WO2011085457A1

WO2011085457A1 - Method for producing firearms

Info

Publication number: WO2011085457A1
Application number: PCT/BR2010/000014
Authority: WO
Inventors: Plinio Assis França NOGUEIRA
Original assignee: Forjas Taurus S/A.
Priority date: 2010-01-15
Filing date: 2010-01-15
Publication date: 2011-07-21

Abstract

A method is described for producing firearms, comprising the following steps: the firearm metallic structure (2, 3) is manufactured by a MIM process; the housings, seats and apertures in the metallic structure (2, 3) are calibrated by machining; the metallic structure (2, 3) is subjected to a surface treatment; the barrel (13) is attached; a polymer material (20, 21) is over-moulded on the metallic structure (2, 3); and the finished firearm (1) is assembled. The metallic structure manufacturing step comprises the manufacture of a metallic structure (2) basically composed of the cylinder frame (10) provided with a threaded aperture (12) for attaching the barrel (13), and with the other seats and apertures for attaching the components of the shooting mechanism. Moreover, the polymer material over-moulding step comprises the arrangement of the assembly formed by the metallic structure (2, 3) and the barrel (13) in a suitable injection-moulding die, and over-moulding an upper part (20) and a front part (21) on the outside of said assembly (2/3, 13). In a preferred embodiment, the upper part (20) and the front part (21) are injection-moulded simultaneously, forming a single, integral, finished polymer part.

Description

Process for the production of firearms

FIELD OF INVENTION

The present invention relates to the field of firearms, and more particularly to a process for producing a firearm from injecting a metal frame and over-injecting the other components from a polymeric material.

ART GROUNDS

As is known in the art, firearms such as, for example, revolvers, pistols, carbines, etc., are produced by a forging process to obtain the metal frame of the weapon. This weapon's metal frame is a solid forged metal monoblock that has an external profile similar to the weapon being produced.

This forged monoblock is then subjected to various machining steps to obtain internal housings. In particular, and in this machining step, the following procedures are performed, which can best be seen from the attached figures 1-4:

Q1. deburring - to adjust the external profile of the weapon;

P2. slotted drum housing pin - to eliminate material and demarcate the drum housing;

P3. trigger mechanism housing;

Q4. bolt hole;

P5. percussion hole;

Q6. mechanism plate housing;

PI. relief for the retains;

P8. machining of the fixed sight handle;

P9. barrel housing bore;

P10. drum holder housing;

P1 1. bore of the drum support shaft;

P12. bolt window;

P13. reference hole for machining; and

P14. real spring plate housing.

The structure thus obtained is then submitted to called machining procedures to obtain external profiles and finishing procedures. Among these procedures, we can highlight the machining performed on the entire contour of the cylinder frame; sanding the entire contour of the cylinder frame; polishing the contour of the cylinder frame; and finally its surface chemical treatment, which varies depending on the material from which the weapon is made. After these procedures, the weapon can be effectively assembled by fixing the other components. Note that these procedures are not performed in the stock area, as the stock is not apparent at the end of the assembly of the weapon, but is wrapped around the handle of the weapon. However, if part of the stock is exposed, the same procedures should be performed in the stock region.

Despite the massive use of this process in the state of the art, it proves to be excessively laborious and expensive, especially in view of the numerous machining steps that must be performed on the forged monoblock. By way of example only, for the production of a conventional weapon in general, at least ten separate machining and drilling equipment are used, which takes up to a minimum of 1, 5 days and may be up to 2 whole days. In addition, it should be emphasized that most drilling performed must respect very tight tolerances in order not to understand the operation of the components to be fixed and / or articulated. In some cases, and for particularly critical components of the firing mechanism, errors of the order of tenths of millimeters may impede the operation of the weapon.

Accordingly, it is an object of the present invention a process for the production of firearms which enables the reduction of machining and finishing steps compared to conventional processes performed by the state of the art.

Furthermore, it is another object of the present invention to provide a simpler and more efficient firearm production process and to reduce the processing time of the weapon structure.

SYNTHESIS In order to fulfill the above objectives, the present invention comprises a process for producing firearms, comprising the steps of: making the metal frame of the weapon from the ME process; qualification by machining of the housings, seats and holes of the metal structure; surface treatment of the metal structure; pipe fixing; over-injection of polymeric material into the metal structure; and final assembly of the weapon.

