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TIPPING GE iNOVATIONS.

26th October 1920
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Page 12, 26th October 1920 — TIPPING GE iNOVATIONS.
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Which of the following most accurately describes the problem?

Where Tipping Bodies are Necessa

What the Sh,

e-way and One-may Tipping Gears it to. the fore.

EFFICIENCY in the handling of all classesof transport has never been more necessary than it is to-day. Few people realize how much the cost of transporting an article is reflected in its price. , Take, for instance, coal: this, at the pit mouth, costs 33s. 3d., but the consumer has to pay over double

• this price; certainly, some of the extra cost is made Up by the expenses and profits of the middle man, but the bulk of it is due to the cost of transporting the coal from the pit mouth to the consumer. As with coal, so it is with every article that has to be carried, whether the distance over which it has to be transported is a matter of yards or miles. With rising rates, the dearth of houses, and the cost and scarcity of coal, the necessity for efficienc;,7 applies even more particularly to. transport for municipalities, building contractors, and the coal trade, than for others. With labour at a premium, one of the chief factors in reducing transport costs is the reduction of the amount of labeur required to load and. 'unload. vehicles. As regards unloading, many materials, such as those employed in building, refuse, coal, etc., readily lend themselves to being Unloaded by tipping the bodies of the' vehicles on which they are being carried. .

In our issue dated December end, 1919, we went very fully into the various types of tipping gears employed at that time. The Commercial 'Vehicle Show which was recently held' at Olympia has brought to the fore several new types which deserve, special consideration. Until recently, efforts to improve tipping gear have been confined to improvements in the mechanism for effecting the tip, but this is notall that is wanted. End-tipping bodies' and side-tipping bodies each have their own good points,and in certain places one or the other only can be employed. Where space is confined, it may be found impossible to unload -a vehicle which has an end-tipping body only, whereas one provided with a side-tipping body

could deposit its load without any difficulty. May instances occur when the position is reversed and .where the end-tipping -body is the one for the job. Hence the contractor or municipal authority has to exercise considerable care in the selection of a vehicle suitable for a particular class of work. If, however, it were possible to coin,bine the advantages of the end-tipping body with those I the side-tipping, one vehicle could be utilized for unloading at any spot, and it is in the design of tipping gears which will tip a body to either side or endways, as desired, that this Show has brought out several commendable efforts.

Three different types were exhibited. The most elaborate of these three-way tipping gears was certainly that on the five ton Saurer tipping wagon, and this has the particular advantage that it can be entirely controlled from the seat. , This, gear is operated hydraulically by an oil pump driven from the gearbox. The -body is supported on four ball joints, each provided with -a bayonet fastening, capable of being locked or unlocked by a quarter turn. The cups of these ball joints are carried by the body, whilst the ball's are supported on the chassis by two special hollow croaa-members. From the cab A. single rod passes through each of these two •cross-members, and this rod is provided with gears and cross-shafts communicating with the bayonet joints. In the cab is a single lever, working in a gate and connected to the operating rod. By moving this lever sideways; the. rod is turned, and a backward movement of the lever into one of three gates releases the bayonet joints at either side or the front, according to the direction in which it is desired to tip the body. Another lever, also situated in the cab, is then Moved to operate the valve controlling the supply of oil to a. hydraulic ram. This ram carries rack teeth which engage with a pinion_ carrying a very powerful lever shaped into the form of a bell-crank. At the front end of this lever are universally jointed arms carrying. a ball, which bears in a cup supported by the powerful underframe work of the body ; as the ram is pushed out the lever is lifted,clansequentlY lifting the body, which naturally swivels on those ball joints, the bayonet fastenings of which are not released. At the maximum point of tip,, a release valve comes into operation so that the tippingangle 'cannot be exceeded.

. Another feature of this gear is that the sides of the body are automatically locked, whilst the body is at rest, arid are .automatically released at the side to which the tipping is to be done. Whilst the body is actually tipping it is impossible to move the lever controlling the bayonet fastenings, so that accidents cannot occur from this cause.

Our criticisms of this gear are that it-appears very expensive to manufacture, and there might be some difficulty in making the body return, go that the balls and sockets exactly coincide, if the vehicle were so Positioned that frame distortion occurs, also the rack and The pinion of the lifting lever appear to be under enormous stresses.

