Cylinder seal

“ Reisner near Girgeh, and as in an example figured in a Fourth Dynasty tomb at Medûm (fig. 18) . Another method of mounting is shown in a hieroglyph (fig. 19) from a Fifth Dynasty Tomb at Sakkara. Here the cylinder appears to be mounted on a metal rod, the projecting ends of which were fixed to either side of a small 45frame, with a handle in which the cylinder seal could revolve. By holding the handle and dragging the cylinder over the clay to be impressed, the seal would revolve as easily and evenly as a wheel on its axle, and consequently leave a good and firm impression behind. ”

“ They are found in great numbers, being from their hardness well-nigh indestructible. They were generally bored through, and through the hole was passed either a string to wear them on, or a metal axis, to roll them more easily. [V] There is a large and most valuable collection of seal cylinders at the British Museum. Their size ranges from a quarter of an inch to two inches or a little more. But cylinders were also made of baked clay and larger size, and then served a different purpose, that of historical documents. ”

“ At times, when working in isolated places, where repairs cannot be had, and no means have previously presented themselves for testing out the cylinders or the apparatus as a whole, it may be found that the threads or ground seat on the cylinder valve of the regulator which is connected will be in such a condition that a leak is in evidence. ”

“ Drying Cylinders.—These cylinders, by the same firm, for which patents were obtained in 1872 and 1887, are made with concave and convex ends, the latter type being shown in Fig. 44. The cylinder body is made [186] of hard cast-iron, turned and polished on outside surface. The ends and trunnions are of tough cast iron, turned to fit into their places, and there secured by bolts and nuts by a patented method, whereby no bolts (excepting for the manhole) are put through the metal, an unbroken surface is preserved, and the annoyance of leakage through the bolt-holes is avoided. ”

“ When all was ready, and the crowded gathering had formed as well as possible to see the test, Keely turned the valve-wheel leading from the receiver to the flexible tube, and through it into the steel cylinder beneath the piston, and simultaneously with the motion of his hand the weighted lever shot up against its stop, a distance of several inches, as if the great mass of iron had been only cork. Then, in order to assure ourselves of the full 25,000 pounds to the square inch claimed, we added most of our weight to the arm of the lever without forcing the piston back again. ”

“ Williams, “we are going to fit a steel cylinder, nine inches in diameter inside, and closed at the bottom. Within the cylinder there is to be a plunger six and one half inches in diameter. The plunger is going to pass through the stuffing-box at the top of the cylinder, just like the stuffing-box of a steam-cylinder where the piston comes out. The plunger is fully as long as the cylinder, and upon it the elevator car is mounted. Now, when water is let into the cylinder under pressure, it forces out the plunger, raising the car. ”

“ In this combination of machinery there are six essential parts:
First. A metal cylinder, capable of receiving the lead in a fluid state, and permitting it to become set or solid therein, and of great strength.
Second. A piston, which is a solid metallic body, fitted to the bore of the cylinder, to work therein accurately, to prevent the charge of lead from escaping around it, and so connected with a hydraulic press, or other motor of great power, as to traverse the length of the cylinder with a force applied of several tons, to force out the charge of lead not in the liquid state. ”

“ In the interior of the cylinder there are two cones, whose bases embrace the hub of the screw in such a way as to obtain a continuous superposition of the layers of liquid, and prevent bodies in suspension from penetrating between the rubbing surfaces of the bearing. One of the cones is made of iron plate, and is connected with the principal cylinder by four radiating braces and small angle irons, and the other is cast in a single piece with the box of the pivot. ”

“ Small cylinders, such as are carried on motor cycles, are sufficiently cooled by a number of radiating ribs cast in a piece with the cylinder itself; but for large machines a water jacket or tank surrounding the cylinder is a necessity. Water is circulated through the jacket by means of a small centrifugal pump working off the driving gear, and through a coil of pipes fixed in the front of the car to catch the draught of progression. So long as the jacket and tubes are full of water the temperature of the cylinder cannot rise above boiling point. ”

“ Your attention is directed to Fig. 119. This shows a design for a model single-cylinder, single-acting steam-engine. The reader should carefully study each drawing before continuing to digest the following matter. The cylinder L can be made from a piece of tubing. This can be either brass or copper. Aluminum should not be used, owing to the fact that it is difficult to solder and difficult to work with. The piston is made so that it will fit nicely into the cylinder and move up and down without binding. ”

“ It is strong, yet light; there is a good base by which to secure the engine to the hull of the boat. Suitable provisions are made for the bearings of the crank-shaft, also for the valve-face and the cylinder trunnion. So long as these are provided for, the mere contour is of little importance.
Fig. 1 gives a side elevation, and Fig. 2 an end view of the same engine. The cylinder is 1 in. bore and 1 in. stroke. The length without covers is 11⁄2 in., that allows 1⁄4 in. for thickness of piston, 1⁄16 in. for each of the projections of the two covers, and the same distance left vacant at each end. ”

“ The cylinders of an engine take the place of the [Pg 49] muscular system of the human body. In Fig. 21 we have a cylinder and its slide-valve shown in section. First of all, look at P, the piston. Round it are white grooves, R R, in which rings are fitted to prevent the passage of steam past the piston. The rings are cut through at one point in their circumference, and slightly opened, so that when in position they press all round against the walls of the cylinder. After a little use they "settle down to their work"—that is, wear to a true fit in the cylinder. ”

“ One set of patterns and core-boxes will thus produce quite a number of cylinder castings, each being similar in every respect to the other, the process12 being a quick and fairly cheap method of reproduction. Later on the cylinder barrel has to be machined and bored out true to very fine limits by the use of boring tools and some kind of boring machine or lathe. The flanges or flat faces have to be planed true in a planing machine and the valve stem guides and valve seatings must be carefully and truly machined to correct size and shape. ”

