US3912895A

US3912895A - Electric switch

Info

Publication number: US3912895A
Application number: US467695A
Authority: US
Inventors: Roberto Plana
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1973-05-14
Filing date: 1974-05-07
Publication date: 1975-10-14
Anticipated expiration: 1992-10-14
Also published as: JPS5048473A; BE814884A; IT1010318B; AR198574A1; CH572661A5; NL7406233A; BR7403821D0; ES414752A2; FR2230062A1; AU6805074A; DE2422021A1; FR2230062B3

Abstract

An electric switch comprises an insulating housing containing a movable contact operably connected to a finger operated pivotable actuator. The movable contact is formed as a resilient arcuate metal strip mounted at one end to the actuator such that the convex surface of the arcuate strip faces away from the actuator. A contact surface is formed on the convex surface of the arcuate strip adjacent the free end of the arcuate strip. The actuator is movable under finger pressure to two pivoted positions, one in which the movable contact surface disengages a stationary contact mounted in the bottom of the housing and one in which it engages the stationary contact.

Description

United States Patent [191 [30] Foreign Application Priority Data May 14, 1974 Spain 414752 [52] US. Cl 200/164 A; 200/241; 200/339 [51] Int. Cl. HOIH l/18 [58] Field of Search 200/339, 292, 159 A, 8 A, 200/6 C, 164 R, 164 A, 153 LA, 153 LB,

[56] References Cited UNITED STATES PATENTS 1,679,192 7/1928 Wheeland 200/8 A 2,681,393 6/1954 Hopkins 200/8 A 3,471,663 10/1969 Farrell et a]. 200/76 [451 Oct. 14, 1975 3,643,051 2/1972 Foley ZOO/164 A Primary ExaminerRobert K. Schaefer Assistant ExaminerWilliam J. Smith Attorney, Agent, or FirmWilliam J. Keating; Jay L. Seitchik; Frederick W. Raring [57] ABSTRACT An electric switch comprises an insulating housing containing a movable contact operably connected to a finger operated pivotable actuator. The movable contact is formed as a resilient arcuate metal Strip mounted at one end to the actuator such that the convex surface of the arcuate strip faces away from the actuator. A Contact surface is formed on the convex surface of the arcuate strip adjacent the free end of the arcuate strip. The actuator is movable under finger pressure to two pivoted positions, one in which the movable contact surface disengages a stationary contact mounted in the bottom of the housing and one in which it engages the stationary contact.

1 Claim, 5 Drawing Figures US. Patent Oct. 14, 1975 Sheet 2 of3 3,912,895

US. Patent oci. 14,1975 Sheet 3 of3 3,912,895

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ELECTRIC SWITCH This invention relates to electric switches, and more particularly concerns a switch having a movable contact which is driven by a finger operated actuator to predetermined pivoted positions to make or break engagement with a stationary contact or contacts.

The present invention is an electric switch comprising a housing of insulating material, a movable contact mounted in the housing and being formed as a resilient arcuate metal strip having a contact surface formed on the convex surface of the arcuate strip adjacent a free end of the arcuate strip for contacting at least one stationary contact, and an actuator to which the arcuate strip is directly connected at its other end with the convex surface of the arcuate strip facing away from the actuator, the actuator being pivotably mounted in the housing and being movable by finger pressure between a first pivoted position in which the contact surface is in a position corresponding to disengagement with the stationary contact and a second pivoted position in which the contact surface is in a position corresponding to engagement with the stationary contact.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of an assembled switch according to the invention;

FIG. 2 is an exploded perspective view of the switch of FIG. 1;

FIG. 3 is a sectional view taken on line A--A showing the switch in an on condition;

FIG. 4 is a sectional view similar to FIG. 3 but showing the switch in an off condition; and

FIG. 5 is an enlarged diagrammatic view illustrating an improvement to the switch of FIG. 1.

With reference firstly to FIGS. 1 and 4, the switch comprises a housing 1 of resilient insulating plastics material, a finger operated rocker actuator 2, a movable metal contact 4 and a bottom plate 5 of insulating plastics material.

The housing 1 is shaped generally as a rectangular box open at its top end 7 and its bottom end 8 and having on each of two opposed sides 9 an integral panel mounting rib 10 tapering from a relatively thick portion adjacent the top end 7 of the housing to a relatively thin portion adjacent the bottom end 8 of the housing. A peripheral flange 11 extends from the top end 7 of the housing, the flange having a rim 12 disposed in parallel spaced relationto the walls of the housing.

