US2218879A - Circuit make and break device - Google Patents

Description

Oct. 22, 1940. w. FoERsTE CIRCUIT MAKE AND BREAK DEVICE Filed July 22, 1937 FIG.3

FIC-3.2

FIG. 1

Flcagf lNvENTOR WiLLsAM FoERsTE ATTORNEY.

Patented Oct. 22, 1940 UNITED STATES PATENT OFFICE CIRCUIT MAKE AND BREAK DEVICE Application July 22, 1937, Serial No. 154,984

1 Claim.

The inventionA relates to electrical apparatus, more especially to a device for making andbreaking electrical circuits of high voltage such, for example, as are met with in the operation of 55 gaseous discharge lamps.

It has for an object the provision of a simple, inexpensive and effective device whereby an electrical circuit is made, or interrupted, electromagnetically and in a manner such that the closure, or interruption, may be caused to occur under relatively high voltage conditions through the control of an independent low-voltage circuit.

In carrying out the invention, a suitable screwsocket or like member is arranged to retain a coil of wire of relatively high resistance and low inductance which is included in circuit with an automatically operating low tension circuit make and break device such, for example, as the wellknown thermal interrupters or flashing devices. By this expedient, long life and effective operation of the flasher or the like is insured.

Within the coil is mounted a magnetizable element which is fixedly located therein to be under the influence of the lines of force developed by said coil. There is associated with the said fixed element a further but movable magnetizable element which is positioned relatively thereto so as to be attracted to, or repelled from, said fixed element in being subjected also to the lines of force developed by the said coil. This latter and movable element carries a suitable contact for engagement with a further contact, both of which are located in the circuit to be controlled. It is preferred to include the aforesaid magnetizable elements as well as the circuit controlling contacts within a suitable envelope and evacuate the same with de-gasiiication of the metals to an extent to prevent ionization.

The nature of the invention, however, will best 40 be understood when described in connection with the accompanying drawing, in which:

Fig. 1 is a front elevation of the novel device, with portion shown in vertical section.

Fig. 2 is an enlarged front elevation of a portion of the device; and Fig. 3 is a side view thereof.

Fig. 4 is a wiring diagram illustrating the electrical connections involved.

Referring to the drawing, I designates a base of insulating material such as the usual porcelain base provided with a screw socket II. A thermal make and break device I2 of well known or special design is mounted on the under side of the base and is included in circuit with the terminals I3 and I4 of the socket whereby an electric current, either direct or alternating, may be supplied to a screw plug I5 adapted to be retained in said socket in the usual manner, and the current periodically interrupted through the action of the thermally actuated device I2.

This plug is provided at its upper portion with a resistance in the nature of an annular winding or coil 20 which affords also a magnetizing field. The said coil is securely retained in the plug and is designed to receive into its central hollow portion 2| one end of an envelope 22 housing contact members adapted to open or close an external circuit connected thereto as will hereinafter be set forth. It is preferred to substantially evacuate the envelope to prevent arcing between the contacts hereinafter described and secure longer life thereof. The evacuation is conducted with degasification of the metals contained in the envelope so that no ionization will take place therein and short-circuiting of the contacts is obviated. It is desirable, also, to make the coil 20 of low inductance and of relatively high resistance to reduce to a minimum deterioration of the contacts of the thermal make and break device I2.

At the end of the envelope which fits into the coil there is provided a fixed magnetizable element 25 in the nature of a strip of iron or steel held in place, for example, by means of a stiff wire 26 carried by a bead 2l resting against the wall of the envelope which may be of glass. The said envelope is introduced into the said coil 20 to an extent suiiicient to cause the element 25 to lie within the field of said coil and become magnetized when the coil is energized. There is associated with said element 25 a further magnetizable element 28 which is mounted within the envelope 22 in such a manner as to be movable relatively to the xed element 25. For example, it may be suspended by a flexible connection as the spring element 29 from an insulation strip 30 of mica or the like positioned in the envelope. The natural period of vibration of this element will, of course, be made sufliciently different from the frequency of the magnetizing current, when an alternating current is utilized for this purpose, so that the said element will not be objectionably affected thereby.

In case it is desired to have element 28 attracted to the element 25 when the latter is magnetized, the said element 28 will be displaced along its magnetic axis to an extent sufficient only to juxtapose its one pole with reference to a pole of opposite polarity of the element 25. Should the control be effected by a repelling action between the two elements, element 28 will be displaced to an extent suiiicient to bring both of its poles opposite corresponding poles of the element 25.

The movable element 28 carries a Contact 3| which is normally held, in the embodiment shown, to a further and X-ed contact 32 through the action of the spring 29; and is separated therefrom only when coil 2G is energized, magnetizing thereby both of the elements 25 and 28 and causing the latter to be attracted to the former. It will be understood, of course, that the action may be reversed and the'contacts closed on energization of the said coil.

Leads 33 and 34 connected tothe respective contacts 3l and 32 connect with suitable ter'- minals 35 and 36, respectively, located exteriorly of the envelope for convenient connection to an external circuit to be controlled by the novel device. For example, the device may be included in a high tension circuit as the secondary circuit 40, Fig. 4, of a gaseous discharge lamp system. embodying a plurality of lamps 4l and 42. The

former lamp may beconnected directly across lamps will be eiected, as the low tension circuit controlled by the thermally actuated device I2 is made and broken to control the energization of the coil 20, and without any direct connection between the low tension and the high tension circuits.

I claim:

A contact device, comprising an elongated envelope, a contact unit for mounting therein and including a single, non-magnetic support resting along its sides against the envelope wall, together with a stiff wire extension projecting from one end of the support and carrying a bead resting against a further and opposite wall portion of the envelope, a magnetizable element xed at said end of the support, said envelope being adapted to iit within a magnetizing coil to position said magnetizable element for magnetization thereby, a second magnetizable element and a resilient connection between the same and the support, said element'being adapted to swing in juxtaposition to the rst-named element and carrying a contact member, and a further and xed contact member attached to the support and located in juxtaposition to the swingable contact member, the latter being normally biased for engagement therewith through its said resilient connection to the support,'together with terminal means secured to the sup-port at its opposite end for suspending the said support from the envelope.

WILLIAM FOERSTE.

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