US1615282A

US1615282A - Internal-combustion engine

Info

Publication number: US1615282A
Application number: US537136A
Authority: US
Inventors: Jorgensen Olav Eskil
Original assignee: Worthington Pump and Machinery Corp
Current assignee: Worthington Pump and Machinery Corp
Priority date: 1922-02-16
Filing date: 1922-02-16
Publication date: 1927-01-25
Anticipated expiration: 1944-01-25

Description

1,615,282 25 1927' 0. E. JORGENSEN INTERNAL COMBUSTIQN ENGINE Filed Feb. 16. 1922 4 Sheetrs-Sheet l vwamfoz @51 flame/1 0 W- ae/$04 n. 25 1927- Ja O. E. JORGENSEN INTERNAL (TYNCUSTIQN ENGINE 4 Sheeis-Sheec 2 '1 led Feb. 16 192? 1,615,282 25 1927' o. E, JofiGENsEN INTERNAL COMBUSTLON ENGINE Filed Feb. 16, 1922 4 Sheets$heet 3 -49 M. [an E 57 q I m if 1 6 g I 4 F L if i F J *1 QNQ Q 5919 MW 5 Patented Jan. 25, 1927.

UNITED STATES PATENT OFFICE.

OLAV ESKIL J'ORGENSEN, 0F FOREST HILLS, NEW YORK,

ASSIGNOR TO WORTHING- TON PUMP AND MACHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA.

INTERN All-COMBUSTION ENGINE.

Application .Lled February 16, 1922.

The present invention relates to improvements in internal combustion engines, and particularly to engines of the Diesel type.

The object of the invention is to provide a durable and etlicient double-acting engine of the two cycle'Diesel type in a compact form particularly suitable for heavy power purposes, as, for example, for marine engines, the construction being such that the various parts of the engine may be readily disassembled and re-assembled.

WVith these general objects in view, the invention consists in the features, details of construction and combination of parts which will first be described in connection with the accompanying drawings and then particularly pointed out in the claims.

In the drawing,-

Fig. 1 is a vertical section, partly in elevation, on an enlarged scale through the center of an engine cylinder embodying certain features of my invention;

Fig. 2 is an enlarged sectional view of the piston with parts of the cylinder;

Fig. 3 is a horizontal section on the line 3-'3 of Fig. 2;

Fig. 4 is a horizontal section on the line 4-4 of Fig. 2;

Fig- 5 is a horizontal section on the line 5-5 of Fig. 1,-

Fig. 6 is a diagrammatic side elevation of the upper part of an engine comprising several engine units and ascavenging air pump embodying my invention;

Fig. 7 is a, detail plan view of the valve mechanism at the upper end of the engine, shown in Fig. 1;

Fig. 8 is a horizontal rod;

Fig. 9 is a diagrammatic transverse sectional view showing the scavenging air pump; and

Figs. 10 and 11 are enlarged sectional views showing the air pump.

Referring to the drawings, A, Fig. 6, indicates the frame of the engine, and B the cylinder base which is supported by the frame and is the sole means for supporting the upper and lower cylinders respectively of the engine. This cylinder base has channels, chambers or passages, some of which serve as the exhaust ports and others as the section of the piston Serial No. 537.136.

inder base has a diaphragm, as indicated at b, Fig. 1, which separates the upper and lower sets of ports from each other.

The cylinders are each formed with an enlarged wall at one end, the upper cylinder having this enlargement at the lower end and the lower cylinder having the enlargement at the upper end. These enlarged portions are cylindrical and fit into corresponding openings in the cylinder base. In the best embodiment of the invention, each cylinder comprises a plurality of parts, in the present example two parts, an outer member 1 and an inner member or cylinder liner 2.

In the best embodiment of the invention the liner 2 extends beyond the corresponding outer member 1 at one end and the liner and its outer member are flanged, as shown at 3 and 4 respectively, to form the enlarged diameter of the cylinder.

Eachliner has itsenlarged end inserted in a corresponding recess in the diaphragm and is provided on one side with inlet ports for scavenging air, as indicated at 5, and on the other side with exhaust ports 6. Each cylinder is held to the cylinder base by suitable means. In the best. embodiment of the invention, the clamping means comprises a clamping ring, as indicated at D, D, secured to the cylinder base by stud bolts? and nuts 8. Each clamping ringhas one inner edge coned or chamfered to bear against the corresponding, coned or chamfered edge of the flange of the respective outer member 1. By removing the nuts 8, the cylinder is released and may be removed from the cylinder base. When in place it is held tightly to the cylinder base by the clamping rin and nuts.

