US2334724A - Rotary positioning control apparatus - Google Patents

Description

Nov. 23, 1943. E. w; PAESSLER 2,334,724

ROTARY POSITIONING CONTROL APPARATUS Filed Dec. 29, 1942 I 3 Sheets-Sheet l FIGJ. 2 I 6 9 /0 8 U 8/ 9 3 A 3 INVENTOR.

ER/c PEP/75554 ER BY E. w. PAESSLER 2,334,724

ROTARY POSITIONING CONTROL APPARATUS Nmn- 23, 1943.,

Filed Dec. 29, 1942 3 SheetS Sheet 2 IN VEN TOR.

Em: 14 P415551. 5/?

Nov. 23, 1943, wfP Ess 2,334,724

ROTARY POSITIONING CONTROL ATPARATUS.

Fi l'ed Dec. 29 1942 3 Sheets-Sheet 3 INVENTOR.

ERIC W P1 75554 5/? 1? TTOZNE) Patented Nov. 23, 1943.

ROTARY POSITIONING APPARATUS CONTROL Eric Walter Pae ssler, Hackensack, N. J assignor to Federal Telephone & Radio Corporation,

New York, N Y a corporation ofjDelaware Application December 29, 1942, Serial No. 470,468

6 Claims.

This invention relates to control and in particular to an apparatus for varying apparatus the reactance of a radio frequency oscillatory circuit so that it may be automaticallytuned to.

a predetermined frequency. I

Many control devices of this general type are to be found in the prior art and considerable development work in the past few years has been directed to their greater simplification and reliability as well as to reduction in size and decreased costs. The present invention is believed to bea distinct step forward. in the attainment of these goals.

.As above indicatedone of the principal uses for this type of control apparatus is to rapidly vary the tuning of radio frequency circuits in either transmitters or receivers wherein it is'desirable that any one of a number of predetermined frequencies be selected .orchanged from one value to another in a minimum of time. With the device of my invention the pressing of a momentary contact initiates a cycle of operation which in a few seconds will change the tuning of a radio circuit to any given predetermined frequency. If the requirements are such that more than one circuit is to be tuned, either a plurality of devices or one device operating on a plurality of circuits through suitable gearing may be employed.

Accordingly it, is an object of my invention to devise a rugged control apparatus capable of tuning the circuits of radio apparatus to a predetermined frequency.

Another object of my invention is to devise anautomatic means for resetting the control apparatus at the beginning of its operating sequences.

Another object of my invention is to devise a a rotary positioning control apparatus whose se quences of operation may be initiated by a momentary contact push button.

Another object of my invention is to devise a control apparatus having, a construction such that an operator may easily and readily adjust and reset the mechanism when it is necessary ample of "control apparatus according to my invention;

Fig. 2 represents an elevation in 'section on 7 line 2 2 in Fig. 1;

Fig. 3 represents an end elevation as seen from the line 3--3-in Fig. 1; N V

Fig. 4 is a plan view of the top of the Fig. 1 apparatus, showing the gear drive and clutch mechanism;

also held together by three rectangular spacers 3, 4 and 5 and a tie-rod 6; The spacers and the tie-rod are more clearly shown in section in Fig. 2.

The end plates I and 2 journal a control shaft or cam shaft 1. A variable tuning reactance (not shown), which may be either a variable capacitor, a variometer, or other variableelement, is connected with control shaft 1 and rotated thereby to predetermined angular positions relative to a fixed radius of the shaft. It is the novel to change from one set of predetermined frequencies to another.

The features of the control apparatus of my invention lie primarily in its simplicity of construction and in its relatively'small number of parts, as will be discerned as I proceed with the specification and description in connection with the accompanying drawings in which;

Fig. 1 represents in side elevation and in partial section a complete assembly view of an exmannerin which the rotation of shaft J! Econtrolled by the operating mechanism which constitutes one of the principal features of my invention.

