US3157322A

US3157322A - Dispensing unit and method of producing the same

Info

Publication number: US3157322A
Application number: US138072A
Authority: US
Inventors: Bernhardt Rudolph
Original assignee: Nibot Corp
Current assignee: Nibot Corp
Priority date: 1961-09-14
Filing date: 1961-09-14
Publication date: 1964-11-17
Anticipated expiration: 1981-11-17

Description

1964 I R. BERNHARDT 3,

DISPENSING UNIT AND METHOD OF PRODUCING THE SAME Filed Sept. 14. 1961 2 Sheets-Sheet 1 3 FIG! 40 3 F| 5. 2 42 INVENTOR. RUDOLPH BERNHARDT ATTORNEYS Nov. 17, 1964 R. BERNHARDT DISPENSING UNIT AND METHOD OF PRODUCING THE SAME Filed Sept. 14, 1961 2 Sheets-Sheet 2 FIG. IO

INVENTOR.

RUDOLPH BERNHARDT United States Patent This invention relates to dispensing units such as those for placement on containers from which fluent materials including liquid and liquid suspensions and granular materials are to be poured and, more particularly, to integral one-piece self-closing dispensing units of resilient plastic material and to an improved method of producing such dispensing units.

It is the custom today in many restaurants and in certain homes to place sugar, cream, syrup and the like on the dining table so that each person can season and apply these materials to the food as he eats it at the table. For the sake of convenience and to minimize contamination and spoilage, these materials are conveniently placed in containers equipped with dispensing tops of the self-closing type having closures which are normally biased closed but which can be manually operated to provide a dispensing opening through which the contents of the container can be applied to food by the user. Self-closing dispensing tops available heretofore have in general been relatively complicated in that they comprise a plurality of parts and further have a structure and configuration such that there are areas which can be cleaned only with difliculty, thus rendering them less than satisfactory for sanitary reasons. Furthermore, the self-closing dispensing tops provided heretofore have been relatively expensive and have been produced and assembled by methods which also are relatively expensive.

Accordingly, it is an important object of the present invention to provide an improved dispensing unit of the self-closing type that is of integral and one-piece construction.

Another object of the invention is to provide an improved integral one-piece self-closing dispensing unit that is formed of a resilient plastic material.

Yet another object of the invention is to provide a dispensing unit of the type set forth which can be easily cleaned after use and which is substantially free of entrapping pockets or cracks in which decaying food and bacteria can be trapped.

Still another object of the invention is to provide an improved dispensing unit of the type set forth which can be easily produced from resilient plastic materials using inexpensive methods of production.

A further object of the invention is to provide an im proved method of making an integral one-piece self-closing or self-restoring dispensing unit of resilient plastic material.

Further features of the invention pertain to the particular arrangement of the elements of the dispensing unit and to the particular sequence of the method steps, whereby the above-outlined and additional objects and operating features thereof are attained.

The invention, both as to'its organization and method of operation together with further objects and advantages thereof, Will best be understood by reference to the following specification taken in connection with the accompanying drawing, wherein like reference numerals have been used to designate like parts throughout, and in which:

FIGURE 1 is a side elevational view of a dispensing unit made in accordance with and embodying the principles of the present invention, the dispensing unit being shown mounted on an associated container for fluent material and the closure flap being illustrated in closed position thereof;

FIG. 2 is a side elevational view similar to FIG. 1 and showing the thumb of a user on a handle of the closure flap, the closure flap having been moved to the open or dispensing position thereof;

FIG. 3 is a top plan view of the dispensing unit illustrated in FIG. 1, the dispensing unit having been removed from the associated container;

FIG. 4 is a bottom plan view of the dispensing unit of FIG. 3 with the closure flap moved to the position of FIG. 2;

FIG. 5 is an enlarged view in vertical section, as seen in the direction of the arrows along the line 5-5 of FIG. 3, the closure flap being shown in the closed position in solid lines .and being shown in the position as molded in dashed or broken lines;

FIG. 6 is a view in vertical section of a molding die useful in producing the dispensing unit of the present invention, the molding die being shown in the closed posithe . tion and having a freshly molded dispensing unit enclosed therein;

