US1318760A - Internal-comibustjow engine - Google Patents

Description

H. A. HUMPHREY AND W. J. RUSDELL.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAR. 16. 1917.

Patented Oct. 14;, 1919.

II, I N L; 34 W; 2, 0

WI; filler/Zea ATES PATENT OFFICE.

HERBERT ALFRED HUMPHREY,

OF LONDON, AND WILLIAM JOSEPH RUSDELL, or

A CORPORATION OF NEW YORK.

INTERNAL-COMBUSTION NGINE.

To all whom it may concern:

Be it known that we, HERBERT ALFREo HUMPHREY, a subject of the King of Great Britain, residing in London, England, and WILLIAM JOSEPH RUsDELL, a subject of the King of Great Britain, residing in Wolverhampton, England, have invented a new and useful Improvement in Internal-Combustion Engines, of which the following is a specification.

Our invention relates to internal combustion engines. Our object is to improve the efficiency and simplify-the construction of such engines.

The invention comprises improvements in the arrangement of the ports, and also in cylinder construction.

Internal combustion engines are frequently constructed with ports in the cylinder wall for passage of elastic fluid, these ports being covered and uncovered by the The usual forms of ports are slots or holes in the cylinder wall, which slots may be inclined to the axis ofthe cylinder.

For several reasons itis desirable that such ports should be narrow, but since the ports must present suflicient area of passage for the gases and their effective. length is limited by the piston travel, it follows that broad ports must be provided or-a greater number of narrow ports. there are great constructional difiiculties, so that broad ports are commonly used.

By the present invention a relatively large port area with little width is obtained by -making the port a continuous or substantially continuous opening following a serrated line around the cylinder wall.

There is particular advantage in making a port of this shape a continuous one, since it then becomes possible to construct the cylinder in two ormore parts, one end of each Working part having tooth-like projections and recesses; those parts may be held together so that the teeth of one pro.- ject into constituting the port being left between them. Such parts may be relatively adjustable- Usually the teeth or serrations are Specification of Letters 1atent.

In the latter case the recesses of the other, a space Patented Oct. 14,1919.

Application filed March 16, 1917. Serial No. 155,288.

similar, so that the port between them is of approximately uniform width.

Other advantages may be mentioned; for instance, when the cylinder is constructed in parts as just mentioned the oppositesides of theports may be so formed or shaped as to'direct in a direction more or less tangential to the inner periphery of the cylinder elastic fluid passing through the ports. Also it follows from the wide area of port uncovered by the piston by a short move-' ment of the latter that there is a greater amount of travel available for performing .useful work thus giving an increase of power to the engine. Further, the piston and piston rings wear 7 with separate slots or ports, because every part of the circumference of the rings and piston passes over the port.

.The invention includes a construction of engine of the type in which combustible mixtureus admitted at one end of the cylinder and products of combustion thereby expelled'at the other end, the admission port 01' ports having the form hereinbefore described.

In the operation of the engine, when the working fluid has expanded sufiiciently the exhaust valve or ports are opened and a little later the piston begins to uncover the more uniformly, than serrated, preferably zig-zig, admission port.

Supposing that this port has somewhat the form ofa continuous sine curve around the cylinder, the piston first uncovers the peaks of the curve and if there are n peaks there will be as it were at this stage n small ports spaced uniformly around the cylinder opening simultaneously to the cylinder and directing n small jets of incoming mixture or constituents so as to 'form a \kind of free vortex owing to the inclination of the edges of the teeth. The further movement of the piston uncovers more of the port and this motion need be only small owing to the very large area capable of being provided in a short length of the cylinder. This method of introducing one" or more constituents of combustible mixture at first through a large number of uniformly spaced ports which rapidly may become a continuous port insures a minimum amount of mixing between the fresh mixture or constituent and the products of combustion displaced thereby and thus gives a better mixture for the new charge, greater efficiency and less liability to back firing.

