|Publication number||US599746 A|
|Publication date||Mar 1, 1898|
|Filing date||Sep 28, 1896|
|Publication number||US 599746 A, US 599746A, US-A-599746, US599746 A, US599746A|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (8), Classifications (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
(NoModel.) G; C. ST. JOHN.
No. 599,746. Patented lvrar.,1, 1898.
UNITED ISTATES PATENT OFFICE.
GAMALIEL o. sT. JOHN, OE NEW YORK, N. Y.
SPECIFICATION forming part of Letters Patent No. 599,746, dated March 1, 1898. Application fuer settembelz's, 1896. serai No. 607,232. (No model.)
The object is to produce a steam-meter presenting in a'few numberof parts and in oompact form a device that will accurately register t-he amount of steam used in a given time and in which the parts will be so constructed and assembled as to present the highest possible range of usefulness with a minimum degree of danger of derangement from longoon tinued use.
With these objects in view the invention consists in the novel construction and com- .bination of parts of a'steam-meter, as will be hereinafter fully described and claimed.
In a patent granted to me September l, 1896, No. 567,054, for a steam-meter I show, among other details of construction, a valve or spindle for controlling the flow of steam through the meter, composed of two cones, each being a true taper, but of different sizes, the difference in the diameters of the .two cones forming a base or circumferential ange to rest upon a seat .to limit the downward movement of the valve, the lower or smallest cone constituting the valve proper, -as it is on this portion of the spindle -that the steam exerts its direct lifting'force. I have found by experiments thata valve constructed on this principleis defective in operation and will not produce. invariably satisfactory results, for the reason that the flow of steam will not be indirect proportion to the lift of the valvethat is to say, the ratio between the iowof steam and the increase in the sizeof the steamescape space between the valve and the valveseat as the valve lifts will notl coincide, resulting in a failure of the meter accurately to register the amount of steam used according to one formula for the entire height the Valve lifts or for the range of the meter. As a result of `my experiments I have discovered that in order to obvia'te this defect the spin dle will have to be increased from a true taper to a parabola, the curve of which will be in accordance with the differential results at- -tained by the height of the lift of the'valve;
a'nd, further, that the proportion between the top and the bottom of the valve should be a xed one, the ordinate of the parabola being determined 'by the difference in cross-diameter of the spindle at these points. This increase in the cross-diameter of the lower portionv of the spindle by a parabolic curve offsets the tendency of the steam to iiow faster than the ratio that would result `from the use of a true taper, and enables lne by knowing the flow when the spindle or valve has been raised-say, one linch-to calculate the flow at any height, thereby giving me a formula 'curve of any valve is to be such as to be capable of overcomin g the tendency of the steam to flow in a greater ratio of increase as the steam-escape space surrounding the valve becomes larger as the valve lifts, or, in other Words, the ratio between the iioW of steam and the increase in the size of thesteam-escape must always remain constant.
In addition to the objectionable features above noted in connection with the Old-form of valve I have found also by experiment that in measuring steam for an engine the vibratory mot-ion caused by the action of the valves in the engine has a tendency tomake the meter register higher than the amount at which I find it will standardize when using steam at a constant iiow. By passing Vsteam from the engine through the meterland conf- SoY IOO
densing it I iind that the registration is about ten per cent. higher than the amount of the water received at the condenser, this being due to the fact that the positive action of the steam carries the valve upward with strong force, and when the demand for steam ceases it falls back by gravity, which is not so potent a force as the force that drove it upward. Therefore to overcome this I provide the piston-head of the dash-pot with numerous perforations, and on the piston-rod of this head I place a plate adapted to rest on and to close the openings of the head when the piston is raised. This plate constitutes a cheek-valve which prevents the water from passing through the openings in the piston-head when the same rises, but compels it to go to the sides thereof,where there is a proper clearance provided, thus tending to retard the upward movement of the valve; but when the pistonhead drops this check-valve will lift and allow the water to escape freely above the head. To prevent any impact or jar between the valve and its seat, I employ a supplemental o1' sub dash-pot which comes into action just as the valve is about to seat itself, and this subdash-pot is engaged by a projection provided on the lower end of the piston-rod of the dash-pot piston-head. The water in the subdash-pot takes the shock and moves out in accordance with the pressure of the proj ection of the piston when it enters the pot. order to prevent the piston from contacting with the sides of the cylinder in which it is contained, I provide a guide at the top of this cylinder in which the piston-rod works.
