Plate 15Larger plate.
Larger plate.
278. Common jaw clutchsliding on a feather key, the loose half being cast on the boss of a wheel.
279. Two forms of jaws for ditto.
280. Cone clutch.Screw gear should be used to operate this, as it is liable to “seize,” and there is considerable end pressure on the shaft to be allowed for.
281. Face (friction clutch)withVgrooves. See remarks toNo. 280.
282. Friction clutchwith three or more segments. See alsoNos. 38and59.
283. Pin and hole clutch.The pin and holes can of course be made parallel to the shaft instead of radial.
284. Cam clutch,used for dexter treadles, also for reciprocating motions driving one way and running loose the opposite way. See alsoSection 62,Nos. 1135,1178, &c.
285. Crank pin and arm driver.
286. Pickering’s self-sustaining clutchfor hoists. The boxAonly is keyed to the shaft, and drives the chain wheel and sleeveBby jamming it with the flange of the ratchet-wheel sleeveCby the sliding action of the toothed faces formed atDon the disc and flange of the sleeveB, these teeth being of the ratchet form.
Several other forms of this clutch are in use. Edwards’, Stevens and Major’s, and others may be consulted.
287. Disc friction clutch,with intermediate leather discs and screw clamping appliance, only the central disc is keyed to the shaft, the others run loose. Mather and Platt’s and Addyman’s patent friction clutches are examples.
Numerous forms of friction clutches are in use, modifications chiefly ofNos. 38,59, and282. See alsoSection 5.
Plate 16Larger plate.
Larger plate.
288. Ordinary flanged coupling,usually made so that the end of the shaft forms a spigot joint with the opposite half of clutch.
289,290,291. Sleeve couplings.See alsoNo. 1430andSection 57. Butler’s patent frictional coupling, Kirkstall Forge Co., Leeds, Seller’s double-cone vice coupling, and others, are sleeve couplings.
294. Flanged coupling,with cross feather or key. This plan gives great torsional strength, especially if the coupling flanges are forged solid with the shafts.
295. Turned and finished linkwithout any adjustments; ends may be solid, or forked asNo. 297.
296. Flat linkof similar description, with raised bosses for facing and wear.
297. Adjustable link,with right and left hand screw coupling. Lock nuts may be added to prevent the coupling working back.
298. Strap link,fitted with brasses, gibs and cotters, and distance bar. In this link the wear of brasses is all taken up one way by the gib and cotter; therefore, if great accuracy in the distance apart of centres is necessary, gibs and cutters should be fitted at both sides of one pair of brasses, orNo. 299adopted.
299. Turned linkwith adjustable end brasses. The forked end should be used where there is the greatest amount of wear.
300. Wood connecting- or pump-rodwith wrought-iron strap ends, fitted with brasses, gibs, and cotters. Much used on mining pumps.
The shafts or rods are sometimes of cast iron of cross orTsection, but are usually of a circular or flat section and swelled in the middle, similar toNo. 299. See Struts and Ties,Section 102.
301. The most usual form of shifting linkfor link-reversing gear, generally got up bright all over.
Plate 17Larger plate.
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302. Similar link,but having the point of suspension on a side pin, fixed by screws to the link, and raised from it sufficiently to allow the sliding block and pin to pass under it.
303. Reversed curve link.
304. Solid bar link,sometimes adopted for cheapness and simplicity, the valve rod and eccentric rods having of course forked ends.
305. Double bar link.This is also a simple and cheap construction; the bars are plain, the rod ends single, and the block turned large enough to have a recess on each side to fit the links.
306. Strap head connecting rod end,with square brasses, double gibs and cotter.
307. Strap head connecting rod end,but with rounded end and set screw fastening for cotter.
308. Similar to the last,but with screw cotter adjusting device for the brasses.
309. Solid end rod.The brasses take out sideways.
310. Forked end rod.
311. Strap end for heavy rods,having cotter for tightening the strap to theV’s in the rod end. The oil cup is often forged and turned solid on the strap, as shown.
312. Rod end with side strap.The brasses take out transversely by taking off the side strap.
313. Solid endand double set screw fastening for cotter.
314&315. Solid ends for small rods.The brasses are usually secured by a set screw.
