Snap action closure with concentric annular flex zones
United States Patent Collie Apr. 1, 1975 I SNAP ACTION CLOSURE WITH 3.260.425 7/1966 Moran 222/541 3,321.1 l4 5/1967 Croyle 222/499 CONCENTRIC ANNULAR FLEX ZONES [75] Inventor: Stafford D. Collie, Glen Ellyn, Ill.  
 [73] Assignee: Phillips Petroleum Company,  
 Bartlesville. Okla.  
 [22] Filed: Apr. 7, 1970 [2|] Appl. No.: 26,257  
  Related U.S. Application Data [63] Continuation-impart of Ser. No. 682,260, Nov. l3,  
 i967, abandoned.  
 [521 U.S. Cl. 222/499 [5 l l Int. Cl B65d 35/44 [58] Field of Search 222/499, 559, 570, 523, 222/525, 54]  
 I 56] References Cited UNITED STATES PATENTS [358.414 5/l934 Bogeaus 222/499 Primary Examiner-Allen N. Knowles Ass/slam Examiner-Norman L. Stack, Jr.  
 [57] ABSTRACT A plastic container has a bottom wall; upstanding side walls; a snap acting top wall with a dispensing opening, said top capable of flexing in two concentric annular zones to assume two stable positions; and a diaphragm across the upper portion of said container just below said top wall, said diaphragm having at least one perforation around the periphery thereof. The top is snapped into a convex up position to dispense the contents through the perforations and thereafter through the dispensing opening, and is snapped into a concave down position to close the container. This container primarily comprises parts fabricated from sheet material by thermoforming and die cutting.  
 1 Claim, 4 Drawing Figures PAIENTEIJAPR 1 ms 3 874.567  
 &#39; sum 1 pg 2 F/G. I 1 FIG. 2  
 INVENTOR.  
 S. D. COLL IE A TTORNEVS PATENTED 3.874.567  
 sum 2 of 2 INVENTOR. S. D. COLL! E A TTORNEVS SNAP ACTION CLOSURE WITH CONCENTRIC ANNILAR FLEX ZON CROSS REFERENCE TO RELATED INVENTION &#39;l his is a continuation-in-part of copending patent application Ser. No. b81260. filed Nov. l3. I967 now abandoned BACKGROUND OF INVE TION This invention relates to a snap action closure type dispensing container.  
  The advent of plastic containers has made it possible to provide consumer goods in packages embodying functional and aesthetically pleasing designs. More durable packages and packages which better protect the contents are also possible. for instance, by virtue of the low moisture permeability of certain plastic materials such as the polyolefins. While such packages are finding widespread acceptance. consumers demand in ad dition greater convenience in opening packages than ever before. especially in dispensing containers. Since plastic containers must compete with paper and the like. there is an additional requirement in a plastic con tainer that it provide all of these features and at the same time be reasonably competitive from an economic point of \ie\\&#39; with the older containers of the prior art. It is apparent that a closure device with mov ing or separate parts. particularly nonplastic parts such as springs and the like. is not desirable. Even a screwon cap more than doubles the cost of many such containel&#39;s.  
  Thus. to fulfill all of the diverse requirements of a commercially successful dispensing container. parts made by complex molding operations such as injection molding must he avoided and the container so designed that the inherent advantages from the standpoint of cost of extruded sheet which can be thermoformed or die cut be utilized to the maximum extent in the fabrication of the container. Further. a dispensing container should provide a positive seal on reclosure. a requirement not generally compatible with the requirement for easy opening and inexpensive fabrication.  
 SUMMARY OF THE INVENTION It is an object of this invention to provide a dispensing container with a snap acting type closure which can be fabricated from a small number of easily fabricated parts.  
  It is a further object of this invention to provide a dispensing container which is easily opened and closed and which provides a positive seal on closing.  
  It is yet a further object of this invention to provide a dispensing container made exclusively of parts fabricated from extruded sheet.  
  In accordance with this invention. a dispensing container which does not require injection molded parts is protidcd having a bottom wall: upstanding side walls; a diaphragm across the upper portion of said side walls. said diaphragm having at least one perforation near its periphery and a solid center section. and a snap acting top all portion having surfaces tapering toward a dispensing opening. said top having two concentric annular flex zones and being capable of assuming two stable positions. a convex open position and a concave position wherein the area around said dispensing opening cooperates with said solid portion of said diaphragm to form a closed position.  
 BRIEF DESCRIPTION OF THE DRAWINGS In the drawings. forming a part hereof. wherein like reference characters depict identical parts in the various views.  
  FIG. I is a perspective view partly in section of a dispensing container according to the instant invention with the snap action top part in the open position;  
  FIG. 2 is a perspective view partly in section of the container of FIG. I with the snap acting top portion in the closed position.  
