US1084847A - Steam-pump. - Google Patents

Description

K. DOUGAN.

u STEAM PUMP. APPLIOATION FILEDv JAN. 1s, 1909.

Patented J an. 20, 1914.

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i? Q NT KENNEDY DOUGAN, 0F MINNEAPOLIS, MINNESOTA.

STEAM-PUMP.

Application filed January 16, 1909.

To all whom it may concern Be it known that I, KENNEDY DoUGaN, a citizen ot' the United States, and resident ot' Minneapolis, county ot' IIennepin, and State ot Minnesota, have invented certain new and useful Improvements in Steam-Pumps; and I do hereby declare the following` to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of this invention is to provide a direct acting` steam pump in which steam may be expanded in such a manner that the etliciency will be equal to that of the best type ot fly-wheel steam pump.

In the invention herein disclosed the excess of steam pressure at the beginning oit' the stroke is utilized to give velocity to a long column oi water which said column ot water gives out the energy stored therein, after the steam pressure, owing to expansion, has fallen below the resisting pressure, which is practically making a column of water answer the purpose of a ily-wheel. That is to say: the acting 'force in excess of the resist ing force in the early part ot the stroke is absorbed by the column ot water in the form ot increased velocity, and the energy thus stored causes the column of water to continue moving forward after said acting` force becomes less than the resisting' torce.

The invention consists mainly in providingl a double action pump of such construction that a long column ot' water can be used to absorb and give out energy at each stroke.

The invention consists furtlier in the arrangement and proportions of the water induction and eduction pipes, in combination with certain governing means claimed broadly and specifically in my copending application executed on even date herewith.

In the accompanying' drawings-Figure 1 is a diagrammatic. view, in vertical longitudinal section, ot' a steam pump embodying this invention; Fig. 2 is a detail view oit' a part ot the steam valve gear, viewed in the opposite direction from that 01:' Fig. 1; Fig. 3 is a detail section of a lost-motion device or slip joint in the valve gear.

In the construction shown, the pumping is done in a cylinder, 100. rl`hc water induction and eduction pipes are connected to the open ends of said cylinder 100. This feature is important, as it provides the reest possible path 'for the water entering Specification of Letters Patent.

Patented Jan. 20, 191,4.

semi No. 472,670.

and leaving the cylinder. Two induction pipes and two eduction pipes are employed, or otherwise stated, there are two sets ot induction and eduction pipes. Connected to one end of the cylinder 100 is a downwardly cnrved branched pipe 107, which is used alternately as a part oit' one ot the induction pipes 107 and one oi the eduction pipes 111.

The latter is curved upward as shown at i 110, and merges into the pipe 107, the curves of said pipes merging` into a continuous curve. Induction pipe 107 has an enlarged bottom provided with toot-valves 10S. 109 designates the level ot the water supply. onneeted to the opposite end oit the cylinder 100 is a branched pipe or pipe union 114 the upper limb ot' which connects with a second eduction pipe 10Q, and the lower limb with a second induction pipe, 115. rl`he latter joins pipe 1111 on an easy curve, as shown at 114V, extends downward, and has an enlarged bottom provided with 'footvalves 11.0. (Indicated.)

Eduction pipe 102 is laid in a straight line with the cylinder 100, and is extended a considerable distance, owing to which the greater part thereof cannot be shown on the d 'awingt .It terminates in a valve chamber 10'1-, in which are headvalves 105i. Chamber 101 opens into a stand-pipe or reservoir 105, near the bottom thereot. The other eduction pipe, 111, is also connected to said reservoir through a valve chamber 119. In practice, the chambers 112 and 101 will be at the same height, but :for clearness of illustration they are shown as at different heights.

The internal diameter of the eduction pipe 102 and the induction pipe 115 should be equal to that of the cylinder 100, these being the pipes connected to the end oi. the cylinder away 'from the piston rod, 117. Said rod enters the cylinder throi'lgh a stalling box, indicated at 151.. The cross sectional area ot' pipes 107, 107 and 111, should be jnst equal to the exposed area ot the rod side of piston 101, to the end that the water passage into this end oi the cylinder shall neither be enlarged nor contracted, and to secure the maximum kinetic energy trom the column o'li water in said pipes. This remark as to size o't` the pipe does not. apply to the part containingr the toot-valves, which part is purposely enlarged to permit a. valve opening equal to the cross sectional area ot' the pipe.

