US2988606A

US2988606A - Electric switch and method of making

Info

Publication number: US2988606A
Application number: US703980A
Authority: US
Inventors: Kenneth C Allison
Original assignee: CTS Corp
Current assignee: CTS Corp
Priority date: 1957-12-19
Filing date: 1957-12-19
Publication date: 1961-06-13
Anticipated expiration: 1978-06-13

Description

June 13, 1961 c, ALLISON 2,988,606

ELECTRIC SWITCH AND METHOD OF MAKING Filed Dec. 19, 1957 2 Sheets-Sheet 1 IN VEN TOR.

Kenneth CAllison June 13, 1961 c, ALLISON 2,988,606

ELECTRIC SWITCH AND METHOD OF MAKING Filed Dec. 19, 1957 2 Sheets-Sheet 2 v Z; /24 22 m 29 5m 2N2 Va 39 22' 2a 2/ fg Z4 Z5 QMW 1 Imam? I. A/Zzsm Hill A m 26 zaiz4 26 /2g M United States Patent Ofiice 2,988,606 Patented June 13, 1961 2,988,606 ELECTRIC SWITCH AND METHOD OF MAKING Kenneth C. Allison, Crystal Lake, 111., assignor, by mesne assignments, to CTS Corporation, Elkhart, Ind., a corporation of Indiana Filed Dec. 19, 1957, Ser. No. 703,980

19 Claims. (Cl. 200-11) The present invention relates to switches of the type having multiple contacts secured to a fixed stator of insulating material so as to present free end portions for sequential engagement by a movable contact or contacts supported for travel along a predetermined path containing said free end portions of the stator contacts.

It is an object of this invention to provide a switch of the type indicated which incorporates structural characteristics that not only simplify the construction and assembly of the switch but also improve the quality of the switch from the standpoint of stability and freedom from servicing problems.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, wherein:

FIG. 1 illustrates the manner in which the stator contacts of a rotary switch embodying the present invention are all simultaneously produced by simply punching out a blank of conductive material, and also showing the manner in which these contacts are mounted in the insulating body of the stator.

FIG. 2 is an edge view of the structure shown in'FIG. 1, with parts broken away and in section.

FIG. 3 illustrates one example of a finished stator contact unit developed from the structure shown in FIGS. 1 and 2 for use as a one-pole sixteen position rotary switch, wherein an annular ground ring or common contact is supported from the body of the stator inside the circle of spaced individual contacts, by an arm which is embedded in the body as are the other stator contacts.

FIG. 4 illustrates a finished stator contact unit of modified design having two separate common or grounding contacts, each supported from the body of the stator by a plurality of arms integral therewith and embedded in the body.

FIG. 5 illustrates a rotary switch unit wherein a rotor assembly embodying the present invention is combined with a modified form of stator contact unit somewhat similar to that shown in FIGURE .4, with a portion of the stator broken away to illustrate the relative arrangement of the rotor and its associated contacts.

FIG. 6 is a sectional view through FIGURE 5 on the plane of line 66.

FIG. 7 is an end elevational view of a one of the rotor contact members shown in FIG. 6.

FIG. 8 is a sectional view similar to FIG. 6 but showing a rotor contact member and rotor assembly of modified form.

FIG. 9 is an end elevational view of the rotor contact member shown in FIG. 8.

FIG. 10 is a plan view shown in FIGS. 8 and 9.

FIG. 11 shows a further modified form of rotor contact member; and

FIG. 12 is a detail fragmentary view of the hub portion of the rotor to show a detail of its construction.

A rotary switch incorporating features of design and construction as contemplated by the present invention is illustrated in the drawings, the stator of which comprises a series of contacts 10 defined by end portions of a plurality of metallic strips 9 embedded in fixed spoke-like arrangement in an annular body 1 2 of non-conductive moldable material such, for example, as Bakelite. The strips 9 are preferably made by stamping perforationsmll of the rotor contact member inner edge 12' in a fiat metal blank so as to produce a perforated blank wherein the outer ends of the strips are joined by an outer peripheral connecting section 13 and the inner ends of the strips are joined by an inner connecting section 14. The blank while in such state is mounted in a suitable mold (not shown) wherein the annular stator body 12 is cast about the stator contact forming strips. As seen in the righthand portion of FIGURE 1, the width of the stator body, i.e., its radial dimension from its inner edge to its outer periphery, is less than the radial distance between the connecting sections -13 and 14. Tabs 15 projecting inwardly from the inner connecting section 14 toward but for a distance short of the section 13 are partially embedded in the stator body 12.

