US2305175A - Mechanical push button tuner - Google Patents

Description

' LE RoY-J. L.EI$HMAN I 2,305,175

MECHANICAL PUSH BUTTON TU NER Filed May 1, 1941 2 Sheets-Sheet l D 1942, LE ROY J. LE ISHMAN 2,305,175

* MECHANICAL PUSH BUTTON TUNER Filed May 1, .1941 '2 Sheets-Sheet 2 INVENTOR.

Patented MECHANICAL PUSH BUTTON TUNER Le Roy J. Leishman, m Angeles, Calif.

Continuation of application Serial No. 253,174, January 27, 1939. This application May 1, 1941,

Serial No. 391,420

18 Claims.

This application is a continuation of my application Serial No. 253,174, filed January 27, 1939.

The invention herein described pertains to antomatic means for moving control members to predetermined positions, and more particularly to such apparatus as applied to radio and/or televisiontuning devices.

For some years, two and three gang variable condensers have been used almost exclusively for tuning radio receivers. Practically all such condensers employ rotors that tum'through an angle of 180 degrees. Her'etofore, there have been only three means by which mechanically operated automatic tuners could be made to turn through so great. an angle upon operation of one of a plurality of push-buttons, levers, or other station selectors. One of these methods employed cords, as described in the Heath patent No. Re. 17,531.

(01. va -1o) treme' positions within its possible angle of rotation, and a contact member that engages a cam surface on the element and rotates it to the tuned-in position. i

In the accompanying drawings: Fig. 11is a fragmentary vertical section of one form of my device, taken along line l'--l of Fig. 4. Fig. 2 is a fragmentary vertical section taken along line 2-2 of Fig. 4. I

Fig. 3 shows a transitional position of the parts illustrated in Figl 2 at the momentwhen the cord gives over the rotation of the positionable mem- While this method provided the necessary 180 degreesv rotation, it was not accurate, as the dial .could vary considerably from the supposed tuned-in position without materially affecting, or

being affected by, the. cord. Another type of mechanism for securing a rotation of 180 degrees requires the use of gears and racks, and is represented in general by the structure described in the Schaefer Patent No. 1,906,106. This is too expensive for use in low-priced table models. A third means employs neither cords, nor gears, and is disclosed in a copending application of my own, Serial No. 179,910, filed December 15, 1937. While this latter means is less expensive than the Schaefer device, there is a demand for a mechanism that is still cheaper. It is the chief purpose of the present invention to provide a simpler and less expensive solution to this problem than any of the three above mentioned.

Other objects of this invention are to make it possible to rotate a control member through at least part of. its maximum angle of rotation by means of a cord without detracting from the accuracy'of the device;' to provide means for causing the cord to become slack before the operating button or lever reaches the end of itsoperating stroke; to make it possible for the adjustable elements required in such apparatus to be are employed-one for each of a group of favoritestations. Each selector comprises a cord for rotating a positionable element from the more eilber to the contact means or shoulder that forms a part of the plunger.

Fig.4 is a plan view, partly in section.

Fig. 5 is a fragmentary rear view of the structure shown in Fig. 4.

Fig. 6 is a fragmentary vertical section of the preferred form of my device, showing the plunger in the rest position, and the positionable mem- -.ber or cam one-half revolution from the tuned-in position. v

Fig. 7 shows a transitional position of the parts shown in Fig. 6 at the moment when the contact means start to rotate the cam.

Fig. 8 shows the parts' shown in Figs. 6 and 7 at the tuned-inposition. g I

Fig. 9 is a fragmentary plan view, partly in section, of the preferred embodiment of my invention.

Fig. 10 shows my cam locking device in th loosened position.

Fig. 11 illustrates the cam locking device after the operating screw has been tightened, showing how one end has moved along the shaft from the position pictured in Fig. 10.

Fig. 12 is a right end view of the longitudinally movable member of my cam locking device shown at the left in Figs. wand 11, revealing the opening for theshaft and the inwardly extending tang that fits the keyway in the shaft.

Fig. 13 is a left end view of the member of my cam locking device shownat the right in Figs. 10 and 11, illustrating its structure and its relationship to the shaft.

