US327672A - Piston water-meter - Google Patents

Description

(No Model.)

G. H. FOX.

PISTON WATER METER.

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GEORGE HENRY FOX, OF BOSTON, MASSACHUSETTS.

PlSTON WATER-METER.

forming part of Letters Patent No. 327,672., dated October 6, 1885.

Application filed December 20, ISSJ.

.To @ZZ whom it may concern.-

Be it known that I, GEORGE HENRY Fox, a citizen of the United States, residing at Boston, in the county of Sul'iolk and State of Massachusetts, have invented certa-in new and useful Improvements in Tater-Meters; 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, reference being had to the accompanying drawings, and-to letters or figures of reference marked thereon, which form a part of this specification.

Ihis invention relates to piston water-meters,77 so called, and belongs especially to that -class in which two reciprocating pistons are employed, and so arranged that a dead-center is avoided and stoppage prevented.

lll y invention consists, essentially, in the employment in the pistons of independent reciprocating plungers,whereby variation in the capacity ot' water-space on either or both sides ot' the pistons is readily accomplished; and, furthermore, in the construction of a mid rib or partition separating the two pistons, and which is provided with oppositely-disposed recesses to accommodate the crank-arms, and an easy and ready way is accomplished of dividing the cylinder into two separate watertight chambe s, and isolated one from the other.

Hitherto in meters ot this class two c linders have generally been arranged side by side, or else the cranks operating the pistons have worked in a common measuring chamber; hence there has always been need of stuiing boxes and packing, while the number of parts has been increased with a large attendant eX- pense. In my present device there are no stuiiing-boxes, and the apparatus is made extremely compact and very much more cheaply than any of the above briefly-described devlees.

In the drawings accompanying this specification, Figure l represents a central vertical longitudinal section of a meter embodying my improvements, while Fig. 2 is a plan of the valve-seats and their passages, and Fig. 3 a plan of the eccentrics as shown in sect-ion in Fig. l. Fig. 4C is a horizontal section on line a" a, (see Fig. 1,) with the crank removed.

(No model.)

In the above drawings I have shown the bodyot' the meter at A,with a cap, B, containing the valves a c', which are ordinary slidevalves, and operated .bythe eecentries b b', mounted upon a shaft, C, located centrally of the meter, and revolving within the bore c formed within the partitionor mid-rib D, which separates the meter into two similar measur` ing-chambers, E F. This partition is cast with two oppositely-disposed recesses, G H, which aii'ord an easy and ready expedient for completely isolating the two chambers from each other, and also affords space for the rotary movements of the cranks d e, to which are attached one end of the piston-rodsfg, while their other extremities are secured to the pistons I J. In order to introduce the shaft G, with the cranks attached, I have made one casting, G', forming the recess G, separate from the partition l), and secured by bolts to the latter. rIhese two pistons with their valves and operating mechanism are disposed very similar to that ofthe same relative parts in a steam-engine-that is, the crank-pins and eccentrics are set quarter-ing, to prevent a deadcenter. The passage oi' tluid through this meter is as follows: rEhe inlet-pipe K delivers the water directly through the port L into the valve-chamber K formed by the cap B,whence it passes into both ends of each cylinder by and through the inlet-ports z' fijj. Furthermore, these ports alternately become exhaustpassages and co -operatc with the exhaustports la k, which communicate by the passages It h2, leading to the outlet-pi pe L, communicating with the building.

An essential and important part of my invention, v however, I consider consists in a plunger or plungers, M N, arranged to move in the piston-heads, which may be, if desired, provided with one or more ot' such plu ngers. These plun gers perform a very important function in meters of this class above premised, since water is non-elastic and decidely different from steam, hence there is an entirely ditterent set ot forces and resultants to be considered in the employment of water as an clement in lieu of steam in such an apparatus. Moreover, there is one obstacle in the working or" a meter of this class consequent upon the non-elastic properties of water very diieult to overcome, which is this: vUpon reference to Fig. l I have shown as nearly as possible the condition of the parts when the trouble to be overcome has occurred. In this ligure the piston J is at half-stroke and piston I just completingv its outward orY advance stroke. Now, at this particular moment the piston-rod f and crank d are in a position,just prior to their alignment on the center, at which time the valve a,moving in the direction of arrow 1,has closed the inlet and outlet ports and the lluid is locked for a very small space of time within the measuringchamber F. Now, the crank andA piston must advance a trifle more to reach their extreme throw-say the distance represented between the broken line l 2 and the line of the piston-and are then actuated and driven by the lopposite piston, J, under the full-supply pressure; but aswater is nonelastic, and a certain part of itis now conliued between the head of the cylinder and piston by the momentary closing of the valve a', it follows that some of the operative parts must either yield or break, thus destroying Ythe apparatusV and preventing its further employment until repaired, or else lift and force the valve a from its seat. rIo overcome this difficulty, I have employed a plunger consisting of a short cylinder, Z, provided with heads m a, and have bored the piston so that the cylinderl snugly lits the hole in the piston-head, which is thickened at. that point to furnish a bearing, while the. heads m n prevent its displacement and coin-Y pel it to reciprocate in its respective head. Thus it follows that as the piston advances this slight. distance to the line 3 4, while the valve has closed both the outlet andninlet ports, it is necessary to employ some means to increase the waterspace in advance of the piston, or else remove some water to allow said pistou, free movement for its pas sage, while on the other hand the waterspace at the rear of said piston requires to be diminished, or else there is a tendency to produce a vacuum.

