Abstract:
A device for cyclically operating a trigger of a firearm includes biasing means for biasing a finger applied to a trigger away from the trigger, and a contact switch coupled to the biasing means and configured to be disposed between the finger and the trigger. In response to the contact switch detecting contact between the finger and the trigger, the biasing means actuates to cyclically bias the finger away from the trigger.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/877,878, filed Sep. 13, 2013, which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to firearms, and more particularly to accessories for assisting in firing firearms. 
     BACKGROUND OF THE INVENTION 
     For hundreds of years, mankind has been fascinated with the propulsion of objects with black powder and the technology for enabling it. Whether launching a cannonball thousands of yards or firing a handgun, the act is an amazing and exhilarating experience. For the hobbyist, discharging a fully automatic weapon is invigorating and can be an incredibly fun and enjoyable sporting experience. 
     Many people have never experienced firing a fully automatic weapon. Fully automatic weapons—weapons which fire multiple rounds in response to a single trigger pull—are heavily regulated at both the state and federal level. Due in part to such legislation, but also because of low supply and complexity of manufacture, fully automatic weapons can be incredibly expensive. 
     As a result of the high price, low supply, and heavy regulation of fully automatic weapons, most hobbyists own only semi-automatic weapons. For purposes of definition, semi-automatic weapons are distinguished from fully automatic weapons in that semi-automatic weapons fire only a single shot for each pull of the trigger. There is thus a one-to-one correspondence between the discharge of a round from the firearm and depression of the trigger of the firearm in a semi-automatic weapon. Continuously depressing the trigger of a semi-automatic weapon does not result in the weapon discharging more than one bullet. 
     Various attempts have been made to modify semi-automatic weapons to fire in a fully automatic mode. However, these modifications usually involve dismantling the weapon and fundamentally altering the mechanisms that control firing. Not only are modifications such as these generally illegal, but they are also highly dangerous. 
     Others have attempted to supplement semi-automatic weapons with mechanisms that allow them to fire rapidly. However, these changes often make the weapon unstable, such that the owner cannot achieve precision or accuracy while shooting, and in some cases, may render the weapon dangerous, illegal, or both. An improved way of firing a semi-automatic weapon like a fully automatic weapon is needed. 
     SUMMARY OF THE INVENTION 
     According to one of a plurality of embodiments according to the principle of the invention, a device for cyclically operating a trigger of a firearm includes a glove having a finger stall and a pull mounted over the finger stall. A drive mechanism is coupled to the pull to move the finger stall rapidly from a bent configuration toward a straight configuration, thereby moving the finger stall away from the trigger very rapidly. When an operator attempts to continuously depress the trigger, the pull cyclically retracts his finger in the finger stall from the trigger, causing the firearm to be fired rapidly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the drawings: 
         FIG. 1  is an enlarged side elevation view of a portion of a firearm; 
         FIGS. 2A and 2B  are top and bottom perspective views, respectively, of a first embodiment of a cyclical trigger operation device for use with the firearm of  FIG. 1 , the device being constructed and arranged according to the principle of the invention; 
         FIG. 2C  is a top perspective view of a second embodiment of a cyclical trigger operation device for use with the firearm of  FIG. 1 , the device being constructed and arranged according to the principle of the invention; 
         FIG. 3A  is a top perspective view of a third embodiment of a cyclical trigger operation device for use with the firearm of  FIG. 1 , the device being constructed and arranged according to the principle of the invention; 
         FIG. 3B  is a top perspective view of a fourth embodiment of a cyclical trigger operation device for use with the firearm of  FIG. 1 , the device being constructed and arranged according to the principle of the invention; 
         FIG. 4A  is a top perspective view of a fifth embodiment of a cyclical trigger operation device for use with the firearm of  FIG. 1 , the device being constructed and arranged according to the principle of the invention; 
         FIG. 4B  is a top perspective view of a sixth embodiment of a cyclical trigger operation device for use with the firearm of  FIG. 1 , the device being constructed and arranged according to the principle of the invention; and 
         FIG. 5  is a side elevation view of a seventh embodiment of a cyclical trigger operation device constructed and arranged according to the principle of the invention, illustrated as it would appear installed on the firearm of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference now is made to the drawings, in which the same reference characters are used throughout the different figures to designate the same elements.  FIG. 1  illustrates a portion of a firearm  10  representative of the family of rifles including rifles such as the M-4, M-16, AR-15, and AR-10. Indeed, the firearm  10  is exemplary of many semi-automatic weapons, and reference in this description will be made to the firearm  10  with the understanding that the description applies equally to other semi-automatic weapons, and that reference to the firearm  10  is not meant to limit the present invention to a particular embodiment for use with an AR-15 firearm  10 . The firearm  10  includes an upper receiver  11 , a lower receiver  12 , and a stock  13  coupled to an end of the upper receiver  11 . The firearm  10  shown in  FIG. 1  can be selectively set in either a semi- or fully-automatic mode; for purposes of discussion here, it will be assumed that the firearm  10  is set in the semi-automatic mode to always fire in a semi-automatic mode such that one bullet is discharged from the firearm  10  in response to each depression of a trigger  20 . The trigger  20  is located on the lower receiver  12  just in front of a pistol grip  21  and within a rigid trigger guard  22  extending forward from the grip  21  and encircling the trigger  20 . 
     The space between the trigger  20  and the grip  21  is herein referred to as a depression gap and is marked with the reference character  23 , and the space in front of the trigger  20  is herein referred to as a finger gap and is marked with the reference character  24 . The trigger itself has a rear face  25  which borders the depression gap  23 , and an opposed front face  26  which borders the finger gap  24 . 
     To fire the firearm  10 , the trigger  20  must be depressed. The trigger  20  must be moved backward from a ready position, shown in  FIG. 1 , toward the grip  21  to a depressed position into the depression gap  23 . Generally, the operator moves the trigger  20  by first extending his index finger proximate the trigger  20 , then placing his index finger over the trigger  20 , and then curling or bending the index finger inward or pulling back on the trigger  20  to depress the trigger  20 . Depressing the trigger  20  once causes the firearm  10  to fire one bullet. Before the firearm  10  can be fired again, the trigger  20  must return from the depressed position to the ready position in  FIG. 1 , so the operator will let go of or release the trigger  20 . Firearms typically have a spring or other mechanism which returns the trigger  20  to the ready position. The trigger  20  generally moves back to the ready position faster than the operator can extend his finger, so that every time the operator moves his finger away from or off of the trigger  20 , the trigger  20  will reset to the ready position. One having ordinary skill in the art will readily understand this conventional operation of a trigger. 
     The present invention is a device that allows the operator of the firearm  10  to fire the weapon rapidly at speeds which emulate the fully-automatic fire of a fully-automatic weapon. The present invention accomplishes this by quickly returning the operator&#39;s finger to an extended position to allow the trigger  20  to return to the ready position, so that the trigger  20  may again be depressed by the finger of the operator. The operator feels as if he is firing a fully automatic weapon because he feels that he is continuously holding down or depressing the trigger down and firing multiple shots, while the device is actually quickly moving his finger off the trigger. 
