US2295389A - Balanced semiautomatic transmitting key - Google Patents

Description

Patented Sept. 8, 1942 T OFFICE BALANCED 'SEMIAUTOMATIC TRAN S- MITTING KEY Joel W. Dickinson, Wilmette, Ill'. Applieatio'n'D'ecember 24, 1940, Serial No. 371,566-

I4 Claims.

The present invention relates. to a telegraphic transmitting key, and is particularly concerned with improvements in semi-automatic. transmitting keys. of the type having a keying lever with opposite dot andldash. sending positions.

The use of semi-automatic keys in both radio and wire telegraphic transmission is quite common, the use. of this type. of key being preferred by most operators who are-capable. of fast sending. Theuse of a semi-automatic key is imperative with many older operators whose muscular coordination has been impaired so that they are no longer able rapidly to operate an ordinary or straighttypev of key so as to transmit clear signals with the proper number of dots While, the. advantages of the semi-automatic type of. transmitting key are generally recognized; the useiof such a key has been limited. up to the present time to stations where it. is possible to mount the semisautomatic key on. a stable platform, This limited use has been necessitated by thefact thatsuch keys have in the past been provided with a pendulum or the-like-whicl 1, being placed. in oscillation by a movementof a key or lever to a dot sending position, the pendulum continues to oscillate, closing a contact momentarily at a. predetermined stage in each cycle of oscillation, to transmit a series of dots until the lever is released from. the dot sending position.

Any change in. the level adjustment of such a key, or accelerating forces acting at an acute angle to the axis of oscillation of the dot pendulum, affects the operation of the key so that it can be. used only when mountedon a relatively stable support.

Therefore, the use of semi-automatic keys has not been practical on board ships, except while the. ships are either. in harbor or while cruising in a straight line on a. substantially calm sea, and the use of. such keys in airplanes has been impossible due to the frequent changes in attitude of. the airplane while. in flight.

It is generally conceded that a capable operator trained in the use-ofa semi-automatic key can transmit nearly twice as. fast as an operator of equal ability, with a straight. action-key. The development of a semi-automatic key which is not dependentupon a stable support for its proper operation will; therefore, clearly facilitate and accelerate transmission. under such conditions.

An. object-of the present invention is to improve andsimplify a semi-automatic-transmitting;key.

Another object of. the invention. is to provide a semi-automatic transmitting key which is operable froma plurality of angularly different positions with respect to an original basic plane of adjustment.

Another object is to balance operatingparts of a semi-automatic transmitting key to maintain required. operating. characteristics of the key when subjected. to accelerating forces. 7

Another object is to provide a semi-automatic transmitting keywith uniform operating characteristics regardless of its attitude with respect to the forceofgravity.

Other. objects and advantages of the invention will be apparent from the following, descriptionand the accompanying drawing in which similar characters of. reference indicate similar parts throughout. the several views.

Referring to. the drawing, of which. there is onesheet:

Fig. lis a plan view showinga. semi-automatic transmitting key, constructedaccording to the invention;

Fig. 2 is a horizontal sectional View taken I on theofiset planes of the broken line 2-2 of Fig. 4;

Fig 3 is a horizontal sectional view taken on the plane of the line 3.3 of Fig. 4; and- Fig. 4 is a vertical longitudinal sectional view taken on. the plane of the line 4-4 of Fig.v 1, a fragment. of a supporting member being illustrated to show a method of mounting the key,

Referring to the drawing indetail, a supporting table 2.0, or mounting board, is providedwith a hole 2i to receive a mounting bolt 22, which is secured-to, the base 23 of. a semi-automatic transmitting key indicated generally by the numeral 24. A Wing nut. 25 is threaded onto the bolt 22 to anchor the key-24 securely in position.

Vacuum cup legs 26 are provided on the base 23 and permit mounting the. key on any smooth non-porous surface for temporary use, or for use where the key is not apt to be inverted, Without the use of the bolt'22. I

Secured to the base23, and forming. a substantially integral part thereof, are a pair of parallel side plates 21 and 28. A keyingslever bearing support-29 is mounted tobridge the space between the ends or the side plates- 21 and 28, and is secured thereto as by means of mounting screws 30-. Y

A bearing adjustment screw 3| is threaded through the support 29, and is provided at its lower end with a bearing whichrnay be-0f conventional jeweled needle type, or Othersllitable low-friction pivotal bearing. A knurled lock'nut 32 is threaded on to the bearing adjustment screw 9! to lock the screw 31 in adjusted position. A second bearing screw 33 is threaded through the base 23 in axial alignment with the screw 3|. A keying-lever 94 is provided with a bearing post 99 to have bearing engagement with the bearing screws 3| and 33.

