US2236309A - Preselecting mechanism - Google Patents

Description

March 25, 1941. bAHLSTRQM 2,236,309

PRES-SELECTING Msqmmsu.

Filed March 29, 1940 2 Sh smm 1 @QQM i KJM March 25, 1941. A. DAH LSTROM PRESELECTING MECHANISM 2 Sheoias-Sheet 2 Filed March 29, 1940 j f W KW \w, a w w Z Q n 4 /n v\ M 2 r Patented Mar. 25, 1941 PATENT OFFICE PRESELECTING MECHANISM Arvid Dahlstrom, Chicago, Ill., assignor, by mesne assignments, to Oak Mfg. Co., Chicago, 111., a

corporation of Illinois Application March 29, 1940, Serial No. 326,625

' 2 Claims.

This invention relates to a preselecting mechanism and has particular application to the setting of apparatus to a plurality of predetermined definite positions lying between two end positions over which the apparatus may be adjusted.

A mechanism of this character finds ready application to a radio receiver, for example, wherein a turning element such as a gang condenser is ordinarily adjustable over a predetermined range. Thus in most instances a gang condenser for a radio receiver may travel over a range of almst-180, the end positions corresponding to maximum and minimum capacitance values hereinafter referred to as full in and out positions.

As is well known, the response of a receiver is conditioned by the adjustment of the tuning mechanism and particular stations may be chosen corresponding to particular adjustments of the tuning mechanism. In many instances, the owner of a receiver is accustomed to tune in frequently a small number of local stations. As to these stations, it is desirable to provide a simple means for preselecting the station without manually adjusting the condenser to the corresponding position.

In general, the invention is applied to any device having a part which may be adjusted to any position over a range extending between two end positions. Means are provided for biasing the movable part toward one end position. A head is provided. which is manually set to any one of a plurality of definite on positions or conditions corresponding to definite positions of the adjustable part. The head also has off positions or conditions existing during short times between the manual manipulation of the head to select a position and the assumption of that position by the movable part; i. e. during the actual operating cycle but prior to the actual response when a preselected position has been established.

During an ofi position or condition, the movable part is forced against its bias toward the other end position. At the on position or condition of the head, the normal bias of the movable part asserts itself. A stop is provided for 1imit ing the bias response of the movable part to establish a preselected position of the movable part. By making the stops adjustable, any part position may be established as a preselected point.

Referring to the drawings:

Figure 1 is an isometric view of the preselecting mechanism applied to a gang condenser;

Fig. 2 is an end elevation view of the preselecting meansin one preselected position;

Fig. 3 is a view similar to Fig. 2 but showing the mechanism in preparation for preselecting a position;

Fig. 4 is a view similar to Fig. 2 but showing the mechanism in a different preselected position;

Fig. 5 is a section on line 5-5 of Fig. 2; Fig. 6 is a section on line ii -6 of Fig. 5; and Fig. 7 is an end elevation view of the index means. 10

The preselector is shown as operating upon .a gang condenser, the latter consisting of a base [0 having a series of stator plates II and rotor plates l2 mounted upon a shaft [3 rotatably journalled in base Ill. Rotor plates I2 normally 1 have almost 180 range of travel from an end full-in to an end full-out position. In the full-in, position strips I! carried by the rotor plates l2 may cooperate with the statorll to determine a stopping position. In the full-out position, strips I! may strike against frame Ill 'to determine the other end position. Any other limiting means may be used or may be omitted entirely and reliance be had upon the preselector means to determine the range limits. I

Rotors l2 of the gang condenser are biased to one end position by a coil spring l5, one end of which is anchored to the shaft l3 and the other end of which is anchored to base l0. As shown here, spring l5 tends to move the rotor plates l2 to a full-out position. Rotor shaft I3 also carries a pinion 20 normally meshing with a rack 2| on an arm 22. Arm 22 has a pair of aligned elongated slots 23 and 24 along the length thereof adapted to restrain arm 22 against transverse 35 movement but permitting longitudinal movement thereof. Thus, rotors l2 and arm 22 have corresponding movements.

