The clock-barrel engine could also be used for cutting the groove in fusees for bracket clocks, except that the cutter would follow the conical profile of a fusee instead of the straight cylinder of a barrel. Because variation was often needed in the pitch of fusee or barrel grooves, a more elaborate form of engine was devised in which the pitch of the groove could be altered. In general terms it follows the same principle as the earlier engine, but in this case the cutter carrier, which is a flat rectangular bed free to travel axially, is moved by a lever from the guiding block on the driving arbour thread, this lever having a pivot which engages a slot in the carrier. By adjusting this pivot the amount of travel of the carrier can be varied; when the piot is nearer the front of the machine the tool carrier will travel less for a given number of turns of the work than when it is at the rear. By this means, and by having differently threaded driving arbours and blocks, considerable variety of pitch of fusee or barrel groove could be cut. Many modern Swiss fusee cutting tools use the same principle.