US2702313A

US2702313A - Morse code educational machine with variable space time control means

Info

Publication number: US2702313A
Application number: US202464A
Authority: US
Inventors: Edward W Andrews
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-12-23
Filing date: 1950-12-23
Publication date: 1955-02-15
Anticipated expiration: 1972-02-15

Description

Feb. 15, 1955 E. w. ANDREWS 2,702,313

MORSE com: EDUCATIONAL MACHINE WITH VARIABLE SPACE TIME CONTROL MEANS Filed Dec. 23, 1950 3 Sheets-Sheet l Edward WMWQJMS fdg 2.01%

Feb. 15, 1955 E. w. ANDREWS MORSE CODE EDUCATIONAL MACHINE WITH VARIABLE SPACE TIME CONTROL MEANS 3 Sheets-Sheet 2 H mmwm (U l5! fIIZVEJYLUF-'" Filed Dec. 23. 1950 Edward wwkzciz ezms' Feb. 15, 1955 E. w. ANDREWS MORSE CODE EDUCATIONAL MACHINE WITH VARIABLE SPACE TIME CONTROL MEANS I5 Sheets-Sheet 3 Filed Dec. 23, 1950 United States Patent MORSE CODE EDUCATIONAL MACHINE WITH VARIABLE SPACE TIME CONTROL MEANS Edward W. Andrews, Chicago, 111.

Application December 23, 1950, Serial No. 202,464

18 Claims. (Cl. 178-115) The present invention relates to improvements in machines for educating students in Morse code, and more particularly concerns novel means for selectively varying the space time interval between the code characters, words and sentences.

As students in telegraphic code reception progress, with corresponding increases in the words per minute rate, the speed of transmision of practice messages to the students must be increased to continue the learning process.

In prior machines for transmitting messages to students at uniform rate for any given speed requirement, the change in spacing time interval between the code characters has either been directly proportionate to the change in the interval between dots and dashes of each character, or, at best, only a very limited and predetermined number of space time changes have been permitted according to a fixed pattern. Where there is a uniform speed-up in both the dot-dash time interval and the space time interval, the individual dots or dashes of at least certain code characters run too closely together at higher speeds, while at low speeds are further apart than student abilities warrant. On the other hand, where only certain fixed space time interval variations are provided for, either the successive stages of space time control are too great for some students, or they are not developed by rapid enough increments to challenge the learning capabilities of the more apt pupils.

It is, accordingly, an important object of the present invention to provide an improved telegraphic code educational transmission machine in which infinitely incremental adjustments in the space time interval can be efiected throughout a wide range for any dot-dash time interval adjustment or setting.

Another object of the invention is to provide an educational telegraphic code transmission machine in which a wide range of both space time interval and dot-dash time interval adjustments can be affected independently of or relatively to one another.

A further object of the invention is to provide in an educational telegraphic code transmission machine improved means for selectively adjusting the space time interval between code characters.

Still another object of the invention is to provide improved multiple selective code signal and space time interval electrical impulse mechanism.

A still further object of the invention is to provide improved perforated tape for use in an educational telegraphic code transmission machine.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of an exemplary embodiment thereof tallleer;1 in conjunction with the accompanying drawings, in w 1c Figure 1 is a front elevational view of an educational telegraphic code transmission machine embodying the invention and with certain parts broken away and in section to reveal details of structure;

Figure 2 is an enlarged fragmentary sectional detail view taken substantially on the line IIII of Fig. 1;

Figure 3 is an enlarged top plan view of the machine;

Figure 4 is an enlarged fragmentary vertical sectional view taken substantially on the line IVIV of Fig. 3;

Figure 5 is an enlarged fragmentary sectional detail view taken substantially on the line V-V of Fig. 3; and

Figure 6 is a vertical sectional detail view through the machine taken substantially on the irregular section line VI-VI of Fig. 3.

