SPRAY CAN

Abstract

An aerosol container comprises a can having an open end. A valve disk fitted to the open end is made of plastic and has a center part formed with a throughgoing hole defining an axis. A plurality of fingers extend axially from an inner face of the center part around the hole into the can and each have an inner end formed with a radially inwardly projecting barb spaced axially from the inner face. A dispensing valve has a tubular valve housing fitted between and gripped by the fingers and having an axially inwardly directed face on which the barbs bear axially outward. A seal is compressed axially between an outer end of the valve housing and the inner face of the disk around the hole.

Description

FIELD OF THE INVENTION

The present invention relates to an aerosol container. More particularly this invention concerns a spray can.

BACKGROUND OF THE INVENTION

A standard aerosol container comprises a vessel or can having a normally upwardly open end to which a valve disk with a dispensing valve is tightly fastened. The valve disk is made of plastic and has a center part with a hole for a valve member of the dispensing valve.

Such an aerosol container with the described features is known from DE 38 07 156. The valve disk and the valve housing of the dispensing valve are integrally formed from plastic. The can is also made of plastic and is welded to the valve disk.

Aerosol containers made mainly of metal, particularly tin or aluminum, are widely used. The valve disk is manufactured as a stamped and bent part from tin or a sheet of an aluminum alloy and positively connected to the can by crimping. The center part of the valve disk is a dome that forms a space for the valve housing of the dispensing valve. The valve housing, a valve member with a valve shaft (stem) and a seal are placed in the dome and fixed in the dome by crimping. The crimping results in a positive connection between the valve housing and the valve disk. An aerosol container with a metallic valve disk and a dispensing valve attached thereto by crimping is known, for example, from DE 20 38 580 [U.S. Pat. No. 3,675,832] and FR 2 925 032.

In practice, aerosol containers are manufactured in collaborative processes in which the container, the valve disk and the dispensing valve are manufactured by different companies. The dispensing valve is available in different structural designs with a great variety of constructions for producing different spray patterns that are selected according to application. The valve housing of the dispensing valve usually has at least similar and in part even standardized dimensions. They usually have a head with a front-side seal that can be inserted into a receiving space of the valve disk a dome.

In view of this background, it is the object of the invention to provide an aerosol container with the features described above that is designed such that the plastic valve disk can be equipped with a separately manufactured dispensing valve. Furthermore, the valve disk is optionally connectable to a metallic can or to an can made of plastic. Both the connection of the valve disk to the can and the equipping of the valve disk with a dispensing valve are to be simple in terms of assembly.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide an improved spray can or container.

Another object is the provision of such an improved spray can or container that overcomes the above-given disadvantages, in particular that is made of plastic and has a center part with a hole for a valve member of the dispensing valve.

SUMMARY OF THE INVENTION

An aerosol container comprises a can having an open end. A valve disk fitted to the open end is made of plastic and has a center part formed with a throughgoing hole defining an axis. A plurality of fingers extend axially from an inner lower face of the center part around the hole into the can and each have an inner end formed with a radially inwardly projecting barb spaced axially from the inner face. A dispensing valve has a tubular valve housing fitted between and gripped by the fingers and having an axially inwardly directed face on which the barbs bear axially outward. A seal is compressed axially between an outer end of the valve housing and the inner face of the disk around the hole.

Alternatively, the seal can be a component that is integrally molded onto the valve disk. After assembly of the dispensing valve, the fingers of the valve disk formed on the lower face are subjected substantially only to tensile stress. Since the fingers must be designed primarily for a single-axis tensile load, the fingers can be thin, have relatively thin wall thicknesses, and also not be subject to any substantial restrictions in terms of their length. The clamping length for the valve housing prescribed by the position of the inwardly projecting barbs can be adapted to the dimensions of the valve housing such that the valve housing rests against the front-side seal with sufficiently great sealing force.

According to a preferred embodiment of the invention, the fingers of the valve disk are spring-biased locking members and cooperate with an annular collar surface on the valve housing. To attach the dispensing valve to the valve disk, the dispensing valve is pushed by a straight-line movement into the space defined by the fingers until the fingers engage on the collar surface of the valve housing. Common assembly systems that commercial users usually already have on hand can be used for assembly.