A preferred bearing arrangement is illustrated, wherein both needle points of the bearings are directed upwardly so that the bearings are selfdraining, to prevent the collection of dust or moisture in the bearing recesses.

The keying-lever 34 is provided at it outer, or right end as illustrated, with a conventional dash button 35 and dot thumb-plate 35. The keyinglever 34 is provided on a side thereof, with a dash contact point 31 which is preferably of silver or other non-corrosive metal of high electrical conductivity.

A spring-retaining stud 98 is also mounted to project from the side of the keying-lever 34 to retain a coil spring 39, which is held in compres sion between the lever 34 and an adjusting screw 49. The adjusting screw 49 is provided with a knurled lock nut 4! to retain the screw 49 in adjusted position.

A screw 42 is mounted to limit the pivotal movement of the keying-lever 34 in a counterclockwise, direction, the lever 42 being provided with a knurled lock nut 43.

A rocking lever 44 is pivotally mounted on a pivot post 45, which in turn is secured to the base 23. One end of the rocking lever 44 bears against the side of the left hand end of the keying-lever 34 as best illustrated in Fig. 3. The other end of the rocking lever is provided with a spring-retaining stud 45, which is inserted in an end of acoil spring 41. The coil spring 41 is held in compression between the rocking lever 44, and an adjusting screw 48. The adjusting screw 48 is threaded through the side frame member 28 and is provided with knurled lock nut 49.

A dash contact screw 58 is threaded through a brass bushing 51 which in turn is mounted in a pair of insulating washers 52, the bushing and the insulating washers 52 being secured in position by a nut 53. A knurled lock nut 54 is provided on the dash contact screw 59.

A conductor 55 is secured to the bushing 5| as by soldering, the conductor passing down through an opening 56 in the bas 23, and thenc across the underside of the base to a binding post 51, which is insulated from the base 23 asby means of insulating washers 58 in a conventional manner. A second binding post 98 is grounded to the frame 23 in a conventional manner.

Where jeweled bearings are used to support the pivoted levers, the keying-lever 34 and the dot lever 59 should be grounded to the frame as by pigtail connections 91.

It will be noted in Fig. 4 that the keying-lever 34, the rocking lever 44, and the dash contact screw 50, are all mounted in substantially the same horizontal plane.

An oscillating dot bar 59 is mounted in a plane above that of the keying-lever 34 and the rocking lever 44. The oscillating bar 59 is provided with a pivot post 99 which. is located at substantially the center of gravity of the oscillating bar 59. The pivot post 99 has bearing connection with a bearing member 9| at its upper end, and with a bearing adjustment screw 62 at its lower end.

The upper bearing member BI is inserted in an opening in a bridge plate 63, the bridge plate being mounted to span the space between the side frame members 21 and 28, and being secured to the frame members as by means of screws 64. The bearing BI is retained in position by means of a set screw 65 (see Fig. 4). The bearing adjusting screw 62 is threaded through the base 23, and is provided with a knurled lock nut 85.

An oscillating-spring holding fork 81 is secured to the oscillating bar 59, and is provided with a pair of adjusting screws 68 and 69, see Figs. 1 and 4, which are mounted to engag opposite sides of an oscillating spring 19 of the leaf type.

The oscillating spring 18 is mounted with the 7 right hand end thereof, as illustrated in Figs. 1

and 4, secured in a slot 1| in an adjustable spring-support member 12. The sides of the slot 1| diverge slightly toward the left hand end of the slot, and a pair of adjusting screws 95 and 99 (see Figs. 1 and 4), are mounted with their ends in contact with opposite sides of the oscillating spring 18. By adjustment of these screws, the bias of the oscillating spring against the adjusting screw 99 can be increased or decreased.

The oscillating spring 18 is formed with a slight bias or curve which, as illustrated in Fig. 1, is upwardly to the left so as to urge the dot lever 59 in a clockwise direction from the position illustrated in Figs. 1 and 2.

The spring-support member 12 is slidably mounted between the legs of a U shaped frame 13 which is secured to the upper face of the bridge plate 63 by screws 14. The spring-support member 12 has a threaded extension 15 which is slidably inserted in an opening 16 in the web portion of the frame 13. A pair of adjusting nuts 11 and 18 are threaded onto the stem 15,.being mounted one on each side of the web of the frame 13,. for longitudinal adjustment of the spring-support member 12.

