US2665344A - Silent magnetic switch - Google Patents

Description

Jan. 5, 1954 l. zozULlN ETAL SILENT MAGNETIC SWITCH 2 Sheets-Sheet l Filed OCb. 22, 1951 Jan. 5, 1954 l. ZOZULIN EVAL 2,665,344 SILENT MAGNETIC SWITCH Filed Oct. 22, 1951 2 Sheets-Sheet 2 Patented `an. 5, 19544 SILENT MAGNETIC SWITCH Igor Zozulin and Geor British C01 ge J. Okulitch, Vancouver, umbia, Canada Application October 22, 1951, Serial No. 252,482

Claims priority, application Canada August 13, 1951 (Cl. 20D-67) 3 Claims.

This invention relates to electric switches and in particular to electric switches in which the operation is induced by a permanent magnet.

In electrical switches and particularly electric switches used to control domestic lighting systems it is the practice to use a construction comprising a series or" levers, linkages and toggles to effect the making and breaking of the circuit. These toggles and levers are moved by the operator from an external point and are held in their two normal positions by means of springs. It was found that this type of switch, with its many moving parts experienced great wear at critical points and that after a limited period of use its operation was erratic and undependable. The pivot joints between the levers became worn and allowed an amount of play between the two parts that was sufficient to destroy the positive action of the switch. The springs which urged the contact points into or out of engagement also lost then` strength after a short time and the operation of the switch was seriously impaired.

The feature of this invention lies in the use of a permanent magnet as the urging means in. place of the springs of the old type of switch and inthe method of constructing the switching mechamsm so as to reduce the number of parts and thereby7 the number of points of wear. The switch that 1s the embodiment of the present invention cannot wear out and is virtually noiseless.

An object of this invention is to provide an electric switch which makes use of a permanent magnet in place of springs.

A still further object of this invention is to provide an electric switch which can be hermetically sealed against moisture and dust.

A still further purpose of this invention is to provide an electric switch, the operation of which is virtually noiseless.

A still further purpose of this invention is to provide an electric switch which will be actuated by the slightest pressure on a flexible plastic diaphragm.

A still further object of this invention is to provide an electric switch which will indicate at a glance whether the switch is in the on or the 01T position.

These and other salient objects of this invention will be apparent from the following description and claims when read in conjunction with the appended drawings of which:

Figure 1 is a plan view of the preferred embodiment of the invention.

Figure 2 is a section view through section line A--A of Figure 1.

Figure 3 is a plan view of another embodiment of the invention.

Figure 4. is a section view taken through section line A A of Figure 3.

