DISPENSING NOZZLE HAVING ELASTICALLY BEND ABLE RIDGES TEMPORARILY FORMING A PIERCING WEDGE

BACKGROUND OF THE INVENTION

[0001] This invention relates generally to dispensing nozzles for containers of useful liquids such as glue and more particularly relates to dispensing nozzles that have a seal piercer for puncturing a sealing membrane that covers the end of an outlet neck of the container.

[0002] A wide variety of useful liquids, such as glue, are packaged and sold in containers that have a membrane seal across the end of an outlet neck of the container. The membrane preserves the container contents. The membrane seal is typically an impervious sheet that is adhered to the circular rim of a cylindrical outlet neck of the container or sealed near but slightly recessed from the end. When a user is ready to apply the liquid to a surface of an object, the user must first puncture the seal so that the contents can be dispensed from the container past the seal and onto the surface of a workpiece. Typically the container is a flexible tube with a threaded outlet so that the contents can be expelled through the outlet by squeezing the container.

[0003] In the past, the prior art has shown container caps that serve only as a combination of a closure having a threaded tubular skirt that is sealed at its top end combined with a puncturing sharp point protruding from the cap in a direction opposite the tubular skirt. Such a cap is rotated to remove it from the container neck, the seal is punctured with the sharp point and the contents can then be dispensed directly from the outlet neck of the container. The cap can be returned onto the neck after use.

[0004] However, it is often preferred to provide a cap with a nozzle so that the nozzle can be used to apply contents more accurately. But a nozzle must occupy the location of the sharp point in the above-described combination and the piercing structure must not block the passage of the tube contents out through the nozzle. Additionally, it is desirable that a nozzle can be installed and simultaneously the sealing membrane can be punctured in a single manual step so that there is no need to use a separate piercing device, remove the piercing device and then install the nozzle.

[0005] The prior art shows many different kinds of self-piercing closures with nozzles all of which have rigid piercing structures that do not move from their molded position during their piercing operation. One common type is a conical or rounded mound-like peak with a central axial hole leading to a spout. As the threaded tubular skirt of the nozzle is threaded onto the threaded neck of the container, the peak is forced through and pierces the sealing membrane. However, because the peak must have a central passage for outflow of the container contents, the piercing structure must be positioned outwardly from that passage and therefore can not taper to a sharp point. As a result, the force applied to the sealing membrane is necessarily distributed over a relatively wide area of the sealing membrane. Consequently, the force required to pierce the sealing membrane is greater than would be necessary for a more concentrated sharper point. Furthermore, some seals are formed of plastic or metalized plastic sheets that are capable of considerable stretching before being punctured. Therefore considerable axial travel is required in order to assure that the sealing membrane is not only punctured but that the puncture is large enough to permit the free flow of liquid out of the container. A puncture that is smaller than the passage through the nozzle will inhibit the outflow of the container contents.

[0006] Other prior art self -piercing nozzles utilize a sharp tooth, or multiple sharp teeth or a sharp cutting edge to assure that the sealing membrane is pierced. However, the use of sharp cutting edges leaves the possibility that a fragment can be severed from the sealing membrane and become lodged in the passageway leading to the nozzle, or in the nozzle itself, thereby interfering with the outflow of the container contents. Alternatively, a fragment can be partially severed and form a flap that could lodge partially over the central opening of the piercing structure and inhibit outflow.

[0007] It is therefore an object and feature of the invention to provide a nozzle that forms a relatively sharp edge at the center of its piercer so that the axial force applied to the sealing membrane is concentrated over a smaller area. With the piercing structure contacting the sealing membrane over a smaller area, a greater force per unit of sealing membrane area is applied to the sealing membrane. That greater force facilitates and assures piercing the sealing membrane. However, in order to maintain a sufficiently large passage for uninhibited outflow of container liquid through the nozzle, the elasticity of the piercer causes the piercer to push the punctured sealing membrane material radially outwardly after the sealing membrane is pierced. That radially outward movement also assures that the remaining membrane material can not interfere with the outflow of the container contents.