A telegraphic code instruction machine with which the present invention is concerned is adapted for group or individual instruction by producing through controlled mechanical means Morse code signals either visually or audibly responsive to electrical impulses initiated with the aid of a record medium, comprising in a simple and inexpensive, practical form a record tape 10. Thin strip material such as plastic or paper is used for the tape 10 which may be of substantial length and carried by a supply reel 11 from which the tape is fed to a driven windup or take-up reel 12.

Support for the

record tape reels

11 and 12 on spaced vertical axes and in a common horizontal working plane is provided by a panel 13 which is preferably made from an insulating material such as wood or Bakelite. In a portable machine as shown, the panel 13 provides a deck or top for an instrument case or box including upright side walls 14, a rear wall 15 and a front wall 17 providing an enclosure supporting the top wall panel 13. Additional intermediate support for the panel 13 is provided by spaced parallel

vertical partitions

18 and 19, the lower edges of which are supported upon a bottom wall panel 20. This provides a rectangular housing adjacent to one front corner of the top wall 13 of which, herein the left front corner, the supply reel 11 is mounted removably upon a spindle 21 while adjacent to the opposite front corner of the top wall the take-up reel 12 is mounted on a rotatable spindle 22. Thus the supply reel 11 is supported for more or less free rotation upon its spindle 21 while the take-up reel 12 is supported relatively rotatably, and if desired, removably about the drive spindle 22.

A releasable driving connection between the drive spin dle 22 and the reel 12 is effected by means such as a pivoted blade latch 23 one end portion of which is pivotally supported by a post 24 carried fixedly by the reel 1 By manipulation of a handle or knob 25 carried by the distal end portion of the latch blade 23, the latch can be swung into and out of latching or coupled engagement within an upwardly opening slot 27 in the upper end portion of the drive spindle 22. Thus, when the coupling latch blade 23 is in the full line position as shown in Figs. 1, 3 and 6, the take-up reel 12 is coupled for rotation with the spindle 22 while when the latch blade is swung to the dash outline position shown in Fig. 6 or even outwardly beyond that position the take-up reel is released (firlom the spindle 22 and may rotate freely about the spin- Release of the coupling between the driven take-up reel spindle 22 and the reel 12 is desirable for re-winding purposes when the record tape 10 is to be re-wound from the take-up reel 12 to the supply reel 11. For this purpose the supply reel 11 carries an upright manipulating handle 28 eccentrically disposed relative to the axis of the reel and adjacent to the periphery of the reel. Rotation of the supply reel 11 by means of the handle 28, after the takeup reel 12 has been uncoupled from the drive spindle 22 effects re-wind of the record tape 10.

Morse code signals are produced electrically under the control of the record tape 10. For this purpose, the tape is provided with coded indicia or signal indicating means, herein in the form of a series of dot-dash apertures 29 in one margin comprising small, preferably round holes denoting dots and longitudinally elongated, slot-like holes denoting dashes. The individual or companion apertures representing the various alphabetical, numeral or punctuation characters are uniformly spaced from adjacent characters in the message to be transmitted, the spacing between the characters appearing as imperforate areas of the tape.

Creation of the electrical impulses for energizing or motivating any preferred visual or audible signal-producing device or apparatus (not shown) under the control of the record tape 10 may be elfected in any preferred manner as by means of an electric eye or similar scanning device trained on the record bearing margin of the tape, but is shown herein as an electrical contact point make and break mechanism 30 (Figs. 3, 4 and 5). This includes a sensitively flexible feeler arm 31 which is secured adjacent to one end as by means of a screw 32 to a supporting post or block 33. The supporting block 33 is preferably made from insulating material such as Bakelite or pressed fiber and the screw 32 preferably extends entirely therethrough to serve at the opposite side of the block 33 as a binding post to which an electrical lead 34 is secured by means of a nut 35. Thereby, the feeler arm 31 which is preferably made from an electrically conducting material such as resilient spring bronze or the like forms part of an electrical circuit with the lead 34.

