Pump (shoe)

“ The brass cylinders of many tire pumps are made of thin metal, and a slight blow may dent them. Such injuries interfere with the action of the plunger, making the pump almost useless. A case which will afford protection to the pump is shown in the sketch. It was made of two strips of wood cored out on the inner sides to fit the pump and provided with small hinges and hooks, to lock it into place.
A Feather as an X-Ray Lens
The outline of the bones in the hand may be seen by holding it before a strong light and looking through a lens made of a piece cut from the tip of a feather. ”

“ The pump is usually of the centrifugal type and consists of a fan-shaped wheel operated in a snugly fitted housing. The water enters at the hub and is thrown out against the housing and is forced on by the rapid action of the fan blades. Another type of pump is used by some manufacturers which consist of two meshed gears of the same size, which operate in a snugly fitted housing. ”

“ Thus, if a man acts on M with a force of sixty pounds, the force transmitted by the plunger P will be 300 pounds, and the force which tends to raise the ram will be 3,000, supposing the section of ram is a hundred times that of the pump plunger.
Over-pressure, is prevented by safety-valve shown in front of the pump A. Fig. 146 shows an enlarged section of the pump used in connection with this press. When the plunger P rises a partial vacuum is formed below it and the suction valve O rises allowing the pump barrel to fill with water through the strainer and suction pipe in the cistern. ”

“ As well known, in every well-constructed injection pump, there is a system of gearing which acts upon the suction valve and stops the operation of the pump as soon as the requisite pressure is reached; but the piston, for all that, continues its motion, and, besides the resistant work of the pump has passed through different degrees of intensity, seeing that at every moment of its operation the piston has preserved the same stroke and velocity. We are speaking, be it understood, of pumps that are controlled mechanically. ”

“ Careful experiments on a large number of pumps of various makes at full speed, show that in a new pump with clean valves, and an air-tight suction pipe, and less than 15 feet lift, the actual delivery is only from 11⁄2 to 5 per cent. less than plunger displacement. This slip will increase with wear, and for a good average pump in practical use, probably 10 per cent. is a fair allowance to cover slip, valve leakage, slight short-stroke, etc. ”

“ We suppose that a headed nipple has always been so headed in order that the jaws of the chuck may slip over the head in the coupling and uncoupling operation. The weakness of the respondent's position is well illustrated by what developed at argument. When interrogated as to how in the claimed combination the function of the nipple could be thought novel in any different sense than the function of the pump, counsel replied that the pump performed a novel function because the pressure it generated forced forward the piston in the coupler and caused the movable jaws to engage the fitting. ”

“ Men sometimes ask why, (if they can run a pump smoothly so as to get a delivery of 1,000 gals. per minute,) we should not accept as “a thousand gallon pump,” irrespective of its suction valve area or its exhaust port area or the size of its cylinders.
To this we reply that when new and favorably set almost any pump built according to these specifications can run at a much greater delivery than here rated, but when lift is unusually high or suction pipe long, or when the pump takes its suction under a head, no pump can be run so fast as on, for instance, a 5-foot lift. ”

“ Another reason might be that the pump lowers the suction supply, thus increasing the lift until there is not sufficient speed for the elevation. If the pump works indifferently, delivering a stream obviously too small, it is generally because the pump was not properly primed and some air remains in the top part of pump shell. Unless primed by steam ejector, the pet cock or plug found on top of pump shell should always be open while priming, and the pump must not be started until water flows out of same. ”

“ The safety valve with lever and weight, shown in the cut, are designed to be attached to the discharge pipe to guard against over pressure, which might occur through the closing of valves.
Fig. 483 shows an emergency pump of the Holyoke rotary pattern. It is of the same general design as the one previously alluded to. It is driven directly from the line shaft by friction gearing instead of toothed wheels. The hand wheel attached to the end of a screw is used to press the smaller friction wheel against the larger and thus transmit the power to drive the pump. ”

“ In the semi-rotary pump a lifting force is obtained by means of the see-saw motion of a plunger with two valves working alternately. Another type of high-speed pump consists of two small gear wheels in mesh with one another in an enclosed space, with just sufficient space for their free revolution. ”

“ It is a decided disadvantage to have to move the plunger so far and in actual commercial practice hand-operated hydraulic presses are not worked in that way. A pump is used to force water into the cylinder so that a great many short strokes may be taken in place of one long one, and the pump handle provides an added leverage, enabling a man with little effort to exert an enormous lift. The water enters the ram cylinder through a valve, and the pressure is maintained on the ram until relieved by the opening of an outlet port. ”

“ The indeterminate thing beside the searchlight turned out to be a hand pump, geared to work against heavy pressure. From the suction chamber of this three tubes extended.
"We inhale the air of the chamber," the Professor explained to me, "and exhale through the tubes into the pump cylinder. Breathe in through the nose and out through the mouth. The pump piston is forced down by this geared handle, sending the used air out of the shell through this sixteenth-inch hole. A ball check valve keeps the water from squirting in when the exhaust pressure is released." ”

“ Although this pump from Colonel Thacher was probably around fifty years old, it proved to be a most reliable and excellent piece of apparatus, consisting of a large, horizontal, single cylinder, “make and break” engine, driving a heavy, eighteen-inch rubber diaphragm pump. It certainly puts to shame some of the modern pump equipment of today, chugging along hour after hour like a patient old horse without much noise and clatter. ”

