Locating Devices

LOCATING & DRIVING DEVICES Dowel pins Dowel pins are often used as precise locating devices in machinery. Steel dowel pins are machined to tight tolerances, as are the corresponding holes, which are typically reamed. A dowel pin may have a smaller diameter than its hole so that it freely slips in, or a larger diameter so that it must be pressed into its hole. When designing mechanical components, engineers typically use dowel holes as reference points to control positioning variations and attain repeatable assembly quality.

1. Application, 2. Assembly procedures Cotter pins

Cotter pin (also known as a cotter key or a split pin) is a metal fastener with two tines that are bent during installation, similar to a staple or rivet. Typically made of wire with a half-circular cross section, cotter pins come in multiple sizes and types. 1. Application, 2. Assembly procedures

Keys

I. Parallel key The simplest key is the square key, placed half in the shaft and half in the hub. A flat key is rectangular in cross section, used similarly as square key.

II. Woodruff key A Woodruff key or half-moon key is a semicircular shaped, removable key that fits into a matching keyway cut into a shaft, leaving a protruding tab. The tab mates with a matching slot on a device mounted flush upon the shaft e.g. a pulley, thus preventing the device from freely rotating about the shaft.

III. Gib head key The gib-head key is tapered on its upper surface and is driven in to form a very secure fastening. The head shape provides removal