Abstract:
A dual piston compression chamber for two-cycle engines wherein a primary piston and an exhaust/intake piston travel at different rates within a compression chamber to draw a charge through one-way intake ports and subsequently through one-way passages extending through the secondary piston so as to trap said charge between the secondary piston and the ascending primary piston with the area therebetween defining the compression chamber where the charge is adiabatically compressed and ignited.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to two-cycle engines and, more specifically, to a dual piston compression chamber for two-cycle engines having a primary piston and an exhaust/intake piston, said exhaust/intake piston having a plurality of one-way valve controlled passages extending therethrough to provide controlled communication between the intake ports and the compression area located between the two pistons. The present invention may also be adapted for application with spark ignition engines. 
     2. Description of the Prior Art 
     There are other two cycle engines. Typical of these is U.S. Pat. No. 780,812 issued to Radovanovic on Jan. 24, 1905. 
     Another patent was issued to Germaine on Dec. 24, 1907 as U.S. Pat. No. 874,634. Yet another U.S. Pat. No. 898,768 was issued to Murphy on Sept. 15, 1908 and still yet another was issued on Feb. 16 1909 to Steely as U.S. Pat. No. 912,751. 
     Another patent was issued to Kulage on Aug. 3, 1909 as U.S. Pat. No. 929,769. Yet another U.S. Pat. No. 931,319 was issued to Krotz on Aug. 17, 1909 and still yet another was issued on May 23, 1916 to Palmer as U.S. Pat. No. 1,183,904. A patent was issued to Carroll on Aug. 9, 1955 as U.S. Pat. No. 2,714,875 and Shapiro was issued U.S. Pat. No. 4,455,974 on Jun. 26, 1984. U.S. Pat. No. 4,964,379 was issued on Oct. 23, 1990 to August and on May 6, 1997 Erickson et al. was issued U.S. Pat. No. 5,626,106. Thompson was issued U.S. Pat. No. 5,809,947 on Sep. 22, 1998. 
     U.S. Pat. No. 780,812 
     Inventor: Andreas Radovanovic 
     Issued: Jan. 24, 1905 
     In combination, a cylinder having midway of its length internal peripheral exhaust-ports, a piston controlling said ports, a piston extension, a mixing-chamber therein having ports adapted to place the cylinder in communication with said chamber, the latter provided with air and gas admission ports and means to supply air and gas to said ports respectively, said supply and the admission of the mixture to the cylinder controlled by the movements of the piston extension, for the purpose set forth. 
     U.S. Pat. No. 874,634 
     Inventor: William A. St. Germain 
     Issued: Dec. 24, 1907 
     In an internal combustion engine, a pair of cylinders arranged head to head and in alignment with each other, pistons in said cylinders, a piston rod extending through the head cylinder and to which both pistons are secured, a crank shaft connected to one of the pistons, upper and lower compression chambers connected to the open ends of the cylinders, inlet ports leading from the compression chambers through the walls of the cylinders, exhaust ports leading from the cylinders and arranged to be uncovered by the pistons at the outer limits of their strokes, all the said ports being controlled by the pistons, a valve chamber intermediate the compression chambers and having a fluid inlet, and valves arranged in said valve chamber and controlling communication between the latter and the compression chambers. 
     U.S. Pat. No. 898,768 
     Inventor: George F. Murphy 
     Issued: Sept. 15, 1908 
     In a two cycle engine, the combination of a cylinder and a piston, the space on one side of the piston being for combustion and having a clearance space so proportioned to the effective piston displacement at this end of the cylinder as to produce a compression and resulting temperature high enough to ignite the fuel to be consumed, the space on the other side of the piston being for initial compression, a valve controlled passage between the two spaces and cooperating with each other 
     U.S. Pat. No. 4,455,974 
     Inventor: Wilbur Shapiro et al. 
     Issued: Jun. 26, 1984 
     A gas bearing supported piston assembly ( 2 ) for an internal combustion engine including a piston body ( 14 ,  14 ′) and a segmented piston ring ( 3 ) arranged to expand to compensate for wear. A piston supporting gas layer ( 27 ) is formed between the cylinder walls ( 8 ) and the exterior surface of each piston ring segment ( 32 ) by means of a plurality of restricted flow passages ( 40 ) formed in each segment ( 32 ) and extending between the inner and outer surfaces of the segment ( 32 ). In one embodiment, gas under pressure is supplied to the ring segments ( 32 ) through a single annular cavity ( 36 ) formed in piston body ( 14 ). In another embodiment, gas under pressure is supplied to the ring segments ( 32 ) through a plurality of corresponding holes ( 70 ) in piston body ( 14 ′). 
