US669568A - Dynamometer. - Google Patents

Description

Patented Mar. l2, I904.

J. B. was. BYNAMUME'TER.

(Applicatio n filed Dec. 29, 1897.)

(No ModeL) in Fig. 1,- with the headset t'wo'bolts show 116B}?.BURKITT(WEBBQQF MILLBERN, NEW JERSEY.

(DY-NAMQMETER.

SPECIFICATION forming part of Letters Patent No. GB-9:568,- d e March 1901- i p Application filed December 29,11897. Serial lie-664,866. (No model.)

To all whom, it may concermh Beitknown tiiatI, JOHN BURKITT WEBB, a

=eitizenof the United. States, residing at Millburrr; in the county of Essex and State of N ew 5' Jersey, have invented a new andnseful Dynainom'eter of which the following is a speci': fication. V V My invention relates to improvements in dynamo'meters in' which the power developed by'a motor is absorbed and measured; and it consists of certain novel parts and combinations of parts particularly pointed out in the claims. 4 v

In the drawings accompanying this specification FigureJ is" a vertical side view, mostly in section, ofthe dynamometer coupied to a gas-motor, shown at the right in outline, for the purpose of nieas 1|-ingthe power of"thelatter; Fig. 2, an end view of the dynamometer alone; Fig.3, an enlarged vertical section of the"restrict ed level shown .atL in FigsLl and 2. Figs. 4; and 5 are sections of the level-tube'in Fig.' 3.

shown .with'no'collars) at B and B inthe was5) ter-tight case B E'B E and has mounted upon it and revolving with it's gan'g'A of goodsized circular saw-blades or other equivalent disks .Four disks are shown in this gang.

For 1 quick speeds a single disk may suffiee,: in which case the unnecessary disks can be dispensed'with,and forslow speeds four may be insufiicient, in which. case the water-tight case must, be'made longenough to a'ccommo: dateailarge number of disks,'(perhaps fifty to one hundred,) which may also be set closer together to'increase. the resistance. These disks are inou'nted upon a hub, into which the shaft is 'firmly fastened, and are kept'at the proper distance apart by washe'rsithe disks and washers beingtightlybolted to the hub." This arrangement issh own in section Dotted. and broken lines are usedto in made, and similar letters'referto similar parts tribute ing at the leftend of the hub D. The di ks-i, are shown pierced with a few equalizing-holes 1' The disks can berun without holes slight irregularities in the distribution of the liquid may throw there'volving plates out of position and' even bring them into contact with the stationary ones.

Fig. 2 Show holes 7 in the outer plate or disk A. Theease-B E B E'is, also fitted with a gang of annnlardisks A (three in this case) intermediate between the revolving disks and perforated in the same.

manner. a They are kept at the rightdistapce apart by rings, (seen at E E, Fig. 1,) which f t snugly the inner cylindrical-wall of thecase and are clamped sutliiently tight by the cover of the case when bolted on, as shown L1 Thehole in these stationary disks is sufficiently :large' to fully clear the hub,-and the inside diainesf ter ofthe separating-rings is larger thana'the T outside of the revolving disks, so as 'tohave no chance of any contact between therevolving and stationary parts' The exteriors of the bearings B B in the case are turned [to fit the hangers F P, which stand upon the base G, and thus support the case. Balls-are introduced to relieve the friction and allow the case to swing freely between the two stops shown on the base at G. When only one re volving disk is used, the caseitsel f furnishes; the stationary surfaces and no inserted disks are needed. Instead of thedisksaii y surfaces of-revolution maybe used, butdisk's are the simplest.