316. Solid end,split with screw bolt tightening device; may be hinged as shown by dotted line.
Plate 18Larger plate.
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317. Covered solid endfor crank pins, with screw adjustments for brasses.
318. Common forked rod end,with cap.
319. Hook bolt attachmentfor gudgeon; sometimes useful where there is thrust only on the gudgeon.
320. Double connecting rod,in which the rods form also distance rods and bolts for the heads, which are in halves and fitted with brasses of the ordinary type.
321. Marine typeof rod end, having solid end, square brasses and cap.
322. Marine head,in which the brasses are extended to form the central block in halves, the rod end being ofTshape and bolted through the brasses and cap.
323&324. Plain links.
There are innumerable varieties of the illustrated types of heads in use, every engineer having his own design.
Our object here is to indicate or suggest general design or arrangement only, from which a selection can be made to suit requirements.
325. Is the common type of wharf cranewith fixed post, the base plate being well bolted down to a solid mass of masonry.
326. Is also a common type of wharf crane,but with the post revolving in a footstep and base plate; this gives a better base thanNo. 325.
327. Has no post,but a revolving frame and base plate with front and back friction rollers, and a centre pin.
328. Post and jib in one piece,usually of wrought iron. A balance weight is fixed atAto balance the overhanging jib.
329. Swing derrick crane,generally of wood. The jib turns three-fourths of a circle, and the two guys are fixed at an angle of 90° apart, and well secured by anchoring or loading, often made with very long jib for builder’s work.
330. Wharf crane,with centre tension bolt instead of crane post. In this arrangement there is a vertical tension on the centre bolt and thrust on the foot of jib.
Plate 19Larger plate.
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331. Warehouse wall crane.
332. Warehouse wall crane, with high jib-head.
333. Whip crane,chiefly used in goods sheds. The barrel is sometimes worked by an endless handrope as shown, and sometimes by a second rope and drum with a hand crank asNo. 1209.
334. Portable hand crane,with balance weight. The balance weight can be shifted in or out to balance the load.
335. Foundry crane,sometimes with travelling carriage on the jib, asNo. 336.
336. Swing bracket craneand traveller, usually formed of flat bars on edge; used only for light loads, for smiths’ shops, &c.
337. Wharf derrick,to turn an entire circle, similar toNo. 329, but employed for heavy loads.
338. Floating derrick.
339. Light balance crane.
340. Trussed jib crane,with centre tension bolt.
341. Simple derrick and winch,with two guy ropes; for temporary purposes only, and may be easily shifted about.
342. Sheers and winch.
343. Tripod and winch.
344. Sheers with screw adjustmentto back leg. This design is adopted for very heavy lifts, such as loading heavy machinery, shipping masts, boilers, &c.
Plate 20Larger plate.
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345. Four-guy derrick and winch,used for fixing columns, bases, masonry, &c.
346. Fixed post steam crane,for wharfs, piers, jetties, harbour works, &c.
347. Portable steam crane,very largely used on wharfs, piers, &c., and sometimes fitted with travelling gear in addition to hoisting and slewing motions.
348. Wharf crane,with fixed engine, centre bolt, and trussed arched jib. This is a very good type, as the ground is kept clear for goods, &c., and of course all motions, hoisting, lowering, and slewing are controlled from the crane above ground by hand levers.
349. Hydraulic wharf crane,with fixed post. The common type universally used in docks, &c., with the ordinary form of multiplying hydraulic cylinder and chain gear; the valve for controlling its movements is operated by hand levers extending up through slots in the floor; the slewing is performed by a separate cylinder and chain gear, with a distinct controlling lever. SeeSections 42and83.
350. Hydraulic short lift ram, centre crane, and traveller,employed chiefly to raise the ingots out of the casting pits of Bessemer steel works. The ram is of course subject to severe cross strains, and many designs provide an overhead guide or support for the ramhead.
351. Automatic balance crane,portable or fixed; the position of the fulcrum varies with the load.
352. Steam multiplying cylinder crane,in which the ram is forced out by steam pressure, acting either directly or by an intervening body of water.
