Abstract: A plug assist drive assembly for driving plug assists in a thermoforming apparatus includes a single centrally located roller screw assembly enclosed in a housing and driving a third platen mounting the plug assist with a group of guide-drive bars connected to a drive platen which is driven by the roller screw nut. The roller screw assembly is removable by removing screws holding the nut to one hub adapter, the screws accessed through an opening in the housing normally covered with a plate.

Abstract: A thermoforming machine utilizes two clamping frames to advance cut sheets through heating and forming stations, with the clamping frames returned via an overhead path above the oven in the heating station. Pneumatic cylinders arranged about the inner perimeter of the frames are operated to grip the sheet and release the sheets, which are pressurized and released via fluid connections established when the frames are lifted from a transfer bar structure at the loading and forming stations. The clamping frames have pivoted end sections which are engaged by extendible gear posts at the forming station to bend the clamped sheet into greater conformity with the tooling shape prior to forming.

Abstract: A method of driving part ejector pins at a high cycle rate by a reversible servo motor rotating a crank unidirectionally to advance a pin mounting structure from a retracted position to an advanced eject position, and back to the retracted position, and reversing the motor to repeat the cycle with only a single motor reversal.

Abstract: A method of driving part ejector pins at a high cycle rate by a reversible servo motor rotating a crank unidirectionally to advance a pin mounting structure from a retracted position to an advanced eject position, and back to the retracted position, and reversing the motor to repeat the cycle with only a single motor reversal.

Abstract: A thermoformer apparatus having a press driving upper and lower platens by respective pairs of servo motors, each pair driving four toggle linkages to stabilize the platen against the forming pressures. Linear bearings are provided on four corner posts for precision guiding of the platen motion.

Abstract: Apparatus for forming articles in a thermoplastic sheet, severing the articles in the sheet, and stacking the articles in a stacking receiver. The apparatus includes upper and lower molds moveable between closed positions in which the molds engage opposite sides of the sheet to differentially pressure form a part in the thermoplastic sheet. The molds in which the article is formed are moved toward each from the closed positions to article trim positions to sever the article from the sheet. The lower mold is then moved linearly away from the sheet in a vertical direction and then transversely moved in a second linear transverse path of travel to a remote discharge location. Apparatus is provided for reorienting the mold between its orientation in the first linear path of travel and its orientation in the second path of travel.

Abstract: A thermoforming press in which the shut height of upper and lower platens is adjustable by a keyed connection between a press frame top assembly and each of four posts of the frame established by pieces which are movable and which also act as cams to raise or lower the frame top assembly, moving the upper platen therewith to vary the shut height. The movable pieces are moved in unison by a drive motor to insure uniform movement of the frame top assembly. The platens are driven by rotary crank plates, which are in turn driven by rotary output shafts of right angle drives. Pairs of rollers engage the perimeter of each crank plate on one side to resist bending loads on each shaft.

Abstract: A thermoforming machine utilizes two clamping frames to advance cut sheets through heating and forming stations, with the clamping frames returned via an overhead path above the oven in the heating station. Pneumatic cylinders arranged about the inner perimeter of the frames are operated to grip the sheet and release the sheets, which are pressurized and released via fluid connections established when the frames are lifted from a transfer bar structure at the loading and forming stations. The clamping frames have pivoted end sections which are engaged by extendible gear posts at the forming station to bend the clamped sheet into greater conformity with the tooling shape prior to forming.

Abstract: Method and apparatus for trimming an article integrally differentially pressure formed in a sheet of thermoplastic material comprising a pair of trim dies which are relatively moveable between spaced apart positions for receiving a sheet carrying an article to be trimmed, closed positions, engaging opposite sides of the sheet, and then to sheet severing positions in which an article is severed from the sheet. The dies are relatively moved via a wedge which is transversely moveable on the machine and includes a first sharply inclined wedge surface for rapidly advancing the trim dies from the spaced apart positions to the closed positions. A second, less inclined wedge surface, which is a continuation of the first wedge surface, is provided for moving the trim dies from the closed positions to the sheet severing positions.

Abstract: A wheeled tooling cart for a thermoformer machine enabling quick and easy removal and installation of upper and lower tooling plates from their respective platens. The tooling plates are held on upper framework on the cart, which are removed one at a time with the cart in position adjacent the machine with one and the opposite end successively. The tooling plates are held in position on the cart for reinstallation when the cart is appropriately repositioned with respect to the thermoformer machine. An elevator mechanism allows an upper framework having attachment brackets and rails for holding the tooling plates to be raised and lowered on a wheeled lower framework to move the attachment brackets and rails into proper position for attachment and removal of the tooling plates.

Abstract: A preheater and method of preheating a thermoplastic sheet prior to entry of the sheet into a differential pressure forming machine which forms an article in the sheet. The preheater includes mechanism for initially threading a sheet in a generally horizontal plane, mechanism for concurrently displacing upstream and downstream portions of the sheet in vertically opposite directions relative to the horizontal plane to dispose a portion of the sheet in an upstanding plane. A heater is provided for heating the upstanding portion of the sheet in the upstanding plane. After the sheet has been repositioned with a portion in the upstanding plane, the heater is laterally moved from an inoperative position to a sheet heating position receiving the portion of the sheet at the sheet heating station. Mechanism is provided for selectively moving the sheet downstream after the sheet has been vertically displaced.

