US3660794A

US3660794A - Electropyrotechnic link

Info

Publication number: US3660794A
Application number: US35493A
Authority: US
Inventors: Henry M Brizzolara
Original assignee: Atlas Chemical Industries Inc
Current assignee: Zeneca Inc
Priority date: 1970-05-07
Filing date: 1970-05-07
Publication date: 1972-05-02
Anticipated expiration: 1989-05-02

Abstract

An electropyrotechnic link having two connectors held together by a ring of fusible material. When the ring is melted by heat, the two connectors separate. The heat may come from an external source such as a fire or from an electrically activated burner positioned so as to melt the ring if activated.

Description

United States Patent is] 3,660,794 Brizzolara 1 May 2, 1972 [54] ELECTROPYROTECHNIC LINK 1,953,582 4/1934 Belknap l69/42 [72] Inventor: Henry M. Brizzolara, Allentown, Pa. 1l6748l 1/1916 F' 169/42 7 3,118,994 1/1964 Kabik ..337/416. [73] Assignee: Atlas Chemical Industries, Inc., Wilming- DeL Primary Examiner-Bernard A. Gilheany 22 Filed; May 7, 970 Assistant Examiner-F. E. Bell pp No 35 493 Attorney-Kenneth E. Mulford and Roger R. Horton [57] ABSTRACT 52 US. Cl ..337 401 337 405,337 416 E Int Cl H0lh3/7/76 An electropyrotechmc lmk havmg two connectors held [58] ashram '5'5'%'/i"'ili'3'"'i2 183 185, together by a ringoffusible material when the ring is melted 337/298 401, 402 404 4] 1:416, 176 178, 407' by heat, the two connectors separate. The heat may come 405 409; 1 2 2 1 9 42 from an external source such as a fire or from an electrically activated burner positioned so as to melt the ring if activated. 56 R f C't d 1 e erences l 5 Claims, 2 Drawing Figures UNITED STATES PATENTS 357,148 2/1887 Hall ..l69/42 P'ATENTEDMAY 21912 I L 3,660,794

FIG. I

INVENTOR Henry M Brizzolom BY M ATTORNEY This invention relates to an electropyrotechnic link which can be actuated either by an external heat source or by an electrically activated burner.

An electropyrotechnic link is often used in a fire alarm V system to detect heat and set off a sprinkler system or an alarm, close a shutter, or similar function. In the device of the present invention, two connectors are held together by a ring of fusible material. When the ring melts, the connectors are freeto separate. The electropyrotechnic link of this invention is easy to make and to assemble. Each connector may be stamped from a single piece of metal and no soldered connections are necessary.

FIG. I shows a side view in section of the electropyrotechnic link of this invention.

FIG. II shows an isometric view of one of the connectors of the electropyrotechnic link.

In FIGS. I and II, a connector 1 has a side arm 2 having a slit 3 through it. The vertical portion 4 of the connector has

burner retaining tabs

5 and 6 and ring retaining tab 7 extending from it. i

In FIG. I, two connectors l are positioned around an electrically activated burner 8 which consists of a container 9 having lead wires 10 and 11 hermetically sealed with glass 12 at its base. Bridgewire 13 joins the two lead wires and is coated with initiating composition 14, for example, barium styphnate, lead azide, lead styphnate, LMNR-chlorate, or zirconium-barium nitrate. Over initiating composition 14 is placed burning composition 15, for example, tungsten powder or silicon-red lead. While the particular burner illustrated in FIG. I is preferred, other types of electrically activated burners may also be used, Finally, ring 16 holds the two connectors in the position shown in FIG. I and is itself held in place by tabs 7. The ring is of a fusible material, i.e., a material which is melted or destroyed by heat such as low-melting metals or plastics; Woods metal is preferred.

The electropyrotechnic link is easily assembled by positioning the two connectors around the burner and pressing the ring down over the vertical portions of theconnectors until tabs 7, which have been pushed inward by the ring, snap out into place.

Slits 3 may be used to connect the electropyrotechnic device to a tire alarm system or other system. In a fire alarm system, the connectors may be placed under a spring tension tending to pull them apart. Thus, when ring 16 melts, connectors 2 are pulled apart setting off a sprinkler system or an alarm. Should it be desirable to activate the electropyrote'chnic link manually as, for example, when a tire is detected which has notyet generated enough heat to melt the ring, a current may be sent through lead wires 10 and 11, heating bridgewire l3 and initiating compositions l4 and 15 thereby melting the ring.

What is claimed is:

1. An electropyrotechnic link comprising A. two connectors each having a vertical portion and a side arm extending outwardly from said vertical portion for affixation to an element to be connected,

B. a ring of fusible material positioned over the vertical portion of each of said two connectors so as to prevent said connectors from moving apart, and

C. an electrically activated burner positioned so as to fuse said ring when activated, thereby permitting said connectors to move apart.

2. The electropyrotechnic link of claim I wherein said burner is positioned at the center of said ring.

3. The electropyrotechnic link of claim 1 wherein said ring is made of Woods metal.

4. The electropyrotechnic link of claim 1 wherein said ring is held in place by tabs extending from the vertical portions of said connectors.

5. An electropyrotechnic link comprising A. an electrically activated burner having side walls B. two connectors each having a side arm extending outwardly in a direction opposite the other from said side walls and each having a vertical portion running along said side walls, said vertical portions being generally opposite one another, and

C. a ring of metal, fusible upon activation of said burner, surrounding and holding together said burner and said vertical portions of said connectors, said ring being held against movement in one direction along said burner by said side arms and being held against movement in the other direction along said burner by tabs extending outwardly from said vertical portions of said connectors.

Claims

1. An electropyrotechnic link comprising A. two connectors each having a vertical portion and a side arm extending outwardly from said vertical portion for affixation to an element to be connected, B. a ring of fuSible material positioned over the vertical portion of each of said two connectors so as to prevent said connectors from moving apart, and C. an electrically activated burner positioned so as to fuse said ring when activated, thereby permitting said connectors to move apart.

2. The electropyrotechnic link of claim 1 wherein said burner is positioned at the center of said ring.

3. The electropyrotechnic link of claim 1 wherein said ring is made of Wood''s metal.

5. An electropyrotechnic link comprising A. an electrically activated burner having side walls, B. two connectors each having a side arm extending outwardly in a direction opposite the other from said side walls and each having a vertical portion running along said side walls, said vertical portions being generally opposite one another, and C. a ring of metal, fusible upon activation of said burner, surrounding and holding together said burner and said vertical portions of said connectors, said ring being held against movement in one direction along said burner by said side arms and being held against movement in the other direction along said burner by tabs extending outwardly from said vertical portions of said connectors.