U.S. patent number 3,775,731 [Application Number 05/254,419] was granted by the patent office on 1973-11-27 for bulb assembly.
This patent grant is currently assigned to Robert Bosch GmbH. Invention is credited to Otto Gorg, Joachim Grupp, Ernst Merki.
United States Patent |
3,775,731 |
Merki , et al. |
November 27, 1973 |
**Please see images for:
( Certificate of Correction ) ** |
BULB ASSEMBLY
Abstract
A lamp socket assembly has a plastic housing and a transversal
flange surrounding the same. Spaced resilient tabs are arranged on
the flange for snapping into a cut-out of a reflector. Additional
spaced tabs having shoulders at the extended ends thereof are
arranged on the flange with spacers provided therebetween. The
height of the additional tabs exceeds that of the spacers. A
conductive bulb carrier for engaging the base of a bulb from one
end of the housing is held between the shoulders and the ends of
the spacers. A conductive resiliently mounted plug engages a center
electrode of a bulb and urges the bulb into engagement with the
conductive bulb carrier.
Inventors: |
Merki; Ernst (Stuttgart,
DT), Gorg; Otto (Rutesheim, DT), Grupp;
Joachim (Esslingen, DT) |
Assignee: |
Robert Bosch GmbH (Stuttgart,
DT)
|
Family
ID: |
5808385 |
Appl.
No.: |
05/254,419 |
Filed: |
May 18, 1972 |
Foreign Application Priority Data
|
|
|
|
|
May 19, 1971 [DT] |
|
|
P 21 24 930.9 |
|
Current U.S.
Class: |
439/556;
439/672 |
Current CPC
Class: |
F21S
41/198 (20180101); F21V 19/0065 (20130101) |
Current International
Class: |
F21V
19/00 (20060101); H01r 013/32 () |
Field of
Search: |
;313/318
;339/59L,61L,127R,127C,128,176L,17D |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Rolinec; Rudolph V.
Assistant Examiner: Punter; Wm. H.
Claims
We claim:
1. In a lamp socket assembly, a combination comprising a housing at
least a portion of which is made from an electrically insulating
material, said housing comprising a substantially cylindrical
hollow portion having an open end for receiving the base of a bulb,
a transversal flange surrounding said cylindrical portion and
having a supporting surface around said open end, at least two
first resilient engaging means projecting from said supporting
surface so as to engage the edge of a cutout into which said
housing is introduced, and second resilient engaging means
projecting from said surface; and electrically conductive carrier
means engageable with said second engaging means and establishing
electrical contact with one of the electrodes of the bulb whose
base is received in said cylindrical portion.
2. A combination as defined in claim 1, wherein said flange is
provided at its supporting surface with an annular face removed a
predetermined distance from said supporting surface to thereby form
an annular ridge in the region of periphery of said flange.
3. A combination as defined in claim 1, wherein said flange has a
cut-out, and said conductive carrier means has a lug extending from
one side of said flange to the other side thereof through said
cut-out.
4. A combination as defined in claim 3, wherein said cut-out has a
rectangular shape.
5. A combination as defined in claim 1, further comprising
protective cap means for covering said other end of said housing
and releasably connected to the latter.
6. A combination as defined in claim 5, wherein said flange has an
annular face on the side of said supporting surface, said
protective cap including resilient snapping means which snap over
said flange and engage said annular face to thereby lock said cap
to said housing.
7. A combination as defined in claim 1, wherein said second
resilient engaging means comprises at least two spaced tabs
projecting from said supporting surface, each tab having a locking
shoulder at its projecting end at a predetermined distance above
said supporting surface; said housing further comprising at least
two spacers in the region of said tabs and projecting from said
supporting surface a distance approximately equal to said
predetermined distance; and said conductive carrier means
comprising a substantially flat annular ring operative to radially
deflect said spaced tabs in response to passage of said ring over
said locking shoulders and being held by said shoulders in abutment
with said spacers once the ring passes the shoulders and is spaced
said predetermined distance from said supporting surface.
8. A combination as defined in claim 7, wherein said conductive
carrier means further comprises two diametrically opposite
supporting arms projecting from said annular ring toward said other
end when said ring is held by said spaced tabs and said spacers,
each supporting arm having at its projecting end a cutout for
engaging a guide pin mounted on the base of the bulb.
9. A combination as defined in claim 7, wherein said spacers are
positioned on said supporting surface in the region of said
supporting arms of said locked ring, each spacer engaging a
respective arm to thereby prevent the latter from being deflected
in a radial direction.
