BLOW MOLDING METHOD AND ARTICLE

METHODE ET ARTICLE DE MOULAGE PAR SOUFFLAGE

English Abstract

ABSTRACT OF THE DISCLOSURE
Blow molded plastic articles such as solvent containers
for use in motor vehicles are often equipped with lugs for
mounting the articles in the vehicles. In order to avoid problems
when removing the articles from the mold, the usual practice is
to mold the lugs separately, incorporate the lugs into the mold
prior to blow molding, and to blow mold the articles with the
lugs on the parting line of the mold, i.e. the line where the
mold halves meet to define the mold cavity. This limits the
design of the blow molded articles, and severely slows down
production, since each molding cycle must be interrupted to insert
the lugs. A solution to the problem is to blow mold the articles
with grooves for receiving separately molded mounting lugs. Thus,
there is no need to reduce production speed, and the grooves
can be provided at locations other than the parting line.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:
1. A method of producing a plastic article of the
type including a plastic mounting lug comprising the steps of
blow molding the article in a mold containing a projection for
defining groove means in an outer surface of the article;
separately molding the plastic mounting lug; and attaching the
mounting lug to the groove means of the blow molded article.
2. A method of producing a plastic container for
mounting in a motor vehicle comprising the steps of blow
molding the container in a mold containing a projection for
defining groove means in an outer surface of the container;
separately molding a plastic lug for mounting the container in
a motor vehicle; and attaching the lug to the groove means of
the blow molded container.
3. A plastic article for mounting in a fixed location
comprising hollow, blow molded plastic body means; groove
means in an outer surface of said body means; separate plastic
lug means insertable in said groove means for securing said
body means in a fixed location; a recess in said groove means;
and a projection on said lug means complementary to said
recess for locking said lug means in said groove means.
4. An article according to claim 3, including
shoulder means on at least two sides of said groove means; and
flange means on said lug means, whereby, when said lug means

in slid into said groove means, the lug means is retained
thereby.
5. A plastic solvent container for mounting in a
motor vehicle comprising hollow, blow molded plastic body
means; groove means in an outer surface of said body means;
separate plastic mounting lug means insertable in said groove
means for securing said body means in the motor vehicle; a
recess in said groove means; and a projection on said lug
means complementary to said recess for locking said lug means
in said groove means.
6. A container according to claim 5, including
shoulder means on at least two sides of said groove means; and
flange means on said lug means, whereby, when said lug means
is slid into groove means, the lug means is retained thereby.
7. A container according to claim 5 or 6, wherein
said lug means includes an elongated planar body; and a base
perpendicular to said body defining said flange means for
sliding engagement with said groove means.

Description

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This invention relates to a method of producing a
plastic article and to a plastic article produced by such method.
; ` More specifically, the invention relates to a method of
blow molding a plastic article of the type including a lug for
mounting the article in a fixed position or location, and to the
article thus produced.
The invention was originally intended to faciLitate the
production of solvent containers for use in motor vehicles.
- However, it will be readily apparent that the invention can be
10 used for producing other molded plastic articles such as dash
assemblies or instrument panels, or molded duct components. For
; the sake of simplicity, the following description is limited to
the production of a solvent container.
In general, solvent containers of the type used in
motor vehicles are produced by blow molding the body of the
container in a mold includ1ng two mold halves, which together define
a mold cavity having the shape of the finished container. When
a mounting bracket or lug is to be incorporated in the container,
the lug is molded separately, and then placed on one of the mold
~20 halv s before each blow molding operation. In other words, the
molding cycle must be~interrupted to insert each bracket or lug,
which severely slows down machine operation. Any bracket or lug
molded during a blow molding operation must be located on the
parting line of the mold. Otherwise, it would be difficult if
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not impossible to remove the molded article from the mold following
blow molding.
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An object of the present invention is to overcome the
above-identified problems by providing a relatively simple method
of produclng a plastic article which permits the incorporation of
a mounting bracket or lug at any location on the article, and
which permits relatively rapid molding of articles.
Anothex object of the invention is to provide a hollow,
; blow molded plastic article incorporating a groove in the outer
surface thereof, and a separate mounting lug for insertion into
the groove.
Accordingly, the present invention relates to a
method of producing a plastic article of the type including a
mounting lug comprising the steps of blow molding the article in
a mold containing a projection for defining groove means in an
~; outer surface of the article; separately molding the mounting lug;
and attaching the mounting lug to the groove means of the blow
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moIded article.
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The invention also relates to a plastic article for
mounting in a fixed location comprising hollow, blow molded body
~ means; groove means in an outer surface of said body means; and
-~ 20 ~separate lug means insertable in said groove means for securing
said body means in a fixed location.
~` The invention will be described in greater detail with
- reference to the accompanying drawing, which illustrates a preferred
embodiment of the invention, and wherein:
Figure 1 is a perspective view from one end and one
side ofa solvent container in accordance with the present invention;
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Figure 2 is a perspective view of the container of
Fig. 1 from the other end and a second side;
Figure 3 is an exploded perspèctive view of a bracket
and a portion of the container of Figs. 1 and 2;
5Figure 4 is a cross-sectional view of the bracket of
Fig. 3 attached to the container.
Referring to the drawing, a solvent container of the
type produced in accordance with the present invention includes
a molded plastic body 1, which is provided on one side with a
generally semicylindrical recess 2 (Fig. 2) for receiving a mounting post
(not shown). A hollow, cylindrical projection 3 extends outwardly
from a second side of the body 1. A hole is cut in the projection
3 for introducing solvent into the containex. A lug 5 extends
outwardly from one end of the body 1 for securing the container in
lS a fixed position. The lug 5 is molded along the parting line of
the mold, i.e. at the location where the two halves of the mold
~1~meet to form a mold cavity. The parting line of the mold defines
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a parting line 6 on the body 1 of the container. The parting line
6~, which is a thin ridge of plastic, extends roughly diagonally
20 ~ across the ends 8~and 9 of the body 1, and along two diametrically
opposed edges 10 and 11 of the body 1.
~; During normal blow molding operations, the location of
the lug 5 is dictated by the parting line of the mold. Any lug
5 or other projection must be molded on such parting line. Otherwise,
it is very difficult if not impossible to remove the finished
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container from mold, particularly when the lug 5 is long.
The above-identified problem is overcome by the mounting
bracket structure and method of the present invention. In
accordance with the present invention a mounting bracket generally
indicated at 14 is molded separately in an injection molding
step, and the body 1 of the container is blow molded with a groove
15 for receiving the bracket 14.
The bracket 14 includes an elongated, planar body 16
with an opening 18 in the outer end thereof for receiving a bolt
or screw (not shown). The bracket 14 is generally L-shaped in
cross section and includes a base 19 integral with the body and
connected thereto by triangular gussets 20. The sides 22 of the
base 19 extend outwardly beyond the sides of the body 16, and
~; one end 23 of the base 19 extends outwardly beyond the plane of
~; 15 ~the body 16. Thus, when the base 19 is slid into the groove 15,
the edges or flanges 22 and 23 slide under and are retained by
a shoulder 25 extending around the periphery of the groove 15.
A triangular depression 26, with a vertical outer edge 28 is provided
in the base of the groove 15 for receiving a triangular projection
~9 on the base 19 of the bracket 14. Thus, once the bracket is
~ slid into place in the groove 15, the bracket cannot readily be
;~ removed, i.e. the depression 26 and projection 29 define a locking
device.
By providing a groove in the body 1 of the blow molded
container, and a separately molded bracket 14, the bracket can be
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located at virtually any position on the body l. It is no longer
necessary to mold the bracket on the parting line of the body
1, or to slow down production while a separately molded bracket
~: is inserted into a mold half before effecting each blow molding
S operation.
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Representative Drawing