Trim apparatus and method for trimming an article from a thermoplastic sheet

Trim apparatus for severing articles which have been differentially pressure formed in a thermoplastic sheet from the thermoplastic sheet comprising:

• a frame;
• means on said frame for supporting a thermoplastic sheet, having articles differentially pressure formed therein, at a trim station;
• a pair of trim platens, each mounting a trim die, mounted on said frame for movement between spaced apart positions, removed from said sheet and first closed positions in which said trim dies engage opposite sides of said sheet, and second further closed sheet severing positions in which at least one of said trim dies penetrates said sheet to sever an article at said trim station from said sheet;
• means for successively moving said trim platens between said spaced apart positions spaced from said sheet and said first closed positions and said second further closed position comprising
• first wedge means, having a first predetermined inclination, for reacting between said frame and at least one of said platens for moving said one platen and one of said trim dies mounted thereon at a predetermined rate toward the other trim die from said spaced apart position to said first closed position;
• second wedge means laterally contiguous with said first wedge means and, having a second lessor inclination substantially less than said first inclination, for reacting between said frame and said one trim platen for incrementally moving said one trim platen and said one trim die at a second lesser rate, substantially less than said predetermined rate, from said first closed position to said second closed sheet severing position to sever said article from said sheet at said trim station;
• means mounting said first and second wedge means for linear transverse movement in a path of movement transverse to the path of movement of said one trim platen to successively present said first and second wedge means between remote non-wedging positions and wedging positions reacting between said frame and said one trim platen;
• and
• motor driven crank means for transversely moving said first wedge means between said non-wedging position and said wedging position to move said one trim platen to said first closed position and for the successively moving said second wedge means between said non-wedging position and said wedging position to incrementally move said one trim platen and said one trim die, from said first closed position to said second closed sheet severing position.

Trim apparatus for severing articles which have been differentially pressure formed in a thermoplastic sheet from the thermoplastic sheet comprising:

• a frame;
• means on said frame for supporting a thermoplastic sheet, having articles differentially pressure formed therein, at a trim station;
• a pair of trim platens, each mounting a trim die, mounted on said frame for movement between spaced apart positions, removed from said sheet and first closed positions in which said trim dies engage opposite sides of said sheet, and second further closed, sheet severing positions in which at least one of said trim dies penetrates said sheet to sever an article at said trim station from said sheet;
• means for successively moving said trim platens between said spaced apart positions and said first and second closed positions comprising
• wedge mechanism for reacting between said frame and at least one of said trim platens;
• and
• means mounting said wedge mechanism for linear transverse movement in a path transverse to the path of movement of said trim platens between a laterally remote position, a first wedging position and successively to a second wedging position;
• said wedge mechanism including
• a first wedge section, having a first inclination, for moving said one trim platen, and one of said trim dies mounted thereon, toward the other trim platen from said spaced apart position to said first closed position when said wedge mechanism is in said first wedging position, and
• a second wedge section, continuing from said first wedge section but having a second inclination different than said first inclination, for moving said one platen, and said one trim die thereon, from said first closed position to said second closed, sheet severing position when said wedge mechanism is in said second wedging position;
• and
• motor driven crank means for moving said wedge mechanism linearly transversely to successively move said wedge mechanism from said remote position to said first wedging position and then to said second wedging position.

Trim apparatus for severing articles which have been differentially pressure formed in a thermoplastic sheet from the thermoplastic sheet comprising

