2464. Valve gear, with single eccentric, and variable travel, adjustable by hand wheel. The eccentric drives a block to and fro in a slot, the angle of which in respect of the slide valve centre line is variable by a rocking motion controlled by a hand wheel.
2465. Newall’s high speed engine, single-acting. In this engine the connecting rod trunk centre and the piston are made to distribute the steam as shown.
2466. Reversing movement for a valve, where the power will only move the valve to the half stroke or mid position, as in a slide valve hydraulic engine (see No. 1026), the rolling weight then completes the movement (see also No. 1740).
2467. Automatic or governor cut-off gear. The governor operates the sleeve, which has a screw movement on the pin fixed to the crank shaft; a parallel feather on the sleeve revolves the cut-off eccentric, and varies the travel of the cut-off valve. The slide valves are of the form of No. 1456.
2468. Eccentric motion to operate two slide valves.
2469. Crank shaft governor. The centrifugal gear acts on an outside crank to which the eccentric rod is attached, instead of a sheave and strap. A spring is applied to return the crank to full gear.
2470. Single eccentric adjustable cut off for a “Fink” link gear; plain D valve gives equal distribution of steam at any cut-off; the travel of the valve is regulated by the hand wheel.
2471. Cam-bar movement for operating two valves used for hydraulic starting valves.
2472. Crank shaft governor cut-off gear. Two hinged centrifugal weights are coupled by links to the cut-off eccentric sheave, and returned to the full open position by springs.
2473. Joy’s locomotive valve gear operated by the connecting rod; the rod A is connected to the starting lever to reverse, vary, or stop the distribution of steam by the slide valve, as in the ordinary link motion.
2474. Lever and T crosshead to open a valve by either motion of the lever to right or left. See also No. 2463.
2475. Crank shaft governor (Prof. Sweet’s), cut-off gear to vary the throw of a cut-off eccentric.
2476. Reversing link motion, with single eccentric; the slot link is hinged to the reversing lever.
2477. Sleeve and eccentric motion for governor cut-off. The inner (longest) sleeve has a longitudinal movement from the governor along a straight feather groove in the shaft, and has a spiral groove in its periphery into which projects a pin or feather on the eccentric sleeve, so that the longitudinal motion of the inner sleeve revolves the eccentric and alters the travel of the cut-off slide.
2478. The Walschaerts valve gear, one eccentric. The slotted link is hung at its centre to a fixed hinge pin, and the reversing gear shifts the link block up or down the slot link.
Slide valves may be worked by rack and pinion on the back or side flanges of the valve, or by a screw and nut; the nut being let into the body of the valve in a recess.
(See also p. 178.)
2479. Wooden springs of lance wood or ash.
2480. Carriage spring, with splayed link suspension. This improves the play and action of the spring over the vertical method.
2481. Duplex compression spring. The two springs are coiled opposite ways.
2482. Equalising lever to distribute the load on two car springs.
2483. Double-ended volute spring for compression.
2484. Spring band.
Spring piston rings. See Section 58.
2485. Conoidal spiral spring.
2486. Adjustable spiral spring. A washer on top has four vanes below it drilled with holes to suit the diameter and pitch of the spring wire, which, being threaded through the vanes, is rendered inactive, so far as it is held by the vanes. This appliance, therefore, is used to shorten or lengthen the live or active part of a spiral spring.
(See also p. 182.)
2487. Guard for spur gearing.
2488. Guard for bevil gearing.
2489. Safety nut for a running screw. The nut takes no strain until the thread in the main nut gives way from wear.
Fire alarms (automatic) depend for their action on increase of temperature above a normal maximum.
Diaphragms are inserted in the pipe connections to hydraulic lift cylinders to admit or discharge the water at moderate speeds only, so that in case of a burst the lift should not descend too rapidly.
Retaining valves, or non-return valves, are employed to confine any sudden shocks from hydraulic machines or from breakages, to local pipes.
Relief valves are applied to all hydraulic pressure systems to obviate the effects of shock.
An extra wire rope is frequently employed on suspended lifts to act as a safety rope.
2490. Safety centrifugal hooks to arrest a revolving shaft when the speed becomes excessive. The hooks fly out and engage with pins on a fixed disc.
Rope guards boards, screens, guard rails, &c., are necessary to protect persons from running ropes in hoisting and rope-driving gears.
