US2236671A - Starter switch for gaseous discharge devices - Google Patents

Description

April 1, 1941 c. GHIRELSTEIN STARTER SWITCH FOR GASEOUS DISCHARGE DEVICES Filed June 25, 1940 Fig"? in U Ill.

? Z i 5 Z r 5 i maria; t'lakelsfiein, I N VE N TOR.

Patented Apr. 1, 1941 haired 2 caries.

STARTER SWKTCH FOR GASEQUS DISCHARGE DEVICES 9 Claims.

fhe invention here disclosed relates to switches for starting gaseous discharge devices, such as fluorescent lamps and the like.

As at present constructed, the switches employed for this purpose have certain serious faults. Because of the fact that the actual point of contact is microscopic and the peak voltage is high, the contact areas are destroyed in a relatively short time. With the form of electrodes used, the ionization lags. making the switch sluggish in action. Further, and particularly for the higher voltage tubes, resistors are required for controlling the ionization current.

Special objects of the present invention are to overcome and obviate the foregoing objections and limitations.

Further objects and advantages of the invention will appear in the course of the following specification.

In the drawing accompanying and forming part of the specification, one practical commercial embodiment of the invention is illustrated, but it will be understood that structure and composition of the actual physical embodiment of the invention may be modified and changed in various ways all within the true intent and broad scope of the invention as hereinafter defined and claimed.

Fig. l is an enlarged and broken part sectional view of one of the commercial embodiments of the invention.

Fig. 2 is a similar view looking at the switch from a different angle.

Fig. 3 is a cross-sectional view as on line 3-3 of Fig. 2.

The contacts of the switch are designated 5 and 6, the first being a looped bimetallic strip element arranged, on heating, to expand into engagement with the second contact. The latter is shown in the form of a rod or wire extending substantially parallel across the flat outer side at the free end of the expanding strip contact, thus to provide for circuit completing contact engagement across the full face width of the strip.

With the structure and relation illustrated, full and complete circuit closing contact is assured at all times, since the full width of the thermal strip is effective and utilized for circuit completing purposes.

The stationary contact 6 also is shown as having the end of the same bent over and across the free end portion of the movable switch element at l, and as carrying the tab or plate 8, over the loop of the movable switch element,

(or. zen-27.5

thus to provide more opposed electrode surface to facilitate ionization and effect both faster operation and at lower voltage.

The rod i9, which carries the bimetallic switch element and the rod 6, which forms the companion switch contact are sealed at H, into the envelope or container l2, and have connected with them external circuit wires H, l 3,

The case or so-called can for the glass envelope and the wiring terminals and insulating mounting for the same are not illustrated, since these accessories form no part of the present invention.

The gases used and pressures employed are important.

For a low voltage v.) glow switch neon and krypton in the proportions of approximately 99- 99%;% to 1 are preferred and for the socalled high voltage (220 v.) switch helium is preierrecl. The use of helium in the high voltage switches eliminates any need for additional series resistors which have heretofore been found necessary and substantially increases the ultimate life of the switch.

The best operating pressures for the low voltage neon-krypton gaseous switches have been found to be about 4 to 6 centimeters and to be within the range of from 1 to 10 centimeters and the best pressure for the high voltage helium switch as about 3 to 5 centimeters and within the range of from 1 to 6 centimeters.

The neon-krypton combination is a marked improvement over the neon and argon combinations now used in comparable starter switches and the helium employed in the place of argon and resistor combinations, similarly, is an important advance over present practice in the high voltage starter switches.

The starter switch disclosed may be used in the conventional circuit arrangements with the switch connected in an auxiliary starter circuit across the outer ends of the tube filaments, that is, those ends which are not connected with the power circuit.

What is claimed is:

1. A starter switch for gaseous discharge devices, comprising a gaseous container, a bowed flat strip of bimetallic material supported at one end in said container with the opposite end free to move under thermal expansion of the strip and a fixed switch contact rod in said container disposed at an angle to the longitudinal extent of said bimetallic fiat strip and extending in substantially parallel relation across the full width of the fiat face of said strip at the free end of the same and an angular extension at the end of said rod contact projecting in spaced relation across the edge portion of said bowed bimetallic contact.

2. A starter switch for gaseous discharge devices, comprising a gaseous container, a bowed fiat strip of bimetallic material supported at one end in said container with the opposite end free to move under thermal expansion of the strip and a fixed switch contact in said container extending in substantially parallel relation across the full width of the fiat face of said strip at the free end of the same and an electrode plate carried by said fixed switch contact and projecting in spaced relation across the bowed portion of said flat strip.

3. A starter switch for gaseous discharge de-v vices, comprising a gaseous container, 2. bowed fiat strip of bimetallic material supported at one end in said container with the opposite end free to move under thermal expansion of the strip and a fixed switch contact in said container extending in substantially parallel relation across the full width of the fiat face of said strip at the free end of the same and said fixed switch contact having an end portion extending angularly across the edge of said bowed switch contact.

4. A starter switch for gaseous discharge devices, comprising a sealed envelope, a mixture of neon and krypton in said envelope in approximately the proportions 9999 /2% to /21% and cooperative thermostatic switch elements sealed in said envelope.

5. A starter switch for gaseous discharge devices, comprising a sealed envelope, a filling of rare gas including neon and krypton at a pressure of 4 to 6 centimeters in said envelope, an expansive thermostatic switch element sealed in said envelope and a companion switch element sealed in said envelope, said cooperating switch elements having extensive opposed and coacting multiple contact areas.

6. A starter switch for gaseous discharge devices, a filling of rare gas including neon and a small proportion of krypton in said envelope under a pressure within the range from 3 to 6 centimeters and a thermostatic switch sealed in said envelope.

'7. A starter switch for gaseous discharge devices, comprising a sealed envelope, a mixture of neon and krypton in said envelope under a pressure within the range of 4 to 6 centimeters and a thermostatic switch sealed in said envelope.

8. A starter switch for gaseous discharge devices, comprising an envelope, an atmosphere of rare gas including neon and a small proportion of krypton sealed in said envelope under pressure of between 1 to 10 centimeters and a thermostatic switch sealed in said envelope.

9. A glow switch for gaseous discharge devices, comprising an envelope, an ionizing atmosphere sealed in said envelope, a bowed bimetallic flat strip contact supported at one end in said envelope, a fixed switch contact in said envelope extending in normally spaced relation across the flat surface of the free end portion of said bowed contact and a plate in angularly projecting relation on the end of said fixed contact and in opposition to the bowed edge portions of said bimetallic contact.

CHARLES CHIRELS'I'EDT.

Images