FIG. 7 is an exploded view of the parts illustrated in FIG. 6 and showing the dispensing unit removed from the molding die;

FIG. 8 is a side elevational view of another embodiment of the dispensing unit of the invention;

FIG. 9 is a top plan view thereof;

FIG. 10 is a vertical longitudinal sectional view thereof, as seen in the direction of the arrows along the line 1010 of FIG. 9, theclosure flap being shown in the closed position in solid lines and in the open position in dashed lines;

FIG. 11 is an enlarged fragmentary vertical cross-sectional view thereof, as seen in the direction of the arrows along the line 11-11 of FIG. 9;

FIG. 12 is an enlarged vertical longitudinal sectional view similar to FIG. 10, with the closure flap shown in its position as molded; and

FIG. 13 is a further enlarged fragmentary sectional view of the closure flap and associated structure as indicated by the number 13 in FIG. 12, illustrating the hinged connection of the parts.

Referring to FIG. 1 of the drawings, there is shown one embodiment of a dispensing unit generally designated by the numeral 10, in operative position on a container 12 for fluent materials such as sugar, cream, syrup and the like, the dispensing unit 10 being made in accordance with and embodying the principles of the present invention. The container 12 is typically formed of glass or plastic and is provided at the upper end thereof with an upstanding neck 14 that is cylindrical in form and is provided with external threads. (not shown) for the attachment of the dispensing unit 10 thereto.

The dispensing unit it) is formed of a resilient synthetic organic plastic material, such for example, as polyethylene or polypropylene resin, .and is formed as an integnal onepiece unit. From FIGS. 3, 4 and 5 of the drawing, it will be seen that the dispensing unit 10 comprises generally a circular- .collar 20 which has an internal diameter such that it can receive the neck 14 of the associated container therein and further is provided with integral internal threads 22 that receive and cooperate with the threads on the container neck 14, whereby firmly to mount the dispensing unit 10 on the container 12. An outwardly extending reinforcing flange 24 is formed around the bottom of the collar 20 as viewed in FIG. 5 and there also are provided on the collar 20 outwardly extending embossments 26 which facilitate gripping by the user when applying the dispensing'unit 10 to the container 12 and when removing it therefrom.

Extending upwardly from the collar 20 and completely thereanound is a closure wall 27 which includes an in- Wardly inclined upstanding circumferential side wall 28 having a small vertical extent on the rear side of the dispensing unit 10, i.e., to the right as viewed in FIGS. 1, 2, and 5 of the drawing and has a substantial vertical extent on the front of the dispensing unit 10, i.e., to the left as viewed in FIGS. 1, 2 and 5 of the drawing. Substantially covering the area enclosed by the upper edge of the side wall 28 is a top wall 30 which is curved in cross section and is provided with a dispensing opening in the front or left portion thereof as seen in FIG. 5 of the drawing, the dispensing opening being generally designated by the numeral 32 (see FIG. 4). That portion of the upstanding wall 28 which forms a portion of the boundary of the dispensing opening 32 has the inner surface thereof beveled as at 34 (see FIG. 5) to form a pouring lip for the dispensing unit and also to guide the movement of the closure flap into the operative closed position as will be explained more fully hereinafter.

There is attached to the curved top wall 30 a closure flap 36 which is shaped generally complementary to the outline of the dispensing opening 32. The top wall 30 and the closure flap 36 are connected by a a hinge 38 having a thickness substantially less than that of either the top wall 30 or the closure flap 36, so that the closure flap 36 can be moved relative to the top wall by bending at the hinge 38. Although the thickness of the material forming the hinge is less than the thickness of the material at other points in the dispensing unit 10, the thickness of the material at the hinge is sufficient to possess substantial resiliency, thereby to urge the closure flap 36 toward a closed position as will be explained more fully hereinafter.

There is provided upon the closure flap 36 a depressible thumb piece or lever arm 40 which is formed integral therewith and extends upwardly therefrom at an acute angle and to the right as viewed in FIG. 5, the thumb piece 40 being relatively stiff thereby to move the closure flap 36 by bending of the hinge 38. Formed along each of the side edges of the thumb piece 40 is a reinforcing flange 42 which extends the length thereof and down onto the closure flap 36 and to an upstanding reinforcing flange 44 which extends around the curved front side of the closure flap 36 and joins with two parallel and substantially straight reinforcing flanges 46 extending along the straight sides of the closure flap 36.

