US442102A - Steam-engine indicator - Google Patents

Description

(No Model.) l1'.Sh@etw-Sheet'. 1. A.VB. OALKINS.'

STEAM ENGINE INDICATOR.

' f Ishee-ts-sn'eet 2.. A. B. GALKINS.

` STEAM ENGINE INDICATOR. y

Patented Dec. 9, 1890.

' (No Model.)

SNO.

8 0M 3 L 0.1 M wm 3. t e e v.hu S w e nu h s 4 .um 0 M SU ID Km Lt". Am um BE. .M A A E T .s .u .d o M o m 10.442,102. Patented Dec. 9, 1890.

l aww' D Pff 1.1. 426 LVM( (No Modem l 4 sheets-sheet 4.

No.442,102'. Patented y1360.9, 1.890.

HILSIIIIHII-IHIIIIIIIIllll |`LIIllllllllllllllllllI `UN1TED STATES PATENT OEEICE.

ALMON B. CALKINS, OF BRDGEPORT, CONNECTICUT.

STEAM-ENGINE INDICATOR.

SPECIFICATION forming part of Letters Patent No. 442,102, dated December 9, 1890.

Application led January 6, 1890. Serial No. 366,018. (No model.)

To all whom, it may concern:

Be it known that I, ALMON ICALKI-Ns, a citizen ot` theUnited States, residing at Bridgeport, in the county of Fairlield and State of Connecticut, have invented certain new and useful Improvements in Steam-Engine Indicators; and Ido dcclarethe following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompany'- ing drawings, and to the letters and figures of reference marked thereon, which form a part of this specitication.

My invention relates to steam-engine indicators.

Among the objects of my invention is the improvement of the parallel movement, perfecting thereby the ratio of movement of the pencil to the piston; also, to improve the indicator in many other respects that will add greatly to its efficiency as well as to simplify and cheapen its construction.

To this end my invention consists, first, in

mounting rigidly or forming at the upper endot the indicator piston-rod a compensating curved surface or guide to engage with the pencil-carrying bar of t-he parallel movement, such curved surface or guide projecting` laterally from the piston-rod and iu the direction or path described by the forward and backward movement of the pencil-carrying bar, and, second, a spring to preserve the contact or engagement of such pencil-carrying bar with the curved surface or guide of the piston-rod.

My invention further consists in providing the hub of the swivel-plate, which plate supports thelevers of the parallel movement, with a hub or projection, which hub operates in a recess of the cylinder-cap and is held in place by means of a ianged projection on the piston-rod guide-sleeve; also, to provide a nipple in the outer casing or shell of the cylinder and above the piston, to which a hose or pipe may be attached to provide an outlet for the steam escaping by the piston; t' urther, to provide means whereby the piston may be lubricated from the exterior of the cylinder-casing, such means preferably consisting of an oil-holethroughsuch casingand a cover for such hole to exclude the dust; further, to provide the paper-carrying drum with a long sleeve mounted on the drum-stud, such sleeve being rigidly attached to the top of such drum, a web rigidly attached to the lower end of such sleeve to assist in strengthening such drum inits position on thecarriage; further, to regulate the tension of the drumcarriage spring by means of a ratchet-wheel rigidly attached to the drum-stud, a horizontally-placed disk attached to a sleeve of tho drum-carriage spring, a pawl mounted on such disk to engage with the ratchet-wheel, the carriage-spring arranged to be reversed that the instrument maybe used either right or left handed, and, further, to provide the drum-carriage with a stop-pin whose head projects below such carriage and engages a stop adjacent to said carriage, and by means of which stop the maximum travel oi' the carriage is limited.

My invention further consists in providing the paper-carrying drum with a compensating balance or weight, which balance or weight is placed ecoeutrically with the axis of suoli drum, such balance arranged to be shifted in any position about such axis, thus balancing such drum in its reciprocating movement, and thereby causing it at. the instant orcommencement of its reverse action to be identical or in time with the reverse action of thepiston of a steamengine, to which engine the indig cator is connected; further, to'hold the drumcarriage and its paper-carrying drum in any position required by means of astop-pin actuated by a spring, said pin and springlocated, preferably, in the frame of the indicator, the projecting end of such pin engaging with the drum-carriage, and, further, in attaching a support to the papencarrying drum in 'such a' manner that sufficient space is left between?" such support and drum to receive the tongue' ot' the paper-spring, which spring by means of said tongue is attached directly to the support instead of the drum, as heretofore constructed, all of which improvements will be more fully described in the speciiication, and particularly pointed out in the claims.