The burnt products are preferably expelled at the end of the cylinder opposite to the admission port or ports either through a positively actuated valve or through an exhaust port or ports uncovered owing to the movement of a moving partor parts. Preferablv the exhaust valve or ports are situated centrally in the. end of the cylinder. \Yhen the admission port or ports direct the elastic fluid as aforesaid, the cool mixture or eonstituent tends to remain near the cylinder \valls"due to its vortex direction of flow and to its centrifligal action, thus fill.-

ing the end of the cyliiuler where the admissiin port is situated and tending to retain the strata. of mixture or constituent separated from the burnt products by a surface approximating to a hyperboloid of revolution with its apex nearer the admission port and gradually approaching the central exhaust outlet as the cylinder fills with mixture? hether. the engine has a. long stroke or a short stroke, this advantage exists, and it is therefore possible to build an etiicient cylinder for abnormally long strokes and for almormally short strokes.

l urther the arrangements permit of the stroke of the piston varying in its cylinder without corresponding loss of efficiency. This is very important when the invention is applied to internal combustion pumps and compressors operating without a fly-wheel and crank to control the length of the strokes.

The working of the piston and cylinder may now be explained Toward the end of the out-stroke the. exhaust outlet first opens, and shortly afterward the admission port begins to be uncovered by the piston, the time interval be ing sufiicient to allow the pressure in the cylinder to fall nearly to the pressure of the exhaust outlet.

Communicating with the admission port there is a reservoir containing combustible mixture or constituent which, just before the admission port is uncovered, is at a pressure higher than that of the exhaust outlet.

Usually this latter pressure is about atm0s phericso that the mixture or constituent will have to be compressed above atmospheric. pressure either by a separate compressor or by the out-stroke.

A convenient arrangement is to allow the iii-stroke of the working piston to draw the elastic fluid into the reservoir past a suitable valve or the like, to be compressed in the reservoir by the out-stroke of the piston.

So soon as the admission port is uncovered, the elastic fluid enters the cylinder from the reservoir, displacing the remains of the products of combustion as already explained.

The admission port may be closed when the piston on, the in-strokc returns to the position it had when the port was opened on the out-stroke.

During the iii-stroke, as soon as both admission ports and exhaust outlet are closed, the compression begins and ignition occurs just before the point of maximum compression.

According to the length of the piston and of the teeth, measured in a direction parallel to the axis of the cylinder the admission port may on the in-stroke be partly or wholly uncovered by the edge of the piston farthest from the combustion end of the cylinder, and the piston may completely cover the port or only partially cover it during the out-stroke; and there may be, an extension of the eylim ler beyond the admission port.

This extension may be always in communication with the reservoir or .it may be in such communication during one part of the stroke and isolated during another part of thestroke, and in the latter case the extension of the cylinder may be used as an elastic cushion.

In an internal combustion engine which has a crank case, the space inclosed by the crank ease mayform part of the combustible mixture reservoir.

\Vhen the cylinder is constructed in two parts as aforesaid, a cooling jacket for the combustion cylinder can be easily constituted in the one part, and the combustible mixture reservoir with its Valves and fittings in the other part.

The method of constructing internal combustion cylinders described may be applied for gas engines, oil engines, automobile engines. internal combustion pumps and compressors. power han'n'ners and pile drivers, devices for governing, lubricating and starting being arranged to suit the particular purpose.

' Referring to the drawings, which illustrate, merely by way of example, suitable embodiment of our invention Figure 1 is a sectional elevation of a com bustion cylinder suitable for an internal combustion pump or compressor.

Fig. 2 is a cross-section on line 2-9 of Fig. 1.

Similar numerals refer to similar parts throughout the several views.

In Fig. 1 the combustion cylinder is formed of two parts 14 and 15 fastened to gether rigidly by studs one of which is shown at 16. The inner working surfaces of the two parts are co-axial and of even diameter. Thc'pistou 17 fitted with piston rings can slide freely from one end of the cylinder to the other.

The port 18 for the admission of combustible mixture or constituent to the cylinder is obtained by making the ends of parts 14 and. 15, which are to be adjacent when the parts are assembled, with serrations of such form that in the assembled cylinder there is an opening which follows a continuous ser rated line around the cylinder wall between the serrations.

