US2520935A - Magnetically operated switch - Google Patents

Description

P 5, 1950 H. HUBBELL.

MAGNETICALLY OPERATED SWITCH Filed Feb. 3, 1945 Patented Sept. 5, 1950 UNITED STATES PATENT OFFICE MAGNETICALLY OPERATED SWITCH Harvey Hubbell, Long Hill, Conn.

Application February 3, 1945, Serial No. 575,960

3 Claims. (Cl. 200-87) This invention relates to electric switches, and more particularly to a toggle type of switch, and has for an obiectto provide a switch of this type which is magnetically operated so that if desired the contacts may be located in a sealed chamber and the movable contact operated by a device located outside this chamber with no mechanical connection between them, and the switch may, therefore, be safely used in locations where there might be explosive atmospheres, and there will be no danger of ignition of gases and other elements by arcing incident to make and break of the contacts.

Another object is to provide a construction in which the operating means is yieldingly but positively held in its extreme opposite positions in such a way that in shifting it the force will be built up without movement of the operating device, and then it will release suddenly for quick movement to its opposite position to cause quick make and break of the switch contacts, similar to a snap action.

With the foregoing and other objects in view I have devised the construction illustrated in the accompanying drawing forming a part of this specification. It is, however, to be understood the device is not limited to the specific details of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In this drawing, the figure is a side elevation of the device with the cover or one side wall of the housing removed so that the various elements are shown in side elevation.

The switch construction shown as illustrating one embodiment of the invention comprises a housing I, preferably of a suitable molded insulating material, such for example as bakelite, and is open at one side to give access to the various elements in the housing, which open side is normally closed by a suitable cover, this cover being removed in the'drawing so that the various parts appear in elevation. The cover may be secured in place by any suitable means, such, for example, as screws threaded into the tapped openings 2, or suitable inserts molded into the material.

Extending through side walls of the housing into the chamber 3 are suitable conductors 4 and 5. These may be flat strips of suitable conducting metal and are provided with any suitable means for securing lead wires to them, such, for example, as the usual binding screws 8. One of these conductors, as the conductor 4, has a stationary contact I, and cooperating therewith is a movable contact 8 movable toward and from engagement with the contact I to close and open the circuit. In the present construction, the movable contact 8 is mounted on a strip 9 of conducting metal mounted to swing about a pivot l0 in the housing, and this strip is electrically connected with the conductor 5 by a flexible jumper ll, usually made of a number of flexible copper wires. The strip 9 may be a spring member if desired and is ordinarily somewhat resilient. magnetic material, which is preferably a permanent magnet, preferably mounted so that one free end or pole l3 swings back and forth about the pivot l0 and by this movement swings the strip 9 to shift the contact 8 to and from engagement with the contact I. For mounting this member I! on the strip 9, it may be provided with recesses l4 and IS in its opposite side walls, and the strip 9 is folded over the inner end of the member I2 and into these recesses as shown at l6 and l! respectively and by its resilient action to grip the member [2 to thus securely mount this member on the strip.

For swinging the member l2, and therefore, the movable contact in opposite directions, a permanent magnet I8 is mounted to swing about a pivot I9 spaced from the pivot l0 and opposite the free end l3 of the member l2. As stated above, the member I2 is preferably also a permanent magnet, although not necessarily so as it could be of soft iron, and the two magnets are preferably so arranged that like poles are adjacent each other, as for example as shown in the drawing, with the two south poles adjacent but spaced a short distance between them. Also the pivot l9 and the magnet l8 are so arranged that this like pole of the magnet l8 may be swung back and forth across the free end and similar pole of the magnet l2, so that as the magnet l8 swings back and forth it will swing the magnet l2 back and forth in the opposite directions due to the mutual magnetic repulsion between the adjacent like poles of the two magnets. Thus, when the upper magnet i8 is swung to the right to the full line position of the figure, the mutual repulsion between the two south poles of the two magnets will shift the lower magnet to the left as shown, bringing the contact 8 in engagement with the contact I to close the circuit. When the magnet l8.is swung in the opposite direction or to the left to the dotted line position, the same mutual repulsion between the two magnets will swing the lower magnet l2 to theright to the dotted line position, and by this movement Carried by the strip 9 is a member I2 of 3 shift the movable contact 8 away from the contact I to open the circuit. If the member I2 is not a magnet, but is made of soft iron or similar magnetic material, or if I! is a magnet with its unlike pole adjacent the free pole of magnet it, it will be operated by magnet it through attraction between them. In this case, the member l2 will follow member I! so that member l2 will move in the same direction as member II. The magnet l8 may be swung back and forth by any suitable means, such for example as the lever 20, which may be provided with a hand grip 2|.

