SWAGED HOLE FIXING
Original Publication Date: 1997-Jun-01
Included in the Prior Art Database: 2002-May-20
To retain a plate (such as a rigidiser on an ECU) within a rebate in a case without using screws. Conventional fixing of a plate to a rebate in a case may be achieved by using a separate fixing component such as screws or rivets or by crimping the case to retain the plate.
@ MOTOROLA Technical Developments
SWAGED HOLE FIXING
by Roger Humphreys
To retain a plate (such as a rigidiser on an ECU) within a rebate in a case without using screws.
Conventional fixing of a plate to a rebate in a case may be achieved by using a separate fixing component such as screws or rivets or by crimping the case to retain the plate.
Costs can be saved by specifying futing systems that do not use a separate component such as a screw or rivet. The manufacturing process of apply- ing a screw or rivet can lead to variability which could result in defects. It is also desirable to keep the bill of materials to a minimum to reduce han- dling costs of material.
A technique that has been used to attach an alu- minum plate to a rebate in a die-cast aluminum housing is to crimp the housing such that the plate
is retained. This involves locally bending the cast material around the periphery of the plate to trap the plate in the desired position. This works on die cast materials that have good ductile properties. Unfortunately, these materials tend to cost more than the lower grade materials which could be used if the crimping were not required.
This solution utilizes the better ductile proper- ties of the plate material rather than the case to achieve a fixing. It can even be used for plastic or other case materials that hitherto could not be con- sidered.
Where the plate abuts the case rebate, holes are created around the periphery of...