US2988597A - Code keyer - Google Patents

Description

June 13, 1961 Filed Oct. 18, 1957 A. J. TREMBLAY CODE KEYER 3 Sheets-Sheet 2 f INVENTOR 29/ J H6, 8 ALEXANDER .1. TREMBLAY 1\\ Y ATTORNEY June 13, 1961 A. J. TREMBLAY CODE KEYER 3 Sheets-Sheet 3 Filed Oct. 18, 1957 INVENTOR ALEXANDER J TREMBLAY v1 2 R 6 m 6 w L w. W 7 7 E 6 Q AMKR w Q C a w 6 1 m Q w 8 WM 3 w wk m0 5 M \1 3 Q w 7 4 M l 3 Y 3 f M M 3 5 0 w R 0 mm 0 M 3 D M ATTORNEY Patented June 13, 1961 2,988,597 CODE KEYER Alexander J. Tremblay, 27 North Ave., St. Johnsbury, Vt. Filed Oct. 18, 1957, Ser. No. 691,019 20 Claims. (Cl. 178-82) characters for the keying of land or radio telegraph circuits.

It is another object of the invention to provide a system for generating telegraphic keying pulses, which does not require or utilize transistors, vacuum tubes o'r the like, and which is maintenance free, simple and inexpensive to construct.

It is still a further object of the invention to provide a self-completing keying system, in which case keying pulse completes itself, once it has been initiated, despite any manipulations of the key which may occur, and in which overlap of successive keying pulses is impossible.

As a further feature and object, I provide a system which is operative from a single battery, and which may therefore be self-contained, and which serves to generate keying pulses by transferring ground to a remote point, at which may be located a load, a keyed transmitter, or the like.

In conjunction with my novel and improved keying circuit, it is an object of the invention to provide a novel single pole double throw switch, which may be employed as a hand key and which then serves to generate a dot when actuated in one sense, and a dash when actuated in the opposite sense.

The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:

FIGURES 1-4, inclusive, are schematic circuit diagrams of keying circuits according to the present invention;

FIGURE is a view in perspective of a keying switch according to the present invention;

FIGURE 6 is a view in plan of the switch of FIG- URE 5;

FIGURE 7 is a view in elevation of the switch of FIG- URE 5; and

FIGURE 8 is a view in section taken on the line 8-8 of FIGURE 7.

Referring now more specifically to FIGURE 1 of the accompanying drawings, the reference numeral 1 denotes an armature of a hand key, movable to either of two operating positio'ns into contact with stationary contacts 2 or 3, but normally in neutral position. The armature 1 is electrically connected with one side of a battery 4 or other suitable source of electric current, the other side of which is connected to a stationary relay contact 5. A re lay armature 6 is normally in contact with contact 5, and is connected to ground. A second stationary contact 7 is connected by means of a lead 8 to a lead, such as the keyed stage of a radio transmitter (not shown).

A magnetic core 9, included in a relay 10, pulls down the armature 6 in response to energization of either of coils L1, L2, wound on the core 9, breaking contacts 5, 6 and making contacts 6, 7.

Connected across coil L1 is a timing condenser C1, while a further timing condenser C2 is connected across coil L2. One terminal 12 of coil L1 is connected to contact 2, While one terminal 13 of coil L2 is connected to contact 3. The remaining terminals 14, 15 of coil L1 and L2 are connected to ground.

The time constants of L1, C1 and of L2, C2 are different, and in a particular application of my invention may be selected to approximate the lengths of a telegraphic dot and dash, respectively. Since normally the coils L1 and L2 may be substantially identical, the required differences in time constants may be accomplished by proper selection of values of capacity of condensers C1 and C2.

