Abstract: A single twin-sheet thermoformed plastic part has parallel bands of plastic forming fillets which allow stiff pallet deck segments to be folded after forming and locked together into a support structure with a planar upper deck spaced above a pallet lower deck with openings for lift truck tines. The lower deck has two segments joined by side stringers to the upper deck. Two central stringer segments extend along folding fillets from lower deck half segments to lock into place with the upper deck. The pallet is locked in its assembled configuration by a rod which passes through knuckles formed beneath the central stringers. The monocoque construction of the pallet provides for advantageous stiffness and load support capacity, while at the same time being economical to produce. For increased load-carrying capability, the pallet may be formed with a reinforcing substrate reinforced with a tubular steel insert.

Abstract: A process is disclosed for producing reinforced twin-sheet thermoformed articles comprising the steps of heating first and second sheets of thermoplastic material; forming the sheets in molds; heating a reinforcing insert of thermoplastic material; placing the heated insert on the first sheet in its mold at the location to be reinforced; pressing the second sheet into contact with the heated first sheet and the heated insert to form the insert between the sheets so that a fusion of the thermoplastic sheets and the insert takes place to produce a reinforced section of the article having a desired shape and thickness. Alternative processes are disclosed wherein a heated quantity of thermoplastic liquid material is extruded or injected between the first and second sheets within the first and second molds either by inserting the liquid material before the molds are closed or by injecting it through one of the molds.

Abstract: A clip is disclosed for connecting adjacent portions of palletized shipping container, the clip including a foldable base for at least partially surrounding a first portion of the shipping container and a key rotatable relative to the foldable base for insertion into and through a slot in a second portion of the shipping container so that the key can be rotated to releasably join the first and second shipping container portions.

Abstract: Two twin-sheet thermoformed thermoplastic sleeve halves engage within peripheral grooves in an underlying pallet and an overlying cover. Each sleeve half has a full wall which is connected by integrally thermoformed hinges to two partial walls. The integral connection between the sleeve walls gives advantageous rigidity to the pallet sleeve assembly, while the hinging of the walls allows economical manufacture and low volume flat storage of the sleeve halves in a knocked-down configuration. The hinges preferably have non-specific hinge axes, thereby providing long hinge life, impact resistance, and ease of operation. Vertical substrate tubes are totally encapsulated into each sleeve half to carry loads from a supported loaded pallet sleeve assembly. To effectively transfer the loads from the cover to the sleeve, sinuous transfer ridges are molded on the sleeves above and below the vertical substrate tubes.

Abstract: The high stiffness of the legs of a twin-sheet thermoformed pallet are effectively made to contribute to the overall stiffness of the pallet deck by utilizing vertical webs which tie into the legs through a plurality of special purpose depressions or knee Joints and which work with narrow channels in the bottom deck which extend parallel to the predominate lines of stress expected to be experienced by the pallet.

Abstract: An upper thermoforming mold is positioned above a lower thermoforming mold on a platen. The platen is provided with an array of position-controlled hydraulic cylinders. A controller drives the array of cylinders to uniformly advance the two molds together once heated sheets of thermoplastic material have been formed thereon. By controlling the position of each actuator, forces may be applied at different levels to the platen to bring about uniform molded parts and reduced deflection of the molds.

Abstract: A process is disclosed for producing reinforced twin-sheet thermoformed articles comprising the steps of heating first and second sheets of thermoplastic material; forming the sheets in molds; heating a reinforcing insert of thermoplastic material; placing the heated insert on the first sheet in its mold at the location to be reinforced; pressing the second sheet into contact with the heated first sheet and the heated insert to form the insert between the sheets so that a fusion of the thermoplastic sheets and the insert takes place to produce a reinforced section of the article having a desired shape and thickness. Alternative processes are disclosed wherein a heated quantity of thermoplastic liquid material is extruded or injected between the first and second sheets within the first and second molds either by inserting the liquid material before the molds are closed or by injecting it through one of the molds.

Abstract: A process is disclosed for producing reinforced twin-sheet thermoformed articles comprising the steps of heating first and second sheets of thermoplastic material; forming the sheets in molds; heating a reinforcing insert of thermoplastic material; placing the heated insert on the first sheet in its mold at the location to be reinforced; pressing tile second sheet into contact with the heated first sheet and the heated insert to form the insert between tile sheets so that a fusion of the thermoplastic sheets and tile insert takes place to produce a reinforced section of the article having a desired shape and thickness. Alternative processes are disclosed wherein a heated quantity of thermoplastic liquid material is extruded or injected between the first and second sheets within the first and second molds either by inserting the liquid material before the molds are closed or by injecting it through one of the molds.

Abstract: The high stiffness of the legs of a twin-sheet thermoformed pallet are effectively made to contribute to the overall stiffness of the pallet deck by utilizing vertical webs which tie into the legs through a plurality of special purpose depressions or knee joints and which work with narrow channels in the bottom deck which extend parallel to the predominate lines of stress expected to be experienced by the pallet.

Abstract: A plastic pallet has a twin sheet thermoformed upper deck reinforced with a tubular metal substrate. Injection molded plastic octagonal posts have support member walls which are positioned beneath reinforced portions of the top deck. The posts also have a sleeve with a central bolt hole which is parallel to the support member walls. A twin sheet thermoformed lower deck is spaced from the upper deck by the posts and receives the posts in recessed pockets. Plastic bolts are inserted through the top deck, each post, and the bottom deck and are held in place by plastic T-nuts. A sawtooth parting line in the twin-sheet thermoforming molds provide accurate alignment and molding of the pallet parts.

Abstract: A wooden upper deck is connected by two types of plastic spacer blocks to a wooden lower deck. The upper deck may be a conventional deck composed of stringers and slats or it may be a twin sheet thermoformed plastic deck. The lower deck is composed of stringers which underlie the plastic spacers and tie boards which abut the ends of the stringers. Connector spacer blocks serve both to join the upper deck to the lower deck and to connect the stringer boards to the tie boards. The stringers and tie boards are held in fixed relation by bolts which join the upper and lower decks passing through sockets in the spacer blocks. The stringers and the tie boards are bolted to the spacer blocks and are thus joined. The joint between the stringers and the tie boards may be strengthened by means of a metal link overlying the stringers and tie boards and linking the bolts together.