Explosion charge driven fastening element setting gun

Abstract

In an explosive charge-driven setting gun which uses a drum type magazine for aligning fastening elements and cartridges with a barrel bore, both the barrel and magazine are axially displaceable into the firing position and are capable of axial movement relative to one another. It is possible for the barrel to be returned to the non-firing position while the magazine becomes jammed in the firing position. To prevent accidental firing of the cartridge in the magazine when the barrel is in the non-firing position, a latch mechanism is provided in engagement with the barrel and the firing pin which prevents the firing pin from igniting a cartridge until the barrel displaces the latch mechanism and releases the firing pin.

Description

SUMMARY OF THE INVENTION

The present invention is directed to an explosive charge driven fastening element setting gun in which a barrel and a drum type magazine are arranged within the gun housing for directing fastening elements positioned within the magazine through the barrel into the receiving material. Both the barrel and magazine are axially displaceable relative to one another within the gun housing. In particular, the invention concerns a latching mechanism for retaining the firing mechanism of the setting gun in the non-firing condition until the barrel is displaced axially by being pressed against the receiving material.

In setting guns of the type mentioned above, it is necessary, in establishing the firing condition of the gun, that the part forming the rearward end of the barrel, that is, the magazine, bears directly against the firing mechanism. Generally speaking, such guns are arranged so that the barrel and magazine are displaced in the operative condition of the gun away from the firing mechanism by means of springs. As a result, the firing pin cannot strike against the cartridge located in the magazine portion of the barrel. Only when the forward end of the barrel is pressed against the receiving material are the barrel and magazine displaced rearwardly against the firing mechanism so that the cartridges in the magazine are positioned to be ignited by the firing pin.

In guns where the bore for firing the fastening elements consists of a two-part arrangement, such as the barrel and magazine, it is necessary for operational reasons to return each part of the bore separately into its inoperative position by different spring members when the forward end of the gun is not pressed against the receiving material. However, it has been found in such setting guns that one of the parts forming the bore may be jammed within the housing, due to unavoidable fouling of the gun or to heat expansion, so that it cannot return into the inoperative positive by the spring action when the setting gun is removed from the receiving material surface. If it happens that the rear portion of the bore, such as formed by the magazine which contains the cartridges, can no longer be returned into its inoperative position, a cartridge remains in the range of the firing mechanism and could possibly be fired. Such accidental firing naturally involves considerable risks. Therefore, the primary object of the present invention is to provide a setting gun construction of the above mentioned type in which the possibility of accidental firing is avoided. In particular, the invention is directed to the improvement of an explosive charge driven setting gun in which an axially movable barrel and drum type magazine are mounted within a housing with the magazine rotatable for aligning a plurality of bores each containing a fastening element and a cartridge, with the bore through the barrel. A breech ring is secured to the rearward end of the housing and contains a firing mechanism so that both the barrel and drum type magazine must be displaced rearwardly by pressing the muzzle end of the gun against the receiving material for placing the setting gun in the firing condition. In the present invention, unless the barrel is displaced rearwardly through the housing the firing mechanism is held in a locked or latched condition so that a cartridge cannot be fired if the drum type magazine is accidentally held in its rearward position.

In accordance with the present invention, an axially displaceable latch is arranged in operative connection with the axially displaceable barrel and prevents the release of the firing pin until the barrel is displaced rearwardly through the gun housing which movement effects the release of the latch so that the firing pin can ignite a cartridge.

Accordingly, it is possible to fire a cartridge only when both the barrel and the magazine are in the rearward or firing position. When the setting gun is lifted off the surface of the receiving material without actuating the firing mechanism, the barrel is pushed forwardly by the force of a spring. Since it is operatively connected to the barrel, the latch moves into a position which prevents the release of the firing pin. It can be appreciated that the invention is not limited to a setting gun using a barrel and a drum type magazine, rather it is applicable to any setting gun in which a two-part barrel bore arrangement is used with the two parts being axially displaceable relative to one another.

Preferably, the firing pin is mounted within the breech ring for rotation about its longitudinally extending or central axis and it includes a release catch which is secured in the nonfiring condition by the latch as long as the barrel or forward end of the setting gun is not pressed inwardly by contact with the receiving material surface. The latch and release catch arrangement has the advantage that the space requirement in the setting gun is kept low, while the operating safety is additionally insured because the tolerances and play of the intermediate elements are avoided by the direct engagement of the latch with the firing pin.

To afford easy replacement of the barrel without any special tools, the latch is preferably connected by means of a resiliently radially mounted pawl which engages within a longitudinal groove in the outer surface of the barrel. By disengaging the pawl, the barrel can be released for removal from the setting gun in a simple manner.

To ensure a safe return of the latch which blocks the firing pin, into position when the setting gun is not pressed against the receiving material, preferably a spring is used for biasing the latch into locking engagement with the release catch when the barrel is removed from contact with the receiving material.

