Device for balancing an arm pivoting about an axis of rotation, for example, an arm supporting a work station all-purpose fume or gas exhaust conduit

A balance assembly comprising:

• a first arm supporting a first portion of a gas exhaust conduit of a workstation;
• a second arm supporting a second portion of the gas exhaust conduit, wherein the first and second arms are arranged to pivot about an axis of rotation;
• a first balancing device comprising:
• a first cam member operatively connected with the first arm;
• a first elastic member having a first side connected to a first fixed element;
• and
• a first sliding sleeve cooperating with the first elastic member and having a first edge abutting against and sliding over an edge of the first cam member,
• a second balancing device comprising:
• a second cam member operatively connected with the second arm;
• a second elastic member having a first side connected to a second fixed element;
• and
• a block cooperating with the second elastic member and having a first edge abutting against and sliding over an edge of the second cam member,
• wherein the first and second cams are calibrated to balance the first and second arms in respective minimum torque angular positions, and
• wherein the first cam acts on the first sliding sleeve to vary compression of the first elastic member according to an angular position of the first arm with respect to the first sliding sleeve, and wherein the second cam acts on the block to vary compression of the second elastic member according to an angular position of the second arm with respect to the first arm.