US2352940A - Fluorescent lamp starting and controlling apparatus - Google Patents

Description

A July 4, 1944. w, CQQK 2,352,940

FLOURESCENT LAMP STARTING AND CONTROLLING APPARATUS Filed 09. 24, 1942 Inventor: Leonard W. Cook,

His Attorney.

, Patented July 4, 1944 FLUORESCENT LAMP. STARTING AND CONTROLLING APPARATUS Leonard W. Cook, Strattord, Conn., assignorto General Electric Company, a corporation of New York Application December 24, 1942, Serial No. 470,008

1 Claim (01. 315-100) My invention relates to fluorescent lamp a'pparatus. More particularly, it relates to the construction and mounting of the switching apparatus by which the lamps are started and con trolled.

In a common form of fluorescent lamp apparatus the lamp and the starting switch therefor are mounted in a panel or reflector by means of holders, one part of each of which extends through an opening in the panel and detachably holds the lamp at one side of the panel and another part at the opposite side of the panel detachably holds the starting switch unit. To pro- Vide ready accessibility to the starting switch unit from the lamp side of the panel or reflector the upper end of the enclosing casing of the unit is made to project up through an opening in the panel directly beneath the lamp which must be removed from its holder before the switch unit is applied or removed. Lamp holders and starting switch units such as those illustrated in the drawing now are in extensive use and as they are being manufactured in large quantities have dimensions which have become standard. In such apparatus the space between the panel and the lamp when the latter is in place is small and the casing of the starting unit extends within close proximity to the lamp. Enough of the casing, however, is designed to extend above the panel to enable a person to grasp it with his fingers and to give it the movement necessary to secure it in and to release it from its socket.

In more recent developments, the starting switch unit includes not only the starting switch but a loch-out switch by which the starting switch is rendered inoperative after it has made a. number of unsuccessful attempts to start the lamp until it is manually reset. According to that construction the lookout switch trips open when the lamp refuses to start after repeated trials and in so doing the switch pushes up a button mounted in the upper end of the enclosing casing whereby the button serves as an indicator or telltale that the lookout switch has operated. By pushing down on the button the lockout switch is reset. A disadvantage of the above described construction when used with standard apparatus is that the resetting button may interfere with the lamp. Moreover, if one seeks to avoid this diiiiculty by materially reducing the height of the casing of the starting switch unit a new difliculty is confronted, namely, not enough of the casing will project above the panel to enable one to get a suflicient hold of the casing to secure the unit in or to release it from its socket.

It is the object of my invention, therefore, to provide an improved construction of this character which avoids the difiiculties mentioned above, is simple in construction, and is inexpensive to manufacture.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its. scope will be pointed out in the appended claim.

Referringto the drawing, Fig. 1 is a perspective view of apparatus illustrating my invention; Fig. 2 is a sideview partly in section and drawn to alarge scale showing that apparatus; Fig. 3 is a perspective view of the starting switch unit with parts thereof disassembled; and Fig. 4 is a and to retain the unit in place, a bayonet type oi.

circuit diagram.

Referring to Figs. 1 and 2 the lamp 1 which may be one of the modern fluorescent type in common use is supported above the panel or reflector 2 by the holder 3 which has suitable contacts for engaging the contacts of the lamp thereby to complete the circuit of the lamp and to retain the lamp in a definite position with respect to the panel. The lamp holder 3 comprises the upstanding portion 4 which extends up through an opening in the panel and directly connects with the lamp and the portion 5 spaced below the panel for supporting the starting switch unit 6. An intermediate portion of the holder has the shoulder l which firmly engages the under face of the panel when the holder is secured thereto by the attaching screw 8.

The starting switch unit 6 comprises the base "plate [0 having two contact-making and securing terminals, one only of which is shown at ll,

and the enclosing casing or can i2 which by means of the lugs 13 is firmly secured to the base plate. The terminals ll serve both to connect the starting and lockout switches of the unit with contacts, not shown, in the part 5 of the holder connection being commonly used. When secured to the holder in proper position the casing of the unit extends up through another opening in the panel in close proximity to the lamp.

The starting unit may comprise starting and lockout switches of various constructions. drawing, I have chosen to show by way of example at IS a starting switch of the well known glow discharge tube type and at i! a lockout switch of a form which I have disclosed and claimed in my copending application Serial No. 470,007, filed December 24, 1942, and assigned to the same In the assignee as my present application. Secured to the base plate It is the insulating supporting plate is at one side or which the glow tube starting switch II and the capacitor II are mounted and on the other side of which the lockout switch I! is mounted. The latter switch comprises the slide bar 20 attached to the'plate ll and guided by the headed pins II secured to the plate. Extending from opposite sides oi! this bar are the cross pins 22 which bear against the plate [8, one pin also iunctioning as one oi! the switch contact elements." The bar is normally urged upward, namely, to its open circuit position by the coil 23 and at its upper end the bar is bent at right angles as shown at 24, The cooperating switch contact element is shown at 25, being a resilient bi-metal strip secured to the plate at its lower end and having a latch at its upper end arranged when the strip is not heated to engage one of the cross pins and retain the bar in its lower position against the force of the spring. Heat from the resistance heater 2]; is accumulated in and transmitted to the bi-metal strip by the metal strap 28, the heater and the switch contacts be-- ing connected in series between one terminal ii and the glow switch IE. If the lamp is defective or for any other reason fails to start after the glow switch has made several attempts to start it the heat accumulated in the heater, in the metal strap and in the bi-metal strip will he sufficient to warp the upper end of the strip away from the plate to release the cross pin it engages, thus opening the circuit of the glow switch. Upon replacement of the lamp, ii defective, with a good lamp the lockout switch needs to be reset. To facilitate this without removing the casing, the casing is provided with a central opening in its end i'ace in which the small button 30 slides, the button having the flange II to limit its outward movement in the casing and to engage the to the lamp, the end of bent part 24 of the bar. To reset the switch one merely presses down on the button with a finger until the switch contacts reclose and the latch engages. As shown particularly in Figs. 2 and 3 the end face of the casing is concave or depressed in the central portion thereof so that even though the resetting button is in its upper position or that corresponding to the open circuit position oi the lookout switch its upper end does not pro- Ject materially, if any, above the side wall of the casing hence does not interfere with the lamp. Since the part oi casing which projects above the panel has not been decreased the starting switch unit may be attached to and detached from the panel just as readil as before and no changes need he made in the dimensions of the parts. Moreover the button will still iunctlon as a telltale indicator of the operation of the lookout switch and serves as a convenient means for the resetting oi that switch.

What i claim as new and desire to secure by Letters Patent oi the United. states is:

In a fluorescent lamp mounting comprising a mounting pane]. having an opening therein, a

memlzner secured to said panel having a part thereabove for detachably holding a fluorescent lamp closely adjacent to said panel, and a startlog switch unit in combination with a telltale adapted. to protrude therefrom to indicate a predetermined condition, said switch unit being detachahly supported by a part of said member below said panel and projecting through said opening a distance suificient to form a hand grasp for manipulating said unit and into close proximity said switch unit being inset to accommodate the protruding movement of said telltale member between said unit and the lamp, so that it does not protrude materially beyond the unit toward said lamp.

LEONARD W. COOK.

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