A Brief Word
Fig. 1. Theoretical card of 4 stroke cycle gas engine
Since this column is being prepared somewhat ahead of the usual deadline, we did some searching through our literature collection, and offer some interesting articles to our readers this month. The first article is a treatise on the Buckeye double-acting tandem engine. This came from the November 1, 1908 issue of Practical Engineer. In reading this over, it becomes immediately obvious that gas engine design was well developed by this time, even though the practical four-cycle engine had been developed some thirty years earlier. Unfortunately though, this article says virtually nothing about the horsepower range and sizes of the Buckeye.
This term, 4 stroke cycle, signifies that 4 strokes are required to complete the action for the engine. The first stroke is occupied with drawing in a charge of air and gas is called the suction stroke. On the second this mixture is compressed and near the end ignition occurs. During the passage of the crankpin past the dead center the combustion or explosion takes place. During the third stroke the expansion of the hot gases is accomplished and during the fourth stroke the burned gases are exhausted from the cylinder, the series of events being as indicated in Fig. 1.
The requirements in arranging the gas engine are that the cylinder shall drain thoroughly, that the exhaust and admission valves shall be kept well apart and shall be so located that the exhaust stroke of the piston will drive out practically all the burned gas from the cylinder. These requirements are met in the Buckeye engine by placing the admission valves at the top and the exhaust valves at the bottom, as shown in Fig. 2. With the exhaust valves at the extreme bottom, oil and other deposits pass out directly through these valves. The incoming charge at the top is not mingled with the burned gases remaining near the exhaust valve in the bottom, and both exhaust and admission valves are placed so that they can be gotten at conveniently for cleaning and inspection.
For small sizes the working barrel is continuous from end to end, but the water jacket has an opening entirely around the circumference, this opening being closed by a cast-iron band drawn tightly around the cylinder. This construction allows of expansion and contraction with varying temperatures without causing strains in the structure. For larger sizes the cylinders are made in halves bolted together in the center.
The main frame of the engine is anchored firmly to the foundation but the rest of the machine is left free to move on fixed guides on cast-iron bases, as shown under the center distance piece and the slide for the rear tail rod.
Ignition and Governing
While theoretically under perfect conditions the firing should be done on dead center and the propagation of flame instantaneous throughout the combustion chamber, actual retarding of this spread of flame by the cool metal of the cylinder walls and the imperfect mixing of gases makes it desirable to have the firing line slope about 5 deg. forward. Compression in the Buckeye engine is kept practically uniform from maximum load to about 0.25 load. From 0.25 load down to no load the ingoing charges are slightly throttled. The valve gear has no sliding or piston valves, so that there is no sticking or clogging. All valves are of the poppet and butterfly type.
Mixing of the gas and air supply is produced as follows:
At maximum load the quality of the mixture is such as to give highest mean effective pressure with a maximum amount in volume and maximum compression. As the load falls off, the mixing apparatus automatically weakens the charge by admitting less gas until the load has decreased to about 0.25 the maximum. After this the charge is no longer weakened but the incoming charge is throttled so that a smaller weight of the mixture is taken.
The engines are designed to operate with either jump or make-and-break spark, the electromagnetic make and break system being the one recommended. In this system the current from any source, such as a storage battery or dynamos, operates the igniter mechanism by means of an iron clad electromagnetic hammer, the circuit being completed and the time of ignition controlled by a timer, which is so set that the governor brings the ignition earlier on light load and later on heavy load. The timer is so arranged that all igniters can be adjusted simultaneously by hand or each igniter can be adjusted independently. In this way it is possible to keep the slope of the varying line practically the same for all loads.
Exhaust valves on all engines are water jacketed and for all engines above 11 in. diameter of cylinder the piston heads and rods are water cooled so that high compression may be used under all conditions. Engines for direct connection to electric generators are rated to allow from 15 to 25 percent overload capacity. For belted engines an allowance of 10 percent is made.
The guides are bored and bolted to the cylinders, making the structure practically one single piece. The main journal bearing has babbitted quarter boxes with wedge adjustment and the crosshead is a steel casting threaded to receive the piston rod, split and clamped on the rod by means of through bolts. The crosshead shoes are steel castings with a swivel connection to the body of the crosshead, adjusted for wear by eccentric bolts.