Referring now to Figures l and 2 it will be seen that the switch is of standard size and will t into the conventional Wall box. The outer casing I of the switch is of a dielectric material and is in the form of a rectangular box, open at one face. Inside the box I at one corner is mounted a permanent magnet 2 held in place by a screw 3 which does not penetrate through the wall of the box I. The magnet 2 is C-shaped and has its north and south poles, N and S respectively, facing each other in spaced relationship. To the left of the magnet 2 is the switching beam l: which is made of Bakelite or other dielectric material. The beam d is mounted on a pivot 5 in v such a position as to enable the projection 5 of beam 4 to lie between the poles of the magnet 2. The end of the projection 6 which is between the poles of the magnet 2 is composed of a magnetic metal 1, such as iron to enable it to adhere to one or the other of the poles of the magnet. The beam 4 is provided with an electrical contact point 8 mounted on a projection of the beam extending in the opposite direction from the magnetic projection 6. This electrical Contact point 8 is in abutment with a second electrical Contact point 9 when the switch is in the on position. At the top of the dielectric box I, i. e, the open side, there is a diaphragm Il! provided with two cylindrical protuberances II and I2. rlhe diaphragm I0 completely covers the open end of the box I and is secured there in such a manner as to hermetically seal the switching mechanism against moisture and dust. On the beam 4, on the side of the pivot 5 remote from the magnet 2 and the contact point 8 are two cylindrical protuberances I3 and I4 of unequal height, the higher one, I 4 being of a height sunicient to enable it to touch the diaphragm I5 directly beneath the outer protuberance I2 when the magnetic end I of the beam :i is adhering to the N pole of the magnet 2. When the member 7 is adhering to the S pole of the magnet 2 the beam 4 will have rotated about the pivot 5 to such an extent that the lower protuberance 3 has been elevated until it touches the diaphragm I 0 directly beneath the outer protuberance Il. In this position, since the beam 4 has rotated slightly the beam 4 has caused the metallic end I to move to the neutral position between the magnetic poles. At that moment the contact points 8 and 9 are still in abutment because of the spring adottati action or" the mounting member 29. As the lbeam fi is in this position the magnetic end 'l of said beam is haii way between the N and S poles of the magnet 2. At this point magnetic attraction is altered and the end l is sharply attracted to the other pole of the magnet to the S pole thus breaking the contact instantaneously. The contact point S mounted on the beam i by means of a metal projection le which is in turn connected electrically by means of a flexible conductor 2S to a screw terminal it on the exterior suriace of the box l.V The screw iii is on the outside oi the box l and is threaded into a metal plug il which passesI 'through the walls oi the box i and is sealed therein so as not to disturb the moisture prooi qualities oi the box. The contact point 9 is secured by means or" a metallic spring I8 directly to a metallic plug I, similar to the plug il, the plug i9 also being provided with a screw terminal 20. At each side of the dielectric box l is a metallic angle bracket 2l and 2S for the purpose oi securing the switch to a standard wall box 2i .by means oi screws 22 and 23. A standard push button switch cover plate 2li is placed over the diaphragm le to complete the assembly and is held in place by screws 25 and 2t.

When the switch is connected to a circuit the conductors are secured to the screws it and to. When the metallic end l of the projection 6 adheres to the N pole oi the permanent magnet ii the contacts il and 9 are touching and the protuberance is touching the diaphragm iii di.- rectly beneath the cylindrical protuberance l2 on the diaphragm it. Since the contacts 3 and 9 are touching the circuit is complete or the switch is in the on position. When the protuberance iti is pressed it transmits the pressure to the protuberance ifi and pushes it down. rhis motion moves the metallic end i oi" the projection e and it snaps over and adheres to the S pole or the permanent magnet 2 thus moving the contact 8 away trom Contact 9 thus breaking the circuit. At the saine time the protuberance it is moved up until it touches the diaphragm it directly beneath the protuberance i i. lThe switch is then in the ofi position. Pressure on the protuberance il will reverse the process.

