Process of photoetching a metal comb
OwnerWilliam Frederick Clark, Philip Noel Baxendale +1inventors
InventorsWilliam Frederick Clark, Philip Noel Baxendale, Michael Noel Peters
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Abstract
A musical movement which comprises, primarily, a metal comb produced by a chemical machining process and, secondarily, a drum in the shape of a frustum of a stepped comb. The comb is advantageously provided with means whereby it can be fastened to a movement base without employing bolts or the like and the drum steps advantageously have projections, for co-operation with the comb teeth, that do not extend further radially than do the immediately neighboring drum steps of larger size.
Claims5
A process for producing a metal comb for use in a musical movement, wherein the process comprises the steps of preparing duplicate photographic negatives of the desired shape of the comb, covering both sides of a sheet of the metal from which the comb is to be formed by a resist, positioning said photographic negatives in accurate alignment with one another and in masking relationship with the resistcovered opposite sides of said sheet, hardening those parts of the resist that are in register with substantially transparent regions of said negatives, removing the negatives, removing the unhardened parts of the resist, chemically etching the areas of the metal sheet that are not protected by the remaining hardened parts of the resist to form individual teeth of the comb which are tonally accurate and require no subsequent mechanical tuning operation, and removing the hardened resist from both sides of the metal comb.
Dependencies are inferred from the claim text.