Assembly

4.1 Ease of Assembly

One of the most overlooked aspects of gas spring applications is the ease of assembly. When designing a gas spring application the designer needs to consider how an assembly operator will install the gas spring. Some designs use bolts to fasten a gas spring to the fixed and moving mounting points. The designer needs to insure that tool required to fasten the gas spring bolts has clear access. Failure to provide clear access may lead to cross-threading the bolts and potentially result in a field failure. Other gas spring designs use snap-on ball and socket connectors. Sometimes designers look only at how the installed position looks on a CAD screen. The designer fails to realize that additional space must be provided to allow the assembly operator to move the connector into position just prior to snapping the connector onto the ball.

Additional consideration should be given to any other obstruction the assembly operator may have to installing the gas spring properly. For example: some trunk systems require the assembly operator to reach under the rear window tray towards the rear seat to install the gas spring. The operator may not have a clear view of the mounting point. Every effort should be made by the designer to reduce the difficulties this causes the assembly operator.

Generally gas springs have shaft and tube tolerances that are less than 0.003" (0.0762mm). Also, connector tolerances tend to have surfaces within 0.005" (0.127mm). These small tolerances allow close clearances to body panels or other components that dictate the required clearance to the gas spring surfaces. The typical clearance used in most automotive applications is .198" (5mm) from the nominal surface. This typical clearance is usually attainable but can be less when needed. When using a clearance less than .198" (5mm), attention should be made to vehicle build tolerances to insure production assembly or that function problems do not occur.

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