A spline or feathered key 8 extends along the control shaft or cam shaft 1 from a point beneath the spur gear 54 to the clamping nut l2. A plurality of spacers 9, each having a keyway for mating with the spline'B are mounted on the v shaft 1. Each spacer has a small shoulder l0 turned on one end thereof. Mounted between the spacers and on the shoulders III are selector cams H', which under operating conditions are securely clamped in position between the nut I2 and the collar l3 the latter being secured to the shaft either by pinning or by a set-screw l4. Theshaft l is held fromaxial displacement by collar l3 held fast to shaft 1 by set-screw l4 cooperating with collar 13 on the opposite side of plate I. On the periphery of each selector cam is a notch i5. When adjusting the tuning device prior to operation, each notch 15 assumes a position corresponding to a predetermined frequency,

as will be more fully explained hereinafter.

When all of the selector cams are properly positioned with respect to their notches i5, they are securely clamped as stated above.

"rality of reset washers 25.

1 the reset, washers and the 26 extending within thekeyway 21 and is employed for manually resetting the mechanism Also mounted between the end plates I and 2, is a reset shaft |6. On this reset shaft, in spaced relation, are mounted a plurality of members l1. Each member has three extensions or arms I8, 20 and 22, the arm l8 being designated a detent arm and having a projection or detent l9 extending from its outer end as shown. The shape of the detent'corresponds'to the shape of the notch in the control cam. Both are slightly tapered or wedge shaped so that when in engagement no lost motion or backlash is permissible. The arm is designated a latch arm and together with the latch 31 functions to control the operation of the mechanism, as will behereinafter explained. The arm 22 is a spring armand between a hole in this arm and a support 24 is a tension spring 23, Fig. 2. It will be noted that the support 24, spring 23, and several other elements have been removed from the apparatus shown in Fig. 1, in

order to show the structure behind these elements.

Also supported on reset shaft l6 are a plu- The washers are formed with an integral internal projection or key 26 which'extends into a key-way 21, the latter extending throughout the length of shaft I6. Each reset washer also has a bent-over portion 28 extending from its outer rim up and over the hub portionof the member H. The members l1 and 2,5 are maintained in spaced relation by .thespacers- 29. These members are not securely clamped together as is the case of the controlcams, but are permitted to hav a rotational slippage'or free motion. The collar 30 at one end of the shaft "5 and the collar 3| at the other end of the shaft position the member I1 withrespect toand in alignment with the control B earns The collar 3| is secured to the shaft by the set-screw. 32. Lever 33, positioned on the shaft |6 between one of the reset washers 25 collar 30, has an integral internal key during periods when the apparatus is' adjusted as a whole; to operate at given predetermined frequencies. I

Between the end plates and 2 is .a third shaft 34 on which are mounted a plurality of levers 35.- Each memberhas oppositely extending arms 36 and 31 which in turn have bent-over portions-38 and 39 respectively. The portions 38 and 39 function as armatures for the electromagnets 48 and 49. 19 determines the limit of rotation of the levers 35. This step extends the whole distance between the end plates and 2. The upper end 40 of the arm 31 together with the surface 4| of the arm 20 functions as a latching device, as will.

be hereinafter more fully described. The levers are maintained in suitable spaced relation on the shaft 34 by spacers 42, collar 43 and collar 44, the latter being fastened to the shaft 34 by set-screw 45. The levers 35 also have a limited amount of free angular motion as is the case with the members l1 and the reset washers 25 on shaft I6.

The spacing members 4 and 5 have mounted thereontwo L-shaped members 46 and 41 which act as supports for electromagnets 48 and 49. These electromagnets 48 and 49 are fastened to the L-shaped members 46 and 41 by passing their cores through slots in these members and riveting over. The L-shaped members are fastened to the supports 4 and 5 by means of screws 50 and 5|. The electromagnets 48 and 49 are mounted in two grdups of five each in order to conserve on space requirements. By so doing the total length of the mechanism can be nearly halved. It will be seen that each lever 35 contains two bent-over portions 38 and 39. The bent-over portion 38 on each of one set of alternate levers 35, serve as armatures for magnets 49, while the bent-over portions 39 on the other set of alternate levers 35 serve as armatures for magnets 48, there being only one magnet 48 or 49 cooperating with any single lever 35.