2491. Collar and set screw, to prevent a key from working out. A set screw only—tapped into the shaft—is sometimes employed for this service.
(See also p. 184.)
2492. Steam trap, operated by expansion of a bent bar, which closes the inlet valve.
(See also p. 186.)
2493. Circular rack (revolving) and sector, used on governors.
2494. Skew worm and wheel gear.
2495. Oval gear, linked together.
2496. Mitre gear, angle of shafts variable. The two bearings are hinged together on the pitch line of the pair of wheels.
2497. Wood-faced spur gear, to run with the wood faces in contact for quietness. The wood faces are renewable, like mortise teeth. See Nos. 1352 and 1353.
2498. Elastic spur gear, to prevent backlash.
2499. Bevil gear, with roller teeth in one wheel of the pair.
2500. Circular rack and pinion gear. The rack can revolve independently of the vertical movement.
(See also p. 192.)
2501. Hydraulic transmission by two motors (rotary), see Section 75, one of which is the driver and the other the driven motor connected by two pipes, through which the oil or water is kept in circulation from one motor to the other.
(See also p. 192.)
2502. Steel bottle for compressed gases, &c.
Barrels and casks are used as tanks.
Tuns and vats are large casks formed of planking hooped at frequent intervals.
Square or rectangular vats are formed either of wood, held together by long bolts, or of slate slabs secured in a similar way.
Compound tanks. Where it is inconvenient to employ or erect one large tank, several smaller ones are connected together by circulating pipes.
(See also p. 192.)
2503. Presser foot for sewing machines, or for intermittent holding of any flat articles; lifted out of gear, and held by the feather end resting on the sliding socket.
2504. Belt shifting bar, adjustable every way.
2505. Revolving worm for operating a belt shifting bar, locking it at the same time.
2506. Worm gear may be thrown out or in by moving the wheel sideways on its shaft.
2507. Bolt and slot device for gearing two wheels together on one shaft, used on lathe headstocks.
2508. Half nut for throwing out of gear, with screw, and fitted with spring to take up the wear of the nut.
2509. Sliding shaft for winch or other gear, to shift the pinion out of gear or change to another speed (as in No. 2293).
2510. Another method of locking a sliding shaft in or out of gear.
(See also p. 194.)
2511. Variable belt drive by elliptic pulley.
2512. Variable drive by an intermediate friction wheel, and two friction cones at right angles.
2513. The same device applied to two discs running in opposite directions on the same axis.
2514. Variable drive by a V belt running between cone discs, the space between which can be varied by a hand lever or screw motion.
2515. Variable compensation weight and parallel motion for steam engines, by M. N. Forney, New York, 1893.
2516. Variable cone driving. Evans’ variable friction gear; a loose leather band, with a traversing motion by hand screw, forms the gripping medium between the cones.
2517. Variable radius lever, operated by a crank motion to give variable angular reciprocating motion to a shaft.
2518. Variable crank pin adjusted by a sector and bolt.
2519. Variable crank pin adjusted by a transverse screw.
2520. Variable driving friction gear to give a variable speed to the bevil-wheel shaft A by varying the position of the friction pinions as regards the disc B.
2521. Variable adjustment for a spiral spring.
2522. Adjustable centre-piece or bearing for a spindle or rod.
2523. Variable radius hand crank.
2524. Variable throw crank pin.
2525. Variable motion taken from a revolving cylinder or shaft by a friction wheel, whose angle can be varied.
2526. Similar motion taken from a revolving disc.
(See also p. 198.)
2527. Slide valve ports, with gradual cut-off.
2528. Piston valve in section. See No. 1654. This construction avoids spring rings, which do not run well across the ports, the entire valve being sprung into the bore.
2529. Tube air valve. Can be made to open and shut by revolving, or by longitudinal motion.
2530. Corliss valve, with rectangular rocking spindle.
2531. Flume valve for water.
2532. Double cone valve for steam or water, closes the leakage round the screw when opened, and requires no packing.
2533. Double ported slide valve.
2534. Cone plug and rubber ring for plugging a pipe.
2535. Reversing valve for gas or air blast.
2536. Slide valve to give a wide port opening with short travel.
2537. Removable valve seat, or gland, secured by three set screws and lugs inside the valve box.
2538. Safety valve, with double ball joint seatings, held down by dead weight, hung on the outer case.
2539. Oscillating ring valve.
High-pressure hydraulic slide valves are now made of hard wood, such as lignum vitæ, running on a bronze face; the wood valve is sometimes enclosed in a bronze body or strap.
