US3431354A - Adapter for semiautomatic radiotelegraph key - Google Patents

Description

L. M. TEMPLE March 4, 1969 Sheet INVENTOR. LEMUEL M. EMF/.5 MM

1.. M. TEMPLE 3,431,354 ADAPTER FOR SEMIAUTOMATIC RADIOTELEGRAPH KEY March 4, 1969 Sheei Filed Oct. 22, 1965 2 ma w N w BE A W. m 1 w L S w A M e I United States 3,431,354 ADAPTER FOR SEMIAUTOMATIC RADIOTELEGRAPH KEY Lemuel M. Temple, Stratton Mountain Road, West Wardsboro, Vt. 05360 Filed Oct. 22, 1965, Ser. No. 501,381 US. Cl. 178-82 4 Claim Int. Cl. H04l15/08, 27/00: H04!) 1/04 This invention relates to radiotelegraph keys of the semiautomatic type used in keying a signal-producing circuit to transmit intelligible code signals; and it is more particularly directed to an adapter for such keys which will permit them to operate as so-called fully automatic keys.

semiautomatic keys employing a mechanical vibrator, such as a weighted leaf spring pendulum, have long been used by telegraph operators for the production of dot" pulses automatically in forming code characters. As is well known, the paddle of such semiautomatic key is simply moved laterally to one side from a central or rest position to produce the dot pulses, and to the opposite side of that central position to produce a dash. Separate sets of keying contacts are employed in producing the dot pulses from those producing the dash? pulses. Because of the vibrator mechanism, the set of keying contacts used for producing the "dot pulses are cyclically opened and closed as long as the paddle is held by the operator in the dot position, within the limits of the mechanical vibrator. However, when the paddle is moved to the opposite or dash" position, the other set of keying contacts is closed and held closed as long as the paddle is held in the dash" position. Thus the operator, in making two or more dashes in forming a code character, must manually release the paddle and again return it to the dash position in order to form more than one dash" pulse. Hence the designation of semiautomatic keyer" for this type of device, since each dash" pulse must be formed manually.

There are, of course, fully automatic keying devices available in which both dash as well as dot pulses are formed automatically, simply by shifting a paddle or keying member from one position to another from a central or neutral position. Generally these fully automatic keyers are electronic devices employing either vacuum tubes or semiconductors and are relatively complicated mechanically and electronically, resulting in substantial investment in equipment.

It is accordingly an object of this invention to provide an adapter for the conventional semiautomatic mechanical key or bug, as it is sometimes referred to, in order to render it capable of fully automatic operation. It is a further objectto do this without impairing the normal functioning of the semiautomatic key or bug, or requiring any major modification of it, so that the bug may be immediately restored to its conventional semiautomatic operation merely by throwing a switch.

As a further object of the invention, provision is made for modifying the automatic dash forming capability of the adapter device so that the operator may manually select either of two diflerent modes of operation. In one mode, the device automatically completes the last dash pulse in any series of dashes, irrespective of the fact that the key paddle may be released to neutral position prior to the completion of such terminal dash pulse. In the other mode of operation, the device provides manual control of the length or period of the last dash in a series. Such latter mode of operation enables the operator more easily to move from a dash producing condition to a "dot producing condition, and back again, without the terminal dash of a proceding group overtaking a succeeding dot or dots, which would of course result in gar- Patented Mar. 4, 1969 bling the code character attempted to be formed. The in terposition of one or more dots between dashes in a code character when an operator is first learning to use a fully automatic key, is particularly difiicult until he has developed skill and timing by experience. In order to facilitate the learning process and to enable an inexperienced operator to transmit intelligible code characters at reasonably rapid speeds, the feature provided by the present invention of manually controlling the terminal dash pulse is accordingly especially advantageous.

Another object of the present invention is to provide an adapter device which is of small, simple mechanical construction and size, such that it may be easily afixed to a standard semiautomatic key and form a part thereof, without cluttering the operating table with accessory equipment.

