POWER TRANSMISSION ELEMENTS AND MECHANISMS 153 



Coiled^ 

 springs 



I Rubber bushings 



Shafi 



FiG. 260. Fig. 261. Fig. 262. 



Fig. 260. — Two flanges and a series of coiled springs give a high degree of flexibility. This type is used only 

 where the shafts have no free end play. It needs no lubrication, absorbs shocks, and provides protection against 

 overloads, but will set up torsional vibrations. Springs can be of round or square wire with varying sizes and pitches 

 to allow for anj' degree of flexibility. 



Fig. 261. — Similar to Fig. 260, except that rubber tubing, reinforced by bolts, is used instead of coiled springs. 

 Construction is sturdier but more hmited in flexibility. This type has no overload protection other than shearing 

 of the bolts. It has good antivibration properties if thick rubber tubing is used. It can absorb minor shocks. The 

 connection can be quickly disassembled. 



Fig. 262. — A series of pins engage rubber bushings cemented into flange. This type will allow minor end play 

 in shafts and provides a positive drive with good flexibility in all directions. 



Fig. 263. — A Foote Gear Works flexible coupling which 

 has shear pins in a separate set of bushings to provide overload 

 protection. The principle is similar to that shown in Fig. 264. 

 Replaceable shear pins are made of softer material than the 

 shear-pin bushings. 



Fig. 264. — A design made by the Ajax Flexible 

 Coupling Company. Studs are firmly anchored 

 with nuts and lock washers and bear in self- 

 lubricating bronze bushings spaced alternately in 

 both flanges. Thick rubber bushings cemented in 

 flanges are forced over bronze bushings. 



