CA1180047A - Attachment of base to lamp unit - Google Patents

Abstract

ATTACHMENT OF BASE TO LAMP UNIT

ABSTRACT OF THE DISCLOSURE
A lamp unit having a housing containing a ballast and provided with a screw base. The base fits over an end of the housing and is attached thereto by a low-cost resin material which, in cooperation with shaped contours on the housing and the base, mechanically locks these parts together.

Description

ATTACH~ENT OF' BASE TO LAMP UNIT
BACKGROUND OF THE INV~NTION
The invention is in the field of screw-in lamp units ha~ing a screw base attached to a housing. The housing may contain a ballast, such as reactor type or an electronic circuit type, which is connected to a lamp such as a fluorescent lamp or an arc type lamp. The lnvention is particularly directed to the attachment of the base to the housing.
Various ways have been used, and proposed, for attaching a screw base to a light bulb or to a housin~ of a lamp unit, such as adhesively cementing or gluing these parts together, or attaching them together with fastening devices such as screws or staples, or by crimping the parts together. For example, U.S. Patents 3,953,761 issued April 27, 1976 to Thomas Lo Guidice; and 2,421,571 to Leyshon disclose lS cementing a base to a lamp unit with adhesive material, and the Leyshon patent also discloses crimping the base to the lamp uni-t. U.S Patents 2,817,004 issued December 17, 1~957 to Geor~e R. Baugar-tnex et al; and 4,161,0~0 i~sued July :L0, 197~ to Jack V. Miller disclose the use of screws ~or a-t-tach:ing a base to a lamp unlt. U.S. Patent 2,525,022 issued October 10, 1950 to Joseph E. Dupuy d:iscloses a twist-lock a-ttachment oE a base to a lamp unit. All o~
these methods incur an amount oE co~t Eor materials and labor.

~t ~ B~4~7 SI~MA:RY OF THE IN~7ENTI:ON
Objects of the invention are to provide a low-cost, and mechanically secure, attachment of a base to a lamp unit.
The invention comprises, briefly and in a preferred embodiment, a lamp unit which includes a housing me~ber pre~erably of plastic, and a base positioned over an end region of the housing member and mechanically attached thereto by a resin material within the base and housing end region which mechanically locks onto shaped contours of the base and end region of the housing. Thus, the resin can be a low-cost non-adhesiYe material, applied in liquicl or paste form and then hardened. The shaped contours of the base and housing can be in the form of notches, depressions, or dimples, and shelves or other projections.
BRIEF DESCRIPTION OF THE D~:AW:ENG
.
- Figure 1 is a top perspective view of a pre~erred embodiment of invention.
Figure 2 is a view similar to Figure 1, but with the circular lamp assembly separated from the central hub.
Figure 3a is a side view of the circular lamp assembly, shown partly broken away to show interior construction.
Figure 3b is a side view of the central hub unit, partly broken away to show ~he interior construction.
Figure 4 is a perspective view of a portion of the circular lamp assembly, along with a schematic diagram o~
the contents of the central hub.
Figure 5 ~nd 6 are broken away perspective views of the lamp un;lt, sllowing its slide connector in disengaged positlon and in enc~a~ed posltion, respectively.
Figure 7 is a side view of the hub, shown partly hroken away to show interior c:onstrwction o~ the hase and housing end region.
Figure 8 is a cross-section view taken on the line 8-8 of Figure 7.

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DESCRIPTION ~OF THE PREFERRED -EM~ODIMENT
The lamp unit comprises a central hub unit 11 and a circular lamp assembly 12 which is replaceable on the hub 11. The hub 11 comprises a plastic housing 13 having a cylindrical portion 14 and a tapered section 16 at the small end to which is attached, by means in accordance with the in~ention as described subsequently, a -threaded screw base 17. ~s shown in Figures 3b and 4, a ballast reactor 18 and thermal circuit breaker 19 are contained within the housing 13 and are electrically connected in series between the threaded base shell 21 and an electrical contact 22 of a raised socket 23 which projects from the side of the cylindrical portion 14 of the hub 11. The thermal circuit breaker 19 is positioned adjacent to the ballast reactor 18 and is designed to open the electrical circuit in the event o~ overheating of the ballast reactor 18. A second socket contact 24 is electrically connected to the button terminal 26 of the threaded base 17. The two socket contacts 22 and 24 are aligned parallel to the axis of the hub 11 and are recessed in a narrow slot 23' for electrical safety. The electrical wiring connections to the base shell 21 and button terminal 26 can be interposed, and the thermal circuit breaker 19 can be located elsewhere in the wiring within the hub 11 if desired.
The circular lamp assembly 12 comprises a sleeve ring 31 wh.ich removably slides over and surrounds the cylindrical portion 14 of the hub 11~ ~ plurality o spokes 32 extend outwardly ;Erom the sleeve ring 31 in a symme-trical manner, and -term.inate with clamp arms 34 which may ~ully ox partia:L.ly surround a circula~ lamp or light bulb 36 and hold it in ~ coaxial relationship with respect to the sleeve ring 31. '~he assembly o~ the sleeve ring 31, spokes 32 and clal~p arms 34 ma~ comprise two substantiall~ similar upper and lower plastic parts which are assembled together with their clamp arms 34 positioned against the upper and lower sides of the circular lamp 36, and may be fastened together by means of tight ~itting fastening tabs, or cement.