'lo more t'ully understand my invention, reference is had to the accompanying drawings, forming a part ot' this specification.

Figure 1 represents a side elevation of my improved indicator. Fig. represents a sectional view et the device shown in Fig. 1. Fig. 3 represents a top plan view. Figs. 4, 5, G, '7, S, and 9 represent detail views. Figs. 10, 11, and 12 are diagranis representing the result or effect of the different construct-ions of the parallel movement. Figs. 115 and lt also represent detail views.

Its construction and operation are as follows:

1 represents the cylinder casingor shell; the frame to which said casingis attached; 3, the cylinder proper, situated within the casing; 4, the piston; 5, the piston-rod; G, the guide-sleeve for said rod; '7, the cylinder-cap;

` S, the nipple attached to the cylinder for an outlet for the steam escaping by the piston; 9, the pressure-spring overlying the piston; lO, the taper-shan k th u mb-n ut to prevent leakage of steam through the piston; 11, the pencil-bar; 12, the vibrating arm loosely engaging with the pencil-bar and standard 13, the link loosely7 engaging the pencil-bar and its connection on the swivel-plate Si); 15, the paper-drinn; 1G, the paper-drum carriage; 17, the drum-carriage spring; 18, the ratchetwheel; 19, the pawl for same; E20, the cordpulley; 21,the cord-guide sleeve; 22,the housing overlying the same; 2S, the tighteningkey for said sleeve.

As before mentioned, one of the objects sought to be obtained by this invention is the improvement of the parallel motion for indicators, it being a well-known fact that an imperfection exists in such motion, which consists in the variable ratio of motion of the piston to the pencil-zl e., the pencil does not move in time at all points ot' its elevation with the piston. This defect bears upon the aecuracy of the diagram, and for correct delineations is unreliable. The movement of the pencil situated at the end of the pencil-bar is in practice four times faster than the piston. New, if the piston should be moved onesixteenth of an inch the pencil should move four-sixteenths of an inch, and tor each succeeding one-sixteenth of an inch movement of the piston four times that distance or four` sixteenths of an inch should be shown or rceorded bythe peneihand this ratio should be represented and maintained throughout-the entire movement ot' the piston and pencilbar. As the travel of the piston is necessarily limited within a small compass, the multiplied movement at the end ot' the pencil-bar is necessary in order to enlarge the diagram stiflieient to obtain a clear and correct reading.

In order to transmit to the pencil a movement exactly in time with the piston, Iprovide the curved surface 24 to the top ot' the pistonrod 5, (see Figs. 1 and 2,) and this curved surface may be a part of the piston-rod proper; or it maybe formed on the separate piece 25 and attached to said rod. The roll 215, which is attached to the pencil-bar, travels on the curved surface 2t.

In order to give a clear idea ot the object sought to be obtained by the use of this curved surface on the piston-rod and its proper relation to the motion of the pencil and piston, it will be necessary to refer to some of the features ot' both the Richards and Thompson indicatorsbearing on this point of the equality of ratios.

The Thompson invention shows an improvement of the Richards parallel motion in the matter of reducing the weight and number of parts. In the effort to do this a very importantfeatnre was necessarily sacrificed, and this was the equal ratio of movement of the pencil to the piston in any desired multiplication.

lly reference to the outline diagram, Fig. 10, the Richardsparallel motion is described. A B represent the line of motion of the piston, and C l) that ot' the pencil. The dotted lines E F and J I represent levers. Line F I represents a link connecting such levers. M represents the pencil-point. The line A B represents the path through which the indicater-piston moves. O I represents a link connecting the line A B with the line E F. Now, as the line 1G F from E as a pivot moves through the are G II and the line .I I from J as a pivot through the arc K L it will carry the point M of the line F I through the straight line C D, which line is parallel with line A B. It follows therefore that the line O I and F I if parallel in one position will be parallel in everyposition. A straightline will always connect E I M, and M, movingin the line C D, will be parallel with P, moving through the line A 13.

