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Publication numberUS3567891 A
Publication typeGrant
Publication dateMar 2, 1971
Filing dateAug 18, 1969
Priority dateAug 29, 1968
Also published asDE1790026A1, DE1790026B2, DE1790026C3
Publication numberUS 3567891 A, US 3567891A, US-A-3567891, US3567891 A, US3567891A
InventorsHinkelmann Rudolf
Original AssigneePreh Elektro Feinmechanik
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Contact assembly for sliding switches
US 3567891 A
Abstract  available in
Images(1)
Previous page
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Claims  available in
Description  (OCR text may contain errors)

1 1 Unlted States Patent 1 13,567,891

[72] Inventor Rudolf llinkelmann 5 nefennm Cited Bid gr Germany UNITED STATES PATENTS [211 Q A- 2? 18 1969 2,672,531 3/1954 Stevenson ZOO/16(X) Pat ented Ma? 2 l97l 2,999,912 9/1961 Kincaid et a1 200/16(X) 9 [73] Assignee mm ElekwFeinmechanische wake 3,157,751 11/1964 Van DenBerk 200/16 Jakob Preh Nachf Bad Neustadt Sade, 3,178,522 4/1965 Passarelll ZOO/166.1(X) German 3,242,273 3/1966 Van Der Put. 200/16 A 29 3,248,488 4/1966 Stephan '200/l66(.1)(X) [321 3,352,980 11/1967 Rougemont =1 61.. 200/16 33] Germany P 17 026 4 3,371,168 2/1968 M11116: 200/16 Primary ExaminerH. 0. Jones Attorney-Stowe and Stowell ABSTRACT: A contact assembly for a sliding switch having a contact bridge made in one piece and disposed in a chamber in a slide for cooperation with relatively fixed contacts spaced [54] FOR SLIDING SWITCHES one from another in the direction of sliding movement of the inns a 8 lg contact bridge. The contact bridge having a substantially [52] US. Cl. 200/166, rectangular frame with the short sides formed integrally with 200/16 inwardly directed convex contact arms and the long sides pro- [51] IIILCI. ....H01h 15/06 vided midway with recesses engaged by projections of the [50] Field ofSearch 200/16, chamber walls, The middle regions of the long sides rest on ledges provided in and at opposite sides of the chamber.

CONTACT ASSEMBLY FOR SLIDING SWITCHES DESCRIPTION This invention relates to contact assemblies for sliding switches, such as are used, for example, in radio and television sets.

An object of the present invention is to devise contact assembly having a contact bridge which, in manufacture, need be subjected only to a comparatively slight deformation by bending in the operative spring regions.

Another object is to devise a contact assembly having a contact bridge which has a very small spacing of the contact points for the two countercontacts, and relatively long spring regions.

According to the invention, there is provided a contact assembly for a sliding switch having a contact bridge made in one piece and disposed in a chamber in a slide for cooperation with relatively fixed contacts spaced one from another in the direction of sliding movement of the contact bridge, in which said contact bridge comprises a substantially rectangular frame having shorter sides formed integrally with inwardly directed convex contact arms arranged to cooperate with the relatively fixed contacts, in which said frame has long sides being provided midway with recesses engaged by projections of the chamber walls, and in which middle regions of the frames long sides rest on ledges provided in and at opposite sides of the chamber.

With this configuration of the contact bridge, the effective spring path always extends from the point of support over onehalf of the long side of the frame, in this operative position there occurring not only bending stress but also torsional stress over half the transverse side to the arched contact arm, the latter also contributing to the'creation of contact pressure by elastic bending deformation. In this, the contact arms only being one-sidedly arched, while the essential spring regions, the long sides, undergo no deformation or very little deformation only during the manufacturing of the bridge, so that the original spring properties of the semimanufactured product remain unchanged.

Due to the completely closed frame, the contact bridge represents a compact, robust spring element which is easily mountable, even in very small executions.

The supporting points of the countercontacts lie very closely adjacent each other on the inwardly directed contact arms, so that the countercontacts may alsobe moved towards each other to the necessary minimum spacing required by voltage safety. By this, it is not only possible to achieve a short stroke, but also even in switches having several changeover contacts, a small overall depth.