By suitably forming the edges of the serrations as indicated in Fig. 2 the port which is continuous, although appearing in this view as separate openings 18, directs elastic fluid passing into the cylinder in a tangential direction as shown by the arrows. Assuming that the chief cause of wear of the piston rings and piston is the action of the edges of the serrations, by allowing the piston rings and piston to pass completely over the. serrations the wear will be perfectly uniform aud'both rings and piston will retain their original shape.

The piston 17 is connected with cross-head 20 by piston rod 19 which passes through a stuffing box 21 in the cylinder cover 22. The cross-head 20 is connected with the pumping plunger (not shown) by external rods, a part of one of which is shown at 23 where it carries a cam 24 for operating by bell crank lever 25 the exhaust valve 26.

In the figures the position of piston 17 eorresponds approximately" with the point of ignition but cam 24 is shown in the position it has when on the upward stroke the exhaust valve 26 is about to open and the lower edge 27 of the piston has arrived at a level near that indicated by dotted line 28. While the lower edge 27 of piston 17 is passing from the level 28 to level 29 the greater part of the burnt products escape past the exhaust valve 26, the pressure in the cylinder usually falling approximately to that of the atmos-- phere. In the example shown there are six projections or teeth on each part of the cylinder and-when the edge 27 of the piston passes beyond level 29 six portions of the admission port are uncovered forming six small ports which simultaneously direct six small jets of combustible mixture (or constituent) from the chamber 30 containing compressed mixture (or constituent)--%angentially into' the cylinder so asto form a kind of free vortex as already explained. The further movement of the piston rapidly uncovers more of the port and at the level 31 the port is completely open if the piston rises so far.

During the downward stroke of the piston fresh mixture is drawn into the chamber 30 past the inlet valve 32. The exhaust valve closes when the edge 27 has returned to level 28. The mixture 111 30 is compressed during the upward motion of the piston, the valve 32 closing under the action of its spring.

In this construction the cooling jacket is around the lower part of the cylinder and the chamber in which the combustible mixture or constituent is compressed is around the upper part.

Since the admission port, is a continuous opening around the working cylinder special means for lubrication are desirable. The lubricant stored in the reservoir 31 passes through passage to valve 36, the stem of which is attached to one end of a plate 37 fixed at the other end to the head of the stuffing box 21. An elastic band 38, such .as a small spiral spring encircling the piston rod, contained in a circular groove in the plate 37 presses against the'piston rod and the friction thus caused when the piston rod moves upward lifts the plate 37 until the valve 36 closes the lubricant passage, whereuponthe rod slips past the band; When the piston rod begins to move downward the valve 86 is opened and then remains open during the downstroke -while the rod again slips through the elastic band.

The effect is to open the valve to admit lu bricant durin the downstroke, this admission being assisted by the reduction of pressure in chamber 30 (now in communication with the upper part of the cylinder) but the valve is closed during an upstroke when there is pressure in chamber 30 thus preventing lubricant being blown back again.

After passing valve 36the lubricant flows through passage 39, down the piston rod to the upper surface of the piston and through passages like 10 in the top of the piston to the working surface of the latter.

What we claim is 1. The combination of a power cylinder and a piston operating therein, the cylin-' der provided with an intake for a combustible medium, comprlslng a continuous opening formed between intermeshing serrations andfollowing a zigzag line around the cylinder, and a reservoir for said medium surrounding and delivering to the intake, the piston controlling said intake, so that the. medium is first introduced simultaneously through small ports evenly spaced aroundthe cylinder, after which, with comparatively small movement of the piston, a

comparatively large continuous area. of in-"f "i take opening 'is uncovered. r

2. The combination defined in claim 1, in which the 'margins of the zigzag opening are inclined to the radius of the cylinder to direct the entering medium tangentially.

3. The combination defined in claim 1, in

which a valve controlled exhaust port is passing through the top of the cylinder, and

a valve operated by the upstroke of the pisl5 ton rod to close the channel to prevent back pressure during the power stroke.

HERBERT ALFRED HUMPHREY. WILLIAM JOSEPH RUSDELL.

Witnesses to the signature of Herbert Alfred Humphrey:

. C. S. HoPKINs,

,W. J. SKERTEN. Witnesses to the signature of \Villiam v Joseph Rusdell:

STANLEY LAwsoN, GEORGE W. A. MARTIN.

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