Intermediate its ends and a substantial distance from its attachment to the supporting block 33, the feeler arm 31 carries a rigid feeler finger 37 which is preferably in the form of a generally comically shaped knob projecting from one face of the arm and disposed to engage the record tape at the marginal area thereof in line with the code signal apertures 29. Through this arrangement, as the record tape 10 is drawn past the feeler finger 37 from the supply reel 11 and over a backing member in the form of a post 38 and with the feeler finger 37 riding the record tape in line with the dot-dash apertures 29 and with the feeler arm tensioned toward the backing post 38, the feeler finger will snap into each of the dot-dash signal apertures in succession as the finger registers with each aperture. In order to increase the depth of penetration of the feeler finger 37, the backing post is provided with a recess 39 opposite the feeler finger.

Upon dropping of the feeler finger 37 into one of the signal apertures 29, as shown in full outline in Fig. 5, the feeler arm 31 flexes toward and into engagement with an electrical contact point member 40 (Fig. 4) to close an electrical circuit including a lead 41 leading from the contact point member 40. This energizes the audible or visual signaling device associated with the machine. As the record tape moves on, the feeler finger 37 is cammingly ejected from the signal aperture 29 by the tape and as a result the feeler finger 37 is flexed out of engagement at its distal end portion with the contact member 40 and the signal circuit is broken. It will be apparent that the time interval between signals will be determined by the extent of imperforate area of the record tape 19 between the dot-dash signal apertures 29.

In a simple and eflicient structure, the contact member comprises a screw threaded through an insulating post 42 secured as by means of a screw 43 to the supporting panel 13. Thereby the contact member 48 can be accurately adjusted with respect to the proximal end por tion of the feeler finger 37 for efficient electrical make and break relationship of the tip of the contact screw member 40 with a contact point 43 carried by the feeler arm 31.

Beyond the backing post 38, the record tape 10 is threaded over an idler roller or post 44 and then passes over a rubber tired drive roller 45 against the periphery of which the tape is pressed by a pressure roller 47. For mounting the pressure roller 47 yieldably and releasably, it is carried rotatably by one end portion of a supporting lever 48 intermediately supported pivotally on a pintle bearing 49 rising from the panel 13. At its opposite end the lever 48 is formed with a manipulating handle 50. Spring bias by means of a tension spring 51 is aflorded by connecting one end of the spring to the handle end portion of the lever 48 while the opposite end of the spring is attached to a post 52 rising from the panel 13 in spaced relation to the normal operating position of the handle end portion of the. lever and on the side of the lever remote from the record tape. Thereby the carrying lever 48 is normally urged to swing the pressure roller 47 into tape-pressing engagement against the drive roller 45, but when it is desired to release the pressure roller the handle 50 can be manipulated to overcome the 'tensioning over another idler roller or post 53 and thence passes to the take-up reel 12.

Means are provided for driving the tape drive or feed roller 45 and the take-up reel 12 in unison. To this end, the feed roller 45 is coupled to a vertical shaft 54 which extends both above and below the panel 13 and below the panel carries a pulley 55. An endless flexible driving member such as a belt 57 runs over the pulley 55 and over a pulley 58 carried by the lower end of the takeup reel shaft 22, an aperture 59 being provided in the partition 19 for passage of the belt 57 therethrough.

At its lower end the shaft 54 carries fixedly a frictional transmission disk or plate 69 of substantial diameter which'normally rests upon a frictional drive roller 61 carried by a shaft 62 coupled with and carried by a pulley 63 journaled on an appropriate bearing carried by a bracket 64 on the partition 19. Trained over the pulley 63 is a flexible endless driving element such as a band or belt 65 which is also trained over a pulley 67 on a transmission shaft 68 on which is also mounted a driven pulley 69 motivated by driving means such as a motor 70 through the medium of a flexible band driving element or belt 71 (Figs. 2 and 6). The motor 70 is mounted within the casing of the machine on the bottom wall 20 and is suitably connected with a source of electrical energy through a cable or electrical cord 72 extending through the rear wall 15 of the housing. For controlling the motor 70 an electrical switch may be provided at a conveniently accessible place on the machine, as for example on the front wall 17, with a manipulating handle 73 conveniently exposed. The other electrical circuits involved in the machine may also be controlled by this same switch.

