Chapter CXLIV: Section 78: SCREW GEAR, BOLTS, &c

(_See also p. 168._)

=2439. Ball head bolt and nut= to allow it to draw up out of line.

=2440. Universal bolt head.=

=2441. Ball joint bolt and nut.=

=2442. Flush head coned bolt.=

=2443. Mutilated screw and nut.=

=2444. Nut lock,= by a fixed lug and split pin.

=2445. Coned bolt= for securing and keying two parts of a machine in exact relation.

=2446. Double-nutted bolt,= easily made of round iron.

=2447. Lever and compound nuts= to obtain great leverage on a screw, as in a press; one nut arm is used as a fulcrum by which the lever forces the other round. Stepped pawls are used to prevent the first nut being loosened while moving the second.

=2448. Screw gear= to operate three worm wheels in the same direction, for chucks, &c.

=2449. Screwed stay bolt,= as a distance stay for boiler plates, &c.

=2450. Screw eye and handle nut.=

=2451. Anti-friction worm gear.= The worm wheel has friction rollers running on pins, which gear with the worm.

=2452. Staple bolt and washer plate.=

=2453. Fang plate washer= for wood.

=2454. Fang plate washer= for wood.

=2455. Sunk set screw,= with differential threads, to draw two plates or pieces together.

=2456. Taper screw,= quickly released.

=2457. Mutilated screw= to slide into a nut having corresponding sections of the thread cut away, and to fix by a partial turn. Used for breech-pieces of cannon.

=2458. Bolt head, with transverse holes,= for a plain “tommy” bar wrench.

=2459. Backlash nut= for a square thread screw.

=2460. Cap nut.=

=Screw stopper.= See No. 2544.

=2461. Slotted nut and set pin= for fine adjustment, or for taking up wear.

=Lock nuts;= usually two nuts are employed, the _thickest_ one
outermost. There are many forms of patent nuts designed to prevent
loosening by vibration.

Nuts can be cast around a screw in white metal or brass.