Eduction pipes 102 and 111 are provided with gate valves 106 and 113 respectively.

The steam end of the pump comprises the steam cylinder 126, piston 142, rod 118, main valve chest 119, and suitable valve gear, one form of which is shown.

Since a column of water in an induction pipe will have momentum when in motion at the end of the stroke, it may be found economical to make the induction pipes equal in length to the eduction pipes. This may be eiiected by connecting the induction pipes to the eduction pipes 111 and 102 at any point between the water cylinder and the discharge ends.

149 indicates the admission ports and 150, the exhaust ports. There are two separate and independent admission valves (not shown) controlled respectively by pilot valves in cases 120 and 121. Each pilot valve is provided with a rock-arm 122, connected with a toggle link 123, in turn connected with a vertically movable rod 124, having an upper guide 125. Vhen either rock-arm 122 is turned toward the end of the cylinder, it opens the pilot valve at the extreme end of the rock-arm stroke. The rods 124 are made in two members, the lower ones being connected to pistons in the dash cylinders 68. The two members of each rod 124 are connected by a slip joint, made as shown in Fig. 3, comprising a small cylinder 126, secured to one member 124, and a head 127, secured to the other member 124 and slidable in the cylinder. The purpose of the slip joint will be indicated later.

The pilot valves are closed by catches or hooks 128, pivoted on slidable sleeves 129 mounted on a rod 130, supported by an arm 131 and by a guide (not shown). Arms 131 and 132 are mounted on piston-rod 118, and carry the cutoff governing cylinders31, 32. Said cylinders contain pistons 2 and 3, connected by a rod 133, which extends from cylinder 31 and carries an adjustable member 134, shown in detail in Fig. 2, engaging one of the sleeves 129, whereby relative motions of the piston rod are imparted to 'one cutoff hook or catch 128. In order that both of said hooks or catches 128 shall be moved equally, oppositely and simultaneously, they are connected by a suitable mechanical movement. As shown, the collars 129 have lateral studs, connected to each other across a fulcrum 137 by lazytong levers 135, 136. Fulcrum 137 is relatively fixed, being carried by a collar 138 fixed upon rod 130.

Members 128 may be made independently adjustable with respect to each other, in ways that will readily suggest themselves to a mechanic.

Integral with collar 138 is a member 139 carrying two antifriction rollers 140, adapted to strike the arms 122 and throw them a little past dead center at the ends of the piston strokes.

For the purpose of delaying the opening of' the admission valves by regulable intervals, retarding devices are applied to some member of the valve-opening gear. For this purpose I prefer to employ the device shown, described and claimed in my copending application Serial Number 472,666 of even date herewith covering single action steam pumps of this type. In the drawings hereof, 69 indicates said retarding device as a whole, one being provided for each of the admission valves. For automatic regulation of the point of cutoff, the means shown herein are the same as those shown, described and claimed in my said copending application, comprising in addition Vto the parts already described herein, the cylinder 4, the hollow rod 5 reciprocating therein, the oil supply tank 6, and the connecting pipes 7 and 8 between said tank and cylinder 4; also the air chamber 9 with air pipe 10, the slow leak outlet 11, the hand valve 12, and the check-valves 13 and 14 in pipe 142.

The exhaust valves are positively opened and closed by reciprocating members 146, acting upon a rock-arm 143, connected to a parallel rock-arm 145 by a rod 144. Members 146 are mounted on a rod 147, secured to and actuated by an arm 148 carried by piston rod 118. The delayed movement may be applied to these exhaust valves instead of, as shown, to the admission valves.