The pistons are carried by the crossheads, the tail rod being carried through the back cylinder head for this purpose. The pistons are appreciably smaller than the working barrel, so that no weight is carried on the cylinder walls. Tightness is secured by the use of a number of packing rings for each piston under slight tension, this having been found more serviceable than few rings under high tension.
Crank disks are of the fan tail type, the engines being side crank in arrangement, and are properly counter-weighted to balance the reciprocating parts. The cylinder heads are large, simple in construction and arranged to be water-cooled, the joint between cylinder and head being made by means of a copper strip which is fitted permanently to the head.
Valves are all driven from a lay shaft which is placed in the horizontal plane passing through the center of the engine. This shaft is driven by a set of steel gears, one of which is mounted on a drag shaft driven from the main crankpin by a universal joint, a construction which insures smooth running, even though the main crank shaft and drag shaft are not in perfect alignment. The governor is driven from the drag shaft by beveled gears.
Each cylinder, cylinder head, exhaust bonnet and exhaust valve is water cooled by its own independent system of water circulation. In the double-acting tandem engines, such as shown in Fig. 2, the cooling water enters the rod through the intermediate crosshead, the stream dividing and leaving the rod at opposite ends, draining through slots in the bed and rear stub end.
Engines are started by the use of compressed air, the usual method being to use a friction clutch so that the engine is started without load. In some installations where it is necessary to do so, the engine can be started under full load and the starting valves will operate automatically until the engine begins work when the compressed air is shut off.
Each engine is furnished with an indicator which at the same time serves to convey oil to the crosshead pin.
Besides the double-acting tandem engines the Buckeye Engine Co. builds single cylinder single-acting and double-acting engines and single-acting tandem engines. The single cylinder single-acting engine is built up to 300 hp. The double-acting engine is practically the same as the first cylinder of the tandem engine. The single-acting tandem is of the trunk piston type and is completely equipped with the improvements which are employed on the largest 4-cycle engines.*
Quite often we get inquiries about the hydraulic ram and its operation. In fact, we know of a few engine collectors who have also been collecting old hydraulic rams. They're quite scarce today, and oftentimes having one and knowing how to make it work are indeed two different things! This article is self-explanatory, in that it illustrates the principles of the hydraulic ram, how it is installed, and how it is started. We hope this might be of help to those interested in unusual and unique mechanical devices.
The hydraulic ram is the simplest mechanism for the elevation, and forcing of water from a given height to another, and is one of the most efficient motors operated by water for this work. The parts are few in number, simple in construction, not liable to' derangement, and the ram requires little attention.
Construction and Operation
The hydraulic ram consists of a supply pipe through which the water enters the ram; the discharge pipe 2, is connected to a suitable opening at the base of the air-chamber 5, which conveys the water to the desired place. The waste-valve 3, allows the stroke of the ram to be regulated, and also allows of an overflow to start the body of water in motion, and develop necessary power to operate the ram.
The check-valve 4, retains the water after its passage through the air-chamber 6, into discharge pipe 2. The main chamber 5, is the receptacle into which the water enters. The air chamber 6, is to allow the entering air to rise to the highest point, and being compressed, cushions the impact of the entering water. The air also assists in reversing the direction of flow of the column of water, prior to each stroke.
The operation is as follows: the valve 3, being open, the water from the supply pipe, entering under a head, flows into the main chamber 5, and out the waste-valve 3. This continues until the velocity of the entering water is sufficient to close the waste-valve 3.
At the instant the flow through the valve 3 stops, the inertia of the moving column of water produces the so-called ramming stroke; that is, it opens the check-valve A, compressing the air in chamber 6. The water during this time passing out the discharge pipe 2 to the desired point.
This continues, until the air pressure, plus the pressure due to the head of water in the main, is sufficient to overcome the inertia of the moving column of water in the supply pipe 1, when the check-valve A closes.
The water in the supply pipe 1, moving backward, with the closing of check 4, tends to create a partial vacuum at the base of the supply pipe 1, in the chamber 6. The partial vacuum causes the check-valve 3, to open, when the preceding cycle of operations is repeated indefinitely.
At the instant the partial vacuum is formed, a little snifting valve opens inward, admitting a small volume of air, which on the following stroke, passes into the air-chamber 6. The admission of air at this point is necessary, otherwise the air-chamber would fill with water, since the water gradually absorbs the air.
The loss in a hydraulic ram arises from water friction, resistance offered by the check-valve, from loss of water during and after the closing of the waste-valve 3. This loss is variously calculated at from 15 to 25 percent, depending upon the construction and adjustment of the waste-valve 3.