Inasmuch as a beginner student must have the code signals transmitted to him rather slowly, or at low speed until his receptive senses become accustomed to the mode of transmission, and as the students receptivity develops transmission should be effected progressively more rapidly, means are provided for adjusting the code transmission speed. According to the present invention such speed control is divided into two phases, namely, a dot dash time control and a space time control.

Dot-dash time control is effected by varying the radial distance of the transmission friction roller 61 from the axis of the transmission disk 60. For this purpose, the friction roller shaft 62 may either be a square shaft or otherwise keyed in relation to the pulley 63 and longitudinally slidable therethrough so that this shaft can be adjusted longitudinally to vary the radial position of the friction drive roller 61 relative to the transmission disk 60. Means for effecting longitudinal or axial adjustment of the shaft 62, in a simple form, may comprise an angular shifting rod 73 rotatably journaled in a bearing 74 carried by the front wall 17 and having a manipulating knob 75 mounted on its outer end and conveniently accessible at the outer side of the front wall 17 of the casing. A pointer 76 on the knob is related to a scale 77 for visual indication of the adjusted condition of the mechanism. The scale may be calibrated for various dot-dash time intervals and may be appropriately identified by a legend as shovm in Fig. 1.

At its inner extremity, the shaft 73 has a depending angular leg 78 having a lost motion coupling 79 with the outer extremity of the shaft 62. This coupling may comprise a ball and sliding socket coupling substantially as shown. Hence, by turning the knob 75, throughout a substantial range of oscillation, axial adjustment of the shaft 62 may be effected from the front of the machine. It will be apparent that as the friction drive roller 61 is driven at a constant speed, adjustment thereof radially with respect to the transmission disk 60 will cause more rapid rotation of the drive shaft 54 as the friction roller is moved toward the axis of the shaft 54 and that the speed of the shaft 54 will be slower as the friction roller 61 is moved toward the perimeter of the transmission disk 60, thereby effecting corresponding adjustment in the speed of travel of the record tape 10 as motivated by the feed roller 45 and thus varying the speed of transmission of the dots and dashes constituting the characters in the message to be transmitted as recorded on the tape.

The second phase of speed control has to do with the space time interval between the characters or words recorded on the record tape 10. By the present invention space time control is adapted to be effected independently of the dot-dash time control. For this purpose, a second but normally idling friction drive roller 80 is provided in a position above the normal position of the transmission disk 60 while the latter is in driving engagement with the friction drive roller 61. By preference the friction drive roller 80 is disposed at the diametrically opposite side of the transmission disk 60 from the dot-dash time control roller 61 and for this purpose is carried by a shaft 81 coupled with a pulley 82 supported within a bracket 83 mounted on the partition 18 and operatively coupled by an endless flexible band such as a belt 84 with a pulley 85 carried fixedly by the adjacent end of the shaft 68. Similarly as in the case of the shaft 62, the shaft 81 is longitudinally reciprocably coupled with the pulley 82 and means are provided for manually adjusting the shaft 31. Such adjusting means herein comprise an angular actuating rod 87 journaled through the front Wall 17 of the housing and having an angular depending leg 88 having a lost motion connection 89 with the outer end portion of the shaft 81. A knob 90 on the outer end of the control shaft 87 is manipulable to effect adjustment of the friction roller 80 radially of the transmission disk 60. Visual indication of the space time adjustment through the medium of the control knob 90 is afforded by means of a pointer 91 on the knob registering with a space time control calibrated scale 92 on the outer face of the front wall 17 of the machine or instrument housing.

