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Ron Cater
Page 101
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There are many occasions in the workshop when the need arises to use some locked insert or dowel. I was therefore interested this week to receive a small booklet, "55 ways to cut costs," from the technical publications department of Firth Cleveland Fastenings Ltd„ Treforest, Pontypridd, Glamorgan. The booklet illustrates by a series of simple drawings different applications of the Rollpin, a slotted, chamfered, cylindrical spring-pin which is heat-treated and tempered to achieve optimum toughness and resilience.
Compression of the pin is such that it locks positively against the sides of the hole into which it is driven: no reaming operation is required to obtain a perfect fit. The design provides that the self-locking action is achieved in preformed or drilled holes conforming to normal production tolerances.
Apart from use as a cotter or driving peg, the pins can be used to clip two metal edges together, to anchor the end of a tension spring, and as electrical plug-sockets, belt guides or bearing shafts. Low-cost captive screws and bolts can be devised by using the Rollpin, and the job that most impressed me was its use as a key to lock pulleys or gears on to a shaft.
In this application a hole is drilled centrally between the shaft and the component carried on it. They are locked together by driving the Rollpin into the hole, making a strong and shake-proof key.
The numerous ideas generated in the booklet will no doubt be multiplied many times over once the Rollpin finds its way into the vehicle workshop.
Readers can obtain a free copy of the booklet by writing to the address mentioned above or phoning Treforest 2633.