Apparatus and method for filling syringe barrels
Apparatus for filling syringe barrels (1) with a product (A, B), includes at least one vacuum unit, at least one filling device, and a metering head (10) which can be moved with respect to the syringe barrel (1). The metering head (10) has a first material inlet valve (11a) and a second material inlet valve (11b) as well as a first vacuum valve (20a) and a second vacuum valve (20b). The material inlet valves (11a, 11b) and the vacuum valves (20a, 20b) are connected to channels (25a, 25b), to each of which a chamber (2a, 2b) of the syringe barrels (1) can be connected, as a result of which the syringe barrel (1) can be filled through the same openings (5a, 5b) as those through which the product (A, B) can be forced out of the chambers (2a, 2b) by pistons (3) for use of the product, where the pistons (3) are inserted into the syringe barrels (1) before the barrels are filled.
1. Field of the Invention
The invention pertains to an apparatus for filling syringe barrels including a vacuum unit, a filling device, and a metering head which can be moved relative to the barrel. The invention also relates to a method for filling the barrel using the apparatus.
2. Description of the Related Art
Apparatus and methods of this type are suitable for filling syringe barrels with, for example, high-viscosity products.
An apparatus and a method of this type are known from DE 43 20 098 A1. Pharmaceutical or other products, especially those of high viscosity, are introduced into the syringe barrel under the application of a vacuum. Then a piston, which can be used later to force the product out, is inserted into the barrel. The insertion of the piston is also carried out under vacuum. How exactly this is done, however, remains unclear; that is, it is not explained how, within the scope of series production, the individual pistons are brought into position and how they are inserted into the syringe barrels.
When the piston is inserted into a syringe barrel which has just been filled with product, it is obvious that some of the product must be displaced from the barrel again. What happens to this displaced product and how contamination-free handling is possible cannot be derived from the document. Nor can it be seen how the piston is introduced into the syringe barrel.
SUMMARY OF THE INVENTIONThe invention is based on the task of simplifying the process of filling syringe barrels.
The apparatus according to the invention is used for filling first and second syringe barrels having respective first and second pistons which are inserted into the barrels prior to filling, and respective first and second openings through which the barrels are filled with product and through which product is discharged. The apparatus includes a metering head having first and second channels which can be connected to respective first and second openings; first and second material inlet valves connected to respective first and second channels for filling respective barrels with first and second products; and first and second vacuum valves connected to respective first and second channels between said material inlet valves and the barrel openings.
In use, the first and second channels are connected to respective first and second openings, and a vacuum is drawn in the channels via the first and second vacuum valves so that the pistons are drawn into the barrels. The vacuum valves are then closed, and the material inlet valves are opened to fill the barrels with product from first and second supply tanks via the first and second inlet valves so that the pistons are displaced in the barrels. The positions of the pistons are detected by means of plungers which operate respective first and second proximity switches, and the material inlet valves are closed in response to signals from the proximity switches.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
Thus, according to the invention, the syringe barrel 1 is filled from the same end as that from which it will be emptied later during use. Thus, for the filling operation, there is no need for sealing parts such as a caps or plugs to seal tightly the opening opposite the filling end during the filling process described in DE 43 20 098 A1.
For the purpose of filling, the syringe barrel 1 can be placed on a metering head 10. This metering head 10 contains a first material inlet valve 11a and a second material inlet valve 11b. These two material inlet valves 11a, 11b can be actuated pneumatically, for example. From the material inlet valves 11a, 11b, product lines 12a, 12a lead to pressure vessels 13a, 13b, in which supply tanks 14a, 14b are provided. Products A and B, that is, the two components to be filled into the barrels, are held in these two supply tanks 14a, 14b. A pressure-regulated system of compressed air 15a, 15b is provided for each of the two pressure vessels 13a, 13b.
The metering head 10 also contains a first vacuum valve 20a and a second vacuum valve 20b. These vacuum valves 20a, 20b can also be actuated pneumatically, for example. From each of the vacuum valves 20a, 20b, a suction line 21a, 21b leads to a vacuum vessel 22a, 22b. A vacuum pump 23a, 23b is connected to each of the vacuum vessels 22a, 22b. A single vacuum pump 23 could also be used instead of the two vacuum pumps 23a, 23b.
The second connections of the material inlet valves 11a, 11b and of the vacuum valves 20a, 20b are connected to channels 25a, 25b. A first channel 25a connects the material inlet valve 11a and the vacuum valve 20a to the chamber 2a of the syringe barrel 1, and a second channel 25b connects the material inlet valve 11b and the vacuum valve 20b to the chamber 2b of the syringe barrel 1. In terms of its construction, the device is advantageously designed so that the volume of the channels 25a, 25b is as small as possible.
It is advantageous to assign an adjustable plunger 30 to each piston 3 of the syringe barrel 1; each plunger cooperates with a proximity switch 31 (only one plunger and only one switch are shown). The function of these switches will be described further below.
