Information
-
Patent Grant
-
6547162
-
Patent Number
6,547,162
-
Date Filed
Friday, December 8, 200023 years ago
-
Date Issued
Tuesday, April 15, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Sleath; Janet
- Benado; Lisa N.
-
CPC
-
US Classifications
Field of Search
US
- 239 398
- 239 8
- 239 333
- 239 343
- 239 344
- 239 350
- 239 353
- 239 357
- 239 360
- 239 370
- 239 409
- 239 413
- 239 419
- 239 426
- 239 427
- 239 434
- 239 5903
- 239 590
- 239 369
- 222 190
- 222 3211
- 222 3219
- 222 1451
-
International Classifications
-
Abstract
A new foam spraying apparatus 1 is described for a liquid container. It comprises a piston and cylinder unit (20; 37) for the air and a piston and cylinder unit (21; 38) for the liquid in which arrangement the piston and cylinder units (20, 37; 21, 38) each are provided with an inlet valve (30; 44) and with an outlet valve (24) and are co-operating being coupled to each other. Furthermore a mixing chamber (14) for the mixture of air and liquid and a spraying head (2) with a foam delivery opening (9) are provided. The cylinder (20) of the first unit and the piston (21) of the second unit are interconnected to an intermediate part (5). Furthermore the piston (37) of the first unit and the cylinder (38) of the second unit are also interconnected to a base part (4) in such a manner that the intermediate part (5) and the base part (4) mesh and are movable relative to each other.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a foam spraying apparatus according to the introductory part of the claim
1
.
2. Description of the Related Art
A foam spraying device of such type is known e.g. from the International Patent Application WO-A-93/13829. There a foam spraying device is described with a container containing a foamable liquid, a valve, a delivery opening for the foam generated as well as a sieve between the delivery opening and the valve for obtaining the desired mixture of liquid and air. Furthermore between the valve and the sieve a perforated disk is provided in which the perforations in the form of holes or slots are arranged along the periphery in order to better mix liquid and air. By using a pump a pressure within the container is built up. A conventional spraying nozzle shall be moved against the force of a pressure spring towards the container body so that the air is entered and mixed with the liquid by means of the sieve and the perforated disk in such a manner that a foam is formed and is given off at the delivery opening.
This known foam spraying device comprises a multitude of individual parts made from various materials such as synthetic materials and metals. Manufacture of a foam spraying device of this type thus is rather expensive. It is a further disadvantage of the known foam spraying device that for generating sufficient pressure within the container the pump must be operated several times before foam can be delivered.
Furthermore from the European Patent Application EP-A-0 392 238 a foam spraying device is known with a shifting piston or media pump for the liquid and an air compressor pump each provided with an inlet valve and an outlet valve. The air compressor pump is arranged on the same axis with, and adjoining, the media pump, both pumps being operated at the same time using a cap-shaped handle. In this arrangement the back piston end of the shifting piston pump is provided with a long piston shaft in which a shaft with a disk-shaped valve closing element is arranged. A set-back spring is provided between the bottom wall and the valve closing element. For generating foam a mixing chamber with an adjacent foaming body is provided.
This foam spraying device also comprises a great number of individual elements which present particularly complex shapes in order to ensure correct co-operation. Due to the line-up of the air compressor pump and the media pump this device is of considerable length which impedes operation.
On the other hand from the French Patent Application FR-A-2 317 969 a spray device is known which comprises two pumps, one for the air and one for the liquid, arranged between the spray head and the liquid container. The liquid pump consists of two tubes shiftable inside each other of which tubes the lower one can be closed against the liquid container by a valve body with a hollow plunger. The spraying cap also forms the cylinder of the air pump which can be moved up and down inside a shorter cylinder portion of a larger diameter. The spraying cap furthermore is provided in its upper zone with a spraying nozzle with a mixing chamber which via valve-like structures is connected to the air pump and the liquid pump. Using a very complex design lay-out with small ducts the connection is ensured between the cylinder elements and the air pump and the liquid pump. No mixing chamber with a foaming body being provided and thus no foam can be generated using the proposed spraying device.
The spaying device so described also comprises a great many individual parts made from various materials. The intake tube e.g. is made from extruded polythene and the spraying cone is injection moulded from polythene. The valve body and the plunger can be made from low density polythene.