Means are provided for effecting shifting of the transmission disk 60 from engagement with the friction roller 61 into engagement with the friction roller 80 automatically under the control of the record tape 10. To this end, the drive shaft 54 is of substantial depending length below the top panel 13 so that a substantial portion of the shaft intervenes between the drive pulley 55 and the transmission disk 60, and on this intervening portion of the shaft is either formed or mounted an armature 93 passing upwardly through the field of a solenoid 94 suspended as by means of hanger bolts and spacers 95 below the top carrying plate or panel 13. When the solenoid is deenergized, the armature 93 and thereby the shaft 54 drops downwardly into a normal position wherein the transmission disk 60 rides upon the friction roller 61 by which control of the speed of the dot-dash time interval is effected. When the solenoid 94 is energized, the shaft 54 is drawn upwardly as indicated in dot-dash outline in Fig. 6 and the transmission disk 60 is correspondingly raised from the friction roller 61 into driving engagement with the friction roller 80 by which the space time interval is controlled.

Energization of the solenoid 94 is controlled by the record tape which, for thus purpose, is provided in the margin thereof opposite the dot-dash aperture carrying margin with longitudinally elongated pause interval or space determining apertures 97 disposed in spaced series alternating with the character apertures in the opposite margin of the tape by being in transverse alignment with the imperforate areas of the tape between the groups or individual apertures indicating code characters. The apertures 97 may be any desirable size, such as the size of the dot aperture 29, but herein are shown as longer than the dash apertures 29. As shown, the character apertures 29 are in the lower margin of the tape while the space time interval apertures 97 are in the upper margin of the tape, although this order could be reversed if desired.

For making and breaking an electrical energizing circuit for the solenoid 94, under the control of the record tape 10 and more particularly the margin thereof having the space time control apertures 97, a sensitively resilient feeler arm 98 which may be in all essential respects identical with the dot-dash signal circuit controlling feeler switch arm 31, is mounted adjacent to one end thereof as by means of a screw 99 to the insulating post 33. The screw 99 serves also as a binding post to which is connected a terminal end on an electrical lead 100 secured in place by means of a terminal clamping screw 101. Intermediately, the feeler arm 98 carries a finger knob 102 of generally rounded tip conical shape which rides against the margin of the tape 10 in alignment with the apertures 97 (Fig. 5) so that as the tape travels thereby, the feeler finger 102 will drop into the successive elongated space time control apertures 97. A recess 103 in the opposing surface of the back-up member 38 provides clearance for fairly deep penetration of the feeler finger 102 through the respective apertures 97 While the feeler tip or finger 102 is riding an imperforate portion of the tape 10 intermediate adjacent space time control slots or apertures 97, the resilient feeler arm 98 is stressed away from the record tape and thereby a contact tip 104 on the distal end portion of the feeler arm is held out of engagement or contact with an electrical contact tip 105 provided by an adjustable screw member threaded through the insulating post 42 and having electrical connection in the post with an electrical lead 107 which completes a circuit with the lead 100 through the solenoid 94. Thus, when the contact point 104 is moved with the flexible feeler arm 98 into the circuit breaking position by riding of the feeler finger 102 on an imperforate portion of the record tape 10 intermediate space time interval slots 97, the solenoid 94 is deenergized and the tape 10 is driven at the controlled speed desired for the dot-dash portion of the tape, by reason of the transmission disk 60 riding the continuously driven friction drive roller 61. However, instantly upon dropping of the feeler finger 102 into one of the space time control slots 97, the electrical circuit energizing the solenoid 94 is completed by engagement of the contact point 104 with the contact tip 105, and the solenoid draws up the armature 93 to disconnect the dot-dash time control drive and connect the space time control drive by engagement of the transmission disk 60 drivingly with the friction drive roller 80. These operations continue automatically throughout the running of the record tape 10. As desired, adjustment of the dot-dash time or of the space time intervals can be adjusted relatively throughout the range of adjustment permitted by the speed control transmission structures including the manipulating

knobs

75 and 90.

