US3187622A - Apparatus for assembly of a primer component with a centerfire cartridge case - Google Patents

Description

June 8, 1965 F. CHARLO 3,187,622

APPARATUS FOR ASSEMBLY OF A PRIMER COMPONENT WITH A GENTERFIRE CARTRIDGE CASE Filed April 19, 1963 2 Sheets-Sheet 1 LOU/S F CHAR/.0

ATTORNEY June 8, 1965 L. F. CHARLO 3,137,522

APPARATUS FOR ASSEMBLY OF A PRIMER COMPONENT WITH A CENTERFIRE CARTRIDGE CASE Filed April 19, 1963 2 Sheets-Sheet 2 INVENTOR.

LOU/S F CHARLO ATTORNEY This invention relates to ammunition primers for percussively igniting primed cartridge cases and to an improved method of so priming cartridge cases.

In center fire ammunition, which is characterized by a head structure of metal, among the important requirements are that the included parts, especially the anvil, be maintained in proper association to achieve ignition reliably and effectively and that the structure at the primer must be able to resist the pressure developed when the primer burns.

Accordingly, an object or" this invention is to provide a way of making a stronger head structure at the primer in cartridge cases or" all calibers, including even the smallest, where the problem of both elastic and plastic expansion of the case faster than the expansion of the primer cup is accentuated particularly when higher propellant pressures are employed in a cartridge case or" small diameter, irrespective of the bullet caliber.

Another object is to shape and put into assembly a component of a simplified primer of small size but adequate volume for effective priming devised in accordance with copending US. patent application Serial No. 274,632, filed April 22, 1953.

Another object, therefore, is the provision of a new method useful in priming cartridges which will provide a simple and reliable primer assembled with ease and economy.

Still another object is theprovision of a new way of providing an anvil in a primer structure having exceptional uniformity of dimensions and sensitivity and which will reliably ignite the priming composition with exact unformity while effectively retaining the primers metallic components and the gases resulting from the ignition.

These and other objects are attained by a novel method and appmatus resulting in a construction constituting a significant improvement over the type of primer shown in U.S. Patent Nos. 92,795 and 94,210, characterized by an anvil having a leg extending through the flash hole or vent in the base of the case.

where these prior art primers have an anvil with a stem fitting relatively loosely in the flash hole to adapt the cartridge for reprimin and reloading, the improvement of this invention involves staldng a new and improved anvil configuration in a novel way in the head of a case to obtain both longitudinal and lateral support for the anvil while maintaining the necessary communication at the flash hole between the priming composition and the charge of propellant in the charger case.

How this is done will become apparent from a description of a preferred embodiment with reference to the attached drawing in which:

FIG. 1 is a longitudinal sectional view of a base portion of a cartridge case at the head;

FIG. 2 is a fragmentary and enlarged view taken on line lI-ll of FEGURE 1;

FIG. 3 is a semidi'tgrarnmatic plan View with parts broken away and in section showing the apparatus used in simultaneously making the anvil and assembling it with the case; and

PEG. 4 is a cross sectional view taken on line Pi -1V of FIGURE 3 and showing the apparatus in a later stage or" propellant charge.

3,l8?,622 Patented June 8, 1%65 operation and an anvil emplaced in the cartridge case head.

Cartridge it has at its head a metal base ill, and joined thereto is the conventional cylindrical wall lll which is integrally formed with the base for containing the usual The solid base is formed with a central primer pocket 12 and has a perforated web portion 23 between the pocket and the cartridge powder cavity. The perforation through the web portion is a central flash passage 14, forming a hole of smaller diameter than that of the pocket.

Emplaced within the head is the anvil 2 and the primer cup 31, the latter being held by frictional or other means, and being loaded with a percussion sensitive mix 4.

The anvil is disposed to extend into both the pocket and flash hole; it has a shank 5 having substantially parallel sides extending over the full length of the passage 14. One extremity is beveled at a to form a short guide means for aiding pressing of the anvil into the cartridge case. At the opposite end the anvil has a projecting point 3 for extension into the primer cup and coaction with a suitable primer mix 4. Between these ends, the anvil has an enlargement 7 providing a shoulder 9 for accurately bot receiving an adequate amount of the primer mix, despite the fact that this construction is generally adaptable for cartridges of small diameter at the head having a primer pocket and cup of reduced diameter.

