US2729799A

US2729799A - Fluorescent lampholder with quickconnect terminals

Info

Publication number: US2729799A
Application number: US465499A
Authority: US
Inventors: John M Pistey
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1954-10-29
Filing date: 1954-10-29
Publication date: 1956-01-03
Anticipated expiration: 1973-01-03

Description

Jan. 3, 1956 J. M. PISTEY 2,729,799

FLUORESCENT LAMPHOLDER WITH QUICK-CONNECT TERMINALS Filed Oct. 29, 1954 in V6)? 6 02"." John M P115529,

MMd-fiadd/wl H/Ls Attorney United States Patent 0.

FLUORESCENT LAMPHOLDER WITH QUICK- CONNECT TERMINALS John M. Pistey, Fairfield, Conn., assignor to General Electric Company, a corporation of New York Application October 29, 1954, Serial No. 465,499

' Claims. (Cl. ss9 s2 The present invention relates to lampholders and particularly lampholders for double-ended electric discharge lamps, commonly known as fluorescent lamps.

In the past it has been common practice to provide screw terminals for making electrical connection between the contacts of the lampholders and the lead wires of a fluorescent fixture. This invention involves an elimination of the screw terminals and the substitution of quickconnect terminals that are designed to reduce the manufacturers time in wiring a fluorescent fixture.

The present construction incorporates the use of contacts in the lampholder which have a terminal portion that is doubled back to form locking tongues that will engage with the stranded conductors of the lead wires to make an electrical connection. A single tapered plunger is mounted for reciprocating movement in the lower portion of the housing of the lampholder so that when the plunger is in its extreme outer position, it is possible to place the bare conductors between the locking tongues and the tapered sides of the plungers. Once the plunger is forced into the housing, the free ends of the locking tongues snap into notches formed in the plunger with the conductors underlying the tongues to restrain the withdrawal of the plunger from the housing. The blade of a screwdriver may be used to provide the necessary prying force acting against the plunger to overcome the resistance of the locking tongues to allow for the Withdrawal of the lead wires from the housing.

The principal object of this invention is to provide a lampholder and particularly a fluorescent lampholder with quick-connect terminals, thereby eliminating the usual screw terminals.

A further object of this invention is to provide a single tapered plunger for a lampholder for effecting a mechanical and electrical connection between the lead wires of a fluorescent fixture and each one of its lampholders.

A further object of this invention is to provide a tapered plunger in a fluorescent lampholder for effecting an electrical connection with the lead wires so that any pulling force tending to remove the leads merely increases the holding force provided by the plunger.

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 claims.

Figure l is a side-elevational view showing the general arrangement of a fluorescent lamp supported between a pair of lampholders embodying my invention.

Figure 2 is a front elevational view of one of the lamp holders of Figure 1.

Figure 3 is a partial cross-sectional right side elevational view taken generally through the nearest fastening screw of Figure 2.

Figure 4 is a rear view of the lampholder of Figure 3 with the back cover removed.

Figure 5 is a view similar to Figure 4 but showing only the lower portion of the lampholder with the tapered plunger in its extreme outer position.

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Figure 6 is a perspective view of the tapered plunger and the terminal portions of the contacts for the lampholder.

Referring in detail to the drawing, Figure 1 shows a conventional bi-pin fluorescent lamp 10 supported at opposite ends in the similar lampholders 11 and 12 which are constructed in accordance with my invention. The lampholders in turn are supported from a reflecting surface 13 forming part of a lighting fixture or the like. The lamp 10 has a tubular glass envelope 14 provided with

bases

15 and 16, each of which is provided with a pair of contact pins (not shown) to be supported in the lampholders 11 and 12. Although I have chosen to illustrate my invention as being incorporated in a bi-pin fluorescent lampholder, it should be recognized that the quickconnect terminals of this invention may also be incorporated in the standard slimline fluorescent lampholder as well as other lampholders and related wiring devices without departing from the spirit of this invention.

