US2620436A - Automatic tuning for radio receivers - Google Patents

Description

Dec. 2, 1952 w. A. ToLsON AUTOMATIC TUNING FOR RADIO RECEIVERS Filed nec'. 1o, 194s 2 SHEETS-SHEET 1 ATTORNEY Dec. 2, 1952 w. A. ToLsoNI AUTOMATIC TUNING FOR RADIO RECEIVERS Filed nec. 10, 1948 2 lSHEETS--SHEET 2 ATTORNEY INVENTOR AM A.T:1Ls DN WILLI All/ Patented Dec. 2, 1952 AUTOMATIC TUNING FOR RADIO RECEIVERS William A. Toison, Princeton, N. J., assigner to Radio Corporation of America, a corporation of Delaware Application December 10, 1948, Serial No. 64,612

(Cl. Z50-2%) 2 Claims. 1

This invention relates to the method of and apparatus for automatically tuning radio broadcast receivers, and more particularly to a tuning system which is caused to operate automatically in accordance with and in response to a previously recorded schedule of desired programs.

One of the primary objects of the invention is to provide a method of an apparatus for automatically tuning a radio receiver through a sequence of programs to which it has been tuned in a previous week, in a manner analogous to memory without a preliminary selecting operation by the user.

Ever since the advent of serially-arranged broadcast programs there has been an ever present need for a device which would automatically tune in one or more favorite programs on a weekly basis. Heretofore, there have been suggested solutions to this problem and a few devices have been produced in small quantities. However, all of these devices required the manual setting up oi' a pre-arranged program schedule by the user. The complexity of these devices from the viewpoint of the user was undoubtedly a major factor in their failure to win wide acceptance from the public. The user was required to familiarize himself with a device which had a large number of adjustable elements, and in order to set up a weekly sequence of desired programs on the basis of minute, or 30 minute program periods, it was necessary for the user to check the position or condition of a great many separate elements. Further, if at any time the user wished to change the recorded program schedule for any particular listening period, it was necessary for him to select the particular element or elements from among the large number which alected the particular listening period which he wished to change. Experience has shown that the average listener is unwilling to do this and the various devices shortly fell into disuse.

It is therefore an object of this invention to provide a simple means for automatically recording the listening habits of the user of a broadcast receiver, and by means of that record to auto- L matically tune in his favorite programs on a weekly basis, and to accomplish this without any conscious eifort on the part of the user.

in order to provide a satisfactory solution to this problem, three major requirements must be fulfilled. First, the device must be reasonably inexpensive to manufacture. Second, it must be sumciently simple mechanically to require little if any servicing. Third, it must be simple in operation, from the standpoint of the user, so

that the user will continue to employ the automatic tuning device throughout the life of the receiver. The present invention meets these requirements.

An example of an automatic memory type tuning system for a radio receiver is set forth in the patent issued to Charles M. Burrill, Number 2,408,370, assigned to Radio Corporation of America. The Burrill patent referred to employs an electrical recording medium, such as a magnetic tape, for electrically automatically recording during reception from a station an indication corresponding to the station, and a timing device for actuating the recording medium to enable the recorded indication to be effective at the next recurring interval for automatically tuning the receiver to the desired station.

The present invention employs a tape which may be made of any suitable material, such as paper, on which perforations are made automatically corresponding to the particular station, and the time at which the particular listening period was concluded. The positions of the perforations across the width of the tape serve to identify the station which was listened to, and the positions of the apertures along the length of the tape serve to identify the particular period during which the program was received. Since the perforations are made at the conclusion of each 30 minute program period, and the tuning action to retune that same program the following week must be completed at the beginning of the program period, the individual apertures are employed to retune the receiver automatically to the particular stations one week later, less 30 minutes. It is thus evident that the length of paper tape between the periorator and the tuning contacts should correspond to an operating time of one week less 30 minutes. In the particular model of automatic tuning device described herein, the tape movement was l@ inch, in steps, at the conclusion of every 30 minute program period. The length of tape between the perforator and the tuning contacts was thus 831/2 inches.

The recording medium, or tape, carries a record which is self-perpetuating, since a new perforation is made at the end of each listening period. However, if the user changes the program by tuning to another station and remains tuned to such other station until the end of the program, the old record is no longer maintained, and the new record for the particular station and at the particular time listened to will be provided by a new perforation in the recording medium.

aezoyiee A discontinuous recording medium is used, since, at the end of each program listening period a new perforation is made automatically for the particular station and program time. The record is thus self-perpetuating unless the user changes it by tuning to another station during the program, or destroys the record by pushing the no record butt-on.

