US 5,635,094 A · Conformal skate for induction welding

Abstract

A conformal skate for use in an inductive welding system for creating a fusion bond along a bond line between two thermoplastic parts includes a wheel having a circumferential casing made of fluid impervious flexible material. The wheel is rotatably mounted on a fixed axle by fluid tight bearings. The axle has an axial passage for admission of pressurizing and cooling fluid, and for power leads for the coil and for leads for sensors inside the wheel. A vertical mount on the axle supports the coil for vertical motion and biases the coil downwardly so that it remains in contact with the inside surface of the casing despite unevenness or contour changes in the upper surface of the top part or changes in the wheel shape when the fluid pressure in the wheel or downward force on the axel is changed. A supporting member such as a strut or frame supports the axle and applies the downward force which the wheel distributes over the footprint in contact with the top part, in line with the magnetic field generated by the coil. The size of the wheel footprint is a function of the amount to liquid in the wheel and the force exerted by the supporting member, which pressurizes the fluid sealed in the vessel and distributes pressure uniformly over the footprint of the wheel to press the top part against the bottom part and facilitate fusion bonding of the thermoplastic in the melt pool created by the inductively heated susceptor.

Claims20

Dependent claims

A conformal skate for exerting pressure on a top part to be inductively welded to a bottom part using an induction coil for generating an alternating magnetic field which inductively heats a susceptor interposed in an interface between the top part and a bottom part made from thermoplastic material along an intended bond line defined by opposed faying surfaces of the top part and bottom part, comprising:

(a) a wheel having opposed side walls and a circumferential casing defining a wheel cavity, the casing being fluid impervious, flexible, inelastic material adapted for receiving a fluid under pressure;
(b) an axle having an axis and having an interior passage communicating through said axle at an intermediate position along the length of said axle:
(c) sealed bearings mounting said wheel on said axle for rotation thereon;
(d) an induction coil mounted on said axle in the wheel cavity on a vertical mount and oriented to project a magnetic field vertically into said parts;
(e) power leads from a power supply routed through said axle passage and connected to said coil;
and
(f) a fluid coupling for connecting a source of fluid under pressure to said axle passage for introducing fluid to the wheel cavity for pressurizing said wheel;
whereby, when the said wheel is rolled over the top part, said coil is energized to inductively heat said susceptor and soften the thermoplastic material in the faying surfaces of said parts to flatten a bottom portion of said circumferential casing conformably against said top part to exert uniform pressure on said bond line over a wide footprint of said wheel and to press said softened thermoplastic faying surfaces together to facilitate fusion bonding.

5 more elements

Dependencies are inferred from the claim text.

Conformal skate for induction welding

Life of this patent

Conformal skate for induction welding

Life of this patent

Abstract

Claims20