The present invention relates to a method for venting and eliminating liquid material of a dispensing appliance prior to the dispensing operation according to claim 1 as well as for venting, leveling, and eliminating incompletely mixed components after the mixing operation of at least two components, and to a device for implementing the method according to claim 1.
U.S. Pat. No. 6,079,868 discloses a device for mixing and delivering a curable biomaterial, the device comprising, besides the usual delivery conduit, a mechanism for controllably shunting an initial portion of mixed biomaterial. This shunting mechanism allows to direct material either to the deliver conduit or to the outlet shunt before, during or after dispensing of the biomaterial.
When multicomponent cartridges are being filled, there are filling tolerances that lead to different volumes or to filling level differences between two or multiple containers. The result of these filling tolerances is that the components are not synchronously dispensed or are not or only incompletely mixed at the beginning of the dispensing operation. Therefore, the components have to be leveled prior to being dispensed and applied. Such a leveling device for syringe and cartridge containers is disclosed in WO 2004/100854.
Another negative influence upon dispensing is the presence of air in the containers as well as in the mixer. Air bubbles in the containers are the result of inadequate venting during cartridge filling or may develop due to subsequent processes such as heating, freezing, sterilization, or irradiation. During dispensing, the air resp. gas is compressed, thereby affecting the mixing ratio and furthermore leading to an unwanted early or prolonged outflow of a component. Also, in certain medical applications, the air enclosed in the mixer must not enter into the body.
Another influence may result from different viscosities of the components. Specifically, the lower viscosity component may precede in the mixer, especially when the mixer is downwardly inclined, thereby preventing a correct mixture in the initial phase. Furthermore, at the beginning of the dispensing operation, the components are only incompletely mixed due to different other factors. This means that in demanding applications, the first portion of the mixed components must not be used.
Mainly in medical applications such as e.g. minimally invasive techniques, where application instruments are directly attached to the mixer, the venting and synchronization of the components and the elimination of incompletely mixed components after the mixing operation is indispensable.
With the current state of the art, an efficient venting and leveling is complicated, requires special attention, and is impossible in the case of fast-reacting adhesives. Since the reaction already starts in the mixer, there is not enough time to connect an application instrument to the mixer after venting and leveling and to place it in the correct location in/on the patient. If it is handled incorrectly or if venting, leveling, and elimination are omitted, the two-component adhesive may fail to function.
On the background of this prior art, it is an object of the present invention to provide a method and device that allow the direct application of a vented material. This is accomplished by the method according to claim 1 and the device according to claim 5.
Another object of the present invention is to provide a method and a device that allow the direct application of a vented, leveled, and completely mixed material from a multicomponent dispensing appliance. This is accomplished by the method according to claim 2 and the device according to claim 5.
These methods and devices allow a substantial increase in safety in critical applications, particularly in medicine, since the venting and leveling operation is visualized and in preferred embodiments also automated.
The invention will be explained in more detail hereinafter with reference to drawings of exemplary embodiments.
This device is essentially composed of a collecting container 7 and a valve assembly 8 in order to first conduct air and material to collecting container 7 after the last mixer element 5 and subsequently dispense the mixed material that has been vented and leveled directly through outlet 9. Collecting container 7 is provided with a closure in the form of a filter 11 that is permeable to air but prevents the outflow of material. A suitable filter material for this purpose is e.g. hydrophobic, porous or provided with fine channels.
In the variant of
Such a filter and cover combination is not only useful for the embodiments shown in the context of this application but for all kinds of filters in devices for leveling and venting cartridges or syringes.
In the embodiment variant according to
In the present exemplary embodiment, the collecting container and the valve assembly are designed as a unit that is adapted to be pushed over mixer housing 2 and secured thereto. At the end of the mixer, valve body 17 is provided with a bore 16 in which a movable valve member 12 is guided that connects to collecting container 7 via a connecting member 14. Movable valve member 12 comprises a dispensing channel 13 and an angled deviating channel 15 extending inside connecting member 14 and connecting the mixer outlet to the collecting container in the illustrated position.