It is a primary object of the present invention to provide an automatic tuning system for radio receivers which employs a novel automatic recording mechanism and a control circuit which may be used with any push button receiver which employs a mechanism whereby the receiver may be tuned by the closure of an electrical circuit. An example of such a receiver is the RCA Model U130, the circuit and general arrangement of parts of which may be found in the Perpetual Trouble-Shooters Manual, by John F. Rider, Volume Q-RCA, pages 9-4 to 9-10 inclusive.

A further object of the invention is to provide in an automatic tuning system for a radio receiver having an automatic tuning unit, a novel control circuit for recording on a recording medium an indication uniquely identifying one or more of the particular stations listened to and the time of listening.

A further object of the invention is to provide a novel automatic recording mechanism responsive to a control circuit which is 'coupled to the automatic tuning unit of a radio receiver to tune in the same station automatically at the same time of day at a later date.

The novel features characteristic of my invention are set forth with particularity in the -appended claims. The invention itself, however, both as to its organization and mode of operation together with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawings in which:

Figure l is a combination pictorial representation and schematic circuit diagram showing a. conventional automatic tuning unit of a radio receiver connected to the novel control circuit for operating the receiver in response to the record, and in accordance with the invention.

Figure 2 is a perspective view of the timing mechanism operated by a, synchronous motor for actuating the automatic recording mechanism which maintains synchronization between the perforated record and `the means for causing operation of the radio receiver at a later date and time as indicated by said record.

Figure 3 is a perspective view of the camming arrangement of the automatic recording mechanism and certain other related parts.

Figure 4 is a perspective view of the recording medium from the source of the tape storage roll to the take-up reel disposed in relation to the tape perforating device and certain of the contacts of the control circuit.

Figure 5 is a side view of the automatic recording mechanism partially shown in Fig. 3, driven by the timing unit, shown in Fig. 2, indicating, in particular, the relation between the tape perforating positioning means and the associated pin stops of the tuning unit disc assembly.

Figure 6 is a plan View of flexible contact l fingers secured on aninsulating member, which contacts are part of certain control and operating circuits shown in Figjl.

Figure 7 is a sectional View taken along lines l-'lV of Fig. 6 with the record medium added 4 showing the flexible -contact fingers in relation to one of the sprocket drums.

Figure 8 is a perspective View of the push button operating latch bar and the associated magnetic release.

Figure 9 is a sectional View taken along lines 9 9 of Figure 8.

Figure 10 is a block diagram showing: the overall system with the various blocks indicated by appropriate legend.

The entire manual operation of the automatic tuning system for the radio receiver is controlled by a three position operating switch 25 (Fig. 1) having an off position contact 25, a memory position contact 2l, and an on position contact 28. There is also a no record push button 18H which eliminates automatic reproduction of a previous record, or prevents a new record from being made.

In order to lend a comprehensive understanding of the invention, the basic operation of the disclosed embodiment of the invention is set forth as follows:

1. After the equipment of the invention has been properly set up for operation, the operator of the receiver turns the operating switch to the on" position and uses the radio receiver in a normal manner for one week. VThe stations that were being received at the end of each half hour listening period will have left a perforated record on the paper tape indicating the station and time of the listening period.

2. When the radio is used during the following weeks, the operating switch may be placed in the memory position. All of the programs that were being listened to at the end of each program period the previous week will again be tuned-in automatically at the proper time.

3. The record is self-perpetuating unless the user changes the record by tuning to another station during the memory program, or destroys the record by pushing the no record button.

e. If the operator wishes to use the radio during any period for which no memory record was made, he turns the operating switch to the on position, and by normal push button control he may tune in the radio to any program. If the operator turns off the radio before the end of the period, no record will be made.

5. However, if the user wishes to make a record of the particular station listened to during a period for which there was previously no memory record, the user merely leaves the operating Y switch in the on position, and a perforated record on the tape is made automatically to provide automatic tuning to the same program the following week.

Referring tothe drawings Vand more particularly to Fig. l, there is shown the schematic wiring diagram of the automatic tuning unit, and the control circuit, which are two of the five units represented in the block diagram of Fig. 10.

