US3529548A - Cartridge - Google Patents

Description

United States Patent [72] Inventors Heinz Gawlick Furth; Hans Umbach, Stadeln, Germany [21] Appl. No. 635,206 [22] Filed May 1, 1967 [45] Patented Sept. 22, 1970 [73] Assignee Dynamit Nobel Aktiengesellschaft Troisdorf, Germany [3 2] Priority April 28, 1966 [3 3] Germany [31 No. B49970 [54] CARTRIDGE 10 Claims, 12 Drawing Figs.

521 US. Cl ..I 102/45, 102/8 [51] Int. Cl F421) 5/26 [50] Field ol'Search l02/38,44, 45, 86.5, 8, 70

156] References Cited UNlTED STATES PATENTS 573,897 12/1896 Mohr 102/45 2,514,401 7/1950 Liljegren 102/8 2,923,237 2/1960 Bleinkamp, Jr 102/8 FOREIGN PATENTS 626,902 l/1963 Belgium 102/8 1,291,034 3/ 1962 France 102/8 Primary ExaminerRobert F. Stahl Attorney-Craig, Antonelli, Stewart and Hill ABSTRACT: The present disclosure relates to a cartridge for driving the working piston of commercial explosive actuated devices, particularly rivet guns wherein a powder charge is contained within a cartridge case along with a primer composition that is very sensitive to impacts. The cartridge has an external configuration of a flat cylindrical capsule having a cup-shaped lower piece subdivided into a central primer charge receiving chamber and an annular propellant charge receiving chamber by a centrally placed relatively small diameter tubular projection. The cartridge case is constructed of a synthetic polymer and has an axial dimension substantially smaller than its diameter. It is provided with either a weakened central portion or a firing pin projection closely adjacent to the primer chamber so that an axial impact from either side will ignite the charge. Predetermined weakened breaking zones are provided for conducting the primer and propellant combustion gases out of the case without distintegrating the case.

Patented Sept. 22, 1970 3,529,548

I N VENTORS HEINZ GAWLICK HANS UMBACH BY 184M ATTORNEYS Patented Sept. 22, 1970 3,529,548

INVENTORS HEINZ GAWLICK HANS UMBACH BY @M ATTORNEYS Patented Sept. 22, 1970 3,529,548

Sheet i of 3 HQIO FIG."

INVENTORS HEINZ GAWLICK HANS UMBACH BY &

ATTORNEYS EA RID In the prior art, it is known to provide a commercial cartridge for rivet guns and the like with a one piece metal case closed at its forward end by folding or crimping and provided at its transition from the bottom to the shank portion with a marginal fold for receiving the primer charge. These cartridges are employed in a magazine that has the shape of the cartridges. It is known to provide a rivet gun with a recess in the form of a blind hole for receiving the driving cartridge so that the bottom of the cartridge faces one end of a working piston that drives the nail, rivet or the like at its other end. Likewise, it is known in the prior art to provide such a cartridge receiving blind hole within the piston itself for driving the rivet, nail or the like into the desired material.

However, the above-mentioned prior art devices have considerable disadvantages in regard to cleaning the blind hole to remove all traces of residual combustion products of the propellant charge, as well as residues of the cartridge case.

This cleaning is required after each firing and is very impor-:

tant to assure the proper loading of the next cartridge and its efficient firing. Such a cleaning process is quite difficult and expensive.

It is an object of the present invention to overcome the above mentioned disadvantages of the prior art by providing high pressure effects of the propellant gases during firing, the

cartridge case is suitably provided with a weakening sections or bursting zones in the region of the annular propellant receiving chamber so that these zones readily burst open to allow escape of the propellant and primer gases without breaking up the cartridge case. Suitably, similar bursting zones or weakening sections are provided in the tubular projection that forms the ignition chamber. Such a construction has the advantage that pieces of the cartridge case are not left in the firing device to foul subsequent firings. Such bursting zones may be advantageously provided in the form of internal and/or external longitudinal grooves distributed along the circumference of the tubular projection or tubular portion of the cartridge case at regular intervals. Upon ignition of the primer easy escape of the propellant gases.

Further objects, features, advantages: and variations of the present invention will become more clear from the following detailed description of specific preferred embodiments of the lid, cover or top piece is secured to the cup shaped lower por- I tion or bottom piece by means of adhesive and/or interengaging projection and groove means.