10. A combination as defined in claim 1, wherein said cylindrical
portion has another end spaced from said open end; and further
comprising electrical contact means arranged at the other end of
said cylindrical portion and contacting the other electrode of the
bulb whose base is received in said cylindrical portion.
11. A combination as defined in claim 10, wherein said electrical
contact means comprises a conductive plug movable axially in
relation to said other end of said cylindrical portion; limiting
means for confining said conductive plug to axial movement between
two positions; biasing means for urging said conductive plug to one
of said positions, said conductive plug being held in a further
position intermediate said two positions in response to engagement
of said conductive plug with said other electrode of the bulb whose
base is received in said cylindrical portion.
12. A combination as defined in claim 11, wherein said housing
includes abutment means at said other end of said cylindrical
portion; said limiting means including a transverse holding member
connected to said conductive plug, and said biasing means
comprising a helical spring compressed between said abutment means
and said transverse holding member.
13. A combination as defined in claim 11, wherein said conductive
plug is in the shape of a flat plate having spaced projections, and
wherein said limiting means comprises a central slotted portion
made from electrically insulating material, said plate being
slidably mounted in the slot of said slotted portion, and said
projections permitting said plate to slide between two axial
positions in said slot.
Description
BACKGROUND OF THE INVENTION
The invention relates to lamp socket assemblies, and particularly
to a lamp socket assembly which can be assembled and mounted in an
opening of a reflecting surface without the need of additional
fastening means.
Various bulb assemblies are already known. Bulb holders or sockets
of this type are generally utilized in conjuction with a lamp
assembly which includes a reflecting surface. In most instances,
the reflecting surface is provided with an opening or a cutout in
which the bulb holder or socket may be releasably held with its
light emitting portion on the reflecting side of the surface. Such
bulb assemblies are mostly used in automobiles and other motor
vehicles for providing signals which indicate that the vehicle is
about to make a turn or is stopping. Bulb holders of this type are
commonly made from plastics since they resist corrosion and
simultaneously provide the necessary insulation between the various
electrodes of the bulb. When plastic housings are utilized for the
holders, it is necessary to simultaneously provide a conducting
path for the ground as well as the hot terminal of the bulb.
In one bulb holder of this type, leaf-shaped bevel tabs are
diametrically arranged on the holder and engage guide openings in
the reflecting surface. Rotation of the housing, and therefore of
the tabs once they have passed through the reflecting surface and
beyond the guide openings, locks the housing to the surface.
However, such a holder is not satisfactory for all applications. In
another such known bulb socket, several outwardly elongated tabs
are somewhat deformed so that they resiliently engage the rim or
edge of a reflector opening. Such engagement arrests the holder and
prevents the same from moving. This known embodiment, however, has
the disadvantage that the resilient connection of the current
carrying and therefore heat forming part makes such holders only
suitable for minor sockets in conjunction with bulbs which do not
dissipate much power.
Also known are plastic housings which have resilient arms and hooks
which engage the rim of a reflector opening. With this known
embodiment, a collar is provided on the reflector which holds the
bulb socket in the desired position. However, this known
construction has the disadvantage that such a collar must be
provided, since without the latter the holder takes on a
complicated construction which is costly to manufacture.
Additionally, with the holder under discussion, the bulb can only
be changed from the front side of the reflector since the opening
in the reflector is smaller than the dimensions of the bulb. In
this connection, modern reflectors are comparatively narrow, so
that the removal of the bulbs from the front may damage the
reflecting surface. With other known constructions, the bulb can
only be removed from the rear side of the reflector because the
light assembly lens is rigidly connected with front reflecting
sides of the reflector.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
bulb assembly which does not possess the above disadvantages.
It is another object of the present invention to provide a bulb
assembly which is simple in construction and economical to
manufacture.
It is still another object of the present invention to provide a
bulb assembly which permits the bulb to be removed from the rear
side of the reflecting surface.
It is a further object of the present invention to provide a bulb
assembly which may easily be engaged with a reflecting surface
without the need for additional fastening means.
It is still a further object of the present invention to provide an
assembly of the type under discussion which also permits changing
the bulb from the reflecting surface side of the reflector.
It is yet a further object of the present invention to provide an
assembly for mounting bulbs which is reliable, resistant to
deterioration due to climatic conditions and which can be assembled
in a short period of time.
With the view of achieving the above objects, the present invention
for a bulb assembly comprises, in combination, a substantially
hollow cylindrical housing at least a portion of which is made from
an electrically insulating material for receiving the base of a
bulb at one end of said housing. A transversal flange is provided
on said housing which surrounds the same and has a supporting
surface facing said one end. At least two resilient engaging means
are provided on said flange projecting from said supporting surface
and arranged to snap into engagement with the edge of a cutout into
which said housing is introduced.
