Thomas Walter Barber

“ An hydraulic cylinder and piston is frequently used as a brake or retarding device for reciprocating motion, the water passing from one side of the piston to the other, through an adjustable valve. Friction brakes are employed as dynamometers to indicate the power given off or absorbed by any piece of machinery. ”

“ Pumping engines may be governed by allowing the pressure of water in the rising main to accumulate in a stand pipe or equivalent device until it stops the engine by excess of pressure. To prevent such an engine running away a catch is used, kept open by the pressure of water; when the pressure falls below a certain point the catch is released and closes the throttle valve.
Steam engines may also be safeguarded in the same way by a catch which is released and closes the throttle valve when the governor becomes fully expanded. ”

“ Cast iron pipes are made in the following strengths:—Rainwater pipes, hot-water pipes, gas mains, water mains, hydraulic mains for high pressure, and the thicknesses of metal vary according to the pressures. Diameters from 11⁄2′′ up to 4′, and lengths usually 6′ and 9′. See Section 57.
Castings are made in cast iron of various mixtures, according to strength, toughness, or hardness required, and of any weight up to 20 tons. Chilled iron castings are made for hard wear, as in crusher rolls, &c., but cannot be machined; they are usually ground smooth by a grindstone or emery wheel. ”

“ Variable delivery single-acting pumps; the eccentrics can be shifted round the shaft 180° by a sleeve and pin motion similar to No. 2467. When the eccentrics are opposite each other the pump does not deliver any water, but when the eccentrics are side by side the pump delivers the full contents of both rams. There is one suction and one delivery valve.
2334. Screw pump for applying heavy pressure to a ram; sometimes used as an adjunct to give the final heavy pressure to an hydraulic press after the pumps have forced the ram as far as their power permits. ”

“ The pin A in the wheel B travels eccentrically in the crank disc, which is eccentric to the fixed boss on which the driving wheel B runs, so that the radius of the driving motion of the pin varies as it revolves and it travels up and down the slot in the disc. ”

“ Two drivers A, A′, equally speeded in opposite directions, will drive the bevil gear at same velocity without revolving the spur wheel C′ which is loose on the shaft; but any alteration in the relative speeds of A and A′, causes the bevil pinion to travel round, carrying the spur wheel C′ at a speed equal to half the difference of the two velocities. ”

“ Variable friction cone gear; the small friction pinion can be moved radially to and fro to alter the leverage and consequently speed of driving radius from the cone.
In the steam engine, compressed air engine, and gas engine (these being all elastic fluids) , the power given out is varied by altering the supply of steam, air, or gas. In the water wheel the power may be varied by altering the quantity of water (or head of water) supplied to the wheel. In the turbine the power can be varied by altering the head of supply water and the angle of vanes ”

“ Joy’s patent hydraulic eccentric for steam engine reversing gear. The centre block—keyed to the crank shaft—has two small rams working in cylinders in the sheave, and the position of the eccentric is controlled by a hand-lever and pump forcing oil into the cylinders through a channel in the crank shaft and rams. ”

“ The drop hammer, for power. The grip pulleys are put in gear by the hand lever to raise the hammer and shaft: it is sometimes worked by hand by a simple cord and pulley.
1911. Dead blow power hammer. The crescent-shaped crosshead bar has a positive motion from the crank pin, but the hammer head is attached to it by strong horizontal springs, and therefore has some little play above and below a horizontal line.
1912. The pile engine and monkey. The latter is generally raised by a hand or power winch, but a multiplying gear steam or hydraulic cylinder has been employed. ”

“ Shifting eccentric and balance sometimes used for reversing instead of double eccentrics and link; the loose eccentric is carried round in either direction by a stop piece on the shaft, fixed so as to give the correct lead both ways.
1444. Murdoch’s variable expansion gear (see Mechanical World, September 29th, 1888) has one eccentric which operates a double arm lever, the outer end of which moves a sliding fulcrum along the valve rod lever, so that the leverage of the valve rod lever varies at different parts of the stroke. The sliding fulcrum is attached to a radius rod. ”

“ For special purposes in connection with machinery various heating devices are required, of which steam and gas are those most universally used. Steam tubes or coils may be carried through any fixed or movable part of a machine. Steam-heated surfaces, such as tables, pans, chambers, &c., steam-jacketed cylinders, and similar contrivances, are much used. Gas jets from perforated tubes, which may be shaped to any required position, are also convenient for dry heat and higher temperatures than can be obtained from steam. ”

