Tubular writing head for a tubular writing pen

Claim 1

A tubular-writing head for a tubular-writing pen, said writing head comprising; a cylindrical member having an externally formed screw thread, an externally formed venting channel, and an internally formed bore, a drop weight positioned within said bore, a writing tube connected to said cylindrical member adjoining said bore, a hair wire extending from the one end of the drop weight disposed nearer to said writing tube and therethrough, retaining means in the form of a cup-shaped member disposed within the bore of said cylinder remote from said writing tube for preventing said drop weight from falling out of said cylinder, means disposed in said bore for urging said drop weight in a direction towards said writing tube, said means being a substantially free-floating tiltable mushroom-shaped loading member having a head portion and a stem portion connected thereto, the face of said head portion, being of a slightly smaller diameter than the diameter of said bore, and being disposed within said bore occupying a defined position limited by the angle of tilt of said loading member, and the center of gravity of said loading member residing in the upper end of said stem portion, said cup-shaped member having an opening in the bottom thereof and said stem portion of said loading member extending through said opening, the thrust and pressure applied to said drop weight by said loading member is in a direction towards the writing tube, and is essentially restrained when said pen is in a position other than vertical, whereby ink flow is smoothly regulated and the clearing action of said hair wire in said writing tube is facilitated so as to minimize forming an inverted meniscus in said writing tube, and said cup-shaped member prevents said drop weight and said loading member from falling outwardly from said bore.