US3718106A - Method of making an electric switch - Google Patents

Abstract

An electric switch having a plurality of individual spaced contacts and a common contact lying in the same plane and supported by a stationary contact carrier of insulating material. Certain of the individual spaced contacts and at least a portion of the common contact have edge portions equally spaced from an elongated surface of the stationary contact carrier. Depending upon the switching requirements, the individual spaced contacts and the common contact can be provided with integral terminal means for connecting the contacts into an electrical circuit or some of the individual spaced contacts can be provided with integral stamped inductance means. A movable contact carrier of insulating material is movable along the elongated surface of the stationary contact carrier and a bridging contactor constrained to move with the movable contact carrier selectively connects or shorts certain individual spaced contacts. The bridging contactor for the electric switch is blanked from sheet material with a plurality of contact portions and stored for future use. Depending upon the application of the switch, the extra contact portions are severed from the contactor which is then curved and ready for assembly to produce the electric switch.

Description

United States Patent 11 1 Beaver 1 Feb. 27, 1973 METHOD OF MAKING AN ELECTRIC SWITCH [75] Inventor: Thomas R. Beaver, Paso Robles,

Calif.

[73] Assignee: C T S Corporation, Elkhart, Ind.

[22] Filed: Feb. 4, 1971 [21] Appl. No.: 112,633

Related U.S. Application Data [62] Division of Ser. No. 843,864, March 10, 1969, Pat.

FOREIGN PATENTS OR APPLICATIONS 408,376 4/1934 Great Britain ..1 13/1 16 P Primary ExaminerRichard J. Herbst Att0rney-John J. Gaydos [5 7 ABSTRACT An electric switch having a plurality of individual spaced contacts and a common contact lying in the same plane and supported by a stationary contact carrier of insulating material. Certain of the individual spaced contacts and at least a portion of the common contact have edge portions equally spaced from an elongated surface of the stationary contact carrier. Depending upon the switching requirements, the individual spaced contacts and the common contact can be provided with integral terminal means for connecting the contacts into an electrical circuit or some of the individual spaced contacts can be provided with integral stamped inductance means. A movable contact carrier of insulating material is movable along the elongated surface of the stationary contact carrier and a bridging contactor constrained to move with the movable contact carrier selectively connects or shorts certain individual spaced contacts. The bridging contactor for the electric switch is blanked from sheet material with a plurality of contact portions and stored for future use. Depending upon the application of the switch, the extra contact portions are severed from the contactor which is then curved and ready for assembly to produce the electric switch.

3 Claims,9 Drawing Figures 'PATENTEUFEBZYIW 3,718,106-

SHEET 10F 2 a /3 95a f 3 V I]? if /9 ,4 15 U 57 if Ha l: i V i a FIGURE-l FIGURE-9 INVENTORS KENNETH C. ALLISON THOMAS R. BEAVER ATTORNEY PATEMED 31718, 106

SHEET 2 BF 2 FIGURE-6 INVENTORS KENNETH C. ALLISON TH MAS R. BEAVER BY ATTORNEY METHOD OF MAKING AN ELECTRIC SWITCH This is a division of application Ser. No. 843,864 filed Mar. 10, 1969, now US. Pat. No. 3,571,535.

The present invention relates generally to an electric switch and, more particularly, to a method of making a movable bridging contactor for an electric switch having a plurality of individual spaced contacts sequentially engaged by the movable bridging contactor.

With the increasing complexity of electronic equipment, more complex switching functions are being performed. A few years ago improved electric switches such as shown in Allison US. Pat. Nos. 2,988,606 and 3,219,785 assigned to the same assignee as the present invention, were capable of performing the complex switching functions then required of electronic equipment. In order to perform the present day complex switching functions with existing switches, it is necessary to combine several switch sections and/or to use clusters or bridging contactors with each of the sections causing an increase in the manufacturing cost of the switch. It would, therefore, be desirable to provide an improved electrical switch for performing a complex variety of switching functions and an improved method of making such switch.