Fig. 14 illustrates a modification in which the operating means is a 1ever, rather than'a plunger,

and shows the positionable member 'from the tuned-in position. I

Fig. 15 showsthe device of Fig. 14' with the positionable member turned to a transitional position in'which it is about to be engaged by the 7 Plates.

shoulder D at substantially the position tratedin the fi ure. The-curveclpor'ition of ,the

, lever-operated modification of the device of Figs.

6, 7, 8 and 9 with the positionable member about to be turned in a clockwise direction from a position 180 from the tuned-in position.

Fig. 19 shows the device of Fig. 18 with the positiona-ble member turned to a transitional position in which it is engaged by the operating lever.

Fig. 20 shows the device of Figs. 18 and 19 with .the positioning lever at the end of its operatin stroke and the positionable member in the final tuned-in position.

In the various figures, parts serving the same or a similarpurpose are indicated by the same reference characters. I

In one form of my invention, a plurality of positionable elements or cams E are adjusta-bly mounted on a rotatable shaft 8, as shown in Fig; 4, and secured in adjusted position with relation to the shaft by means to be described later. This shaft is rotatably mounted in a supporting frame consisting of end plates in and lb, 9. front plate FI and a back plate F2. A series of plungers P, one for each positionable element, are slidably mounted in slots provided in the front and back These are normally held in an inoperative rest position by springs J attached to lugs 8 and 9, formed on the plunger and front plates respectively. Each plunger is provided with an operating button B, additionally identified-by a number. Shaft S may be connected to the control shaft of a variable condenser or other tuning device in any convenient manner, or may itself be an extension of such control shaft.

Two cords, Cl and C2 are used for each positionable element, as shown in Figs. 1 to 4 inclusi've. One end of each of these cords is secured to a lug 3 sheared from and formed on the associated plunger P. These cords may be placed through a hole in this lug and the sides of the hole then pressed together. The other end of each of these cords is similarly secured to OPP site sides of the cam or positionable element E,

either direction from a central position without the cords in-any way interfering with such rotation. If the cam should be in the extreme position shown in Fig. 2 whenthe corresponding button (Bl, Fig. 4) is pressed, cord Ci becomes taut,

positionable element that connects this initial point of engagement with the corresponding point on the opposite side of the element is therefore not useful as a cam, but the element is flared out here to avoid any projections that might catch on the slack cord.

Shaft S is provided with a keyway ID, as indicated in the various figures. This shaft has a reduced end l2, Fig. -4, and the keyway extends from the shoulder at which the reduction commences to a point ii near the opposite end of the shaft. There are two holes in this shaft, near the ends, to receive the pins II and I4.

In assembling the device, pin I3 is first driven in the shaft. Member G is then placed on the shaft, and member K slipped on from the reduced and so that the inwardly extending tang I5, Fig. 12, fits into the keyway ll. Washer I8 is next placed on the shaft, then spring washer ll, washer IS, the spacing sleeve i9, positionable element E, sleeve 20, the keyed washer 2 la, sleeve 22, element E, sleeve 23, keyed washer 2ib, sleeve 24, element E, sleeve 25, keyed washer 2ic, sleeve 26, another element E, sleeve 21, and collar 2!, which has a hole to accommodate pin I4. This pin is then inserted through both the collar and the shaft, which, as already explained, is provided with a hole for the purpose. When the shaft is mounted in the supporting frame, longitudinal movement is prevented by collar 29, held in position by screw 30. 1

