Patent Application
20130144213
This is a continuation application of co-pending international patent application PCT/EP 2011/062824, filed Jul. 26, 2011 and designating the United States, which was published in English as WO 2012/016884 A1, and claims priority to German patent application DE 10 2010 033 576, filed Aug. 3, 2010. These priority applications are incorporated herein by reference.
The present invention relates to a device for dosed dispensing of a fluid medium, said device comprising a pen-like housing which has a storage chamber for accommodating the fluid medium and which has at its front end a tip in which there is provided an outlet opening for the fluid medium, and further comprising a valve element which is arranged in the front end, closes the outlet opening under the force of a spring and is arranged such that it at least partially opens the outlet opening in the event of radial pressure being applied from the outside on the front end of the housing.
Such a device is known from EP 0 256 279 A1.
The known device is what is known as a metering pen with which fluid media can be dispensed in a dosed manner.
A “fluid medium” is understood within the context of the present invention to mean flowable liquids, materials and substances of any kind, which are held in a storage chamber in a metering pen and are dispensed in a dosed manner as desired. These include, for example, refinish paints and liquid or pasty correction agents which are applied to the surfaces to be treated via an applicator, for example a brush or wick, provided in the tip of the metering pen.
Such metering pens are for example used to eliminate paint damage on motor vehicles or to repair scratches and scores on structural elements such as window frames, etc., before they are painted over.
On account of the possibly relatively long storage time of the metering pens filled with the fluid media, it is frequently necessary to remix the medium, for which purpose there is provided in the metering pen a mixing ball which ensures that the medium is mixed again when the metering pen is subjected to a shaking movement.
What is also important is the option of being able to dispense the fluid media in a dosed manner, since it is frequently the case that only small amounts of the medium are required for the work to be carried out and the applicator should not become oversaturated with the medium.
In order to make this possible, the device known from above-mentioned EP 0 256 279 A1 has a cylindrical housing in which a storage chamber for the respective liquid medium to be used is provided. At its tip, the housing has an opening which is closed by an axially movable valve element in the form of a sealing rod. At the upper end of the sealing rod there is arranged a membrane plate which is pushed forwards by a compression spring so that the sealing rod closes the outlet opening by way of its front end.
In the region of the tip, the housing is produced from an elastically deformable shell so it can be pushed in there. Pushing in the housing shell on radially opposite sides or from one side only causes the membrane plate to be bent upwards, as a result of which it moves the sealing rod likewise upwards and thus lifts the sealing element fitted at the front end of the sealing rod off the outlet opening, thereby opening an annular gap through which medium can emerge.
Disadvantages with this device are in particular the large number of parts required and also the welded connection required between the tip, which consists of the elastically deformable and therefore thin housing shell, and the rest of the housing.
It is also disadvantageous that the mixing of the medium with the aid of the mixing ball is not always ensured, because the medium that accumulates in the region of the front tip cannot move readily into the rear region, since the membrane plate causes virtually complete sealing off of the chamber in the front tip from the rear storage chamber.
A comparable device is known from U.S. Pat. No. 3,902,815 A. In this device, the outlet opening for the liquid at the tip of the housing is closed by a stem-like valve member which is pushed axially forwards by a compression spring into the closed position. In order to open the outlet opening, there are provided push buttons, which are arranged diametrically in the housing wall and when pushed together ensure via interposed leaf springs that the valve member moves axially towards the rear and opens the outlet opening.
FR 1 434 743 A1, too, describes a comparable device, in which the outlet opening is closed via an axially adjustable valve member.
The two last-discussed devices are also structurally complex and so have problems associated with assembly and with use.
US 2007/0201940 A1 discloses a liquid applicator having an applicator that is displaceable in longitudinal direction and interacts with a front end of a valve element.
DE 199 34 445 A1 discloses a device for dispensing a fluid like ink from a fluid chamber through an inner channel provided in a valve part. The valve part has a tip protruding from the fluid chamber through a further channel provided in an inwardly pointing cylindrical shank provided at a front face of the fluid chamber.
The rear end of the valve part is a cylindrical block having the same outer diameter as the shank. The inner channel terminates in lateral openings provided between the shank and the cylindrical block. By this, fluid from the fluid chamber can pass through the lateral openings into the inner channel and therefrom to the outside.
However, provided on the shank and the cylindrical block is a helical spring which separates the fluid chamber from an inner chamber surrounding the lateral openings. The coils of the helical spring are tightly compressed such that no fluid can pass from the fluid chamber into the inner chamber, so that the valve is closed.
The tip is arranged within the channel such that it can be tilted. When the tip is tilted this bulges the helical spring such that the coils are splayed apart to open a fluid passage from the fluid chamber to the inner chamber.
