US3745276A

US3745276A - Circuit breaking device

Info

Publication number: US3745276A
Application number: US00230622A
Authority: US
Inventors: J Mcpherson
Original assignee: Cartridge Actuated Devices Inc
Current assignee: STURDOBE Corp A CORP OF DE
Priority date: 1972-03-01
Filing date: 1972-03-01
Publication date: 1973-07-10
Anticipated expiration: 1990-07-10

Abstract

A device for breaking a circuit which comprises an anvil and a cutter cooperating with the anvil and a printed circuit board between the anvil and cutter, the circuit to be broken comprising conductors in each of the cutter and anvil and a connection between those conductors through the printed circuit board. Actuation of the device, for example by an explosive cartridge, causes the cutter to move toward the anvil and break a piece from the printed circuit board and at the same time to break the connection between the conductors of the anvil and cutter.

Description

United States Patent 1 1 McPherson 1 11 3,745,276 1 July 10, 1973 CIRCUIT BREAKING DEVICE James II. McPherson, Succasunna NJ.

Assignee: Cartridge Actuated Devices, Inc.,

Fairfield, NJ.

Filed: Mar. 1, 1972 Appl. No.: 230,622

Inventor:

3,309,961 3/1967 Lee 89/1 B Primary Examiner-Darrell L. Clay Attorney-Albert C. Nolte Jr. et al.

[5 7] ABSTRACT A device for breaking a circuit which comprises an anvil and a cutter cooperating with the anvil and a printed circuit board between the anvil and cutter, the circuit to be broken comprising conductors in each of the cutter and anvil and a connection between those conductors through the printed circuit board. Actuation of the device, for example by an explosive cartridge, causes the cutter to move toward the anvil and break a piece from the printed circuit board and at the [56] References Cited f t b ak th b t th 3,136,842 6/1964 Perkinset a1. l74/88R 3,195,097 7/1965 McLain 339/45 M 9 Claims, 2 Drawing Figures 72 a 6 I //4, I! /7 60% 54 14 m q d A;

67 :1 M 1 40 g 56 0 '1! r", T /7 1 a n 77' i y, F if I 'l /5Z 7 I I I, I 7 I A i l 7 $-32;

Patented July 10, 1973 CIRCUIT BREAKING DEVICE This invention is concerned with a device for breaking a circuit and for positively maintaining that circuit broken. It is particularly but not necessarily exclusively, concerned with explosive actuated devices.

The nearest art of which applicant is aware is that illustrated in U.S. Pat. No. 2,929,892 issued Mar. 22, 1960 to Axel E. Blomgren.

Briefly, that patent shows a switching device comprising an enclosure within which is disposed a sleeve across one end of which a flattened and weakened bight portion of a U-shaped wire conductor extends. A plunger in the form of a disc is located opposite to that end of the sleeve and is mounted so that upon detonation of a motive charge it is moved into the sleeve to break the weakened portion of the wire. Attention is directed to that patent for a fuller description of its parts and operation.

Mechanically, that device is relatively complex and it is useful only for the severance of a single wire. It will be apparent that to modify that device to break more than a single wire or circuit would be extremely difficult.

Additionally, the arrangement of the Blomgren Patent is one in which both ends of the bight portion of the single wire are severed, which is in itself a somewhat questionable approach to the problem of simply interrupting the wire, but one which also raises the possibility that only one end of the bight may be severed, in which case, because the device not only is intended to break the single wire but also to make another circuit at the initially remote end of the sleeve, there is a possibility of a short circuit being made.

This invention seeks to provide a device for positively breaking a circuit and one which is readily adaptable to break more than one circuit or more than one connection.

An embodiment of this invention is illustrated, schematically, in the accompanying drawings, in which:

FIG. 1 is a longitudinal section of a unitary device embodying this invention; and

FIG. 2 is a section on the line 2-2 of FIG. 1.

The circuit breaker device of the drawings comprises a generally cylindrical housing of which the exterior is shaped to fit the physical environ of the device and which in this particular embodiment has a first large diameter portion llat one end; a central, externally screw threaded portion 12 of lesser diameter than portion 11 and a still smaller diameter portion 13 at the end remote from portion 11.

