WO2005092537A1

WO2005092537A1 - Method of molding and assembling valve components

Info

Publication number: WO2005092537A1
Application number: PCT/US2005/002976
Authority: WO
Inventors: Richard D. Lohrman
Original assignee: Portola Packaging, Inc.
Priority date: 2004-03-05
Filing date: 2005-02-02
Publication date: 2005-10-06

Abstract

A method of molding and assembling valve components by providing a mold cavity (39) defining the outside surface of a valve cover (35), a first mold core defining the inside surface of the valve cover, and a second mold core (49) defining the insider surface of a valve member (37); closing the first mold core against the mold cavity, injecting a first material to form the valve cover between the first mold core and the mold cavity, and retracting the first mold core from the mold cavity and the newly formed valve cover; closing the second mold core against the mold cavity with the valve cover within the mold cavity, injecting a second material to form the valve member in situ between the second mold core and the valve cover, and retracting the second mold core from mold cavity and the newly formed valve member; and removing the valve member and the valve cover from the mold cavity.

Description

METHOD OF MOLDING AND ASSEMBLING VALVE COMPONENTS

BACKGROUND OF THE INVENTION

Field of the Invention

[oooi] This invention relates, in general, to method of molding and assembling valve components and more particularly to a method of molding a valve component in situ on a valve cap in order to facilitate assembly thereof with a separately molded valve body.

Description of Related Art

[00021 A variety of fluid containers that are capable of dispensing fiowable materials are well known. Some fluid containers include vacuum valves to prevent spillage of the contents of the container. For example, U.S. Patent No. 6,554,023 to Danby et al. discloses a vacuum demand flow valve for a fluid container. The vacuum demand flow valve generally includes a housing 12, a diaphragm 14, and a cover 20. The diaphragm includes a stop 18 that is configured to close a passageway extending through the housing upon application of vacuum to a first opening 28.

[ooo3] While such vacuum valves a quite useful in preventing inadvertent spillage of the contents of the respective fluid container, the manufacture of such vacuum valves is not simple. The housing, diaphragm and cover are discrete components that are often injection molded and subsequently assembled. The relatively small size, complex shape and resilient nature of the diaphragm may necessitate manual assembly of the diaphragm with the housing. Disadvantageously, such assembly increases the costs involved in manufacturing such vacuum -valves.

[000 ] What is needed is an improved method of molding and assembling valve components that overcomes the above and other disadvantages of manufacturing such prior vacuum valves.

BRIEF SUMMARY OF THE INVENTION

[0005] On aspect of the present invention is directed to a method of molding and assembling valve components. The method of molding and assembling valve includes the steps of: providing a mold cavity defining the oxitside surface of a valve cover, a first mold core defining the inside surface of the vaK/e cover, and a second mold core defining the insider surface of a valve member; closing the first mold core against the mold cavity, injecting a first material to form the ^{^}valve cover between the first mold core and the mold cavity, and retracting the first mold core from the mold cavity and the newly formed valve cover; closing the second mold core against the mold cavity with the valve cover within the mold cavity, injecting a second material to form the valve member in situ between the second mold core and the valve cover, and retracting the second mold core from mold cavity and the newly fonxted valve member; and removing the valve member and the valve covear from the mold cavity.

[0006] In one embodiment, the first material is a thermoplastic. The first material may be polypropylene. Alternatively, the first material may >e polyethylene. The second material may be a thermoplastic elastomer.

[oooη In one embodiment, the valve member and the valve cover are removed from the mold cavity as an integral valve unit. The valve member may be adhesively bonded to the valve cover. The valve cover may include a vent hole. The method may further include the step of applying pressure to the vent bxole to overcome the adhesive bond between the valve member and the valve cover. [0008] The method may further include the step of aligning the integral unit with a valve chamber opening of a valve body. In one embodiment, the valve member includes a diaphragm and a valve stem and the valve body includes a valve seat opening. The method may further include the step of inserting the valve stem through the valve seat opening. In one embodiment, the method may further include the step of aligning the integral unit with a valve chamber opening of a valve body. The valve member may include a diaphragm and a valve stem, and the valve body may include a valve seat opening. The method may further include the step of mounting the valve unit on the valve body such that the valve diaphragm covers the valve chamber opening. In one embodiment, the valve cover includes a vent hole, and the method may further include the step of applying pressure to the vent hole to overcome the adhesive bond between the valve member and the valve cover and seat the valve stem against the valve seat opening.

[0009] An object of the present invention is to reduce manufacturing costs involved with molding and assembling valve components.

[ooioi The method of molding and assembling valve components of the present invention has other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description of the Invention, which together serve to explain the principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[ooii] FIG. 1 is a schematic, cross-sectional view of a mold cavity and a first mold core utilized to form a valve cover in accordance with the present invention, the mold cavity and the first mold core shown closing together.

[ooi2] FIG. 2 is a schematic, cross-sectional view of the mold cavity and first mold core in a closed position forming a void corresponding to the shape of the valve cover. [0013] FIG. 3 is a schematic, cross-sectional view of the valve cover formed between the mold cavity and first mold core.