When the waste-valve 3, begins to close, there is resistance offered to the entering water; and from that time, until the check-valve 4 opens, no useful work is performed: The water escaping during this time is wasted.
First, place the weight X, over the center of the rod used to balance the waste-valve 3, securely fastening it. Then raise and lower the valve stem lever, by means of the nuts on the stem. This regulates the opening of the waste-valve 3, and graduates the volume of water used and delivered by the ram.
The greater the number of strokes the ram makes in a given time, the less the volume of water delivered.
The smaller the number of strokes, the greater the volume of water delivered in a given time.
When a large quantity of water is to be elevated, or forced a reasonable distance, the ram should be placed at a level of 2 or more feet below the surface of the water supplying the ram. A suitable drain must be provided to carry off the water used as power in the ram.
The ram should be set level both ways, on a firm foundation of sufficient area to prevent settling. The drive pipe, or pipe supplying the water, should be laid on a straight incline, without bends, except where it enters the ram. The pipe should be submerged at least 1 ft. in the water to prevent the admission of air; a good strainer should also be secured to the upper end of the pipe. In practice, if the drive head is small, a larger pipe should be used than where the head is greater, to reduce the friction. For ordinary conditions the head of the water to the ram should not exceed 12 or 15 feet. If the head is greater, it must be reduced.
The delivery pipe can be laid with bends if necessary, care being taken to have all bends of large radius.
Finally, since we're into the 'engine operating season' now, we've culled some diagrams under the heading of Electric-Ignition Apparatus for your perusal and possible application. For some of us, this information has been long since committed to memory. For many others, especially those who are relatively new to our hobby, it seems quite complicated. Figure 1 shows an ignitor block with all of its parts properly named. Figure 2 demonstrates the usual method of hooking up a low tension ignitor to a battery and coil. One of the problems frequently encountered is with the movable electrode. If it binds, the return spring may not pull it back properly. Also, if the shaft binds the electrodes will not make that quick break necessary for a big fat spark.
Over the years we've heard about all the tricks imaginable for ignition batteries. . . all the way from using old Polaroid batteries to getting old batteries from a salvage yard that had a little life in them. Long ago, we abandoned lantern batteries and what have you, in favor of small lawn mower or motorcycle batteries. Perhaps some will disagree, but we have found that a decent 12 volt battery eliminates most of the ignition problems. While some companies originally used four dry cells (6 volts), many of them used five cells for 7 volts, and many others used six cells to give 9 volts. We've concluded that by going to 12 volts, the ignitor points stay clean longer, and that high-compression engines run better.
Figure 3 illustrates the usual connections for a high tension system. In this instance, the need is imperative for a good battery, otherwise the spark is simply too weak. Even though a particular system might show a good spark in open air, when under compression, it takes a lot more voltage to push that arc across the points. There are few better illustrations of this than with the Cushman engines. They used a rather high compression ratio compared to their contemporaries. Trying to get one of these little engines to run under a load with a poor battery is about impossible. It's been our experience that using a 12 volt battery with these engines smooths out problems like nothing else. We still like to use those old Ford Model T spark coils. They're very hot, they're quite dependable, and they're fairly easy to locate.
Our first query this month is:
29/7/1 Foos Engine Registry
Preston Foster, 3231 Randolph St. NW, Warren, OH 44485 is building a registry of Foos engines. If you are a Foos engine owner, kindly send along the horsepower, serial number, pedigree if known, and other pertinent information to Mr. Foster.
29/7/2 What Color Did It Have? Q. It seems to me that most of your readers are most concerned with 'What is It?' and 'What Color did it Have?' I will admit these things are necessary when restoration time comes around, but I have not seen many engines you can make run with paint, un-less you use a lot of thinner. . . NOT RECOMMENDED! Anyway, perhaps? a nice little booklet at a fair price, listing color matches. And as for 'What is It?', stress the importance of attending as many shows as possible in search of identification. The knowledge, sometimes firsthand, would fill volumes.
Second, I being an Agrarian. . . Indus' trial Archaeologist, find that a lot of engine collectors have at least one steam related device which does not fit the normal coverage afforded a train, traction engine, or a pump house engine, yet these devices were just as important. Speaking of live steam, did you know your ultra-modern coffee maker was patented in 1698 by Thomas Savery (English) as a steam water pump for the raising of water from coal mines? And duplex pumps abound, and a large number have improperly set valves causing short stroking and slippage. I guess I'm asking if you could include some friendly technical tips in your magazine if some were submitted.