2540. Hydraulic high-pressure valve, with renewable face.
2541. Tap, with crank movement, to open and close an ordinary mushroom valve.
2542. Spring loaded valve. May be opened by lifting, as shown, or by a horizontal pull in any direction, the pull rod being attached to the top of a fixed stud in the centre of the valve, which then tilts in opening.
2543. Safety valve, with knife edge.
2544. Screw plug bottle stopper. (Codd’s patent.)
2545. Dished grating valve.
(See also p. 208.)
2546. Water-jet double turbine motor.
(See also p. 212.)
2547. Spider wheel or tension wheel. Cycle wheels are constructed on this principle, as also were the great wheels at Chicago and Earl’s Court. There are many varieties of this type.
2548. Steel railway wheel, with dished web. Wrought iron or steel disc fly-wheels are now in some cases replacing wheels with arms.
Fly-wheels are also constructed with the rim formed of wrought-iron bars wound round and rivetted together, or of heavy wire coiled round and secured with steel belts.
(See also p. 214.)
2549. Differential weighing beam. The lower hook is suspended very near the centre line of the upper one, giving a close adjustment with a short graduated arm.
2550. Measuring or feed wheel, for seeds, &c. The little cups dip into the material, and carry it up to a shoot.
Even-flow regulator, for a tap. See No. 2204A.
2551. Wire and sheet V gauge.
2552. Balance, with angular weight, and graduated sector.
2553. Measuring tap.
(See also p. 216.)
2554. Rotary clothes washer. Consists of an internal perforated drum driven round in alternate directions inside a fixed drum, or other vessel containing soap and water.
2555. Archimedean circulator, for a washing trough.
(See also p. 218.)
2556. Feathering paddle wheel, or tide wheel. The three floats are maintained vertical by spur wheels on their spindle ends, which gear with idle pinions driven by a fixed central spur wheel of same size as those on the floats.
2557. Wind turbine. The vanes are formed as No. 1967, to receive the wind parallel to the axis.
Windmills are fitted with automatic regulating devices to adjust their angle area and direction to the force and direction of the wind.
(See also p. 220.)
2558. Fusee for round rope.
(See also p. 220.)
2559. Dished handwheel.
2560. Bent handle, with looped end.
2561. Handle key for cock.
2562. Handwheel lock nuts for a screwed bolt or other fastening.
2563. Coned handle.
2564. Cranked key or spanner.
2565. Loop handle for plain lever.
2566. Hinged spanner for tightening nuts or screwed glands, having pin holes or notched edges.
2567. Cranked handle, offset.
2568. Bow handle. May be fixed or made to swivel.
2569. Balanced hand crank.
2570. Hand crank, with holes to vary the radius.
2571. Locked handwheels for valves, to be movable in a certain order only.
(See also p. 224.)
2572. Cycloidograph. The pencil is fixed to a sliding rod A, sliding in a socket on the pinion spindle B, and also is forced to travel along the slot C, in an open disc revolving between four rollers D.
(See also p. 224.)
2573. Ribbed plate or tram plate.
2574. Trough plate for flooring bridges &c.
2575. Trough plate for flooring bridges &c.
2576. Curved ditto. Hobson’s patent.
2577. Wrought-iron or steel dished piston forging.
2578. Wrought-iron flanged manhole forging.
2579. Trough flooring.
2580. Trough flooring.
Iron and Steel Plates.—It is essential to possess some knowledge of what sizes and weights are obtainable at ordinary prices, because it is frequently desirable to utilise the largest available, in order to save the cost of making joints. Frequently joints are made by riveting, not because they are wanted at all, but simply because they cost less than single plates would do. Information of this kind is only to be obtained from the price-lists of the iron and steel manufactures, which are supplied to the trade.
