BACKGROUND OF THE INVENTION 
     The present invention relates to an archery device for assisting in producing accurate shots. In particular, the present invention relates to a bowstring release mechanism with a delayed release. 
     Many archers in both hunting and target shooting experience inaccurate shots due to flinching or movement at the critical time of releasing the bowstring to launch an arrow. Flinching or movement may be caused by anticipation of a shot, physical breakdown, or mental deterioration. 
     Anticipation of the shot, or target anxiety, often causes tension and excessive movement of the bow due to the expectation of the coming explosion and recoil of the shot. After drawing the bowstring and arrow, the archer takes aim. Physical breakdown of the shot normally occurs when the archer has aimed too long. The maximum ideal holding period is 5-7 seconds. Thus, when an archer is at full draw for too long, his or her muscles begin to weaken and shooting form breaks down causing an inaccurate shot. Finally, mental deterioration occurs due to the mind&#39;s inability to concentrate on more than one thing at a time. During execution of a shot, the archer should be focused exclusively on aiming. Focusing on other events such as gently releasing the bowstring or a trigger, utilizing a proper breathing technique and exercising self control to drawn down if all the requisite conditions to a good shot are not met, may inhibit the archer from maintaining a proper site picture and thus result in an inaccurate shot. 
     The use of conventional mechanical or electrical release mechanisms do not address or alleviate these concerns. The archer must still perform the aforementioned requisite conditions along with aiming during the critical time of shot release thereby increasing the likelihood of flinching or movement during that time. 
     U.S. Pat. No. 5,243,957, incorporated by reference herein, illustrates these limitations with a release mechanism for use with a two handed bow activated by a trigger switch on one of the hand grips. At the critical time of releasing the bowstring, an archer still must be concerned with gently activating the trigger, utilizing a proper breathing technique, exercising self-control to draw down the bow if the requisite conditions are not met, and maintaining a proper site picture or focus on the target. Attempting to achieve all these conditions at the critical time increases the likelihood of mental deterioration and physical breakdown. Furthermore, because the archer knows the bowstring will release immediately upon activation of the switch, anticipation of the shot and the associated movement or flinching will only compound the difficulty of achieving an accurate shot, all generally referred to as “target panic”. 
     Harklau, U.S. Pat. No. 5,575,269, discloses a bowstring release apparatus with a bowstring affixed to a bow. The bowstring release mechanism is comprised of an activation switch, a timing device, and a release mechanism. The activation switch is connected to the timing device which in turn is connected to the release mechanism. The bowstring release apparatus is activated by the activation switch which initiates the start of a timing period. The timing device, connected to the activation switch, establishes a length of time representing the time period. The release mechanism, connected to the timing device, releases the secured bowstring after expiration of the time period. Unfortunately, the electronic based device taught by Harklau is expensive, complicated, and difficult to repair while hunting away from town. Accordingly, if the electronics malfunction, there is little likelihood that the archer will be able to repair the device. Moreover, if the device of Harklau becomes wet, such as being used while hunting, or the battery runs low, then the device will not function at all. 
     What is desired, therefore, is a bowstring release apparatus that relieves “target panic”, is relatively easy to repair while hunting, and is inexpensive. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the aforementioned drawbacks of the prior art by providing a release system for use with a projectile firing device that includes a trigger for initiating a time period. The device includes a timer with fluid that is operable with the trigger for establishing, at least in part, a time period. The device also includes a release mechanism operable with the timer for propelling the projectile based upon the time period. 
     The foregoing and other objectives, features and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a perspective view of a drawn bow incorporating the bowstring release mechanism of the present invention. 
     FIG. 2 is a exemplary embodiment of an archery release apparatus including a fluid based timer in the opened position and a flow resister. 
     FIG. 3 is the archery release apparatus of FIG. 2 in the closed position. 
     FIG. 4 is a partial view of a flow resister for the release apparatus of FIG.  2 . 
     FIG. 5 is a partial view of a variable flow resister for the release apparatus of FIG. 2, shown at two different positions. 
     FIG. 6 partial view of an alternative variable flow resister for the release apparatus of FIG. 2, shown at two different positions. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a preferred embodiment of the present invention includes a bowstring release mechanism  10  used by an archer  12  to shoot an arrow  14  by releasably securing a bowstring  16 . The bowstring release mechanism  10  may include a retainer wrist loop  18  and a case  20 . Alternatively, the retainer loop  18  (if included) may be any type of retention device or structure that assists the archer in holding the case  20  while being tensioned by the bowstring  16 . Referring to FIG. 2, the case  20  may include a head  22  with a release mechanism  24 . A trigger  26  is pushed or otherwise biased forward toward the front of the head  22  thereby releasing the jaw  28  and permitting it to be opened. After locating the bowstring  16  within the jaw  28 , the trigger  26  is pulled or otherwise biased backward away from the front of the head  22 . With the trigger  26  moved backward, the jaw  28  may be locked in a closed position with the bowstring  16  retained therein. The head  22  maybe modular and attached to a body  27  by a securement mechanism, such as a pair of bolts  31 . The body  27  defines a cavity  40  therein, generally having a piston supply conduit  42  and a fluid reservoir  44  filled with a fluid  45 , such as hydraulic fluid. The trigger  26  is pulled against a first piston  50  which in turn forces fluid  45  within the cavity  40  to press against a second piston  52 . As the second piston  52  moves, as a result of pulling on the trigger  26 , a spring  54  is compressed or otherwise tensioned, as shown in FIG.  3 . The first and second pistons  50 ,  52  may include a respective gasket  55 ,  56  to prevent the passage of the fluid  45 . After the archer releases the trigger  26 , the spring  54  pushes the second piston  52 , which in turn forces fluid  45  within the cavity  40  to press against the first piston  50 , which in turn presses against the trigger  26 . As the trigger  26  is pressed outward, the jaw  28  opens under tension thereby releasing the bowstring  16  retained therein. 
