Abstract: A counterbalancing arrangement and a method for counterbalancing two mutually movable parts, which is arranged to counteract the gravitational force of at least one of the movable parts. The counterbalancing arrangement includes a gas spring and a compressor system. The compressor system is designed to sense a pressure in the gas spring and to adjust the pressure if the pressure deviates from a predetermined value. The counterbalancing arrangement can be used for counterbalancing an industrial robot arm and is capable of maintaining its working capacity regardless of any gas leakage and variations in the ambient temperature so as to result in very few unwanted stops occasioned by a need for servicing the balancing spring of the counterbalancing arrangement.

Abstract: A counterbalancing arrangement and a method for counterbalancing two mutually movable parts, which is arranged to counteract the gravitational force of at least one of the movable parts. The counterbalancing arrangement includes a gas spring and a compressor system. The compressor system is designed to sense a pressure in the gas spring and to adjust the pressure if the pressure deviates from a predetermined value. The counterbalancing arrangement can be used for counterbalancing an industrial robot arm and is capable of maintaining its working capacity regardless of any gas leakage and variations in the ambient temperature so as to result in very few unwanted stops occasioned by a need for servicing the balancing spring of the counterbalancing arrangement.

Abstract: The invention relates to an arrangement in a pressing tool for braking the return movement of pistons/piston rods (D1) of gas-filled springs (D) and thereby also of a sheet metal holder (B) supported thereon after pressing has been performed. The invention is characterised in that each gas-filled spring device (D) is designed with a separate brake cylinder part (E) and brake piston part (F), in which the brake cylinder part (E) is situated adjoining the outer end of the gas-filled spring (D) and in which the brake piston part (F) is situated adjoining the inner end of the piston rod (D1).

Abstract: The invention relates to an arrangement in a pressing tool for braking the return movement of pistons/piston rods (D1) of gas-filled springs (D) and thereby also of a sheet metal holder (B) supported thereon after pressing has been performed. The invention is characterised in that each gas-filled spring device (D) is designed with a separate brake cylinder part (E) and brake piston part (F), in which the brake cylinder pail (E) is situated adjoining the outer end of the gas-filled spring (D) and in which the brake piston part (F) is situated adjoining the inner end of the piston rod (D1).

Abstract: A gas spring device is provided with a safe and effective way to reduce to zero the velocity of a piston rod which is traveling at a high velocity in the gas spring device during a failure of the gas spring device. This achieved by stopping the piston rod in a controlled manner through a stepwise reduction in its energy and velocity to keep the force on the piston to a minimum at all times during the failure. The reduction in energy is caused by a plurality of frangible components associated with the gas spring device which are designed to break during a failure, thereby dissipating the kinetic energy of the piston rod.

Abstract: Arrangement in a pressing tool for sheet metal forming in order to shut off or retard an oil flow in a hydraulic system at an arbitrarily chosen time in coordination with the closing and opening movements of the said tool. When the tool closes, a non-return valve (6) permits a flow in one direction from a primary hydraulic cylinder/piston unit (7), which is thereby compressed, to an accumulator (8). A first valve (9) selectively permits a flow between the accumulator (8) and a secondary hydraulic cylinder/piston unit (10) which, in the event of such a flow, passes from a compressed basic position to an expanded position.