The coc'kH furnishes waterinto a tunnel,

from wligh it flows into the case andisdisby centrifugal action. When in uch; peweris co'e kfl is set to furnish enough wateriper minute to absorb the power without becoming unduly heated, and its escapeis regulated of water in the case to givethe resistancereequally around the interiprthereof.

bythe-cock J so as to keep the properdepth quit-ed. To further facilitate this regulation,

a numberof holes (three are shown) are provided; in any one of which the escapepipe can be s' 'rewed. Hose connections may also be used flint any disturbing action onithegcase by the Water-jets or hose shoul heavoided.

is needed.

which there is virtually no static friction,

To measure the moment with which the stationary disks or surfaces are sucked or dragged around aft-er the revolving ones, a Spring-balance'may be used, or a scale-beam K, with suitable weights, maybe attached to the case, as seen in Fig. 2, the weight M being used to balance the case to its zero position when the shaft is not running and the l The horse and by. the moment measured on the scalebeam, as Customary in all such dynamometers.

To accurately indicate the central or zero position ofthe scale-beam, an accurate level (Shown at L in all the figu res and ,in detail in Figs. 3 and 4.) .This level is of a special and improved construction, which I designate as a restricted level. The ex treme sensitivencss of a dynamonieh-r, in

makes it liable to various oscillations difficult to avoid, even when the power supplied is quite regular-l; but in many cases there is also an unavoidable slight irregularity in the power supplied, which necessarily causes oscillations, so that an ordinary level sufficiently sensitive is kept in such constant motion that it cannot be read accurately. To

overcome this defect of an ordinary level, the

rcstricted' level used. is constructed as'shown in Figs. 3, 4, and 5, where the level is shown in section, longitudinal through its center in .Figs. 3 and and crosswise through its center in Fig. 4. lnstead'of hermetically sealing the ends of the glass tube a the brass end pieces 0 and p are cemented to it. One of these, 1), is made to unscrew, and thus allow access to the interior of the tube. The end pieces have the usual adjustingscrews for setting: the level properly in position on the scale-beam K. Inside the level-tube a channel r r is formed to-confine somewhat the bubble. This is shown in cross-section in Fig.

4 and may consist (regarding these views asfull-sized) of a central strip of brass the full length of the level-tube and about a quarter of an inch wide by an eighth of an inch thick. This strip fits a notch in 0 to keep it horizontal and is held fast by the screw t. At each end of the strip a hole is bored through it for the slow passage of the oil or other liquid contained in the tube, and at one end this is slotted out to allow the flattened end of the conical. plug q to enter'and act somewhat as a cock, so that the area of the passage at that end can be controlled somewhat by revolving what narrower the plug qftrom the outside by means of its slotted head. The strip is also filed someat the ends (see Fig. 5) than it is in the center, and to complete the channel. a vertical strip of brass is screwed to each lines in Figs.

edge of it, as indicated by the heavy vertical 4 and. 5; with the screw-heads showing. Four screws in all are sufficient,

placed at the ends, as indicated by the two black dots in Fig. 3. The side pieces being, sprin'gy and the strip narrower at the ends, the channel can be closed slightly at the ends by means of these screws. This furnishes a means of varying the sensiliveness" of the level without depending on the exact ourva 'ture of the glass tube. in fact, the tube may be ofany slight.- cnrvature or even straight, and the proper sensitiveness can be obtained by adjusting these side or check pieces to narrow the channel toward the ends by the proper amount. Of course a single piece can be used with the suitable channel in it; but it isbett-cr made in three pieces, as shown, and they do not need to fit the glass tube tightly to sufliciently conlin'e the bubble. Some liquid may get past the bubble underneathit, a-s the ubble need not fit against the strip as closely as shown in Fig. 4; but the main part has to flow down through the hole at one end and up through the hole at the other when the bubble moves, so that it cannot violently oscillate and will yet creep to the correct position in a fraction of a minute. it. can evidi l ntly. be arranged to control the curvatui'eol this channel from the outside, so as to make the sensitivcness adjustable at will'without opening the level-tube. Of

course a curvature could be given to the upalso asuitablc place for thc'graduationsshow-' iny, the exact position of the bubble. course l do not hold to the particular matcrials and construction described, so long as the essential features are secured, and the level-vial may easily be made entirely of glass and hermetically sealed, with the return-passage arranged inside of it or through a separate tube or passage outside of it.

