Abstract: A molding machine including a plurality of carriages for carrying mold blocks in an axial direction. The carriages each include wheels on opposite sides which follow a guide track along an endless path including a molding section extending in the axial direction. Two wings are secured to the carriages for pivoting about an axis extending in the axial direction whereby in one pivotal position the mold blocks are together in a molding position and in another pivotal position the mold blocks are separated in a releasing position. Each of the wings is adapted to carry one of the mold blocks and has a flat axially extending surface and guide wheels. A wing guide track engages the wing guide wheels and is adapted to place the wings in the molding position when the carriage is in the molding section. A first set of track rollers along the molding section engages the flat axially extending surface of one of the wings of carriages in the molding section along a first rolling plane extending in the axial direction.

Abstract: A molding machine including a plurality of carriages for carrying mold blocks in an axial direction and a track for the carriages including a molding section, the track including spaced apart channels receiving the carriage wheels for guiding the carriages along the track. The carriages each include wheels on opposite sides of the carriage, a first set of oppositely facing and axially extending flat surfaces on one side of the carriage, a second set of oppositely facing and axially extending flat surfaces on the other side of the carriage, and centering rollers having facing rolling surfaces spaced apart a distance X. The track includes first and second sets of track rollers associated with one of the channels, the first and second track roller sets defining a first pair of axially extending, parallel facing rolling planes whereby the first and second roller sets engage the first set of flat surfaces of carriages in the molding section.

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: 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.