FI77166B - DOSERINGSPIPETT. - Google Patents

Description

77166

The present invention relates to a pipette having a plunger and a cylinder and two operating buttons, one of which can be filled with liquid with one push and the other of emptying in successive steps of the desired size of the piston. There may be one or more piston-cylinder combinations.

Such so-called there have been several types of step pipettes in the past, e.g. according to the Finnish public patent application 10 FI 802 ^ 03 or according to the German application publication DE

2926691 (: QB 2 057 58I). However, they often have the disadvantage that the filling lever has to be operated by lifting, in which case two hands are usually required. In addition, when using known devices, 15 errors often occur when the last dose is also inadvertently dispensed, so that the piston no longer travels a long enough distance.

A dispensing pipette has now been invented in which, in a manner known per se, a plunger is connected to a rack which can be pushed out of the pipette by a predetermined number of steps by means of a dispensing lever and a striker mounted thereon. New in the pipette is a flexible lifting lever on the side of the toothing, the distance from the end of the rack can be adjusted as desired and with a cam that lifts the striker off the toothing stage. At the upper end of the rack, it is preferable to have a cam which, as the rack approaches the lower position, raises the lifting lever by the height of the toothing. In this case, the cam of the lifting lever raises the striker so much that the striker no longer extends into the toothing when the lever is pressed. In addition, the rack has a second toothing, it relies on the gear 30, which rests on the other side with a second toothed rod which is the button.

The pipette is easy to use because it can be filled with one hand while the other hand remains free, for example for handling test tubes. In addition, the described lever-sys-35 theme is simple and reliable in construction. In addition, the nozzle mounted at the top of the rack can be used to avoid pipetting the last, too small dose.

2 77166

The invention is further illustrated by the accompanying drawings. Figure I shows an embodiment in cross-section from the side and Figure II shows a specific section from above. Figure III shows a detail of the tip portion of the multi-tip tip-5 bed.

The pipette includes an elongate handle 1 with a cylinder 2 at the lower end and a piston 3 inside it. · The cylinder can be attached to the handle, e.g. with a bayonet attachment. Attached to the upper end of the piston is a handle-parallel tooth-10 rod with two teeth 5 and 6. A force 8 is pressed into the toothing 6 by a spring 16 which is mounted on a lever 9 · Lever 9 is mounted on a shaft 15 in the handle. keep the lever in its up position. The movement of the striker 8 in the lower position-15 stops at the stop 18.

With the toothing 5 of the rack 4, a gear 7 »is mounted in a rush, which is mounted on the shaft 10. The gear 7 operates in a rush on the other side with a rack 11, the upper end of which has a button 12.

On the side of the toothing 6 of the rack 4 there is a flexible lifting lever 20 and a cam 21 which lifts the striker 8 off the toothing 6 during the rising phase of the lever 9. At the upper end of the lifting lever there is a guide pin 23 which is fitted in the guide groove 25 in the adjusting wheel 2 * J · The adjusting wheel is mounted on the shaft 26.

The upper end of the rack 4 further has a cam 22 which, as the rack approaches its lower position, moves the lifting lever 20 towards the striker 8.

The pipette operates in such a way that with the lever 9 in the upper position-30 and the striker 8 thus detached from the toothing 6 and the piston 3 in the cylinder 2 in its lower position, the button 12 is pressed down, causing the gear 7 to rotate and raise the 2 upwards. This creates a suction in the cylinder 2, whereupon it is filled with liquid 13 ·

When the cylinder 2 is completely filled and the button 12 is in its lower position 1 * 1, dosing can be started with the lever 9.

3,771 66

When the dosing lever 9 is pressed down, the spring 16 presses the striker 8 into the toothing 6, whereby the striker 8 starts to push the toothed rod h and the piston 3 downwards until the striker 8 meets the stop 18, where the movement stops. The spring 19 returns the dispensing lever 9 back to its upper position when the pressing is completed. In this case, the striker 8 has to jump over the toothing 6 until the flexible cam nose 21 on the side of the rack 4 near the upper position of the striker 8 lifts the striker 8 off the toothing 6.

10 The dosing can be repeated until the rack 4 and the piston 3 approach their lower position. In this case, the cam 22 at the upper end of the rack 4 strikes the lifting lever 20, raising it to the toothing 6 by height. In this case, the cam 21 of the lifting lever 20 in turn raises the striker 8 so much that the striker 8 no longer extends with the new dispensing push of the lever 6 on the toothing 6. This prevents the piston 3 from hitting the bottom of the cylinder 2, which could make the last dose inaccurate.

By turning the adjusting wheel 2¾, the guide groove 25 moves the lifting lever 20 up or down by means of the pin 20 23, whereby at the lower end of the lifting lever the cam 21 moves, allowing the striker 8 to move by the toothing 6 by the desired amount, e.g.

1 »2, 3, 4 or more teeth, with each press of the dosing lever 9. This gives a 1, 2, 3 or 11-fold dose.

In Figures I and II, the teeth 5 and 6 are shown in succession, but if desired, they can also be placed side by side on the rack 4.

Claims (5)

771 66 il A dosing pipette with a handle (1), a cylinder (2) attached thereto, a piston (3) inside the cylinder, a dosing rack (* 4) attached to the piston, a striker (8) resting on its dosing teeth (6), which is mounted to the dosing lever (9) so that when the dosing lever is pressed the striker pushes the rack outwards, characterized in that the side of the dosing tooth has a flexible lifting lever (20), the distance from the rack end 10 can be adjusted as desired by the adjusting device (24). which lifts the striker off the dosing tooth during the ascent step, and that the dosing rack has in addition a second toothing (5), a gear (7) resting on it, which on one side rests on another tooth-15 size (11) with a fill button (12). Pipette according to claim 1, characterized in that the upper end of the dosing rack has a cam (22) which, as the dosing rack approaches its lower position, pushes the lifting lever towards the striker so that the lifting lever 20 prevents the striker from touching the teeth. Pipette according to Claim 1 or 2, characterized in that the teeth of the dosing rack are arranged side by side. Pipette according to Claim 1 or 2, characterized in that the teeth of the dosing rack are arranged in succession. Pipette according to one of Claims 1 to ¾, characterized in that the filling button is on the side of the handle.