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AssigneeLeesona Corporation
InventorsAlbert W. Arends, George L. Pickard, G. Allan West, Edward J. Russell
Estimating the term…
A thermoforming machine having opposed mold platens includes a linkage system driven in cyclic movement by a single rotary cam to cyclically shift the platens between their open and closed position. The cam is driven by a variable speed motor which is controlled in a manner such that the rotary speed of the cam during different portions of a cam revolution may be set to a speed which is different than the rotary speed of the cam during other portions of each revolution. By adjusting the speed differential or by adjusting the angular extent of that portion of a revolution of the cam over which the different speed is maintained the time duration of any chosen portion of the cycle may be adjusted independently of the time duration of other portions of the cycle. The platens are mounted for reciprocatory movement upon a three-post frame.
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 motor driven means including cam and cam follower means operable when driven to cyclically drive said platens between said mold open and mold closed position, the improvement wherein said motor driven cam and cam follower means comprises a cam mounted on said frame for rotation about a first axis and having a dwell portion of given angular extent lying at a constant radius from said axis, said follower means including a cam follower engaged with said cam and operable to maintain said mold platens in said mold closed position when said cam follower is engaged with said dwell portion of said cam, variable speed motor means for driving said cam in rotation about said axis, and control means for selectively controlling the speed of said motor means during that portion of the rotary cycle of said cam when said cam follower is engaged with said dwell portion to thereby adjustably vary the time during which said mold platens are held in said mold closed position.
In a thermoforming machine having a frame, upper and lower mold carrying platens mounted upon said frame for vertical movement between a mold open and a mold closed position, and means for cyclically driving said platens between said mold open and mold closed positions;
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 said platens in intermittent motion through a cycle wherein said platens are shifted from said mold open position to said mold closed position and subsequently returned to said mold open position;
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 said platens and are operable to maintain said mold platens in said 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 which includes the time when said platens are in mold closed position.
Dependencies are inferred from the claim text.