US1609094A - Internal-combustion engine - Google Patents

Description

Nov. 30 I926. 1,609,094

B. c. SMITH INTERNAL COMBUSTI ON ENGINE Filed June :5, 1925 4 Sheets-Sheet 1 Elwwemtoz Nov. 30 1926. 609,094

B. c. SMITH INTERNAL COMBUSTION ENGINE Filed June 5, 1925 4 Sheets-Sheet 2 Nov. 30 1926.

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Patented Nov. 30, 1926.

UNITED STATES PATENT o i-"ics.

BENJAMIN 0. SMITH, 0F BAYONNE, NEW JERSEY, ASSIGNOR TO STANDARD MOTOR CONSTRUCTION COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

INTERNAL-COMBUSTION ENGINE.

Application filed June 8, 1925. Serial No. 34,546.

This invention relates to improvements in internal combustion engines of the so called high compression fuel burning Diesel type, in which fuel is forced into the engine cylinders and ignited at the proper time when the latter are filled with air under heavy compression. This fuel feed is caused to occur at the proper time and 1s contlnued for the desired period to generate the desired power. In such engines the fuel is usually spontaneously ignited, due to the high compression in that particular cylinder into which the fuel is being fed.

One main object of the invention 1s to provide an engine construction whlch will guarantee a powerful and eflicient starting effort under all conditions for both forward and reverse rotation.

Another object is to provide means which is applicable to any engine of the four-cycle type and especially to those havlng a plurality of cylinders, and whlch means w1l l 1nsure positive starting of the engine in either direction in any position of the crank shaft ofi center.

Other objects will appear to the skilled mechanic from a reading of the following description and an examination of the accompanying drawings, in which- Fig. 1 is-a side elevat on of a portion of an engine of the multi-cylinder type, three cylinders being conventionally shown;

Fig. 2 is a relatively enlarged side elevation, partly in section, showing certain details including the compressedair valve;

Fig. 3 is a view taken at right angles to that shown in Fig. 2, showing the engine cylinder in section;

Fig. 4 is an end elevation of the cam shaft with the so called valve lifters assoelated therewith;

Fig. 5 is aside view of the cam shaft shown in Fig. 4;

Fig. 6 is a view similar to Fig. 5, showmg said cams rotated one-quarter of a turn;

Figs. 7 to 13 inclusive are diagrammatic views toillustrate the effect-of the various cams on the various valve lifters in the various positions of adjustment of the cam shaft, and, in these views the cam bumps are illustrated without regard to their relative cir cumferential posit on on the shaft;

Figs. 14 to 20 dlagrammatlcally illustrate respectively the active cam bumps in the various positions of adjustment of the cam shaft as shown in Figs. 7 to 13respectively, and these views show the relative circumferential position of the said active cam bumps on said shaft.

1 represents the base of an engine. 2-2-2 represent cylinders. 3 represents a portion ofthe crank shaft, the cranks of which-are preferably so designed that one crank will always be off center. The several cranks are, of course, connected with the usual pistons by means of the usual connecting rods, the same being too well understood to require illustration. Each cylinder is provided with an atmospheric air intake valve 4, a compressed air inlet valve 5, an exhaust valve 6 and a fuel feed valve 7. All of these valves are preferably mechanically operated by cam bumps on the cam shaft 8, although in some constructions the atmospheric air intake valve 4 may be of the automatic type. In the form shown the cam shaftis adjustable longitudinally to bring the proper bumps in line with their respective valve lifters, so as to cause the valves to function in the manner hereinafter described.

The particular means by which the mot-ion is transmitted from the cam bumps to the valves themselves may be varied at will, but in the particular form shown so called valve lifters.are provided, the same being mounted to rock on a countershaft 9, said valve lifters being connected by means of suitable rods and rockers which, in turn, engage their respective valves to lift the same from their seats.

. In the preferred construction the valve lifters are provided with rollers, which directl engage the cam shaft, thereby reducing riction and wear. Inasmuch as various means for transmitting motion from the cam shaft to the valves are generally well known, and as no invention is claimed for the particular means employed herein, a further description is unnecessary.

