US2544535A - Switching apparatus - Google Patents

Description

March 6, 1951 G. J. KENNEDY 2,544,535

swITcHING APPARATUS Filed June ll, 1947 4 Sheets-Sheet l y FVG. .9.

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wwf-M March 6, 1951 Filed June ll, 1947 G. J. KENNEDY SWITCHING APPARATUS 4 Sheets-Sheet 4 INVENTOR. q/Laffr 1Km/)foy Patented Mar. 6, 1951 SWIT CHING APPARATUS Gilbert J. Kennedy, Philadelphia, Pa., assignor to Philco Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application June 11, 1947, Serial No. 754,013

(Cl. ZOO-16) 7 Claims. 1

This invention relates to circuit selector switches and more particularly to push-,button station selector switches for use in radios of the multiple circuit type.

The principal object of the invention is to provide improved means for selecting one of a plurality of circuits, and more particularly one of a plurality of pretuned circuits of a radio or similar device.

Another object of the invention is to provide a switch mechanism which is operable to select one only of a plurality of circuits, regardless of whether more than one selector key or pushbutton is operated simultaneously.

Still another important object of the invention resides in the particular construction and arrangement of the various physical components of the mechanism, by virtue of which assembly and repair of the apparatus is facilitated and a considerable cost reduction is effected.

The manner in which the aforesaid and other objects are attained, will become apparent from the following specification and the accompanying drawings illustrating a preferred embodiment of the invention, and in which:

Figure 1 is a general view, in perspective, of apparatus incorporating the present invention;

Figure 2 is a bottom plan view of a preferred embodiment of the switch mechanism of the invention, illustrated as removed from its housing and with certain parts broken away more clearly to illustrate the various physical components thereof;

Figure 3 is a sectional View taken substantially along line 3-3 of Figure 2;

Figure 4 is a sectional View taken substantially along line 4--4 of Fig. 2;

Figure 5 is a fragmentary bottom plan view, with parts broken away and with one of the selector switches shown in its operative position;

Figure 6 is a rear elevational view of the mechanism;

Figure 'l is an exploded view, in perspective, of a portion of the switch mechanism, showing more clearly the details and interrelation of various elements thereof;

Figure 8 is a perspective View of an element of the invention; and

Figure 9 is a diagrammatic view of the switching means of the invention, shown in association with an exemplary control circuit.

Referring now in detail to the drawings, and more particularly to Figure 1 thereof, there is shown a casing or housing IIJ in which is housed selector switch mechanism embodying the present invention. Disposed on the front wall of the housing are various control elements, which, in the particular embodiment shown, comprise a plurality of push-buttons II, a conventional On-Off volume control element I2, and a manual tuning knob I3. Neither the element i2 nor the manual tuning mechanism controlled by knob I3 forms a part of the present invention and, thereforey detailed illustration and description of these elements are not necessary herein.

Referring now to Figures 2 through 6, in which the switch mechanism is shown removed from housing I, the numeral I4 designates a base member which, as seen more clearly in Figure 7, is provided with a plurality of suitable recesses, indicated generally by the numeral I5, adapted to receive various components of the device. The mechanism, as seen in Figure 2, comprises a plurality of switches I6, II, I8, i9, 20 and 2i which, as shown in Figure 9, are adapted to close associated circuits including branches ISa, Ila, IBa, I9a, 20a and 2Ia, respectively, and each of which circuits, as shown in this, the preferred form, operates the selector mechanism (so labeled on Figure 9) to effect selection of one of a plurality of conventional pretuned station cirsuits indicated diagrammatically by the block so labeled.

It should be understood, that, although the invention has been illustrated with one type of circuit means, seen in Figure 9, in its primary aspect the invention is concerned with physical features of the switch mechanism (as illustrated in Figures 1 through 8) and not with the particular circuit arrangement shown, which may take other forms.