It also lies within the scope of the invention for the valve housing to have segmented projections that form a bayonet joint with the barbs of the fingers. The bayonet joint is a positive connection that is produced by a straight-line movement in conjunction with rotation. By means of an axial assembly movement, the segmented projections of the valve housing can be introduced into the free space between the fingers of the valve disk. The axial assembly movement is executed until the valve housing reaches a stop, for example the center part of the valve housing. The valve housing is then rotated until the segmented projections on the valve housing engage behind the inwardly projecting barbs at the free ends of the fingers. By means of wedge-shaped sliding surfaces, the rotation can be combined with an axial actuation that presses the valve housing with a defined force against the seal.

Independently of whether the fingers are spring-biased locking members or cooperate in the manner of a bayonet joint with segmented projections on the valve housing, the fingers advantageously rest against a cylindrical annular ridge of the valve housing, thus securing the valve housing against transverse movement. According to a preferred embodiment of the invention, in order to connect the valve housing, four fingers are provided on the valve disk that enclose the valve housing.

The center part of the valve disk preferably has stiffening ribs. The number, geometry and alignment of the stiffening ribs are selected such that sufficient dimensional stability is imparted to the center part in order to withstand the axial forces that are produced by the pressure within the aerosol container and can occur both during the assembly of the dispensing valve and when filling the aerosol container. The stiffening ribs can particularly be aligned radially to the hole.

The valve disk can be manufactured cost efficiently as a plastic injection-molded part. It is particularly made of a fiber-reinforced plastic but can also be made from a plastic without fiber reinforcement. Plastics worthy of consideration are thermoplastic polymers, particularly polyethylene terephthalate (PET), polyamide (PA), polyethylene (PE), polypropylene (PP) and polybutylene terephthalate (PBT). When using a multi-component injection molding technique, the valve disk can have integral sealing components that are made, for example, of a thermoplastic elastomer, silicon rubber or rubber.

According to a preferred embodiment of the invention, the center part is outwardly convex. The inventive shape of the center part enables the valve disk to be manufactured with little material.

Advantageously, the valve disk also has a collar that rests on a can inner surface bordering the can opening and is supported on the can wall, As a result of the collar, the can opening is centered within the can opening. The axial support facilitates, among other things, the positioning of the valve disk during the assembly process.

The can may be made of metal or plastic. A metal can is advantageously connected positively to the valve disk by crimping. If the valve disk is intended for a positive connection to a metal can, the valve disk advantageously has a collar with at least one radial rib, the rib being flanged to the sheet metal of the can and a seal being clamped between the collar and the sheet metal of the can.

If the can is made of plastic, several possibilities for connecting the valve disk to the can are worthy of consideration. For instance, the valve disk can be welded or adhered to the plastic can. A positive connection to the can edge can be produced by hot shaping the valve disk. Moreover, it is possible to connect the valve disk and a can made of plastic by hot stamping. To connect the plastic head to a can that is preferably made of plastic, a non-detachable screw connection or a plug connection using a multi-part clamping device is also suitable.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a longitudinal axial section through the invention;

FIGS. 2a and 2b are perspective bottom and top views of a valve disk for the container shown in FIG. 1;

FIG. 2c is a large-scale partly sectional side perspective view of the valve disk; and

FIGS. 3 to 14 show additional embodiments of the container shown in FIG. 1.

SPECIFIC DESCRIPTION OF THE INVENTION

FIG. 1 shows a cup-shaped vessel or can 1 having an open upper end to which a valve disk 2 with a dispensing valve 3 is tightly attached. The valve disk 2 is made of plastic and has a center part 4 with a hole 5 for a valve body of the dispensing valve 3. The can 1 and hole 5 are centered on a normally vertical axis A. The valve member is also referred to as a stem. Fingers 6 are formed on the lower face of the center part 4 that have radially inwardly projecting barbs 7 on their free end. The dispensing valve 3 has a tubular valve housing 8 that extends into a space defined by the fingers 6 of the valve disk 2, the barbs 7 of the fingers 6 engaging axially behind an radially projecting ridge 9 of the valve housing 8 and pressing the valve housing 8 against a seal 10 between the valve housing 8 and the valve disk 2.

