The body f is bolted by the flange i to a face plate in the live spindle or shaft of the machine, and through slots in this body pass the holders or cases c containing the chasers or dies. Upon f is the piece d provided with a slot to receive the die cases and a tongue to move them. This slot and tongue, which are shown at e′, are at an angle to the axis of f; hence if d be moved endways upon f the cases and dies are operated radially in or through the body f. To operate d laterally or endwise upon f the clutch ring h and the toggles g are provided, the latter being pivoted in the body f, and h being operated endwise upon f by the lever shown at n in the general view, [Fig. 1820]. The amount to which the dies will be closed is adjustable by means of the adjusting screws e, which are secured in their adjusted position by the set-screws r, [Fig. 1821]; it being obvious that when h meets the shoulder s of g and depresses that end of the toggle, head d is moved to the right and the dies are closed when the end of g meets e, and ceases to close when g has seated itself in f and can no longer move e. The backward motion of the clutch ring h, and therefore the amount to which the dies are opened, is regulated by the screw b and stop a in [Fig. 1822], it being obvious that when b meets a the motion of h and d to the left upon f ceases and the dies are fully opened. The amount of their opening is therefore adjustable by means of screw b. j is simply a cap to hold the dies and cases in their places.
Fig. 1823.
In the end view, [Fig. 1823], e, e are the adjustment screws for the amount of die closure, and b, b those for the amount they will open to, t representing the screws for the cap j, which is removed for the insertion and extraction of the dies and die cases.
Fig. 1824.
The construction of the dies p and cases c is shown in [Fig. 1824]. Two screws at n secure the dies in their cases and a screw m adjusts them endways so as to set them forward when recutting them. By inserting the dies in cases they may be made of simple pieces of rectangular steel, saving cost in their renewal when worn too short.