     U.S. Pat. No. 4,964,379 
     Inventor: Paul August 
     Issued: Oct. 23, 1990 
     Two pistons in adjacently situated cylinders in a twin-piston two-stroke engine share a common combustion chamber. To ensure low exhaust gas emissions with low consumption, a lean mixture is burnt whereof the complete combustion is made possible by designing the combustion chamber so that circulation of the ignited mixture takes place and the mixture burns through rapidly. The twin-piston two-stroke engine may also be devised to run with a stratified charge, the centrally arranged partition in the twin cylinder providing excellent separation between the lean and rich mixture portions. 
     U.S. Pat. No. 5,626,106 
     Inventor: Frederick L. Erickson et al. 
     Issued: May 6, 1997 
     Design Improvements are disclosed which enhance the migrating combustion chamber engine&#39;s ability to achieve improved performance, obtain higher durability and cost less to manufacture. These include strip seals between the combustion chamber member and orbiting piston which are adapted to respond to the pressure of combustion to increase contact pressure and improve retention of the gases in the combustion chambers as well as improved porting located in at least one power block sidewall and cooperating with the migrating combustion chamber to convey hot combustion gasses from a combustion chamber to a corresponding secondary expansion chamber. The combustion chamber member may be formed of two reciprocable piston portions and a pair of separate alloy steel connecting bars coupling the piston portions together. The connecting bars made of a low thermal conductivity material to remain hot and aid in fuel evaporation. A one piece counterweight hub provides all required counterweights. It attaches to the crankshaft by a first clamp which clamps the counterweight hub onto the crankshaft, and second clamp which pulls an inside bore of the hub axially tight against an end of the crankshaft. Improvements in exhaust porting, ignition location, manifold and combustion chamber member designs as well as unique power block housing wear strips and crankshaft counterbalancing techniques are also disclosed. 
     U.S. Pat. No. 5,809,947 
     Inventor: Kevin R. Thompson 
     Issued: Sep. 22 1998 
     A valve is provided for a piston of a two stroke engine wherein the piston has a sidewall and top and bottom surfaces with the top surface having a first opening therein and a second opening extending between the top and bottom surfaces for receiving the valve, and wherein the piston has a plurality of pressure relief openings extending between the top and bottom surfaces. The valve comprises a valve plate positioned in the opening in the top surface overlaying the pressure relief openings with the valve plate having a central opening extending parallel to the sidewall. The valve plate is movable from a seated position covering the pressure relief openings to an unseated position exposing the pressure relief openings when pressure inside the piston exceeds a predetermined value. A retainer pin has an elongated body extending through the central opening in the valve plate, a head atop the retainer pin overlying the valve plate, and a hollow end portion flared radially outward against the bottom surface of the piston to limit upward movement of the retainer pin. The valve opens on the downstroke of the piston to relieve some of the crankcase pressure allowing the piston to descend with less resistance. 
     While these two cycle engines may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described. 
     SUMMARY OF THE PRESENT INVENTION 
     A primary object of the present invention is to provide a dual piston compression chamber for two cycle engines having a primary piston and an exhaust/intake piston that cooperate with one another and form a compression chamber therebetween. 
     Another object of the present invention is to provide a dual piston compression chamber for two cycle engines wherein the exhaust/intake piston has a plurality of passages extending the rethrough and one-way check valves residing therein to regulate the directional flow of fuel and air from the intake ports to the compression chamber. 
     Yet another object of the present invention is to provide a dual piston compression chamber for two cycle engines wherein the check valves could include but are not limited to reed valves or inertial valves. 
     Still yet another object of the present invention is to provide a dual piston compression chamber for two cycle engines that will enable a two cycle engine to perform with a similar efficiency and emissions as a four cycle engine while maintaining a low RPM, increased torque, and greater power for engine weight. 
     Yet another object of the present invention is to provide a dual piston compression chamber for two cycle engines that is inexpensive to manufacture and operate. 
     One more object of the present invention is to provide a dual piston compression chamber for two cycle engines that is simple to use. 
     Additional objects of the present invention will appear as the description proceeds. 
     The present invention overcomes the shortcomings of the prior art by providing a dual piston compression chamber with positive displacement for two cycle engines that will produce four cycle efficiency and emissions with reduced RPM and increased torque. The present invention could be particularly useful in aircraft engines due to the greater power for a given engine weight and fewer moving parts wherein the design allows for applications with a variety of fuels. 