     A First Embodiment 
       FIG. 2A  and  FIG. 2B  illustrate an embodiment of the present invention, constructed and arranged according to the principle of the invention, referred to as a cyclical trigger operation device (hereinafter, “CTOD”) and marked with the reference character  30 . The CTOD  30  is adapted to be used with the firearm  10  of  FIG. 1  to enable the operator to quickly and cyclically depress the trigger  20  of the firearm  10 . The CTOD  30  includes a glove body  31  for receiving a human hand, having a palmar side  32  and an opposed dorsal side  33 , a proximal end  34  with an opening  36 , and an opposed distal end  35 . The glove body  31  has an exterior surface  40  and an opposed interior surface  41  which bounds and defines an interior volume for receiving a hand which has been applied through the opening  36 . A strap  42  is disposed on the exterior surface  40  and has an end secured to the exterior surface  40  and an opposed end free of the exterior surface  40 . The strap  42  carries a fastener for adjustably fastening the strap  42  across the exterior surface at the opening  36 , so as to selectively adjust the diameter of the opening  36  to fit loosely or snugly on a hand. The fastener is preferably a hook-and-loop fastener, with complemental fastening components on the strap  42  and on the exterior surface  40 . In other embodiments, the fastener is a series of buttons, snap-buttons, magnets, or other suitable fasteners for releasably adjusting the dimension of the opening  36 . In yet other embodiments, instead of a glove body  31 , the CTOD  30  is applied and secured on the hand with several adjustable straps. A lower strap forms an annular band at the distal end of the base pad  50 . An upper strap forms an annular band at the other end of the base pad  50 . The lower and upper straps are constructed similarly and are adjustable to fit securely on the operator&#39;s hand. In some embodiments, the lower and upper straps are continuous elastic bands. In other embodiments the lower and upper straps each have first and second strap members with free ends which are secured to each other with hook-and-loop engagement elements, buttons, snap-buttons, magnets, or other suitable fasteners. 
     The glove body  31  includes a thumb stall  44 , an index finger stall  45 , and three other finger stalls  46 . Each of the stalls  44 ,  45 , and  46  are full-fingered sleeves extending from the glove body  31  to closed distal ends proximate the distal end  35  of the CTOD  30 . In other embodiments, the stalls  44 ,  45 , and  46  may only partially cover the thumb and fingers. The thumb stall  44  is for receiving a thumb of a human hand, the index finger stall  45  is for receiving the index finger, or trigger finger, on a human hand, and the three remaining finger stalls  46  are for receiving the middle, ring, and pinky fingers on a human hand. Each of the stalls  44 ,  45 , and  46  fits snugly over the respective fingers so that there is little play in material over the fingers. The glove body  31  and the finger stalls  44 ,  45 , and  46  are constructed from a material or combination of materials having material characteristics of durability and flexibility, such as nylon, polypropylene, or other similar material. Additionally, the palmar side  32  of the CTOD  30  may have a textured surface or pattern for enhanced gripping of an object such as the pistol grip  21  of the firearm  10 . 
     The CTOD  30  includes a pull assembly having a base pad  50 , a rigid spar  51  extending from the base pad  50  along the index finger stall  45 , and a pull  52  pivoted to the spar  51  and further extending along the index finger stall  45 . The pull  52  is a generally elongate beam member having a wide proximal end  53  proximate to the base pad  52  and formed with a hole  54 . Two struts  55  and  56  extend from the proximal end  53  forwardly along either side of the index finger stall  45  to a distal end  60  of the pull  52 . A wide, flat, coplanar stop  57  extends between the struts  55  and  56  proximate to the proximal end  53 . 
     A cradle  61  is disposed at the distal end  60  of the pull  52  for holding the index finger stall  45  and preferably cradling a finger installed in the index finger stall  45 . The cradle  61  is a concave, bowl-shaped member at the distal end extending between and supported by the struts  55  and  56 . Seen best in  FIG. 2B , a hole  62  is formed through the cradle  61  at a generally central and intermediate location in the cradle  61 . When the CTOD  30  is worn by an operator, the cradle  61  is disposed near the pad of the operator&#39;s finger, and the hole  62  is disposed at a site along the operator&#39;s finger at which his finger contacts the trigger  20 . The hole  62  thus allows the operator to feel the trigger  20  when wearing the glove body  31  and through the pull  52 . 
     The pull  52  is pivoted to the spar  51  at a distal end  63  of the spar  51  to move along a path identified with double-arrowed arcuate line A in  FIGS. 2A and 2B . The distal end  63  of the spar  51  carries an axle  64  extending between the struts  55  and  56  of the pull  52 . The struts  55  and  56  are mounted for pivotal movement to the axle  64  at a generally intermediate location with respect to the proximal and distal ends  53  and  60  of the pull  52 , and between the second and third knuckles (where the first knuckle is the knuckle closest to the tip of the finger and the third knuckle is the knuckle closest to the palm). The pull  52  pivots between (1) a first position, in which the pull  52  is transverse to the spar  51  and the base pad  50 , and the index finger stall  45 , as shown in broken line in  FIGS. 2A and 2B , is curled, as would occur when the operator is depressing his finger against the trigger  20  in a curled position of the finger, and (2) a second position, in which the pull  52  is generally parallel to the spar  51  and the base pad  50 , and the index finger stall  45 , as shown in solid line in  FIGS. 2A and 2B , is straightened, as would occur when the operator&#39;s finger is moved off of the trigger  20  in an extended position of the finger. Movement past the second position is limited by the stop  57 , which, when the pull  52  is in the second position thereof, is in contact with the spar  51  and prevents further movement along line A. In the first position of the pull  52 , the pull  52  is proximate to the trigger  20 , and in the second position of the pull  52 , the pull  52  is away from the trigger  20 . 
     Still referring to  FIGS. 2A and 2B , the spar  51  supports the pull  52  and the movement of the pull  52  through and between the first and second positions of the pull  52 . The spar  51  is integrally formed to the base pad  50  and extends parallel from the base pad  50  to the distal end  63  of the spar  51 . The base pad  50  carries a drive mechanism  65  for controlling the movement of the pull  52  and the index finger stall  45 . 
