ES294873A3 - Retractable ball-point pen - Google Patents

Abstract

Improvements in the construction of ballpoint pens, of the type comprising a hollow envelope having an open end for writing axially opposite to an upper open end, a plunger axially movable within said envelope between upper and lower positions, and located next to the upper end of the envelope, and a writing element fixed to the piston and protruding axially through said end to write when the piston is in its lower position, characterized by providing the ballpoint pen with a ratchet tooth that extends radially from one side of said piston, said tooth having a locking edge oriented towards the upper end and a sliding edge oriented towards the writing end, of a spring member that pushes said piston against the corresponding wall of said envelope, said tooth being housed in an opening in the envelope when the piston is in its lower position and being radially movable said plunger inside the casing against the push of said spring member to withdraw the tooth from the inside of said opening, said plunger being axially movable from the writing end to its position, superior in which the tooth is outside its opening, and for also providing the pen with elements that cooperate with each other and are arranged in the piston and in the casing, which produce a locked coupling when said piston reaches its upper position and prevent the movement of said piston beyond said upper position, said elements comprising a projection and a recess suitable for receiving said projection inside, said recess having been practiced in the piston or in the casing and said projection having been arranged in the other of these two parts. (Machine-translation by Google Translate, not legally binding)