US237243A - Steam-pressure gage - Google Patents

Description

(Mode=1.)

^ J. BURRELL,

Steam Pressure Gage. i

No. 237,243.- Patented Feb, 1,' 1881.

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JPETERS, PHOTD-IITNOGRAPHER, WASEINGTON D c a front view of the interier of my improved` UNITED STATES i PATENT OFFICEO J ARVIS BURRELL, OF 'EAST BRIDGEWATER, ASSIGNOE TO GEORGE H. P. FLAGG, OF BOSTON, 'MASSACHUSETTS STEAM- PRESSU RE GAG E.

SPECIFIGATION forming parttof Letters Patent No. 237,243, dated February 1, 1881.

Application filedseptmber 24, 1880. (Model) To all whom it may concern Be it known that I, JARVIS 'BURRELL,`O" East Bridgewater, in the countyot' Plymouth I and State of Massachusetts, have invented certain Improvements inSteam-Gages, of I which the following is aspecification.

Figure 1 ot' the accompanyingdrawings is gage. Fig. 2 is a central transverse vertical section ot' the same. Figs. 3 and bare 'respectively a side and front view of parts, in

detail, of my invention.

The object of the present invention is to effect certain new and useful improvements `in stean or pressure gages, but more particularly to obviate objections in an invention of` like nature for which Letters Patent No.-10l,636 were granted to James W. Maloy, April 5, 1870. In the patented invention referred toinaccuracy in the operation of the gage is apt tooccur, mainly owing to thedependency of the lever for its action on separate bearings or fulcrums-that is, the-stem of the button, which is movable and subject to slight variation, is very liable to vary in its `distance from the fixed knife-edge or fulcrum on which the lever vibrates, thereby causing an nncertainmeasurement of the pressure; and, further, the curved spring is weakened so as to frequently break by having an aperture formed through its center to admit the sten of the button, and the ends of the spring are made to abut at the joints of the casting, which is liable to give way and forms a movable and uncertain bearing.

These objectons are obviated by my improvements, which consist, mainly, of a lever having knife-edge fnlcrums and hearing cast in one piece with it, and arranged, as will be hereinafter more fully described, to be operated by one action.

These improvements otherwise consist in varying the construction of several of the devices of the gage to perform their required functions in a more perfect manner, all of which I will now proceed to desoribe.

In the drawings, A represents a metallic casing having a glazed screw-cover, B, and a suitably-marked dial-plate, G, and having attached within a triangular metallic frame, E, formed with bottom projecting plates, E screwed to the top of the vertical sides of a The screw-head H is formed with a central aperture opening into the chamber b and eX- tcnding throughan outward stem or steam or pressure tube or pipe, H'. Theinteriorsides of the casting F are notched or grooved laterally at f to receive and firmly hold the ends of a conoavely-cnrved spring, I, which passes through a transverse slot, o, of ayoke, lK,whose bottom or button-like portion abutson the top, so as to receive the action of the disk or plate Gr; and the top of the yoke is curved upward from the ends to form a central bearinor seat for the knife-edge of an` arm, l, projecting forward of and centrali between lateralextending arms or fulorums l' ourving downward from on either side of a vertical lever, L, and each fulcrum formed with an upper knife-edge bearin g in grooves' formed in the bottom of a hearing or plate, M, projecting at a right angle from the bottom of the frame E` and cut out in the center of its lower portion to admit the projection of the center arm, l.

Connected with the top of the lever L is a segmental ratchet-bar, N, whose teeth mesh with a pinion, n, turning in abearing., O, slot `ted to receive and allow the action of the ratchet IOO H' into the chamber b, acts on the plate or disk G and bears it` against the button or bottom portion of the yoke K, which is raised thereby and bears up the arm l, which vibrates partially the lever L, whose lateral arms or fulcrums l' act in the grooved or notched bottom of the hearing M and actuate the ratchet and pinion and operate the index over the dialplate to the point determined by the amount of pressureexerted. The spiral spring t serves to secure the required tension to the lever L, and the spring I supplies the required tension to the yoke K.

By means ot' the regulating screw stem or pin 7' the distance of the throw of the lever may be varied to regulate the movement of the index, so that it shall always start from the zero or starting point.

By the above description, reference being .made to the drawings, it will readily be seen that the action of the lever must be accurate under any variation ot' prcssure or circumstances, as its bearingand fulcrums are formed on it, and there is nothing to vary their distances, as there is in the previous invention, where the lever turns on a fixed ful'crum connected with the frame, and its bottom arm bears on a movable hearing or fulcrum forned by the stern of the button.

By the regulating-stem r the lever may be adjusted in its movement to always start the indexfrom the required point, thereby preventing inaccuracy in the measurement, otherwise liable to occnr by the index being carried beyond or not quite to the startin g-point.

By extending the spring I through the yoke K the weakness occasioned by the aperture for the button-stern in theinvention is prevented; and by notchiug the sides of the casting F to receive the ends of the spring I, instead of abutting the ends at thejoints of the casting, as heretofore mentioned, the spring is more securely and steadily'held and more accurate in its operation.

By my improvements I insure a more perfect operation without incrcasing the expense of the gage.

A steam-gage has leretofore been made in which the index-moving lever has been provided with a removable or separable pivot to rest upon the diaphragm below, and apin extended through its lower end, on both sides, to engage notohes in a casting from above.

Having thus described my improvements, what I claim as my invention, and desire to have secured to me by Letters Patent, is

1. In a steam-gage'having a fiexible disk, Gr, and a movable yoke, K, resting upon said disk, a lever, L, for Operating the index, cast in one piece with a central extension, Z, having its hearing upon the movableyoke, and laterally-projecting arms l' l', combined With the casting M, against which said arms bear. substantially as shown and described.

2. In a steam-gage, the disk Gr, the yoke K,

loosely placed thereupon, the hearing F,-

ings M, the one-piece furcated lever L, and an index or indicating mechanism, combined and arranged to operate substantially as described.

3. The disk G, the yoke K, loosely placed thereupon, the inperforate spring l and its bearings F, for supporting the yoke, the beariugs M, the forked lever L, and an index or indicating mechanism, combined and arranged substantially as described.

In testimony whereofI have signed my name to this specification, in the presence of two subscribing witnesses, this 2lst day of September, A. D. 1880. e

JARVIS BURRELL.

Witnesses O. F. BROWN, J osEPH F. BALDWIN.

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