US1378254A - Internal-combustion engine - Google Patents

Description

J. B. MAcDONALD.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED JAN. 25. 1918. RENEWED NOV. 8, 920.

1,378,254. Patented May 17-, 1921.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JAN. 25. I918- RENEWED NOV.B, 1920.

Patented May 17, 1921.

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J. B. MACDONALD.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED JAN. 25,'19I8. RENEWED NOV. 8, 1920.

78,254 Patented May 17, 1921.

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J. B. MACDONALD.

JNTERNAL COMBUSTION ENGINE. APPLICATION um) JAN. 25, 191B. RENEWED NOV. 8. 1920.

1,378,254. Patented M 7, 1921.

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JACK B. MACDONALD, 0F OAKLAND, CALIFORNIA.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented May 17, 1921.

Application filed January 25, 1918, Serial No. 213,735. Renewed November 8, 1920. Serial No. 422,689.

To all whom it may concern:

Be it known. that I, JACK B. MACDONALD, citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Internal- Combustion Engines, of which the following is a specification.

This invention is an improvement in internal combustion engines.

The principal object of the invention is the creation of a new type of engine provided with means for scavenging or decarbonizing the cylinder or cylinders after each explosion, in order to prevent overheating, especially of airplane motors running at high speed with heavy loads.

It is the particular object of the invention to provide means for cooling the exhaust manifold of motors, because of the numerous accidents resulting from overheated ex: haust manifolds of airplane motors which, in some instances have melted from the intense and continuous'heat.

These objects are fully accomplished in the novel structure described in the following specification and illustrated in the accompanying drawings, in which Figure 1 1s a vertical central section of my improved engine showing the piston in lowest possible position. Fig. 2 is a view similar to Fig. 1, but with the piston in its highest possible position. Fig. 3 is an end view of a cam and cam shaft. F i 4 is a vertical central section of a modi ed form of my invention showing an improved cylinder. Fig. 5 is a vertical sectional viewv of the cam and housing, the line of section being taken parallel to the sides of the housing, and in front of the cam ring. Fi 6 is a rear elevation of the same. Fig. 7 IS a bottom plan view of the cam mechanism, to show the securing screws and the slot in the yoke. Fig. 8 is a fragmentary sectional view of the casting 22, to show the annular portion of the valve stem and the position of the air pipe which cools the valve. An inlet valve 50 and an exhaust valve 27 are suitably provided in the cylinder, as shown.

Referring to the drawings, 1 indicates a cylinder of an engine suitably secured at its base to a crank-case 2. The cylinder is provided with a c linder head 3, here shown with water jac et ports 4 communicating with ports 5 in the cylinder. The cylinder head is provided with a spark plug 6.

for connection with an exhaust pipe.

Mounted for reciprocation within said cylinder l is a piston 7 having rings 8 and secured to a piston rod 9 slidable through a stufiing box 10 and gland 11 in the cylinder floor.

The under side of the cylinder casting is bored 'coaxially with the piston rod and the hole tapped to receive one threaded end of a cylindrical piston guide 12 extending downwardly into the crank case.

Slidable within the said cylindrical guide 12 is an auxiliary piston 13 provided with piston ring 14; and secured to the piston rod 9.

The purpose of the cylinder 12 and piston 9 is to draw cold air into the said cylinder 12 on the explosion stroke of the plston through a pipe 16, (having its intake without the cylinder,) and compress it on the up stroke of the piston within the crank case 2. p

The piston 13 is provided with a check valve 18 which is arranged to admit air into the crank case 2 on the up stroke and close on the down stroke to draw air into cylinder 12 through pipe 16.

The end of pipe 16 is also provided with a check valve 19 arranged to admit air on the down stroke of piston 13 and close on the up or compression stroke of said piston.

It will be seen that by reason of this construction cold air is compressed and is delivered to the crank case 21 during the operation of the engine.

The air so compressed in the crank case is delivered through a pipe 21 extending through the side wall of the crank case 2 upwardly through the bottom of a casting 22 and terminating in a nozzle 23. As the speed of the engine increases, also will the air pressure and the amount of air be increased in order to take care of the increase in temperature due to the increased speed of the engine.

The casting 22 is in effect an ell, one end of which is threaded into the upper end of the cylinder 1 as shown at 24. The opposite end of the casting 22 is internally threadgd s cold air is blown through the nozzle 23 into the exhaust pipe, it draws the burned and carbon laden gases from the interior of the cylinder in the direction indicated by arrows in Fig. 1, and into the exhaust after each ex losion.

he casting 22 is provided with a valve as shown at 32, and is pivotally connected at its opposite end to one end of a rod 33, the opposite end of which is secured to a yoke 34 in which is journaled a roller 36 adapted which exten to traverse the perimeter of apointed cam rinlg 37 secured to a shaft 38.

' he shaft 38 has acrank 39 to which is connected one end of a connecting rod 41, the opposite end of which is suitably secured to the piston 13.