“ Richmond’s patent balance hydraulic lift. A is the lift cylinder, connected openly to the balance cylinder B, which is weighted to nearly balance ram A and cage. Pressure water is applied to ram C to raise the load in cage.
2397. Waygood’s patent hydraulic balance lift. A is the lift cylinder communicating with the interior of cylinder and ram B which are fixed; cylinder C and ram D are loaded to nearly balance the cage and ram A, and the load is raised by admitting pressure water to cylinder C.
2398. Lever and rack lifting motion. The rack may be held up at each lift by a pawl. ”

“ Differential hydraulic accumulator. The effective area of the ram is the annular shoulder, or the difference between the areas of the top and the bottom rams.
556. Differential governing device. The motive power drives A which winds up the large weight; the small weight tending to run down, drives the fan regulator, and the two weights are so adjusted that when the proper speed is attained, both weights are stationary; any change of speed causes them to run up or down, so actuating the regulation by the bell crank lever and rod. ”

“ Expansion of air and gases. Ascending currents of hot air from a fire are used to drive a light screw motor, fan, &c. Hot-air engines, see Ryder’s patent and numerous others, which depend upon alternate expansion and contraction of air by heating and cooling. ”

“ In lieu of the weighted lever valve gear for single cylinder water pressure engines, the engine may be arranged to compress a spring during the stroke, which at the end of the stroke shall be released, and by its expansion reverse the valve. ”

“ Diagonal engine, with vertical air pump, worked by a bell-crank lever.
Vacuum engines. Two forms of this type of engine have been manufactured in which steam is employed at atmospheric pressure and condensed in a jet or surface condenser, the working pressure being therefore atmospheric and never exceeding 14 lbs. per square inch absolute. These engines and their boilers are free from risk of explosion, but require a good supply of condensing water. ”

“ Direct-action water pressure self-acting pump; performs the same work as the hydraulic ram, that is by using a low fall and large quantity of water it raises a smaller quantity to a greater height, the low-pressure water acting on the large double-acting piston. The valve is reversed by the motion of the engine.
1027. Hydraulic pumping engine. A modification of the Robinet. A is the driving cylinder, B the pump. The main slide valve is worked by two pistons, and the pressure water distributed by an auxiliary four-way cock or small slide valve, connected to a stop rod from the main crosshead. ”

“ Oscillating valve, with plunger face kept up by a spring. The oscillating valve has two ports passing out at opposite ends, through stuffing boxes, to either end of the cylinder; the inlet is at top and discharge at bottom.
1514. Balanced self-acting starting valve, suitable for large machines and low pressure. The upper piston is larger than the lower or main piston, and the space above the upper piston can be put in communication with the pressure water below it, or the exhaust port by the small piston valve at top operated by the hand gear ”

“ 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. ”

“ See Morton’s ejector condenser, which requires no air pump; Hayward’s exhaust condenser, which employs the water in suction pipe of a pumping engine to condense the steam. See Messrs. Tangye’s list. Water tube cooling coils are used for tuyeres and other hot surfaces.
Air-compressing and gas engine cylinders are water jacketed to carry off the heat of the compressed air or gas. Cooling by exposing a large surface to air is sometimes employed for exhaust steam on tram car engines &c., the apparatus consisting generally of numerous wrought-iron tubes or coils. ”

“ Other metals employed are copper, brass, tin, zinc, phosphor-bronze, lead, antimony, bismuth, pewter, Muntz metal, aluminium, sodium, potassium, platinum, gold, silver, nickel, and a great variety of the bronzes, which are valuable compounds varying in tenacity and hardness from the hardest steel to that of soft copper. Most of the above are manufactured into wire, sheets, tubes, rods, &c., and can in addition be cast into any form from a crucible. Copper can be forged but not welded; joints in it are generally brazed or soldered. ”

“ Is the ordinary slide valve gear with single eccentric for engines running always in one direction.
1436. Ordinary link motion reversing gear with two eccentrics; the link, having a shifting motion, is so arranged that either eccentric can be put into gear with the slide valve, the other eccentric running idle; or when in the mid position, as in sketch, both eccentrics run idle and the slide valve has no motion. By setting the link at intermediate positions the travel of the valve can be varied, and consequently the cut off also within certain limits. ”

“ Various automatic doors, revolving shutters, and other devices have also been tried. A simple and effectual protection is a continuous open-work screen wound upon a roller at top and bottom of lift, and attached to the top and bottom of cage and rising and falling with it, so that the doors into lift are all covered at all times except the one at which the cage happens to stand. ”