Sidney Straker and Squire, Limited.
Page 36
Page 37
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Principal Exhibits :—Three Petrol Chassis ; one ,Petrol-electric Chassis ; one Van; two Buses.
The two adjacent stands contain no less than six vehicles, all of which are interesting, and form one of the most important exhibits to be found at Olympia. First in the category comes the company's new 3oh.1i. model, which has all the improvements that have suggested themselves as being desirable departure; from earlier patterns. The other vehicles include : a t-ton delivery van, which has been designed to meet the requirements of those who have to transport light loads at comparatively high speeds ; a petrol-electric chassis ; a 1907-type Bussing motorbus chassis ; a complete Bussing vehicle of the t906 type ; and a steam wagon with a locomotive boiler.
The 1907 vehicles have a 3oh.p. engine, and its cylinders have a bore of 5 inches, the piston-stroke being the same. The overhead camshaft is entirely enclosed, to prevent the ingress of dust to the bearings. The shaft is driven by means of a vertical spindle, from the forward end of the crankshaft, by skew gearing. A small, but important, alteration has been made in the method of mounting the vertical spindle. The bearings were, formerly, non-adjustable, so that the relative positions of the pinions and their corresponding wheels could not be altered. This deficiency has now been done away with, and the bearings are capable of an eccentric adjustment, which permits of the teeth on the pinions being brought into absolutely correct pitch with the driven skew wheels. The vertical
spindle carries a governor of the usual centrifugal type, and this is enclosed in an aluminium casing. The governor spring projects upwards from the top of the casing, and the loading is easily altered to give the required engine speed. A cap can be placed over the spring and sealed, so that there can be no undetected tampering with the
governor. Low-tension magneto is employed, and the magneto is set on the right-hand side of the engine. The carburetter is the company's own make, and two separate supply pipes are employed. One pipe is sufficient to supply the carburetter, and the other is a stand-by in case of fracture. Both pipes have cocks at their junction with the petrol tank.
The radiator is of the gilled-tube type, and the large fan is mounted directly upon the crankshaft. A centrifugal water pump is used. Lubri
cation of the engine is on the splash system. Nine sight-feeds are carried upon the dash, and four of the tubes which lead from these are carried to the crankshaft bearings, the fourth being necessary as the front crankshaft bearing is split to allow of the insertion of the skew wheel which drives the vertical camshaft spindle. Four other leads carry oil to the cylinder walls, and the ninth commands the clutch bearing.
The clutch-operating mechanism is excellent, and is fitted with one of the simplest adjustments we have yet seen. The clutch fork is vertical, and the central fulcrum, is in the form of a jaw : this jaw is at the outer end of a screwed portion, which is adjustable in a bracket bolted to a transverse member carrying the clutch-pedal mountings. The upper end of the clutch fork is provided with a vertical roller which lies between two small lugs. l'he above-mentioned bracket is fitted, at its end adjacent to the transverse member, with two eyes. One of the ends of each of two strong spiral springs is hooked to each of the eyes, whilst the two free ends are attached to two short threaded rods which pass through the lugs. Two adjusting nuts are placed on each rod, one each side of the lug. The springs are given sufficient tension to draw the upper half of the clutch fork backwards, which has the effect of forcing the male portion of the clutch inwards. The de-clutching device is now explained. The clutch pedal is keyed to a short shaft, which is mounted in two bearings upon the transverse member. The opposite end of the pedal shaft carries an arm, the end of which has a cam profile.
The arm rests, normally, upon the edge of the steel roller, Depression of the foot pedal simultaneously forces the arm downwards and, in so doing, drives the top half of the clutch fork in a forward direction ; this causes the lower half of the fork to take a reverse direction, at the same time withdrawing the male portion of the clutch.
A new form of gear is employed in the 1907 model. The wheels upon the first shaft revolve loosely, whilst those
upon the second shaft are cut from the solid. The method of locking the desired pinion upon the first shaft allows of the pinions meshing with the correct wheel before the actual locking takes place, and this provision eliminates any possibility of injury to the edges of the teeth. A through drive on the fourth speed is obtained. The reduction between the driving pinion and the large bevel wheel upon the differential gives a reduction of 2.8 to r. Ball bearings are fitted to the gearbox shafts, and the differential shaft. The gear wheels are cut from steel having a tensile strength of 70 tons to the square inch, whilst the pinions in the differential gear are made from steel having a tensile strength of 102 t011S to the square inch.
Visitors to the show should make a point of thoroughly examining the chassis under notice, because it confains many new features, which must appeal to all, whether present owners, or possible users.
The petrol-electric chassis is fitted with a standard 30h.p. engine. In this system, a dynamo, the armature of which is rotated directly from the crankshaft of the engine, supplies current to two continuous-current motors. These motors drive two short secondary shafts, by means ef worm gearing. The final transmission is by side chains, and the usual differential gear is rendered unnecessary, as each driv
lag wheel is rotated by its motor independently of the other. The equipment has been supplied, experimentally, by the British Thomson-Houston Company. A reference to our census of motorbuses in Greater London (page 49) will show that Sidney Straker and Squire, Limited, has a very large number of its motorbuses in regular daily use, and the total there given is only part of the aggregate number which are in service in the country as a whole. Recent modifications of detail have resulted in the practical disappearance of noise when running, and the vehicles now continue in that desirable condition in spite of hard usage.