The safety device of the present invention is particularly applicable to setting guns which utilize a drum type magazine for aligning the fastening elements and cartridges with the barrel bore. In such a setting gun it is important that the barrel and the magazine can be axially displaced independent of one another and that each of them can be returned separately into the non-firing position, because the magazine, in addition to being axially movable, must also be rotatable for moving the fastening elements and cartridges into position aligned with the barrel.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention .

BRIEF DESCRIPTION OF THE DRAWING

In the drawing a side view of the setting gun, mostly in section, is shown in its inoperative or nonfiring condition.

DETAILED DESCRIPTION OF THE INVENTION

In the drawing an explosive charge driven fastening element setting gun is illustrated which includes a housing 1 located forwardly of a breech ring 2 to which a handle 3 is secured. The breech ring 2 is attached to the housing 1 by means of screws 4. The forward end of the housing contains a bore followed by a chamber opening to the bore. A barrel 5 is positioned within the bore in the forward end of the housing and the barrel is mounted for limited axial displacement relative to the housing. At its forward end, the spring 6 biases the barrel forwardly in the driving direction for retaining it in the inoperative condition of the setting gun. As is standard procedure with such guns, the barrel is displaced into the firing position by pressing it against a receiving material and displacing it rearwardly against the biasing action of the spring 6. A protective cap 7 is secured to the forward end of the housing 1 by means of a pin 8 so that it laterally encloses the front end of the barrel when it is displaced rearwardly into the firing position. Within the chamber in the housing located rearwardly of the barrel 5, a drum type magazine 9 is mounted for rotation on an axle 10 supported in the housing and it is also arranged for limited axial displacement along the axle. A plurality of receiving bores 9a are located in parallel relationship with and radially outwardly from the axis of rotation in the magazine and each bore contains a cartridge 11 and a fastening element or bolt 12. The outer surface 5a of the barrel at its rearward end is tapered inwardly from the normal outside dimension of the barrel. Similarly, the forward ends of the receiving bores 9a have enlarged frusto conically shaped surfaces 9b with which the tapered end 5a of the barrel seats when it is displaced rearwardly. The contacting engagement of the two tapered surfaces provides a centering as well as sealing effect. Rearwardly of the magazine 9, a bushing 13 is slidably mounted within the breech ring 2 and it is biased in the firing or driving direction of the setting gun by a compression spring 14. The bushing 13 and spring 14 normally press the magazine 9 so that its forward face contacts the bearing surface 1a on the housing of the gun. Within the breech ring, a firing pin 15 is mounted for axial displacement and for rotation about its longitudinal central axis. At its rearward end, the firing pin is non-rotatably connected to a release catch 16 which is preferably secured by spring force into the position shown, that is, with the firing pin in the non-firing position. A spring 17 urges the firing pin toward the rear end of the magazine 9 and a catch 18 is supported in the bushing 13 and extends in blocking engagement into the path of the firing pin.

Forwardly of the spring 17, another spring 24 is disposed between the breech ring 2 and the firing pin so that when the setting gun is not pressed against the receiving material, is in an equilibrium condition held by the catch 18.

When the front end of the setting gun is pressed against a receiving material, the barrel is first displaced rearwardly in the bore in the housing into the chamber where it contacts the drum type magazine 9. With the tapered surfaces 5a and 9b in contacting engagement, the barrel 5 and magazine 9 are displaced rearwardly against the biasing action of the bushing 13 and the spring 14 until the rear face of the magazine bears against the front face 2a of the breech ring 2. As the bushing 13 is displaced rearwardly it carries the catch 18 with it which, in turn, displaces the firing pin 15 toward the rear end of the gun. The firing pin is then in position ready to fire a cartridge. By turning the release catch 16, the firing pin rotates about its axis and a groove-shaped recess in the pin becomes aligned with the catch 18. When such alignment occurs, the firing pin is released and is driven forwardly by the action of the spring 17 so that it ignites a cartridge 11 within the bore 9a in the magazine aligned with the bore in the barrel 5.

To prevent the release of the firing pin when the barrel is not pressed in the rearward direction, but when the magazine 9 is blocked in the rear position against the breech ring due to some jamming action, a latch 19 lockingly engages a notch in the release catch 16. The latch extends forwardly from the release catch in the driving direction of the gun and it is connected to a rod 20. A spring 21 mounted within the breech ring 2 is disposed into contact with the latch 19 and biases it and the rod 20 forwardly against the rearward end of a pawl 22. Forwardly of its contact point with the rod 20, the pawl 22 is pressed by a leaf spring 23 in contact with the housing 1 inwardly into an axially extending groove 5b in the outer surface of the barrel 5. In the inoperative or non-firing condition of the gun, the forward end of pawl 22 contacts stop surface 1b on the housing. When the barrel is displaced rearwardly through the housing, the latch 19 is also displaced rearwardly by the combination of the pawl 22 and the rod 20 so that it becomes disengaged from the release catch 16. Accordingly, the firing pin is released only when the barrel is displaced rearwardly against the magazine to the extent that both the barrel and the magazine are located in the firing position in the setting gun.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

