US 2374032 A
Description (OCR text may contain errors)
April A. G.'MUIELLER- 2,374,032
LAMP HOLDER Filed Feb. 14, 1944 FigL.
- Inventor Adolf G. Mueller,
' 'fjww f by Hmttorn ey Patented Apr. 11. 1945 LAMP HOLDER. r
g Adolf G. Mueller, Fair-field, Conn assignor to General Electric Comp New York any, a corporation of Application February 14, 1944, Serial No. 522,253
2 The present invention relates to lamp holders, more particularly to lamp holders for tubular lamps, such as fluorescent lamps. It is especially useful in lamp holders for tubular lamps of the 7 type having a single oval-shaped contact at each end and it is this application of my invention which I have elected specifically to illustrate and describe. It is to be understood, however, that thisis only 'by way of example and that the invention may be used wherever found applicable.
The object of my invention is to provide an improved lamp holder which offers a high degree of safety as hereinafterpointed out, and for a consideration of what I believe to be novel and my invention, attention is directed to the following specification and to the claims appended thereto.
In the drawing, Fig. 1 is a side elevation showing two lamp holders embodying my invention mounted in spacedrelation on a supporting plate and having a tubular lamp mounted therein, the
tubular lamp before being mounted in the lamp.
holder being shown in dot and dash lines; Fig. 2 is a perspective view of one of the lamp holders and an end of a lamp ready to be inserted into the holder; Fig. 3 is a sectional view through the lamp holder; Fig. 4 is a detail sectional view taken on line 4-4, Fig.3, and Fig. 5 is a detail sectional view showing certain of the parts in a position different from that in Fig. 4.
Referring to the drawing, I indicates a tubular lamp having a single oval-shaped contact 2 at each end for insertion into a lamp holder. At opposite ends, the lamp is provided with shoulders 3 for cooperation with the lamp holders as hereinafter pointed out. Lamps of this type are mounted: in their holders by inserting the contacts 2 edgewise into the lamp holders and then turning the lamp through an angle of 90 to bring the oval-shaped contacts to a position transverse to the lamp holders.
- Referring now to Figs. 2 to 5. inclusive, the lamp .holder comprises a base 5 of suitable insulating material, such asporcelain, the base being formed of walls which define a tubular passage a suitable distance. The wall adjacent slot ll is countersunk to provide a ledge l2 which surrounds the slot. This end of the base is provided also with inwardly extending projections 13 which terminate in spaced relation to each other to form a continuation of. slot H. In other words. projections l3 form in substance an end wall for the base through which end wall the slot H extends. At its outer portion, the end wall is beveled as indicated at I 4 to provide surfaces for directing a contact 2 into the slot II. On the inner sides of projections l3 are inwardly extending parts 15 which form spaced stops, one on eaph side of the slot I I.
Fixed against mounting surface It! is a contact carrying block comprising a rectangular plate It of suitable insulating material on the outer surface of which is riveted a metal contact late I! by means of rivets I8. One end of the block is attached to surface II] by a hollow rivet IS, the other end of the block projecting into passage 6. Rivet Is at its inner end is threaded to receive a contact screw 20 by means of which an electrical conductor may be connected to the lamp holder. Attached to contact plate H by means of 'spot welding or the like is a U-shaped contact member comprising a base 2| and two spring contact arms 22 which extend along the opposite sides of passage 6 as shown particularly in Fig. 4. Thus, the contact arms 22 are connected with the binding post 20 through contact plate ll. The free ends of contact arms 22 are spaced back from slot H as shown particularly in Fig. ,4 so as to be out of line with the slot. Attached to insulating member l6 by suitable rivets 23 are a pair of spring arms 24 which extend parallel to contact arms 22 and at their free ends terminate I in reversely bent parts 25 for the reception of a lamp contact 2 between them. The extremities of spring arms 24 are angularly bent for engagement with stops l5. Spring arms 24 are connected together at their ends adjacent insulating member 16 by a rivet 26 which holds in place also a, pair of spring arms 21 which at their free ends have contact buttons 28 which engage with parts 25. The purpose of spring arms 21 is to give added spring tension to the arms 24, the inherent spring of arms plus the spring of arms 21 serving to hold the free ends of arms 24 in engagement with stops l5 and, when spread apart, to hold firmly a lamp end 2.
Normally the several parts stand in the positions shown in Fig. 4 which shows also in dotted lines an oval lamp contact 2 between the spring arms 24. When the lamp is turned through an angle of the contact 2 is brought to the'position shown. in Fig. 5 wherein the spring arms 24 and 21 are spread apart and brought into engagement with the contact arms 22, thus connecting lamp contact 2 to the binding screw 20. With this arrangement, it will be seen that a circuit is not closed on a lamp contact until the lamp is turned to bring the contact 2 from the position shown in Fig. 4 to that shown in Fig. 5. Thus, with this arrangement, when the lamp contacts are first positioned in the two holders, they are not connected into the circuit. They are connected into the circuit, as well as locked in the lam holders, by turning the lamp through an angle of 90.