BRIEF SUMMARY OF THE INVENTION

[0008] The invention is a seal piercer formed in a dispensing nozzle that has a spout extending from a screw cap. The seal piercer has at least two resiliently flexible piercing ridges spaced apart on opposite sides of an inlet opening into the spout. The ridges extend in the screw cap in a direction opposite the spout and are separated from each other by interposed notches at the ends of the ridges. The ridges are elastically bendable toward each other by forced engagement against a sealing membrane that seals the end of a container holding a liquid, such as glue. The bending of the piercing ridges causes them to move together to form a piercing wedge. After puncture of the sealing membrane, the ridges elastically expand away from each other to spread the pierced sealing membrane outwardly away from the central liquid flow path.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0009] Fig. 1 is a view in perspective of the preferred embodiment of the invention

[0010] Fig. 2 is a top plan view of the embodiment in Fig. 1.

[0011] Fig. 3 is a view in side elevation of the embodiment in Fig. 1.

[0012] Fig. 4 is a bottom view of the embodiment in Fig. 1.

[0013] Fig. 5 is a view in axial section of the embodiment in Fig. 1 taken substantially along the line A-A of Fig. 4.

[0014] Fig. 6 is a view in axial section of the embodiment in Fig. 1 taken substantially along the line B-B of Fig. 4.

[0015] Fig. 7 is a bottom perspective view in axial section of the embodiment in

Fig. 1 taken substantially along the line A-A of Fig. 4.

[0016] Fig. 8 is a bottom perspective view in axial section of the embodiment

Fig. 1 taken substantially along the line B-B of Fig. 4.

[0017] Fig. 9 is a bottom perspective view of the embodiment in Fig. 1.

[0018] Fig. 10 is another bottom perspective view of the embodiment in Fig. 1. [0019] Fig. 11 is a view in axial section of the embodiment in Fig. 1 taken substantially along the line B-B of Fig. 4 and illustrating the operation of the preferred embodiment.

[0020] Fig. 12 is a partial view of a segment of the preferred embodiment illustrated in Fig. 1 taken substantially along the line B-B of Fig. 4 and illustrating the dimensions of the preferred embodiment.

[0021] Fig. 13 is a specification sheet showing the characteristics of the material of which the preferred embodiment is fabricated.

[0022] In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. DETAILED DESCRIPTION OF THE INVENTION

[0023] Referring simultaneously to Figs. 1 through 10, a dispensing nozzle embodying the invention is shown and is preferably molded as a unitary body from a synthetic resin material or plastic. The dispensing nozzle is intended to be sold in a state of sufficiently loose connection to a deformable container that is does not pierce the seal of the container's outlet neck. When a user is ready to apply the liquid contents of the container to a workpiece, the user rotates the dispensing nozzle to screw the nozzle further onto the outlet neck and pierce the seal. The entire container is not shown because a variety of such containers are well known in the prior art.

[0024] As illustrated in Fig. 11, a typical container has a threaded outlet neck 10 with an internal diameter 12 and is sealed by a sealing membrane 14. In the conventional manner, before connection of the dispensing nozzle, the sealing membrane 14 extends in a plane across the outlet neck 10 of the container. The dispensing nozzle pierces the sealing membrane 14 as the dispensing nozzle is forced onto the outlet neck 10. An open- ended outlet passageway 16 through the nozzle guides container contents flowing out from the container.

[0025] A portion of the dispensing nozzle is formed as a screw cap 18 with a wall

20 that is transverse to the central axis of the nozzle for engaging the outer end 22 of the outlet neck 10. An inlet opening 24 through the transverse wall 20 permits axial outflow of the contents from a container. The screw cap 18 also has a threaded tubular skirt 26 that is fixed to and extends from the transverse wall 20. The tubular skirt 26 has female threads 28 that are formed on the interior of screw cap 18 and are threadedly engageable with the male threads 30 of the container outlet neck 10. The threaded engagement allows rotation of the nozzle to force the nozzle in an axial direction onto the outlet neck 10 in the conventional manner.

[0026] A spout 32 is fixed to and extends in a first direction (opposite the tubular skirt 26) from the transverse wall 20 of the screw cap 18. The spout 32 has the nozzle outlet passage 16 extending through the spout 32 and in fluid communication through the inlet opening 24 of the screw cap 18.