The diagram in Fig. 11 represents the Thompson parallel motion. A I3 represents the piston-rod, and U I) the line through which the pencil nieves. The dotted lineEF represents the pencil-bar swinging from E of the dotted line E L, which dotted line represents a link. The dotted line O I represents a link connecting E F with A B. New, as I) of the line O I moves through the line A I3 it will cause I of the line I l( to move through the are M N, E F through the line C D, and E of the line E L through the arc T IV. O will also move through the angular curve R S. New, as the ares M N and T Ware tixed and constant, the position ol F, by means of the versed sine of the are T W, will cause the position of F to vary with each ot' the several positions occupied by I), moving through theline A ll. This is made apparent in a practical manner by the following operation: A model ot this parallel motion having been made, a micrometer-screw cut forty to the inch, with a graduating-sleeve reading to thousandths, is fitted under the piston in the line ABwith the screw just touching the piston. A paper is placed on the drum of the indicator and the pencil jin the end of the pencil-bar is brought into contact with the paper. The drinn is turned slightly and the li rst or lower and will also carry F ofthe line IOL) IOO

mark of the series of graduations 27 at the left of Fig. ll is traced, one turn of the inicrometer-screw is made and the second line of the series is traced, and each succeeding turn of the screw a corresponding line of the scale is made. As themultiplication of movement was four to one, the lines drawn in the scale 27 should be exactly one-tenth of an inch apart for every one-fortieth-of-an-inch movement of the piston. A falling off in the graduating-scale is very apparent when'the scale of inches 28 is consulted; a shortening of the scale is very perceptible in the lower graduations. An examination of the diagram in Fig. 1l will show why these errors occur. )When the lower mark ofthe graduating-scale 27 was made, the line O P at O was in the irregular curve R S, nearly to the arc M N; but as motion was given thepiston the point O moved in a line drawing rapidly away from arc M N, and at the same time the point E moved rapidly through the elevation represented by the versed sine of the are T V,

causing by this counteraction the pencil to fall, and thus record irregular gradnations.

To rectify these errors, I have devised a compensating medium in the curved upper surface 24 of the piston-rod.

By referring to diagram in Fig. l2 will be shown the principle on which curve 24 operates to correct the errors above described. A B represent the line of motion of the piston, C D that of the pencil. The dotted lines represent the moving parts, line E F representing the pencilbar, which turns at E on the fulcrum-link E L, substantially as in the Thompson.

I K represent the vibrating' arm pivoted at I to the pencil-bar E F. This arm moves about the fulcrum K in the arc M N. Through the medium of such arm the point F of the bar on line E F is caused to move in the line C D an'd the point E in the arc T YV. The pencil-bar or line E F has the roll 26 connected thereto, as before described, which engages' with the line O P, which line represents the curved surface 24 of the upper part of the piston-rod, as the saine law governs the action of the pencil under the influence of the vibrating links I K and E L in this case as in the Thompson invention.

The curved surface 24 (represented by line O P) is so formed or adjusted that while the piston is being moved in the line A B the point S (which is the center of the circle described bythe roll 26, whose periphery touches the line O P) moves on the left-hand side of line A B and at right angles to such line and on the right-hand side through an arc, the relative combination of these surfaces compensating for the variations represented at this point by thev Thompson parallel motion.

The same practical test of the microi'neterscrew applied under the piston of my improved device resulted in producing the uniform scale 29. (Seen to the left of the diagram in Fig. l2.) As the multiplication of the power of the levers in this device is tive to one, the scale will be, as represented, in oneeighth of an inch. The inch-scale to the left of graduating-scale 29 shows the value of my improvement in obtaining the exact subdi- Y vision of the inch into equal parts. It will be observed on referring to the drawings, Figs. l and 2, that the curved surface is an irregular one, which curve is the path of the roll 26, thus compensating for the variations above alluded to. The pencil-bar 1l has the forked end ll (see Fig. 3, Fig. 2 showing one of such forks removed) to admit the upper curved top 37 of the pistonrod, the roll 2G being supported on pin 30, passing transversely through such forks, as seen at Fig. l. To keep the roll always in contact with the surface 24, the spring 31 (see Fig. 14, which represents a perspective view of such spring, a sectional view being also shown in Fig. 3) is coiled around the hub of the vibrating lever l2, which hub is secured by the screw 32 to the standard 33, one arm of such spring engaging with the vibrating lever l2, and the other arm 35 engaging with pin 3G of the standard 33. Thus a downward pressure is always exerted on the pencil-.bar through such lever. This pencil-bar spring keeps such bar steady, and prevents undue oscillation or iiing,and would be an important feature on any parallel motion, even if not used in connection with the upper curved surface of the piston-rod. It will be observed that in appearance the upper portion or top of the piston-rod is an irregular-shaped slot; but it must be distinctly understood that the upper portion 37 has no reference to theV compensating-curve 24. Such upper portion 37 may be removed entirely, as shown in Fig. 2. Therefore it does not operate in any manner to assist such curve in performing its part in establishing the equality of ratios. It simply prevents the dislodgment of the roll 26 in shipping or rough handling of the instrument. The standard and the lug 3S, to which the link 13 is hinged, are both mounted on the swiveljplate 39. This plate is provided on the swivel with the boss 40, whichtits a recess in the cap 7. This plate is held in position by the piston-rod guide-sleeve G, which sleeve is double-shouldered at 4l and 42,one of which shoulders abuts firmly against the cap 7, and the other holds the swivel-plate sufficiently firm to enable the latter to turn or swing to and from the drum. The proper relation of the pencil to said drum is regulated by means of the screw 43, (see Fig. 3,) which screw passes through said plate and engages with the pin or standard 44 of the frame 2. The jam-nut 45 on said screw locks it in any position required. y