In connection with the foregoing arrangement, it is important to avoid any possibility oi the contact at either end of the lamp being accidentally connected to a contact arm 22 while the lamp is being inserted, it being important that such contact be made only after the contacts at both ends of the lamp have been properly inserted into the holders and the lamp then turned. Otherwise the person inserting the lamp might receive an electrical shock. To obviate the possibility of a contact at one end of a lamp being inserted in the holder and moved to an angle such that a spring arm 24 is brought into electrical contact with a contact arm 22, there is provided a guide or guard 30 on each lamp holder which makes it necessary that the lamp be in line with the two slots II when the contacts 2 are inserted into the slots. The guide or guard comprises two parallel arms 30 which define between them a groove 3| which stands in line with slot i l and is spaced a suitable distance from the adjacent surface of base 5. In the present instance, arms 30 are shown as being formed integral with a base plate 3i] which is attached to a flange 32 which forms in Fig. 1. Following this, the lamp is moved upwardly to bring its ends between the two guides SI, the contacts 2 at the same time entering the slots II and being brought to a position between spring ends 25, as shown in Fig. 4. The lamp is then turned through an angle of 90", thus locking the contacts 2 between the spring ends 25 and at the same time spreading the spring ends apart to make engagement with the contact arms 22. By the provision '0! guides or guards 30, it is not possible after a contact 2 has been inserted into a slot II to move the lamp angularly to one side or the other to bring a spring arm 26 into engagement with a contact arm 22. Were it not for the guides or guards 30, this might happen thus accidentally closing a circuit on one end or the lamp, a thing which might result in the person 1 inserting the lamp accidentally receiving an an integral part of base 5. Arms 30 are spaced apart a distance equal to the diameter of the end of lamp I. The guide or guard 30 is fastened to flange 32 by. means of a bolt 33 which serves also to fasten one side of the lamp holder to a base or support 34, the other side of the lamp holder being fastened to the base or support 34 by a bolt 35 which extends through an opening in a flange 36 formed integral with the other side of base 5. Base or support 34 may be a part of a lamp fixture.
Carried by flange 32 and mounted thereon so that it may swing to a limited extent is a hook 31 which may be used to temporarily support a lamp end when the lamp is being positioned in its holders. In the present instance, hook 37 is shown as being provided with two inwardly facing,
ends 38 which hang in notches in flange 32. The
cross bar 39, which forms a part'of the hook, is
spaced sufficiently from the under surface of flange 32 to permit of the desired amount of swinging movement of the hook. Hooks 31 serve also to catch a lamp and support it should a lamp accidentally fall out of the lamp holders.
Fig. 1 shows two lamp holders mounted on a electrical shock. The arrangement of the contacts in the holders so that the lamp is not connected into the circuit until it is turned to lock it in position in the holders, in combination with the guides or guards 80, gives to the lamp holder a high degree of safety. I regard this arrangement as being an important feature of my invention.
In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out,
- by other means.
common support 34 and spaced apart a distance order of 5 feet, for example. A lamp is inserted in the holders usually by a person standing on a ladder. In inserting a lamp in a holder, one end of the lamp may be rested in the book 31 of one holderafter which the other end of the lamp is positioned in the hook 31 of the other holder after the manner shown in dot and dash lines What I claim as new and desire to secure by Letters Patent of the United States is:
1. A lamp holder for an elongated discharge lamp having contact means at each and comprising, in combination, a base having a guide slot therein extending to one edge of the base. a contact member carried by said base with an end adjacent the slot but out of alignment therewith, a movable member positioned in said base between an edge of the slot and said contact member and being adapted to be'engaged by the lamp contact means seated in the slot, said movable member being normally spaced from said contact member so that it is out of the electric circuit but being movable upon rotation of the lamp contact means to complete an electrical connection between the contact member and the lamp contact means, and a member having guide edges parallel with the edges of the slot but spaced therefrom to provide a guide for the lamp end for guiding the lamp contact means into the slot for engagement with the movable member upon transverse movement of the lamp, said guide edges preventing angular sideways movement of the lamp so that said movable member cannot be moved into engagement with the contact mem ber except upon rotation of the lamp.
2. In a lamp holder for an elongated discharge lamp, abase having walls provided with a guide slot. contact means carried by said base adjacent the slot, said slot beingadapted to guide a lamp contact into engagement with said contact means and hook means carried by saidbase for initially supporting a lamp spaced from said base but so that the lamp contact is in alignment with said slot for engaging said contact means upon transverse movement of the lamp into the lamp holder.
ADOLF G. MUELLER.