US2740056A - Selective rotary reversing switches - Google Patents

Description

March 1956 A. T. PARKER ETAL SELECTIVE ROTARY REVERSING SWITCHES Filed April 5, 1955 lvl. g

INVENTORS ALFRED T. PARKER JAMES W- SHAW erators,

United States Patent 2,740,056 SELECTIVE ROTARY REVERSING SWITCHES Alfred T. Parker andiJames'W; ShawuLos Angeles, Calif., assignor toStoddai-tAircraft-Radio Co., Iac.,:Los Aw geles, Calif., a corporation of- California Application April'S, 1955, Serial No. 499,356 1'4"Claims. (Cl. 307-149) This invention relates to a rotaryjeversing.switch in combination with a rotary selector sWitch-andisparticularly characterizedby automaticoperation of the reversing switch upon completionof a cycle of operation-of the selector switch.

In certain kinds of electrical apparatus requiring reversing switches theadvantages of automaticoperation are apparent. The operation of.the apparatus is simplified. Simplicity of control is'an accomplishment so .wellrecognized'that it has a tangible value in the market for. such apparatus.

.When the reversing switchis combined with another switch required to be turned in order to turn theapparatus ofi their can" be no doubt'that the reversingfraction will'be performed. 'The possibility of damage or unwanted wear to the device required .to be reversed is eliminated due to carelessness orv lack of instructionon the part of the operator. Uncertainty. as..to which position therever'sing switch occupiedforthe last: operating interval isalso removed.

Our reversing switch'is .of simple and sturdy. construction. Being a part of a rotary switchspace issaved inthe apparatus in which it is used, .as is labor. in installation. In .a typical embodimentthe main rotary switch is used'to change range or'function of an apparatus andHit includes an off position. The reversing. element is preferably assembled'in relation to the rotary switch .such that the former'is'actuated whenthe latter..-is. turned'to the oil position. However, the reversingelement-may be'actuated atthe opposite .end ofthe. arcuate rangezof the rotary switch by oppositelyassembling .thecornponent parts.

One usefor our automatic. reversingswitch-is forreversing thepolarity' of the power supply to amovingcontact pulse oscillator, such as..described in thecopending application of Donald S. Radmacher for .Pulse. Gen- Serial No. 407,890,- 'filed February -3, 1954.

Another use is for reversing. the .polarity. of directrcurrent vacuum tube filaments. Another. use is for. the control of dual-vibrator power supplies, as found in aircraft, where each isprotected'from fault .by a fuse and each-is. connected to oppositeposi'tions of our switch element. ;In case of a fault, the usual operation. of turningthe e q ipment on connects the unusedand operative vibrator thereto and merely turning the equipment on again :gives further operation. Similarly, when .theusebf standby equipment is'involved, our element may' be used.to change from'main'to standby equipment each'timethe apparatus is turned off. Where the current and/0r voltage demands of such equipment exceed the contact capabilities of the switch a suitable relay may be operated therefrom in the known manner. A still further application involves-change of attenuation insome part of the apparatus with operation of the main rotary switch. In this instance difiFerent attenuator units are connected to each of the stationary contacts of the reversing element.

An object of our. invention is to accomplishareversing switch function automatically .as the operator performs a thereto. Shaft 1 isjfree to rotate in. either gear having a a diameter springs 5 and'6. It is positioned relatively nearaperfure plate'10'and; is'therefore engaged by the springs when 'these pass fully through i teeth are such that'clockwise to disappear to the opposite 2,740,056 Patented Mar. 27, 1956 .tion as the rotary switch.

Another object is'to provide a switch which alters an electrical circuit each time a mechanically'linked switch assumes a given position from a given direction of rotation.

Another object is to, provide a reversing switchiwhich is,.actuated each time the apparatus ofwhiehitis apart is turned off.

Another object is to provide a reversing switchwhich is actuated each time the rotaryswitch of which itj'isa part is turned'to an extreme rotationalposition.

Other objects of our'in'vention .Willbecome'apparent .upon reading the following detailed specification and upon exaniiningthe related drawings, in which:

Fig 1 showsthe essentials of our invention iii-exploded perspective,

Fig. 2 is a side elevation of a typical switch, assembled,

Fig. 3 is an .end elevation of a typical switch-with an illustrative. electrical circuit, and

Fig. '4 is a schematic electrical. diagram ofatwo-wafer embodimentof the reversing switch element.