In operation, and assuming armature 6 to be unactuated, movement of armature 1 to its left position completes a circuit from ground terminal 14, through coil L1 to terminal 12, to contact 2 and via armature 1 to battery 4, which is connected to ground through contact 5 and armature 6. Relay L1 is then energized and condenser C1 instantaneously charged to the potential of battery 4. Alternately, when armature 1 is moved to the right, coil L2 is energized and condenser C2 charged. Since, as will be shown, energization of either of coils L1, L2 breaks the battery circuit, coils L1 and L2 are energized selectively, and cannot be energized simultaneously. Since, moreover, the condensers C1, C2 are selectively connected directly across battery 4 during charging, the process of charging is instantaneous.

When either coil L1 or L2 is energized armature 6 pulls down, breaking the circuit between the energized coil and the battery 4, and opening the circuit between the unenergized coil and the battery 4, so that the unenergized coil cannot be energized until the energized coil has released armature 6.

Upon bringing armature 1 back to its neutral position, or upon breaking of contact between contact 5 and armature 6, the previously charged one of condensers C1, C2 discharges through its coil, maintaining that coil energized for a period depending on the time constant involved. Obviously, after a sufiicient time the energized coil will become de-energized, and armature 6 will pull up. If at that time armature 1 is in neutral position no further action will occur. If it is in contact with one of contacts 2, 3 the appropriate one of coils L1, L2 will be again energized for the predetermined time appropriate thereto. started, regardless of manipulation of the keying armature 1, since a coil, once energized can only be de-energized by discharge of its condenser and keying pulse overlap cannot occur since the battery 4 i maintained out of circuit by armature 6, once the latter has pulled down, until discharge has been completed.

In FIGURE 2 of the accompanying drawings is illustrated a modification of the system of FIGURE 1, to which has been added a reversing and on/oif feature, a keying speed adjustment feature, and a three position test switch for continuous dots or dashes.

The keying speed adjustment feature includes two supplementary condensers CIA and C2A. One side of each of condensers CIA, C2A is grounded. The remaining side of condenser CIA is connectable to terminal 12 via switch 16a, while the remaining side of condenser CZA is connected to terminal 13 via switch 16b. Switches 16a and 16b may be commonly actuated via a mechanical linkage 17. When closed, condensers CIA and C2A are connected in parallel with condensers C1 and C2, respectively, increasing the time constants of the relay circuits. When switches 16a and 16b are open condensers CIA and CZA are ineffective.

A keying cycle will always be completed, once In the system of FIGURE 1 the positive side of battery 4 is directly connected to armature 1. In the system of FIGURE 2, on the other hand, the positive terminal of battery 4 is connected to a movable contact 19 of a two position reversing and on/oif switch 20, the stationary contacts 21, 22 of which are jointly connected to the armature 1. In its neutral position switch 20 serves, accordingly, to disconnect the positive terminal of battery 4 from the armature 1. In either actuated position of movable contact 19, however, the positive terminal of battery 4 is connected to armature 1.

The contact 2 of the keying switch K is connected to stationary contacts 23 and 24 of switch 20, while contact 3 is connected to stationary contacts 25, 26.

The movable contacts 27, 28 of switch 28 are ganged with movable contact 19. Movable contact 27 is connected to terminal 12 of coil L1 and movable contact 28 to terminal 13 of coil L2.

Actuation of contacts 27, 28 upwardly, accordingly, connects contact 2 to terminal 12 and contact 3 to terminal 13, while actuation of contacts 27, 28 downwardly effects connection of contact 2 to terminal 13 and of contacts 3 to terminal 12. In application of the present invention to keying dots and dashes, the reversing switch 20 enables dots to be generated when armature 1 is actuated in right or left, according to the condition of switch 28, dashes being then generated when armature 1 is actuated in the opposite sense.

In the system of FIGURE 3 is provided a first relay 30 having core 31 and a coil L1 for magnetizing the core 31, The relay 30 includes an armature or movable contact 32 which normally maintains contact with an upper contact 33, but is actuated into contact with lower contact 34 when the relay 3% is energized. A second relay 35 is provided which includes core 36, coil L2, and a movable armature 38 which is normally up, an upper contact 39 and a lower contact 40.

