Plastic molding machine

Claim 2

A vacuum molding apparatus comprising: frame means for receiving and holding a plastic sheet, heater means mounted for heating and softening said sheet, a forming bed having a mold receiving surface for receiving a mold, and means defining a plurality of vertical and horizontal air channels for guiding air being removed from said bed including a tray having a bottom floor with an opening for removing air, side walls extending upwardly from said floor to define a continuous peripheral edge, said floor having a plurality of grooves for channelizing air flow, a mesh screen lying on said floor, a further board lying atop said mesh screen and having grooves on the surface remote from said screen for channelizing air flow, and apertures extending therethrough, and a composition board lying atop said further board having a corduroy upper surface on which molds can be placed as desired with the corduroy ridges also channelizing air flow. vacuum means connected to said forming bed for removing air from a space between a softened plastic sheet and said bed to cause said softened sheet to be drawn about a mold on said mold receiving surface, and means for moving said frame means and a held sheet between a position adjacent said heater means for softening and a position engaging said forming bed for molding a softened sheet about a mold.

Claim 3

An apparatus as in claim 1 wherein said composition board is removable.

Claim 4

An apparatus as in claim 2 wherein said opening of said grooved floor of said tray is connected to said vacuum means.

Claim 5

An apparatus as in claim 1 wherein said vacuum means includes a surge tank connected to said forming bed and a vacuum pump connected to said surge tank.

Claim 6

A apparatus as in claim 1 wherein said moving means includes a manually operable raise switch and a manually operable lower switch, a hydraulic cylinder mounted for raising and lowering said frame means including a piston connected to said frame means movable within a cylinder defining a space above and below said piston, control means, responsive to manual operation of said raise switch, for causing the atmosphere to be connected to said space below said piston and said vacuum means to said space above said piston to create a differential pressure causing said piston to raise said frame means and for causing, responsive to manual operation of said lower switch, the atmosphere to be connected to said space above said piston and said vacuum means to said space below said piston to create a differential pressure causing said piston to lower said frame means.

Claim 7

An apparatus as in claim 5 wherein said vacuum means includes a surge tank and a vacuum pump.

Claim 8

An apparatus as in claim 1 further including means for mounting said heater means for horizontal movement between a storage position and a position above said frame means and wherein said moving means moves said frame means vertically.

Claim 9

An apparatus as in claim 7 wherein said heater means includes a housing open at the bottom, and at least a single resistive heater rod mounted in said housing and wherein said heater mounting means includes a pair of rails along which said heater housing can be manually and horizontally moved.

Claim 10

An apparatus as in claim 1 wherein said tray upwardly extending side walls define a continuous peripheral edge and includes means for engaging said softened sheet and providing a positive seal.

Claim 11

An apparatUs as in claim 8 wherein said heater rod is shaped and mounted to extend substantially about the periphery of a rectangle which matches said continuous peripheral edge defined by said walls so that the portion of said sheet which engages said continuous peripheral edge is fully and completely softened to ensure sealing.

Claim 12

An apparatus as in claim 10 wherein three heater rods are provided, two C-shaped rods extending substantially about the periphery of said rectangle and a center rod.

Claim 13

An apparatus as in claim 1 further including housing means for mounting said forming bed, heater means and moving means.

Claim 14

An apparatus as in claim 1 wherein said frame means includes an upper and lower frame portion pivotably connected together along one edge.

Claim 15

An apparatus as in claim 1 wherein said plurality of grooves in said tray bottom include a first set of grooves extending parallel to each other and a second set of grooves extending parallel to each other and perpendicular to said grooves of said first set.

Claim 16

An apparatus as in claim 1 wherein said grooves of said further board include a first set extending parallel to each other and a second set extending parallel to each other and perpendicular to said grooves of said first set and wherein said apertures are located at the intersections of grooves of said first and second sets.

Claim 17

An apparatus as in claim 1 wherein said composition board is porous.

Claim 18

A forming bed for vacuum molding comprising: a tray having a bottom floor with an opening for removing air and side walls extending upwardly from said floor to define a continuous peripheral edge, said floor having a plurality of grooves for channelizing air flow, a mesh screen lying on said floor, a further board lying atop said mesh screen and having grooves on the surface remote from said screen for channelizing air flow, and apertures extending therethrough, and a composition board lying atop said further board having a corduroy upper surface on which molds can be placed as desired with the corduroy ridges also channelizing air flow.