- Referring now to Fig. 4, the spur gear 54, keyed to shaft 1 mates with spur gear 55, mounted on shaft 56, the latter also extending between and being 'journalled in the two end plates and 2 of the supporting framework. Mounted on the shaft 56 and pinned or otherwise fastened thereto is a threaded sleeve 51. On one end of the sleeve is a clutch plate 58 having a hole in its center whereby it may move freely in an axial direction along the surface of the sleeve 51, the clutch plate 58' being splined to the sleeve 51 to prevent relative rotational motion therebetween. A compression spring 59 surrounding the sleeve 51 and held in position by the adjustable threaded collar 60, presses clutch plate 58 to the left in Fig. 4. A friction disc 6|, made of cork for example, is posi tioned between the spur gear 55 and the clutch plate 58. The gear 55 is not keyed to the shaft but is driven through the clutch mechanism as a result of friction and axial pressure exerted by An adjustable eccentric stop spring 59. A spur gear '63 is also pinned or otherwise fastened, such as by set screw 64, to the shaft 56. Axial motion of the shaft 56in either direction is prevented by the hub of the spur gear 63 and the collar 62, both of which are fast to shaft 56 and acting as retaining collars on either side of the end plate I. Gear 63 is rotated by a motor (not shown) and serves as the driving gear for the complete mechanism. Its rotation causes the rotation of the shaft 56, the sleeve 51 and the clutch plate 58. The latter drives the gear 55 through the friction disc 6|.

Mounted on the right hand side of the ear 63, Fig. 4, is a pivoted lever 65 which acts at the beginning of the operating cycle to reset or take out of engagement any detent l9 which may have been positioned in notch l5. In the position shown in Fig. 3, the spring 66, having one end supported by screw 61 fast to gear 63 and its other end passing through a hole in the upturned end 68 of the lever 65, holds the lever against a stop pin 69 mounted on gear 63. The lever is pivotedly supported by gear 63 at the point 10.

On the shaft |6 is supported a lever 1| having two arms 12 and 13. Integral with lever 1| is a key 14 which fits into the keyway 21 of the shaft l6, so that any rotation of lever 1| rotates shaft I6. Arm 13 of the lever 1| is held against an adjustable eccentric stop 15 by a spring 16, one end of which passes through a hole in the arm 13 while the other end is held in fixed position by the screw 11. When the gear 63 rotates in the direction shown by the dotted arrow at the beginning of the cycle of operation, the upturned edge 18 of the lever 65 pushes the arm 12 of lever 1| in an upward or clockwise direction, Fig. 3, thus rotating shaft |6 and disengaging any detent H) which may be positioned in notch |5, Fig. 2. As the rotation of gear 63 continues, theend -18 of lever 65 passes beyond the arm 12 and the motion has no effect on the lever II, since the end 18 of lever 65 merely lifts over the end of the arm 12.

Fig. 7 is a' schematic wiring diagra'm of electrical circuits which, in conjunction with a driving motor (not shown), relays, cams, etc., op-

erates the control mechanism of my invention,

reduction gearing not shown. A selector switch I05 selects for energization any one of the electromagnets 48 or 49 (see Fig. 2) depending upon the predetermined frequency to be selected. The mechanism, as illustrated and described, is suitable for determining any one of a total of ten frequencies. However, for simplification of the schematic wiring diagram, only one set of five electromagnets 48 have been shown connected with the five position selector switch I05 for selecting for operation the desired one of magnets 48. It will be understood, however, that any desired number of magnets 48 and 49, greater or less than ten, may be provided with a corresponding number of contacts in switch I05 for selecting the desired magnet for operation, each magnet 48 or 49 being employed to control the selection of a different predetermined frequency.