The piston-rod guide-sleeve G (see Fig. 2 serves a threefold purpose. It holds the swivel-plate in position, it serves as a guide` for the piston-rod, and the threaded end 46, which projects through the cap 7, engages witlrthc threaded mounting 47, to which the IIO pressure-spring 9 is secured. As more or less steam will leak by the piston and create back-pressure thereon, an outlet is provided for such leakage through the nipple S, which nipple is screwed into the casing l. The outer projecting end of such nipple is made sufficiently long to receive preferably a flexible tube, and this tube will carry the steam Vfar enough away from the instrument se as to avoid soiling the card.

The oil-hole 48 is provided through the casing just above the cylinder 3, so that the piston may be lubricated without removing the same. )Vlien not used and te prevent the escape of steam, said hole is closed by the guard 49, controlled by stud 50. A clearer view of this feature may be seen in the section de tail view in Fig. 7, representing a section of the stud through line x7 of Fig. 2. The thumbnut l0, (see Fig. 2,) which engages with the lower threaded end of the piston-rod 5 and connects the piston and rod, is provided with the taper head 5l, which fits closely a taper seat provided in the upper part of said piston. This ground taper joint prevents the steam escaping through the pistoni'od opening in the piston.

As an improvement in the manner of attaching the instrument to the engine-cylinder, the lower end et the cylinder' is provided with the tlange52. The flange 53 of the shell 5l engages therewith. The internal-threaded ring 55 is placed within the shell 5l and held there by means of the screwed ends 56 of handles 57, passing through the shell 5st and inte threaded holes in the ring 55. The cock (not shown) to which the indicator is supposed to be attached is provided with a taper mouth te receive the taper end 5S of the cylinder. The threaded ring 55 engages with a thread formed on the cock, se that by means of the iianges ot the cylinder' and shell, together with the threaded ring` and the handles, a iirm connection is made to the cock. Formerly the eonnection between the indicator and the cock was too frail. As the whole weight ot` the instrument must be supported en the cock a iirm connection is very essential, in order te prevent undue vibration of the moving parts. Another advantage of this connection aside from its importance as a rigid connection, is the simplicity et' construction. All the parts are susceptible ot being duplicated by means of the proper tools and at small cost.

To preserve the alignmentef the drum and take the strain from the drum-carriage, the long central sleeve 50, mounted on the drumstud, is attached to the top or cap of the drum and also to the tlange or web 62, which web and sleeve by their rigid connection with each other practically ferm one piece. This arrangement thoroughly braces the drum and stea'dies it in its rotating movement. This internal support also enables the drum to withstand such outward pressure or blow as would otherwise dent or distort its surface.

The central bearing of the drum-carriage 1G (see Fig. 2) engages with the enlarged portion G3 of the drum-stud. The hub (Si of said carriage also lits a recess in the bushing 65, a reduced portion of which bushing enters the frame 2. An enlarged portion of the bushing (35 also enters plate 6G. The sheulder 67 of the drum-stud is also seated in the betteln of the recess in the bushing and held there by means of the lower threaded end 08. A thumb-nut G9 and washer 70 hold the cordguide plate (JG in any position required. 'lhe inner end of the coiled clocksprin g 17 within the drum-carriage is attached to sleeve 72, mounted on the drum-stud 60. Each end of such sleeve is squared. One et such squared ends 73 can be seen more readily in Fig. 5, which represents a plan ofthe frame 2 and drum-carriage mounted thereon with drum and disk 74 removed, showing an interior View of the carriage.

