US2885135A

US2885135A - Molded pulp container

Info

Publication number: US2885135A
Application number: US454443A
Authority: US
Inventors: Paul D Friday
Original assignee: PAPER MAID Inc
Current assignee: PAPER MAID Inc
Priority date: 1954-09-07
Filing date: 1954-09-07
Publication date: 1959-05-05
Anticipated expiration: 1976-05-05

Description

y 1959 P. D; FRIDAY I 2,885,135

MOLDED PULP CONTAINER Filed Sept. 7, 1954 2 Sheets-Sheet 1 7 '7- TUFNE 8 5 y 1959 P. D. FRIDAY I 2,885,135

v MOLDED PULP CONTAINER Filed Sept. 7, 1954 2 Sheets-Sheet 2 MOLDED PULP CONTAINER Paul D. Friday, Portland, reg., assignor to Paper Maid, Inc., Portland, 0reg., a corporation of Oregon Application September 7, 1954, Serial No. 454,443

4 Claims. (Cl. 229-25) This invention relates to improvements in containers or cartons, and more particularly to a container molded from paper pulp or the like for use in storing, shipping or merchandising food.

Objects of the present invention are to provide a container which is simple in structure and which can be molded from paper pulp at low cost; to provide a container which is molded integrally with a lid therefor; to provide a container having a lid structure and engageable means therefor which impart structural rigidity to said container and form an effective seal for the filler opening of said container; to provide a novel hinge means on a container which is molded integrally with said container and lid; to provide an improved lidded container of flat top configuration which permits stacking of a plurality of filled containers; to provide a container of the type described which is adapted, when empty, to nest readily with a quantity of other similar containers in order to facilitate shipping and reduce transportation costs; and to provide a container especially suited for the quick freezing of foods.

The present container is primarily intended for food and in one embodiment of the invention it is especially adaptable to quick freeze processes. The container is molded from a pulp material, such as waste paper pulp, and an important feature is that the body portion, lid and hinge thereof are molded integrally in a single operation. The lid is molded in an open horizontal position on the container, and has an indentation or depression therein to reinforce the lid and in turn to assist in reinforcing the container when the lid is closed. Other important features reside in the joint formed between the lid and the body portion and in the hinge structure which is molded integrally with the lid.

The invention will be better understood and additional advantages will become apparent from the following description taken in connection with the accompanying drawings which illustrate preferred forms of the device. It is to be understood, however, that the invention may take other forms and that all such modifications and variations within the scope of the appended claims which will occur to persons skilled in the art are included in the invention.

In the drawings:

Figure 1 is a perspective view of one form of the present container, showing the lid open in the position. in which the container is molded;

Figure 2 is a perspective view of the container with the lid partially closed;

Figure 3 is a perspective view of the container with the lid fully closed;

Figure 4 is a sectional view, taken on the line 4-4 of Figure 3, showing the sealed joint between the lid and body portion of the container;

Figure 4a is a sectional view taken on the line 4a--4a of Figure 1, showing the hinge structure;

Figure 5 is a perspective view of a modified form of the container;

Patented May 5, 1959 Figure 6 is a perspective view of the container of Figure 5 showing the lid thereof in closed position;

Figure 7 is a sectional view, taken on the line 7-7 of Figure 5; and

Figure 8 is a sectional view taken on the line 8--8 of Figure 6.

Referring first to Figures l-4a, a preferred embodiment of the present container comprises, in general, a body or receptacle'portion 10 and a lid structure 11. The body portion and lid are formed simultaneously in a single mold with the lid in horizontal open position as shown in Figures 1 and 4a. Body portion 10 has a front wall 12, rear wall 13 and side walls 14, these walls being inclined outwardly toward the top forming a tapered structure to facilitate stacking of a plurality of the containers one within another for storage or shipment prior to use. The lids of the containers may thus remain in their open horizontal position until the containers are put to use. It is understood that the receptacle also has a bottom wall, not shown.

The top edges of the front and

side walls

12 and 14, respectively, of the body portion 10 terminate in horizontal shoulders or

flanges

15 and 16, respectively. Lid 11 is formed with a shallow recessed center 18 having an inside depressed surface 19 closing the top of the container below the level of

flanges

15 and 16. Surrounding the recessed center 18 on its four sides are marginal walls 21 which are inclined at the same angles as the

container walls

12, 13 and 14. The marginal walls 21 connect with a peripheral flange 20 of the lid which is adapted to overlie the

container flanges

15 and 16.

In the form in which the article is molded the lid flange 20 forms a continuation of the container flanges 16 and a connecting portion 211a joins the lid with the container rear wall 13. A linear depression or groove 22 is molded into the underside of the connecting portion 20a in Figure 4a midway between rear wall 13 and the adjacent marginal wall 21 of the lid to form a fold line or hinge whereby the lid may be folded over on the line of depression 22 to close the container Without breaking the material. The depression 22 provides an extra length of material to bend around the convex edge of the fold without producing excessive tension in the material. To avoid weakening the material in the hinge a ridge may be formed on the top side of portion 20a which will maintain a substantially uniform thickness of material.

The outer dimensions of the Walls 21 around the depressed surface 19 are identical with the dimensions of the filler opening of the container, and when the lid is closed on the container the walls 21 are wedged into the container opening and thereby snugly engage the inner surfaces of the

Walls

12, 13 and 14. Flange 20 of the lid seats on the

flanges

15 and 16 of the body portion 1.0 and, together with the seal made by the Walls 21, forms a tight closure to prevent escape of contents of the container. The container and lid flanges may be stapled together and the joint may be further sealed with paraffin, wax or other adhesive if desired.

