Section 42.—HYDRAULIC MULTIPLYING GEAR.

[747]. Is the ordinary “chain and sheave” multiplying gear, unequally geared, thus—

Ram end.			Cylinder end.
With	1	sheave	1	sheave	it is geared	3	to	1.	&c.
„	2	„	2	„	„	5	to	1.
„	3	„	3	„	„	7	to	1;

[748]. Is the same plan, but equally geared—

Ram end.			Cylinder end.
With	1	sheave	No sheaves		it is geared	2	to	1.	&c.
„	2	„	1	sheave	„	4	to	1.
„	3	„	2	„	„	6	to	1;

[749]. An arrangement of the sheaves suitable for vertical working, geared 8 to 1.

[750]. An arrangement of the sheaves suitable for vertical working, but geared 6 to 1.

[Larger plate.]

[751]. An arrangement of the sheaves suitable for vertical working, but geared 4 to 1.

[752]. Stevens and Major’s patent for horizontal working. The angle of the chain helps to support the weight of the ram.

[753]. Modification of [752], sometimes used, and suitable for both horizontal and vertical positions, with any required multiplication of speed.

[754]. Rack gear; short stroke piston cylinder plan.

[755]. Double rope vertical ram gear.

[756]. Arrangement with the sheaves all at head of cylinder.

For Telescopic Hydraulic Lift, see [Nos. 1217] & [616].

Hydraulic Balance gear, [Nos. 371], [373].

Section 43.—HOOKS, SWIVELS, &c.

For Chains and Links, see [Section 11].

[757]. Double or match hook.

[758]. Split link. See also the common Key Ring.

[759]. Self-locking hook, with inclined shoulder and pin.

[760]. The common “Lewis.”

[761]. Self-gripping claw grab. See also [516], [505].

[762]. Grab bucket, on same principle.

[763], [764], & [765]. Double S links.

[766]. Hook with rope grip.

[767]. Snap hook.

[768]. Snap link.

[769]. Slip hook for a monkey or pile engine; a rope is attached to the eye in end of lever which pulls the loop link away from the bottom link to which the “monkey” is suspended, allowing it to fall.

[Larger plate.]

[770]. Automatic slip hook; slips the T end of the “monkey” by the curved arms striking the sides of a fixed stop hole.

[771]. Draw bar hook, self-locking.

[772]. Fixed bar hook, with snap.

[773]. Slip hook.

[774]. Hook, with mousing ring; slip hook.

[775]. Crane hook, with swivel.

[776]. Double swivel links, inserted in a chain to take out the twist.

[777]. Triangular link, to attach two chains to one.

[778]. Safety link. Has a flat on link to slip in notch of hook.

[779]. S link.

[780]. Split link.

[781]. Bolt shackle.

[782]. Double link and bolt connection for ordinary chain.

[783]. Pin shackle.

Section 44.—INDICATING SPEEDS, &c.

[784] & [785]. Hand (portable) indicator, to indicate speed of revolution of a shaft, &c., by simple wheel work and dial plate.

[786]. Governor gauge, indicates the speed by the angle of the balls moving a finger on a vertical scale.

[787]. Steam engine indicator, of which there are many varieties. Macnaught’s, Richards’, Darke’s, Kraft’s, Casartelli’s, &c., are examples, in which a small steam piston operates a marking point by the varying pressure of steam acting against a spring; the paper is usually coiled on a cylinder having a reciprocating motion by a string from the engine.

[788]. Morin’s dynamometer. Consists of two belt pulleys connected by a spring; one receives the strain of driving belt, and the other transmits it, the spring indicating the tension on the belts.

[789]. Regnier’s dynamometer indicates the tension on the connections by contraction of the spring operating a dial plate.

[790]. Bourdon tube pressure indicator. The tube is of flat section, and its curved portion expands with the pressure, operating a finger on the dial by rackwork.

[791]. Worm gear and dial to register the number of revolutions. See [No. 1559].

Other forms of pressure gauges are—1st. The mercurial gauge, in which the pressure is indicated by the height of a column of mercury in a glass tube. 2nd. The water gauge, in which a column of water replaces the mercury. 3rd. The spring balance (see [No. 1729]). See also [Nos. 1730], [1728].

[Larger plate.]

[792] & [793]. Winding engines are provided with indicators on the principle of [No. 744]. The travelling nut has a pointer whose position on a vertical graduated scale shows the position of the cage in the pit.

Vertical scale indicators are also employed to show the level of water in tanks, reservoirs, &c. See [No. 1730].

Water tube indicators are employed to show the level of water in boilers, &c., as also gauge cocks fixed at various heights in the boiler.