US2956555A

US2956555A - Free piston engine

Info

Publication number: US2956555A
Application number: US713812A
Authority: US
Inventors: Braun Anton
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-02-07
Filing date: 1958-02-07
Publication date: 1960-10-18
Anticipated expiration: 1977-10-18

Description

w" il-1- Oct. 18, 1960 A. BRAUN FREE PISTON ENGINE Filed Feb. 7, 1958 INVENTOR ATTORNEY United States Patent FREE Prs'roN ENGINE 7 Anton Braun, 437A Johnson St., Kingston, 2 i 2 Ontario, Canada Filed Feb. 1, 1958, Set. No. 713,812

2 Claims. Cl. 123-46) This invention relates to internal combustion freepiston engines. a

A general object of this invention is to provide a free piston engine of much simplified overall design.

Another object is to provide a free piston engine, the

elements of which are simple and effective in design.

and operation, and which permits the convenient asso ciation therewith of an eflicient cooling system.

The invention will be described with reference to the accompanying drawing, in which The single figure is a longitudinal sectional elevation of a free piston engine illustrating one embodiment of the invention.

Referring to the drawing, the free piston engine therein illustrated includes a centrally disposed compressor cylinder 90 which may also constitute the main center frame of the engine. Fixed to one end of cylinder 90 is an aligning disc 91 and to the other end thereof an aligning disc 92.

A pair of engine cylinders 93 and 94 are mounted on disc 91, each such cylinder extending outwardly therefrom and secured to disc 91 at openings 95. A cylinder head 96 is mounted on the outer ends of cylinders 93, 94 and provides a communicating passage 97. A fuel injection nozzle 98 is mounted on the head 96 for injection of fuel into passage 97.

Similarly, a pair of

engine cylinders

99 and 100 are mounted on disc 92, each such cylinder extending outwardly therefrom and secured to disc 92 at openings 101. A cylinder head 102 is mounted on the outer ends of

cylinders

99, 100 and provides a communicating passage 103. A fuel injection nozzle 104 is mounted on head 102 for injection of fuel into passage 103.

Mounted for reciprocation in compressor cylinder 90 are two

compressor pistons

105 and 106. Piston 105 is provided with a plurality of openings 107 controlled by valves 108 and piston 106 is provided with a plurality of openings 109 controlled by valves 110, the arrangement being such that on inward movement of the pistons towards each other the

valves

108 and 110 are closed but on outward movement the valves open to provide communication between the portions of cylinder 90 on the outer sides of

pistons

105 and 106 and the portion between such pistons. The outer portions of cylinder 90 and the outer sides of the pistons are open to atmosphere through respective series of openings 111 and 1 12 in aligning discs 91 and 92.

Mounted on piston 105 are a pair of engine pistons 113 and 114 complementary to and reciprocating in engine cylinders 93 and 94. Pistons 113 and 114 are hollow, their inner ends being closed by a plate 115, which forms a part of compressor piston 105.

Openings

116 and 117 in plate 115, with controlling

valves

118 and 119, provide communication between the interior of engine pistons 113 and 114 and the space between

compressor pistons

105 and 106, such valves opening during a piston -113 through ports 121, 122, thence through cyl- ICC a of; piston 113, ports 120 are arranged to register with ports 121 in the cylinder 93. Ports 121 communicate with a second series of ports 122 in cylinder 93 by meansof an annular passage 123 provided by the ring 124. Thus,-air or gases may pass from the interior of inder 93, passage 97, and cylinder 94, and is discharged through a series of ports 125 into an exhaust duct 126.

. Engine piston 114 is of unported conventional type. It will be apparent that, in its innermost position, ports 125 are open but are closed thereby during its initial outward motion.

Mounted on compressor piston 106 are a pair of engine pistons 127 and 128 complementary to and reciprocating in

engine cylinders

99 and 100. Pistons 127 and 128 and their associated elements are identical to and symmetrical with pistons 113 and 114. The corresponding associated elements include plate 129,

openings

130 and 131 in the plate, controlling

valves

132 and 133, ports 134, registering ports 135, communicating ports 136, passage 137, ring 138, exhaust ports 139, and exhaust duct 140.