The cylin ers are provided with water jackets, indicated at C, C, respectively.

inlet ports for the scavenging air. The cyl- Each jackethas one end arranged to enter a counterbore in the clamping ring-and to make a water-tight joint therewith. To insure this under all conditions, a packing ring may be inserted between the end of the jacket and the clamping ring, as indicated at 9. The packing ring may be inserted in a counterbore in the end of the jacket, as will be clear from Fig. 1. The jacket is held in place by suitable means. In the best embodiment of the invention, the jacket is held in place by its cylinder, only, so that when the cylinder is released from the cylinder base, the cylinder and its water jacket may be removed as a unit. In order to accomplish this result, the cylinder has a screw threaded boss to which is screwed a

thimble

10, 11 having an outwardly extending flange counterbored at the corner, as shown in Fig. 1, and the jacket has an inward extending flange arranged to enter the counterbore. Suitable stud-bolts and nuts serve to secure the jacket to the thimble.

The thimble 10 for the upper cylinder is arranged to receive a cylindrical block 12 carrying suitable poppet valve mechanism hereinafter more fully described. The thimble 11 for the lower cylinder, serves as the packing-chamber to receive the pistonrod packing, not shown. This packing, when in place, may be tightened by a stuffing box gland 13 held in lace by bolts 13 which extend through the ange of the water jacket and are screwed into the flange of the lower thimble.

The lower jacket E, Fig. 6, is provided with a boss 14 to receive a circular block 15 which carries the valve device for supplying fuel to the lower cylinder. The circular block 15 has a cylindrical projection 16 which fits into a recess in a boss 17 formed on the lower cylinder.

In the best embodiment of the invention the ends of the cylinders are of a novel construction which gives great strength with relatively light weight. In this construction, the cylinder end where the

thimble

10 or 11 is screwed to it, is made thick enough to form a substantial ring of metal which will successfully resist any stresses to which it may be subjected. The Wall of the cylinder end from the ring toward the cylindrical portion constituting the main body of the cylinder, comprises two zones, viz, a conical zone and a spherical-zone, the latter being next to the cylinder body, while the conical zone joins the spherical zone to the ring. In the best embodiment of the invention the conical portion is tangential to the spherical portion, and, while in practice a small deviation from this ideal is not a serious objection, the more nearly the approach to the ideal condition, the lighter the wall may be for the same strength.

While the piston may be of any suitable construction, the present invention includes a new type of piston particularly coacting with the cylinder. This piston has one end domed as indicated at 18, Figs. 1 and 2, to enter the corresponding end of the cylinder and nearly but not quite fill the space therein, only a small amount of clearance being left therein, say. for example, from about 5 to 7 per cent. The crank end 19 of the piston must be of such exterior configuration as to reduce the final or minimum clearance to a relative amount suitable in engines of this type, while locating it so that the fuel valves may discharge into it at the proper time. This is accomplished in the present example by forming this end of the piston so that its portion next to the piston-rod is substantially cylindrical in cross-section, while the intermediate portion is substantially elliptical in cross-section, as shown in Fig. 4. In this way a space is left on each side of the piston opposite the fuel injection nozzles. From this elliptical portion the piston-end 19 flares outward to the full diameter of the piston body.

In the best embodiment of the invention, the piston and piston rod are specially constructed to provide a durable, readily assembled device. The piston-rod 2U is formed with an enlarged end 21 having a flange 22, while near the other end of the piston the rod has an intermediate flange 23 below which is an enlargement 24 providing a shoulder.

The piston-wall comprises two cylindrical body portions, 25 and 26, each provided with a series of grooves for the packing rings 27.

These two cylindrical portions have their adjacent ends somewhat reduced in diameter, the reduced portions being received within the corresponding circular portions or rings of an intermediate split ring member 28 formed of three sections joined by bolts and nuts passing through radially extending flanges 29 formed on flat webs 30, extending like chords of the circumference of the piston, as will be clear from Fig. 3.