When the various parts' are first assembled, members G and K assume the positions indicated in Fig. 10, with member G held between the pin l3 and the sloping sides of member K. There I is then only enough pressure on spring Washer H to prevent the various positionable elements E from turning of their own accord. Before the The operator presses down the button that he desires to use in the future for bringing in a given station. This brings the button to the position 'in which B3 is shown in Fig. 4, and the plunger rotates element E in the manner previously described to the position illustrated in Fig. 1. While holding the button down to immobilize the positionable element, the desired station is tuned in with the regular manual knob, which is neither illustrated nor described in this specification"- as it forms "no part of this invention. Since shaft 3 is connected to the variable condenser or other as shown in Fig. 2, and rotates the cam. As this movement continues, the shoulder or contact means D, formed on the plunger, finally engages the cam, as pictured-in Fig. 3. From this point on, it is necessary that the shoulder D-move the cam faster than it is moved by the cord, for it is imperative that the cord become slack before the cam has been turned to the final position pictured the proper angular position with respect'to the The operator's shaft that this station requires. finger may then be, removed from the button, allowing the spring J to return the plunger to its normal rest position. The cam, however, is. kept from moving by the tension furnished by the spring washer il. While other buttons are pressed and held in, the associated camsare also set for the desired-stations in the manner. Just described. As the shaft is rotatedduring the setting operations, the friction between' the immob'iiized cam and the adjoining sleeves will tend to immobilize these sleeves also. If these sleeves were permitted to come in cont-act with cams that have already been set, the positioned cams would be thrown out of adjustment. This action is prevented by the keyed washers that are inserted between the cams, thus preventing any angular movement of the sleeves with respect to the shaft from being passed along any further than the nearest keyed washers, which thus serve to prevent the adjusted cams from being disturbed while the others are being adjusted. Fig. 4 shows the lugs of keyed washers Nb and Mo fitting in the keyway Ill-of shaft S, indicating the manner in which theyare prevented from turning on the shaft so that the rotation of a sleeve on one side of the washer cannot affect a sleeve on the opposite side.

After all the cams have been set for the desired stations, shaft S is turned to the right as far as possible, its rotation being limited when pin I4 strikes the stopper 3i, formed on end plate 1b This brings screw 32 in member G into axial alignment with the small auxiliary screw driver 34, which extends through holes in plate FI and the small bracket 35, formed on end plate la. This small auxiliary screw driver is normally held in an outward position with pin- 36 against the front plate by the action of spring 31. To

look the cams in their adjusted angular positions, the operator places-a screw driver in the slot in the head of the auxiliary screw driver and presses itdown against screw 32. Upon slight rotation, the flat end of the auxiliary screw driver will slip into the slotted head of screw 32. It must be remembered that'member G and screw 32 are now in the positions. indicated in Fig. 10. Inasmuch as screw 32 is threaded into member G, its rota- -tion to the right will force it further through side H, as shown in Fig. 4, the movementof member- K flattens out the spring washer and tightly clamps all the parts on shaft S against pin M. The cams are thus locked in the angular positions to which they were adjusted in the setting operations, and the shaft and all the parts on it henceforth turn as a unit until screw 32 is released for some future resetting operation. The subsequent pressing of the various buttons of course rotates the cams to the tuned-in positions, but as they are now locked on the shaft, it follows that the shaft itself is turned in each case to the proper angular position to bring in the stations for which the cams were set.

The auxiliary screw driver may be extended still further and equipped with an operating end to match the buttons on the plungers, thus making it-unnecessary to use any tool whatever for setting the device. If desired, the auxiliary screw driver may be dispensed with entirely and the bracket and front plate Fl provided with sufii-ciently large holes to permit the end of an ordinary screw driver to be inserted directly into the slot of screw 32.

Figs. 6, '7, 8 and 9 illustrate a modification that constitutes my preferred embodiment of the invention. The chief difference lies in the fact that .each positionable element requires onlv ne cord instead of two, and that the cord turns on a specially shaped eccentric, collar or hub instead of a round sleeve. This embodiment requires about additional button movement when the various parts of the tuner are of the size shown in the drawings.