10 is a pipe which leads from any suitable source of compressed air supply to the housings for the several compressed air valves, one of which valves is shown in detail in Fig. 2, in which 11 represents a housin for one of the compressed air valves 5. ompressed air enters the housing in the ch m,-

her directly above the valve 5. The chamber directly below this valve has a passage 12, which communicates with that particumeans of a suitable rod with one of the cam-actuated rockers on the countershaft 9.

16 is an overbalancing piston mounted on that part of the stem above the valve 5 and positioned in the cylindrical part of the housing adjacent thereto. Vthen the compressed air is on, it is manifest that this overbalancing piston will cause the valve 5 to become seated and normally closed, as shown in Fig. 2.

17 is a throttle valve for the compressed air supply. When the compressed air is turned oi the valve 5 may drop by gravity to an open position, so that its rocker will be out of the range of action of its cam bump, thereby avoiding noise and Wear. 18 is the check valve between the compressed air valve 5 and the interior of the cylinder 2, the function of which is to prevent any pressure within the cylinder in excess of the compressed air pressure from being forced back into the valve housing 11. The cam shaft 8 is driven from the main shaft 3 in the usual manner, as by gears 19-20, the same being so proportioned that the cam shaft rotates at one-half engine speed, as is customary in four-cycle engines.

21 is a manually operable lever suitably connected with the rotatable cam shaft, by which the same may be adjusted endwise for the purpose of engine control.

Before describing the operation of the engine, which will be done by referring to the diagrammatic views 7 to 20, I desire to have it understood that in each of said views 22 represents the valve lifter roller for the atmospheric air intake valve 4 of one cylinder, 23 represents the lifter roller for the fuel feed valve 7 for one cylinder, 24 represents the lifter roller for the compressed air valve 5 for one cylinder, and 25 represents the lifter roller for the exhaust valve 6 for one cylinder.

When the parts stand in the position indicated in Figs. 10 and 17, the rotation of the cam shaft will have no effect on the valve lifters, and consequently the engine is idle. To start the engine ahead or in a forward direction, the cam shaft 8 is shifted longitudinally to the first starting position indicated in Figs. 9 and 16. I The com pressed air throttle valve 17 is then opened. In this position certain cam bumps on the cam shaft 8 are so located relatively to the lifters that the compressed air valve will be opened, whereby compressed air will be admitted to the cylinders, causing the engine to turnin a forward direction. In this position of the cam shaft two cam bumps will successively engage the compressed air valve lifter 24, so as to admit compressed air on each down stroke of the piston, thus securing'what is termed a, two-cycle operation. At the same time the valve lifter 25 for the exhaust valve 6 will be operated on each up stroke of the piston to allow the air in the cylinder to escape. In this first starting position there are no cam bumps so positioned as to operate the valve lifters 22 and 23, hence the atmospheric air intake valve and the fuel feed valve will remain motionless. When the engine has been speeded up sufficiently under the two-cycle operation of compressed air, the cam shaft 8 is shifted to a second starting position, indicated in Figs. 8 and 15. In this position the bumps on the cam shaft will serve to operate the compressed air valve lifter 24 only on every other down stroke of the iston, whereas the exhaust valve lifter wil still be operated as before to open the exhaust valve on each up stroke of the piston. It will also be observed that in this second starting position another cam bump is brought into action to operate the lifter for the atmospheric air valve 4, which is now opened on each four-cycle suction stroke. In these two views, Figs. 8 and 15, the fuel valve 7 is still motionless. The cam shaft is maintained in this second starting position for only a brief period, an important purpose being to release, on the regular four-cycle compression stroke, the compressed air that would otherwise be retained in that cylinder from a previous two-cycle compressed air power stroke. If this were not done an excessive compression might occur in that particular cylinder on the up stroke suflicient to materially retard the rotative effort of the engine.

From the so called second starting position, the cam shaft 8 is shifted fromthe position shown in Fig. 8 to that shown in Figs. 7 and 14. In this latter position the bumps on the cam shaft are so arranged that they will operate all of the valve lifters 22, 23, 24 and 25 in such an order that the engine will operate normally as a fourcycle engine, atmospheric air being admitted on the suction stroke; that air being compressed on the compression stroke; fuel being forced in and ignited at or about the top of the compression stroke to furnish power during the next down stroke; the exhaust valve being opened on the next up stroke to permit the escape of burnt gases.

