US3310644A

US3310644A - Snap-action electrical switch

Info

Publication number: US3310644A
Application number: US508939A
Authority: US
Inventors: Kittel Gunther
Original assignee: Alex Neher AG Metallwaren & We
Current assignee: Alex Neher AG Metallwaren & We; Alex Neher AG Metallwaren- & Werkzeugfabrik
Priority date: 1964-11-25
Filing date: 1965-11-22
Publication date: 1967-03-21
Anticipated expiration: 1984-03-21
Also published as: ES319732A1; DE1540240C3; GB1132863A; DE1540240A1; FR1454744A; CH424923A; DE1540240B2; NL6515264A; BE672812A

Abstract

1,132,863. Retractive switches. ALEX NEHER AG. METALLWAREN & WERKZEUGFABRIK. 10 Nov., 1965 [25 Nov., 1964], No. 47650/65. Heading H1N. A snap-action switch comprises a contact blade 3 connected to one end of a leaf spring 9 having a bowed portion joined to a straight portion forming a chord to the bowed portion. A lever 10 acted on by a push-button 8 is connected to the other end of the spring 9. Modifications are described in which the lever presses on the chord, the said other end of spring 9 being connected to a fixed point, and the button may be connected to the lever on a second spring of similar form. The first and second springs may be formed of two parts hinged together.

Description

March 21, 1967 G. KITTEL 3,310,644

7 Y SNAP-ACTION ELECTRICAL SWITCH Filed Nov. 22, 1965 2 Sheets-Sheet l March 21, 1967 G. KlTTEL SNAP-ACTION ELECTRICAL SWITCH 2 Sheets-Sheet 2 Filed Nov. 22, 1965 United States Patent M 3,310,644 SNAP-ACTION ELECTRICAL SWITCH Gunther Kittel, Ebnat-Kappel, Switzerland, assignor to Alex Neher AG Metallwaren & Werkzeugfabrik, Ebnat-Kappel, Switzerland, a Swiss firm Filed Nov. 22, 1965, Ser. No. 508,939 3 Claims. (Cl. 200-67) This invention relates to an electrical switch which comprises fixed contact parts, and movable contact means which are arranged on a metal blade, this blade being movable by a loaded spring, when the switch is operated, to bring its contact means into impacting engagement with one of the fixed contact parts.

It is an object of the invention to provide a switch of this type with an improved spring action for the purpose stated.

To this end, in the switch according to the invention the spring, which comprises a leaf spring, has a part of bowed curvature and a part which follows a chord of this curve, and one end of this spring is connected to the free end of the movable metal blade, whilst the other end of the spring is connected either to a lever or to a fixed part, whilst a press button for operating the switch, for the purpose of actuating the spring, engages the latter or directly engages the movable metal blade, through a lever arm which is mounted for free pivotal movement in the switch.

The invention is illustrated by way of example in the accompanying drawings in which:

FIGURES 1 to 6 illustrate six embodiments of the switch in side view, with the side wall of the switch housing removed, and

FIGURES 7 and 8 are respectively a side view and a plan view of a modified form of spring which can be used in the embodiments illustrated in FIGURES 1 to 6.

In all the embodiments of switch illustrated in FIG- URES 1 to 6, use is made of a housing 1 of electricallyinsulating material. Metal plates 2 are embedded in the material of this housing, and one end thereof projects from the housing to provide for connections to electrical equipment with which the switch is used. A metal blade 3 is inserted in the central plate, and the part thereof projecting into a recess 4 in the housing has contacts 5 for cooperation with the two outer plates 2.

In addition to the recess 4, the housing 1 is formed with a bore 6 which opens into this recess, and with a number of slotted recesses 7 which extend outwards from the recess 4 and have their ends cocked off at an angle. In addition a press button 8 is displace-ably mounted in the wall of the housing 1.

In the embodiment illustrated in FIGURE 1, one end of a leaf spring 9, which is composed of a part following a bowed curve, and another part disposed as a chord to this curve, is connectedto the end of the blade 3. Coupled to the other end of this spring 9, i.e. of the chord-forming part of the latter, is a lever arm 10 which is held in a pin 11 pivotable in the bore 6. An intermediate part of the lever arm 10 is disposed beneath the press button 8.

The switch illustrated in FIGURE 2 differs from that of FIGURE 1 in that a holder 12 is inserted in one of the recesses 7 and is connected to the free end of the chordforming part of the spring 9, and the end of the lever arm, in this case denoted 10a, bears against the chord-forming part of the spring 9.

In the form of switch illustrated in FIGURE 3 a second spring 13, of similar form to spring 9, is disposedbeneath the press button 8 and is arranged to transmit the motion of the latter to the lever arm (here denoted 10b). The secondary spring 13 is of like form to spring 9, i.e. has a curved portion adjoined to a chord-forming portion,

3,310,644 Patented Mar. 21, 1967 and it is mounted in the housing by a holder 14 which engages the end of the chord-forming part of the spring. The opposite end of the spring 13 engages an upper part of the arm 10b, and it will be observed that this has a downwardly-extending section 10 which is coupled at its lower end to the outer end of the chord-forming part of spring 9.

The further embodiments of switch according to the invention and illustrated in FIGURES 4 to 6 all use this feature of a secondary spring 13 of the nature illustrated in FIGURE 3.

Thus, in FIGURE 4 the end of the chord-forming part of the spring 9 is anchored by a holder 15' mounted in one of the slots 7 in the body of the housing in a similar fashion to the holder 12 of FIGURE 2. The section 10 of the lever arm (which is somewhat similar to that carrying the same reference numeral in FIGURE 3) bears at its lower end against a point on the chord-forming part of spring 9 away from the anchored end of this part. In this case the spring 13 is connected between the lever arm 10c and a holder 14, similarly to the arrangement of spring 13 in FIGURE 3.