In this modification, when the positionable element E is 180 degrees from the timed-in position, as shown in Fig. 6, the point where the single cordis attached is diametrically opposite from the center of ing 3 where the other end of the cord is fastened. This is true, of course, re-

gardless of the direction in which the element would consequently move amuch shorter distance during the final 90 degrees of rotation of the ele-,

ment than during the first 90 degrees or movement. With a cam of the shape shown in the drawings, the cord would thus rotate the element faster than shoulder D in this final quadrant of its movement, with the result that the cord would pull the cam away from shoulder D, and the taut cord stop the plunger with the shoulder still out of contact. A specially shaped collar or hub 39 is employed to prevent this. The collar may be cast as a hub onthe element,.cast as a single piece, or built up by using from two to four stampings. Since this collar must retain a definite angular relationship, with the positionable element, it must be anchored to the element in some suitable way. As shown in Figs. 6, '1 and 8, the sides of the eccentric camare notched to receive the' lugs 40 cut out and formed on the element. The height of this lug above the element should be slightly less than the thickness of the collar, as indicated at 43, Fig. 9; but if the collar is laminated, the lug should belong enough to make certain that the top piece is engaged. It is not. necessary that the stamped pieces be rigidly attached to the element. They may therefore be strung on 'the shaft during assembly and merely slipped between the lugs 40.

The movement of the plunger from the position shown in Fig. 6 to the position pictured in- Fig. 7, causes the-cord C to rotate the element from any position that it may occupy between those shown in these two figures to the position illustrated in Fig. '7. At substantially this latter point, the positioning means D engages the cam in position, the part of the cord that previously passed around the projection is left free, leaving sufilcient-slack in the cord to permit the contact means D: to remain in engagement with the cam surface and to come toerest on both sides of the cam without again tightening the cord. It will thus'be seen that in this modification as well as in the form first described, there-is never any strain on the cord, that it in no way affects .the accuracy of the device, and that the plunger never presses on the cord excepting when the positionable element is free to rotate.

To keepthe cord on the irregular periphery ,of its pulley, or the eccentric collar around which must as a consequence be longer than the corresponding sleeve in the other form of the device, as illustrated by the diiference in the length of sleeve 22 in Figs. 4 and 9.

Inasmuch as the plunger in this form has a slightly longer stroke, plates Fl and F2 must be approximately inch further apart.

With the exception of the differences above explained, the two forms of the invention de-.

scribed in this specification may be substantially the same. Fig. 9 therefore shows only enough of the last described embodiment to illustrate the differences that would appear in a plan view. The same device for locking the cams may of course be used, as could any other suitable means, and the method of setting is the same.

In either modification, it will be obvious that the pressing of one of the operating buttons will effect the rotation of the associated positionable I element to the tuned-in position from any angular position that it may occupy within 180 de grees on either side of the central tuned-in position. If the element is to be moved less than approximately 90 degrees, the cord does not function, and the element is rotated entirely by the action of the positioning means on the cam surface of the element; but if the element lies more than substantially 90 degrees on either side of the tuned-in position, the cord will pull the element until the positioning shoulder has engaged the cam.

To avoid the occurrence of a high point between the extreme points at which the projection D may be in contact with the cam in the tunedin position, it is advisable that either the cam or the contact projection, or both, be slightly concave.

It will be obvious to those skilled in the art, that the operating members, or manual selectors, may move in an are instead of rectilinearly, and that levers may therefore be used instead of plungers. Modifications of this sort are illustrated in Figs. 14 to 20.

Many other modifications from the embodiments described will suggest themselves to those skilled in the art, and it is obvious that numerous variations are possible without departing from the broad scope of the invention.

' I claim as my invention:

1. In a mechanism for positioning a control, a combination including: a rotatable positionable element; and instrumentalities for rotating and positioning said element; said instrumentalities comprising a member movable in a path transverse to the axis of said element, a flexible means having one end attached to said element and the other end attached to said member for rotating said element through part of its maximum angle of rotation, and contact means for engaging said I combination including: a rotatable shaft; an angularly adjustable element mounted on said shaft; and instrumentalities for rotating said shaft to anangular position predetermined by asoarw the adjustment of said element; said instrumentalities comprising a device movable in a path transverse'to said shaft, a flexible member for pulling said element through part of its maxi- .mum angle of rotation, and contact means for trol, a combination including: a rotatable shaft; V

a plurality of selectors adapted to move substantially transverse to said shaft; a plurality of adjustable elements each operatively interposed between one of said selectors and said shaft; a plurality of flexible members each connected to one of said selectors and to one of said elements for' rotating said elements; each of said selectors having means for engaging the associated element and directly applying a turning moment thereto; and means for locking said elements in adjustment. I

4. In a device for angularly positioning a control, a combination including: a rotatable element; a structure adjacent said element. adapted to act substantially as a pulley; a member movable in a path transverse to the axis of said element; flexible means connecting said member and said element for rotating said element from certain angular positions, said means adapted to pass at least part way around said structure; and abutment means on said member for directly engaging and applying a turning moment to said element; said element and said structure so shaped and proportioned that said abutment means rotates said element farther than said. flexible means during an equal length of travel of said member.