This dynamomctcr is self-starting, inas much as the liquid oli'ers no resistance when at rest in contradistiuction to solid frictiondynamometers in which the friction must be relieved at starting.

The particular construction described can be varied in many Ways, some of which are: The case may be supported on rollers, knifeedges, or springs or by floating or other frictionless way. The bearinigs B B may be omitted and the shaft arranged to run without touching the case, water not being liable to escape around the shaft at B. The shaft need not be horizontaL' The case may be supported principally from one side. a It may be hung on the shaft by the bearings B B, their friction counting in with that of the water. To put any of the disks out of action, some of the annular plates can be without holes and the water supplied only to those revolving plates whichare to act, which is equivalent to making the dynamometer compound, with separate com partmeuts and a Water supply and escape for each. End pressure on the shaft is prevented by holes in the revolv-.

5 3 kneading, dragging, and sucking on these need holes if the water be furnished to different parts of the case otherwise. To regulate the power absorbed, the compartments may b'e'filled with water one afterthe other. Instead of the restricted level a mirror reflecting a beam of light upon a fixed or fed sensitive plate may be used to record the average position of the case ora mechanical trace made on smoked glass. Any holes, roughenin'g, or other cutting of the plates, such as saw-teeth on the outside, makes no essential changein their nature. While there must be chance for the water to properly distribute and while the plates are not run excessivelyclose to avoid dangerof contact and expense of making them true, yet theyare so close that each interposed annular disk of water is held in place, with little chance to do anything but revolve with an average speed about half that of the plates. Each annular disk of water, revolving at snch'speed, acts like a solid body would, acquiring by its motion such hardness as a stream has when forced from a hose-nozae under pressure, and the power is absorbed by the plates, rubbing,

quasi solids.

In the foregoing specification I have incidentally referred to some of the modifications which might be adopted in the practice of my invention; but I have not endeavored to specify all the modifications which might be employed, the object of this specification being to instruct persons skilled in the art to practice my invention in the form at present preferred by me and to enable them to un-v derstand its nature, and I desire it to be distinctly understood that mention by me of a few modifications is in no way intended to exclude others not referred to, but which are within the spirit and scope of my invention.

Many of the details and combinations illustrated and above described are not essential claims, where the omission of an element or the omission of reference to the detail features of the'elcments mentioned is intended to be a formal'declaration of the fact that the omitted elements or features are not essential to the inventions therein severally covered.

What I claim is 1. In a dynamometer the combination with a series of revolving plates or disks and substantially parallel opposing surfaces not in contact with the plates or pressed against them, of a body of liquid interposed and ofiering a resistance to the motion and cor munifaces forming independent compartments, of

a body or bodies of liquid interposed and oifering a resistance to the motion and comm unieating the moment from said plates to said surfaces and means for measuring said moment. r

3. In a dynamometer the combination with a revolving plate or disk and substantially parallel opposing snrfaces,notin contact with the plate or pressed against it, of a body of freely-circulating liquid interposed and offering a resistance to the motion and communieating the moment from said plate to said surfaces, means for measuring the moment required to drive the revolving part at any certain speed and means for controlling the quantity of liquid contained therein.

4. In a dynamometer the combination with. a revolving plate or disk and substantially parallel opposing surfaces of a body of freely-1 circulating liquid interposed and offering a resistance to the motion and communicating the moment from said plate to said surfaces, perforations through one or more of said elements and means' for measuring the moment required to drive the revolving part at any' certain speed.

Signed at the city of New York,in the county of New York and State of New York, this 28th day of December, A. D. 1897.

JOHN BURKITT WEBB. Witnesses:

J. EDGAR BULL, M. WILSON.-

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