US2656521A - Fluorescent lamp holder - Google Patents

Description

w. E. BARR E, JR FLUORESCENT. LAMP HOLDER Oct. 20, 1953 Filed Sept. 27, 1951 INVENTOR: WADE e. BARRE,JR. BY

Isa m ATTORNEY Patented Oct. 20, 1953 UNITED PAT ENT 2,656,521

FLUORESCENT LAMP HOLDER Wade E'. Barre, Jr., Warren, Pa., assignor to- Syllvania.ElectricProducts Inc., Salem, Mass" a. corporation of: Massachusetts Application September 2'7, 1951, Serial No. 248,567

2 Claims; 1

This invention relates to lampholders for elongated lamps such as tubular fluorescent lamps havi'nga contact pin at'each end.

Such lamps have previously been provided with holders in which an insulating member, having an opening to receive the pin, is pushed back against a. metal contact cup biased by a spring, forexample as shown in United States Patent 2,446,154, granted on July 27, 1948 to Roger W. Haven. The depth of the contact cup is made less than the length of the lamp contact pin so that when the insulating piece meets the lamp base, the pins will push the contact cup back from the insulating piece and against the spring. This leaves the insulating piece in a mechanically floating condition, not backed up by the spring.

To prevent such a condition, the present invention provides a contact piece having one portion held against the back of the insulating piece by a spring and another portion of suflicient resilience to be pushed back by the contact pin without separating the first portion from the insulating piece. The holder accordingly supports the lamp not only at the latters contact pin, but also at the end of its base. This allows a more steady and firm seat for the lamp, and is less susceptible to vibration.

In one specific embodiment of the invention, an annular portion of the contact piece is biased by a spring against the insulating member, and resilient metal fingers extend into the open center of the annular portion to contact the lamp contact pin.

One such embodiment of the invention is described in detail in the following specification,

Figure 2 is a sectional view of the device, showing its interior construction;

Figure 3 is a back view of the device;

Figure 4 is a front view of the contact piece; and

Figure 5 is a sectional profile of the same piece.

In Figure 1, the tubular lamp I 6 having a base I5 at each end, is held between a forwardly-extending cup-shaped insulating plunger 6, and a fixed holder 25, the latter being attached to an end plate 26. The plunger 6 extends out of a cylindrical member 3, fixed to an end plate 20. The end plates 20 and 26 are joined to a supporting chassis member 21 by screws 28, 29.

In Figure 2, the conically-helical spring I extends from the back portion 2 of the hollow the form ofa hollow cup slidably mounted in the hollow cylindrical member" 3. Theinsulating plunger 6 has a narrow flange I on its open end, the-flange I bearing against a stop!) at the'outer end of its travel. The stop 8 is ametal ring set in a groove around the inner circumference of cylindrical member 3 near the end thereof. The large-diameter end of the spring I bears against the outer annular portion of contact piece 5, and the small-diameter end fits around a small cylindrical projection at the back 2 of piece 3.

The contact fingers 9, I0, extend toward the axis of the plunger 6 and backwardly from the inner face I9 of said member. They extend toward each other, but do not meet, being spaced from each other at their inner ends. The piece 5 or at least the fingers 9, I0, should be of a resilient material, for example, Phosphor bronze.

A pigtail connection I8 is attached to spring I by solder 33 at a point intermediate the ends thereof, and extends out of the cylindrical member 3 through the opening 36 in the projection 30. The back 2 of the cylindrical member 3, shown in Figure 3, has the threaded holes II, I2, in the bosses 3 I, 32, to facilitate attachment of the lampholder to supports such as the end plate 20.

The insulating plunger 6 has an opening I3 in its front face I4, through which the contact pin I! of a lamp such as I6, can be inserted. The fingers 9, III will bend back as the pin pushes against them until'the lamp base I5 bears against the front face I4, and then as the lamp is pushed further into the holder, the whole assembly 4 -9I0--5 moves back together, the annular portion 4 of the contact piece 5 being kept always against the back face of member 6 by the spring I. The lamp base I5 is thus always seated firmly against the outer surface of the front I4 of cup 6 by the pressure of spring I, and at the same time good resilient contact is made between the lamp pin I! and the contact fingers 9, I0. To achieve this result, the coiled spring I must be stiffer than the spring contact fingers 9, I 0; that is, the spring I must exert somewhat greater force against the contact piece 4 than the fingers 9, ID of that contact piece exerted against the lamp pin I5.

The pin I5 will ordinarily have a shoulder 34 of slightly largerdiameter where it is fixed to the insulating boss I5. To insure that the shoulder 34 will not prevent proper seating of the end 35 of base l5 against the piece I4, the hole through which pin I1 is inserted is made slightly larger than said pin, and is flared outwardly to a diameter slightly greater than that of shoulder 34, so that the shoulder 34 fits into the hole and allows the end 35 of base [5 to seat firmly against the outer surface of member [4.

A plan view of the contact piece 4 is shown in Figure 4, and Figure 5 shows the contact fingers 9 and Ii in their position before the pin I5 is inserted and shows the fingers in phantom as 9 and It, in their position with the pin i1 inserted.

The lampholder described is for the so-called high voltage end of the lamp circuit. Any suitable lampholder 25 can be used for the lowvoltage end of the lamp circuit, for example, the holder shown for that end of the lamp in U. S. Patent 2,446,154, issued July 27, 1948 to Roger W. Haven.

. What I claim is:

1. A lampholder comprising a hollow insulating support member, a hollow plunger slidable therein and having a front face with an opening for receiving a lamp contact pin, a spring biasing said support member and said plunger away from each other, a contact piece held firmly against the inner surface of the front face of said plunger by said spring and having at least one spring contact finger in position to meet said lamp contact pin, the spring of said contact finger being of lesser stiffness than said firstmentioned spring in order to exert a smaller force on said lamp than that exerted against the contact piece by the first-mentioned spring.

2. A lampholder comprising a hollow insulating support member, a hollow plunger slidable therein and having a front face with an opening for receiving a lamp contact pin, a spring biasing said support member and said plunger away from each other, a contact piece held firm- 1y against the inner surface of the front face of said plunger by said spring and having two spring contact fingers in position to meet said lamp contact pin,- the spring of said contact fingers being of lesser stifiness than said firstmentioned spring in order to exert a smaller force on said lamp than that exerted against the contact piece by the first-mentioned spring.

WADE E. BARRE, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,404,176 Huelster July 16, 1946 2,447,676 Webster Aug. 24, 1948 2,473,705 George June 21, 1949

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