A front wall 15 is provided at the bottom end 8 of the housing with two spaced mounting arms 16 extending below the housing and terminating in a wedge-shaped detent 17. Two similar mounting arms, one of which is shown in FIG. 2, are provided on the rear wall 18 of the housing.

The front wall 15 and rear wall 18 are each provided with a through aperture 20 disposed intermediate the sides 9 and adjacent the top end 7 of the housing. Each aperture forms a recess in the adjacent portion of the flange l1 and a semi-circular bearing surface 21.

Located in the corner defined by the left-hand (as seen in FIGS. 3 and 4) housing side 9, the front wall 15 and the bottom plate 5 is a projection 22 defining a stop shoulder 23 facing the top end 7 of the housing, the projection being integrally formed with the housing. A similar projection 22 is formed in the corner defined by the right-hand (as seen in FIGS. 3 and 4) housing side 9, the rear wall 18 and the bottom plate 5.

The rocker actuator 2 is a hollow plastics molding and has a V-shaped finger engaging portion 25 formed between two arcuate surfaces 26. From each of two sides 27 of the actuator 2 extends a cylindrical boss or trunnion 28 one of which can be seen in FIG. 2.

An abutment surface 29 is formed at the end of each arcuate surface 26 remote from the finger engaging portion 25. A slot 30 extends inwardly of the underside of the actuator 2 from a position adjacent one of the abutment surfaces 29 in a direction towards the finger engaging portion 25, the slot being formed in a thickened portion 31 of the actuator 2.

The movable contact 4 is an arcuate metal strip having barbs 33 adjacent one of its free ends. The other free end is formed generally as a V-shaped bifurcated to form two spaced contact portions 34 each of which has a downwardly directed dimple 35 serving as a contact surface.

The bottom plate 5 is generally rectangular with two spaced notches 46 in each of the longer edges 47, the notches being complementary in shape to the wedgeshaped detents 17 on the arms 16 of the housing. Two aligned through holes in the plate 5 receive stationary contacts 48 which have tabs 49 projecting from the lower surface of the plate 5 for connection to circuitry (not shown) to be controlled by the switching and contact surfaces 50 lying just proud of the upper surface of the plate 5.

Assembly of the switch is carried out as follows: The movable contact 4 is assembled to the actuator 2 by pushing the end of the contact containing the barbs 33 into the slot 30, the barbs engaging the sides of the slot to secure the contact to the actuator.

The two components thus assembled are then inserted through the top end 7 of the housing 1 until the trunnions 28 on the actuator 2 engage the flange 11 where they are recessed by the apertures 20. Application of downward pressure on the actuator 2 causes the walls 15 and 18 of the housing to flex outwardly so that the trunnions 28 snap on to the bearing surfaces 21 of the apertures 20 and under the flange 11. In this assembled condition, the finger engaging portion 25 is disposed above the top end 7 of the housing 1, the arcuate surfaces 26 substantially closing the top end 7.

The bottom plate 5 is then mounted to the bottom end 8 of the housing 1 by snapping resiliently the detents 17 of the mounting arms 16 under the plate 5, the arms 16 being received in the notches 46 in the plate 5. This completes assembly of the switch.

The switch has two distinct pivoted positions. To achieve the first, the left-hand part of finger engaging portion 25 of the actuator 2 is depressed causing the actuator to be rotated anti-clockwise from the position of FIG. 3 to that of FIG. 4 in which the contact portions 34 are out of engagement with the stationary contacts 48 in the bottom plate 5 and in which the left-hand abutment surface 29 engages the left-hand shoulder 23 of the housing. It is noted that initially the movable contact resiliently opposes rotation of the actuator 2 but there is an angular position after which the spring force acting between the contact 4 and the bottom plate 5 acts in a direction to assist the anti-clockwise rotation so that a toggle action providing positive bias to the fully off position is present. By depressing the right-hand half of the finger-engaging portion 25 of the actuator 2, the actuator is rotated clockwise from the position of FIG. 4 to that of FIG. 3, engagement of the right-hand abutment surface 29 with the right-hand shoulder 23 of the housing limiting the extent of clockwise rotation of the actuator. In this position, the dim ples 35 of the contact 4 are in engagement with the contact surface 50 of respective stationary contacts 48. Again it is noted that initial clockwise rotation is opposed by the contact 4 but after the over-center toggle position is reached the actuator is biased to the fully on position of FIG. 3.