  FIG. 3 is an exploded view of an alternate embodiment of this invention showing one method of fabrication; and  
  FIG. 4 is an exploded view of a container according to this invention showing an alternate method of fabrication.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS Any suitable thermoplastic material can be used in the fabrication of the containers of the instant invention such as polymers of at least one l-olefin. said 1- olefin having from 2 to 8 carbon atoms per molecule. poly(vinyl chloride) impact polystyrene. and the like. Preferred materials are polymers of a l-olefin selected from the group consisting of ethylene. propylene. butene and mixtures thereof. Polypropylene is an especially preferred material for the fabrication of the snap acting top portion because of the ease with which integral hinges can be produced from polypropylene. All of the parts of the container can be made of the same thermoplastic material or different thermoplastic materials can be used for the various parts. It is also within the scope of an alternate embodiment of the invention to form the body of the container of a material other than plastic such as paperboard; however. in all instances. it is absolutely essential that the snap acting top portion be of a thermoplastic material of sufficient flexibility to assume two positions and sufficient rigidity to be stable in each of these positions. preferably a polymer of l-olefin selected from the group consisting of ethylene. propylene. butene and mixtures thereof. more preferably polypropylene.  
  The containers of the instant invention are useful for packaging l&#39;lowable granular products such as soap powder and the like and food products such as salt. sugar. and the like. and some liquids.  
  Packages of the instant invention may be decorated. can carry promotional material. or have a discardable outer package of cellophane or the like over the entire container or over the dispensing opening.  
  While the containers of the instant invention are preferably circular. they can also be oval. square. rectangular. or the like.  
  The various parts of the container can be affixed together by various techniques such as solvent welding. spin welding. gluing or mechanical snapping into place. Spin welding is an especially preferred method of affixing the bottom or the snap acting top part. In some instances the diaphragm may be held in place mechanb cally by the snap acting top part.  
  Perforations may vary in size or shape depending on the nature of the granular material being packaged; if the material to be packaged is powdery then the perforations will be small. with material having larger granules the perforations may be larger.  
  Referring now to FIGS. 1 and 2 there is shown a dispensing container having a bottom wall 12. upstanding side walls l4 and a snap acting top wall I6: said snap top wall has sloping surface I8 between concentric annular flex zones 37 and 46 which slopes generally toward dispensing opening 20. A web 22 (an integral part of the top wall of the container is the preferred embodiment) extends part of the way across dispensing opening to provide a means for grasping said snap acting top wall to open the container. Diaphragm 24 extends across the upper portion of said container just below said snap acting top wall. Diaphragm 24 has holes or perforations 26 in an annular configuration around the periphery of said diaphragm such that the dome-shaped center section 28 of said diaphragm in the area corresponding to the position of said dispens ing opening 20 when said snap acting top part is in the closed position is solid. FIG. I shows the snap acting top part in the first of its two stable positions, the open position. FIG. 2 shows the snap acting top part 16 in the second of its two stable positions. the closed position.  
  As can be seen from FIG. 2. contact ofthe underside of the snap acting top \\&#39;all around the periphery of the dispensing opening with the top surface ofthc solid. Linperforated central portion of diaphragm 24 along line I9 prevents the contents coming through holes 26 from escaping through the dispensing opening. By top surface of the central portion of diaphragm 24 is meant the generally flat upper surface as opposed to side surfaces 27. This generally flat surface may be completely flat as in FIG. 3 ol&#39; dome-shaped as in FIGS. I. 2 and 4. The container can easily be opened by pulling up on web 22. and closed by depressing the central area of snap acting top wall I6.  
  Referring now to FIG. 3. there is shown an exploded view of the container of the instant invention showing one of the alternate methods of fabrication. In this em bodiment. upstanding side walls I4. snap acting top wall 16 and web I22 are formed as an integral unit by blow molding and then cutting out bottom end 32. or more preferably by vacuum forming. In the case of vacuuming forming. bottom I I2 is fabricated as a separate member. In the case ofblow molding. it can he the POP tion cut out to form the open bottom end. Perforated diaphragm I24 is then inserted into the body portion 30 comprising the side walls I4. snap acting top wall I6. and web I22, through open bottom end 32 and affixed to said body portion across the top of the container near the top portion of upstanding side walls l4. (While it cannot be seen in this view the bottom end 32 is open.) This may be done by gluing. spin welding. or snapping the diaphragm into indentations fornted in the body portion during the fabrication of the body portionv The contents may be added at this time or the bottom H2 may be affixed and the contents added later through the dispensing opening. Since the contents can be added through the dispensing opening it is not essential that the package be filled prior to completion of the fabrication of the container. Bottom II2 which forms bottom wall 12 on being affixed to body portion 30 is affixed across open end 32 by gluing. heat fusion. solvent welding. or preferably by the specific heat fusion method of spin welding. The dispensing opening 20 (not shown in FIG. 3) is then formed by removing a portion of web I22. This may be done during the fabrication of the container or it may be left in place with only a score line indicating the portion to be removed so as to form a seal which is removed by the consumer when the package is initially opened. It is apparent that in instances where the bottom H2 is affixed to open end 32 prior to filling the container that dispensing opening 20 must be provided prior to the filling of the container. Diaphragm I24 and bottom I I2 are prefera bly formed from sheet material; thus in the embodiments where body portion 30 is thermoformed this entire highly complex. contoured. reclosable. dispensing container is fabricated from inexpensive. easily ex truded sheet material. In the embodiment shown in FIG. 3 the diaphragm is simply die cut from a flat sheet. This diaphragm has a solid center section I28 corresponding to section 28 in the other embodiments.  