     The base pad  50 , which may be flexible, is applied to the dorsal side  32  of the CTOD  30 . The base pad  50  is a mount for a pneumatic cylinder  70  with a stroke that is generally aligned along the length of the spar  51 . The base pad  50  also carries a gas supply  71  to supply a gas to the pneumatic cylinder  70 . In  FIG. 2A , the gas supply  71  is a cylindrical housing. The gas supply  71  is preferably a replaceable gas cartridge, such as a CO2 cartridge. Such CO2 cartridges can be coupled to the pneumatic cylinder  70 . An onboard programmable logic controller  72  is mounted on the base pad  52  and powered by a small battery  73 . The programmable logic controller  72  controls the application and removal of gas to and from the pneumatic cylinder  70 . A plurality of switches  74  are also carried on the base pad  52  and coupled to the programmable logic controller  72 , so that the user may depress or select one of the plurality of switches to instruct the programmable logic controller to control the drive mechanism  65  in a particular, pre-programmed way, as is discussed later. A cable  75  extends from the pneumatic cylinder  70  to the hole  54  in the proximal end  53  of the pull  52 , thereby operatively coupling the drive mechanism  65  to the pull  52  to impart movement to the pull  52  in response to actuation of the drive mechanism  65 . 
     The pneumatic cylinder  70  is aligned with the index finger stall  45 , and the cable  75  is coupled to a piston in the pneumatic cylinder  70 . The piston in the pneumatic cylinder  70  intermittently and cyclically reciprocates between a forward position and a retracted position in the pneumatic cylinder  70 . Actuation of the pneumatic cylinder  70  retracts the cable  75 . When the index finger stall  45  is bent, such as would occur when a finger applied to the index finger stall  45  is curled around the trigger  20 , the cable  75  is extended and ready to be retracted so as to extend the index finger stall  45  and the index finger applied thereto. When the cable  75  is retracted, the cable  75  is drawn back, and the proximal end  53  of the pull  52  is drawn toward the proximal end  34  of the glove body  31  to move the pull  52  into the second position thereof. This causes the index finger stall  45  to extend toward a straightened configuration. When the pneumatic cylinder  70  retracts the cable  75  quickly, the operator&#39;s index finger is moved quickly toward the extended and straightened position thereof. 
     In operation, an operator places his hand into the CTOD  30  by applying his hands fingers-first through the opening  36  and directing each of his fingers into the appropriate finger stall. The operator ensures that the cradle  61  is on the underside of his finger. When the operator has comfortably fit the CTOD  30  on his hand, he adjusts the strap  42  by drawing the free end back away from the exterior surface  40  of the glove body  31  and re-applying it so as to secure the fastener and fix the dimension of the opening  36  as is comfortably snug on the operator&#39;s wrist. 
     The operator then selects the desired performance of the CTOD  30  by selecting one of the plurality of switches  74 . The switches  74  each correspond to various performance functions of the CTOD  30 . Some of the switches allow the operator to select a cycling speed. For instance, the operator may select a switch setting the cycling speed at three hundred revolutions per minute (“rpm”), in response to which the pneumatic cylinder will reciprocate approximately three hundred times in one minute to cycle movement of the pull  52  three hundred times in a minute, emanating a fast firing firearm. In another example, the operator may select a switch setting the cycling speed at nine hundred rpm, in response to which the pneumatic cylinder will reciprocate approximately nine hundred times in one minute to cycle movement of the pull  52  nine hundred times in a minute, emulating a very fast firing firearm. Some of the switches allow the operator to select a cycling duration. For example, the operator may select a switch setting the cycling duration to three pulses, in which case the pneumatic cylinder will reciprocate three times and then pause or stop, so as to emulate a three-round burst of fire. In another example, the operator may select a switch setting the cycling duration to five pulses, in which case the pneumatic cylinder will reciprocate five times, so as to emulate a five-round burst of fire. In yet another example, the operator may select a switch setting the cycling duration to two seconds, in which case the pneumatic cylinder will reciprocate for two seconds, so as fire repeatedly for two seconds and then pause or stop. 
     After setting the performance of the CTOD  30 , the operator grips the firearm  10  at the pistol grip  21 , placing his index finger proximate to the trigger  20 . The operator shoulders or readies the firearm  10  and takes aim at a target. Once a target is acquired, the operator fires the weapon by placing his finger against the trigger  20  and depressing or pulling the trigger  20  back toward the grip  21 . Preferably, the operator continuously depresses his finger against the trigger  20 . 
     The cradle of the pull  52  carries a contact switch  80 . As seen in  FIG. 2B , the contact switch  80  is located on the palmar side  32 , or underside, of the index finger stall  45 , against the cradle  61  but within the hole  62 , such that the contact switch  80  is disposed between the finger applied to the index finger stall  45  and the trigger  20 . The contact switch  80  is preferably a pressure switch which detects contact between the finger and the trigger  20 , responsive to two to three pounds such that when two to three pounds of pressure are applied at the contact switch  80 , the contact switch  80  issues an activation signal. When the operator&#39;s finger is placed against the trigger  20  and curled into the first position of the pull  52 , thus depressing to pull the trigger  20 , the contact switch  80  is closed, and the contact switch  80  transmits an activation signal to the programmable logic controller  72  in the drive mechanism  65 . 
     The activation signal is transmitted along an electrical wire (not shown) which is coupled to the programmable logic controller  72 , and which is preferably sewn into the index finger stall  45  and the glove body  31 . In response to receiving the signal, the programmable logic controller  72  causes gas to be intermittently and cyclically supplied to and drawn from the pneumatic cylinder  70 , such as through an on-board valve, according to the pre-programmed control instructions corresponding to the selected one the of the plurality of switches  74 , causing the pneumatic cylinder  70  to reciprocate, and causing the cable  75  to be intermittently and cyclically retracted. In response, the operator&#39;s index finger, applied in the index finger stall  45  is intermittently and cyclically retracted toward the extended position along double-arrowed arcuate line A in  FIGS. 2A and 2B . The operator, however, continues to hold his finger down in the curled position to depress the trigger  20 . When the pneumatic cylinder  70  retracts the cable  75 , a greater force is applied to the operator&#39;s finger than he applies to it, so that the finger is pulled to the extended position and the first position of the pull  52 . In the extended position of the finger, the finger is pulled off of or away from the trigger  20 , and the trigger  20  is returned to the ready position by the spring or other mechanism which returns the trigger  20  to the ready position. When the pneumatic cylinder  70  has retracted a full stroke, the supply of gas to the pneumatic cylinder  70  is removed, as instructed by the programmable logic controller  72 , the operator&#39;s own force of his finger is now able to overcome the pneumatic cylinder  70 , and his finger curls along line A to depress the trigger  20 . When his finger depresses the trigger  20 , it extends the pneumatic cylinder  70  a full stroke length so that the pneumatic cylinder  70  is ready to retract. With the operator continuing to curl his finger, and with the pneumatic cylinder  70  intermittently and cyclically retracting the cable  75  to intermittently and cyclically extend the finger, the pull  52  is intermittently and cyclically moved between the first and second positions thereof, the index finger stall  45  is moved intermittently and cyclically between the bent and straightened configurations, the operator&#39;s finger is intermittently and cyclically curled and extended, and the trigger  20  is intermittently and cyclically depressed to the depressed position and allowed to return to the ready position. In this way, the firearm  10  intermittently and rapidly fires bullets, emulating fully-automatic fire. 