A cycle of operation will now be described. The position of all cams, relays, etc., of Fig. '7, are shown in the position they will acquire-at the end of a cycle of operation or in other words when thev driving motor is deenergized. When a new or different frequency is to be selected, the switch arm I06 of the selector switch is moved so as to make contact with a predetermined switch point I01 corresponding to the new frequency; The pressing of push button I08 closes two pair of contacts I09 and H0. The closing of contacts I09 completes a circuit from the positive terminal of battery I50 through contacts I09, contacts I on cam I03, conductor II2, winding of relay H3, conductor H4 to the negative terminal of battery I50, thereby energizing relay I I3. ihe energization of this relay opens back contacts H5 and H6 and closes front contacts H1 and H8. The closing of contacts II1 completes a circuit from the A. C. power supply I5I through motor field winding IOI, contact H1, conductor H0, conductor I20, contacts H (which are momentarily closed when push button I08 is depressed), conductor I2I, conductor I22, back to the power source II. The motor operates to drive cams I03 and I04 in the direction indicated by the anows whereupon contacts I23 and H4 are closed by the raising of tongue I32 by cam I04. Contacts L23 being in parallel with contacts I it] permit the release of push button I00 without disrupting the power supply to the motor which continues to operate.

When relay II3 operates, it is locked by the closure of contacts H8 in parallel with contacts I00 over conductors I25 and I26. The motor advances cam I03 until the tongue I21 falls into slot I28. At this point contact III opens, thereby deenergizing the winding of relay II3. This results in the closure of contacts H5 and IIS and the opening of contacts I I1 and H8, thereby reversing' the direction of rotation of the motor and also the cams I03 and I04. The motor circuit is nowtraced from the A. C. power source I5I,

'field winding I02, conductor I29, contacts H6,

conductor II9, contacts I23, conductor I22 back 'to the power source I5I. The closure of contacts II5 completes a circuit'from the positive terminal of battery I through contacts II5, conductor I30, contacts I24, winding of selected magnet'48, contacts I01 and arm I06 of selector switch I05 back to batteryI50. Cams I03 and I04 are now rotating in a direction opposite to that of the arrow shownthereon and continue to do so until'tongue I32 falls into'notch I33 of cam I04. Atthis point the motor is deenergized by the opening of contactsxl23 and the winding of magnet 48 is deenergized by the opening of contact I24. This completes the-cycle of control circuit operation.

During the cycle of electrical operations above described the following mechanical operations of the control mechanism take place. It is assumed that in the beginning of any cycle the various parts of the control mechanism'are in a position suchas is shown in Fig. 2. The detent I9 is within the notch I5 of one of the cams II, thus fixing the angular position of reactance control shaft 1, corresponding to a certain predetermined frequency. When some other predetermined frefull arrows as shown in Fig. '7. Gear 63 rotates shaft 56 to'which the sleeve 51 is fastened. Clutch plate 58 which is splined to sleeve 51 is rotated by the latter. Spring 59 presses against clutch plate 58, which in turn forces the friction disc 6| against gear 55. This tends to rotate the gear 55, but at' the beginning of an operating cycle this rotation cannot take place since gear 55 is in mesh with gear 54 and this latter gear is prevented from rotating by the \detent I9 in notch I5. There is therefore a slippage of the clutch mechanism. However, gear 63 in its counter-clockwise rotation, Fig.- 3, also rotates the lever 65 and the end 18 of this lever in pressing against arm 12 of lever 1I,' disengages the detent I9 from the notch I5. This disengaging is actually done by the bent-over portion 28 of the reset washers 25, the latter being also keyed to the shaft I8. When this occurs the latch-arm 20 of the member I1 raises and the spring 52 rotates the latch 31 into the position shown in Fig. 5, wherein the end 40 of arm 31 engages surface 4| and prevents arm 20 from clockwise rotation, thus preventing detent -I 9 from latching into notch I5, none of the operating magnets 48 or 49 being energized at this time. The withdrawal of the-detent I9 permits gear 54 'and in turn all of the control cams to be operated through the clutch mechanism 58, 6|, 55. The rotation of gear 54 continues until the tongue I21 drops into slot I20 of the cam I03; see Fig. '1. At this point the reversal of the driving motor takes place and gear 63 through the clutch mechinto position under the detent I9 and since the armature 3B or 39 as the casemay be has been pulled up by the operating magnet, the arm 20 is free to rotate and the detent I9falls into the notch I5, thus stopping the rotation of all cams II and the gear 54-. mechanism again takes place but the driving motor continues to rotate cams I03 and I04 until the tongue I32 falls into slot I33 at which time the cycle of operation is completed.