Momentarily referring to the` block diagram of Fig. l()` for the purpose of presenting an overall picture, there is shown a block 29 representing a radio receiver such as the RCA AModel U referred to above, having an automatic tuning unit 2l as a component of the radio receiver. A control circuit represented by block 22 controls the tuning unit 2l for operating the radio receiver section per se in accordance with the record tape operated by the automatic recording mechanism 23, the periodic movement of which is controlled by the timingunit24.. Y

Timing unit Referring to Fig. 2, the timing unit which operates the automatic recording mechanism periodically, is essentially a clock consisting of a gear train driven by a synchronous motor 3D which has a pinion gear 3| in mesh with a gear 32 securely connected to a shaft 33 which makes ve revolutions per minute. A four tooth driving disc 34 is pinned on the shaft 33 so that the driving disc 34 is constantly rotating with the shaft 33. The driven gear 29 is free on the shaft 33, and is connected only periodically by a pawl arrangement for one revolution of the shaft 33, the operation of which will be explained later. The end of the shaft 33 opposite to the gear 32 has a gear 35 in mesh with a larger gear 36 which makes one revolution per minute. A cam disc 31 having a detent 38 formed therein, and a pinion gear 39 are connected on one end of the shaft 4|), which shaft is secured to the larger gear 35. A second cam disc 4| has a detent 42 formed therein and is secured with a gear 44 on a rotatable shaft 43. A shaft 45 has a gear 45 on one end thereof which meshes with the pinion gear 39, and a gear 41 secured on the other end of the shaft meshes with the gear 44. The cam disc 31 makes one revolution per minute while the cam disc 4| makes one revolution every 30 minutes. A yoke 48 is pivoted on a shaft 58, and has two pawls 5| and 52 which are adapted to engage the detents 38 and 42, respectively of the cam discs 31 and 4|, simultaneously once every thirty minutes as the timer release means for initiating the periodic actuation of the driven gear 29, which gear ultimately drives the automatic recording mechanism via gear S9 and shaft 6|.

A spring actuated pivot pawl 53 is pivoted by pin 54 to the driven gear 29, with the lower end of said pawl adapted, when released, to engage one of the four teeth of the driving disc 34. A pawl 55 secured to the yoke 48, engages the upper end of the spring actuated pivoted pawl 53, thereby preventing the rotation of the driven gear 29 until the pawl 55 is released from the path of the upper end of the pawl 53 which is only possible when both of the yoke pawls 5| and 52 are in periodic engagement with their complemental detents thereby causing operation of the yoke 48. One end of a holding pawl 56 under iniiuence of a spring 51 is urged into a notch 58 formed in the side of the driven gear 29 at the position shown in Fig. 2. In operation, the synchronous motor 38 constantly drives the shaft 33 and the driving disc 34. Once every half hour the pawls 5| and 52 of the yoke 48 will simultaneously engage their complemental detents, and the pawl 55 will release the pivoted pawl 53 thereby permitting engagement between the lower end of the pawl 53 and one of the teeth of the driving disc 34, so that the driven gear 29, which is pivotally connected to the pawl 53, will make one revolution.

The shaft 33 which is connected to the driven gear 29, will make ve revolutions per minute. Therefore the driven gear 29 will make one revolution in l2 seconds, this time factor being important in the operation of the cam shaft of the recording mechanism. As the driven gear 29 completes its periodic revolution, the yoke 48 will have been restored to its position shown in Fig. 2, under influence of the cam discs 31 and 4| thereby permitting the pawl 55 to again engage the upper end of the pawl 53, which rocks the lower end of pawl 53 out of engagement with the driving disc 34. At this position the holding pawl 56 engages the notch 58 formed in the side of the driven gear 29, thereby preventing any appreciable counter rotation of the driven gear 29, and thus holds the driven gear securely in a stationary position. Gear 60 is in mesh with the driven gear 29 and is secured to the shaft 6|, which is, in fact, the cam shaft that operates the four cams of the automatic recording mechanism.

Automatic tuning unit The automatic tuning unit such as the type utilized in the RCA Model U130 is shown in Fig. l, and will be described at this time to preface a description and operation of the automatic recording mechanism.

The representation in Fig. 1 shows a capacity tuning unit having a movable capacity element 62 connected to a shaft 53, which shaft also has a gear 64 and a selector disc 85 secured thereon. The selector disc has two metallic semicircular sectors 86 and 81 with an insulating strip 68 disposed therebetween, which insulating strip also insulates the sectors 88 and B1 from the shaft 53. A conventional reversible tuning motor 10 has field coils 1| and 12 which each have one side connected respectively to the metallic sectors 55 and 61. The tuning motor is coupled to the gear G4 by means of a worm gear and shaft 85 and 81 respectively. The opposite ends of the field coils are connected through winding 13 through the conductor 14 to the terminal 15 of one side of the power transformer 16. A plurality of station setting contacts 11A through 11G as employed in the RCA Model U130, are disposed to slidably engage the selector disc 65. Each of said station setting contacts is connected through a conductor to the back contact |59 of their respective push buttons 18A through 18G. It being understood that the back contacts |68 are the contacts shown at the right side of the movable push button element, and that the front contacts |59 would be the contact to the left of the movable push button element.