Since the frames longitudinal sides are only supported in the middle, this contact bridge has the properties of a rocker, by which also the contact pressures are balanced even in the event of nonuniform position of the counter contact.

In the assembled condition of the slide, the contact bridge is held in the chamber by bearing resiliently on the counter contacts. So as the to prevent the contact bridges also when the slide is fitted with the contact bridges from falling out of the chamber, it is proposed in a further development of the contact assembly to deform plastically on their end faces the projections engaging the recesses in the longitudinal sides of the frame. This deformation takes, however, only place to such an extent that a certain rocking movement of the contact bridge on its supporting ledges or banks is retained.

For obtaining the lowest and most constant contact resistance possible, the contact bridge may be made, as known per se, of spring band with a noble metal coating, preferably a silver coating.

So as to accommodate the largest possible number of switchover contacts in a switch of small overall lengths, two contact systems may be accommodated in mirror-image fashion on opposite sides of the slide, whereby there is obtained at the same time a two-sided, mutually balancing resilient guide of the slide in the stationary part of the switch.

For a better understanding of the invention reference will now be had, by way of example, 'to the accompanying drawings, which represent, on an enlarged scale, one embodiment of the invention and in which:

FIG. I shows part of a switching slide for a slide switch, the switch having one fitted and one unfitted chamber;

FIG. 2 represents a section through the slide along the central plane of a chamber;

FIGS. 3 and 4 show a plan view and a side elevation respectively, of the contact bridge, and

FIG. 5 shows diagrammatically the contact assembly in part of a slide switch.

Referring to the drawings, the slide 1, part of which is shown in FIG. 1, is made of a plastics material and is provided on both sides of its longitudinal axis with shallow chambers 2. Both the longitudinal sidewalls of the chambers have in the middle thereof semicylindrical supporting banks or ledges 3, 3', above which there are provided likewise semicylindrical projections 4, 4 of somewhat smaller diameter.

FIGS. 3 and 4 show, on a greatly enlarged scale, a contact bridge for the sliding switch, this contact bridge being made of silver-plated bronze strip or band. It comprises a rectangular frame with outer rounded-off corners, the longitudinal sides 5, 5' of which being formed at the middle with semicircular recesses 6, 6. Contact arms 8, 8, directed inwardly towards the middle of the frame and arched towards the same side, are cut into the transverse sides 7, 7 of the frame. The contact bridge is so dimensioned that its outer contour fits with a certain clearance into the rectangular chamber 2 of slide 1. The contact bridge is inserted into the chamber so that the middle regions of the longitudinal sides 5, 5 rest on the ledges or banks 3, 3 of chamber 2 and that the projections 4, 4' engage the recesses 6, 6 with a tight fit. Upon insertion of the bridge, the end faces of the projections 4, 4' are slightly thermoplastically deformed so as to prevent the bridge from falling off the supporting ledges 3, 3' by its own weight, while retaining such mobility that it can perform a certain tilting or rocking movement on the said banks.

The mode of operation of this contact assembly is recognizable from the diagrammatic representation of FIG. 5. This figure shows part of a slide switch having a slide according to FIG. 1 fitted with contact bridges inserted into a chamberlike switch casing, the latter having its walls provided with stationary counter contacts 10a, 10b, 10e, l0a, l0b, l0'c. Upon insertion of the slide, the prearched contact arms 8, 8, initially projecting beyond the profile of the slide, are pressed back in resiliently deforming the contact bridge, so that the contact arms to rest with pretension on the counter contacts. Through resilient deformation of the contact bridge, there occurs both bending and torsion of the longitudinal sides 5, 5' and bending of the contact arms 8, 8'. The contact pressure between arms 8, 8 is substantially balanced or equalized by the rockerlike mounting of the bridge on the supporting banks, even in the case of deviating position of the counter contacts.

When the slide is moved in the direction of the arrow by one contact distance (switch stroke), the connections between contacts 10a and 10b, and 10a and l0' b are opened and connection is established between contacts 10b and I00 and l0b, and 10's, so that the function of a double-pole changeover switch is provided. On account of the construction in accordance with the invention, the spacing of the fixed contacts and the switch stroke may be kept very small, which in an actually constructed assembly amounts to but 2.5 mm.