The intermediate member is locked to the lower cylindrical portion 26 of the piston wall, in any suitable way, as, for example, by providing the intermediate split-ring member with an inward extending circumferential rib 31 extending into a circumferential groove in the outer surface of the lower cylindrical portion, as will be clear from Fig. 2. The upper cylindrical portion 25 is not locked to the intermediate portion but is left free to expand and contract, the joint between the two being, however, a water tight sliding connection. The up er cylindrical body portion 25 is provided elow its upper end with an inward extendin flange 32 which rests on the flange 22 at the upper end of the piston-rod, and against which rests the upper dome-shaped piston end 18, suitable machine screws 33 holding the parts together,.as shown in Fig. 2. The lower cylindrical body portion 26 is provided with an inward extending flange 34 making a tight fit with the outer surface of the intermediate flange 23 of the piston rod. The lower piston end 19 fits against the lower surface of said flange 34 and is held to the flange by machine screws 35. Suitable long machine screws 36 pass through the intermediate flange 23 and are threaded into the lower piston end portion 19.

In an engine of this type it is important to provide water circulation forcooling the piston heads or end portions and this may be done, as shown in Fig. 2, by making the piston rod 20 hollow or tubular and insertmg within it a water pipe, as indicated at 37, whose exterior diameter is less than the interior diameter of the rod, so as to leave an annular water space around the pipe. To the pipe 37 is secured a collar 38 forming a baflle or diaphragm; The piston rod has water passages, above and below the collar 38, as indicated at 39 and 40, these connecting the space inside the lower piston end 19 with the annular space of the piston rod. The water pipe 37' has a collar 41 secured to it near its upper end, this collar being provided with holes 42 for the passage of water. A bushing 43 threaded into the piston rod is provided with an inturned flange which laps over the collar 41. While the water may flow up through the water pipe and thence down through the annular passage, it will be advantageous to allow the cooling water to flow up the annular passage and thence down and out through the Water pipe, because in this way the coldest water will be next to the piston rod. The water may be admitted to the moving piston-rod, and discharged therefrom in any suitable way, as, for example, by any of the means already well known in the art.

In order to assist in maintaining a water tight joint at the circumference of the intermediate fla-nge 23, the piston-rod periphery of this flange is provided with a .groove into which may be cast a suitable alloy through a notch provided for that .purpose. The alloy inthe groove is indicated at 44, Fig. 2, and the notch,also filled with alloy, is indicated at 45.

The

collars

38 and 41 are secured to the wateriipe 37 by electric welding,.as is indicate by the solid block in Fig. 2.

It will be obvious that by the construction of the piston as described, a light yet strong piston is produced, which may be readily assembled and disassembled. Also, the longitudinal expansion and contraction of the piston due to temperature changes is provided for.

The valve mechanism at the upper end of the cylindercomprises an air-starting valve and a fuel valve, with valve operating devices by which, at starting, the air valve may be operated with proper timing, and so soon as the engine is operating properly the air-starting valve may be cut out of operating and the fuel valve put in action.

The air-starting valve is an ordinary poppet valve, opening inward, as indicated at 46, Fig. 1. It is yieldingly held shut by a shown. The

spring 47 and its spindle projects outward 'moving part of the engine, not shown. The

rocker-arm 50 carries a fulcrum 52 at its free end on which is journaled an adjustable trip-arm 53 having one end provided with a screw 54 which, under certain conditions, will strike the free end of the starting-air valve spindle 48 and thus force the valve open. The other end of the trip-arm 53 is pivotally connected to the end of an eccentric rod 55 arranged to be adjusted by an eccentric 56 fixed on an eccentric shaft 57. This eccentric shaft is provided, with a handle 57, shown in Fig. 7, by which its eccentric may be rotated to adjust it. The pivot which connects the trip arm to its eccentric rod has-its axis coincident with the axis of the fulcrum of the rocker-arm 5O when'the corresponding ecentric, is in such a position as to hold-the trip arm out of engagement with the starting air-valve.

The fuel valve 58 is also of the poppet type normall ClOL'Gd. by a spring 59 and having its spindle arranged to be struck by the end of a screw 60 carried by the triparm 53. When the trip-arm is out of action on the starting air-valve 46, it is in action on the fuel valve, and vice-versa, this being determined by the position of the eccentric 56.

With a plurality of engine-units, one or more cylinders may be supplied with start ing air to start all the engines, the other cylinders receiving fuel at the proper time. As soon as the engines are. turning under the pressure of the combustion gases in some cylinders, the eccentric or eccentrics 56 may be turned over so as to shift the trip-armor trip-armsv and cut out the starting-air mechanism, thereby cutting in the fuel valves for those cylinders.