In order to permit vertical reciprocations of the drive shaft 54 without corresponding reciprocations of the tape feed wheel or roller 45, a suitable sliding key coupling is provided. In a preferred arrangement, such coupling comprises an eccentric arm 108 (Figs. 1, 3 and 6) attached to the upper end portion of the drive shaft 54 projecting above the feed roller 45 and overlying the feed roller in vertically spaced relation. Depending from the distal end portion of the arm 108 is a keying stem or coupling stud 109 which slidably engages in a vertical coupling bore or aperture 110 adjacent to the perimeter of the drive roller. Thus, as the shaft 54 is alternately reciprocated upwardly and then downwardly during operation of the instrument, a constant drive coupling is maintained with the feed roller 45 but the roller remains in a horizontal plane so as to avoid vertical shifting of the record tape 10.

When the record tape 10 is being threaded through its operative path, and more especially while it is being disposed about the flanged guide and back-up member or post 38, it is desirable that the feeler fingers 31 and 93 be moved entirely clear of the post. To this end, the supporting block 33 is preferably mounted upon the supporting panel 13 in such a manner that it can be swung out of the operative position to effect clearing of the feeler fingers from the back-up post 38. This is accomplished by providing a bolt 111 and a thumb nut 112 for securing the block in place. Thereby, by loosening the thumb nut 112, the block 33 is loosened and can be swung into an out-of-the-way position as indicated in dash outline in Fig. 3. The block 33 can then be quickly returned to the operative position by swinging it back to the full line position as shown, which may be accurately determined by engagement of the block with a stop screw 113 threaded through a post 114 and maintained in adjusted position by a lock nut 115.

From the foregoing it will be apparent that the present invention provides a telegraphic code teaching instrument which is virtually infinitely adaptable to the rate of progress of a group or of an individual receiving instruction in this subject. tion provides for adjusting the space time interval inde pendently of the dot-dash space time interval. The process of learning telegraphic code can thus be substantially speeded because the students ability to distinguish between telegraphic characters develops more rapidly than the ability to distinguish between the dots and dashes which are combined to represent the telegraphic characters. Hence the space time interval can be reduced appreciably before it is expedient to reduce the dot-dash time interval. By the present invention this can be accomplished with facility with full relation to the capabilities of the particular students involved.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In combination in an educational code transmission instrumentality, means for automatically producing telegraphic code electrical character impulses,'means for electrically controlling the space time intervals between character impulses, means for manually adjusting said space time interval control means to vary the length of the space time interval, and means for adjusting the More especially, the present inven 7 length of the character impulses independently of said space time interval adjustment means.

2. In combination in an educational telegraphic code transmission machine, a record tape, means for motivating the tape through a longitudinal path, telegraphic code signal-producing means, means on said tape cooperating With said signal-producing means to control the production of telegraphic signals by said signal-producing means, space time interval control means cooperatively related to said motivating means, means on said tape cooperating with said space time interval control means to control the duration of space pauses between code signal characters, and means for adjusting said space time interval control means for varying the duration of space pauses between code signal characters as determined by motivation of the tape through said path by said motivating means.

3. In combination in an educational telegraphic code transmission machine, a supporting member, a record tape, a supply reel supporting the tape, a take-up reel receiving the tape as fed from the supply reel, a feed device for moving the tape from the supply reel to the take-up reel, said tape having parallel rows of spaced apertures therein, the apertures in one row corresponding to dots and dashes of a message, the apertures in the remaining row corresponding to space intervals between telegraphic code characters, means cooperating with the code signal apertures of the tape for effecting code signals, and means motivated by the remaining row of apertures for controlling the space time intervals between code characters.

4. In combination in an educational code sending machine of the character described, a support, supply and take-up reels supported in spaced relation on said support and adapted to support a record tape to be unwound from the supply reel onto the take-up reel, an electrical switch mechanism cooperative with the tape for control by the tape to create electrical code signal impulses, means for feeding the tape from the supply reel to the take-up reel, and means carried by said support and under the control of the tape for controlling said feed means to control the space time interval travel of the tape between code signals.