Connecting member 14 is guided inside another smaller bore 18 of the valve body, as appears when comparing
In
A third exemplary embodiment is described with reference to
A comparison of the two
In the embodiment variant of
In contrast to the embodiment according to
In
The movable valve member consists of a plug 43 that is displaceable in a transversal bore 44 in the valve body and is provided with a deviating channel 45, and at the end of which a cap 46 is arranged whose front side is provided with venting slots 47 above which filter 42 is arranged. In order to prevent that the movable valve member may be withdrawn, cap 46 comprises a circular collar 48 that cooperates with a collar 49 on cylindrical portion 40.
In the position illustrated in
In
Valve body 51 is provided with a transversal bore 52 in which the movable valve member 53 is arranged. The movable valve member has a dispensing channel 54 followed by an intermediate portion provided with deviating channel 55 that leads to collecting container 56 with filter 57. A compression spring 58 is arranged between the end of the movable member and the bottom of the transversal bore. The section of the movable valve member provided with the dispensing channel has a larger diameter than the intermediate portion so that a circular collar 59 is formed at the junction between these two parts, thereby preventing that the movable valve member may be removed from the valve body.
In the position illustrated in
A spring-loaded valve member is also illustrated in the exemplary embodiment according to
Carrier member 63 comprises both deviating channel 65 and dispensing channel 66, a section of the deviating channel serving as the dispensing channel in the open position. In a manner known per se, nonreturn valve 62 is provided with a valve ball 67 that is loaded by a compression spring 68 and pushed against a valve seat 69 in carrier member 63. Carrier member 63 connects to collecting container 70 with filter 71.
This embodiment operates automatically, the air and the unwanted material first being transferred via deviating channel 65 to collecting container 70, and when the latter is filled, the valve being opened by the buildup of a higher pressure to allow the mixture to be dispensed.
In the exemplary embodiment according to
Such an arrangement is advantageous mainly in medicine, e.g. in the application of two-component substances as a nucleus replacement in intervertebral disks or for filling up osteoporotic bones with bone cement, to prevent overfilling.
In the exemplary embodiment of
With this device, the starting phase and the dispensing operation remain the same as previously. When the pressure in the system increases during dispensing and the cavity is full, pressure relief valve 103 opens at a previously specified pressure, which pressure is determined by the compression spring.
Instead of a pressure relief valve it is also possible to provide a signaling device that controls the dispensing appliance, or a display device that indicates the current pressure.
The pressure relief assembly is fully effective in combination with the venting and the leveling of the components for achieving best operating conditions, but a pressure relief assembly as described with reference to
In the variant of
In the variant of
According the above description, the venting and leveling device follows after the mixing operation. It may be used for static mixers, as shown, or also for dynamic mixers. Furthermore, the device may not only be arranged inside the mixer housing, after the last mixing element, or between the mixer and the following application instrument, but also integrated in the latter.
Instead of the illustrated straight embodiments, versions that are angled after the mixer are also conceivable. Also, the different valves and assemblies may be combined with each other as desired.
The invention described above eliminates the following system inherent weaknesses in multicomponent dispensing appliances:
It is therefore possible to use such dispensing appliances also for critical applications in surgery as it is ensured that neither air nor incompletely mixed materials can be applied.
The method and the device have been described with reference to multicomponent dispensing appliances as they are most useful in this case, but an analogous method and an analogous device may as well be used for a single component dispensing appliance, in which case the venting and the elimination of the unwanted starting phase, which may e.g. also contain air bubbles, are of particular importance.
The differences in the devices according to the drawings are e.g. found in the use of an outlet nozzle instead of a mixer in
Number | Date | Country | Kind |
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1097/05 | Jun 2005 | CH | national |
1408/05 | Aug 2005 | CH | national |
1761/05 | Nov 2005 | CH | national |
2091/05 | Dec 2005 | CH | national |
This is a national stage of PCT/CH2006/00326 filed Jun. 15, 2006, which claims priority to Switzerland applications nos 1097/05, filed Jun. 29, 2005, 1408/05 filed Aug. 29, 2005, 1761/05 filed Nov. 3, 2005 and 2091/05 filed Dec. 29, 2005, the respective disclosures of which are hereby incorporated by reference in their entireties.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CH2006/000326 | 6/15/2006 | WO | 00 | 12/3/2007 |