I have thus described how the engine is started in a forward direction from the by shifting the cam shaft longitudinally in one direction away from said neutral position thereof. To start the engine in a reverse direction the camshaft is shifted in an opposite direction, there being a corresponding set of cam bumps on the cam shaft coacting with the several valve lifters at the proper time to cause the engine to rotate in a reverse'dire'ction, v

It will be-observed that whenever the throttle valve 17 is 0 en the compressed air valve lifters 2 1 will he in position to operate .the compressed air valves 5 so that, in the event the workin pressure in the working cylinders2 falls elow that of the compressed 'air, said compressed air will then ow into the cylinder to prevent stalling and to assist in maintainingrotative effort. This is very advantageous, particularly. in starting up the engine under a heavy load when cold. Manifestly, when the engine has been warmed up and is operating with normal efliciency, the throttle valve 17 may be closed.

It should be understood that the means for; operating the various valves may be varied at will, so long as such means are capable of operating the valves in such or der as to cause the engine to function as above described.

It will also be understood that, so far as concerns the construction of the various parts of the engine, the same may be modified in a variety of ways, so long as the aforesaid functioning is not interfered with.

From the foregoingit will be seen that the improvements relate not only to the mechanical-construction described, but to the method employed in starting the engine.

What I claim is: 1. In an internal combustion engine of the four cycle high compression fuel burn ing type, a cylinder, a piston therein, an atmospheric air intake valve, a compressed air 'inlet valve, an exhaust valve and a fuel feed valve for said cylinder, valve controlling means to cause, when the same is in one position, the compressed air valve to be held open and admit compressed air to said cylinder on each down stroke of the piston and to cause the exhaust valve to be held open on each up stroke of the piston; and when in another position to cause the compressed air inlet valve to be held openand admit comstroke, to cause the atmospheric air intake valve and the exhaust valve to remain-closed during the greater part of the next down stroke, and to cause the exhaust valve to be held open on the next up stroke.

2. In an internal combustion engine of the. four cycle high compression fuel burning type, a cylinder, a piston therein, an atmospheric air intake valve, a compressed air inet valve, an exhaust valve and a fuel feed valve for said cylinder, valve controlling means to cause, when the same is in one position, the compressed air valve to be held ripen and admit compressed air to said cylinder on each down stroke of the piston and to cause the exhaust valve to'be held open on each up stroke of the piston; and when in another position to cause the compressed air inlet valve to be held open and admit compressed air to said cylinder on each alternate down stroke of the piston, and to cause the atmospheric air intake valve to be held open on each intermediate down stroke of the piston, and to cause the exhaust valve to be held open on each up stroke of the piston; and when in another position to cause the atmospheric valve to be held open on one down stroke, to cause the fuel feed valve to be opened at about the top of the next up stroke, to cause the atmospheric air inlet valve and exhaust valve to remain closed during the greater part of the next down stroke, and to cause the exhaust valve to be held open on the next up stroke, provided with compressed air operated means to nor mally hold the compressed'air valve closed excepting when opened by said mechanic-a1 valve operating means, and with means provided for shutting off said compressed air.

3. In a fuel burning engine of the Diesel type, a plurality of cylinders, valves in one of said cylinders for atmospheric air admission, for exhaust, forfuel feed, and for admission of compressed air, means to control said valves whereby under one condition said cylinder will be operated by compressed air on the two-cycle principle, and under a second condition will be operated partly on of; second, means for introducing compressed air into the cylinder on every alternate down stroke of the piston therein and for openingthe same to atmosphere on each intermediate down stroke, while still continuiiig to open the cylinder to atmosphere on each up stroke of the piston; and, third, will generate pressure against the piston to means for admitting atmospheric. air to the force it down on its next stroke. and for engine cylinder on every other down stroke then opening said cylinder to atmosphere 10 of the piston therein, for compressing said whereby on the next up stroke of said pisair on its next up stroke, for then forcing ton the gases in said cylinder will be ex- :fuel into said cylinder at about the top of pelled. said stroke, whereby said fuel when ignited BENJAMIN C. SMITH.

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