In contrast to the conventional type of primer as shown in US. Patent Nos. 208,589, Gardner; 962,888, Buell;

and 1,571,510, Dickerman and where the anvil occupies around 40% of the primer cup volume in this type of ammunition, the primer construction of this invention utilizes only around 10% of the cup for reception of the anvil projection.

Where with such a relatively wide conventional primer it is necessary to have a coned anvil involving blanking, bending, drawing, or swaging to make the anvil point supported by two or more legs between a like number of flash notches of the anvil, which must be press fitted into the cup in a precision assembly involving two small diameters held to very close tolerances, in contrast the relatively slender anvil 2 is merely blanked to final finished shape and size and pressed into the flash hole 14 into final position rather than into the usual preassembly with the cup which must then be pressed in turn into the pocket. Thus, the problem of tolerances is largely eliminated and the primer is completed with remarkable uniformity by merely press fitting in the reduced diameter cup 3 carrying mix 4 in a condition suitable for safe assembly. Di-

.ensional variation from metal spring back and flexing is avoided.

As a result, the diameter of the cup 3 and pocket 12 can be reduced by about a third to give more strength at the base id. Even at higher propellent powder pressures, dropped primers and leaky primers were eliminated. The added metal grip on the anvil at web 13 makes for consistent sensitivity and firing.

Where in the conventional primer the flame must flow in a circuitous path around the widespread configuration of the anvil before it reaches the flash hole, the primer of this invention in contradistinction offers less obstruction to the passage of the flame straight from the cup to the flash openings 15 and 16. Since this reduces the heat and energy lost, the primer efliciency is improved.

The anvil shank 5 of this primer is of rectangular cross section, i.e. it is of a width in excess of the thickness, and its dimension of width is substantially equal to the diameter of the flash hole 14, so that diagonally from ,3 I I A to C, or B to D, it is slightly in excess of the hole diameter and will cut into the web 13 and stake itself rigidly upon being pressed into the flash hole to divide it into the two adequate openings and 16 left since the thickness from A to D, or from B to C extends over only part of the diameter, preferably not more than 40% of it, but not less than 30% of the diameter. For example, in a flash hole having a diameter of about 0.060 of an inch, a thickness of a typical anvil from 0.018 to about 0.020 of an inch was found satisfactory together with an anvil width of about 0.060 of an inch.

An anvil width about three (3) times its thickness is contemplated for providing bothdesired anvil rigidly and desired freedom of flash passage. The shank length shown is about twice the width.

By employing staking over substantially all the shank and flash hole length together with bottoming at the shoulders 9, anvil 2 is positively anchored in the case head not only against slippage lengthwise but also against tipping. Unlike prior art anvils with a stem extending rather loosely in the flash hole, the present primer anvil is not adapted to facilitate extraction of the exploded primer by pressing onthe stem. Moreover, it avoids the obstruction frequently offered by this type of prior art anvil, which at that time suggested the need for a tiny central flash passage in the already minute stem of these anvils. Unlike the prior art, anvil 2 cannot tip to shut hole 14 and is anchored straight in the case and anvil anchoring, independently of the anchorage of the cup 3, has the advantage of avoiding difliculties of preassembly, for example, either by crimping the cup in under the anvil head, or by precision fitting of the anvil inside the cup. By staking, all desired accuracy, nevertheless, is achieved, together with consistent sensitivity.

For the best cutting or indenting to stake the anvil, the substantially parallel sides of shank 5 preferably are I slightly tapered on a side at a rate of about 1 in 40 giving an overall divergence of about 1 in from a width substantially equal to the flash hole diameter adjacent beveled end 6 to the greatest excess adjacent shoulder 9.

For example, for a flash hole having a nominal diameter of about 0.060 of an inch, the shank width varies from about 0.0600.061 of an inch adjacent end '6 to about 0064-0065 of an inch next to shoulder 9.

At the enlargement 7 there is no problem of clearance or fit in the pocket 12, because the width of the enlargement is made sufiiciently smaller than the pocket diameter. In a pocket having a diameter of 0.120. of an inch, for example, the width of enlargement 7 is about 0.100 of an inch.

The anvil is adaptable for rapid assembly with the case in a new and economical way suitable for. mass production priming, despite its miniature size.

In the apparatus of FIGURES 3 and 4, anvils are progressively struck out of a strip of sheet metal 18 by stamping and transferring punch 20 having a shaped cutter 21 operating on the strip in die cavity 62 of the apparatus, and in alternation With the stamping the formed anvils are transferred in proper orientation one at a time by a seating punch 30 for pressing an anvil into assembly with a cartridge case I mounted on a reciprocating case support pin 33.

