ACCOMPANYING PISTON FOR BALLPOINT PEN AND METHOD OF ITS MAKING Russian patent published in 2004 - IPC

FIELD: stationary.

SUBSTANCE: proposed piston contains element in form of stable gel whose hardness measured by method of cone forcing is from 100 ^. 10-1

mm to 400 ^.10^-1 mm. Said stable gel is obtained from polyorganosiloxane polymers, polyurethanes, polyesters or epoxy resins. Accompanying piston can have hard porous element partially immersed in gel and formed by rod made by pressing from plastic material or from thermally sintered powder of high molecular polyethylene or formed by open porous structure. Method of making accompanying piston in pen comes to filling liquid reaction medium into tube through its open end opposite to tip over ink. If necessary, hard element is formed and than fitted into tube inside liquid medium, thus forming gel element owing to chemical reaction of liquid medium in place of formation of piston. Said piston prevents flowing out of ink through rear end of rod.

EFFECT: improved convenience in use.

29 cl, 3 tbl, 3 ex