For the construction of range-change switches for radio and television sets, the individual slide switches may conventionally be provided with several contact assemblies arranged one after the other, and several such switches may be combined by known means to form a switch unit for mutual release of the individual slides.

While one particular embodiment of the invention has been shown and e described, it will, of course, be understood that various modifications may be made without departing from the principles of the invention. The appended claims are,

therefore, intended to cover any such modifications within the true spirit and scope of the invention.

I claim:

I. In a contact assembly for a slide switch: a casing, a slide slidingly arranged in said casing, said slide providing a chamber; fixed contacts spaced from one another in the direction of sliding movement of said slide and attached to said casing; a contact bridge located in said chamber and adapted to cooperate with said fixed contacts; said contact bridge comprising a substantially rectangular frame; longitudinal sides and shorter sides on said frame; said shorter sides formed integrally with inwardly directed arched contact arms adapted to cooperate with said fixed contacts; said longitudinal sides of said frame provided midway along their length with recesses engaged by projections of said chamber walls; midregions of said longitudinal sides resting on ledges formed on opposite sides of said chamber.

2. In a contact assembly according to claim 1, comprising end faces of the projections, said projections engaging said recesses of the longitudinal sides being plastically deformed upon insertion of said contact bridge.

3. In a contact assembly according to claim 1 characterized in that said contact bridge is provided on one side with a noble metal coating.

4. In a contact assembly according to claim 1 characterized in that said contact bridge is provided on one side with a coating of silver.

5. In a contact assembly according to claim 1, comprising a plurality of contact bridges which are arranged in mirrorimage fashion on opposite sides of said slide.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3747044 *Aug 19, 1971Jul 17, 1973Rca CorpMicrowave integrated circuit (mic) ground plane connector
US3775575 *Jun 30, 1972Nov 27, 1973Alarm Products Int IncSwitch for connecting window foil with a burglar alarm circuit
US3783204 *Sep 11, 1972Jan 1, 1974Oak Industries IncMultiple circuit control pushbutton switch assembly with improved pushbutton actuator latch bar mechanism and movable contacts
US3857008 *Jul 25, 1973Dec 24, 1974Philips CorpAlternate make-break type slide switch with improved movable contact
US4001526 *Jul 12, 1974Jan 4, 1977Molex IncorporatedAlternate action switch
US4064385 *Oct 24, 1975Dec 20, 1977Evg Entwicklungs-U. Verwertungs-Gesellschaft M.B.H.Multipoint mesh welding machine
US4075441 *Feb 12, 1976Feb 21, 1978U.S. Philips CorporationSlide switch having resilient movable contact arm twisted to provide efficient electrical connection
US4137440 *Jun 28, 1977Jan 30, 1979Bryant Manufacturing Pty. LimitedElectrical switch
US4163135 *Jan 30, 1978Jul 31, 1979The United States Of America As Represented By The Secretary Of The NavyHigh current switches using multi-louvered contact strips
US4393281 *Aug 18, 1981Jul 12, 1983Matsu Kyu Kabushiki KaishaDip switch
US5744764 *Sep 26, 1996Apr 28, 1998General Signal CorporationModular de-energized switch for transformer tap changing
US6064016 *Aug 4, 1998May 16, 2000Itt Manufacturing Enterprises, Inc.Wiper switch terminal and contact
US6891114May 5, 2003May 10, 2005Honda Giken Kogyo Kabushiki KaishaSwitch assembly for a sunroof
US20040222075 *May 5, 2003Nov 11, 2004Honda Giken Kogyo Kabushiki KaishaSwitch assembly for a sunroof
US20090247706 *Jan 31, 2005Oct 1, 2009Rayner KristaContinuous extrusion process for producing grafted polymers
Classifications
U.S. Classification200/16.00B, 200/270, 200/257, 200/283, 200/16.00R, 200/16.00D
International ClassificationH01H11/06, H01H15/06, H01H11/04, H01H13/12, H01H15/00, H01H1/36, H01H1/12
Cooperative ClassificationH01H11/06, H01H15/06
European ClassificationH01H11/06, H01H15/06