US 3085730 A
Description (OCR text may contain errors)
April 16, 1963 A. FIBISH 3,085,730
PLASTIC CONTAINERS Filed May 1, 1961 1N ENTOR.
United States Patent 3,085,730 PLASTIC CONTAINERS Arthur Fibish, Prospect Heights, 11]., assignor to Illinois Tool Works Inc, a corporation of Delaware Filed May 1, 1961, Ser. No. 106,619 4 Claims. (Cl. 2291.5)
This invention relates to containers, and more particularly to a thin walled plastic container especially useful as a drinking cup.
Disposable or throw away cups designed to be used in vending machines, and for other purposes in which the cup is to be used only once have generally been made of paper. Paper cups have variousdisadvantages, including taste, touch, and lack of complete liquid and vapor proof qualities even when waxed. Additionally, the glued seams which are inherently required in paper cups are often objectionable. For these, and other reasons, efforts have been made to produce disposable plastic cups. Such cups overcome the listed drawbacks of paper cups, but the material cost is somewhat higher.
One expedient for reducing or overcoming the inherently higher cost of plastic material is to use less of it. For a given size of cup, this means that the wall thickness of the cup must be reduced. Unfortunately, reduction in wall thickness results in a concomitant reduction in wall rigidity. This is of rather considerable importance in the larger size cups, say on the order of eight ounces or so capacity, wherein thin walls will readily tend to bulge or bow outwardly under the pressure of liquids in the cup, and conversely will tend to deflect inwardly under the pressure of fingers lifting the cup. Furthermore, cups and the like to be dispensed from automatic vending machines are subjected to a combined axial and torsional force during feeding within the machine to the liquid receiving station.
Accordingly, it is an object of this invention to provide a thin walled container, specifically a cup, requiring a lesser amount of plastic material for a wall of given rigidity.
More specifically, it is an object of thi invention to provide a plastic cup having embossments in the side wall thereof with vertical, horizontal, and diagonal components, whereby to stifien the wall in a plurality of directions.
Generally speaking, it is necessary to provide draft to allow shaped plastic articles to be withdrawn from a mold. This makes it difiicult to provide embossments in a circumferential wall, unless they can be arranged in stepwise fashion.
A further object of the present invention is to provide a plastic cup having an embossed side wall for stiffening the side wall, wherein advantage is taken of the inherent resiliency of the plastic material to facilitate withdrawal of the cup from a mold.
Other and further objects and advantages of the present invention will be apparent from the following description when taken in connection with the accompanying drawings wherein:
FIG. 1 is an elevational view of a cup constructed in accordance with the principles of the present invention, and in the original patent drawings on a scale just slightly larger than full scale;
FIG. 2 is an enlarged fragmentary elevational view approximately three times full scale showing details of the embossed side wall of the cup;
FIG. 3 is a horizontal sectional view through the side wall of the cup as taken substantially along the line 3-3 in FIG. 1, on an enlarged scale, approximately six times actual size;
FIG. 4 is a view similar to FIG. 3 but taken at a different elevation, as along the line 4-4 in FIG. 1; and
3,985,730 Patented Apr. 16, 1963 in accordance with the principles of the invention. The
cup is of generally frustoconical configuration having an outwardly tapering side wall 12 terminating at the upper end at :an open mouth surrounded by a radially projecting rim 14, preferably in the form of a rolled over lip. The bottom portion of the cup is provided with a stacking ring 16 of stepped configuration adapted for supporting one cup within another in stacked, telescoped relation.
The side wall 12 through the greater portion of its height is provided with an embossed herringbone or zigzag pattern of peripherally spaced alternate ribs 18 and valleys 20. The ribs project out beyond the nominal surface of the cup side wall, while the valleys are de pressed below the nominal surface at the uppermost portion thereof.
As may be seen particularly in FIGS. 2 and 7, each rib 18 has a rounded bottom end 22 projecting smoothly out from the subjacent section 24 of the side Wall 12. The rib extends diagonally up and to the right to a point of inflection 24, and then extends up and to the left to another point of inflection, etc. At the upper end, each rib 18 (FIGS. 2, 6 and 7) tapers back at 26 to the level of the immediately overlying surface 28.
Conversely, the valleys 20 (FIGS. 2 and 7) start out on a level with the underlying surfaces 24, and gradually extend inwards to the upper ends (FIG. 6) whereat they taper out at 30 to become flush with the overlying surface 28. The upper ends of the ribs 18 and valleys 20 form a more or less continuous line 32 extending peripherally about the cup. Although the cup is shown with this line spaced down from the rim or li 14, it is to be understood that this line could be positioned considerably closer, even substantially against the rim or lip 14.
Each rib 18 has a more or less flat outer surface 34, and conversely the floor 36 of each intervening valley is also substantially fiat. The upper side Wall of each rib section, referring to the direction of the top or open end of the cup, is at an obtuse angle to the more or less flat tops and bottoms 34 and 36 of the ribs and valleys respectively, such side Wall being indicated at 38. The opposite rib side walls 40, those on the lower side of each rib section relative to the upper end of the cup, are close to perpendicular relative to the rib tops 34 and valley bottoms 36.
. The disposition of the upper rib side wall 38 at a rather shallow angle relative to the cup surface is important in that it allows a cup tobe ejected from a female mold. The cup preferably is formed by a combination of mechanical and differential fluid pressure molding, and the ribs extend into complementary recesses in the female mold. Normally, this would tend to make the cup stick in the mold. However, with the shallow angle, as aforesaid, and with the inherent flexibility of the plastic materialof which the cup is made, the ribs simply cam or flex out of the recesses in the female mold as the cup is ejected axially upwards. The diverse angles of the upper and lower side walls of the ribs may also provide a somewhat great stiffening effect than with equal angles on both sides.