[ooi4] FIG. 4 is a schematic, cross-sectional view of the first mold core retracted from the mold cavity and valve cover, the valve cover remaining within the mold cavity.

[ooi5] FIG. 5 is a schematic, cross-sectional view of the mold cavity and a second mold core utilized to form a valve member in situ against the valve cover in accordance with the present invention, the mold cavity and second mold core in a closed position forming a void corresponding to the shape of the valve member.

[ooi6] FIG. 6 is a schematic, cross-sectional view of valve member formed in-situ against the valve cover, between the mold cavity and the second mold core.

toon] FIG. 7 is a cross-sectional side view of the second mold core retracted from the mold cavity and with a valve unit, that is, the valve cover and valve member remaining within the mold cavity.

[ooi8] FIG. 8 is a cross-sectional side view of the valve unit removed from the mold cavity.

[ooi9] FIG. 9 is a cross-sectional side view of the valve unit after the valve member has been separated from the valve cover.

[0020] FIG. 10 is a cross-sectional side view of the valve unit in an aligned position ready for assembly with a valve body.

[0021] FIG. 11 is a cross-sectional side view of an assembled valve including the valve cover and valve member mounted on the valve body. [0022] FIG. 12 is a cross-sectional side view illustrating an alternative method of assembly in which the valve unit is in an aligned position ready for assembly with the valve body but the valve member has not yet been separated from the valve cover.

[0023] FIG. 13 is a cross-sectional side view of the valve unit is mounted on the valve body and the valve member still has not been separated from the valve cover.

[0024] FIG. 14 is a cross-sectional side view of the assembled valve in which the valve member has been separated from the valve cover while the valve unit is mounted on the valve body.

DETAILED DESCRIPTION OF THE INVENTION

[0025] Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

[0026] Turning now to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is directed to FIGS. 1-7, which figures illustrate a method of molding valve components in accordance with the present invention.

[0027] In one embodiment, the method of molding valve components of the present invention may be utilized to form a valve-cover/valve-member assembly, generally designated as valve unit 30 (FIG. 8), that, in turn, may be used in the manufacture of a suction valve 32 (FIG. 11). In some aspects, the valve is similar to the vacuum demand flow valve for a fluid container disclosed by U.S. Patent No. 6,554,023 to Danby et al., the entire content of which is incorporated herein by this reference. One will appreciate that the method of the present invention may also be utilized in the manufacture of other types of valves utilizing discrete components of differing materials. One will also appreciate that the method of the present invention may also be utilized to manufacture other products having a relatively rigid component and complementarily shaped, relatively resilient component.

[0028] The inventive manufacturing process of the present invention is particularly suitable for molding and assembling valve components of the type including a resilient valve member 33 encased by a relatively rigid valve cap 35 and a valve body 37. In particular, the process is capable of molding the valve cap and valve member together as a pre-assembled valve unit 30 and applying the pre-assembled unit to the valve body.

[0029] The rigid valve cap and the resilient valve member are molded in a single mold cavity 39. The valve member is preferably formed of a thermoplastic elastomer (TPE) while the cap is preferably formed of a thermoplastic such as polypropylene (PP) or polyethylene (PE). One will appreciate, however, that other suitable materials may be utilized for the valve cap and the valve member. For example, the valve member may be formed of any relatively flexible material that provides a resilient valve element, while the valve cap may be formed of any relatively rigid material that provides structural integrity to the valve.

[0030] The mold cavity defines the outer surface 40 of the valve cap and is used in combination with a first mold core 42 to form the shape of the valve cap (FIGS. 1-3). The first mold core defines the inner surface 44 of the valve cap. The mold cavity is also configured to form a vent hole 46 extending through the top of the valve cap. Preferably, the vent hole is located above the valve member, as will be appreciated below.

[0031] Once the valve cap is molded, the first mold core is removed (FIG. 4). The inner surface of the cap may now be utilized as an "interim cavity" upon which the valve member may be formed in situ against the valve cap. The interim cavity, that is, the inner surface 44 defines the outer surface 47 of the valve member and is used in combination with a second mold core 49 to fonn the shape of the valve member (FIGS. 5 and 6). In particular, the inner surface of the valve cap defines the outer surface of a valve member diaphragm 51, while the second mold core defines the inner surface of the diaphragm. The second mold core also defines the overall shape of a valve stem 53 and a valve seal 54 of the valve member.

[0032] The valve member is molded in situ against the inner surface of the valve cap and thus pre-assembled with the valve cap and remains with the valve cap within mold cavity as the second valve core is retracted (FIG. 7). Thus, the valve member and the valve cap may be ejected or otherwise removed from the mold cavity as an assembled unit, that is, as an integral valve unit 30 (FIG. 8).

[0033] Suitable means may be employed to separate the valve member from the valve couple in accordance with the present invention (see FIG. 9). In one embodiment, a fluid pressure source 56 is fluidly coupled with the vent hole in order to quickly and efficiently separate the valve member from the valve cover. For example, pressurized air may be applied to the vent hole to force the valve diaphragm, and remaining portions of the valve member, away from the inner surface of the valve cover. Preferably, the amount of pressure and volume of air is sufficient to overcome any adhesive bond between the valve member and the valve cover, but insufficient to unseat the valve member from the valve cover. One will appreciate that suitable tooling or clamping means maybe employed, if necessary, to prevent the valve member from "popping out" of the valve cover.