353. Breakwater swing crane.
Plate 21Larger plate.
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354. Overhanging travelling crane,for use on breakwaters, &c.
355. Overhead hydraulic travelling goliath,to span a railway; has slewing motion and a balanced jib.
356. Single rail cranewith top guide rail.
357. Overhead travelleron gantry.
358. Goliath.
359. Steam overhead crane,with carriage to span a railway. Largely used on dock wharves, &c., as they give a high lift and do not encumber or encroach on valuable quay space.
360. Hydraulic cylinder post crane;sometimes adopted instead of the typeNo. 349.
361. Heavy hydraulic crane,with suspended cylinder; employed for work of the very heaviest class.
362. Ship’s Davit.
363. Balanced jib post crane,no tie rod. The weight must be sufficiently heavy to balance the jib and load.
364. Hydraulic strut jib crane.The load is raised by raising the jib.
365. Overside dock crane,for discharging from ships into barges. The overhang being very great in this design, it must be provided with a heavy frame or balance weight.
366. Wagon tip crane,for loading vessels.
367. Double sheave4 to 1 purchase for crane jib. See alsoSection 69.
Messages can be conveyedby—
1.Speaking tube;for distances up to say 300 feet,3⁄4″ to 1″ bore tubes.2.Telephone;any distance.3.Telegraph;any distance.4.By signals—(a) Wire or cord and bell; (b) sight signals, such as the semaphore, lamps, heliograph, flags, and other devices; (c) by sound, such as a bell, trumpet, siren, whistle, &c. SeeSection 105.5.By pneumatic despatch:that is, by forcing a piston carriage containing the message or small parcel through a tube by compressed air.6.Carrier pigeons.
1.Speaking tube;for distances up to say 300 feet,3⁄4″ to 1″ bore tubes.2.Telephone;any distance.3.Telegraph;any distance.4.By signals—(a) Wire or cord and bell; (b) sight signals, such as the semaphore, lamps, heliograph, flags, and other devices; (c) by sound, such as a bell, trumpet, siren, whistle, &c. SeeSection 105.5.By pneumatic despatch:that is, by forcing a piston carriage containing the message or small parcel through a tube by compressed air.6.Carrier pigeons.
1.
1.
Speaking tube;for distances up to say 300 feet,3⁄4″ to 1″ bore tubes.
Speaking tube;for distances up to say 300 feet,3⁄4″ to 1″ bore tubes.
2.
2.
Telephone;any distance.
Telephone;any distance.
3.
3.
Telegraph;any distance.
Telegraph;any distance.
4.
4.
By signals—(a) Wire or cord and bell; (b) sight signals, such as the semaphore, lamps, heliograph, flags, and other devices; (c) by sound, such as a bell, trumpet, siren, whistle, &c. SeeSection 105.
By signals—(a) Wire or cord and bell; (b) sight signals, such as the semaphore, lamps, heliograph, flags, and other devices; (c) by sound, such as a bell, trumpet, siren, whistle, &c. SeeSection 105.
5.
5.
By pneumatic despatch:that is, by forcing a piston carriage containing the message or small parcel through a tube by compressed air.
By pneumatic despatch:that is, by forcing a piston carriage containing the message or small parcel through a tube by compressed air.
6.
6.
Carrier pigeons.
Carrier pigeons.
1.Speaking tube;for distances up to say 300 feet,3⁄4″ to 1″ bore tubes.2.Telephone;any distance.3.Telegraph;any distance.4.By signals—(a) Wire or cord and bell; (b) sight signals, such as the semaphore, lamps, heliograph, flags, and other devices; (c) by sound, such as a bell, trumpet, siren, whistle, &c. SeeSection 105.5.By pneumatic despatch:that is, by forcing a piston carriage containing the message or small parcel through a tube by compressed air.6.Carrier pigeons.
1.Speaking tube;for distances up to say 300 feet,3⁄4″ to 1″ bore tubes.
2.Telephone;any distance.
3.Telegraph;any distance.