To facilitate further understanding of the invention, the description immediately following will have reference to switch I6 only. Referring t0 Figure 3, it is seen that this switch includes a switch key 22 mounted for reciprocatory movement in a recess or guide-Way 23, formed in base member I4, the key 22 being normally urged to a projected position relative to base I4 (as illustrated in Figure 3) by a coil spring 24 positioned beneath the switch key in a recess 25. The righthand end of the spring is adapted to react against the inner end wall 26 of the recess while the other end is biassed against a downwardly projecting key portion 2l and normally urges the key to its fully projected position in which the depending portion 2l is against front wall 28 of the recess. Manual actuation of the switch key is facilitated by providing on its outer end, one of the push-buttons II, which may be attached thereto in any convenient manner, but, as illustrated in Figure 7, is preferably forced over serrations 29 formed on the outer end 30 of the key.

Referring now to Figures 2 and '1, it is seen that the right-hand inner corner of key 22 is bevelled, as indicated at 3l, and is so positioned as to bear against a similarly but oppositely bevelled edge 32 on one of a plurality of fingers 33 projecting forwardly from a slide bar 34. The slide bar is positioned for reciprocatory movement in a transverse guide-way 35, formed in base I4, and extends across the base to a point slightly past the inner end of switch 2| and into abutting relation with a resilient movable contact element`36 of a switch 31. Transverse movement of the slide bar to the right, as illustrated in Figures 2 and 5 will move the end 38 of movable element 36 into contact with the stationary contact element 39 of the switch to thus close an associate circuit, which, in the present case, controls circuits (not shown) to open the loud speaker circuit and. thus mute the radio during actuation of the switching mechanism.

A recess 46 is located to the left of switch I6, as seen in Figures 2 and '7, and receives a resilient conductor strip 4I which is lockedv within said recess by a portion 42 (see Figure '7) extending downwardly into a deeper recess 43 (Figure 2) which is oi substantially the same width as portion 42, and thus prevents lateral displacement of the conductor relative to the base structure. The innerend of this conductor is provided with a contact loop 44 which extends through an aperture or slot 45 in the side wall 46 of switch key guide-way 23 and-into Contact with theleft side edge of the keyl A second resilient conductor strip 41 is positioned'at the oppositel side of the recess 40 and is locked therein by a downwardly extending portion 48 depending into a recess 49 of substantially the same width as portion 48. The inner end of this latter conductor is also provided with a contact loop 50 which extends through anaperture or slot I in the side of wall 46 of guide-way 23 in a manner similar to that already described with reference to contact'loop 44 of conductor 4 I.

Switch key 22 has its edge portion cutaway in the region of aperture 5I thereby preventing contact of the key with loop 50, when the key is in its projected position, and thus maintaining circuit branch IBa -out of the Vcircuitucontrolled by switch I6. To close switch I6, pressure is exerted against its push-button II, thus moving key 22 inwardly along guide-way 23 against the tension of spring 24, until the left sidev edge of the key (as viewed in Figure 2) contacts loop 53 of conductor 41 and thus closes a circuit including branch I6a, in the manner described hereinafter. It will be noted that immediately upon inward movement of the switch key, toward depressed or operative position, bevelled edge 3I thereof will move against the bevelled edge 32 of nger 33 to urge slide bar 34 transversely to the right, and thus close muting switch 31 before closing the circuit including branch I6a, as described above. from push-button II, coil spring 24 immediately returns the key to its normal projected position and, concurrently therewith, slide bar 34 is returned to its normal position by the inherent resilience of contact element 36 of the muting switch.

Having described the construction and operation of switch I6, which conditions the mecha- When the pressure is removedl nism for manual operation by knob I3, the various switches for selecting a particular station circuit will now be described.

From the drawings, it is seen that each of the remaining switches (I1 through 2l) is provided with a switch key 22 similar in every respect to that just described in connection with switch I6, and that each of the keys is mounted in a similar guide-way 23. Each key has its bevelled inner end 3l abutting the bevelled end 32 of a corresponding nger 33 on slide bar 34 so that actuation or any one of the keys will move the slide bar to the right, to close muting switch 31 in the manner described heretofore. In addition to the above-described similarities, each key is similarly held in its projected position by a spring 24 positioned; in a recess 25 therebeneath, in the same manner as described above with respect to switch I6;

Provided between each pair of switch keys 22 is a recess 524 (Figure 7), each having positioned therein a resilient U-shaped conductor strip 53 (Figure 8) having its end portions terminating in contact loops 54 and 55 which extend through apertures 56 provided in the walls 51 and 58 of adjacent guide recesses 23 and into contact with adjacent switch keys. With reference to Figure 4, itis seen that each of these strips is provided with a portion 59 which depends from its forward end loop 66 into a recess 6 i of greater depth than that portion of recess 52 immediately beneath the side portions of the strip.