Thus, when the tip is at rest, the coil closes off the fluid chamber. When the tip is tilted, the coil opens fluid passages that allow flow of ink from the fluid chamber through the lateral openings and the inner channel to the outside.
In this construction, the valve element, in the meaning of the present invention, is the helical spring, although it cannot be opened by applying radial pressure to the fluid chamber.
This construction has several disadvantages. When the tip is at rest, the inner chamber is still connected via the lateral openings to the inner channel, so that over the time all fluid trapped within the inner chamber can either drop out or get dried. This, of course, cannot be accepted.
Further, as the helical spring has tightly compressed coils in order to ensure closure of the fluid chamber, a large tilting force is required to open the fluid passages between certain coils.
Still further, a sealing ring is provided in the further channel provided in the inner shank. This sealing ring surrounds the tip of the valve part and allows the tilting thereof. The further channel is in fluid communication with the fluid chamber as soon as the tip is tilted. However, tilting the tip stresses the sealing ring so that fluid may pass the sealing ring and rinse out of the fluid chamber on the outer surface of the tip. This can by no means be accepted.
Seen as a whole, this known device is unsuited for dosed application of a fluid medium in the meaning of the present application.
In view of the above, it is among others one object of the present invention to improve the device mentioned at the outset in such a way that it has a simple structure and is easy to assemble and reliable to use.
In the case of the device mentioned at the outset, this and other objects are achieved in that the valve element is arranged in a tiltable manner at the outlet opening.
The inventor has thus departed from the path specified in the prior art of closing and opening the outlet opening via an axially movable sealing element, but rather has created a tiltable valve element, the guidance of which in the housing is subject to fewer demands than an axially adjustable element.
On account of the fewer demands made of the guidance, the novel device can be constructed with a smaller number of individual parts, and is also very failsafe in its operation and function, since all that is required to open the outlet opening is to tilt the valve element to the side. This results in the formation of an opening through which the medium can pass to the outlet opening.
The inventor has found that the tilting of the valve element also opens the outlet opening much more than in the case of a prior art sealing element which is merely lifted off axially.
According to one object, the valve element has at its front end a sealing element for closing the outlet opening and is designed at its rear end to accommodate the front end of an axially acting compression spring.
This measure is structurally advantageous since a single valve element ensures at its front end that the outlet opening is closed and is provided at its rear end with an axially acting compression spring which in the first instance exerts a closing pressure on the valve element.
The valve element can be designed in this case at its rear end as a stem or pin, onto which the front end of the compression spring is pushed. The pin can in this case be in the form of a star in cross section so that medium can flow forwards past the outside of the pin to the outlet opening.
However, an axially acting compression spring also makes it possible to push the valve element radially outwards at its rear end in order in this way to open the outlet opening. As soon as the opening pressure is relieved, the compression spring moves the valve element back in the axial direction and thus closes the outlet opening. In this case, it is not necessary to fix down the valve element at the outlet opening for example by way of a joint or similar structural element; it can rest in a freely tiltable manner at the outlet opening or the edge thereof and be held in this position by the compression spring.
In order to allow the dosing function, according to one object of the invention just one valve element and one compression spring are required.
The valve element can according to one object be a one-piece plastics part, wherein the compression spring may be produced from metal or likewise from plastic. The compression spring may also be formed in one piece with the valve element, for which purpose the valve element and the compression spring are produced for example from plastic.
According to another object, the housing has at its front end a preferably flattened gripping region which is made of material that can be elastically deformed under pressure and which is located approximately at the same axial level as the rear end of the valve element.
This measure increases in particular the operability of the novel device, since the gripping region indicates where pressure needs to be applied to the wall of the housing in order to tilt the valve element.
If the gripping region is additionally flattened, only a small force is required in the region of this flattening to push in the wall and to tilt the valve element. The circumferentially remaining region of the housing at the axial level of the gripping region is formed in a circular manner and thus is pressure-resistant despite a possibly thin wall of the elastic material.
This is a particular advantage over the device from the generic EP 0 256 279 A1, where the gripping region is provided circumferentially with a thin wall.
Furthermore, it is one object that the rear end of the compression spring extends as far as approximately above the gripping region and is anchored there inside the housing.
This measure ensures in an advantageous manner the tiltability of the valve element, since the compression spring, which can be in the form of a helical compression spring, extends over a certain length of the housing and so the force required to tilt the valve element is low, but the spring, on account of its compression force acting in the axial direction, nevertheless ensures reliable sealing of the outlet opening when the radial pressure is removed.
According to a still further object, the valve element is designed at its rear end as a cylindrical bushing in which the front end of the compression spring is arranged.
This measure, too, is structurally advantageous, since the front end of the compression spring is seated in an immovable manner in the cylindrical bushing, and so when excessive force is exerted on the gripping region the compression spring does not accidentally come out of the valve element.
