Rotary atomizer cup

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS.
1 and 5, a forward portion of a rotary atomizer 10 is illustrated which is of the type disclosed in U.
S.
patent application Ser.
No.
07/503,310, filed Mar.
30, 1990 by Wacker et al, which is owned by the assignee of this invention and the disclosure of which is incorporated by reference in its entirety herein.
The structure of the rotary atomizer 10 apart from that portion illustrated in the Figs.
forms no part of this invention per se and is thus not discussed herein.
The rotary atomizer 10 mounts a cap assembly 12 including a tapered central recess 14 from which a rotary atomizer head in the form of a cup 16 extends.
A substantially annular space or flow passage 17 is formed between the wall of recess 14 and the exterior surface of cup 16.
The cup 16, described in further detail hereinafter, includes a base 18 which is threadably secured to a shaft 20 having a frusto-conical portion 22.
The shaft 20 extends from a motor 24 which rotates cup 16 at high speed.
Motor 24 preferably comprises an air driven type turbine which includes internal air bearings, a driving air inlet and a braking air inlet for controlling the rotation of cup 16, all of which components are well known in the art and do not form a part of the invention.
The motor 24 is received within a motor housing 26 which is preferably formed of an electrically non-conductive material.
Motor housing 26 has a forward end 28 secured to cap assembly 12 by screws 30.
A locator pin 31 extends between aligning bores formed in the forward end 28 of motor housing 26 and cap assembly 12 to ensure proper alignment of these two elements prior to assembly.
Motor 24 is also formed with a bore 32 which traverses the entire length of motor 24 and shaft 20.
This bore 32 receives a coating material feed tube 34 having an end 36 which communicates with the interior of cup 16 and which carries a nozzle 38.
The feed tube 34 preferably has a first portion 40 formed of a rigid material such as stainless steel and a second portion 42 formed of an electrically non-conductive material