5. In combination in an educational code transmission device of the character described, a pair of electrical circuits including respective make and break switches, means for moving a record tape having parallelspaced rows of apertures therein past said switches, one of said switches having means riding the tape in line with one of said rows of apertures and the other of said switches having means riding the tape in line with the remaining row of apertures, one of said circuits controlling said feed means and the other of said circuits controlling telegraphic code signal production.

6. In combination in a telegraphic code instruction machine of the character described, means for feeding a perforated tape having a parallel pair of rows of perforations therein in a given path, one of said rows of perforations comprising a telegraphic code message record and the other of said rows of perforations comprising a space time interval control record, a flexible feeler arm having a feeler finger riding said tape in line with said one row of apertures. an electrical circuit controlled by said feeler arm for elfecting a code signal responsive to dropping of said finger into the successive apertures in said one row of apertures, electrically actuated control means for controlling the feeding speed of said tape feed means, and a flexible feeler arm having a feeler finger enga eable with the tape in line with the second row of apertures, and an electrical circuit under control of the last mentioned feeler arm for controlling said electrically actuated speed controll means upon dropping of the feeler finger of said last mentioned arm into one of said second row of apertures.

7. In combination in an educational telegraphic code transmission machine, a supporting member, a supply reel support, a take-up reel support, means for feeding a record tape having a pair of parallel rows of control apertures therein from the supply reel to the take-up reel, a feeler arm having a feeler point engageable with the tape in line with one of said rows of apertures, a second feeler arm having a feeler point engageable with the tape in line with the remaining row of apertures, an electrical circuit including a switch controlled by the first feeler arm for creating code signals upon dropping of the point of said first arm into the successive apertures in said one row of apertures, solenoid actuated means for controlling said feed means, an electrical circuit including a switch controlled by said second feeler arm and arranged to be closed for energizing said solenoid when the point of said second feeler arm drops into an aperture in said remaining row of apertures.

8. In a telegraphic code educational device of the character described, a support, means on said support for passing a perforated record tape past a given point, an insulating post mounted on said support adjacent to said point, a pair of spaced flexible feeler arms carried in fixed relation on said post, each of said arms having means thereon engageable with the tape at said point, and respective electrical control circuits controlled by said feeler arms, said post being movable to swing said feeler arms into and out of operative relation to the tape.

9. In combination in a machine of the character described, a tape feed roller, a shaft running through said roller, a slidable coupling between said shaft and said roller enabling reciprocations of the shaft relative to the roller, said shaft having a transmission disk thereon, separate friction drive rollers opposing respectively opposite sides of the disk and with the operative planes of the disk-opposing portions of the roller peripheries spaced apart farther than the sides of the disk, means for driving said friction rollers, and means for effecting reciprocations of said shaft to carry said disk from one to the other of said rollers.

10. In combination in a machine of the character described, a record tape drive comprising a shaft having a transmission disk thereon, a pair of separate friction drive rollers engageable with respectively opposite sides of said disk, means for adjusting said rollers radially relative to the axis of said disk to vary the driving speed of said disk when engaged with the respective rollers, and means for shifting the disk to engage said rollers alternately.

11. In combination in a telegraphic code educational machine of the character described, a record tape feeding mechanism including a drive roller, a shaft coupled with said drive roller, a friction transmission disk carried by said shaft, a pair of separate friction drive rollers opposing respectively opposite sides of the transmission disk and alternately engageable by the transmission disk, means for shifting the shaft reciprocably and thereby alternately engaging the transmission disk from one to the other of said-rollers, and manually operable means for shifting said rollers radially relative to the axis of said transmission disk to vary the speed with which the transmission disk is rotated by the respective drive rollers.

