Note: Descriptions are shown in the official language in which they were submitted.
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.
3~
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
-- 6 --
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
-- 7 --
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~.
