P. and M.
For 1912 the alterations to the P. and M. are of a minor description. The engine dimensions remain unaltered. A foot starter is now fitted which is operated by a pedal on the right side. The pedal, when sharply depressed, revolves a shaft carried on a bush through the 2 to 1 gear box, this shaft being connected to the pedal by a small chain. On one end of the shaft is a small chain wheel, on the other end are ratchet-faced teeth, which engage similar teeth on the mainshaft. On releasing the pedal these automatically become disengaged. The subsidiary-shaft is held out of engagement by a coiled spring. This, in conjunction with the half-compression device, enables rapid starting with one downward thrust of a pedal. This, of course, can be done with the wheels resting on the ground and with the rider seated on the saddle. The 1912 carburetter is of an entirely new pattern, combining great efficiency and simplicity. The single jet can be removed by unscrewing one screw; the air and throttle pistons can also be withdrawn simultaneously by the removal of one screw, both these screws having the same sized head, which fits the small B.S.A. key supplied with the machine. The float chamber cap is instantly detachable, being held in position by a flat spring of the same type as used on a magneto contact breaker cover. The petrol level is adjusted by means of two small nuts threaded on the needle valve stem.
1911 Olympia Show - The Motor Cycle November 9th, 1911. Page 1181
Further P. and M. details.
In our last issue we outlined some of the more important P. and M. improvements. We are now enabled to illustrate a few of the special details for 1912. The kick starting device consists of a semi-circular drum, at the corners of which are anchorages for a short length of chain, which passes over a small sprocket supported by a projection cast on the timing gear case. Internally this sprocket carries a ratchet tree wheel with under-cut teeth, a similar ratchet forming the end of the engine-shaft. The under-cutting of the teeth prevents the two disengaging themselves so long as pressure be applied to the foot crank. The manner in which the, free wheels are engaged is ingenious. Normally a short spiral spring holds them out of engagement, but on the crank is a U-shaped flat spring, the inner face of which, when the crank is pressed forward in order to start the engine, rubs against the end of a small sprocket, and in doing so forces it inwards, thereby engaging the two free wheels. A helical spring, not shown, is wound round this shaft on which the semi-circular drum is mounted, and when pressure of the foot is relaxed it returns the drum to its original position.
The new carburetter contains several improvements, notably the ready detachability of all parts, including the float chamber, the throttle and air slides; the latter are depicted withdrawn from their tubes. The float chamber is formed with a concentric boss in which is turned a groove for the reception of a peg on the flat spring which holds it in position. Upon lifting the springy and turning it slightly sideways, the lid is free to be removed. Another item is the new P. and M.. exhaust lifter, which consists of a short crank hinged to a projection cast on to the aluminium cover of the tappet guide.
The arrangement of the foot brake has been entirely re-designed, the pedal being now operated by the heel. The footrests also carry a very practical and neat front wheel stand. The magneto advance is now operated from the handle-bar. The bracket, which forms both the guide for the Bowden cable and an anchorage for bolted to the magneto itself, from which it is rendered detachable, the fixture being an extremely neat and simple one. The other refinement is a petrol priming device. Owing to the inclined position of the cylinder, a specially turned -up compression tap is required, and in order to make this operation easy, the cock-plug is considerably extended forward so that the handle of the cock does not foul the cylinder support. A short tube from the tank leads to the tap. the outlet being controlled by a screw-down needle valve. With regard to the 2½ h.p. lightweight, this will have the latest B. and B. carburetter and handle-bar control to the magneto.
Armstrong Gears.
A few days ago we were given an opportunity of thoroughly inspecting the manufacture of the Armstrong three-speed hub for motor cycles. Accompanied by Mr. Reilly (works manager), we made a tour of the splendidly equipped works, and one of the first things we noticed was the special machinery for cutting the pinions. A row of these machines has been laid down, and no drifting or broaching of the pinions is allowed in the manufacture of this gear. All the pinions of the Armstrong gear are milled, and subsequently gauged to a thousandth part of on inch. Our visit was of absorbing interest, and we feel confident that, equipped as the Armstrong Gear Co. is. no inaccurate part can issue from its works.
For next year a few slight alterations have been made, as the firm will market two types, one called the Mark 2 which is suitable for machines up to 3½, h.p. solo, and the other Mark 3. which is intended for 3½ h.p. sidecar machines. The latter model will have a slightly increased number of plates in the friction clutch, and they will be made alternatively of phosphor bronze and steel. The total number of plates in this hub is fourteen, and the added weight 2 lbs. All the hubs before being sent out are subjected to an extremely severe test to prevent any possibility of clutch slip.
The best way to lubricate the hub is to disengage the clutch, and to lubricate on the clutch side with thin lubricating oil such as is employed for push cycles. If this be done the oil will reach the clutch plates more readily.
At the Armstrong stand. No. 33, will be found sections of the gear and other interesting items.
1911 Olympia Show - The Motor Cycle November 16th, 1911. Page 1218
P. AND M., No. 70.
Phelon and Moore, Ltd., Tottenham Court Road, W. – Several interesting improvements have been incorporated in the new model. A front wheel stand is fitted just beneath the crank case, which when out of use springs automatically into position. Last week we described the new foot starting device, the carburetter (the lid of the float chamber of which is held in position by a spring, the sliding back of which allows it to be removed instantly), and the cover for the gearshaft, allowing oil to be squirted into the bearing. An important improvement in the engine is the provision of drilled cylindrical washers between the valve springs and the cylinder, which effectually keep the heat from the springs and allow them to retain their tension for a much longer period. The petrol fillet is not provided with a vent hole, so that splashing is impossible, the vent being on a guide on the needle valve feed to the priming device, which possesses a small groove to allow the air to reach the petrol. The rear brake is improved, and is worked by the rider's heel, the pedal operating the rod, which pulls directly on to the brake band. The front wheel is especially well protected by means of a very efficient mudguard. A variation of the above model is the colonial type, in which all the parts usually plated are black. A larger petrol tank is fitted, extra girders to the forks, heavier spokes and rims, and footrests placed in a higher position, so as to afford an ample ground clearance.
The well-known 2½ h.p. model, which has acquitted itself so well since its introduction, remains practically unaltered except that the B. and B. carburetter is now fitted. The finish of the P. and M. machines is excellent throughout.
1911 Olympia Show - The Motor Cycle November 23rd, 1911. Page 1259