     A Second Embodiment 
       FIG. 2C  illustrates an embodiment of the present invention, constructed and arranged according to the principle of the invention, referred to as a cyclical trigger operation device (hereinafter, “CTOD”) and marked with the reference character  90 . The CTOD  90  is adapted to be used with the firearm  10  of  FIG. 1  to enable the operator to quickly and cyclically depress the trigger  20  of the firearm  10 . The CTOD  90  is very similar to the CTOD  30  and includes many identical structural features elements with the CTOD  30 . Those structural features and elements of the CTOD  90  which are identical to corresponding structural features and elements in the CTOD  30  are marked with identical reference characters, but are designated with a prime (“′”) symbol to distinguish them from those of the CTOD  30 . In some cases, the CTOD  90  has identical structural features and elements as the CTOD  30  but located in alternate locations. In such cases, the same reference character will be used, with the prime symbol, but the alternate location will be described. Where the CTOD  90  has identical structural features and elements as the CTOD  30  and those structural features and elements are located and used in an identical manner as in the CTOD  30 , they will merely be listed, as describing them would be unduly repetitive and burdensome for the reader. It should be understood, then, that the description for the particular structural feature or element with respect to the CTOD  30  is equally applicable to the corresponding identical structural feature and element with respect to the CTOD  90 , unless otherwise described. Finally, for simplicity of the illustrations, not all identical reference characters will be shown, if their corresponding identical reference characters are shown in a figure illustrating an alternate embodiment. 
     The CTOD  90  includes a glove body  31 ′, a dorsal side  32 ′, a palmar side  33 ′, a proximal end  34 ′, a distal end  35 ′, an opening  36 ′, an exterior surface  40 ′, an interior surface  41 ′, a strap  42 ′, a thumb stall  44 ′, an index finger stall  45 ′, and finger stalls  46 ′. The CTOD  90  includes a base pad  50 ′, a spar  51 ′ extending from a distal end  63 ′ at the base pad  50 ′ to an axle  64 ′, and a pull  52 ′ pivoted to the axle  64 ′ on the spar  51 ′ for movement along the double-arrowed arcuate line A′ in  FIG. 2C . The pull  52 ′ includes a proximal end  53 ′, a hole  54 ′, struts  55 ′ and  56 ′, a stop  57 ′, a distal end  60 ′, a cradle  61 ′, a hole  62 ′, and a contact switch  80 ′. The base pad  50 ′ also carries a pneumatic cylinder  70 ′, which is coupled to the pull  52 ′ with a cable  75 ′. However, the gas supply  71 ′, the programmable logic controller  72 ′, the battery  73 ′, and the switches  74 ′ are off of the glove body  31 ′, preferably on a mount or platform  91  carried on a belt  92  around the operator&#39;s waist. A long hose  93  extends from the gas supply  71 ′, off the belt, across the operator&#39;s torso, down the operator&#39;s arm, and onto the base pad  50 ′, where the hose  93  couples with the pneumatic cylinder  70 ′ to provide gas to the pneumatic cylinder  70 ′. With the gas supply  71 ′ located off the glove body  31 ′, a larger-sized gas supply  71 ′ is carried than in the CTOD  30 , so that the gas supply  71 ′ lasts longer and needs to be replaced less frequently than with the CTOD  30 . 
     Operation of the CTOD  90  is similar to that of the CTOD  30 . The piston in the pneumatic cylinder  70 ′ intermittently and cyclically reciprocates between a forward position and a retracted position in the pneumatic cylinder  70 ′. Gas is supplied to the pneumatic cylinder  70 ′ through the hose  93 . Actuation of the pneumatic cylinder  70 ′ retracts the cable  75 ′. When the index finger stall  45 ′ is bent, such as would occur when a finger applied to the index finger stall  45 ′ is curled around the trigger  20 , the cable  75 ′ is extended and ready to be retracted so as to extend the index finger stall  45 ′ and the index finger applied thereto. When the cable  75 ′ is retracted, the cable  75 ′ is drawn back, and the proximal end  53 ′ of the pull  52 ′ is drawn toward the proximal end  34 ′ of the glove body  31 ′ to move the pull  52 ′ into the second position thereof. This causes the index finger stall  45 ′ to straighten. When the pneumatic cylinder  70 ′ retracts the cable  75 ′ quickly, the operator&#39;s index finger is quickly returned toward the extended position thereof. 
     A Third Embodiment 
       FIG. 3A  illustrates an embodiment of the present invention, constructed and arranged according to the principle of the invention, referred to as a cyclical trigger operation device (hereinafter, “CTOD”) and marked with the reference character  100 . The CTOD  100  is adapted to be used with the firearm  10  of  FIG. 1  to enable the operator to quickly and cyclically depress the trigger  20  of the firearm  10 . The CTOD  100  is very similar to the CTOD  30  and includes many identical structural features elements with the CTOD  30 . Those structural features and elements of the CTOD  100  which are identical to corresponding structural features and elements in the CTOD  30  are marked with identical reference characters, but are designated with an asterisk (“*”) symbol to distinguish them from those of the CTOD  30 . Where the CTOD  100  has identical structural features and elements as the CTOD  30 , they will merely be listed, as describing them would be unduly repetitive and burdensome for the reader. It should be understood, then, that the description for the particular structural feature or element with respect to the CTOD  30  is equally applicable to the corresponding identical structural feature and element with respect to the CTOD  100 , unless otherwise described. Finally, for simplicity of the illustrations, not all identical reference characters will be shown, if their corresponding identical reference characters are shown in a figure illustrating an alternate embodiment. 
     The CTOD  100  includes a glove body  31 *, a dorsal side  32 *, a palmar side  33 *, a proximal end  34 *, a distal end  35 *, an opening  36 *, an exterior surface  40 *, an interior surface  41 *, a strap  42 *, a thumb stall  44 *, an index finger stall  45 *, and finger stalls  46 *. The CTOD  100  includes a base pad  50 *, a spar  51 * extending from a distal end  63 * at the base pad  50 * to an axle  64 *, and a pull  52 * pivoted to the axle  64 * on the spar  51 * for movement along the double-arrowed arcuate line A* in  FIG. 2C . The pull  52 * includes a proximal end  53 *, a hole  54 *, struts  55 * and  56 *, a stop  57 *, a distal end  60 *, a cradle  61 *, a hole  62 *, and a contact switch  80 *. 
     The base pad  50 * carries a drive mechanism  101  for controlling the movement of the pull  52 * and the index finger stall  45 *. The base pad  50 * carries an electronic solenoid  102 , which is coupled to the pull  52 * with a cable  75 *. The solenoid  102  includes a piston or piston head that reciprocates through a stroke that is generally aligned parallel to the length of the spar  51 *. A battery  102  is coupled to the solenoid  102  to provide the solenoid with power. An onboard programmable logic controller  72 * is mounted on the base pad  52 * and powered by the battery  103 . The programmable logic controller  72 * controls the provision of current to the solenoid  102 . A plurality of switches  74 * are also carried on the base pad  52 * and coupled to the programmable logic controller  72 *, so that the user may depress or select one of the plurality of switches to instruct the programmable logic controller to control the drive mechanism  101  in a particular, pre-programmed way. 