These and other objects and advantages of the present invention are illustrated by the device and circuits shown in the accompanying drawings and described hereinafter. It is of course understood that the specific mechanical construction and particular circuit arrangements hereindescribed are by way of illustration rather than limitation of the invention which is defined in the accompanying claims.

In the drawings:

FIG. 1 is a perspective view of a conventional semiautomatic key with an adapter unit of the present invention attached thereto;

FIG. 2 is a schematic diagram of a semiautomatic key and the adapter;

FIG. 3 shows a modified circuit for the adapter; and

FIG. 4 illustrates a still further modification of the basic circuit design. I

The arrangement whereby the adapter unit is physically attached to a conventional semiautomatic key is illustrated in FIG. 1, wherein the key 10 is provided with an outboard chassis or adapter unit 12 suitably secured along one edge of the key base, serving to house and support the several components incorporated in the adapter unit. Attachment of adapter 12 to the base of key 10 may be accomplished in any suitable manner, such as by means of machine screws 14 passing through the adapter unit 12 into the base of the key, or by means of bus bars 15 used for electrical connections as described below. For purposes of convenience of illustration and description here, key 10 and adapter unit 12 are shown as provided with corresponding external paired terminals 16-16, 18-18, 20- 20", each pair of which is joined by a bus 15. Again for purposes of convenience of description, terminals 16-16 are referred to hereinafter as the common or ground terminals for adapter 12 and key 10, respectively; terminals 18-18 are termed the dot" terminals of the adapter and key, respectively; and terminals 20-20 are hereinafter termed the dash terminals of the adapter and key, respectively. It will of course be understood that this specific arrangement of the terminals is not necessary and, in fact, in most instances the members comprising such terminals will be located within the chassis of adapter 12 and within the base of key 10, and connecting leads run between them so that there is no external exposure of such terminals or leads.

Key 10 is provided with a pair of terminals and as sociated paired conductors 22 for connection to the circuit to be keyed. Adapter 12 is supplied with low voltage through a power cord 24 for operating a relay 26 forming part of the adapter unit. The adapter is further provided with variable resistors 28, 30. Resistor 28 controls the length or period of each dash pulse, while resistor 30 controls the speed at which the combination of key and adapter produces dash pulses automatically. In addition, the adapter unit includes manually controlled switches 32, 34, 36; switch 32 being used to turn on'the power supply, switch 34 serving to provide optional modes of automatic dash formation by the adapter and switch 36 being used to connect the adapter into the keyed circuit or to return the key to its normal operating condition.

As is well known, such semiautomatic keys are operated by manually moving a central key or paddle member 38 horizontally to the left or right of a central or neutral position to which it is normally biased. Moving paddle 38 to the right sets in motion a type of spring leaf vibrator which carries an electrical contact which is intermittently brought into engagement with a stationary insulated contact so long as the paddle is held in the dot forming position, within the limits of course of the period of vibration of which the key is capable. Such intermittent closing of this set of contacts, hereinafter re ferred to as the dot forming contacts 19-19, completes the circuit through paired conductors 22 and produces corresponding pulses in the keyed circuit. Thus the operator is relieved of the task of forming each dot pulse separately in transmitting code characters. When paddle 38 is moved in the laterally opposite direction, a second set of contacts 2121', hereinafter referred to as the dash contacts, is closed. These dash contacts are in electrical parallel with the dot" contacts and in the normal function of the semiautomatic key the operator must manually form the dash pulses of the code characters being transmitted by moving the paddle 38 to and releasing it from the dash position. As has been above indicated, however, with the provision of the adapter unit 12 herein disclosed, the operator is relieved of the necessity for forming a series of dashes manually, as the adapter unit takes over this function and performs it automatically so long as the paddle 38 is held in the dash forming position.

