US842128A - Engine. - Google Patents

Description

:PATBNTED JANyzz, 1907.

A. BALL.

ENGINE.

APPLIOATION FILED AUG.9.1905.

MNM.

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rimini) srarns PATENT curren- ALBERT BALL, OF OLAREMONT, NEW HAMPSHIRE, ASSIGNOR TO SULLIVAN MACHINERY COMPANY, OF CLAREMON'I, NEW HAMPSHIRE, A CORPO- RATION OF MAINE.

ENGINE.

Specification of Letters Patent.

Application filed August 9, 1905. Serial No. 273.381.

To all whom t may concern:

Be it known that I, ALBERT BALL, a citizen of the United States, residing at Claremont, in the county of Sullivan and State of New Hampshire, have invented an Improvement in Engines, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention relates to engines, and more particularly, though not exclusively, to direct-acting engines employing tappet-valve devices-such, for example, as those frequently used with stone-working machinery.

My invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific embodiment thereof submitted for illustrative purposes, while its scope will be more particularly pointed l out in the appended claims.`v

Of the drawings, Figure l is a vertical longitudinal central section, partially broken away, showing the valve mechanism. Fig. 2 is an end view of the same, partially in section. Fig. 3 is a section through the valvestem on the line 3 3, Fig. 1 and Fig. 4 is a section in plan of the valve-stem, taken on the line 4 4 in Fig. 3.

Referring to the drawings, a represents the cylinder of a direct-acting engine employed in connection with a rock-drill, the piston therefor being shown at b and the steam or air chest at c. The pressure fluid, which is here supposed to be air, but which obviously may be of any suitable kind, enters the airchest from a source of supply (not shown) through an appropriate air-inlet d at either side of the air-chest, whence it passes'from the air-pressure space e to thecylinder through one or the other of the ports f and g, according to the position of the controlling-valve, thereby to produce movement of the piston.

The valve is controlled, primarily, by the segmental tappet h, and the latter slides or rocks in a guideway formed between the portion a of the cylinder and the walls of the air-chest c. The segment is thereby effectually guided for its rocking movement, and since the segmental guide-walls are formed partly by the cylinder and partly by the airchest the removal of the latter leaves the tappet ready for withdrawal.

The usual inclines i fi, appropriately shaped and positioned, are provided upon the piston b so that the opposite ends of the tappetor actuator may be alternately engaged by the piston toV throw the valve. In this class of apparatus the inclines upon the piston and 4 the ends of the tappet which engage with the inclines frequently become worn through continued use, so as to result in considerable lost motion. This isparticularly the case where a slide or other unbalanced valve is employed, which imposes more or less load upon the tappet. When the engaging surfaces become worn, it follows that the tappet movement is less than it should be and that the valve does not receive its full designed movement. This causes an lincomplete admission, materially reducing the efficiency of the engine, particularly when the wear becomes pronounced.

In the described embodiment of my invention I relieve the tappet of much of its load by providing a balanced piston-valve, thereby reducing the'wear upon the engaging surfaces of the piston and the tappet. provide means for supplementing the action of the tappet, so that if the valve moves but a fraction of its travel the supplemental controlling means will complete the valve movement, whether or not the movement of the tappet would otherwise be suflicient to accomplish this. For this purpose I have here shown the balanced piston-valve j, having the spools 7c and l, and the cupped piston ends m and n. In the position shown pressure is being admitted from the pressurespace e to the port f to the right-hand end of the piston, the valve-spool lf: shutting off the central exhaust-space. At the same time the exhaust is passing fromthe left-hand end of the piston through the port g and the central exhaust-space and out of the'side exhaust-passage o. When the piston moves in a left-hand direction far enough to bring the right-hand incline in contactwith the segmental tappet, the valve will be thrown to the left, the spool l then shutting off the central exhaust-space from the port g, the spool m shutting off the pressure-space from the portf, and the spool k moving to open the latter to the exhaust-space. If for the reason stated or otherwise the movement of the tappet is incomplete, full travel of the valve may be assured by the supplemental motive means referred to. As illustrative of one I also' embodiment thereof I havev shown the valve provided with supplemental pressure-passages p and g, the former leading from the cupped piston end n lengthwise the valvestem and having an outlet between the piston m and the spool lc, and the passage g leading from the piston m lengthwise the valve-stem and having an outlet between the piston n and spool Z. The passage p therefor connects the space back of the piston m alternately with the pressure and exhaust, and the passage g likewise connects the space back of the piston n alternately with the exhaust and pressure, one of said passages being connected to the pressure and the other to the exhaust at all times. The result of this construction is that as soon as the tappet moves the valve, for example, from the position shown far enough to close the passage p to the exhaust and open the same to the pressure-space the air or steam under pressure is conducted through the said passage behind the piston fm, and the pressure behind the piston n being simultaneously relieved through the opening of the passage g to the exhaust the piston-valve is thereby thrown to the left through the action of the pressure without the necessary assistance of the tappet. Full travel of the valve, therefore, and the full admission of steam to the cylinder-piston are assured so long as the tappet moves sufficiently to give the initial travel to the valve. The required initial travel herein is approximately one-third of the entire travel but obviously this fractional amount may be' varied as desired.

