No Sink Boss
Original Publication Date: 1996-Nov-01
Included in the Prior Art Database: 2005-Apr-01
Bigelow, SP: AUTHOR [+6]
Disclosed is a method to produce a screw boss that will eliminate sink on the cosmetic surface of plastic computer covers.
No Sink Boss
a method to produce a screw boss that will
eliminate sink on the cosmetic surface of plastic computer covers.
surfaces of injection molded plastic computer covers
can be marred by depressions called sinks. These sink marks can be
most evidential over hidden screw boss locations. When the screw
boss is long, it impinges on the inner wall of the cover with greater
than the recommended thickness causing sink. This sink is especially
conspicuous when dealing with black and off-black covers.
long screw boss usually produces sink on the
opposite side of the surface to which it is attached. If the screw
boss were to end before the surface, no sink would be associated with
it. In order to accomplish this, the boss must be supported by
gussets or ribs. These features would extend toward adjacent walls
and support the boss. The ribbed features would have the correct
rib-to-wall ratio so as not to create sink themselves. The space
between the boss and back of the cosmetic wall would be filled by a
'lifter" during the molding process. The design of the No Sink Boss
must accommodate clearance angles for this lifter. An example of the
No Sink Boss is shown in the Figure.