     The solenoid  102  is aligned with the index finger stall  45 *, and the cable  75 * is coupled to the piston in the solenoid  102 . The piston in the solenoid  102  intermittently and cyclically reciprocates between a forward position and a retracted position in the solenoid  102 . Actuation of the solenoid  102  retracts the cable  75 *. When the index finger stall  45 * is bent, such as would occur when a finger applied to the index finger stall  45 * is curled around the trigger  20 , the cable  75 * is extended and ready to be retracted so as to extend the index finger stall  45 * and the index finger applied thereto. When the cable  75 * is retracted, the cable  75 * is drawn back, and the proximal end  53 * of the pull  52 * is drawn toward the proximal end  34 * of the glove body  31 * to move the pull  52 * into the second position thereof. This causes the index finger stall  45 * to straighten. When the solenoid  102  retracts the cable  75 * quickly, the operator&#39;s index finger is quickly returned toward the extended position thereof. 
     As with the CTOD  30  and the CTOD  90 , the operator can select the desired performance of the CTOD  100  by selecting one of the plurality of switches  74 *, and, when the operator&#39;s finger is placed against the trigger  20  and depressed to pull the trigger  20 , the contact switch  80 * is closed, and the contact switch  80 * transmits a signal to the programmable logic controller  72 * in the drive mechanism  101 . In response to receiving the signal, the programmable logic controller  72 * causes current to be intermittently and cyclically supplied to the solenoid, according to the pre-programmed control instructions corresponding to the selected one the of the plurality of switches  74 *, causing the solenoid  102  to reciprocate, and causing the cable  75 * to be intermittently and cyclically retracted. In response, the operator&#39;s index finger, applied in the index finger stall  45 * is intermittently and cyclically retracted toward the extended position along double-arrowed arcuate line A* in  FIG. 3A . The operator, however, continues to hold his finger down in the curled position to depress the trigger  20 . When the solenoid  102  retracts the cable  75 *, a greater force is applied to the operator&#39;s finger than he applies to it, so that the finger is pulled to the extended position. In the extended position of the finger, the finger is pulled off of or away from the trigger  20 , and the trigger  20  is returned to the ready position by the spring or other mechanism which returns the trigger  20  to the ready position. When the solenoid  102  has retracted a full stroke, the application of current to the solenoid  102  is removed, as instructed by the programmable logic controller  72 *, the operator&#39;s own force on his finger is now able to overcome the solenoid  102 , and his finger curls along line A* to depress the trigger  20 . When his finger depresses the trigger  20 , it extends the solenoid  102  a full stroke length so that the solenoid  102  is ready to retract. With the operator continuing to curl his finger, and the solenoid  102  intermittently and cyclically retracting the cable  75 * to intermittently and cyclically extend the finger, the operator&#39;s finger is intermittently and cyclically curled and extended, and the trigger  20  is intermittently and cyclically depressed to the depressed position and allowed to return to the ready position. In this way, the firearm  10  intermittently and rapidly fires bullets, emulating fully-automatic fire. 
     A Fourth Embodiment 
       FIG. 3B  illustrates an embodiment of the present invention, constructed and arranged according to the principle of the invention, referred to as a cyclical trigger operation device (hereinafter, “CTOD”) and marked with the reference character  110 . The CTOD  110  is adapted to be used with the firearm  10  of  FIG. 1  to enable the operator to quickly and cyclically depress the trigger  20  of the firearm  10 . The CTOD  110  is very similar to the CTOD  100  and includes many identical structural features elements with the CTOD  100 . Those structural features and elements of the CTOD  110  which are identical to corresponding structural features and elements in the CTOD  100  are marked with identical reference characters, but are designated with a double asterisk (“**”) symbol to distinguish them from those of the CTOD  100 . In some cases, the CTOD  110  has identical structural features and elements as the CTOD  100  but located in alternate locations. In such cases, the same reference character will be used, with the prime symbol, but the alternate location will be described. Where the CTOD  110  has identical structural features and elements as the CTOD  100  and those structural features and elements are located and used in an identical manner as in the CTOD  100 , they will merely be listed, as describing them would be unduly repetitive and burdensome for the reader. It should be understood, then, that the description for the particular structural feature or element with respect to the CTOD  100  is equally applicable to the corresponding identical structural feature and element with respect to the CTOD  110 , unless otherwise described. Finally, for simplicity of the illustrations, not all identical reference characters will be shown, if their corresponding identical reference characters are shown in a figure illustrating an alternate embodiment. 
     The CTOD  110  includes a glove body  31 **, a dorsal side  32 **, a palmar side  33 **, a proximal end  34 **, a distal end  35 **, an opening  36 **, an exterior surface  40 **, an interior surface  41 **, a strap  42 **, a thumb stall  44 **, an index finger stall  45 **, and finger stalls  46 **. The CTOD  110  includes a base pad  50 **, a spar  51 ** extending from a distal end  63 ** at the base pad  50 ** to an axle  64 **, and a pull  52 ** pivoted to the axle  64 ** on the spar  51 ** for movement along the double-arrowed arcuate line A** in  FIG. 3B . The pull  52 ** includes a proximal end  53 **, a hole  54 **, struts  55 ** and  56 **, a stop  57 **, a distal end  60 **, a cradle  61 **, a hole  62 **, and a contact switch  80 **. The base pad  50 ** also carries an electronic solenoid  102 **, which is coupled to the pull  52 ** with a cable  75 **. The solenoid  102 ** includes a piston or piston head that reciprocates through a stroke that is generally aligned parallel to the length of the spar  51 *. However, the battery  103 **, the programmable logic controller  72 **, and the switches  74 ** are each off of the glove body  31 **, preferably on a mount or platform  91 ** carried on a belt  92 ** around the operator&#39;s waist. A long cable  111  extends from the battery  103 **, off the belt  92 **, across the operator&#39;s torso, down the operator&#39;s arm, and onto the base pad  50 **, where the cable  111  couples with the solenoid  102 ** to provide current to the solenoid  102 **. With the battery  103 ** located off the glove body  31 **, a larger-sized battery  103 ** is carried than in the CTOD  100 , so that the battery  103 ** lasts longer and provides more current, and thus needs to be replaced less frequently than with the CTOD  100 . 
