US299677A - Speed-indicator - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

R. J PRATT.

SPEED INDICATOR.

Patented June 3,1884.

no Model.) 2 SheetsSheet 2..

R.J.PRATT. SPEED INDICATOR.

No. 299,677; Patented June 3, 1884.

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ROBERT JAMESPRATT, OF GREENBUSH HEIGHTS, NEW YORK.

SPEED-INDICATOR.

SPECIFICATION forming part of Letters Patent No. 299,677, dated June 3, 1884.

Application filed January 2, 1884. (No model.)

To aZZ whom it may concern:

Be it known that .1, ROBERT J. PRATT, of Greenbush Heights, in the county of Rensselacr and State of New York, have invented certain new and useful Improvements in Speed -Indicators; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to theaccompanying drawings, and to the letters of reference marked thereon, which form part of this specification.

My invention relates to that class of devices for measuring and recording the number of revolutions made by the armatureshaft of a dynamo-machine, in which the motion of the shaft is transmitted by means of a wormspindle to a toothed recording-dial intermeshing with the latter.

Previous to my invention, hereinafter described, speed indicators embodying these generic features were, by reason of defects in their specific construction and the means adapted for clutching them upon the shaft, incapable of performing their function with the accuracy required in delicate calculations. It is the object of my improvement to ob viate these difficulties; and for that purpose it consists in providing the dial with means for engaging it at will with the spindle, and automatically throwing it out of gear with the latter when the recording operation is finished.

It further consists in providing the indicator with means for preventing abrasion of the dialteeth, and also in certain details of construction, as hereinafter described, and more particularly pointed out in the claims.

In the drawings forming part of this application and hereunto annexed, Figure 1, Sheet 1, represents in plan my improved indicator. Fig. 2, Sheet 1, represents in cross-section upon the line y y, Fig. 1, the recording-dial. Fig. 3, Sheet 1, is a similar view upon the line 2 2, Fig. 1. Figs. 4 and 5, Sheet 1, represent, upon a smaller scale, side and end elevations, respectively, of one of the means I employ for clamping the socket-clutch upon the armature-shaft. Figs. 6, 7,8, and 9, Sheet 2, are like views of modifications thereof.

In the several figures like letters indicate like parts.

The indicator proper consists of a framepiece, L, provided with the opposite bearings U and V, in which plays the worm-spindle R. The spindle is provided with a fixed shoulder, T, and terminates in a square or polygonal extension, S. At the point M is pivoted the arm W, slotted for the reception of the graduated toothed dial 1?, and carrying on each side an indicating-finger, o. The arm is provided with a detachable dial-guard, N, and extending through aslot in an offset, V, of the bearing V, terminates in a handle, W. In the slot is located a coiled spring, X, bearing against the frame and the arm, a set-screw, Y, regulating its tension. A second set-screw, Y, is inserted opposite a higher offset on the bearing V, and limits the inward movement of the arm and dial. The dial is graduated on both sides from 1 to 100, the numbers on the reverse side to that shown in the drawings running in an opposite direction thereto. If, therefore, the armature of the dynamo revolves in such a manner that the wheel WV is made to turn in a direction opposite to that indicated by the arrow in Fig. 1, itis merely necessary to insert the indicator with the reverse side uppermost and read from the second dial-face. One hundred revolutions of the shaft and spindle effect a single revolution of the dial-wheel.

All the parts of the indicator are preferably of brass, exeeptthe spindle and screws, which should be made of cast-steel.

In Figs. 4 to 9, inclusive, I have illustrated various means for securing and maintaining a firm connection between the indicatorspindle and the armature-shaft, which I find to be useful in connection with my invention. The construction of these devices may be briefly summarized as follows: In Figs 4 and 5 jawpieces B, hollowed out, as shown, and bearing the adjustable socket-bar D, may be clamped upon and released from the dynamo-shaft A by means of the screw-threaded rod 0, attached to one of the jaw-pieces, and the butterfly-nut f, bearing against the other. In Figs. 6 and 7 the jaw-pieces are operated by right and left hand screws G, and, converging upwardly, form supports for the correspondingly-hollowed under surfaces of the socket-bar carrying pieces II. In Figs. 8 and 9 is shown an annular socketed cap or shell, 0, provided with bindingscrews It, and preferably with an internal split collar, 0, which may be varied in size to correspond to slight variations between the shell and shaft.

The operation of my invention is as follows: Upon the end of the shaft is affixed one of the several modifications of clamping devices shown. In the socket-clutch of such clamp is inserted the extension S of the worm-spindle XV. The shaft is then set in motion and carries with it the clamp and spindle, the latter turning loosely in its bearings U and V. hen the shaft has attained the speed which it is desired to record, the operator is enabled, by means of the handle of the pivoted arm, to instantl y gear the indicating-dial with the wormshaft at the very beginning of the period of time for which the velocity is to be calculated. At the end of such period the dial is as quickly disengaged, the recoil of the spring, when the handle is released, forcing the pivoted arm at once from the spindle. The presence of the set-screw Y, whose distance from its bearing on the offset It is so graduated that the arm shall approach during the recording operation only with sufficient nearness to fairly engage the worm with the dial-teeth, prevents the latter from being forced or crowded in upon the spindle with so much frietionas to abrade or wear off their faces.

In applying my invention to dynamo-machines when a number of experiments have to be made in succession, I have found it useful to secure the worm-spindle firmly to the clamping device and allow it to turn with the armature during the running of the dynamo then, whenever a measurement is desired, the frame is slipped over the spindle, whence it may be removed when the recording operation is completed, and until another measurement is to be taken.

It is evident that my invention can be used in connection with other machines where sin1i- 'lar calculations are required.

Having thus described my invention, what 1.

claim and desire to secure by Letters Patent, 1s

1. In a speed-indicator, the combination, with the main frame L, within which is joun naled the loosely-turning worm-spindle R, of a hinged arm, IV, carrying a toothed dial, I, the main frame and arm being provided with hand-grasps, substantially as described.

2. In a speed-indicator, the combination, with the main frame L, within which is journaled the loosely-turning worm-spindle R, of a hinged arm, \V, and a spring, X, interposed between the main frame and arm, substantially as described.

3. In a speed-indicator, the combination, with the main frame L, within which is journaled the loosely-turning worm-spindle 1%, of the hinged arm \V, the main frame and arm being provided with hand-grasps, and an interposed spring, whose recoil forces the dial from the spindle at the end of the recording operation, substantially as described.

4. In a speed-indicator, the combination, with the frame L, carrying the looselyjournaled worm-spindle It, of the hinged arm XV, carrying the graduated toothed dial I, and provided with the set-screw Y, for limiting the inward movement of the arm, substantially as shown and described.

5. In aspeed-indicator,the combination ,with the frame L, provided with the loosely 'ournaled worm-spindle R, of the hinged arm XV, carrying the graduated toothed dial 1, said arm extending through an offset, V, on the frame, and provided with the spring X and set-screw Y, substantially as shown and described. I

In testimony that I claim the foregoing as my own I allix my signature in presence of two witnesses.

ltOIBEl-t. J. PRATT.

lVitnesses:

HENRY Z. PRATT, Guns. ID. BRONSON.

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