US1341719A - Key-switch - Google Patents

Description

B. L. MOORE.

KEY SWITCH.

APPLICATION FILED Aue.24.191s.

1,341,719. Patented June 1 1920.

fir TOPNZY PATENT osr cs.

Briton L. MOORE, or BUFFALO, new ron'x.

KEY-SWITCH.

Specification of Letters Patent.

Patented June 1, 1920.

Application filed August 24,1918. Serial No. 251,213.

To all whom it may concern:

Be it known that I, BYRON L. MOORE, a

citizen of the United States of America,

and a resident of the city of Buffalo, county of Erie, and State of New York, have invented certain new and useful Key-Switches, of which the following is a full, clear, and exact description. 1

My invention relates generally to key switches, which are used in telephone, radio telephone, and radio telegraph systems, sometimes referred to as anti-capacity keys. It will be understood by those skilled in the art, that previous forms of similar-apparatus have been detrimental, in that they have been constructed with flat springs insulated from each other but facing each other in close proximity and, therefore, having considerable'electrostatic capacity. Due to this fact, these'keys, when the springs thereof were in oroutof mechanical contact with each other, have permitted the passage of a perceptible amount of induced alternating current. It has, therefore, been difficult to entirely interrupt alternating currents, particularly those of high-frequency with these previous forms of keys; it being well lmown that two flat metal surfaces facing each other in close proximity separated by a dielectricsuch as air or an insulating compound-act as a condenser with considerable apparent conductivity to alternating currents of high-frequency.

The general object of my invention has been to provide a key or switch which shall overcome defects inherent in the keys of previous construction, with respect to the capacity effects just described.

Another object has been to provide a mounting for the master springs, which shall furnish air spaces around thesprings for the purpose of reducing the electrostatic capacity.

Another object has been to provide a key of this nature which shall be of simple and rugged construction, and one cheap to manufacture.

The above objects and advantages have been accomplished by the device shown in the accompanying drawings, of which:

Figure .1 is a side elevation of the complete device; a portion thereof being shown in section.

Fig. 2 is a sectional elevation thereof,-

Fig. 3 is a sectional, plan view, taken on line 3-3 of Fig. 1.

Fig. 4 is a side elevation of one. of the master springs.

Fig. 5 shows a modified form of master spring.

Fig. 6 shows another form of master spring.

' My switch comprises an insulating block 5, which carries the contact springs of the device. This block is carried by a frame 6, preferably U-shape and having its ends 7 and 8 fastened to the block. 5. This frame may be made either of metal or insulating material. Carried by the top of the frame 6 is a cam actuating mechanism of the well known type, and preferablycom prising a lever 10, a cam '11, and cam rollers rotation and the air spaces 28 are provided.

The upper .end 29 of each spring is bent inwardly toward the center of. the key and then outwardly, or otherwise formed so as to be; mechanically engaged by the rollers 12 and be actuated thereby. The upper end 29 of each of the master springs is so angularly arranged that when the cam actuating mechanism is operated, the rollers will be locked in osition .until manually released.

isposed opposite and facing each of these master springs 13, and of different electrical polarity or potential, are one or more anvil springs 14. These springs are also secured near their lower ends within the insulated block 5, and have their upper ends extending to near the top of the master springs 13. The portion of the spring which engages with the block may be knurled or roughened, but is preferably provided with projecting tabs 30, which prevent the spring from rotating. The anvil springs 14 are preferably cylindrical in shape and each has its upper end portion bent inwardly so as to bring the end thereof in close proximity to the masterspring, at the same time keeping the'greater part of the spring as distant as possible from the master spring, within the limits of the construction. This construction affords a small area of opposing surface and at the same time maintains a substantial distance between the springs referred to. As the result of this construction, my key has the advantages of low electric capacity, mechanical rigidity of the anvil spring, and permits the adaptation of the spring end to contact uses. 4

While I have shown and described the anvil springs of round cross-section, they may, if desired, be of any other suitable cross-section, as diamond-shape or squareshape.

In Fig. 5, I show a modified form of master spring. In this figure, the upper end 9 of the spring 21, which contacts with the cam actuating mechanism, is provided with a return bend 22 arranged in interspaced relation. This construction provides means for dampening the -vibration of the master spring when suddenly operated or released. In Fig. 6, I showanother form of spring end 23 for accomplishing the same purpose as the form shown in Fig. 5. In this form, a piece of spring metal 20 is riveted to the upper end of the master spring 24:.

The master springs, instead of being formed of flat material, as shown, may be made of any other desirable cross-section, such as round, square, or diamond-shaped wire and may have their upper ends formed in any desired manner.

t will be clear that when the cam lever is operated, the rollers 12 will contact with the upper bent ends of 'the-master springs and move these springs intt) or out of elec trical contact with the anvil'springs.

It is obvious that while, for purposes of illustration, I have shown my key provided with a certain number of springs, it may contain-any other number and arrangement of springs to adapt it for use in connection with'difi'erent electrical circuits; the lower ends of the springs being, of course, connected in the well known manner with the circuits being controlled. It is also evident that the frame supporting the mechanical parts may take any desired form or be constructed of a single material or materials.

Having thus described my invention, what I claim is: i

-1. In a key switch, the combination, with a frame and a cam actuating mechanism carried by the frame, of a block of insulatmg material carried'by the frame, master springs fastened near their lower ends within the block and having their upper ends bent so as to be mechanically engaged by the cam actuating mechanism and be'actuated thereby, anvil springs, each having the surface adjacent the master spring of small, superficial area as compared to the area ofthe master spring, said, anvil springs bein secured near their lower ends within the b ock, the upper ends of the anvil springs being bent toward the adjacent master springs so as to bring the upper end in close proximity thereto. 1

2. In a key switch, the combination, with a frame and a ca m actuating mechanism carried by the frame, of a block of insulating material carried by the frame, -master springs fastened near their lower ends within the block and having their upper ends' bent so as to be mechanically engaged by the cam actuatin mechanism and be actuated thereby, anvi springs, cylindrical in cross section and secured near their lower ends within the block, the upper ends of the anvil springs being bent toward the adjacent master springs so as to bring the upper end in close proximity thereto.

3. In a key. switch, the combination, with a u shaped. frame and a cam actuatin mechanism carried by the frame, of a bloc of insulating material carried at the lower end of the frame, master springs fastened near their lower ends'within the block and having their upper ends bent so as to be mechanically engaged by the cam actuatin mechanism and be actuated thereby, an springs substantially, cylindrical in crosssection and secured near their lower ends within the block, the upper ends of the anvil springs being bent toward the adjacentmaster spring so as to bring the upper ends a in close proximity thereto.

In testimony whereof I have hereunto si ed m name. I

'gn BYRON L. MOORE.v

Images