“ The sheet brass speedily puts an excellent polish upon the rod, and such a packing is more easily kept, and requires less tallow than where hemp alone is employed. In side lever marine engines the attachments of the cylinder to the diagonal stay are generally made of too small an area, and the flanges are made too thick. A very thick flange cast on any part of a cylinder endangers the soundness of the cylinder, by inducing an unequal contraction of the metal ”

“ A metal cylinder grooved with a continuous square-section thread of many turns to the inch was mounted horizontally on a long axle cut at one end with a screw-thread of the same “pitch” as that on the cylinder. The axle, working in upright supports, and furnished with a heavy flywheel to render the rate of revolution fairly uniform, was turned by a handle. Over the grooved cylinder was stretched a thin sheet of tinfoil, and on this rested lightly a steel tracing-point, mounted at the end of a spring and separated from a vibrating diaphragm by a small pad of rubber tubing. ”

“ Making the Cylinder Slide and Valve.—The cylinder barrel must be perfectly cylindrical and free from any dents. Mandrel-drawn brass tubing, 1/16-inch thick, may be selected. If you cannot get this turned off at the ends in a lathe, mark the lines round it for working to with the aid of a perfectly straight edged strip of paper, 2-13/16 inches wide, rolled twice round the tube. The coils must lie exactly under one another. Make plain scratches at each end of the paper with a sharp steel point. ”

“ Our cylinder is to be horizontal, and the steam to work with equal force at each end. The mode by which we obtain (what I take the liberty of terming) a vacuum is, we believe, entirely new; as is also the method of letting the water into it, and throwing it off against the atmosphere without any friction. It is expected that the engine, which is a 12-inch cylinder, will move with a clear force of 11 or 12 cwt., after the frictions are deducted; this force is to act against a wheel of eighteen-inch diameter. ”

“ The object of the side tube f is to avoid disturbing d when it becomes necessary to refill the cylinder, for when it is once opened to the right degree, it hardly requires to be touched again during a night’s work. In order to arrest the downward motion of the piston at any point, a clamp screws on the piston rod, and can be brought into contact with the cylinder head, as in the figure. ”

“ In the annexed diagram, the cylinder A is furnished with a steam-tight piston, the rod of which is supposed to be connected with the working beam. B represents the pipe which admits the steam from the boiler, the quantity being regulated by the throttle valve c, and the elastic vapour is now passing through the box d d, so that it enters beneath the piston. At the same instant of time, a communication is formed through the aperture m n to the pipe p, which leads to the condenser. ”

“ Two 1/8-inch holes are drilled in this piece as shown in the drawing. The hole at the top is the steam entrance and exhaust for the engine; that is, when the cylinder is at one side steam enters this hole, and when the crank throws the cylinder over to the other side steam leaves through the same hole after having expanded in the cylinder. [62] This cylinder block is soldered to the piston as shown in Fig. 56. The pivot upon which the cylinder swings is then put in place in the hole at the bottom of the block. Solder is flowed around the pivot to hold it securely in place. ”

“ We have now to notice the double cylinder engine constructed by Woolfs, which will be found, by reference to the diagram in the preceding page, to consist of a high pressure cylinder, connected with a condensing apparatus.
A and B represent the two cylinders, in the larger of which the steam is allowed to expand itself, after passing from the high pressure cylinder B. The steam, which in the first instance is of considerable elasticity, is admitted to the cylinder B, by the tube and valve E, and entering the cylinder above its piston, impels it to the bottom. ”

“ When dealing with such materials as malt and grain, it is an advantage to be able to inspect the material entering the receiver, and at least one maker secures this advantage by constructing the chamber of a glass cylinder to which are bolted cast iron top and bottom pieces carrying the necessary pipe connections and discharge valves. ”

“ The axis of the steel cylinder or barrel was terminated by an endless screw composed of twelve threads, above which was placed a small arm of copper, with a steel stud made to fit the threads of the worm, which, by its vertical motion, was continually pushed forward. Hence, if a lever was moved, by a peg placed on the cylinder, in any one revolution, it could not be moved by the same peg in the succeeding revolution in consequence of the lateral motion communicated by the worm. ”

“ There is a smooth iron cylinder set horizontally over a furnace, the heat of which can be nicely regulated. A reel is so placed on each side of it, that the cloth which is rolled round the one, when wound off on the other, is lightly drawn over the cylinder, and comes in contact with its red-hot surface, with just sufficient velocity to allow the loose woolly filaments to be burned without injuring the cloth. ”

“ Early in the liberty engine project it became apparent that one of the great stumbling blocks to volume production would be the steel cylinder, if it were necessary to machine it out of a solid or partially pierced forging such as is used for shell making. This problem was laid before Henry Ford and the engineering organization of the Ford Motor Co., at Detroit, and they developed the unique method of making the cylinders out of steel tubing. ”

“ Each cylinder with piston and piston-rod weighs no less than 38 tons, while each pair of cylinders with its crank, condenser, and air-pumps, forms in itself a complete and separate engine, and each of the four cylinders is so constructed that it can be, at once, disconnected when required, from the other three, so that the whole forms a combination of four engines, altogether complete in themselves, whether worked together or separately. ”

“ The remainder of the holding down bolts may be of iron, and may, by means of a square neck, be screwed into the timber of the keelsons as wood screws--the upper part being furnished with a nut which may be screwed down upon the sole plate, so soon as the wood screw portion is in its place. If the cylinder be a fixed one it should be bolted down to the sole plate by as many bolts as are employed to attach the cylinder cover, and they should be of copper or brass, in any situation that is not easily accessible. ”