Also positioned inV each of recesses 52 is the inner end 62 of` a resilient conductor strip 63 which, as shown in Figure 4, has its intermediate portion 64 extending rearwardly and-downwardly through an aperture 65 in base I4, and its outer end 66 terminating. just beyond-the rear edge of the basemember to provide means for connecting a circuit wire. thereto. The other end portionof this conductor, as illustrated in Figures 4, 5 and '1, is also provided with a laterally extending. portion 61 terminating in an upwardly extending lamp contact strip 68, the purpose of which will be described-hereinafter.

The. inner end 62 of this strip comprises a U-shaped member 69, oneend of which comprises a Contact loop 10 which extends through an aperture 1I in the` right-,hand wall 58 (as viewed in Figure 2) of each .recess 52, while its other side 12 bears vagainst the left-hand wall 51 of the recesses to bias the Vcontact loop 10 in a counterclockwise direction and into contact with switch keys 22 when the Ykey is-in its operative or depressed position. It willbe noted that in switches i1 through 2I-the contact loop 10 of each of conductor strips 63 is in a position corresponding to that of contact loop o conductor member 41 relative tothe switch key 22 of switch I6, and that'each ofthe keys has its left-side edge cut away, or notched, in the region of contact loop 10 so that, when the keys are in their normal projected or lrest position, no contact is made between the loop and the key. Therefore, it can be seen that, with the particular arrangement of switch keys and hair pin conductor elements, as shown in Figure 2, all of the switch keys are in series circuit with conductor strip 4i., but, by reason of the notches,all of the associated circuits are open.v

When it is desired-to close one of the switches, the proper push-button is depressed, for example, switch 2D, as shown in Figure, to cause the associated switch key 22 to bear against contact loop 10` of .conductor 63 and/thus to completey a circuit including branch 20a. Each of switch keys 22 is provided with a recess or notch 'I3 in its right-hand side edge. When the key is in its projected or rest position, these notches lie just forward of the plane of the contact loops 55. The purpose of this is explained below.

A particular feature of the invention resides in the arrangement of the various switch elements just described. It is evident that, when one switch key is depressed to select a particular circuit, notch 'I3 moves into alignment with contact loop 54 of hair pin conductor 53 so that all the other switches to the right thereof. as seen in Figures 2 and 5, are out of circuit with those to the left. This is illustrated most clearly in Figure 5, in which it can be seen that the first three of the conductors 53 (counting from the left) are in circuit contact with switch `keys 22 of switches I8, I9 and 20, but, because notch 13 in the right-hand edge of the switch key of switch 20 has been moved into alignment with contact loop 54 of the next succeeding or fourth hair pin conductor 53, switch key 22 of switch 2| is out of circuit with the switch to the right thereof and, therefore, even if switch 2| be pushed in it would not close its associated circuit.

It is apparent, of course, that a similar condition exists with each of the other switches upon actuation thereof and that, regardless of which one is actuated, or whether more than one switch is actuated at one time, only one switch can possibly be operative to close the circuit controlled thereby; the controlling switch of those actuated being the one closest to conductor strip 4|. Thus, for example, and with reference to Figure 2, it can be seen that, if switch should be actuated, all of the switches to the lright thereof are out of circuit contact therewith and operationof any one, or more, would be ineffective to close another circuit.