t~

One of the spokes 32' is provided with an enlarged pair of clamp arms 34' so as to also function as a connector housing which fits around and conceals the end regions 37 of the lamp 36, and associated wiring thereof~ as will be described and which is best shown in Figure 4. The spokes 32 may be relati~ely thin in horizontal cross--section and may ha~e a vertical heigh dimension as disclosed and claimed in U.S. Patent 4,244,013 issued January 6, 1981 to Wotowiec, titled "Circular Fluorescent Light Unit" and assigned to the present assignee. The spoke 32', which terminates at a housing 34' surrounding the ends 37 of the circular lamp, may be provided with an enlarged hollow tapered region 38 adjacent to the connector housing 34', to help facilitate accommodation of a glow started switch 39 and associated capacitor 41.
A slide connector 46 is provided within the spoke 32', and is adapted to slide along the axis of spoke 32' and toward or away from the hub 11. A pair of finger grips 47 extend from opposite sides of the slide connector 46 and through openings 48 in the sides of the spoke 32', so they can be gripped by a person's thumb and finger ~or manually sliding the connector 46 toward or away from the hub 11. The slide connector 46 and its finger grips 47 can be integrally molded from plast.ic or rubber. A
vertical slot 51 at the inside of the sleeve ring 31 mates with the raised socket 23 of the hub 11, for preventing the lamp assembly 12 from rotating on the hub 11, and for also al.ignin~ the lamp assembly spoke 32' with the socket 23 o;E the hub~ A pair o~ electrical connector prongs 52, 53 e~tend ~rom the slide connector 46 toward and re~pectivel~
in alig~ment w.lth the socket contacts 22 and 24. The slide connector 46 can be, manually maved .~ar enough away ~rom the hub 11 ~o that the tips of the p.rongs 52 and 53 will not touch nor in~er~ere with the sliding insertion of lamp assembly 12 over and around the cylindrical portion 14 o the hub 11, whereupon the slide connector 46 is manually ~3q~