I'd like to offer the following diagram of the Witte ignition. This may come in handy for anyone having a volume governed engine with a dead magneto. I have a 1923 2 HP that I converted when the Bosch began malfunctioning. If you have a buzz coil you're all set, if not, a regular 6 or 12 volt coil will work. Also you need a capacitor to match the voltage of the coil. I used 12 volts. The trick when using an automotive coil is to adjust the timer blade to break contact with the cam lobe just as the word 'Ignition' on the flywheel is aligned with the wooden block pictured. The normal setting for a Witte of 5 HP is 40 degrees before TDC, almost all other engines are 20 degrees before head end TDC. The method of connecting the coil, capacitor, and timer (the timer block must be a non-conductive material) is to connect the low tension wire from the coil to the ground side of the capacitor, connect the negative side of the battery. Connect the insulated wire of the capacitor to the negatively marked post of the coil, the timer connects onto this post too. Then all that is left to do is connect the positive wire from the battery to the knife switch and then on to the positive post of the coil. When you put all this in a nice ignition box like the ones advertised in GEM, you'll have a show-ready engine that runs too! Howell T. Mauney, 1170-D Golfview Dr., Carmel, IN 46032.
29/7/3 Ironton Engine Company Q. I am trying to locate any information concerning the Ironton Engine Company which operated in Ironton, Ohio from the early 1900s until just after World War Two. It is my understanding that they manufactured various types of small engines over the years. Any information would be appreciated. Jeff Hood, 703 5th Avenue, Huntington, WV 25701.
29/7/4 F-M Eclipse Engine Q. I have an Eclipse No. 2 engine, s/n B16436. B51 the serial number lists, that would put it prior to 1911, yet cast in the hopper is Mar. 17 -14- If a sixth digit was unstruck, the s/n list would put it at about 1915, which would fit all the other criteria. Also, what is the significance of the 'B' prefix in the s/n? Modie Driskill, HC 89, Box 50B, Eden, TX 76837-9303.
A. We simply cannot tell you the significance of the letter prefix. However, having studied the F-M records to some extent, we would suggest that this engine might have been built as part of a special run outside of the normal production run. That would account for the unusual serial number.
29/7/5 Information Needed Q. What is the year built of a 1 HP Clinton engine, Model 703ABR6, s/n CC58587, 3200 rpm; also who is the manufacturer and year built for a 1 HP Montgomery Ward engine, Model RSC591, s/n 6-67005, Catalog No. 87-5131H, 2300 rpm. Gary Radue, 14123 April Lane, Warren, MI 48093.
A. We have no information on either of these engines.
29/7/6 Christensen Air Starter Q. Can anyone provide information on the Christensen air starting system made by Christensen Engineering Company, Milwaukee, Wisconsin? It has a 1916 patent date. This is an air-start system as used on Hall-Scott aircraft engines. Also would like information on Nordyke & Marmon of Indianapolis, Indiana, as a licensed (?) manufacturer of Hall-Scott products. Bruce Hall, Rt. 90, King Ferry, NY 13091.
A. We're not sure of how extensively the Christensen air-start system was used. It was, as you note, used on the Hall-Scott aircraft engines, but we aren't sure whether it was applied to other engine types, particularly the diesel. We have an extensive run of Compressed Air Magazine, but perusing these pages is beyond our timeframe for this month. Christensen Engineering was heavily into the development of air-brake systems and other compressed air applications. Their sideshaft engines were built for a few years, but were definitely a sideline to their activities in pneumatic equipment. Nordyke & Marmon made their early history in manufacturing flour milling equipment. Eventually they branched out into other areas, such as the Marmon automobiles, an ill-fated adventure.
29/7/7 Woodpecker Engine Q. I'm rebuilding a Woodpecker engine made at Middletown, Ohio, and would like to hear from anyone with information on the proper color, striping, logos, etc. Ronald McCleary, RR3, Box 446, Hollidaysburg, PA 16648.
