US1605688A

US1605688A - Method of making detonators

Info

Publication number: US1605688A
Application number: US721173A
Authority: US
Inventors: John M Olin; John B Smith
Original assignee: Western Cartridge Co
Current assignee: Western Cartridge Co
Priority date: 1924-06-20
Filing date: 1924-06-20
Publication date: 1926-11-02
Anticipated expiration: 1943-11-02
Also published as: DE446204C; FR591307A; GB239418A

Description

Nov.. 2 1926. i l,605,688

J. M. oLlN y|:1- AL METHOD OF MAKING DETONATORS Filed June 20, 1924 fig -5- Patented Nov. .2, 1926.

UNITED STATES PATENT OFFICE. i

JOHN M. OLIN AND JOHN B. SMITH, 0F ALTON, ILLINOIS, ASSIGNORS TO WESTERN CARTRIDGE COMPANY, OF EAST ALTON, ILLINOIS, A CORPORATION OF DELAWARE.

METHOD OF MAKING- DETONATORS.

Application tiled .Tune 20,

'lhis invention pertains lo detonators and more particularly to the igniters used in the same and lo a method for making the same.

One ol the objects of this invention is to provide an improved lnethod for making ignilers for detonators and particularly for at. taching the fuse or filament to the igniter connections.

Another objectis to provide a method of making such connection without altering the operating characteristics ot' the igniter.

Further objects will appeal' from the following description taken in connection wit-h the accompanying drawing,-in Which,

Figure 1 is a cross sectional view somewhat enlarged of' a detonator embodying this invention.

Figure 2 is a View illustrating the opera tion of notching the connections.

.Figure 3 is a perspective View of the igniter plug with the connections notched preparatoryto assemblingthe filament.

l `igure 4 is an enlarged diagrammatic view illustrating the operation ot' swaging the connections to secure the filament; and

Figure 5 is a perspective view of the completed igniter with the filament in place.

Referring to the accompanying drawing and morel particularly to Figure 1. the detonator shown comprises a shell 1. which may be ol drawn metal, and has

charge components

2 and 3 of any approved composition or arrangement, such as a mixture of picric acid and trinitro-toluene capped by fulminate of mercury. The upper end of the shell is beaded as shown at 4. In this shell are arranged terminals 5 of the connections which pass through a plug 7 formed on the connections and of a suitable composition, a satisfactory one being a mixture of sulphur and graphite. The connections are insulated Wires which are stripped from where they project through the plug and these connections are formed, as hereinafter described, to receive the filament 8. This filament may be of any suitable resistance wire, a satisfactory one being the composition of nickel, iron and copper. The plug with its terminals is secured Within the shell by additional plugs 9 and 10 of sulphur and pitch Which serve to seal andcap the shell and the terminals therein.- These plug components are poured into the shell so as to flow around the connections and it will be noted that the 1924. Srial N0. 721,173.

composition flows into the bead l, so as to firmly secure and lock the parts together.

The plug 7 may be formed on the connection 6 and the ends of the connections stripped of their insulation so as to provide the terminals 5 in any suitable manner. A method for carrying out these operations is described in co-pending application Serial No. 609,954, filed December 30, 1922. After the plug 7 has been formed and the terminals stripped the same may be mounted in 'a suitable die 11 cooperating with a V-shaped notching cutter 12, as illustrated in Figure 2. The cutter 12 moves endwisein a groove 13 in the die 1-1. The terminals 5 project into the groove 13 and as Vthe cutter 12 moves along the groove notches 14 are cut in the ends of the terminals 5.

Upon the completion of the notching operation, the terminals have the form illustrated in Figure 3. Each terminal is notched at its end and the notches lie in the same direction so that the filament may be laid in said notches so vas to bridge the gap between the terminals. The igniter may then be mounted in any suitable support in cooperative relation with a pair of swaging members 15. The members 15 are arranged to be brought forcibly together upon the notched ends of the terminals 5 so as to force the prongs thereof together upon the filament 8 which notches 14. This operation is illustrated in Figure 4. The tips of the terminals are thus reformed so as to be clamped upon the filament. The filament is thus securely held Without the use of solder' or other securing means Which is objectionable for the reason that it is liable to form a heavy coating on the filament and thus materially change the resistance thereof. A change of resistance of the filament alters its operating characteristics and affects reliability of ignition.

After the filament has been so secured, the filament and the terminals of the igniter connections to Which it is attached are immersed in a protective coating. This coating is preferably of non-conductive ma' ferial so as to leave the resistance of the filament unimpaired; it is, however, preferably also infiammable. A suitable Coating material .is a solution of nitro-cellulose in a suitable solvent such as ethyl-acetate;

has been laid in theimmersion of the filament and terminals in such a solution leaves a thin non-conducting but infiammable coating thereon.

When the swaging and coating operations have' been completed, the igniter is in the form illustrated in Figure 5 in which the filament 8 is securely clamped in the ends of the terminals 5 and is both electrically and mechanically connected thereto without the use of solder or similar connecting means. The igniter is then ready l' or insertion in the shell 1- of the detonator, as already described. The coating protccts the filament and terminals against corrosion, either from the sulphur of the plug or from the materials of the charge; accordingly it is not necessary to use expensive filament material like platinum, but base metal can be used as heretofore described. It will be clear, therefore, that this invention provides an improved igniter in which the Iilament is securely connected to the terminals, and a method for making `the same which is simple and which does not aiect the operating characteristics of the igniter.

It is obvious that various changes may be made in the details of construction Without departing from the spirit of this invention; it is therefore to be understood that the invention is not to be limited to the specific details shown and described.

Having thus described the invention, what is claimed is:

l. In the art of making detonators, the method comprising, assembling a, air of igniter terminals in a plug, cutting V- notches in said terminals, assembling a -filament in said notches, and crimping said terminals on said filament.

2. In the art of making detonators, the method comprising, assembling a pair of igniter terminals in a plug, cutting V- notches simultaneously in both of said terminals, assembling a filament in said notches, and crimping said terminals on said filament.

3. In the art of making detonators, the method comprising, assembling a pair of igniter terminals in a plug, cutting V- notches in said terminals, assembling a filament in said notches, crimping said terminals on said filament, and coating said filament.

4. In the art of making detonators, the method comprising, assembling' a pair of igniter terminals in a plug, mounting said terminals in a support, cutting V-notches in said supported terminals, assembling a filament in said notches, and crimping said terminals on said filament.

5. In the' art of making detonators, the method comprising, assembling a pair of igniter terminals in aV plug, mounting said terminals in a die, passing a V-shaped cutter through said die to cut V-notches in said terminals, assembling a filament in said notches, and crimping said terminals on said filament.

In testimony whereof We aiiix our signatures this 6th day of June, 1924.

JOHN M. OLIN.

JOHN B. SMITH.