US3192781A - Tuning apparatus - Google Patents

Description

July 6,

Filed June 19. 1963 at. LYON, JR

TUNING APPARATUS I 2 Sheets-Sheet 2 United States Patent Ofifice Patented July 6, 1965 This invention relates to pushbutton actuated tuning apparatus for radio receivers, and more particularly to an adjustable actuator assembly which may be preset to permit repeated selection of a given station.

The present invention is particularly designed for use in connection with radio tuners wherein a cam member supported on an actuator assembly may engage a treadle bar structure to rotate a carriage coupled to the tuning elements associated with resonant circuits. In such mechanisms it is common for the cam member to be fixed at a certain angle with respect to its supporting actuator assembly so that, as the assembly is moved with respect to the parallel members, the cam may bring the members into alignment with the surface thereof. This sets the carriage and the resonant circuits to the proper adjustment for reception of the desired station. It is important that the cam be firmly locked with respect to its supporting actuator assembly so that exact tuning may be obtained upon repeated operation of the actuator assembly. However, there should be incorporated in the assembly provision for unlocking the cam to permit changing its setting so that the receiver may be tuned to any desired frequency by operation of a pushbutton.

Under certain circumstances, the depth of the tuning mechanism, and hence the depth of the entire radio receiver, may be substantially reduced by constructing the apparatus such that the pushbuttons and their respective actuator assemblies move in an arcuate path rather than a linear path.

An object of this invention is to provide an improved presettable actuator assembly which furnishes smooth and positive automatic release and locking of the cam by an arcuate movement.

Another object is to provide a presettable actuator assembly for pushbutton tuning requiring but few component parts and in which the movement of the pushbutton is arcuate and wherein a substantial mechanical advantage is provided for securely locking the cam.

A feature of the invention is the provision, in a treadle bar tuning apparatus, of a pivotal member having a pair of levers thereon, one of which is operable to clamp a pivotal positioning cam against the member and the other of which is operable to both pivot the member and operate the first lever.

Another feature of the invention is the provision, in treadle bar tuning apparatus, of an elongated pivotal member having a pivotal positioning cam thereon and a clamping bar for the positioning cam pivotally supported in an aperture in the member adjacent the cam. An actuator bar, operable by a pushbutton, is pivotal on the member and has a cam thereon between its pivot and the pushbutton for operating the clamping bar as a lever.

In the drawings:

FIG. 1 is a perspective view of a portion of the dash board of an automobile having a radio receiver incorporating the invention mounted therein;

FIG. 2 is a side elevation of a portion of a tuner mechanism constructed in accordance with the invention;

FIG. 3 is a sectional View taken along the line 3-3 of FIG. 2;

FIG. 4 is a side elevational view similar to FIG. 2 showing variations in the positioning of the mechanism; and

FIG. 5 is an exploded view of an actuator assembly constructed in accordance with the invention.

In practicing the invention, a pushbutton tuning apparatus is provided which includes an elongated member mounted for arcuate movement with respect to the frame of the tuning apparatus for operating a treadle bar mechanism therein. The elongated member carries a treadle bar positioning cam rotatably mounted thereon and is ivotal to cause the cam to engage the treadle bar for positioning the same. A clamping bar is pivotally supported on the elongated member adjacent the cam and has a portion thereon engageable with the cam to clamp the same against the elongated member. An actuating member is pivotally mounted on the elongated member and has an extension thereon for pushbutton actuation. The actuating member carries a projection which is engageable with the clamping bar at a point which provides a mechanical advantage for the clamping bar to clamp the positioning cam against the elongated member. Accordingly, movement of the actuating member relative to the elongated member serves to lock and unlock the positioning cam. In normal operation of the tuning mechanism, the actuating member may be moved to pivot the elongated member for engaging the positioning cam with the treadle bars.

Referring now to FIG. 1, a radio receiver 13 is shown mounted in the dash board 11 of an automobile. Receiver 3 drives a speaker 15, also mounted in the dash board behind grill 17. A volume control 19 and a con tinuous rotary tuning control 21 extend through the dash board 11. Indicator dial 23 is visible through an opening in the dash board 11. A plurality of pushbuttons 25 are also provided for permitting repeated selection of given stations as is well known in the art. Pushbuttons 25 are mounted for arcuate movement, as will be explained.

Referring now to FIGS. 2 through 5, the operation of the tuning apparatus is more clearly seen. There is provided a tuner frame structure 27 which supports a plurality of inductive tuning elements 29 which are associated with resonant circuits in the receiver, as is well known in the art. Elements 2? are tuned by a plurality of movable cores or slugs 33, which are attached to a movable carriage frame 33 by threaded screws 3:5 and mounting bushings 37. Carriage frame 33 is attached to a treadle bar assembly 39 by means of a link member ll. Treadle bar assembly 3? includes a pair of rotatable arms 43 and 45 which are pivoted at 47 and on tuner shaft 4%, respectively, on frame 27. A pair of parallel rods 51 and 53 connect arms 43 and 45 on opposite sides of pivot point 47 and 49. It may be seen that the angle of the plane of the treadle bars formed by rods 51 and 53 will determine the position or" carriage 33, and hence of cores 31 Accordingly, the tuning of the receiver may be varied according to the angular position of the plane of rods 51 and 53.