The fingers are spring-biased locking members and cooperate with the annular ridge on the valve housing 8. The fingers 6 rest against a cylindrical circumferential surface or annular collar surfaces 11 of the valve housing 8 (FIG. 10).

It can be seen from FIG. 1 in conjunction with FIGS. 2a to 2c that four fingers 6 provided for attaching the valve housing 8 surround the valve housing 8 equiangularly. The center part 4 of the valve disk 2 has stiffening ribs 12 extending radially to the hole 5. In the illustrated embodiment, the stiffening ribs 12 are on the lower face of the center part. However, the stiffening ribs 12 can also be provided on the upper face of the center part 4. The stiffening ribs 12 impart dimensional stability to the valve disk 2 to absorb the container inner pressure and absorb axial forces that can occur during mounting of the dispensing valve 3 on the valve disk 2 and during filling of the aerosol container in a filling system.

The valve disk 2 shown in FIGS. 2a to 2c has a collar 13 that rests against a can inner surface of the can opening and is supported axially on the can rim. The center part of the valve disk is arched outward.

The valve disk 2 is made of a fiber-reinforced plastic. Examples of suitable plastics are polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polyamide (PA) and polybutylene terephthalate (PBT), and the fiber content can be 30 to 40% by weight. Depending on requirements, unreinforced plastics can also be used. The valve disk 2 is preferably injection-molded.

The can 1 can be made of metal or plastic. The embodiment shown in FIG. 3 is a can 1 made of sheet metal that is connected positively to the valve disk 2 by crimping. The valve disk 2 has a collar 14 with two radially projecting ridges 15, 15′ of which one is being flanged by the sheet metal of the can 1, and a seal 16 is clamped between the collar 14 and the sheet metal of the can 1.

In the embodiment of FIG. 4, the can 1 is made of plastic and has a mouthpiece 17 that engages in an annular groove 18 of the valve disk 2 and rests against a seal 19 in the annular groove 18. The seal 19 can be laid into the annular groove as a separate seal ring or be made of a sealing component that is integral with the valve disk 2 or injected into the annular groove 18 before assembly and hardened chemically, thermally or with special light. The annular groove 18 is bordered by an inner wall 20 of the valve disk 2 resting against the can inner wall and by an outer wall 21. The outer wall 21 has a profile created by thermal shaping that engages positively around the mouthpiece 17 of the can 1.

In FIG. 5, the can 1 is also made of plastic. The valve disk 2 has a collar 22 that is connected by hot stamping to a mouthpiece 23 of the can 1. A seal 24 is provided between the collar 22 and the wall surface of the can 1. This seal 24 can be a seal ring. The seal 24 can particularly be made of a thermoplastic elastomer that has been formed on the valve disk 2 in a multi-component injection molding process, for example. FIG. 5a shows one design variant. The seal 24 is formed here on an annular bearing surface of the valve disk.

FIGS. 6a and 6b also show a valve disk 2 that has been connected to the mouthpiece 23 of the plastic can 1 by hot stamping. The seal 24 consists of an elastic sealing component that is formed on the valve disk 2. The valve disk 2 has stiffening ribs 12 both on the upper face and on the lower face of the center part 4. An arrangement of annular stiffening ribs and stiffening ribs aligned radially to the hole is provided.

In the embodiment of FIG. 7, the valve disk 2 is connected by a laser weld seam 25 to the plastic can 1. The laser weld seam 25 connects a collar 13 of the valve disk 2 that rests against a can inner surface of the can opening. The laser weld seam 25 can be produced by a radial laser welding method in which the laser beam is deflected by a mirror such that it strikes the rotationally symmetrical surface of the parts to be welded. Alternatively, welding methods can also be used in which the workpiece is rotated about its longitudinal axis. With the aid of the laser welding method, a pressure-tight, non-detachable connection can be produced. Additional seals can be eliminated. The weld joint can be produced with short cycle times. The wall of the can 1 must be laser-permeable, while the valve disk 2 is made of a laser-absorbing material. According to a design variant shown in FIG. 7a, the laser weld seam 25 is on an annular end face.

