Paint ball guns were originally developed for marking uses such as forestry and cattle ranching, in which frangible projectiles (or paint balls, as they are more commonly called) were fired against trees to be harvested or onto cattle to be taken to market, for example. For this reason, the paint ball guns themselves are frequently referred to as “markers.” But, more recently paint ball guns are much more widely used in various recreational environments, such as simulated war games wherein it is the intent to shoot at an opposing player with the paint ball gun, thus hitting and marking this opposing player with a particular color of paint splattered from a frangible paint ball.
Paint ball guns using compressed air or gas for power are well known. Until recently, most paint ball guns were pneumatically powered, mechanically operated guns. The entry of electro-pneumatically operated paint ball guns provided more consistent and better performing guns for the recreational market. An electro-pneumatic paint ball gun provides improved performance with fewer component malfunctions than the earlier mechanical-pneumatic paint ball guns.
However, a common problem with the conventional electro-pneumatic paint ball guns is that they use a mechanical sear device to release a hammer. The hammer is spring loaded to a position at which it impacts a valve stem, opening a flow path for high pressure gas to communicate to a paint hall, propelling the paint ball through and from a barrel of the gun. The adjustment of the engagement and release of the mechanical hammer and sear remains an uncertain element of conventional paint ball gun operation, requiring frequent adjustments in order to operate at high cyclic rates.
A more recent paint ball gun is shown in U.S. Pat. No. 6,532,949 (hereinafter, the “949” patent). In the '949 patent, a hammer of a paint ball gun is moved in each of two opposite directions by respective ends of a rod member, to which respective pneumatic pressures are applied sequentially by a solenoid valve. In this '949 patent, the hammer must be moved in each direction of its stroke by a respective pneumatic pressure, and these respective pneumatic pressures must be sequentially controlled by a solenoid valve.
Further, a deficiency of conventional paint ball guns becomes apparent when attempts are made to achieve a high cyclic rate of fire. That is, competition rules prohibit the operation of paint ball guns in a full-automatic mode in which the gun cycles many times and fires many paint balls with a single pull or movement of the trigger. In full-automatic mode, a paint ball gun would continue firing paint balls as long as the trigger is pulled and held, and as long as its ammunition supply lasts. But, competition uses of such full-automatic paint ball guns is prohibited, and only semi-automatic guns are allowed in which a single paint ball is fired for each pull of the gun trigger.
Nevertheless, paint ball players desire to achieve a high rate of fire with semi-automatic paint ball guns. This is desired in order to provide the highest chance of obtaining hits on dodging and running competitors in paint ball competition. This rapid semi-automatic paint ball gun fire is ordinarily attempted by “vibrating” or shaking the trigger fingers against a two-fingered trigger structure of the conventional paint ball gun.
An improved apparatus and method for allowing rapid firing of a semi-automatic paint ball gun is desired.