SU1662676A1 - Pipette - Google Patents

Abstract

The invention is intended for the collection and metering of micro-quantities of liquids and allows for improved serviceability. When working with a pipette, the following operations are performed: air is expelled from the plunger chamber 20 (plunger forward stroke), 3 doses of fluid are injected into the tip (plunger reverse stroke), plum plunger forward dose, plunger return to its initial position (reverse stroke) plunger). The plunger moves forward by applying pressure to the push button 9 of the dose-taking stock 7, as a result of which it moves up to the stop 12 on the lid 13, or by applying pressure to the push button 10 of the dose-8 stem 8, causing it to move until the protrusion 14 on the plunger 5 reaches the stop 15 connected through the rods 17 to the sleeve 19 for resetting the tip 3. The plunger retracts under the action of the spring 4 when the load is removed from the push button 9 or 10. Resetting the tip 3 takes place at an additional right Single doses drain 8, whereby the projection 14 is located at a distance equal to the move of the plunger when draining dose over abutment 15 placed with connected thereto the ends of rods in the casing 1, acts on the stop 15, moving the sleeve 19. The 1-yl.

Description

The invention relates to pipettes for sampling and dosing of micro-quantities of liquids during analytical and research work.

The purpose of the invention is to improve serviceability.

The drawing shows a pipette, a longitudinal section.

The pipette contains a hollow body 1 with a fitting 2, onto which the tip 3 is fitted. The spring-mounted 4 has a plunger 5 connected to a sleeve 6 connected to two rods 7, 8, respectively, taking the dose and draining the dose, equipped with pressure buttons 9,10 respectively. The means of limiting the movement of the rods provide a dose plunger stroke greater than the dose withdrawal stroke, and are made in the form of a stop 11 on the dose pickup rod 7 and an stop 12 on the housing lid 13, and the dose limiters 8 of the dose drain rod 8 are a protrusion 14 on the plunger 5 and the stop 15, spring-loaded spring 16 and connected to the rods 17 passing through the openings 18 in the choke 2. The rods 17 are rigidly connected to the sleeve 19, which is put on the choke 2 above the nozzle 3. The plunger 5 is passed into the plunger chamber 20 through the seal 21, pressured by sleeve 22, odzhata spring 16. Vyo of th on

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The mortar 14 on the plunger 5 spring-loaded stop 15 is placed relative to each other at a distance equal to the course of the plunger 5 when the dose is drained. The dose plumming rod 8 has an additional stroke required to collect the tip. The stroke restriction is carried out by stopping 23 on the stock 8 of the dose draining and by stopping 24 on the housing cover 13. The upper position of the rods is limited by the protrusion 25 of the dose pickup 7 and the protrusions 26, 27 of the dose plunger 8, which interacts with the sleeve 28 connected to the lid 13.

When working with a pipette, it performs the following operations: displacing air from the plunger chamber 20 through the tip 3 (plunger forward stroke); set in the tip of 3 doses of fluid proportional to the volume of the displaced air from the plunger chamber (plunger reverse stroke); discharging the selected dose into the container (forward stroke of the plunger); returning the pipette plunger to its original position (plunger return stroke).

The plunger 5 moves forward by creating pressure on the push button 9 of the dose-taking stem 7, as a result of which it moves up to the stop 12 on the lid 13, or by applying pressure to the push button 10 of the dose-8 stem 8, resulting in

which it moves until the protrusion 14 on the plunger 5 reaches the stop 15.

Reverse plunger occurs

under the action of spring 4 when relieving pressure from push button 9 or 10

The tip is discharged with an additional direct flow of the dose stem 8, resulting in a protrusion 14 of the plunger

5, acting on the spring-loaded stop 15, moves the sleeve 19. The dose-return rod 8 drains the dose after the tip has been discharged under the action of springs 4 and 16 when the load is removed from the push button 10.

Claims (1)

Claims of the invention: A pipette containing a hollow body with a fitting, mounted in the body a spring-loaded plunger with a rod, worn on the nozzle, the nozzle and the sleeve for its discharge, connected through a rod with an emphasis, spring-loaded relative to the housing, and means of limiting the stroke of the plunger during the selection and discharge of the dose, By the fact that, in order to improve serviceability, the stop and the end of the rod connected to it are placed inside the body, and the suture of the plunger or stem at a distance different to the course of the plunger when the dose is drained, has a protrusion.