Mounted en the drum-stud GO and just over the disk 7l, but not in contact therewith, is the ratchet-wheel 18, its pawl l0 and pawlspring 75 beingattaehed te the disk 7i. A pin 7 G passing transversely through the ratchetand d rum-stud rigidly secures said wheel to the stud. The object ot' the ratehet-wl1eel is te wind up the clock-spring in the drum-carriage to the proper tension required to return the drum back te its normal position. W'hen the drum is being revolved, the disk 7l, sleeve 72, and pawl lf) remain stationary.

The outer end of the cleck-spring 17 is provided with the loop or eye a, which eye engages with the stud 77. (See Fig. 5.) This stud has an intermediate thread, which is fittcd te a hole, which hele passes through the base et' the drum-carriage. (See Fig. 2.) The head 7S of such stud enters the circular groove 79, which groove is lformed in the upper surface of the frame 2. This groeve dees not extend entirely around. the circle, the narrow bridge or neck SO (see Fig. 5) being left to for'm a step for the head 7S, so as te limit the travel of the drum-carriage- The instrument is intended te be used right or left handed, the views all showinga righthand construction. 'lhe cord Sl, which passes around the outer circumference of the drumcarriage in groeve S2, rota-tes the drum and carriage from right to let't. To reverse this motion, the spring 17, together with its sleeve 72, is removed from the drum-stud and turned over. This brings the lower squared end 83 (see Fig. 2) of the sleeve 72 uppermost. This reverses the retractile power et the springi. e., the spring unwinds in the opposite directien. 'lhe pawl is also turned over on the disk, so as to engage the ratchet in the opposite direction, said ratchet being also reversed. The lead of the cord 8l around the carriagedrum will also be reversed. The position of the spring-stud 77 will be at the right side et` the bridge SO", instead of theleft, as shown in Fig. 5.

In changing from right to left handthe pencil-bar l1 is placed on the opposite side of the stanf'lardfrom what it now occupies in the different views. The stop-pin will also be. entered from the opposite side ot swivelplate 39. Said plate will then be turned around, bringing the pencil in contact with the opposite side of the drum 33 in the above operation is also turned on its axis simply by loosening screw 84E.

Heretotore it has been customary to detach or unhook the indicator-cord from its engineconnection in order to stop the drum, to remove the card afteradiagram-has been taken. The rapid movement of the cord under high speeds renders this a diliicult operation. To overcome this dit'liculty, I propose to stop the drum at the point of its forward completed stroke. This I accomplish by means of a spring stop-pin in the following manner: This stop-pin 85, which proj ects through frame 2, (see Fig. 2,) is actuated bythe spring 86 in the pocket 87, which pocket projects downward from said frame. The pin 85 has the projection 88, (see also Fig. 8,) which engages with the lower end of the pocket when the spring S6 is compressed and drops into the notch or slot 89 when said pin is released. )Vhen the drum by means of its connection with the engine has been carried or rotated to the proper point, then the stop-pin 85 is released and its conical-shaped point engages indentations 90, provided on the under side of the drum-carriage. In place of such indentations, as shown in Fig. 2, the bottom surface 90' of the drum-carriage may be corrugated, as shown in Fig. S. This will check the movement et the drum, so that the card or diagram-paper may be removed and replaced by a new one. In the meantime the cord-connection between the indicator and the engine is unbroken. As the drum was stopped when the slack of the cord was all taken up, said cord will merely vibrate with the motion of the engine. Disengaging the stop-pin will instantly cause the drum to resume its rotating motion.

Another feature in my improved indicator is the manner of constructing the paperspring which holds the card or diagram-pa- 'per to the face of the drum. Ileretofore the spring has been screwed directly to the drum and the drum made thick enough to support the screw. To avoid this extra thickness of the drum, which should be as light as possible, I'provide the support 91, (see Fig. 1,) which support is attached to the drum bythe rivets 92, (see also Fig. 4,) which View represents a plan of the bottom of the drum and a section of the spring-support through the line of the rivets. The lugs 93 are formed on the inner face of such support, so as to form the bridge 94, thus leaving an open space between the drum and spring-support. The hole 95 (see Fig. 4) is also provided through the bridge. Wit-hin the open space between said drum and bridge is inserted the tongue (Sec lower broken section ot the paper- The tapped hole 9S is 96. spring 97 in Fig. 6.)