4.By signals—(a) Wire or cord and bell; (b) sight signals, such as the semaphore, lamps, heliograph, flags, and other devices; (c) by sound, such as a bell, trumpet, siren, whistle, &c. SeeSection 105.
5.By pneumatic despatch:that is, by forcing a piston carriage containing the message or small parcel through a tube by compressed air.
6.Carrier pigeons.
368. Signalling dialsandbevel gearing.
Plate 22Larger plate.
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It is of the utmost importance that every revolving or reciprocating part of any machine should be as nearly as possible balanced, to obtain smooth running with the least amount of wear.
The following are types of the most important devices and theirapplications:—
369. Balanced lever,having a sliding cheese or ball weight fixed with a set screw.
370. Balanced cage of hoist.It is usual toover-balancethe cage to divide the work between the up and down journeys in hand-power lifts to assist the load; but in power and hydraulic lifts the cage isunder-balanced so as to descend when empty.
371. Hydraulic balance lift,in which the dead or constant load of cage and ram are nearly balanced by a loaded piston in a supplementary cylinder; to raise the loaded cage the pressure water is admitted to the upper side of this piston. Many varieties of this type are in use; see Ellington’s, Johnson’s, Stevens and Major’s, Waygood’s, and other patent lifts.
372. Variable volute compensating balancefor revolving shutters, blinds, curtains, &c., to maintain an even balance in all positions, The weight chain is as thick as the coiling shutter on blind, so that the acting radii of the shutter and weight are always proportional.
373. Variable compensating balancefor hydraulic lift rams, to compensate for loss of immersion of the ram as it ascends (Berly’s patent). See also Stevens & Major’s patent, where bell-crank levers and weights are employed instead of loaded chains. SeeNo. 383.
374. Balanced fly-wheel.For balanced cranks, seeNos. 172&173.
375. Increasing balance by sections,lifted at intervals as the chain rises.
376. Balanced riveting machine.See Tweddell’s patents.
377. Variable lever balance.For balanced cranes, seeSection 18.
378. In deep lifts,to balance the weight of chain or rope, it is made endless.
379. Another method.The loose chain hung from cage is of the same weight per foot as the lifting chain.
380. Balance weight on a screw armfor adjustment, employed on weighing machines.
Plate 23Larger plate.
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381&382. Worthington’s compensating air cylinders,employed on direct-acting horizontal pumps, working expansively, in lieu of fly-wheel. The oscillating or vertical cylinders are air or spring pistons, absorbing power the first part of stroke and giving it out during the latter part.
383. Variable balance weightby bent lever.
384. Variable balance weightby double links and sliding joints.
385. Dawson’s compensating governor.SeeMechanical World, August 25th, 1888.
386. Balanced doors, hinged vertically.
387. Balanced sashes,or vertical sliding doors.
388. Method of balancing a bloomin charging or withdrawing from a furnace, or any similar use.
389. Balancefor link motion.
390. Weightto keep a cord or rope in tension.
391. Mode of balancing two sliding doorsso that they rise and fall at proportionate speeds.
Hoisting and winding engines (seeNos. 1222,1223) are balanced by having an ascending and descending cage, and two ropes, one winding on as the other winds off the drums.
Double cage hoists similarly balance themselves. Heavy slide valves, and other reciprocating parts of steam engines, are balanced by small steam pistons. SeeNos. 1651-1654.
Foot treadles, when required to always stop at a point off the dead centre, have a balance weight fixed to fly-wheel, at right angles to the dead centre.
A water tank is often used to serve as a counterpoise, or balance, and may be made variable by varying the quantity of water by a siphon or other device.
For Balanced Valves, seeSection 89.
392. The ordinary type of piston-rod and crank motionas universally used.
393. Watt’s substitute for the above,or “sun-and-planet” gear. Note that the crank shaft revolves twice for each double stroke or revolution of the engine. The crank being a loose link only, the planet wheel does not revolve.
394. Epicycloidal parallel motion and crank.The pinion is one-half the diameter of the wheel on pitch line, and the connecting pin is fixed on the pitch line of pinion.
395. Bernay’s patent crank motion;radius of crank = stroke × ·25.