APPARATUS FOR FABRICATING A HOLLOW ARTICLE

• US 3,867,088 A
• Filed: 03/16/1973
• Issued: 02/18/1975
• Est. Priority Date: 07/03/1972
• Status: Expired due to Term

• Current Assignee: John Brown Industries Limited
• Original Assignee: Gaylord W. Brown, George L. Pickard
• Inventors: Brown, Gaylord W., Pickard, George L.
• Primary Examiner(s): Spicer, Jr., Robert L.
• Application Number:
  US05/342,094
• Time in Patent Office: 704 Days
• Field of Search: 425/395,388,45R,109,451,413,437,DIG.48,397
• US Class Current: 425/504
• CPC Class Codes: B29C 51/12 of articles having inserts or reinforcements
• CPC Class Codes: B29C 51/18 Thermoforming apparatus
• CPC Class Codes: B29C 51/261 Handling means, e.g. transfer means, feeding means B29C51/44 takes precedence
• CPC Class Codes: B29C 51/267 Two sheets being thermoformed in separate mould parts and joined together while still in the mould B29C49/0691 takes precedence
• CPC Class Codes: B29C 51/46 Measuring, controlling or regulating
• CPC Class Codes: Y10S 425/048 Sheet clamping

Abstract

Methods and apparatus for fabricating a hollow article from sheets of juxtaposed, deformable, thermoplastic material wherein mold apparatus is provided for thermoforming a shape in at least one of the sheets. In one aspect of the invention, apparatus is provided for depositing a reinforcing member on one of the sheets, and the sheets are then fused together to sandwich the reinforcing member between the sheets. The reinforcing member may move a portion of one of the sheets into a mold cavity before it is released. In another aspect of the invention, a plug assist member is moved to a position between a pair of molds and is then swung into a cavity in one of the molds to assist in moving a portion of a plastic sheet into the mold cavity. The plug assist member is then removed and the molds are brought together to fuse the edge of the sheets.

Claims

1. Apparatus for forming a hollow article from sheets of deformable thermoplastic material comprising:

frame means with a forming station and a sheet heating station;

sheet heating means at said sheet heating station for heating sheets of deformable thermoplastic material;

carriage means on said frame supporting a pair of sheets of thermoplastic material for movement from said sheet heating station to said forming station;

mold assembly means at said forming station including a differential pressure mold member having a mold cavity for forming a shape in at least one of said sheets and an opposed member at least one of said members being mounted on said frame for movement toward and away from the other between a removed position and a sheet engaging position, and means for applying a differential pressure to opposite sides of said one sheet when said differential pressure mold member is in said sheet engaging position;

carrier means for moving article reinforcing means to a position between said members when said one member is in said removed position and depositing it on said one sheet;

means for moving said one member toward the other member to fuse said sheets together and sandwich said reinforcing means between said sheets; and

means for separating said members.

2. The apparatus set forth in claim 1 wherein said carrier means for moving and depositing said article reinforcing means comprises a carrier movable in a to-and-fro path of travel between a discharge position between said members and a removed position;

gripper means on said carrier for gripping said reinforcing means when said carrier is in said removed position and for releasing said reinforcing member on said one sheet between said members when said carrier is in said discharge position.

3. The apparatus set forth in claim 2 wherein said carrier is movable in a horizontal path of travel, said gripper means being mounted on said carrier for vertical movement between raised and lowered positions, and means is provided for moving said gripper means from said raised position to said lowered position when said carrier is in said discharge position to deposit said reinforcing means on said one sheet.

4. The apparatus set forth in claim 3 including supply meaNs for supporting reinforcing means to be gripped by said gripper means;

and means is provided for moving said gripper means between said raised position and said lowered position to grip said reinforcing means on said supply means when said carriage means is in said removed position.

5. The apparatus set forth in claim 4 wherein said supply means includes support means movable between a position underlying said gripper means when said carriage means is in said removed position, and an offset position for receiving reinforcing means, and control means is provided for coordinating the movement of said supply means, said carrier means, said sheet supporting carriage means, and said member moving means.

6. The apparatus set forth in claim 2 wherein said gripper means is mounted on said carrier for swinging movement between raised and lowered positions;

and means is provided for swinging said gripper means between lowered positions when said carrier is in said removed position and said discharge position for picking up and discharging reinforcing means, respectively, and a raised position when said carrier is moving between said removed and discharge positions.

7. The apparatus set forth in claim 6 wherein said gripper means comprises a plurality of suction means.

8. The apparatus set forth in claim 1 wherein said means for moving said reinforcing means moves in a path of travel transverse to the path of travel of said sheets between said heating station and said forming station.

9. The apparatus set forth in claim 1 wherein said sheet heating means comprises a pair of plastic sheets heaters on opposite sides of said forming station at which sheets of deformable thermoplastic material are concurrently heated;

said carriage means comprises upper and lower carriers for supporting upper and lower sheets of thermoplastic material;

said upper and lower carriers being mounted for movement between positions at said sheet heating stations and confronting positions at said forming station.

10. Apparatus for forming a hollow object from a pair of thermoplastic sheets comprising:

a frame, a pair of mold members having generally flat opposed surfaces mounted on said frame for movement wherein at least one of said members is movable toward and away from the other between an open position wherein said surfaces are in spaced substantially parallel relationship with each other and a closed position wherein said members clamp a pair of thermoplastic sheets between said opposed surfaces, one of said mold members having a cavity extending inwardly of the member from its generally flat surface, first means operable when said mold members are in said open position for locating a pair of sheets of thermoplastic material respectively adjacent the opposed surfaces of said mold members, cavity entering means including a carrier and a cavity entering member mounted on said carrier, second means operable when said mold members are in said open position for advancing said cavity entering means from a retracted position outside the space between said mold members to an extended position wherein said cavity entering means is located between said mold members in operative alignment with said cavity in said one of said mold members and for subsequently projecting said entering means from said extended position to a projected position wherein said entering member projects into said cavity in engagement with the thermoplastic sheet located on the flat surface of said one of said mold members, differential pressure means operable to form the thermoplastic sheet to the shape of said cavity, said second means being operable subsequent to the operation of said differential pressure means to return said carrier to its retracted position, and third means operable upon the return of said carrier means to its retracted position for driving said mold members to their closed position to clamping fuse-bond said sheets to each other.

11. Apparatus as defined in claim 10 further comprising means dEtachably mounting said cavity entering member upon said carrier, control means operable when said cavity entering means is in said projected position for detaching said cavity entering member from said carrier to deposit said cavity entering member in said cavity for enclosure between said thermoplastic sheets.

12. Apparatus as defined in claim 11 wherein said differential pressure means is operated to conform said one sheet to said cavity prior to movement of said cavity entering means to said projected position.

13. Apparatus as defined in claim 10 wherein said cavity entering means is moved to said projected position to deform said one sheet into said cavity prior to operation of said differential pressure means.

14. Apparatus as defined in claim 13 wherein said cavity entering means comprises a carrier, a cavity entering member detachably mounted upon said carrier, control means operable when said cavity entering means is in said projected position for detaching said cavity entering member from said carrier to deposit said cavity entering member in said cavity for enclosure between said thermoplastic sheets.