Accordingly, it is an object of the present invention to provide a method of making an improved electric switch. An additional object of the present invention is to provide a method of making an electric switch for sequentially connecting a plurality of individual spaced contacts to other selected individual spaced contacts or shorting a group of selected individual spaced contacts without engaging a common contact. A still further object of the present invention is to provide a method of making an electric switch with a bridging contactor having certain contact portions that are severed prior to assembly of the bridging contactor with the movable contact carrier of the switch for performing a specific switching function. Further objects and advantages of the present invention will become apparent as the following description proceeds, and the features of novelty characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Briefly, the present invention comprises a plurality of individual spaced contacts and a common contact lying in the same plane and fixed to a stationary contact carrier with the edge portions of certain preselected individual spaced contacts and of a portion of the common contact equally spaced from an elongated surface of the carrier. A pair of radially extending support arms are integral with the contact carrier and terminals are embedded in one of the support arms. In another embodiment, certain of the individual spaced contacts are fixed to the carrier and extend a different predetermined distance from the elongated surface. Depending upon the switching requirements, certain of the individual spaced contacts are provided with terminals for securing components or lead wires thereto or are provided with integral stamped inductance members. A movable contact carrier supporting a bridging contactor selectively connects the individual spaced contacts with the common contact or with other individual spaced contacts or shorts certain individual spaced contacts as the movable contact carrier is actuated from one position to another.

For a better understanding of the present invention, reference may be had to the accompanying drawings wherein the same reference numerals are applied to like parts and wherein:

FIG. 1 is an isometric view of an electric switch having terminals and stamped inductance members integral with the individual spaced contacts embedded in a molded stator;

FIG. 2 is a fragmentary sectional view taken along line II-II of FIG. 1;

FIG. 3 is a fragmentary sectional view taken along lines III-III of FIG. 1;

FIG. 4 is an exploded view of the electric switch shown in FIG. 1;

FIG. 5 is a fragmentary top plan view of the switch stator shown in FIG. 4;

FIG. 6 is a top plan view of a blanked bridging contactor before any of the individual contact portions have been severed therefrom;

FIG. 7 is a side view of a bridging contactor with certain of the contact portions removed and wherein the base portion of the bridging contactor has been curved;

FIG. 8 is another embodiment of a stator of the electric switch shown in FIG. 1 wherein terminals are integral with all the individual spaced contacts and the common contact; and

FIG. 9 is a side view of the switch shown in FIG. 8.

Referring now to FIGS. 1 through 5 of the drawings, there is illustrated an electric switch of the type employed in electric equipment such as television receivers, aircraft transmitters and receivers, and twoway radios generally indicated at 10, comprising a switch stator 11 and a switch rotor 12 rotatably mounted within the switch stator 1 1.

Considering first the switch stator l 1, it comprises an annular contact carrier 13 molded of suitable electrical insulating material having embedded therein a plurality of radially disposed individual spaced contact fingers 14. The contact carrier 13 is defined by a top surface 13a, a bottom surface 13b parallel to the top surface and by elongated inner and outer surfaces 13c and 13d transverse to the top and bottom surfaces. The contact fingers 14 are provided with individual spaced contacts 14a and 14b (see FIG. 4) arranged in a row along the elongated inner surface 13c of the contact carrier 13. Extending radially outwardly from the contact carrier 13 are a pair of support or mounting arms 15 and 16 having reduced end portions 15a and 16a insertable into not shown channels provided in a housing forming a part of the electrical equipment.

The switch stator 11 of the present invention is produced by forming groups or clusters of perforations in a strip of sheet metal for spacing partly defined contact fingers, molding the contact carrier 13 above and below the partly defined contact fingers of each group of perforations, and then blanking the remaining portions of the contact fingers from the strip of sheet metal to produce the switch stator 11. Reference should be made to Allison US. Pat. Nos. 2,988,696 and 3,219,785 for a more thorough description of the manufacturing process employed in making the present type of switch stators.

A common contact 17 also is supported by the contact carrier 13 and supporting means integral with the common contact 17 are embedded in the contact carrier 13 for fixedly securing the common contact 17 to the contact carrier. Preferably the individual spaced contact 140 and 14b and the common contact 17 are coplanar, i.e., lie in the same plane. Depending upon the application of the switch, the individual spaced contacts are long and short contacts 14a and 14b, as best shown in FIG. 4 of the drawings. Both the long and short individual spaced contacts are coplanar with the common contact. For convenience, the long and short individual spaced contacts will hereinafter be referred to as long contacts 14a and short contacts 14b.

