US 3639887 A
This invention relates to a push-in type of lampholder for a bi-pin type of fluorescent lamp and the contacts employed therein.
Claims available in
Description (OCR text may contain errors)
ilnited States Patent Johnson et a1.
2,238,151 3,052,864 3,337,837 8/1967 Pistey..
LAMPHOLDER FOR FLUORESCENT LAMPS Inventors: George E. Johnson, Bronxville; Walter Newman, Forest Hills, both of NY.
Leviton Manufacturing Co., Brooklyn, NY.
Filed: Jan. 29, 1970 Appl. No.: 6,789
US. Cl. ..339/53, 339/258 R Field ofSearch ..339/17,53, 50, 258,52
References Cited UNITED STATES PATENTS 4/1941 Alden ..339/53 9/1962 Gaynor Feb. 1, 1972 FOREIGN PATENTS 0 APPLICATIONS 1,164,318 5/1958 France ..339/53 Primary Examiner--Marvin A. Champion Assistant Examiner-Terrell P. Lewis Altorneyl-1anse H. Hamilton ABSTRACT This invention relates to a push-in type of lampholder for a bipin type of fluorescent lamp and the contacts employed therein.
The lampholder has a hollow housing of insulating material in 1 which a pair of pin-engaging contacts are mounted in spaced relation to each other. The contacts are formed of thin sheet 1 material such as brass and each has a pair of lamp pin engaging fingers formed at one end thereof by a slit extending lengthwise of the contact and through a leg or base portion of I the contact extending at right angles to the fingers.
Said lamp pin engaging fingers of the contacts are aligned with open ended slots in the housing in position for reception of a lamp pin in the slits between the fingers with a straight movement of the lamp.
4 Claims, 8 Drawing Figures LAMPHOLDER FOR FLUORESCENT LAMPS The present invention relates to a lampholder for a fluorescent lamp and it relates, more particularly, to a new and improved contact for such a lampholder.
Generally speaking, the present invention relates to a pushin type of lampholder for use with bi-pin fluorescent lamps in which spaced pins extend from opposite ends thereof and electrical connections for operation .of the lamp are established by means of the pins.
An object of the present invention is to provide a lampholder having contacts therein which permit installation or removal of the lamp by a straight push-in or pull-out movement of lamp relative to the lampholder. Such an arrangement does not require turning or rotation of the lamp which is often difficult to accomplish, particularly with long lamps and which may damage either the lampholder or the lamp pins.
Another object of the invention is to provide a push-in lampholder having contacts which will ensure the establishment of good electrical connections with the lamp pins and which will securely hold the lamp against accidental displacement from the lampholder.
A further object of the invention is to provide a push-in type.
of lampholder for a bi-pin fluorescent lamp with is economical to manufacture and assemble. In this connection, the subject lampholder employs a pair of lamp pin engaging contacts which are formed from relatively thin sheet metal stock of a suitable electrically conductive material such as brass and both of the contacts are alike. The foregoing and other objects of the invention will be understood from the following description and the accompanying drawing, in which:
FIG. 1 is a front view of a lampholder embodying the present invention with a pair of lamp pin engaging contacts mounted therein;
FIG. 2 is a rear view of the lampholder shown in FIG. 1 with a part thereof being broken away to show one of the lamp pin engaging contacts;
FIG. 3 is a side view in vertical section taken along the line 3-3 of FIG. 1;
FIG. 4 is a rear view of one of the contacts employed in the lampholder shown in FIG. 1 and which is drawn to a slightly larger scale;
FIG. Sis a side view of the contact shown in FIG. 4;
FIG. 6 is an end view of the contact shown in FIG. 4 as seen from the upper end thereof;
FIG. 7 is a section view taken along line 7-7 of FIG. illustrating the partial introduction of a lamp pin into engagement with the lamp pin engaging end of the contact; and
FIG. 8 is a view corresponding to FIG. 7, but with the pin being fully seated in engagement with the lamp pin engaging end of the contact.