Continuous tuning may be accomplished by operating the carriage frame 33 and slugs 31 through a gear train (not shown) linking control 21 with tuner shaft 49, as is well known in the art. A cross bar 55 extends across the tuner frame 27. A plurality of actuator assemblies containing presettable cams for positioning rods 51 and 53 are pivotally mounted on cross bar 55. These actuator asemblies are moved by arcuate displacement or pushbuttons 25, and the cams which they carry may be preset to permit repeated selection of a given station as will be subsequently explained. Each of the actuator assemblies includes an elongated member 57 pivotally mounted on cross bar 55. The opposite end of member 57 contains a projection 59 thereon which mates in a guide slot 6% of frame 27 of the tuner o stabilize the assembly. A torsion spring er maintains a bias on member 57. Elongated member 57 has a portion thereon upon which is mounted a rotatable cam 5. Cam 65has a oair of cam surfaces 67 69 thereon which are engageable respec tively with rods 53. and 53 of the treadle assembly to position the same, according to the position of the rotatable cam 65.

Elongated member 57 further cont a right angle 7i thereon which has an aperture 73 formed therein. A clamping bar or ver 75 has a notched key portion 7'? which extends in aperture 73 to pivotaliy mount the clamping bar 75 on elongated member 57. Clamping bar '75 has a clamping portion 7% which is engageable with cam 65 when clamping bar '75 is moved toward elongated member 57 to clamp cam secur ly against member 57. Pin 8 on member 57 prevents the clamping bar '75 from twist g v ten the cam is cl mped. The me chanical advantage provided by clamping bar 75 sufiicient force to prevent cam 65 from rotating, and the cam is therefore able to position the treadle bars properly.

An actuator member 81 is pivotally mounted through a mounting fiange 33 to a corresponding mounting flange 85 on elongated member 57. Actuator member 81 further includes an extension 3'7 which is adapted to receive one of pushbuttons 2-5 thereon. Actuator member oil is also provided with a driving shoulder 5? which is engageable with the edge of elongated member 5? for pivoting the same about cross bar to engage cam with the rods of the treadle bar assembly. A slanting projection 91 is provided on the inner surface of actuator member 81 between its pivot and extension S7 to be engageable with the tapered end 93 of clamping bar '75. When pro- ,iection 9ft engages tapered end fiS, the mechanical advantage of actuator member 81, with respect to projection 9i, is supplemented by the mechanical advantage of clamping bar to clamp cam 65 securely against elongated member 57. A fiat spring 95 has end received in opening 97 in elongated member 5"], and further has an opening 93 therein which mates with a pin 99 on clamping bar 75. Spring 95 serves to bias clamping bar '75 against actuator member 31. Extensions E61 and 183 of actuator member 81 provide holding force to permit locking of the arm against elongated member 57.

The various positions of the mechanism may be seen clearly from FEGS. 2 and 4. PEG. 2 shows the mechanism in its normal rest position. Downward pressure on a pushbutton 25 will move extension 8'7 arcuately and pivot the entire assembly on cross bar 55 to cause cam 65 to align the trcadle bar assembly as shown in solid lines in PEG. 4. When the pushbutton is released, spring 61 returns the actuator assembly to normal position. The cam 65 may be unlocked by raising the pushbutton to the position shown in phantom in FIG. 4. When this is done actuating member 81 will pivot with respect to support member 57 to disengage projection 91 from clamping bar 75. This releases pressure on cam s5 enabling it to be freely rotatable on member 57. When rods 53 and 51 have been properly positioned by manually tuning through knob 21 to the desired frequency, the cam may be locked in place by pressing the pushbutton 25 down sui'liciently to cause the com to align itself with the rods. This presets the cam and provides bearing pressure whereby actuator member 31 will pivot with respect to elongated member 57 to cause projection 91 to force end E5 of clamping bar '75 away from actuator member 31 and toward member 57, placing locking pressure on cam 65, as previously explained.

It may therefore be seen that the invention provides an improved presettable actuator assembly for treadle bar tuning apparatus wherein the assembly is actuated by arcuate movement of a pushbutton, and wherein positive sure locking of the positioning cam may be accomplished with a minimum of manual force.

