US308598A - Duplex-crank-piston engine - Google Patents

Description

YNo Model.) 2 sheets-sheet 1.

J. DOW.

DUPLEX GEANK EISTON ENGINE.

Patente'd Deo. 2, 1884.

2 Sheets- Sheet- 2.

(No Model.)

J. DOW.

DUPLEX GRANK PISTON ENGINE.

Patented Deo. 2, 1884,

11pm@ N* Z f.

v M A miv ummm wmingwn. D. c.

Nrrnn STATES Plrrinvr` OFFICE.

J OSIAH DOV, OF LOYVELL, MASSACHUSETTS.

DUPLEX-CRANK-PISTON ENGINE.

SPECIFICATION forming part of Letters Patent No. 308,598, dated December 2` 1984.

Application filed March 10, 1854. (No model.)

To @ZZ whom t may concern.-

Be it known that I, Josmrr Dow, a citizen of the United States, residing at Lowell, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Duplex-Crank-Piston Engines; and I do hereby declare that the same are fully described in the following specilication and illustrated in the accompanying drawings.

This invention relates to improvements in dupleX-crank-piston steam-engines; and it is carried out. as follows, reference being had to the accompanying drawings, in Which- Figure l represents a side elevation of the improved engine. Fig. 2 represents an end View, seen from x in Fig. l. Fig. 3 represents a central longitudinal section on the line A B, shown in Fig. 2. Fig. 4 represents a crosssection on the line C I), shown in Fig. 3. Fig. 5 represents a cross-section on the line E F, shown in Fig. 3. Fig. 6 represents a side elevation 4of one of the intermittently rotary valves for admitting steam to the cylinders. Fig. 7 is a section of the same on line G H in Fig. 6. Fig. S represents a detail view of the valveopening mechanism, and Fig. 9 represents a similar detail view of the valve-closing mechanism. l

Similar letters refer to similar parts wherever they occur on the different parts of the drawings. In the drawings, a is the piston-shaft, to which the duplex-crank pistons are secured. Said-shaft is located in suitable bearings in the ends of the shell or cylinder, hereinafter to be described, and has attached to it a spurgear, a', that gears into a gear, b', of equal diameter and of equal number of teeth, the latter being secured to the shaft b, to which the rotary abutinents are secured.

c is the shell or steam-cylinder cast in one piece with the abutmentchamber c and base c, as shown, and c3 is a division-wall cast in one piece with cylinders c c. Said wall c3 is arranged midway between the ends of shell c c, and by its use the said shell is divided in two equal compartments, U and V, as shown in Fig. 3, each of such compartments contain-- ing a rotary piston and corresponding abutment-cylinder.

d represents the head, secured by means of sleeve or bearing a, on shaft a, such bearing i having a cap, da, or equivalent device for holding sleeve a in place. The sleeve c may be made in two semicircular parts or in one single piece, as may be desired.

a3 is a packing surrounding the shaft a at the inner end of bearing or stuflng box: a, in the usual manner, to effect a steam-tight joint between the shaft c and its head d, as shown in Fig. 3. In a similar manner the bracket d supports the bearing b for the shaft b, and is provided with cup d'l and stuffing b, for the same purpose, as above described.

To the opposite end of shell c c is secured the head e, in one piece with which is cast or otherwise secured the outwardly-projecting valve-chamber e', having a central bearingsleeve, e, provided with stuffing-box c3 and stuiing e* for the piston-shaft c, as shown in Fig. 3. In its lower end the head e has an outwardly-projecting bracket, e5, supporting the bearing b* and its cap eG for the abutmentshaft I), in the same manner as the corresponding bearing in head d, heretofore described.

b is the stuffing for shaft b in the head e, as usual.

On the shaft a, within the compartment U,

is secured the rotary cylinder f, provided with annular tapering grooves at the junction of roo or suitable material, resting in a corresponding groove in the sides and outer end of said piston, as shown, so as to effect a steam-tight n parts on cylinder j, with this differencathat joint between it and the interior of compartment U.