5. ma mechanism for positioning a control, a combination including: a rotatable shaft; a positionable element mounted on said shaft; and instrumentalities for rotating and positioning said element, said instrumentalities comprising a member movable in a path substantially transverse to the axis of said element, a flexible means attached to said element and said member and adapted to extend at least part way around said shaft for rotating said Kelement upon movement of said member in one direction, and contact means carried by said member for engaging and rotating said element to a definite angular position with respect to said member, said element s0 shaped that its angular rotation under action of said contact means is sumciently great to produce slack in said flexible means before said element reaches said definite angular position.

6. In a mechanism for positioning a control, a combination including: a rotatable positionable element; a structure adjacent said element and turning substantially as a unit ,with said element; instrumentalities for rotating said element, said instrumentalities comprising .a device movable in a path transverse to the axis of said element, and a flexible member attached to said device and connected to said element at a point that has a shorter radius than'the portion of the periphery of said structure that has the greatest radius, said member adapted to extend around said portion and to turn said element from certain angular positions upon movement of said device in one direction; said device comprising means for engaging said element and applying a turning moment thereto.

. 7. In a mechanism for positioning a control, a

element; a structure adjacent said element adapted to turn substantially as a unit with said element and having a recess in the periphery thereof; a device movable ina plane transverse to-the axis of said element; a flexible member connected to said device and to said element at a point within said recess and adapted to rotate said element upon movement of said device in one direction; and contact means carried by said device forvengaging said element and app ing a instrumentalities for rotating said element, said instrumentalities comprising a device movable in a plane transverse to the axis of said element and a flexible member connected to said device and to said element at a point within said recess for turning said element upon movement ofsaid device in one direction.

9. In a mechanism for positioning a control, a positionable element; and instrumentalities for positioning said element, said instrumentalities 2,365,175 combination including: a rotatable positionableshaft; a plurality of operating devices movable substantially transversely to said shaft; a flexible connection between each of said devices and one of said elements for rotating said element upon movement of said device in one direction; and

- contact means carried by said device for engaging said element and applying a turning moment thereto. I

- sitions predetermined by the adjustment of said ing the frictional pressure on said elements; said including: a movablev operating member, flexible means having a connection to said member and to said element for moving said element from certain positions upon operation of said member; and abutment means carried by said device for engaging and pushing said element.

10. Ina mechanism for.positioning a control, a rotatable shaft; a plurality of angularly adjustable elements mounted on said shaft; and instrumentalitiesfor rotating said shaft to positions predetermined by the adjustment of said elements, said instrumentalities comprising: a plurality of movable selectors; a plurality of flexible means for rotating said shaft from certain angular positions, each of said means having a connection to one of said selectors and to one of said elements; each of said selectors having a contact means-for engaging and applying a turning moment to the associated element and rotating said shaft to a position predetermined by the adjustment of the engaged element; and means common to all of said elements for locking said elements in respect to said shaft.

adjusted position with elements; spacing and friction means intermediate said positionable elements; means for varyelements, said spacing andfriction means and said pressure-varying means axially slidable on said shaft substantially as an assembly; abutments at each end of the assembly for limiting the axial movement of said assembly in both directions; said pressure-varying means comprising a member adapted to straddle said shaft and having substantially parallel sides withedges that diverge from a connecting side of said member that is substantially transverse to said parallel sides and to said edges, and a screw threaded through said connecting side and adapted upon rotation to press against said shaft and move said member transversely to said shaft substantially as a wedge to force said assembly against said abutments for applying sumcient pressure to said positionable elements to lock them in their adjusted positions with respect to said shaft.

