The engineer's sketch-book of mechanical movements, devices, appliances, contrivances and details employed in the design and construction of machinery for every purpose

by Thomas Walter Barber

[938]. Crank arm device, to lock a valve or lever in two positions. See also [No. 16].

[939]. Gun, breech-loading, sliding cylindrical block locked by turning the arm into a notch.

[940]. Door fastening staple and cotter.

[941]. Common cotter.

[942]. Half nut locking and unlocking device, used for lathe leading screws; the half nuts are moved simultaneously in opposite directions by cams on the lever spindle.

[943]. Swinging catch to secure end of a drop bar.

[944]. Tool post, to swivel and lock in any position. See also [No. 493].

[945]. Locking screw, to lock the hand wheel and spur pinion to the shaft when required to be driven by it.

See also Lock Nuts. The common varieties of lever locks with stepped key-wards.

See [No. 1723].