The document US 2015/0211822 describes a design of the trigger mechanism for automatic and semi-automatic pistols that uses a one-sided trigger lever with one tension spring. A disadvantage of this design consists in the fact that the control mechanism gets distorted at the end of the trigger lever due to one-sided pressure acting upon the trigger lever.
Trigger mechanisms that are known at present comprise containers that are used for guiding the rear part of the breech and for housing and control of the trigger lever. However, these well-known containers do not feature two spaces for insertion of springs and do not provide the possibility to control the functional surfaces of the trigger lever on one vertical plane comprising the longitudinal axis of the gun and the axis of the firing pin. Thus, asymmetrically acting forces are generated, increasing resistance friction, which impairs the reliability of the gun.
A part of the trigger mechanism is also the tripping pin of the trigger lever, which is used to lower the rear end of the trigger lever to disengage the tooth of the trigger lever from the tooth of the firing pin when the firing pin spring is fully tensioned. The prior-art structural designs do not enable arrangement of the functional surfaces on one vertical plane passing through the longitudinal axis of the gun and axis of the firing pin and in addition, in these designs the control edge is established in the bottom part of the breech, which increases production demands.