Adhesive joints between the valve disk 2 and a plastic can 1 are shown in FIGS. 8 and 9. In the embodiment of FIG. 8, the rim 26 of the can 1 defining the can opening engages in an annular groove 27 of the valve disk 2, the gap between the mutually engaging parts being filled with a hardened hot melt adhesive 28. To make the adhesive joint, a welding auxiliary body is placed in the annular groove 27. Through inductive heating of the welding auxiliary body, it is liquefied and fills the gap between the parts to be connected. This results in permanent, heat-resistant and impact-resistant adhesion with a high degree of strength.

According to FIG. 9, the can has a collar 29 with at least one pocket 30, it being possible for the pocket 30 to be an annular groove. The valve disk 2 rests on the collar 29 and has a connecting member 31 engaging in the pocket 30. The gap of the mutually engaging parts is filled by a hardened hot melt adhesive 28. The adhesive joint is made in the same way as described above.

FIGS. 10 and 11 relate to screw connections between the valve disk 2 and the can 1. The can 1 is a blow-molded plastic can and has a collar 32 with a screwthread that can be an internal screwthread 33 or external screwthread 34. In the embodiment of FIG. 10, the screwthread is an internal screwthread 33. The valve disk 2 is connected by a non-detachable screw connection to the collar 32, a seal 35 being provided between the collar 32 and the valve disk 2. In the embodiment of FIG. 11, the screw connection comprises a lock nut 36 that is screwed onto an external screwthread 34 of the collar 32 and presses the valve disk 2 against the collar. Here, too, a seal 35 is provided between the collar 32 and the valve disk 2. The screw connections shown in FIGS. 10 and 11 are non-detachable. They advantageously have locking members that prevent rotation of the screw-together parts in the opening direction.

Instead of a screw connection, a positive connection by a bayonet joint is also possible.

FIG. 12a shows a plug connection 37 using a clamping member 38 shown in FIG. 12b for connecting the valve disk 2 to a plastic can. The plastic can 1 has a cylindrical neck 39 in which a collar 40 of the valve disk 2 engages. An outer clamping ring 41 is connected to the valve disk 2 that encloses the neck 39 and borders a cross-sectionally wedge-shaped annular space between the neck 39 and the outer clamping ring 41. The outer clamping ring 41 is firmly connected to the valve disk 2, for example by laser welding. An inner clamping ring 42 is provided within the outer clamping ring 41 that fills the wedge-shaped annular space. The arrangement shown in FIG. 12b must still be completed through the mounting of a dispensing valve that can be pushed into the neck 39. Once the position shown in FIG. 12a is reached, the arrangement can no longer be pulled off the neck 39, since the inner clamping ring 42 wedges the outer clamping ring 41 with the neck 39. If the interior of the can 1 is pressurized after a container filling, forces are exerted on the valve disk 2 and neck 39 that are indicated by arrows in FIG. 12a. As a result of these forces, the parts 39, 41, 42 wedge each other.

A seal 43 is provided in the wedge-shaped annular space that is deformed by an axial relative movement of the two clamping rings 41, 42 and rests against an inner surface of the outer clamping ring 41 and an outer surface of the neck 39. Moreover, at least one ring seal 44 is provided on the collar 40 of the valve disk 2 that rests against the inner surfaces of the neck 39. Finally, the surfaces of the inner clamping ring 41 and of the neck 39 that face each other have profiling 45 for relatively locking their surfaces. The connection can no longer be detached after assembly. The internal pressure in the container after filling of the aerosol container increases the clamping effect between the parts.