We claim:

1. In an explosive charge driven fastening element setting gun comprising a housing having a front end facing in the firing direction and rear end facing in the opposite direction, said housing having a first bore extending from its front end toward its rear end with the rear end of said first bore spaced forwardly of the rear end of said housing and a chamber located at the rear end of said first bore and extending rearwardly therefrom, means arranged in said housing within said first bore and chamber and axially displaceable therein, said means comprising a first part and a second part disposed in a serially arranged manner one behind the other each axially displaceable relative to the other with said first part having its forward end extending forwardly of the front end of said housing, means for biasing said first and second parts in the direction of the forward end of said housing, a breech ring attached to the rearward end of said housing, said second part under the action of said biasing means having its rearward end spaced forwardly of said breech ring, a firing mechanism axially displaceably mounted in said breech ring, said firing mechanism including a firing pin and a spring biasing the firing pin in the direction of the forward end of said housing, said first and second parts forming a bore for firing fastening elements from the setting gun into a receiving material, said first and second parts being axially displaceable rearwardly through said housing by pressing the forward end of said first part against the receiving material in opposition to the action of said biasing means acting on said first and second parts until the rearward end of said second part contacts said breech ring, wherein the improvement comprises latch means for preventing said firing pin from moving in the direction of the forward end of said housing, said latch means operatively connected to said first part and arranged to prevent the movement of said firing pin in the forward direction when said first part is positioned under the action of said biasing means and said latch means releases said firing pin when said first and second parts are displaced rearwardly in opposition to the action of said biasing means.

2. In an explosive charge driven fastening element setting gun, as set forth in claim 1, wherein said firing pin has its axis extending in the direction of movement of said first and second parts, said firing pin being mounted in said breech ring for rotation about its axis, said firing pin includes a release catch secured thereto, said release catch being displaceable between a locked position holding said firing pin in the non-firing position and an unlocked position for releasing said firing pin so that it can ignite a cartridge, and said latch means includes a member engageable with said release catch for maintaining it in the locked position when said first part is positioned under the action of said biasing means and for releasing said release catch when said first and second parts are displaced rearwardly in opposition to the action of said biasing means.

3. In an explosive charge driven fastening element setting gun, as set forth in claim 2, wherein said first part comprises a barrel axially movably positioned within said first bore, said barrel having a second bore extending axially therethrough, the outer surface of said barrel having an axially extending groove therein, and said latch means includes a pawl resiliently mounted in the radial direction of said barrel and engageable within said groove in said barrel.

4. In an explosive charge driven fastening element setting gun, as set forth in claim 3, wherein said latch means includes a spring biasing said latch means toward the forward end of said housing when said barrel is displaced forwardly under the action of said biasing means.

5. In an explosive charge driven fastening element setting gun, as set forth in claim 4, wherein said second part is a drum type magazine rotatably mounted within said chamber in said housing, said magazine has a plurality of angularly spaced third bores therein each arranged to align with the second bore in said barrel for firing a fastening element contained within the third bore into the receiving material, the forward end of each said third bore having a tapered surface and the rearward end of said second bore in said barrel having a complementary shaped tapered surface arranged to seat in contact with the tapered surface of said third bore aligned therewith when said barrel is displaced rearwardly by being pressed against the receiving material in opposition to said biasing means.

6. In an explosive charge driven fastening element setting gun, as set forth in claim 5, wherein said member engageable with said release catch extends axially forwardly from said release catch, said spring biasing said catch means is disposed in contact with said member forwardly of said release catch, an axially extending rod disposed in contact at its rearward end with said member and extending forwardly into contact with said pawl, and a leaf spring mounted in said housing radially outwardly from said barrel and resiliently biasing said pawl inwardly into contact with said groove in said barrel.

7. In an explosive charge driven fastening element setting gun, as set forth in claim 6, wherein a bushing is movably mounted in said breech ring for displacement in the axial direction of said barrel, a spring biasing said bushing into the chamber in said housing for contact with said magazine positioned therein, a catch mounted in said bushing and extending transversely of the axial direction of said firing pin, said catch positionable in the path of said firing pin for restraining it in the non-firing position, said firing pin having an axially extending groove-shaped recess arranged therein and said groove-shaped recess being alignable with said catch by moving said release catch to the unlocked position so that said firing pin can be moved axially in the direction of the forward end of said housing for igniting a cartridge.

8. In an explosive charge driven fastening element setting gun, as set forth in claim 7, wherein said firing pin includes a first spring for biasing said firing pin in the firing direction and a second spring spaced from said first spring and biasing said firing pin in the opposite direction for maintaining said pin in equilibrium condition when it is in the non-firing position.