US3344246A - Snap-action operating system in an electric switch - Google Patents

Description

Sept. 26, 1967 SHlGEO MAMIYA 3,344,246

SNAP-ACTION OPERATING SYSTEM IN AN ELECTRIC SWITCH Filed March 18, 1966 5 Sheets-Sheet 1 INVENTOR. SHIGEO MHMW BY WW Se t. 26, 1967 SHIGEO MAMIYA SNAP-ACTION OPERATING SYSTEM IN AN ELECTRIC SWITCH 5 Sheets-Sheet 2 Filed March 18, 1966 fig. 4

INVENTOR. SH/GEO MHMNH BY WM W W Se t. 26, 1967 SHIGEO MAMIYA SNAP-ACTION OPERATING SYSTEM IN AN ELECTRIC SWITCH 5 Sheets-$heet 3 Filed March 18, 1966 INVENTOR. SH/GEO HEMP/H BY MM 6% P 26, 1967 SHIGEO MAMIYA 3,344,246

SNAP-ACTION OPERATING SYSTEM IN AN ELECTRIC SWITCH Filed March 18, 1966 5 Sheets -Sheet 4 Fig. 11

(Contact ressure) INVENTOR. SHIGEO MAM/YR p 1967 SHIGEO MAMIYA 3,344,246

SNAP-ACTION OPERATING SYSTEM IN AN ELECTRIC SWITCH Filed March 18, 1966 5 Sheets-Sheet 5 INVENTOR. SH/GEO I IHMIYH United States Patent Ofiice Patented Sept. 26, 1967 3,344,346 SNAP-AtITION OPERATING SYSTEM EN AN ELECTR SWITCH Shigeo Mamiya, Tokyo, Japan, assignor to Kahushiiai- Keisha Saginomiya Seisairusho, Tokyo, Eapan Filed Mar. L3, 1966, Ser. No. 535,499 3 Claims. (Cl. 2D0-67) This invention relates to a snap-action operating system in an electric switch.

An object of the present invention is to provide a novel snap-action operating system in an electric switch wherein a movable contact plate having a movable contact thereon may have a predetermined contact pressure applied thereto notwithstanding fluctuations in contact pressure due to the make and break operations of the switch, so that a decrease in contact pressure acting on the movable contact, and consequently chattering between the movable contact and the fixed contacts may be prevented, and wherein the reversible movement of the movable contact between the fixed contacts may be rapid and smooth.

As a rule, when the movable contact plate, having its movable contact in touch with one of the fixed contacts disposed in spaced parallel relation, is to be reversed by the pressure acting thereon to make contact with the other fixed contact, the movable contact has to be reversed quickly from one to the other of the fixed contacts, and the reversing force of the movable contact plate, that is, the contact pressure applied to the movable contact, has to be maintained at a predetermined value notwithstanding fluctuations in contact pressure resulting from the maize and break operations of the switch. However, an electric switch of the ordinary type, especially a switch using the snap action of the spring for reversibl operation of the movable contact, has the disadvantage that the pressure acting on the movable contact plate will ecrease while the latter is reversibly operated, and this results in a so-called chattering between the movable contact and the fixed contact due to the oscillations of the movable contact, especially where the decrease in the pressure acting on the movable contact plate is considerable.

The snap-action operating system in an electric switch according to the present invention comprises at least one movable contact plate having at least one movable contact thereon and provided with a gap or aperture at one end and a quick-reverse spring at the other end; at least one pair of fixed contacts disposed in opposition and facing toward opposite sides of said movable contact; a first operating plate having a button to press the same and a Ushaped leaf sprin carried at one end by it and at the other end by a second operating plate; said second operating plate extending, near its end carried by the U-shaped spring through the gap formed at the one end of the movable contact plate.

In the drawings:

FIGS. 1 to 8 are explanatory side elevational views showing the structure of an embodiment of the snapaction electric switch in accordance with the present invention, with the parts thereof in successive operative states;

FIG. 9 is an explanatory side elevational view showing the pressure applied to each part of the switch in the position indicated in FIG. 1;

FIG. 10 is an explanatory side elevational view similar to FIG. 9 and showing the pressure applied to each member of the switch in the position indicated in FIG. 5;

FIG. 11 is a graph showing the pressure applied to the movable contact of the switch While the movable contact is reversibly operated;

FIGS. 12 and 13 are explanatory perspective views showing two alternative constructions of the movable contact plate of the switch;

FIG. 14 is an explanatory perspective view showing, in concrete form, an embodiment of the operating plate of the switch having a U-shaped leaf spring; and

FIGS. 15 and 16 are explanatory side elevational views showing other embodiments of the snap-action electric switch according to the present invention.