Not shown is a holder for the syringe barrel 1, into which the barrel can be inserted. Not shown either is a transport device, by means of which the metering head 10 can be moved with respect to the syringe barrel 1 and thus lowered onto the syringe barrel 1. As a result, it is ensured through pneumatic control, for example, that the openings 5a, 5b of the syringe barrel 1 will be aligned precisely with the channels 25a, 25b. In terms of design, the man of the art in question is familiar with appropriate possibilities. For safety reasons, the entire device can be designed for two-handed control.
The device shown in
After a syringe barrel 1 has been positioned correctly under the metering head 10, the two vacuum valves 20a, 20b are opened, so that a vacuum of predetermined strength is created in the chambers 2a, 2b and in the channels 25a, 25b. A pressure difference thus acts on the pistons 3, so that the pistons are pushed into their uppermost position, unless they are already there to begin with. After a predetermined period of time such as 1 second, the two vacuum valves 20a, 20b are closed, and immediately thereafter the two material inlet valves 11a, 11b are opened. Because the pressure vessels 13a, 13b, in which the supply tanks 14a, 14b are held, are under a pressure of, for example, 2-6 bars, the two products A, B are simultaneously forced from the supply tanks 14a, 14b through the product lines 12a, 12b and the material inlet valves 11a, 11b into the channels 25a, 25b and onward into the chambers 2a, 2b. The pistons 3 are automatically displaced. Each piston 3 then strikes the plunger 30 assigned to it and moves it outward. With the help of the associated proximity switches 31, the material inlet valves 11a, 11b are closed independently of each other, either simultaneously or in succession. The two chambers 2a, 2b have now been filled with products A and B. The chambers 2a, 2b, however, are still at this point under the pressure which prevails in the pressure vessels 13a, 13b.
To prevent the products A, B from escaping and contaminating the area when the connection between the syringe barrel 1 and the metering head 10 is broken, the two vacuum valves 20a, 20b are opened briefly to reduce the pressure.
Then the metering head 10 is moved a short distance away from the holder carrying the syringe barrel 1. Between the chambers 2a, 2b and the channels 25a, 25b there is now a gap, into which air can enter. Then the vacuum valves 20a, 20b are opened again briefly. As a result, excess amounts of products A, B are suctioned out of the openings 5a, 5b. These excess amounts of products A, B are simultaneously suctioned out of the channels 25a, 25b and transported through the suction lines 21a, 21b back into the vacuum vessels 22a, 22b, where they collect at the bottom and in some circumstances can be used again later.
The syringe barrel 1 is shown in the lower part of all three figures. On top, i.e., at the end facing the metering head 10 (
In
The invention simplifies the filling of syringe barrels 1.
The invention is not limited by the embodiments described above, which are presented as examples only, but can be modified in various ways within the scope of protection defined by the appended patent claims.
Claims
1. Apparatus for filling first and second syringe barrels having respective first and second pistons which are inserted into the barrels prior to filling, and respective first and second openings through which the barrels are filled with product and through which product is discharged, the apparatus comprising a metering head, the metering head comprising:
- first and second channels which can be connected to respective said first and second openings;
- first and second material inlet valves connected to respective said first and second channels for filling respective barrels with first and second products; and
- first and second vacuum valves connected to respective said first and second channels between said material inlet valves and said openings of said barrel.
2. The apparatus of claim 1 further comprising means for actuating the material inlet valves and the vacuum valves pneumatically.
3. The apparatus of claim 2 further comprising first and second plungers which operate first and second proximity switches in response to movement of said pistons, said switches being effective to close the inlet valves when the barrels are filled.
4. The apparatus of claim 1 further comprising first and second chambers filled with said first and second products, said chambers being connected to said channels through said inlet valves.
5. The apparatus of claim 1 further comprising first and second vacuum vessels connected to said channels through said vacuum valves.
6. A method for filling first and second syringe barrels having respective first and second pistons which are inserted into said barrels prior to filling, and respective first and second openings through which the barrels are filled with product and through which product is discharged, the method comprising:
- providing a metering head having first and second channels, first and second material inlet valves connected to respective said first and second channels, and first and second vacuum valves connected to respective said first and second channels;
- connecting said first and second channels to respective said first and second openings;
- drawing a predetermined vacuum in said channels via said first and second vacuum valves so that said pistons are drawn into respective said first and second barrels;
- closing said vacuum valves after a predetermined time;
- opening said material inlet valves;
- filling said barrels with product from first and second supply tanks via said first and second inlet valves so that said pistons are displaced in said barrels;
- detecting the positions of the pistons by means of plungers which operate respective first and second proximity switches; and
- closing the material inlet valves in response to signals from the proximity switches.
7. The method of claim 6 further comprising:
- opening the vacuum valves in order to reduce pressure in the barrels after the material inlet valves are closed; and
- closing the vacuum valves.
8. The method of claim 7 further comprising:
- disconnecting the channels from the syringe barrels; and
- opening the vacuum valves.
Type: Application
Filed: Aug 8, 2007
Publication Date: Feb 14, 2008
Applicant: DOPAG Dosiertechnik und Pneumatik AG (Cham)
Inventors: Urs Luthi (Steinhausen), Marc Lang (Luzern), Peter Suter (Hagendorn)
Application Number: 11/890,847
International Classification: B65B 31/00 (20060101);