Rotary engine.

Application filed May 27, 1905. Serial No. 262,559.

To dll whom it may concern:

Be it known that I, George Hidden, a citizen of the United States, residing at Wayland, in the county of Middlesex and State of 5 Massachusetts, have invented certain new and useful Improvements in Rotary Engines, of which the following is a specification.

My invention relates to rotary engines, em10 ploying a rotary disk provided with pistons in contact with the inside surface of a cylinder, the axis of the disk being eccentric with that common to the cylinder and the pistons.

My invention has for its various objects 15 the provision of first, a steam tight joint between the periphery of the rotary disk and the adjacent surface of the cylinder; second, one of more ports connected with a chamber formed in a part of the disk, to prevent ob20 jectionable compression in said chamber; third, a steam port that can not be closed by the piston; and fourth, a balanced piston.

The steam joint commonly used between the disk and the cylinder is at a point com25 mon to the surface of the disk and the cylinder, and is provided with a block of packing material, but as each piston at that joint rubs across the packing, and therefore tends to wear it out, it has to be narrow, because, if it 30 is not, it touches the disk for such a distance on each side of the point of contact between the disk and the cylinder, that it extends up into the space between the disk and cylinder, lies in the path of the end portions of 35 the pistons and is therefore soon destroyed, tends to stop the pistons and hence the engine, and uses up in wasteful friction much valuable power. Now by means of the first feature of my invention, these objections are 40 overcome, by substituting for this point contact and packing between the disk· and the cylinder, a depression in the inner face of the cylinder, the surface of which depression lies in an arc having the same radius and center 45 as does the disk; in this way a comparatively wide packing surface between the disk and the cylinder results, and lies outside of the path of the outer end portions of the pistons wliich always move in a circle having the 50 same radius and center as does the inner surface of the cylinder. In short, contact between the pistons and the packing is utterly impossible.

The pistons of the above type, have by 55 reason of the eccentricity between the cen ters of the disk and the cylinder, a movement relatively to that of the disk; the inner end portions freely moving in suitable recesses in the disk; but as each piston with a portion of a movable part of the disk forms a chamber 60 which is, comparatively speaking, steam tight, obviously any inward movement of a piston is resisted by the resistance offered by any air, steam, or liquid that there may be in the chamber, to compression; also there 65 would be a tendency to resist any outward movement of a piston, because of a greater or less vacuum created in the chamber by such outward movement of the piston.

By employing the second feature of my in- 70 vention, viz. a port connecting this chamber with the outside air, the objectionable compression, vacuum, or both, may be obviated.

In the operation of engines of the above type, a piston often stops over and com- 75 pletely covers the steam port, and hence to ' start the engine, the piston has to be moved clear of the port, the reason being that the piston is wider than the port. To overcome this serious defect, I have made the port 89 wider than the piston is thick, so that the port is always open to permit the passage of steam to one or two of the pistons.

The pistons formerly used have had their centers of gravity distant from their pivots, 3.5 and consequently, when in use centrifugal force has caused their pivoted bearing surfaces in the cylinder heads, and also the connecting surfaces of the cylinder and the pistons, to wear, all of which results in friction, 90 wear, loss of power, and a shortening of the life of the engine. By providing the piston with a counter-balance, so that the center of gravity of the piston is at the pivoted center, these troubles are greatly reduced. 95

Figure 1 is an elevation, showing my invention, when the cylinder head is removed, and the cylinder is sectional on line 1—1, Fig. 3. Fig. 2 is a perspective view of a balanced piston. Fig. 3 is a reduced vertical 100 longitudinal section, on line 3—3, Fig. 1, the piston being left in solid lines. Fig. 4 is a reduced elevation showing the inside face of a cylinder head, with counter - balanced pistons, partly in section, mounted in their re- 105 spective grooves; and an air passage. Fig. 5 is a perspective view of a cylindrical part -or plug for a piston.

In the drawings illustrating the principles of my invention and the best modes now 110

893,801 known to me of employing those principles, a cylinder 1, is provided with suitable heads 2, 2, mounted upon a base 3. A shaft 4 for transmitting power, and suitably supported 5 as by bearings not shown in the drawings, extends through the heads 2, 2, and the in side of the cylinder 1, and has fixed to it, in the cylinder, a circular disk 5; the axis 6 of the shaft 4, being eccentric to the axis 7 of 10 the inside surface of the cylinder 1.

In the inner surface of the cylinder 1 is a depression 8, the surface of which is concentric with and has the same radius and axis as does that of the disk. It will be noticed that 15 the eccentricity of the shaft 4, in its relation to the axis 7 or the cylinder 1, is such that a portion of the disk 5 lies outside of the curvature of the inside surface of the cylinder 1, shown by a dotted line Fig. 1. Between 20 these parallel adjacent surfaces of the disk 5, and the depression 8, is packing 9, adjustably held against the contacting surface of the disk, as by spring 10.

