Firearms – Firing mechanism – Rearward sliding breech bolt
Reexamination Certificate
1999-06-30
2001-07-24
Carone, Michael J. (Department: 3641)
Firearms
Firing mechanism
Rearward sliding breech bolt
Reexamination Certificate
active
06263606
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a pistol, comprising a housing containing a trigger device and comprising a slide which slides on the housing and contains the barrel and the breech, in which case the breech is provided with a firing bolt which can be driven by a mainspring, and a trigger acts via a trigger rod on a trigger device, which trigger device has a trigger stop having a tab which engages in the movement path of the firing bolt.
Self-loading pistols without hammers have the advantage of simple construction and operation in comparison with those of a hammer or a hammer action. They operate using a “double action” or “single action” mode, or intermediate forms. In the former case, when the trigger is operated, the mainspring is first of all loaded, and the shot is automatically fired after passing through the trigger movement. This involves a long cocking movement and a high trigger operating force, which place a strain on the trigger finger. This method of operation is thus predominantly used by the authorities, and is less suitable for the civil market.
In the second case, the mainspring is cocked by the breech moving backward and forward and is held in the cocked position by the trigger stop, until the shot is fired by operating the trigger. However, since the mainspring must be strong in order to provide the required firing energy, the trigger operating weight is considerable. Safety measures are, of course, of major importance in this mode.
AT 395 909 B (GLOCK) discloses a pistol of this generic type, in which the mainspring is half-cocked in advance and, during operation of the trigger, the second half of the initial cocking process is carried out first, and the shot is then fired, for which purpose the trigger rod has a slotted link, and a complicated and filigree mechanism is provided for the first half of the initial cocking process. As a result of the partial precooking process, and despite a relief spring which is provided specifically for this purpose, the work that has to be carried out by the trigger finger is admittedly somewhat reduced in terms of force and movement, but this does not result in the shot being fired with precision.
EP 730 135 A1 (WALTHER) discloses a further pistol of this generic type, which can be operated using both the “double action” and “single action” mode. For the former mode, a trigger rod is provided which interacts with the firing bolt and is guided by a slotted link while, for the second mode, a trigger stop is provided which rests on a support and can only pivot. During operation of the trigger, there is an initial very long slack movement, as a result of the kinematics, before the support is tilted away by the action of the trigger rod, during which process considerable friction and lever-arm influences have a disturbing effect. The mechanism, which has a large number of parts and whose dimensions are critical, is intended to allow the transition or easy changeover from the one operating mode to the other.
It is an object of the present invention to improve a pistol without a hammer such that a major improvement is achieved in the trigger characteristic while satisfying stringent safety requirements and with a design that is as simple as possible.
SUMMARY OF THE INVENTION
The foregoing object is achieved according to the invention wherein:
(a) a trigger stop is guided in the housing such that it can move in the longitudinal direction and can pivot downward, and is biased on upward by a first spring;
(b) a threshold is provided, which is fixed to the housing and interacts with a ramp on the trigger stop so that, during operation of the trigger, the trigger stop is first of all moved in the longitudinal direction and, after passing over the threshold, the trigger stop pivots downward;
(c) a drag lever is provided in front of the trigger stop, and pivots about a shaft that is fixed to the housing, is loaded to the rear, toward the trigger stop, by a second spring, has an apex edge at a distance from its axis and, in its furthest-forward position, is supported on the housing; and
(d) at the front, the trigger stop has a small tab which rests on the apex edge of the drag lever when the trigger stop and the drag lever are located in a rear position.
The required parts are few in number and they are also simple and cheap to manufacture while being suitable for installation by machine. The major advantages of this design result from the interaction of all the parts, see the functional description further below. In particular, the ramp according to feature b) ensures that shots are fired with precision with a short and dry shot firing movement, the second spring according to feature c) reduces the trigger operating weight to a noticeable extent, and the small tab according to feature d) by interacting with the first spring in accordance with feature a), ensures that the trigger stop returns to the safe initial position again. Finally, the trigger mechanism can be changed over even more easily to the “double-action” mode, by removing the drag lever and installing a longer trigger stop.
In an embodiment of the invention, the threshold which is fixed to the housing is formed as a bolt with a circular cross section, and the ramp is designed as an edge at an obtuse angle. This feature further reduces the cost of manufacture and, despite shots being fired with precision, and the high accuracy, achieves a smooth transition from the initial trigger movement to firing.
In a further preferred embodiment, the firing bolt has a lug with an inclined actuating surface, and the tab of the trigger stop has an inclined actuating surface, and the inclination angles of these two actuating surfaces and the obtuse angle of the edge are approximately the same. This feature results in a further improvement in the trigger since, during rearward movement, the trigger stop slides on the lug, and downward on the obtuse angle. The friction force is thus distributed over a longer distance and, despite the rearward movement, no further cocking of the mainspring takes place, which would increase the trigger weight.
A further improvement in safety and operating convenience is achieved in that the trigger stop has a recess with a pushing surface at the rear and a control surface further forward, and that end of the trigger rod which interacts with the trigger stop can be placed against the pushing surface so that the end of the trigger rod disengages while the trigger stop is pivoting downward. As a consequence, at the moment of release, the trigger rod is decoupled from the trigger stop, and is automatically coupled again on reaching the ready-to-fire position. This improves safety, to a particularly major extent, if the front end of the trigger rod is articulated on the trigger and the trigger is provided with a trigger safety device. This also provides complete safety if the pistol is dropped.
In a further development of the invention, the trigger weight can be adjusted, in that the force exerted by the second spring can be adjusted by means of an adjusting screw which acts on its second limb and if the force exerted by the second spring is less than the force of the mainspring.
REFERENCES:
patent: 2584299 (1952-02-01), Sefried, II
patent: 2785605 (1957-03-01), Jourdat
patent: 3027811 (1962-04-01), Young
patent: 5906066 (1999-05-01), Felk
patent: 395909 (1983-04-01), None
patent: 0730135 (1996-02-01), None
Bachman & LaPointe P.C.
Buckley Denise J
Carone Michael J.
Steyr Mannlicher AG & Co KG
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