US1880223A - Meter chamber - Google Patents

Description

Patented Oct. 4, 1932 vireo STATES HARRY G. wEYMonTH AND HoEAo .CHRiSMAN, or PITTSBURGH, PENNSYLVANIA, I

ASSIGNORS To PITTSBURGH EQUITAIBLE METER SYLVANIA, A CORPORATION OIE PENNSYLVANIA PATENT,

coiurerir, or 'rrTTsBUeGn, PENN- METER CHAMBER This invention relates to measuring chambers for meters, and particularly to chambers for meters of the nutating disk type.

'These measuring chambers of liquid meters heretofore have usually been cast in two parts that are assembled with their meeting edges in fluid tight engagement. It has been the usual practice to cast the parts of the chamber in sand molds and then machine them to size and to provide the necessary close fitting joint between the parts. Many difficulties have been experienced with these cast metal chambers in liquid meters principally because of the inherent porosity of the castings.

The chambers as heretofore used are generally cast from bronze. which has been extensively used is composed of alarge proportion of copper, and small equal proportions of lead, zinc and tin. For very many years difliculties were experienced in using such cast metal chambers in the manufacture of fluid meters, and the compositions of the alloys have been varied from time to time in efforts to secure castings that did not deteriorate and disintegrate in the course of time and cause a substantial change in accuracy of the meter after use for a comparatively short period. These difficulties are believed to be largely due to the fact that cast metal chambers are porous and quickly affected by the corrosive action of acid or-alkaline waters or other liquids which thus materially affect their strength, accuracy and durability.

Considerable time, thought and money have'been expended in the direction of experimenting and changing the alloys of the materials used in the internal parts of fluid meters, with the object in view of overcomin these objections, but'onlypartial success has been attained. These efforts were made in the belief that the difliculties were due to the alloy used. s

Applicants have discovered that these clifficulties are largely due, not to the nature of the alloys, but principally to the porous nature of the castings. The meter chamber parts were cast because of their relatively complex form, and it has been generally as- One .bronze alloy 1930. Serial N5! 460,975.

sumed that casting the chamber parts was essentialand that improvements could only be sought in the direction of varying the al: loy compositions. We have found that the meter chambers can be die forged and we thus do away with defective castings caused by sand, faulty venting, and porous metal; and have found that such chambers have far more uniformity prior to machining due to elimination 'of the irregularities inherent in sand cast chambers. This makes it unneces: sary torough machine our improved forged chamber. parts. Our die forged chambers also eliminate the necessity of chipping and filing the chamberports to obtain regularity of said cast chambers.

The measuring chambers as cast from the sand molds heretofore used are first subjected to operations of cutting off the gates and risers and then ground. They are then of the casting to thereby minimize the work to be done by the finishing tool. These first operations are troublesome and add materially to the cost of the castings. The chambers as cast are difficult to securely mount in machines on account of their warped condition, and the abrasive action of the sand in the castings drills and wears away the cutting tools, making it necessary to grind and rest the'tool frequently. Sand cast chambers are frequently defective due to cold shots, gas pockets and improperf pouring, and such chambers have to be discarded. In many instances the defects do not become apparent until some of the finishing cuts have been made, so that the loss whensuch defective density much greater than cast chambers,

liquid meters. The detailed structure thereof and better wearing qualities, making them the necessity for the initial removal of gates and risers, grounding, sand blasting, pickling, drying, and rough machining are eliminated. i

The principal object of this invention therefore is to provide a novel method of producing the chambers of liquid meters, which is simple and relatively inexpensive to carry out and in which the chambers produced thereby are superior in every way to the cast chambers heretofore used.

Another object of this invention is to pro-. vide a liquid meter chamber made of a metal alloy whichis less subject to corrosion by acid or alkaline waters, and to provide a chamber made from an alloy, hitherto never used for manufacturing liquid meter chambers, and which readily adapts itself toa die forging operation. 1 I 7 Further objects of our invention are to provide a method of producing the chambers of fluid meters which is cheaper than the present method, in that there are materially less chambers discarded as defective, in that the number of machining and other operations are greatly reduced, and in that the chambers are more uniform in size and in thickness of the walls.