Turning now to a consideration of the arrangement for accomplishing this objective, one form of adapter circuit is illustrated in FIG. 2 of the accompanying drawings wherein it is shown schematically connected to key 10.

The relay of the adapter includes an energizing coil 40 operating an armature 42 which normally makes contact with relay contact 44 but which is moved to an alternate position making contact with relay contact 46 when relay coil 40 is energized. Armature 42 is permanently connected to the ground or common terminal 16, and also the B position of switch 34. The relay circuit of the adapter further includes a time-delay network comprising a capacitor 48, and the variable resistors 28, 30 previously mentioned. Variable resistor 30 is connected in parallel across the combination of resistor 28 and coil 40. Capacitor 48, in turn, is connected directly across resistor 30 when switch 34 is in the A position, whereas the capacitor circuit, when switch 34 is in the B position, includes the dash contact-s 2121' of key 10.

Switch 36 merely serves to insert the adapter unit 12 into the keying circuit when moved to the B position, or to restore the key to its normal operating condition when switch 36 is in the A position.

In the conventional key, keying contacts 19 and 21 are normally connected in parallel by an internal conductor, indicated at 50 in dotted lines in FIG. 2, and to the ungrounded conductor of the keyed circuit 22. It is accordingly necessary to remove or disconnect conductor 50 of the key when attaching adapter 12.

The operation of the device as illustrated in FIG. 2 occurs as follows. Adapter 12 is connected into the circuit of key by moving switch 36 to the B position, and to a suitable power source, such as battery 52, by closing switch 32. Assume first that switch 34 is in the A position, in which condition the adapter is arranged to complete the last dash in a series of such dashes automatically, irrespective of the opening of the key by the operator prior to the normal termination of such final dash.

When paddle 38 of key 10 is moved to the dash position, closing contacts 2121', relay coil 40 is energized by completion of the circuit from the positive side of battery 52 through the relay coil 40, through switch 36, dash contacts 2121', the common or ground terminals 1616', armature 42 and contact 44 to the negative side of the battery. Since condenser 48 is connected across energizing coil 40 of the relay, the condenser is also charged when paddle 38 of key 10 is moved to the dash position. I

Energizing of relay 26 causes armature 42 to break contact with relay contact 44 and to make contact with relay contact 46. This then completes a circuit between the dot terminals 1818 and the common or ground terminals 16-16, thereby producing a pulse in a keyed circuit 22. By reason of the resistor-capacitor network in the relay circuit, the charge accumulated by the condenser holds the relay closed momentarily, depending upon the resistance and capacitance values of the components. In a typical circuit employing a relay of 5,000 ohms resistance, suitable values for resistors 28, 30 are 10,000 ohms each, with a capacitor 48 having a value of 16 mfd. When the capacitor is discharged, relay 26 will again open and armature 42 will return to its initial position making contact with relay contact 44. If paddle 38 of key .10 is still held in the dash position by the operator, then the foregoing steps are repeated and a second dash pulse is produced in the keyed circuit 22, and this cycle of operation continues until the key is opened.

Key 10 in the circuit of FIG. 2 continues to operate in its normal manner when paddle 38 is moved to the dot forming position, in that the cyclical closing of contacts 19-19 takes place as before to produce dot pulses in the keyed circuit.

In the condition of the circuit just described, wherein switch 34 is in the A position, the terminal dash, in a series of dash pulses automatically produced, takes the same time interval as the preceding dash pulses, regardless of the fact that the operator may have opened key 10 before that last dash is completed. In other words, the terminal dash in a series of such dashes is completed automatically regardless of the fact that the operator may release the key prematurely. This mode of operation is referred to as self-completing mode of automatic dash formation.