Let it now be assumed that one wishes to change the adjustment of one of the cams II so that the control apparatus will tune the radio apparatus to a difierent frequency. The nut I2 is loosened thereby relieving the pressure existing between all of the spacers 9 and the cams II. In order not to disturb the adjustments of other cams, the nut I2 is loosened only when the detent I9 is in the notch I5= of the cam which is to be readjusted. After the nut has been loosened and the cams are free to rotate, a manual turning of the knob 80 which is also splined to the shaft 1 rotates all cams except the one which is held in position by its detent IS. The oscillatory circuit reactance which is controlled by the rotation of shaft I is varied by turning knob 80 until the desired new frequency is obtained. The nut I2 is again tightened and the apparatus is now in adjustment for the new frequency. It will be seen that the procedure for changing the frequency is of the utmost simplicity and is one of the features of the invention. In order to exert a certain amount of pressure between all spacers 9 and cams II, when the nut I2 is loosened, a spring washer 8|, located between the collar 82 and one of the cams I I, exerts sufficient pressure against the spacers and cams to-prevent any slippage which might otherwise accidentally occur.

The invention has been described primarily as a mechanism for automatically tuning radio frequency circuits to predetermined frequencies. It is obvious, however, that the apparatus of my invention could be used in any arrangement where a predetermined setting of any movable part is required and it-is intended that the scope of my invention be not limited except in accordance with the following claims.

What is claimed is:

1. Rotary position determining means comprising an angularly movable cam shaft, a plurality of spacers splined on said shaft, a plurality of circular cams, each provided with a notch on its periphery, mounted on and between said spacers,

A slippageof the clutch means for clamping said cams between saidspacers whereby said notches may be fixed at predetermined angular positions relative to a fixed radius of said shaft; a reset shaft, a plurality of members comprising detents and latch arms mounted on said reset shaft, each detent having an engaged and disengaged position with.

placed said disengaged position, means for latching said detents in said disengaged position during said forward direction ofrotation of said driving means, means for reversing said direction of rotation, and means for unlatching a predetermined one of said detents whereby said unlatched detent may move to the engaged position with its cooperating notch and stop the motion of said cam shaft.

2. Rotary position determining means comprising an angularly movable cam shaft, apluity of circular cams, each provided with a notch on its periphery, mounted on and between said spacers, means for clamping said cams between said spacers whereby said notches may be fixed at predetermined angular positions relative to a fixed radius of said shaft; detent meanshaving engaged and disengaged positions with respect to cooperating notches on said cams, driving means for rotating said cam shaft alternately in a forward direction and in a reverse direction, means for urging said detents to their disengaged positions at the start of said forward direction of rotation, means for latching. said de-- tents in their disengaged positions, means for reversing said direction of rotation, and means for unlatching a selected one of said detents whereby *said unlatched detent may move to the engaged position with its cooperating notch and stop the motion of said cam shaft.

3. In a rotary position determining control apparatus, a rotary control shaft, a plurality of selector cams mounted on said control shaft, a reset shaft, a plurality of detents mounted on said reset shaft, said detents having an engaged and a disengaged position, means on the periphery of said selector cams for engaging with said detents at predetermined positions of said control shaft, reset means mounted on said reset shaft, latching means for maintaining said detents in their disengaged position during certain periods of operation of the control apparatus, means for releasing said latching means during certain other periods of operation of said apparatus, driving means for rotating said control shaft, and reset control means operative in response to said rotation of said driving means for momentarily angularly moving said reset shaft whereby all detents are placed in said disengaged position.

4. In rotary position determining control apparatus in accordance with claim 3, the combination in which said reset control means comprises a first lever pivotedly mounted on said driving means and a second lever mounted on said reset shaft and in operative relationship with said first lever.

5. In rotary position determining control apparatus in accordance with claim 3, the combination in which said reset means mounted on said reset shaft comprises a plurality of reset washers, at least one of said washer-s having means for disengaging one of said detents in response to the operation of said reset control means.

6. In rotary position determining control apparatus in accordance with claim 3, in the combination in which said driving means include means for rotating said shaft alternately in a forward direction and in a reverse direction and said reset control means is responsive to said forward rotation. ERIC WALTER PAESSLER.

Images