A somewhat similar but less complicated gear was that shown on the 6 ton British-Berna tipping wagon. This gear, however, is operated by a screw and nut with square threads. At the top of the gearbox are two constant mesh pinions, either of which can be locked to a shaft carrying the large phosphor-bronze nut by means of: a double dog clutch. It. will be understood that by moving this dog clutch in one direction the body is lifted, ,and in the other lowered. The phosphor-bronze nut is supported in ball bearings. The screw is fastened to a crosshead somewhat similar to that On a locomotive, and links connect this crosshead to the lower arm of a huge bell-crank lever, which is pivoted on to a stout channel-steel frame carrying the nut and crosshead. At the other end ot this bell-crank lever is a short, stout, universally jointed shaft pivoted to the centre of the steel frame supporting the body. When at rest, the body is .supported on four steel brackets, bolted to the frame side members, and locked into position by stout pins. The brackets on the body framing form the female portions of hinges, whilst those on the chassis can swivel in the other direction, thus making a type Of universal joint.

To tip the body to .either side or to the rear, the locking pins at the opposite 'side, or end. are withdrawn, and the sliding dog put into meth with dog teeth on one of the constant-mesh pinions. The bell

crank then rises rapidly and tips the body. The angle of tip in each direction is: quite surprising; to the rear it is 55 degrees and to the side as degrees. To prevent any danger of overtipping or jamming of the worm and screw, when the body lifts to its maximum height it tightens a chain which, throngh the medium of levers and' rods, pulls the deg clutch out of mesh with the constant-mesh pinion. A similar action occurs when the body is lowered, but, in this case, the body, as it coines to rest, depresses a lever..

In this type of gear the stresses on the operatiug mechanigna do not appear to he nearly so great as those On the gear which we described previously, although it does not possess the advantage of being capable of being operated entirely from the driver's seat.

Another neat device utilized with this gear is a spring stiv, which is automatically dropped over each rear spring as the body tips, and thus prevents the rear springs from being strained by the extra load i

thrown on them when a loaded body s tipped. Also, when the body is at rest, the four locking pins take no load. An additional advantage is that the whole of the operating mechanism is totally enclosed and runs in. oil.

The third three-way tipping gear which we observed was that fitted .to a Fiat chassis and constructed by the Eagle Engineering Co., Ltd., of Warwick. This gea;.° is operated by hand and consists of the usual either-side tipping gear manufactured by the company, comhined with a double-screw situated between the cab and the body.

This gear, although very simple, would appear suitable for many classes of work, and would certainly be considerably less expensive than the two previously described. In addition to• the gears described above, a novel type of hydraulic end tipping gear has been evolyed by the Associated Equipment Co., Ltd. This gear is, • in certain respects, similar to the well-known Wood hydraulic, and it is situated in the same place, between the cab and the body. The Wood gear, however, owing to its pulley and wire ropes, takes up a considerable amount of room, whereas the A.E.C. gear is a slender steel barrel provided with two rams, one of which telescopes into the other. The upper ram carries a T piece connected to brackets an the body by two steel strips.

When in operation the body is lifted to a certain height by the large ram, and is then tipped to a greater angle by the small rain. In this gear the hydraulic pump, which is of the doubleplunger type, is driven by a pinion carred in in the top of the gearbox. This gear will tip to an angle of 40 degrees in 30 seconds, and, after tipping, the body drops back between stout steel guides bolted to the frame side members. The price of the outfit, including a steel tipping body, is £225. One very substantial twin-ram hydraulic and tipping gear was observed on a 7 ton Renault tipping wagon ; in this gear the rams are positioned well to the rear of the chassis, and, to prevent the front portion oethe body from swaying, a stout angIe-iron stay is positioned between the chassis and body ; the end of this stay is free to slide longitudinally on a bar attached to the latter.

The 5 ton Maudslay side tipper is actuated by a somewhat novel gear consisting of two hydraulic barrels carried upside down, one at each end of the body and swivelling on the latter, the ends of the rams being fulcrumed on the chassis frame. A rack, also fulcrumed on the chassis, is positioned close to each ram and meshed with a pinion carried by th-e body; the two pinions are connected together by a stout rod, so that any movement of one entails a corresponding movement of the other, and the body cannot be strained by the rams exerting more pressure at one end than the other. The pump of this gear is driven by a V friction wheel meshing with V-grooved wheel bolted to the clutch centre, and controlled tv a lever in the cab.

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