The operation of starting the apparatus when there is little or no water in the standpipe 105, is as follows: rlhe operator turns up the cutoff members 128 to inoperative positions, opens the throttle slightly, and operates the pilot-admission valves by manipulating two levers 122, until the pump is primed, when the operator restores the parts 128 to operative positions and gradually opens the throttle. The steam ports are set in from the ends of the cylinder to provide air cushions for the piston in addition to the cushioning effect of the live steam. As the water piston 101 moves to the right, it draws water into pipes 107 and 107 behind it and forces water ahead of it through pipe 102, into the reservoir 105. On its return stroke the piston draws water into pipes 115, 114/ and 114, and forces water forward through pipes 107 and 111, into the reservoir. rEhe water path through pipes 107 and 111 is longer than the path through pipes 114 and 102 which causes greater frictional resistance than in said last named pipes, but there is a proportional increase of acting force owing to the proportional increase in effective steam piston area over effective water piston area on the rod side ot' said pistons.

1n operation, the excess of steam pressure at the beginning of each stroke is absorbed by the long column of water in pipe 102 or 111, said water column acquires momentum which persists while the steam pressure falls. For this reason, the mean effective steam pressure need exceed but slightly the resisting water pressure, and will admit of high initial pressure, early cut oft' and expansion to any point desirable.

Fluctuations in steam or water pressure are met by necessary changes in the cutoff through the medium of the mechanism hereinbefore described. lVhen the cutoff is late, the piston will be carried past the normal end of its stroke. At the first stroke of this kind toward the water end of the pump, the hollow rod 5 will force more oil into cylinders 31 and 32, and rod 133 will be moved to the right thereby proportionally shortening the cutoff; when the cutoff is early the leakage in left end of cylinder 31 will allow the compressed air in chamber 9 to force piston 2 and connections slowly toward the right thus lengthening the cutoff.

The number of strokes of the pump per unit of time is regulable by means of hand valves '77 in bypasses of the aforesaid retarding devices. In addition to the hand valves, automatic valves may be provided, which will be controlled by the pressure of the water in the stand-pipe 105. As the water rises therein the valve will be gradually closed. thereby delaying the operation ofthe admission or exhaust valves and slowing down the pump.

`Where the relative diameters of the steam-and-water pistons are properly proportioned, the steam may be expanded to any extent required.

The function of the device 126 on each dash-rod 124 is to permit the rod to be thrown down quickly without creating any excessive pressure in the dashpot or bending said rod. The downward motion referred to will be caused by the valve hooks 128 pulling the rock-arms 122 past their dead centers.

1t is to be understood that the invention is not limited in any respect, by the construction and arrangement of parts and devices shown in the accompanying drawing. This has special reference to the valve gear and speed controlling devices.

ln operation, the stand 132 and parts carried thereby and connected therewith, including rods 130 and 133 will be reciprocated by and with the piston rod 118. The rollers 1-10 on the member 139 are alternately brought into engagement with arms 122 connected with and adapted to rotate the admission valves. The movement of the rollers 1-10 is such as to push the toggle formed by arm 122 and link 123 pivoted thereto somewhat past dead center. This will operate to put the valve mechanism in position to open the valve but will not infact quite accomplish the opening of the valve. The dash pot 68 and retarding device 69 is similar in action to that shown and claimed in my co-pending application 472,666 in which when the piston in the dash pot is raised by means of rods 124i operated by the toggle link 123, liquid, either oil or water, will be trapped beneath a special piston in the rctarding cylinder 69. The valve mechanism 77 permits it to tlow gradually back up into the dash pot 68 until the aforesaid piston in cylinder 69 has descended to a point where the upper edge thereof reaches the opening into a by-pass, when the piston will be free to move downward and the dashpot action will quickly draw down rods 124 and through toggle link 123 swing arm 122 into position to hold open the admission valve. The opening of the admission valve, therefore, is eii'ected by dashpot action and not by the rollers 1110 on member 139. lVhat these rollers in fact do is to lift the piston in the dash pot cylinder and position the parts so that the dash pot action can operate to open the valves, and the retarding device 69 delays such action to an appreciable extent which may be varied by means of the hand valve 77. To prevent breakage, in case the stroke of the engine piston 142 shall be excessive and the toggle joint formed by members 122 and 123 be moved farther than normal, the yielding connection 126-127 in rods 1211 is provided. rlhis is necessary because as already pointed out, the piston in cylinder 69 is held by trapped oil from rapid downward movement. The position of member 139 is, of course, always fixed on rod 130 so that the valve operating arms 122 are always positioned for actuation by the dashpots at the end of a complete stroke in either direction. The retarding device in cylinder 69, however, prevents the dashpot action from actually opening the valve until an appreciable time after the completion of the stroke in one direction. The cut-oil' is ell'ected by means of the hooks 128 engaging the hooked ends of arms 122 and this is variable by the means already described. The travel of the steam piston carries with it as before stated cylinders 31 and 32 and hollow piston 5 operating in cylinder 41:. lVhen too much steam has been admitted and the stroke of the pumping' piston is too long, oil in the cylinder l will be forced through rod 5 to the cylinder 31, moving the piston therein to the right and through rod 133 and connecting link 1311 operate the lazy-tongs joint to cause hooks 123 to approach one another thereby shortening the time of cut-olf of the admission valves. The structure and operation of this controlling mechanism is similar to that described and claimed by me in my aforesaid co-pending application Number 472,666. The operation of the exhaust valves as already pointed out, is efals ected by means of the stops 146 on rod 147 movable with the engine piston 142, said stops alternately engaging the arm 143 and opening the exhaust at the end ot the stroke beyond the pumping piston 142.