A battery 4, or similar source of electric power, is connccted at its negative terminal to upper contact 33, while upper contact 39 is connected to a terminal 42. The positive terminal of battery 4 is connected to the movable armature 43 of a keying switch 44, having a neutral, a left and a right position.

Connected across coil L1 is a timing condenser C1, prviding a first time constant for the coil Ll. Connected across the coil L2 is a further condenser C2, which provides a second and different time constant for the coil L2.

Connected across condenser C1 is a resistive network consisting of a variable resistance 45a, in series with a fixed resistance 45b. In similar manner, a resistive network is connected across the condenser C2, consisting of a variable resistance 45a in series with a fixed resistance 46b.

One terminal of each of coils L1 and L2 is connected to terminal 42. The remaining terminals of coils L1 and L2 are connected via reversing switch 48 to the stationary contacts 49 and 50 of the keying switch 44.

The movable sliders 51 which adjust the values of resistances 45a, 4611 are connected directly to terminal 42, so that the portion of the resistances 45a, 46a subsisting between sliders 51 and the terminal 42 are shorted out. The total resistance in parallel with condensers C1, C2 may accordingly be reduced or increased by adjustment of sliders 51 and since the condensers C1, C2 discharge through the resistive networks consisting of resistances 45a, 45b and 46a, 46b, respectively, positioning the sliders 51 varies or adjusts the time constants of relays 30 and 35. The adjustment may be individual to the separate relays or simultaneous.

So long as the armatures 32, 38 are up negative voltage is conveyed to terminal 42. Circuits for relays 30, 35 may be then selected by actuating movable arm 43 of keying switch 44 left or right.

Once a relay has been energized its armature is pulled down, breaking the circuit from the negative side of battery 4 to terminal 42. The timing condenser of the energized relay maintains the relay energized until the condenser has discharged, and until this occurs actuation of key 44 is ineffective. Each keyed pulse is thereby always completed, once it has been initiated, and an interfering pulse cannot be generated until a previously initiated pulse is completed.

Armatures 32, 38 are grounded. Actuation of either of relays 30, 35 serves to transfer ground to lead 52, which extends to a keyed circuit or load (not shown), and serves to key the latter, in conventional fashion.

A switch 53 is provided with a terminal of coil L2 to terminal 42 or to ground, selectively. Connection to ground serves to disconnect condenser C2 from coil L2, so that relay 35 may be employed to generate pulses which are mutually controlled instead of automatically controlled by circuit operation. Dashes are, in the manual position of switch 53, generated once for each actuating key 43 to Dash position. In the Dot position repetitive dots are generated. This simulates bug operation, while retaining self-completing and interlocking of pulses.

The sliders 51 may be adjusted jointly, which provides the result that having established a ratio of dash to dot time, by choice of values for condensers C1 and C2, this ratio may be approximately maintained for any adjustment of dot time.

A disconnect switch 55 may be provided in the lead between the positive terminal of battery 41 and the keying switch 44. The switch 55 may be ganged with sliders 51, to disconnect battery 41 at the minimum setting of the sliders. Resistances 45a and 45b, connected in series, may be equal to the series combination of resistors 46a and 46b and are valuable for determining the value of maximum keying speed of which the system is capable.

It will be clear that key pulse timing resistances may, following the teaching of FIGURE 3, be connected in parallel with any of the timing condensers employed in the various embodiments of my invention described herein.

In the system of FIGURE 4, I have added to the system of FIGURE 3, auxiliary main keying relay 60, and have made certain modifications of circuitry. Identical elements of FIGURES 3 and 4 are identified by the same numerals of reference.

In FIGURE 4 stationary contact 33 of relay 30 is directly connected to movable contact 38 of relay 35. Contact 32 of relay 30 is connected to ground and to one side of battery 41. Contacts 34 and 40 are connected together and via switch 61 to output lead 62 leading to a load or keyed circuit.