In, order to permit an operator to employ a mode of operation in which he controls, or at least is able to shorten, the time period of the terminal dash in a series, switch 34 is switched to the B position. When the system is so used, an operator may then deliberately shorten the terminal dash in a series, and this will help an inexperienced operator in learning to use the key. The short ening of the dash may be almost imperceptible, but is sufficient to provide a better opportunity for the inexperienced telegrapher to insert a dot in the code character being transmitted without being overtaken by a following dash. As mentioned above, this condition is likely to occur when the system is operated in the self= completing mode by an inexperienced operator.

In the non-completing mode of operation, since switch 34 is in the B position, the discharge of condenser 48 does not take place directly through energizing coil 40 of the relay but instead is completed through the dash contacts 2121' of key 10. Thus if key 10 is opened, the holding circuit for the relay is interrupted and the relay immediately returns to its normal position.

A modification of the foregoing circuit is shown in FIG.. 3. This is essentially similar to that of FIG. 2 except for the inclusion of diodes 52, 54 in connection with switch 34. Diode 54 is placed in series between position B of' the switch and armature 42 of the relay 26 to allow cur rent to flow from capacitor 48 to armature 42 but not in the opposite direction. Diode 52 is connected between the A and B positions of switch 34 in a direction to allow current to flow from A to B but not in the reverse direction.

This arrangement is useful in permitting a lower im= pedance relay to be used than is needed in the circuit of FIG. 2, and in this manner reducing the expense of the adapter unit. Unless the energizing coil 40 of the relay has a sufficiently high impedance and high mechanical sensitivity, the keyed circuit may be adversely affected when using the circuit shown in FIG. 2. However, by means of the blocking arrangement provided by diodes 52 and 54 in the circuit of FIG. 3, this problem is avoided and a lower cost relay may then be satisfactorily employed.

Another modification of the circuit is shown in FIG. 4 in which provision is made for controlling an external circuit concurrently with the operation of the key, for such purposes as operating a tone oscillator for monitoring transmission, or to serve as a break-in switch for transferring a single antenna from .a receiver to the transmitter whenever the key is closed, or for providing an isolated keying circuit for the transmitter instead of the normal key contacts of the semiautomatic key itself. The circuit of FIG. 4 is essentially the same of that of FIG. 3 except for the inclusion of an additional switch 38, .and a second armature 56 and contacts 58, 60. Armature 56 and its associated contacts are electrically insulated from armature 42 and its contacts in the relay assembly. Armature 56 and relay contacts 58, 60 are connected, respectively, to terminals 62, 64 .and 66 for control of any external circuit as mentioned above. If armature 56 is employed for actually keying the transmitting circuit, the keyed circuit would be completed through terminals 62 and 66 upon energization of relay 26. In such a circuit, therefore, both the formation of dot pulses as well as dashes must be accomplished by means of the relay and further revision of the circuits previously described is therefore necessary in the connections made between the adapter 12 and key 10.

As mentioned above, the circuit of FIG. 4 incorporates an additional single-pole double-throw switch 38. The pole of this is connected to a terminal 39 from which a bus bar 15' leads to terminal 18' of the key. Lead 17 from the ungrounded side of the keyed circuit is run directly to terminal 18 of the adapter instead of to terminal 18' of the key as before. The switch 38 contacts for the A and B positions of switch 38 are connected, respectively, to terminals 18 and 20 of the adapter unit.

To operate the circuit of FIG. 4 as a fully automatic system in which a remote or separate circuit is keyed by armature 56 through terminals 62, 66 of the adapter, each of switches 34, 36, 38 is placed in the B position. If it is desired to operate the system in the same manner as that of FIG. 3, then switch 38 is moved to its A position, in which condition dash pulses are made automatically by the adapter unit while the dot pulses are made directly by the key. And finally, if the adapter circuit is to be bypassed entirely and the key operated in its original manner, then switches 36 and 38 are both moved to their A positions.

The arrangement of FIG. 4 provides maximum flexi- 'bility of control and affords ease of operation for a semiautomatic key of an order not heretofore realizable.