Referring to the drawings in detail, there is a lampholder 10 of the tombstone type for use with a bi-pin type of fluorescent lamp having a pair of spaced lamp pins extending from opposite ends thereof. A lampholder is usually employed at each end of such a lamp to support the lamp and to establish electrical connections to the lamp by means of the lamp pins.
As illustrated, the lampholder 10 comprises a hollow housing 11 which may be formed of a suitable plastic insulating material such as a phenolic resin. The housing 11 is open at the rear thereof and has an upwardly extending portion 12 and a base 13 which extends forwardly from the lower end of the upper portion thereof. Grooves 14 extend along oppositely disposed outer sides of the housing at the point where the upper portion 12 joins the base 13 of the housing. The grooves 14 are positioned to receive opposing side edges of a supporting panel which defines an opening in the panel. When the lampholder is mounted on a panel in this manner, the upper portion 12 of the housing 11 projects upwardly from the panel and the forwardly extending portion of the base 13 extends beneath the panel at one end of the opening.
If desired, the grooves 14 may be made somewhat deeper than the width of the panel opening so as to permit lateral adjustment of the lampholder relative to the panel. When a second lampholder is mounted on the panel, such movement compensates for possible variations in the distance between the legs of a U-shaped lamp.
The frontwall of the upper portion 12 of the housing 1] contains a pair of spaced parallel openings or slots 15 having open ends at the tops thereof and which are positioned to receive the lamp pins carried by the lamp. The rear wall at the upper end of the housing 11 is interrupted as indicated at 16 to receive the upper end of the backplate 38. This permits the upper 'housing to be made with a minimum thickness. To facilitate introduction of the lamp pins into the slots, the sidewalls 15a of the slots may be relieved outwardly at the upper ends of the slots so as to widen the entrances thereto The slots 15 extend through the front wall of the housing 11 and at their lower ends provide access to the interior of the upper end 12 of the housing 11 in which lamp pin engaging contacts 17 are mounted in alignment with the slots. A partition 18 divides the interior of the upper end of the housing into two contact-receiving compartments or chambers 19. A pair of spaced ribs 20 and 21 extend transversely of the housing near the lower end of each chamber.
Immediately adjacent the upper surface of the rib 20 and the lower surface of rib 21, recesses 22 and 23, respectively, are formed in opposing sides of the partition 18 and the housing 11 to receive portions of the contacts 17 as will be described later. In addition, bosses 20a and 21a are carried by the ribs 20 and 21, respectively, in position to engage portions of the contacts. Beneath the lower rib 21, portions 24 of the chambers 19 are located in the lower end or base 13 of the housing 11. Wire-receiving openings 25 extend through the base 13 of the housing from the front thereof to the portion 24 of the chamber 19 and provide access thereto for the introduction of the bare ends of conductor wires into the housing.
The "contacts 17 which are mounted in the compartments 19, are alike and hence, only one of the contacts need be described. As shown in FIGS. 4, 5 and 6, the contact 17 is formed from a flat thin sheet of an electrically conductive material such as brass and is in the form of a strip. Although the strip is flexible transversely, it is relatively rigid and resists bending in a widthwise direction.
At one end of the contact 17 there is a lamp pin engaging portion 26 and at the other end there is a wire-engaging terminal portion 27. These portions are connected by a U-shaped bend formed in the strip which extends around the ribs 20 and 21.
The lamp-pin engaging portion 26 of the contact includes a pair of fingers 28 having opposing side edges and which extend upwardly from an upper leg 29 of the U-shaped bend. The leg 29 extends rearwardly and is angularly disposed relative to the fingers 28.
The opposing fingers 28 are formed by a slit 30 which extends lengthwise of the lamp pin engaging portion 26 of the contact from the outer end thereof and partially through the upper leg 29 of the U-shaped bend, as shown in FIG. 6.