After the stator body is hardened from its molten state, the connecting

sections

13 and 14 are severed along selected lines whereby the embedded strips present a circular row of spaced contacts 10 projecting radially inwardly from the inner edge 12' of the stator body 12 and outwardly extending terminals or soldering lugs 16.

As will be observed in FIG. 3, one of the strips designated 9 supports an annular common contact 10a in concentric and radially inwardly spaced relation to the extremities of the contacts 10, the terminal 16' for this common contact being provided by the outer end of the strip 9. The common contact 10a is severed from the inner connecting section 14 on a circular line in spaced concentric relation to the inner edge of the stator body so that its sole connection with the stator body is through the strip or supporting arm 9' which is integral therewith. If additional support for the common contact 10a is needed, certain of the tabs 15 may be left connected thereto. This will support the common contact at spaced points along its length, as shown in FIGURE 4 wherein two arcuate common contacts 10b are substituted for the single annular common contact 10a of FIGURE 3. Thus, the arrangement of contacts 10 and 10a in FIG- URE 3 provides for a single-pole sixteen-position rotary switch with the positions 22 /2" apart, whereas the arrangement of contacts 10 and 1% shown in FIGURE 4 provides a double-pole six-position rotary switch with the positions 30 apart.

It is a significant feature of this invention that the common contact, whether it be annular as in FIGURE 3 or arcuate as in FIGURE 4, lies in front of one or more of the individual contacts, and that all of the contacts, common as well as individual, and also the supporting arm or arms for the common contact or contacts, are coplanar, and lie in a common plane which intersects the of the annular body 12 and is parallel to and equispaced from the opposite sides or faces thereof.

The inner edge 12' is preferably a straight-walled bore as shown, and since its diameter is considerably greater than the thickness of the body 12, the edge 12 may be regarded as an elongated surface.

The rotor or movable contact carrier of the switch is designated generally by the numeral 17. It comprises a circular disc like unit having a diameter slightly smaller than the inside of the annular stator 12 and a thickness substantially equal to that of the stator. It is rotatably held in place within the stator by the reception of the flat coplanar stationary contacts in a groove 18 formed in the rotor and opening to its periphery. This groove is equispaced from the opposite faces or sides of the rotor, and its month which is the narrowest part thereof is but slightly wider than the thickness of the coplanar stationary contacts. Hence, the opposite sides or faces of the rotor are flush with those of the stator.

The rotor unit 17 consists of two identical sections molded of suitable insulating material. Each section has a hub 20, a flange 2 1 projecting from the hub, a rim 22 and spokes 23 connecting the rim with the flange. The

3 hubs 20 of the two rotor sections abut and their combined thickness is equal to that of the stator 12. The abutment of the hubs results in the formation of the groove 18 since the flanges, the rims and the connecting spokes are all narrower than the hubs and have their outer faces flush with those of the hubs.

Any suitable means may be provided to secure the rotor sections together, as for instance, a pair of pronglike fingers 24 projecting from the inner flat face of each hub and received in a mating socket 25. Since both sections are identical, each has a pair of these prong-like fingers and a socket, the fingers and the sockets of each section being diametrically opposite one another; and to effect their purpose of securing the sections together, the fingers have hooks 26 on their extremities which snap over shoulders 27 in the sockets.

Since the spokes 23, like the flanges 21, are narrower in the axial direction than the rims 22, the groove 18 has a reentrant cross section with the mouth of the groove defined by the opposed edges of the rims being the narrowest part of the groove.

As will appear hereinafter, it will be convenient to consider the outer peripheral surfaces of the rims 22 and the inner circular surface of the stator 12, contiguous edges of the rotor and stator, respectively, or more broadly, of the movable and stationary contact carriers.

Obviously, the rotor carries one or more bridging contactors 28, each of which is preferably a unitary stamping. In the switch shown in FIGURES and 6, each bridging contactor comprises two

U-shaped contacts

29 and 30, the bights of which are integral portions of a curved base or anchoring strap 31. The arms of the U-shaped contacts are resilient and biased towards each other so that the

contacts

29 and 30 may be considered jaws between which the stationary contacts are gripped, and to facilitate movement of the contactor from one switching position to another, the extremities of the arms are cupped or rounded as shown.