In particular, the step of making the metal frame comprises the making of a metal frame basically composed of the cylinder frame provided with a threaded hole for fixing the pipe, as well as other seats and holes for fixing the components of the mechanism. firing Alternatively, the steel frame fabrication step comprises fabricating a metal frame basically comprised of the cylinder frame provided with a threaded hole for fixing the barrel, butt, as well as other seats and holes for fixing the components. of the firing mechanism.

In addition, the over-injection step of the polymeric material comprises placing the assembly formed by the metal frame and the barrel in an appropriate injection die, as well as externally injecting an upper portion and a front portion externally into said assembly. In particular, the upper portion and the front portion are injected concomitantly, forming a single-piece, fully finished polymeric part.

DESCRIPTION OF DRAWINGS

The present invention will be better understood in light of the following detailed description relating to an illustrative and non-limiting embodiment of the invention, which is accompanied by the accompanying figures in which:

Figures 1 to 4 illustrate steps of a process for manufacturing a revolver structure from a forged according to the state of the art;

Figure 5 is a perspective view of a cylinder frame obtained in accordance with the present invention; Figure 6 is a perspective view of the cylinder frame of Figure 5 attached to the barrel and with the over-injection of the polymeric material;

Figure 7 is a perspective view of an alternative structure obtainable; and

Figure 8 is a side elevational view of a weapon produced in accordance with the process of the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

In accordance with the present invention, it has now been discovered, and thus constitutes the object of the invention, a new firearm production process which eliminates the need for forging a metal block for the production of the firearm structure. In addition, the process also allows a substantial reduction in the machining, qualification and finishing steps of the metal portion of the weapon, which leads to a substantial reduction in processing times and the related production costs.

Based on the research, it has been found that it is possible to produce the structure of a firearm from a process known in the art as Metal Injection Molding (MIM).

Such a process is basically similar to the plastic injection process but operates from metal powders to result in a finished part with a good geometric definition. Specifically, the MIM process comprises the steps of metal powder production, injection or feedstock preparation, mold injection, binder extraction, and sintering.

More specifically, the first step consists in selecting the metal powders that will compose the desired final structure according to their metallurgical characteristics. Once these powders are selected and weighed, they are mixed with the binder, which is a temporary material and intended to hold the metal powders together. This mixture is then pelleted and the resulting pellets are injected into an injection mold through a injector. Injected the preform, it is submitted to a binder extraction step in order to eliminate it, but keeping the shape of the part only from the metal powders, which extraction can be done by chemical, thermal action or a combination between the two. The last step is sintering, in which the molded powders are joined thus resulting in the formation of the desired part, maintaining the structural definition and geometry unchanged with respect to the injection molded part.

Thus, according to the present invention, a new process for the production of firearms is now proposed, which comprises the steps of:

a) preparation of the weapon structure from the ME process;

b) qualification, by machining, of the housing, seats and holes of the structure;

c) surface (chemical) treatment of the structure;

d) pipe fixing;

e) over-injection of the polymeric material into the structure; and

f) assembly of weapon components (cylinder, firing mechanism, cable, etc.).

In accordance with the above steps, the process according to the invention begins with the fabrication of a metal frame 2,3 from the process known as MIM as described above. From this process a metal frame 2 is obtained, as illustrated in Figure 5, which basically comprises the cylinder frame 10. According to the art, the cylinder frame 10 is a cross-sectional structure. basically rectangular designed to surround cylinder 11 as well as supporting a plurality of components of the firing mechanism of the weapon. Said cylinder frame 10 comprises in its front portion a hole 12 internally threaded for receiving barrel 13. In the preferred embodiment described herein, the metal frame 2 of weapon 1 is basically composed of the cylinder frame . However, and as illustrated in Figure 7, a metal frame 3 may further comprise a stock 14 over which the handle 18 is attached.

Next, the metal structure 2, 3 resulting from the The process of Injection Molding of Metal Powders, or simply ME, is subjected to a known stage in this industrial sector by qualification. At this stage, the various faces, contours and holes obtained from the MIM process are qualified, ie measured and then ground and / or machined to give the necessary final measurements.

