D; The Purchase Pi
Page 21
If you've noticed an error in this article please click here to report it so we can fix it.
Department.
Where to Buy your Supplies. 4
Notices of Useful Specialities, from the Factorykand in the Showroom.
Hammered Concentric Piston Rings.
It will be at once agreed that the efficiency of an engine, be it either petrol or steam-driven, depends in no small measure on the fitting of piston rings correctly turned and ground to suit the bore of the engine. The rings must, of course, form with the
walls -of the cylinder a gas or steam-tig4 sliding joint with the minimum amount of .friction ; moreover, it would appear that the pressure exerted by the rings upon the walls should be as uniform as possible. A special make of piston ring, which, it is claimed, conforms in every respect to the above necessary requirements, is made by the patented Faudi process, and is marketed in this country by W. J. Bithell arid Co.., 46; Cannon Street, London, E.C.
As will be seen from our illustration, the rings are of the same thickness throughout' their periphery, and, being machined concentric, are uniformly seated within the grooves of the piston.
The manufacturer has, we understand, specialized for many years in the making of piston rings, and after protracted experiments, has laid down special plant, with which is incorporated a patented system of hammering for the manufacture of the rings. By his methods, it is claimed that the spring action of the concentric rings can, during the process, be reduced to a strict minimum without impairing their tightness; as the subsequent pressure on the cylinder walls is rendered constant and uniform, through the special nature of the hammering plant used hi their construction. Cast iron of a special composition is used for their manufacture, the rings are ground, and as supplied, are ready for immediate use.
A Hub Mileage Recorder.
A fitting which will appeal to many usersof industrial vehicles is the neat form of mileage recorder constructed by the manufacturers of the well-known Bruhn taximeter, whose London offices are situated at 245, Gray's Inn Road, W.C. As its name implies, the accessory is fitted to one of the front hubs, being screwed to the ordinary axle-cap, and requiring no
additional attention when once in place. The naecha nism is entirely enclosed and, if necessary, can hi readily sealed, and all unauthorized use of a vehicle may at once be detected. The recorder shows correctly the mileage in tenths of a mile up to 10,000 miles. It can be fitted to machines running on pneumatic, solid or steel tires, its registering being absolutely reliable in each case. The method of driving the instrument is quite simple ; it merely consists of a small pin screwed into the axle-nut, and this impelling the recorder mechanism. The recorder should be fitted to the off-side front wheel, and when ordering, it is necessary to give the diameter of the road wheel in inches.
A Handy Garage Lamp.
Many lamentable accidents have occurred through petrol and other highly,inflammable material taking fire in garages and on miotorvans owing to the use
of naked lights: ' It essential, even in daylight, for some light to be used when examining certain parts of the under frame. Where garages have electric light installed, it is a comparatively simple matter to connect a hand Lamp and a long stretch of cable to any suitable switch or plug for the use of electric light, and all danger of petrol taking fire is thus avoided when the machine is under examination. Garages not so fitted can very usefully employ the type of lamp illustrated herewith. Brown Bros., Ltd., Great Eastern Street, E.C., sells a. large number of these accessories for garage use. The dry battery fitted is capable of supplying the lamp for a period of 50 hours and at the end of that time can be renewed at the price of a few shillings. The switch on the top enables the light to be cut out when not required. Both battery and bulb are strongly enclosed, and a reliable light can be obtained under almost any conditions. After being submersed in water for a period of 40 minutes, no ill effect was noticed on the lamp when tested at these offices.