When the movable member of the operating switch 25 is in the on position so that the movable member is in engagement with the on contact 28, the winding of the relay 88 will be energized since it is connected across the terminals 15 and 8| of the power transformer 16. When relay is energized the movable armature 82 will engage contact 83. When one of the push buttons, such as TSG, is depressed, the slidable contact 11G will be connected with the sector 66 of the selector disc 65 via conductor 84. The tuning motor will thereby be energized through the motor eld winding 12, the motor now being connected on one side through conductor 14 to the terminal 15 of the power transformer i5 While the other side of the motor is connected through conductor 84, back contact |69, push button 18G, conductor 85 through contact set 82-83 to the terminal 8|, which is the other side of the power transformer 16. The selector disc will thus be caused to rotate in a given direction until the sliding contact 11G engages the insulating strip 68 which separates the two sectors 65 and 61. Interruption of the energy flowing to the tuning motor 10 will cause the tuning motor to cease operating whereby the movable tuning element 52 will have reached a point where the particular station indicated by push button 18G will be tuned in. A conventional clutching arrangement, not shown, or an 7 arrangement as set forth in the patent to Beizer et al., 2,204,065, may be used to hold the tuner ina fixed position after the desired station is properly tuned in.

The tuning condenser shaft -63 has a tuning disc assembly 88 composed of eight tuning discs such as 90, each one of which has a pin, such as 9|, secured thereto. The pin on the largest disc is similar to the other pins 9|, but will be referred to as the no record disc pin 92, since this particular pin will be referred to again in relation to the no record operation to be ex- -plained later. A perforator positioning shaft 93 which is adapted to engage any one of the tuning disc pins such as 9| or 92 will be described later in relation to the automatic recording mechanism operation.

The eight tuning discs are adjustably mounted on shaft 63. The discs are prevented from moving on the shaft 63 in the direction of the Vgear 64 by a pin (not shown) or other suitable limiting means. A nut 94 which is threadedly connected on the shaft S3 is used to clamp the discs in a fixed position after they have been adjusted. The purpose of the tuning disc assembly is to line up the various pins such as 9| and 92 with the perforator limiting shaft 93, each pin being rpositioned for its respectively tuned station. This is done in the following manner:

To set 'the various discs of the tuning disc assembly for proper operation in conjunction with the automatic recording mechanism, the various stations are independently tuned in by push button tuning in the ordinary manner.

For example, push button 18G is depressed until the shaft -63 has been properly rotated to tune in the -particular station represented by push button 18G. One of the discs 90, for example the disc having the disc pin v9| closest to the tuning condenser shaft 03, is rotated until the pin 9| is in axial alignment with the perforator positioning pin, or shaft 93 so that the shaft 93 may engage the disc pin 9|. A second push button -18F is then depressed. When the corresponding station is tuned in,the second disc is then rotated until its pinj9| is in axial alignment for engagement vwith Vthe positioning shaft 93. All of theremaining push buttons from 18A to 18E inclusive, are independently pressed and their respective tuning disc pins 9| are aligned with the shaftl93. rthe largest tuning disc `which carries pin 92, and corresponds to the no record push button 18H, is finally aligned with shaft 93 to tune the receiver to a positiony in thefrequenoy spectrum where no station will be heard. Further, there will be no record made since the position of pin 92 prevents the perforator punch Vper se from moving into register with the recording medium or tape. The perforator limitingshaft 93 is carried by the perforator of the recording mechanism for positioning "the Yperforator assembly to punch a hole in the paper Vtape in the proper position depending on the particular .tuning disc pin such as v9| vor '92 which is vpositioned during the tuning operation.

Automatic recording mechanism The automatic recording Amechanism 4shown particularly in Figs. 3 and 5, has abase '95 which has secured thereto vertical sideframes 945. and 91. The cam shaft El is supported-by.A the :side frames `96 andr 9 1. and is ldirectly connecte'd'to Vthe gear 'shownin Eig. V2of the timing unit.