     The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawing, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawing, like reference characters designate the same or similar parts throughout the several views. 
     The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which: 
     FIG. 1 is a diagram of the present invention at the beginning of the compression stroke; 
     FIG. 2 is a diagram of the present invention in the middle of the compression stroke; 
     FIG. 3 is a diagram of the present invention during the end of the compression stroke/beginning of the power stroke; 
     FIG. 4 is a diagram of the present invention during the middle of the power stroke; 
     FIG. 5 is a front view of the present invention showing the mechanical drive arrangement; 
     FIG. 6 is a side view of the cam wheel method taken from FIG. 4 as indicated; 
     FIG. 7 is a diagram of the present invention during exhaust; 
     FIG. 8 is a diagram of the present invention during the compression stroke; 
     FIG. 9 is a diagram of the present invention at the end of the compression stroke; and 
     FIG. 10 is a diagram of the present invention during the power stroke. 
    
    
     DESCRIPTION OF THE REFERENCED NUMERALS 
     Turning now descriptively to the drawings, in which similar reference character denote similar elements throughout the several views, the Figures illustrate the valveless revolving cylinder engine of the present invention. With regard to the reference numerals used, the following numbering is used throughput the various drawing figures. 
       10  dual piston compression chamber for two cycle engines 
       12  primary piston 
       14  intake/exhaust piston 
       15  cylinder 
       16  engine housing 
       18  connecting rod 
       20  intake port 
       22  exhaust port 
       23  piston port 
       24  fuel injector 
       25  atomized fuel 
       26  one-way check valve 
       28  air charge 
       29  burned gases 
       30  crankshaft assembly 
       32  cam wheel 
       34  intake/exhaust piston follower 
       36  spark plug 
       38  spark 
       40  compression chamber 
       44  burned gases 
       46  connecting rod 
       48  follower connecting rod 
       50  intake/exhaust piston follower track 
       52  fuel/air mixture 
       54  combustible media 
       56  synchronization regulation means 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well. For a definition of the complete scope of the invention, the reader is directed to the appended claims. 
     FIGS. 1,  2 ,  3  and  4  are cross sectional front views of the present invention  10  as applied to a two-cycle compression ignition engine with FIGS. 1,  2  and  3  demonstrating stages of the compression stroke. FIG. 1 shows the end of the power stroke/beginning of the compression stroke. At the beginning of the compression stroke the primary piston  12  has fully descended and the exhaust ports  22  are uncovered thus allowing the descending intake/exhaust piston  14  to purge the burned gases  29 ; simultaneously, scavenging air  28  is entering the cylinder  15  above the intake/exhaust piston  14  through the intake ports  20  to provide a combustible media  54 . One-way check valves  26  in the intake ports  20  permit a fresh air charge  28  to travel into the cylinder  15  while prohibiting it from exiting therethrough. Piston ports  23  extending through the intake/exhaust piston  14  also include one -way check valves to allow for the directional transfer of gases therethrough from the portion of the cylinder  15  above the intake/exhaust piston  14  to the area between the primary piston  12  and the intake/exhaust piston  14  which defines the compression chamber  40  while preventing the backflow of such gases. FIG. 2 depicts the present invention  10  in the middle of the compression stroke wherein the intake/exhaust piston  14  is advancing towards the top of the cylinder  15  where a fresh air charge  28  has been introduced through the intake ports  20  which are now sealed by the one-way valves  26  incorporated therein due to the back pressure resulting from the advancing intake/exhaust cylinder  14  thus channeling the charge  28  though the piston ports  20  and into the compression chamber  40  where it is contained due to the following primary piston  12  having sealed off the exhaust ports  22 . The primary piston  12  will continue to compress the charge  28  therein for the remainder of the stroke. The end of the compression stroke/beginning of the power stroke is shown in FIG. 3 wherein the intake/exhaust piston  14  has reached its zenith and has channeled the charge  28  into the compression chamber  40  where it is compressed adiabatically to a high temperature with the advance of the primary piston  12 . When near maximum compression has been achieved, just before dead center, a fuel injector  24  introduces a finely atomized fuel  25  into the heated air charge  28  in the compression chamber  40  initiating auto-ignition of the mixture and the subsequent power stroke which is illustrated in FIGS. 3,  4  and  1 . 
