Apparatus and method for filling syringe barrels

Abstract

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 ( 11 a ) and a second material inlet valve ( 11 b ) as well as a first vacuum valve ( 20 a ) and a second vacuum valve ( 20 b ). The material inlet valves ( 11 a, 11 b ) and the vacuum valves ( 20 a, 20 b ) are connected to channels ( 25 a, 25 b ), to each of which a chamber ( 2 a, 2 b ) of the syringe barrels ( 1 ) can be connected, as a result of which the syringe barrel ( 1 ) can be filled through the same openings ( 5 a , 5 b ) as those through which the product (A, B) can be forced out of the chambers ( 2 a, 2 b ) 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 . 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.