In the arrangement illustrated in FIGURE 5 the spring 9 is mounted in similar fashion to the arrangement depicted in FIGURES 2 and 4, that is to say it is connected at one end to the blade 3 and at the opposite end, i.e. the ultimate end of the chord-forming part, is engaged by a holder 17, corresponding to the

holders

12 and 15 previously described. The secondary spring 13 is in this case generally similar in form to the secondary springs 13 in the embodiments previously described, but is, in effect, reversed in relation to the press butt-on 8, the end of the straight chord-forming part of spring 13 being disposed at the right-hand side of press button 8 and there being anchored to a holder 18 engaged in the wall of the housing. The other end of this secondary spring 13 is connected to the lever arm, here denoted 10d, and it will be observed that the latter has a knee-forming portion which bears slidingly against the chord-forming part of the main impact spring 9.

In the case of the switch illustrated in FIGURE 6, it will be observed that the end of the chord-forming part of spring 9 is engaged by a holder 19, which projects inwards from the right-hand end wall of the housing, whilst the opposite end of this spring, i.e. the free end of the curved portion, is connected to the blade 3. V

In this instance, moreover, the secondary spring 13 is mounted similarly to the corresponding spring in the FIG- URE 3 construction, that is to say the free end of the chord-forming part is engaged by a holder 20 which is mounted in the slot 7 in the upper wall of the housing, whilst the opposite end of the spring, i.e. the free end of the curved part thereof, is engaged with the upper portion of the lever arm (here denoted 102). This lever 10e is formed with a downwardly extending section 10g which is provided with an opening which receives the blade 3.

The form of spring 9 devised in accordance with this invention, has a spring characteristic providing for a relatively high stress build up when the button 8 is depressed, and this characteristic is further augmented where use is made of the similar form of secondary spring 13. In use, the blade 3 will be flipped over abruptly as soon as the transmission to the blade 3 is suflicient to flex this beyond the rest position of the blade. As a consequence of the nature .of spring 9, or

springs

9 and 13 where the secondary spring is employed, the blade 3 will make or break the contacts very rapidly and cleanly, and any arcing will be immediately extinguished.

Moreover, the form of the spring(s) devised in accordance with the invention, and the resulting spring characteristics,fhave the effect of increasing the ratio between the pressure applied to the button 8, and the pressure applied between the contacts.

Instead of being in one piece, as illustrated in FIG- URES 1 to 6, the

leaf springs

9 and 13 may be made in two parts. This modification is illustrated in side view and plan view in FIGURES 7 and 8, here being shown on a somewhat larger scale. As will be observed from these figures, in this modification the chord-forming part 21 of the spring is articulated adjacent one end with the part 22 of the spring which is of curved form.

What I claim is:

1. In an electrical switch having a housing containing spaced apart fixed contacts and a metal contact blade movable in said housing between said fixed contacts to selectively engage the latter; the combination of an impact-controlling leaf spring having a curved section and a straight section extending chordally in relation to said curved section to define first and second termini of said leaf spring at free ends of said curved section and said straight section, respectively, one of said termini of the leaf spring being articulately connected to said movable contact blade, and actuating means including a lever arm pivotally mounted in said housing and articulately connected to the :other of said termini of the leaf spring to move said contact blade through said leaf spring in response to rocking of said lever arm and a press button mounted in said housing and operable from the exterior of the latter to rock said lever arm.

2. An electrical switch according to claim 1; wherein said press button bears directly :on said lever arm to eifect rocking of the latter.

3. An electrical switch according to claim 1; wherein said actuating means further includes a second leaf spring of a form similar to that of the first mentioned leaf spring and having one of said termini of said second leaf spring connected to said lever arm and said press button engaging said straight section of said second leaf spring so that the latter forms a motion-transmitting means between said press button and said lever arm.

References Cited by the Examiner UNITED STATES PATENTS 2,487,374 11/1949 Riche et al. 3,176,109 4/ 1965 Wodtke. 3,210,497 10/ 1965 Schwartz.

ROBERT K. SCHAEFER, Primary Examiner.

D. SMITH, Assistant Examiner.

Claims

1. IN AN ELECTRICAL SWITCH HAVING A HOUSING CONTAINING SPACED APART FIXED CONTACTS AND A METAL CONTACT BLADE MOVABLE IN SAID HOUSING BETWEEN SAID FIXED CONTACTS TO SELECTIVELY ENGAGE THE LATTER; THE COMBINATION OF AN IMPACT-CONTROLLING LEAF SPRING HAVING A CURVED SECTION AND A STRAIGHT SECTION EXTENDING CHORDALLY IN RELATION TO SAID CURVED SECTION TO DEFINE FIRST AND SECOND TERMINI OF SAID LEAF SPRING AT FREE ENDS OF SAID CURVED SECTION AND SAID STRAIGHT SECTION, RESPECTIVELY, ONE OF SAID TERMINI OF THE LEAF SPRING BEING ARTICULATELY CONNECTED TO SAID MOVABLE CONTACT BLADE, AND ACTUATING MEANS INCLYDING A LEVER ARM PIVOTALLY MOUNTED IN SAID HOUSING AND ARTICULATELY CONNECTED TO THE OTHER OF SAID TERMINI OF THE LEAF SPRING TO MOVE SAID CONTACT BLADE THROUGH SAID LEAF SPRING IN RESPONSE TO ROCKING OF SAID LEVER ARM AND A PRESS BUTTON MOUNTED IN SAID HOUSING AND OPERABLE FROM THE EXTERIOR OF THE LATTER TO ROCK SAID LEVER ARM.