Pistons, 11, 12, 13 are mounted equi-dis25 tant apart in suitable recesses 14, 15, 16, in the disk 5, and also pivotally mounted in circular grooves 17, 18, 19, Figs. 3 and 4, in the cylinder heads 2, 2. Each piston, see Figs. 2, 5, comprises a bar 20 extending across the 30 entire peripheral face of the disk 5; rings 21, 21 connected with the bar 20 and engaging its respective groove, 17, 18, or 19, in the cylinder heads 2, 2, the center of each ring and groove being in the axis 7 of the cylinder 35 1; and a counter-balance 22, of such weight, fixed to its respective ring, and located at such a distance from the center 7 of the rings, as will counter-balance the weight of the bar 20 of its piston. The pistons 13, 14, 15, are 40 alike, except that their respective rings 21 and grooves 17, 18, 19., in the cylinder heads 2, 2, are of different diameters to enable the pistons to be mounted in the faces of the cylinder heads. Each piston is operatively con45 nected with the disk 5, by a slotted cylindrical part 23, mounted in a cylindrical chamber 24 of the same diameter and extending the full width of the disk 5, the bar 20 of the piston playing in the slot 25 of the part 23, 50 see Figs. 1, 3 and 5. A groove 26 is cut in the cylindrical part 23, Figs. 1, 3, 5, so that it opens into the bottom portion of the slot 25, and also into a passage 27, cut in the inner face of the cylinder head 2, and open to 55 the air. It is desirable, as is shown, to have two of such grooves 26 in each cylindrical part 23, and also two passages 27, one in each cylinder head 2, but plainly one will suffice. A steam port 28, Fig. 1, is provided, and its 60 size is so proportioned that a piston can never completely close it; the thickness of the former being less than the width of the latter.

For the sake of clearness, and also as 65 valves operating the ports, means for operating the valves, and a few other well known parts form no part of my invention, they are omitted.

The operation of the various features of my invention are as follows: Assuming that 70 the engine is taking steam through the port 28, and the piston 12 is in the position shown in Fig. 1, steam forces the pistons 12 and 13 about their center 7, in the direction indicated by the arrow, and the pistons in turn 75 acting through the cylindrical part 23 in the disk 5, cause the latter, and consequently the power transmission shaft 4, to turn. As the piston 12 continues in . its. movement about its center 7, more and more of its sur- go face is exposed to the action of the steam, until it reaches the position occupied by piston 13, when, as the piston moves on,.less and less of its surface is exposed until it passes by the intersection 29 of the cylinder 35surface and the surface of the depression 8; the steam, of course, exhausting at exhaust port 30, the moment the piston passes it. Each piston operates in the above manner.

It will be plain that, after the extreme 90 outward movement of the piston in its relation to the disk, the bar 20 of the piston begins to approach the bottom of the slot 25, Figs. 3, 5, in the cylindrical part 23, and begins to tend to compress any air, or steam 95 that may be confined in the chamber formed between the bar 20 and the walls of the slot 25 in the part 23; but as this compression is not very appreciable until the piston has reached, say, the position of the exhaust 30, 100 the passages 27, in the cylinder heads 2, 2, are shown as becoming connected with the grooves 26, and hence the said chamber, after that time. When this connection is made the compression is relieved, and any 105 liquid, as condensed steam, is permitted, by its own weight, to flow out of chamber, through the grooves 26, passage 27, and away from the engine. It will also be apparent that each of the pistons, after it has 110 passed the line of intersection 29, between the surfaces of the cylinder 1, and the depression 8, recedes within the periphery of the disk 5., the ends of the pistons describing the path indicated in dotted line in Fig. 1, 115 but at this moment, the periphery of the disk 5 comes opposite, and into intimate proximity with the surface of the depression 8, and the packing 9; the outer end portions of the piston being distant from, and inside 120 of the periphery of the disk, thus avoiding all chances of interfering with the wide steam joint formed between the packing 9, and the disk 5; and not emerging through the periphery of the disk until it reaches the other 125 intersection 31 of the surface of the depression 8, and the inside surface of the cylinder 1. As the thickness of each piston, see Fig. 1, is less than the opening of the port 28, the port is always open for the passage of steam 130

893,801 to one or two of the pistons, and a piston therefore, cannot so stop as to close the port and thus require aid, outside of the engine, to start the latter.

The operation of each balanced piston is plain. The only friction retarding the movements of the piston is due to the weight of the piston; the wear on the rings, cylinder, and pistons, due to the very rapid revolu10 tions of the pistons, is reduced to a minimum; the life of the engine is greatly pro longed, and for a given amount of steam used, the efficiency of the engine is increased.

Having described all the features of my 15 invention, and desiring to claim them in the broadest manner legally possible,