US2933927A

US2933927A - Slide tuner

Info

Publication number: US2933927A
Application number: US760325A
Authority: US
Inventors: Jr Charles E Lyon
Original assignee: Motorola Inc
Current assignee: Motorola Solutions Inc
Priority date: 1958-09-11
Filing date: 1958-09-11
Publication date: 1960-04-26
Anticipated expiration: 1977-04-26

Description

April 26, 1960 c. E. LYON, JR

SLIDE TUNER 2 Sheets-Sheet 1 Filed Sept. 11, 1958 ill] II/ Ill 40 Jill/l A fizz/2712407:

April 26, 1960 c. E. LYON,.JR 2,933,927

SLIDE TUNER Filed Sept. 11, 1958 2 Sheets-Sheet 2 are quite complex and relatively costly.

positively and which requires "lateral movement to a locks the same by movement of the actuating portion of when the worm screw is SLIDE TUNER "CharlesjE. Lyon, Jr., Motorola, Inc., Illinois Application September 11, .1958, Serial No. 760,325

lo Claims. (CL 74-1037) Des Plaines, Ill., assignor to Chicago, Ill., a corporation of This invention relates generally to tuning apparatus for radio receivers,-and more particularly to a'tuner'for automobile radioreceivers having a pushbutton operating mechanism which maybe readilypreset to select predetermined frequencies within a frequency range, and having a continuous operating mechanism for manual tuning throughout-the frequency range.

United States v Patent;

Tunershaving pushbuttons for automatic tuning are commonly provided with a mechanism which may be adjusted to set up the predetermined frequencies for auto matic selection. Known tuners of this type are somewhat bulky and, therefore, are not ideally suited for use radios which must be small because of Some known conso that the average automatic stations conveniently. Constructions which may be set up easily Accordingly, it is an object of this invention to pro- -vide a tunerforautomobile radio receivers which is substantially reduced in size and which may be mass produced at low cost.

Another object of the invention is to provide a pushbutton tuner with a simple adjustment mechanism for setting up automatic stations which operates easily and few component parts.

A feature of the invention is the provision of a small and compact tuner for a radio receiver including a plurality of movable key slides having adjustable pins which are located in predetermined control positions with respect to V-shaped cam surfaces on a core carriage, and which are 'engageable with these cam surfaces upon movement of the respective key slides to move the core .carriage to-predetermined tuning positions.

Another feature of the invention is the provision of key 'slideshaving laterally movable pins for cooperation with the V-shaped cams as described above, and a quick- .release locking construction which frees the pins for new control position and then theslide.

A further feature of the invention is the 'provisionof a tuner as described above including a compact con- "tinuous tuning mechanism having a worm screw and a "meshing-worm gear connected core carriage, so that the worm gear rotates and walks by a friction clutch to the along the worm screw when the carriage is moved by the key slides but remains rotationally fixed and follows the threads of the worm screw to move the core carriage rotated by a manual tuning shaft.

The invention is illustrated in the accompanying drawings in which: 7

Fig. '1 is a top view in longitudinal section of a tuner .in accordance with the invention;

I Jfig. '2 isa front view vof the tuner of Fig. .1 with the .key slide in the unlocked carriage during continuous operation. slides are operated, the friction clutch slips and permits .the Worm gear to rotate and walk along the worm screw "locking lever which guided in slots 17 provided 2,933,927 Patented Apr. 26,1960

front plate broken away to reveal the internal mechanism;

Fig. 3 is an end view in transverse section of the tuner of Fig. 1;

Fig. 4 is a detail view of one of the key slides of the tumor of Figs. 1--3; and

Fig. 5 is a detail view similar to Fig. 4 showing'the condition.

In' practicing the invention there is provided a tuner having an automatic control mechanism including a longitudinally movable core carriage having a pluralitytof V-shaped cam surfaces and a plurality of key slides mov- :ablev laterally with respect'to the carriageand eachhavmg an adjustable pin which is-engageable with 'one of the cam surfaces to move the carriage to a predetermined tuning position. Acontinuous control mechanism :15 provided including a worm screw and a meshing worm gear which is held rotationally fixed by a friction clutch and follows the threads of the worm screw to-move the When the key as the core carriage moves, so that it is not necessary to provide parts to uncouple the continuouscontrol during automatic operation. The continuous control mechanism is very compact and cooperates with the automatic control mechanism in a manner which permits a substantial reduction in the size of the tuner. In normal operation the adjustable pins of the key slides are held in place by a quick-release lock mechanism including a is forced against the pin by an actuating portion of the key slide.