Since the purpose of the contactors is to selectively bridge the common stationary contact with any one of the individual stationary contacts spanned by the common contact, the arms of the contact or jaw 29 are longer than the arms of the contact or jaw 30, and the contactors are so placed in the rotor that the extremities of the long jaws 29 travel in an orbit to have gripping engagement successively with the individual stationary contacts 10, whereas the extremities of the short jaws 39 travel in a path coincident with the arcuate common contacts 100. Hence, as the rotor is turned, each bridging contactor will electrically connect a common stationary contact with first one and then another of the individual contacts spanned by the common contact.

As is conventional in this art, detent means (not shown) are provided to identify the various switching positions of the rotor, but the detent means forms no part of this invention, and in fact is a separate unit extraneously connected to the stator and the actuating shaft, not shown.

The bridging contactors 28 are wholly confined within the groove 18, and are held in place by having their bases or connecting straps 31 confined between the side of the hubs 20 which together form the bottom of the groove, and lugs or bosses 3 2. projecting from the flanges 21. The lugs or bosses 32 are located at the junctions of the spokes 23 with the flanges, and the spacing between the long and short U-shaped contacts or

jaws

29 and 30 is such that they lie between angularly adjacent lugs or bosses. This not only constrains the contactors to move with the rotor as it is turned, but also places the contact portions thereof between the spokes where they may be reached for adjustment even after the entire switch is assembled.

As will be apparent, it is necessary during assembly of the switch to first place the bridging contactors on the stationary contacts and then engage the rotor sections therewith and with each other, making certain that the bridging contactors are properly oriented before the rotor sections are secured together.

An important feature of the rotor construction is that the lugs or bosses 32 are so spaced with respect to one another and the hubs 20 that the contactors have a degree of freedom to adjust themselves to the stationary contacts without restraint from the rotor.

As noted hereinbefore, the contactors 28 lie wholly within the rotor unit so that the spokes 23 and the rims Z2 cooperate to shield all the contacts of the switch against damage incidental to shocks and pressures incurred during assembly, or when the switch is in actual service. This disposition of all of the contacts, both stationary and movable, within the stator and rotor bodies, gives the switch fiat opposite faces. Hence, a number of the switches may be axially stacked directly against one another to be actuated by a single shaft without danger of having the contacts or terminals of the several switches come into contact. Such close stacking of the switches achieves optimum compactness.

FIGURE 8 illustrates another way of axially stacking at least two separate rotary switches. The stators of each of these two switches are identical and are like that employed in the rotary switch of FIGURES 5 and 6. Also, in essence, the rotor of this modified embodiment of the invention is similar to that of the switch shown in FIGURES 5 and 6, i.e. it also consists of two like complementary rotor sections held assembled by the interengaging hooks and shoulders shown in FIGURE 12.

However, in this case the flanges 21 are spaced apart a greater distance and, accordingly, the pockets in which the bridging contactors are seated are axially much longer. The principal difference resides in the construction of the bridging contactors and in the provision of a spacer ring 35 encircling the hub portions of the two rotor sections and confined between shoulders thereon.

As best seen in FIGURE 10, the spacer 35 has radially outwardly projecting arms 36, the sides of which are grooved as at 37 to provide recesses which align with the pockets in the rotor sections and coact with the lugs or bosses 32 to hold the rotor-carried bridging contactors properly assembled with the rotor. The contacts of each of the contactors are axially aligned in this case, and comprise an upper pair of long jaws 38 to selectively grip the contacts 10 of the upper stator as the rotor is turned, and a lower pair of shorter jaws 39 to coast with the common contact of the lower stator.

Preferably, one of the long upper jaws 38 and one of the short lower jaws 39 are connected by a strap 40 integral therewith, while the other upper long jaw 38 and the other lower short jaw 39 are connected by a strap 41. The two

straps

40 and 41 are, in turn, secured together.

Obviously, of course, certain of the rotor carried contactors of the tandem connected switches of FIGURE 8, may she like those of the switch shown in FIGURES 5 an I-n FIGURE 11, a rotor contactor is illustrated which is similar to that employed in the switch of FIGURE 8, but modified to the extent that it includes a second pair of lower jaws 42, circumferentially oifset from the jaws 39, but connected thereto by a lateral branch or extension 43 integral with the strap 40. This contactor thus may be said to combine the functions of the contactors shown in FIGURES 7 and 9.

What is claimed is:

1. An electric switch having a stator member and a movable switch member and cooperating contacts on said members including first and second stator contacts arranged in spaced planes parallel to the path of movement of said movable switch member, and a rotor contact simultaneously engageable with said first and second stator contacts, said rotor contact comprising a first strip and a second strip each folded upon itself to provide a first jaw and a second jaw joined at one end by a base with the jaws of the first strip in straddling relation to the jaws of the second strip whereby the first stator contact is engageable between the first jaw of the first strip and the first jawof the second strip and the second stator contact is engageable between the second jaw of the first strip and the second jaw of the second strip.

