US670758A - Cut-off valve. - Google Patents

Description

No. 670,758. Patented Mar. 26, |90I.

F. H. BATES.

CUT-UFF VALVE.

(Application'led Jan. 19, 1901.) (NoModel.)

. f\ Hllillt FRANK Il. BATES, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO FRANCIS G. BATES, OF SAME PLACE.

CUT-OFF VALVE.

SPECIFICATION forming' part 0f Letters Patent N 0. 670,758, dated March 26, 1901.

Application tiled January 19, 1901. Serial No. 43,880. lNo model.)

To all whom, it nto/y concern:

Be it known that I, FRANK H. BATES, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Cut-Ott Valves for Motive- Power Engines, of which the following is a specification.

The object of my in vention is to so construct the inotive-iiuid-supplyin g devices of a rotary engine as to effect the quick and accurate cut-off of the motive fluid for each stroke of the piston, whereby said motive iluid can be used expansively throughout any desired portion of the stroke. This object I attain by controlling the admission of motive fluid to the cylinder of the engine by means of a motive-fluid-actuated valve and governing the operation of said valve by means of a supplementary valve under control of suitable cam mechanism, whereby it may be held open or closed for any desired fractional part of the stroke.

In the accompanying drawings, Figure 1 is a side view of su fiicient of a rotary engine to illustrate my present invention. Fig. 2 is a transverse section of the same on the line a a; and Fig. 3 is an enlarged View of the valve mechanism to which my invention particularly relates.

1 represents the cylinder of the engine, which may contain a single piston-chamber in the case of a single high-pressure engine or two or more piston-chambers side by side in the case of a multicylinder or compound engine, each of the pistons in the present instance consisting of an eccentric 2, upon which is mounted by suitable ball-bearings a ring 3, having a rocking connection with a sliding partition-plate 4, which is guided in a chamA ber in the structure 5, projecting from the cylinder-casing, and serves at all times to separate the inlet from the exhaust side of the cylinder, as set forth in my application for Letters Patent filed December l5, 1900, Serial No. 40,016. The structure 5 also contains a reversing and directing valve 6, similar in character to that set forth in the application of Francis G. Bates tiled May 28, 1900, Serial No. 18,260, this valve serving to direct the motive iiuid to either of two passages 7 and 7a, formed in the structure 5, and from the other passage to the exhaust or to an adjoining cylinder in the case of a compound engine, the direction of flow to the cylinder being governed by a partial turn of the valve, so as to readily effect a reversal of the engine.

That portion of the engine which constitutes my present invention is shown above the reversing-valve chamber; and it consists of a valve S, closing downwardly against a seat formed in the chest- 5 at the top of the passage which leads to the primary7 inlet-port of the valve 6, the stem of said valve 8 having at the upper end a suitably-packed piston 9, which is adapted to a cylinder l() in the upper portion of the chest 5, motive fluid from the supply-pipe 10a being admitted to this cylinder below the piston 9. Motive Huid is also admitted to a chamber 11 in a cap 12 of the chest 5, communication between thisl chamber 11 and a central chamber 13 in the cap being opened or closed by the adjustment of a valve 14C, which is adapted to a seat at the junction of the t-wo chambers. The stem of the valve la also carries another and oppositely-facing valve 15, which is adapted to a seat at the outer end of' the chamber 13, the two Valves being so disposed in respect to each other and to the valve-seats that when the valve l-l is open the valve 15 Will be closed, and vice versa. The constant pressure of motive fluid maintained in the chamber 1l tends to keep the valve 14 constantly open and the valve 15 constantly closed, and as there is a communication 16 between the chamber 13 and the cylinder 16 above the `piston 9 the valve 8 will normally be kept closed and no motive fluid permitted to tiow to the cylinder of the engine, the area of the upper side of the piston 9 being in excess of the area exposed on the lower, side of the piston to the extent of the area of the stem connecting said piston and the valve 8. When,

