Chapter XXIV: Section 28: Chucks, Grips, and Holders

Common devices for gripping articles comprise the ordinary vice, tongs, pincers, pliers, joiners’ handscrew, cramp bench screw, parallel vice, instantaneous grip vice, &c.

=488. Hollow chuck,= with radial knives, for rounding wood rods. See also No. 458.

=489. Barber’s patent= grip for shanks of drills, brace bits, &c., having square taper shanks.

=490. Collar grip= and bolt, or set screw.

=491. Cone and screw lever grip,= with two or more jaws; with two jaws only it serves as a small vice.

=492. Taper grip= for vices.

=493. Tool box,= for lathes, planing machines, &c., with central revolving tool post and set screw.

=494. Tool box,= with two tool stocks and set screws sliding in ~T~ grooves in the slide rest.

=495. Tool box,= with clamping screw and plate, which can be revolved to any angle.

=496. A modification of 495,= the tool being secured by set screws in the clamping plate.

=497. Rail grip= for holding a crane, car, &c., down to its railway.

=498. Cam-lever rail grip= for safety gear on inclines; this is usually thrown into action by a spring released by the breakage of the hauling rope.

=499. Cone centering grips= for machine tools.

=500. Hinged clamp,= with screw and nut.

=501. Fitter’s clamp or cramp.=

=502. ~V~ grip vice= for round rods and tubes. This is frequently made with multiple ~V~’s to hold cylindrical articles such as drills, &c., and is a common device for drill chucks.

=503. Lathe carrier,= for round rods, spindles, &c.

=504. Bench cramp;= employed to hold down to the bench work operated upon; the bench has a series of holes bored in it to receive the vertical leg of the cramp.

=505. Grip tongs,= used for draw benches, &c., the bite of the jaws increasing with the strain on the chain.

=506. Split cone expanding chuck= for rods, &c.; the centre cone is split into three or four parts, and the screwed ring or collet contracts the split cone upon any cylindrical article inserted in the central aperture.

=507. Le Count’s patent expanding mandril,= with cone and three sliding feathers which are fitted into dovetail grooves in the conical mandril. The travel of the feathers being limited, they are provided with steps to take various sizes of holes.

=508. Bell chuck= and set screws for lathes.

=509. Three jaw grip,= or stay bearing, used as a steady for long shafts or spindles.

=510. Pipe tongs,= self gripping; there are several modifications in use.

=511. Paper grip,= used for holding sheets of paper; released by striking a stop ~A~ at any point in the travel of the machine.

=512. Split bar grip,= or tool holder.

=513. Eye-bolt tool holder.=

=514. Hand pad= for holding small tools.

=515. Self-adjusting jaws= for round articles.

=516. Adjustable gripping tongs= for lifting heavy stones, boxes, &c. See also No. 761.

=517. Revolving tool post, or head,= to carry a variety of tools, each being required in use in a certain order, as in special repetition turning work.

=518. Double screw gripping tongs.=

See also No. 944, 912, 918, 917, 919, 923.

The ordinary three or four-jaw chucks, wood chucks with centre screw
or fork, and numerous varieties of self-centering chucks, are well
known. See tool makers’ lists.

Spindle grips, Nos. 917, 918, 919.

There are numerous forms of three and four-jaw chucks, both with
universal or centering motions, and with independent jaws. See
Horton’s, Cushman’s, the Sweetland, Pratt and Whitney’s, Westcott’s
and others, chiefly American.

These are various combinations of the scroll (No. 1384) and screw
jaws, as in the ordinary dog chuck. See also Nos. 1378 and 1381.

Section 29.--CUSHIONING.

For checking the impact of a blow, or more generally the momentum of a heavy moving part of a machine. The devices in use comprise (_a_) springs, see Section 80; (_b_) air cylinder, see No. 1480; (_c_) pistons driven by _elastic_ fluids, such as steam and air, can be cushioned by imprisoning a portion of the fluid at each end of the cylinder; (_d_) brakes of various kinds, see Section 5.

=519. Hydraulic cushion.= The descending ram, by its tapered end, closes gradually the discharge outlet for the water.

Hydraulic buffer stops are constructed on this principle.

=520. Cushioning device,= at the upper end of a steam-hammer cylinder. Should the piston pass the exhaust holes, the steam above is imprisoned, and checks the piston without shock.

Section 30.--DRILLING, BORING, &c.

Besides the ordinary tools in use, as gimlets, bradawls, pin and brace bits, augers, &c., which do not need description, the following are noteworthy:--

=521.= Is the =ordinary ~V~ drill= for metal work.

=522. Flat point,= or “bottoming” drill.

=523 & 524. Countersinking drills= for metal.

=525. Centre bit= for wood.

=526. Twist bit= for wood; clears its own borings. There is a variety with rounded cutter edges.

=527, 528, & 529. Rock drills,= or “jumpers.”

=530. Earth borer,= or mooring screw.

=531. Twist drill= for metal.

=532 & 533. Countersinking drills= for wood.

=534. Diamond drill= for rock; bores an annular hole, the core of which breaks out at intervals.

=535 to 545. Well boring tools= for different kinds of strata; tools for raising broken rods, &c.

=546. Hollow boring cutter= for cutting a shoulder on a central core; dowelling bit.