US1497145A - Safety igniter - Google Patents

Description

June 10 1924.

E. P. JONES ET AL SAFETY IGNITER Filed Sent. 1. 1923 W 4M ATTORNEY.

Patented June 10, 1924.

UNITED STATES PATENT OFFICE.

EDWARD r. JONES, name-L w. FALL, a m FRANCIS E. Jones, or BRECKENRIDGE,

, coLoRAno.

SAFETY IGNITER.

Application filed September 1, 1923. Serial No. 660,635.

T cZZ whom it may concern.

Be it known that EDWVARD P. Jonas, DAN- inL YV. FALL, and Funnels E. Jonas, citizens of the United States, residing at Bracken ridge, in the county of Summit and State of Colorado, have invented certain new and useful Improvements in Safety Tgniters, of

which the following is a specification.

The present invention relates to safety ign) niters for all sorts of high explosives, such for example, as are used in blasting, mining, and like operations.

In the fuses or igniters now commonly used, considerable danger is occasioned by hanging of tire, sometimes for many hours, which causes delayed explosions, at an annual cost of many lives in mining and other operations. This danger from hanging fire exists in fuses or igniters of all kinds wherein lint or like slow burning materials are used to ignite, confine or are in contact with, the more rapid burning powder or like combustible materials. In tuses of this kind a blank space or break in the powder train has been known to stop the burning of the powder, and thelint or container has smouldered for over 12 hours until the powder has been reignited and caused a fatal explosion.

An object of the present invention is to provide an igniter or fuse in which all possibility of hanging fire with its resulting disastrous consequences is eliminated.

A further object of the invention is to provide a safety igniter wherein the only combustible material used is the rapid burning powder or other fusible or combustible material train which may be readily manufactured for different timing of operation, and in'which defects may be seen ata glance.

Another object of the invention is to provide a more simple and efiicient igniter and fulminate, or other high explosive cap than has heretofore been produced.

Other objects of the invention will appear in the following detailed description of the preferred embodiments of the invention of which- Figure 1 is a sectional elevation of a short time train igniter.

Figure 2 is a plan view of the igniter shown in Figure 1.

Figure 3 is a sectional elevation of a long time train igniter.

Figure l is a sectional plan view taken along line AA of Figure 3.

Figure 5 is a sectional elevation showing the igniter as applied to a fulminate or high explosive cap.

Figure 6 is a plan view of the form shown in Figure 5.

Referring to Figures 1 and 2, 1 represents a tube made of porcelain, cement, glass or other transparent and noncombustible materials. .A passage '2 extends through the main portion of 1 and connects at the top with a larger recessed or chamber portion 3. Passage 2 and part of recess 3 is filled with powder or'like combustible material 4. A coating 5 of easily fusible and preferably combustible material, for example water glass, wax,.or paraffin is spread over the lower end of 1 and serves to seal material 4.- in place in the passage and to maintain this material in dry condition. Coating 5 is thin enough to be broken by the burning train. The upper end of recess 3 is then sealed her.- metically with a plug 6 of cement paste, .or like material. Sealed into and extending through plug 6 are electrical conductors 7.

and 8 which are bent and shaped to form'a pair of spark points in the part of chamber 3 containing material 4:. Wires 7 and 8 are properly insulated from each other and if desired, an insulating cover 9 may be provided to cover both.

In operation, wires 7 and 8 are connected to a source of electrical energy such as a battery or magneto and a spark is jumped between the points of 7 and 8 in well known manner. This ignites the material 4 which then burns through passage 2 and plug 5, and ignites a high explosive or charge with which it has been placed in contact.

The material in passage t burns at a definite rate for a given material and the time before the material will have burned through to the high explosive will be determined by the length of the passage. Accordingly, to make a quick acting igniter, passage 2 is shortened and to make a slow acting igniter passage 2 is lengthened. It will therefore be obvious that by cutting ofi the tube 1 properly, any desired timing may be obtained.

To avoid the necessity of making the body 1 inconveniently long for slower timing of operation, passage 2 may be made. in a winding or helical form as shown by passage 2' in Figures 3 and 4. The remaining structure of this form is, as indicated by fec'tive' no harm can result.

the reference numerals, the same asshown in Figures 1 and 2.

In- Figures 5 and 6, an igniteras set forth in Figure 1 is shown as applied to a form of fulminate cap. In a cap as disclosed the seal 5 may be omitted. A container 10 has the lower end thereof filled with dynamite or fulminate 11. A rubberpacking or washer 12 provided with a perforation 13 is placed over and acts' as yielding bufier between fu lmi-nate 11, and the body 1 of the igniter. Perforation 13 permits the burning material 1 to ignite 'fulminate 11. The igniter fits snugly into container 10 andis sealed tightly therein by means of paste or cement plug 14 through which wires '7 and '8 extend. Ignition of the cap occurs in the manner explained for the fuse.

' The interposition of washer 12 between the igniter and the fulminate adds consideraly tothe safety of the cap during manufacture and other necessary handling.

It will be seen that all possibility of hanging-fire has been removed in the construction disclosed by the complete elimination of all slow burning materials such as lint. If. the time train should'happen to be deif the body 1 is made of transparentmaterial such as glass, fany blank or empty spacesin the-time train or other defects can immediately be seen and the defective igniters may be discarded. This arrangement will permit o f co'nvenie'nt inspection immediately before use, and the use of trans- 7 Furthermore,

parent materials to confine the time train is an important feature of the invention.

Having described and shown preferred embodiments of the invention, what is de sired to be secured by Letters Patent and claimedas new is:

1. An igniter comprising a body of in-' combustible material, an igniting chamber formed in the upper end of said body, a pair of electrical spark points sealed into said ignitin chamber, a helicalpassage conn'ecting wit said chamber and extending through said body, and combustible material confined in said passage 'to form atime train. 7

2. A high explosive cap embodying a contamer and a high explosive in said container; an igniter comprising a body of incombustible material, a passage or openmg formed in and extending-through said body,

combustible material confined in said passage to form a time tr a1n,and, means for igniting said combustible nraterial; and a member of yielding material interposed be--

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