According to another important feature of the present invention,
additional resilient engaging means are provided which also project
from said supporting surface. Conductive carrier means which are
engageable with said second resilient means are provided and are
arranged to make contact with one of the electrodes of the bulb
when mounted in said housing. Electrical contact means are also
provided at the other end of said housing for making contact with
the other electrode of the mounted bulb.
The novel features which are considered as characteristic for the
invention are set forth in particular in the appended claims. The
invention itself, however, both with additional objects and
advantages thereof, will be best understood from the following
description of specific embodiments when read in connection with
the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded view, in perspective, of the bulb holder in
accordance with the present invention; and
FIG. 2 is a side elevational view, in cross section showing the
bulb holder of FIG. 1 assembled and carrying a bulb.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the Figures, where similar reference numerals have
been utilized to identify similar parts throughout, and first
referring to FIG. 1, the bulb holder comprises a plurality of
separable parts, namely a plastic housing 10, a conductive bulb
carrier 11, a conductive plug 12, a helical spring 13 and a
transverse holding member 14. These separable parts are
independently manufactured and assembled in a manner to be
described.
The plastic housing 10 comprises a substantially hollow cylindrical
cup-shaped portion 15. The housing 10 is, in accordance with the
presently preferred embodiment, advantageously made from an
electrically insulating material such as plastic. A transversal
flange 16 is arranged around the cup 15 surrounding the same and
having a supporting surface 16a which faces one end of the housing
10. An annular face 17 is spaced downwardly of the supporting
surface 16a to form a ridge 17a. In the outer periphery of the
flange 16 there is provided a rectangular cutout 18.
The housing 10 can be made by injection molding and made from
polyamide.
The plastic housing 10 is substantially hollow and has a
cylindrically formed space 19. Projecting from the supporting
surface 16a is a wide locking tab 20 and two narrow locking tabs 21
and 22 which are substantially diametrically opposed from the wide
locking tab 20. The interiorly facing surfaces of all the locking
tabs form extensions of the cylindrical opening 19 in the cup 15.
Provided on the top of each locking tab is a locking shoulder 23
which has a triangular or bevelled upper portion and retaining
surface 24 which is substantially parallel to the supporting
surface 16a. The tabs 20, 21 and 22 are, in the present embodiment,
made integral with the plastic housing 10 and are resilient so that
they may be somewhat flexed in radial directions by applying inward
forces to the locking snaps 23.
Spaced between the wide locking tab 20 and the narrow locking tab
22 is a spacer 25, while a spacer 26 is positioned between the wide
locking tab 20 and the narrow locking tab 21. The spacers 25 and 26
are substantially at the same radial distance as are the locking
tabs so that their inwardly facing surfaces likewise form
extensions of the inner surface of the opening 19. Each of the
spacers 25 and 26 is provided with a cylindrical cut out section 27
and 28 respectively, defining recesses which receive the conductive
bulb carrier 11, as will hereafter be described.
The tabs 20, 21 and 22 extend above the surface 16a so that the
retaining surfaces 24 are positioned a predetermined distance above
the supporting surface. On the other hand, the extended ends of the
spacers 25 and 26 are positioned a distance above the supporting
surface 16a which is slightly less than said predetermined
distance. In this manner, as will hereafter be described, the
locking tabs and the spacers cooperate to rigidly secure the
conductive bulb carrier 11 to the plastic housing 10.
Further provided on the conducting surface 16a are five resilient
tabs 29 which are spaced from one another and are, in the presently
preferred embodiment, positioned at the same radial distance from
the axis of the housing. Each resilient tab is also integral with
the plastic housing 10 and has an upper protuberance 30 which is
formed by an upper surface 31 and a lower surface 32. The upper
surface 31 is inclined upwardly and inwardly while the lower
surface 32 is inclined downwardly and inwardly. With this
construction, the resilient tabs 29 first are deformed inwardly and
then snap outwardly when forced past the edge of a relatively thin
plate, such a reflector opening edge.
The conductive bulb carrier 11 is made from sheet metal and
includes an annular ring 33 from which are suspended in one
direction two diametrically opposite supporting arms 34 which are
provided at their lower ends with cutouts 35. The supporting arms
34 project from the inside periphery of the ring 33. Also
projecting from the inside periphery are two projections 36 and 37
which project inwardly. Projecting from the outer periphery of the
ring 33 is a ground lug 38 which projects in the same direction as
the supporting arms 34, approximately perpendicularly to the ring
23. Provided at the end of the ground lug 38 is a connecting tab 39
which is suitable for connection to an electrical conductor in a
well known manner. The connecting tab 39 is so configurated that it
can form the male contact of a plug commonly used in motor vehicles
(not shown).