Carried by base I0 is a pin 25 fitting in slot 23, the pin being provided with a shoulder 26. Slot 24 is provided with a pin 28'mounted between spacedbrackets 29 and; 30 carried by condenser base Ill. Pin 28 has a sleeve 3| between arm 22 and bracket 29. Between bracket 30 and arm 22 a manual control head 32 is rotatably mounted on pin 28. This head consists of a hub 33 and a peripheral flange portion 34 joined together by a radial side portion 35. It will be noted that arm 22 is snugly shouldered between sleeve 31 and head 32.

Carried by flange portion 34 at one side thereof,

. are a plurality of uniformly disposed pins 31.

Cooperating with pins 31 is a dog 40 having a cam surface 4| and carried by arm 22 in the path of pins 31 so that upon rotation of the head a pin engages the cam surface 4| and depresses dog 40 and arm 4| down to its lowest position as seen in Fig. 3. The direction of rotation of the head in Fig. 3 is clockwise.

It might be noted here that the bias of the gang condenser due to coil spring l5 will tend ,full closed position. When pin 31 has passed cam surface 4! of dog 40, it is clear that the bias of coil spring l5 upon the rotors l2 oithe gang condenser will tend to move arm 22 upward from its bottom position. The manual control for determining the precise position oi stoppage on this return movement of the gang condenser will now be described.

Corresponding to each pin 31 there is provided a screw 45 whose tip 45 and head 41 are rotatably journalled in hub 33 and fiange portion 34 respectively. Peripheral portion 34 is provided with a suitable aperture so that milled head 41 may be reached for turning by a screw driver. A

- spring 48 is disposed around the body of the bolt drawal.

and bears against the inside of the flange portion 34 to retain the bolt in position against with- Carried by each bolt 45 is a nut 50 which may have a generally triangular shape as shown in Fig. 6 with the base 5i normally bearing against the adjacent surface of radial portion." while the tip 52 extends outwardly.

Turning of bolt 45 will cause nut 50 to ride up and down and alter its distance from hub 33. A finger 54 carried by the free end of arm 22 normally extends into the head interior and cooperates with the under surface of tip 52 of a nut to function as a stop for upward movement of lever 22.

' The various screws 45 are so disposed angularly with respect to pins 31 as to permit a pin 31 to depress arm 22 to its lowest position as shown in Fig. 3 and then, after pin 31 has cleared dog 40, permit coil spring l5 to move the mechanism including arm 22 back until finger 54 is stopped by one of the nuts. At this point the entire mechanism has reached a preselected position. In

order to index the head, a star-shaped index wheel 60 may be carried by hub'33 near bracket 3|. This index wheel 60 is naturally rotatable with member and has as many points as the head has screws 45. A roller 5| carried by an arm 62 pivotally mounted at 53 to bracket 3| may be pulled against wheel 30 by means oi a coil spring 64 to obtain an index action for the head.

If desired, one or more of the screws 35 may have a thumb piece 86 so that direct manual control is provided rather than through a screw driver as with the other screws.

Flange portion 34 may have a plurality of ribs or finger pieces 58 for'providing a grip for-turning part 35. Suitable clips 10 may be provided at each bolt head 45 to cover the same and to permit a. card to be clipped in upon which the name of some radio station may be indicated.

It is to be understood that in the broader aspects of this invention, the head may be any movable meanswhich when operated will first release the part to indexed from any previous setting, move said part against its bias to the end position and then permit said part to respond to the bias and move up to any position determined by the movable means.

It is also to be understood that instead of am moving the movable part against its bias to one end position and thereafter permitting said spring to return the part to a predetermined position,

that the movable part may first be permitted to move toward the other end position under the influence of the spring and thence the part moved against its spring bias toward the stop. To accomplish this, coil spring l5 may be made so that it tends to open up and bias the rotor to the position for maximum capacitance. Then, upon movement of the head, it will be necessary to pull up finger 54 against the desired stop and maintain the linger in that position against the bias of coil spring l5, or simply have finger 54 rest against the outer side of stop nut 55.