12. In combination in a telegraphic code educational machine of the character described, a record'tape feeding mechanism including a drive roller, a shaft coupled with said drive roller, a friction transmission disk carried by said shaft, a pair of separate friction drive rollers opposing respectively opposite sides of the transmission disk and alternately engageable by the transmission disk, means for shifting the shaft reciprocably and thereby alternately engaging the transmission disk from one to the other of said rollers, and manually operable means for shifting said rollers radially relative to the axis of said transmission disk to vary the speed with which the transmission disk is rotated by the respective drive rollers, said means including a manually engageable knob for each of said friction rollers and a linkage mechanism connecting the respective knobs with the respective friction rollers.

13. In an educational telegraphic code transmission structure, a record tape having two laterally spaced longitudinal series of apertures therein, one of said series constituting code message apertures with imperforate areas of the tape intervening between character denoting groups of the message apertures, and the other of said series being in the form of longitudinally elongated apertures of uniform length and with one of said apertures disposed in transverse alignment with each of said imperforate areas for determining uniform space time interval between message characters.

14. In an educational telegraphic code transmission structure, a record tape having two laterally spaced longitudinal series of apertures therein, one of said series comprising circular dot indicating and elongated dash indicating apertures disposed by groups or individually and with imperforate pause space areas therebetween in accordance with telegraphic code characters for controlling code signal means, and the remaining series of apertures comprising spaced longitudinally elongated apertures of substantially greater length than the dash apertures and with single ones of the apertures of greater length disposed in transverse alignment with each of said space areas for controlling a tape feed mechanism to afford uniform space time intervals between the code characters.

15. In a Morse code educational machine, a supporting structure, spaced reels mounted on said supporting structure and having connected thereto a flexible tape provided with transversely spaced respective series of apertures, one of which series comprises dot-dash apertures and the other of which series comprises space determining apertures, means for driving the tape including a rotary member having connected thereto a disk, :1 pair of continuously rotary drive rollers respectively operably disposed at opposite sides of the disk, and electrically operable control means for motivating said disk to move alternately into engagement with one or the other of said rollers and having means operatively cooperating with said tape at said space determining apertures.

16. In a Morse code educational machine, a supporting structure, spaced reels mounted on said supporting structure and having connected thereto a flexible tape provided with transversely spaced respective series of apertures, one of which series comprises dot-dash apertures and the other of which series comprises space determining apertures, means for driving the tape including a rotary member having connected thereto a disk, a pair of continuously rotary drive rollers respectively operably disposed at opposite sides of the disk, and electrically operable control means for motivating said disk to move alternately into engagement with one or the other of said rollers and having means operatively cooperating with said tape at said space determining apertures, said rollers having means for adjusting the same radially with respect to said disk for varying the driving ratio thereof with respect to the disk.

17. In combination in an educational instrumentality for telegraphic code transmission, an elongated record element having respective longitudinal code signal and space control areas thereon, means for moving said record element in a longitudinal path, means cooperating with the code signal area of said record element for effecting code signals as the record element moves in said path, means cooperating with the moving means and the space control area of said record element for determining the space time interval between signals as the record element moves in said path, and means for adjusting said space time interval determining means to adjust the speed of operation of said moving means during space control cooperation of said space time interval-determining means to vary the space time interval independently of said signal-etfecting means.

18. In combination in a device for producing tele graphic code signals for educational purposes, a pair of electrical circuits including respective make and break switches, a record tape having two laterally spaced longitudinal series of apertures therein, one of said series constituting code message apertures with imperforate areas of the tape intervening between character-denoting groups of the message apertures and the other of said series being in the form of longitudinally elongated apertures of uniform length with one of said apertures disposed in transverse alignment with each of said imperforate areas for determining uniform space time interval between message characters, means for moving the tape past said switches, one of said switches having means riding the tape in line with the code message apertures and the other of said switches having means riding the tape in line with the space time interval apertures, and means operable by the electrical circuit controlled by the switch riding the area of the tape having the space time interval apertures for determining the length of the space time interval incidental to the closing of such switch at each of the space time interval apertures and including means for varying the length of the interval.

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