A cartridge constructed according to the present invention does not require a specially formed and adapted receiving and storing magazine; to the contrary, such a cartridge can be ignited between two smooth surfaces of the firing device, that is, for example, between the mutually parallel plane surfaces of the rivet set and working piston of a rivet gun. At the most, the surfaces may be interrupted by a firing pin or the like.

Whenever a cartridge is fired by an external firing pin, that is, a firing pin that is a part of the firing device, particularly careful measures must be taken to assure that the cartridge is always in such a position that the firing pin will impact upon it I A to strike the primer composition at a precise angle and position. This can be accomplished most simply by making the diameter of the cartridge the same as that of the working piston, or rivet set, according to the present invention. Also,

problem of centering an external firing pin is solved, because v the firing pin location is fixed with respect to the primer composition and is independent of the device in which the cartridge is to be fired. For securing such a cartridge against accidental firing, it is advantageous according to the present invention to provide the firing pin projection with a shoulder, annular collar, flange or the like to axially engage the tubular projection forming the central primer chamber so that the firing pin is held a sufficient and safe distance from the primer charge. The flange collar or shoulder is sufficiently strong to maintain the firing pin in this position during the shocks encountered in storage and transportation, but will readily yield upon an impact serving to fire the cartridge. Substantially the same effect can be achieved by having the firing pin joined to the top piece by means of a predetermined breaking zone, instead of providing the pin with a shoulder or an annular collar, so that the firing pin will break away from the top piece upon receiving an impact blow sufficient for firing the device so that it will move to strike and ignite the primer charge.

In order to prevent the cartridge case from being broken up into a plurality of relatively small pieces and sections, by the Play n a firing p E 45 present invention, in conjunction with the attached drawing;

further modification of the present cartridge case employing the firing pin as a part of the top piece;

'FIG. 6 is a further modification of the present invention em- FIG. 7 is another modification of the present invention that does not employ a'firing pin and shows an axial cross-sectional view;

FIG. 8 is a partial axial cross-sectional view of a modification of the FIG. 7 cartridge;

FIG. 9 is a plan view of the external configuration of either the bottom piece according to FIG. 7 or FIG. 8;

Like numerals have Bee; used throughout the drawings to indicate like parts of the various cartridge cases for purposes of simplicity and to provide an easily recognizable correspondence between the various modifications.

In the cartridge cases according to FIGS. 1 -15, the cartridge case is in the form of a cylindrical capsule having a relatively small axial dimension and a relatively large diameter. The cartridge case comprises a cup-shaped lower portion or bottom piece 1 having an annular cylindrical tubular projection 2 within its central region, and a top piece or cover 3. The top piece 3 is provided with an integral downwardly projecting firing pin 4. The top piece and the bottom piece have telescopically interengaging tubular portions together defining a tubular portion of the cartridge case. The bottom piece 1 and the top piece 3 are connected together by an annular projection 5 interengaging with a correspondingly shaped annular groove 6, or as in FIG. 2 by having the annular projection 5 engage behind the annular bottom of the bottom piece I to form a snap type joint. Preferably, these cartridge cases and the fol lowing cartridge cases to be described are constructed of a synthetic polymer, particularly a thermosetting plastic molded into only two pieces, that is, the bottom piece and the top piece with all other features integral thereto.

The tubular projection 2 defines a central primer receiving chamber 7 that is filled with the primer composition 8. Also, the tubular projection 2 subdivides the capsule into an annular propellant receiving chamber 9 that surrounds the central primer receiving chamber 7 and carries the propellant powder charge 10 therein.

In FIG. I, the various portions of the cartridge case are dimensioned and constructed so that the lowermost tip of the firing pin 4 is spaced a sufficient safe distance from the primer charge 8 so that undesired ignition of the primer charge 8 by means of the firing pin 4 will not occur during accidental and normal shocks encountered in storage and transportation. According to FIG. 2, this particular safety requirement is further carried out by means of an annular collar or flange II that is formed on the exterior of the firing pin 4 to axially engage the free end of the tubular projection 2 and hold the firing pin in its spaced relationship with the primer composition (not shown in FIG. 2). FIG. 3 shows a construction similar to FIG. 2 in that the firing pin is provided with a forwardly facing annular seat or shoulder portion 12 axially engaging the free end of the tubular projection 2 to likewise hold the firing pin spaced from the primer charge.