Mechanism is provided for indicating, by i1- lumination on the face of the dial 14 of bezel I5 (see Figure l), the particular circuit or station in operation. With reference to Figures 2, 3, 5 and '7, it can be seen that this mechanism comprises a part of the switch mechanism and includes a plurality of lamps 16, one for each of switches II through 2|, mounted in recesses l1, of which the lower half 'I8 is formed in base I4 adjacent the rear edge 'I9 thereof, while the upper half 80 is formed in a cover member 8l secured to the base in any suitable manner, as, for example, by screws 82. One of the contacts for energizing the lamps is provided by the upstandin'g end portion 68 of conducting strip 63 which, as shown, abuts the rear contact element 83 of the lamp. The other contact is provided by a strip 84 secured to the rear edge 19 of base I4 (see Figure 6). With reference to Figure 4, it is seen that this strip is provided at intervals, along its top and bottom edges, with clamping elements 85 and 86, respectively, which are adapted to t into top and bottom recessed portions 87 and 88, respectively, of base I4, to hold the strip firmly to the rear edge thereof. The strip is also provided at its right-hand with a tab 89 for connecting it with one side of the lamp circuit and, at intervals corresponding to the space between the bases of the lamps, with loops 90 in which the side wall contact studs 9| of the lamps are engaged. Energization of the lamps is by any suitable means in circuit with each of the corresponding push-buttons, so that actuation of any one of the push-buttons Will also energize the associated lamp, for example, see the lamp circuits illustrated in Figure 9. In this ligure the lamp shown associated with circuit Ia is adapted to illuminate dial 'I4 during manual tuning by knob I3.

In accordance with a further feature of the invention, means is provided to conduct the light forwardly to indicate on the dial the station selected. This is accomplished by providing a light conducting element 92 which may comprise any suitable substance, such as one of the clear plastics of the methyl-methacrylate family, of which the light conducting characteristics are well known. Each of these light conducting elements comprises a flat elongate strip portion 93 positioned in a groove or recess 94 in the under, plane surface 95 of base I4, as illustrated in Figure 3, but which is, in actuality, the top surface of the present embodiment, when assembled in the housing I0. This position is, of course, a matter of choice, it being understood that the mechanism may assume any convenient position permitting manual actuation of the push-buttons.

As seen in Figure 3, the groove 94 extends from the lower front edge 96 of the base to a position beneath the lamp-receiving aperture and terminates in an enlarged portion 91 extending upwardly into lamp recess TI. An inner end portion 98 of light conducting element 92 extends upwardly into and substantially fills aperture 91, and the innermost end 99 is so positioned as to receive light from the lamp, which light is conducted forwardly through the strip portion 93 and directed upon the dial 'I4 immediately above the particular push-button actuated (see shaded area above switch 2D in Figure 1). A cover plate I9!) is secured over the surface 95 to prevent displacement of the light directing elements from grooves 94.

With reference to Figure 7, another of the primary advantages of the invention becomes apparent. This view illustrates the simplicity of assembly of this switch, it being necessary merely to drop most of the parts in the particular recess or aperture adapted to receive them.

It should be understood that the normal condition of each of the resilient conductor elements is preferably somewhat extended in comparison to its condition when disposed within base I4. See, for example, Figure 8, which shows one of the hair pin conductors 53 in its normal condition when removed from the base member I4. As seen in this gure, the side walls are spread outwardly at an angle greater than the angie therebetween when the element is in its recess. Therefore, when it is stated in the following description that the various resilient connectors are dropped into their recesses, it is to be understood that they are rst flexed to the condition in which they are shown in Figure 2. f

In the process of assembling the various elements of the switch in proper position in base I4, spring 24 is dropped into recess 25 after which switch key 22 is dropped into its guide recess 23 with its downwardly extending portion 2l between the front wall 28 of the recess and the outer end of the spring; the connectors 4| and 41 are dropped into the recess 40, and slide bar 34 into its guide recess 35. Conductor strip 63 is assembled with the base by passing its inner end 62 upwardly through aperture 65 into recess 52, as shown, and then lifting its outer end 66 upwardly over a stud IDI, depending from and preferably integral with base I4, a hole I Illa being provided for that purpose. After this a speed nut |02 is secured over the stud to hold the strip securely in place. When these various physical components of the mechanism have been assembled as described, a cover plate |03 is secured over these elements, as by screws |04, to prevent displacement of the various elements.