This method of priming avoids storage of a large supply of tiny articles, the damage that occurs when such articles are held in inventory, and the need for orienting the articles when drawing them out of the usual random arrangement preparatory to assembly with the other ammunition components.

The typical apparatus illustrated has a die holder including base 40 provided with receptacle means in the form of a cartridge head receiving recess 41, a seating punch bore 42, and a die block cavity 43 in which is mounted the blanking die 50.

Die 50 has a stamping die bore forming a first anvil transfer p g 51 and a seating blade groove in its underside forming with the base a seating bore 52 intersecting the passage in communication not only for receiving anvils, one at a time from the series 102 stored and sized in passage 51, but also for slidably receiving the seating blade 31 extending from the end of punch 30 driven and associated in reciprocating relationship with base 40 by any suitable means. The blade has an end configuration 32 for guiding abutment with the projection 8 of each anvil fed into passage 51.

Also associated with base 40, is a cartridge mandrel means or support pin 33 mounted for reciprocation with respect to recess 41. This pin carries a resilient or other suitable member 34 for biasing the guide pin 35 outwardly for extension into and reciprocation with respect to the cartridge case flash hole 14. The end of the pin is formed with a concavity 36 adapted for guiding abutment with beveled end 6 of the anvil while the other end of the anvil is in abutment with blade 31'during anvil transfer in passage 52 and staking in the cartridge web portion 13. I

Mounted over base 40 and die 50 as part of the holder is a cover and stripping plate 60 having not only guide hole 61 for the shaped cutter 21, but also a groove 62 forming with the die a cross channel means for receiving the strip stock 18 and passing out the spent strip 19 as scrap, after anvil stamping by the cutter.

A punch guide block 70, which is also part of the holder, is mounted opposite die 50 over plate 60 to'provide a bore 71 for slidably mounting the punch shank 22 which is cut away on one side to provide a punch retaining groove and detent 23 for cooperation with a stamping or blanking punch key 73 extending into the groove for providing interference retaining thepunch 20 in the apparatus against the bias of a punch return spring 24. The parts are fastened together by any suitable means such as screws 75.

- Punch 20 is actuated by any suitable means such as the ram of an assembly press with which die base 40 and the other parts of the apparatus are also associated:

In operation the present method of priming involves,

V in seriatim and in alternation:

(a) Fabrication of the miniature anvil 2 by shaping it in the holder, and

(b) Assembly of this relatively tiny piece and the cartridge case, all occurring in a single'holder common to both the function of anvil fabrication and the function of transfer and seating this piece in the head of a cartridge case in preparation for completion of the primer assembly by addition of a primer cup and its included mix.

A cartridge case 1 is placed on the support pin 33 with the guide pin 35 located concentrically in the flash hole 14 under the outward bias of resilient member 34. So positioned and mounted, the case 1 is thrust with its head 10 received in the cartridge positioning recess 41. By movement of support pin 33 into the holder, the case head is bottomed in recess 41 so the location of the anvil in depth is referred from this point .to further minimize the problem of tolerance accumulation. At the same time, guiding concavity 36 is disposed in the seating bore forming a second anvil transfer passage 52 for receiving and guiding an anvil into the flash hole as guide pin recedes.

Strip material 18 is fed through the channel 62 by any suitable strip feed indexing device in coordination with the movement of support pin 33 and also the movement of seating punch 30. Any suitable means of mechanical synchronization is contemplated.

Stamping punch 20 pressed by ram 80 blanks out from this strip an anvil and at the same time indexes.

with the passage 52. Here an anvil is peeled off from the end of the stack and transferred for seating of anvil 2 in the cartridge case as shown in FIGURE 4. Stack 102 is retained in the die by friction. As soon as a sufficient quantity of anvils are stacked up in die passage 51, the fabrication of another anvil will place the leading anvil from the bottom of the stack into the guiding and seating passage 52 forming a track leading from the end of anvil die passage 51 to the flash hole 14 maintained in proper alignment by the holder.

Although in operation, either the cartridge case may be stationed in recess 41 before punch 20 stamps out an anvil, or the punch may stamp out an anvil before the cartridge case is so stationed, it is preferred that the stationing of the cartridge case and stamping of the anvil occur simultaneously.