These and various other objects of our invention will be apparent from the follow: ing description and the appended claims when taken in connection with the accompanying drawing wherein:

Figure 1 is a top plan of the upper portion of a liquid metering chamber made inaccordance with our invention. 7

Figure 2 is a section on line22 of Figure 1.

- Figure 3 is a plan view looking into the bottom chamber.

Figure 1 is a section on line 4:4 of Fig ure 3.

Figure 5 is a side elevation looking into the meter chamber with the two parts there of assembled. l 7 1 It will be seen that the chamber of a liquid meter as illustrated is similar in general configuration to that in common use today in however, will be described in order to more fully emphasize the. various differences between the old form of sand cast meter ng "is provided on its upper surface with anupstanding annular ring 2 having tapped holes "3 therein for the reception of screws to hold a disk controlling frame (not shown) in position.

At its center the chamber is provided with a central opening, said opening being defined by an upper truncatedconical wall 4 and a lower spherical wall 5. As seen in Figure 2, walls 4 and 5 extend upwardly from the centerof the wall 1 with the upper portionof the wall slightly below the plane defined by the upper surface of annular ring 2. Bracing ribs 6 connect the annular ring 2 withthe upper. wall at for strengthening the parts.

The main body portion of the upper cham ber has a downwardly extending outwardly spherical wall 7 forming with upper wall 1 a cup-shaped member. This wall 7 is cut away as .at 8 to provide the upper half of a curved port opening for the assembled chamber. Thedownwardly extending wall 7 has three lugs 12, 13 and 14 thereon which extend outwardly from said wall and also project slightlyabove the upper portion thereof as seen clearly in Figure 5. i. Lugs12, 13 and 14 have vertical outer faceswhich are adapted to be positioned in verticalalignment with similar faceson lugs of the bottom half of the chamber, these lugs cooperating with similarly shaped surfaces on an outer enclosing water meter casing of .well known construction to position the metering chamber therein. 1

The outer dependingwall 7 is further provided with a lug 15 which is of greater arcuate length than thelugs 12, 13 and 14 to provide adequate bearings around the outlet port, and which has a vertical outer wall 16 as. seenin .Figure 5 for further assisting in maintaining the chamber within the outer meter casing. Adjacent the lower edge thereof the outer depending wall 7 is-pro vided with 'anoutstanding ledge 17 which is flush with the outer surfaces of the lugs 12, 13, 14: and15 for the purpose of reinforcing the chamber edge. and. providing a suitable joint section;- Thelower edge of the depending wall 7 is provided with an inner groove 18 for cooperative engagement with a similar member on the lower half ofthe chamber. f The upper half of the chamber is provided with a radial gro ove,21 on the inner surface thereof which groove extends, inwardly from opening 8 to the central opening provided by the wall 5. seen in Fig positioned therein.

ures 1 and 2, groove 21 extends upwardly through the upper surface of the lug 15. This groove 21 is adapted for the reception of a division plate for separating opening 8 into an inlet channel an outlet channel for the chamber. i

Depending wall 7 has a notch 22 cut in the inner surface thereof adjacent lug 13 adapted to receive a thrust roller mounted on a nut ting disk (not shown) of any well known construction, which is positioned-within the chamber of an assembled meter. Lug 1% has a hole 23 drilled therein from the external surface. Hole 23 adapted to receive pos tioning pin for cooperation with the outer meter casing when the central chamber is A depending pin 2st is provided on the lower edge of the depending wall 7 for reception in an opening in the lower half of the chamber.

The lower half of the chamber is shown in detail in Figures 3 and l and comprises a cup-shaped member having a. mam conical H c) J \v lvt t 1 nah .6 sloping upivai or owait e con el with a central opening dehned by the spherical wall 27 and the wall of a central opening 28. The lower half of the chamber is provided with lugs 29, 31 and 32 similar to the lugs 12, 13 and i l of the upper half of and in opposite directions. extending wall 39 is provided with a slot 33 the casing and arranged to align therewith when the chamber is assembled. It will be noted that the outer side surfaces of lugs 12, 1 t, and 29, 32 and 38 incline inwardly The upwardly similar to and in alignment with the slot 22 adjacent the lug 13 of the upper chamber, and is further provided with a ring 34 on its lower face, and connected to the outstanding annular ring 35 surrounding the central opening 28, said rings 34; and 35 being connected by webs 36. r