There is formed on the top wall 30 adjacent to the hinge 38 and opposite the thumb piece 40 an upstanding abutment 48 which is adapted to contact the underside of the thumb piece when it and the associated closure fiap 36 are moved to the pouring position as illustnated in FIG. 2 of the drawing, to limit the movement thereof. There is also provided a pair of spaced apart semicircular stop members 50 integral with the upstanding wall 28 and disposed adjacent to the sides of the dispensing opening 32, as may be best seen in FIG. 4 of the drawing. The stop members 5% contact the underside of the front end of the closure flap 36 when it is moved to the closed position as illustrated in FIGS. 1 and 5 of the drawing, to normally limit the downward movement of the closure flap 36 in the closing direction.

The dispensing unit 10 is formed integral and in one piece by molding from a synthetic organic plastic resin such as polypropylene or polyethylene, it being understood that other like plasticresins can be utilized provided that they possess equivalent molding and resilient characteristics to those possessed by polyethylene. The molding is preferably carried out by injection utilizing a die set illustrated in FIGS. 6 and 7 of the drawing and including an upper female die member 60 and a lower male die member 62 which when closed co-operate to form a cavity having the required shape to produce a dispensing unit 10 when a suitable amount of plastic resin is injected thereinto. More specifically, the female die member 66 has a generally cylindrical opening 64 therein and against the wall of which is molded the circular collar 2%} having the embossment 26 thereon. Communicating with the opening 64 is an upstanding opening or passage 66 in which is formed the circumferential side wall 28. Also communicating with the opening 64 is an opening 68 shaped to mold the thumb piece 40 and the reinforcements 42 thereon. Likewise, there is provided an opening 70 for molding the abutment 48, together with the usual gate opening 72 to the lower right as seen in FIG. 7. The male die member 62 has an upstanding wall 74 with grooves 76 therein to mold the inner surface of the collar 20 and the threads 22 thereon, respectively. The closure flap 36 is molded against complementary-

shaped surfaces

78 and 80 on the

die members

60 and 62 and the top wall 30 is likewise molded between a pair of spaced apart complementary-

shaped surfaces

82 and 84 on the die

members

60 and 62, respectively.

In the molding of a dispensing unit 10, the

die members

60 and 62 are assembled in the position as illustrated in FIG. 6 of the drawing and thereafter a suitable quantity of the synthetic organic plastic resin, such as polypropylene as polyethylene, is heated to molding temperature thereof and injected through the gate 72 into the molding cavity provided by the facing surfaces of the

die members

60 and 62, care being taken completely to fill the molding cavity while pressing the

die members

60 and 62 firmly against one another along the part line 86. After the plastic resin has been cooled sufficiently to permit handling thereof, the die

members

60 and 62 are separated, the molded dispensing unit 10 being retained upon the die member 62 because of the presence of the threads 22 on the dispensing unit 10 engaging in the grooves 76 of the die member 62. Thereafter the dispensing unit 10 is stripped from the die member 62 and the plastic material in the gate 72 removed therefrom.

It will be noted that at this state in the manufacture of the dispensing unit 10, the closure flap 36 is in the position illustrated in FIG. 7 of the drawing and in the position illustrated by dashed lines in FIG. 5 of the drawing. The closure flap 36 in order to be operative as a selfclosing element in a dispensing unit must be moved from the first or molded position thereof illustrated in FIG. 7 to a second position as illustrated by solid lines in FIG. 5 wherein the closure flap 36 closes the dispensing opening 32 in the closure wall 27. The movement of the closure flap 36 from the first position illustrated by dashed lines in FIG. 5 to the second position illustrated by solid lines in FIG. 5 past the stop members 50 is readily accomplished since the closure flap 36 and the associated parts are all flexible whereby the closure flap 36 can be sufficiently deformed to permit movement thereof past the stop members 50 and the closure fiap 36 is further sufficiently resilient to resume the molded shape thereof after being placed in the second position illustrated by solid lines in FIG. 5. It will be noted, however, that the closure flap 36 can be moved to the first or dashed line position of FIG. 5 from the second position or solid line po sition of FIG. 5 past the stop members 50 only with difficuity, although such movement is possible by deforming the closure flap 36.