     Operation of the CTOD  110  is similar to that of the CTOD  100 . The piston in the solenoid  102 ** intermittently and cyclically reciprocates between a forward position and a retracted position in the solenoid  102 **. Current is supplied to the solenoid  102 ** through the cable  111  from the battery  103 **. Actuation of the solenoid  102 ** retracts the cable  75 **. When the index finger stall  45 ** is bent, such as would occur when a finger applied to the index finger stall  45 ** is curled around the trigger  20 , the cable  75 ** is extended and ready to be retracted so as to extend the index finger stall  45 ** and the index finger applied thereto. When the cable  75 ** is retracted, the cable  75 ** is drawn back, and the proximal end  53 ** of the pull  52 ** is drawn toward the proximal end  34 ** of the glove body  31 ** to move the pull  52 ** into the second position thereof. This causes the index finger stall  45 ** to straighten. When the solenoid  102 ** retracts the cable  75 ** quickly, the operator&#39;s index finger is quickly returned toward the extended position thereof. 
     A Fifth Embodiment 
       FIG. 4A  illustrates an embodiment of the present invention, constructed and arranged according to the principle of the invention, referred to as a cyclical trigger operation device (hereinafter, “CTOD”) and marked with the reference character  120 . The CTOD  120  is adapted to be used with the firearm  10  of  FIG. 1  to enable the operator to quickly and cyclically depress the trigger  20  of the firearm  10 . The CTOD  120  is similar to the CTOD  30  and includes many identical structural features elements with the CTOD  30 . Those structural features and elements of the CTOD  120  which are identical to corresponding structural features and elements in the CTOD  30  are marked with identical reference characters, but are designated with a tilde (“˜”) symbol to distinguish them from those of the CTOD  30 . Where the CTOD  120  has identical structural features and elements as the CTOD  30 , they will merely be listed, as describing them would be unduly repetitive and burdensome for the reader. It should be understood, then, that the description for the particular structural feature or element with respect to the CTOD  30  is equally applicable to the corresponding identical structural feature and element with respect to the CTOD  120 , unless otherwise described. Finally, for simplicity of the illustrations, not all identical reference characters will be shown, if their corresponding identical reference characters are shown in a figure illustrating an alternate embodiment. 
     The CTOD  120  includes a glove body  31 ˜, a dorsal side  32 ˜, a palmar side  33 ˜, a proximal end  34 ˜, a distal end  35 ˜, an opening  36 ˜, an exterior surface  40 ˜, an interior surface  41 ˜, a strap  42 ˜, a thumb stall  44 ˜, an index finger stall  45 ˜, and finger stalls  46 ˜. The CTOD  120  includes a base pad  50 ˜, a spar  51 ˜ extending from a distal end  63 ˜ at the base pad  50 ˜ to an axle  64 ˜, and a pull  52 ˜ pivoted to the axle  64 ˜ on the spar  51 ˜ for movement along the double-arrowed arcuate line A˜ in  FIG. 2C . The pull  52 ˜ includes a proximal end  53 ˜, a hole  54 ˜, struts  55 ˜ and  56 ˜, a stop  57 ˜, a distal end  60 ˜, a cradle  61 ˜, a hole  62 ˜, and a contact switch  80 ˜. 
     The base pad  50 ˜ carries a drive mechanism  121  for controlling the movement of the pull  52 ˜ and the index finger stall  45 ˜. The drive mechanism  121  includes a lever arm  122  having a pivot end  123  secured to the base pad  50 ˜ and an opposed free end  124 . A cable  75 ˜ extends from the free end  124  to the hole  54 ˜ in the proximal end  53 ˜ of the pull  52 ˜, so that movement of the lever arm  122  imparts movement to the cable  75 ˜ and thus also to the pull  52 ˜. The drive mechanism  121  also includes an eccentric  125  mounted for rotational movement on the base pad  50 ˜. The eccentric  125  is disposed proximate to the lever arm  122  between the pivot and free ends  123  and  124 . The eccentric  125  is mounted to a motor  130 , powered by a battery  131  on the base pad  50 ˜, and as the motor rotates the eccentric  125 , which has an off-center axis of rotation, the eccentric  125  rotates as a plain bearing against the lever arm  122 , causing the lever arm  122  to pivot cyclically, or oscillate, about the pivot end  123  in response to the rotational movement of the eccentric  125 . An onboard programmable logic controller  72 ˜ is mounted on the base pad  52 ˜ and powered by the battery  131 . The programmable logic controller  72 ˜ controls the provision of current to the motor  130 , and thus controls the rotation of the eccentric  125  and the oscillation of the lever arm  122 . A plurality of switches  74 ˜ are also carried on the base pad  52 ˜ and coupled to the programmable logic controller  72 ˜, so that the user may depress or select one of the plurality of switches to instruct the programmable logic controller to control the drive mechanism  121  in a particular, pre-programmed way. 
     The lever arm  122  oscillates between a forward position and a retracted position. Actuation of the lever arm  122  in the retracted position retracts the cable  75 ˜. When the index finger stall  45 ˜ is bent, such as would occur when a finger applied to the index finger stall  45 ˜ is curled around the trigger  20 , the cable  75 ˜ is extended and ready to be retracted so as to extend the index finger stall  45 ˜ and the index finger applied thereto. When the cable  75 ˜ is retracted, the cable  75 ˜ is drawn back, and the proximal end  53 ˜ of the pull  52 ˜ is drawn toward the proximal end  34 ˜ of the glove body  31 ˜ to move the pull  52 ˜ into the second position thereof. This causes the index finger stall  45 ˜ to straighten. When the lever arm  122  retracts the cable  75 ˜ quickly, the operator&#39;s index finger is quickly returned toward the extended position thereof. 
     As with the other embodiments of the CTOD  30 ,  90 ,  100 , and  110 , the operator can select the desired performance of the CTOD  120  by selecting one of the plurality of switches  74 ˜, and, when the operator&#39;s finger is placed against the trigger  20  and depressed to pull the trigger  20 , the contact switch  80 ˜ is closed, and the contact switch  80 ˜ transmits a signal to the programmable logic controller  72 ˜ in the drive mechanism  121 . In response to receiving the signal, the programmable logic controller  72 ˜ causes current to be supplied to the motor  130  to rotate, according to the pre-programmed control instructions corresponding to the selected one the of the plurality of switches  74 ˜. In response, the eccentric  125  rotates against the lever arm  122 , imparting oscillatory movement to the lever arm  122 . The cable  75 ˜, connected to the free end  124  of the lever arm  125 , is intermittently and cyclically retracted in response. This causes the pull  52 ˜ to intermittently and cyclically move along the double-arrowed arcuate line A˜, and, in response, the operator&#39;s index finger, applied in the index finger stall  45 ˜ is intermittently and cyclically retracted toward the extended position along line A˜ in  FIG. 4A . The operator, however, continues to hold his finger down in the curled position to depress the trigger  20 . 