frees the pin for lateral movement on the slide. When the key slide is then depressed, the movable pin engages the V-cam and follows its sloping cam surface to the base of the V. Further pressure on the key slide moves and an end portion 49 which supports four cores 51 in alignment with four tuning coils 52 contained in a coil housing 53. Part of the housing 53 is broken away in Fig. 1 to give a better viewof the core carriage 40. 'The tuning coils 52 are connected to terminals 54 mounted on the housing 53, and the terminals 54 may be wired into the tuning circuits of a radio receiver. The cores 51 arermoved'in and out of the coils 52 upon longitudinal movement of the core carriage 40, and the position of the cores with respect to the coils determines the 'frequency of the radio signals picked up and reproduced by the associated receiver.

The core carriage 40 may be moved to presettuning positions toselect radio signals of predetermined frequencies by operation of an automatic control mechanism including a plurality of key slides 2126'which are disposed in two rows on the frame 11 and which are actuated to engage the V-cams 41-46 by depressing the pushbuttons 29. The key slides each include a slide portion 27, and a key portion 28 which is normally locked in a fixed position with respect to the slide. The edges of the slide members 27 fit into notches 56 provided in When the actuating portion is pulled out, the locking lever is released, and this 59 which engage the front plate 12 to define the initial position of the key slides. Coil springs 61 (Fig. 3) may be attached to the front plate 12 and to the bent-over ear 62'on the slide member 27 to return the key slides to their initial position when they are released.

The key slides 2126 are respectively provided with pins 31-36 which are engageable with V-shaped cam surfaces 4-1-46 formed in the channel portions 47 of the core carriage 40. The pins 31-36 are normally locked in place on the key slides by a locking mechanism which will be explained later, but it may be noted at this point that thepins are movable along the slots 37 laterally with respect to the key slides to different control positions. The spacing between the centers of the slots 37 is the same as the spacing between the bases 50 ofthe V-cams 41-46, so the condition where the centers of slots 37 and the bases 50 are aligned as illustrated is a convenient reference position. The amount the pins are offset from the centers of their guide slots 37 controls the displacement of the carriage 40 from this reference position when any one of the key slides is actuated.

The automatic operation may be understood most clearly from a consideration of Fig. 1. The key slide 21 is shown in the fully depressed position with the pin 31 engaging both sides of the V-cam 41 adjacent the base 50. It may be noted that the base 50 is slightly narrower than the diameter of pin 31 to ensure that the pinchgages both sides of the cam surface in the fully depressed position, and this positively locates the core carriage. The position of the cores 51 with respect to the coils 52 controls the inductance value of the tuning circuits of the associated radio receiver and, there- .fore selects a radio signal of a particular frequency. If

it is desired to tune in a signal of another frequency, the key slide 23, for example, may be pushed in. When the pin 33 engages the cam surface 43, the carriage 40 will be moved to the right and the pin 33 will follow the right side of surface 43 as the slide is depressed further until the pin reaches the base 50. The sides of the cam surfaces are slightly curved so that as the pin moves along the 'side, the direction of the resultant force acting on the carriage varies. The curvature is convex so that as the lateral distance between the pin 33 and the base 50 decreases, less actuating force is required to move the carriage. This controls the touch or feel of the pushbuttons and helps to make the keyslides operate smoothly. The cores 51 move into the coils 52 changing the inductance value in the tuning circuits of the receiver and selecting a new station. The core carriage 40 is held in the selected position by the resistance of the gear train associated with the continuous control mechanism 19 which will be explained later. A dial mechanism 13 including a pointer 63 on a pivotal arm 64rnoves across the face of a dial panel 65 to give a visual indication of the station which has been selected. The arm 64 is connected to a support bracket 66 by a pin'67 which is slidable in a slot 68, and its movement .is controlled by a link 69 pivotally connected to arm 64 at one end and pivotally connected to the support 66 at the other end.