8 The cam shaft 6| carries four cams, namely the switch cam |00, the perforator cam |0|, the perforator positioning cam |02 and the drum stepping cam |03. As previously explained, the timing unit will rotate the cam shaft 6| one revolution at the end of each 30 minute period. Since the cam shaft 6| is secured to the gear of the timing unit, which gear rotates at the rate of 5 revolutions per minute, vthe cam shaft 6| will make its single revolution, at the end of each 30 minute period, in 1/5 the time, or in l2 seconds. A positioning cam arm |04 is pivotally mounted on shaft |05. The other end of the positioning cam arm has a pin |06 which has a flexible cord |01 connected thereto, which cord is positioned over pulleys |09 and |09 with the opposite end of said cord being connected to the perforator assembly ||0. A perforator supporting framework is slidably carried on a guide rod `I|2 which rod is connected at one end thereof to the frame 96 with the opposite end thereof supported in any convenient manner such as by means of a bracket (not shown) connected to the base 95. As soon as the cam shaft 6| starts to rotate in the direction indicated by arrow X, the positioning cam pin H3 which normally rests in the position shown in Fig. 3, will ride down the edge H4 of cam |02 thus permitting the perforator assembly ||0 to be drawn to the left under inuence of spring H5, which spring is connected between the perforator assembly and the side frame 98. Assuming that the automatic tuning unit has been operated in response to depressing one of the keys, for example key 18H, the tuning disc assembly will likewise have been rotated until the no record disc pin 92 is axially aligned with the perforator positiong shaft 93 as shown in Fig. 5. The initial rotation of cam |02 will permit the Vperforator assembly to move to the left until the positioning shaft 93 engages the tuning disc pin 92 thereby limiting the travel of the perforator so that the metallic punch ||6 isA laterally aligned above the tape ||1 in a position corresponding to the angular position of the shaft |53 of the tuning unit. The perforator cam |0| 'has a'lip I9 thereon which lip width is substantially equivalent to the width of the paper. When the perforator positioning shaft 93 engages the tuning disc pin .92, after the no record tuning button has been pressed, the head of the metallic punch |||5 is beyond range of the cam lip H9, so thatthe cam lip will not engage the metallic punch H6, and consequently no perforation will be kmade in the tape ||1. However, when any other tuning button, other than the no record tuning button 18H, is depressed, the metallic punch ||6 will be in the path of the perforator cam lip H9. The drawing ofthe perforator assembly as shown in Fig. 3,'has had its position exaggerated for the sake of clarity so lthat it is shown moved forward in the drawing. Actually, the normal positionrof the metallic punch IIB is disposed just below the cam lip ||9 so that as soon as the cam shaft 6| starts to ro- `tate, the cam lip ||9 will engage the head of the metallic punch H6, urging lit downwardly until the tape |11 is perforated. The punch ||9 will then be urgedupwardly under infiuence of its spring |20. As soon as the cam'lip 9 Vrides off of the .head surfaceof the punch H6, vthe rotation of the perforator positioning cam n|021Wil1 operate kto urge thepin H3 of the positioning cam arm |04 upwardly, thereby moving the perforator assembly to its retracted position as shown in Fig. 5, where it remains quiescent.

The stepping cam arm |2| has one end thereof pivoted to a link |22, with the opposite end of the link pivoted on the drum shaft |41. A second link |24 has one end supported on a pivot shaft with the opposite end of said link |24 being pivoted at |26 to the stepping cam arm |2|. A camming pin |21 is secured to the free end of the stepping cam arm |2| and is adapted to engage the camming surface of the drum stepping cam |03 and be held thereagainst under iniiuence of spring |28. A ratchet is pivoted to the link |22 with the ratchet engageable with the pins |3| equidistantly disposed on the end of drum |32. The purpose of the drum stepping cam |03 is to cause the drum shaft |41 and its two drums |32-I48 to be simultaneously rotated in two successive steps to properly move the tape so that the individual perforations will be periodically aligned rst with one of the contacts (Figs. 6 and '1) and then with one of the contacts |36, which contacts are carried by the contact support |31. The drum stepping cam |03 when rotated by shaft 6| in the direction of arrow X will cause the stepping cam arm |2| to move, rst, in the direction of arrow Y so that the ratchet |30 on the link |22 will be moved over one of the pins, such as |3|. As the pin |21 rides outwardly on the camming surface the movement of the stepping cam arm |2| in the direction opposite to the arrow Y will cause a rotation of the drum |32 so that one of the perforations will come under one of the contacts |35, which are the tuning contacts in parallel with the Various push buttons 18A to 18G. The drum 32 at the beginning of the cam operating cycle, will remain stationary for approximately 4 seconds during the automatic tuning operation caused by perforations being under one of the contacts |35 which will be explained later. The second half of the operating cycle of cam |03 will again move the drum 32 until the perforation is now under the complemental contact |36. At the end of the operating cycle of cam |03, the drum |32 will thereafter remain stationary, with said complemental contact |36 engaging the metallic shell |46 of the drum |32 through said perforation. The complemental contact |36 is used for completing a circuit to turn on power to operate the radio receiver proper which will be explained in detail in relation to the control circuit.

