The shear-face should be ground on the side of the wheel until a flat surface is formed, nearly reaching the cutting edge ; the cutting face is then ground on the periphery of the wheel, until this surface meets the shear-face at a sharp edge.
When the cutting edges have been correctly formed in this way, the blades should be reassembled ; and if a rivet was fitted in the first place, a bolt should be substituted in order to allow of ready adjustment of the blade contact, and also to facilitate dismantling on future occasions.
It should be emphasised that the contact between the blades should not be unduly heavy, for this will cause unnecessary wear of the shear faces. The pivot joint should be well oiled as it is under considerable stress when the shears are in operation.
As illustrated in Fig. 56, shears designed for cutting on a curved path have a narrow and heavily relieved shear face, so as to allow the work to be turned between the jaws.
The grinding of both these shear and cutting faces is carried out as in the case of the straight shears, but great care should be taken to preserve the original angles ground on the jaws, in order to restore the full cutting efficiency of the shears.
End Gutters. As these tools are usually made with a riveted joint which is not readily detachable, they may have to be resharpened while in the assembled state.
The design of the bevelled cutting edges is shown in Fig. 57 and 59 and the method usually employed for grinding them is illustrated in Fig. 58.
Care must be taken during the grinding operation to ensure that the cutting edges are made to meet evenly as represented in Fig. 59. There are, however, some makes of end cutters, notably those manufactured by Messrs.
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