The meaning of “maximum dimensions” is thus:—Taking a 11⁄2″ plate, for example, the maximum dimensions of which are given in a list as 40′ in length by 10′ in width, it is not possible to get a plate measuring 40′ by 10′, for that would make a united area of 400′, and the list limit is 150′ area. But the area can be taken out either in length or in width, within the limiting length of 40′ and width of 10′. The maximum area divided by any length in feet not exceeding the maximum, will give the maximum width for that length; and the maximum area divided by any width in feet not exceeding the maximum, will give the maximum length for that width. Thus, 150′ area divided by the maximum length, i.e. 40, gives 3′ 9″ width of plate. Or 150′ divided by the maximum width, i.e. 10, gives 15′ length of plate. And for anything over these maximum dimensions special quotations have to be made. But no plate can be rolled to contain the greatest length and the greatest width at the same time.
Again, in reference to “extras,” many points have to be borne in mind. Thus, as regards shape, any departure from the rectangular form is an extra, as tapered plates, sketches, i.e. any irregular outlines, and also circles. The extra, under this head, may be about 25s. per ton. As regards thickness, plates under 1⁄4″ thick are an extra, rated at from 10s. to 20s. per ton more. As regards width and length, quite special terms are made, amounting to 5s. perhaps on each 3″, a serious item. And as regards weight, steel plates over about 40 cwt. are charged extra, at the rate of about 5s. per 5 cwt.
To give examples: The Steel Co. of Scotland roll steel plates from 1⁄16″ to 11⁄2″ thick, and from an area in the first case of 30′ to 150′ in the latter. The thicknesses advance by thirty-seconds in thickness up to 3⁄16″, by sixteenths up to 1⁄2″ and by eighths up to 11⁄2″. The following table will give an idea of their limiting sizes, which may be taken as fairly typical of steel plates in general. It will be seen that I have included only a few of the thicknesses named above.
| Maximum. | ||||||
|---|---|---|---|---|---|---|
| Thick- ness. |
Length. | Width. | Area. | |||
| in. | ft. | in. | ft. | in. | ft. | |
| 1⁄8 | 22 | 0 | 5 | 0 | 50 | |
| 1⁄4 | 33 | 0 | 6 | 3 | 90 | |
| 3⁄8 | 38 | 0 | 7 | 4 | 100 | |
| 1⁄2 | 40 | 0 | 8 | 3 | 110 | |
| 3⁄4 | 40 | 0 | 9 | 3 | 140 | |
| 1 | 40 | 0 | 10 | 0 | 150 | |
| 1 | 1⁄4 | 40 | 0 | 10 | 0 | 150 |
| 1 | 1⁄2 | 40 | 0 | 10 | 0 | 150 |
David Colville and Sons roll plates from to 1⁄4″ to 11⁄2″ in thickness with an area of 80′ in the first and 140′ in the last; other sizes intermediate. But by special arrangement plates 1⁄4″ thick can be rolled to 140′ area, and 11⁄2″ of 170′. Thirty hundredweight is the limit of weight in ship plates, and 40 in boiler plates. Plates up to 61⁄2 tons weight each can be rolled at special prices. It is impossible to roll plates exactly to weight, and it is usual to allow a deviation of from 21⁄2 per cent. to 5 per cent. over weight for boiler plates, and under or over for ordinary plates.
The Parkhead Steel Works roll 1⁄16″ plates to a maximum area of 36′, 1⁄4″ plates to 70′, 1⁄2″ plates of 110′, 3⁄4″ plates of 140′, 1″ plates of 150′, and 11⁄4″ plates of 150′ area. The limiting weights are 20 cwt. for ship plates, and 40 cwt. for boiler plates. Above these 5s. per 5 cwt., or part of the same, is charged.
The Weardale Iron and Coal Co. roll steel plates from to 1⁄4″ to 11⁄2″ thick, with a maximum area of 60′ in the first, and 120′ in the second; 30′ is the maximum length, and 8′ the maximum width. Circular plates are also rolled from 5′ 6″ diameter of 1⁄4″ thick, to 8′ 6″ diameter in 11⁄2″ thick. All ordinary thicknesses, also intermediate between these, are rolled.
The limiting weights and dimensions of the steel plates of Bolekow, Vaughan and Co. are 18 cwt. 80 sq. ft. in area, 23′ in length, and between 12″ and 60″ in width. Extras are, for every hundredweight, or part of the same above 18 cwt., 10s.; for every foot, or part of a foot, above 23′ in length, 5s.; for every square foot above 80 sq. ft., 1s.