In order to change the station or radio signal which is set up-for selection by any one of the key slides, the pin of the key slide may be moved to a new control position. This operation may be understood by considering Figs. 1, 4 and together. The key slide 23 is shown in detail in Figs. 4 and 5 to illustrate the locking construction which holds the pin 33 in place and which may bequickly released to free the pin for adjustment. It may be seen that both the slide member 27 and the key 28 are plates and that the pin 33 has an enlarged base portion 38 between the plates which is held tightly against the slide 27 adjacent the slot 37 by a locking lever 71. The lever '71 is supported at both "ends in openings which are cut out of the bent-over -leg anama?

c portions

81 and 82 of the slide 27. The opening in leg 82 is large enough to permit pivotal movement of the lever. The lever 71 has a bump 72 which engages another hump 73 in the plate 28 when the key slide is in the locked condition, and the

hump portions

72 and 73 apply resilient pressure to the lever 71 so that raised surface 74 is forced firmly against the pin 33 to hold it in place. They key 28 is movable with respect to the slide 27 between the locked position shown in Fig. 4 where the tongue 75 abuts one end of the opening 76, and an unlocked position shown in Fig. 5 where the bent end 78 of key 28 engages leg 82. To unlock the pin 33 the key 28 is pulled out, and the hump 73 in the key 28 slides out from underneath the hump 72 in the locking lever 71. This permits the lever 71 to move away from the pin 33 under pressure applied by the leaf spring 83. The station which is to be set up for selection by the key slide 23 is tuned in by operating thecontinuous control 19. The key slide 23 is then pushed in, and the pin 33 engages cam surface 43 and is moved along slot 37 as it follows surface 43 to the base 50 of the V-cam. The pin 33 is now positioned to provide automatic selection of the desired station and may be locked in place. This is accomplished by pushing harder on the button 29 so that the key 28 moves with respect to slide 27 to engage the

bumps

72 and 73 and force lever 71 against .the pin 33; It may be noted that during the first portion of the movement of the key slide, the

members

27 and 28 move together and not relatively because of the resistance between the

humps

72 and 73 and also because of the resistance between the hump 77 and the leg 81. .When the key slide 23 is in the fully depressed position, increased force must be applied to overcome these resistances and move the key 28 to the right relative to the slide 27 as illustrated.

The continuous control mechanism, designated generally as 19, will be explained with reference to Figs. .1'-

Rotation of the knob 84 turns the shaft 85 and rotates the crown gear 86 on the end of the shaft. A pinion gear 87 meshes with the crown gear 86 and this rotates the worm screw 91. A worm gear 92 meshes with the worm screw 91 and is afiixed to a shaft 93 which also has a disc 94 of ferro-magnetic material affixed thereto. The shaft 93 is rotatably supported by a support arm-97 which has a permanent magnet 96 attachedthere- .to.-- A friction washer 95 is secured to the magnet and frictionally engagesthe disc 94. The assembly including disc 94, shaft'93'and gear 92 will rotate only when the force applied to gear 92 is not sufficient to overcome the resistance of the movable parts connected thereto but is sufficient to overcome the frictional resistance of the washer 95 so that disc 94 slips. The magnitude of this frictional resistance is determined by the coeflicient of friction be- ,tween disc 94 and washer 95 and the pull exerted by the magnet 96 on disc 94. When the worm screw 91 is turned during continuous tuning, the worm gear 92 does not rotate because the resistance of the carriage to movement is very slight, so the teeth of gear 92 follow the threads of worm screw 91 and the core carriage moves. When one of the pushbuttons 29 is depressed, the force exerted through the worm gear 92 on the worm screw 91 is not sufficient to turn it, but is suificient to overcome the frictional force holding gear 93. Therefore, disc 94 slips .and gear 93 rotates and walks along the threads -of worm screw 91. The support arm- 97 is pivotally connected to a bracket 98 which is attached to the core carriage 40, and a spring 99 biases the arm 97 to keep the teeth ofgear 92 in full engagement with the threads of screw 91 so that there is no slippage and the corecarriage does not drift under vibration. It is apparent from the foregoing description that the tuner of the invention is very compact and is easily operated. The efficient arrangement of gears and clutch parts in the continuous tuning control mechanism combined with the compact arrangement of the V-can'1sand key slides provides a tuner of considerably reduced size :as

,port, circuit means controlled by said carriage for selecting radio signals of predetermined frequencies within a frequency range upon movement of said carriage to predetermined tuning positions, said carriage havingja plurality of V-shaped cam surfaces, a plurality of key slides movable linearly on said support perpendicular to the movement of said carriage, means limiting-the movement of said key slides to a predetermined range of movement, said key slides each having a cam member thereon engageable with a corresponding one of said V-shaped cam surfaces to move said carriage to one of the predetermined tuning positions thereof, means on said key slides to permit lateral movement of said cam members with respect to the associated key slides to different tuning control positions, and locking means carried on each of said key slides and engageablewith said cam .members to lock the same in selected control positions, said key slides each having an actuating member movable with said key slide and relatively movable with respect to said key slide in a direction perpendicular to ,said carriage to release and re-engage said locking means.