A generally radial shoulder 14 is formed at the junction of portions 11 and 12 and inclined shoulder 15 is formed at the junction of

portions

12 and 13.

Internally of the housing an anvil compartment 16 is separated from a lesser diameter cutter compartment 17 by a radial shoulder 18 and an even lesser diameter explosive charge compartment 19 is separated from compartment 17 by a radial shoulder 20.

Fitted into the compartment 17 is a plunger member 22 into an annular groove 23 of which an O-ring 24 is inserted to provide an effective seal between the plunger and the wall of compartment 17.

Behind the plunger 22 and in compartment 19 a charge of an explosive material is inserted and the open end of the compartment 19 is closed by a disk 25 which is retained in position by crimping of an end portion 26 of the body 10.

The end 30 of plunger 22 has a cylindrical recess 31 formed therein and fitted into that recess is a cutter 32 the cutter 32 being bonded to the plunger 22 by means of a cement such as an epoxy resin.

A plurality of spaced passages 33 are formed axially through the cutter and communicate with an opening 34 to the interior of the plunger and within those passages 33 are located conductors 40 those conductors being bonded in the passages 33 and in the plunger by a cement such as an epoxy resin. In this embodiment of the invention, the conductors are part of a circuit within the plunger 22 which will in fact be a detonating circuit but which clearly may take other forms. Equally clearly the conductors 40 may haveexternal connections to alternate or additional circuitry.

At the end face 46 of the cutter the ends of conductors 40 project, to be connected, in a manner described hereinafter, to a printed circuit board 52.

The circumferential edge 47 of the cutter body cooperates with an anvil to sever the printed circuit board again, in a manner described hereinafter.

Fitted into the compartment 16 to abut shoulder 18 is an insulating ring 50 the face of which, remote from shoulder 18 is recessed as at 51 to receive a printed circuit board 52.

The ring 50 has a central opening 54 which embraces the cutter body 32 to guide the cutter.

The printed circuit board has a number of connection openings 55 formed therein equal in number to the numbers of conductors 40 of the cutter body and in one mode of assembly of this device when the printed circuit board is located against shoulder 46 the ends of the conductors 40 are soldered to the printed board to make a connection with one end of the conducting paths 56 of the printed circuit board. Alternatively, the plunger, cutter, insulating ring and printed circuit board could be preassembled outside of the device and inserted as a unitary assembly into the housing 10 from the left hand end of that housing.

The printed circuit board has a thickness somewhat greater than the depth of the recess 51 in the face of the insulating ring 50 so that its left hand face, as viewed in FIG. 1, is proud of the left hand face of the ring.

After this, assembly conductors 60 are connected to the opposite ends of the connector elements 56 of the printed circuit board by soldering as at 63. Thus a circuit is established comprising conductors 40 within the cutter the connecting bridge or path 56 of the printed circuit board and the conductors 60 of the anvil assembly.

The anvil 6-1 is then located on the conductors 60 and moved inwardly to abut the printed circuit board. To this end the anvil 61 has a number of axially extending grooves or holes 66 cut in its outer surface for the reception of conductors 60 those grooves or holes being equal in number to the number of conductors 60. The grooves are continued across the axial face of the anvil as at 67 to a central junction 68.

Additionally, on the conductors 60 there is mounted a clamping or locking ring 70 which has a central opening 71 through which the conductors pass. The clamping ring has external screw threads 72 which cooperate with internal screw threads 73 of compartment 16 of the housing. When the anvil is in position and the conductors are secured to the printed circuit board by soldering the ring 70 is inserted into the end of the housing and screwed inwardly to lock the anvil in position and cause the anvil to be securely held with the printed circuit board between the insulating ring 50 and the anvil.

Finally, a cement is filled into the passages 66 of the anvil the central opening 71 of the clamping ring 70 to firmly secure the conductors 60 therein.

