Section 49.—LOCKING DEVICES.

(See also [p. 110].)

[2266]. Lever action for a door, &c., to lock it, open or shut, in fixed positions.

[2267]. Lever action for a gate or door, to open or close it and lock it in either position.

[2268]. Revolving eyelet to lock or release a rod or cord.

[2269]. Abutment lock. Can only be opened by revolving the tumbler by a key.

[Larger plate.]

[2270]. Secret screw attachment. The screw is fixed to the back of any article, and fastened to the fixing A by sliding along the slot. Two, three or four screws and slots are generally used.

[2271]. Bolt lock. The bolt can be released by revolving it 180°.

[2272]. Gib-key fastening for a sliding block or bracket on a plain bar.

[2273]. Similar fastening, using a wooden bar.

[2274]. Locking stud, used for iron bedstead laths.

[2275]. Catch and hook.

[2276]. Hinged catch to lock a screwed gland or nut.

[2277]. Letter lock, or combination lock. Any number of discs may be arranged on a spindle having a feather key, so that they must be all in a certain position to allow the key to slide through a notch or key way cut in each disc, so as to open the loop.

[2278]. Locked nut.

[2279]. Spring pawl, umbrella catch.

[2280]. Spring snap, released by pressing the open ends together.

[2281]. Locking pawl for spur teeth.

[2282]. Spring handle.

[2283]. Spring pawl, locks the wheel against a moderate force, but gives way to a greater force.

Locked pawl motions. See [Section 62].

[2284]. Locking device for lathe headstock or tool rest. The head of the central pin runs in a T groove or under the lathe bed, and is clamped by the cone pointed set screw, which bears against a conical recess in the central pin.

[2285]. Radius bar, with notches to lock a hand lever in various positions. The lever may be hinged to lift out of the notches, or made thin enough to spring sufficiently for this purpose.

[2286]. Coned screw lock for a standard foot, pin, or socket and spigot.

[Larger plate.]

[2287]. Set screw fixing for needles, wires, cord, &c.

[2288]. Split block to grip a rod, with handle nut.

[2289]. Cam catch to lock a wheel or spindle.

[2290]. Locking gear for a shaft driven by spur gearing, used in place of a clutch.

[2291]. Similar lock for a revolving head, standard tool post, &c.

[2292]. Tee groove for a T head bolt for [Nos. 2290] and [2291].

[2293]. Horse-shoe distance piece to place between a sliding pinion and the shaft collar to keep it either in or out of gear.

[2294]. Wedge plate and screw fastening for cutters, &c.

[2295]. Locking device for a spring lever, handle, button hook, &c.

[2296]. Locked centre pin.

[2297]. Cotter to lock a sliding spindle.