In moving the closure flap 36 from the first or dashed line position of FIG. 5 to the second or solid line position thereof, stresses are produced in the hinge 38 and because of the resilient character of the plastic forming the unit 10, the stresses are substantially permanent and continually urge the closure flap 36 toward the first or dashed line position thereof and therefore against the upper surfaces of the stop members 50 as viewed in FIG. 5. The stresses created in the hinge 38 are not sufficient, however, to deform the closure flap 36 and to force it past the stop members 50.

With the closure flap 36 and the associated parts in the second or full line position illustrated in FIGS. 1, 3 and 5 of the drawing, manufacture of the dispensing unit 10 is complete and it can now be placed upon an associated container such as the container 12 by engaging the threads 22 of the collar 20 with the mating threads on the neck 14 of the container 12. In order to dispense materials from the container 12 through the dispensing unit 10, the user grasps the container 12 and places his thumb or a finger upon the thumb piece 40 and moves it and the attached closure flap 36 from the second or full line position illustrated in FIGS. 1 and of the drawing to a third or open position illustrated in FIGS. 2 and 4 of the drawing wherein the closure flap 36 is raised from the stop members 50 and is removed from covering relationship with respect to the dispensing opening 32. By tilting the container 12, the contents thereof can now be poured or dispensed therefrom through the dispensing opening 32 and across the pouring lip 34. When the desired amount of contents from the container 12 have been dispensed, the user removes his thumb or finger from the thumb piece 40. Movement of the closure flap 36 from the second or full line position of FIG. 5 to the third or dispensing position of FIG. 2 has created yet further stresses in the hinge 38 which tend to urge the closure flap 36 toward the stop members 50 and, upon the removal of the thumb or finger of the user from the piece 40 at the end of a dispensing operation, the stresses in the hinge 38 move the closure flap 36 and the associated parts to the second or closed position illustrated in FIGS. 1 and 3 and by full lines in FIG. 5 of the drawing. The bevel pouring lip 34 aids in guiding the closure flap 36 to the closed position thereof against the upper ends of the stop members 50. As has been explained above the abutment 48 contacts the underside of the piece 40 when the closure flap 36 is in the fully open position thereof and thus determines the fully open or third position of the closure flap 36 as is illustrated in FIG. 2 of the drawing.

From FIGS. 4, 5 and 7 of the drawing, it will be seen that the unit is substantially free of cracks, crevices or other material trapping areas that'will collect material to permit spoilage thereof. This smooth inner construction of the dispensing unit also facilitates removal of any materials therefrom which may tend to adhere thereto despite the smooth non-catching construction thereof. It is further noted that the method of molding the dispensing unit 10 can be carried out using standard equipment and standard molding procedures that are economical to construct and to operate.

A second embodiment of the invention is illustrated in FIGS. 813 of the drawings. A dispensing unit generally indicated by the number 100 includes, similarly to the embodiment of FIGS. 1-7, a collar 102 internally threaded at 104, a closure wall 106 which includes a side wall 108 and a top'wall 110, a closure flap 112, a thumb piece 114 of increased thickness integral therewith, and two spaced parallel longitudinal upstanding reinforcing ribs 116 integral with the flap and the thumb piece. In addition, a pour spout 118 is integrally formed on the front of the closure wall 106, and it projects therefrom and defines an internal flow channel or recess 120 (FIGS. 10 and 12). An inner bevel edge 122 defines the lip of the pour spout, and it mates with an inner bevel edge 124 on the free end of the closure flap 112, as illustrated particularly in FIGS. 10 and 12. The closure flap is supported on the pour spout bevel edge 122 in the second position of the flap, in which it closes the dispensing opening 126. Respective side bevel edges 128 and 130 (FIG. 11) are provided on the flap 112, and they facilitate movement of the flap into its position closing the dispensing opening 126, in general alignment with the top wall 110.

