US3713765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential pressure thermoforming apparatus for forming large articles such as trailer bodies and boats
Assignee: Individual
•
Filing: 1970-10-22
•
Granted: 1973-01-30
•
Expires: 1990-10-22
Abstract
Abstract Differential pressure thermoforming apparatus for forming large articles such as trailer bodies and boats in relatively thin sheets of thermoplastic material comprising a sheet supporting box frame for clamping the edge portions of a sheet of thermoplastic material and defining a cavity spanned by the clamped sheet. Load assist bars are disposed in the cavity to initially support the mid-portion of the thermoplastic sheet while it is being clamped on the frame and then fluid under pressure is admitted to the cavity to lift the midportion of the sheet upwardly off the bars. A sheet heating oven is mounted laterally adjacent one side of the mold box frame and is movable into superposed relation with the box frame where it is then tilted so that the sheet carried thereby is heated to a substantially uniform temperature. The clamped sheet, having its mid-portion supported by fluid pressure, is then moved upwardly toward a differential pressure mold to form a shape in the sheet of material. Doors are provided on the sides of the mold box frame and are opened to exhaust cooling air which is introduced to the cavity. After the shape is formed and the mold box frame is moved away from the mold, the load assist bars function to eject the molded part from the frame.
Inventors
- 👤 D Rise
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:40
CPC Classifications
B; B29; B29C; B29C51/00; B29C51/18; B29C51/10
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
272 words
Differential pressure thermoforming apparatus comprising: support means; first and second laterally spaced sheet supporting box frame means on said support means each including means for supporting the edge portions of a sheet of thermoplastic material; first and second differential pressure mold means on said support means in juxtaposition with said first and second sheet supporting box frame means for forming shapes in sheets of thermoplastic material; means on said support means for alternately relatively moving said first and second sheet supporting box frame means and said first and second mold means, respectively, between removed positions and operative molding positions so that sheets of thermoplastic material on said first and second sheet supporting box frame means are brought into engagement with said first and second mold means to mold shapes in said sheets; means for alternately introducing fluid under pressure to said first and second sheet supporting box frame means to support the mid-portions of the heated sheets on said first and second sheet supporting box frame means as said first and second sheet supporting box frame means and said first and second mold means, respectively, are relatively moved to said operative molding pOsitions; and heating means movable on said support means alternately to a first position between said first sheet supporting box frame means and said first mold means in said removed positions and a second position between said second sheet supporting box frame means and said second mold means in said removed positions to heat sheets of material supported on said first and second box frame means, respectively, and while the mid-portions of said sheets are supported by said pressurized fluid.
Claim 2
Dependent Claim
272 words
Differential pressure thermoforming apparatus comprising: support means; first and second laterally spaced sheet supporting box frame means on said support means each including means for supporting the edge portions of a sheet of thermoplastic material; first and second differential pressure mold means on said support means in juxtaposition with said first and second sheet supporting box frame means for forming shapes in sheets of thermoplastic material; means on said support means for alternately relatively moving said first and second sheet supporting box frame means and said first and second mold means, respectively, between removed positions and operative molding positions so that sheets of thermoplastic material on said first and second sheet supporting box frame means are brought into engagement with said first and second mold means to mold shapes in said sheets; means for alternately introducing fluid under pressure to said first and second sheet supporting box frame means to support the mid-portions of the heated sheets on said first and second sheet supporting box frame means as said first and second sheet supporting box frame means and said first and second mold means, respectively, are relatively moved to said operative molding pOsitions; and heating means movable on said support means alternately to a first position between said first sheet supporting box frame means and said first mold means in said removed positions and a second position between said second sheet supporting box frame means and said second mold means in said removed positions to heat sheets of material supported on said first and second box frame means, respectively, and while the mid-portions of said sheets are supported by said pressurized fluid.
Claim 3
Dependent Claim
272 words
Differential pressure thermoforming apparatus comprising: support means; first and second laterally spaced sheet supporting box frame means on said support means each including means for supporting the edge portions of a sheet of thermoplastic material; first and second differential pressure mold means on said support means in juxtaposition with said first and second sheet supporting box frame means for forming shapes in sheets of thermoplastic material; means on said support means for alternately relatively moving said first and second sheet supporting box frame means and said first and second mold means, respectively, between removed positions and operative molding positions so that sheets of thermoplastic material on said first and second sheet supporting box frame means are brought into engagement with said first and second mold means to mold shapes in said sheets; means for alternately introducing fluid under pressure to said first and second sheet supporting box frame means to support the mid-portions of the heated sheets on said first and second sheet supporting box frame means as said first and second sheet supporting box frame means and said first and second mold means, respectively, are relatively moved to said operative molding pOsitions; and heating means movable on said support means alternately to a first position between said first sheet supporting box frame means and said first mold means in said removed positions and a second position between said second sheet supporting box frame means and said second mold means in said removed positions to heat sheets of material supported on said first and second box frame means, respectively, and while the mid-portions of said sheets are supported by said pressurized fluid.