A. If you can be of help, kindly drop Mr. McCleary a line.
29/7/8 Lansing Company Q. See Photo 8A of a cement mixer made by the Lansing Company. The s/n on the engine house is No. 1742 Lansing, Mich. 4-B. The engine (Photo 8B) also says: Lansing Company, Lansing, Mich. No. 114484, Speed 500. The HP was not stamped. The engine looks like an Alamo. If any one has any information on the engine or on the mixer, I would appreciate it. O. H. Friesen, 7243 West Titan Rd., Littleton, CO 80125.
29/7/9 Bessemer Engine/Compressor Q. Nicholas Bettevy, 1685 Hwy 452, Marksville, LA71351 has a Bessemer vertical engine/air compressor. It was a starting engine for a larger engine and is No. 138X, Series 1, 4 x 5 bore and stroke on the engine, and 3 inch bore and stroke on the compressor. He would like more information on this unit. If you can be of help, please drop him a line.
29/7/10 Elgin Red-E-Motor Q. See the photos of my HP Elgin that is now ready to run. This is the smallest of the Elgin line with a bore and stroke of 1 x 2 inches. That is smaller than some model engines. By the small amount of wear on the internal parts I would have to believe that horsepower would no do much more than turn the flywheel to cool the Redemotor. I would like to contact other Elgin or Maytag HP owners to obtain a copy of an owners manual. Robert Seibert, 3280 S. Academy, #68, Colorado Springs, CO 80916.
29/7/11 F-M 10 Horsepower 'Z' Q. See the photos of a 10 HP F-M engine. It is on a grist mill that belonged to my grandfather on his Kentucky farm. The mill was run regularly and was a local gathering place; some of the young boys that helped him operate it are still in the area. A one-in-three sacks tariff was charged to neighbors. The farm and mill are still in family hands, and we are trying to rework the mill for a display and demonstration unit.
Is a manual available for this engine? Will it have specs such as bore, stroke, weight, original cost, etc.? Can I find out who sold the engine, etc.? Any information will be appreciated. Don Young, 285 Milford Pt. Dr. , Merritt Island, FL 32952.
A. Our book, Fairbanks-Morse: 100 Years of Engine Technology, capsulizes most of the information we have on Fairbanks-Morse engine. Although we have some specific information, we do not have a lot in the way of specifications. Most Fairbanks-Morse advertising did not include the bore and stroke data.
29/7/12 Standard Separator Engines Q. I have a Standard engine as shown on page 479 of American Gas Engines. It is a four-cycle, but has no crankcase oil supply, only a drip oiler on the side of the cylinder head. Could someone explain the lubrication of the crank pin and the main bearings? Any information will be appreciated, as well as some clue to the original colors. Dick Morine, 7812 Evans St., Omaha, NE 68134.
29/7/13 MECO Engine Q. What is the year built and the color for a 2 HP MECO engine, s/n A1698? Also the year built of a 2 HP Alamo, s/n 115415? Thank you. Gerry Canright, E1622 North Crescent, Spokane, WA 99207.
A. The MECO was shipped in October 1930, but we have no further information. There are no s/n lists for the Alamo line.
29/7/14 Collis Engine Q. We are restoring a Collis engine and would like to have any available information. Lawrence L. Schuldheisz, 851 Doss Ave., Orlando, FL 32809.
29/7/15 Huber Company Q. Is the Huber Company still in business making road equipment? Any information would be appreciated. Jim Luper, 5430 Voice Rd., Kingsley, MI 49649.
29/7/16 New Way Restoration Q. See the photo of a restored New Way engine. It belonged to my grandfather. Some 20 years ago it was torn down and he gave it to my father. He did some work on it, lost interest, and it sat in the back comer of his basement. Last summer I began work on the engine, put it on a cart, and as my father can best recall it has been 40 years or more since the engine last ran. While it is running, it leaks oil out of each side of the flywheel shaft and oil was forced up to the top of the drip oiler. Is this because of too much oil? Thanks for any help you can provide. Richard J. Fry, 563 Ridge Road, Ontario, NY 14519.
A. We don't have a New Way, but would guess that the oil level is too high. Those experienced with these engines will hopefully give you some advice in this regard.
29/7/17 Minneapolis 27-42 Tractor Q. This is my second query on a Minneapolis 27-42 tractor. I need to know the proper color, the striping and size on the fuel tank and fenders of this tractor. Also what words are on the fuel tank, and are the wheel spokes striped? David R. Aikens, 12985 Rt. 5 So., Waterford, PA 16441.