It is not necessary that the auxiliary airports for controlling the pressure for mo ving the valve should be constructed as shown, although such construction has the advantage of simplicity and effectiveness. Instead of passing through the valve -stem such ports might be formed in the body of the air-chest and numerous other constructional changes might be adopted without departing from the spirit of my invention. The valve being balanced moves under relatively slight impulses, for although having a constant pressure to overcome upon one end or the other by reason of the auxiliary pressure-ports this load or opposition may be reduced to an insignificant amount. For this object the area4 of the piston ends may be diminished to some extent or the pressure admitted through the auxiliary ports may be throttled to any desired degree by reducing the area of the port-openings, it being necessary to admit but a relatively slight pressure to give the desired movement to the valve.

While for illustrative purposes I have herein shown and described one form of my invention, it is to be understood that the same is not limited to the described details of parts or the form and relative arrangement thereof, but that extensive modifications may be made therein without departing from the spirit of my invention.

I claiml. A direct-acting engine having a cylinder, a piston, a valve-chamber, a balanced piston-valve slidably mounted in the valvechamber, a segmental tappet having a toothed portion directly engaging the pistonvalve and slidably mounted in suitable guiding-walls in the cylinder, suitable inclines upon the piston for moving the tappet outwardly. in opposite directions and thereby imparting initial reciprocatory movement to the valve, admission and exhaust passages for the cylinder controlled by the valve, separate admission and exhaust passages-leading to opposite ends of the piston-valve, said valve lbeing constructed to open said assages one to the exhaust and the other to the admission on initial tappet-actuated movement of the valve simultaneously with the opening of the cylinder-passages to the exhaust and admission, acting thereby to insure the completion of the valve movement.

2. A direct-acting engine having a cylinder and piston, a valve-chamber, a balanced piston-valve slidably mounted in the valvechamber, a segmental tappet slidably mounted in suitable guide-walls in the cylinder and directly engaging the piston-valve, suitable inclines upon the piston for moving the tappet alternately in opposite directions and thereby imparting an initial reciprocatory movement to the valve, admission and exhaust passages for the cylinder controlled by the valve, and separate admission and exhaust passages leading to opposite ends of the valve, said latter passages being also controlled by the initial tappet-actuated movement of the valve to cause completion of the valve movement. 3. A direct-acting engine having the cylinder a, the piston b, the valve-chamber c, the tappet h, valve y' and pressure-passages p and q.

4. A direct-acting engine having a piston, a cylinder, a valve-chamber, a valve for controlling the piston, a tappet directly connected to move the valve longitudinally immediately on engagement of the tappet by the piston, cylinder-ports controlled by the longitudinal valve movement, and separate ports opened or closed by the tappet-actuated valve movement after its commencement for admitting or exhausting pressure to or from suitable pressure areas upon the valve to assist in moving the latter.

5. An engine having a cylinder, a piston, pressure-ports, a balanced piston-valve controlling said ports, a slidable segmental tappet engaging said valve intermediate its ends, and supplemental pressure means for insuring the full travel of the valve.

6. A direct-acting engine having a cylin- TOO IIO

der, a piston, pressure-passages for the cylinder, a slidably-mounted controlling-valve, a tappet engaging said valve-body for imparting initial longitudinal sliding movement to said valve, and supplemental pressure means set in operation on the initial longitudinal sliding movement of the valve for insuring completion of said sliding valve movement.

7. A direct-acting engine having a cylinder, a piston, pressure-passages, a valve controlling said passages, a tappet locatedin said cylinder and adapted to impart directly longitudinal sliding movement to the valve, and means set in operation by said initial longitudinal sliding valve movement for admitting pressure to or exhausting it from opposite ends of said valve to insure completion of the l tappet-actuated valve movement.

8. A direct-actlng engine having a cylin- Ider, a piston, a slidably-mounted controllingvalve, pressure-passages for the cylinder, a tappet located in said cylinder and engaging said valve-body and adapted to be actuatedvalve, and separate pressure-passages lead-l ing to the ends of said valveand adapted to be placed in communication with the pressure and exhaust spaces respectively of' the valve-chamber on initial tappet-actuated valve movement.

l0. An engine having a cylinder, a piston, pressure-passages, a valve-chamber, a valve slidably mounted in said chamber, said chamber being provided With an exhaustspace and a live-pressure space, a tappet for imparting initial sliding movement-to said valve, and separate pressure-passages lead- 11, An engine having a cylinder, pressurel passages, a piston, a tappet actuated by said piston, a valve-chamber, a balanced pistonvalve in said valve-chamber, pressure-chambers at opposite ends of said valve, reduced portions provided for said valve to Which pressure is alternately admitted and exhausted from opposite ends of the cylinder, and pressure-passages leading rom the opposite ends of the valve through the valve-stem, each of said passages opening through a reduced portion of the valve. Y

12, An engine having a cylinder, a piston, pressure-passages, a valve-chamber, a valve slidably mounted in said chamber, said chamber being provided With an exhaustspace and a live-pressure space, a tappet for imparting initial sliding movement to the valve and passagesleading kto the ends of the valve and adapted to be placed in communication With the pressure and exhaust spaces respectively of the valve-chamber after initial tappet-actuated valve movement.

13. An engine having a cylinder, a piston, pressure-passages, a piston-valve controlling said passages, a tappet Working in the cylinder and adapted to impart initial longitudinal sliding movement to the valve and means set in operation by the initial longitudinal sliding movement of the valve in one direc-- tion for admitting pressure to the rear of the piston-valve and exhausting it from the iront end thereof to cause the completion of the valve movement under the iniiuence of the pressure.

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

ALBERT BALL.

Witnesses:

FRANK A. BALL, MORRIS P. HoLMEs.

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