US3098898A

US3098898A - Telegraph key

Info

Publication number: US3098898A
Application number: US114959A
Authority: US
Inventors: Jakosky John Jay; Jr John J Jakosky
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-06-05
Filing date: 1961-06-05
Publication date: 1963-07-23
Anticipated expiration: 1980-07-23

Description

July 23, 1963 J. J. JAKOSKY ETAL 3,098,898

TELEGRAPH KEY Filed June 5, 1961 Filed June 5, 1961, Ser. No. 114,959 Claims. (Cl. 178-408) This invention relates to an improved dual type of telegraph key, or electric key mechanism, whose operating lever is actuated in a horizontal plane, to make electrical contact when moved to the right or left of its center position of rest. The prime object of the invention is to provide a keying mechanism which mechanically will have a definite center-rest position, be positive in its operation and free of undesirable loose-play.

Another object of the invention is to provide a keying mechanism which will make a firm, continuous contact without chatter and contact-bounce.

Another object of the invention is to provide a simple mechanical arrangement whereby the operating lever is precisely positioned at its center position of rest, and at the same time allow independent adjustment to be made of the spring tension controlling the movement to either the right or left.

Another object of this invention is to provide :a simple mechanical keying mechanism for controlling the operation of an automatic electronic keyer, which latter forms no part of the present invention.

Another object is to provide a key having a base which will provide maximum stability against turning moment, with a minimum overall weight.

Electrically, the key functions as a single pole, double throw switch, whereby electrical contact may be made with either one of two circuits. When connected to an automatic keyer, in the conventional manner, the keyer will automatically form dashes as long as the lever is held to the left, and dots as long as it is held to the right. In other words, the object of this invention is to provide an electric key mechanism, or switching device, to control an electronic keyer. The keyer then automatically forms the dots or dashes, in response to the movement and timing of the key lever.

Previous keys having definite center-rest positions, have been of complicated mechanical design with one or more of the contact points and restoring springs positioned on the opposite side of the pivot from the handle where the actuating side pressures are applied to operate the key. The inevitable loose-play in the pivot point, therefore, results in sloppy mechanical action with resultant poor keying action, especially at the higher operating speeds. To overcome this very undesirable action, the present invention places the restoring spring pressures, the contact points, and the actuating side pressures, all on the same side of the pivot or axis of rotation. As a result, the injurious effects of a loose pivot and complicated mechanical linkages are greatly minimized.

Other important objects of the invention will be apparent upon reading the following descripiton, together with a study of the drawings showing a preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a general top plan view of the embodiment of the invention.

FIGURE Q is a general side view of the embodiment.

FIGURE 3 is an isometric top view of the moving mechanism, comprising the lever and a bifurcated yoke or rocker-arm, and removed from the base.

The invention is described in the following specifications and drawings; and comprises essentially, a heavy base 1 which rests upon three

frictional rubber feet

2, 2', and 2". A vertical shaft 3 is supported by the base, and pivoted on this shaft is a lever 4. Pivoted coaxial it States Patent 3,098,898 Patented July 23, 1963 with the lever is a bifurcated yoke or rocker-arm 5 which is pivoted at its bight so it can move either with or independent of the lever. The yoke 5 brackets lever 4 and is normally held against the lever, at bearing point 6, by means of the compression of a spring 7, which exerts pressure between the left arm of yoke 5 and the lever 4. The compression of this spring may be adjusted by means of screw 7 and held by lock-nut 7. When at its centerrest position, the left arm of the yoke is normally held against a stop screw 8, having lock-nut 8, by the force exerted by the compression of a spring positioned between the base and the right arm ofyoke 5. The compression in spring 9 may be adjusted by means of the screw 9", having lock-nut 9".

A contact point 10 is fastened to the yoke, and spaced from a companion contact point 10' which is fastened to the adjusting screw 11, with lock-nut 11', supported by the post 12. The post -12 is mounted on and electrically insulated from the base and is connected for conventional operationto the dot forming circuit of the keyer. A second contact point 13 is fastened to the opposite side of the lever, and is spaced from its companion contact point 13' mounted upon the adjusting screw 1-4 with its locknut 14, and supported by the post 15. The post 15 also is mounted on and electrically insulated from the base and normally is connected to the dash forming circuit of the automatic keyer. This describes the normal or centerrest position of the mechanism.

An insulated handle or handles, of special mechanical characteristics 16 and/or 16', are provided, and electrically insulate the operator from the lever. These handles, or paddles, are usually positioned bet-ween the thumb and the fore-finger of the operating hand. For right-handed operation, the lever is moved to the right to form dots, by exerting pressure of the thumb against handle 16. Movement of the lever to the left to form dashes, is obtained by exerting pressure of the fore-finger against the handle 16.