29/7718 Cushman Man Wanted! Q. Would the man that came to the 1993 Waukee Swap Meet with a Cushman two-cycle marine engine contact me? C. C. Burns ,39010 Plum Creek Rd., Osawatomie, KS 66064. (Also see ad in the June 1994 GEM).
29/7/19 Two Recent Finds Q. See 19-A illustrating a Fairbanks-Morse electric plant. It has a two-cylinder flat-head engine by Onan. Do you have any information on this?
Photo 19-B shows an Ottawa Buzz Master. It is self-propelled by a Wisconsin 7 HP engine. Any information on this unit would be appreciated. Wayne Rogers, 10076 Quail Run Road, Tyler, TX 75709-9761
A. During the late 1940s and early 1950s Fairbanks-Morse marketed equipment built by other firms, usually with the F-M logo. Even within the present company, there seems to be little information as to these activities. We have no information at the Ottawa, but we'd bet this one is a safety engineer's nightmare!
In regard to the engine pictured on page 4 of the April 1994 GEM, this is a 1940 American Bantam engine. It was built by the American Bantam Car Co., Butler, PA. This firm started as the American Austin Car Co., and built cars from 1930 to 1934 under license from British Austin Car Co. Production closed in 1934, and the company was later purchased by Roy Evans of Palm Beach, Florida, who recapitalized. Production of Bantams was started in 1938 with a redesigned engine with two main bearings, until 1940 when the three-main engine was produced. This is a 3-main babbitted engine with the same basic design as previous engines. Note the hex bolt head below the carburetor which is the retainer for the center main. It was originally equipped with a Zenith Model 61A5 carburetor; the number is located on a round tag above the float bowl. The transmission was a T-84 from Borg-Warner.
There are two clubs in operation connected with American Austin and Bantamthe Pacific Bantam Austin Club, and the American Austin/Bantam Club, whose 'Club News' is published by Bob Brandon, 499 No. Duffy Rd., Butler, PA 16001.
At one time I owned several Austins and Bantams and numerous engines. I still have one Bantam 3 main. Incidentally, this is the company that designed and produced the first Jeep for the Army in 1941. However, it didn't use this engine. Everett Kroll, PO Box 727, W. Yellowstone, MT 59758.
Regarding Mr. Cawley's query, I have a small Maynard from Charles Williams Stores. It is s/n W8592 with a 3 x 5 inch bore and stroke. It has 16-inch flywheels and a Remy magneto. There are two soft plugs in the bottom of the water jacket. The magneto bracket has WA-1 and below the name on the hopper is cast TA-4. The paint seems to be maroon, with the name and the striping in yellow. John Supple, RD 5, Mullen Rd., Fulton, NY 13069.
The April Mystery Engine
This (Photos RW-1 and RW-2) is a complete engine the same as in the April 1993 GEM, pages 9 and 29. These engines were built for Montgomery Ward by Nelson Bros, and sold under the Sattley name. Shown here is a 2 HP model, with a speed range of 1200-1800 rpm. Carlton B. Kolstad, 5595 Olson Rd., Ferndale, WA 98248.
A Closing Word
Somewhere in our travels we acquired a little book entitled Pumps and Hydraulic Rams by Paul N. Hasluck. Within this 1909 title is the only reference we've ever seen on how to make pump leathers. While we suppose there are yet a few places where they are available, we thought it interesting that this information was set into print many years ago.
We also ran across some information about excelsior (those fine wood ribbons that formerly were used for packing) and how it was made. Now we think a model of an excelsior machine would be just the ticket. Is there anyone out there who has one of these machines or knows anything about them? If so, let us know!
As the efficiency and satisfactory running of a pump largely depends on the proper packing of the bucket, and as cup leathers are almost exclusively used for this purpose, too much stress cannot be laid on the necessity for having leather of the best quality only, and using it so that the fibres may not be unduly stained in pressing.
For making cup leathers, metal moulds and stamps, or pistons, will be required. If only a few cup leathers are to be made by a rough method, very hard wood moulds may answer instead of metal. The cups are made of the best oil-dressed leather, 3/16 inch or inch thick, steeped in warm water at about 180 degrees F., and each is forced gradually into the mould by means of a bolt and nut, and left till it is again hard. The leather should be cut out of the back in preference to the belly or limbs of the hide. If desired, the leather can be planed down to ? inch. The flesh side should be outwards. The leather should be cut circular, the diameter being the diameter of the pump plus 1 inch to 3 inches, according to the size of the pump, to form the cup sides. The leather is placed on the mould as shown, and then slowly forced down with a lever, screw, or other mechanical appliance. A different mould must be used for each size of pump. The center of the bottom is cut out after the leather has been pressed and the top edges of the cup are trimmed.