The lower cylinders are notarranged for the use of starting-air but have only fuel valves of the poppet-valve type, as shown at 61, each being operated by a rocker 62 secured on a rocker arm 63 oscillated by a rod 64 from a moving part of the engine, not poppet-valve is held closed by a spring 65.

The fuel valves illustrated for the upper and lower cylinders are of any suitable type inwhich the oil is blown in by injection air. As valves of this type are well known no specific description of the same is required.

An important feature of the power plant here set forth comprises an improved arrangement of a plurality of double-acting engines of the Diesel type on a cylinder base in the manner described, with a scavenging air pump. Such an arrangement is shown in Fig. 6 in which E, E are the air-pump cylinders. The general arrangement of the airpump will be clear from Figs. 9, 10 and 11, the air pump being shown as of the type described and claimed in my Letters Patent No. 1,447,514, dated March 6, 1923.

Referring to Fig. 11, E is the cylinder of the upper air-pump, and E, the cylinder of the lower air-pump. F is the upper piston, F, the lower piston, and G the piston rod connected to both pistons. H is the upper cylinder head, H, the lower cylinder head and H an intermediate head common to both cylinders.

The intermediate head H is flanged and is fitted into a seat formed in a .septum or horizontal partition a. Fig. 10, which constitutes a part of the cylinder base B, the partition 11 having a horizontal flange a, and a vertical annular flange (1 at the seat. The intermediate head H is secured in its seat in an suitable way as, for example, by machine screws 1 which are accessible from the upper side of the cylinder base when the upper air pump is removed.

The upper cylinder E provided with a supporting member having a cylindrical hub-portion 6, Fig. 10, arranged to enter a corresponding hole in the upper member or plate a of the cylinder base and having a flange 6,, overhanging said platea,, to which it may be secured in any suitable way, as, for example, by machine screws, as indicated at m, Fig. 11. The cylinder E is otsuch length that its lower end reaches nearly but not quite to the upper surface of the intermediate head H whereby a suitable passage or port for the entrance and discharge of air beneath the upper piston F is provided all around the cylinder, this opening leading into an upper chamber or space I formed in the cylinder base above the septum a. The lower cylinder is similarly constructed and. mounted in the cylinder base, being inserted into the cylinder base from below upward and held in place by the machine screws 3. Its upper edge extends nearly but not quite to the lower surface of the intermediate head H so as to leave an air assage or port all around the cylinder where y the space in the lower cylinder above the piston F, is put in communication with a lower chamber or space 1,, Fig. 10, formed in the cylinder base below the septum a.

The side walls of the cylinder base are provided with openings leading from the upper and lower chambers I, 1,, respectively, to a suction valve chest K, and corresponding openings leading to' a discharge valve chest K,. These valve chests are secured to opposite sides of the cylinder base and each has two sets of valves. The 0t suction valves are indicated at L,, L, and the sets of discharge valves at M,, M respectively. \Vhile any suitable valves may be employed, those indicated are of the plate spring variety, for example, such as are fully disclosed in Patent No. 1,341,145, dated May 25, 1920.

The upper end of the cylinder E is connected by a suitable passage N with the chamber I, below the diaphragm a, the passage N opening into the top of the cylinder, as will be clear from Fig. 11. The lower end of the cylinder E, is connected, by a passage N,, with the chamber I above the diaphragm a, the passage N, opening into the bottom of the cylinder E,, as will be understood t'rom Fig. 11. Each passage N or N, is formed partly in its own cylinder, and partly in the cylinder base B, as shown in Fig. 11. The part of each passage within the cylinder base is enclosed by a wall a.

The piston rod (iv is reciprocated in any suitable way from the main shaft D, as, for example, through a crank 0, connecting rod 1, and cross-head Q1 running in guides B.

By this combination a large yet short conduit S may be carried closely alongside the cylinder base to supply scavenging air to each engine in its turn, the engines of course having their cranks set at angles to one another so that the working strokes of the engines will occur in the desired timed relation.

By this arrangement oi the engines and the-scavenging air-pumps, any engine or the air-pump may be dismantled more readily than has heretofore been possible and with the removal of a minimum of parts, but, also, there is less loss by friction in the How of air to the engines from the pump and hence a greater relative eiliciency.