SUMMARY OF THE INVENTION
It is the objective of the present invention to improve a foam spraying apparatus of the type described above in such a manner that it comprises a substantially reduced number of individual parts and permits foam generation in a simple manner.
These objectives are met using an apparatus presenting the characteristics according to the patent claim 1.
The inventive foam spraying apparatus for a liquid container with an air suction device, a mixing chamber for the air and liquid blend and a spaying head with a foam delivery opening comprises between the spraying head and the liquid container a first piston and cylinder unit for the air and a second piston and cylinder unit for the liquid each provided with an inlet valve and an outlet valve which co-operate being mutually coupled. Thus the inventive foam spraying apparatus presents the substantial advantage that in one manual movement air is compressed as well as liquid is expulsed whereas during expansion of the spraying head air and liquid are sucked in again. In this fast and simple manner a large quantity of foam can be generated without application of the usual propellant gases. The inventive foam spraying apparatus furthermore is characterised in that the cylinder of the first unit and the piston of the second unit are interconnected to an intermediate part and that the piston and the cylinder of the second unit are interconnected to a base part in such a manner that the intermediate part and the base part engage one another movable relative to each other.
In an advantageous embodiment of the present invention the cylinder of a first unit and the piston of the second unit form a unit body as intermediate part and the piston of the first unit and the cylinder of the second unit form a unit body as base part. In a further advantageous embodiment the piston of the second unit is laid out eccentrically with respect to the first unit. In this arrangement a space saving engagement of the two piston and cylinder units is obtained A further variant is laid out in such a manner that the piston of the second unit is arranged concentrically with the cylinder of the first unit, i.e. inside the latter unit. This presents the advantage that the insert containing the mixing chamber is shorter and thus an optimum layout of the foam spraying apparatus can be achieved It proves advantageous to provide the pistons of both units each with a sealing ring in order to ensure optimal intake of air and liquid.
Advantageously the mixing chamber is formed by an insert between the spraying head and the intermediate element. In this arrangement the mixing chamber can present a tapered inlet opening for the air and a tapered inlet opening for the liquid. For correct foam generation it has proven advantageous if after the air inlet opening and after the liquid inlet opening, as seen in the flow direction, a fine mesh sieve is provided. It has proven particularly advantageous if a foaming chamber with a second fine mesh sieve is provided. In practical use it has proven useful if the spraying head, the insert, the intermediate element, and the base part are made from an injection moulded hard synthetic material.
Manufacture of the foam spraying apparatus advantageously is effected using injection moulding of a two-component synthetic material. Particularly proven is if simultaneously the elements serving as valves and as sealing rings made from a rubber plastic synthetic material in the injection moulding process are surrounded by the corresponding elements coordinated to them.
Manufacture of the inventive foam spraying apparatus thus is much simpler and more cost-efficient as only a small number of individual parts is required.
BRIEF DESCRIPTION OF THE FIGURES
Further advantages of the invention are described in the dependent claims and in the following description in which the present invention is discussed in more detail with reference to a design example illustrated in the schematic drawings. It is shown in:
FIG. 1
a cross-sectional view of a foam spraying apparatus with a spraying head and a screw-on part for the container (not shown) in its released state,
FIG. 2
the same foam spraying apparatus according to the
FIG. 1
in its compressed state,
FIG. 3
an axonometric view of the foam spraying apparatus according to the
FIG. 1
,
FIG. 4
an axonometric view of the foam spraying apparatus according to the
FIG. 2
, and
FIG. 5
an axonometric exploded view of the foam spraying apparatus.
In the Figures identical elements are designated by the same reference signs and explanations given pertain to all subsequent Figures unless stated otherwise.
DETAILED DESCRIPTION OF THE INVENTION
In the
FIGS. 1 and 2
a cross-sectional view is shown of a foam spraying apparatus
1
which can be screwed onto a container or bottle (not shown). This apparatus
1
essentially comprises four parts, namely a spraying head
2
, a base part
4
provided with a threaded portion
3
, an intermediate part
5
and an insert
6
. The spraying head
2
essentially presents a circular cylindrical envelope surface
8
with a foam conducting tube
10
forming a foam delivery opening
9
. The insert
6
is formed by a circular cylindrical flow chamber
12
for the liquid, a connecting tube
13
, a mixing chamber
14
with a tapered inlet opening
15
for the liquid and a tapered inlet opening
16
for air, and a foaming chamber
17
with two circular sieves
18
and
19
. The intermediate part
5
essentially consists of a cylindrical air chamber
20
and a cylindrical piston
21
for the liquid, which are interconnected via a circular plate
22
(compare FIG.