FIG. 5 shows diagrammatically an improved form of the switch of FIGS. 1 to 4 in which like parts bear like reference numerals. Extending from each lateral edge of the contact 4 is a curved portion 52 integral with the contact 4. The housing 1 is provided with two similar guide members 53, only one of which is shown, spaced one on each side of the path of movement of the contact 4, the guide member 53 being integrally formed with the walls and 18, respectively, of the housing 1. Each guide member 53 has a curved cam surface 54 facing the top end 7 of the housing.

As the contact 4 is moved from the on or closed position shown in full lines to the off or open position shown in phantom by depressing the actuator as described above, the curved portions 52 of the contact 4 engage the cam surface 54 of respective guide members 53 and the free end portion of the contact 4 is cammed upwardly so that the dimples 35 leave the contact surfaces 50 and follows the path marked by arrows in FIG. 5. The cam surfaces 54 are so shaped that near the end of the anti-clockwise rotation the curved portions 52 leave the lower end of the cam surfaces and the contact portions 34 drop into the position shown in phantom in which the dimples 35 engage the bottom plate 5. Movement of the contact 4 from the off position shown in phantom to the on position is obviously effected in a manner reverse to that described above, the contact portions 34 dropping on to the contact surfaces 50 as the curved portions 52 leave the upper end of the cam surfaces 54. As the dimples 35 are lifted clear of the bottom plate 5 during switching between the two positions, wear is reduced to a minimum. It is noted that, in this case, the positive detent action ensuring a fully on" or fully off condition is achieved by action of the cam surfaces 54 on the curved portions 52.

The switch of the invention may be modified by providing another pair of stationary contacts in the bottom plate 5 so that when the actuator is in the position shown in FIG. 4 the contact 4 bridges the other pair of stationary contacts. In this modification a lateral groove may be provided in the bottom plate 5 between the two pairs of stationary contacts. The switch will, therefore, have three positions; one in which one pair of stationary contacts is closed, one where the other pair is closed, and an intermediate position in which both pairs are open.

In another modification, the movable contact 4 is made longer than in the specific embodiment described which has the effect of continuously biasing the switch to one of the two extreme angular positions. It can be arranged that the switch is biased to the off position and is maintained in the on position only when finger pressure is maintained on the actuator 2.

The switch described has only one movable contact 4; in a modification a further movable contact identical with the first movable contact may be received in a slot similar to slot 30 specially provided for that purpose in a thickened portion 31' (indicated in FIGS. 3 and 4) on the other side of the trunnions 28 from the thickened portion 31, the further movable contact curving in an opposite sense to the first movable contact. The two movable contacts are not in alignment but are so arranged that they move along parallel spaced paths. The bottom plate 5 is provided with a further pair of stationary contacts spaced from the first pair and lying in the path of the further movable contact so that when the first movable contact is in the on position with respect to its associated pair of stationary contacts the further movable contact is in the of position with respect to its associated pair of stationary contacts and vice versa.

Instead of using the bottom plate 5, the switch could be clamped directly on the surface of a printed circuit board for making and breaking connection with a selected conductor or conductors on the circuit board. Alternatively, the bottom plates could be molded integrally with the housing.

When the three-position modification as described above is combined with the improvement shown in FIG. 5, a stable intermediate position in which both pairs of contacts are open is obtained by providing a recess on each cam surface in which recesses the curved portions 52 may be received.

What is claimed is:

1. An electric switch comprising a housing of insulating material, a movable contact mounted in the housing and being formed as a resilient arcuate metal strip having a contact surface formed on the convex surface of the arcuate strip adjacent a free end of the arcuate strip for contacting at least one stationary contact, and an actuator to which the arcuate strip is directly connected at its other end with the convex surface of the arcuate strip facing away from the actuator, the actuator being pivotably mounted in the housing and being movable by finger pressure between a first pivoted position in which the contact surface is in a position corresponding to disengagement with the stationary contact and a second pivoted position in which the contact surface is in a position corresponding to engagement with the stationary contact, said housing having two shoulders engageable with respective abutment surfaces on the actuator to define the first pivoted position and the second pivoted position of the actuator, said housing further having two similar guide members spaced one on each side of the path of movement of the arcuate strip, each guide member having a cam surface engageable with a respective portion on the arcuate strip, the guide members serving to cam the free end portion of the arcuate strip upwardly from the bottom of the housing while the actuator is between the first and second pivoted positions.