A's above2indicated, the circuit selecting apparatus of the invention has been illustrated, in Figure 9, in association with an exemplary circuit adapted to be controlled by su'ch apparatus', while-insofar as the concepts of the present inventi'on are concerned-other circuits may be employed, reference to the showings 'of Figure 9 provides a proper basis for an exposition of the complete operational sequence.

In general, the arrangement of Figure 9 comprises, inter alia, a schematic representation of the switch device hereinbefore described, a battery |09 (for example, a 'ii-volt storage battery, if the apparatus is 'employed in an automobile), a rotary switch having a rear section H9 and a front section |20, suitable pretuned' station-'selecting circuits |2|, and an actuating solenoid I |4 which, when energized from the storage battery |09, is effective to step or rotate the rotary switch from a given switch position to a succeeding position. The front and rear sections of the rotary Switch, the actuating solenoid, and the pretuned station-selector device l2| are. mechanically ganged by conventional means (illustrated diagrammatically by the broken lineV I3) so that upon each operation of the actuating solenoid H4 the station-selector device |2| is switched from one position, in which a predetermined station is received, to another position in which a different station is received. Such station-selectin'g arrangements are well-known in the art and it is unnecessary here to describe this device in additional detail.

The actuating solenoid |`|4 is of a type, well known in the art, which, when energized, functions to effect a step-by-step rotation of the rotary switch. In the arrangement illustrated there are three switch points per quadrant, and the solenoid is adapted to step'the rotary switch through a sector of 30 Der sten.

The circuit condition illustrated in Figure 9 is that vobtaining as the result of a prior actuation of switch 2|. This, as will be understood hereinafter, can be determined from the fact that top gap H8 in the iront section of the rotary switch is opposite the contacter associated with branch or conductor 2|a which, in turn, is associated with switch 2|. The mode of operation ofA the circuit in response to the actuation of any 'of the push-buttons will be readily understood by trfacing the actions resulting from a depression of` a specic push-button, for example, that associated with the switch 20. When switch 20 is depressed a connection is effected between the contact elements 55 and 'l0 associated with the said switch 20. This completes the actuating solenoid circuit, which circuit comprises4 the grounded negative terminal of the battery, switch-key grounding conductor 4|, switch-keys and key interconnectors 53, contact elements 55 and 10 associated with selector switch 20, conductor a, the rotary switch contactor (HT) associated with the conductor 20a, front section of the rotary switch, conductor H2, commutating switch |3, and finally the upper terminal of the actuating solenoid H4. As soon a's the circuit is completed through the solenoid H4, as above outlined, the actuating solenoid is 'energzed'and functions, in known manner, to step or advance the rotary switch, clockwise, through an angle of 30. This stepping action of the actuating solenoid will be continued step-bystep, until the above-'described circuit is broken. In thepres'e'nt instance the circuit is broken immediatelyup'on the rst 30 rotation of the 1'0- t'ar'y switch, for in that position the gap H8 in the front section of the switch falls beneath the contacting element associated with the conductor 20a. Upon the return of the selector Switch 20 to its rest position (shown) the indicator lamp H5 is energized and serves to identify the selected station. The circuit which results in the illumination of the lamp corresponding to the station-selector switch 20 may be traced as follows: the upper terminal of the selected lamp is connected directly to ground through the agency of the rear section H9 of the rotary switch which, through the action previously outlined, has been turned to a position 30 clockwise from that illustrated. The lower terminal of the lamp is connected through 'all of the remaining lamps and throughkthe conductors |G`a, Ha, |80., |`9a and 2|a to the front section |20 of the rotary switch and thence through the conductor H2, con'unutat'or switch H3, and the solenoid H4 to the positive terminal of the battery |09. It will oe observed that the current which energizes the lamp shown at H5 divides equally between the other iive remaining lamps, the current in the latter lamps being insuflicient to effect incandescence therein. It is to be noted that none of the lamps is'illuniinated during the period of rotation of thel rotary switch. The illumination from lamp H5 is, of course, conducted to the region of the dial in the manner described hereinabove.