With the above safety construction to assure the spacing of the firing pin from the primer composition through a satisfactory combination of the relative strength and stiffness of the cartridge case material and the dimensioning of the various components, it is assured that the primer composition will be ignited only upon a firing impact blow that is above a predetermined pre-selected value and in the axial direction so that the firing pin will strike the primer charge.

In the cartridge according to FIGS. 3 and 4, the tubular projection 2 is provided on its external circumference with four weakening grooves 13 forming predetermined bursting zones that are arranged in equal spacing from one another. With this arrangement, the ignited propellant charge gases break through the reduced thickness portions of the grooves 13 to distribute the igniting gases evenly about the internal circumference of the annular propellant charge 10. In this manner, a uniform, satisfactory, safe and rapid firing of the propellant charge is obtained while at the same time it is assured that the cartridge case will not distintegrate and foul the firing mechanism. Also, it is contemplated that the same bursting grooves 13 may be provided in the cartridges according to FIGS. 1 and 2, which may be either on the outside as shown or on the inside of the tubular projection 2.

In the cartridges according to FIGS. 5 and 6, a firing pin 4 is also provided on the top piece 3 for igniting the primer composition 8 in the manner discussed above. However, there is the difference that the top piece 3 is constructed as a substantially planar plate in contrast to the cup-shaped construction of the top piece in FIGS. 14. The top piece 3 is retained in a suitably formed annular rim or groove of the cup-shaped bottom piece I by means of a snap-type connection or joint to hold the firing pin 4 spaced from the primer charge 8 and provide a connection that is sufficiently strong to withstand the relatively high forces produced by the high pressure propellant gases within the cartridge during firing. In. FIG. 5, the lid 3 has a particularly sturdy construction and extends over the lower section or bottom piece 1 in self-supporting manner, whereas the thinner lid or top piece 3 of FIG. 6 axially engages and rests upon the tubular projection 2. In FIG. 6, the firing pin 4 extends inwardly beyond the top piece 3, extends outwardly beyond the top piece 3 and is connected to the top piece 3 by means of a predetermined breaking zone 14 formed by a reduced thickness portion between annular grooves either on the inside and outside as illustrated or on the inside or outside. V

With the cartridges constructed according to FIGS. 1-6, the firing pin is an integral component of the cartridge so that it makes no difference on -which side the firing pin 4 is located when it is being used. that is. it is of no significance whether the firing pin is of a side facing the rivet set or on the side facing the working piston of a rivet gun. It is contemplated that the cartridges according to FIGS. 5 and 6 may be provided with weakening grooves similar to those shown at 13 in FIG. 4.

In the cartridge according to FIG. 7, the cup-shaped bottom piece I is provided with an annular, cylindrical projection 2 that forms the central primer receiving chamber 7 and the propellant powder charge receiving chamber 9 'for respectively holding the primer composition 8 and the propellant powder charge 10. The top piece 3 is connected with the bottom piece I by means of a snap type connection between the inside of the bottom piece tubular wall and the annular cylindrical shoulder I5 of the top piece 3 that are respectively provided with annular grooves 16 and annular protuberances or projections I7. Immediately adjacent to and aligned with the primer receiving chamber 7, the bottom piece I and the top piece 3 are each provided with reduced wall thickness areas to allow easy penetration by the firing pin so that it makes no difference whether the firing pin penetrates the cartridge on the top side or on the bottom side defined respectively by the top piece 3 and the bottom piece 1. Accordingly, the cartridge may be inserted in the firing chamber facing in either axial direction even though it is not absolutely symmetrical. In order to increase the sensitivity of the primer composition 8, it is provided on both axial sides with a layer of powdered glass 18; this feature may be employed in the other embodiments of the present invention.

In the cartridge according to FIG. 8, the layer of powdered glass has been omitted when the construction is compared with the FIG. 7 device and the bottom piece 1 as well as the top piece 3 are provided with depressions or recesses 19 immediately adjacent to and aligned with the central primer receiving chamber 8. The bottom wall thickness of these depressions or recesses I9 is uniform and relatively weak so that again the non-orientated insertion of the cartridge case is possible while assuring the penetration of the firing pin provided on the firing device.

