the shuttle 78 are minimized.
The processing circuit 172 may be operable to determine the duty cycle in accordance with a control system theory. In the first embodiment, the processing circuit 172 is preferably operable to determine the duty cycle in accordance with a proportional-integral-derivative (PID) control system. However, the processing circuit 172 may be operable to determine the duty cycle in accordance with other feedback control systems, including a negative feedback control system.
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Block 276 directs the processing circuit 172 to determine whether a stall condition of the shuttle motor 82 is occurring. Block 276 may be implemented in a manner similarly, analogously and/or identically to block 234, for example. If the processing circuit 172 determines that the shuttle motor 82 is in a stall condition, then the processing circuit 172 is directed to execute block 236.
Block 236 directs the processing circuit 172 to execute steps to correct the stall condition in the manner previously described herein. When block 236 has been executed, the processing circuit 172 is directed to return to re-execute block 276.
Still referring to
Block 278 then directs the processing circuit 172 to produce a shuttle motor 82 speed value such that the shuttle motor 82 becomes de-activated and stops operation.
De-activation of the shuttle motor 82 when projectiles 14 are not being dispensed advantageously permits the processing circuit 172 to determine a value associated with the number of projectiles 14 dispensed from the number of cycles of the shuttle 78. The processing circuit 172 may be operable to determine the number of cycles of the shuttle 78 from the duration of time elapsed during which the shuttle motor 82 has been operating at a given shuttle motor 82 speed, for example.
The apparatus 10 is preferably operable to determine a current operation count of the number of projectiles 14 dispensed, which can be displayed on the display 132 and can be reset to zero by actuating the count reset switch 144. Typically, the current operation count is associated with the number of projectiles 14 dispensed since the count reset switch 144 had been actuated. The apparatus 10 is also preferably operable to determine and store in non-volatile memory of the memory circuit 174 a lifetime count of the number of projectiles 14 dispensed during the lifetime of the apparatus 10. Typically, the lifetime count is set to zero by the manufacturer prior to its first use by a purchaser. In some embodiments, the apparatus 10 is operable to perform other data logging tasks, including possibly determining when a series of projectiles 14 had been dispensed and determining where a given series of projectiles 14 had been dispensed.
Block 280 then directs the processing circuit 172 to assign values to flags in the memory circuit 174 associated with the RUN/STOP indicator 142 and the remote RUN indicator 156 such that these indicators 142 and 156 are continuously activated, thereby stopping any flashing effect and maintaining these indicators 142 and 156 steadily activated.
Block 282 then directs the processing circuit 172 to determine whether the RUN/STOP switch 140 is set to its STOP position. If the processing circuit 172 determines that the RUN/STOP switch 140 is not set to its STOP position (i.e. set to its RUN position), then the processing circuit 172 is directed to return to execute block 202 (
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Referring back to
In addition to the methods described above, the apparatus 10 may be operable to cause short bursts of movement of the shuttle 78 by activating the shuttle motor 82, executing a time delay, and de-activating the shuttle motor 82. For example, the apparatus 10 may cause a short burst of movement of the shuttle 78 in response to momentary actuation of the jog switch 146 (
It is understood that the embodiments described and illustrated herein are merely illustrative of embodiments of the present invention. Other embodiments that would occur to those skilled in the art are contemplated within the scope of the present invention. For example, the processing circuit may execute blocks of code in a different order than that described herein above and illustrated in the Figures, including executing blocks of code in parallel. The invention may include variants not described or illustrated herein in detail. Thus, the embodiments described and illustrated herein should not be considered to limit the invention as construed in accordance with the accompanying claims.
Number | Date | Country | Kind |
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60891939 | Feb 2007 | US | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA2008/000359 | 2/27/2008 | WO | 00 | 10/14/2009 |