Differential pressure forming machine with variable mold closed cycle

In a thermoforming machine having a frame, a pair of mold carrying platens mounted on said frame for movement toward and away from each other between a mold open and a mold closed position, and variable speed drive means for driving each of said platens in intermittent motion through a cycle wherein each of said platens are shifted from said mold open position to said mold closed position and subsequently returned to said mold open position;

• the improvement comprising control means operable for varying the speed of drive of said drive means driving each platen during said cycle to cause said drive means to drive each platen at different speeds during different portions of the same cycle.

In a thermoforming machine having a frame, a pair of mold carrying platens mounted on said frame for movement toward and away from each other between a mold open and a mold closed position, and a motor operable when driven to cyclically drive said platens between said mold open and mold closed position, the improvement wherein drive elements driven by said motor are connected with each of said platens and are operable to maintain each of said mold platens in mold closed position during a dwell period, and control means is provided for varying the speed of said motor during a portion of the cycle of said drive elements for each platen which includes the time when each platen is in mold closed position.

A method of operating a thermoforming machine having a pair of mold carrying platens mounted on a frame for movement toward and away from each other between a mold open and a mold closed position, a motor operable when driven to cyclically drive said platens between said mold open and mold closed position, and drive elements driven by said motor connected with each of said platens and operable to maintain each of said mold platens in mold closed position during a dwell period, comprising varying the speed of drive of said motor during a portion of the cycle of said drive elements for each platen which includes the time when each platen is in mold closed position.

In a thermoforming machine having a frame, a mold and platen assembly mounted on said frame and including a pair of mating molds mounted for relative movement between a mold open and a mold closed position, and a continuously driven motor operable when driven to cyclically drive said assembly and to effect the mold open and mold closed positions, the improvement wherein drive elements driven by said motor in continuously consecutive cycles are connected with said assembly and operable to drive said assembly through consecutive cycles effecting said relative movement and in which said molds are maintained in said mold closed position during a dwell period, and control means is provided for varying the speed of revolution of said motor during selected portions of the same cycle of the assembly to drive the motor at a different speed during a portion of each cycle which includes at least part of the dwell period.

A thermoforming machine having a frame;

• a mold and platen assembly mounted on said frame and including a pair of mating molds, at least one being mounted for movement between a mold open and a mold closed position;
• a drive motor;
• driving elements, driven by said motor, connected with said one mold, said motor being operable when driven to cyclically drive said one mold relatively between mold open and mold closed position, and operable to maintain said one mold in said mold closed position during a dwell period, and control means for varying the speed of revolution of said motor during each cycle of said drive elements and driving said one mold at predetermined different speeds during each cycle from mold open to mold closed position and back.