US1105882A - Two-cycle internal-combustion engine. - Google Patents

Description

H. J. CRAWFORD. TWO-OYOLE INTERNAL GOMBUSTIN ENGINE.

APPLICATION FILED MAB. 1R, 1018.

Patented Aug. 4, 1914.

HENRY J. CEAWIFOBD, OIE' LOS ANGELES, CALIFORNIA.

TWO-CYCLE INTEENALCOMBUSTION ENGINE.

Specification of Letters Yatent.

Patented Aug. 4, 1914.

.application filed March 12, .1913. Serial No. 753,822.

i To all whom 'it may conce/m:

Be it known that I, HENRY J. CRAWFORD, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful TwoCycle Internal-Conibustion Engine, of which the following is a specification.

This invention relates to internal combustion engines of the two cycle type and the main object of the invention is to provide improved valve means for controlling the supply of mixture to the engine cylinder, so as to increase the efficiency of the scavenging operation.

Another object of the invention is to provide valve means for this purpose which will be movable rotatably with the engine shaft, so as to reduce to a minimum the number of parts required and render the valve mechanism certain and effective in its operation.

Another object of the invention is to allow more time for the intake of mixture to crank case and cylinder.

Other objects of the invention will appeal' hereinafter.

The accompanying drawings illustrate an embodiment of the invention, and referring thereto:

Figure 1 is a side elevation of the engine. Fig. 2 is a vertical section thereof. Fig. 3 is an endelevation of the engine with parts broken away. Fig. 4 is a section on line no4-m4 in Fig. 2. Fig. 5 is a section on line .m5-m5 in Fig. 3.

The invention is herein shown as applied in connection with a single cylinder engine, but it will be understood that it is equally applicable with an engine having any number of cylinders.

1 designates the engine cylinder, 2 the crank case, 3 the engine shaft rotatably mounted in bearings 8 on said crank case, and 4 the piston working in said cylinder and connected by connecting rod 5 to wrist pin 6v engaging in crank disks 7 upon the en gine shaft, said engine shaft bcng'divided so as to allow the connecting rod to work betweensa-id crank disks. Said crank disks preferably occupy as much as possible of the space Within the crank case so as to pro vide formaximum effectiveness of compression, said crank case being used, as a compression chamber. The crank case is shown as formed in two parts, connected by bolts 2.

Valve means are provided for controlling admission of air or mixture to the crank case and for controlling supply of compressed mixture from the crank case to the cylinder. For this purpose one end portion 3 of the shaft 3 is bored or made hollow as indicated at 9 to form a. passage communieating at its inner end wlth the interior of the crank case and closed at its outer cud as shown at 9', a lateral port 10 extending from said bore to the outside of the shaft near its outer end coperating with ports 12 and 13 in a valve sleeve 11. Said, sleeve 11 operates as an adjustable valve member and is supported adjustably in position within a bearing sleeve 14, formed cn or attached to the crank case. An inlet pipe 15 for mixture of air and combustible communicates with the port 12 in said sleeve 11, and a transfer pine or conduit 17 communicates at one end with the port 13 in said valve sleeve and in its other end with an inlet port 19 in the engine cylinder, said inlet port being located in position to be exposed by the piston when the latter is near the lower end of the stroke. Directly opposite the inlet port 19 and preferably somewhat lower down, so as to be closed somewhat earlier in the upward stroke .is an exhaust port 20, communicating with exhaust pipe 21.. Suitable means are provided for exploding the charge comprising, for example, a spark plug 22 and a timer 23 connected in circuit in the usual manner with a magneto or battery andcoil to produce a spark at the spark plug at the proper time.

The operation` is as follows: Assuming that the parts are in position shown in Fig. 2, and that the piston is moving upwardly, a condition of suction will be produced within the crank case and at this time the port 10 in the shaft is in communication with the port 12 in the valve casing 11, which communicates with the inlet pipe 15 for mixture, so the mixture is drawn in from the carbureter through this inlet pipe, through port 12, port 10 in theshaft and bore or longitudinal passage 9 in the shaft, to theinterior of the crank case.` As the piston reaches the upper endof its stroke the port 10 in the shaft passes the port 12 closing this inlet opening and cutting oil' the supply of mixture. In the succeeding descent of the piston the mixture thus introduced into the crank case is compressed, and during the whole time of compression thc compressed mixture to pass from the crank case through the passage 9 in the shaft through ports 10 and 13 and transfer pipe or conduit 17 and port 19 to the cylinder directly abor'e the piston, blowing the charge of mixture into the cylinder and expelling the burnt gases in the cylinder through the exhaust port 20, therebyl performing the scavenging operation and charging the cylinder with fresh mixture. Immediately thereafter the continued ascent of the piston closes the exhaust port, allowing the charge in the cylinder to be brought up to the same pressure as in the crank case and the further upward movement of the piston then closes the inlet port 19 and compresses the mixture above the piston, the cycle being completed when the piston reaches the upper end of this stroke.

What I claim is:

An internal combustion engine comprising a cylinder, a crank case, a piston Working in said cylindcr,-a shaft rotatably mounted in said crank case and connected to be operated by the piston, said shaft having a longitudinal passage communicating with 'the crank case and provided with a lateral port, a valve member having two ports communicating with the lateral port in the shaft, a mixture supply means communicating' with one of said. ports, a transfer conduit communicating with the other of said ports, said cylinder having an inlet port communicating with said transfer conduit to receive mixture therefrom, and lSaid `cylinder being provided .With an outlet port. In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 5th 'day of March, 1918.

HENRY J. CRAWFORD.

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