     To control the rate of the fluid flow and provide a delayed release after releasing the trigger  26 , a flow resistor  60  may be included, as shown in FIG.  4 . The flow resistor  60  includes an orifice  62  that inhibits the free flow of the fluid  45  from the reservoir  44  into the piston supply conduit  42  (and vice versa). While the use of a flow resistor  60  is acceptable, many archers may desire to vary or otherwise select the delay incurred. One technique to vary the delay is to select a fluid  45  with the appropriate characteristics, such as viscosity. Referring to FIG. 5, the preferred technique to vary the delay is to include a variable flow resister  70 . The variable flow resister  70  may include a metering valve  72  comprised of a nut  78  or other device that may be adjusted in depth, a needle  74  affixed to the nut  78 , and a spring  76  surrounding the needle  74 . By varying the proximity of the needle with respect to the orifice  62 , the archer may readily adjust the delay, as shown in the two expanded views of FIG.  5 . This variance in the proximity may be achieved, for example, by screwing the nut  78  within a threaded cavity. 
     The archer  12  utilizes the bowstring release mechanism  10  by securing it to the bowstring  16 . The archer  12  then draws the bowstring  16  and obtains a proper sight picture. Upon achieving a proper sight picture, the archer  12  releases the trigger  26  which initiates a firing sequence. It is to be understood that the “trigger” as used herein, relates to any mechanism, such as an action by the archer or simply the lack of an action, that thereafter results in the releasing of the arrow  14 . A delay, or variable time delay mechanism is incorporated into the firing sequence and occurs after releasing the trigger  26 . The delay, or variable time delay, allows the archer  12 , after releasing the trigger  26 , to reacquire the proper sight picture and focus exclusively on aiming. Upon expiration of the time delay, the bowstring release mechanism  10  causes the jaw  28  to release the bowstring  16  and launch the arrow  14 . 
     The preferred embodiment improves the shot of the archer  12  by incorporating a time delay into the firing sequence to prevent archer flinching or movement. Shot anticipation is eliminated, or otherwise reduced, due to the shot occurring at a time after releasing the trigger  26 . It is to be understood that the time delay may likewise be triggered based on any other “releasing action” of the bowstring release mechanism  10 , which is dependant on the particular type of bowstring release mechanism  10  used. Mental deterioration does not occur once the trigger  26  is released, no other actions are required, and thus the archer  12  may focus exclusively on aiming. Also, physical deterioration is prevented by establishing a range of potential times to ensure that the shot occurs prior to physical breakdown. 
     If desired, the bowstring release may include an indicator, preferably on the side thereof, indicating the time duration of the delay. Adjustment of the delay, such as by changing the relative proximity of the needle valve to the orifice, likewise results in a change in the indicator. 
     After further consideration, the present inventor came to the realization that the flow resistor, and variable flow resistor, results in substantial resistance to the pulling of the trigger  26 . The archer  12  may tend to get tired having to pull hard on the trigger  26  to move the fluid from the piston supply conduit into the reservoir. Referring to FIG. 6, an alternative embodiment includes spring based variable valve resister  90 . The variable valve resister  90  includes a nut  92 , a support  94  defining a hole therein, a spring  96  sized to fit within the hole, and a needle  98  including a hole  100  therethrough. The needle  98  is secured with a pin  102  through an elongate vertical slot  104 . As the trigger  26  is pulled, the fluid is pressed against the metering valve and accordingly compressing the spring and lowering the needle  98 . This moves the metering valve away from the orifice  62  resulting in less resistance to the movement of fluid from the piston supply conduit to the reservoir. After the trigger  26  is fully retracted, or otherwise maintained in a relatively constant position, the metering valve will have a tendency to move the needle  98  forward under pressure of the spring  98  until the pin  102  reaches the top of the elongate vertical slot  104 . In addition, upon releasing the trigger  26  the metering valve will likewise move forward, if not already moved forward in the same manner, thereby inhibiting the flow of fluid through the orifice  62  to a greater extent than during pulling of the trigger  26 . This dual resistance fluid system reduces the stress on the archer to move additional fluid into the reservoir while simultaneously permitting effective control over the delay. In addition, the delay may be readily changed modifying the height of the nut  92 . It is to be understood that the fluid based timer may operate in conjunction with any other suitable mechanism to result in the release of the arrow. In addition, it is to be understood that a variable flow resister may change resistance based on other fluid or mechanical techniques. 
     All the references cited herein are incorporated by reference. 
     The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
A release system for use with a projectile firing device includes a trigger for initiating a time period. The device includes a timer with fluid that is operable with the trigger for establishing, at least in part, a time period. The device also includes a release mechanism operable with the timer for propelling the projectile based upon the time period.