EP1428628A1 - Bolt driving tool acting via an intermediate anvil - Google Patents

Abstract

The apparatus has a feeder (2) moving in a canon (3) between firing and fixing positions. Brake ball bearings (6) for the feeder and lever arms (7) are pivoted on a guide plug. The arms are arranged to modulate radial action of the ball bearings based on relative movement of the canon and feeder between a maximum force when the feeder advances the canon and a minimum force when the feeder backs up.

Description

The invention relates to a device for indirect fire sealing, by which a fastener is entrained in a support material under the action of propellants of an explosive charge through a flyweight mounted mobile in a cannon, between a firing position and a fixing position, and a buffer guide in which is mounted a ball brake, or retention, counterweight mechanism radial action on the flyweight.

When fired, the flyweight was driven forward in the barrel, against the action of the ball mechanism, weaker than that of the load explosive.

Under the action of lifting weights, in particular elastic return means, combustion gas or return pawl weight that retains the weight when you open the device while driving the barrel forward, the counterweight retreats relatively in the barrel.

When the camera is closed, the barrel moves backwards in driving the flyweight which should always remain in its position relative to the barrel under the action of the braking balls.

In conventional brake ball mechanisms, the balls exert their action on the counterweight thanks to a spring of radial force constant, so that the ball retaining force that has to be overcome when the counterweight backs into the barrel is the same as that balls exert on the counterweight during the shootings.

We have already proposed devices with a mechanism to overcome this disadvantage, for example the one described in the American patent 4,941,391 In this apparatus, on the other hand, during the relative displacement of the counterweight to the rear, the balls no longer exert a radial action on the flyweight, so this flyweight may not be perfectly ascent to firing position.

By document DE 201 00 837, we know yet another apparatus of the type mentioned above, in which the braking mechanism has wedge effect shells arranged to modulate the action radial of the balls, depending on the relative displacement of the barrel and the counterweight, between a maximum force, when the counterweight advances in the gun, and a non-zero minimum force, when the counterweight moves back.

However, in the apparatus of this prior art, the braking force of wedge effect shells is modulated based on the single displacement of the flyweight. In addition, the brake shells are mounted against rubber elements which reduce their radial action.

The present application proposes a retention mechanism for more efficient flyweight and whose action is better dosed during the displacement of the counterweight.

Thus, the invention relates to an indirect fire sealing apparatus, by which a fastening element is driven in a support material under the action of propellant gases from an explosive charge by through a flyweight mounted mobile in a cannon, between a firing position and a fixing position, and a tampon guide in which a counterweight ball brake mechanism is mounted, exerting a radial action on the counterweight and comprising means arranged for modulate the radial action of the balls, as a function of the relative displacement of the barrel and the flyweight, between a maximum force, when the flyweight advance in the barrel, and a non-zero minimum force, when the flyweight backwards, device characterized by the fact that the balls are constrained radially by lever arms for clamping and modulating the action radial of the balls, pivotally mounted on the buffer guide under the action of marbles rolling on the arms.

Preferably, the lever arms are also arranged to exert an axial force of return towards the rear on the balls, in case progress of these.

Preferably always, the balls are arranged to roll on the arms between arm end retaining fingers, opposite elbows pivoting lever arms, and a radial abutment edge of the buffer guide extending between the pivot elbows and the retaining fingers arms.

Advantageously, each lever arm is pivotally mounted against the action of an elastic ring.

Advantageously also, the radial thickness of each arm of lever decreases backwards.

Thanks to the invention, when the weight moves forward, the angle formed between the articulated levers increases and the braking force increases with this angle, so that this effort depends not only on the displacement of the counterweight but also of the angle between the arms of the sink.

When the flyweight is pulled back into the barrel under the action of the return means, the balls continue to exert a force on the flyweight. When the device is opened, the flyweight is not likely to be entrained in a relative displacement of bad direction. We are sure that the counterweight remains held in position. The balls are balls of braking and holding in position in the barrel. In addition, once the barrel replaced backwards, if the flyweight re-advances in the barrel, the balls advance on the arms and, due to the shape of the latter, are re-propelled backwards, dragging with them the counterweight which is found in good shooting position.

