The Supply Department.
Page 21
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Iron Castings in London.
We have been requested by a correspondent to draw the attention of London readers of this journal to the fact that he has obtained very-satisfactory iron castings— cylinders, brake drums, flywheels, geareases, brake blocks, etc.—from an old-established foundry in the heart of the West End. He says that he has, hitherto, found considerable difficulty in securing quick delivery combined with first-class material in fulfilment of orders to be executed in London. Commercial-vehicle users, of whom the number is now so surely increasing in and around the Metropolis, occasionally require high-grade iron castings at very short notice, and London, in this respect, is none too well equipped with suitable foundries to meet the demand. Jas. Bartle and Company, 236a, Lancaster Road, W., are the owners of the foundry whose work has secured the commendation of our correspondent.
An Articulated Tool-driver.
We have recently been exclusively afforded an opportunity to inspect a unique tool, by the use of which it is possible to operate screwdrivers, box spanners and similar accessories in all sorts of awkward positions. The construction of this ingenious device is apparent from the photograph which we reproduce herewith. It consists, essentially, of an ordinary screwdriver shaft, half-way along which is introduced a pair of small gear wheels,
whose teeth arc of such a shape that the drive may be satisfactorily transmitted through them, although the two portions of the shaft be allowed to assume any angular position—up to 90 degrees—relatively to each other. The geared ends of the shaft, with their respective gear wheels, are enclosed in suitable outer casings, which are linked together as shown in the illustration of the device on this page. The lower end of this tool-driver is provided with the usual form of socket which is, of course, adapted to take a series of different sizes of screwdriver or boxspanner ends. The driving end may be provided either with an ordinary wooden handle or a metal end drilled with tommy holes. The device is made in a variety of lengths and overall sizes, and, by its use, it is quite possible to remove an obstinate nut or screw which is located M an out-of-the-way position, without the necessity of the operator's performing elaborate contortionist feats in order to " get a drive " on to the job. We understand that the inventor wishes either to dispose of his patent rights or to make some arrangement for the manufacture and sale on a large scale of this interesting invention. We shall be happy to place him in communication with any of our readers who are interested in this class of production. Micrometer Gauge for Testing Cylinder Bores.
Two of the illustrations which we give on this page show an extremely useful instrument which has been invented and placed on the market by Mr. A. E. S. Craig, of 23, Loveday Road, West Ealing. It is a small instrument which may be used for all purposes where the diameters of bored chambers, such as cylinders, need to be accurately measured or tested for true parallelism. When applying the instrument to a piece of work, it is only necessary to note that the bulb of the spirit level he at rest in midposition, and the reading may then be taken from a graduated scale; special skill is not, therefore, needed by the workman. The spirit level may be swung round at right angles, and, when in that position, the gauge may be used for the measurement or gauging of vertical cylinders. Of the two contacts, the upper one is a hardened steel bar of definite length (a number of bars, of varying lengths, is supplied with the instrument), whilst the lower one consists of a disc which makes a two-point contact on the are of any circle on which it rests. Thus, when the instrument is pushed into a cylinder, the axis of the two contacts automatically bisect the bore of the cylinder at any desired point, and as the lower contact is of circular form and its axis coincident with the axis of the upper contact, no error is caused should the instrument be moved radially, and horizontally, about the point of contact. A steady rest, which may be clamped on to the mouth of the cylinder, also forms part of the outfit, but it will be found sufficient in most cases to support the outer end of the instrument by hand, whilst the reading may be noted in much the same way as is shown in one of the illustrations where a. workman is gauging a cylinder on a grinding machine, When it is desired to use the instrument for the actual measuring of the diameter of a cylinder, a hardened steel button contact is screwed into the circular disc contact.
The actual movement of the contacts is multiplied 50 times by a long indicating lever, or needle, so that a difference of half a thousandth of an inch in the diameter of the cylinder is clearly shown on the scale. The instruments are now being put on the market by Mr. Craig. and we anticipate that their introduction will he welcomed by many engineers who have experienced difficulty in measuring and gauging the internal surface of cylinders.