A dot contact member 19 is carried by a light leaf spring 89 which is secured to a side of the oscillating bar 59. A dot contact adjusting screw 8| is threaded in a brass bushing 82, which in turn is mounted in insulating washers 83, and is secured in position by means of a nut 84. A knurled lock nut is provided on the dot contact adjusting screw 8|.

A conductor 86 is soldered to the bushing 82, and passes down through an opening 81, and thence across the underside of the base 23 to the insulated binding post 51.

A stop screw 88 is threaded through the side frame member 21 to engage the oscillating bar 59, to thereby limit its swing in a counter-clockwise direction. The stop screw 88 is provided with a lock nut 89. The stop screw 88 is adjusted to be in light contact with the side of the oscillating bar 59 when the keying-lever 34 is in a neutral position.

A stud 90 is secured to the underside of the oscillating bar 59 to project downwardly therefrom into the path of pivotal movement of the rocking lever 44, as illustrated in Figs. 2, 3 and 4.

The coil spring 39,.which is held in compression between the adjusting screw 49 and the key ing-lever 34, is relatively weak, while the coil spring 41, which is held in compression between the rocking lever 44 and the adjusting screw 48, is stronger, so that normally, without the intervention of the oscillating spring 18, the rock ing lever 44 would be moved pivotally in a counter-clockwise direction from its position illusscrew 50.

The oscillating spring. 79, however, due..to its.

initial bias, engage the. adjusting screw 69: of:

the fork 67, as shown. in Fig. 1-,. thereby urging the oscillatingbar 59 in a. clockwise direction-,so that the stud 90 engages the opposite end ofthe rocking lever? to resist the thrust of the spring 41. The composite actions of' these springs result. in. substantially balancing the three levers, comprising. the keying-lever, the rocking: lever. 44, and the oscillating bar 59, in the relative positions illustrated in the drawing. The adjusting screw 8t prevents counter-clockwise.

movement of theoscillating bar 59, and thereby also: limits the counter-clockwise. movement of the rocking lever.44.

To adjust the key for semi-automatic sending; the dash contact adjusting screw 59is adjusted to have a slight clearance from the dash contact member 3?, and the adjustment screw 49 is adjusted to cause the spring 39 to exert a light pressure against the keying-lever 34, usually just sufficient to. force the keying-lever 34' against the side of the right-hand end. of. the rocking lever 44 to thereby hold the dash contact 31 out of contact with the dash contact screw 55. When thus adjusted, in order to senda dash, pressure is applied to the dash button 35 to close the dash contact 3'! with the dash contact adjusting screw 59;

To operatethe dot lever 59 to send a series of. dots, the thumb or dot plate 36 is moved to the operators right, or upwardly from the positions shown in Figs. 1 to 3' inclusive, thereby moving the keying-lever 35 counter-clockwise until it encounters the limit adjusting screw 42; This movement swings the rocking lever M clockwise.

against the resistance of the coil spring 41 and frees the stud 95 carried by the dot lever 59 so that the biased. oscillating spring 10 swings the dot lever clockwise beyond the neutral position of the spring it. As the spring 19' passes its neutral position, the other adjusting. screw68= engages the opposite side of the spring 16', overcoming the inertia of the oscillating bar and swinging itin the opposite direction. This s.- cillating movement is continued, momentarily closing a contact between the dot contact member 79 and the dot contact adjusting screw 81 on each clockwise oscillation of the dot. lever 59, until the oscillation dampen out, or until the keying-lever 34 is released to stop the oscillating bar by bringing the rocking lever 44 into engagement with the stud 99;

Ordinarily the oscillations are continued throughout eight, ten, or more cycles, depending on the adjustment of the various parts. Since, however, the maximum number of successive dots in any character of the standard codes is five, any adjustment to send a greater number is surplusage.

The rate of oscillation of the dot bar 59canbe controlled by longitudinal adjustment of the oscillating spring support F2 to increase or decrease the eiiective length of the oscillating spring 19.

The initial bias of the spring T0 can be adjusted by means of the adjusting screw 69, as

Well as by means of the bias adjusting screws 95 and and the period of closure of the dot contacts; as well as the dampening of the oscil-- lations ofthe bar 59, can be controlledby adjusting. the separation betweenthe adjusting: screws 68 and 69. .The relative length of. the dots with respect to' the intervening spaces; can alsobe controlled by means of the dot. contact adjusting screw 8|.

