摘要 |
A method for producing a vent passage for an in-the-ear hearing aid shell. One or more vent holes are drilled in the shell, and a vent tubing having a copper core is laid against the shell interior wall extending through the vent holes. Electricity is passed through the core to heat the vent tubing rapidly (e.g. within 15 seconds) to 60 DEG C. Simultaneously with the heating, acrylic monomer and polymer are mixed. The mixture is poured promptly into the shell over the tubing, and excess mixture is then poured out, after which the coating on the tubing is cured and the tubing is removed. The rapid heating causes onset of polymerization adjacent the tubing but not elsewhere, so that a very compact vent passage is formed with minimal labor and little excess acrylic polymerization in unwanted areas. The heating is performed using a fixture having clamping plates mounted on a rod. A timer causes clamping of the plates to hold the ends of the core and passes electricity through the core for a timed period, after which the clamping pressure is released.
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