[0027] The improvement of the invention is a seal piercer that comprises at least two resiliently flexible piercing ridges 40 and 42. These piercing ridges 40 and 42 are spaced apart on opposite sides of the nozzle's central inlet opening 24. They extend from the screw cap transverse wall 20 in a direction opposite the spout 32. The piercing ridges 40 and 42 are separated from each other by interposed notches 44 and 46 at the ends of the ridges 40 and 42. As seen in the Figures, the preferred ridges 40 and 42 lie along diametrically opposite segments of a circle and each ridge has a concave side 48 and 50 respectively facing the inlet opening 24. The preferred ridges 40 and 42 are nearly semicircular except for the segments of the circle where the notches 44 and 46 are formed. The ridges 40 and 42 have crests 52 and 54 respectively that are spaced apart from each other by less than the internal diameter 12 of the neck 10 so that they do not engage the container neck 10 when the dispenser nozzle is screwed down onto the container neck 10.

[0028] The ridges 40 and 42 are elastically bendable toward each other by forced engagement against the sealing membrane when the dispenser nozzle is screwed down onto the container neck 10. As will be described further in connection with the operation of the invention, as the elastically bendable ridges 40 and 42 are forced against the sealing membrane 14, the ridges are deformed and forced toward each other to form a piercing wedge. When the sealing membrane is pierced, and consequently the sealing membrane ceases to apply a significant force against the crests of the ridges, the elasticity of the ridges causes them to expand apart and away from each other to spread the pierced sealing membrane away from the central exit path along which the container contents flow through and out of the spout. [0029] The piercing ridges 40 and 42 of the preferred embodiment that is illustrated in the drawings have some preferred structural characteristics. It is preferred that the piercing ridges 40 and 42 have conically contoured, outwardly facing side wall surfaces 56 and 58. The base of the conically contoured outer surfaces 56 and 58 should have a diameter that does not exceed the internal diameter 12 of the container outlet neck 10 so that inner wall of the outlet neck 10 does not partially prevent the elastically bendable piercing ridges 40 and 42 from spreading back apart after the sealing membrane is punctured.

[0030] It is also preferable that the spout passage 16, the inlet opening 24 of the nozzle's screw cap 18 and the centrally facing side walls of the piercing ridges 40 and 42 are formed as a unitary, continuous, cylindrical passage that is aligned axially through the nozzle. Desirably, the notches 44 and 46 that separate the piercing ridges 40 and 42 are formed as slots along radials of the axis through the outlet passage 16 and most preferably are aligned along 180° opposed radials. The notches 44 and 46 desirably also have a trapezoidal outline and have side walls that taper further apart as they progress away from the wall 20 of the screw cap 18. The trapezoidal outline of the notches allows the ridges to bend further toward the central axis of the dispenser nozzle before the sidewalls of the notches make contact with each other after the ridges bend together. The notches also preferably extend from the crests of the piercing ridges toward, but less than the entire distance to, the screw cap wall 20.

[0031] Although prototypes of alternative structures have not been constructed and tested, it is believed that there are several structural variations from the preferred embodiment that can be made. For example, there can be more than two ridges separated from each other by notches. There could be three, four or more piercing ridges positioned around the central axis of the dispensing nozzle. Although arcuate ridges are preferred, the ridges could follow an alternative arrangement such as linear ridges. There could be three or more, such as several more, short ridges that come together as a more pointed piercing wedge, such as a pyramid or cone.

[0032] Of course the screw threads of the preferred embodiment of the invention are not limited to conventional threads that have several helical turns. Other twist and lock connections can be used that have short, high pitched segments of a helix that allow a cap to be axially translated a relatively long distance by a relatively short angular rotation. [0033] Referring to Fig. 11, as a dispensing nozzle embodying the invention is screwed onto the outlet neck 10, the elastically bendable ridges 40 and 42 move toward, and eventually against, the sealing membrane 14. The sealing membrane 14 initially contacts the crests 52 and 54 of the ridges. As the ridges are pressed into the sealing membrane, the membrane makes contact with and applies a force against the outer side walls 56 and 58 of the ridges. The force applied by the membrane against the outer side walls has a force component in the inward direction thereby bending the ridges toward the central axis. The inwardly directed force component deforms and bends the ridges forcing them toward each other. The notches 44 and 46 facilitate the bending of the ridges by preventing each ridge from applying a force against the opposite ridge as the ridges move toward each other. When the ridges contact each other, the piercing wedge that they form is then held rigidly in place by the opposite radially directed forces that each ridge applies to the other.