It is also structurally advantageous here in particular that the compression spring does not have to be specially fixed in or on the valve element; the front end of the compression spring merely needs to be inserted into the cylindrical bushing.
At least one through-opening for the fluid medium may be provided in or on the valve element.
In the case of this measure, it is advantageous that the region in the tip is fluidically connected to the rear storage chamber and so when the medium is mixed after a long period of storage it is ensured that even the medium present in the front region of the metering pen can be supplied for mixing.
Generally, the outlet opening may be enclosed by an annular shoulder on which the sealing element rests, and the valve element may have preferably at its front end a sealing element, which further preferably is a sealing plate consisting of a flexible material, and/or comprises a peripheral sealing ring.
These measures are advantageous individually and in combination, because they ensure good sealing of the outlet opening. The sealing cone can in this case engage at least partially into the outlet opening, with a sealing plate produced from flexible material ensuring reliable sealing of the outlet opening even in the case of slight material unevenness by resting flat against the annular shoulder. The peripheral seal also contributes to nevertheless ensuring reliable sealing in the case of slight manufacturing inaccuracies.
Overall, these and other measures allow simple and cost-effective manufacturing of the novel device without the sealing reliability being negatively affected by relatively small manufacturing inaccuracies.
A lateral recess may be provided on the inside of the tip at the outlet opening, said lateral recess facing a gripping region via which the valve element can be tilted.
It is advantageous with this measure that the outlet opening and the wall which surrounds it inside the tip are laterally enlarged where the valve element is lifted off the outlet opening in the case of tilting brought about via the gripping region, so that a large opening is opened for the medium and the medium can flow through this opening in a sufficient quantity.
Generally, a channel for accommodating an applicator may be provided in the tip of the housing, wherein the outlet opening opens out into the channel.
It is advantageous here that various applicators can be inserted into the channel, with consideration being given in particular to wicks or brushes which can be inserted without problems into the channel with the aid of a fitting bushing.
This measure, too, contributes to a structurally simple construction of the novel device.
According to another object, a sensing tip may be provided on the valve element, said sensing tip extending through the outlet opening and the channel and protruding forwards beyond the channel.
This measure provides a further actuation option for the valve element. This is because when radial or axial pressure is applied to the sensing tip that protrudes forwards beyond the channel, the valve element is lifted off the outlet opening and so the medium can flow into the channel, where it then saturates the applicator.
With this measure, it is thus not necessary to tilt the valve element by applying pressure to the actuating region; rather this can also take place while the metering pen is being used by the corresponding application of pressure to the sensing tip extending in the applicator.
One possible application consists here in that the applicator is initially saturated with medium by the application of lateral, i.e. radial pressure on the valve element at the gripping region, with it then being possible, during the application of the medium to the surface to be treated, for the “subsequent delivery” of fluid to be controlled by the applicator and thus the sensing tip being pressed more or less strongly onto the surface. This allows particularly elegant and simple use of the novel device.
The sensing tip may be formed in one piece with the valve element, so that, in spite of the additional possibility of controlling the flow of medium, the structurally simple construction of the novel device from as few parts as possible is retained.
Alternatively, the applicator may be arranged such that it can be displaced longitudinally in the channel and projects towards the rear through the outlet opening so that it interacts with the front end of the valve element.
This constitutes a further way of actuating the valve element via the applicator. By axial displacement of the applicator into the housing, the valve element is lifted off the outlet opening and so medium can pass to the applicator.
As already mentioned in connection with the sensing tip, in this way the applicator can be saturated with medium initially by the application of radial pressure to the gripping region, it then being possible to control the subsequent flow of the medium in a very simple manner by the pressure of the applicator on the surface to be treated.
According to a further object, the applicator may be held in an insert which is mounted in the channel such that it can be displaced longitudinally to a limited extent and which interacts by way of its upper end side with the front end of the valve element.
It is advantageous here that the stroke of the applicator is limited, so that the valve element can be lifted off the outlet opening only to a predefined degree. As a result, the opening for the subsequent flow of the medium is limited, and so the permissible stroke of the valve element also determines the amount of medium which can pass per unit time to the applicator.
It is thus possible for the applicator not to be pushed fully into the channel, which makes use easier, since the user does not have to pay attention, when applying the medium to the surface to be treated, to how far he pushes the applicator into the channel.
Finally, it should be mentioned that in the context of the present invention “lower end” or “front end” means the region towards the front tip of the metering pen where the applicator protrudes out of the housing and the metering pen is grasped by the user.
Accordingly, “upper end” or “rear end” means the region remote from the lower end of the metering pen, where the closure for the storage chamber is fitted.
