US1523463A - Water-meter frost bolt - Google Patents

Description

J. THOMSON WATER METER FROST BOLT Filed Feb. 15 1923 INVENTORZ j and the disc chamber term, frost-bolt,

bot-tom.

Patented Jan. 20, 1925.

JOHN THOMSON, BROOKLYN, YORK.

WATER-METER raosr Bom'.

I Application filed February 15, 1923. Serial No. 619,214.

To all whom it may concern:

Be it known that I, JOHN THoMsoN, a citizen of the United States, and a resident of the borough of Brooklyn, city and State of New York, have invented a VVater-Meter Frost Bolt, of which the following is a specificatio This invention relates to. water meters, particularly consisting in means, empirically termed a frost-bolt, for preventing the operative parts of meters from being damaged When water therein is partially or wholly frozen, and also to avoid'damaging the functioning means itself. 7 The. said is a unitary expression like that of the now common trade nomenclature, such as frost-bottom, or frostprotector.

' It is believed that of the prior and existing state of the art will here sufiice. The present applicant was the original designer andexploiter of the disc water meter known'by the trade-name of Trident, in which the discv casing was formed oftwo parts provided with a horizontal snap-joint secured each to the other, and also held in place in a main casing, by a cast-iron head popularly known as a frost- This head has arms, flange bolts; whereby,vwhen water within the meter freezes and theexpansion thereof develops sufiicient pressure, the following results ensue:

Usually, (a) two or three of the arms fracture, permitting the head to tilt outwardly; (b) the disc-casingis pushed down- Wardly, or it may be upwardly; and (0) the two sections of the disc-casing separated at the aforesaid snapoint. Hence, the interior parts are neither broken nor deformed, and the application of a new head restores the meter to its former operative condition. Follo mg the foregoing, this applicant applied a system of springs, acting against a head," whereby, when frozen, the said headwas pressed outwardly was shifted and separated; then, the ice having melted, the

resilient springs automatically reset all of the functioning parts to their normal position. j

The aforesaid system of frost protection has been universally adopted with but few, minor modifications; and it is indubitable that the industrial savinghas amounted to of the meter shall be able to' test-pressure.

a very brief recitation engaged byare slightly millions of dollars. sible to still further hitherto attained.

However, it is yet pos- Thus, in regular practice, water meters are subjected to a hydraulic test-pressure of say, 200 pounds to the square inch; therefore, the frost bottom, or its equivalent element, must possess an additional margin of safety equal to not less than 25 to 50 pounds per square inch to prevent fracture or deformation of the frost bottom itself under the test-pressure; and this necessitates that the main casing withstand an ice-pressure, without permanent deformation, some 25% to 40% greater than the As will shortly be pointed out, the recited objections are overcome or largely minimized by the present invention.

In the drawings, which constitute a part of this specification Figure 1- is a diagrammatic sketch-view of a disc water meter wherewith to elucidate the frost protection; and also showing the frost-bolt in place, the scale of the latter being about full size, as applied to the house sizes of meters;

Figure 2 is a detached enlarged scale view of the bolt and its free co-ordinating nut, the latter being in section;

Figure 3 is a revolved view of the aforesaid bolt and its nut;

Figure 4 is a plan view, projected from Figure 2';

Figure 5 is a detached section, still further enlarged, to better illustrate a preferred form of the threads; and i ,Figure 6 is a transverse section of the bolt-rod in'a form best adapted for inexpensive manufacture.

The principle here employed maybe thus summarized: the employment of clamping bolts and nuts of such form and material that, when subjected to an adequate separating pressure, their threads will slip over each other; and then, when free to doso, may automatically resume their normal engagement without rupturing or deforming the co-ordinating surfaces and parts.

7 The upper member 7 and the lowermember 8, denote the main casing of a disc water meter having flanges 9, 10, whilstthe disc casing, also formed of two members, 11, 12, has a snap-joint 13. The disc and itsball are partially denoted in dotted outaugment the advantages principle of the recited system of line. The disc chamber rests in a tapered side-bearing 14 in the lower portion of the main casin and is secured together, and to its seat l5,l y an overlapping portion of the upper section of the main casing acting upon an interposed gasket, 16. Thus, when water within both the main casing and the 'disc casing freezes, if the two portions which constitute the main casing can separate sufficiently to allow for theme-expansion (about 8 ,per centum) the disc chamber will becarried upwardly, and also slightly separated, without damage thereto.

