US1079374A - Discharge-valve gear for blowing-engines. - Google Patents

Description

C. G. SPRADO.

DISCHARGE VALVE GEAR PoR BLOWING ENGINBS. APPLICATION FILED 1113.15, 1911` 1,979,374.

Patented Nov. 25,1913.

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UNITED sTATEs PATENTI oEEioE.

CARL G. SPRADO, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 ALLIS-CHALMERS MANUFACTURING COMPANY, A CORPORATION 0F DELAWARE.

DISCHARGE-VALVE GEAR FOR BLOWING-ENGINES.

To all whom t may concern Be it known that I, CARL G. SrnADo, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee andi State of Wisconsin, have invented a certainnew and useful Improvement in Discharge- Valve Gears for Blowing-Engines, of which the following is a specification.

This invention relates to improvements in the construction of valve gears for blowing engines, and more particularly to the construction of discharge valve gearssuch as may be used in combination with the Slick: type of inlet valve for such blowing engine.

The object of the invention is to provide a valve gear for the discharge valves of blowing engines which is simple in construction, efficient in operation, and` in which when the valve is seated, the kinetic energy of the gear is t-aken up by a stop and not by the valve seat.

A clear conception of one embodiment of the invention can be obtained by referring to the accompanying drawing in which like reference characters designate the. same or similar parts in the various views.

Figure 1 is a fragmentary central vertical section through a discharge valve gear and a portion of the cylinder of a blowing engine having the Slick type ofinlet gear. Fig. 2 is an end view of the discharge valve gear shown in Fig. 1. Fig. 3 is a transverse vertical section through the valve gear, the sectio-n being taken along the line III-111 o-f Fig. 1, looking toward the cylinder.

The discharge chamber 1 of the cylinder, see Fig. 1, is connected to the interior or piston chamber of the cylinder by a port 6. The piston 5, which is of the usual construction, is adapted to reciprocate within the cylinder, thereby approaching and receding from the discharge port 6. The tub or cylinder wall 3 is adapted to be mechanically reciprocated so that during the suction stroke of the blower the suction ports 4 form communicating passages between the suction chamber 2 and the interior of the cylinder.

The discharge valve bonnet 13, see Figs. 1, 2 and 3, is fixed to the end of the cylinder and has a spring casing 9 projecting inwardly therefrom in a direction parallel to the cylinder aXis. The valve plunger rod 10, which is mounted concentrically within the bonnet 13 and spring casing 9, carries a Specification of Iiettersatent.

Application filed February 15', 1911.

Patented Nov. 25, 1913.

Serial No. 608,689.

plunger 8 at its valve end, the plunger 8 coacting along the inner cylindrical surface of the discharge cup valve 7. The sprin seat 11 is fixed to the plunger rod 10, an forms a seat for one end of the compression `spring 12, the opposite end of said spring coacting against an end surface of the bonnet 13.

The bonnet 13. is provided with guides or ways in which a crosshead 15 is adapted to .reciprocate The crosshead 15, see Figs. 1, ,2 and 3, is provided with two coaxial outwardly projecting ins 17. The plunger rod 110 passes freely tirough the crosshead 15 and is adjustable within the crosshead 15 by means of a squared portion 20 at its outer extremity and a nut 21 having screw thread Vcoaction with the outer end of the rod 10 and coacting against an outer surface of the crosshead 15. A stop plate 18, which is alsoy penetrated by the plunger rod 10, is securely fixed to the bonnet 13 by means of `bolts 19 or other suitable fastenings.

The rocker arms' 25 take over the outwardly projecting stud 17 formed on the crosshead 15 and have upper cam surfaces `which ride upon the cam'tracks 14 formed on the bonnet 13. Adjacent rocker arms 25 fare rigidly connected by means of a cross rod '22. The operating connection 24, which is driven mechanically from the main engine shaft in any suitable manner, not shown, is connected to the rocker arms 25 by means of the pivot pin 23.

A suitable stuiiing boX 16 which may be of any of the well known forms, is provided to maintain a tight joint between the bonnet 13 and the plunger rod 10. In actual construction of the device, suitable oiling arrangements should also be provided at the various bearing surfaces within the cylinder head, these being omitted from the disclosure since they form no part of the present invention and would only tend to complicate the drawings.

During the discharge stroke of the piston, namely, toward the left in Fig. 1, the pin 23 is raised, causing the rocker arms 25 to ride with their cam surfaces upon the adjacent cam tracks 14, mechanically drawing back the crosshead 15, and the plunger 8. This withdrawing of the plunger 8 is accomplished during the early part of the forward stroke so that the valve is left free to open at any time as the pressure within the cylinder increases. The opening of the valve 7 occurs when the pressures within the cylinder and in the discharge chamber l become slightly unbalanced, the pressure within the cylinder being the greater.

When the piston 5 has reached the end of its stroke, the valve 7 should be suddenly clo-sed. This closing of the valve 7 is accomplished first by the forward pressure of the spring l2 on the plunger 8, and later by the discharge pressure in the chamber l acting directly on the valve 7. With such arrangement the plunger 8 can force the valve 7 to nearly its closed position, or until the plunger, stem and crosshead are arrested by stop 18, the forward motion of the plunger 8, however, being either rapid or slow, depending upo-n the force of the rush of air from the cylinder, thus permitting automatic closing of the valve. In other words, the plunger is spring actuated and mechanically restricted in the closing direction up to a point where the over pressure inside of the blowing cylinder is equal to the spring pressure exerted on the plunger, and an automatic spring closing takes place from this point on at the time when the main piston comes to a stop. It will be noted that a slight air space is shown existing between the plunger 8 and the valve 7. The depth of this air space represents the distance through which the valve 7 is actually forced by the high air pressure within the chamber l after spring closing.

With the arrangement of plunger rod 10 as shown, namely, extending through the crosshead 1,5, and having the adjusting means on the outer end thereof, it will be noted that the adjustment of the plunger 8 can be easily and quickly made during normal operation of the blower.

It should be understood that it is not desired to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent,-

1. In a valve gear, a Valve, means for permitting opening of said valve, means for mechanically operating said opening permitting means in one direction, means for automatically operating said opening permitting means in the opposite direction to move said valve toward closed position, and a stop for said opening permitting means.

2. In a valve gear, a valve and seat therefor, a plunger contractible with said valve, means for withdrawing said plunger from Contact with said valve, impositivo means for urging said plunger in the opposite direction, and a stop for said plunger to limit the action of said impositive means.

3. In combination, a valve, a plunger, means operating said plunger to move said valve toward closing position, and a stop for said plunger.

In testimony whereof, I aiix my signature in the presence of two Witnesses.

CARL G. SPRADO.

Witnesses:

CHAs. L. BYRON, W. II. LIEBER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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