     The introduction of fuel  25  into the compression chamber  40  as shown in FIG. 3 causes the combustion thereof and the expanding hot mixture acts upon the primary piston  12  and thrusts it downward as shown in FIG. 4 for the remainder of the power stroke. Referring back to FIG. 1 the intake/exhaust piston  12  soon follows and scavenges a fresh air charge  28  through the intake ports  20  and the continued descent of the primary piston  12  exposes the exhaust ports  22  through which burned gases  29  are expelled by the descending intake/exhaust piston  12 . 
     FIGS. 5 and 6 show the preferred mechanical drive arrangement of the primary components that provide synchronization regulation means  56  of the primary piston  12  and the exhaust/intake piston  14  while allowing for the differences required in timing for the travel of the two pistons although any other suitable drive arrangement may be used that would accomplish the objectives of the present invention. FIG. 5 is a side view of the present invention showing the primary piston  12  driven by a substantially conventional crankshaft assembly  30  and connecting rod  46 . A cam wheel  32  is connected on either side of the crankshaft assembly  30  and has an intake/exhaust piston follower track  50  as is shown in FIG. 6 in which intake/exhaust piston followers  34  are entrained. The intake/exhaust piston followers  34  are in communication with the intake/exhaust piston  14  via at least one follower connecting rod  48  thus providing the reciprocating action of the intake/exhaust piston  14  in response to the axial rotation of the cam wheels  32  thereby enabling the crankshaft assembly  30  to regulate the travel of both the primary piston  12  and the intake/exhaust piston  14  even though each travels at its own rate and distance to provide synchronicity thereof for the alignment of the various pistons and ports through the operating cycle. 
     FIGS. 7,  8 ,  9  and  10  are cross sectional side views of the present invention  10  as adapted for application to a two-cycle spark ignition engine with FIGS. 7,  8  and  9  demonstrating stages of the compression stroke. FIG. 7 shows the end of the power stroke/beginning of the compression stroke. At the beginning of the compression stroke the primary piston  12  has fully descended and the exhaust ports  22  are uncovered thus allowing the descending intake/exhaust piston  14  to expel the burned gases  29 ; simultaneously, an air/fuel mix  52  is entering the cylinder  15  above the intake/exhaust piston  14  through the intake ports  20 . One-way check valves  26  in the intake ports  20  permit the air/fuel mix  52  to travel into the cylinder  15  while prohibiting it from exiting therethrough. Piston ports  23  extending through the intake/exhaust piston  14  also include one -way check valves to allow for the directional transfer of gases therethrough from the portion of the cylinder  15  above the intake/exhaust piston  14  to the area between the primary piston  12  and the intake/exhaust piston  14  which forms the compression chamber  40  while preventing the backflow of such gases. FIG. 8 depicts the present invention  10  in the middle of the compression stroke wherein the intake/exhaust piston  14  is advancing towards the top of the cylinder  15  where an air/fuel mix  52  has been introduced through the intake ports  20  which are now sealed by the one-way valves  26  incorporated therein due to the back pressure resulting from the advancing intake/exhaust cylinder  14  thus channeling the air/fuel mix  52  though the piston ports  20  and into the compression chamber  40  where it is contained due to the following primary piston  12  which has sealed off the exhaust ports  22  and will compress the air/fuel mix  52  therein for the remainder of the stroke thereby progressively increasing the pressure and temperature of the mixture. The end of the compression stroke/beginning of the power stroke is shown in FIG. 9 wherein the intake/exhaust piston  14  has reached its zenith and channeled the air/fuel mix  52  into the compression chamber  40  where it is compressed to a volatile temperature and pressure by the advance of the primary piston  12 . When near maximum compression has been achieved just before dead center a spark plug  36  introduces a spark  38  into the volatile air/fuel mix  52  in the compression chamber  40  initiating auto-ignition of the mixture and the subsequent power stroke which is illustrated in FIGS. 9,  10  and  7 . 
     The introduction of a spark  38  into the compression chamber  40  as shown in FIG. 9 causes the combustion thereof and the expanding hot mixture acts upon the primary piston  12  and thrusts it downward as shown in FIG. 4 for the remainder of the power stroke. Referring back to FIG. 7 the intake/exhaust piston  12  soon follows and scavenges a fresh air/fuel mix  52  through the intake ports  20  and the continued descent of the primary piston  12  exposes the exhaust ports  22  through which burned gases  29  are purged by the descending intake/exhaust piston  12 . 
     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.