US2352936A - Operating system for discharge lamps - Google Patents

Description

y 1944. F. D. BRYANT 2,352,936

OPERATING SYSTEM FOR DISCHARGE LAMPS Filed July 21', 1942 9 2/ /& za Z0 Inventor: Fran k D. Bngant,

His Attonneg.

Patented July 4, 1944 OPERATING SYSTEM FOR DISCHARGE LAMPS Frank D. Bryant, Syracuse, N. Y., assignor to General Electric Company, a corporation of New York Application July 21, 1942, Serial No. 451,699

2 Claims.

My invention relates to an operating system for discharge lamps and more particularly to electric switches for use with discharge lamps of the type now on the market, such as fluorescent lamps.

The object of my invention is the provision of a new and improved switch mechanism which may be manually operated to control the operation of such lamps and which may be used with one or more lamps as occasion requires.

In the accompanying drawing, Fig. l is an elevational view of my switch; Figs. 2, 3 and 4 are cross-sectional views through the switch taken along the lines 2-4, 3-3 and 44, respectively. of Fig. 1; Fig. 5 is a view of the switch mech anism showing the positions of the elements when the lamps are lighted and Fig. 6 is a diagrammatic view showing one manner of connecting the switch in c rcuit with a plurality of discharge lamps and showing the switch elements in position to start the lamps.

Referring to the drawing, my switch includes a housing H) which is preferably made in two parts of any suitable insulat ng material, such as a molded plastic. The two parts of the housing are held together by suitable fastening means, such as the screws ll. Each one is hollowed out so that when assembled together they form a chamber 12 within which is pivotally mounted an operating member l3. This member is provided I with a handle H wh ch extends beyond the confines of the housing and is movable through a slot IS in the outer wall 01 the housing. Opposite side walls of the housing are provided with projecting bosses l6 which form arbors and which are seated in recesses I1 formed in complementary projecting bosses IS on the operating member l3. When the two parts of the housng are assembled around the operating member. the member is securely held in position for pivotal movement within the housing since the arbors l6 project into the recesses l1. Recesses H are somewhat elongated. as indicated in Fig. 5. so that the operating member has a certain degree iiftglay or movement for a purpose to be descr bed Opposite walls of the housing are formed with recesses I9. Within the recesses spaced contact blades 20 and 20 are mounted one on each side of the operating member. Each contact blade is formed of a strip of suitable flexible conducting material, such as spring bronze, and each is pro vided with a projectng or cam surface 2| which co-operates with and is engaged by a conducting or shorting member 22 carried by the operating member l3. In assembled position, the contact blades 20 and 20 are fitted closely adjacent the walls of the recesses I9. When the handle of the operating member is moved to the extreme left, in the showing of Figs. 1, 4 and 5, the shortlng member 22 is of such a length that it does make electrical contact with the fixed contact members. However, when the handle of the operating member is moved to the right to mid-position or beyond the shorting member engages the projecting surfaces 2| of the contact blades to complete an electrical connection between the blades. The resiliencyof the contact blades 20 and 20' is such that the operating member will be held in mid-position, as shown in Figs. 4 and 5. by the biasing action of the blades on the shorting member. Each contact blade is pro vided with an offset terminal portion 23 which is seated in a recess 24 adjacent the chamber [2 where connection is made to the conductors 25 and it for connection to a current supply in a manner to be described later. The terminal portions 23 on the respective contact blades are separated and insulated from one another by a barrier plate 21 which, as shown in Fig. 4, is clamped between the two parts of the housing in a position to separate the contact blades from one another.

In a portion of the chamber 12 spaced from the contact members 20 and 2!! are a plurality of spaced flexible contact members 23 and 29 co=- operating with fixed contacts 38 and 3t, respectively; they aremade of suitable conducting material, such as spring bronze. The flexible con tact members 28 and 29 rest on the bottom wall of the chamber l2 and are provided with a re versely bent portion 32 in the form on an 8 so that they are capable of a certain degree of movement when engaged by the operating member 83. The operating member is formed at its lower end with projecting portions 33, as shown by Figs. 3 and 5, which when the handle 84 is moved to the right. in the view of Fig. 5, engage the fienible contact members 28 and 29 and depress them into engagement with the fixed contacts 30 and it. Both the fixed and movable contact members are provided at their engaging ends with contact surfaces or buttons 34 of high conductivity material, such as silver, to insure a good electrical connection between these elements. The movable contacts 28 and 29 are connected to conductors 35 and 36, respectively, shown most clearly by Fig. 6. Similarly, the fixed contacts 30 and 3| are connected to conductors 31 and 38, respectiveha. The fixed contacts 30 and 3! are each formed of sheet material, such as spring bronze, and the outer end is bent at an angle, as indicated at 29, so that the contact button II is presented for contact with the corresponding button on the movable contacts. The contacts are insulated from one another adjacent the contact buttons 24 by an additional barrier 40 of insulating material, as shown by Fig. 2. They are held in position in the housing by being clamped between the side walls of the housing and the barrier member.