Further and more specic details of construction will be hereinafter more fully described.
In the accompanying drawings, forming a part of this specification and in which like letters of reference indicate corresponding parts, I have illustrated one form of embodiment of my invention, although it is to be understood that other forms of embodiment thereof may be employed without departing from the spirit of the same.
In the drawings, Figure l is a view in vertical transverse section showing the parts of the meter as they appear when assembled for use. Fig. 2 is an enlarged detail view of the lower portion of the valve-stem,showing more clearly the peculiar arrangement of the checkvalve for retarding the upward movement of the valve and for permitting free downward movement. Fig. 3 is a view in the nature of a diagram illustrating one manner of determining the curve of the parabola of the lower portion of the valve.
Referring to the drawings, A designates a suitable casing provided with an ingressopening a, an egress-opening a2, and a hollow projection a3, the function of which will appear farther on. The casing is provided at its upper portion with an internal guide a4, having an opening a5, located, preferably, at its center, and with a valve-seat a6, arranged in a diaphragm or partition a7, located below the guide.
Fitting within the valve-seat is a tapered or conical valve or spindle B, having its upper end provided with a stem b, preferably one that is removable from the valve, the said stem being designed to engage the opening ai in the guide a4, and at its lower end with a second stem or projection b2, carrying a piston-head b3, which works in a dash-pot C, located at or near the lower end of the casing, a guide-opening as, formed in the top of the dash-pot casin g, in conjunction with the guide a4, serving to cause the valve to move in a vertical line. The piston fits loosely within the dash-pot, in order that when the valve starts to rise the movement will be as free from friction as possible and also gradual as possible, the accomplishment of this latter result being due to the fact that the water in the dash-pot surrounding the piston has to pass between the walls of the dash-pot and the periphery of the piston and thus presents resistance to the lifting force of the steam to prevent the valve from being thrown upward with great violence and thereby cause the indicator to register improperly. l The piston b3 is provided with numerous orifices 1)", (indicated by dotted lines,) and resting upon the top of this piston and freely working vertically upon the stem b2 is a plate 1f, constituting a check-valve for closing the said orifices when the valve rises and for opening them when the valve drops, the object of this arrangement being to retard the upward movement of the valve and not retard its downward movement. To allow free vertical movement of the plate b5 on the stem b2, the upper face of this plate is provided with a boss or extension 67, having therein vertical slots D8, (one only being shown,) through which projects a pin b, extending through the said stem, as clearly shown in Fig. 2. To prevent any jar or impact between the valve and its seat, I provide a second or sub dash-pot c, formed in the removable bottom of the easing of the dash-pot C, the sub dash-pot being engaged when the valve is seated by a teat Z1, projecting below the piston. This sub dashpot is of course filled with water and does not come into action until the valve is about to seat itself. Vhen the teat enters the pot c, the water therein receives the shock of the drop of the valve and allows the latter gently to resume its seat. It will be seen that the .dash-pot C subserves the function of retarding the upward movement of the valve and that the sub dash-pot subserves the function of preventing any jar or impact between the valve and its seat which might result in injury to one or both.