Claim 4
Dependent Claim
272 words
Differential pressure thermoforming apparatus comprising: support means; first and second laterally spaced sheet supporting box frame means on said support means each including means for supporting the edge portions of a sheet of thermoplastic material; first and second differential pressure mold means on said support means in juxtaposition with said first and second sheet supporting box frame means for forming shapes in sheets of thermoplastic material; means on said support means for alternately relatively moving said first and second sheet supporting box frame means and said first and second mold means, respectively, between removed positions and operative molding positions so that sheets of thermoplastic material on said first and second sheet supporting box frame means are brought into engagement with said first and second mold means to mold shapes in said sheets; means for alternately introducing fluid under pressure to said first and second sheet supporting box frame means to support the mid-portions of the heated sheets on said first and second sheet supporting box frame means as said first and second sheet supporting box frame means and said first and second mold means, respectively, are relatively moved to said operative molding pOsitions; and heating means movable on said support means alternately to a first position between said first sheet supporting box frame means and said first mold means in said removed positions and a second position between said second sheet supporting box frame means and said second mold means in said removed positions to heat sheets of material supported on said first and second box frame means, respectively, and while the mid-portions of said sheets are supported by said pressurized fluid.
Claim 5
Dependent Claim
40 words
The differential pressure thermoforming apparatus as set forth in claim 1 wherein said pressurized fluid introducing means is operative to billow the mid-portions of clamped sheets outwardly away from said sheet supporting means in a direction toward said mold means.
Claim 6
Dependent Claim
59 words
The differential pressure thermoforming apparatus as set forth in claim 2 including sensing means for sensing the position of the billowed mid-portion of said sheets; and means responsive to said sensing means for interrupting said pressurized fluid introducing means when said sheets are billowed outwardly a predetermined distance in a direction away from said sheet supporting box frame means.
Claim 7
Dependent Claim
50 words
The differential pressure thermoforming apparatus of claim 1 wherein each of said sheet supporting box frame means defines a space spanned by a sheet supported thereon; said pressurized fluid being admitted to said spaces; and means for introducing cooling air to said spaces to cool shapes molded in said sheets.
Claim 8
Dependent Claim
64 words
The differential pressure thermoforming apparatus of claim 4 wherein each of said sheet supporting box frame means includes exhaust port means; means for opening and closing said exhaust port means; and means for moving said exhaust port opening and closing means to an exhaust port opening position so that the cooling air introduced to said spaces may be exhausted through said exhaust port means.
Claim 9
Dependent Claim
105 words
The differential pressure thermoforming apparatus of claim 1 wherein each of said first and second sheet supporting box frame means defines a space spanned by a sheet supported thereon; and including means disposed in said spaces and being movable relative to said sheet supporting box frame means for supporting the mid-portions of said sheets when said box frame means and said mold means are in said removed positions and for ejecting the parts formed in the sheets from the mold box frame means when said mold box frame means and said mold means are moving from said operative molding positions to said inoperative removed positions.
Claim 10
Dependent Claim
58 words
The differential pressure thermoforming apparatus of claim 6 wherein said means for supporting and ejecting comprises a plurality of load assist bars disposed in each space and being movable relative to said box frame means; said pressurized fluid introducing means being operable to lift the mid-portions of the sheets of material upwardly away from said load assist bars.
Claim 11
Dependent Claim
97 words
The differential pressure thermoforming apparatus as set forth in claim 1 wherein means is provided on said support for reorienting said heating means relative to said first and second sheet supporting means when said heating means is in said first and second positions, respectively, so that the portions of the sheets of thermoplastic on said first and second frame means remote from said second and first mold means respectively, are nearer to the heating means than the portions of the sheets on said first and second frame means closest to said second and first mold means respectively.
