US340958A - Steam-actuated valve - Google Patents

Description

(No Model.) 3 Sheets-Sheet 1. W. L. SHEPARD.

STEAM AGTUATED VALVE. No. 340,958. Patented Apr. 27; 1886.

Witmeooao (No Model.) 3 Sheets-Sheet 3.

W. L. SHEPARD.

STEAM AGTUATED VALVE.

No. 340,958. Patent'edApr. 2'7, 1886.

UNTTET) STATES PATENT OFFIC WILBUR L. SHEPARD, OF HARTFORD, ASSIGNOR TO THE SHEPARD MANU- FACTURING COMPANY, OF NAUGATUCK, CONNECTICUT.

STEAM-ACT UATED VALVE.

SPECIFICATION forming part of Letters Patent No. 340,958, dated April 27, 1886. Application filed January 25, 1886. Serial No. 199,567. (No model.)

To all whom it may concern.-

Be it known that I, WILBUR L. SHEPARD, of Hartford, Connnecticut, have invented a new and useful Improvement in Steam-Actuated Valves, of which the following description and claims constitutethe specification, and which is illustrated by the accompanying three sheets of drawings.

This invention relates to that clsss of steam engines which work reciprocating machinery without the intervention of rotary motion, and it is particularly suitable to work the plunger of a steanrpump.

Figure 1 is a central vertical longitudinal section of a steam-engine with my present improvements. Fig. 2 is a longitudinal section on the line a a of Fig. 3, whileFig. 3 is a cross section on the line b b of Fig. 1, these two sections looking in the direction of the arrows at and y, respectively. Figs. 4 and 5 are perspective views of the valves 8 and 11, respectively.

The numeral 1 indicates the cylinder, while 2 denotes the piston, and 3 the piston-rod. An arm, 4, is fastened to the piston-rod and slides freely on the valve-rod 5, between the adjustable tappets 6and 7. The valve-rod is fixed to the valve 8, which slides on ways on the upper side of the cylinder, and is provided with the ports 9 and 10, the latter being a counterpart of the former both in form and in location. The valve 11 also slides on the upper side of the cylinder within the frame of the valve 8, and on the same plane as that valve, and it is provided on its under side with two semi-cylindrical ports, 12 and 13, and on its upper side with the concaved projection 14. The steam-chest 15 is fastened to the upper side of the cylinder, so as to inclose the valves 8 and 11, together with the hollow piston 16. The ends of that piston work in the cylindrical ends of the steam-chest, and are provided with the small blow-holes 17 and 18, respectively, while the body of the piston between its ends is provided with one or more much larger openings, 19. Midway between its ends the piston 16 is provided with the two annular flanges 20 and 21, for engagement with the concaved projection 14 on the valve 11. The ports 22 and 23 connect the two ends of the cylinder 1 with the ports 12 and 13, re

spectively, and the exhaust-port 24 connects the ports 12 and 13 with the external air, alternately. The ports 25 and 26 connect the two cylindrical ends of the steam-chest 15, respectively, with the port 9, and the corresponding ports, 25' and 26, on the other side of the vertical longitudinal center of the engine, connect the same cavities with the port 10. The ports 9 and 10 are always connected with the exhaust-port 24. The port 27 connects the steam-chest with the boiler. (Not shown in the drawings.)

The mode of operation is as follows: When the piston 2 is in the position indicated in Figs. 1 and 2, and is moving in the direction of the arrow z, steam at boiler-pressure is passing from the steam-chest 15, through the ports 12 and 22, into the left-hand end of the cylinder, while spent steam is being forced from the other end of the cylinder through the ports 23 and 13, into the exhaust'port 24, and thence out of the engine. At that time the piston 16 is stationary in the position indicated in Figs. 1 and 2, because boiler-pressure steam 7 5 is pressing equally 011 both its ends, having been admitted equally to the ends of the steamchest through the blow-holes 17 and 18; but

when the onward motion of the piston 2 carries the arm 4 into collision with the tappet S 6 the rod 5 is carried along with the arm and pulls upon the valve 8, thus disconnecting the ports 9 and 10 from the ports 25 and 25, re spectively, and connecting them with the ports 26 and 26, respectively. Then the steam in the right-hand end of the steam-chest finds instant egress to the exhaust-port 24.. The pressure upon the right-hand end of the piston 16 is not maintained against this egress by the ingress ofsteam through the blow-hole o 18, because the capacity of that blow-hole is much less than the joint capacity of the ports 26 and 26. For a similar reason the pressure upon the left-hand end of the piston 16 is not correspondingly reduced, and therefore that piston moves at once to the right, carrying the valve 11 along with it. This motion of the valve 11 soon reverses the motion of the piston- 2, and the accompanying motion ofthe piston 16 soon covers the ports 26 and 26. her this latter event occurs, the further motion of the piston 16 is stopped by the confined Soon af- 10o steam in the extreme right-hand end of the steam-chest. When the piston 2 is on its return-stroke, the arm 4 collides with the tappet 7, thus reversing the former motion of the valve 8, and so disconnecting the ports 9 and 10 from the ports 26 and 26, respectively, and connecting them, respectively, with the ports and 25 Then the steam in the left-hand end of the steam-chest fin'ds'egress to the exhaust-port 24, thus instantly reducing the pressure upon the left-hand end of the piston 16. The pressure upon the right-hand end is not correspondingly reduced, and therefore the piston 16 moves at once to the left, can rying the valve 11 along with it to the respec tive positions shown in Figs. 1 and 2, where they both stop, as before. Thus the piston 16 continues to be worked by the steam controlled by the valve 8, and it continues to work the valve 11 by means of its mechanical connection therewith. Should the piston 16 at any time be caused, by rust or otherwise, to adhere to the surfaces of the ends of the steam-chest beyond the power of the adjacent steam to move it, the valve 8 will collide with the valve 11, and will start it and the piston upon the retarded stroke. When once started in that manner, the piston 16 will usually continue to move under the action of its own steam, and

will perform its function as above described. Should it not continue to move under the action of its own steam it will perform no function, but the valve 8 will carry the valve 11 till the latter cuts off the steam from both ends of the cylinder 1, when the engine will stop without having received any injury.

The ports 10, 25, and 26 may all be dispensed with; but when they are omitted, the ports 9, 25, and 26 should be made larger than they otherwise would require to be, to the end that the outlet from each end of the steam-chest be given a greater capacity than the inlet thereof.

I claim as my invention- The combination of the auxiliary valve and frame attached to the valve-rod 5, and the main valvell, attached to the valve-piston 16 and located within the frame of the auxiliary valve, the construction and arrangement of V ILBUR L. SHEPARD.

lVitnesses:

ALBERT H. \VALKER, XVILLARD EDDY.

Images