It will be appreciated that upon detonation of the charge in compartment 19 of the housing as for example by signal or detonating current to the conductors 60, connectors 56 and conductors 40 or a heating current through that circuit, the plunger 22 will be driven forcefully to the left as viewed in FIG. 1 to punch out that portion of the printed circuit board overlying the recess in the anvil, thus breaking the paths 56 and interrupting the circuit completely by those connections. The material of the anvil and of the cutter is a high dielectric material so that the impedance of the circuit breaker is very substantial, i.e., the resistance to electrical leaks between the severed ends of the paths of the circuit board is extremely substantial.

It is to be appreciated that in the particular embodiment illustrated the anvil is recessed and the cutter is operable to extend into that recess. However, the terms cutter and anvil are used here as a matter of convenience and the cutter is that part which moves towards the anvil. Under these circumstances it is to be appreciated that what is the anvil of this embodiment, if it were movable towards the element which is identified as the cutter, would indeed be the cutter.

The applications of this invention are several and varied but one particular application is described in our copending application entitled POSITIVE PISTON STOP AND LOCK, dated Mar. 1, 1972, allotted Ser. No. 230,837 and in the name of ROBERT I-I. SAW- YER in which special provision is made to insure that the cutter and anvil cannot bounce after detonation.

I claim:

1. A circuit breaking device comprising an anvil, a cutter having a cutting edge for cooperation with the anvil, a printed circuit board disposed between the anvil and the cutter, a conductor in the anvil and a conductor in the cutter, said conductors being connected to a common conducting path of the printed circuit board, said path crossing said cutting edge and said cutters being connected to the path at opposite sides of said edge and actuating means for forcing the cutter towards said anvil to cut a portion from the printed circuit board whereby said path is broken between the connections of said conductors thereto.

2. A device as claimed in claim 1 wherein one of said cutter and said anvil has a female configuration and the other of said cutter and anvil has a cooperating male configuration the edges of said configurations cooperating to cut said portion from the printed circuit board.

3. A device as claimed in claim 2 wherein the cutter has a male configuration and the anvil a female configuration.

4. A device as claimed in claim 3 wherein said actuating means comprises an explosive charge.

5. A device as claimed in claim 2 wherein said actuating means comprises an explosive charge.

6. A device as claimed in claim 1 wherein said actuat ing means comprises an explosive charge.

7. A device as claimed in claim 6 wherein said conductors are connected to a detonating circuit for said explosive charge.

8. A device as claimed in claim 1 wherein said'conductors are connected to a circuit for activating said actuating means.

9. A circuit breaking device comprising a housing, an explosive charge within said housing a cutter mounted for sliding movement in said housing upon detona-tion of said charge, a cylindrical projection on that side of the cutter opposite to said charge and defining an annular cutting edge, an anvil having a recess opposite to the projection to the cutter for the reception of said projection upon detonation of said charge, a printed circuit board disposed between the anvil and cutter and extending over the recess of the anvil, at leastone conductor disposed in the anvil, at least one conductor in the cutter, said conductors being electrically connected to a conducting path on the printed circuit board, said path extending across said cutting edge whereby upon detonation of said charge said cutter is forced so that the projection thereon is moved into the recess of said anvil and a portion of said printed circuit board is separated from the remainder whereby said conducting path is broken and the connection between the said conductors is interrupted, said cutter and anvil being of high dielectric material.

* k k l

Claims

6. A device as claimed in claim 1 wherein said actuating means comprises an explosive charge.

8. A device as claimed in claim 1 wherein said conductors are connected to a circuit for activating said actuating means.

9. A circuit breaking device comprising a housing, an explosive charge within said housing a cutter mounted for sliding movement in said housing upon detonation of said charge, a cylindrical projection on that side of the cutter opposite to said charge and defining an annular cutting edge, an anvil having a recess opposite to the projection to the cutter for the reception of said projection upon detonation of said charge, a printed circuit board disposed between the anvil and cutter and extending over the recess of the anvil, at least one conductor disposed in the anvil, at least one conductor in the cutter, said conductors being electrically connected to a conducting path on the printed circuit board, said path extending across said cutting edge whereby upon detonation of said charge said cutter is forced so that the projection thereon is moved into the recess of said anvil and a portion of said printed circuit board is separated from the remainder whereby said conducting path is broken and the connection between the said conductors is interrupted, said cutter and anvil being of high dielectric material.