U.S. patent number 3,803,402 [Application Number 05/323,713] was granted by the patent office on 1974-04-09 for lens structure for a combination signal lamp.
This patent grant is currently assigned to Ichiko Industries Limited. Invention is credited to Akihiro Nasu.
United States Patent |
3,803,402 |
Nasu |
April 9, 1974 |
LENS STRUCTURE FOR A COMBINATION SIGNAL LAMP
Abstract
A lens structure for a combination signal lamp for automobiles
is comprised of at least two lens pieces connected to each other.
Each of the lens pieces has a side wall at which they can be
connected together. The side wall of one of the two lens pieces is
provided with spaced, exposed vertical dovetail grooves each having
a closed top and an open bottom and this side wall also has a notch
which runs horizontally at the bottom thereof and includes the open
lower end portions of the grooves. The side wall of the other lens
piece is provided with spaced dovetail projections which fit in
said dovetail grooves and with an elongated horizontal flange which
fits in said notch. This lens structure is made by placing the
dovetail grooves and the dovetail projections together and also by
putting the flange in place in the notch, and then by welding
together the abutting walls of the flange and the notch integrally
relying on known welding techniques utilizing, for example,
supersonic waves.
Inventors: |
Nasu; Akihiro (Yamato,
JA) |
Assignee: |
Ichiko Industries Limited
(Tokyo, JA)
|
Family
ID: |
11708528 |
Appl.
No.: |
05/323,713 |
Filed: |
January 15, 1973 |
Foreign Application Priority Data
|
|
|
|
|
Jan 20, 1972 [JA] |
|
|
47-9005 |
|
Current U.S.
Class: |
362/360;
362/363 |
Current CPC
Class: |
F21S
43/51 (20180101); B29D 11/00009 (20130101) |
Current International
Class: |
B29D
11/00 (20060101); F21V 17/00 (20060101); F21v
005/04 () |
Field of
Search: |
;240/8.3,106,106.1,41.55,41.5 ;46/25 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Matthews; Samuel S.
Assistant Examiner: Adams, Jr.; Russell E.
Attorney, Agent or Firm: Wenderoth, Lind & Ponack
Claims
1. A lens structure for a combination signal lamp, comprising at
least two lens pieces each having a side wall to be joined
together, each side wall having upper and lower edges and vertical
side edges,
the side wall of one of said two lens pieces having at least one
exposed, vertical dovetail groove having first and second ends,
said first end being opened and a horizontal notch joining said
open first end,
the side wall of the other one of said two lens pieces having at
least one vertical dovetail projection, having first and second end
surfaces, located at a site corresponding to that of said groove
and provided with a configuration complementary to that of said
groove, this latter side wall further having a horizontal flange
extending from said first surface and being of a configuration
complementary to that of said notch,
said dovetail projection being received in said dovetail
groove,
said flange being received in said notch, and said flange and walls
of said
2. A lens structure for a combination signal lamp according to
claim 1, in which the side wall of one of the two lens pieces has
two of said dovetail grooves in parallel relation with each other
and the side wall of the other of the two lens pieces has two of
said dovetail projections in parallel relation with each other at
sites corresponding to those of said
3. A lens structure for a combination signal lamp according to
claim 1, in which said flange and walls of said notch are
fusion-welded together by a
4. A lens structure for a combination signal lamp according to
claim 1, in which the outer surface of said side wall of either one
of said two lens pieces is coated with a light-shielding opaque
material.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention is concerned with a structure of a
combination signal lamp, and more particularly, it relates to a
lens structure of the type described such as the combination of a
tail lamp and a turn signal lamp for automobiles.
2. Description of the Prior Art:
Lens structures for combination signal lamps for automobiles are
usually made with molded plastic lens pieces. It is, however,
technically impossible to mold a plurality of plastic pieces
simultaneously into an integral combination lens structure, because
of the fact that these lens pieces are of different colors.
Therefore, the conventional lens structures of this kind have been
produced by the following complicated steps.