Claim 19

A forming bed for vacuum molding comprising: a tray having a bottom floor with an opening for removing air and side walls extending upwardly from said floor to define a continuous peripheral edge, said floor having a plurality of grooves for channelizing air flow, a mesh screen lying on said floor, a further board lying atop said mesh screen and having grooves on the surface remote from said screen for channelizing air flow, and apertures extending therethrough, and a composition board lying atop said further board having a corduroy upper surface on which molds can be placed as desired with the corduroy ridges also channelizing air flow.

Claim 20

A bed as in claim 17 wherein said plurality of grooves in said tray bottom include a first set of grooves extending parallel to each other and a second set of grooves extending parallel to each other and perpendicular to said grooves of said first set.

Claim 21

A bed as in claim 17 wherein said grooves of said further board include a first set extending parallel to each other and a second set extending parallel to each other and perpendicular to said grooves of said first set and wherein said apertures are located at the intersections of grooves of said first and second sets.

Claim 22

A bed as in claim 17 wherein said composition board is porous.

Claim 23

A vacuum molding apparatus comprising: frame means for receiving and holding a plastic sheet, a forming bed having a tray with upwardly extending side walls defining a continuous, peripheral edge which engages a softened sheet and provides a positive seal. heater means mounted for heating and softening said sheet, including a housing open at the bottom and at least a single register rod mounted in said housing and shaped to extend substantially about the periphery of a rectangle which matches said continuous edge so that the portion of said sheet which engages said continuous edge is fully and completely softened to ensure sealing, vacuum means connected to said forming bed for removing air from a space between a softened plastic sheet and said bed to cause said softened sheet to be drawn about a mold, and means for moving said frame means and a held sheet between a position adjacent said heater means for softening and a position engaging said forming bed for molding a softened sheet about a mold including a manually operable raise switch and a manually operable lower switch, a hydraulic cylinder mounted for raising and lowering said frame means including a piston connected to said frame means movable within a cylinder definIng a space above and below said piston, control means, responsive to manual operation of said raise switch, for causing the atmosphere to be connected to said space below said piston and said vacuum means to said space above said piston to create a differential pressure causing said piston to raise said frame means and for causing, responsive to manual operation of said lower switch, the atmosphere to be connected to said space above said piston and said vaccum means to said space below said piston to create a differential pressure causing said piston to lower said frame means.

Claim 24

A vacuum molding apparatus comprising: frame means for receiving and holding a plastic sheet, a forming bed having a tray with upwardly extending side walls defining a continuous, peripheral edge which engages a softened sheet and provides a positive seal. heater means mounted for heating and softening said sheet, including a housing open at the bottom and at least a single register rod mounted in said housing and shaped to extend substantially about the periphery of a rectangle which matches said continuous edge so that the portion of said sheet which engages said continuous edge is fully and completely softened to ensure sealing, vacuum means connected to said forming bed for removing air from a space between a softened plastic sheet and said bed to cause said softened sheet to be drawn about a mold, and means for moving said frame means and a held sheet between a position adjacent said heater means for softening and a position engaging said forming bed for molding a softened sheet about a mold including a manually operable raise switch and a manually operable lower switch, a hydraulic cylinder mounted for raising and lowering said frame means including a piston connected to said frame means movable within a cylinder definIng a space above and below said piston, control means, responsive to manual operation of said raise switch, for causing the atmosphere to be connected to said space below said piston and said vacuum means to said space above said piston to create a differential pressure causing said piston to raise said frame means and for causing, responsive to manual operation of said lower switch, the atmosphere to be connected to said space above said piston and said vaccum means to said space below said piston to create a differential pressure causing said piston to lower said frame means.

Claim 25

An apparatus as in claim 21 wherein said forming bed includes a removable composition board with an upper corduroy surface onto which molds are placed, said corduroy surface defining horizontal air channels.

Claim 26

An apparatus as in claim 22 wherein said forming bed further includes a tray having a grooved bottom surface and an opening for connection to a vacuum source.

Claim 27

An apparatus as in claim 21 wherein said vacuum means includes a surge tank connected to said forming bed and a vacuum pump connected to said surge tank.