The lower chamber is further provided on the inner face of wall 26 with a slot 37 which projects downwardly through the lug 38,

which lug corresponds to lug 15 of the upper half of the chamber. The upperedge of the upstanding wall 39 of the lower chamber is suitably rabbetted as at 41 for cooperative engagement with inner groove 18 of the depending wall 7 of the upper chamber, thus forming a snap joint for the upper and lower chamber sections.

The wall 39 of the lower chamber is further provided with an openin 42 for the reception described in sand molds and then to carry out the operatlons as above set forth to reduce them to fimshed form for use. These castings have many defects as previously nointed out,

and the casting and manufacturing operations thereon are expensive. In order to produce chambers which do not havethe faults of the sand cast chambers, we proceed as follows:

One alloy found by careful investigation and research tobe suited for die forging of inch round bars, and cut off in suitable lengths or disks having ust sufficient material in the pieces thereof to make one-half of the complete measuring chamber. The disks of the alloy are then heated to approximately 1250 F. and placed in a drop forging press between suitably shaped male and female dies and subjected to pressures of the order of 600 tons. The male and female dies are of course, carefully machined to exact size and the metal of thealloy is caused to flow therein to assumethe shapes shown onthe drawing. The machines for making up these chambers by a die-forging operation are capable of producing approximately 50 forgings per minute. r T

When the two halves of the metering chamber come from the die forging press, the enormous pressure to which they have been subjected has caused the metal to be much more dense than the metal of the sand cast cally all perfect, since there are no air pockets or holes therein, due to the fact that the enormous pressures prevent the formation of such pockets or holes and consequently the discards are eliminated. The walls of the die forged chambers are uniformly thick at all points and the resultant chamber is strong and rigid, and has many advantages over thesand cast type of chamber. r 7

The invention may be embodied in other specific forms without departing from the Chambers made in accordance with th1s lnvention are pract1-' spirit or essential characteristics thereof. The present embodiment istherefore to be considered in all respects as, illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the'foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

l/Vhat we claim as new and desire to secure by United States Letters Patent is 1. A corrosion-resistant measuring chamber for the nutating disk of a liquid meter comprising two mating generally cupshaped brass members, said members being separately die forged under high pressure to provide a hardened'surface of dense texture which is substantially corrosion-resistant to acid and alkaline liquids.

2. The invention as defined in claim 1 wherein said members are formed of a brass alloy of approximately 60% copper, 37 70 zinc and 2 lead.

3. A meter chamber consisting of mating generally cup-shaped members designed to be brought together to form said chamber, each member consisting of metal having smooth dense non-porous surfaces, said members being adapted for use in meters subject to the action of acid or alkaline fluids.

4. A meter chamber consisting of mating generally cup-shaped members designed to be brought together to form said chamber, each member being constructed by a dieforging operation on a suitable brass alloy under suliicient pressure to cause the surface of each forging to be dense and non-porous and of sufficient smoothness to enable the forging to be used as one of said members without roughing cuts.

5. The chamber defined in claim 4 in which said alloy consists approximately of copper, 37%% zinc and about 2 lead.

6. A meter chamber consisting of mating members each provided with spherical zones and frusto-conical surfaces and designed to be brought together to form said chamber, each member consisting. of metal having smooth dense non-porous surfaces, said members being adapted for use in meters subject to the action of acid or alkaline fluids.

7. A meter chamber consisting of mating generally cup-shaped members each provided with spherical zones connected by frustoconical surfaces and designed to be brought together to form said chamber, each member being constructed by a die forging operation on a suitable brass alloy under sufficient pressure to cause the surface of each forging to be dense and non-porous and of suficient smoothness to enable the forging to be used as one of said members without roughing cuts 7 8. The chamber defined in claim 7 in consists approximately of which said alloy copper, 37 zinc and about 2 tures.

' HARRY G. WEYMOUTH.

HORACE CHRISMAN.

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