U.S. patent number 3,902,628 [Application Number 05/288,707] was granted by the patent office on 1975-09-02 for plastic container hinge and latch.
This patent grant is currently assigned to The Plastic Forming Company, Inc.. Invention is credited to Peter T. Schurman.
United States Patent |
3,902,628 |
Schurman |
September 2, 1975 |
Plastic container hinge and latch
Abstract
Blow-molded plastic container body and cover parts are hinged
together by a cover joint formation integrally formed thereon and
received in a body trough formation having sockets at the opposite
ends thereof receiving hinge pins integrally formed at the opposite
ends of the cover joint formation. A tapered latch tongue formed
integral with the cover is received in snap-fitted engagement with
a tapered latch receiving formation on the body for releasably
latching the cover and body parts in closed position.
Inventors: |
Schurman; Peter T. (Woodbridge,
CT) |
Assignee: |
The Plastic Forming Company,
Inc. (Woodbridge, CT)
|
Family
ID: |
23108282 |
Appl.
No.: |
05/288,707 |
Filed: |
September 13, 1972 |
Current U.S.
Class: |
220/835;
220/844 |
Current CPC
Class: |
B65D
43/164 (20130101); B65D 2251/105 (20130101) |
Current International
Class: |
B65D
43/16 (20060101); B65d 043/10 (); B65d
043/16 () |
Field of
Search: |
;220/31S,31R,6R,306,307,343 ;24/28A,213R,224PS,224R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Ross; Herbert F.
Assistant Examiner: Shoap; Allan N.
Attorney, Agent or Firm: Christel & Bean
Claims
I claim:
1. A container comprising a body of thermoplastic material, a cover
of thermoplastic material hinged to said body for movement between
open and closed positions relative thereto, a latch member formed
integral with said cover, said cover being of double wall
construction and said latch member comprising a tongue of tapered
side wall form joined to a wall of said cover by a connecting
portion, said body being of double wall construction formed to
provide a tongue receiving recess in a wall thereof, said recess
being of tapered side wall form corresponding to the tapered side
wall form of said tongue, the side walls of said recess being
undercut and the side walls of said tongue having snap-fitting
engagement with said undercut recess side walls for releasably
confining said tongue within said recess, said tongue and said
recess being tapered toward said cover and coacting when engaged to
releasably latch said cover in closed position.
2. A container as set forth in claim 1, wherein said latch member
is of single wall form whose position of repose is closely adjacent
its position of latching engagement within said recess.
3. A container as set forth in claim 1, said body being formed to
provide a pair of opposed shoulder portions along the outer edges
of said recess side walls and projecting into said recess to form
said undercut therebehind.
4. A container as set forth in claim 3, said tongue side walls
having laterally projecting beads for snap-fitting past said
shoulder portions into said undercut.
5. A container as set forth in claim 1 wherein said connecting
portion is formed integral with the upper end of said tongue and
with said cover wall and positions said tongue just outside of said
recess in its natural condition of repose, said connecting portion
providing a hinge about which said tongue is pivoted through
relatively small angular movements between latching and unlatching
positions.
6. A container as set forth in claim 1 wherein said tongue has a
thickness greater than the wall thickness of said cover portion and
of progressively increasing thickness from said connecting portion
to the free end thereof.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to the plastic container art, and
more particularly to a new and improved hinge joint and latch for
joining blow molded cover and body parts and latching them together
in closed position.
The forming of separate container bodies and covers offers certain
advantages in production and also enables merchandise to be
shrink-wrapped in the body prior to assembly of the cover.
Moreover, the body and cover can be formed of different materials
and colors, as desired. Blow molding such container parts to form
double wall constructions also is desirable from various parts of
view. For example, the double wall construction provides a
cushioned arrangement wherein the inner wall can be shaped to form
pockets conforming generally to the shape of the articles to be
received therein for packaging. However, a problem arises in
hinging such blow molded parts together, particularly in heavy duty
applications. While such parts can be separately pinned it is
advantageous, where possible, to provide a selfcontained hinge
construction which can be quickly and easily assembled by either
the molder or the packager without need for complex tooling.