The conductive plug 12 is similarly made from sheet metal and is
provided with a connecting tab 40 similar to tab 39. Again, the
connecting tab 40 may be either soldered to an electrical lead or
it may be inserted into a plug to which the electrical conductor is
connected. To each side of the conductive plug 12 is a projecting
tab 41, which serves to limit the movement of the plug, as will
hereafter be described. The plug 12 is also provided with two
rectangular cutouts 49 at one end thereof. The transverse holding
member 14 comprises a plastic plate which has an H-formed opening
42 and rectangular end bars 56. The opening 42 is arranged to
receive the end of the conductive plug 12 which bears the cutouts
49 so that the bars 56 become lodged inside the cutouts 49 to
thereby form a locking engagement between these two elements.
Referring now to both FIGS. 1 and 2, the assembly of the bulb
holder will now be described. The conductive bulb carrier 11 is
angularly positioned so that when it is axially aligned with the
plastic housing 10, the projections 36 and 37 are positioned
intermediate the locking tabs 21 and 22 and the locking tab 24 and
the spacer 26 respectively. In this manner, the projections 36 and
37 do not come into contact with any of the projecting members
which extend from the surface 16a. The conductive bulb carrier 11
is then pressed against the locking tabs 20, 21 and 22 so that the
inside edge of the ring 33 bears against the exterior sloping or
bevelled surfaces of the locking snaps 23 to thereby force the
locking tabs to be deflected or deformed radially inwardly until
the inside edge of the ring 33 passes over the locking shoulders
23. Once such passage is fully achieved, the lower surface 11a of
the ring 33 comes to bear on the upper projecting ends of the
spacers 25 and 26 while the locking tabs 20, 21 and 22 spring back
outwardly and engage the upper surface 11b of the ring 33 with the
retaining surfaces 24. In this manner, the ring 33 is rigidly fixed
and prevented from moving in axial directions of the housing 10.
Also, because of the projections 36 and 37, which are positioned
between the projecting members as described above, the ring 33 is
also prevented from moving angularly. When such conductive bulb
carrier 11 engagement is achieved, the ground lug 38 projects past
the flange 16 by passing through the rectangular cutout 18 in the
direction of the cap 15. Also, when so engaged, the supporting arms
34 are positioned interiorly of the spacers 25 and 26 and are
lodged within the cut out sections 27 and 28 of the latter. In this
mounted position of the conductor bulb carrier 11, the interiorly
facing surface of the locking tabs 20, 21 and 22 and the inner
surfaces of the supporting arms 35 are substantially flush with the
interior surface of the cutout or open cylindrical space 19 which
extends into the cup 15.
Referring to FIG. 2, the cup 15 at the end facing away from the
supporting surface 16a is provided with an inwardly projecting
portion 48 which is integral with the housing 10. The projecting
portion 48 is provided with a slot 47 through which the plug 12, in
the form of a flat plate, passes through. Therefore, after the
conductive bulb carrier 11 has been mounted, the conductive plug 12
is inserted through the slot 47 from the top towards the bottom as
viewed in FIG. 2. The dimension of the slot 47 is selected so that
the plug 12 can pass therethrough but the projecting tabs 41 cannot
so that the plug 12 can only be partly passed through the slot 47.
The helical spring 13 can now be placed into the cap 15 through its
lower end, and through the ring 33, until it abuts with the annular
shoulder serving as abutment means for the spring and located in
the region of the inwardly projecting portion 48. The helical
spring 13 is now compressed and the plastic plate or transverse
holding member 14 is forced ont the conductive plug 12 so that it
engages the latter in the cutouts 49 as well as the lower turns of
the helical spring 13 and maintains the latter compressed. With
this arrangement, the helical spring 13 biases the conductive plug
12 in a downward direction, as viewed in FIG. 2, through the
pressure applied on the plate 14. With this arrangement, it is
clear that the conductive plug 12 can move between two axial
positions. An upper axial position is determined by the abutment of
the plate 14 with the inwardly projecting portion 48. A lower axial
position results when the projecting tabs 41 come into contact with
the inwardly projecting portion 48. Between these two limiting
positions, the conductive plug 12 may move, although it is biased
in a downward direction so that it normally rests in its lower
position when no bulb is secured in the holder. When a base 50 of a
bulb 43 is inserted into the space 19, it is initially inserted so
that the guide 51 of the base 50 of the bulb moves axially along
the supporting arm 34. When the bulb has been fully inserted into
the opening 19, thereby forcing the conductive plug 12 to move to
its upper axial position, the bulb is rotated so that the guide
pins 51 become angularly aligned with the cutouts 35. At such time,
the bulb 33 can be released and the spring biased conductive plug
12 will force the bulb 43 to move in a downward direction so that
the guide pins 51 engage the cutouts 35. In this position, the
guide pins 51, which are integral with the base 50 and form one
electrode of the bulb 43, are placed in contact with the ground lug
38, while the center electrode 50a of the bulb 43 is in abutment
with the conductive plug 12, the electrode 50a forming the other
electrode of the bulb.
