Abstract:
A method of firing a paintball marker and dual trigger mechanism for a paintball marker are disclosed. The dual switch includes a first and a second trigger position sensors configured and arranged to detect the position of said trigger. A circuit is operatively connected to the first and second trigger position sensors and the projectile firing mechanism of the paintball marker. The circuit is configured to initiate a firing operation with said projectile firing mechanism when the first and second trigger position sensors indicate that the trigger has been depressed. The method includes the steps of detecting the position of the trigger with the first trigger position sensor and the second trigger position sensor and initiating a firing operation when the first and second trigger position sensors indicate that the trigger has been depressed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to earlier filed U.S. Provisional Patent Application Ser. No. 60/864,176, filed on Nov. 3, 2006, the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to electrical and optical trigger mechanisms and more specifically to a dual trigger mechanism for a paintball marker. 
     2. Background of the Related Art 
     There are a number of methods employed by the manufacturers of paintball markers for detecting the movement of the trigger of a device, such as a paintball marker, in order to initiate a firing cycle. Such a firing cycle can be carried out in a purely mechanical nature where a linkage, for example, opens a valve to release air for launching. Alternatively, an electrically actuatable valve, such as a solenoid valve, can be used for this purpose. 
     First, an electrical switch may be used. In particular, the electrical switch is in direct or indirect mechanical contact with the trigger such that when the trigger is depressed, the switch is actuated and therefore makes—or in some cases, breaks—an electrical circuit in order to generate an electrical signal which is used to initiate a firing cycle. 
     Second, an optical sensor assembly may be used. The optical sensor assembly includes an emitter which typically, but not exclusively, emits infra-red radiation and a receiver; the assembly is mounted in such a way as to generate an electrical signal which varies in magnitude in relation to the position of the trigger, without having any mechanical contact with the trigger; the firing cycle is initiated when the magnitude of the signal reaches a preset level. 
     Each of these methods has advantages and disadvantages. In particular, the electrical switch mechanically “clicks” when actuated which provides positive tactile feedback to the user, which some users find desirable. The switch is also internally sprung in order to return the switch to its non-actuated position which removes the need for an external trigger return mechanism and also provides the user with further tactile feedback. However, switches are prone to electrical noise from a phenomenon common to all electrical switches called “switch contact bounce,” which can result in unwanted firing cycle initiation. To counteract switch contact bounce electrical or software filtering of the switch generated electrical signal is required. Furthermore, an electrical switch can only generate a digital signal, where the switch is either actuated or not, which limits how easily the electrical noise can be filtered. 
     The optical sensor does not suffer from switch contact bounce as there are no electrical contacts and the analogue electrical signal provides better monitoring of the trigger position. Also, because the sensor assembly has no moving parts it is not prone to wear and tear. However, the non-contact arrangement of the sensor means that there is no return mechanism for the trigger, which means that an external trigger return mechanism is required. Furthermore, the non-contact arrangement provides no tactile feedback in the form of a “click,” which many users find desirable. 
     Typically, paintball marker users will prefer one system or the other which means that the market for a product which uses one system over the other is divided. It is therefore commercially advantageous for a paintball marker to satisfy both groups of users. 
     Additionally, in the prior art, it is know that it is possible, on only one pull of the trigger of a paintball marker, to issue multiple firing signals to fire multiple paintballs. In electronic markers, a single trigger pull can cause switch contact bounce resulting in multiple firings. Also, in all types of markers it is possible to exploit the recoil of the marker during firing while holding the trigger down to enable the marker to fire automatically without pulling the trigger again. This phenomenon is referred to within the art as “mechanical bounce” or “trigger bounce” and is undesirable, particularly in tournament play. 
     SUMMARY OF THE INVENTION 
     The present invention solves the problems of the prior art by providing a dual trigger mechanism that is selectable by the user to use either an electrical switch, an optical sensor switch or both as desired. Furthermore the invention of the present invention eliminates “mechanical bounce” operation of a paintball marker. 
     The dual switch includes a first and a second trigger position sensors configured and arranged to detect the position of said trigger. A circuit is operatively connected to the first and second trigger position sensors and the projectile firing mechanism of the paintball marker. The circuit is configured to initiate a firing operation with the projectile firing mechanism when the first and second trigger position sensors indicate that the trigger has been depressed. The method includes the steps of detecting the position of the trigger with the first trigger position sensor and the second trigger position sensor and initiating a firing operation when the first and second trigger position sensors indicate that the trigger has been depressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where: 
         FIG. 1  is a cross-section view of a grip of a paintball marker, which illustrates the dual switch mechanism of the present invention; 
         FIG. 2  is a block diagram of the circuit for the dual trigger mechanism; 
         FIG. 3  is a flow diagram of the firing circuit logic when both the electrical switch and the optical sensor are enabled; 
         FIG. 4  is a flow diagram of the firing circuit logic when the optical sensor has been disabled; and 
         FIG. 5  is a flow diagram of the firing circuit logic when the electrical switch has been disabled. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In an effort to provide a complete solution that will overcome the problems associated with each system, the present invention proposes a dual trigger mechanism, which combines an electrical switch with an optical sensor assembly in order to produce a mechanism which has all of the advantages of each type of system and none of the disadvantages. 