2. An electric switch according to claim 1 wherein the base of one of said strips has an integral branch terminating in a pair of jaws with which the second stator contact is engageable.

3. An electric switch comprising: a stationary contact carrier of insulating material having an elongated surface transverse to and lying between two parallel planes; a plurality of individual spaced stationary contacts fixed to the stationary contact carrier and projecting from said surface thereof, said individual stationary contacts being arranged in a row along said surface and lying in a common planes which intersects said surface; a common stationary contact; supporting means integral with the common stationary contact and fixed to said carrier mounting the common stationary contact in a position extending along said surface of the carrier but farther therefrom than the extremities of the individual stationary contacts and with a part thereof opposite and spaced from at least one of said individual contacts; a movable contact carrier of insulating material in front of and movable along said surface of the stationary contact carrier; and a bridging contactor carried by the movable contact carrier, said bridging contactor having long and short contact engaging portions, the latter moving in a path to have circuit making engagement with said common stationary contact and the former moving in a path to be selectively engageable with the individual stationary contacts as the movable contact carrier is actuated to selectively electrically connect the individual stationary contacts with the common stationary contact.

4. The electric switch of claim 3, wherein said com mon stationary contact is long enough to span a number of the stationary contacts and wherein the supporting means for the common. stationary contact comprises a plurality of spaced arms integral therewith, each arm projecting from said surface of the stationary contact carrier between and in spaced relation to two of the individual stationary contacts.

5. The electric switch of claim 3, wherein the movable contact carrier comprises a pair of complementary sections shaped to jointly form a groove opening towards the stationary contact carrier and a retaining pocket, the groove accommodating the stationary contacts and the pocket having a part of the movable contactor seated therein; and means securing said complementary sections together.

6. The electric switch of claim 5, wherein the pocket is large enough to allow the contactor limited movement with respect to its carrier to thus afford the contactor a degree of freedom to adjust itself to the stationary contacts as the switch is actuated.

7. A multiposition electric switch comprising cooperating relatively movable contact carriers of insulating material having contiguous edges, one of said contact carriers having a groove extending along and Opening to its contiguous edge so that said groove is substantially closed by the contiguous edge of the other contact carrier; a row of spaced contacts projecting from the contiguous edge of said other contact carrier and into said groove, all of said contacts being fiat and coplanar and the mouth of said groove being defined by parallel lips spaced a distance slightly greater than the thickness of said flat coplanar contacts so that the reception of the contacts in the mouth of the groove holds the contact carriers against relative movement in directions transverse to the faces of the contacts; abutting surfaces on the contact carriers holding the same against separation in a direction parallel to said coplanar contacts and coacting with the reception of the contacts in the mouth of the groove to secure the contact carriers in assembled relation and constrain them to relative movement along their continguous edges; and a contactor in the groove of the grooved carrier selectively engageable with said spaced coplanar contacts by relative motion of the contact carriers.

8. A multiposition electric switch comprising: cooper ating relatively movable first and second contact carriers of insulating material having contiguous edges; means constraining said contact carriers to relative movement along their contiguous edges; the first contact carrier having a groove extending along its said edge and opening towards the contiguous edge of the second contact carrier to be substantially closed thereby; a plurality of individual contacts fixed to the second contact carrier and projecting in a row from said edge thereof into the groove in the first contact carrier, all of said individual contacts being flat and coplanar; an elongated flat common contact long enough to span a plurality of the spaced individual contacts; a supporting arm for the common contact integral therewith and fixed to the second contact carrier to support the common contact from the second contact carrier, said supporting arm being flat and coplanar with the individual contacts and spaced from the nearest thereof and holding the common contact coplanar with the individual contacts in edgewise spaced relation to the ends of those of said individual contacts spanned by the common contact so that the common contact is also inside the groove in the first contact carrier; and a bridging contactor supportingly connected with the first contact carrier and disposed inside the groove therein, said bridging contactor having contact engaging portions spaced different distances from the mouth of the groove corresponding to the spacing between the common contact and the adjacent individual contacts, to selectively electrically connect different individual contacts with the common contact upon relative motion of the contact carriers.