I claim: 5.. A presettable actuator appar us having a treadle b assembly for use in tuning ar mechanism, said assembly includi g in cor nation, a i otal elongated member having an aperture therein, a cam rotatably mounted on said elongated member adjacent said aperture for engaging the trcadle bar r to operate the same, said cam and said elongated member being pivotal in parallel planes, a clamp ng lever having first and second ends and being pivo ly support d at said first end in said aperture and having a first portion between said first and second ends engage ble with said cam to clamp the same against sai elongated member, said clamping lever being pivotal in a plane transverse to said parallel planes, an actuator member pivotally mounted on said elongated member and having an e ension th reon for pushbutton actuation and further hav 3 a projection thereon, said actuator member being pi otal in a. plane parallel with said parallel planes, sa d clamping lever further having a second portion at S d second end engageable with said projection and providing a mechanical advantage for said clamping lever to clamp said cam when engaged, said actuator member being operable to pivot said elongated member to operate the trendle bar mechanism, and being further operabie to pivot with res to said elongated member to cause said clamping lever to clamp said cam.

2. A press-Lt? ttor assembly for use in tuning apparatus having a treache bar mechanism, said assembly including in combination, a pivotal elongated fiat member having first second sides, said elongated member further having a right angle flange portion proximate one end thereof and extending outwardly from said first side, said right angle portion having an aperture therein, a cam rotatably mounted on said first side of said elongated member adjacent said right angle flange portion for ging the trends bar mechanism to operate the same, s: d cam and said elongated member being pivotal in parallel planes, a clamping lever having first and second ends and being pivotaliy supported at said first end in said aperture, said clamping lever extending substantially parallel with said elongated member along said first side thereof and having a first portion between said first and second ends ageable with said cam to clamp the same aga'nst said elongated member, said clamping lever being pivotal in a plane transverse to said parallel planes, an actuator member pivotaliy mounted on said elongated member proximate the end thereof opposite to said one end, said actuator member having an extension thereonfor pushbutton actuation and further having a raised cam projection proximate the pointwhere said actuator membe: is pivotally mounted to said elongated member, said actuator member being pivotal in a plane parallel with said parallel planes, :1 spring proximate said second end of said clamping lever and between said clamping lever and said elongated member and biasing the same apart, said clamping lever further having a second portion at said second end engageable with said cam projection and being displaced against the bias of said spring to clamp said cam when engaged by said cam projection, said actuator member being operable to pivot said elongated 1116.1 her to operate the treadle bar mechanism and being further operable to pivot with respect to said elongated member to cause said clamping lever to clamp said cam.

References (Jited by the Examiner UNITED ST TBS PATENTS 2,266,709 12/41 Plensler 74 10.33 ,3Gl,l4l 11/42 Plensler 74-l0.33

BROUGHlTGi. G. DURHAM, Primary Examiner.

Claims (1)

1. A PRESETTABLE ACTUATOR ASSEMBLY FOR USE IN TUNING APPARATUS HAVING A TREADLE BAR MECHANISM, SAID ASSEMBLY INCLUDING IN COMBINATION, A PIVOTAL ELONGATED MEMBER HAVING AN APERTURE THEREIN, A CAM ROTATABLY MOUNTED ON SAID ELONGATED MEMBER ADJACENT SAID APERTURE FOR ENGAGING THE TREADLE BAR MECHANISM TO OPERATE THE SAME, SAID CAM AND SAID ELONGATED MEMBER BEING PIVOTAL IN PARALLEL PLANES, A CLAMPING LEVER HAVING FIRST AND SECOND ENDS AND BEING PIVOTALLY SUPPORTED AT SAID FIRST END IN SAID APERTURE AND HAVING A FIRST PORTION BETWEEN SID FIRST AND SECOND ENDS ENGAGEABLE WITH SAID CAM TO CLAMP THE SAME AGAINST SAID ELONGATED MEMBER, SAID CLAMPING LEVER BEING PIVOTAL IN A PLANE TRANSVERSE TO SAID PARALLEL PLANES, AN ACTUATOR MEMBER PIVOTALLY MOUNTED ON SAID ELONGATED MEMBER AND HAVING A EXTENSION THEREON FOR PUSHBUTTON ACTUATION AND FURTHER HAVING A PROJECTION THEREON, SAID ACTUATOR MEMBER BEING PIVOTAL IN A PLANE PARALLEL WITH SAID PARALLEL PLANES, SAID CLAMPING LEVER FURTHER HAVING A SECOND PORTION AT SAID SECOND END ENGAGEABLE WITH SAID PROJECTION AND PROVIDING A MECHANICAL ADVANTAGE FOR SAID CLAMPING LEVER TO CLAMP SAID CAM WHEN ENGAGED, SAID ACTUATOR MEMBER BEING OPERABLE TO PIVOT SAID ELONGATED MEMBER TO OPERATE THE TREADLE BAR MECHANISM, AND BEING FURTHER OPERABLE TO PIVOT WITH RESPECT TO SAID ELONGATED MEMBER TO CAUSE SAID CLAMPING LEVER TO CLAMP SAID CAM.

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