# US 5,710,414 A · Internal tooling for induction heating

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- Number: US 5,710,414 A
- Document ID: US5710414A
- Status: Granted
- Kind: A
- Application number: 08/469,985
- Filed: 1995-06-06
- Granted: 1998-01-20
- Earliest claimed: 1991-04-05
- Assignees: The Boeing Company
- Inventors: Marc R. Matsen; Allan R. Hodges
- Web page: https://patentgrep.com/patent/US5710414A

## CPC

- B22F 3/105: by using electric current {other than for infrared radiant energy}, laser radiation or plasma (B22F3/11 takes precedence){; by ultrasonic bonding (B22F3/115 takes precedence)}
- B21D 26/021: Deforming sheet bodies
- B21D 26/025: Means for controlling the clamping or opening of the moulds
- B21D 26/053: characterised by the material of the blanks
- B21D 26/055: Blanks having super-plastic properties
- B22F 3/18: by using pressure rollers
- B23K 1/002: Soldering by means of induction heating
- B23K 20/023: {Thermo-compression bonding}
- B29C 33/06: using radiation {, e.g. electro-magnetic waves, induction heating}
- B29C 33/60: Releasing, lubricating or separating agents {(in general C10M)}
- B29C 35/08: by wave energy or particle radiation {(B29C64/00, B29C71/04 take precedence)}
- B29C 43/3642: {Bags, bleeder sheets or cauls for isostatic pressing}
- B29C 43/52: Heating or cooling
- B29C 65/18: using heated tools
- B29C 65/32: Induction
- B29C 65/34: using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C 65/364: {being a woven or non-woven fabric or being a mesh}
- B29C 65/3644: {being a ribbon, band or strip}
- B29C 65/3676: {being metallic}
- B29C 65/4815: {Hot melt adhesives, e.g. thermoplastic adhesives}
- B29C 65/4875: {being spherical, e.g. particles or powders}
- B29C 65/489: {being metals}
- B29C 66/1122: {Single lap to lap joints, i.e. overlap joints (B29C66/45, B29C66/472, B29C66/52272 take precedence)}
- B29C 66/524: {Joining profiled elements}
- B29C 66/54: {Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles}
- B29C 66/634: {using an inflatable core}
- B29C 66/721: {Fibre-reinforced materials (B29C66/729 takes precedence)}
- B29C 66/8122: {characterised by the composition of the material constituting the pressing elements, e.g. constituting the welding jaws or clamps}
- B29C 66/81455: {being a fluid inflatable bag or bladder, a diaphragm or a vacuum bag for applying isostatic pressure (inflatable element positioned between the joining tool and a backing-up part B29C66/82421)}
- B29C 66/81457: {comprising a block or layer of deformable material, e.g. sponge, foam, rubber (pressing elements supported or backed-up by resilient material B29C66/8161)}
- B29C 66/81811: {of the welding jaws}
- B29C 66/81821: {of the welding jaws}
- B29C 66/8223: {Worm or spindle mechanisms}
- B29C 66/8322: {Joining or pressing tools reciprocating along one axis}
- B29C 66/8432: {Machines for making separate joints at the same time mounted in parallel or in series}
- B29C 70/44: using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
- B29C 70/506: {and impregnating by melting a solid material, e.g. sheet, powder, fibres (B29C70/508 takes precedence)}
- B29C 70/542: {Placing or positioning the reinforcement in a covering or packaging element before or during moulding, e.g. drawing in a sleeve}
- B32B 37/06: characterised by the heating method
- B64C 3/18: Spars; Ribs; Stringers
- B64C 3/185: {Spars}
- C22C 47/00: Making alloys containing metallic or non-metallic fibres or filaments
- C22C 47/068: {Aligning wires}
- C22C 47/20: by subjecting to pressure and heat an assembly comprising at least one metal layer or sheet and one layer of fibres or filaments
- H05B 6/365: {using supplementary conductive or ferromagnetic pieces}
- B22F 2003/1046: {with separating means for articles to be sintered}
- B22F 2003/1053: {by induction}
- B22F 2998/00: Supplementary information concerning processes or compositions relating to powder metallurgy
- B23K 2101/18: Sheet panels
- B29C 33/08: for dielectric heating
- B29C 65/3476: {being metallic}
- B29C 65/3492: {being carbon}
- B29C 65/3668: {characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special induction coils}
- B29C 65/368: {with a polymer coating}
- B29C 66/63: {Internally supporting the article during joining (B29C66/49 takes precedence)}
- B29C 66/71: {characterised by the composition of the plastics material of the parts to be joined (welding bar compositions B29C65/125)}
- B29C 66/7212: {characterised by the composition of the fibres}
- B29C 66/72141: {Fibres of continuous length}
- B29C 66/72143: {Fibres of discontinuous lengths}
- B29C 66/727: {being porous, e.g. foam}
- B29C 66/7392: {characterised by the material of at least one of the parts being a thermoplastic}
- B29C 66/81261: {Thermal properties, e.g. thermal conductivity, thermal expansion coefficient}
- B29C 66/929: {characterized by specific pressure, force, mechanical power or displacement values or ranges}
- B29C 66/949: {characterised by specific time values or ranges}
- B29C 2035/0811: {using induction}
- B29C 2043/3233: {exerting pressure on mould parts}
- B29C 2043/3655: {Pressure transmitters, e.g. caul plates; pressure pads}
- B29K 2105/0854: {in the form of a non-woven mat}
- B32B 2305/024: Honeycomb
- B32B 2309/62: Inert
- B32B 2310/0812: using induction
- C09K 2205/12: Hydrocarbons
- Y02P 10/25: Process efficiency
- Y02T 50/40: Weight reduction
- Y10T 428/1234: Honeycomb, or with grain orientation or elongated elements in defined angular relationship in respective components [e.g., parallel, inter- secting, etc.]
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F)
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B64C: AEROPLANES; HELICOPTERS
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

If internal support is required to keep thermoplastic parts from sagging during thermoplastic welding, silicone rubber bladder inflated to fill the space between the prefabricated composite parts, such as wingskins and spaced spars, provides positive reaction pressure. To protect the bladder we cover the sharp edges at the interface of the parts with foam or silicone rubber pads.

## Claims

### Claim 1

A method for counteracting sagging during thermoplastic welding of prefabricated, thermoplastic resin composite parts having internal hollow spaces accessible before and after welding, comprising the steps of:
(a) positioning an inflatable bladder in the hollow spaces when assembling a preform of the parts and susceptors, the preform being positioned in a die set;
(b) applying heat and pressure to the preform;
(c) inflating the bladder to substantially fill the hollow spaces and to provide a reaction force to counter sagging of the parts;
(d) welding the parts together to form welds on bondlines containing the susceptors while maintaining pressure on the bondlines from the die set and the reaction force by heating the susceptors to melt thermoplastic resin at the bondlines;
(e) deflating the bladder after completing the welds; and
(f) extracting the bladder.

### Claim 2 (depends on 1)

The method of claim 1 further comprising the step of adding protective insulation at intersections between the parts to protect the bladder from sharp comers or contact with not susceptor.

### Claim 3 (depends on 1)

The method of claim 1 wherein the bladder is inflated with air to a pressure of about 30-100 psi.

### Claim 4 (depends on 1)

The method of claim 1 wherein the bladder is filled with a mineral oil.

### Claim 5 (depends on 1)

The method of claim 1 wherein the bladder is filled with water.

### Claim 6 (depends on 2)

The method of claim 2 wherein the protective insulation is a foam.

### Claim 7 (depends on 1)

The method of claim 1 wherein the bladder is silicone rubber.