The switch cam |06 has a pivotally mounted contact arm 4| (Figs. 3 and 5) with one end of said arm riding on the cammina surface of said cam. It will be seen that the movable contact |4| is normally engaging the contact |42. As soon as the cam shaft 6| starts to rotate, contact set |4||42 is broken and the movable contact |4| engages the upper contact |43. The closure of contact set |4||43 energizes the latch bar release relay |44 (Figs. 1 and 8) which is used to actuate the push button latch bar |62 to prevent manual operation of the tuning unit during the 12 second operating cycle of the automatic recording mechanism. Further operation of the switch lai, which is operated by cam |60, will'be explained in detail in relation to the control circuit operation.

The Contact support |31 and its associated drum |32 shown in Figs. 6 and 7, has a rectangular frame |45 of insulating material which is supported in relation to the drum in any convenient manner such as by a bracket (not shown) supported on the base member 95. The contacts |35 and |36 are shaped in a conventional manner so that they may positively engage the metallic drum shell |46 of the drum |32 to permit circuit closure through a characteristic marking, or perforation in the tape between any one of the tuning contacts |35 and the drum shell |46, or between any one oi the contacts |36 and the drum shell |46. It being understood that the shaft |41 is insulated from the drum shell |46 in any convenient manner. The drums |32 and |48 are secured to the drum shaft |41. Each of the drums has a plurality of sprocket pins |50 (Fig. 4) equidistantly spaced on their respective drum surfaces. The pins |50 are similarly disposed on both of the drums |32 and |48 and form sprockets which engage perforations such as ist formed on opposing sides of the tape to control the movement of the record perforations between the metallic punch ||6 of the perforator assembly |0 and the contacts |35 and which contacts are the automatic tuning control and automatic power control contacts, when the tuning unit is operating in accordance with the perforated record.

The paper tape disposition presented in Fig. i shows a roll of paper tape ||1 mounted cn a shaft |53 with the opposite end of the tape beingr wound on a take-up reel |54. A pulley |55 is connected by a belt |56 to a second pulley |51 which latter pulley is mounted on cam shaft 6| also shown in Figs. 3 and 5. As described above, rotation of the cam shaft 6| rotates both sprocket drums |32 and |48 simultaneously, so they will be synchronized, or in step with each other. The perforator assembly |0 is shown in a representative form in Fig. 4 to indicate its relative position in relation to the contact support |31. Since each perforated record is made at the close of a 30 minute program period, while the tuning action to retune that same program the following week should occur at the start of the program period, it is evident that the length of paper tape between the punch ||6 and the tuning contacts |35 should correspond to an operating time of 1 week less 30 minutes. In the particular model of the invention described herein, the tape movement was one-quarter of an inch every 30 minutes. The length of the tape between the punch ||6 and the contacts |35 was thus eighty three and one-half inches. Guide rolls such as |53 are used to facilitate movement of the tape. Guide rolls such as |66 and |6| are employed to cause the tape ||1 to be properly aligned and to provide a suitable twist therein to permit free movement of the tape between the tape roll |52 and the take-up reel |54.