When the electric switch is employed for altering the inductance of a circuit, certain of the contact fingers 14 comprise a long or short contact 14a or 14b, an embedded portion 140 (see FIGS. 2 and 3) and a stamped inductance member 18 extending radially outwardly from the contact carrier 13. Terminals 19 are integral with the contact fingers not provided with stamped inductance members 18. The stamped inductance members 18 provide adequate inductance values above 100 MHZ. To increase the inductance of the inductance members 18, an elongated slot 18a is provided in each of the inductance members 18, the length of the slot varying with the inductance desired. In the embodiment shown in FIGS. 1 to 5, all of the inductance members 18 are connected to each other with U-shaped connecting members 20 (see FIG. 5), the ends 20a of the legs of each of the U-shaped connecting member 20 being connected to each of the distal ends 1811 of the inductance members 18. Fine adjustment between adjacent inductance members 18 is obtained by bending the fan or inner section 20b of each of the connecting portions 20 out of the plane defined by the inductance members 18. The length of the slot 20c also varies with the inductance desired. Not shown inductance coils can be connected between adjacent terminals 19 when it is desired to obtain inductance values below 100 MHZ. One of the inductance members 180 and a terminal 14c are at least partially embedded in the radially extending support arm 16. As the switch rotor 12 is rotated from one position to another to connect electrically one of the long or short contacts 140 or 14b to the common stationary contact, the inductance in the circuit is increased or decreased.

For the purpose of electrically connecting the long contacts to the short contacts or to the common contact, a bridging contactor 21 provided with long and short contact portions 21a and 21b is constrained to rotate with the switch rotor or movable contact carrier 12. The rotor 12 is preferably actuated with a not shown shaft received in an aperture 12a provided in the center of the rotor, the angular position of the shaft being determined by a not shown indexing mechanism well known in the art. As shown in the drawings, the switch rotor 12 comprises a pair of circular sections 22, having a diameter slightly smaller than the inside diameter of the contact carrier 13. Each of the circular sections 22 is identical to keep to a minimum the number of different parts necessary for making the switch 10. Each of the circular sections 22 comprises an outer rim portion 22a and an inner hub portion 22b provided with the aperture 12a for receiving a shaft. As best shown in FIGS. 3 and 4, a peripheral lip 22c depending from the rim portion slidably engages the contacts 14a and 14b as the switch rotor 12 is actuated and limits axial movement of the rotor 12 relative to the stator ll. Radially spaced runners 22d extend from the hub portion 22b to the peripheral lip 22c and define cavities 23 for receiving the contact portions 21a and 21b of the bridging contactor. The bridging contactor 21 is also provided with a plurality of laterally spaced tabs 216 connected together with a base portion 27 receivable respectively in arcuate slots 24 and a groove 24a provided in the circular sections 22 for constraining the bridging contactor 21 to rotate with the switch rotor 12.

When the circular sections 22 are assembled to the contact carrier 13, the rim portions 220 of the pair of circular sections have their outer surfaces spaced apart a distance substantially equal to the thickness of the contact carrier (see FIGS. 2 and 3) while the hub portions 22b are of a slightly larger lateral dimension for receiving a shaft. The circular sections of the rotor are held together with a plurality of longitudinal pins 25 extending from each circular section and receivable in holes 26 provided in the other circular section. After a pair of circular sections are assembled with the tabs 21c of the bridging contactors received in the arcuate slots 24, the ends of the pins 25 projecting through the holes 26 are enlarged in a suitable manner to maintain the circular sections in assembled relationship with the switch stator 11. Preferably one bridging contactor 21 is employed with each of the circular sections 22 of the movable contact carrier for balancing contact pressures and keeping contact resistance to a minimum. The switch stator 11 is usually fixedly secured to suitable not shown mounting means provided in electronic equipment and the switch rotor 12 is rotated through a predetermined angle to alter the relationship of the bridging contactor 21 relative to the contacts.

An important feature of the present invention is the method of making the bridging contactor. As best shown in FIG. 6 of the drawings, the bridging contactor after being blanked from sheet material, is provided with a pair of long contact portions 21a and a plurality of short contact portions 21b. Depending upon the switching function required, all of the contact portions can be long or short or any combination thereof. More specifically, the bridging contactor comprises an elongated base portion 27 with the long and short contact portions 21a and 21b extending laterally in the same direction from the base portion 27. The plurality of tabs 21c extend laterally from the base portion in a direction opposite to the contact portions and are receivable in the arcuate slots 24 provided in each of the circular sections 22 of the rotor for constraining the bridging contactor 21 to rotate with the circular sections. Before the bridging contactor shown in FIG. 6 of the drawings is assembled toone of the circular sec tions 22, certain of the short contact portions usually are severed from the base portion. The bridging contactor 21 employed with the electric switch shown in FIG. 7 of the drawings employs a pair of long contact portions 21a and a single short contact portion 21b adjacent to one of the long contact portions 21:: The long contact portions of the bridging contactor shown in FIG. 7 always engage the short or long contacts 14a, 14b while the short contact portions engage only the common contact 17 or the long contacts 14a. The contact portions 210 have a predetermined transverse dimension d and, since the edge portions of the common contact 17 and the long stationary contacts 140 lie in an imaginary circle having a radius R, it is necessary that the longitudinal axis of the short contact portions 21b be spaced from each other at least twice said predetermined dimension. If the common contact 17 is removed from the switch stator, then the long contact portion 210 should be spaced approximately 180 apart from the short contact portion 21b in order that the bridging contactor can sequentially connect the long contacts to the short contacts.