The opposing edges of fingers 28 are bevelled at their outer ends to permit the insertion therebetween of a lamp pin 31 as shown in FIG. 7. As the lamp pin is introduced, the opposing side edges of the fingers 28 are forced apart and such movement is permitted by the slit portions of the leg 29 of the U- shaped bend tilting upwardly on opposite sides of the slit as illustrated in FIG. 7. The force required to separate the opposing edges of the fingers 28 will depend, in part, on the depth or length of the slit in the upper leg 29 of the U-shaped bend and can be regulated thereby. Continued insertion of the lamp pin seats the lamp pin in recesses 32 formed in opposing edges of the fingers 28 where the pin is also held under pressure exerted thereon by the fingers 28. Thus, the fingers 28 engage the lamp with a clamping action which holds the lamp securely in place. As the lamp pin is inserted, a wiping action takes place between the opposing side edges of the fingers 28 and the lamppin 31 which results in good electrical contact being established between the contact and the lamp pin.
The upper leg 28 of the U-shaped bend is connected by a downwardly extending member 32 to a lower leg 34 thereof. The inner end of the lower leg 34 carries a pair of wire-engaging tongues 35 which extend downwardly therefrom. When installed in the housing 11, the U-shaped bend in the contact 17 extends around the transverse ribs 20 and 23 with the flat faces of the lamp pin engaging fingers 28 resting against the rear face of the front wall of the housing 11 as shown in FIG. 3 and with the upper end of the slit between the fingers 28 and the seating recesses 32 therein being exposed through the slots 15 so as to permit insertion of the lamp pin between the fingers with a straight push-in action.
The wire-engaging tongues 35 extend downwardly from the U-shaped bend and across the inner ends of the wirereceiving openings in the base 13 of the housing 11. The free ends of the tongues are positioned so as to bend rearwardly and enter into pressure locking engagement with the bare ends of conductor wires introduced through the openings 25 in the base. If desired, other types of terminal connections may be employed.
The upper leg 29 and the lower leg 34 of the U-shaped bend in the contact 17 have tabs 36 and 37 extending outwardly therefrom. The tabs extend into the positioning recesses 22 and 23 respectively. The tabs 37 on the lower arm rest on the lower walls of the lower recess 23 and thus, hold the contact in We claim:
1. In a push-in type of lampholder for a bi-pin fluorescent lamp, the improvement which comprises:
a. a hollow housing having front and sidewalls defining a pair of contact chambers therein;
b. said front wall containing slotted openings for receiving a pair oflamp pins;
c. said slotted openings having open upper ends and each communicating with one of the contact chambers;
d. a riblike support formed in and extending transversely of each contact chamber at a point beneath said slotted opening; an electrical contact formed of a relatively thin strip of conductive material loosely mounted in each of said chambers;
f. each of said electrical contacts having a slit upper end forming opposing edges of a pair of lamp-pin-engaging fingers and having a wire-engaging terminal formed at a lower end thereof;
. said lamp-pin-engaging fingers extending lengthwise in the chamber and being aligned with one of the slotted openings therein;
. said upper and lower ends of the contact being connected by a U-shaped bend in the contact;
. said U-shaped bend in the contact extending around and resting on the transverse support and having an upper portion disposed in angular relation to said fingers;
j. said upper portion of the bend containing a continuation of the slit defining the lamp-pin-engaging fingers whereby the fingers are permitted to twist relative to each other; and
. means formed on said upper portion ofthe bend engaging with recesses in sidewalls of the chamber and restricting lengthwise movement of the contact relative to said chamber in introduction and removal of the lamp pins.
2. In a push-in type of lampholder for a bi-pin fluorescent lamp, the improvement as defined in claim 1 wherein:
a. the last-mentioned means comprises tabs formed on opposite sides of the upper portion of said U-shaped bend and extending into recesses formed in the sidewalls of the chamber.
3. In a push-in type of lampholder for a bi-pin fluorescent lamp, the improvement as defined in claim 1 which includes:
a. means for adjustably mounting the lampholder in an opening in a fixture panel;
b. said adjustable means permitting transverse movement of the lampholder relative to the panel by a distance equal to differences allowed by manufacturing tolerance in pacing of two legs ofa lamp.
4. In a push-in type of lampholder for a bi-pin fluorescent lamp, the improvement as defined in claim 3 wherein:
a. said adjustable means comprises a pair of slots formed in and extending lengthwise along opposite sides of the housing at a lower end thereof;
b. said slots being adapted to receive edges of the panel opening and being of greater depth than the width of the opening.