Problems also are encountered in providing a suitable latch for
such hinged container parts. Where the latch is formed separate
from the container parts, an additional assembly step is involved,
adding to production costs. While this can be avoided by molding
the latch integral with one of the container parts, problems remain
in providing a latch of sufficient strength and durability without
imposing undesirable design limitations.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to provide an improved
hinge joint formed integral with blow molded container parts which
facilitates assembly without complex tooling, contemplates a wide
range of container styling variations, provides a substantially
continuous or closed hinge construction to enhance container
appearance, and provides a positive stop for the container cover in
an open position.
Another object of this invention is to provide an integral latch
construction for blow molded container parts which has excellent
latching action and securing characteristics, is only moderately
stressed during movement between the latched and released
positions, and which is esthetically extremely pleasing.
In one aspect thereof, a plastic container of the present invention
is characterized by the provision of a blow molded cover having
formed as an integral part thereof a pair of hinge pins and a joint
formation extending therebetween, and a body having spaced apart
hinge pin receiving means and a trough formation extending
therebetween receiving the cover joint formation in assembled
relation. In another aspect thereof, a plastic container of this
invention is characterized by the provision of a latch tongue of
tapered side wall form integral with one container part and having
snap-in engagement with a recess of tapered side wall form on the
other container part for securing the container in closed
position.
The foregoing and other objects, advantages, and characterizing
features of the present invention will become clearly apparent from
the ensuing detailed description of an illustrative embodiment
thereof, taken together with the accompanying drawings wherein like
reference numerals denote like parts throughout the various
views.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a top plan view of an illustrative container embodying
the present invention, in closed position;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a side elevational view thereof;
FIG. 5 is a vertical sectional view, on an enlarged scale, taken
about on line 5--5 of FIG. 1, showing the container in a fully
opened position;
FIG. 6 is a fragmentary front elevational view, on an enlarged
scale, showing container in an open position with the latch
disengaged;
FIG. 7 is a view similar to FIG. 6 but showing the container in
closed position with the latch fully engaged and locking the
container parts closed;
FIG. 8 is a fragmentary top plan view of the container body,
looking in the direction of arrows 8--8 in FIG. 7;
FIG. 9 is a fragmentary horizontal sectional view, taken about on
line 9--9 of FIG. 6;
FIG. 10 is a fragmentary horizontal sectional view, taken about on
line 10--10 of FIG. 7;
FIG. 11 is a fragmentary top plan view, partially in section, on an
enlarged scale, showing the hinge joint formation of this
invention;
FIG. 12 is a fragmentary top plan view, on an enlarged scale, of
the container body, showing the hinge trough formation therein;
FIG. 13 is a transverse, cross sectional view, on an enlarged
scale, taken about on line 13--13 of FIG. 1 parts being broken away
in FIGS. 11, 12 and 13 for convenience in illustration; and
FIG. 14 is a fragmentary vertical sectional view, taken about on
line 14--14 of FIG. 11.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
The illustrative container depicted in the accompanying drawings
comprises a base or body, generally designated 20, and a lid or
cover therefor, generally designated 21. Body 20 is formed of a
suitable thermoplastic material blow-molded into the desired shape
and having a hollow, double wall construction formed by an outer
shell 22 (FIGS. 5 and 13) comprising opposite side walls 23, a
front wall 25, a rear wall 26 and a bottom wall 27, and an inner
shell 28 formed to provide a generally recessed compartment (FIGS.
5 and 13) within outer shell 22 in spaced relation thereto except
adjacent the edge portions thereof where it is connected to the
upper edge of the outer shell. If desired, inner shell 28 can
extend across the upper end of outer shell 22 and can be
compartmented or provided with pockets for receiving variously
shaped articles therein. Also, after body 20 is removed from the
mold, one or more portions of inner shell 28 can be cut-away, as
desired, to provide access to the interior of body 20 between the
inner and outer shells for storage or any other purpose.