Claim 12
Dependent Claim
207 words
Differential pressure thermoforming apparatus comprising: a frame; sheet supporting means for supporting sheets of thermoplastic material; mold means on said frame disposed in juxtaposition with said sheet supporting means for forming parts in the sheets supported thereon; heating means for heating said sheets supported by said sheet supporting means; means mounting said sheet supporting means and said heating means for relative movement between laterally adjacent positions, in which said heating meAns is positioned laterally adjacent on lateral side of said sheet supporting means, and juxtaposed positions; means for relatively moving said sheet supporting means and said heating means between said laterally adjacent positions and said juxtaposed positions; means for automatically tilting said heating means in said juxtaposed position so that said heating means is nearer to the portion of the sheet adjacent the laterally opposite side of said sheet supporting means than to the portion of the sheet adjacent said one side of said sheet supporting means so that the sheet of thermoplastic material is heated to a uniform temperature; and means for relatively moving said sheet supporting means and said mold member when said heating means is in said adjacent position to move a heated sheet into engagement with said mold member to form a part.
Claim 13
Dependent Claim
207 words
Differential pressure thermoforming apparatus comprising: a frame; sheet supporting means for supporting sheets of thermoplastic material; mold means on said frame disposed in juxtaposition with said sheet supporting means for forming parts in the sheets supported thereon; heating means for heating said sheets supported by said sheet supporting means; means mounting said sheet supporting means and said heating means for relative movement between laterally adjacent positions, in which said heating meAns is positioned laterally adjacent on lateral side of said sheet supporting means, and juxtaposed positions; means for relatively moving said sheet supporting means and said heating means between said laterally adjacent positions and said juxtaposed positions; means for automatically tilting said heating means in said juxtaposed position so that said heating means is nearer to the portion of the sheet adjacent the laterally opposite side of said sheet supporting means than to the portion of the sheet adjacent said one side of said sheet supporting means so that the sheet of thermoplastic material is heated to a uniform temperature; and means for relatively moving said sheet supporting means and said mold member when said heating means is in said adjacent position to move a heated sheet into engagement with said mold member to form a part.
Claim 14
Dependent Claim
61 words
The differential pressure thermoforming apparatus of claim 9 wherein said heating means is pivotally mounted on said frame and said tilting means comprises cooperating cam means and cam follower means positioned on said heating means and said frame which cooperate when said heating means and said sheet supporting means are in juxtaposition to pivot the heating means relative to said frame.
Claim 15
Dependent Claim
112 words
The apparatus set forth in claim 9 wherein said mold means comprises first and second laterally spaced differential pressure mold members and said sheet supporting box frame means comprises laterally spaced first and second sheet supporting box frames in juxtaposition with said first and second mold members, said means for relatively moving said sheet supporting means and said heating means comprises means for moving said heating means alternately to a first position between said first mold member and said first sheet supporting box frame and a second position between said second sheet supporting box frame and said second mold member to heat sheets supported on the first and second box frames respectively.
Claim 16
Dependent Claim
74 words
The differential pressure thermoforming apparatus of claim 10 wherein said heating means comprises resilient centering means on opposite sides of the pivotal mounting for yieldably urging said heating means to a position parallel with a sheet on said sheet supporting means, said cooperating cam means and cam follower means being operable to swing said heating means about said pivotal mounting when said heating means and said sheet supporting means are in said juxtaposed positions.
Claim 17
Dependent Claim
64 words
The differential pressure forming apparatus as set forth in claim 11 wherein said heating means includes a carriage and a plurality of heating elements on said carriage; said means for relatively moving said sheet supporting means and said heating means includes means for moving said carriage from a position laterally adjacent said sheet supporting means to a superposed position with said sheet supporting means.
Claim 18
Dependent Claim
56 words
The differential pressure forming apparatus as set forth in claim 13 wherein said means for relatively moving said mold means and said sheet supporting means comprises rack means mounted on said support, and sprocket means disposed on opposite sides of said box frame drivingly connected to each other and in driving engagement with said rack means.
Claim 19
Dependent Claim
179 words
Differential pressure thermoforming apparatus comprising: support means; sheet supporting box frame means on said support means for supporting the edge portions of a sheet of thermoplastic material and having sides defining a space spanned by a sheet supported thereon; differential pressure mold means mounted on said support means for forming a shape in said sheet of thermoplastic material; means on said support means for moving said sheet supporting means from a removed position to an operative shape forming position adjacent said mold means whereby said sheet is moved into engagement with said mold means to form a shape and for returning said sheet supporting means to said removed position to withdraw the shape from said mold means; and meaNs disposed in said space between the sides of said box frame means for supporting the mid-portion of said sheet when said box frame means is in said removed position and for ejecting a shape formed in the sheet from said box frame means when said box frame means is moving from said operative shape forming position to said removed position.