One of the conventional production methods comprises separately
molding the required lens pieces of different colors, forming rough
surfaces of those walls of the lens pieces which are to be
connected together, and then bonding them together by the use of an
adhesive.
Another conventional production method uses a metal mold provided
with at least one space for accommodating a pre-fabricated lens
piece of a first color. In use one places this pre-fabricated first
lens piece in place in said space and then molds a fresh lens piece
of a second color integrally with said first lens piece in the
metal mold, thus welding these at least two pieces together. In
this case also, said first lens piece is given a roughening
treatment at the connecting surface to increase the welding force
of the surface.
However, these conventional producing methods have the following
drawbacks. In the first-mentioned method, the adhesive used
requires 1-2 hours to harden. Therefore, the bonded pieces have to
be left at rest for this time until a firm bond is established.
The other method described above, on the other hand, requires the
use of a large mold having a size sufficient for accommodating the
pre-fabricated lens piece or pieces, and will have the troublesome
steps of mounting these pre-fabricated lens pieces in the space
within the metal mold for each manufacturing process, thus lowering
the production efficiency. Furthermore, there may arise the
inconvenience that the mounted pre-fabricated lens pieces may break
at the time of final molding.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to
provide a lens structure for a combination signal lamp of the type
described, which is free from the aforesaid drawbacks and which can
be produced with an improved efficiency.
Another object of the present invention is to provide a lens
structure for a combination signal lamp of the type described, in
which the respective lens pieces are connected together firmly and
wherein the resulting structure can withstand the externally
applied bending forces.
These and other objects as well as the features and advantages of
the present invention will become apparent by reading the following
detailed description of an embodiment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side view of an example of a combination
signal lamp with two lens pieces firmly joined together.
FIG. 2 through FIG. 4 show one of the two lens pieces to be joined
together, in which: FIG. 2 is a view of that wall of the lens piece
to be connected; FIG. 3 is a sectional view of the same, taken
along the line III -- III in FIG. 2; and FIG. 4 is a sectional view
of the same, taken along the line IV -- IV in FIG. 2.
FIG. 5 through FIG. 7 show the other of the two lens pieces, in
which: FIG. 5 is a view of the wall of said other lens pieces to be
joined; FIG. 6 is a sectional view of the same, taken along the
line VI -- VI in FIG. 5; and FIG. 7 is a sectional view of the
same, taken along the line VII -- VII in FIG. 5.
FIG. 8 is an explanatory illustration, showing the manner in which
two mating lens pieces are placed together.
FIG. 9 is a sectional view, showing the connecting walls of the
lens pieces as they are fastened together.
FIG. 10 is a sectional view, taken along the line X -- X in FIG.
9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, A represents generally a first lens piece and B
represents generally a second lens piece. The first lens piece A
has a side wall 1, and the second lens piece B has a side wall 2.
These lens pieces A and B unite integrally together at the surfaces
of these side walls 1 and 2.
Description will hereunder be made of an example of such lens
structure.
The side wall 1 of the first lens piece A is provided, on its outer
surface, with exposed vertical dovetail grooves 3, and 3' which are
open at their lower ends. In addition, at its lower end face piece
A is provided with a horizontally extending elongated notch 4 which
includes said dovetail grooves 3 and 3'. More specifically, said
vertical dovetail grooves 3 and 3' are, as shown in FIG. 3, so
formed that they are widened progressively as they go toward the
inner face of the side wall 1 forming generally a V-shape so that
these grooves have inclined inner side faces 31, 31'. Said vertical
grooves 3 and 3' are such that their upper ends are lower in level
than the top of this lens piece A and that the lower ends thereof
which are open join the horizontal notch 4 formed at the bottom of
said side wall 1.
The second lens piece B has, at its side wall 2, vertical dovetail
projections 5 and 5' which are complementary in configuration to
said dovetail grooves 3 and 3' of the first lens piece A so as to
be able to fit therein when the two lens pieces A and B are
assembled together. This second lens piece B also has an elongated
horizontal flange 6 extending from the lower end of the side wall 2
and is complementary in configuration to said notch 4 of the first
lens piece A so as to be fittingly received in said notch 4. Said
dovetail projections 5 and 5' are provided on the side wall 2 at
the sites corresponding to those of said dovetail grooves 3 and 3'
on the side wall 1, respectively. From the foregoing description,
it should be understood that the outer side faces 51 and 51' of
said dovetail projections 5 and 5' extend in progressive widening
fashion from the surface of the side wall 2, forming substantially
a V-shape as shown in FIG. 6, and that said bottom flange 6 extends
beyond the outermost edges of the dovetail projections 5 and 5'.
Needless to say, said vertical dovetail grooves 3 and 3' and said
complementary dovetail projections 5 and 5' are formed to be
parallel to each other.
The following is a description of the manner in which the first and
the second lens pieces A and B are assembled together. These first
and second lens pieces A and B having the aforesaid configurations
are first brought to such positions as shown in FIG. 8 in which the
lens piece A is positioned closely above the lens piece B so that
the side wall 1 is located directly above the side wall 2. Then,
said vertical dovetail projections 5 and 5' of the second lens
piece A are slid into said vertical dovetail grooves 3 and 3'
beginning at the open lower ends of said grooves so that said
inclined inner side faces 31 and 31' of said grooves are
progressively slidably engaged with their mating outer side faces
51 and 51' of said projections to establish dovetail joints and so
that said bottom horizontal flange 6 of the second lens piece B is
fitted progressively into said notch 4 of the first lens piece A.
The first and second lens pieces are thus firmly united together.
Thereafter, the bottom flange 6 is welded firmly to the walls of
the notch 4 by relying on a known supersonic or high-frequency
welding technique.
It should be noted that an opaque light-shield paint may be applied
to the outer surface of either one of the two side walls 1 and 2
before uniting the first and second lens pieces A and B together to
keep the colored light rays of one lamp A from mingling into the
lens piece material of the other lamp B when these two lamps are
lighted.
An advantage of the present invention is that it takes only 3-5
seconds to establish the firm fastening of the two lens pieces A
and B because of the complementary lower end structures of the side
walls of these two pieces. More specifically, after these two
pieces are put together, it is only necessary to weld the bottom
ends of these two pieces A and B together in 3 to 5 seconds by the
use of, for example, supersonic waves. The invention does not use
the conventionally employed adhesives which require a lot of time
to harden.
Another advantage of the present invention is that the aforesaid
"dovetail joint" portion plus the fusion-welding at the bottom
portions of the two pieces A and B cooperatively exhibit a
resistance which is sufficiently powerful to cope with any external
forces such as a bending force or a pulling force in spite of the
small area of the fusion-welded portion of the lens structure.
A further advantage of the present invention is found in that,
unlike the conventional manufacturing processes -- i.e., the
process using an adhesive and the integral molding process which
uses a large-size metal mold for housing a pre-molded lens piece or
pieces and which molds the final lens piece together with the
pre-molded lens pieces in said mold to produce an integrally fused
lamp assembly -- there can be obtained a much improved productivity
and what is more, the products of the present invention are
substantially free from any breakage, thus eliminating the
occurrences of rejected lamps which are frequently encountered in
the prior art. Besides, this simple structure of the lamps and the
simplified manufacturing method significantly lower the number of
manufacturing steps and time and as a result, the manutacturing
time and costs are accordingly lowered.
The foregoing description in conjunction with the accompanying
drawings illustrates an embodiment in which only two lens pieces
are joined. It should be understood, however, that the present
invention is not limited to said one embodiment. It should be also
understood that the present invention can be applied to a
combination lamp comprised of three lamps, for example, a
tail-lamp, a turn signal lamp, and a stop lamp without departing
from the spirit and scope of this invention. It should be
understood also that an embodiment has been described where each of
the side walls of these two lens pieces has two vertical dovetail
grooves and complementary vertical dovetail projections, but that
only one or more than two of these grooves and projections may be
formed. Therefore, needless to say, other variations and
modifications can be made also within the spirit and scope of the
present invention.
* * * * *