In operation, after piston assemblies 105, 113, 114 and 106, 127, 128 have reached their innermost position, as shown in the drawing, suflicient energy is stored up in the clearance space between them to drive them apart in order to elfect the engine compression stroke of pistons 113, 114 and 127, 128. During this outward stroke, fresh air enters the space between

compressor pistons

105, 106 through

intake valves

108, 110, the outer faces of such pistons being exposed to atmosphere. Outward motion of engine pistons 1'13, 114 and 127, 128

closes ports

121, 122, 125 and 134, 135, 139 and compression occurs in cylinders 93, 94 and passage 97 and cylinders 99, and passage 103. On completion of the outward stroke, fuel is injected through nozzles 98, '104 and the piston assemblies are driven back to perform the compressor compression and discharge stroke. When the air within the compression chamber between pistons and 106 reach discharge pressure, it is discharged through

valves

118, 119 and 132, 133 into the interiors of pistons 113, 114 and 127, 128. When the latter pistons uncover

ports

121, 122, and 134, 135, 139, the air flows through the paths previously described to eiiect scavenging, cooling and supercharging and the exhaust gases are discharged into

exhaust ducts

126, 140.

It will be apparent that various changes may be made in the structure described within the contemplation of the present invention. For instance, while but two engine pistons have been described as attached to a common compressor piston (one acting as an intake piston and the other as an exhaust piston), it will be understood that any suitable number of engine pistons may be attached to each compressor piston. The arrangement of engine pistons with respect to each compressor piston should, of course, be symmetrical. When more than one pair of engine pistons is attached to each compressor piston the engine could be run at full load with, say, two pairs of engine pistons, for instance, two intake and two exhaust pistons on one common compressor piston. At a certain partial load point, one pair of engine pistons, for instance, one intake and one exhaust piston, could be shut off.

I claim:

1. An internal combustion free piston engine compris- Patented Oct. 18, 1960 pressor pistons reciprocally mounted in said compressor cylinder and each having inner and outer faces, said compressor pistons providing a space between said inner faces thereof in said compressor cylinder, a plurality of engine cylinders extending outwardly from and secured to each said aligning disc, a plurality of engine pistons carried by and extending outwardly from the outer face of each said compressor piston, each said engine piston having reciprocal engagement with one of said engine cylinders, a plurality of air intake openings in each said compressor piston, a valve controlling each said air intake opening to close said openings during the inward stroke of said compressor pistons and to open saidopenings during the outward stroke of said compressor pistons for inlet of air into said space between said compressor pistons, each said engine piston being hollow and having at least one opening communicating with said space, valve means controlling each said engine piston opening to open said engine piston openings during the inward stroke of said compressor pistons and to close said engine piston openings during the outward stroke of said compressor pistons, at least one of said engine pistons having air discharge ports, said engine cylinders having air discharge passages communicating with said air discharge ports when said engine pistons are in the vicinity of their innermost positions.

2. An internal combustion free piston engine comprising a compressor cylinder having an aligning disc at each end thereof, each said aligning disc having openings for passage of intake air to portions of the interior of said compressor cylinder, a pair of opposed compressor pistons reciprocally mounted in said compressor cylinder and each having inner and outer faces, said compressor pistons providinga space between said inner faces thereof in said compressor cylinder, a plurality of engine cylinders extending outwardly from and secured to each said aligning disc, a cylinder head providing communication between the outer ends of said engine cylinders, a plurality of engine pistons carried by and extending outwardly from the outer face of each said compressor piston, each said engine piston having reciprocal engagement with one of said engine cylinders, a plurality of air intake openings in each said compressor piston, a valve controlling each said air intake opening to close said openings during the inward stroke of said compressor pistons and to open said openings during the outward stroke of said compressor pistons for passage of intake air into said space between said compressor pistons, each said engine piston being hollow and having at least one opening communicating with,

said space, valve means controlling each said engine piston opening to open said engine piston openings during the inward stroke of said compressor pistons and to close said engine piston openings during the outward stroke of said compressor pistons, at least one of said engine pistons and cylinders having registering air discharge ports when said engine pistons are in the vicinity of their innermost positions, means forming a passage leading from said registering air discharge ports to said engine cylinders, and gas discharge ducts leading from said engine cylinder.

References Cited in the file of this patent UNITED STATES PATENTS