As previously mentioned, the lever and the yoke are suspended independent of each other for horizontal movement and in the preferred embodiment is mounted coaxially upon the same shaft. The assembly has a stable center-rest position due to the pre-stressing action of spring 9 holding the yoke against a fixed stop means or stop-screw 8, and the pre-stressing action of spring 7 holding the lever against the anvil point 6 on the yoke. The contact screws 11 and 14 are adjusted so that the lever is positioned midway between these contacts, but not touching. When pressure is applied to handle 16 toward the left, the lever 4 moves toward the left against the spring 7, and contact is made between 13 and 13', without any movement of the yoke 5, but the levelwhen in this position leaves the anvil point 6 on the rockerarm. When pressure is released on the handle, the lever returns to its original center-rest position due to the action of spring 7. When pressure is applied to the handle 16 toward the right, the lever 4 moves toward the right, simultaneously shifting with it the yoke 5, against the action of spring 9, closing contacts 10 and 10', but the yoke while in this position leaves the stop-screw 8. When the pressure is released on the handle, the assembly of lever and yoke returns to its original center-rest position due to the action of spring 9.

The lever 4 has a firm center point of rest by virtue of the pre-stressing of springs 7 and'-9. Thus, to move the lever either right or left from its rest position requires appreciable finger pressure, so that the lever is held at rest against transient forces.

When the lever 4 is moved to either the right or left, to make contact with the rigid stationary contacts, there is a tendency for the lever to chatter or bounce against the contact, causing contact bounce. The frequency of this 3 detrimental bounce or chatter appears to be a function of lever mass and its moment arm, spring tension, and the side pressure against the handle; Due to the very minute currents (usually measured in rnicro-amperes) handled by the contacts when controlling an electronic keyer, this contact bounce often causes erratic keying. This condition becomes particularly aggravated as the contacts become oxidized or dirty. To remedy this condition, the handles 16 and '16 are designed to have .a certain amount of flexibility. In accordance with this invention, it has been found that when the handles comprise approximately /3 the length of the total moving arm, their flexibility serves to dampen the detrimental chattering, thereby very effectively eliminating the problems of contact bounce, and giving a smooth, uniform keying action. For any given set of handles, the amount of flexibility required to give the desired damping action is dependent upon the stiffness to which the springs 7 and 9 are adjusted. For the usual stiffness to which these springs are adjusted for normal operation, the handles should deflect between .001 and .010 inch, when side pressure is applied near their outer extremity to move the lever to make contact to either the right or left of the center-rest position.

The base 1 is made preferably of metal with a weight of about three pounds to give the desired stability, to prevent walking or side movement during operation of the key. An excess of weight, however, is detrimental as it interferes with the portability of the key, and also increases shipping charges and the manufacturing costs. It thereiore is very desirous to have the weight of the base positioned or placed at the most advantageous position. Since the side-thrusts to move the lever are applied at 16 or 16', the base tends to rotate about the foot 2', and the turning moment is the product of the side-thrust multiplied by the length of the moment arm 16-2' or 16 To resist this turning moment and obtain the desired stability, there exists the downward pressure exerted against the

feet

2 and 2" multiplied by the coeflicient of friction, which product is then multiplied by the moment arm or distance between 2 (or 2") and the pivot foot at 2'. It will therefore be seen that it is desirable to concentrate all possible weight as far forward as possible; i.e., away from the pivot foot 2'. Tests have shown that at least 65 percent of the weight of the base should be concentrated forward of the mid-point, 17 of the lever 4.

An eminently satisfactory key mechanism is being marketed embodying the present invention and having the following parameters: Length of key lever from pivot 3 to end of handles 16, 4% inches. Distance from pivot 3 to center of rear foot 2', /2". Weight of base 1, 3 pounds. Typical operating compression in bias springs (adjustable by screws):

spring

7, 3 ounces; spring 9, 4 ounces. Pressure to move lever to either right or left, is one ounce. Typical adjustment between

contacts

10, 10' and 13, 13' (adjustable) .006 inch. All parts are metal, except the paddles 16 which are Cycolac or Tenite plastic, having dimensions of about .100 inch thick, one inch wide, and two inches in length, overall.

Although there has been shown and described herein a preferred embodiment of the invention, it is to be understood that this invention will not be limited to this particular description, and that changes may be made in the materials, and in the structure and arrangement of the parts, within the spirit of this invention and the scope of the appended claims.