'2. A tuner for a radio receiver including in combination, a support, an elongated carriage movable longitu- Ldinally on's'aid support and including spaced parallel plates,

circuit means controlled by said carriage for selecting radio signals of predetermined frequencies within afrequency range upon movement of said carriage to.

predetermined tuning positions, a plurality of generally V-shaped cam surfaces on said plates of said carriage,

each-of said cam surfaces having predetermined curvature, a plurality of key slides disposed in parallel rows on said support and movable linearly in a direction perpendicular to the movement of said carriage, said key slides each having a laterally adjustable cam member thereon engageable with a corresponding one of said V- shaped cam surfaces to move said carriage to one of the predetermined tuning positions thereof, with the curvature of said cam surfaces controlling the pressure required to depress said key slides and move said carriage.

3. A tuner for a radio receiver including in combination, a support, a carriage movable linearly on said support, circuit means controlled by said carriage for selecting radio signals of predetermined frequencies within a frequency range upon movement of said carriage to predetermined tuning positions, a plurality of V-shaped,

cams on said carriage, a plurality of key slides movable linearly on said support in a direction perpendicular to the movement of said carriage, said key slides each having a laterally adjustable cam member thereon engageable with a corresponding one of said V-shaped cams to move said carriage to one of the predetermined tuning positions thereof, said V-shaped cams having sides of predetermined curvature for controlling the effective force transmitted to said carriage according to the lateral position of said cam members with respect to said V-shaped cams upon engagement therewith.

4. A tuner for a radio receiver including in combination, a support, a carriage movable linearly on said support, circuit means controlled by said carriage for selecting radio signals of predetermined frequencies within a frequency range upon movement of said carriage to predetermined tuning positions, a plurality of V-shaped cam surfaces on said carriage, a plurality of key slides movable linearly on said support in a direction perpendicular to the movement of said carriage, said key slides each f -i,ngv an actuating portionand an adjustablecammem- 'berengageable with one of said V-shaped cam surfaces positions having a predetermined relation to the V-shaped cam surface associated therewith for controlling the tun- .ing positions to which said carriage is moved upon actuation of said key slides, said key slides each having quickrele'aselock means engaging and holding said adjustable cam members in selected control positions, ,said vlock means being released upon predetermined movement of said actuating portion away from said carriage and reengaged upon predetermined movement of ,said

actuating portion toward said carriage.

,5. A tuner for a radio receiver including in combination, a support, a carriage movable linearly on said support, circuit meanscontrolled by said carriage for selecting radio signals of predetermined frequencies within a .fre uency range upon movement of said carriage to redetermined tuning'positions, a plurality of V-shaped cam surfaces on said carriage each having sides of predetermined curvature, a plurality of key slides movable linearly on said support perpendicular to the movement of said carriage, said key slides each having an actuating portion and an adjustable vpin engageable with one 'of said cam surfaces to move said carriage to one ofthe predetermined tuning positions thereof, said adjustable pins each being movable laterally on said key slides to various control positions having a predetermined relation to the cam surface associated therewith for controlling the tuning positions to which said carriage is moved upon actuation of said key slides, said key slides each having quick-release lock means for engaging and holding said adjustable pins in selectedcontrol positions, said lock means being held against said pin by said actuating portion, and said lock means releasing said pin upon predetermined movement of said actuating portion away from said carriage and re-engaging said pin upon predetermined movement of said actuating portion toward said carriage.

6. A tuner for use with a radio receiver to select radio signals of predetermined frequencies within a frequency range, including in combination, a support, a carriage movable linearly on said support through arange of movement, circuit means controlled by said carriage according to the movement thereof for controlling the tuning of the radio receiver, a plurality of V-shaped cam surfaces on said carriage, a plurality of key slides movable linearly on said support perpendicular to the movement of said carriage, said key slides each having an adjust'able member thereon engageable with one of said V-shaped cam surfaces to move said carriage to a predetermined tuning position, said adjustable members each being laterally movable with respect to saidkey slides, quick-release lock means for holding each ofisaid adjustable members in a selected position and for releasing the same for adjustment, each of said adjustable members when in the released condition being moved laterally by the associated V-shaped cam surface upon engagement therewith and riding said cam surface to a control posi tion aligned with the base thereof upon depressing the associated key slide, said lock means being operable upon further depression of said key slide to hold said adjustable member in said control position for setting a corresponding tuning position for said carriage.

