Chapter List

31.1 Materials for a Compression Spring

In an indexing fixture, shown in Figure 31.1 , a compressed spring and a holding pin are used to hold the fixture in specific location. To rotate the fixture, the pin is removed and the spring is relaxed. The fixture is then rotated by a specific amount, the spring is engaged again, and the fixture is locked in location by the retaining pin. The dimensions of the hole wherein the spring is located are given in the figure caption 31.1

Figure 31.1: Indexing Fixture. 1) pull knob; 2) tapered retaining pin; 3) hardened bushing with press fit; 4) body of fixture; 5) indexing pin; 6) work piece holder. Space for the spring is 5/8 in OD by 1/4 in ID and 1 3/8 in long, with the pin down as shown. The pull knob must be raised 3/4 in to permit indexing. (From: J.E.Shigley and C.R.Mischke, Mechanical Engineering Design, 5 ^th ed., McGraw-Hill, p. 426. [31.1] Reproduced with permission from The McGraw-Hill Companies, Inc.)

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