The standard t provided in the tongue to receive a screw 99 (see Fig. 1) and hold it rigid to the bridge ot the support. By this method of attaching the spring it is rendered more liexible and even in its action and less liable to break.

A further improvement in connection Wit-h the drum consists in providing a compensating balance thereon for the purpose of causing the oscillations ot said drum to be more equally in time in its relative positions with the positions of the piston of the engine during its stroke. In other words, this compensating balance placed eceentricaily with the axis ot the drum will preserve the equilibrium of such drum in its reci procative action and prevent undue fling or throw et the drum, so that the steam-engine at the beginning of its return-stroke andthe reverse or return motion of the drum shall be ident-ical, both movements occurring simultaneously. I accomplish this by means ot the adjustable radial arm 100, (see Figs. 2 and 13, Fig. 13 being an inverted sectional plan of the drum through line Y13 of Fig. 2,) which arm is attached to the end of the central sleeve 59, which projects below the web 62. The huh ot' the arm alouts against said web, and is held there rigidly by means of the threaded n ut 102. The slot 103 is provided in said arm for the weight. Such weight is provided with the slot-ted head 104: and athreaded body,which passes through the slot ot' the arm and engages the threaded nut 105, the whole forming the counter balance or weight.

The compensating feature of this balance lies in the ability with which it can be adjusted to any angle of any fixed positions of the drum. These fixed positions relate to the different positions ot said drum under the different tensions of the drum-carriage spring 17. This is accomplished by adjusting the weight in or out on the radial arm or turning said arm on its axis, or both. As the horizontal line drawn by the pencil on the drum represents in its length the stroke of the piston et the engine in reduced form, any position in this line must exactly represent the position of the piston of the engine in it-s stroke. To make the drum under the influence ot the spring under various tensions at various speeds perform this duty, the counteracting influence of the weight has necessarily been called into play.

A further improvement et my device vre-A lates to the construction of the cord-guiding attachment, which attachment is mounted on. the plate 66, a hole in said plate engaging -with the enlarged portion of the bushing G5,

and such plate held in any required position by the n ut 69 and washer 70. The housing 22 has the threaded stud 106, which projectsv through said plate and is held there by nut 107. The hole 108 is provided through suclr housing to admit the hub or sleeve 21ot thel pulley-hanger 110. (See also Fig. 9,which.is a section through fof Fig. 2.) Saidhub has ythe hole 111, through which the cord passes IOO tothe pulley 20. The object of this construction is, iirst, to carrythe cord from the drumcarriage to the engine-connection through the medium of the pulley, with an equal tension between said pulley and the drum-carriage; second, insuring the positive turning of the pulley ou its axis 112; third, that the cord shall be kept in position about the drumcarriage and not allowed to drop away. All these features are accomplished by widening the face of the pulley, so thatthe cord may be wound once or more times aroiuid the same.

The housing may be turned on its supportiiig-plate at any angle required, or said plate turned on its support on such bushing U5, or both, so that the cord may lead from either side of the drinn-carriage for either a right or a left hand arrangement cl3' the instrument.

I have provided a novel feature in clamping the cord attachment to its supportingplate. The hub 21 of the piilley-lianger has the groove 113 formed around its face, and into such groove the projection 11-1 of the key 23 is forced when the housing is drawn downward by means of the nut 107, thus eft'ectually clamping such hub firmly against the upper wall ot' the hole in such housing.

lleretoforc a plain hoek has been used to connect the indicator with the engine. This does not admit of the stretch of the cord being taken up. To overccinc this, I have provided the adjustable hook 115, having` its end threaded, which threaded end engages the threaded swivel 11G, by means ol` which any stretch of the cord may be taken up without loss of time.

lleretcfore a plain hole has been provided in the end et' pencil-bar to admit the pencil, and much difficulty has been experienced in getting a nice adjustment of the point in its proper relation with the diagram-paperon the drum. 1 have provided the threaded hole 117 (see Fig 3) in the end of the pencil-bar, and into which is screwed the threaded metallic pencil 118.

To further facilitate the construction of the device, the frame 2 (see Fig. 9) and the casing 1 are made separate. lhe shoulder 11i) on such casing forms a seat for such frame, The hole 120 (see Fig. 5) is provided in the frame to engage with the body of the easing above the shoulder 119. The thrc aded nut 121 engages a thread on the exterior of the casing-body and holds said frame firmly on its seat.