A preferred feature of the invention resides in the mounting of the closure flap 112 as illustrated in FIGS. 8-13, and particularly as shown in FIGS. 12 and 13. The flap is molded in a first position which is at a preferred angle A to its second or unit closing position, as illustrated in FIG. 12, on the order of 80. The flap 112 is mounted on an integral S-shaped hinge 132 which is also integral with the top wall 110, and the hinge has a reduced thickness relative to the flap and the wall. As

-to its second'position.

an example of the thicknesses, theflap and wall thicknesses may be about .05 inch and the hinge thickness at the center thereof may be about .016 inch, or about onethird of the former thicknesses. The hinge 132 includes a bend 134 integral with the underside of the fiap 112 and curved rearwardly in the direction of the thumb piece 114, and a reverse bend 136 integral with the top wall 110 and curvinginwardly thereof.

The foregoing construction provides a strong resilient snap action of the closure flap 112 in closing the dispensing opening 126. Movement of the flap through the described angle A from its molded position and the resulting compression of the rearwardly directed bend 134 and opening of the reverse bend 136 cause the hinge 132 to function also as an effective flap closing spring.

The unit 100 is molded in like manner to the preceding embodiment, with the flap 112 at the angle A and as illustrated in FIG. 12. In moving the flap angularly from this first position to its second position illustrated in full lines in FIG. 10, the flap is moved past a ledge 138 at the base of the pour channel 120, which ledge is a continuation of an inner peripheral rim 140 serving to engage the rim of a container 12. The flap flexes slightly to clear the ledge 138 and as the flap is moved in the channel 120 of the pour spout 118 outwardly to a position seated on the bevel edge 122.

The outer surface of the top wall 110 provides abutment means for thethumb piece 114, shown in its abutting position in phantom in FIG. 10. The abutment means restricts the angle B between the second or full line position and the third or phantom position of the flap 112 to an angle which together withthe angle A illustrated in'FIG. 12 is within the limits of the memory of the material of construction, or within its ability to return the flap 112 In the illustrative embodiment employing resilient molded polypropylene or polyethylene, the angle between the first and third positions of the flap is maintained within about 100. With a preferred angle A on the order of the angle B may be, correspondingly, on the order of 20. This construction provides excellent flap closing action and ample room for pouring with the flap open, and the flap continues to provide an effective closure over extended use.

Achanneled handle 142 for supporting the unit is formed integrally in the unit. It includes spaced parallel

angular sides

144 and 146 which are integral with the collar 102 and the side wall 108 on the rear side of the unit. The handle sides are joined by a cross member 148 integral therewith and with the collar 102 at its junction with the side wall 108. When the unit is assembled on a container 12, the assembly is grasped by the handle 142, and the thumb piece 114 is engaged by the thumb or a finger of the hand. The container is tilted with the thumb piece depressed to pour its contents from the pour spout 118. When the thumb piece is released, the flap 112 returns to its position on the bevel edge 122 of the spout and effectively close the dispensing opening 126. The dispensing unit 100, like the preceding embodiment 10 of the unit, is Well adapted to be maintained clean and sanitary.

It will be seen that there has been provided an improved dispensing unit of the self-closing type and a method of producing such a dispensing unitwhich fulfill all of the objects and advantages of the invention set forth above. While there has been described what are at present considered to be preferred embodiments of the invention, it will be understood that various modifications can be made therein and its is intended to cover in the appended claims all such modifications asfall within the true spirit and scope of the invention.

I claim:

1. An integral one-piece self-closing dispensing unit of resilient plastic material comprising, a closure wall having an inner surface and an outer surface and a dispensing opening therein, and a closure flap joined integrally with said closure wall along one edge of said dispensing opening for closing said opening, said closure flap being adapted to occupy afirst unstressed position extending inwardly through said dispensing opening and beyond said inner surface, said closure flap also being capable of being flexed and angularly movable from said first position through said dispensing opening and to a second position wherein said closure flap closes said dispensing opening, said closure flap being thereafter angularly movable to a third position extending outwardly from said outer surface to open said dispensing opening, the movement of said closure flap from said first position to said second position creating stresses in said resilient plastic material urging said closure flap toward said second position closing said dispensing opening.

2. A dispensing unit as defined in claim 1 wherein the angle between said first and third positions is within about 100 degrees.