John Brown and Co., Sheffield, roll steel plates from to 1⁄8″ to 11⁄4″ in thickness. A few selected thicknesses are given below.
| Thick- ness. |
Length. | Width. | Area. | |||
|---|---|---|---|---|---|---|
| in. | ft. | in. | ft. | in. | ft. | |
| 1⁄4 | 30 | 0 | 6 | 0 | 72 | |
| 3⁄8 | 35 | 0 | 6 | 9 | 120 | |
| 1⁄2 | 40 | 0 | 8 | 0 | 130 | |
| 3⁄4 | 40 | 0 | 9 | 6 | 180 | |
| 1 | 40 | 0 | 9 | 6 | 180 | |
| 1 | 1⁄4 | 40 | 0 | 9 | 6 | 180 |
Circular and square plates of the same thicknesses can be rolled as follows:—
| Thick- ness. |
Diameter. | Square. | |||
|---|---|---|---|---|---|
| in. | ft. | in. | ft. | in. | |
| 1⁄4 | 6 | 6 | 6 | 6 | |
| 3⁄8 | 7 | 0 | 7 | 0 | |
| 1⁄2 | 8 | 3 | 8 | 3 | |
| 3⁄4 | 10 | 6 | 9 | 9 | |
| 1 | 10 | 6 | 9 | 9 | |
| 1 | 1⁄4 | 10 | 6 | 9 | 9 |
The Dalzell Steel Works of David Colville and Sons, make a difference in the extras in the case of steel boiler and of ship plates. Ordinary prices are charged to 84″ wide in boiler plates, but to 72″ only in ship plates. Above that they charge 5s. per ton for every 3″, or part of 3″. So in weight, 40 cwt. is the limit for boiler plates, and 30 cwt. for ship plates; over those 5s. per ton is charged for every 5 cwt., or part of 5 cwt. Circular plates for boiler ends and crowns are rolled by David Colville and Sons, who supply at ordinary prices the following: 3⁄4″ thick, 9′ 10″ diameter; 11⁄16″, 9′ 6″; 5⁄8″, 9′, and 9⁄16″, 8′ 6″.
As a sample of the usual limiting sizes of iron plates, I give the following:—It consists of a few selected Snedshill plates rolled by the Lilleshall Company, one of the most favourably known Shropshire houses. They roll iron sheets and boiler plates from 1⁄16″ to 1″ in thickness, advancing by thirty-seconds to 3⁄16″, and by sixteenths to 1″.
| Thick- ness. |
Length. | Width. | Area. | |||
|---|---|---|---|---|---|---|
| in. | ft. | in. | ft. | in. | ft. | |
| 1⁄4 | 30 | 0 | 5 | 0 | 5 | |
| 3⁄8 | 30 | 0 | 5 | 6 | 7 | |
| 1⁄2 | 30 | 0 | 6 | 0 | 8 | |
| 5⁄8 | 30 | 0 | 6 | 0 | 80 | |
| 3⁄4 | 30 | 0 | 6 | 0 | 80 | |
| 1 | 30 | 0 | 6 | 0 | 80 | |
It will be observed that the limiting sizes of iron are much less than those of steel.
The Butterly Company roll both iron and steel plates. The limiting weights and dimensions are as follows:—For iron boiler quality, 8 cwt., above that the extra prices are, 20s., 40s., 60s., 80s. respectively, from 8 cwt. to 10 cwt., 10 cwt. to 12 cwt., 12 cwt. to 14 cwt., and 14 cwt. to 16 cwt. respectively. For bridge quality, 10 cwt. is the limit, and extras are 20s. and 40s., from 10 cwt. to 12 cwt., and from 12 cwt. to 16 cwt. respectively. Area 60′, and for every 10′ or part above that, 20s.; length 25′; width 4′6″; over those various extras, ranging from 20s. to 80s.
(See also p. 234.)
2581. Bending block, for bar iron.
(See also p. 242.)
2582. Screw plug, with two lugs to screw it up by a plain bar placed between them.
2583. New form of manhole door.
2584. Screw fixing for a plug, door, or valve, quickly released or secured.
2585. Hollow plug, with square recess for a key or spanner. Flush plug.
2586. Soot door.
2587. Funnel plug, for filling oil reservoirs, &c.
2588. Wrought iron or steel manhole door, dished.
2589. Oven door, lifts out of the catch by leaving sufficient play in the top hinge.