Abstract: The invention provides an automatic die changing system for a power press with at least one carrier for transporting dies to and from a selected location in the press. The carrier is supported on a set of wheels, which are driven by at least one AC induction motor. An adjustable frequency AC motor drive supplies an AC frequency and voltage to the AC induction motor to control the speed of the motor and therefore the speed of a horizontal movement of the carrier into or out of the press. The speed of the carrier may be rapidly increased by increasing the AC frequency supplied to the motor on the individual wheels. A proximity detector signals the motor drive to trip a dynamic braking resistor, which electronically changes the phase order of the motors to reverse the direction of motor rotation, to decelerate the carrier in order to locate the carrier in the proper position.

Abstract: Disclosed is a tubular luminescent solar collector structure containing semiconductor photocells bonded to the surface thereof along the length of said tube.

Abstract: Disclosed is a structure which in one apparatus converts a part of incident solar energy to electrical energy by the use of photocells mounted on a luminescent solar collector of tubular design while another portion of such incident energy is converted to thermal energy.

Abstract: Disclosed is a structure which in one apparatus converts a part of incident solar energy to electrical energy by the use of photocells mounted on a luminescent solar collector of tubular design while another portion of such incident energy is converted to thermal energy.

Abstract: In a power press having a vertically moveable slide and upper and lower dies which may be transported to and from the power press by means of mobile bolsters, an automatic die change system utilizing microprocessor control. The microprocessor storing data regarding each die set and carrying out the die change operation based on that stored data. The microprocessor control permitting multiple steps in the die change procedure to be carried out simultaneously, thereby reducing the time necessary to effect a die change. The microprocessor control further reducing the time necessary to change a die set by adjusting the slide counterbalance pressure to a level within a predetermined range.