In the unenergized condition of relays 30 and 35 lead 62 is isolated from ground, and terminal 42 is connected to ground, via contacts 39, 38, 33, 32. Energization of either of relays 30, 35 transfers ground potential to lead 62, breaking the circuit to the energized relay. The system of FIGURE 4 operates generally, therefore, as does the system of FIGURE 3.

If switch 61 is thrown to its alternate position, i.e., to make a circuit to contact 65, lead 62 is connected to the operating coil L3 of relay 60, which returns to one side of battery 41 via lead 66.

It follows that an energizing circuit is provided for relay 60 whenever either relay 30 or 35 is energized, for the duration of the latter energization, and that failing energization of one of relays 30, 35 relay 60 also remains deenergized.

When relay 60 is energized it closes normally open contacts 67, 68 of which 67 is grounded at pivot 69 and 68 is connected to lead 62. Thus energization of relay 60 brings ground to lead 62 and to the load or keyed circuit.

Connected across coil L3 is an RC circuit, consisting of resistance 70 and condenser 71 in series, to prevent arcing. Variable resistance 72 in series with coil L3 serves to adjust current flow to the coil, providing for light or heavy characters at will.

The manually operating keying switch of FIGURES to 8, inclusive, includes a rectangular plastic plate 80 of insulating material which is normally stationary and a movable keying lever 81, fabricated of a plate of plastic sheet insulating material, and including a paddle element 82. Secured to one side of paddle element 82, and spaced therefrom by spacing rods 83, is a further paddle element 84. The paddle elements 82, 84 are secured to the spacing rods 83 by suitable screws 86, and may be individually operated by the thumb and forefinger of an operators hand, in a manner which is per se conventional in telegraphic keying.

The plate 80 and the keying lever 81 contain aligned apertures 84a and 85, through which extends closed elastic band or loop of elastic material 86a. The ends of the latter extend over exteriorly located pins 87, 88, which are longer than the diameters of apertures 84a, 85, and hence retain the band 860 in operative position. The loop of elastic material 86a is under tension and maintains the block 80 and the keying lever 81 pressed together.

Four apertures 89 are drilled through near the corners of block 80. Aligned apertures 90 are provided in keying lever 81. The adjacent ends of the apertures 89 and 90 are countersunk and small ball bearings 91 are seated in the countersinks and serve as hearing elements between the plate 80 and the keying lever 81. Actuation of the keying lever then occurs against the tension of elastic band, against one or another pair of balls acting ,as a pivot, 91.

Extending transversely of block 80 along one edge of the side thereof is a metallic strip '92, to one end of which is secured a connector lug 93 by means of a screw 94, which, together with screw 95 serves to secure the strip 92 to the block 80.

Two further metallic resilient strips 96, 97 extend perpendicularly of strip 92, being normally out of contact with strip 92 at ends '98. The strips 96, 97 are secured to block 80 by means of screws 99, the heads of which hold lugs 100 and 101 against spacers 102 and 103, respectively.

Extending through the keying lever 81 are two bolts 104 and 105, in alignment with the center line of paddle 82. The bodies of bolts 104, 105 ride free in the keying lever 81 and also ride free Within apertures in block 80, extending to the outside of resilient strips 96, 97. Nuts 106 and 107 threadedly engage the bolts exteriorly of the block 80, serving as actuators for contact strips 96 and 97, in response to actuation of paddle 82, and also serving as adjustable stops for controlling the maximum angular actuation permitted.

Tapped mounting holes 110 are provided in an edge of the plate 80, or other provision for mounting keying switches may be made.

While I have described and illustrated one specific embodiment of my invention, it will be clear that variations of the details of construction which are specifically illustrated and described may be resorted to without departing from the true spirit and scope of the invention as defined in the appended claims.