The valve or spindle B is composed of two truncated substantially cone-shaped parts,integral or otherwise, the difference in the diameters of the two parts forming a base or circumferential iange Z210, which is designed to rest upon the seat d and thereby limit the downward movement of the valve. The lower or smallest part constitutes the valve proper, as it is on this portion of the spindle that the steam exerts its direct lifting force. The ex- IOO ternal area of this valve is not a true taper, but is paraboliform, the parabola curving inward from the top to .the bottom thereof. The proportion between the top and the bottom of the valve or spindle should be a fixed one, so that to compute the ordinate of the parabola the difference in the cross-diameter of the spindle at these two point-s is all that is necessary to be known. vOne manner of determining the curve of the parabola of the lower section of the valve is demonstrated in dia.- gram in Fig. 3, wherein a cone is shown i-n dotted lines with the parabola indicated thereon, one-half of the parabola constituting one limb or curve of the lower portion of the valve. The advantage of this improvement will be obvious. Where the valve is a true taper, the iiow of steam will not be in direct proportion to the lift of the valve-that is to say, the ratio between the flow of steam and the increase in the size of the steam-escape space formed between the valve and its seat as the valve lifts will not coincide-resulting in a failure of the meter accurately to measure and' register the amount of steam used according to one formula for the entire height the valve lifts or range of the meter. By the employment of the parabola this objectionable feature is entirely obviated, for it will be seen that as the valve rises/the space between the val-ve-seat and the valve is gradually lessened,the ratio of this decrease being proportionate to the increase of the size of the steam-escape space when the spindle or valve is atrue taper.
Projecting upward from the dash-pot C or from the lower portion of the casing to a point near the valve-seat a6 is a deflecting and pressure-equalizing shield a, which is to protect the valve from the direct impact of steam when it enters the casing and thereby prevent such impact from tilting the valve and causing it to bind in its seat and thus work unevenly, and also serves to deiiect the steam and bring ituniformly toward and up to the seat a6,where by its force it raises the valve and escapes between the seat and the valve and thenceto the egress-opening a2, the guide a4 being so constructed as to obviate the presentation ofan obstruction to the free escape of the steam.
The registering mechanism comprises a rod or lever D, pivoted near the outer portion of the projection 0.3 and within the same, the inner free end ofthe rod having a stud or projection d, which engages a groove bu, provided -at the upper portion' of the valve, so that movement of the valve will cause the rod to rock on its pivot d2, and thus move a hand or pointer d3, located externally of the casing and traversing a strip of paper E, moved by clockwork, (not shown,) whereon the movements of the valve are recorded and the amount of steam used and the amount of time of its use are thus rendered ascertainable.
To free the casing and dash-post from water of condensation, petcocks am, anfand c2 are provided, the operation of which will be obvious. I
Having thus fully described my* invention, what I claim as new, and desire to secure by Letters Patent, is
l. A steam-meter comprising a suitable casing provided with an ingress and an egress opening and with an internal valve-seat, in combination with a paraboliform valve operating to compensate for the differential results attained by the varying heights of the lift of the valve, whereby the ratio between the flow of steam and the increase in the size of steam-space between the valve and its seat will remain constant, substantially as described.
2. A steam-meter comprising a suitable casing provided with an ingress and an egress `opening and with an internal valve-seat, in
combination with a paraboliform valve operating to compensate for the dierential re-4 sults attained by the varying heights of the lift of the valve, whereby the ratio between the fiow of steam and the increase in the size of the steam-space between the valve and its seat will remain constant, and registering mechanism operated by the movements of the valve, substantially as described.
3. A steam-meter comprising a suitable casving provided with an ingress and an egress opening and with an internal valve-seat, in combination with a valve engaging the seat, the upper portion of the valve being approximately cone-shaped and the lower portion paraboliform, substantially as described.
4. A steam-meter comprising a suitable casing provided with an ingress and an egress opening vand with an internal valve-seat, in combination with a paraboliform valve engaging the seat,'and means for retarding the upward movement and for permitting free downward movement of the valve, substantially as described.
5. A steam-meter comprising a suitable casing provided with an ingress and an egress opening and with an internal valve-seat, in combination with a paraboliform valve engaging the seat, means for retarding the upward movement and for permitting free downward movement of the valve, and a shield for protecting the valve from the direct impact of the steam, substantially as described.
ln'testimony whereof I aftiX my signature in presence of two witnesses.
GAMALIEL C. ST. JOHN.
Witnesses y GUsTAv SAUER, FRANK SLEviN.
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