The spring pressure on the dot thumb. plate 36 can be adjusted. by means of the spring: ad;- justin-gscrew 48: to increase ordecrease the compression. of: the coil spring 41:

It is: an important feature of. my invention that all three ofgthe levers, namely the. keying-lever 34, the rocking lever'M', and the oscillating bar 59, shouldgbev statically balanced with respect. totheir pivotal supports; but particularlyis this. true of the oscillating bar 59-. I

By this;b.alancing thelevers about. their'pivots, changes in: the position. of the key'or. variations in accelerationof movement, such as would; be experienced" on board ship in. a seaway, or in an airplane. in rough air at least within limits. wherein. the. operator could satisfactorily manipulate the key, would not aiifect the operation of the key, anditv could be used for semi-automatic transmission under most circumstances. Whileit is perhaps theoretically possible by sudden reversal of curvilinear movement to disturb the functioning of. the oscillating lever by means of gyroscopic action, such. sudden reversals are not.

characteristic of ship or airplane movement due tothe inertia of the ship or plane and the fluidity of the medium in which. is moves.

It would, of course, be impossible for an operator to send by means of semi-automatic transmission from an airplane engagedin aerial combat, or in the performance of acrobatics, not necessarily through any. failure of the key to function, but rather due to the stresses to: which the operator himself is subjected. In such casesthe key may be usedfor straight sending by using the dash button only, and sending both dashes and dots thereby. If desired under such circumstances, the dot sending mechanism of the key can be rendered inoperative by screwing the adjustmentscrew 42 inwardly to engag the side of the keying-lever 34, so as to prevent a counterclockwise movement of the keying-lever 34 from the position illustrated in Figs. 1 to 3, inclusive.

Under suchccircumstances a larger gap and greater spring pressure is usually. desired to permit more forceful operation of th key, so the dash contact screw 50 can be screwed outwardly to the desired position, and the tension of the spring 39' can be increased by means of the adjusting screw 40'.

' Since in military aviation the key would be mainly-used in observation and bombardment, and since in observation and bombardment missions aerial combat is to be avoided where possible, the key could be used as a semi-automatic key throughout the larger part of most of such missions. The same is true in naval work where the key would be principally used on board ships, and, by naval aviation for fleet reconnaissance and patrol.

The key is capable of quick and easy adjustment to' satisfy the most exacting requirements of the operator or the needs of service.

The key is also simple and rugged in construction, is long lived; and iswell adapted to: quantity production.

While I have illustrated a preferred embodiment of my. invention, manymodifications may be made without departing fromthe spirit of'the invention, and I do not wish to be limited to the precise details of construction as set forth; but

desireto avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. In a semi-automatic transmitting key including a frame, a keying-lever having a dashsending position and a dot-sending position, and an oscillating dot contact member mounted to b placed in oscillation by a movement of the keying lever to a dot-sending position, the oscillating member being mounted with its axis of oscillation at substantially its center of gravity.

2. In a semi-automatic transmitting key including a frame, a keying-lever having a dashsending position and a dot-sending position, and an oscillating dot contact member mounted to be placed in oscillation by a movement of the keying lever to a dot-sending position, the oscillating member being substantially non-resilient, and being mounted with its axis of oscillation at substantially its center of gravity.

3. In a semi-automatic transmitting key including a frame, a keying-lever having a dashsending position and a dot-sending position, and an oscillating dot contact member mounted to be placed in oscillation by a movement of the keying-lever to a dot-sending position, the oscillating member being substantially non-resilient, and being mounted with it axis of oscillation at substantially its center of gravity, and a spring carried by the frame, and loosely mounted between spring engaging parts of the oscillating member, to urge the oscillating member toward a neutral spring position on displacement of said oscillating member, in either direction from said neutral position, the oscillating member having suflicient mass to produce a continued oscillation from an initial impulse by said oscillating spring.

4. In a semi-automatic transmitting key including a frame, a pivoted keying-lever having a dash-sending position and a dot-sending position, an oscillating dot contact member mounted to oscillate about its center of gravity, an intermediate spring pressed pivoted lever operatively positioned between the keying-lever and the oscillating member to normally hold the oscillating lever against oscillating movement, the intermediate lever being pivotally movable by the keyinglever to free the oscillating member for oscillation.

5. In a semi-automatic transmitting key including a frame, a pivoted keying-lever having a dash-sending position and a dot-sending position, an oscillating dot contact member mounted to oscillate about its center of gravity, an intermediate spring pressed pivoted lever operatively positioned between the keying-lever and the oscillating member to normally hold the oscillating lever against oscillating movement, the intermediate lever being pivotally movable by the keying-lever to free the oscillating member for oscillation, the keying-lever and th intermediate lever being each mounted in static balance about its pivotal support.

