Switchable braking mechanism, especially for the individual threads of an embroidery machine

摘要

The needle of an individual embroidery location of a multitude or row of linearly arranged embroidery locations in an embroidery machine is mounted at an axially displaceably guided needle carrier. According to a programmed control and by means of a related switching lever the needle can be individually coupled to or decoupled from an oscillating drive rail which is common to all the needles of the row. A thread guiding roller which is journaled for free rotation at a roller supporting lever and associated with a related one of the needles supplies a thread to the related needle. Simultaneously with the coupling or decoupling of the needle to the oscillating drive rail the roller supporting lever is pivoted between an operative position and an inoperative position in which the thread guiding roller is respectively coupled to or decoupled from a braking member which is common to all embroidery locations. The driving connection arrangement between the thread guiding roller and the common braking member is designed to act in the manner of a reducing gear, so that a rotary movement of the thread guiding roller causes a significantly less extensive rotary movement of the common braking member. The pivoting of the roller supporting lever is effected via a connecting member which may constitute a cord or a wire and which is connected to the switching lever which activates or deactivates the related embroidery location.