What is claimed is:

1. In a device for adapting a semiautomatic radiotelegraph key to enable it to be used in producin dash pulses automatically in a keyed circuit as well as the dot pulses of which it is regularly capable, the combination which comprises a mounting member having thereon a dot terminal,

a dash terminal and a common or ground terminal, each of which has provision for electrical connection to corresponding terminals of the key, and power terminals for connection to a source of electric power;

a relay and switch means operated thereby carried by said mounting member, said switch means having a normally biased position in which it completes a first Ercuit between ground and one of said power terminals and being operable by said relay to break said first circuit and complete an alternate circuit between ground and said dot terminal;

a relay-energizing circuit connected between the other of said power terminals and said dash terminal and adapted to be completed by the key in dash position, said energizing circuit including the operating coil of said relay, said energizing circuit also including a time-delay network to produce a momentary delay in the return of said switch means to its normal position upon interruption of the relay-energizing circuit by the key.

2. A device as defined in claim 1, wherein said timedelay network includes a capacitor and manually controlled switch means, said capacitor being connected at one electrode to the other of said power terminals, and alternative circuits selected by said manual switch connecting the opposite electrode of said capacitor to said ground terminal and to said dash terminal.

3. A device as defined in claim 2, which further includes diode means in said alternative circuits selected by Said manual switch, one such diode means connected in the circuit leading from the capacitor to said ground terminal to prevent current flow toward said capacitor, and another of such diode means connected between the capacitor side of said first diode means and the circuit leading to said dash terminal to prevent current flow toward the latter.

4. In a semiautomatic telegraph keyer of the mechanical type having two sets of electrical contacts for producing, respectively, dot and dash electrical pulses in an external circuit upon closing of the contacts of the respective sets by manual movement of a key member from a normal rest (no-contact-producing) position to either of two alternate positions, whereby the dash contacts produce a continuously closed-circuit condition when said key member is held in the dash position and the dot contacts produce a series of interrupted closed-circuit conditions when said key member is held in the dot position,

the improvement which adapts said telegraph keyer automatically to produce a series of interrupted circuit-closing conditions in the dash position of the key member and comprises a mounting member having thereon a dot terminal,

a dash terminal and a common or ground terminal, each of which has provision for electrical connection to corresponding terminals of the key, and power terminals for connection to a source of electric power;

a relay and switch means operated thereby carried by said mounting member, said switch means having a normally biased position in which it completes a first circuit between ground and one of said power terminals and being operable by said relay to break said first circuit and complete an alternate circuit between ground and said dot terminal;

a relay-energizing circuit connected between the other of said power terminals and said dash terminal and adapted to be completed by the key in dash position, said energizing circuit including the operating coil of said relay, said energizing circuit also including a time-delay network to produce a momentary delay in the return of said switch means to its normal position upon interruption of the relay-energizing circuit of the key.

References Cited UNITED STATES PATENTS 2,235,627 3/1941 Boor. 2,302,290 11/ 1942 Breedlove.

THOMAS A. ROBINSON, Primary Eran liner.

US. Cl. X.R. 178-66; 325-161

Claims (1)

1. IN A DEVICE FOR ADAPTING A SEMIAUTOMATIC RADIOTELEGRAPH KEY TO ENABLE IT TO BE USED IN PRODUCING "DASH" PULSES AUTOMATICALLY IN A KEYED CIRCUIT AS WELL AS THE "DOT" PULSE OF WHICH IT IS REGULARLY CAPABLE, THE COMBINATION WHICH COMPRISES A MOUNTING MEMBER HAVING THEREON A "DOT" TERMINAL, A "DASH" TERMINAL AND A COMMON OR "GROUND" TERMINAL, EACH OF WHICH HAS PROVISION FOR ELECTRICAL CONNECTION TO CORRESPONDING TERMINALS OF THE KEY, AND "POWER" TERMINALS FOR CONNECTION TO A SOURCE OF ELECTRIC POWER;

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