What I claim is:

1. A keying circuit, comprising a relay device comprising a first relay coil, a second relay coil, a first timing condenser connected across said first relay coil, a second timing condenser connected across said second relay coil, a two terminal source of DC. voltage, a keying switch having two stationary contacts and a movable contact movable between said two stationary contacts, means grounding one end of each of said relay coils, means for connecting the other ends of said relay coils to said stationary contacts, respectively, means connecting one terminal of said source of DC. voltage to said movable contactor, relay contacts including fixed contacts and a movable armature normally contacting a first of said fixed contacts and actuatable in response to energization of either of said relay coils into contact with the other of said fixed contacts, an output lead connected to said other said fixed contacts, means including said movable armature for connecting the other terminal of said source of DC. voltage to one of said first of said fixed contacts, and means including said movable armature for connecting the other of said first of said fixed contacts to ground.

2. A keying circuit comprising a relay, said relay including a magnetizable core and two similar coils wound on said core for magnetizing said core, a separate timing condenser connected across each of said coils, each of said coils having two terminals, means for grounding one terminal of each of said coils, a circuit for selectiviely applying energizing DC. voltage to said coils, whereby the condenser connected across the energized coil is charged, and means responsive to energization of either of said coils for interrupting said circuit.

3. A keying circuit, comprising a relay device, said relay device including two similar coils, a separate timing condenser connected across each of said coils, a single source of DC. voltage having two terminals,. a normally closed circuit making and breaking device connected in series with one terminal of said single source of DC. voltage, said circuit making and breaking device being responsive to energization of one of said coils, means connecting said relay coils in parallel to each other and each in series with said circuit making and breaking device, a two position switch having two stationary contacts and a movable contact selectively actuatable into contact with said stationary contacts, a direct connection between said movable contact and the other terminal of said single source of DC. voltage, and means including said circuit making and breaking device connecting each of said stationary contacts in series with a difierent one of said coils.

4. A keying circuit comprising a relay device, said relay device including two similar relay coils, a separate timing condenser connected in parallel with each of said coils, a single source of DC. voltage, means for selectively connecting said single source of DC. voltage in series with either of said coils and with the condenser connected in parallel therewith to the exclusion of the other condenser, and means including said last named means for disconnecting said single source of DC. voltage from said coils in response to energization of either of said coils.

5. A timing circuit comprising two relay coils, a source of DC. voltage, means for connecting said two relay coils in parallel to said source of voltage, means responsive to energization of either of said coils for disconnecting said source of voltage from both said coils, means for selectively connecting said source of voltage in energizing relation to either of said coils to the exclusion of the other, means comprising a separate condenser connected across each of said coils for delaying the de-energization of the energized coil following disconnection of said energized coil from said source of voltage, and means for charging each of said condensers selectively and only con-currently with energization of the relay coil connected in parallel with that condenser from said source of voltage.

6. The combination according to claim 5, wherein is further provided a separate relatively high variable resistance in shunt to each of said condensers, and means for jointly and similarly varying the resistances of said variable resistances.

7. The combination according to claim 5, wherein is provided two distinct magnetic cores, each of said coils being wound on a different one of said cores.

8. A keying circuit, comprising a relay system, said relay system including two similar coils, a separate timing condenser connected across each of said coils, a single source of DC. voltage having two terminals, a normally closed circuit making and breaking system connected in series with one terminal of said single source of DC voltage, said circuit making and breaking system being responsive to actuation of one of said coils, means connecting said relay coils in parallel to each other and each in series with said circuit making and breaking system, a two position switch having two stationary contacts and a movable contact selectively actuatable into contact with said stationary contacts, a direct connection between said movable contact and the other terminal of said single source of DO. voltage, and means connecting each of said stationary contacts in series with a different one of said coils.

9. A keying circuit according to claim 8 wherein one terminal of one of said coils is connected to one of said stationary contacts, and a switch for connecting the other terminal of said one of said coils to ground.