Cover 21 also is formed of thermoplastic material blow-molded into
a hollow, double wall construction defined by an outer shell having
opposite side walls 30, a rear wall 31, a front wall 32 and a top
wall 33, and an inner shell extending across the outer shell in
spaced relation thereto except adjacent the edge portions thereof
where it is connected thereto. The cover inner shell has a top wall
35 formed to provide a recessed compartment 36, front and rear
walls 37, 38 and opposite side walls 40. A generally horizontal
ledge 41 extends outwardly from the outer ends of front wall 37 and
side walls 40 and connects the cover inner shell to the outer shell
thereof.
The outer shell of body 20 is formed to provide an outwardly offset
band 42, extending horizontally around body 10 adjacent the upper
end thereof and the juncture of the outer shell 22 with inner shell
28. The inner shell 28 is formed, adjacent its connection with the
outer shell band 42, with a raised shoulder 43 (FIG. 5) extending
inwardly from the upper edge of band 42 and terminating at its
lower end in a generally horizontal ledge 45 which extends about
the upper inner edge of body 10 and against which cover ledge 41
abuts when cover 21 is closed. Thus, the parting line between cover
21 and body 20 at the abutting ledges 41 and 45 is disposed below
and concealed by the upper edge of band 42, thereby creating an
attractive container appearance.
An important feature of this invention resides in the provision of
a closed hinge joint all parts of which are formed with and as an
integral part of either the body or the cover. To this end, a
trough formation 46 of a generally U-shaped transverse
configuration is provided along the upper rear edge of body 20
between ledge 45 and the upper end of band 42. As shown in FIGS. 5
and 13, trough formation 46 is a channel defined by an inclined
outer wall 47 joined to the upper edge of band 42, a stepped inner
wall 48 extending downwardly from the outer edge of ledge 45, and a
bottom wall 50 connecting the outer and inner walls 47 and 48.
Stepped inner wall 48 as shown in FIG. 13 consists of a vertical
portion 48a, an inclined portion 48b and a short ledge or step
portion 48c. Elements 48b, 50 and 47 form a trapezoidal channel in
trough formation 46.
A pair of hollow, bulbous formations or sections 51 are formed
integral with the upper, rear edge of body 20 at the opposite ends
of trough 46 and are provided with openings 53 through the inner
transverse walls thereof which are upstanding at the opposite ends
of trough 46 to define inwardly opening sockets 52 therein (FIG.
11) aligned with trough 46 for receiving cover hinge pins,
hereinafter described. The inlet openings of sockets 52 are defined
by annular walls 55 which serve as hinge pin bearings in the
assembled relation.
Container cover 21 is provided with an elongated joint formation 56
formed integral with cover 21 along the lower rear edge thereof. As
shown in FIGS. 5 and 13, joint formation 56 is hollow and is formed
in part by the outer portion of the inner shell rear wall 38 and an
arcuately curved wall portion 57 connected to outer shell rear wall
31 by a straight wall portion 58. A pair of coaxially aligned
hollow hinge pins 60 also are formed integral with joint formation
56 and project axially outwardly from the opposite ends thereof so
as to be oppositely directed. Wall portion 57 is curved on a radius
about the axis of hinge pins 60, such radius being larger than the
radius of hinge pins 60.
When cover 21 and body 20 are assembled, the cover joint formation
56 is received in trough formation 46 and hinge pins 60 project
through openings 53 into sockets 52 the walls 55 of which serve as
hinge pin bearings when cover 21 is swung between open and closed
positions. In assembling cover 21 to container body 20, the
inherent resiliency of the plastic material of which body 20 and
cover 21 are formed permits both to be flexed sufficiently to allow
the passage of hinge pins 60 past the opposed faces of socket
formations 57 and into sockets 52 for pivotal engagement therein.
Thus, cover 21 is easily attached to body 20 by a simple mechanical
fixture without the use of complex tooling and without need for
hinge parts separate from the molded container parts. When cover 21
and body 20 are assembled, joint formation 56 extends into trough
46 for the full length thereof between sockets 52. As shown in FIG.