• la figure 1 représente une vue en coupe partielle de la forme de réalisation préférée de l'appareil de la présente invention ;
• la figure 2 représente une vue en coupe du mécanisme à billes de maintien de masselotte de l'appareil de la figure 1, lorsque la masselotte est en position de fixation ;
• la figure 3 représente une vue en coupe, suivant l'axe III-III' de la figure 1 et
• la figure 4 représente une vue éclatée du mécanisme à billes de maintien de masselotte de l'appareil de la figure 1.

The invention will be better understood with the aid of the following description of the preferred embodiment of the apparatus of the invention, with reference to the appended drawing, in which:

• Figure 1 shows a partial sectional view of the preferred embodiment of the apparatus of the present invention;
• Figure 2 shows a sectional view of the counterweight ball mechanism of the apparatus of Figure 1, when the counterweight is in the fixing position;
• FIG. 3 represents a sectional view, along the axis III-III 'of FIG. 1 and
• FIG. 4 represents an exploded view of the mechanism for holding the counterweight of the apparatus of FIG. 1.

The following description will be made with reference to a sealing in which the buffer guide is fixed relative to the barrel. The Applicant does not intend to limit itself to this type of device, the invention can be applied to any type of device using balls for braking the flyweight, in particular devices in which the buffer guide is connected to the barrel by means of a spring and is therefore mobile relative to the barrel.

Referring to Figure 1, the sealing apparatus includes a counterweight 2 mounted mobile in a barrel 3 and a buffer guide 5, extending along an axis 20. More specifically, the counterweight 2 comprises a 2 "feeder head and a 2 'feeder rod. The 2' rod is movable in the buffer guide 5 in which a cylindrical bore 5 ′ is provided of axis 20 and of diameter substantially equal to that of the flyweight rod 2 ' to drive it along the axis 20. The 2 "flyweight head is movable in the barrel 3 in which a cylindrical bore 3 ′ with an axis 20 and of diameter substantially equal to that of the 2 "feeder head for the drive along the axis 20. The flyweight 2 is movable between a position of shot, in which the rear of the flyweight head is close to a surface 10 'of the barrel perpendicular to the axis 20, according to the power setting, from so as to close off a combustion chamber 4, and a fixing position, in which the 2 "flyweight head has advanced in the barrel, in a position at most in front stop on a rear surface 10 of a shock absorber.

Referring to Figure 2, the ball mechanism 6 for holding counterweight 2 here comprises two balls 6, two clamping lever arms 7 and an elastic ring 8, here metallic. Referring to Figure 4, the rod 8 consists of a ring which is split in order to allow the mounting of the mechanism and elasticity required. Each arm 7 extends along the axis 20, and includes a pivot elbow 72 between a heel 74, bearing in a recess of the buffer guide 5, and a forearm here parallelepiped 75 which is sandwiched between the buffer guide 5 and the rod 8. Each arm is extended, at the rear of the forearm 75, by a rear arm 76 providing an external shoulder 77 with the forearm 75, receiving of the rod 8, and whose inner surface 73 flares towards the rear. The rear arm 76 ends with a retaining finger 71 substantially perpendicular to the axis 20, intended to retain the ball 6 on the counterweight 2.

Referring to Figure 3, the arms 7 are mounted on either side of the counterweight 2, opposite with respect to the axis 20 of the counterweight 2. Each ball 6 is wedged between the counterweight 2 and an associated arm 7.

Each inner surface of arm 73 in contact with ball 6 is here a cylinder portion inclined on the axis 20 of the counterweight 2. In other words the contact surface 73 between each arm 7 and its ball associated 6 has the shape of a gutter. By the way, this is the radial thickness of each rear arm 76 which decreases towards the rear.

With reference to Figures 2 and 4, each ball 6 is arranged to roll on its lever arm 7 between the end retaining finger 71 of the arm 7, opposite the pivot elbow 72, and a radial abutment edge 11 of the pad guide 5, extending between the swivel bend 72 and the retainer 71 of the arm 7. Each arm 7 is pivotally mounted against the action of the rod 8 and under the action of the associated ball 6 moving forward.

The action of the ball mechanism 6 for braking and maintaining counterweight 2 during the various phases of use of the sealing will now be described.