     When the lever arm  122  retracts the cable  75 ˜, a greater force is applied to the operator&#39;s finger than he applies to it, so that the finger is pulled to the extended position. In the extended position of the finger, the finger is pulled off of or away from the trigger  20 , and the trigger  20  is returned to the ready position by the spring or other mechanism which returns the trigger  20  to the ready position. When the lever arm  122  has retracted a full stroke, the eccentric is in contact with the lever arm  122  and is about to rotate to a low displacement position in its cycle, as instructed by the programmable logic controller  72 ˜, and so the operator&#39;s own force on his finger is now able to overcome the lever arm  122 , and his finger curls along line A˜ to depress the trigger  20 . When his finger depresses the trigger  20 , it moves the lever arm  122  into the forward position thereof, where the lever arm  122  is ready to be pushed back into the retracted position by the rotating eccentric  125 . With the operator continuing to curl his finger, and the lever arm  122  intermittently and cyclically retracting the cable  75 ˜ so as to intermittently and cyclically extend the finger, the operator&#39;s finger is intermittently and cyclically curled and extended, and the trigger  20  is intermittently and cyclically depressed to the depressed position and allowed to return to the ready position. In this way, the firearm  10  intermittently and rapidly fires bullets, emulating fully-automatic fire. 
     A Sixth Embodiment 
       FIG. 4B  illustrates an embodiment of the present invention, constructed and arranged according to the principle of the invention, referred to as a cyclical trigger operation device (hereinafter, “CTOD”) and marked with the reference character  140 . The CTOD  140  is adapted to be used with the firearm  10  of  FIG. 1  to enable the operator to quickly and cyclically depress the trigger  20  of the firearm  10 . The CTOD  140  is very similar to the CTOD  120  and includes many identical structural features elements with the CTOD  120 . Those structural features and elements of the CTOD  140  which are identical to corresponding structural features and elements in the CTOD  120  are marked with identical reference characters, but are designated with a double tilde (“˜˜”) symbol to distinguish them from those of the CTOD  120 . In some cases, the CTOD  140  has identical structural features and elements as the CTOD  120  but located in alternate locations. In such cases, the same reference character will be used, with the prime symbol, but the alternate location will be described. Where the CTOD  140  has identical structural features and elements as the CTOD  120  and those structural features and elements are located and used in an identical manner as in the CTOD  120 , they will merely be listed, as describing them would be unduly repetitive and burdensome for the reader. It should be understood, then, that the description for the particular structural feature or element with respect to the CTOD  120  is equally applicable to the corresponding identical structural feature and element with respect to the CTOD  140 , unless otherwise described. Finally, for simplicity of the illustrations, not all identical reference characters will be shown, if their corresponding identical reference characters are shown in a figure illustrating an alternate embodiment. 
     The CTOD  140  includes a glove body  31 ˜˜, a dorsal side  32 ˜˜, a palmar side  33 ˜˜, a proximal end  34 ˜˜, a distal end  35 ˜˜, an opening  36 ˜˜, an exterior surface  40 ˜˜, an interior surface  41 ˜˜, a strap  42 ˜˜, a thumb stall  44 ˜˜, an index finger stall  45 ˜˜, and finger stalls  46 ˜˜. The CTOD  140  includes a base pad  50 ˜˜, a spar  51 ˜˜ extending from a distal end  63 ˜˜ at the base pad  50 ˜˜ to an axle  64 ˜˜, and a pull  52 ˜˜ pivoted to the axle  64 ˜˜ on the spar  51 ˜˜ for movement along the double-arrowed arcuate line A˜˜ in  FIG. 4B . The pull  52 ˜˜ includes a proximal end  53 ˜˜, a hole  54 ˜˜, struts  55 ˜˜ and  56 ˜˜, a stop  57 ˜˜, a distal end  60 ˜˜, a cradle  61 ˜˜, a hole  62 ˜˜, and a contact switch  80 ˜˜. The base pad  50 ˜˜ also carries a cable coupling  141 , to which the cable  75 ˜˜ is coupled, and which is inside of a coupling housing  142 . A cable housing  143  extends from the coupling housing  142  off the glove body  31 ˜˜ to a mount or platform  91 ˜˜ carried on a belt  92 ˜˜ around the operator&#39;s waist. A cable  144  is disposed within the cable housing  143  and is coupled to the cable coupling  141  in the coupling housing  142  at one end. At its other end, the cable  144  is coupled to a free end  124 ˜˜ of a lever arm  122 ˜˜ mounted for pivotal movement about a pivot end  123 ˜˜, so that the free end  124 ˜˜ oscillates and imparts reciprocal movement to the cable  144 . The platform  91  includes an eccentric  125 ˜˜ driving the lever arm, a motor  130 ˜˜ rotating the eccentric  125 ˜˜, and a battery  131 ˜˜ powering the eccentric  125 ˜˜, as well as a programmable logic controller  72 ˜˜ and switches  74 ˜˜. The cable  144  is carried in the cable housing  143  without slack, so that movement of the free end  124  of the lever arm on the platform  91  on the belt  92  immediately imparts movement to the cable  75 ˜˜ and to the pull  52 ˜˜. With the battery  131 ˜˜ located off the glove body  31 ˜˜, a larger-sized battery  131 ˜˜ is carried than in the CTOD  120 , so that the battery  131 ˜˜ lasts longer and provides more current, and thus needs to be replaced less frequently than with the CTOD  120 . 
     Operation of the CTOD  140  is similar to that of the CTOD  120 . The motor  130 ˜˜ rotates, according to the pre-programmed control instructions corresponding to the selected one the of the plurality of switches  74 ˜˜. In response, the eccentric  125 ˜˜ rotates against the lever arm  122 ˜˜, imparting oscillatory movement to the lever arm  122 ˜˜. The cable  144 , connected to the free end  124 ˜˜ of the lever arm  125 ˜˜, is intermittently and cyclically retracted in response. This causes the cable  75 ˜˜, on the glove boy  31 ˜˜ and to which the cable  144  is attached, to also intermittently and cyclically retract. In turn, this causes the pull  52 ˜˜ to intermittently and cyclically move along the double-arrowed arcuate line A˜˜, and, in response, the operator&#39;s index finger, applied in the index finger stall  45 ˜˜ is intermittently and cyclically retracted toward the extended position along line A˜˜ in  FIG. 4B . The operator, however, continues to hold his finger down in the curled position to depress the trigger  20 . When the index finger stall  45 ˜˜ is bent, such as would occur when a finger applied to the index finger stall  45 ˜˜ is curled around the trigger  20 , the cable  75 ˜˜ is extended and ready to be retracted so as to extend the index finger stall  45 ˜˜ and the index finger applied thereto. When the cable  75 ˜˜ is retracted, the cable  75 ˜˜ is drawn back, and the proximal end  53 ˜˜ of the pull  52 ˜˜ is drawn toward the proximal end  34 ˜˜ of the glove body  31 ˜˜ to move the pull  52 ˜˜ into the second position thereof. This causes the index finger stall  45 ˜˜ to straighten. When the lever arm  122 ˜˜ oscillates to the rearward position thereof, it retracts the cable  75 ˜˜ quickly, and the operator&#39;s index finger is quickly returned toward the extended position thereof. 