  Referring now to FIG. 4. there is shown an alternate embodiment with regard to the method of fabricating the novel container of the instant invention. In this embodiment there is provided body portion 34 comprising upstanding side walls l4 and bottom wall [2. Body portion 34 can be fabricated by means of blow molding or preferably by means of thermoforming from sheet. Diaphragm 24 has large rectangular holes 26. domeshaped solid center section 28 and flange 36. Holes 26 may be round. rectangular, or any other suitable shape. Snap acting top I I6 which becomes the snap acting top wall 16 ofthe finished container has sloping surface I8. dispensing opening 20. web 22. and annular inwardly projecting ridge 40. To assemble this container. diaphragm 24 is positioned across the top of upstanding side walls I4 with llangc 36 contacting the end portions of said walls. Snap acting top 116 is then affixed over open top end 42 of body portion 34 by means of inwardly projecting annular ridge 4&#34; snapping into annular groove 44. These parts can also be affixed by gluing. solvent welding. spin welding. and the like. Diaphragm 24 has large rectangular holes 26 and an upwardly projecting curved solid center section 28. The removal of the material forming the large rectangular holes 26 gives the remaining web connecting said dome-shaped solid center section 28 a spring effect so that when the snap acting top wall assumes the downward stable position and contacts domushaped solid center section 28 along annular flex zone 46 said dome-shaped solid section can be depressed slightly to account for irregularities in the surface of the parts so as to effect a positive seal. The area of top [I6 forming inner flex zone 46 contacts the dome-shaped solid center section as shown in FIG. 2 along line I9.  
  By comparing FIGS. I and 2, for instance. it can be seen that annular flex zones 37 and 46 form concentric integral hinges separated by annular surface I8. which hinges bend as the top wall snaps from one stable position to the other.  
  It is to be noted that both snap acting top [I6 and diaphragm 24. while being separate elements. are both thermoformed from sheet material. Diaphragm 24 can also be a simple flat sheet which is simply die cut and does not undergo a thermoforming operation as in FIG. 3. Thus in the preferred embodiment where body portion 34 is thermoformed. this entire complex. highly contoured. dispensing container is fabricated from inexpensive. easily extruded sheet material. Furthermore. since it is possible to thermoform tough ultra high molecular weight polymer which cannot be injection molded. the instant invention makes possible not only lower cost containers but also containers ol&#39;exceptional durability EXAMPLE A lb-ounce round bottle was blow molded from (L3 melt index (AS&#39;l&#39;M I.) l2384i2l&#39;. (ondition l&#39;i). 0.9M) density (AS&#39;IM l) lSllS-(Lll polyethylene and the top cut out to gi\e a body portion such as that shown in H0. 4.11 l t-mill sheet ol&#39;(|.l melt flow tAS&#39;lM Dl 238- 621. (&#39;ondition 1.) 0.905 density ASTM D l5tl5-b3&#39;l&#39;) polypropylene was vacuum formed into a diaphragm such as is shown in l&#34;|(i. 4. The holes were cut out in a post l&#39;orming operation. A ZR-mill sheet identical to that used in forming the diaphragm was vacuum l&#39;ornied into a snap acting top such as is shown in FIGS. 1. 2. and 4. The dispensing opening was cut out in a post forming operation. The diaphragm was positioned .iver the open end of the body portion and the snap act- .ng top affixed to the body portion by means of the in- .vardly projecting ridge on the top portion fitting into :he annular groove on the body portion. (ilue was utiizcd to lurther secure the top portion to the body por- ;ion. This container was filled with finely powdered ioap through the dispensing opening. The resulting :ontainer was easily opened to dispense the contents md was easily closed to t&#39;orm a positive seal to prevent eakage ol&#39; the contents. Because the center section of he diaphragm was dome shaped it was l&#39;ound that the iowdered soap tended to fall back ol&#39;tol&#39; this solid secion so that a pull of powdered soap did not blow up Ill  6 through the dispensing opening when the snap acting top portion was closed.  
  While this invention has been described in detail for the purpose ol illustration it is not to be construed as limited thereby but is intended to cover all changes and modifications within the spirit and scope thereol.  
 I claim:  
  I. A dispensing container containing a material to be packaged comprising:  
 a bottom wall:  
 side walls upstanding from said bottom wall.  
 an integral. one-piece snap acting top wall connecting with said side walls. said top wall having a generally centrally located dispensing opening having a web extending part ol the way across said dispensing opening to provide a gripping means and being so contoured as to have two concentric annular integral hinges around said dispensing opening. said hinges being separated by an annular surface said hinges being capable of bending so that said top wall can assume two stable positions. an open convex position. and a closed concave position:  
 a diaphragm across said container. positioned just below said top wall. said diaphragm having at least one hole around its periphery and further having a solid center section corresponding to the position of said dispensing opening. a generally flat top surface ol said center section cooperating with said top to close said containers.