ES257760A1 - Electrostatic pick up - Google Patents

Abstract

Improvements introduced in the electrostatic phono-developers, characterized by the fact that the electrostatic phono-developer is constituted by a thin sheet of metal or other conveniently flexible metal material, essentially rectangular, supported and joined, in correspondence of one of its minor sides, between protruding means made or being on two opposite sides of rigid insulating material, one or two metal inserts respectively being applied and fixed to the interior walls of said sides; Between the central flexible sheet and said metal insert or inserts (and the two faces respectively facing each other) there is a narrow space free of air to allow the mobile central sheet to be able to move elastically without contacting the opposite fixed inserts. to her; On the two major opposite sides of the movable sheet, near the end of it, two points of hard stone (of known constitution and shape) are joined, one suitable to follow the undulations of the grooves of the disks that operate at a speed of 78 revolutions per minute, and the other suitable to follow the undulations of the grooves of the discs that operate at a speed of 45 revolutions or 33 1/3 revolutions per minute (microgroove); the group consisting of the two rigid sides comprising the fixed insert or inserts between which the free part of the flexible sheet can move elastically is attached to a rotating axis on a support and controlled by a button, the support being able to be fixed on a phonographic developer arm of any known type. (Machine-translation by Google Translate, not legally binding)