10. The combination according to claim 4 wherein is further provided a switch connected to disconnect one of said relay coils from the condenser connected in parallel with that coil.

11. The combination according to claim wherein is further provided a switch for at will disconnecting one of said relay coils from the condenser connected in parallel with that relay coil.

12. A keying circuit comprising a relay system, said relay system including two similar relay coils, a separate timing condenser connected across each of said coils, each of said coils having two terminals, a source of voltage having two terminals, means for connecting one terminal of each of said coils to a common terminal of said source of voltage, a circuit for selectively connecting the other terminal of said source of voltage to the remaining terminals of said coils only one at a time said circuit including means for immediately charging the condenser connected across the selected coil to a voltage substantially equal to the voltage of said source, and means responsive to energization of either of said coils for interrupting the circuit between said source of voltage and said coils.

13. A keying circuit comprising a relay system, said relay system including two similar relay coils wound on a single relay core, a separate timing condenser connected across each of said coils, each of said coils having two terminals, a source of voltage having two terminals, means for connecting one terminal of each of said coils to a common terminal of said source of voltage, a circuit for selectively connecting the other terminal of said source of voltage to the remaining terminals of said coils only one at a time, whereby the condenser connected across the selected coil is immediately charged, and means responsive to energization of either of said coils for interrupting the circuit between said source of voltage and said coils.

14. The combination according to claim 12 wherein said coils are each provided with a separate core.

15. The combination according to claim 12 wherein said circuit for selectively connecting the other terminal of said source of voltage to the remaining terminals of said coils only one at a time is a switch having a contact movable between two positions, a separate stationary contact at each of said two positions, each of said stationary contacts being connected to a different one of said remaining terminals, and means connecting said movable contact to one terminal of said source of voltage.

16. A keying circuit comprising a relay system, said relay system including two similar relay coils, a separate timing condenser connected across each of said coils, each of said coils having two terminals, a source of voltage having two terminals, means for connecting one terminal of each of said coils to a common terminal of said source of voltage, a circuit for selectively connecting the other terminal of said source of voltage to the remaining terminals of said coils only one at a time, whereby the condenser connected across the selected coils is immediately charged, and relay contact means responsive to energization of either of said coils for interrupting the circuit between said source of voltage and said coils.

17. The combination according to claim 12 wherein said means for interrupting the circuit between said source of voltage and said coils includes normally closed contacts operative to open position in response to energization of either of said coils and consequent magnetization of said core.

18. The combination according to claim 12 wherein said relay system includes two relay cores, each of said coils being wound on a different one of said cores, wherein said means for interrupting the circuit between said source of voltage and said coils includes two pairs of normally closed contacts in series between said source of voltage and both of said coils, said pairs of contacts being each operative to open condition in response to magnetization of a different one of said cores in response to selective energization of the coils wound on said cores.

19. The combination according to claim 18 wherein is further provided a switch for at will disconnecting one of said timing condensers from the coil across which it is normally connected.

20. A keying circuit comprising a relay device, said relay device including two similar relay coils, a separate timing condenser connected in parallel with each of said coils, a pair of terminals connecting a power source to the circuit, means for selectively connecting said terminals in series with either of said coils and with the condenser connected in parallel therewith to the exclusion of the other condenser, and means including said last named means for disconnecting one of said terminals from said coils in response to energization of either of said coils.

References Cited in the file of this patent UNITED STATES PATENTS 287,267 Field Oct. 23, 1883 1,613,266 Dorsey Jan. 4, 1927 1,650,137 Kopp et a1. Nov. 22, 1927 2,150,241 Nichols et al. Mar. 14, 1939 2,235,627 Boor Mar. 18, 1941 2,302,290 Breedlove Nov. 17, 1942 2,303,734 Garceau Dec. 1, 1942 OTHER REFERENCES Publication, A Single-Tube Electronic Key, by D. Geppert, pages 42-43, Radio & T.V. News, October 1950, 178-82A.

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