The valve disk can also be connected to the can by a locking connection. In the embodiment of FIG. 13, the valve disk 2 has locking hooks 46 that engage behind an annular collar 47 of the inner surface of the can. The locking connection on the inner surface of the can is inaccessible from outside and non-detachable. Moreover, an elastomeric sealing surface 48 is formed on the valve disk 2. According to the illustration in FIG. 14, the locking hooks 46 can also engage behind an annular ridge 47′ on the outer surface of the can. To secure a locking connection on an outer surface of the can, a clamping ring (not shown) can be used that prevents the locking hooks from being bent up.

Claims

1. An aerosol container comprises:

a can having an open end;

a valve disk fitted to the open end, made of plastic, and having a center part formed with a throughgoing hole defining an axis;

a plurality of fingers extending axially from an inner face of the center part around the hole into the can and each having an inner end formed with a radially inwardly projecting barb spaced axially from the inner face;

a dispensing valve having a tubular valve housing fitted between and gripped by the fingers and having an axially inwardly directed face on which the barbs bear axially outward; and

a seal compressed axially between an outer end of the valve housing and the inner face of the disk around the hole.

2. The aerosol container defined in claim 1, wherein the valve housing is formed with an annular shoulder forming the inwardly directed face that is planar.

3. The aerosol container defined in claim 1, wherein the valve housing has segmented projections that form a bayonet joint with the barbs of the fingers.

4. The aerosol container defined in claim 1, wherein the valve housing is formed with a radially projecting ridge against which the fingers bear elastically and radially inwardly.

5. The aerosol container defined in claim 1, wherein the center part is formed with stiffening ribs.

6. The aerosol container defined in claim 5, wherein the stiffening ribs extend radially outward from the hole.

7. The aerosol container defined in claim 1, wherein the disk is of a fiber-reinforced plastic.

8. The aerosol container defined in claim 1, wherein the center part is axially outwardly convex.

9. The aerosol container defined in claim 1, wherein the valve disk has an outer periphery formed with an axially inwardly projecting annular collar fitted to the open end of the can.

10. The aerosol container defined in claim 9, wherein the can is made of sheet metal and connected positively to the valve disk by crimping.

11. The aerosol container defined in claim 10, wherein the collar is formed with at least one radial rib crimped to the open end of the sheet-metal can, the container further comprising a seal between the collar and the can.

12. The aerosol container defined in claim 1, wherein the can is made of plastic and has a mouthpiece centered on the axis and formed with an axially outwardly projecting rim, the disk being formed with an annular axially inwardly open groove fitting complementarily over the rim and formed between an inner wall and an outer wall, the outer wall being thermally shaped to engage positively around the rim.

13. The aerosol container defined in claim 1, wherein the valve disk has an outer periphery, the can being made of plastic and thermally deformed at the open end around the outer periphery, the container further comprising

a seal between the outer periphery and the open end of the can.

14. The aerosol container defined in claim wherein the can is made of plastic and is adhered to the valve disk or tightly connected thereto by at least one laser weld seam.

15. The aerosol container defined in claim 1, wherein the can has a collar with a screwthread and that the valve disk is provided with a screwthread fitted to the screwthread of the collar, the container further comprising

a seal between the collar and the valve disk.

16. The aerosol container defined in claim 15, wherein the screwthreads have locking members that prevent rotation of the screwed-together disk and can in an opening direction.

17. The aerosol container defined in claim 1, wherein the valve disk has an outer periphery formed with an axially centered annular collar and the can is made of plastic and has a cylindrical neck in which the collar fits, the container further comprising:

an outer clamping ring attached to the disk and forming with the can a triangular-section space; and

a triangular-section inner clamping ring fitted in the space and engaging radially inward on the can and radially outward on the outer clamping ring.

18. The aerosol container defined in claim 1, wherein the can has at its open end a radially projecting annular collar centered on the axis and the lid is formed with axially projecting barbed arms that snap into engagement under the collar when the disk is fitted to the open end.

19. The aerosol container defined in claim 1, wherein the can and valve housing are rotation symmetrical to the axis of the hole.

20. The aerosol container defined in claim 1, wherein the dispensing valve includes a spring-biased valve body inside the valve housing.