3. A dispensing unit as defined in claim 1 including an integral curved hinge joining said closure wall and said closure flap.

4. A dispensing unit as defined in claim 1 including a thumb piece integral with said closure flap.

5. A dispensing unit as defined in claim 1 including a stop member integral with said closure wall and extending inwardly into said dispensing opening, said closure flap being capable of being flexed past said stop member in moving from said first position to said second position and thereafter being disposed on said stop member in said second position.

6. An integral one-piece self-closing dispensing unit of resilient plastic material comprising, a closure wall having an inner surface and an outer surface and a dispensing opening therein, a closure flap having an outline complementary to said dispensing opening substantially to close said opening when disposed therein in general alignment with said closure wall, a hinge of reduced thickness between said closure wall and said closure flap, said hinge being integral with said closure fiap and integral with said closure wall along one edge of said dispensing opening, and a thumb piece integral with said closure flap, said closure flap being adapted to occupy a first position wherein said hinge is unstressed with said closure flap extending inwardly through said dispensing opening and beyond said inner surface, said closure flap also being capable of being flexed and angularly movable about said hinge from said first position through said dispensing opening and to a second position wherein said closure flap closes said dispensing opening, said closure flap being thereafter angularly movable about said hinge to a third position extending outwardly from said outer surface upon engagement of said thumb piece to remove said closure flap from said dispensing opening, the movement of said closure flap from said first position to said second position creating stresses in said hinge urging said closure flap toward said second position closing said dispensing opening.

7. An integral one-piece self-closing dispensing unit of resilient plastic material comprising, a collar b aving threads on the inner surface thereof to engage threads on an associated container, a closure wall closing one end of said collar and having an inner surface and an outer surface and a dispensing opening therein, a closure flap joined integrally with said closure wall along one edge of said dispensing opening and having an outline complemen' tary to said opening substantially to close said opening when disposed therein in general alignment with said closure wall, the juncture between said closure wall and said closure flap being of reduced thickness to provide a hinge therebetween, a thumb piece integral with said closure flap and extending therefrom away from said outer surface, said closure flap being adapted to occupy a first unstressed position extending inwardly through said dispensing opening and beyond said inner surface, said closure flap also being capable of being flexed and angularly movable about said hinge from said first position through said dispensing opening and to a second position wherein said closure flap closes said dispensing opening, said closure flap being thereafter angularly movable about said hinge to a third position extending outwardly from said outer surface upon engagement of said thumb piece to remove said closure flap from said dispensing opening, and means abutting said thumb piece to limit the movement of said closure flap from said second position to said third position thereof, the movement of said closure flap from said first position to said second position creating stresses in said hinge urging said closure flap toward said second position closing said dispemng opening.

8. An integral one-piece self-closing dispensing unit of resilient plastic material comprising, a closure wall having an inner surface and an outer surface and a dispensing opening therein, a closure flap joined integrally with said closure wall along one edge of said dispensing opening and having an outline complementary to said opening substantially to close said opening when disposed therein in general alignment with said closure wall, an integral curved hinge of reduced thickness joining said closure wall and said closure flap, an inner bevel edge on said closure wall opposite to said one edge of said dispensing opening, a mating inner bevel edge on said closure flap, a thumb piece integral with said closure flap for moving the flap angularly about said hinge, said closure flap being capable of being flexed and angularly movable from a first position extending inwardly through said dispensing opening and to a second position wherein said closure flap is disposed with said bevel edge thereof upon said closure wall bevel edge and closes said dispensing opening, said closure flap being thereafter angularly movable to a third position extending outwardly from said outer surface upon engagement of said thumb piece to remove said closure flap from said dispensing opening, means abutting said thumb piece to limit the movement of said closure flap from said second position to said third position thereof, the movement of said closure flap from said first position to said second position creating stresses in said hinge urging said closure tlap toward said second position closing said dispensing opening, and a handle for supporting the unit integral with said closure wall.