To the shaft Z), directly below the cylinder j', is secured the abutment-cylinder g, which is of exactly the same diameter as the cylinder f, and said cylinders are heldin contact with each other, so as to allow the one to roll on the other with equal surface velocity, and at the same time preventing the steam from escaping between them. Directly opposite the piston f is made on the abutment-cylinder g a curved cut-away portion, g', to permit the piston f "to pass by the cylinder g as they rotate together in opposite directions. The curvature of the cut-away portion f/ is such as to keep the piston f in immediate Contact with it, so as to prevent escape of steam during such passage of the said piston.

The cylinder g is provided with webs g3 g3 on the ends of the cut-away portion g', between which webs the piston f enters during its passage into said space g', to still further prevent the escape of steam at this point.

At the junction of the ends and curved part of abutment cylinder g, I make tapering grooves, into which are iitted the tapering packings g4 g4, made of metal or suitable materials, to effect a tight connection between said cylinder and the interior of the chamber in which it revolves.

I prefer to make the abutment-cylinder g Skeleton fashion-that is, with a central hub, g5, secured' to shaft b and radial arms g, as shownso as to make it as light as possible.

g" is a semicircular (more or less) space between the exterior of abutment-cylinder g and interior of abutment-chamber adapted to receive steam, and thus to equalize the pressure in compartment U, and causing the cylinders f g to be held in close contact against each other during their rotation, and also to aid in lubricating the said abutment-cylinder in its motion.

g8 g5 are packing-rods of metal or'other material located in corresponding grooves, g gg,in the upper sides of abutment-chamber,as shown in Figt, such grooves being made deep enough to contain springs, if desired, to hold said packings against the abutment cylinder to effect a close joint at such place.

Behind the cylinderf is secured to the shaft a the secondary cylinder 7L constructed in the same manner as cylinder f, and secured to it in a suitable manner. The cylinder 7L is located in compartment V, and is provided with tapering packing-rings Zt h', projecting piston 71,, having packing h3 like the corresponding the piston f is located in a diametrically-opposite direction to t-he piston h, as shown in the drawings, to etfect a perfect balance of said cylinders.

Below the cylinder h. in the corresponding abutment-chamber, is located on the shaft b the abutment cylinder Z, of equal diameter with said cylinder h, and provided with curved cut-away portion fi, webs i i, tapering packings Z* t, central hub, i5, radial arms i,semi circular space Z7, packings and grooves in a similar and corresponding manner to those on abutment-cylinder `f/,with this difference, that the cutaway portion z" is located in a diametrically-opposite direction to the cut-away portion g on cylinder g,to effect a perfect balance of said abutment-cylinders.

e7 is the steam-inlet to the valve-chamber e', as shown in Fig. 3, from which the steam is conducted back of the respective pistons f h, as follows:

Through the cylinder j' is made two longitudinal conduits, k and'Z, the former leading to the cylindrical valve Za in cylinder f, and the latter leading to the corresponding cylindrical valve, Z, in cylinder h.

k and Z are the valve-stems, respectively` for the valves 7c and Z, as shown in Figs. 3 and 4.

M is a flanged collar or bearing-piece secured to the outer end of cylinder f, and adapted to serve as a bearing for the outer ends of valve-stems k Z, as shown in Fig. 3.

f* and h* are steam-channels in the respective cylinders f and h, leading from the respective valves 7c and Z directly behind the respective pistons f h, as shown in Fig. 4, by means of which the steam-pressure is conducted back of the pistons f lfin the respective compartments U and V.

The cylindrical steam-valve 7c has three communicating side openings, (more or less,)lt3 k3 k3, with preferably a central core, Zt, for strengthening it, as shown in Figs. 6 and 7, and the valve-stem k has attached to its outer end a cam-disk, 7e, which I term the steam-supply or valve-opening cam,T7 and said cani is provided with three side-projections, 7c k, one of which is actuated by the projection m on the stationary ring m, that is secured to the exterior of the valve-chamber-bearing sleeve e, as shown in Figs. 5 and 8, for each time that the cylinder f completes its revolution, and thus causes the valve Zt' to be turned onesixth of a revolution around its axis to admit steam through channel f4. The cam-disk 7c is also provided with three radial projections, k6 k 7c, and concavo-convex curves connecting said projections, as shown in Figs. 5 and 8, adapted to lie in contact with the ring on, and to retain the valve k in an open position, in connection with corresponding openingcurves on closing cam-disk, until acted on by a corresponding cut-off mechanism.