Turning now to a consideration of the lampholder 11 which is identical with lampholder 12, attention is directed toward Figures 2 through 4 which best illustrate the details of construction. The present lampholder comprises a recessed body member 20 having a cover mem-. ber 21 for closing the back of the holder to form a hollow housing of suitable insulating material and a front face 22 provided at its upper end with a circular opening 23 that communicates with the interior of the holder. A vertical partition 24 formed centrally within the body member 20 has a split cylindrical embossment 25 centrally located within the circular opening 23. A vertical slot 26 at the top of the body member 20 provides an open ing through which a pair of vertically aligned contact pins on the lamp base may be inserted until the lower pin rests on the edge of the circular opening 23. The present holder is provided with a pair of symmetrical contacts 27 for making electrical connection with the contact pins extending from the ends of the lamp. These contacts 27 are separated by the partition 24 and are provided at their upper ends with inwardly facing V-shaped notches 28 which are located at either side of the split.

embossment 25. Accordingly, after inserting the contact pins of a lamp through the slot 26 until the lower pin rests on the edge of opening 23, a twisting force applied to the lamp will move the contact pins against the contacts 27 to spread them apart until the contact pins slip into the V-shaped notches 28 which is the normal lamp supporting position.

Looking at Figure 4, the interior of the body member 20 is provided with a pair of spaced protrusions 30 which extend from the side walls of the body member to serve as a fulcrum means for the contacts 27 as well as to reinforce the screw openings 31 that extend therethrough. As seen in Figure 3, the screws 32 extend through the openings 31 in the body member 20 and into the tapped Openings 33 in the cover member 21. Since the cover member 21 is generally of thin plate construction which would not be able to support a tapped opening, a pair of embossments 34 are provided thereon having the same general cross section as the protrusions 30 in the body member 20. Thus, the tapped openings 33 are formed in the embossments 34 of the cover member as is best shown in Figure 3. The construction which has been described above is mostly of conventional design for my invention primarily relates to the quick-connect terminal means for joining the contacts 27 with the lead wires 40 of a fluorescent fixture as will be discussed in detail hereinafter.

The lower or terminal portion 41 of each contact 27 is generally of hairpin shape with the U-shaped bend 42 located within. the notch 43 adjacent each corner at the bottom of the body member 20. The free end 44 of the terminal portion 41 constitutes a locking tongue which is capable of a limited amount of pivotal movement with relation to the bond 42 in the terminal portion ofthe contact. The free edge 45 of the locking tongue 44 is bifurcated to define a central slot 4-6, the purpose of which will be explained later. The bifurcations 47 are bent to lie substantially at right angles to the plane of the tongue 44 to provide rounded surfaces 47 for cooperating with the tapered surfaces of the plunger. As is seen in Figure 4, the contacts 27 are symmetrically arranged within the back of the body member 20 with the locking tongues facing each other. A bottom wall 48 is provided for the body member 20 to insulate the contacts from a supporting surface on the fluorescent fixture. A pair of inwardly converging conductor openings 51 are provided through this bottom wall so that the stripped ends of the stranded lead wires 49 may be inserted into the interior of the holder.

A tapered plunger 52 of suitable insulating material is located in a central opening 49'through the bottom wall 48 between the terminal portions 41 of the contacts 27. The upper portion of the plunger is provided with a guiding tongue 53 which engages in the groove 54 formed in the lower end of the partition 24 to limit its operation to straight line movement. The two end portions of the plunger 52 are larger than the opening 49 through the bottom wall 48 so that when the cover member 21 is in place, the plunger cannot be removed from the holder although it may slide back and forth within the housing.

Referring now to Figure 6, the tapered plunger 52 comprises a base portion 55 with a projecting ledge 50, a stem portion 56 and a pair of parallel flanges 57 and 58 which enclose the tapered section of the plunger to serve as a guide for the locking tongues 44. The flange 57 is also seated within a rectangular depression 59 in the back surface of the front face 22 of the body member 20. Consequently, the plunger 52 is guided by the tongue 53 and groove 54, the opening 49 in the bottom wall 48, and by means of the sliding engagement between the flange 57 and the depression 59.

Tapered surfaces 60 are provided on opposite sides of the plunger 52 while the conductors of the lead wires 40 are adapted to seat in the central notches 61 formed therein. A transverse V-shaped indentation 62 is located below each tapered surface 60 so that when the plunger 52 is in its extreme outer position, as shown in Figure 5, there is no obstruction to the free entrance of the stripped lead wires into the holder. Once both lead wires have their ends stripped a desired amount, as would be determined by a strip gauge (not shown) marked on the back cover 21 of the holder, the leads 40 would be inserted as far as possible through the openings 51 in the bottom wall 48 of the holder. By simply pushing on the plunger 52, the tapered surfaces 60 will react against the rounded surfaces 47' of the locking tongues 41 to spread them apart until the plunger reaches the position shown in Figure 4 with the bifurcations 47 opposing the upper inclined walls of the V-shaped indentations 62. Itshould be recognized that when the plunger is in its locking position shown in Figure 4, a force tending to pull the lead wires 40 from the holder also acts to force the free edge of the locking tongues 44 further into the locking indentations 62, thereby increasing the resistance to the withdrawal of the leads from the holder. It is practically impossible to remove the leads by exerting a pulling force on them since the plunger 52 must be backed out first to make room for the conductors to slip from the housing. An occasion might arise, however, where it would be expedient to remove the lead wires from the housing and this can only be done by inserting the blade of a screw driver 65 or any similar tool between the projecting ledge 50 at the bottom of the plunger and the lower edge of the back cover 21, as best seen in Figure 3, and twisting the blade until'this force overcomes the locking engagement between the plunger and the locking tongues 44 of the contacts 27.

