Machine for automatically tying knots in meat stuffed in a casing by means of a string

A machine for automatically tying knots in meat stuffied in a casing by means of a string, comprising means to squeeze the casing over a given stretch in order to remove the sausage therefrom prior to tying, a spool assembly comprising a spool carrying a supply of string, a housing for said spool which is movable parallel to the axis of feed of the casing, a rotatably mounted mechanism having an opening for the passage of the casing on its way to being tied and a hook-shaped portion for the passage of the spool assembly therethrough, aid mechanism having memebers for temporarily supporting a length of string over a polygonal path, and an axially moving element for detaching said length of string from said supporting members, in which the knot is tied by movement of the spool to various positions, namely:

• a final position (E) of the spool assembly upstream of said mechanism which rotates in order to form the polygon of string;
• a position (F) of the spool assembly downstream of said mechanism to allow the latter to make a first rotative and tying motion;
• a position (G) rotated angularly and downwardly from position (F) to allow said mechanism to unwind, through a rotative motion, the length of string required for the tying, followed by its return to the previous position (F), finally assuming its final position (E) downstream of said mechanism in order to achieve a second tying stage, comprised by pulling the string so as to form the knot.