The rib configuration and inherent flexibility of the side walls, although greatly limited by the embossed ribs, militates against telescoped cups sticking together. In fact, it will generally be found that the stacking ring sections 16 cause adjacent telescoped cups to be offset sufliciently vertically that the rib sections in large measure cross one another, thereby avoiding any tendency for the ribs to nest within one another. The ribs have still a further advantage, particularly considering the crossed relation thereof in telescoped cups, of providing air passages for bleeding air into the lowest cup in a stack to allow ready feeding thereof from a vending machine. As will be apparent, if no provision were made for air to enter the space between adjacent telescoped cups, it would be extremely diflicult to separate them, and there would be substantially no tendency for gravitational dropping.
It has been found that production of a smooth walled cup having approximately nine fluid ounces capacity, and of a wall thickness suflicient to insure the requisite rigidity requires about seven grams of material. On the other hand, a cup of equal size constructed in accordance with the principles of the present invention, and with equal wall rigidity requires only about three and one half to four grams of the identical material. Such material preferably is polystyrene plastic. The wall thickness of a typical cup is on the order of .010 inch, and the apparent or overall wall thickness in the rib and valley area about doubles that of the inherent thickness of the wall.
The specific embodiment of the invention as shown and described herein is for illustrative purposes only. Various changes in structure will no doubt occur to those skilled in the art, and will be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.
The invention is claimed as follows:
1. A thin walled nestable plastic cup-like container made from a web of substantially uniform thickness material and comprising a bottom, and side wall having a substantially frustoconical configuration, said side wall being provided with a stacking ring spaced from the bottom of said cup, said side wall being provided at the other end of said cup opposite said bottom with a thickened lip portion intended to rigidify the side wall of said cup in the vicinity of the mouth of the container, at least a portion of the side wall intermediate said stacking ring and said thickened lip portion having impressed thereon an embossed herringbone pattern having a pluarlity of channel shaped ribs equally spaced circumferentially on said side wall, portions of said pattern extending radially outwardly beyond and other portions extending radially inwardly beyond a medial plane interconnecting the aforementioned thickened lip portion and said stacking ring and affording an apparent wall thickness substantially heavier than the web from which the container is fabricated, each rib of said embossed pattern having a zig zag configuration extending generally axially of the container with adjacent sections in each rib extending alternately on opposite sides of a vertical line running generally axially of said container and the material thickness of said bottom and side walls including said embossed patern being substantially uniform whereby said pattern substantially rigidifies said side walls against axial compression and torsional forces.
2. A device of the type claimed in claim 1 wherein each rib in said pattern includes in the portion of said pattern extending radially outwardly as viewed in trausverse section a flat top surface and two side edges, the side edge of each section of the rib which are disposed relatively toward the top of the container forming a shallow angle with a plane passing through said top surface and the aforementioned medial plane and the opposite side edge being disposed substantially normal to the top surface and medial plane whereby said container can be readily ejected from a female mold.
3. A device of the type claimed in claim 1 wherein the spacing and angular disposition of sections of adjacent ribs is controlled so that a vertical line placed on the side wall and lying generally parallel to the axis of the container will pass through sections of more than one rib whereby the overlying configuration of channel shaped ribs substantially rigidifies an otherwise weak and collapsable container.
4. A plurality of thin walled plastic cup-like containers adapted to be telescoped into stacked nested relation, each container being made from a web of substantially uniform thickness material and including a bottom and a side wall extending upwardly from said bottom, said side wall having a substantially frustoconical configuration, stacking means in said side wall spaced from the bottom of said container, said sidewall being provided at the end of said container opposite said bottom with a thickened lip portion intended to rigidify the side wall in the vicinity of the mouth of the container, at least a portion of the side wall intermediate said stacking ring and said thickened lip portion having impressed thereon an embossed herringbone pattern including a plurality of "channel shaped ribs equally spaced circumferentially about said side wall, portions of said pattern extending radially outwardly beyond and other portions extending radially inwardly beyond a medial plane interconnecting the aforementioned thickened lip portion and said stacking ring, each rib of said embossed pattern having a zig zag configuration of sections extending angularly first to the right to a point of inflection and then to the left to a point of inflection and continuing alternately to the terminal end of the rib, the zig zag rib extending generally axially of the container, adjacent sections in each rib extending alternately on opposite sides of an imaginery vertical line running generally axially of said container, said stacking means being adapted to maintain the bottoms of adjacent containers in spaced relation and causing the rib sections of adjacent cups to be offset sufliciently vertically so that a rib section of one cup extending angularly to the right will overlie a rib section of the next adjacent cup extending angularly to the left thereby preventing nesting of one rib within another and elimination of jamming of stacked containers, said channel shaped ribs providing passageways for air between adjacent cups to assist in the separation of the terminal container from a stack of nested containers.
References Cited in the file of this patent UNITED STATES PATENTS D. 18,225 Barr Apr. 3, 1888 2,352,205 Karlson June 27, 1944 2,905,350 Edwards Sept. 22, 1959 2,915,176 ONeil Dec. 1, 1959 2,967,652 Canfield et al Jan. 10, 1961 3,029,963 Evers Apr. 17, 1962 FOREIGN PATENTS 17,971 Great Britain 1894