To permit the projections he to pass by the circular ring m at the time its projection m acts on either of theside projections, ki, I make a depression, m, on the ring m in close proximity to the ring projection m, as shown in Fig. 8.

The steam cut-0H or valve-closing mechanism is carried out as follows:

On the valve-stem lo, outside of the camdisk 7c", is secured a similar cam-disk, K4, which I term the cut-off cam,77 and said cam is provided with three side projections, K K5 IOO iol;

IlO

K5, and three radial projections, K6 K6 K, and intermediate concavo convex surfaces precisely like those described on disk 704, and adapted to engage with the projection u on the movable ring a, that is loosely supported and made to turn around the bearingsleeve e, as shown in Figs. 3 and 9.

n" is a depression on the outside of ring n,

in close proximity to its projection n, for the sainefpurpose as described relative to projection m on ring m-that is, to permit the radial projections K to pass by ring a while the valve is in the act of being turned. The ring a is toothed on'its outer surface, and into it is geared the worm o, secured to worm-shaft o', located in suitable bea-rings in valve-chamber e', as shown in Figs. 3 and 5.

. To the outer end of worm-shaft o is secured the small bevel-pinion o", that gears into the bevel gear p,secured to shaft p, located in bearings -in the bracket l), secured to valve-chamber e', as shown in Figs. l, 2, and 3.

The shaftp is rotated more or less in either direction to cut off the steam at any desired part of the stroke, or to maintain any desired and uniform speed of the engine, by the following mechanism:

To the main shaft a is keyed the eccentricblock q, surrounded by the loose ring q', having an upwardly-projecting rod, Q, attached to it, the upper end of which plays loosely in the sleeve r, forming a part of the hub r', loosely supported on shaft p, as shown in Fig. 3. j

' To the hub r is made an upward extension, r, having hinged to it loosely the two pawls fr and r4, as shown in Figs. 2 and 3.

Directly below pawls r3 and r4 is secured on shaft p the spur or pawl gear s.

To the shaft p is hinged loosely the shieldplate t, that overlaps the upper portion of gear s, and may be swung on the said shaft p to the right or left by its connection to any ordinary governor, so as to permit one of the pawls r3 or r* only to engage at one time into the teeth of gear s, as shown in Fig. 2.

t is a downwardly -projecting balanceweight cast onto the lower side of the hub on shield-plate t, as shown in Figs. l, 2, and 3, such balance-weight being arranged for the purpose of balancing or steadying the plate or shield t in its rocking motion on shaft p.

t is a short lever attached or made in one piece with shield t or its hub or balanceweight t, which is to be connected in any suitable manner to a governor or regulator of any desirable construction, such governor being, however, not shown in the drawings. This speed-regulating mechanism acts as follows: By the eccentric q q', rod g", and sleeve r the pawls r3 r4 are oscillated on top of gear s continually, the shield t being, however, during this motion of pawlsa13 r so worked and held in position by its connection to the governor-lever u that only one pawl at the time,or neither of then1,acts on the gears, the other one, or both,` sliding looselyon top of shield t, as shown in Fia'. 2, so as to cause the gear s to turn in one direction, according to whether the governor and engine runs above or below its normal speed. As the gear s is turned it imparts motion to the loose ring a by the connecting mechanism, as described, and said ring is thereby automatically turned around the bearing-sleeve e to cause its projection n to act on the cut-oftl cam K4, and its side projections, K5, to turn the cylindrical valve Zt one-sixth ot' a revolution, so as to cut off the supply of steam to piston f at any desired position of its stroke or revolution, as may be desired. In a similar manner to the valve Zt, the valve Z has attached to its valvestem Z, on the outer end thereof, the steamsupply cam-disk Z, having side projections, Z5, and radial projections Z, as shown in Figs. 3 and 8. p

To the valve-stein Z" is also secured the corresponding cut-oif cam, L, provided with side projections, L, and radial projections LG, as shown in said Figs. 3 and 9. The valve Z has, like the valve k, -threc communicating side openings, Z3 Z3 I, to permit the steam to pass from conduit Z through the valve Z and conduit or channel h into the compartment V, back of the piston h. rlhe valve Z has, like the valve 7c, a central core to strengthen it. f

The valves k and Z are made to rotate intermittently in one and the same direction by the opening and closing mechanism, as above described.