The inwardly projecting portion 48, which is not visible in FIG. 1,
resiliently supports the center electrical contact which makes
contact 12 with the center electrode 50a.
The supporting arms 35, as well as the spacers 25 and 26 are
invisible in FIG. 2. However, as explained above, the spacers 25
and 26 would normally project from the surface 16a to the surface
11a of the ring 33.
By so biasing the bulb in a downward direction, as described above,
the bulb 43, engaging the supporting arms 34 of the rigidly fixed
ring 33, is prevented from falling out of the holder. A female
connector or plug 46 is forced onto the upper connecting portion of
the conductive plug 12, as suggested above, the plug 46 being
connected to a cable 45. The ground lug 38 and the cable 45 can now
be connected to the poles of a battery which energizes the bulb
43.
If such a bulb holder is to be used in connection with a reflector
53 which is electrically conductive, it is possible to replace the
ground plug 38 with a spring lug (not shown), which is forced into
contact with the reflector 53 when the ring 33 is mounted as
described above. In this case, no additional wires need be
connected to the ground lug, rather the electrical circuit is
completed directly through the conductive reflector.
The advantage of the above-described lamp holder or bulb holder
consists mainly in that it is mountable on the refelecting surfaces
without the necessity of utilizing additional fastening means, e.g.
without screws or spring like projections in the reflecting surface
or separately provided fastening means which are connected to the
housing itself. Additionally, with the above-described embodiment,
the resilient tabs 29 cannot undesirably disengage from the
supporting surface 16a and therefore provide a good fastening
connection thereto. Additionally, the electrical contacts 11 and 12
which must contact the various electrodes of the bulb are simply
and quickly mounted into the housing and do not require further
elaborate fastening means. The mounting of the electrical contacts
is therefore reliable and does not permit the same to become
disengaged from the housing.
According to a further advantageous feature of the present
invention, a protective cover 44 is provided which prevents dirt as
well as the elements from coming into contact with the electrical
contacts. The protective cover 44 has a lower portion, as viewed in
FIG. 2, with an annularly shaped disk 55 which is adapted to engage
the flange 16 by snapping over the outer periphery and engaging the
annular surface 17 thereof. The lower surface of the disk 55 is
substantially coplanar with the supporting surfaces 16a so that
both of these surfaces rest against the non-reflecting surface of
the reflector 53 when the holder is mounted therein. When the bulb
is to be changed, the entire housing 10 as well as the protective
cover 44 can easily be separated from the reflector 53 by placing a
coin or a tool, such as a screwdriver, underneath the disk 55 and
prying it up against the reflector 53. Such action causes the
resilient tabs 29 to bend inwardly in response to the relative
movement of the flange 16 with respect to an edge 54 of a cutout in
the reflector 53.
When such lamp or bulb holder-lamp assembly is not provided with a
covering which protects the holder from the outside, as described
above, it may be advantageous that the housing be provided with a
releasably engaging cap which mates with the portion of the housing
to cover the portion of the latter which has a slot for the
conductive plug 12. In this manner, dirt is prevented from entering
the slot where it would otherwise arrest the axial movements of the
plug 12 which have been described above. When high requirements are
made to seal the housing against moisture, e.g., water spray or
heavy rain, then in accordance with a further of the present
invention, the entire cup or the above selected regions, can be
further protected by an additional protecting cover.
It will be understood that each of the elements described above, or
two or more together, may also find a useful application in other
types of bulb holders differing from the types described above.
While the invention has been illustrated and described as embodied
in a bulb for a bulb assembly which does not require additional
fastening elements to connect the same to a reflecting surface and
wherein the electrical contacts are securely mounted in a plastic
housing, it is not intended to be limited to the details shown,
since various modifications and structural changes may be made
without departing in any way from the spirit of the present
invention.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can be applying current
knowledge readily adapt it for various applications without
omitting features that, from the standpoint of prior art fairly
constitute essential characteristics of the generic or specific
aspects of this invention and therefore such adaptations should and
are intended to be comprehended within the meaning and range of
equivalence of the following claims.
What is claimed as new and desired to be protected by Letters
Patent is set forth in the appended claims.
* * * * *