Leesona Corporation

Brown Machine, LLC

John Brown Inc.

Other

Albert W Arends

George L Pickard

Roland Karklin

Victor L Chun

Robert C Whiteside

Andrew P Richard

Edward J Russell

George A West

Gaylord W Brown

Ronald E Henke

James H Martin

James A Robbins

Brian Keeley

Fred L Greynolds

Terrance L Brokoff

James R Greiner

G Allan West

A drive system for double toggle mechanisms used to move upper and lower platens with an electric servo motor-gear box drive shaft driving a crank arm arranged to drive a respective double toggle mechanism in turn connected to the platen. The drive shaft axis is located below the toggle mechanism link pivots and driven in a direction so that the motor acts to assist the double toggle mechanism in lifting the platen, reducing the servo motor peak load. The various components are arranged for symmetrical loading of the pivots concerning the toggle links to increase the evenness of the platen when being raised or lowered.

Toggle drive system for driving in a thermoforming press

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.

Thermoformer plug assist drive assembly

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.

Thermoforming machine with linear recirculation of sheet holding frames

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.

Method of driving ejector pins to eject formed parts

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.

Thermoforming apparatus with improved press

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.

Differential pressure forming, trimming and stacking apparatus

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.

Shut height adjustment and crank support arrangements and methods for a

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. Servomotor driven crank mechanism is provided for selectively transversely concurrently moving the wedges in opposite direction through selected lengths of travel to selectively move the trim platen to any selected one of a plurality of different strokes between the open positions and the closed positions.

Trim apparatus and method for trimming an article from a thermoplastic

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.

Cart and method for changing tooling in a thermoformer machine

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.

Preheater for differential pressure forming machine

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.

Apparatus for differential pressure forming and trimming

A trim press for severing articles differentially pressure formed in a thermoplastic sheet comprising a stationary die member and a movable trim die member mounted on a frame for movement toward and away from the stationary trim die member between a spaced apart position and a closed position in which the trim die members engage opposite sides of a sheet to sever the article from the sheet. Dynamically balanced drive mechanism is provided for moving the platen in a to-and-fro path of travel while concurrently oppositely moving a counterbalance weight movably mounted on the frame.

Trim press with counterbalance

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. Mechanism is then activated to move the opposing mold to a position in which the foam injection head is now aligned with the female mold, whereupon the molds are again closed to bring the injection head into the pocket, whereupon the foam injection head is operated to charge a settable foam material to the pocket formed.

Differential pressure thermoforming and foam injection process and

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.

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Gladwin, MI, United States of America

Albert W Arends