13 the configuration of the arcuate curved wall portion 57 of the
joint formation 56 is such that when the cover is closed, portion
57 is located in the channel defined by walls 48b and 47 and bottom
wall 50. When the cover is raised as shown in FIG. 5, arcuate
curved wall portion 57 contacts vertical wall portion 48a, inclined
portion 48c and bottom wall 50. Thus the configuration of joint
formation 56 is such that a portion of the full length thereof is
disposed within the channel of trough formation 46, below the upper
plane of body 20, at all positions of cover 21. This, together with
the concealment of hinge pins 60 within sockets 52 effects a
substantially continuous hinge joint which, as viewed from the
inside or open position of the container, is closed at all times
during opening and closing of cover 21, as clearly apparent from
FIGS. 5 and 13. This closed hinge construction eliminates the usual
gap or open spaces commonly found between the bodies and covers of
conventional containers in an open position and greatly enhances
the appearance of the container. Furthermore, this closed hinge
construction permits numerous container styling variations to be
made without detracting from the overall appearance of the
container.
Another advantage residing in the closed hinge construction of this
invention is in the provision of a positive stop for cover 21 at a
predetermined open position. As shown in FIG. 5, the inwardly
offset orientation of outer shell rear wall 31 relative to arcuate
wall portion 57, together with the upper recessed edge 61 of band
42 along the rear end of body 20, enables cover 21 to be swung past
90.degree., for example to about 120.degree., for more convenient
access into body 20. However, at the full open position, rear wall
31 engages the recessed edge 61 of band 42, limiting further
opening of cover 21. The flat rear wall 38 of the cover inner shell
provides clearance assuring proper closing of cover 21 without
interference with any other portion of body 20. Hinge pins 60 are
of relatively large diameter, several times the wall thickness of
the container, for greater bearing area and strength.
Another significant feature of the present invention resides in the
latching arrangement provided thereby. As shown in FIGS. 6-10 and
13, a latch member, generally designated 62, is formed integral
with the lower edge of cover front wall 32 for reception into an
associated latch receiving means, generally designated 63, provided
along the upper portion of body front wall 25 for releasably
locking cover 21 to body 20 in closed position. It should be
appreciated that in larger, heavier container constructions, two or
more latches with corresponding latch receiving means can be
provided, as desired.
Latch member 62 comprises a tongue 65 of a generally trapezoidal
outline having tapered side edges extending toward cover 21 in a
converging relation and joined to cover 21 by a connecting flange
portion 66 formed integral with the upper end of tongue 65 and with
the lower edge of cover front wall 32. Flange 66 projects forwardly
of cover front wall 32 and serves as a pivotal, hinge connection
for swinging tongue 65 through relatively small arcuate movements.
Tongue 65 is provided with a pair of inturned side walls 67
extending substantially the length of the tapered side edges
thereof and of progressively increasing width from the upper end of
tongue 65 to the bottom end thereof. Also, the wall thickness of
tongue 65 progressively increases from the top to the bottom
thereof. Cover 21 and body 20 are blow molded, as by trapping a
portion of a parison of thermoplastic material between a pair of
mold sections and expanding the same into conformance with the mold
faces, in a manner well known in the art. Tongue 65 is formed with
cover 21 by compressing together opposite wall portions of the
trapped material during the blow molding operation to form a tongue
wall which is thicker, in part at least, than the individual wall
thickness of the trapped material or the walls of the finished
container parts. Each side wall 67 is formed with a laterally
projecting bead or protuberance 68 for a purpose to the
explained.
The upper central portion of container body front wall 25 is formed
with a slight recess, as defined by a generally vertical wall
surface 70 (FIG. 13) terminating at its upper end in an outwardly
directed ledge 71 having a central recess 72 therein (FIG. 8).