13. In a mechanism for positioning a control, a combination including: a supporting frame; a

shaft rotatablymounted in said frame; a plurality of positionable elements angularly adjustable on said shaft; a plurality of instrumentalities for selectively rotating said shaft to positions predetermined by the adjustment of said elements; means carried by said shaft for locking said elements in their adiusted positions with respect to said shaft; said locking means'having 11. In a mechanism for positioning a control,

a combination including: a rotatable shaft; a plurality of positionable elements on said shaft; spacing and friction means intermediate the posiscrew driver disposed so that said locking means may be rotated with said shaft to bring said screw substantially into axial alignment with said screw driver.

- 14. In a device for positioning a control, a

tionable elements; means for varying the frictional pressure on said elements; said pressure-varying means axially slidable with said elements and spacing and friction means substantially as an assembly; abutments at each end of the assembly for that diverge froma connecting side of said member that is substantially transverse to said parallel sides and to said edges, and a screwthreaded through said connecting side and adapted upon rotation to press against said shaft and move said member transversely to said shaft sub- -stantiallyi'as a wedge to force said assembly against said abutments for applying sumcient pressure to said positionable elements to prevent rotation of said elements with respect to said is shaft rotatably mounted in saidframe; a plu- -rality of positionable elements angularly adjustable on said shaft; a plurality of selectors movable transversely to said shaft; a.plurality of flexible means each connecting one vof said ele- V ments to one of said selectors for rotating said element upon movement of said selector in one direction; each of saidselectors having contact means for engaging and directly applying a turning moment to said element; spacing and friction means intermediate said positionable .ele-

I ments; means on said shaft for locking said elements in their adjusted positions with respect to assembly; means at each end of said assembly for limiting the axial movement of said assembly; said pressure-varying means comprising a member adapted to straddle said shaft and having substantially parallel sides with. edges that diverge from a thirdside connecting said par-' allel sides, a screw threaded through said third side toward said shaft and adapted upon rotation to engage said shaft and to move said member transversely to said shaft substantially as a wedge to spread said assembly against said limiting. means for applying sufiicient pressure to said positionable elements to look them in adjusted position with respect to said shaft; a screw driver mounted in said frame for rotary and axial movement, said screw driver disposed so that said member may be rotated with said shaft to bring said screw into axial alignment with said screw driver. V

15. A combination including: a shaft, a plurality of angularly adjustable elements on said shaft; spacingand friction means intermediate said elements; means on said shaft for locking said elements in their adjusted positions; said elements, said spacing and friction means and said locking means axially slidable on said shaft substantially as an assembly; means at each end of said assembly for limiting the axial movement of said assembly; said locking means comprising a first member having substantially parallel sides with edges that diverge from a third side connecting said parallel sides, and a second member adjacent said first member and having sides formed at an angle to fit against the diverging edges of the parallel sides of said first member; an operating screw threaded through the third side of said first member disposed to engage said shaft and adapted upon rotation to move said first member so that said diverging edges move against the sloping sides of said second member substantially as a wedge to spread said assembly against said limiting means for applying suiflcient pressure to said adjustable said shaft.

16. In a mechanism for positioning a control ofZ a radio device: a rotatable positionable element; and instrumentalities for rotating and positioning said element, said instrumentalities comprising a, rectilinearly movable operating element disposed transverse to the axis of rotation of said element and movable across said axis on one side of said axis only, said instrumentalities alsocomprising flexible means operatively interposed between said member .and said element for applying a turning moment to said element in either rotative direction to rotate said element through at least part of its maximum angle of rotation upon movement of said member from a position in which said flexible means is slack.

17. In a radio tuning mechanism, a combination including: a rotatable positionable element; and instrumentalities for rotating said element;

said instrumentalities comprising a rotatable operating structure movable in a path transverse to the axis of said element and manually operable from a portion of said structure lying on one side of its rotational axis, and a flexible means operatively connecting said element to a part of said structure disposed on an opposite side of its rotational axis.

18. In a radio tuning mechanism, a combination including: a rotatable control" element; and

. between said portion and said part.

- LEROY J. LEISHMAN.

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