As shown in FIG. 9, the bottom piece 1 may be provided on its annular outer portion 20 and its tubular projection 2 with a plurality of bursting grooves extending for the full axial dimension along its entire circumference, which are defined by the longitudinally extending ribs 21; this produces a plurality of uniformly spaced relatively thin walled webs that will readily break open upon a predetermined pressure during firing to allow the escape of the ignition flame and the propellant gases correspondingly easily. The longitudinal ribs 21 may also be provided on the internal surface of the respective elements and may be combine d with the features of the cartridges according to any of the other figures illustrated in the drawing. The actual configuration of the ribs has been shown for only a relatively small arcuate portion of the outer circumference; however, it is understood that the ribs 21 extend uniformly in a like manner around the entire circumference of their respective portions.

According to FIG. 10, a cartridge case that is substantially the same as the cartridge shown in FIG. 7, but having a lens shape, is arranged between the rivet set 22 and the working piston 24 of a rivet gun, which is otherwise not shown in detail for purposes of simplicity. The rivet set 22 is provided with a firing pin type of lug 23. The cartridge diameter substantially corresponds to the diameter of the rivet set 22 and the working piston 24. The internal diameter of the annular cylindrical projection 2 on the lower piece 1 is substantially identical to the outer diameter of the firing pin lug 23.

As shown in FIG. 11, the firing pin lug 23 penetrates the lid 3 into theprimer receiving chamber 7 while simultaneously axially compressing the cartridge to engage the primer charge and ignite the same when a firing blow is exerted on the riveting set 22; in turn, the ignited primer composition ignites the propellant powder charge by bursting through the tubular projection 2 to thus drive the working piston 24 in the working direction. in order to prevent destruction and disintegration of the cartridge case into a plurality of relatively small pieces that might foul the firing mechanism, there are provided four relatively weakened bursting zones in the top piece 3 and a corresponding number of like bursting zones in the bottom piece 1 that are arranged uniformly in concentric circles (FIG. 12). These bursting zones will burst open relatively easily to allow the ready escape of the propellant powder gases upon firing. Thereby, the particular advantage is obtained that the cartridge case remains practically intact after firing so that it remains in one piece clamped onto the firing pin lug 23 of the riveting set 22 so that it can be easily removed from the device when the rivet set is taken out. The predetermined bursting zones 25 may be employed in a like manner in any of the cartridges that have been illustrated in the preceding described cartridges according to the other figures.

While several preferred embodiments of the present invention have been described in detail, it is understood that further modifications, variations and embodiments according to the broader aspects of the present invention are contemplated within the spirit and scope of the present invention as defined by the following claims.

We claim:

1. A cartridge for driving the working pistons of commercial explosion actuated devices, particularly rivet guns, comprising: a cartridge case consisting of only two homogeneous pieces and being of substantially flat cylindrical capsule external configuration, one of said pieces being a bottom piece having a generally tubular portion closed at one end, the other of said pieces being a top piece closing the other end of said tubular portion, and said bottom piece further having and being one piece with an integral substantially centrally located generally tubular projection extending inwardly generally coaxially with and of smaller external circumference than said tubular portion internal circumference to divide said bottom piece into a central primer receiving chamber and an annular propellant receiving chamber; a propellant powder charge within said annular propellant receiving chamber; and a primer composition within said central primer receiving chamber, wherein said tubular projection axially engages said top piece in an unstressed storage position prior to firing.

2. The cartridge according to claim 1, wherein said top piece has a central wall immediately opposite said primer receiving chamber that is of substantially less thickness than the remaining portions of said top piece.

3. The cartridge according to claim 2, wherein the average transverse dimension of said tubular portion is substantially larger than the axial dimension of said cartridge case; said cartridge case being constructed of a synthetic polymer; at least one of said bottom piece and said top piece having weakened portions of less thickness than the remaining portions to constitute means for bursting and quickly releasing the propellant gases to the outside of said cartridge case and preventing disintegration of said cartridge case during firing; said tubular projection having reduced thickness bursting means for bursting upon ignition of said primer charge to quickly conduct the ignition through said tubular projection at spaced intervals and retain said tubular projection in one piece.

4. The cartridge according to claim 1, wherein said top piece is provided with an inwardly extending integral firing pin projection aligned with said central primer receiving chamber to constitute means for igniting said primer in response to an axial impact upon said cartridge case.

5. The cartridge according to claim 4, wherein said top piece includes an annular predetermined breaking zone means for separating said firing pin from the remainder of said top piece upon a predetermined axial impact on said firing pin; and said zone means including wall portions between said firing pin and the remaining portions of said top piece having a thickness substantially less than the immediately adjacent radially outward portions of said top piece.