Claim 20
Dependent Claim
179 words
Differential pressure thermoforming apparatus comprising: support means; sheet supporting box frame means on said support means for supporting the edge portions of a sheet of thermoplastic material and having sides defining a space spanned by a sheet supported thereon; differential pressure mold means mounted on said support means for forming a shape in said sheet of thermoplastic material; means on said support means for moving said sheet supporting means from a removed position to an operative shape forming position adjacent said mold means whereby said sheet is moved into engagement with said mold means to form a shape and for returning said sheet supporting means to said removed position to withdraw the shape from said mold means; and meaNs disposed in said space between the sides of said box frame means for supporting the mid-portion of said sheet when said box frame means is in said removed position and for ejecting a shape formed in the sheet from said box frame means when said box frame means is moving from said operative shape forming position to said removed position.
Claim 21
Dependent Claim
35 words
The differential pressure thermoforming apparatus of claim 15 wherein said means for supporting and ejecting comprises a plurality of load assist bars disposed in said space and being movable relative to said box frame means.
Claim 22
Dependent Claim
175 words
Differential pressure thermoforming apparatus comprising: support means; a sheet supporting box frame on said support means for supporting a sheet of thermoplastic material and defining a space spanned by said sheet of material, said frame including an exhaust opening communicating with said space; closure means for said exhaust opening movable between an open position uncovering said exhaust opening and a closed position so as to cover said exhaust opening; differential pressure mold means on said support means for forming a shape in a sheet of thermoplastic material supported on said sheet supporting box frame; means for relatively moving said sheet supporting box frame and said mold means between removed inoperative positions and adjacent operative molding positions to form a shape in said sheet of material; and means for cooling a shape formed in said sheet comprising means for introducing cooling air into said space and means for moving said closure means from said closed position to said open position to permit the cooling air admitted to said space to be exhausted through said exhaust opening.
Claim 23
Dependent Claim
175 words
Differential pressure thermoforming apparatus comprising: support means; a sheet supporting box frame on said support means for supporting a sheet of thermoplastic material and defining a space spanned by said sheet of material, said frame including an exhaust opening communicating with said space; closure means for said exhaust opening movable between an open position uncovering said exhaust opening and a closed position so as to cover said exhaust opening; differential pressure mold means on said support means for forming a shape in a sheet of thermoplastic material supported on said sheet supporting box frame; means for relatively moving said sheet supporting box frame and said mold means between removed inoperative positions and adjacent operative molding positions to form a shape in said sheet of material; and means for cooling a shape formed in said sheet comprising means for introducing cooling air into said space and means for moving said closure means from said closed position to said open position to permit the cooling air admitted to said space to be exhausted through said exhaust opening.
Claim 24
Dependent Claim
22 words
The differential pressure thermoforming apparatus as set forth in claim 17 including means yieldably urging said closure means to said closed position.
Claim 25
Dependent Claim
77 words
The differential pressure thermoforming apparatus of claim 18 wherein said closure means comprises a door pivotally mounted on said sheet supporting box frame; said means for moving said closure means comprises cooperating cam means and cam follower means connected with said door and said support means for pivoting said door to said open position when said sheet supporting box frame and said mold means are in said operative molding position against the force of said yieldable means.
Claim 26
Dependent Claim
91 words
The differential pressure thermoforming apparatus as set forth in claim 17 wherein said sheet supporting box frame includes a cooling air inlet opening; and means for said inlet opening selectively movable between an open position removed from said inlet opening and a closed positions so as to cover said inlet opening; said means for introducing cooling air includes means for moving said second closure means between said closed and open positions; and fan means for drawing cooling air into said space when said second closure means is in said open position.
Claim 27
Dependent Claim
81 words
The differential pressure thermoforming apparatus as set forth in claim 20 wherein said means for selectively moving said second closure means to said open position to permit cooling air to enter through said inlet opening comprises a door pivotally mounted on said sheet supporting box frame, and cooperating cam means and cam follower means mounted on said box frame and said support means cooperating to move said door to said open position when said box frame is in said operative position.
References Cited (Backward Citations)
US2160182A
Cited
US3007206A
Cited
US2952875A
Cited
US3441983A
Cited
US3267521A
Cited
US3307222A
Cited
US3341895A
Cited
US3377656A
Cited
US3543335A
Cited
US3566650A
Cited
US3568253A
Cited
US3597799A
Cited
US3540113A
Cited
US3600753A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |