U.S. patent number 3,706,393 [Application Number 05/161,589] was granted by the patent office on 1972-12-19 for plastic container and method of making the same.
This patent grant is currently assigned to Pelorex Corp.. Invention is credited to George L. Curtis, Ralph E. Kelly, James H. Riesenberg.
United States Patent |
3,706,393 |
Curtis , et al. |
December 19, 1972 |
PLASTIC CONTAINER AND METHOD OF MAKING THE SAME
Abstract
A plastic container has a cylindrical body member and a bottom
member which are separately molded. The body member is formed with
an open bottom and has an annular groove in its bottom edge. The
bottom member has a pair of concentric upstanding annular flanges,
the outer one fitting within the annular groove in the bottom edge
of the body member, and the inner one fitting within the open
bottom of the container to abut the lower portion of the interior
wall thereof. The parts are permanently sealed to each other by
ultrasonic welding, usually after a bottom-filling operation with
the container in an inverted position.
Inventors: |
Curtis; George L. (Wilton,
CT), Riesenberg; James H. (Amherst, NY), Kelly; Ralph
E. (Lancaster, NY) |
Assignee: |
Pelorex Corp. (Buffalo,
NY)
|
Family
ID: |
22581830 |
Appl.
No.: |
05/161,589 |
Filed: |
July 12, 1971 |
Current U.S.
Class: |
220/613; 220/617;
220/DIG.31 |
Current CPC
Class: |
B65D
11/02 (20130101); B29C 65/08 (20130101); B65D
83/38 (20130101); B29C 66/12463 (20130101); B29C
66/542 (20130101); B29C 66/832 (20130101); Y10S
220/31 (20130101) |
Current International
Class: |
B29C
65/08 (20060101); B65D 83/14 (20060101); B65d
007/42 () |
Field of
Search: |
;220/66,67,4R,4A,4B,42D
;229/5.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Leclair; Joseph R.
Assistant Examiner: Garrett; James R.
Claims
We claim:
1. In a plastic container for pressurized contents, a body member
comprising a generally cylindrical wall formed with an open bottom
end and having a bottom wall member secured thereto, said body
member bottom end having an annular groove therein, said bottom
member having an annular flange formation fitting snugly within
said groove and a second concentric flange fitting within the said
bottom end of the container body with the outer surface of said
second flange in abutment with the lower portion of the interior
surface of said container body to reinforce the same against
external impact forces, said body member and said bottom member
being sealed to each other at least in the area of said first
flange formation.
2. A plastic container according to claim 1 wherein said sealing of
the body and bottom members extends from said first flange
formation inwardly and along at least part of the abutting surfaces
of second flange and the interior surface of the container
body.
3. A plastic container according to claim 1 wherein said members
are sealed by an autogenous weld.
4. A plastic container according to claim 1 wherein said members
are sealed by an ultrasonic weld.
5. A plastic container according to claim 2 wherein said members
are sealed by an autogenous weld.
6. A plastic container according to claim 2 wherein said members
are sealed by an ultrasonic weld.
Description
BACKGROUND OF THE INVENTION
This invention relates to the manufacture of plastic containers
and, more particularly, to plastic containers wherein the body
portion of the container is made with an open bottom and a bottom
wall is subsequently attached thereto.
Plastic containers molded by various methods such as injection
molding, blow molding, and otherwise, are of course in widespread
use.
In many plastic containers the bottom wall is molded integrally
with the side wall or body of the container but the present
invention relates particularly to containers wherein the container
body and the upper end or neck portion thereof are molded
integrally with the bottom end of the container open. In such
containers the bottom member is subsequently applied.
This type of container is employed in cases where the upper end
construction of the container has a relatively constricted neck
formation and wherein the body, including the upper wall structure,
is desired to be injection molded.
A particular area wherein containers with separate later-applied
bottom members are desirably employed is in the field of aerosol
containers wherein the contents of the container and the propellant
are deposited in the container with the same in inverted condition,
the contents and propellant being deposited in the container before
the bottom wall is applied.
In containers having separately applied bottom wall members, the
joint between the container body and the bottom wall is frequently
inadequate structurally and hermetically. When containers of this
kind are dropped, they commonly plummet downwardly bottom first and
usually land angularly on the bottom rim of the container with the
frequent result being leakage of the joint between the container
body and bottom. In fact the pressure of the contents under impact
dropping of the container as heretofore constructed sometimes blows
the bottom completely from the container body.
