1results about How to "Prevent from drying out" patented technology

The application discloses an engineering marker pen and belongs to the technical field of marker pens. The engineering marker pen comprises a shell, a fixing seat is fixedly connected to the inner wall of the shell, a pen barrel vertically and slidably arranged in the fixing seat, and a first thread is arranged on the bottom end inner wall of the shell. The engineering marker pen is characterized in that: the connecting plate is rotated counterclockwise and clockwise, the fourth thread is rotated clockwise or counterclockwise in the third thread, the gap between the connecting plate and the cap gradually increases or decreases, the pushing plate is subjected to the extrusion force of the bottom surface of the cap, the extrusion force of the pushing plate increases or decreases, the shrinkage or extension of the protection plate is controlled, the protection plate is retracted into the slot when the marker pen is used, the protection plate is extended from the slot after the use of the marker pen, the protection plate and the shell form a sealed cavity, the pen end of the pen barrel is prevented from being exposed to the air and dried, the marker pen can be continuously used, the waste of the marker pen is avoided, and the use cost of the marker pen is reduced.