7. A tuner for a radio receiver including in combination, a support, a carriage movable linearly on said support, circuit means controlled by said carriage for selecting radio signals of predetermined frequencies within a frequency range upon movement of said carriage to predetermined tuning positions, a plurality of V-shaped cam surfaces on said carriage, a plurality of key slides movable linearly on said support perpendicular to the move-' ment of said carriage, said key slides each having a laterincluding a lever supported on each of said key engageable with the pin thereof, each of said key slides tally movable pin thereon engageable with one of said cam surfaces to move said carriage to one of the predetermined tuning positions thereof, quick-release lock means for holding each of said pins in a selected position and v which said carriage is moved upon actuation of said key "slides.

8. A tuner for a radio receiver including in combination, a support, a carriage movable linearly on said support, circuit means controlled by said carriage for selecting radio signals of predetermined frequencies within a frequency range upon movement of said carriage'to predetermined tuning positions, a plurality of V-shaped cam surfaces on said carriage, a plurality of key slides movable linearly on said support perpendicular to the movement of said carriage, said key slides each having an adjustable pin thereon engageable with one of said cam surfaces to move said carriage to one of the predetermined tuning positions thereof, said key slides including a slidable plate having an elongated slot therein receiv- -ing and guiding said pin,

a lock plate movable between first and second positions with respect to said slide plate and having an actuating portion thereon, and a lever supported on said slide plate and engageable with said pin to hold the same against said slide plate,

said lock plate including a resilient portion engaging and applying resilient pressure to said lever in said first position for locking said pin and releasing said lever in said second position for permitting movement of said lever to release said pin, said adjustable pins when in the released condition being movable in said slots to various control positions having a predetermined relation to the V-shaped cam surface associated therewith for controlling the tuning positions to which said carriage is moved upon actuation of said key slides.

9. A tuner for use with a radio receiver including in combination, a support, a carriage movable linearly on said support through a range of movement, circuit means controlled by the movement of said carriage for selecting radio signals within a range of frequencies, a plurality of V-shaped cam surfaces on said carriage, a plurality of movable members each having a portion engageable with one of said V-shaped cam surfaces upon movement of said movable member for moving said carriageto' predetermined tuning positions, continuous control means coupled to said carriage for moving the same through the range of movement thereof, said continuous control means including a worm screw and a meshing worm gear,

friction clutch means coupling said worm gear to said carriage, and driving means for rotating said worm screw, said clutch means including a magnet, and a magnetic member coupled to said worm gear, with friction material between said magnet and said magnetic member frictionally holding said magnetic member and said worm gear so that the meshing teeth thereof follow the threads of said worm screw for moving said carriage upon actuation of said driving means, and said carriage moving in response to actuation of said movable members and applying force to said magnetic member causing the same to slip so that said worm gear rotates and walks along said worm screw absorbing said force without transmitting the same.

10. A tuner for use with a radio receiver including in combination, a support, a carriage movable linearly on said support through a range of movement, circuit means controlled by the movement of said carriage for selecting radio signals within a range of frequencies, a plurality of movable members each engageable with one of said V-shaped cam surfaces for moving said carriage to predetermined tuning positions, continuous control means coupled to said carriage for moving the same through the range of movement thereof, said continuous control means including a worm screw, a worm gear meshing with said worm screw and having a rotary shaft afi'ixed thereto, friction clutch means coupling said worm gear to said carriage, said clutch means including a support arm pivotally connected to said carriage and supporting said shaft, a magnetic disc affixed to said shaft, a permanent magnet afiixed to said support arm and attracting said magnetic disc, and friction material interposed between said disc and said magnet and engaging said disc for resisting rotation of said shaft and said gear, means biasing said pivotal support arm for maintaining said worm gear in full tooth engagement with said worm screw, and driving means for rotating said worm screw, said magnetic disc being held by said friction material and said magnet to prevent rotation of said worm gear upon actuation of said driving means so that the teeth of said worm gear follow the threads of said worm screw and apply force through said shaft to move said carriage, and said carriage moving in response to actuation of said movable members and applying force to said shaft thereby causing said magnetic disc to rotate and slip on said friction material so that said Worm gear rotates and walks along said worm screw absorbing said force without transmitting the same.

References Cited in the file of this patent UNITED STATES PATENTS