Y is the exhaust-opening leading from compartlnents U and V. Such exhaust may be common to both of said compartments, or it may bc divided in two exitsf-one for each compartment-if so desired.

The operation of this my improved engine is as follows Steam, being admitted through steam inlet e7 into valve-chamber c', passes through steam-conduits k' and Z to valves Zt' and Z, and out through openings f* It" into the respective compartn'ients U and V and back of pistonsf h. Fig. 4 shows the position of pistonf and its corresponding abutment-cylinder, g, at the time of admitting steam through opening f. The piston h is then diametrically opposite, and may be pressed onward by live or expanded steam, as may be desired. j

The steam in advance of the respective pistons f h is free to pass out through exhaustopening Y. Duri-ng the rotation of pistons f Zt and their respective abutment-cylinders g t' the valves k and Z are intermittently rotated in a constant direction by the opening and closing rings m and n, their respective projections m and n', and the opening and closing cam-disks on the valve-stems, as hereinabove set forth and described, the whole of the mechanism being balanced properly, so that the engine may be run at a very quick speed without causing any noise or pounding and with 'a minimum of frietional resistance. The driving-shaft a may be supported outside of the shell or case c c in suitable bearings or pillow-blocks, and be provided with a suit- IOC IIO

able ily or balance wheel in the usual manner,

`such devices being, however, not shown in the drawings.

Having thus fully described the nature, construction, and operation of my invention, I wish to secure by Letters Patent and claiml. In a steam-engine, the shell c c', heads d e, the shafts a b, equally geared together, iu combination with diametrically-opposed cylinders and pistons ff h h, and their respective diametrically-opposed abutments g i, the steam-chest e at the outer end of head e, into which the steam is admitted through the steam-supply pipe situated upon and through the said steam-chest e', as described.

2. In a steam-engine, the rotary cylinder f and its piston f, combined with abutmentcylinder g, of equal diameter with cylinder f, the cut-away portion g', to permit passage of piston f, and curved steam-space gl on the interior of abutment-chamber, into which the steam passes from the main cylinder for the purpose of pressing the abutment-cylinder g against and securing perfect contact with the rotary cylinder f, as described.

3. In a steam-engine, the rotary cylinder f and its piston f, in combination with an abutment-cylinder of equal dia-meter, made skeleton fashion, with hub g5, arms g, side Webs, g3 g3, and having cutaway portion g, substantially as described.

4. In a steam-engine, a rotary cylinder having arrangedwithin it acylindrical valve, k, with side openings, 76315576, adapted to rotate ina continuous intermittent direction around its axis, to'deliver and cut off thc supply of steam, as set forth.

5. In a steam-engine, the rotary cylinderf, having arranged within it the cylindrical valve 7c, in combination with valve-opening cam k", secured to valve-stein k, and provided with side projections, k, and radial projections la, to operate with stationary ring fm, its projection m', and recess m, for the purpose of automatically opening the said valve 7c, as set forth.

6. In a steam-engine, the rotary cylinder f, having arranged Within it the cylindrical valve 7c, upon the stem 7c of which is arranged the steam-cutoff cam-disk Kt, having side projections, K5, and radial projections K6, in combination with the adjustable ring a, its projection a, and recess a, for the purpose of automatically closing said valve k, as set forth and described.

7. In a steam-engine, the stea1ncut-off mechanism, as described, consisting of eccentrics q, its ring q, and rod q, rocking piece r r, with its sleeve i', the hinged pawls r3 r, shield-plate t, connected to the governor, and provided with a counter-balance, t', the gear s, secured to shaft p, the bearing-bracket P, and intermediate `connecting mechanism, substantially as described, from shaft p to the loose ring a, as and for the purpose set forth.

`8. In a steam-engine, the rotary cylinder f, V

having a steam passage or passages .7c,located between the axis and outer periphery of said cylinder and communicating with the steampassage f, located behind the piston f, as set forth and described.

9. In a steam-engine, the movable ring or collar n, geared to the Wornrshaft o, for the purpose of adjusting the point of cut-off by the action of the governor, as set forth and described.

In testimony whereof I have affixed my signature in presence of two witnesses.

JOSIAH DOW.

Witnesses: j

ALBAN ANDRN, HENRY CHADBoURN.

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