therefore, it is desired to open the valve 8 and permit motive fluid to liow to the cylinder of the engine, thc valve-stem 17 must be pushed inwardly to such an extent as to close the valve 14c and open the valve 15, thereby cutting off the access of motive fluid to the chamber 13 and opening the same t0 the exhaust, whereby the pressure of motive fluid beneath the piston 9 will cause the same IOO ' of any suitable gearing to rise and Will open the valve 8 and permit fioW of motive fluid to the cylinder, this flow continuing as long as the valve 14 is held closed and the valve 15 open. As soon as the pressure is removed from the outer end of the valve-stem 17 the pressure of the motive fluid upon the valve 14 will open the same and close the valve 15, so as to cut off the exhaust from the upper end of the cylinder 10, thereby causing the descent of the piston 9l and valve 8, so as to again cut off the How of motive Huid to the cylinder. By holding the valve 14 closed, therefore, during any desired fractional portion of the rotation of the piston in the cylinder of the engine the motive fluid will be admitted to the cylinder during such fractional part of a rotation and will then be cut off, so as to permit said motive Huid to be -used expansively during the remainder of the stroke.

A convenient means of effecting the operation of the valve-stem 17 is a cam A18 on a shaft 19, mounted in suitable bearings alongside of the valve-chest 5 and rotated synchronously with the shaft of the engine by means as, for instance, by means of the sprocket-Wheels 2O and 2 1 and chain 22, as shown in Fig. 1.

When a variable cut-off is desired, a variable or differential cam 18 may be employed-that is to say, a cam of such conformation that longitudinal adjustment of the same on the shaft 19 or like longitudinal adjustment of the shaft itself Will vary the ex* tent of the fractional portion of a rotation during which the cam will serve to depress the valve-stem 17. Where the variation of the cut-olf is intended to be controlled by an attendant-as, for instance, in the case of an engine intended for a self-propelled vehiclesuch longitudinal movement of thev cam or cam-shaft may be effected by hand; but Where an automatic cut-off is desired longitudinal movement of the cam or cam-shaft should be under control of a suitable governor operated by the engine. Thus, as shown in Fig. 1, a centrifugal governor 23 on the engine-shaft operates a lever 24, Which engages with a grooved collar 25 on the cam-shaft 19, so as to impart the desired longitudinal movement thereto.

As both movements of the main cut-off valve 8 are controlled by the pressure of the motive fluid and as the movement of the supplementary or controlling valve-stem 17 in one direction islikewise due to the pressure of the motive iiuid, all springs are avoided and the sluggish action due to the use of such springs is overcome. Hence I am enabled to effect accurate cut-off of the motive fluid at any desired point in the stroke, even though the engine is running at the excessively-high rate of speed for Which most rotary engines are designed.

It Will be evident that my improved cutoff-valve mechanism may be employed in connection with various forms of rotary engines and without the use of the reversing or directing valve 6, and in the case of a multicylinder engine I may use a cut-off valve of the character described for each cylinder, whether all of the cylinders are high-pressure cylinders or Whether the engine is a compound engine in which the exhaust from one cylinder serves as the motive Huid for another.

Having thus described my invention, I claim and desire to secure by Letters Patent- 1. A cut-olfl valve for motive-power engines comprising a main cut-off valve moved in both directions by the pressure of motive fluid and a supplementary controlling-valve moved in one direction by the pressure of the motive fluid and in the other direction by mechanical means, substantially as specified.

2. The combination in a motive-power engine, of a main cut-off valve moved in both directions by the pressure of the motive duid, and a supplementary controlling-valve moved in one direction by the pressure of the motive fluid and in the opposite direction by means of a cam deriving its motion from the engine, substantially as specified.

3. The combination in a motive-power engine, of a main cut-off valve operated in both directions by the pressure of the motive fluid, a supplementary controlling-valve operated in onedirection by the pressure of the motive fluid and in the other direction by a differential cam driven from the engine, and means for adjusting said cam so as to vary the extent of cut-oif, substantially as specified.

4. The combination in a motive-power engine, of a main cut-off valve operated in both directions by the pressure of the motive fluid, a supplementary controlling-valve operated in one directionv by the pressure of the motive uid and in the other direction by a differenltial cam deriving its movement from the engine, and engine-controlled mechanism for shifting said cam so as to vary the extent of cut-off, substantially as specified.

5. The combination in a cut-off valve for motivepower engines, of the main cut-off valve having a stem with piston thereon subjected on the valve side to the constant pressure of the motive fluid, a duplex valve controlling the admission of motive fluid to and its exhaust from the opposite face of the pistou, and means for operating said valve so as to alternately admit the motive fluid to and exhaust it from said face of the piston, substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

FRANK H. BATES.

Witnesses:

F. E. BEcHToLD, Jos. H. KLEIN.

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