In Fig. 1 only the essentialsof our invention aresh'own in an exploded view so that the mode of operation thereof may be most easily comprehended. Numerall identities the shaft, normally used for operation, whichjiscommon to the usual rotary portion of theswitchianddo the reversing element by virtue of plate2 being fastened direction within limits 'setbyithe number of contact positions on the rotary'switch; two as aminimum and no'limit within reason as a maximum, with five beinga representative number. The shaft is provided with one or moregfl'at portions-3, which, serveto idriveplate 2 rotationally by meansof'non-circular hole 4. ,Springs 5:.and 6 are identically formedin circumferential shape and are heldeq'uispaced upon the rear of plate'2 by rivets7 an'd'8.

Aperture-plate 10 is stationary, or essentially so,' in the switch assembly. It is provided with a round. center hole-11 to act as a bearing for second shaft 12 and'two screw-holes Band {14 for fastening to thefram'ef of the switch assembly. Most important are two circumferen-- as when assembled,'-springsSand 6 pass through the slots axially when the spring plate is rotated counter-clockwise. Element'I8 is -an-axially actuatable ratchetwheelor equal to the outer extent of apertures 15 and 16. The tilt of "the teeth of the ratchet wheel are such that. each of -thesprings press upon wedge 19 diametrically, opposite,

when engagementoccurs. Engagement occurs onl'yin the counter-clockwisedirection of rotation'for theffabricationofelements 2 and 18 as shown. The slant oflthe rotation transmits noBCiion from'spring to wheel; and beyond the first position'clockwise 'the limits of the apertures cause the springs to start side of the aperture plate; Shaft 1- is hollow at'23 and shaft 12 has a projection 24 which-enters thereinwith a sliding fit to provide a two bearing support for-both shafts.

In a'repre'sentative embodiment-the last switch position whenmoving-in a'counter'clockwise direction operates the reversing switch, the position before that one. places 'the'springs in -position-with-"respectto ratchet wheel 13 =sucl1tliat the next counterclockwise"move-operates the reversing switch, the next prior position removes the springs from the plane of the wheel, the next prior position moves the springs completely back through the aperture plate and even with the initial edges of the holes therein, and any further prior positions cause the springs to retreat from the holes, the springs being restrained in axial position by the aperture plate on the side away from the ratchet wheel. The aperture plate and/ or the edges of the holes therein restrain the springs axially in each position save the first two mentioned. In these, the teeth of the ratchet take over.

Insulating wafer supports the stationary contacts of the reversing switch. Insulating piece 22 fits over fiattened shaft 12 with a matching hole required for turning said piece by shift 12 and rotary ring 21 is attached to piece 22. The several radial fingers of the ring coact with stationary contacts 60, 61 and 62 to accomplish the reversing action as will be later described.

In Fig. 2 the reversing switch is shown assembled and in elevation view with a one-wafer multicontact rotary switch. In this view detent means for positively positioning the rotary members upon the switch contacts are shown for both the reversing switch and the rotary switch. These means and the rotary switch were omitted in Fig. l for sake of clarity.

In Fig. 2 shaft 1 is shown provided with a manual operating knob 30. A threaded bushing 31 is afiixed to front stationary plate 32, which latter also supports the broad leaf front detent spring 33. Through a hole in plate 32 a steel ball 34 is urged into depressions of a rotary wavy plate 35 rigidly aflixed to shaft 1.

In known wafer switch fashion two long bolts 36 and 37 extend from front stationary plate 32 through each of the other stationary plates to bind the switch into a rigid body. Spacers 38, 39 position insulating wafer 40 a suitable distance from the front plate. Wafer 40 is provided with one or more stationary silver or silver-plated spring contacts, such as 41, 42, 43 and 44, held in place by eyelet type rivets and contacting rotor ring contact 45 of the general type more fully shown as 21 in Figs. 1 and 3. One of the stationary contacts, 44, maintains contact with the rotor ring at all times whereas the other stationary contacts make contact with one or more radial fingers extending to a greater radius than the ring as represented at 63 in Figs. 1 and 3.