Figs. 42 and 43 are section and plan of a moulding press. A is a cast-iron mould, with a recess bored to the outside diameter of the finished cup, and on the outside are the two lugs B to screw the press to a bench or table, two ? inch holes in the bottom of the mould allowing the air to escape while the leather is forced down. The center of the mould takes the ? inch bolt C; D is an iron block turned to the inside diameter of the finished cup. A piece of leather is shown forced into shape.
Fig. 44 and 45.Sections of Pump Cup Leathers and Buckets.
Dress the cups after moulding with the following: Four parts of best linseed oil, 2 parts of olive oil, 1 part spirit of turpentine, 2 parts of castor oil, part of beeswax, and part of pitch. Boil these together over a gentle fire in an earthenware vessel, and during ebullition dip in the leather, and let it remain in for a few minutes, fifteen minutes being sufficient for thick leathers.
If the leathers are required to be hardalmost like vulcanite, when finished, use the ordinary best sole leather, and soak it for three days in a bath composed of slaked lime 3 lb., to 1 gal of water. Then pass it through water heated to about 180 degrees to 190 degrees F., and while hot press it in the mould. The finished cups may then be dressed with the hot lubricant.
To understand the requirements of a suitable leather for pumps, an investigation of the action going on in a pump barrel is necessary. Fig. 44 is a section of pump leather and bucket, the cup leather being indicated by the thick black line. Assuming that the bucket is making its up-stroke, the water above the bucket will press the ends of the leather against the inside of the barrel, making a perfectly water-tight joint. There will be a certain amount of friction between the leather and the barrel:
The greatest friction will be at the point indicated by the arrow, the amount of friction depending on the pressure and the quality of the leather. Cup leathers at this point should be well supported, as shown by a clamping ring, which should be a good fit in the barrel, with just sufficient clearance to allow the bucket to work up and down freely without side play. Some cheap, badly designed pumps have this clamping ring much too small, there being in some cases as much as inch clearance between the bucket and the wall of the barrel; many have even more than this. With such pumps, the leather, not being supported at the point of greatest pressure, after a little time is forced between the bucket and the barrel, which ultimately jams the bucket on the upstroke, often to such an extent that it is impossible to move the bucket either up or down without exercising great force. This fault is shown on the left-hand side of Fig. 45. Another important point is the depth of the leather. With leather too deep, the top edge bends inwards, as shown on the right of Fig. 45, and the water gets between it and the barrel wall, forcing the leather away instead of making a perfectly water-tight joint.
The following table of thickness of leather and depth of cup for different diameters is based on experience, and if followed will give an ideal cup for lifts up to about 100 ft.
Cups of these dimensions make a perfectly water-tight joint, and the friction is reduced to a minimum. Fig. 46 shows the proportions of thickness T, depth D t, and diameter D of a 3-in. leather.
There is no advantage in having a deep cup, and undoubtedly a shallow leather is preferable. It works better than a deep one, and in moulding considerable less strain is required. Consequently the fibre at the sides is much stronger. With a deep cup the fibre is practically destroyed in pressing, on account of its having to be pressed to a greater depth than is really necessary.
It should be borne in mind, when pressing, that the pressure should be evenly distributed over the leather. This is impossible when employing a rough-and-ready method of pressing. To obtain an even pressure all over the surface of the leather, the pressure will have to be applied at the center, as shown in Figs. 42 and 43, these indicating the method generally employed in the manufacture of cup leathers.
Some people prefer cup leathers with the skin side outwards, and others with the flesh side outwards. Cup leathers with the flesh side outwards last longer, and make a more perfect water-tight packing; this is no doubt due to the outer stronger fibres of the leather not being worn away, as is the case when the skin side is outwards.
When putting in a leather, it is very important that it should be well lubricated with tallow, which should be well worked into the leather with the hands. Another way of lubricating is to soak the cup in neats-foot, sperm, olive, or castor oil, for some time before putting in. In no case use mineral oil, as this will make the leather rotten and pulpy.
Ordinary machine oil is largely composed of mineral oil, and therefore should not be used to lubricate the leathers.*
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