Referring to the accompanying drawings, by way of explaining in more detail some of the embodiments of the present invention illustrated therein, 1 in each figure is a movable operating plate on finger secured at one end and 2 is a U-shaped leaf spring carried by the free end of operating plate 1. The U-shaped leaf spring 2 is interposed between said operating plate 1 and a second rocka'ole operating plate on finger 3 pivoted at one end, and is held at p and q by the free ends of the operating plate 1 and of the second operating plate 3, respectively. 4 is a button for pressing the operating plate 1, and 5 is a reversible contact plate or finger having a quick-reverse spring 6. Fixed contacts 8, 9 are disposed above and beneath the movable contact 7 in alignment with the latter and with each other. A gap G is provided on the bent portion 10 of the snap-action contact plate 5, and the second operating plate 3, operatively connected with the operating plate 1 by the U-shaped leaf spring 2, is inserted rockably through gap G.

Based on the structure of the snap-action operating system in an electric switch as above noted, the operation thereof will now be described with reference to FIGS. 1 to 11. The button 4 as indicated in FIG. 1 is operated in the first place in a direction to press the operating plate 1, which reaches the operative state as indicated in FIG. 5 by passing through the states of FIGS. 2, 3 and 4. At this time, the movable contact 7 of the reversible contact plate 5 engages the fixed contact 9 on the side opposite to the fixed contact 8. Conversely, if the pressure on the button 4 is released from the state as shown in FIG. 5, the movable contact 7 is reversed and reaches the state as indicated in FIG. 1 by passing through the states of FIGS. 6, 7 and 8.

With the operating plate 1 in a state as shown in FIG. 1, the second operating plate 3 is urged into contact with the reversible contact plate 5 by the U-shaped leaf spring 2 with compressing force Pa and by the tension of the quick-reverse spring 6 of the reversible contact plate 5 with compressing force fa as shown in FIG. 9. In efiect, the contact pressure applied to the fixed contact 8 by the movable contact 7 is given by f'(f )+f"( in which 1" and f" are constants.

If the button 4 is pressed at this state, the U-shaped leaf spring 2 starts to be deformed gradually and the second operating plate 3 is moved in a direction as indicated by the arrow mark to the right of gap G. The second operating plate 3, while it is reversed quickly through the states of FIGS. 2 and 3, engages with the marginal edge of the gap G in the state of FIG. 4, and rotates the reversible contact plate 5 quickly. Thus the movable contact 7 is disengaged from fixed contact 7 and is reversed with a quick snap action, assuming the state as shown in FIG. 5. At this instant, the quick-reverse sprin also recoils quickly and the movable contact is pressed with a predetermined contact pressure to mak contact with the fixed contact 9. With the switch in the state of FIG. 5, the contact pressure acting on the fixed contact 9 will be considered with reference to FIG. 10. If the pressure applied to the second operating plate 3 by the U-shaped leaf spring 2 of the operating plate l is Pb and the pressure applied to the second operating plate 3 by the quick-reverse spring 6 is fb, then the contact pressure acting on the fixed contact 9 is given by in which 7" and f are constants.

If new the pressure applied to the button 4 is released from the state of FIG. 5, the second operating plate 3, engaging the one marginal edge of the gap G, moves the operating plate 1 by degrees in a direction shown by the arrow mark in FIG. 6, due to the deformation of the U-shaped leaf spring 2, and reaches the operative state as shown in FIG. 7 by passing through the state of FIG. 6. At this instant, the compressing force applied by the U-shaped leaf spring 2 is reduced to Zero, and only the reversible contact plate is applying pressure to the second operating plate 3. When the switch device reaches the state as shown in FIG. .8, the second operating plate 3, engaging at this time with the opposite marginal edge of the gap G, presses the reversible contact plate 5 in the opposite direction until the operative state indicated in FIG. 1 is assumed a second time.

Thus, it will be appreciated that the reversible operation of the movable contact by the pressing and release of the button 4 is the so-called reversible kicking system and that, as shown in FIG. 11, the contact pressure applied to the fixed contact is never reduced to zero regardless of the positions assumed by the button 4 while the latter is in operation, the contact pressure acting on the movable contact remaining substantially above f'(fa) or f"'(f It is to be noted that the present invention includes a modified structure in which the two snap-action operating systems each having a U-shaped leaf spring of the type as above described are stacked or connected in parallel as shown in FIGS. and 16. These embodiments use the component constructions shown in FIGS. 13, 14 and 15.

