Abstract: A machine for making plastic tubing including a plurality of separate carriages for carrying mold blocks about the continuous path. First and second wheel pairs on opposite sides of each carriage ride on first and second tracks respectively through a molding section of the path. An offset wheel is disposed between the wheels of each pair and rides on guide tracks associated with and facing oppositely to the first and second tracks respectively through the molding section. Each mold block is a plurality of sub-blocks secured end to end, with each sub-block having an arcuate face and corrugated with not more than one complete wavelength. Vacuum channels about sub-block end surfaces connect the block face to a vacuum port.

Abstract: A machine for making plastic tubing including a plurality of separate carriages for carrying mold blocks about the continuous path. First and second wheel pairs on opposite sides of each carriage ride on first and second tracks respectively through a molding section of the path. An offset wheel is disposed between the wheels of each pair and rides on guide tracks associated with and facing oppositely to the first and second tracks respectively through the molding section. Each mold block is a plurality of sub-blocks secured end to end, with each sub-block having an arcuate face and corrugated with not more than one complete wavelength. Vacuum channels about sub-block end surfaces connect the block face to a vacuum port. Cooling water channels about sub-block end surfaces connect to water inlet and discharge ports for selectively circulating cooling water through the blocks.

Abstract: A machine for making plastic tubing including a plurality of separate carriages for carrying mold blocks about the continuous path. A mold train drive engages a selected number of carriages at the beginning of the mold tunnel to continuously drive the carriages along the mold tunnel. A shuttle drive follows the continuous path through a shuttle area and spaced from the path along a substantial portion of the mold tunnel, and includes first and second carriage engaging sections at substantially opposite points along the drive so that a carriage at the end of the mold tunnel becomes engaged by one shuttle drive engaging section while the other shuttle drive engaging section engages a carriage at the beginning of the mold tunnel.

Abstract: A machine for making plastic tubing including a plurality of separate carriages for carrying mold blocks about the continuous path. First and second wheel pairs on opposite sides of each carriage ride on first and second tracks respectively through a molding section of the path. An offset wheel is disposed between the wheels of each pair and rides on guide tracks associated with and facing oppositely to the first and second tracks respectively through the molding section.

Abstract: A manually manipulatable flexible toy includes an elongated tube unitarily fabricated of semi-rigid material such as plastic. The tube forms bellows which, in turn, define a plurality of larger diameter rings and a plurality of smaller diameter rings joined in an alternating array lengthwise of the tube by frusto-conical walls. The tube or any portion thereof is extendable and retractable and manipulatable into various curvilinear configurations, with the tube maintaining its last chosen extended or retracted or curvilinear condition. A pair of the frusto-conical walls diverge radially inwardly from any given larger diameter ring to an adjacent pair of smaller diameter rings when the tube is in the extended condition. A pair of the frusto-conical walls extend radially inwardly offset to one side of any given larger diameter ring when the tube is in the retracted condition. The tube is of a length sufficient to be curved into a closed configuration such as a circle and the like.

Abstract: An apparatus for forming tubular tile, including an endless trackway having at least two substantially straight portions defining first and second molding sections, a plurality of mold blocks supported for movement about the trackway, and a plurality of mating mold blocks supported for mating with the first mold blocks along each molding section to form a segment of a corrugated molding tunnel. Extruders introduce moldable material at the beginning of each molding section, and the material is conformed to the molding tunnel along the molding sections for forming the tile, with the mold blocks being separated when they move past the end of each molding section. The extruders are mounted for movement toward the beginning of the two molding sections when initiating tile formation therein.

Abstract: A corrugated mold block for a vacuum machine for molding corrugated tubes is formed of a plurality of sub-blocks rigidly secured end to end. Each sub-block has an arcuate face which is corrugated with not more than one complete wavelength of circumferential grooves and lands, and two longitudinally spaced end surfaces. A vacuum channel is provided about one of the end surfaces of each sub-block, and openings in each sub-block connect the channel and the face. When the sub-blocks are secured together into a mold block (and when mold blocks abut during molding), the vacuum channels and openings together define vacuum passages for each of the corrugation grooves, which passages are all connected to a vacuum source for drawing a vacuum during molding.

Abstract: A corrugated mold block for a vacuum mold machine is provided with a face arcuate about a longitudinal axis and corrugated in the longitudinal direction with alternating grooves and lands, said face being formed of sheet metal. A housing is provided about the back of the face and adapted for carriage about an endless path, and reinforcing members are provided which are secured to the face and housing and extend therebetween to maintain the desired shape of the face. Openings extend through the grooves of the face to the back thereof and communicate with vacuum passageways formed by a plurality of arcuate channel members secured to the back of each of the face grooves and communicating with a vacuum port through the housing. The housing further defines a cooling passage therethrough in communication with input and output cooling ports through the housing.

Abstract: A tile perforating unit wherein tile is continuously advanced through a frame by advancing means. Moveably mounted on the frame and directed toward the tile is at least one perforating tool. From an initial position, the tool extends and engages a point along the wall of the tile at which perforation is desired. As the tool moves to maintain engagement with the advancing tile a harpoon is extended from the tool to perforate the tile wall. Once perforation is completed, the harpon is withdrawn and the tool retracts and returns to the initial position for repeated perforation of the tile.

Abstract: A corrugator for receiving plastic from an extruder and continuously molding corrugated plastic tile therefrom. The corrugator has a plurality of mold assemblies which are continuously driven to roll about an endless trackway on the corrugator frame, a portion of which defines a molding section. Each mold assembly includes a pair of mold blocks mounted to pivotally open and close. As the mold assemblies enter the molding section, the mold blocks thereof pivotally close and come into abutting relationship with the closed mold blocks of preceeding mold assemblies to cooperatively form a corrugated molding tunnel. Extruded plastic is received by the molding tunnel which moves with and molds the corrugated tile. At the end of the molding section the mold blocks pivot away from and release the tile. To augment the formation the tile the mold blocks are cooled. Additionally a vacuum is induced between the extruded plastic and the wall of the molding tunnel to assure the mating thereof.