Itis evident that Sonie ot the details ol' construction in the above-described device may be modified or changed without departing from the spirit ot' my invention-such, for instance, as the position ci' the drinn counter balance or weight, which would be equally as effective if placed on the'drinn-carriage instead ot' on the drinn, as shown.

Having thus described my invention, what I claim, and wish to secure byliettters Patent, is as follows:

1. As an iinprovenieiitI in steam-engine indicators, as a compensatingfeature in t-he parallel motion to equalize the motion of the pencil to the motion of the piston, the combination, with the piston-rod and the pencilcarrying bar,of a contact-surface, preferably situated at the upper end of such rod and rigidly secured thereto and projecting laterally therefrom and in the direction of the forward and backward movement of the pencil-carrying bar, such surface to engage with said bar, and means to bring about such engagement', the contour of the tace ot` such sm'- l'ace of the pistonrod engaging such pencilcarrying bai' being so formed or shaped that the piston in Vits movements will ca use the pencil at the end of the pencil-carrying bar to move throughout its full range in an equal ratio of time with thcmovementof the pistou, substantially as and for the purpose set forth.

2. The combination, in a steam-engine indicator, of a pencil-carrying bar and a vibrating arm or link loosely connected by one ot its ends to the pencil-carrying bar, its other end loosely journaled to a fixed standard, with a spring exerting a downward pressui'eto the pencil-carrying bar through the medium of the vibrating arm or link, so as to prevent undue vibrations while such pencil-bar is in motion, substantially as set t'orth.

3. The combination, ina steam-engine indicator, of the piston-rod 5,havingat its upper end the laterally-projecting surface 2t, pencil-carrying har 11, havingl the roll 96 to engage with such uppersuiface of the piston-rod, and the spring 231, exerting a downward pressure to the pencil-carrying bar through the medium of the vibrating arni 12, so as to keep the roll ol the pencil-carrying` bar always in contact with such upper surface of the piston-rod, as described.

l. The coinbination,hi a steam-engine indicator, of the swivel-plate 39, having standard and lugSS mounted tliereoinwhicli standard and lug support the several levers of the parallel movement, said plate having a circular hub or projection engaging with a recess in the cap of the cylinder shell or easing and arranged to revolve thereon, with the pistonrcd guide-sleeve t, having lower threaded end to engage a threaded hole in said cap, and a projecting shoulder on such sleeve to engage with and hold in place the swivel-plate, as set forth.

5. The combination, in a steam-engine indicator, of the piston-rod and the casing-cap with the long guide-sleeve mounted on such rod, said sleeve having a threaded end engaging a threaded hole in such cap, a portion 0f such threaded end projecting through said cap and engaging with the upper spring-mounting` of thepressure-spring within such casing, as described.

U. The coinbination,in a steani-engineindieater, et the swivel-plate 39 with the standard 33, said standard arranged to be revolved upon its axis on such plate, and means to se- IIO cure such standard lixedly in any position required, as setforth. Y

7. In a steam-engine indicator, the outci casing or shell of the cylinder provided with the nipple 8, to which a hose or pipe may be attached to provide an outlet for steam escaping by the piston, substantially as set forth.

8. Iii a steam-engine indicator, the cyliiider casing or shell having an oil-hole coinniunicating with the interior of such shell and the cylinder,such hole situated in said casing at a point above the cylinder, and a cover to close such hole, so as to prevent' the entrance of dust and escape of steain from the casing, as described.

9. The combination, in a steain-engineindicator, of the piston-rod 5, having` its lower end threaded, piston 4, attached to such lower end, thumb-n ut lO, having a threaded hole to engage the threaded end of said rod, and a.

taper head 5l, which engages with a corresponding taper seat provided in the piston, so that by the engagement of such taper surfaces a close joint is formed to prevent the escaping of steam by the piston, as set forth.

10. The coinbination,in a steain-engine indicator, of the drum-carriage, druin-stud, frame 2 to support suoli stud with the drum, having the long sleeve journaled on said stud, said sleeve rigidly attached to the upper portion or cap of said drum, and a Web radiating from the lower end of said sleeve and rigidly secured to the internal surface of the drum, whereby the same is braced and strengthened on its support, as set forth.

11. The combination, in a steain-eii gine indicator, of the drum-carriage, the coiled drumearriage spring mounted thereon, the outer end of such spring attached to said carriage, the drum-stud, a sleeve journaled on such stud, said sleeve attached to the inner end of `the coiled druin-carriage spring, a ratchet? Wheel rigidly attached to the drum-stud, a horizontally-placed disk attached to the springsleeve, and a pawl mounted on such disk to engage the ratchet-wheel, so that the tension of the drum-carriage spring may be regulated.