[0034] The valve unit, that is, the valve cover with the valve member still seated therein, may be aligned with a valve chamber opening 58 the valve body (FIG. 10) using an assembly machine or other suitable means. Next, the valve unit may be mounted on the valve body such that valve stem is inserted into a valve seat opening 60 (FIG. 11).

[0035] Advantageously, the inventive manufacturing process significantly reduces manufacturing costs. Firstly, the process reduces the number of mold cavities and molding machines required to manufacture the components of the valve. Secondly, the process requires the assembly of only two parts instead of three, namely, the pre- assembled unit and the body. Thirdly, the process eliminates separate handling of the TPE valve member that, due to the inherent flexibility of the valve member, is generally difficult to feed into an assembly machine and often requires manual handling and/or assembly. Thus, the inventive manufacturing process increases speed and lowers assembly costs.

[003 ] In another embodiment, the valve member is not separated from the valve cover until the valve unit has been mounted on a valve body. In this embodiment, an assembly machine, or other suitable means, may be used to align the pre-assembled valve unit 30 to the valve body 37 (FIG. 12) while the valve member remains attached to the inside surface of the valve cover, and subsequently mounted on to the valve body (FIG. 13). Due to the resilient nature of valve member 33, valve seal 54 may or may not fully seat within valve seat opening 60 of the valve body (see, e.g., FIG. 13). The assembly machine may be configured to apply air pressure through the vent hole of the cap to separate the valve member from the valve cover and ensure that the valve seal is fully seated (FIG. 14). In the event that the valve member is separated, or partially separated from the valve cover prior to assembly with the valve body, air pressure may be applied simply to ensure that the valve seal is fully seated through the valve seal opening. In either case, the air pressure will cause the valve member diaphragm to flex downwardly from the valve cap and will thus complete assembly of the valve by pushing the valve seal through the valve seat opening of the valve body.

[0037] For convenience in explanation and accurate definition in the appended claims, directional terms such as "up" or "upper", "down" or "lower", "inside" and "outside" are used to describe features of the present invention with reference to the positions of such features as displayed in the figures.

[00381 The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.

Claims

WHAT IS CLAIMED IS: 1. A method of molding and assembling valve components, said method of molding and assembling valve components comprising: providing a mold cavity defining the outside surface of a valve cover, a first mold core defining the inside surface of said valve cover, and a second mold core defining the insider surface of a valve member; closing said first mold core against said mold cavity, injecting a first material to form said valve cover between said first mold core and said mold cavity, and retracting said first mold core from said mold cavity and said newly formed valve cover; closing said second mold core against said mold cavity with said valve cover within said mold cavity, injecting a second material to form said valve member in situ between said second mold core and said valve cover, and retracting said second mold core from mold cavity and said newly formed valve member; and removing said valve member and said valve cover from said mold cavity.

2. The method of molding and assembling valve components according to claim 1, wherein said first material is a thermoplastic.

3. The method of molding and assembling valve components according to claim 2, wherein said first material is polypropylene.

4. The method of molding and assembling valve components according to claim 2, wherein said first material is polyethylene.

5. The method of molding and assembling valve components according to claim 2, wherein said second material is a thermoplastic elastomer.

6. The method of molding and assembling valve components according to claim 1, wherein said valve member and said valve cover are removed from said mold cavity as an integral valve unit.

7. The method of molding and assembling valve components according to claim 6, wherein said valve member is adhesively bonded to said valve cover.

8. The method of molding and assembling valve components according to claim 7, wherein said valve cover includes a vent hole.

9. The method of molding and assembling valve components according to claim 8, further comprising the step of applying pressure to said vent hole to overcome the adhesive bond between said valve member and said valve cover.

10. The method of molding and assembling valve components according to claim 6, wherein said valve cover includes a vent hole.

11. The method of molding and assembling valve components according to claim 10, further comprising the step of applying pressure to said vent hole to overcome the adhesive bond between said valve member and said valve cover.

12. The method of molding and assembling valve components according to claim 11, further comprising the step of aligning said integral unit with a valve chamber opening of a valve body.

13. The method of molding and assembling valve components according to claim 12, wherein said valve member includes a diaphragm and a valve stem and said valve body includes a valve seat opening, said method further comprising the step of inserting said valve stem through said valve seat opening.

14. The method of molding and assembling valve components according to claim 6, further comprising the step of aligning said integral unit with a valve chamber opening of a valve body.

15. The method of molding and assembling valve components according to claim 14, wherein said valve member includes a diaphragm and a valve stem and said valve body includes a valve seat opening, said method further comprising the step of mounting said valve unit on said valve body such that said valve diaphragm covers said valve chamber opening.

16. The method of molding and assembling valve components according to claim 15, wherein said valve cover includes a vent hole, said method further comprising the step of applying pressure to said vent hole to overcome the adhesive bond between said valve member and said valve cover and seat said valve stem against said valve seat opening.