It is to be understood that several wafer assemblies may be positioned one after the other to the left of the one, 40, shown. In any event, to the left of the last one the spring plate 2 is rigidly fastened to shaft 1. Next, and closely adjacent, is located aperture plate 16; this being held stationary by virtue of bolts 36 and 37 passing through holes therein and spacers 46, 47 placed between plates 40 and 10 on the bolts.

Closely adjacent to the aperture plate is axial ratchet wheel 18, this being rigidly mounted on shaft 12 at essentially the right end thereof. Next to the left is a stationary plate 48, essentially the same as front plate 32, and this is fitted with broad leaf detent spring 49, ball 50 and wavy plate 51 as was the front plate. The second detent assembly is required to give the reversing switch a positive contact-positioning means independent of the means for the wafer switch proper. Spacers 52, 53 locate plate 48 the necessary axial distance from aperture plate 10.

The final stationary piece is reversing switch insulating wafer 20, which is suitably spaced from stationary plate 48 by spacers 54, 55. The final rotating piece is insulating piece 22, holding rotor ring 21. Locking type nuts 56 and 57 rigidly hold the stationary assembly together.

Rotational stop 58, bent out from the material of wavy plate 35 and impinging upon stop- 59 bent out of front plate 32, is preferably provided to prevent rotation beyond the o position. Another stop for the other rotational extreme may be similarly bent out to coact with stop 58.

In Fig. 3 the reversing portion of the switch is shown in somewhat greater detail than in Fig. 2. Wafter 20 is provided with a minimum of three contacts; outer radial contacts 60 and 61 and inner radial contact 62. The former alternately make contact with one of the six radial extensions 63 while the latter is in constant contact with the inner rotor ring 21. With six extensions 63 on the ring each of the previously described detent assemblies is to have twelve positions of stable equilibrium; i. e., each 30".

An example of a reversing circuit is shown in Fig. 3. One terminal of a battery 64 is connected to contact 60 and the opposite terminal thereof to terminal 61. The battery is provided with a center tap 65, which is connected to one terminal of a load 66, while the other terminal of the load is connected to contact 62.

With the position of the switch shown the negative terminal of the battery is connected to terminal 67 of the load. When the reversing switch is moved one detent (30) counterclockwise the positive terminal of the battery would be connected through terminal 60 of the switch to terminal 67 of the load.

Two more stationary contacts 68 and 69 have been shown dotted on wafer 20. Contact 68 is shown connected for energizing a lamp 70, in which connection the lamp lights each time one of the two polarities is used. Other auxiliary circuits may be excited as will be understood by those skilled in the art.

Similarly, other reversing functions may be accomplished by adding reversing wafers to that element of the switch. With two wafers the capability of the usual double-pole double-throw knife blade reversing switch is obtained. A motor having armature 73 and field 74 may then be reversed in rotation by reversing the connections to the field, as shown in Fig. 4.

The upper wafer assembly 21, 6t 61, 62, 63 is the same as shown in Fig. 3. Constant contact 62 is merely con nected to one terminal of the field rather than to the load and the alternate contacts 66), 61 are connected to opposite sides 75, 76 of the power line. In the same way in the lower wafer assembly 71, 8t), 81, 82, 83, constant contact 82 is connected to the other terminal of the field and alternate contacts 80, 81 are connected to opposite sides 75, 76 of the power line, but in the opposite relation as shown. When the two mechanically coupled wafers are in one position the line is connected to the field in one direction and when in the next position the connection is in the opposite direction. Four wafers in the reversing element of the switch would reverse two separate circuits, and so on, as will be understood.

While we have described a preferred form of our in vention supra, it will be understood that numerous variations thereof are possible and may be preferred in certain situations.

Rather than two springs 5 and 6 and corresponding holes in aperture plate 10 only one spring may be used, particularly where the switch is small or the contact pressures light. Conversely, for heavy duty service three or four springs may be used.

Switch parts are often fastened and mechanically driven in wafer switches merely by non-circular holes engaging flats (3) on the shafts. This allows easy assembly. In such construction an even number of springs is of advantage in symmetrically driving the parts, such as the ratchet wheel (18).

A radial rather than an axial spring and ratchet wheel assembly may be used. In this instance the springs become tangential, the aperture plate becomes an aperture drum and the ratchet Wheel has saw-tooth instead of fanlike teeth.

Any practical number of detent positions may be used as long as the relation between that number and the number of radial contacts (63 of Fig. 3) remains in the ratio of two to one.

Should actuation of the reversing switch in a clockwise direction be desired the direction of the free ends of springs 5 and 6 is reversed and corresponding circumferential alteration of spring plate 2 with respect -to.aperknown tap switchwith a spring contact arm, byaudrum and rolling-contact construction, or by others. We prefer positive positioning by detent assemblies but these need not be employed if careful manipulation or other means are employed to insure proper contact relation in opera- .tion.

Rather than constant contact 62 a pigtail wire connection. may be: made from rotative contact 21 and others. The'switch characteristically is restrained from repeated revolution of the control shaft.

- Fluted shafts may be used at 1 and.12 rather than flats for driving the rotative members, in which case the holes in elements 2, 18, 22, etc. are also fluted to match.

Likewise, battery 64 may be replaced with an equiva- .lent power supply, or by two power supplies connected in series at tap 65, or instead of a power source the outputs of a push-pull amplifier or other electroniccircuit may be substituted.

Specific embodiments have been shown and described in this specification to most fully set forth how thisinventionmay be practiced. Wide variations may be takenfrom these embodiments and changes in details, size and proportions made without departing from the spirit and domain of our invention.

switch conductor mechanically connected tosaid second shaft, and stationary reversing switch contacts coacting;

therewith; the recited structure proportioned-so that rotation of said operating shaft in one direction urges said spring through said hole and revolves said toothedipiece incrementally to circuitually reversev saidreversing. element.

2. In a rotary switch, a circuit reversing elementcom- ,prising an operating shaft, two cantilever springs having axial tension attached to said operating shaft, a stationary plate having two elongated holes bearing against; said springs, said holes located in said plate to allow said springs upon rotation of said operating shaft to pass throughsaid holes, a second shaft colinear with said operati11g;shaft,.a

.ratchet wheel having axially disposed teeth coaXially-attached to said second shaft and positionedadjacent said plate on the side opposite said springs, detentmeans coacting with said second shaft, a rotative contact attached to said second shaft, and a plurality of fixed contacts at .least one thereof positioned to engage said rotative contact only at each rotative position determined by said detent means, said springs, plate and ratchet proportionedv to advance said rotative contact by one. of said plurality of fixed contact each time said springs engage said ratchet wheel.

3. The circuit reversing element of claim 2,.in which a second rotative contact and a second plurality of fixed contacts coactive therewith are circumferentially' aligned with those correspondingly first mentioned and are adaptedfor actuation by said second shaft.

4. In a bidirectionally operable rotary switch a unidirectionally operable reversing element comprising an operating shaft common to said switch and to a strip spring attached thereto, an essentially stationary member positioned adjacent said spring, said member havinga hole locatedto pass said spring upon rotation of said operating shaft, a second shaft, a circular toothed piece vpositioned adjacent said strip,

related such that rotation of ,tion urges said strip throughv shaft. adjacent said member, a.second rotary ment attached to said second shaft having operational positions angularly equal tothe pitch of the teeth of said side thereof opposite :attached to said second: shaft adjacent said member on .the side thereof opposite said spring, a. rotative reversing conductor having'radial contacts attached to said second shaft in one, directionurges said spring through said hole and, revolves said toothedpiece anvamount equal to the spacing of said. stationary contactstoi reverse the conductive relation, of thecontacts ofsaid reversing element .and also so proportionedthat rotation of said operating shaft in the opposite direction toothed piece.