4
). The piston
21
furthermore comprises a tubular protrusion
23
of a smaller diameter. A rubber elastic disk
24
acting as a valve is connected via a cross-member
25
with a sealing ring
26
arched towards the inside. For fastening the disk
24
and the sealing ring
26
, which are interconnected and form a unit, a passageway
27
is provided between the piston
21
and the protrusion
23
. Also an inlet opening
28
(compare
FIG. 5
) and an outlet opening
29
are provided in the air chamber
20
which are sealed by rubber elastic disks
30
and
31
acting as valves, the disk
31
of the outlet opening
29
only being visible. These disks are similar to the disk
24
with the cross member
25
, in which arrangement on the counter side a smaller rubber elastic disk or a similar element is provided for fastening the disk. The base part
4
is provided with an outer ring
35
with a threaded portion
3
and forms a cylindrical piston
37
for the air and a circular cylindrical liquid chamber
38
which are interconnected via a cross-member,
39
formed by a cut-out circular plate. The liquid chamber
38
is provided with a intake tube
40
of smaller diameter extending into the container or bottle (not shown). The piston
37
on its side opposite the air chamber
20
is provided with a sealing ring
41
arched towards the inside and inserted into a seat
42
. Furthermore on the intake tube
40
on its side opposite the liquid chamber
38
a valve seat
43
is provided, into which a rubber elastic disk
44
is inserted as a valve. The disk
44
is connected to an L-shaped connecting element
45
which extends via a passageway opening
46
between the liquid chamber
38
and the intake or aspiration tube
40
.
As can be seen from the above description the cylindrical air chamber
20
and the correspondingly formed cylindrical piston
37
form a first piston and cylinder unit for pressing the air into the mixing chamber
14
. Similarly the cylindrical piston
21
and the cylindrically formed circular liquid chamber
38
form a second piston and cylinder unit for the liquid. In this arrangement the rubber elastic disks
30
and
44
each serve as inlet valves and the disk
31
of the outlet opening
29
and the disk
24
serve as outlet valves.
As further can be seen from
FIG. 1
between the intermediate part
5
and the base part
4
in the zone between the air chamber
20
and the liquid chamber
38
a helical spring
50
is provided which on the one hand rests against a tubular protrusion
51
in the air chamber
20
and on the other hand is inserted into a stepped tube
52
of the piston
37
. Thus the two parts
4
and
5
in their released state are distanced at a certain distance (as indicated in the state shown in FIGS.
1
and
3
).
The various parts
2
through
6
of the foam spraying apparatus
1
can be seen still more clearly in the exploded view shown in
FIG. 5
which should be self-explanatory in combination with the
FIGS. 1 through 4
.
The foam spraying apparatus
1
described above now functions as follows:
For generating foam the spraying head
2
is pressed down against the helical pressure spring
50
. In this manner the air present in the air chamber
20
is pressed via the outlet opening
29
and the outlet valve
31
into the mixing chamber
14
. Simultaneously also the liquid in the liquid chamber
38
is conveyed by the compression via the flow chamber
12
into the mixing chamber
14
. The air stream thus mixes in the mixing chamber with the liquid and this mixture of air and liquid is transferred via the first sieve
18
into the foaming chamber
17
where the foam formed is pressed through the second sieve
19
and flows via the foam conveying tube
10
through the outlet opening
9
of the spraying head
2
. Then the spraying head
2
is released again in which process the intermediate part
5
and the base part
4
are pressed away from each other under the influence of the helical spring
50
in such a manner that air is sucked in via the air intake opening into the air chamber
20
. At the same time via the suction tube
40
liquid is sucked from the bottle (not shown) and via the valve
44
is transported into the liquid chamber
38
. Each time the spraying head
2
is depressed a small quantity of foam thus is formed which, among other factors, depends on the diameters of the tapered inlet openings
15
and
16
leading into the mixing chamber
14
, on the mesh opening size of the two sieves
18
and
19
and on the size of the foam chamber
17
.