As noted in the foregoing, the present invention provides a snap-action operating system embodying the socalled discontinuous contact pressure system in which the contact pressure may be maintained in excess of a predetermined value while the contact means are reversibly operated. The make and break operation of the electric switch may be done rapidly and smoothly, and the snap-action operating system of the present invention enables the switch system to be controlled or adjusted smoothly and positively if it is utilized in a switch system for automatic regulation or adjustment of electric apparatuses.

What is claimed is:

1. A snap action electric switch comprising, in combination, at least one quickly reversible contact member in the form of a relatively elongated first plate of resilient material fixedly mounted at one fixed end and having an opposite free end, said free end having a flange bent substantially at right angles to the general plane of said plate and formed with a substantially rectangular first aperture therethrough having first and second substantially parallel edges substantially parallel to the general plane of said plate; at least one movable contact carried by said contact member adjacent its free end; said contact member having a second aperture intermediate its ends, having an edge remote from said fixed end extending transversely of said first plate; a quickreverse spring having a fixed end engaging an abutment adjacent said fixed end of said first plate and a free end 0 end adjacent the fixed end of said contact member and having an opposite free end, said operating member including a portion extending through said first aperture of said contact member and being formed with a third aperture which is substantially rectangular and has opposite end edges extending substantially parallel to said flange; a first tongue extending from one end edge of said third aperture and a second tongue extending from the other end edge of said third aperture toward said first tongue, the adjacent ends of said first and second tongues being spaced longitudinally from each other; said first tongue constituting said operating member portion extending through said first aperture of said contact member, and the adjacent ends of both tongues being outwardly of said flange; a U-shaped leaf spring having the end portion of each leg engaged with the end of a respective tongue, said U-shaped leaf spring being compressed between the adjacent ends of said tongue; an operating button engaged with said operating member adjacent its free end beyond said third aperture; the distance between said first and second substantially parallel edges of said first aperture being substantially less than the range of movement of said first tongue extending through first aperture; said U-shape leaf spring being rockable about the adjacent free ends of said first and second tongues and rocking about said adjacent free ends responsive to movement of said second tongue in either direction to effect a snap displacement of said first tongue into engagement with a respective one of said first and second substantially parallel edges of said first aperture to snap said contact member in a respective direction to disengage said movable contact from one of said fixed contacts and snap said movable contact into engagement with the other of said fixed contacts.

2. A snap action electric switch, as claimed in claim 1, in which said abutment comprises a second edge of said second aperture substantially parallel to said firstmentioned edge and closely adjacent the fixed end of said contact member.

3. A snap action electric switch, as claimed in claim 2, in which said abutment comprises a fixed abutment extending through said second aperture of said contact member immediately adjacent the fixed end of said contact member.

References Cited UNITED STATES PATENTS 2,487,374 11/1949 Riche et al 20067 2,515,528 7/1950 Rothwell 20067 2,574,429 11/ 1951 Wood 20067 2,581,705 1/1952 Riche 20067 3,226,511 12/ 1965 Mertler 2001382 ROBERT K. SCHAEFER, Primary Examiner.

D. SMITH, In, Assistant Examiner.

Claims (1)