The flyweight 2 is initially in the firing position, so at the rear in the barrel 5, in abutment on the surface 10 ', completely sealing the combustion chamber 4. The sealing device is pressed on the support in which we want to insert a buffer and, for reasons of security, firing is only possible once this support has been applied. The action on the trigger causes the propellant charge to explode and the propellant expansion in the combustion chamber 4.

The propulsion of the flyweight 2 forwards in the barrel 3 is done against the action of the balls 6. When the counterweight 2 moves forward, the balls 6 roll by friction on the counterweight 2 which drives them towards the front and the articulated arms 7 pivot on the buffer guide 5 to move away to each other at the level of their fingers 71. The radial force exerted by the arm 7 on the balls 6 and therefore by the balls 6 on the counterweight 2, due to the increase in the angle formed between the arm 7, increases when the balls 6 advance on the arms 7, and therefore when passing from the firing position of the counterweight 2 in its fixing position. However, due to the large force provided by the propellant gases, the counterweight can advance against the action of the braking balls 6. The balls 6 are then in abutment on the abutment surface 11 of the buffer guide, as seen in FIG. 2. Due to the opening of the arms 7, the braking force is better dosed and is exercised when necessary along the travel of the flyweight.

The flyweight 2 being in the fixing position, the device is opened to drive the barrel 3 forward, to access the chamber combustion and replace an explosive charge. In doing so, the flyweight 2, under the action of means of recall or ascent well known to those skilled in the art and therefore not shown in the drawing nor described here, back off relative to the barrel 3. The balls 6 are quickly found in abutment on the retaining fingers 71 of the arms 7; the force exerted by the balls 6 on the flyweight 2 is then weak but not zero. It is therefore possible to train the barrel 3 forwards without much effort, while preventing the flyweight 2 to be dragged into a relative move in the wrong direction.

The device is then closed, that is to say that the barrel 3 is driven backwards. Under the action of the weights holding balls 6 2, the flyweight is driven with the barrel 3.

The flyweight 2 and the barrel 3 are then in the firing position. However, a forward movement of the counterweight 2 relative to the gun is still possible, for example by rebound. However, a advance of the flyweight 2 relative to the barrel 3 causes the advance of the balls 6 on the arms 7. Due to the cooperation of the elastic ring 8 and the arm 7, as well as the flaring of the arms 7, this advanced ball 6 immediately causes pressure on the arms 7 which propel by elasticity of the balls 6 towards the rear towards the retaining fingers 71, these last resulting in their ascent the flyweight 2 which is then found in good position. Thus an advance of the flyweight 2 causes on the part arms 7, in cooperation with the counterweight 2, an axial deflection force which propels the balls 6 backwards and with them the counterweight 2. The the flyweight is therefore finally well maintained in the firing position.

Claims (5)

Indirect fire sealing apparatus, by which a fastening element is entrained in a support material under the action of the propellant gases of an explosive charge by means of a counterweight (2) mounted movably in a barrel (3 ), between a firing position and a fixing position, and a buffer guide (5) in which is mounted a ball mechanism (6) for braking the counterweight, exerting a radial action on the counterweight (2) and comprising means (7) arranged to modulate the radial action of the balls (6), as a function of the relative displacement of the barrel (3) and the counterweight (2), between a maximum force, when the counterweight (2) advances in the barrel (3), and a non-zero minimum force, when the counterweight (2) moves back, apparatus characterized in that the balls (6) are constrained radially by lever arms (7) for clamping and modulating the action radial of the balls (6), pivotally mounted on the buffer guide (5) under the action of the balls ( 6) rolling on the arms (7). The apparatus of claim 1, wherein the lever arms (7) are also arranged to exert an axial force of return towards the rear on the balls (6), in the event of their advancement (6). Apparatus according to one of claims 1 and 2, wherein the balls (6) are arranged to roll on the arms (7) between fingers (71) of arm end retainer (7), opposite pivot elbows (72) lever arms (7), and a radial edge (11) of abutment of the buffer guide (5) extending between the pivot elbows (72) and the retaining fingers (71) arms (7). Apparatus according to one of claims 1 to 3, in which the arms lever (7) are pivotally mounted against the action of an elastic ring (8). Apparatus according to one of claims 1 to 4, in which the radial thickness of the lever arms (7) decreases towards the rear.

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