     A Seventh Embodiment 
       FIG. 5  illustrates an embodiment of the present invention, constructed and arranged according to the principle of the invention, referred to as a cyclical trigger operation device (hereinafter, “CTOD”) and marked with the reference character  150 . 
     The CTOD  150  is rail-mounted to a barrel  14  of the firearm  10 , as firearm accessories commonly are, and is adapted to enable the operator to quickly and cyclically depress the trigger  20  of the firearm  10 . The CTOD  150  includes a pull  151  and a housing  152  containing a drive mechanism  153  coupled to the pull  151  to impart intermittent and cyclical movement to the pull  151 . The pull  151  is a solid body in the form of a loop or ring sized and shaped to receive a finger. The pull  151  is rigid and is sized to fit in the finger gap  24  in front of the trigger  20  on the firearm  10 . A cable  154  is secured to the pull  151  and extends forwardly to the drive mechanism  153  in the housing  152 .  FIG. 5  shows the interior of the housing  152 , as it would appear with a cover removed, for clarity of the illustration and description. 
     The drive mechanism  153  of the CTOD  150  is identical to the drive mechanism  153  of the CTOD  30 . It includes a pneumatic cylinder  160  with a stroke that is generally aligned along the length of the barrel  14 . The drive mechanism  153  has a gas supply  161  to supply a gas to the pneumatic cylinder  160 . In  FIG. 5 , the gas supply  161  is a cylindrical housing. The gas supply  161  is preferably replaceable gas cartridges, such as CO2 cartridges. The CO2 cartridges can be coupled to the pneumatic cylinder  160 . A programmable logic controller  162  is carried in the housing  152  and is powered by a small battery  163 . The programmable logic controller  162  controls the application and removal of gas to and from the pneumatic cylinder  160 . A plurality of switches  164  are also carried in the housing  152  and are coupled to the programmable logic controller  162 , so that the user may depress or select one of the plurality of switches to instruct the programmable logic controller to control the drive mechanism  153  in a particular, pre-programmed way, as is discussed later. Though the drive mechanism  153  shown in  FIG. 5  is identical to the drive mechanism  65  used with the CTOD  30 , one having ordinary skill in the art will readily appreciate that the drive mechanism  153  may be replaced with the drive mechanisms  101  or  121  for the CTODs  100  and  120 , respectively. When the drive mechanism  121  is sued, it is preferable that the cable  75 ˜ is routed through one or several pulleys to increase the retracting force of the lever arm  122 . 
     The cable  154  extends from the pneumatic cylinder  160  to the pull  151 , thereby operatively coupling the drive mechanism  153  to the pull  151  to impart movement to the pull  151  in response to actuation of the drive mechanism  153 . The pneumatic cylinder  160  is aligned with the movement of the trigger  20 , and the cable  154  is coupled to a piston in the pneumatic cylinder  160 . The piston in the pneumatic cylinder  160  intermittently and cyclically reciprocates between a forward position and a retracted position in the pneumatic cylinder  160 . Actuation of the pneumatic cylinder  160  retracts the cable  154 . 
     In operation, an operator selects the desired performance of the CTOD  150  by selecting one of the plurality of switches  164 , and then energizes the CTOD  150 . The switches  164  each correspond to various performance functions of the CTOD  150 . Some of the switches allow the operator to select a cycling speed. For instance, the operator may select a switch setting the cycling speed at three hundred rpm, in response to which the pneumatic cylinder will reciprocate approximately three hundred times in one minute to cycle movement of the pull  151  three hundred times in a minute, emanating a fast firing firearm. In another example, the operator may select a switch setting the cycling speed at nine hundred rpm, in response to which the pneumatic cylinder will reciprocate approximately nine hundred times in one minute to cycle movement of the pull  151  nine hundred times in a minute, emulating a very fast firing firearm. Some of the switches allow the operator to select a cycling duration. For example, the operator may select a switch setting the cycling duration to three pulses, in which case the pneumatic cylinder will reciprocate three times, so as to emulate a three-round burst of fire. In another example, the operator may select a switch setting the cycling duration to five pulses, in which case the pneumatic cylinder will reciprocate five times, so as to emulate a five-round burst of fire. In yet another example, the operator may select a switch setting the cycling duration to two seconds, in which case the pneumatic cylinder will reciprocate for two seconds, so as fire repeatedly for two seconds and then pause or stop. 
     After the performance of the CTOD  150  is set, the operator grips the firearm  10  at the pistol grip  21 , placing his index finger proximate to the trigger  20 . He then places his index finger through the pull  151  until the pull  151  fully and securely encircles his index finger. In some cases, a thimble may be worn which has a hook to improve the securement of the pull  151 . The operator shoulders or readies the firearm  10  and takes aim at a target. Once a target is acquired, the operator fires the weapon by placing his finger against the trigger  20  and depressing or pulling the trigger  20  back toward the grip  21 . 
     Upon the operator initially energizing the CTOD  150 , the programmable logic controller  162  receives an activation signal and causes gas to be intermittently and cyclically supplied to and drawn from the pneumatic cylinder  160 , such as through an on-board valve, according to the pre-programmed control instructions corresponding to the selected one the of the plurality of switches  164 , causing the pneumatic cylinder  160  to reciprocate, and causing the cable  154  to be intermittently and cyclically retracted. In response, the operator&#39;s index finger, applied in pull  151 , is intermittently and cyclically retracted toward the extended position along double-arrowed arcuate line B in  FIG. 5 . The operator, however, continues to hold his finger down in the curled position to depress the trigger  20 . When the pneumatic cylinder  160  retracts the cable  154 , a greater force is applied to the operator&#39;s finger than he applies to it, so that the finger is pulled to the extended position. In the extended position of the finger, the finger is pulled off of or away from the trigger  20 , and the trigger  20  is returned to the ready position by the spring or other mechanism which returns the trigger  20  to the ready position. When the pneumatic cylinder  160  has retracted a full stroke, the supply of gas to the pneumatic cylinder  160  is removed, as instructed by the programmable logic controller  162 , the operator&#39;s own force on his finger is now able to overcome the pneumatic cylinder  160 , and his finger curls along line B to depress the trigger  20 . When his finger depresses the trigger  20 , it extends the pneumatic cylinder  160  a full stroke length so that the pneumatic cylinder  160  is ready to retract. With the operator continuing to curl his finger, and the pneumatic cylinder  160  intermittently and cyclically retracting the cable  154  to intermittently and cyclically extend the finger, the operator&#39;s finger is intermittently and cyclically curled and extended, and the trigger  20  is intermittently and cyclically depressed to the depressed position and allowed to return to the ready position. In this way, the firearm  10  intermittently and rapidly fires bullets, emulating fully-automatic fire. 
     The present invention is described above with reference to a preferred embodiment. However, those skilled in the art will recognize that changes and modifications may be made in the described embodiment without departing from the nature and scope of the present invention. To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope thereof.