Push button release mechanism The push button release mechanism is part of the automatic tuning unit, and its electrical operation will be fully explained later in relation tc the control circuit. The mechanical operation of the push button release mechanism will be described in relation to Figs. 8 and 9, in conjunction with the schematic wiring diagram of Fig. l. A latch bar |62 is pivotally mounted on a shaft |63 and is normally held downwardly in a latched position under influence of spring |64. A plurality of apertures |65 are formed in the latch bar to permit latching engagement with any one of the push button movable contacts 18A to 18H. Springs, such as |38, normally urge the movable contacts, such as 18A, out of engagement with the latch bar |62. The manually operable push buttons |66 (only one of which is shown) have a shaft |61 which is held in a panel |66 with a spring 69 on said shaft normally urging the push button outwardly in the direction opposite to that shown by arrow Z. When the push button |66 is urged in the direction of arrow Z, the free end of the shaft |61 will engage its respective movable contact, which in turn engages the curved lip portion |16 of the latch bar |62 thereby raising said latch bar until the movable contact such as 18G is urged into its complemental aperture |65 formed in the latch bar |62, thereby holding said movable contact in a latched position. A further operation performed, when latch bar |62 is raised by action of a push button, is to release any other push button which has previously been engaged. This action prevents the possibility of having two push buttons engaged at the same time. When the release coil |411 is energized, the latch bar |62, which is of a magnetizable material, will be elevated to the position shown dotted as |62', as shown in Fig. 9. When the movable Contact, such as 18G, is in the latchcd position (Fig. 9), the corresponding back contact |69 (see Fig. 1) will be closed. When the push button is in the released position, as is contact 18A in Figs. 8 and 1, the front contact is closed. Therefore, it will be seen that each individual push button at all times will have either its front or its back contact closed. When the latch release relay |44 is energized, the latch bar will be drawn into the upper position, shown dotted in Fig. 9, and all of the movable contacts such as 18G will be released under influence of their respective springs, such as |65, so that all of the front contacts, such as |59, are closed.

Control circuit and electrical operation The schematic diagram shown in Fig. 1 has the movable member of the operating switch 25 on the off contact 26. With the operating switch in this position, the relay 86 and the relay |1| are deenergized. Assuming, for the moment, that the automatic recording mechanism is in its normal rest position, the contact set MI-UBS will be open so that the latch release relay |46 will be deenergized, and the contact set bil- |42 will be closed. Under these conditions, all of the circuits presented in Fig. 1 are normally inactive with relays 8D, |1| and |44 being deenergized.

As previously explained, the sprocket drum |32 will be rotated every half-hour throughout the 24 hour period of each day, seven days a week. The periodic rotation of the sprocket drum at halfhour intervals takes place continually whether or not the radio is in actual use. This condition exists because the radio is at all times tuned for reception for the particular program for a given period according to the record established by the perforations in the tape.

As previously explained, the manual push button operation will tune in any station corresponding to the particular push button pressed. For example, if push button 18G is depressed, there will be closure of the back contact |69 with its movable contact 18G. Assuming relay 86 is energized by movement of the operating switch to the on position so that contact set 25-28 is closed, a circuit may be traced from terminal 15,

which is one side of the power transformer 16 through conductor 14, to the motor 1D through conductor |12, selector disc 6E, sliding contact 11G, conductor 8A, contact' set |69-18G, conductor 85, through contact set 153-82, through contact set #i2-I4 thence to terminal 6| which is connected to the opposite side of the transformer 16. The tuning motor will rotate until the insulating strip 68 engages the sliding contact 11G'at which time the motor circuit is interrupted and the station corresponding to push button 18G is tuned in.

It will be seen that each one of the tuning contacts |35 are connected to a corresponding back contact of one of the push buttons 18A to 18G inclusive. All of the contacts |66 are connected to a common terminal |13 which in turn is connected to the memory contact 21 of the operating switch. A conductor |16 connects the metallic shell of the drum |32 to the terminal 6| of the power transformer 16.

As previously explained, the periodic rotation of the sprocket drum |62 after completing its 12 second operating cycle at the end of each halfhour period, will leave the particular perforation, if any exists for that program period, under one of the contacts |36. Consequently, if a record exists on the tape for that particular program time, the first part of the operating cycle of the automatic recording mechanism will bring the perforation, first, under one of the contacts |65 so that there is a closure of about 4 seconds duration between the particular contact |36 and the metallic shell of the drum |32. During this four second interval when the particular tuning contact |35Y engages the metallic shell of the sprocket drum |32, a circuit may be traced from the power transformer contact 15, through cone ductor 14|, the motor 16, either one or the other of the selector discs, depending on which station is selected by the perforation in the drum, through conductor |14, thence to terminal 8| which is the other side of the power transformer 16. At that time, the station corresponding to the particular perforation in the tape will be automatically tuned in. Further rotation of the sprocket drum in the remaining portion of the 12 second duration operating cycle of the auto'- matic recording mechanism will rotate the sprocket drum |32 sufficiently to progressively move the perforation under the corresponding contact 36. The engagement of contact |36 with the metallic shell |66 of the sprocket drum |32 will complete a circuit between the terminal 8| of the power transformer and the stationary memory contact 21 of the operating switch.

