THE ARCHIBALD WHEELS FOR FIRE APPARATUS.
We illustrate on this page the machine employed by the Archibald Wheel Company, Lawrence, Mass., in the manufacture of their Improved Metallic Hubbed Wheels. Few of our readers but have seen these wheels, as nearly all the steam fire engines built in the United States within the past five years are furnished with them. We presume, however, that very few may know why they stand the severest Fire Department service, as none others can. Surely nothing but the best stock known can stand what these do, yet wheels of equal quality stock fail where these stand firm. We take pleasure in presenting, so far as we may, the method of manufacture that centers in this patent press, which may be described as follows :
The machine acts to force into close contact the flat surfaces of the spokes at their inner ends, and thus compact them, so that their faces form true circular planes, upon which the inner faces of the hub flanges rest.
It will be seen that the machine occupies space upon two consecutive floors. A strong circular plate of cast-iron about seven feet diameter, having its upper surface faced off true, Is placed horizontally level with the floor of the shop. Arranged at equal distances around its outer edge, are a number of levers, B, equal to the number of spokes to be set in the wheel— sixteen in this case— having their fulcrums securely bolted to the plate. The long arms of the levers radiate from the plate about three feet, all around ; the short arms are formed into cams, or rolling inclines, acting upon sliding-pins of cast-iron, which move freely in a radial direction, in guides formed in the fulcrum-blocks. When the long arms of the levers are raised, the slidingIMPROVED MACHINE EOR THE MAN, pins are pressed outward by a spring until they bear upon the cam-shaped short arms of the levers at the point nearest the fulcrum or centre of motion of the lever. When the long arms of the eversare lowered, their sliding pins are forced inward by the cams, and unite in pressing inward the wheel properly placed in their embrace. The levers are all actuated with rapidity, uniformity and certainty, by means of wrought-iron rods, C, extending downward from the ends of the levers, converging to a vertical column, D, under the centre of the plate, much as the braces of an umbrella extend downwards from the ribs to the stick. A screw is cut upon the central column D, and a nut, E, answering to the slide upon an umbrella-stick, raises or lowers all the levers at once with great facility, and with any required power. Motion is given to the nut by means of beveled gears, and open and cross belts with fast and loose pulleys, so arranged, that, at the upward and downward limits, the belts are thrown automatically upon the loose pulleys and the motion of the nut and levers stopped. Any required motion, either up or down, within the range of the screw, can be obtained with great delicacy and convenience by a shipper, F actuated by a shippingrod, G. The fellies and spokes, having been perfectly shaped and completely finished by machinery, are first put together by driving the spokes into the felly or rim, one at a time j the felly being held firmly in a vise, II, specially constructed to prevent splitting of the felly or twisting of the spoke so that an exact fit is obtained at this impottant point. The fellies, with their spokes, are then placed in the press, when the perfection of the fitting is shown by the perfect joint made by the spokes when they meet in the circle to be curved and embraced by the hub, and by the coincidence of the half-holes in the contiguous sides of the spokes, .4, which together form the holes for the eight bolts that are finally to hold the hub-plates together.
Temporary hub-plates, /—one above, and one below—with a powerful screw in their centre, hold the ends of all the spokes truly in the plane of the circular plate while undergoing the pressure of the levers. The extent of this pressure is ascertained by PACTUKE oe MBTALLIC HUE WHEELS. marking carefully with a j sharp pencil around the circumference of the upper temporary hub-plate after the spokes have been brought to a close, firm joint ; and then the pressure is put on till the joint of the fellies closes up firm. Another similar mark being made, upon removal of the temporary hub-plate it is found that a space of a quarter of an inch is made between the two pencil marks—a reduction in diameter of half an inch. Now, as the difference in circumference corresponding to a difference in diameter of half an inch is 1-5708 inches, this, divided by sixteen (the number of spokes), gives 0-698 of an inch, at substantially one-tenth of an inch, as the lateral compression of each spoke. This is by no means the limit, but is regarded sufficient to secure the spokes against being loosened by shrinkage in any climate, and this pressure is what gives this wheel its enormous strength and durability.
The hub, 0 0, is firmly bolted together while the wheel is In the press,and holds the spokes securely, the bolts fitting snugly in both spoke and hub. The fellies spring apart a little when taken from the press, but only a little ; and the tire easily makes that all firm again.
So great is the facility with which this machine is operated, that one man with an assistant easily puts together a set per hour, including the time of adjusting machinery for the difference in diameter of the wheels.
The great point in this wheel made in this manner is the thorough compactness of the hub-end of the spokes, though the other end of the spokes and the joints in the fellies receive scarcely less benefit. By observing an old wheel it will be seen that the spokes are bedded into the fellies and hub. This is done by degrees, and is unavoidable in wheels made in the usual way. The only way to keep such a wheel together is to reset the tire, so as to take up the looseness caused by the slow crushing and grinding process. This is all prevented in the Archibald process of manufacture, by putting on a pressure at every joint, of more than ten times the amount the wheel will ever be called upon to sustain in actual use, and at a time when the wheel is so held as to receive this pressure without possible injury to it. One tenth of this pressure from a tire would ruin the wheel, but the tire when properly put on will hold all this pressure and remain on tight until worn out. The hub holds all the pressure of the spokes within it independent of the tire. Wheels made by this method are perfectly round and true. The pressure distributed about the rim can be varied from nothing to 100 tons asrequired. We cannot here describe the manifold other machines and processes employed in preparing with the utmost care and accuracy the several parts of the wheel, before it is assembled within the press, but we think from our knowledge of the comeliness of the wheel—its mode of manufacture and its practical working for years in the severest service known, that it is the best mechanical and most perfect method of constructing’wheels for heavy and severe work yet devised. These wheels are used on every conceivable kind of heavy vehicle, and in all parts of the country.
A represents the Axle. B is the Hack of Hub which is also the Axle Box. C is the front or Loose Flange. D Bolts through Spoke and Flanges. F. F. Spokes. F Brass Cap. G Axle Nut. II Small Screw to be removed to Oil the Axle. / Axle Collar.
These Hubs are fitted to the various sizes of axles used on Amoskeag, Ahrens, Babcock, Clapp & Jones, Jeffers & Co., Silsby, La France, and Cole Brothers Steam Fire Engines and other Fire Apparatus made by these manufacturers.