By making the bridging contactor in accord with the present invention, only one type of bridging contactor 21 instead of several need be blanked from sheet metal and stocked. After the specific configuration of the bridging contactor 21 is determined from a customer application, that is, the number and location of the short and long contact portions, the extra portions are severed from the base portion 27 and the remaining contact portions are formed normal to the base portion and dished as shown in FIGS. 2 and 4 of the drawings. The contact portions can also be dished when the bridging contactor is being blanked from sheet metal. In the last manufacturing step, the base portion of the bridging contactor 21 is curved to facilitate insertion of the tabs 21c into the arcuate slots 24 provided in the circular section of the rotor.

In the switch stator 111 shown in FIGS. 8 and 9 of the drawings, the arrangement of the long and short contacts and the common contact is identical to that shown in the embodiment shown in FIGS. 1 through 4 of the drawings. The only difference between the two switch stators is that the stator 111 shown in FIGS. 8 and 9 of the drawings has terminals 1 l9 integral with all of the contacts 114a and 1141; instead of having stamped inductance means integral with some of the contacts. Also the stator 111 is provided with a pair of apertures for receiving of securing rods. v

The electric switch of the present invention can, therefore, be provided with stamped inductance members 18 for altering the inductance of the circuit or with terminals 19 or 1 19 for connecting each of the contacts into an electric circuit.

Preferably and in accord with the present invention, the long contacts 14a 1 14a and the common contact 17 or 117 are provided with edge portions lying in an imaginary circle having a radius R while the short contacts 14b or 114b have-edge portions lying in an imaginary circle spaced a distance R which is greater than R. Preferably the short contacts are spanned by the common contact as best shown in FIGS. 4 and 8. By having the edge portions of the long contacts and the common contact spaced the same predetermined distance from the elongated surface 13c of the contact carrier 13, selectivity spaced short contact portions on the bridging contactor can connect predetermined long contacts to the common contact.

While there has been illustrated and described what is at present considered to be a preferred embodiment of the present invention and an additional modification thereof and a method of making the bridging contactor thereof, it will be appreciated that numerous changed and modifications are likely to occur to those skilled in the art and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present inventlon.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A method of making a bridging contactor of an electrical switch comprising the steps of:

a. blanking from a strip of sheet material a bridging contactor having an elongated base portion and a plurality of long and short contact portions extending transversely from and integral with the base portion,

b. dishing the long and short contact portions integral with the base portion,

0. separating the bridging contactor from the strip of sheet material,

(1. severing predetermined contact portions from the base portion to provide a bridging contactor having at least two contact portions comprising a long and a short contact portion connected to the base portion, and

e. forming said at least two unsevered contact portions transverse to the base portion to produce the bridging contactor of the electric switch.

2. A method of making the bridging contactor of claim 1, comprising the additional step of curving the base portion of the bridging contactor to produce the bridging contactor of an electric switch having an annular stator.

3. A method of making the bridging contactor of claim 1, comprising the additional step providing tabs on the bridging contactor in a direction opposite to the contact portions.

Claims (3)

1. A method of making a bridging contactor of an electrical switch comprising the steps of: a. blanking from a strip of sheet material a bridging contactor having an elongated base portion and a plurality of long and short contact portions extending transversely from and integral with the base portion, b. dishing the long and short contact portions integral with the base portion, c. separating the bridging contactor from the strip of sheet material, d. severing predetermined contact portions from the base portion to provide a bridging contactor having at least two contact Portions comprising a long and a short contact portion connected to the base portion, and e. forming said at least two unsevered contact portions transverse to the base portion to produce the bridging contactor of the electric switch.

2. A method of making the bridging contactor of claim 1, comprising the additional step of curving the base portion of the bridging contactor to produce the bridging contactor of an electric switch having an annular stator.

3. A method of making the bridging contactor of claim 1, comprising the additional step providing tabs on the bridging contactor in a direction opposite to the contact portions.

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