卡接结构设计教程.pdfVIP

The First Snap-Fit Handbook Paul R. Bonenberger Creating and Managing Attachments for Plastics Parts ISBN 3-446-22753-9 Leseprobe Weitere Informationen oder Bestellungen unter http://www.hanser.de/3-446-22753-9 sowie im Buchhandel 120 Enhancements [Refs. on p. 134] method can be designed into the interface at the same time. Once the design is proven in testing and production, the back-up lock can be eliminated. Should the snap-fit prove unreliable, the back-up lock allows the development program to continue with a reliable attachment for that application. While the design itself may not be a technical reach, incomplete data about the service loads, material properties or other application requirements may add uncertainty to the design. A back-up lock can allow the snap-fit design to proceed with the confidence that a reliable attachment is possible if the snap-fit does not work. The design may be such that the locking features of the snap-fit are susceptible to bending or breakage during shipping, handling, assembly or disassembly. If the features cannot be protected by design (see guards) and damage that would render the lock unworkable is possible, a back-up lock ensures the entire part will not be lost because of damage to one feature. If parts are intended for new designs and also expected to be used on existing designs without provisions for snap-fits, allowing for both methods of attachment accommodates both appl