Consequently, “from below” means the direction pointing from the lower to the upper end and “from above” means the direction pointing from the upper to the lower end. “Above” and “below” accordingly mean “in the direction towards the rear end” and “in the direction towards the front end”, respectively.
“Axial direction” means accordingly the longitudinal direction of the device from its front to its rear end, i.e. the longitudinal center axis in the case of a metering pen.
Further advantages can be gathered from the description of the appended drawings.
It goes without saying that the abovementioned features and those mentioned below can be used not only in the respectively stated combination but also in other combinations or on their own, without departing from the scope of the present invention.
Embodiments of the invention are illustrated in the drawing and explained in more detail in the following description. In the drawing:
The device 10 comprises a pen-like housing 11 which has a storage chamber 12 for accommodating the fluid media. At its front end 14, the housing 11 is equipped with a tip 15 in which there is arranged a channel 16 which extends axially to an outlet opening 17.
An applicator is to be inserted in a manner yet to be described in the channel 16 in order that the medium can be applied to a surface to be treated.
Inside the housing 11, a valve element 18 is fitted on the outlet opening 17, said valve element 18 resting, such that it can tilt freely, on the edge, which can be seen more clearly in
The tip 15 is adjoined axially to the rear, i.e. to the right in
The material of the gripping region 21 can be elastically deformed under pressure, and so a pressure exerted in the direction of the arrow 24 leads to the valve element 18 tilting, i.e. moving in
In the tip 15 there is now fitted an applicator 27 in the form of a wick, which is held in the channel 16 via a fitting bushing 28.
The housing 11 is provided at its rear end 29 with a closure plug 31 so that medium 32 introduced into the storage chamber 12 cannot run out.
It can be seen in
A mixing ball is indicated at 33 in
It can be seen from
At its rear end 36, the valve element 18 is provided with a cylindrical bushing 37 in which the front end 38 of the spring 19 is arranged such that it rests on a shoulder 39 provided in the bushing 37.
The spring 19 extends to the rear along the entire gripping region 21 and its rear end 41 is fixed in a suitable manner, for example clamped in or adhesively bonded, inside the housing 11, above the gripping region 21, i.e. above the transition region 40 from the gripping region to the wall 23.
In this way, the compression spring 19 presses the valve element 18 onto the outlet opening 17 and closes the latter via the sealing element 35, which is arranged at the end at the front end 34 of the valve element 18.
The valve element 18 is shown in detail in
Since the gripping region 21 is located at the same axial height as the rear end 36 of the valve element 18, i.e. at the same axial height as the bushing 37, this pressure 24 causes the valve element 18 to carry out a tilting movement in the direction of the arrow 42, as a result of which the sealing element 35 at the end is lifted off the outlet opening 17.
This tilting movement 42 of the valve element 18 is made possible by the compression spring 19 having an appropriate axial length so that it so to speak “buckles” in the middle and allows the tilting movement 42. At the same time, the compression spring 19 exerts such an axial force on the valve element 18 that, as the radial pressure 24 is reduced, it aligns itself axially again and recloses the outlet opening 17.
A lateral recess 46 is provided on the inside of the tip 15 at the outlet opening 17 in that region which is opened by the tilting of the valve element 18, i.e. which faces the gripping region 21, said lateral recess 46 ensuring even better discharging of the medium into the channel 16; in this regard, see the description below relating to
Also inserted into the channel 16 with the aid of a fitting bushing 48 is an applicator in the form of a brush 49, in which the sensing tip 47 then runs.
Otherwise, the construction of the device 10 from
If the sensing tip 47 is now pressurized either in the axial direction or transversely, this leads to the valve element 18 being lifted axially off the outlet opening 17 or else being tilted as is shown in
In this way, it is possible to ensure the subsequent flow of medium out of the housing 11 to the brush 49 by applying appropriate pressure via the sensing tip 47.
The rear end 52 of the wick 50 protrudes through the outlet opening 17 and rests against the sealing element 35 of the valve element.
In
As in the case of the device from
At the rear end 61, the insert 59 is provided with a shoulder 62 which is directed towards the rear and is assigned a forwardly directed shoulder 63 inside the tip 15.
In
In this case, an end face 64 provided at the rear end 61 and directed towards the rear comes into abutment against the valve element 18 which is acted on by the compression spring 19, which is not shown in
As a result, the sealing element 35 on the valve element 18 is lifted off the annular shoulder 54 surrounding the outlet opening 17 and the outlet opening 17 is thus opened. The medium can now pass to the wick 50, with passages (not shown) in the rear end 61 allowing the medium to pass through.
If the axial pressure on the wick 50 is removed, the insert 59 is moved back into the position in
Therefore, what is claimed is:
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 033 576.2 | Aug 2010 | DE | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2011/062824 | Jul 2011 | US |
| Child | 13753583 | US |