Abstract: Apparatus for differential pressure forming an article in a sheet of thermoplastic material having a pair of opposed differential pressure molds at a forming and trimming station moveable between open positions and closed positions engaging opposite sides of the sheet of thermoplastic material for differentially pressure forming an article in the sheet. Mechanism is provided for severing the article from the sheet and includes a pair of opposed trim dies mounted on the molds for movement therewith between spaced apart positions and sheet engaging positions when the molds are moved between open and closed positions. After the part is formed, wedge mechanism is moved transversely of the relative path of travel of the dies for incrementally indexing one of the dies toward the other of the dies to sever the article at the forming and trimming stations.

Abstract: A differential pressure thermoforming machine has a female mold with a female mold cavity, and an opposing mold, with a mold closing portion cooperable therewith. A foam injection head is perimetrally separated from the mold closing portion and is provided on the opposing mold. When the molds are initially closed, a differential pressure is created in the molds to cause the heated plastic sheet to move into contact with the mold cavity and form a configured pocket in the sheet. Mechanism is provided for releasing the plastic sheet from the carriage in which it has been moved between the molds, after the molding operation, to the cavity in the female mold, after which the molds are restored to spread-apart position.

Abstract: Thermoforming machines with a heating station and a downstream mold station have carrier clamp frames for gripping the edges of sheets of plastic at a load station and indexing them successively to a heating station and a mold station. The carrier frame members to which the plastic may be releasably clamped carry their own remotely operated clamps and are themselves expandable and contractible to a condition in which, prior to molding, they control the sag in the sheet formed during heating of the sheets to differential pressure forming temperature. The plastic sheet can be molded to only a portion of a product which functions as a mold member.

Abstract: Improvements in differential pressure, thermoforming machinery for molding articles in thermoplastic material wherein a mold station incorporates female mold mechanism and opposed mold mechanism, a web advancing mechanism indexes a plastic web in which products are to be formed between said mold mechanisms, a drive moves the female and opposed mold mechanisms between open and closed positions on opposite sides of the plastic web, severing knife means is cooperable with a final increment of said relative movement to dispose said mechanism in closed position to sever the products formed from the web, and ejector mechanism is operable after severing is accomplished and there has been relative movement of said mold mechanisms toward open position to eject the product.

Abstract: Thermoforming machines with a heating station and a downstream mold station have carrier clamp frames for gripping the edges of sheets of plastic at a load station and indexing them successively to a heating station and a mold station. The carrier frame members to which the plastic may be releasably clamped carry their own remotely operated clamps and are themselves expandable and contractible to a condition in which, prior to molding, they control the sag in the sheet formed during heating of the sheets to differential pressure forming temperature. The plastic sheet can be molded to only a portion of a product which functions as a mold member.

Abstract: A mechanism for clamping a web of thermoplastic material against the face of a female mold prior to closure of the mold includes a clamping ring assembly mounted on the machine frame for movement relative to the frame independently of the molds. The clamping assembly is driven to and from its web clamping position by a cam mounted on the rock shaft which drives the molds between their open and closed positions and a constant radius section on the cam holds the clamp in its clamping position throughout a substantial portion of the operating cycle.

Abstract: Stacks of generally dish-shaped, nested plastic articles are gripped and transferred from elevated, horizontally adjacent chutes comprising circumferentially disposed, axially extending supports, which are open at both ends to permit articles to be both fed thereto and removed axially therefrom, to a conveyor disposed at a lower level. A transfer arm, mounting stack gripping receivers, which pivot on the transfer arm, is swung in an arcuate path and the receivers are moved relative to the transfer arm, responsive to swinging movement of the transfer arm, such that the receivers travel from a first position, horizontally axially aligned with said chutes and axially intermeshed with the supports, in a path having a first axially linear increment, then a downward arc to rotate said stacks substantially 90.degree., and finally a vertically linear path to deposit the stacks on the conveyor.

Abstract: A system for curling turned-in lips about the open mouths of thin walled, stacked, thermoplastic containers, having brims which extend in a return direction axially, utilizes a plurality of externally helically grooved, tubular, thermally conductive, synchronously rotated rollers equiradially spaced from a common central axis to define an annular passageway between them through which a stack of the containers pass with the brim of the containers simultaneously engaged in the grooves of the rollers. While the brims are being heated radiantly and via conduction substantially to the critical forming temperature, the brims are engaged in the transport portions of the grooves, but the peripheral side wall portions of the container are not contacted.

Abstract: A thermoforming machine having opposed mold platens includes a linkage system driven in cyclic movement by rotary cam mechanism to cyclically shift the platens between their open and closed position. The cam mechanism is driven by a variable speed motor which is controlled in a manner such that the rotary speed of the cam mechanism during different portions of a cam revolution may be set to a speed which is different than the rotary speed of the cam mechanism 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 mechanism 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.