I claim:

1. In a direct acting steam pump of the kind described, a steam cylinder provided With a piston, and admission valves; said piston having a variable stroke and said valves having a variable cutoi; positive means for starting said valves toward open position, yielding means for completing the opening movement, and automatic means governed partly by the length of piston stroke for adjusting the point of cutoff.

2. In a direct acting steam pump, of the kind described, a steam cylinder provided with independent admission valves, said valves having variable cutott a steam piston having a variable travel; automatic means for slowly lengthening the cutoi during normal operation of the pump, and means actuated by excess travel of said piston for shortening said cutoii.

8. In a direct acting steam pump of the kind described, a steam cylinder provided with independent admission valves, said valves being provided with projections eX- terior to the valve-chest, reciprocable rods connected Wit-li dashpot pistons, and connected With said projections by toggle links; valve-opening and closing members adapted to actuate the valve projections for opening and closing the valves; said valves being opened by dashpot action.

4. In a direct acting steam pump o the kind described, a steam cylinder provided with independent admission valves, said valves being provided Wit-h projections eX- terior to the valve-chest, reciprocable rods connected with dashpot pistons, and connected with said projections by toggle links; valve-opening and closing members adapted to actuate the valve projections for opening and closing the valves; and automatic means for timing the engagement of the cutoff-actuating members with the valve projections.

5. In a direct acting steam pump of the kind described, a steam cylinder provided with independent admission valves, said valves being provided with projections exterior to the valve-chest; reciprocable rods connected with dashpot pistons, and connected with said projections by toggle links, valve-opening and closing members adapted to actuate the valve projections for opening and closing the valves; the initial opening movement of each valve-projection retracting the daslipot piston, and the opening of the valve itself being actuated by dashpot action.

G. In a direct acting steam pump of the kind described, a steam cylinder provided with independent admission valves, yielding means for opening said valves, and means for retarding` the movementl of the valveopening means to delay the opening of said valves.

7. In a direct acting steam pump of the kind described, a steam cylinder provided with independent admission valves, yielding means for opening said valves, and regulable means for retarding the movement of the valve-opening means to delay the opening of said valves.

8. In a direct acting steam pump of the kind described, a steam cylinder provided with independent admission valves, each having 'a project-ion exterior to the valvehousing, a reciprocative member carried by the piston rod of the pump, valve-closing members mounted slidably upon said member and adapted to engage said valve projections, and automatic means for shifting said valve-closing members equally.

KENNEDY DOUGAN.

Vitnesses L. It. CLEMENT,

O. C. GUERMER.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patente. Washington, D. C.

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