Finally, in any event, seating punch 30 moves seating blade 21 forward in the track provided by passage 52 to peel an anvil from the stack and to further move blade 31 to put the anvil being transferred into abutment with the spring loaded pin 35 so as to guide the anvil both fore and aft until the anvil has begun to be seated in the case. Thus, the anvil is retained between the concavity 36 of the spring loaded pin and the blade end 32 in accurate alignment for seating.

To complete the cycle, seating punch 30 and support pin 33 are both retracted.

The apparatus serves (a) To station the cartridge case in proper alignment for accurate insertion of the anvil,

(b) To receive and position the sheet stock from which the anvil is stamped,

(c) To simultaneously fabricate, convey, and store the anvil blank at all times with protection before assembly and proper orientation for assembly, and

(d) To transfer an anvil blank maintained in such orientation for impaling it in the stationed case by a pressing operation involving staking the anvil at the flash hole at a series of indentations permanently deforming at least the case and/ or the anvil for improved retention.

What is claimed is:

1. Apparatus for assembly of a primer component with a centerfire cartridge case having a longitudinal primer pocket and flash hole in the case head, said component being an anvil of cruciform shape characterized by a reduced end extension, an anvil projection at the oppo- 6 site end and an enlargement intermediate said anvil ends, said apparatus comprising a die holder having receptacle means for receiving said case stationed in alignment for pressing in said anvil longitudinally, mandrel means associated with said holder for delivering cases one at a time to said receptacle means, a stamping die having a bore transversely extending in said holder and configured in correspondence with said anvil shape for forming a first anvil transfer passage, a second anvil transfer passage disposed in said holder in said alignment transversely to said first passage, said passages being in communication with each other, and channel means in said holder for guiding sheet stock transversely to said die bore, punch means mounted reciprocable with respect to said die bore and acting with said die for stamping said anvil shape from said stock into said first passage and for advancing said shape through said first passage into said second passage in said alignment, and a second punch means operable with said holder for transferring said anvil shape through said second passage and pocket and for seating said anvil in said case by staking said extension into said flash hole by indentation of said case longitudinally.

2. The apparatus of claim 1 wherein the first anvil transfer passage is adapted to size the anvil while advancing it in said passage.

3. The apparatus of claim 1 wherein the mandrel means has a central guide pin mounted in telescoping relation resiliently biased outwardly for extending telescopingly with respect to the cartridge case flash hole, and wherein an end of both the pin and the second punch means is configured for guiding abutment with the anvil ends.

References Cited by the Examiner UNITED STATES PATENTS 237,094 2/81 Curley 86-38 572,888 12/96 Gardner 102-45 711,231 10/02 Robinson 86-36 1,446,207 2/23 Payette 59-25 2,340,291 2/44 Wirtz 29-3391 2,388,094 10/45 Snell 102-44 2,604,167 7/52 Oliver 83-86 2,808,640 10/57 Biddison 29-3331 BENJAMIN A. BORCHELT, Primary Examiner.

Claims (1)

1. APPARATUS FOR ASSEMBLY OF A PRIMER COMPONENT WITH A CENTERFIRE CARTRIDGE CASE HAVING A LONGITUDINAL PRIMER POCKET AND FLASH HOLE IN THE CASE HEAD, SAID COMPONENT BEING AN ANVIL OF CRUCIFORM SHAPE CHARACTERIZED BY A REDUCED END EXTENSION, AN ANVIL PROJECTION AT THE OPPOSITE END AND AN ENLARGEMENT INTERMEDIATE SAID ANVIL ENDS, SAID APPARATUS COMPRISING A DIE HOLDER HAVING RECEPTACLE MEANS FOR RECEIVING SAID CASE STATIONED IN ALIGNMENT FOR PRESSING IN SAID ANVIL LONGITUDINALLY, MANDREL MEANS ASSOCIATED WITH SAID HOLDER FOR DELIVERING CASES ONE AT A TIME TO SAID RECEPTACLE MEANS, A STAMPING DIE HAVING A BORE TRANSVERSELY EXTENDING IN SAID HOLDER AND CONFIGURED IN CORRESPONDENCE WITH SAID ANVIL SHAPE FOR FORMING A FIRST ANVIL TRANSFER PASSAGE, A SECOND ANVIL TRANSFER PASSAGE DISPOSED IN SAID HOLDER IN SAID ALIGN-

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