DE1260826B - Valve arrangement on pipetting devices with suction ball - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

GOIn

German class: 421-3 / 02

Number: 1260 826

File number: B 56081IX b / 421

Filing date: December 30, 1959

Open date: February 8, 1968

The invention relates to a valve arrangement on pipetting devices, in which balls made of hard material within lines made of elastic material at expanded points are stored and designed so that the finger pressure to operate the valve is to the side of the center of the ball is exercisable.

It is true that pipetting devices with screwable connections have become known in which however, there is an intermediate piece between the pipetting tube on the one hand and the pipetting ball on the other hand is interposed. This not only complicates the structure of the device, it complicates it there is also a risk of leaks occurring.

The inventive concept of the present invention avoids the disadvantages of the known device, in that the ventilation nozzle is detachably connected to the suction ball by means of a screw connection, wherein the vent nozzle sits in a union nut, the threaded nipple in the suction ball or is vulcanized into a cap vulcanized onto this.

According to the invention, a pipetting device is obtained which is simple in construction because there is no special intermediate piece between the suction ball and the pipette tube is switched on, on the other hand but the possibility of a quick and thorough cleaning of the internal parts by unscrewing them is possible.

Further details of the invention will be explained in more detail with reference to the exemplary embodiment in the drawing. It shows

F i g. 1 is an elevation and partial longitudinal section through a pipetting device, in which on the Suction ball a spherical cap for receiving a threaded attachment is vulcanized,

F i g. 2 shows part of another embodiment of a pipetting device, in which the bead edge is pressed in one piece with the suction ball to accommodate the threaded attachment,

F i g. 3 an axial section through the union nut with the connecting piece, F i g. 4 is an elevation of the thread attachment and

F i g. 5 is a plan view of the threaded attachment of FIG. 4.

According to the embodiment of FIG. 1, the pipetting device consists of a hollow spherical suction ball 22 made of soft rubber with a lower air outlet opening 23. A spherical cap 24 is also vulcanized onto this, also made of soft rubber, to which a suction nozzle 25 is connected at the bottom, which is connected to the valve arrangement on pipetting devices
Suction ball

Applicant:

Franz Bergmann K. G.,

1000 Berlin-Zehlendorf, Berliner Str. 25

Named as inventor:

Alfred Klingbeil, 1000 Berlin-Lankwitz;

Fritz Szezinsky, 1000 Berlin-Reinickendorf

Contains an air duct 8 inside. This channel 8 widens to a valve chamber 26 in which a valve ball 3 made of hard material is included. In the drainage port 27 of the suction port 25 a branch channel 28 is provided, which also widens to a valve chamber 29, in which a valve ball 30 made of hard material is mounted. The drainage nozzle 27 is expanded to the outside to a hollow ball 31 with an outwardly opening channel 32. To the im Inside the suction nozzle 25 located valve balls 30 can be controlled arbitrarily, are on the outer surfaces diametrically opposite, circular pressure surfaces 33 on the suction port 25 are provided.

Opposite the air outlet opening 23, the inlet opening 34 is provided on the suction ball 22, in FIG the area of which a cap 35 made of soft rubber is vulcanized onto the suction ball. In ring grooves The cap 35 engages ring disks 36, 37 which are provided on a threaded nipple 38. For the fixed anchoring are on one of the ring disks, namely on the larger ring disk 36, in a circle distributed bores 39 (F i g. 5) are provided, into which the rubber material enters during the manufacture of the cap. This prevents the threaded nipple from falling apart when the device is handled robustly from the cap.

The threaded nipple 38 is used to attach the ventilation port 40, which is also made of soft rubber and which has a flange 41 at the lower end, by means of which and a union nut 42, which is made of metal, the vent port 40 is screwed onto the threaded nipple 38. A central bore 43 is provided in the vent port 40, which closes in the upper part a valve chamber 44, in which a valve ball 45 is mounted, in the area of which there are two dia-

809 507/312

metrically opposite points on the outer surface of the vent 40 two pressure plates 46 are provided. By applying pressing pressure the ball 45 can be clamped in the desired position in the chamber 44 by means of two fingers. In this way, the pipetting process can be directed as desired.

According to the embodiment of FIG. 2 and 3, no special cap 35 is provided, rather it is the threaded nipple 38 is fastened in annular grooves which are located in a beaded rim 47 which is connected to the suction ball 22 is made from one piece. During the press production of the suction ball, the threaded nipple 38 attached in the beaded rim. The invention has compared to the known pipetting devices with Suction ball has the advantage that after unscrewing the lower connection piece, the inside of the suction ball can clean easily and properly.

To use the device, the ball is in held cupped in one hand. With your thumb and forefinger, the pressure plates 46 of the upper Valve - the so-called vent valve - compressed and at the same time with central and Ring finger the ball is pressed together in the hand so that the air can escape from the bore 43 of the vent port 40.

Now the upper valve is released for the purpose of suction, the device with the Pipette tube 48 is immersed in the liquid and held with thumb and forefinger or middle finger slowly squeeze the valve of the suction nozzle 25 until the desired liquid level is in the pipette tube is reached, the elasticity of the suction ball ensuring the suction.

To empty the pipette, the valve of the suction nozzle 25 is released and with your thumb and Forefinger or middle finger, the valve 30 of the emptying nozzle is pressed together. This will the pipette ventilates and empties. The remainder is made by squeezing the air chamber eliminated in the hollow ball 31 with simultaneous pressure on the vent valve 30. Here is first squeeze off the outlet opening 49 of the air chamber 31 with your thumb and forefinger and the in the To divert air located in the air chamber 31 into the pipette 48. This removes the liquid residue from the Pipette squirted out.

Claims (6)

Patent claims: 1. Valve arrangement on pipetting devices with suction ball, in which balls made of hard Material stored within lines made of elastic material at expanded points and are designed so that the finger pressure to operate the valve to the side of the Ball center can be exercised (using the construction already known in pipetting devices with screwable connections), characterized in that the vent connection (40) releasably connected to the suction ball (22) by means of a screw connection (38, 42) is, wherein the vent nozzle sits in a union nut (42), the threaded nipple (38) is vulcanized in the suction ball (22) or in a cap (35) vulcanized onto it. 2. Arrangement according to claim 1, characterized in that the vent port (40) a one-piece flange (41) that fits into the union nut (42) and abuts against the threaded nipple (38). 3. Arrangement according to claim 1, characterized in that the threaded nipple (38) outside its threaded attachment has two ring disks (36, 37), one of which (37) acts as an end disk of smaller diameter than the other disc (36) and the other Annular washer (36) with a larger diameter limits the thread attachment and with several lengthways the circumference distributed through bores (39) is provided for the rubber. 4. Arrangement according to claims 1 and 3, characterized in that the annular disc (36) provided with the holes (39) is vulcanized into a beaded rim (47) of the suction ball (22) or the vulcanized-on dome (35) surrounding it. 5. Arrangement according to claims 1 to 4, characterized in that the non-releasable emptying nozzle consists in a known manner with a dome-like cap in one piece and with this on the opposite, an opening (23) having rubber ball (22), this opening ( 23) is covering, vulcanized and the opposite vent port (40) can be unscrewed. 6. Arrangement according to claim 5, characterized in that the drainage port (27) having suction nozzles (25) fixed to the rubber suction ball (22) by vulcanization by means of its cap is connected, while the opposite vent port (40) means Screw connection is detachable. Considered publications:
German patent specifications No. 959 766, 906 860,
930 1 sheet of drawings 809 507/312 1.68 © Bundesdruckerei Berlin