The tapered construction of the present container provides sufiicient vertical stiffness so that the containers, when in use and closed, can be stacked upon each other without danger of collapsing. Recess 18 is of a dimension to receive the bottom of a similar container seated thereon and furnishes strong support in stacking the containers in tiers. In addition, the recess 18 in the lid and the flange 15 on the

walls

12, 13 and 14 provide lateral reinforcement and protection to resist crushing forces which may act on the sides of the container.

The filled container is compact and economical of storage space and, for some purposes, may be used repeatedly. To make the container non-absorbent to liquids and moisture, the pulp slurry used for molding s,sss,1as

. 3 the container may be admixed with a water resistant sizing substance, or, if desired, the container may be coated with a water resistant substance subsequent to the molding process. 4 .4

A further embodiment of molded food container is shown in Figures 58. Similar to the embodiment of Figure: 1, this container comprises, in general, a body portion 25 and an integral lid 26 molded simultaneously in a single die. Body portion 25 has a front wall 27, rear wall 28 and side walls 29, these walls being inclined outwardly toward the top to form a tapered construction. On the top edge of front wall 27 and side walls 29 are outwardly olfset rim sections 32. A shoulder 33 is formed by the offset wall sections and forms a seat for the lid 26 in closed position.

Lid 26 is molded in an open horizontal position with the upper surface thereof being in the same plane as the upper edge of wall 28 and shoulder 33, Figure 7. i

The lid is molded with a continuous rectangulargroove or depression 35 on its upper or. inside surface, and a corresponding projection or ridge 36 on its under or outside surface. Groove 35 andridge 36 are: spaced inwardly from the side edges of the lid to provide rigidity for the lid. The ofiset wall portions 32 impart structural rigidity to the container walls, and when the lid 26 is closed. the container is quite rigid and is resistant to lateral forces which may be imparted thereon.

The hinge structure for this embodiment comprises a linear groove 38 and a corresponding ridge 39 which are molded in the lid closely adjacent the rear wall 28 of the body portion 25. Ridge 39 and groove 38 pro videa fold line which permits the lid to swing 180' to its closed position. In closing the lid, ridge 39 flattens out and disappears, as seen in Figure 8, and the curved wall of groove 38 similarly flattens out and forms a straight rear edge 40. With the excess length of material provided in the hinge joint, the lid can swing to closed position without tearing or cracking the material at the joint.

When the lid is closed, its marginal portions seat flat against the shoulder 33 and its front and side edge porplates which engage the upper and lower surfaces of the containers. When the containers are inserted between and flattened for permitting the upper freeze plates to contact the whole top surface of the lid in good thermal I conducting relation. This embodiment is also preferably treated as hereinabove described to make the pulp moisture resistant.

Both types of container nest together compactly with the lids in the open position shown in Figures 1 and 5 for convenience in shipping the empty cartons. The lids, being integral with the main parts, cannot become lost. In the molding process the integral lids materially reduce the cost of the manufacturing equipment and also the cost of handling and packaging for shipment. Further cost advantage is derived from the utilization of waste materials.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. A re-usable hinged lid container comprising integrally molded receptacle and, lid parts of fibrous pulp material, said lid and receptacle parts each having at least one straight side and being joined together therealong by a flexible connecting portion of said material forming a hinge along said straight side, said receptacle part having side walls and a substantially flat bottom, said side walls being slightly flared outwardly angularly from said bottom toward the mouth of said receptacle part, a lip around the mouth of said receptacle part extending outwardly and having a flat upper surface substantially parallel to said bottom, an angularly outwardly flared inner side surface on said receptacle part adjoining said flat lip surface, the underside of the marginal portions of said lid part being flat and adapted to seat flat against said receptacle lip when said lid part is closed over the mouth of said receptacle part, said lid part having a portion with a flared surface extending angularly outwardly toward the topside of said marginal portions thereof at substantially the same angle to the plane of said marginal flat underside as said outwardly flared receptacle surface adjoining said lip, said lid part flared portion being of such a size and configuration relative to said outwardly flared receptacle surface adjoining said lip for providing a snug ,wedging engagement of said flared surface thereof with said flared surface of said receptacle part adjoining said lip when said lid part is closed over the mouth of said receptacle part so as to hold said lid part closed in sealing engagementwith said receptacle part, and said flaring of said receptacle sides being of such size and configuration as to provide for compactly nesting a plurality of said containers in a stack with said lid parts thereof open.

2. A container as set forth in claim 1 in which said lid portion with a flared surface comprises a depressed wall portion formed in said lid part inwardly of said marginal portions and having an outer wall surface configuration mating the interior configuration of the mouth of said receptacle part.

3. A container as set forth in claim 1 in which said flared surface of said lid part comprises the peripheral edge of said lid part, and said outwardly flared inner side surface of said receptacle part adjoining said lip thereof comprises the inner surface of an outwardly flared flange extending peripherally around said. lip from adjacent to one end of said hinge to the other end thereof.

4. A container as set forth in claim 2 in which said depressed wall portion forms the perimeter of a shallow recessed area substantially in the center of the topside of said lid part and at least as large as the outside of the receptacle bottom providing for convenient stacking of closed containers.

References Cited in the file of this patent UNITED STATES PATENTS