1. A SNAP ACTION ELECTRIC SWITCH COMPRISING, IN COMBINATION, AT LEAST ONE QUICKLY REVERSIBLE CONTACT MEMBER IN THE FORM OF A RELATIVELY ELONGATED FIRST PLATE OF RESILIENT MATERIAL FIXEDLY MOUNTED AT ONE FIXED END AND HAVING AN OPPOSITE FREE END, SAID FREE END HAVING A FLANGE BENT SUBSTANTIALLY AT RIGHT ANGLES TO THE GENERAL PLANE OF SAID PLATE AND FORMED WITH A SUBSTANTIALLY RECTANGULAR FIRST APERTURE THERETHROUGH HAVING FIRST AND SECOND SUBSTANTIALLY PARALLEL EDGES SUBSTANTIALLY PARALLEL TO THE GENERAL PLANE OF SAID PLATE; AT LEAST ONE MOVABLE CONTACT CARRIED BY SAID CONTACT MEMBER ADJACENT ITS FREE END; SAID CONTACT MEMBER HAVING A SECOND APERTURE INTERMEDIATE ITS ENDS, HAVING AN EDGE REMOTE FROM SAID FIXED END EXTENDING TRANSVERSELY OF SAID FIRST PLATE; A QUICKREVERSE SPRING HAVING A FIXED END ENGAGING AN ABUTMENT ADJACENT SAID FIXED END OF SAID FIRST PLATE AND A FREE END ENGAGED WITH SAID EDGE OF SAID SECOND APERTURE, WHEREBY SAID QUICK-REVERSE SPRING IS COMPRESSED BETWEEN SAID ABUTMENT AND SAID LAST-NAMED EDGE AND OPERABLE TO SNAP THE FREE END OF SAID CONTACT MEMBER IN OPPOSED RESPECTIVE DIRCTIONS AFTER A PREDETERMINED INITIAL MOVEMENT OF SAID CONTACT MEMBER IN A RESPECTIVE DIRECTION; A PAIR OF SPACED FIXED CONTACTS ALIGNED WITH EACH MOVABLE CONTACT AND FACING RESPECTIVE OPPOSITE SIDES OF THE LATTER; AN OPERATING MEMBER IN THE FORM OF A RELATIVELY ELONGATED SECOND PLATE OF RESILIENT MATERIAL FIXEDLY MOUNTED AT ONE FIXED END ADJACENT THE FIXED END OF SAID CONTACT MEMBER AND HAVING AN OPPOSITE FREE END, SAID OPERATING MEMBER INCLUDING A PORTION EXTENDING THROUGH SAID FIRST APERTURE OF SAID CONTACT MEMBER AND BEING FORMED WITH A THIRD APERTURE WHICH IS SUBSTANTIALLY REECTANGULAR AND HAS OPPOSITE END EDGES EXTENDING SUBSTANTIALLY PARALLEL TO SAID FLANGE; A FIRST TONGUE EXTENDING FROM ONE END EDGE OF SAID THIRD APERTURE AND A SECOND TONGUE EXTENDING FROM THE OTHER END EDGE OF SAID THIRD APERTURE TOWARD SAID FIRST TONGUE, THE ADJACENT ENDS OF SAID FIRST AND SECOND TONGUES BEING SPACED LONGITUDINALLY FROM EACH OTHER; SAID FIRST TONGUE CONSTITUTING SAID OPERATING MEMBER PORTION EXTENDING THROUGH SAID FIRST APERTURE OF SAID CONTACT MEMBER, AND THE ADJACENT ENDS OF BOTH TONGUES BEING OUTWARDLY OF SAID FLANGE; A U-SHAPED LEAF SPRING HAVING THE END PORTION OF EACH LEG ENGAGED WITH THE END OF A RESPECTIVE TONGUE, SAID U-SHAPED LEAF SPRING BEING COMPRESSED BETWEEN THE ADJACENT ENDS OF SAID TONGUE; AN OPERATING BUTTON ENGAGED WITH SAID OPERATING MEMBER ADJACENT ITS FREE END BEYOND SAID THIRD APERTURE; THE DISTANCE BETWEEN SAID FIRST AND SECOND SUBSTANTIALLY PARALLEL EDGES OF SAID FIRST APERTURE BEING SUBSTANTIALLY LESS THAN THE RANGE OF MOVEMENT OF SAID FIRST TONGUE EXTENDING THROUGH FIRST APERTURE; SAID U-SHAPE LEAF SPRING BEING ROCKABLE ABOUT THE ADJACENT FREE ENDS OF SAID FIRST AND SECOND TONGUES AND ROCKING ABOUT SAID ADJACENT FREE ENDS RESPONSIVE TO MOVEMENT OF SAID SECOND TONGUE IN EITHER DIRECTION TO EFFECT A SNAP DISPLACEMENT OF SAID FIRST TONGUE INTO ENGAGEMENT WITH A RESPECTIVE ONE OF SAID FIRST AND SECOND SUBSTANTIALLY PARALLEL EDGES OF SAID FIRST APERTURE TO SNAP SAID CONTACT MEMBER IN A RESPECTIVE DIRECTION TO DISENGAGE SAID MOVABLE CONTACT FROM ONE OF SAID FIXED CONTACTS AND SNAP SAID MOVABLE CONTACT INTO ENGAGEMENT WITH THE OTHER OF SAID FIXED CONTACTS.

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