     Referring now to  FIGS. 1 and 2 , the dual trigger mechanism of the present invention comprises a trigger  10  mechanically connected to and movable within a grip frame  12  of a paintball marker. The trigger  10  may be configured to pivot or slide and be spring-biased as desired. The trigger  10  further includes two prongs  14 ,  16 , one of which has either a fixed or an adjustable length, the other of which has an adjustable length. An optical sensor assembly  18  is also provided and includes an emitter  22 , which emits electromagnetic radiation, such as infra-red or visible light radiation, and a receiver  20  which receives the radiation. The optical sensor assembly  18  is mounted in such a way that one prong, prong  16 , for instance, on the trigger  10  interrupts the passage of radiation from the emitter  22  to the receiver  20  as the trigger  10  is pivoted or slid from a “released” position at one end of its range of travel to a “depressed” position at the other end of its range of travel. The second prong  14  makes contact with an actuator of an electrical switch  24 , such that the actuator is actuated as the trigger  10  is depressed. A compact micro switch is preferable for use as the electrical switch  24 . However, any type of switch or sensor may be used. The length of this second prong  14  can be adjusted in order to move the actuation point with respect to the trigger travel, or to remove any contact between the prong  14  and the switch  24  altogether. It is also possible that prong  16  is adjustable. 
     Both the switch  24  and the optical sensor assembly  18  are electrically connected to an electronic circuit board  26  which also includes an electrical circuit to control the firing of the paintball marker. In the case of the micro switch  24 , it may be desirable to include a low pass filter  28  to “debounce” the switch. The optical sensor assembly  18  may also be converted to a digital signal by an analog to digital converter  30 . 
     The electrical switch  24  and optical sensor assembly  18  may be selectively enabled depending upon the desires of the user, via programmable settings  32 ,  34 . This feature enables the user to select either the switch  24  or the optical sensor assembly  18  or both as the source of the signal that is used to initiate the firing cycle. In particular, a microprocessor  36  is provided with firing circuit logic  38 , described further below and shown in  FIGS. 3-5 . The microprocessor  36  is electrically connected to the firing control  40  of the paintball marker. The microprocessor  36 , through application of the firing circuit logic  38 , determines if the preconditions for initiating a firing cycle have been met and, if so, initiates the firing control  40  of the paintball marker to discharge a paintball. 
     Referring to  FIG. 3 , during dual operation of the switches or sensors  18 ,  24  and prior to the first shot, when the trigger  10  is released, the micro switch  24  is open and the signal from the optical sensor  18  is at its minimum, which may be referred to as 0%. As the user starts to pull the trigger  10 , the signal from the optical sensor  18  starts to increase, i.e. greater than 0%. As the user pulls the trigger  10  further the micro switch  24  is closed, which begins initiation of the firing cycle. The user then continues to pull the trigger  10  until the signal from the optical sensor  18  rises above a preset maximum level, for example 85% or 90%, to complete initiation of the firing cycle. After the firing cycle has initiated, the user begins to release the trigger  10 , which subsequently opens the micro switch  24 . As the user releases the trigger  10  further, the signal from the optical sensor  18  drops below a preset minimum level, for example 15% or 10%. The firing cycle can now be repeated. 
     In the event that the two limits of the optical sensor  18  are not reached before the micro switch  24  is closed again then one of two things can occur, both of which are designed to prevent false trigger pulls generated by the recoil of the marker (often referred to in paintball as “mechanical bounce” or “trigger bounce”). The marker can be inhibited from firing on that trigger pull and a delay can be introduced into the firing cycle in order to slow the response time. A delay may be introduced at two distinct points in the firing cycle. A first timing cycle may be initiated when the trigger  10  is released and a second timing cycle may be initiated when the trigger  10  is depressed. The first timing cycle ensures that the trigger  10  has been released for sufficient time prior to initiating a subsequent firing cycle. The second timing cycle ensures that the user depresses the trigger  10  for sufficient time prior to releasing the trigger  10  and beginning a new firing cycle. One or both delays may be adjusted to prevent mechanical bounce. Typically, these timing cycle delays are set to 8 milliseconds, but can be set anywhere between 1 and 100 milliseconds as desired. 
     Referring to  FIG. 4 , if the user disables the optical sensor  18 , the firing logic for the micro switch  24  is shown. To prevent mechanical bounce, a timing delay is started and firing is inhibited. If the switch  24  is closed to early, the timing delay is reset. As the user pulls the trigger  10  and the micro switch  24  is closed, a second timing delay is calculated. The second timing delay ensures that the micro switch is held closed for sufficient time in order to begin initiation of the firing cycle. After the firing cycle has initiated, the user begins to release the trigger  10 , which subsequently opens the micro switch  24 . The firing cycle can now be repeated. These timing delays are fractions of second to ensure that the user is making legitimate trigger pulls rather than using mechanical bounce. 
     Referring to  FIG. 5 , if the user disables the micro switch  24 , the firing logic for the optical sensor  18  is shown. Prior to a first shot, when the trigger  10  is released, the signal from the optical sensor  18  is at its minimum. To prevent mechanical bounce, a timing delay is inserted. If the sensor reaches its critical threshold too early, the timing delay is reset and firing is inhibited. As the user starts to pull the trigger  10 , the signal from the optical sensor  18  starts to increase. The user then continues to pull the trigger  10  until the signal from the optical sensor  18  rises above a preset maximum level, to complete initiation of the firing cycle. However, the user must hold the trigger  10  for sufficient time to complete initiation of the firing cycle. A second timing cycle is calculated to ensure that the user has held the trigger  10  for sufficient time and is not relying on mechanical bounce. If the user releases the trigger  10  prematurely, the second timing cycle will reset. After the firing cycle has initiated, the user begins to release the trigger  10 , which subsequently allows the sensor  18  level to drop below its preset minimum level. The firing cycle can now be repeated. 
     Therefore, it can be seen that the present invention provides a unique solution to the problem of providing a switching mechanism for a device that includes both the tactile feel of an electrical switch and the accuracy and reliability of an optical sensor switch. Moreover, the mechanism of the present invention is user selectable, which allows the user to choose the mechanism that he or she finds most desirable. In addition, the undesirable trait of ‘mechanical bounce’ can be eliminated. 
     It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be within the scope of the present invention, except as limited by the appended claims.