US 3260821 A
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Description (OCR text may contain errors)
July 12, 1966 YUSAKU YOKOO PUSH swI'rcH Filed Sept. 21, 1964 FIG.
United States Patent 3,260,821 PUSH SWITCH Yusaku Yokoo, 28-12 Ikegami Tokumochi-cho, Ohta-ku, Tokyo, Japan Filed Sept. 21, 1964, Set. N 0. 397,697
Claims priority, application Japan, Oct. 4, 1963,
2 Claims. (Cl. 200-87) This invention relates to improvements of push switches.
An object of the present invention is to provide a push switch which is very stable and light in many switching times.
FIGURE 1 is a vertically sectioned view of a push switch embodying the present invention.
FIGURE 2 is a vertically sectioned view of the same as closed.
FIGURE 3 is a vertically sectioned view of another embodiment.
FIGURE 4 is a vertically sectioned view of the same as closed.
FIGURE 5 is a perspective view of some component parts of the same.
An embodiment of the present invention shall be explained with reference to FIGURES 1 and 2 in the following. 1 is a housing made of a nonmagnetic material. 2 is an switching part contained in said housing and made by enclosing two movable contact pieces 4 and 4 made of a magnetic material and an inert gas in a sealed glass container 3 and connecting lead wires 5 and 5' to'said contact pieces 4 and 4', respectively. 6 is a push rod loosely inserted through both side walls of said housing 1 so as to be movable to right and left. A cylindrical permanent magnet 7 loosely fitted around said switching part 2 and a stopper flange 8 are fixed to the right end part of said push rod 6. A cylindrical permanent magnet 9 and a stopper flange 8' are fixed to the left end part of the push rod 6. Said cylindrical permanent magnet 9 is movably loosely inserted in a cylindrical permanent magnet 10 fixed to the left end part of the housing 1. In the push switch illustrated in these drawings, if the push rod 6 is pushed in the direction indicated by the arrow X in FIGURE 1 so as to be as shown in FIGURE 2, both movable contact piece-s 4 and 4' in the switching part 2 will be completely inserted into the cylindrical permanent magnet 7 and will be brought into contact with each other by the magnetic force of the magnet 7 so as to close the electric circuit connected to said contact pieces. Further, at this time, the cylindrical permanent magnet 9 will be pushed leftward out of the permanent magnet 10. The distribution of the mutual attraction between both cylindrical permanent magnets 9 and 10 in such case will be maximum at the moment when the cylindrical permanent magnet 9 is pushed out of the cylindrical permanent magnet 10 and will subsequently quickly reduce as shown by the curve A in FIGURE 2. Therefore, both contact pieces 4 and 4 in the switching part 2 can be thereby quickly brought into contact with each other to close the circuit. Then, if the pushing pressure on the push rod 6 is removed in FIGURE 2, the push rod 6 and the cylindrical permanent magnet 7 will be moved rightward by the mutual attraction between the cylindrical permanent magnets 9 and 10 so as to be again as in FIGURE 1, both contact pieces 4 and 4' in the switching part 2 will be separated from each other by their resiliency so as to open the electric circuit connected to both contact pieces. In such case, too, the distribution of the attraction between the cylindrical permanent magnets 9 and 10 will be as shown by the curve A in FIGURE 2 as mentioned above. Therefore, both con- 3,260,821 Patented July 12, 1966 tact pieces 4 and 4 in the switching part 2 can be thereby quickly separated from each other.
The embodiment illustrated in FIGURES 3 and 4 is exactly the same as the embodiment in FIGURES l and 2 in the structure and operation except that a U- shaped, permanent magnet 7 is used instead of the cylindrical permanent magnet 7 in the embodiment illustrated in FIGURES 1 and 2.
In conventional push switches of this kind, the resiliency of a spring is utilized to open and close the contact of the switching part and therefore, in many switching times, the spring will be fatigued and its resiliency will reduce so much that it will be no longer endurable to the use as such and the switching action will become very unstable. Further, in such conventional push switches, the push rod must be pushed against such high resiliency of the spring that a high pushing pressure will be required in the pushing operation. Further, if the diameter of the wire of the spring is reduced or the material of the spring is changed in order to reduce the pushing pressure, in the case of as many as million switching times, for example, as in a push switch for the operation of an electronic calculator, the spring will be likely to break.
On the other hand, in the push switch according to the present invention, the attraction by the permanent magnets is utilized but no spring is used for the returning motion of the push rod. Therefore, if such permanent magnet high in coercive force and not likely to change with the lapse of years as, for example, of ferrite 1s used, as many as 100 million switching times will be able to be made substantially permanently and positively with very light touching operations.
Further, in the present invention, the permanent magnets for opening and closing the contact are a fixed cylindrical permanent magnet and a movable cylindrical permanent magnet to come into and out of said fixed magnet. Therefore, at the moment when the movable cylindrical permanent magnet comes into or out of the fixed cylindrical permanent magnet, the attraction between both cylindrical permanent magnets will become maximum. Therefore, the switching velocities of both iontact pieces in the switching part can be made very igh.
While the subject matter of this application has been described in connection with the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein Without departing from the invention, and it is aimed, therefore, to cover in the appended claims all such changes and modifications as fall within the true spirit and scope of the invention.
What is claimed is:
1. A push switch comprising a housing made of nonmagnetic material and having opposite side walls;
a push rod loosely inserted through both side walls of said housing;
within said housing a switching part comprising two movable contact pieces, formed of a magnetic material, contained in a sealed container; a permanent magnet fixed to said push rod and loosely fitted around said switching part; a first cylindrical permanent magnet fixed to an end part of said push rod; 21 second cylindrical permanent magnet fixed to a wall of said housing; said first cylindrical permanent magnet being movably loosely inserted in said second cylindrical permanent magnet;
said push rod switch being characterized in that said push rod is so arranged as to be quickly returned to an initial position by magnetic attraction between said first and second cylindrical permanent magnets 3 4 when the first cylindrical magnet is pushed out of FOREIGN PATENTS the second cylindricahmagnet. 809,090 2/1959 Eng1and push switchf accoridlnfg tlo clam:1 1 gvhe rem sa d 581,023 8/1958 Italy sea e contalner 1s .orme o g ass an w erern gas is sealed within said sealed glass container. 5 OTHER REFERENCES Berkman, J. W.: IBM Technical Disclosure Bulletin, References Ci by the Examiner Magnetically Actuated Switch, vol. 5, No. 5, page 27,
October 1962. UNITED STATES PATENTS Moore X Pl'in'lal') Examiner.
3 17 097 3 1965 Wood 20 37 J. J. BAKER, Assistant Examiner.