As is well known, the preform that originates the final part through the MIM process has a larger dimension than the desired part, because during the preform sintering phase, the interstitial spaces left by the removed binder are filled by the powders. Metallic Such occupation of these interior spaces causes a proportional reduction in the dimensions of the part in production. Although such a reduction is proportional, it is not always sufficiently precise, which is why tests conducted by the inventor have shown that a qualification is always necessary to ensure the accuracy required for the metal structure 2, 3 of weapon in production. In addition, eventual positioning errors of the firing mechanism parts, even if in the order of tenths of a millimeter, can lead to the inability of firing by the weapon, that is, the loss of all the work of making it.

Furthermore, and as an important feature of the process of the invention, during the qualifying step only those parts of the metallic structure 2, 3 which will be apparent are machined to form smooth and finished surfaces. In particular, and as will be described below, the surfaces of the metal frame 2, 3 which will preferably be injected should have a surface roughness in order to improve the adhesion of the polymeric material to the faces of the metal frame.

After the qualification of the metallic structure 2, 3, it is submitted to a surface treatment step, which is basically chemical treatment and intended to treat the metal component of the weapon against corrosion, as well as to give the weapon its appearance and characteristic colors. By way of illustration only, when the weapon material is carbon steel, the finish may be of high gloss black or matte black; when the weapon material is stainless steel, the finish may be matte or high gloss; and when The weapon is made of aluminum, the finish can be matte black, high gloss black or natural anodized.

With the metal frame 2, 3 of the weapon properly finished, the step of over-injection of the polymeric material is passed. The over-injection step of the polymeric material is carried out in an injection matrix, within which the metal structure thus obtained is arranged. Said injection matrix is such that it has an internal seat capable of receiving said weapon's metallic structure, and has chambers, interconnected or not, as the case may be, to inject an injected polymeric element onto certain parts of the metallic structure.

More particularly, and as illustrated in Figure 6, the over-injection step is such that it forms a polymeric part to form the entire upper portion 20 of the weapon, as well as wholly or partially surrounds barrel 13 in addition to the front portion 21 of the gun.

As a result of this over-injection step, a metal / polymeric structure 4 is obtained which has an external conformation of polymeric material in its front and upper portions, which eliminates the need for further finishing steps.

The last step in making the weapon, therefore, is the assembly of the trigger mechanism and cable components. In particular, the assembly of the trigger mechanism components follows the conventional technique and order, since the resulting metal / polymeric structure does not differ from the art-only metal structures in their functionality.

Thus, and for the case of the metal / polymeric structure resulting from structure 3, illustrated in figure 7, the assembly step comprises assembling the triggering mechanism components and then assembling the cable structure 15 which, in this embodiment of the invention, protrudes upwards to enclose the entire rear portion of the weapon 1, i.e. surrounding the firing mechanism components that are attached to the front and lower portions of the weapon.

To this end, the cable structure 15 is a component in the form of a shell of injected material, ie internally hollow and externally finished, which comprises the handle 18 itself, ie the grip of the weapon, the trigger guard 16 and the rear portion 17 which joins the bush guard 16 and cable 18. Such a cable structure 15 is mounted to the weapon after assembly of the triggering mechanism components to surround them as well as surrounding the breech 14 and the trigger 19. In particular, the dog 22 is mounted only after securing the cable frame 15 to the above described metal / polymeric frame, since the dog shaft (not shown) also serves as one of the attachment points of the cable frame 15 to said metal / polymeric frame. .

As a result of this assembly step, the weapon 1 results externally almost entirely of polymeric finishing elements. Thus, handle 18, trigger guard 16 and the entire lower portion of the cylinder frame 10, front portion 21 and upper nut 20 of the weapon are shown to the user as polymeric elements enclosing a metal core. The user-viewable metal structures are cylinder 11, dog 22 trigger 17, and eventually the front portion of barrel 13 in addition to the lower sides of the cylinder frame 10.

In an alternative embodiment of the present invention, and in particular obtained from the metal frame shown in FIG. 5, i.e. the metal / plastic frame 4 of FIG. 6, the assembly procedure follows as described and illustrated in the application. Patent of the same inventor, filed on the same date as the present and entitled "Functional and stand-alone metal firearm structure and resulting metal / plastic composite revolver", which is hereby incorporated in its entirety by reference. The only difference from this alternative embodiment of the invention is that, since all components of the firing mechanism are fixed directly to the cylinder frame 10, the dog structure then used also incorporates the stock.

