US1912423A - Blasting cap - Google Patents

Description

June 6, i933. W T AYER 1,912,423

BLASTING CAP Filed Deo. l2, 1951 Patented .lune 6, i933 istanza NT@ TTES .PATENT @FFEQ WILLIAM T. AYER, OF WILMINGTON, DELAWARE, ASSGNOR TO HERCULES POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION F DELAWARE BLASTINC CAP Application led December 12, 1931.

This invention relates to an improvement in blasting caps such as are used in the firing of commercial explosives, and more particularly relates to4 an arrangement whereby 5 blasting caps may be protected during shipment and storage with avoidance of accidental discharge.

As is well known, blasting caps adapted for electrical firing are equipped with a pair of lead wires by which they are connected into a firing circuit after they are placed within an explosive charge to be fired.- Customarily for shipment and storage of such caps the lead wires are bundled and tied centrally of the bundle and with the free ends of the lead wires and the cap at oppo site ends of the bundle.

The customary bundling and tying of the lead wires of such caps is ordinarily sutlicient to Aenable convenient packaging and handling of the caps, but since the cap itself is wholly unprotected, it is liable to accidental firing by any shock to which it may be subjected, as for example, by striking another cap in a package, or by striking the wall of a package during shipment, from being dropped in handling, or otherwise. As will be appreciated, such caps are usually loaded with fulminate of mercury, which is 0 very sensitive and which is of great power so that the possibility of accidental firing presents a large risk.

Now, it is the object of this invention to provide an arrangement whereby such caps will be adequately protected from shock,

whether during shipment, in storage, or in handling, until it is desired to prepare them for use.

In accordance with this invention there is provided a protector for the cap in the form of a sleeve, which is slipped over the cap and lead wires bundled in the customary manner, the protector or sleeve being retained and being made of any suitable ma- 45 terial and being retained in position at one end by turns o f the end portions of the lead wires about the bundle and at the other end by bending one or more of the lengths of the bundle over the end of the protector.

Having now indicated in a general way Serial No. 580,557.

the nature and purpose of my invention, l will proceed to a detailed description of preferred embodiments thereof with reference to the accompanying drawing in which:

Figure 1 is a side View of a blasting cap embodying my invention.

Figure 2 is a plan view showing a blasting cap and modified form of protector for application thereto.

Figure 3 is an end view of the arrangement shown in Figure l, the protector being of the form shown in Figure 2.

Figure 4 is a perspective View of a form of protector.

Figure 5 is an end View of the arrangement shown in Figure l, the protector being of the form shown in Figure 4. i

Referring more particularly to Figures 1, 4 and 5, A indicates a blasting cap, provided with lead wires which 'are bent back and forth in lengths b, b to form a bundle. In forming the bundle the lengths are arranged so that the cap A lies on the bundle roughly between the middle and one end of the bundle and a free end portion is turned about the bundle roughly at its middle acting to tie the bundle and as a stop for the protector, as will be described. The turns of the free end portion of the wires about the bundle are shown at C.

As is customary, the lead Wires are insulated except adjacent their free ends, by which they are connected into a firing circuit. The insulated end portions of the Wires are desirably shunted by means of a Vmetal, or conducting clip D, or otherwise as by twisting together, in order to prevent accidental iiring of the cap through contact of the uninsulated portions of the wires with any solirce of current.

The protector` E is made of any suitable material, as fibre, bakelite, cloth covered metal, etc., etc., is in the form of a sleeve of a length at .least equal to and desixably in excess of that of the cap. In cross section the protector or sleeve E may be generally circular, as shown in Figure 4, or it may be of any other form as, for example, polygonal. The protector will, however, be of sufficient area in cross section to slip, lo(

freely or with relative ease, over the cap and bundled lead wires, into a position covering the cap and with its inner end abutting the turn D of the lead wires, as shown in Figure With the protector in the position shown in Figure 1, the end ,portion of a length or lengths b of the bundled lead Wires is bent over the end of the protector or sleeve E to retain it in place.

Referring now to Figures protector E is formed from a metal f, the surfaces of which arecoveref. with cloth g, suitably adhered thereto.

The application of the protector E to the cap is eii'ected by bending the protector 2 and 3, the light sheet of about the cap and bundle to form a sleeve, P

which may be accomplished manually or by any suitable bending mechanism. The lprotector E may be held in place as shown in Figure l.

As will be obvious, removed from the cap bysimply drawing 1t off with the fingers and the cap may, after removal of the protector, be prepared for use as usual.

It will be understood that it is not contemplated that this invention shall be limited to details described herein for the purpose of illustration and fullnessof disclosure, since it will be appreciated that various modifications in detail may be made. Thus, for example, the protector may be retained in position embracing the cap and bundle adjacent thereto by various means.

What I claim and desire toy protect by Letters Patent is:

1. In combination, a `blasting wires extending from the cap and bundled therewith by bending back and forth into lengths, and a protector formed from cushioning material and loosely embracing the cap and the bundle of lead wires adjacent thereto.

2. In combination, a blasting cap, lead wires extending from the cap and bundled therewith by bending back and forth into lengths, a protector formed from cushioning material and loosely embracing the cap an the bundle of lead wires` adjacent thereto and means for retaining the protector in position. i

3. In combination, a blasting cap, lead wires extending from the cap and bundled therewith by bending back and forth into lengths, a free end portion of the lead Wires being turned about the bundle, and a protector formed from cushioning material and loosely embracing the cap and the bundle of lead wires adjacent thereto and having one of its ends adjacent to said turns about the bundle.

4. In combination,

the protector may b e wires extendingV Jfrom the cap and" bundled and forth into thnmwith by bending back tof lead Wires adjacent thereto,

cap, lead lengths, and a protector formed from cushioning material and loosely embracing the cap and the bundle of lead Wires adjacent thereto, one of the lengths forming the bundle being bent over an end of the protector.

5. In combination, a blasting cap, lead Wires extending from the" cap and bundled therewith by bending back and forth into lengths, a free end portion of the lead Wires being turned about the bundle, and a protector formed from cushioning material and loosely embracing the cap and the bundle said turns acting as a stop, for the protector in one direction and one of the lengths JI'orming the bundle being bent over an end of the rotector and acting as a stop for the protector in the opposite direction.

In testimony of which invention, I have hereunto set my hand, at Wilmington, Delaware, on this 9 day of December, 1931.

WILLIAM T. AYER.

a blasting cap, lead

Images