I claim:

l'. In a switching device, an insulating base member provided with a plurality of recesses, a plurality of conducting keys each disposed in a corresponding one of said recesses and movable therein between operative and rest positions, a plurality of conductor elements each disposed in others of said recesses and normally making contact with said keys and connecting the same in series circuit relation, and a plurality of contacts supported by said base member and each associated with a corresponding one of said keys and normally spaced therefrom, each key being engageable with its associated contact in response to movement of the key to operative position, whereby to provide for closing of a circuit which includes the contact engaged by the key and at least certain of said conductor elements.

2. In a switching device, an insulating base member provided with a plurality of recesses, a plurality of conducting keys each disposed in a corresponding one of said recesses and movable therein between operative and rest positions, a plurality of conductor elements each disposed in others of said recesses and normally making l contact with said keys and connecting the same in series circuit relation, said keys and conductor elements being individual members readily insertable in and withdrawable from said recesses whereby to facilitate assembly and disassembly of said switching device, a plurality of contacts supported by said base member and each associated lwith a 'corresponding one of said keys and normally spaced therefrom, each key being engageable with its associatedl contact in response to movement ofthe key to operative position whereby to provide frclosing of acircuit which includesth contact engaged by the key and at least certain of said conductor elements, and cover means effective to retain said keys and conductor elements in assembled relation.

3. In a switching device, an insulating` base member provided with a plurality of recesses, a plurality of conducting keys each disposed in a corresponding one of said recesses and movable therein between operative and rest positions, and a plurality of conductor elements each disposed in others of said recesses and normally making contact with said keys and connecting the same in series circuit relation, said keys and conductor elements being individual members readily insertable in and withdrawable from said recesses whereby to facilitate assembly and disassembly of said switching device.

4. In a switching device, an insulating base member having surface portions provided with a plurality ofy outwardly-facing recesses, a plurality of conducting keys each disposed in a corresponding one of said recesses and movable therein between operative and rest positions, a plurality of conductor elements each vdisposed in others of said recesses and normally making contact with said keys and connecting the same in series circuit relation, said keys and conductor elements being individual members readily insertable in and withdrawable from said recesses whereby to facilitate assembly and dis assembly of said switching device, and cover means disposed across the surface of said base member and effective to retain said keys and conductor elements in assembled relation within said recesses.

5. In a switching device, an insulating base member provided with a plurality of recesses, a plurality of conducting keys each disposed in a corresponding one of said recesses and movable therein between operative and'rest positions, a plurality of conductor elements each disposed in others of said recesses and normally making contact with said keys and connecting the same in series circuit relation, said keys and conductor elements being individual members read-ily insertable in and withdrawable from said recesses whereby to facilitate assembly and disassemblyl of said switching device, a plurality of contacts supported by said base member and each associated with a corresponding one of said keys and normally spaced therefrom, each key being engageable with its associated contact in response to movement of the key to operative position, and cover means effective to retain said keys and conductor elements in assembled relation, at least certain of said keys being provided with a notched portion so disposed that movement of a key to operative position breaks contact between the moved key and an adjacent conductor element.

6. In a switching device, an insulating base member provided with a plurality of recesses, a

plurality of conducting keys each disposed in a corresponding one of said recesses and movable therein between operative and rest positions, a plurality of conductor elements each disposed in others of said recesses and normally making contact with said keys and connecting the same in series circuit relation, said keys and conductor elements being individual members readily insertable in and withdrawable from said recesses whereby to facilitate assembly and disassembly of said switching device, a plurality of contacts supported by said base member and each associated with a corresponding one of said keys and normally spaced therefrom, each key being engageable with its associated contact in response to movement of the key to operative position, and a plurality of lamps each disposed within still others of said recesses and each associated with a corresponding one of said keys and adapted to be illuminated in response to movement of the corresponding key to operative position.

7. A construction in accordance with claim 6, and further including a plurality of light-conducting members supported upon said base member in cooperative light-conducting relation with respect to said lamps, said light-conducting members extending to a predetermined visible region of said base member, whereby to provide indicating illumination in said region.

GILBERT J. KENNEDY.

-REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Abstract, 691,280, O. G. May 9, 1950, p. 646.

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