As a result of the process according to the present invention, a weapon 1 of very modern design is obtained, that is, involving the combination of materials, light and having a cost and a greatly reduced production times compared to conventional state-of-the-art weapons.

In particular, whereas a conventional revolver takes 1, 5 to 2 days to produce, and the operations performed involve about 10 different equipment for its qualification, a weapon produced according to the invention can be produced in less than one day and using only one equipment to qualify any of the metal structures 2, 3.

The main reasons leading to such equipment and time savings is that the lengthy procedures of finishing the outer surfaces of the weapon are almost completely eliminated. In particular, the metal surfaces that are exposed to the user are basically the underside and inner faces of the cylinder frame 10 and therefore no further finishing operation is required on the other surfaces of the metal body of the weapon. In contrast, the greater the roughness of these other metal surfaces, the better the adhesion of the polymeric elements 15, 20 and 21 applied to them.

On the other hand, the very qualification of the weapon is greatly expedited since all holes, surfaces and openings need only to be checked and rectified. As a result of the MIM process used for the production of metal frame 2, 3, most holes, openings and the like are formed upon injection of the preform into the MIM injection mold, and therefore such structures must be made from scratch. , but simply qualified, which makes for a much shorter operation time.

To the wearer, most of the outside of the gun will appear to be made of polymeric material, which, as known, has a natural finish and does not require roughing or deburring procedures to make it look satisfactory and clean.

In addition, the appearance of the weapon may be widely varied depending on the injection molds used for both the upper 10 and front 21 over-injection and the cable structure 15 injection. Aesthetic amplitude involves not only the possible forms to be obtained, but also the finish itself, which can be either smooth, wholly or partially rough.

Claims

1. Process for the production of firearms, characterized in that it comprises the steps of:

a) fabrication of the metal frame (2, 3) of the weapon from the ME process;

(b) qualification by machining of the housings, seats and holes of the metal structure (2, 3);

c) surface treatment of the metal structure (2, 3);

d) fixing the pipe (13);

e) over-injection of the polymeric material (20, 21) into the metal frame (2, 3); and f) final assembly of the weapon (1).

Process according to Claim 1, characterized in that the step of making the metal frame comprises the making of a metal frame (2) basically composed of the cylinder frame (10) provided and the threaded hole (12). ), for fixing the barrel (13), as well as other seats and holes for fixing the components of the firing mechanism.

Process according to Claim 1, characterized in that the step of making the metal frame comprises the making of a metal frame (3) basically composed of the cylinder frame (10) provided and the threaded hole (12). ), intended for fixing the barrel (13), the stock (14), as well as the other seats and holes for the attachment of the firing mechanism components.

Process according to Claim 1, characterized in that the step of over-injection of the polymeric material comprises placing the assembly formed by the metal frame (2, 3) and the barrel (13) in an injection die. as well as externally over-injecting said assembly (2/3, 13) with an upper portion (20) and a front portion (21).

Method according to Claim 4, characterized in that the upper portion (20) is injected above the upper portion of the cylinder frame (10) as well as the upper portion of the barrel (13).

Method according to Claim 4, characterized in that the front portion (21) is injected into the sides and below the barrel (13) and into the front and partially lower portions of the cylinder frame (10).

Method according to Claim 4, characterized in that the upper portion (20) and the front portion (21) are injected concomitantly, forming a single-piece, fully finished polymeric part.

Method according to Claims 1 and 3, characterized in that the final assembly step of the weapon (1) comprises the assembly of the firing mechanism components and then the assembly of the cable structure (15).

Method according to Claim 8, characterized in that the cable structure (15) is a layer of injected polymeric material comprising the trigger guard (16), the rear portion (17) and the cable (18), intended to surround the entire rear portion of the weapon (1), that is, the components of the firing mechanism that are fixed to the front and bottom portions of said weapon (1).

Method according to Claims 1 and 2, characterized in that the final assembly step of the weapon (1) comprises the assembly of the firing mechanism components and then the assembly of the cable structure (15).

Method according to claim 10, characterized in that the cable structure (15) is a layer of injected polymeric material which comprises the trigger guard (16), the rear portion (17), the stock (14) and the cable (18), intended to surround the entire rear portion of the weapon (1), that is, the components of the firing mechanism that are fixed to the front and bottom portions of said weapon (1).