9. The method of producing from a resilient plastic material an integral one-piece self-closing dispensing unit, having a closure wall with a dispensing opening therein and a closure flap integral therewith and biased toward a position closing said dispensing opening, comprising the steps of molding said dispensing unit with said closure wall and said closure flap joined integrally and with the closure flap in a first position protruding inwardly through said dispensing opening into the interior of said dispensing unit, and then forcefully flexing and angularly moving said closure flap outwardly through said dispensing opening, thereby to stress said resilient plastic material at the juncture of said closure wall and said closure flap to produce stresses therein biasing said closure flap to a second position closing said dispensing opening.

10. The method of producing from a resilient plastic material an integral one-piece self-closing dispensing unit, having a closure wall with a dispensing opening therein and a closure flap integral therewith and biased toward a position closing said dispensing opening, comprising the steps of molding said dispensing unit with said closure wall and said closure flap joined integrally by a hinge of reduced thickness, and with the closure flap in a first position protruding inwardly through said dispensing opening into the interior of said dispensing unit, and then forcefully flexing and angularly moving said closure flap about said hinge outwardly through said dispensing opening, thereby to stress said resilient plastic material at said hinge to produce stresses therein biasing said closure flap to a second position closing said dispensing opening.

11. The method of producing from a moldable resilient plastic material an integral single-piece article having a body with an opening therein and a self-closing closure element for said opening, comprising the steps of molding said article with said body and said closure element integrally joined and with said closure element extending angularly in one direction from said body, then forcefully flexing and angularly moving said closure element generally in the opposite direction and bodily through said opening, thereby to stress said resilient plastic material adjacent the juncture of said closure element and said body to produce stresses therein constantly biasing said closure element toward a closing position with respect to said opening.

12. A self-closing dispensing device formed entirely of resilient plastic material, comprising a wall of said resilient plastic material having an opening therein, a substantially rigid closure flap of said material for closing said opening, means including a flexible junction section of said resilient plastic material integral with said closure flap and adjacent an edge of said opening for connecting said flap to said Wall, said junction section having a thickness less than that of said closure flap and said wall, said junction section being permanently stressed constantly to urge said closure flap in a direction toward said opening and toward a closing position with respect thereto, and a substantially rigid projection on said closure flap extending to a position spaced from said Wall and adapted to be finger-pressed temporarily to overcome said stresses and to pivot said closure flap about said junction section toward an open position with respect to said opening.

References Cited in the file of this patent UNITED STATES PATENTS 2,312,380 Bernhardt Mar. 2, 1943 2,573,378 Zurlinden Oct. 30, 1951 2,821,319 Bladh Jan. 28, 1958 2,875,472 Marcus Mar. 3, 1959 2,886,218 Marcus May 12, 1959 2,937,794 Quandt May 24, 1960

Claims

1. AN INTEGRAL ONE-PIECE SELF-CLOSING DISPENSING UNIT OF RESILIENT PLASTIC MATERIAL COMPRISING, A CLOSURE WALL HAVING AN INNER SURFACE AND AN OUTER SURFACE AND A DISPENSING OPENING THEREIN, AND A CLOSURE FLAP JOINED INTEGRALLY WITH SAID CLOSURE WALL ALONG ONE EDGE OF SAID DISPENSING OPENING FOR CLOSING SAID OPENING, SAID CLOSURE FLAP BEING ADAPTED TO OCCUPY A FIRST UNSTRESSED POSITION EXTENDING INWARDLY THROUGH SAID DISPENSING OPENING AND BEYOND SAID INNER SURFACE, SAID CLOSURE FLAP ALSO BEING CAPABLE OF BEING FLEXED AND ANGULARLY MOVABLE FROM SAID FIRST POSITION THROUGH SAID DISPENSING OPENING AND TO A SECOND POSITION WHEREIN SAID CLOSURE FLAP CLOSES SAID DISPENSING OPENING, SAID CLOSURE FLAP BEING THEREAFTER ANGULARLY MOVABLE TO A THIRD POSITION EXTENDING OUTWARDLY FROM SAID OUTER SURFACE TO OPEN SAID DISPENSING OPENING, THE MOVEMENT OF SAID CLOSURE FLAP FROM SAID FIRST POSITION TO SAID SECOND POSITION CREATING STRESSES IN SAID RESILIENT PLASTIC MATERIAL URGING SAID CLOSURE FLAP TOWARD SAID SECOND POSITION CLOSING SAID DISPENSING OPENING.