Original Publication Date: 1973-Sep-01
Included in the Prior Art Database: 2005-Feb-26
DePew, JR: AUTHOR [+3]
AbstractThis fixture is used to selectively plate an annular commutation track of various metals onto one surface of a flat motor armature.
This fixture is used to selectively plate an annular commutation track of various metals onto one surface of a flat motor armature.
An armature of this type is shown in Fig. 1. One side of the armature is covered by a large number of individual conductors 10, for example, copper or aluminum. The opposite flat side of the armature is covered by a like number of conductors, portions of which are shown in dotted lines. Each conductor on one side of the armature connects to one conductor on the opposite side at outer annulus 11, and connects to a different conductor on the opposite side at inner annulus 11a. The armature's commutation track, upon which the motor's stationary brushes ride, is identified by broken lines 12.
In Fig. 2, the flat armature 13 of Fig. 1 is shown mounted within the plating fixture, which is used to plate various metals onto track 12. This fixture outlines or masks track 12 and protects the remaining armature area from the plating environment. This fixture includes an annular stainless steel contact plate 14, which electrically engages armature conductors 10 at points 15 by virtue of pressure contact.
The fixture includes a solid bottom disc 16, a ring 17 and a plug 18, all of which are made from an inert material such as polytetrafluoroethylene. These three members include annular cavities 19 which are filled with a resilient, chemically inert material, such as a room-temperature-vulcanizing type of silicone rubber. When bolt...