Located on opposite sides of the control magnet and at the extremes of its movement in opposite directions are abutments 22 of some magnetic material, such for example as iron or steel, and these abutments are preferably so arranged as to limit the opposite movements of the magnet It, or engage it or at least be sufficiently close to it when it is at these extreme positions to hold it therein. They may be mounted in the housing by any suitable means, such for example as the laterally curved end portions 23 molded into the extensions 24 of the walls of the housing, or slipped into suitably shaped recesses molded in these extensions. The magnet I8 engages the abutments at the limits of its opposite movements, and by attraction between the magnet and these abutments the magnet will be firmly held in the positions at its extreme opposite movements. Therefore, in swinging the magnet la in opposite directions by action of the lever 20, sufiicient force or pressure must be applied to or stored up in the lever to first release the magnet from its holding abutment 22 and then the magnet will swing-with a rapid sudden movement to its opposite position, imparting a resulting and sudden rapid movement to the other magnet l2 and the movable contact, thus imparting to the movable contact what is in effect and equivalent to a rapid, quick or snap action, effecting a quick make and break of the contacts 1 and 8, reducing arcing to a minimum.

As there is no mechanical connection between the control or operating element I8 and the switch element, the switch elements and the operating means for the movable contact may be enclosed in a sealed chamber, such for example as sealing th chamber 3, and the element It mounted entirely outside this chamber as it will operate on the movable element l2 through a nonmagnetic material located between the two elements, such for example as brass, glass, aluminum, plastics, and so forth. This is illustrated in the drawing by a transverse partition 25 which may be located between the two elements [2 and I8, but if it is not necessary to seal the switch contacts this partition may be omitted.

It will be seen from the above that the device is a very simple one, requiring a small number of parts; that the make and break contacts and immediate operating means may, if desired, be mounted in a sealed chamber and operated by control mechanism located outside this chamber with no mechanical connection between them,-

4 similartoasnapactionordinarilysecuredwith a toggle type of switch.

Throughout the specification and claims the term "magnetic material" is used in a generic sense to indicate a material which is afiected by magnetic action whether it is sufiiciently hard or retains sumcient magnetism so that the member made of it is itself a permanent magnet, or it is soft iron or some other material which is affected by another magnet but itself does not retain sufiicient magnetism so that th member made of it would be called a magnet when not under the influence or the other magnet.

Having thus set forth the nature of my invention, what I claim is:

1. An electric switch comprising a housing, a stationary contact in the housing, a second contact movable to and from the first contact, means for mounting the second contact comprising a conductor strip pivotally mounted in the housing, a permanent magnet mounted on said strip provided with shoulders on opposite sides, said strip embracing one end of the magnet and including inwardly extending side portions engaged over said shoulders to secure the magnet to the strip, a second permanent magnet mounted with a like pole adjacent the opposite end pole of the first magnet and movable across s id l e p 1 to shift it in opposite directions by the repulsion between the adjacent poles, and means for shifting the second magnet in opposite directions to swing the movable contact to and from the stationary contact.

2. An electric switch comprising a housing, a stationary contact in the housing, a second contact movable to and from the first contact, means for mounting the second contact comprising a conductor strip pivotally mounted in the housing, a permanent magnet mounted on said strip arranged so that one end pole thereof swings about said pivot, said magnet being provided with recesses in opposite side walls, said strip embracing the other end of the magnet and provided with inwardly extending portions seated in said recesses to secure the magnet to the strip, a second permanent magnet pivotally mounted in the housing arranged with a like pole adjacent the swinging pole of the first magnet and movable across said latter pole to shift it in opposite directions by mutual magnetic repulsion between the poles, and means for swinging the second magnet in opposite directions to shift the first magnet and the movable contact.

3. An electric switch comprising a housing enclosing a chamber, conductors leading through the walls of the housing to said chamber, a stationary contact connected to one of said conductors, a second contact movable to and from the first contact, a conductor strip carrying the second contact and mounted to swing about a pivot, a flexible connection from said strip to the other conductor, a permanent magnet provided with recesses in its side walls, and said strip being bent about one end of the magnet and into said recesses so as to retain the magnet with one pole free to swing about the pivot and shift the movable contact, a second permanent magnet mounted to swing about a pivot with a like pole movable past said pole of the first magnet adjacent thereto so as to swing said first magnet in opposite directions by the mutual magnetic repulsion between the poles, abutments of magnetic material arranged one on each of the opposite sides of said second magnet at the limit of its movement in opposite directions and by mutual attraction between them to retain the magnet in its extreme positions, and means for swinging said magnet in opposite directions between said abutments.

HARVEY HUBBELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Allen Mar. 6, 1906 Jeffrey Jan. 29, 1935 Bates Aug. 20, 1935 Hubbell July 13, 1943

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