[0034] As the dispensing nozzle is rotated and progresses along the threads onto the container neck, those forces increase and consequently the amount of bending of the ridges increases, preferably until the ridges meet in contact to form a piercing wedge. Although it is not essential that the ridges move all the way into contact, the closer they come toward each other the smaller is the area over which the axial piercing force is distributed. As the contact area becomes smaller, the force per unit of area that is applied to the sealing membrane increases thereby making puncture more likely.

[0035] When the sealing membrane is eventually pierced, the puncture through the weakened and relaxed sealing membrane slides along the sidewalls of the ridges toward the transverse wall 20 of the screw cap. At that point the force applied by the sealing membrane to the ridges is drastically reduced or ceases completely. That reduction in the force against the outer sidewalls of the ridges allows the ridges to relax so that the elastic force of the bent ridges causes the ridges to expand apart and back toward the original position of their manufacture. This expansion apart of the ridges spreads the pierced sealing membrane away from the central exit passage so that there is a wide open passage for the container contents to flow out of the spout.

[0036] It should be apparent to those skilled in the art that this operation is dependent upon the interaction of many variables in the characteristics of both the elastically bendable ridges and the sealing membrane. These include the elasticity, tensile strength, flexural modulus and flexural strength of both the ridge and the sealing membrane materials, the physical structural configuration of the ridges and the dimensions of the ridges. Consequently, testing is desirable for any chosen combination of dispensing nozzle material and configuration and sealing membrane material and thickness. A dispensing nozzle designed for a particular sealing membrane may not function properly for one or more other sealing membranes.

[0037] Dispensing nozzles can be molded by selecting their material from a variety of alternative materials, commonly a plastic such as polyethylene, that have differing physical characteristics such as those mentioned above. The configuration and dimensions of the piercing ridges can also be varied. For example, the piercing ridges can be made higher or shorter and wider or narrower to modify the elasticity of the ridges and thereby modify the amount of bending that occurs as a function of the forces applied to the ridges by the sealing membrane. The surface configuration of the ridges can be another variable. The ridges can be formed with sharper or more smoothly rounded edges at the intersections of their surfaces. For example, it can be seen in the Figures that there is a chamfered surface 60 between the crests 52 and 54 of the piercing ridges 42 and 44 and the outer side walls 56 and 58 of the ridges 42 and 44. The number of piercing ridges that are arranged around the central axis of the nozzle can also be increased above two.

[0038] Fig. 12 shows the dimensions of the preferred embodiment that is illustrated in Figs. 1-11. Fig. 13 is a specification sheet for the material from which the preferred embodiment of the invention is made and illustrates the properties of materials that are suitable for constructing embodiments of the invention.

[0039] REFERENCE NUMERAL LIST

[0040] 10 container outlet neck

[0041] 12 internal diameter of the outlet neck

[0042] 14 sealing membrane

[0043] 16 outlet passage of the nozzle

[0044] 18 screw cap

[0045] 20 transverse wall of the screw cap

[0046] 22 end of the outlet neck

[0047] 24 inlet opening of the nozzle

[0048] 26 tubular skirt of the screw cap

[0049] 28 female threads of the screw cap [0050] 30 male threads of the container outlet neck

[0051] 32 spout

[0052] 40 one piercing ridge

[0053] 42 other piercing ridge

[0054] 44 first notch between the piercing ridges

[0055] 46 second notch between the piercing ridges

[0056] 48 concave side of ridge 40

[0057] 50 concave side of ridge 42

[0058] 52 crest of ridge 40

[0059] 54 crest of ridge 42

[0060] 56 conically contoured outer side wall of ridge 40

[0061] 58 conically contoured outer side wall of ridge 42

[0062] 60 chamfered surface on ridges

[0063] This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims.