Fig. 429.
Fig. 430.
Lost motion in square threads and nuts may be taken up by forming the nut in two halves, a and b, in [Fig. 429] (a being shown in section) and securing them together by the screws c c. The lost motion is taken up by letting the two halves together by filing away the joint face d of either half, causing the thread in the nut to bear against one side only of the thread of the screw. The same end may be accomplished in nuts for V-shaped threads by forming the nut either in two halves, as shown in [Fig. 430], in which a is a cap secured by screws b, the joint face c being filed away to take up the lost motion. Or the nut may be in one piece with the joint c left open, the screws b crossing the nut upon the screw by pressure. In this case the nut closes upon the circumference of the thread, taking up the wear by closing upon both sides of the thread instead of on one side only as in the case of the square thread.
Fig. 431.