12. The combination, in a steam-engine indicator, of the drum-stud, aframe to support such stud, the drum-carriage journaled on said stud, a spring mounted on such carriage, the inner end of such spring attached to a sleeve journaled on the drum-stud, the outer end of such spring attached to the drum-carriage, a ratchet-wheel rigidly attached to the drum-stud, and a disk carrying a pawl, which pawl engages said wheel, said disk mounted on one end of the sleeve of the drum-carriage spring, said sleeve so constructed that it may be reversed and either end engage with such disk, and by such construction the indicator may be used either as a right or left hand instruinent, as described and set forth.

13. The combination, in a steam-engine indicator, ot' the drum-stud, the drum-carriage journaled on such stud, and the coiled drumcarriage spriiighaving its outer end attached to said carriage and its inner end attached to a sleeve journaled on such druiircarriage, as set forth.

l-l. The combination, iii a strain-engine indicator, ot the drum-stud 60, the drunrcarriage 15, journ aled th ereon, the drumcarriage spring l 7, and sleeve 72, to which the inner end of such `spring is rigidly attached, such sleeve journaled on the drum-stud,the outer end of such spring provided with a ring to engage the stud 77 ot' said drum-carriage, head 7S of such stud projecting below said carriage to engage a stop adjacent to such carriage, and by means of which stop the maximum travel of the drum-carriage is limited,substantially as described.

15. The combiiiatioii,in a steam-enginemdicator, of the drum-carriage, the paper-cai'- rying drum mounted thereon, druin-stnd on which said carriage is journaled, drum-carriage spring, druin-carriage-spring sleeve j ourn aled on said stud, stud 77, attached to said dru m-ca'rriage to engage with the outer end of said drum-carriage, spring-head 78 of such stud proj ecting below such carriage, groove 79, formed in the frame 2 to admit such head, and a stop provided in such groove to act as a stop against which said head may engage to limit the maximum travel of the drum -carriage, substantially as set forth.

16. The combination, in a steamengine 1ndicator, of the drum-stud 60, the drum-carriage 17 journaled thereon, drum 15 mounted on such carriage, with a stoppin 85 ot' frame 2, spring S6 actuating such pin, and means provided on said druin-carriage to engage with the point of said stoppin to hold said carriage in any position required, as set forth.

17. The combination, in a steam-engine indicator, of arotating drum-carriage, a papercarrying drum mounted on such carriage, a compensating balance or Weight attached to such drum or carriage, such balance placed eccentrically with the axis of such drum or carriage, such balance arranged to be shifted in any position about such axis, thus causing the moment of the reverse action of said drinn and carriage to be in exact time with the moment of reverse action of the piston of the engine, as set forth.

1S. The combination, in a steam-engine indicator, of the wide-faced cord-guiding pulley 20, its pulley-hanger 110, on which such pulley is journaled, housing 22, within which is journaled hub 2l of such frame, said housing mounted on plate GG and arranged to turn in a horizontal plane thereon, so as to guide the cord from either side of the drum-carriage, key 23, to clamp against said hub of the pulleyframe, and nut 107, to hold such cord-guiding attachment firmly on said supporting-plate in any position required, as described and set forth.

19. The combination, in asteain-engine indicator, of the casing 1, having the projecting shoulder or flange 119, frame 2, situated on KOC IIC

Such flange projeeiion, und threaded nut 121, engaging a threaded portion of the casing to hold Su'eh frame firmly on its sont, all substantially :is desi-ribed, :1nd for the purpose Set forth.

20, The eolnl ination,with the paper-carrying drum oi' a steam-engine indicator, of the spring-support 91, lugs 93, projecting from the inner face of such support, said lugs nr ranged to rest upon the outer surface of the drum, thereby forming an open space hetween such drum and the inner farce of the support, means, substantially as shown, to Secure said support to the face of the drum,

the paper-holding spring having the tongue 0G, which tongue is inserted within the said open space between the support and drum, and means, substantially :is shown, for holding sneh spring through the medium ot' its tongue rigidly to the support, :ill Suhstan tially as set forth.

In testimony whereof I allix my signet ure in presence of two witnesses.

ALMON l. CALKIN S.

Witnesses;

SIGMUND LoEWITH, GEO. D. PHILLIPS.

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