6. A semi-automatic transmitting key having a frame, a keying-lever carried by the frame, the keying-lever having a neutral position, a dashsending position and a dot-sending position, a rigid oscillating contact member pivotally supported on the frame, the oscillating contact lever being statically balanced about its pivotal support, an oscillating spring mounted normally to urge the oscillating contact member resiliently toward an oscillating position, spring-pressed means normally holding the keying-lever in a neutral position, said spring-pressed means normally holding the oscillating member in a nonnormal position against the resilient action of the oscillating spring, and a cooperative connection between the keying-lever and the springpressed means to release the oscillating contact member for oscillation on a movement of the keying-lever to a dot-sending position.

'7. A semi-automatic transmitting key having a frame, a keying-lever carried by the frame, the keying-lever having a neutral position, a dash-sending position and a dot-sending position, a pivotally oscillating contact member pivotally supported on the frame, an oscillating spring mounted normally to urge the oscillating contact member resiliently toward an oscillating position, an intermediate lever pivoted on said frame, and having operative connection with the keying-lever and the oscillating lever, the intermediate lever being spring pressed to move the oscillating member against a balancing pressure of the oscillating spring, the keying-lever eing positioned to pivotally move the intermediate lever on a movement of the keying-lever to a dot sending position, to free the oscillating member for oscillation.

8. A semi-automatic transmitting key having a frame, a keying-lever carried by the frame, the keying-lever having a neutral position, a dashsending position and a dot-sending position, a pivotally oscillating contact member pivotally supported on the frame, an oscillating spring mounted normally to urge the oscillating contact member resiliently toward an oscillating position, a lever pivoted on said frame, and having operative connection with the keying-lever and the oscillating l'ever, the intermediate lever being spring pressed to move the oscillating member against a balancing pressure of the oscillating spring, the keying-lever being positioned to pivotally move the intermediate lever on a movement of the keying-lever to a dot sending position, to free the oscillating member for oscillation, the keying-lever, the intermediate lever, and the oscillating member each being statically balanced about its mounting support.

9. A semi-automatic transmitting key having a frame, a keying-lever mounted thereon, an oscillating member pivotally mounted on the frame, the axis of the pivotal mounting of the oscillating member passing substantially through its center of gravity, an oscillating spring mounted to engage the oscillating member, the oscillating member being normally held by the keying lever against pivotal movement and against a bias thrust of the spring, the oscillating member having a contact mounted to close at a predetermined stage of each cycle of oscillation, the keying-lever being movable to free the oscillating lever for oscillating movement.

10. In a semi-automatic transmitting key, a keying-lever and oscillating member, the oscillating member being pivotally mounted at its center of gravity, means for holding the oscillating member in a biased position, and means operatively connecting the keying-lever and the oscillating member to release the oscillating member for oscillation on a predetermined movement of the keying-lever.

11. In a semi-automatic transmitting key, a keying-lever and an oscillating member, the oscillating member being pivotally mounted at its center of gravity, an oscillating spring mounted to swing the oscillating member through an oscillating cycle, spring pressed means normally maintaining the oscillating member against a balancing sprin pressure of the oscillating spring, the keying-lever and the spring pressed means being interconnected to move the spring pressed means in the direction of pressure of the oscillating member for oscillation on a predetermined movement of the keying-lever.

12. In a transmitting key, a keying-lever, an oscillating contact member mounted to oscillate about its center of gravity, the oscillating contact member being mounted for oscillation by the keying-lever on a movement of the keyinglever in one direction for signals of automatically determined length and frequency, and a contact mounted adjacent the keying-lever to be closed by a movement of the keying-lever in another direction for a signal of manually controlled length.

13. In a semi-automatic transmitting key including a frame, a keying-lever having a dashsending position and a dot-sending position, and an oscillating dot contact member mounted to be placed in oscillation by a movement of the keying-lever to a dot-sending position, the oscillating member being substantially non-resilient, and being mounted with its axis of oscillation at substantially its center of gravity, and a leaf spring having one end thereof secured to the frame, and having the other end thereof loosely mounted between adjustable spring engaging parts of the oscillating member, to urge the oscillating member toward a neutral spring position on displacement of said oscillating member,'in either direction from said neutral position, the oscillating member having sufficient mass to produce a continued oscillation from an initial impulse by said oscillating spring.

14. In a semi-automatic transmitting key, a keying-lever and a substantially rigid oscillating dot contact lever, the dot contact lever being pivotally mounted at its center of gravity, means for holding the dot contact lever in a biased position, and means operatively connecting the keying-lever and the oscillating dot contact lever to release the oscillating dot contact lever for oscillation on a predetermined movement of the keying-lever.

JOEL W. DICKINSON.

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