The benign action just mentioned is now attained by the resilient pronged bolt 17, and its free nut 18, Whose co-acting threads are preferably of ratchet, or saw-tooth form,

their sloping surfaces, as 19, 'being .their thrust-resisting portions. It will doubtless already be apparent that when the stress,

, or pull, is sufficient to cause the wedge-like spring thebolt-prongs inwardly, as see dotted lines 20, 21, Figures 2 and 4, the; threads surface of the nut-thread to sufficiently are thenfree to separate each from the other, of them'to the extent of one of m ore pitchspaces, as the case may be; Again, when free to do so, the prongs will snapback and the co-ordinating threads will re-engage when the nut can be turned down or up, from the shifted position.

But to realize'the foregoing simple action,

the following details must be observed,"

namely: The bolt. at right angles to the prong-slot 22, must be flattened, as 23, 24,

and the sharp intersections should preferably be slightly rounded, as 25, Figure 6..

The prong-slot should be of such a width that when the two upper edges come togethei, as see Figures 2 and 4, the outer corners of the bolt-thread, 'at the flats of the bolt, will just clear the inner edges of the nut-thread. Moreover, to avoid an undue width of the'prong-slot, the bore of the nut should betapered, as line 27 Figure 5, fiaring outwardly from top to bottom; hence when the prongs are thrust inwardly, as to line 28, all of the edges of the nut-thread will be free to slip over those of the boltthread.

-' While the bolt and'its fixed head, 29, could be formed as one part, it is advantageous to apply a separate head, in thatthe bolt-portion may be drawn in long rods to be thenafter threaded and'slotted, after which the prongs maybe heat-treated, or spring-temor by weakening the prongs at their roots,

servable as by drilling a-transverse hole thereat, 30,

tapped in a flange, whereby frost protection is readily applicable to large sizes of meters, which has not hitherto been the case.

Then, too, it is not necessary to provide, as in prior practice, an excessive margin of safety in the main casing; for the prongbolts can be adapted to release at .a pressure equal toor even less than, that of the usual hydraulic test-pressure. This is feasible because, when the test pressure is being applied, which is usually but once in the life of ameter, wedges. may be inserted in'the prong-slots to prevent them from functionmg 2 When the go point, as in 'a frost bot-- tom, is very high, the excessive pressure lowers the temperature of transformation into ice within the meter; consequently, upon a sudden relief thereof, ice may be formed with explosive rapidity; but with a substantially lower go point, ice formation proceeds more slowly; it is less likely to cause internal damage and the main casing of the meter may be considerably lighter.

It is not-without pertinency to here observe that the operation of this frost-bolt is an interesting exhibit of the principle that the friction of rest is greater than that of the friction of motion; for, the prongthreads cling to the nut-threads without obeflection of the prongs until well up to the go-point and then, once started, they move inwardly with but a moderate additional application of pressure although the side-tension of the prongs are becoming progressively greater.

The boltmay readily be formed with, say, four or six prongs; and such in fact has been tested; but, the two-prong form is unquestionably the preferable; for, among other reasons, a plurality of prong-slots so reduce the a gregate cross-sectional area of the prongs tiat the bolt and its'nutmust be so increased in, their diameters as to be ob ect1onable or even commercially unfeasible. So, too, ordinary V-threads may be employed, the VVhitworth standard being the better; yet the ratchet or saw-tooth form is distinctly the preferable in that, if no more, and pitches being equal, the area of bearing surface is or may be the greater. Theoretically, any form of thread is operative whose resisting surface is disposed within an included an le of substantially less than between the vertical and the horizontal; but, in practice, the most effective results will be attained between a swing of about 30 to 50.

A contingent advantage of this frost-bolteas es.

is that is serves to prevent needless and even destructive straining of the bolt and meterflanges. Thus, if the nut is excessively turned down .the prongs will spring inwardly and automatically release. in a normal application, all that needs be observed is to apply pressure until a slight inward movement of the prongs is observable, then fback-ofi? until they resiliently retrieve their normal position.

In sum, by thus utilizing ones earlier and well-proven separable system of parts within awater meter, which may be of the disc b or other types, and applying this frostbolt to the exterior casing, or head, as the case may be, a. frozen meter, or any part therein, or of the protector itself, does not require removal; nor does an expert needs be called to read ust 1t; for, once the ice 1s melted, anyone can turn down the nuts to place.

'ing to that of said bore, all

What I claim is:

1. A water meter frost-bolt comprised in prongs whose free ends are threaded and engaged by. a co-ordinating nut, the crosssectional form of the threads being like ratchet or saw-teeth and whose slopes serve as the strain-resisting surfaces.

2. In water meters, a frost-bolt in the form oftwo flattened prongs, the cylindrical portions of their free ends being suitably threaded to normally engage a continuous nut-thread, the inner bore of said nut-thread are sprung inwardly to an angle correspondof the thrustresisting surfaces of the threads are simultaneously disengaged.

This specification signed on this the 9th 'day of February, A. D, 1923.

' JOHN THOMSON.

eing tapered; whereby, when the prongs

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