The rod 33 is depressed, to contact roller 36 with cam 37 by an expansion spring 42 surrounding the said rod and bearing at one end against the casting 22 and at the other end against a collar 43 secured to'the said rod 33. I

It results from this construction that a supply of compressed cold air is kept in the crank case 2- while the engine is running and a stream of relatively cold air from this supply is forced through nozzle 23 into the exhaust drawing the carbon and refuse from the cylinders by vacuum from without coacting with pressure within, resulting in cleaning or scavenging the cylinder and cooling the exhaust pipe.

In the modification of my engine shown in Fig. 4, I have shown an unusual form of cylinder. The head portion of the cylinder is integral with said cylinder and is curved to prevent accumulation of carbon. It is also provided with a widened curve port leading to the exhaust as shownat 51. It will be seen that in this figure the casting 22 is threaded into the exhaust port of the cylinder and secured by a bolt 52.v This construction gives easy access to the interior of the cylinder for cleaning purposes.

In Fig. 4, I haveshown a different valve control. The shaft 33 is here shown extending from the interior of the crank case being journaledin a bearing 53 secured to the side walls of the crank case by bolts 54.

The rod 33 extends through a stufling box 56 and through the base of casting 22 and,

when driven by cam 37, raises one end of a rocker arm 57, one end of which is provided with a hole to receive the end of said rod and bears against a nut 58 threaded on the rod 33.

The rocker arm 57 is pivoted on a bolt 61 near its center, and the opposite end of the said arm is rovided with a hole through d the reduced threaded end of a valve stem ;62 attached to valve 27. As a means of adjustment a wing nut 63 is threaded onthe end of valve stem 62.

The valve 27 is normally held in closed position by a coiled expansion spring 59 one end of which bears against a pin 64 through the valve stem 62 and the opposite end bears against casting 22.

The cold air is conducted as in the previous figures through pipe 21 and nozzle 23 into the exhaust pipe. This cools the exhaust pipe as well as having a somewhat cooling influence on the cylinder.

The valve stem 62 has an annular reduced portion 66 thereon, and the pipe 21 has a branch passage 67 terminating in front of the'reduced portion 66, Fig. 7. In the normal closed position of the valve 27, air passes through the passage 67 to blow onto the valve stem and also on the rear face of the valve, as can be clearly seen, this cooling the valve and the adjacent parts.

The valve upon being opened by the action of the cam 36, its stem moves forward and causes the pipe 67 to be closed. This allows all of the alr to pass out through the nozzle 23. The valve is actuated by means of a pointed cam ring 37, which traverses the perimeter of the yoke '34. Upon coming slot 73 cut into the rear face of the yoke 34 acts as a guide for the cam and prevents any side movement.

What I claim asnew and wish to cover by Letters Patent is:

' 1. An internal combustion engine comprising a crank shaft, a connecting rod, a

piston rod provided with a piston reciprocable within an upper cylinder and the .said piston rod also provided with an auxiliary pistonreciprocable within an auxiliary cylinder secured to the nether surface of said upper cylinder, the said upper cylinder secured to an air tight crank case, the said auxiliary cylinder provided with an air intake pipe leading to the exterior of the crank case and provided with a check valve arranged to allow ingress and prevent egress of air, the said auxiliary piston provided with a check valve to permit ingress of air into said crank case on the up stroke of the said piston and to prevent ingress of air and allow compression of air in the crank case during the down stroke of said auxiliary piston, the said crank case provided with a discharge pipe leading to and discharging within a valve casting suitably connected at one end with an exhaust pipe and suitably connected at the other end with the said upper cylinder near the top of said upper cylinder, the said casting provided with a valve adapted when r'eciprocated to open and close a port in said casting leading to the interior of said upper cylinder, said valve provided with a coiled expansion spring adapted to normally close said valve by pressing at one end against the said casting and at the opposite end against a pin in the stem of said valve.

2. An internal combustion engine comprising a crank shaft, a connecting rod, a piston rod provided with a piston reciprocable within an upper cylinder and the said piston rod also provided with an auxiliary piston recip-rocable Within an auxiliary cylinder secured to the nether surface of said upper cylinder, the said upper cylinder se cured to .an air tight crank case, the said auxiliary cylinder provided with an air intake pipe leading to the exterior of the crank case and provided with a check valvearranged to allow ingress and prevent egress of air, the said auxiliary piston provided with acheck valve to permit ingress of air into said crank case on the up stroke of the said piston and to prevent ingress of air and allow compression of air in the crank case during the down stroke of said auxiliary piston, the said crank case provided with a discharge pipe leading to and discharging within a pipe of the engine suitably connected at one end with an exhaust pipe.

3. In an internal combustion engine, the combination with the exhaust pipe and exhaust valve thereof, of means actuated by the'engine for supplying cold air during the operation of the engine, a connection from said means fordirecting streams of 'air from said supply into the pipe, a passage from 'said connection for directing streams of air from said supply upon the valve, said passage being controlled by the position of the valve.

In testimony whereof I ailix my signature.

JACK B. MACDONALD.

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