While.in the foregoing specification, the invention has been more particularly shown and described as embodied in a vertical engine, it is to be understood that the invention is applicable to horizontal or inclined engines, and that the terms upper and lower referring to the cylinders, are to be understood as including cylinders which are not above and below each other, but nearest to or farthest from the crank shaft.

What is claimed is:

1. In an internal combustion engine, the combination, with a cylinder base having a vertical bore and having scavenging air inlet passages and exhaust passages, of a crank shaft, a cylinder projecting into the said vertical bore and provided with inlet and exhaust ports in communication with the corresponding passages of the cylinder base, said cylinder being detachably secured to the cylinder base on the side awa from the crank shaft and having its com ustion chamber portion above the cylinder base, a piston movable in the cylinder, and means for driving the crank shaft from said piston.

2. in an internal combustion engine, the combination, with a cylinder base having a vertical bore and inlet and exhaust passages,

of a crank shaft, a cylinder detachably secured to the cylinder base on the side away from the crank shaft, said cylinder comprising an outer member and a liner, the latter extending beyond the outer member and having inlet and exhaust ports communicating with the corresponding inlet and exhaust passages of the cylinder base, a piston movable in the cylinder, and means for driving the crank-shaft from the engine. V

3. In an internal combustion engine, the con'ibination, with a cylinder base having a vertical bore, and having scavenging air inlet passages and exhaust passages, of a crank shaft, a cylinder projecting into the said vertical bore and provided with inlet and exhaust ports in communication with the corresponding passages of the cylinder base, said cylinder being detachably secured to the cylinder base on the side away from the crank shaft and having its combustion chamber portion above the cylinder base, a water-jacket for said cylinder, said waterjacket being fastened only to the outer end of the cylinder, whereby upon removal of the cylinder from the cylinder base the waterjacket also is removed with ,it, a piston movable in the cylinder, and means for driving the crank shaft from said piston.

4. In an internal combustion engine, the combination, with a cylinder base having a vertical bore and having scavenging air inlet passages and exhaust passages, of a pair of cylinders projecting into the said vertical bore from opposite sides ofthe cylinder base, each cylinder being provided with inlet and exhaust ports in communication with the corresponding passages of the cylinder base, said cylinders being detachably secured to the cylinder base, one cylinder having its combustion chamber portion above the cylinder base and the other having its combus tion chamber portion below the cylinder base, and a piston arranged to work in both cylinders.

5. In an internal combustion engine, the combination, with a cylinder base having a vertical bore, and havlng scavenging air inlet passages and exhaust passages, of a pair of cylinders projecting into the said vertical bore from opposite sides of the cylinder base, each cylinder comprisingan outer member and a liner, ,the latter extending beyond the outer member and having inlet and exhaust ports in communication with the corresponding passages of the cylinder base, said cylinders being detachably secured to thecylinder base, one cylinder having its combustion chamber portion above the cyl inder base and the other having its com bustion chamber portion below the cylinder base, and a piston arranged to work in both cylinders.

6. In an internal combustion engine, the combination, with a cylinder base having a vertical bore, and having scavenging air inlet passages and exhaust passages, of a palr of cylinders projecting into the said vertical bore from opposite sides of the cylinder base, each cylinder comprising an outer member and a liner, the latter extending beinder base and the other having its combustion chamber portion below the cylinder base, a water jacket for each cylinder, each water jacket being fastened only to the outer end of its cylinder, whereby upon removal of a cylinder from the cylinder-base its water jacket also. is removed with it, and a piston arranged to Work in both cylinders.

7. In an internal combustion engine, the combination, with a cylinder base having a vertical bore and having an intermediate diaphragm provided with an opening, of a pair of cylinders arranged on opposite sides of the cylinder base, each cylinder having an end portion projecting into the vertical bore and contacting with the diaphragm, a clamping ring for each cylinder, said rin being arranged on opposite sides of the cylinder base, and means for detachably securing each clamping ring to the cylinder base to hold its respective cylinder in place.

8. In an internal combustion engine, the combination, with a cylinder base having a vertical bore and having an intermediate diaphragm provided with an opening, of a pair of cylinders arranged on opposite sides of the cylinder base, each cylinder having an end ortion projecting into the vertical bore and contacting with the diaphragm, a clamping ring for each cylinder, said rings being arranged on opposite sides of the cylinder base, means for detachably securing each clamping ring to the cylinder base to hold its respective cylinder in place, and a water jacket for each cylinder, each jacket being detachably secured only to the outer end of its respective cylinder and being arranged to have a slidable water-tight connection with its respective clamping ring.