Also, the outwardly offset band 42 is discontinuous adjacent the
central portion of body front wall 25, forming a recess 73 defined
by a pair of axially spaced, tapered walls 75 extending inwardly to
the plane of vertical wall surface 70 to form the latch receiving
means 63 of this invention. Walls 75 are inclined toward cover 21
in a converging relation corresponding to the tapered side edge
form of tongue 65 to accommodate the latter in the latched
position. A pair of shoulders 76 are formed at the juncture of band
42 with walls 75 and have outer portions 77 projecting forwardly
out of the plane of band 42 and inner edge portions 78 projecting
inwardly from walls 75 into recess 73 to provide undercut recesses
in the side walls defining recess 73. These undercut shoulders 76
are blow molded with and as an integral part of container body 20
and complete the latch receiving means 63 of this invention.
When cover 21 is pivoted into a closed position with the cover
ledge 41 confined within band 42 and abutting container body ledge
45, tongue 65 lies in its normal plane of repose with the major
portion thereof disposed outwardly of recess 73 and with locking
beads 68 positioned adjacent the outer portions 77 of shoulders 76,
as shown in FIG. 13. In order to latch cover 21 in this closed
position, tongue 65 is depressed toward body 20, and pivoted
inwardly into recess 73 about a horizontal axis defined at the
juncture of connecting flange 66 and the lower end of cover front
wall 32. The inherent resiliency of the plastic material forming
the latch permits the passage of beads 68 past the inwardly
directed portions 78 of shoulders 76 and into the undercut recess
73 behind shoulders 76 with a snap-fit engagement (FIG. 10), the
inner portions 78 of shoulders 76 resiliently yielding and
deforming to permit snap passage of beads 68 through the restricted
inlet defined between shoulder inner portions 78. Once assembled,
the engagement of beads 68 behind shoulders 76 precludes accidental
removal of latching tongue 65 from recess 63. Any force tending to
move cover 21 upwardly, away from container body 20, is resisted by
the wedging coaction between the tapered walls 75 of band 42 and
the inclined side walls 67 of tongue 65, and tends to more securely
lock tongue 65 in place.
When latch member 62 is in the latched position with tongue 65
within recess 73 and beads 68 engaged behind shoulders 76, latch
member 62 lies closely adjacent its natural plane of repose whereby
it is not under any significant stress. Ledge 71 offers a measure
of support to latch portion 66 in latched position. Latching beads
68 are snapped past shoulders 76 by depressing or lifting tongue 65
to latch and release the container cover 21. In the latched
position, the lower edge of tongue 65 is sufficiently spaced from
the vertical wall surface 70 to permit insertion of the user's
thumb or finger to readily lift or release tongue 65 from recess
73. As shown in FIG. 13, tongue 65 extends at about a right angle
to the connecting hinge 66 which is molded at a slight, e.g.
20.degree. upward angle to cover ledge 41, whereby in its natural
condition of repose tongue 65 just clears the associated body
portions 76 as cover 21 is moved into closed position. Tongue 65
therefore is flexed through a relatively small or angle during
latching and unlatching movement thereof so as to produce only a
minimum of stress and strain thereon. Moreover, this short pivotal
movement facilitates dimensional accuracy in positioning tongue 65
in the desired holding position. As a result, latch member 62 is
assured a relatively long useful life, assuming normal usage
thereof, and requires only to be formed of a suitable tear
resistant material, such as polyethylene or polypropylene, for
example, having a long flex life.
The container parts, including the hinge joint and the latch, can
be made of any suitable thermoplastic material, such as high
density polyethylene and polypropylene, which are given by way of
example only. It should be understood that the hinge joint and
latch of this invention are not dependent upon or limited to use
with each other, nor are they intended to be limited in use with
the specific container described and illustrated, but have utility,
whether taken together or separately, in a wide variety of
applications where it is desired to hingedly mount one part to
another and/or releasably latch them together.
Also, it will be appreciated that the foregoing detailed
description is given by way of illustration only, and that trough
46, for example, can be of curved rather than straight wall
form.
From the foregoing, it is apparent that the objects of the present
invention have been fully accomplished. There is provided an
improved closed hinge construction formed integral with the
container parts for simplicity and enhancing the appearance of the
container while permitting a wide range of container styling
variations. A latch member is formed integral with the cover and
offers improved latching action while permitting a wide range of
styling variation.
* * * * *