MAI-IIIM: I>K\WIN<; AM* 



deeper at one end than the other to acc<> tin nipn -of 



the key. The sides of the key are parallel. 



The round key or taper pin shown :it (d) is in pcnernl only 

 nted for wheels or cranks which have ITCH pn-\ iou^ly shrunk 

 on to their shafts or forced on by great pressure. After the 

 wheel or crank has bcc>n shrunk on, a hole is drilled, half into 

 the shaft and half into the wheel or mini:, to receive the 

 pin. 



\Vhenthepointof a k< -\ > the other end is 



id* d with a (jib head as shown at (), to enable the key to 

 be withdrawn. 



A sliding or feather hey secures a piece to a shaft so t 

 to prevent the one from rotating without the other, luit al. 

 <>f relative motion in the direction of the axis of the d 

 This form of key has no taper, and it is secun -d t., the ( 

 carried liy the shaft, but is made a s/i>/iii>/ fit in thek- 

 the shaft. In one form of feather key the part within tin- 

 piece carried by the shaft is dovetailed as shown at (/). In 

 another form the key has a round projecting pin forged upon 

 it, which enters a corresponding hole as shown at (</). The 

 feather key may also be secured to the piece carried l-y the 

 shaft by means of one or more screws as shown at (//). The 

 key way in the shaft is made long enough to permit of th- 

 ssary sliding motion. 



Cone Keys. These are sometimes fitted to pulleys, and ax 

 shown in fig. 42, page 46. In this case the eye of the pulley 

 is tapered and is larger than the shaft. The space l>< t 

 the shaft and the boss of the pulley is filled with three sadtl 



- keys. These keys are made of cast iron and are all cast 

 together, and before being divided the casting is bored to fit 

 the shaft and turned to fit the eye of the pulley. l>y tin, 



tngement of keys tl pulley may be ti.\-d on 



different diameters by using keys of different thi< -km-sses ; also 

 tin- pulley may be bored out large enough to pass over any 

 lioss which may be forged on the shaft. 



portions of Keys. The folio win-; rules are taken 

 I n win's ' Machine Design,' Part I. pp. 17". in. 