5. In a bidirectionally operable rotary switch a unidoes not revolve said directionally operable reversing switch means comprising a manually operablefirst, shaft, said. shaft adapted to actuate said rotary switch, a cantilever spring-like strip attached to said first shaft, an essentially stationary member said member having a hole located to pass said strip.upon rotation of said first shaft in one direction, a second shaft, a circular toothed element attached to said, second shaftadjacent said member on the side thereof opposite said strip, -aconductive ring having contacts, saidringmechanically attached to said second shaft, said contacts aligned with each second tooth of saidtoothed element, and at least two stationary contacts coacting with said ring contacts, said stationary contacts. aligned with successive teeth of said toothed element; the recited structure proportioned and angularly saidffirstshaft in one direcsaid ,hole. and revolves. said toothed element one tooth, and so that rotation of. said "first shaft in the. opposite direction does not revolve said toothed'element.

positioned to allow, said spring to pass through said member. upon rotation of said operating shaft in one direction. av second shaft, a toothed .pieceattached to said second switchv eletoothed piece; said stop, spring, member and piece proportioned and angularly related such that rotation of said operating shaft in said v onedirection engages said spring anda tooth of said toothed piecea circumferential distance equal to the pitch of one tooth thereof in advance of the .limit of travel imposed-by, saidstop, and rotation to said stop moves said second rotary switch element one operational position in the said one direction, while rotation of ,said operatingshaft in the reverse direction is ineffectual inmoving said second element.

7.' In combination, a rotary: multiposition switch and a rotary reversing switch actuated in common therewith comprising, a common operating shaft, a rotary multiposition switch means adapted for operation by said operating shaft, a spring attached to said operating shaft, an essentially stationary memberrbearing against said spring having a hole through which said spring may pass upon rotation of said operating shaft, a second shaft, a ratchet connected to said second shaft adjacent said member on the said spring, movable reversing .switch contacts connected to said second shaft, and stationary reversing switch contacts coacting therewith; said spring, member and ratchet so'related that rotation of said operating shaft in one direction passes said spring through saidhole and revolves saidv ratchet an increment to effect circuitual reversal of said reversing switch.

. 8.,rIn combination, .a rotary multiposition switch and a rotary reversing switch comprising a common operating shaft, a rotative contact connected thereto, more than two fixed contacts positioned to coact with said rotative conact to form a multiposition switch; a cantilever spring driven by said operating shaft, a stationary plate having a hole positioned to axially deform said spring and to urge said spring through said hole upon rotation of said operating shaft, a second shaft colinearly disposed with respect to said operating shaft, a multitoothed gear attached to said second shaft positioned on the side of said plate opposite said spring, detent means coactive with said second shaft to urge it to discrete positions, a second rotative contact attached to said second shaft, a plurality of further fixed contacts positioned to coact with said second rotative contact at each said discrete position; said spring, plate and gear proportioned to advance said second rotative contact one said further fixed contact each time said spring engages said gear.

9. In combination, a rotary multi-position switch and a rotary reversing switch comprising a first operating shaft, a first rotative contact attached to said first shaft, more than two fixed contacts positioned to engage said first rotative contact to form a multi-position switch; two cantilever springs tangentially connected to said first shaft, stationary plate having two circumferentially shaped holes positioned to allow said springs upon rotation of said first shaft to pass through said holes, a second shaft colinear with said first shaft, an axially toothed ratchet coaxially positioned adjacent said plate on the side opposite said springs and attached to said second shaft, detent means coacting with said second shaft, a second rotative contact attached to said second shaft, a plurality of fixed contacts at least one thereof positioned to engage said second rotative contact at each rotative position determined by said detent means; said spring, plate and ratchet proportioned to advance said second rotative contact by one of said plurality of fixed contacts each time said springs engage said axially toothed ratchet.

10. In combination, a rotary multi-position switch and a rotary reversing switch comprising a first operating shaft, more than two fixed contacts positioned to engage said first rotative contact to form a multi-position switch; two cantilever springs tangentially connected to said first shaft, a stationary plate having two circumferentially shaped holes positioned to allow said springs upon rotation of said first shaft to pass through said holes, a second shaft colinear with said first shaft, an axially toothed ratchet coaxially positioned adjacent said plate on the side opposite said springs and attached to said second shaft, detent means coacting with said second shaft,

second and third rotative contacts attached to said second shaft, two pluralities of fixed contacts, at least one of each of said pluralities positioned to engage said second and said third rotative contacts at each rotative position determined by said detent means; said springs, plate and ratchet proportioned to advance said second and third rotative contacts by one of said pluralities of fixed contacts each time said springs engage said axially toothed ratchet.