In the showing of Figs. 4 and 5, the operating member I2 is in mid-position which corresponds to the lighted position of the lamps with which the switch is used. If the handle it is moved to the left, as shown in Fig. 5, the circuits through contacts 2| and 2| remain open; at the same time the circuit through the contact members 2| and 2| is also interrupted due to the fact that the shorting member is not in engagement with them. This corresponds to the "off position of the lamps. when it is desired to light the lamps, the handle II is moved to the right to the position shown by Fig. 6 so that the circuits through the movable contact members 2| and 29 are closed while a separate circuit is also established through the contacts and 2| in the manner aforementioned. Upon release of the operating member, the biasing action of the blades 2| and 2| will return it to mid-position, as shown by Fig. 5. The biasing action of the resilient contact blades is increased due to the fact that the operating member may move on its pivots within the range of the elongated slot l1 thereby making possible a further initial defamation of the blades. The manner in which the switch operates to control the operation of a discharge lamp and the manner in which it is connected into an operating circuit with the lamp w ll now be described with particular reference to Fig. 6.

I have shown two lamps ti and 42, such as fluorescent lamps. operatively connected in circult with my switch and with the ballast B of a type now commercially available. The ballast is provided with a reactor 4| having a lagging power factor connected to lamp 4| while a second reactor 4| having a leading power factor by reason of the capacitor II is connected to the other lamp l2; a compensator it in the form of a reactor adds inductance to the heating circuit of the second lamp 42 to insure quick starting. As mentioned above, this is an exampl of a ballast of a type now available on the market and of itself forms no part of my invention. Fluorescent lamp ll is provided with emissive filaments t1 and 4| at opposite ends thereof while the lamp I2 is likewise provided with such filaments designated 49 and Ill. The manner in which the sw tch operates to start the lamps, will now be described. it being noted that in the diagrammatic showing of Fig. 6 the switch is in the start" position with the circuit through the contact members 2| and 20' closed by the shorting member 22 and with the flexible contact members 2| and 2| depressed to form an elec trical connection with the fixed contacts 30 and 2|, respectively.

When the operating handle it has been moved clear to the right, as indicated in F'g. 6, the circuit through the shorting member 22 will be closed in the manner already described. Current thus flows from one side 5! of an alternating current supply l ne to the reactors 43 and it of the ballast 13. Current from reactor 43 flows through a conductor I2 to the filament 48 at one 2|, conductor II to the compensating reactor 4|,

then by a conductor It to the filament 5| at the other end of the lamp, then by conductor 21 to conductor 25, contact 2|, shorting member 22, contact 20, conductor 2| to the other side of the supply line.

It will be apparent that the arrangement is such that as long as the handle it is manually held turned to the right in the position indicated current will flow through the electrodes of both fluorescent lamps in the manner just described to heat them. Usually, this preheating time is of the order of 1 to 5 seconds. After that time, the operating handle II is released so that the resilient spring contact members 2| and It move the operating member 12 to mid-position, as shown in Fig. 5, the circuit through the movable contact members 22 and 2| being simultaneously opened. Upon opening of the circuits through the contacts 2| and 2|, the circuits across the filaments of the lamps are opened so that the reactors lil and II provide an inductive kick, causing a glow discharge to strike between the electrodes of each lamp, lighting the lamps. When this occurs, the circuit through my switch is as follows.

Current flows from one side of the supply line to reactor 0, through line II to filament 0, across the glow discharge through lamp II to the filament l1, line l2, conductor 2|, contact 2|, shorting member 22, contact 2| and conductor 2| to the other side of the supply line. simultaneously, current flows from reactor ll through conductor 28 to filament 4|, across the flow discharge in lamp 4! to filament I0, then by conductors l1 and 25 to contact 20', shorting member 22, contact 20, conductor 2| to supply line ll.

When it is desired to turn off the lamps, the operating handle it is moved to the left, in the views of Figs. 5 and 8, thereby moving the shorting member 22 out of engagement with the fixed contacts 2| and 2|, interrupting the circuit through the lamps. After the lamps have been turned off, they may be turned on again simply by moving the handle it to the right so that the movable contacts 2| and 2| again engage the fixed contacts and the shorting member 22 spans the contacts 2| and 2|, the handle being manually held in this position for a time sufiicient to permit preheating of the lamp filaments and thereafter being released.

While I have illustrated my switch as being used with two fluorescent lamps, it should be manifest that the switch will operate equally as well with only a single fluorescent lamp simply by omitting the connection to one of the pairs of contacts 2| and 20 or 22 and II.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric switch for starting and operating a discharge lamp having spaced filaments comprising a base forming a chamber, a pair of main contacts and spaced auxiliary contact means held in the chamber, an operating member pivotally supported on the base, a shorting member held on the operating member for closing the main contacts in a starting position or the operating member, a projection on the operating member for closing the auxiliary contact means in the starting position, said auxiliary contact means including a spring blade which in the starting position exerts a biasing force on the operating member and upon manual release of the latter forces it away from the starting position into an operating position in which the main contacts only are closed.

2. An electric switch for starting and operating a discharge lamp having spaced filaments comprising a base forming a chamber, main contacts located in lateral recesses of the chamber, auxiliary contacts held on the bottom or the chamber and including a contact blade, an operating member pivotally held in the chamber and having a shorting member and a projection for closing the main and auxiliary contacts respectively in a starting position of the operating member, said contact blade in the starting position of the operating member exerting a biasing 10 force thereon suflicient upon manual release in the starting position automatically to force the member into operating position in which the main contacts only are closed.

FRANK D. BRYANT.

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