6. A cartridge for driving the working pistons of commercial explosion actuated devices, particularly rivet guns, comprising: a cartridge case consisting of only two homogeneous pieces and being of substantially flat cylindrical capsule external configuration, one of said pieces being a bottom piece having a generally tubular portion closed at one end, the other of said pieces being a top piece closing the other end of said tubular portion, and said bottom piece further having and being one piece with an integral substantially centrally located generally tubular projection extending inwardly generally coaxially with and of smaller external circumference than said tubular portion internal circumference to divide said bottom piece into a central primer receiving chamber and an annular propellant receiving chamber; a propellant powder charge within said annular propellant receiving chamber; a primer composition within said central primer receiving chamber; said cartridge case is constructed of a synthetic polymer; said tubular projection being integral with said bottom piece; said tubular portion having a plurality of radially inwardly extending groove means forming wall portions of reduced thickness at their inner portions for bursting at a predetermined pressure to allow escape of said propellant powder gases and to maintain said cartridge case in one piece during and after firing; said bottom piece being substantially cup-shaped; said top piece and said bottom piece having radially interengaging flange and groove means for establishing axial abutment to prevent axial separation of said bottom piece and said top piece during handling and firing.

7. A cartridge for driving the working pistons of commercial explosion actuated devices, particularly rivet guns, comprising: a cartridge case consisting of only two homogeneous pieces and being of substantially flat cylindrical capsule external configuration, one of said pieces being a bottom piece having a generally tubular portion closed at one end, the other of said pieces being a top piece closing theother end of said tubular portion, and said bottom piece further having and being one piece with an integral substantially centrally located generally tubular projection extend-ing inwardly generally coaxially with and of smaller external circumference than said tubular portion internal circumference to divide said bottom piece into a central primer receiving chamber and an annular propellant receiving chamber; and a primer composition within said central primer receiving chamber, wherein one of said pieces has a central wall immediately opposite said primer receiving chamber that is of substantially less thickness than the'remaining portions of said one of said pieces.

8. A cartridge for driving the working pistons of commercial explosion actuated devices, particularly rivet guns, comprising: a cartridge case, of substantially flat cylindrical capsule external configuration and having a generally tubular portion, a bottom piece closing one end of said tubular portion, a top piece closing the other end of said tubular portion, and a substantially centrally located generally tubular projection extending inwardly from one of said pieces generally coaxially with and of smaller external circumference than said tubular portion internal circumference to divide said cartridge case into a central primer receiving chamber and an annular propellant receiving chamber; a propellant powder charge within said annular propellant receiving chamber; a primer composition within said central primer receiving chamber; said top piece being provided with an inwardly extending firing pin projection aligned with said central primer receiving chamber to constitute means for igniting said primer in response to an axial impact upon said. cartridge case; said tubular projection is mounted on said bottom piece and extends longitudinally inwardly to a free end closely adjacent to said top piece; said firing pin projection having radially extending flange means axially engaging said free end of said tubular projection for normally preventing relative movement between said firing pin and said central primer receiving chamber below a predetermined axial impact.

1 9. The cartridge according to claim 8, wherein said tubular projection is an integral part of said bottom piece and normally axially engages said top piece.

'10. A cartridge for driving the working pistons of commercial explosion actuated devices, particularly rivet guns, comprising: a cartridge case, of substantially flat cylindrical capsule external configuration and having a generally tubular portion, a bottom piece closing one end of said tubular portion, a top piece closing the other end of said tubular portion, and a substantially centrally located generally tubular projection extending inwardly from one of said pieces generally coaxially with and of smaller external circumference than said tubular portion internal circumference to divide said cartridge case into a central primer receiving chamber and an annular propellant receiving chamber; a propellant powder charge within said annular propellant receiving chamber; a primer composition within said central primer receiving chamber;

said top piece being provided with an inwardly extending firing pin projection aligned with said central primer receiving chamber to constitute means for igniting said primer in response to an axial impact upon said cartridge case; said firing pin projection is integral with said top piece and is joined thereto by means of a predetermined breaking zone means for separating said firing pin from the remainder of said top piece upon a predetermined axial impact on said firing pin, and including wall portions between said firing pin and the remaining portions of said top piece having a thickness substantially less than the immediately adjacent radially outward portions of said top piece.

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