SUMMARY OF THE INVENTION
In the present invention the container body or side wall is
generally cylindrical and is formed about its lower edge with a
groove which receives an annular tongue formation on the bottom
element. This much is known in the present art and the container
construction of the present invention also includes an upstanding
annular flange on the bottom member which engages the lower
interior wall of the container body, and which in effect backs up
the tongue and groove joint to prevent loosening of this joint by
impact, as when the container is dropped. More importantly, this
upstanding flange prevents internal pressure in the container from
having direct access to the tongue and groove joint per se, which
joint has heretofore been the weakest point in container
constructions of this general type.
The bottom construction of the present invention, including the
tongue and groove joint and the additional internal flange which
rigidifies the same, is also highly effective in autogenously
welding the bottom to the container body as by ultrasonic vibration
of the parts since the parts are fixed to each other throughout the
tongue and groove construction, and also throughout at least a
portion of the abutting surfaces of the interior wall of the
container and the adjacent internal upstanding flange of the bottom
member.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a general elevational view of a plastic aerosol container
having a bottom wall construction in accordance with one form of
the present invention; and
FIG. 2 is an enlarged view of the lower portion of the container of
FIG. 1 shown inverted and partly in cross section to illustrate the
interfitting connection between the side wall of the container and
the bottom wall thereof.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
In FIG. 1 the numeral 10 designates a generally cylindrical
container body having a bottom wall member 11 and an aerosol
dispensing means 12 at the upper end thereof. FIG. 2 shows the
lower portion of the container of FIG. 1 on a considerably enlarged
scale and in an inverted position, in which position the container
is filled through its open bottom and then provided with the bottom
wall member of the present invention.
In the form shown in FIG. 2, the generally cylindrical side wall of
the container may be injection molded or otherwise formed of
plastic material and the side wall flares toward its lower edge to
provide a lower edge portion of increased thickness. An annular
groove 14 having flaring side walls is formed in the bottom edge of
container body 10 and groove 14 has an annular enlargement or
extension at its outer portion as shown at 15 in FIG. 2.
Bottom wall 11 has a tongue formation 16 which fits snugly into
groove 14 and an annular flange formation 18 which fits within the
wall of container 10 and abuts the lower interior portion of such
wall as shown in FIG. 2. The numeral 20 designates one of a series
of circumferentially spaced vertical grooves of generally
semi-circular cross section which are provided for purposes having
to do with the filling and evacuating of the interior of the
container and are not otherwise involved in the present
invention.
Excepting where interrupted by the grooves 20 the internal flange
18 seats against the interior wall of container 10 for
substantially the full height of flange 18. The tongue 16 and
annular flange 18 define in bottom 11 an annular groove which fits
over the flange or rib 21 at the bottom of container 10 at the
interior wall thereof adjacent to flaring groove 14.
Tongue and groove joints for container bodies are not broadly new
but the construction of the present invention differs therefrom in
providing the additional internal flange 18 which abuts against the
interior of container body 10 and thus stiffens the same and
militates against loosening of the tongue and groove joint 14, 16,
particularly against impact forces from the outside of the
container body and bottom as when the same is dropped.
In FIG. 2 the container is shown fragmentarily in the inverted
position after the material to be dispensed and the propellant have
been placed in the container through the open bottom and after such
other treatment as partial evacuation has been performed. Bottom
member 11 is shown in its finally assembled position ready to be
permanently sealed to body 10. The numeral 25 designates the horn
of an ultrasonic vibration apparatus by means of which the abutting
surfaces of the container body and bottom 10 and 11 are fused or
welded. Horn 25 in the present instance comprises a cylindrical
member having a radial end face which is pressed against bottom
member 11 to transmit ultrasonic vibration to the assembly and
produce the required welding.
This welding fuses all of the abutting surfaces of tongue 16 of
bottom 11 with groove 14 of body member 10 and ordinarily this
welding or fusion will extend approximately halfway along the
abutting surface of flange 18 and the interior of container 10. The
welding or fusing operation may produce a slight flash or roughness
at the edges of the welded surfaces and the auxiliary groove
portion 15, shown in FIG. 2, insures a smooth bottom finish for the
container even through some of the plastic material may ooze from
the welded surfaces as at the deepest part of groove 15.
A preferred embodiment of the present invention has been described
and illustrated herein to illustrate the principles of the
invention but it is to be understood that numerous modifications
may be made without departing from the broad spirit and scope of
the invention.
* * * * *