9. In a multiposition electric switch: a contact carrier of insulating material; a row of spaced individual contacts fixed to the carrier and projecting therefrom, all of said spaced individual contacts being fiat and coplanar; an elongated flat common contact long enough to span a plurality of the spaced individual contacts; and a supporting arm for the common contact integral therewith and fixed to the carrier to support the common contact from the carrier in front of the adjacent individual contacts, said supporting arm being flat and coplanar with the individual contacts and spaced from the nearest thereof and holding the common contact coplanar with the individual contacts in edgewise spaced relation to the ends of those of said individual contacts spanned by the common contact.

10. In a multiposition electric switch, the structure of claim 9 wherein said supporting arm projects from the contact carrier between two adjacent spaced individual contacts.

11. In a multiposition electric switch: a contact carrier of insulating material; a row of spaced individual con tacts fixed to the carrier and projecting therefrom, all of said spaced individual contacts being fiat and coplanar; an elongated fiat common contact long enough to span a plurality of the spaced individual contacts; and a plurality of supporting arms for the common contact integral therewith and fixed to the carrier to support the common contact from the carrier in front of the adjacent individual contacts, said supporting arms being Hat and coplanar with the individual contacts and interposed between pairs thereof in edgewise spaced relation thereto, said supporting arms holding the common contact coplanar with the individual contacts in edgewise spaced relation to the ends of those of said individual contacts spanned by the common contact.

12. A rotatry multiposition electric switch characterized by a stator comprising: an annular member of insulating material having inner and outer edges; a plurality of individual contacts fixed to said annular member and projecting in a circle from the inner edge thereof, all of said individual contacts 'being flat and coplanar; a fiat arcuate common contact inside the circle of individual contacts and spanning a number thereof; and a supporting arm for the common contact integral therewith and fixed to said annular member and projecting from its inner edge in spaced relation to the nearest of said individual contacts, said supporting arm being flat and coplanar with the individual contacts and holding the common contact coplanar with the individual contacts in edgewise spaced relation to the ends of those of said individual contacts spanned by the common contact.

13. The rotary multiposition switch of claim 12, wherein the annular member is a molding and wherein the individual contacts and the supporting arm for the common contact are fixed to said annular member by having portions thereof embedded in the annular member between the opposite sides thereof; and further characterized by a rotor inside the annular stator, said rotor having a circular periphery contiguous to and slidingly engaging the inner edge of the annular stator, so that the rotor is journalled in the annular stator, the rotor further having a groove in and extending along its periphery, the stator contacts being received in said groove and by their reception therein holding the rotor assembled with the stator and constraining it to rotary motion with respect to the stator; and a bridging contactor carried by the rotor and having contact engaging portions inside said groove located to have switching engagement with the common contact and different ones of the individual contacts as the rotor is turned.

14. The rotary multiposition switch of claim 13, wherein the walls of the groove in the rotor have radially and angularly spaced shoulders cooperating to form a retaining pocket, and wherein the bridging contactor has a base portion seated in said pocket, the pocket being slightly larger than said base portion so that the bridging contactor has a degree of freedom to adjust itself to the stator contacts.

15. The rotary multiposition switch of claim 14, wherein the contact engaging portions of the bridging contactor are in the form of jaws shaped to grip the stator contacts therebetween.

16. The rotary multiposition switch of claim 14. wherein the rotor comprises a pair of complementary mating sections, each having a hub and a rim encircling the hub, each of said sections being shaped to form one half of the groove; and securing means on the hubs of said sections to hold the sections together with their hubs abutting and their rims spaced apart a distance slightly greater than the thickness of the stationary contacts.

17. The rotary multiposition electric switch of claim 16, wherein the combined thickness of the two complementary mating sections does not exceed that of the annular stator; and wherein the outer faces of said mating sections are substantially flush with the opposite sides of the annular stator and all portions of the bridging contactor lie beneath said outer faces of the sections.

18. The rotary multiposition electric switch of claim 17, wherein the complementary mating sections are identical moldings.

19. The rotary multiposition electric switch of claim 16, wherein the rim and hub of each rotor section are connected by spokes, the spaces between which afiord access to the contact portions of the bridging contactor.

References Cited in the file of this patent UNITED STATES PATENTS 2,447,718 Simpson Aug. 24, 1948 2,734,257 Ionsson Feb. 14, 1956 2,755,347 Allison July 17, 1956 2,805,291 Eikhorst Sept. 3, 1957 2,807,868 Knapp Oct. 1, 1957 2,870,274 Thias Jan. 20, 1959 2,870,276 Gelzer Jan. 20, 1959 FOREIGN PATENTSv 103,183 Australia Feb. 17, 1938 1,061,083 France Nov. 25, 1953 1,077,397 France Apr. 28, 1954