Manufacture of the foam spraying apparatus
1
described above is effected as follows:
The spraying head
2
, the base part
4
, the intermediate part
5
and the insert
6
are made from a synthetic material such as Duroplast using an injection moulding process known as such. For this purpose negative moulds are placed into an injection mould and the synthetic material heated to the melting temperature is injected under high pressure into the injection mould. Simultaneously with the manufacture of the parts
2
, and
4
through
6
also the rubber elastic elements (disks
30
and
31
with the connecting cross-member
32
; disk
24
with sealing ring
26
and connecting cross-member
25
; disk
44
and sealing ring
41
with L-shaped connecting cross-member
45
) which are made from an elastomer material such as e.g. LDPE or a similar material, are placed in the injection mould in such a manner that these elements already in the manufacturing process are connected to the co-ordinated parts. In this manner the foam spraying apparatus
1
can be manufactured in a particularly simple and cost efficient manner.
One of skill in the art would acknowledge that the foam spraying apparatus
1
described above is not limited exclusively to the embodiment shown. In a slightly changed embodiment the circular cylindrical piston
21
can be arranged coaxially with the axis of the intermediate part
5
instead of eccentrically in which arrangement the pressure spring
59
surrounds the piston
21
and the insert
6
is laid out correspondingly shorter. Since only very few elements are required for producing the foam spraying apparatus
1
which now can be manufactured much faster in a easy manufacturing process, a material saving and thus environmentally feasible production process is achieved. Energy cost for the manufacture of the foam spraying apparatus
1
also can be lowered very substantially in comparison to the manufacturing methods known thus far.
Claims
- 1. A foam spraying apparatus for a liquid container comprising:(a) a first piston-and-cylinder unit for air, comprising a first cylinder and a first piston, the first unit having an inlet valve and an outlet valve; (b) a second piston-and-cylinder unit for liquid, comprising a second cylinder and a second piston, the second unit having an inlet valve and an outlet valve and cooperating with the first unit by a mutual coupling; (c) a mixing chamber for mixing air and liquid; and (d) a spraying head provided with a foam delivery opening, wherein the first cylinder and the second piston are interconnected to form an intermediate part and the second cylinder and the first piston are interconnected to form a base part, and wherein the intermediate part and the base part mesh and are moveable relative to each other.
- 2. The foam spraying apparatus according to claim 1, wherein the second piston is laid out eccentrically with respect to the first cylinder.
- 3. The foam spraying apparatus according to claim 1, wherein the first piston and second piston each are provided with a sealing ring.
- 4. The foam spraying apparatus according to claim 1, wherein the mixing chamber is formed by an insert between the spraying head and the intermediate part.
- 5. The foam spraying apparatus according to claim 4, wherein the mixing chamber is provided with a tapered inlet opening for the air and a tapered inlet for the liquid.
- 6. The foam spraying apparatus according to claim 5, wherein, seen in the flow direction, after the air inlet opening and the liquid inlet opening a first fine mesh sieve is arranged.
- 7. The foam spraying apparatus according to claim 6, wherein, seen in the flow direction, after the first sieve a foaming chamber and a second fine mesh sieve are arranged.
- 8. The foam spraying apparatus according to claim 1, wherein the spraying head, the insert, the intermediate part and the base part are made from a synthetic material formed by an injection moulding process.
- 9. A method of manufacturing a foam spraying apparatus according to claim 1, wherein the spraying head, the first piston and first cylinder of the first unit for the air and the second piston and second cylinder of the second unit for the liquid are injection moulded using a two component synthetic material.
- 10. A method according to claim 9, wherein the inlet and outlet valves of the first unit and second unit are made from a rubber elastic synthetic material and during injection moulding are surrounded by the intermediate and base parts coordinated to them.
- 11. The foam spraying apparatus according to claim 1, wherein the first cylinder and the second piston form a unit body as the intermediate part and the first piston and the second cylinder form a unit body as the base part.
Priority Claims (1)
Number |
Date |
Country |
Kind |
879/98 |
Apr 1998 |
CH |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/IB99/00704 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO99/54054 |
10/28/1999 |
WO |
A |
US Referenced Citations (8)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0392238 |
Mar 1990 |
EP |
317969 |
Nov 2002 |
FR |
9313829 |
Jul 1993 |
WO |