What is claimed is:

1. A preselector mechanism for apparatus having a part movable over a continuous range between two end positions, said mechanism comprising means for biasing said part toward one end position, a control head'manually adjustable to any one of a plurality of definite on settings,

each setting corresponding to a preselected partposition, said head having an of! setting during the operating cycle of said mechanism prior to the actual response, cooperating means on said head and part for moving said part against its normal bias substantially. to the other end position automatically upon movement of said head from one on position to an oil position in preparation for another on position, said cooperating means only operating during oil position settings of said head and releasing said part for bias response when said head has attained the other on position and means for each on position head setting for limiting the bias response of said part to determine a preselected position.

' 2. A preselector mechanism for apparatus having a part movable over a continuous range between two end positions, said mechanism comprising means for biasing said part toward one end position, a rotatable control head manually movable from one definite position to another definite position in succession and having a plurality oi definite on positions corresponding. to preselected part positions with intermediate oil! positions for said head, means for moving said part against its bias toward the other end position, said means being inoperative at on positions of the control head, means on said control head movable therewith cooperating with said part moving means for operating said means during the movementof said control head from one position to.a succeeding position, and means for limiting the bias response of said part to determine a preselected position.

3. A preselector mechanism for apparatus having a part movable over a continuous range between two end positions, said mechanism comprising means for biasing said part toward one end position, a control head rotatable about an" axis and manually movable to any one of a plurality of definite positions corresponding to a preselected stop positiQn means coupled to said 1 means for movingsaidarm substantially to'an 1 end position corresponding to movement of said' head axis of rotation and was corresponding to the control head positions, said stops having predetermined distances from said control head axis of, rotation, and means on said arm ior'engaging a selected stop upon the return-motion of said' arm.

' 4. A preselect'or mechanism for apparatus having a part movabl'eover a continuous range between two end positions, said mechanism comprisingv means for biasing -said part toward one end position, an-arm movable along it straight line, means-coupling .lsaid; and said part whereby both have corresponding movements,

part against its bias towardth e other-position, means for releasing said arm, '9 Permit said part bias to reassert itself, and means for stopping said arm at a preselected point in 'its returntravel-f 5. A preselector mechanism for apparatus having a part. movable over a continuous range between two end positions, said mechanism comprising means for biasing said part toward oneend position, an arm movable in a straight line between two end'positions and coupled to'said part so that the position 01' said arm corresponds to the position of said part in its range, a control head vmanually movable to any one or a plurality of definite positions corresponding to preselected part positions, means on said control head operating when said head is being moved to a new position for moving said arm substantially to an end position corresponding to a movement of said part against its spring biasto theother position, said control head means thereafter reIeas-J ing said arm to permit end position, an arm movable along a straight line between two end positionasaid am being coupled to said part whereby said M and arm said bias to reassert itself. and means on said control-head for'stoppingsaid arm at;a -predetermined positiononthe return movement thereof,-

have corresponding motions,- a rotatable control head manually movable to any one of a. plurality of definite positions corresponding to preselected part positions, means onsaid control head for moving said arm substantially to an end position corresponding to the-other position -oi. said part v againstthe bias thereoffsaid means being operatlve onlywhen said control'head is between two adjacent positions, a'plurality'of stops carried byv 5- said control head, each stop corresponding toa "head position the radial distance or a stop ,from the-axis of rotation of said head-determining the; preselectedposition otthe part, andmeanson saidarm idr engagingeach stop in successionas;

the control head'jis rotated through successive positions to determine the return positions of l; A preselector mechanism for apparatus having a part movable over a continuous range between two end positions, said mechanism comprising means for biasing said part toward one end position, an arm movable along a straight line between two end positions and coupled to said part so that said arm and said part have corresponding positions, a control head comprising a wheel rotatable about an axis, said wheel having a plurality or set positions, means on said wheel for moving said lever upon wheel movement tojforce said arm substantially to an end position corresponding 'to the other position or said part and against the part bias, said means on said wheel releasing said arm when said wheel has reached a deiinitepositicma stop carried by said wheel at each position thereof and disposed at a radial distance from the wheel center corresponding to a desired preselected part position,

.said arm line of motion lying in a plane parallel to the plane of rotation of said wheelr each wheel position being at a point wherea wheelradius through a desired stop is parallel to the line or motion or said arm, and'means on said lever for engaging said desired stop to determine the return position or said arm when said part bias reasserts-itseli.

I ABVDDAHLSTROML

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