ln a second embodiment of this invention as illustrated in lligs. 3 and 1i shows the mechanism of the switch in closed circuit position (Fig. 4) The mechanism is mounted in a rectangular box lo oi a dielectric material, the box la, being open at its upper face. Following assembly or the switch parts inside the box la, a flexible diaphragm 2a oi transparent plastic is tted over the open iace of box and hermetically closed so that the switch mechanism is sealed against dust and moisture. A second rectangular box 3a is provi-ded, similar in construction to standard type switches, to house the dielectric box la and to provide mounting means for the switch. Brackets da and 5c are pressed into dielectric box lc and screws da and. la are provided to atV tach the dielectric box la to the outer box 3a. A cover plate da provides a iront face for the switch and protects the flexible diaphragm 2a against any possible damage. Screws 9a and ia are provided to hold the cover plate 8a in place. A cylindrical protuberance im is formed integrally on flexible diaphragm 2a, this protuberance ila extending through an opening in the cover plate The components to be mounted inside dielectric box ia, comprise a permanent magnet i205 which is fastened to an end face of dielectric box la by means of fastening screw 53a. A moving beam lila constructed of a dielectric material is pivotally mounted on shaft ica so that the beam can oscillate about the axis of shaft ld. rIhe ends oi shaft 15a are sealed into box la. A sleeve ld is mounted on beam Ella to provide bearing surface with shaft 15d and to prevent lateral movement of beam lila. Armature pieces lla and ita of a ferromagnetic substance are secured to the end of beam ita adjacent the N and S pole faces, which faces are shown sloping in order to obtain maximum contact with the armature pieces ila and ita. The other end oi beam iria carries a switch contact ida and electrical means oi connection are provided between Contact lila and a flexible conductor 20a. The other end of conduct-or 26a is attached to outlet contact i c which has a screw 22a to which outside circuit connection can be made. A resilient arm 23a or" conducting material is provided having Contact 2da xed at its end in juxtaposition to Contact 19a and outlet contact with screw 25o is provided for outside circuit connection at the opposite end of the resilient arm 23a. Attached to beam iria and preferably formed integrally with it are two curved branch arms having knobs Zia and 23d to engage in the small cavities in member lita. 'i-'lember 29a is substantially cylindrical in shape except ior the slight flange at its 'lower end in which the two cavities are formed. This member :lila is attached by pin :ica to the under side oi protuberance lia, so that pressure on the protuberance lia unit be transmitted through diaphragm Zd and the member Zed to the knobs 2id (or 28d) and hence to actuate beam idc.

To provide indication for oil or on position o the switch, a curved arm i la is shown being a part oi beam iria and when the curved arm is in the position indicated in dotted lines the end or" the arm will show as a spot on the transparent diaphragm. ri`his spot will disappear with the downward movement of arm tic indicating that the switch is in closed circuit position.

The operation oi the switch is very simple as slight finger pressure on protuberance ila causes deflection or"v the diaphragm 2a which in turn causes member 29a to press downwards on the knob 2id and thereby iorces ,armature ila to break contact with the N pole of magnet |20.. As the switching beam ida is pressed downwards the magnetic end lla moves to the neutral position between the N and S poles oi the magnet. Contact points ld and 2da are still in'abutment because of the spring action of the mounting member 23a but the attraction ci' the S pole becomes great enough at this point to cause end ila or beam ido' to snap over sharply breaking the Contact instantaneously. Armature ld is then contracted by theS pole of magnet its which holds the switch in open position. To close the switch a very slight pressure again on protuberance ila repeats the above operation with the direrence that the pressure is now transferred to Knob 28a causing the armature lg3d to break away from the S pole or magnet 52a and the attraction of the N pole results in the switch being again placed in closed circuit position.

We claim:

l. An electric switch hermetically sealed within an insulating box open at one side, by a iiexible diaphragm, a per ianent magnet having a north pole and a south pole facing each other across a gap, a beam carrying an armature at one end and an electrical Contact at the opposite end www pivotally mounted within said casing, the said armature extending into the gap between the said north and south poles, said electric Contact on said beam making contact with an electric oontact on the wall of said box when said armature adheres to said north pole and said Contact on said beam separating from said Contact on said box when said armature adheres to said south pole, a protuberance on said diaphragm comprising a button, a pressure and motion transmitting member on the side of the diaphragm remote from said button and arms on said beam to contact said pressure transmitting member.

2. An electric switch as claimed in claim 1 in which the said arms on said beam are separated by the said pivot and only one arm contacts said pressure and motion transmitting member at a time.

3. An electric switch as claimed in claim 1 in which said exible diaphragm is capable of distortion in a direction at right angles to its plane a distance equal to slightly more than one half the distance between the said north pole and the said south pole of the said magnet.

IGOR ZOZULIN. GEORGE J. OKULITCH.

References Cited in the le 0f this patent UNITED STATES PATENTS Number Name Date 1,701,357 Butler Feb. 5, 1929 2,267,602 Claytor Dec. 23, 1941 2,302,250 Penn Nov. 17, 1942

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