Claim 28

An apparatus as in claim 21 wherein said forming bed includes: a tray having a bottom floor with an opening for removing air and side walls extending upwardly from said floor to define a continuous peripheral edges, said floor having a plurality of grooves for channelizing air flow, a mesh screen lying on said floor, a further board lying atop said mesh screen and having grooves on the surface remote from said screen for channelizing air flow, and apertures extending therethrough, and a composition board lying atop said further board having a corduroy upper surface on which molds can be placed as desired with the corduroy ridges also channelizing air flow.

Claim 29

An apparatus as in claim 25 wherein said plurality of grooves in said tray bottom include a first set of grooves extending parallel to each other and a second set of grooves extending parallel to each other and perpendicular to said grooves of said first set.

Claim 30

An apparatus as in claim 25 wherein said grooves of said further board include a first set extending parallel to each other and a second set extending parallel to each other and perpendicular to said grooves of said first set and wherein said apertures are located at the intersections of grooves of said first and second sets.

Claim 31

An apparatus as in claim 25 wherein said composition board is porous.

Claim 32

An apparatus as in claim 21 further including means for mounting said heater means for horizontal movement between a storage position and a position above said frame means and wherein said moving means moves said frame means vertically.

Claim 33

An apparatus as in claim 29 wherein said heater mounting means includes a pair of rails along which said heater housing can be manually and horizontally moved.

Claim 34

An apparatus as in claim 21 wherein three heater rods are provided, two C-shaped rods extending substantially about the periphery of said rectangle and a center rod.

Claim 35

A vacuum molding apparatus comprising: frame means for receiving and holding a plastic sheet, a forming bed dimensioned to fit within the inside boundry of said frame means having a mold receiving surface including a upwardly extending side walls defining a continuous peripheral edge which engages a softened sheet and provides a positive seal, heater means mounted for heating and softening said sheet, including a heater element shaped and mounted to extend substantially about the periphery of a rectangle which matches said continuous peripheral edge defined by said side walls so that the portion of said sheet which engages said continuous peripheral edge is fully and completely softened to ensure sealing, vacuum means connected to said forming bed for removing air from a space between a softened plastic sheet and said bed to cause said softened sheet to be drawn about said mold, and means for moving said Frame means and a held sheet between a first position adjacent said heater means for softening and a second position which engages said forming bed by moving the outside edges of said held sheet past said upwardly extending sidewalls thereby providing said positive seal and for thereafter molding a softened sheet about said mold.

Claim 36

A vacuum molding apparatus comprising: frame means for receiving and holding a plastic sheet, a forming bed dimensioned to fit within the inside boundry of said frame means having a mold receiving surface including a upwardly extending side walls defining a continuous peripheral edge which engages a softened sheet and provides a positive seal, heater means mounted for heating and softening said sheet, including a heater element shaped and mounted to extend substantially about the periphery of a rectangle which matches said continuous peripheral edge defined by said side walls so that the portion of said sheet which engages said continuous peripheral edge is fully and completely softened to ensure sealing, vacuum means connected to said forming bed for removing air from a space between a softened plastic sheet and said bed to cause said softened sheet to be drawn about said mold, and means for moving said Frame means and a held sheet between a first position adjacent said heater means for softening and a second position which engages said forming bed by moving the outside edges of said held sheet past said upwardly extending sidewalls thereby providing said positive seal and for thereafter molding a softened sheet about said mold.

Claim 37

An apparatus as in claim 32 wherein three heater rods are provided, including two C-shaped rods extending substantially about the periphery of said rectangle and a center rod.

Claim 38

An apparatus as in claim 32 wherein said tray has a bottom floor with an opening for removing air and side walls extending upwardly from said floor to define a continuous peripheral edge, said floor having a plurality of grooves for channelizing air flow, and wherein said forming bed further includes: a mesh screen lying on said floor, a further board lying atop said mesh screen and having grooves on the surface remote from said screen for channelizing air flow, and apertures extending therethrough, and a composition board lying atop said further board having a corduroy upper surface on which molds can be placed as desired with the corduroy ridges also channelizing air flow.

Claim 39

An apparatus as in claim 34 wherein said plurality of grooves in said tray bottom include a first set of grooves extending parallel to each other and a second set of grooves extending parallel to each other and perpendicular to said grooves of said first set.

Claim 40

An apparatus as in claim 34 wherein said grooves of said further board include a first set extending parallel to each other and a second set extending parallel to each other and perpendicular to said grooves of said first set and wherein said apertures are located at the intersections of grooves of said first and second sets.

Claim 41

An apparatus as in claim 34 wherein said composition board is porous.