444. Effect of the expression 'substantially as described'.

444.     Effect of the expression 'substantially as described'.

It was formerly customary to end claims1 with such phrases as 'substantially as described' or 'substantially as and for the purpose described'. In such a case, these words will be read as importing into the claims the limitation, upon the features listed in the claim, that they should have those characteristics set out as essential for them in the body of the specification2. The modern practice is, however, to include only one or at most a few such claims, following upon broad claims without such words; and to include