The plunger M during the entire advance Vthe head m bearing against the piston under the inilueuce of thesupply-pressure through the port j, which is greater than that upon the outer exhaust side of said piston. This position is maintained until the valve a has closed all communication with the chamber F, when, as the piston advances slightly, the space occupied by the Water on the hitherto exhaust side is diminished. Now, the Waterspace at this time must be increased, since the water cannot escape, and consequently the plunger at once reciprccates to its opposite extreme, as now shown. By this movement the water-space in advance of the piston is increased by an amount equal to the cubic contents displaced by the length of cylinder Z, projecting into said water-space, and the pressure is at once relieved. On the other hand,the slight advance of the piston has increased the water-space upon its rear side, and the tendency to a vacuum is at once obviated in the said watenspace by the move- 'ment of the plunger rearward, and thus said Space has been diminished by an amount equal tol the cubic cont-ents of the same cylinder, which has just been removed from the waterspace upon the other or advance side, and a complete balance is maintained without any undue strains being brought to bear upon any of the operative parts of the meter.

The plunger now remains in `this position after the valve chas moved sufficiently to admit supply-water between the piston and the head of the cylinder to compel it to advance on its retreat movement-,and so continues until the valve again covers both inlet and outlet ports preparatory to a change of position, in order to alter the movement of said piston.

It will not be necessary for me to enter into a detailed description` of the complete operation of this apparatus, since reference to the ligures will readily convey to the mind the cooperation andn relation of the various parts one to the other. Fig. 1 the valve a is advancing in the direction of arrow l to permit the `measured fluid in chamber F to exhaust by the passages j, la', and h2 to the outlet-pipe L, While fresh liquid is permitted to enter through inlet-pipe K., passages h j', and thence between the piston I and the cylinder-head. On the other hand, the valve a is in such position that supplyliquid is flowing from the inlet-'pipe Kthrough ports h and z' into the left-hand side of measuring-chamber E, and has driven the piston J one half of its stroke in the direction of arrowY Y2,;'and the recently-measured fluid is exhausting from the other portion of the chamber E by and through the passage i', leading to the ports k and passage, h, to the outlet L.

The registering apparatus is to be connected to the top of the shaft C by some simple mechanical means, and every revolution oi the shaft is recorded; or, in other Words, double the amountotl liquid contained in each cylinder, or twice the cubic content-s of the latter, is thereby registered upon the dial.

It is evident that one or more of these plungers above described may be arranged in a single piston-head, and, furthermore, the diameter and length of the cylinder or compensating part thereof may be changed, and thus variation of the Water space on either or both sides of a piston is easily adjusted to any desired amount.

An apparatus similar to the one above described and embodying my invention is simple, cheaply made, and very effective in its I will simply say that in IIC' IBO

operationsfsince the valves are positively I claiml. A meter arranged as herein described, and divided into two measuring-chambers separated by a partition provided with hol- 5 low oppositelydisposed recesses,substantially as described, and for the purposes herein set forth.

2. The combination, with a piston and its cylinder, of a device operating to increase the 1o water-space in front of the piston proportionally to the advance of said piston at the moment of closing the adjacent outlet and inlet ports, substantially as herein described.

3. The combination, with a piston and its f 5 cylinder, of a device operating to decrease the Water-space in rear of the piston proportionally to the retreat of said piston at the moment of closing the adjacent outlet and inlet ports, substantially as and for purposes herein 2o set forth.

4. The combination, with a piston and its cylinder, of a device operating to increase or diminish the water-space upon either side of the piston at the moment of closing both the adjacent outlet and inlet ports, substantiallyT 25 as described.

5. The plunger, as a mechanical device for effecting the variations in the capacity of the Water-space on either or both sides of the piston, and operating substantially for the pnr- 3o poses herein set forth.

6. The combination of a cylinder and its pistons with their operative mechanism and the compensating plungers, substantially as stated. 35

In testimonyT whereof I affix my signature in presence of two Witnesses.

GEORGE HENRY FOX.

Witnesses:

H. E. LODGE, A. F. HAYDEN.

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