9. In an internal combustion engine, the combination, with a cylinder base having a vertical bore and a diaphragm provided with an opening, a pair of cylinders arranged on opposite sides of the cylinder base, each having an end projecting into the vertical bore and making contact with the diaphragm, a clamping ring .for each cylinder, said rings being arranged on op osite sides of the cylinder base, each ring having a counter-bore in its outer face, and means for detachably securing each ring to the cylinder base to holdv the cylinders in place, of a water jacket for each cylinder, each jacket having one end arranged to enter the coun ter bore of the corresponding clamping ring, and means for detachably connecting each water jacket to the outer end of its respective cylinder.

10. In an internal combustion engine, a cylinder having a dome-like end provided with only one opening, which is circular and centrally arranged, the wall of the cylinder being thickened around said opening to form a ring, the wall of the dome comprising two zones, that zone next to the cylindrical body portion of the cylinder being the zone of a sphere and the remainder of the dome being a conoidal zone tangent to the spherical portion and connecting it with the ring, substantially as described.

11. In a doubleacting internal combustion engine, the combination, with a pair of cylinders, each having a dome-like end provided with a central opening, the wall of each end being thickened around the opening to form a ring, each dome-like end comprising the zone of a sphere next to the cylindrical body portion of the c linder and a conoidal zone tangent to the sp ierical zone and connecting it with the corresponding ring portion, of a piston working in both cylinders, a piston-rod connected to the piston and passing through the central opening of one end, a stuflin box secured to the ring around said centra opening for packing the piston-rod, and a plug inserted in the central opening of the other cylinder, and provided with valve mechanism for the admission of fuel to its cylinder, substantially as described.

12. In a double'acting internal combustion engine, the combination, with a pair of cylinders, each having a dome-like end provided with a central opening, the wall of each end being thickened around the opening to form a ring, each dome-like end comprising the zone of a sphere next to the cylindrical body portion of the cylinder and a conoidal zone tangent to the spherical zone and connecting it with the corresponding ring portion, of a piston working in both cylinders, a piston-rod connected to the piston and passing through the central opening of one end, a stuflin box secured to the ring around said centra opening for packing the piston-rod, a plug inserted in the central opening of the other cylinder and provided with valve mechanism for the admission of fuel to its cylinder, and a fuel valve mechanism for admission of fuel to the cylinder having the stalling box, said fuel valve mechanism being arranged in the conoidal zone portion.

13. In an internal combustion engine, the combination, with a cylinder having an outwardly domed end provided with a central opening, a piston rod passing through said opening, and a packing gland arranged to pack the opening, of a piston secured to the rod and having an end arranged to enter the domed end of the cylinder, said end being shaped to form a clearance space in said domed end separated from and closed to the packing gland to protect the packing gland from the combustion, and means secured to the domed end of the cylinder for injecting fuel into said clearance space.

14. In an internal combustion engine, the ('()llll)llltlll0ll, with a cylinder having a domed end provided with a central opening. a piston rod passing through said opening, and a packing gland arranged to pack the opening, of a piston secured to the rod and having an end arranged to enter the domed end of the cylinder, said end being circular in cross section near the piston rod and near the cylindrical body portion of the piston and elliptical in cross section at its intermediate portion, whereb a clearance space is formed between this e1 iptical portion and the domed end of the cylinder, and means for injecting fuel into said clearance space.

15. In an internal combustion engine, the combination. with a cylinder base, a frame for supporting the same, a plurality of engine units, each comprising a pair of cylinders detachably connected to opposite sides of the cylinder base in line with each other, said cylinders havin scavenging air ports within the cylinder liase, a piston for each engine unit working in both of its cylinders, a piston-rod for each piston, a main crankshaft, and connections between each pistonrod and the crankshaft whereby the shaft is rotated, of a double-acting scavenging airpump comprising two cylinders secured on opposite sides of the cylinder base in line with each other and having the air outlets of the two cylinders on the same side of the cylinders, and an air conduit connected to said air outlet extending along the cylinder base and connecting to the scavenging air ports of each engine cylinder.

In testimony whereof, I have hereunto set my hand.

OLAV ESKIL JORGENSEN.