It will be seen that if the operating switch movable member 25 isrmoved to the memory position, whereby contact set 25-21 is closed, a circuit will be completed from the terminal 8| of the power transformer thence through conductor |16, drum shell |46, contact |36, contact set 21-25, conductor |18, through the winding of relay 86, thence to the terminal 15, of power transformer 16. Under these conditions, the energization of relay 86 will close contact set 83-92 and will also close contact set |15. Contact set |15 is connected in a conventional manner to substitute for the power switch on the volume control of the radio receiver, such as is shown in the RCA Model U130.

If the user of a set wishes to play the radio, he merely turns the operating switch to the memory position. Y If a record has been previously made the lprogram which has been automatically tuned in will be heard. If after turning the operating switch to the memory position no program is heard, the listener knows that no record was previously made for that particular program. Therefore the operator merely turns the operating switch to the on position. Closure of the operating switch contact set -28 will complete a circuit from terminal 8| connected to one side of the power relay 16 through the contact set 28-25, thence through conductor |18, through the winding of relay 80, and thence to terminal 15, which is the opposite side of the power relay 16. Energization of relay 80 will cause closure of Contact set |15 thereby turning on the power to the radio receiver proper. Closure of contact set 82-83 o-f relay 80 will also connect power from terminal 8| of the transformer 16 to all of the serially connected movable contacts of push buttons 18A through 18H, so that manual operation of any one of the push buttons will cause the corresponding station to be tuned in.

When a record exists for a particular program period, relay |1| will be energized through a cir#- cuit which is traceable from the terminal 15 of the power transformer through conductor |16 thence through the winding of relay |1| through one of the contacts |36, to the conductor |14 which is slidably connected to the shell |46 of the sprocket drum |42, thence to the terminal 8| which is connected to the other side of the power transformer 16. The energization of relay |1 I, therefore, does not interfere with the normal function of the radio operation when a. record exists.

However, where there -is no record for the particular program period, and the radio during that particular period was used and tuned in by the manual push button operation, but was shut off before the end of the program period, it is assumed that the operator did not desire to create a record. The relay |1| prevents the creation of a record by automatically tuning the radio to the no record position as soon as the radio operating switch is turned to the off position, since the deenergization of relays |1| and 80 will cause closure of contact sets |11 and 82|39 respectively, which feed power to the tuning motor via the sliding contact 11H.

If there is a program record for a particular period, but the user desires to eliminate that particular program he merely presses the no record button which turns the radio to a portion of the spectrum where no record exists, as previously explained.

If a program record exists for a. particular period but the user desires to listen to a special program on another station, but also wishes to retain the record, he may do so. Before the program period changes, he merely presses the manual push button to the previously recorded sta.- tion.

If a record is desired where no record previously existed for that particular program period,

the user merely leaves the receiver tuned to the desired station until the end of the program, and the record is made automatically at the end thereof in vthe normal manner.

What is claimed is:

1. In combination a radio receiver having a manual operating means and an automatic tuning mechanism, an automatic recording mechanism for marking characteristically laterally and longitudinally spaced markings on a moving tape and for causing said marking thereafter to tune said receiver to said stations and control operation of said radio receiver automatically at predetermined recurring time intervals, said automatic recording mechanism comprising a periodic driven shaft having a perforator positioning means responsive to the movement thereof for causing the positioning of a perforator to various locations laterally across said tape representative of stations tuned in, a perforator actuating means positioned on said shaft for causing said tape to be perforated in said various locations, and a pair of cylindrical drums in contact with said tape and linked to and actuated by said shaft for causing the periodic moving of said tape thereby to provide said perforations in longitudinally spaced as well as laterally spaced relation to each other, the stationary intervals between the periodic movements of the driven shaft representing substantially the duration of the program time intervals; a timing unit for controlling the periodic operation of said automatic recording mechanism; and a control circuit for automatically operating the radio receiver in accordance with the lateral and longitudinal locations of the perforations of said tape means, said control circuit including a portion of said manual operating means for preventing the automatic recurrence of the marking of a characteristic perforation on said tape representing substantially a station previously tuned in at any given time interval.

2. The combination as defined in claim 1, wherein there are provided means responsive to operation of the automatic recording mechanism for inactivating the manual operating means during said automatic recording mechanism operation.

WILLIAM A. TOLSON.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,983,759 Houston Dec. 11, 1934 1,989,558 Myers et al. Jan. 29, 1935 2,055,031 Hutchings Sept. 22, 1936 2,083,722 La Via June 1'5, 1937 2,089,618 Plym et al Aug. 10, 1937 2,333,024 Mathes Oct. 26, 1943 2,337,568 Owens Dec. 28, 1943 2,408,370 Burrill Oct. 1, 1946

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