What is claimed is:

1. Manually operable electric key mechanism comprising a base, an elongate key lever pivoted one end to said base for oscillation about a substantially vertical axis, a bifurcated yoke bracketing said lever and pivoted at its bight to said base coaxially with said lever, a spring compressed between said lever and one arm of said yoke and biasing said lever into firm engagement with the other arm or said yoke, a stop on said base for limiting movement of said yoke, a spring compressed between said yoke and said base and biasing said yoke into said firm engagement with said stop, a first pair of spaced contacts mounted on said base and lever, respectively, and engageable by moving said lever in the opposite direction, said lever having at least one flat paddle on the end thereof opposite said axis and made of material appreciably more i flexible than the remainder of said lever.

. pivoted and elongate and extending from the pivot axis in generally the same direct-ion, said stop member comprising a member having portions extending on both sides of said key member, said first biasing means comprising a spring compressed between said key member and one side portion of said stop member, to bias said key member into engagement with the other side portion of said stop member, said fixed stop means being fixed to said base on the same side of said key member as said first biasing means, and said second biasing means comprising a spring compressed between said :base and said other side portion of said stop member.

3. Manually operable electric key mechanism comprising; a base, a movably mounted key member, a movably mounted stop member, means engaging said key and stop members for biasing said key member into engagement with said stop member, fixed stop means for limiting movement of said stop member in a given direction, and means for biasing said stop member into engagement with said stop means; said members being coaxially pivoted and elongate and extending irom the pivot axis in generally the same direction, said stop member comprising a bifurcated yoke pivoted at its bight and bracketing said key member, said first biasing means comprising a spring compressed between said key member and one arm of said yoke to bias said key member into engagement with the other arm of said yoke, said fixed stop means being fixed to said base, and said second biasing means comprising a spring compressed between said yoke and said base.

4. Manually operable electric key mechanism compmsing; a movably mounted key member, a movably mounted stop member, means engaging said key and stop members for biasing said key member into engagement .With said stop member, fixed stop means for limiting movement of said stop member in a given direction, and means for biasing said stop member into engagement with said stop means; said members being coaxially pivoted and elongate and extending from the pivot axis in gen enally the same direction, said stop member comprising a member having portions extending on both sides of said key member, said first biasing means comprising a spring compressed between said key member and one side portion of said stop member, to bias said key member into engagement with the other side portion of said stop member, said fixed stop means being fixed to said base on the same side of said key member as said first biasing means, and said second biasing means comprising a spring compressed between said base and said other side portion of said stop member, there being a contact point on the said other side portion of said stop member.

5. Manually operable electric key mechanism comprising; a base, an elongate key lever pivoted at one end of said base for pivoting about a substantially vertical axis, a first pair of contacts mounted respectively on said lever and base and engageable by movement of said lever in one direction, a second pair of contacts mounted respectively on said lever and base "and engageable by movement of said lever in the opposite direction, means References Cited in the file of this patent UNITED STATES PATENTS Martin Feb. 13, 1923 Martin Feb. 21, 1939 Heatherly June 29, 1943

Claims

1. MANUALLY OPERABLE ELECTRIC KEY MECHANISM COMPRISING A BASE, AN ELONGATE KEY LEVER PIVOTED ONE END TO SAID BASE FOR OSCILLATION ABOUT A SUBSTANTIALLY VERTICAL AXIS, A BIFURCATED YOKE BRACKETING SAID LEVER AND PIVOTED AT ITS BIGHT TO SAID BASE COAXIALLY WITH SAID LEVER, A SPRING COMPRESSED BETWEEN SAID LEVER AND ONE ARM OF SAID YOKE AND BIASING SAID LEVER INTO FIRM ENGAGEMENT WITH THE OTHER ARM OF SAID YOKE, A STOP ON SAID BASE FOR LIMITING MOVEMENT OF SAID YOKE, A SPRING COMPRESSED BETWEEN SAID YOKE AND SAID BASE AND BIASING SAID YOKE INTO SAID FIRM ENGAGEMENT WITH SAID STOP, A FIRST PAIR OF SPACED CONTACTS MOUNTED ON SAID BASE AND LEVER, RESPECTIVELY, AND ENGAGEABLE BY MOVING SAID LEVER IN THE OPPOSITE DIRECTION, SAID LEVER HAVING AT LEAST ONE FLAT PADDLE ON THE END THEREOF OPPOSITE SAID AXIS AND MADE OF MATERIAL APPRECIABLY MORE FLEXIBLE THAN THE REMAINDER OF SAID LEVER.