• a frame;
• means on said frame for supporting a thermoplastic sheet, having articles differentially pressure formed therein, at a trim station;
• a pair of opposed cooperating trim dies mounted on said frame for movement in a first path of travel between spaced apart positions, removed from said sheet, first closed positions engaging opposite sides of said sheet, and second further closed, sheet severing positions to sever an article from said sheet at said trim station;
• means for successively moving said opposed cooperating trim dies between said spaced apart positions, said first closed positions and said second further closed, sheet severing positions comprising
• a wedge mounted on said frame for movement in a second linear path of travel transverse to said first path of travel, between a non-wedging mode, a first wedging mode, and a second wedging mode;
• said wedge including
• first wedge means, having a first inclination relative to said first path of travel, for moving at least one of said opposed cooperating trim dies toward the other of said opposed cooperating trim dies at a predetermined rate of travel from said spaced apart position to said first closed position when said wedge is in said first wedging mode;
• second wedge means, contiguous with said first wedge means and having a second inclination relative to said first path of travel, for moving said one opposed cooperating trim die toward said other opposed cooperating trim die at a second lesser rate of travel substantially less than said predetermined rate of travel from said first closed position to said second closed position when said wedge is in said second wedging mode and
• means for successively transversely moving said wedge from said non-wedging mode to said first wedging mode and then to said second wedging mode comprising
• a crank rotatable about an axis and including an eccentric portion eccentrically coupled to said wedge, and
• a motor rotatable about said axis and drivingly coupled to said crank.

Trim apparatus for severing an article integrally differentially pressure formed in a thermoplastic sheet, from the sheet, at a trim station comprising:

• a frame;
• a pair of trim platens, each mounting a trim die, mounted on said frame for relative movement in a longitudinal path of travel between spaced apart open positions, less spaced apart closed positions, and further less spaced apart sheet severing positions;
• first wedge means linearly moveable between a remote position and a wedging position disposed between said frame and one of said trim platens for relatively moving at least said one trim platen toward the other of said trim platens from said open position to said closed position at a first rate of travel;
• second wedge means, laterally adjacent said first wedge means, linearly moveable between a second remote position and said wedging position between said frame and said one trim platen for relatively moving at least said one trim platen from said closed position to said sheet severing position at a second rate of travel substantially less than said first rate of travel to sever an article from said sheet at said trim station;
• and
• means for concurrently reciprocally moving said first and second wedge means laterally adjacent each other in a to-and-fro transverse path of travel to successively dispose said first and second wedge means in said wedging position comprising
• crank means, rotatable about an axis, having an eccentric portion eccentrically coupled to said first and second wedge means for moving said first and second wedge means in said to-and-fro transverse path of travel, and
• servomotor drive means drivingly coupled to said crank means for rotating said crank means about said axis and reciprocally move said first and second wedge means in said to-and-fro transverse path of travel;
• said first wedge means comprising a first wedge surface having a predetermined inclination relative to said transverse path of travel for moving said one trim platen at said predetermined rate of travel;
• said second wedge means comprising a second wedge surface having a second lesser inclination relative to said transverse path of travel, substantially less than said predetermined inclination, to successively move said one trim platen from said closed position to said sheet severing position at said second rate of travel.

A method of trimming and severing an article, which has been integrally, differentially formed in a thermoplastic sheet, from the thermoplastic sheet comprising the steps of:

• indexing a sheet of thermoplastic material, having an article differentially pressure formed therein, to a position disposed between a pair of spaced apart, opposed, trim dies at a trim station;
• relatively moving said trim dies in a longitudinal path of travel between spaced apart positions and closed positions engaging opposite sides of said sheet;
• moving at least one of said trim dies toward the other of said trim dies to relatively move said trim dies from said closed positions to sheet severing positions to sever an article from said sheet at said trim station;
• said step of relatively moving said trim dies being accomplished by linearly moving first vertically inclined wedge means, having a first predetermined inclination, in a transverse path of travel transverse to said longitudinal path of travel to move said one trim die relative to said other trim die at a predetermined rate of travel;
• said step of moving at least one of said trim dies toward the other of said trim dies being accomplished by sequentially linearly moving second wedge means, having a second lesser vertical inclination substantially less than said first predetermined inclination, in said transverse path of travel to move said one trim die at a substantially lesser predetermined rate of travel substantially less than said predetermined rate of travel;
• said steps of moving said first and second wedge means being accomplished by converting rotary motion to linear motion.