moved toward the hub 11 so that its connector prongs 52 and 53 entex into the hub socket 23 and engage its contacts 22 and 24, respectively. A pair of flexible ~ires 56, 57 are attached to the connector prongs 52 and 53, respectively, and the other ends of the wires 56 and 57 are respectively connected to lead wires at respective ends 37 of the circular lamp 36, each of these lead wires being respectively connected to the end of a filament in each of the two ends of the lamp 36. These filaments are conventional and are not shown in the drawing. The lamp starting switch 39 is electrically connected to the lamp 36 lead wires 58 and 59 which are respectively connected to the remaining ends of the filaments of the lamp 36. The capacitor 41 is electri-cally connected across the starting switch 39, to reduce radio interferance emmissions.
Figure 5 illustrates the posiJ-ion of the slide connector 46 when it is retracted, for insertion of the circular lamp assembly onto, or removal ~rom, the hub 11.
Figure 6 shows the arrangement of the invention with the slide connector 46 in its operating position, with the electrical prongs 52 and 53 inserte~lnto the socket 23 and in engagement with socket contacts 22 and 24, whereby the hub 11 and lamp assembly 12 provide an integra:L
operational lamp unit. An outwardly extending flange 61 around the bottom portion of the cylindrical hub part 14 facilitates initial positioning of the sleeve ring 32 with respect to the socket 23, for the aforesaid insertion of the connector prong 52 and 53 into the socket, in cooperation w.ith the a.eore~aid mating o~ the e.xkended socket 3~ 23 and slot Sl in the ~leeve ring, :eor preventing rota-tional relaklve motion. The aforesald positionin~ of the said lamp as~embly on the hub 11 can ~u.rther be facilitaked by providln~ a slee~e ring slot 51 which e.xtends not ~uite ully to the upper inner surf~ce of khe sleeve ring 31, as illustrated hy the numberal 62 in Figure 3~. ~he mechanical connection o~ the lamp assembly 12 to the hub 11 is facilitated by providing a locking prong 63 extending from the slide connector 46 toward the hub 11, and located between the connector prongs 52 and 53; this locking prong mates into a suitable opening 64 in the center region of the socket 23. The locking prong 63 can be molded integrally with slide connector 46.
The lamp unit is easily placed in a socket, by first screwing the base hub 11 into the socket. This is easily don~, because of the compact and circular shape of the hub. Then the lamp assembly 12 is slid over and around the cylindrical portion 14 of the hub, and the slide connector 46 is moved toward the hub to complete the electrical and mechanical connection as described above. To easily remove the lamp uni.t, the foregoing steps are repeated in reverse or~er. To replace the lam~ assembly the slide connector 46 is moved away from the hub 11, the lamp assembly is lifted off the hub, and a new lamp assembly is placed on the hub as has been de~cribed. To place the lamp unit of the invention in ~ floor or table lamp having a shade supported by a harp, the shape and harp are removed, and only the hub 11 is easily screwed into the socket, as described above. The circular lamp assembly 12 is then slid over and around the hub ana the slide connector 46 is moved toward the hub to complete the connections. The harp is then placed through spaces between spokes 32 and reconnected, and the shade is reconnected to the harp. The overall diameter of the hub 11 and sleeve rlng 31 can be made about the same or smaller than that o.~ a conventional incandescent light bulb used in tahlc or ~loo.r lamps, and the inner cliameter oE the circular ll~ht hulb 36 is lar~er -than the Width o~
con~entional lamp harps.
Xn accordance with the inYention, and as ~hown in ~i~ures 7 and 8, the lower end region 71 o:~ the hub housing 13 is provided with a cylindrical shape over which a portion of the threaded shell 72 o~ the base 17 its.
The lower end region 71 is provided with an inwardly extending shelf 73 which may extend continuously or partly, or .in spaced-apart sections, around the lower part of the inner surface of the lower end region 71. One or more notches or grooves 74 are provided in the end recJion 71 at the bottom thereof. An off-center depression or dimple 76 is provided in the insulation material 77 which holds toge-ther the threaded shell 72 and the button terminal 26 of the base 17. For convenience and economy, the base 17 may be a three-way light ~ulb base having a rin~ terminal 78 intended for connection to a third lead-in wire of a three-way bulb;
the depression 76 is provided so that the third wire can be connected to the ring terminal 78. Further in accordance with the invention, the base 17 is mechanically attached and locked to the housing 13 by means of a resin 79 which may be placed into the base 17 in a liquid or paste ~orm~
The base is then placed over the lower region 71 of the housing 13, and the resin 79 is cured by heat and/or temperature and/or catalyst or chemical curing agent until it hardens and solidifies. The base is filled with the resin 79, or sufficient resin is provided, so that the top of the resin extends above the top of the shelf 73, and also the base 17 is positioned around the housing end region 71 so that some of the threads of the threaded shell 72 are exposed to the resin 79. Thus, the base 17 is mechanicaaly locked to the housing 13, as follows. The base canrlot be pulled from the housing because the resin 79 overlaps the top edge of the shelf 73 and also internally engages some threads of the base ~hell 72, thus locking the base to the housin~.
~lso, the base cannot be twisted or rotated with respect -to the hc~us.inc~, because the resin 79 projects into the housing notch 7~ and into -the bas~ dimpl~ 7~, thus lockincJ the parts aga.inst relat.ive rotation. Instead o;~ p.rovidincJ the housing no-tch 7~, the shelf 73 can be provided with a ~.lot or a projection for loclcin~ -to the resin, and var;ious notches, dimples, and other contouxs can bc pxovided on the base ancl hou~ing to mechanically lock them to~e-thex b~ means of the resin 79~

P~

Since, in accordance with the invention and as described above, the base and housing are mechanically locked together by the resin, an adhesive type of resin is not re~uired, and therefore various lower cost and non adhesive resins can ~e used, such as polyester resins. Another reason that low-cost resins can be used, is that it does not matter if the resin shrinks a bit during curing; a slightly shrunk resin will lock the base to th~ housing satisfactorily. The invention 1~ obviates the need or using relatively expensive adhesive and non-shrinking resins (an adhesive resin, if it shrinks, will not adhere to the parts satisfactorily).

The invention has been found to achieve its objectives of providing secure and low-cost attachment of a base to a lamp housing, and permits a wide scope of resins to choose ~rom since the resin need not be adhesive and need not be non-shrinkable. The invention is not limited to the particular lamp assembly disclosed herein.

While preferred embodiments o~ the in~ention have been shown and described, various other embodiments and modifications thereof will become apparent to person~
skilled in the artt and will ~all within the scope of ~he invention as de~ined in the following claim~.

Claims (6)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A lamp unit comprising a housing and a base positioned over an end of said housing, and means attaching said base and housing together comprising a resin material within said base and said end of the housing, said base and said end of the housing being contoured to engage said resin so that the resin mechanically locks together said base and said housing.

2. A lamp unit as claimed in Claim 1, in which said resin is a non-adhesive type.

3. A lamp unit as claimed in Claim l, in which said resin is a type that may shrink during curing.

4. A lamp unit as claimed in Claim 1, in which said base and housing end are contoured to engage said resin to prevent the base from being pulled from the housing and are further contoured to prevent the base from twisting with respect to the housing.

5. A lamp unit as claimed in Claim 1, in which said end of the housing is provided with an inwardly extending shelf which engages with said resin, and in which said base is provided with screw threads which engage with said resin, thereby preventing the base from being pulled from the housing.

6. A lamp unit as claimed in Claim 1 or Claim 5, in which said end of the housing is provided with a notch engaged by said resin, and in which said base is provided with an off-center dimple engaged by said resin, thereby preventing the base from twisting with respect to the housing.