11. In a rotary switch system, in combination, manually operable circuit reversing means comprising an operating shaft, a spring attached to said operating shaft, a stationary member positioned to deflect said spring, said member having a hole through which said spring may pass upon rotation of said operating shaft, a second shaft, a toothed circular piece connected to said second shaft adjacent said member on the side thereof opposite said spring, a movable reversing switch conductor mechanically connected to said second shaft, said conductor having radially extending contacts, two stationary contacts coacting with said radially extending contacts, said stationary contacts circumferentially spaced half the distance between adjacent radially extending contacts, a third stationary contact in continuous contact with said movable conductor; a load circuit, said third contact connected to said load circuit, means having opposite electrical polarities, one of each of said two stationary contacts connected to one polarity of said means, rotation of said movable conductor an amount equal to the spacing between said stationary contacts reversing the polarity of said means with respect to said load.

12. In a rotary switch system, in combination, a multiposition bidirectionally operative rotary switch and a unidirectionally operative rotary reversing switch comprising a rotary switch having contacts, an operating shaft common to both said switches, an axially distended spring attached to said common shaft, an essentially stationary member positioned axially adjacent to said spring, said member having an arcuate hole located to pass said spring upon rotation of said common shaft in one direction, a second shaft colinearly related to said common shaft, an axially toothed gear attached to said second shaft adjacent said member on the side opposite said spring, a detent spring, detent means coacting with said detent spring and attached to said second shaft, said detent means restraining said second shaft in a number of rotational positions equal to the number of teeth on said gear, rotative revers ing switch contacts connected to said second shaft spaced two teeth apart with respect to said gear, stationary reversing switch contacts coacting with said rotative contacts spaced half as far apart as said rotative contacts; the recited structure proportioned and angularly related such that rotation of said common shaft one contact of said rotary switch in one direction urges said spring through said hole su-tficiently far to revolve said gear one tooth, and also so that rotation of said common shaft in the opposite direction does not revolve said gear.

13. A compound switch having two mechanical operative routines with a single operating shaft comprising, a bidirectionally rotatable multi-position switch structure, a stop to limit the rotation of said operating shaft, an axially deformable spring attached to said operating shaft, an essentially stationary member located axially adjacent said spring, said member having an aperture positioned to pass said spring axially through said member upon rotation of said operating shaft in one direction, a second shaft colinearly positioned with respect to said operating shaft, an axially toothed piece attached to said second shaft adjacent said member on the side thereof opposite said spring, movable contacts connected to said second shaft having a spacing equal to a multiple of the tooth spacing of said piece, essentially stationary contacts coacting with said movable contacts having a spacing equal to a different multiple of the tooth spacing of said piece; the recited structure proportioned and circumferentially related such that rotation of said operating shaft in one direction to the circumferential position limited by said stop revolves said piece one tooth and that rotation of said operating shaft in the opposite direction does not revolve said piece.

14. In combination, a rotary multi-position wafer switch and a rotary wafer reversing switch comprising an operating shaft, a first rotative contact attached to said operating shaft, a wafer having more than two fixed contacts positioned to engage said first rotative contact to form a multi-position wafer switch, first detent means coacting with said operating shaft, stops coacting with said operating shaft; a plate attached to the end of said operating shaft, two cantilever leaf springs attached to said plate adjacent the periphery thereof and deformed to project axially therefrom, a stationary aperture plate positioned to stress said springs and having two arcuate apertures located in the path of said springs adapted to pass said springs axially through said aperture plate upon rotation of said operating shaft in one direction, a second shaft colinear with said operating shaft, an axially toothed ratchet coaxially positioned adjacent said aperture plate on the side opposite said springs and rigidly attached to said second shaft, second detent means coacting with said second shaft, a second rotative contact having half as many radially extending contacts as the detents in said detent means, a wafer having a plurality of fixed contacts at least one thereof positioned to engage a contact of said rotative contact at each rotative position determined by said second detent means; said springs, aperture plate and ratchet axially related to each other and to said stops that said springs advance said ratchet 10 one detent position upon rotation of said operating shaft from the detent position of said first detent means next to last to the last detent position as determined by said stops, said springs so related as to not alter said ratchet position upon opposite rotation of said operating shaft away from said last detent position.

No references cited.

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