To assemble this lampholder the plunger 52 is first 4 inserted in the back of the body member 20. Then the terminal portion .41 of each contact 27 is located between the flanges 57 and 58 of the plunger, and the U bend 42 is seated in the notch 43 of the housing, while the upper portions of the contacts 27 are located on opposite sides of the central partition 24. The cover plate 21 is then placed over the back of the body member and the screws I 32 are inserted to fasten the parts together.

Consequently, having described my invention of a quick connect terminal means for a lampholder and particularly a fluorescent lampholder, it will be readily apparent to those skilled in this art that I have provided a simple connecting means which is easy to manufacture. It is also reliable in operation and capable of withstanding a stronger pulling force on the lead wires than wouid ever be experienced in normal usage. With Single pushing force, the tapered plunger locks both lead wires simultaneously which increases the facility of wiring these lampholders and should considerably reduce fixture manufacturers time in wiring these lampholders in fluorescent fixtures.

Modifications of this invention will occur to those skilled in this art and it is to be understood, therefore, that this invention is not limited to the particular embodiments disclosed but that it is intended to cover all modifications which are within the true spirit and scope of this invention.

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

l. A lampholder comprising a hollow housing having at least one contact member of resilient material, a terminal portion of said contact being bent at a reentrant angle and serving as a movable locking tongue, a manually operated plunger extending through one outer wall of the housing and guided for reciprocating movement adjacent the free end of the locking tongue, the plunger having an indentation in one side face for receiving the free end of the tongue, and a lead-wire-receiving opening in said outer wall adjacent the plunger, so that when the plunger is in its outer position, a lead wire may be inserted between the plunger and. the locking tongue of the contact, while the wire may be gripped in the housing when the plunger is forced inwardly thereof and the tongue becomes seated in the indented side face of the plunger.

2. A wiring device comprising a hollow housing having a pair of resilient contact members located therein, the terminal portions of the contacts being in opposed relation and each supported for limited pivotal movement to serve as spring locking tongues, and a tapered plunger extending through one outer wall of the he rs ing and guided for reciprocating movement between said locking tongues, the plunger having opposite side faces with an indentation in each that receives the free end of the locking tongue when the plunger is fully depressed in the housing, and lead-.wire-receiving openings formed in said outer wall of the housing on opposite sides of the plunger so that when the plunger is in its retracted position, a lead wire may be inserted between each locking tongue and the related side of the plunger, the plunger in its fully depressed position having the lead wires wedged in the said indentations by a clamping force provided by the locking tongues, said tongues also acting as a restraining means to temporarily latch the plunger in its depressed position.

3. A wiring device as recited in claim 2 wherein the outer end of the plunger is provided with a projecting ledge which may be engaged by a suitable tool to pry the plunger open against the restraint of the locking tongue so that the lead wires may be removed from the holder without damaging the wires or the holder.

4. A wiring device as recited in claim 2 wherein the locking tongues are each provided with ,a bifurcated free end with the bifurcations angularly formed to define rounded surfaces for engagement with the opposite side faces of the plunger.

5. A wiring device comprising a hollow housing having a pair of resilient contact members located therein, the terminal portions of the contacts converging toward each other from an outer wall of the housing and serving as spring locking tongues, a manually operable plunger extending through said wall of the housing and between said locking tongues and guided for reciprocating movement therein, the opposite side faces of the plunger being convergent toward the interior of the housing and each being provided with an indentation, the said spring locking tongues being inherently biased into engagement with said side faces, and lead-wire-receiving openings in the said outer wall of the housing on opposite sides of the plunger so that lead wires may be in- References Cited in the file of this patent UNITED STATES PATENTS 2,260,365 Charmoy Oct. 28, 1941 2,499,507 Jordon Mar. 7, 1950 2,618,676 Howard Nov. 18, 1952 FOREIGN PATENTS 802,261 Germany Feb. 8, 1951