Flow control for writing or drawing instrument

摘要

A writing or drawing instrument including a writing tip (1) disposed at a front end of the writing instrument which can be brought into contact with a writing or drawing pad, a writing fluid reservoir (7) for supplying the writing tip (1) with writing fluid, and a writing fluid chamber (9) disposed between the writing tip (1) and the writing fluid reservoir (7). The writing fluid chamber (9) consists of a bubble of a flexible, inelastic material. The writing fluid chamber (9) is connected to the writing tip (1) on one side and is connected on the other side to a barrier (12). The barrier (12) is connected with the writing fluid reservoir (7) and can be opened in a controlled manner. When a lower fill level is reached in the writing fluid chamber (9), the barrier is briefly opened to fill the writing fluid chamber (9). During the filling of the writing fluid chamber (9), the volume of the writing fluid reservoir (7) is reduced in accordance with the consumption of the writing fluid.