“ The pump shown has a stroke of 14 ins., with an air-cylinder diameter of 28 ins. The machine is a dry air pump, and is fitted with Corliss inlet valves and special leather exhaust valves: it is fitted with ring-oiling bearings and automatic continuous lubrication, and under test it shows a mechanical efficiency of 78 per cent. from power input to air horse-power delivered. Such a pump is suitable for a plant handling 20 to 25 tons per hour and, if preferred, the pump may be driven through gearing from an electric motor on the same bed-plate. ”

“ Both suction and delivery pipes should be of ample size, as the pump works very fast. The pump is mounted on a foot, F, made by turning up the ends of a piece of brass strip, and filing them to fit the barrel.
The bed can be fashioned out of stout sheet brass or zinc. Let it be of ample size to start with, and do not cut it down until the pump is complete. Rule a centre line for cylinder and pump, and mount the cylinder. ”

“ After the pump is in condition (6) , motion of the plunger is followed by a more or less regular discharge of water through the spout, and the quantity of water which gushes [192] forth depends upon the speed with which the piston is moved. A strong man giving quick strokes can produce a large flow; a child, on the other hand, is able to produce only a thin stream. Whoever pumps must exert sufficient force to lift the water from the surface of the well to the spout exit. For this reason the pump has received the name of lifting pump. ”

“ If you do understand the old town pump, I will not have much trouble with you, for while there is no old style wooden pump used on the engine, the same principles are used in the cross head pump. Do not imagine that a cross head pump means something to be dreaded. It is only a simple lift and force pump, driven from the cross head. ”

“ PUMP, [1] a machine which drives a liquid from one point to another, generally at different levels, the latter being usually the higher; an air-pump is an appliance for exhausting or removing the air or other gas from a vessel, whilst a compression pump compresses the air. The simplest forms of pumps employed for forcing liquids are “plunger pumps,” consisting essentially of a piston moving in a cylinder, provided with inlet and outlet pipes, together with certain valves. The disposition of these valves divides this type of pump into suction pumps and force pumps. ”

“ The Double-acting Force Pump is in principle a double plunger pump. The discharge fluctuates from zero to a maximum and back to zero each stroke, but is not arrested for any appreciable time.
4. Bucket and Plunger Pumps consist of a lift pump bucket combined with a plunger of half its area. The flow varies as in a double-acting pump.
5. Diaphragm Pumps have been used, in which the solid plunger is replaced by an elastic diaphragm, alternately depressed into and raised out of a cylinder. ”

“ European centrifugal pumps with their small impellers and consequent high speed of rotation, are especially liable to this repelling action, and very often are wholly inefficient from this cause. One maker who claims a high duty for his pumps, attaches a screw at the sides of the impeller to coax the water into the pump, and the idea is a good one if the difficulty is not otherwise provided for. In this way a pump can be made of smaller diameter for a given duty, but it is commonly inferior to a larger one for the same work.”—Industries. ”

“ Hand screws, with V grip.
Section 29.—CUSHIONING. (See also p. 72.)
2118. Rubber pad or buffer.
2119. Cushion tyre for road wheels.
2120. Cushion tyre, pneumatic. The resistance in this tyre is increased by compression of the enclosed air by a portable pump.
Duplex pumps are cushioned at each end of the stroke by trapping part of the exhaust steam by the piston closing the port.
Air vessels are used to cushion the action of a pump, both on the delivery and suction.
2121. A spring piston is used for the same purpose. ”

“ The general form of the blades is of great importance in this type of pump, because the water is driven through the fan partly by the pressure of the blades on the water and partly by centrifugal force. The ratio which each of these forces bears to the other varies in the same pump, depending upon the proportion the speed bears to the height of it. ”

“ Owing to the very high speed at which these pumps are liable to be run during a fire, all the working parts are made excessively strong, and the valve area and water passages are larger than usual. The interior of each Underwriter pump is treated with a rust-proof coating, and every precaution taken so that the pump will start instantly after an indefinite period of disuse. ”

“ Fig. 163 represents a widely used type of suction pump, it is designed for vessels of not more than fifteen to twenty feet deep; for contractors who wish to pump large quantities of water from excavations, etc.; for irrigation or any other purpose where a compact and capacious pump is desired.
The lever may be worked from three different points as shown by lugs on the illustration. The lever socket is made at such an angle that the bent wrought iron lever when put in one side up, is right for ordinary pumping and by simply changing it the other side up, it becomes a vertical lever. ”

“ The pump consists of a central double-sided impeller 12 in. diameter. The water entering at the bottom divides and enters the runner at each side through a bell-mouthed passage. The shaft is provided with ring and groove glands which on the suction side keep the air out and on the pressure side prevent leakage. Some water from the pressure side leaks through the glands, but beyond the first grooves it passes into a pocket and is returned to the suction side of the pump. For the glands on the suction side water is supplied from a low-pressure service. No packing is used in the glands. ”

“ When a pump fails to start after standing for some time it should be primed by filling the barrel with water and starting the pump slowly. If after priming it fails to raise water, the suction pipe should be examined and also the plungers and the valves. If the plunger packing has become dry and hard, merely filling the water end with water will not at once remedy the trouble because the packing must be thoroughly soaked before it will work properly.
* * *
Pumps should be packed with the same care and consideration as is used with the best steam engines. ”

“ It will be seen, by reference to the cuts, that all of the valves can be easily and quickly examined, and also replaced, by removing the caps that enclose the chambers; all joints required for this purpose are made between flat surfaces planed true, as shown in Fig. 404; gun metal, or other suitable composition, is used and no part of the pump body is subject to wear, either by friction or corrosion. All valve seats are screwed into place, and either these or the working barrels of the pump may be readily replaced with new ones, in case the same should become worn. ”