US1542697A - Two-stroke-cycle engine - Google Patents

Description

Jun 16, 1925.

L. H. HOUNSFIELD TWO-STROKE CYCLE ENGINE Filed Jan. 30, 1923 .mvnrroll;

MFm WM/y W Patented June 1,6, 1925.

UNITED. STATE LESLIE HAYWOOD nounsrrnnn, or CROYDON, ENGLAND.

'rwo-sraoKE-cYoLn ENGINE.

! Application filed January 30, 1923 Serial No. 615,801.

To all whom it may concern: i y

Be it known that I, LnsL'In HAYWOOD HOUNSFIELD, a subject of the King of England, residing at Croydon, Surrey, England, have invented certain new and useful Improvements in Two-Stroke-Cycle Engines, of which the following is a specification.

This invention relates to improvements in and connected with two-stroke cycle engines of the three port type using crank chamber compression, and wherein the cylinders are connected in pairs at the combustion chamber' end and so constructed that the piston movement alone, without the use of auxiliary valves, controlsan inlet port between the carburettor and the crank-chamber, a transfer port leading from the crank-chamber to the combustion space, and an exhaust port leading from the combustion space to the exhaust. In engines of this type the charge passes through thecrank case before reaching the cylinders and in so doing is liable to pick up lubricating oil, even in engines in which lubrication is not effected by mixing the oil with the petrol or other fuel. If the oil thus picked up is not separated from the fuel but is allowed to collect in the cylinders, theengines and plugs areliable to become foul and oil is wasted. The present invention, therefore, has for its object the production of an engine which fouls less readily, and uses less lubricating oil than do engines as heretofore constructed.

In carrying out the invention the engine is so constructed as to afford the greatest possible opportunity for oil to separate and gravitate out of the charge into the crank chamber before the charge passes to the combustion chamber, and is further so constructed that such oil as may pass into the I combustion space cannot remain there but must gravitate away therefrom and pass direct out from the exhaust. More particularly the engine is so constructed'that the fuel passage from the carburettor to the crank chamber contains no liquid collecting pockets, and in addition isso constructed that the chargehaving entered the crank chamber (where the gas velocities are comparatively low) has to traverse it in an up ward direction before reaching the transfer port from the crank chamber to the combustion chamber. Thus 'thebulk of the oil which separates out is caused to settle in the crank chamber, and by arranging the axes of the cylinders constituting each of the connected pairs approximately horizontally, wlth the intake cylinder (i. e. the cylinder containing i the piston which controls the new charge) above the exhaust cylinder (i. e. the cylinder containing the piston controlling the exhaust port), such oil asmay enter the combustion space is promptly drained and blown away through thee);- haust. 1 i

In the accompanying drawings which.

Figure 2 represents a cross section on the line 22 of Figure 1, and

Figure 3 is a section on the line 33 of Figure 2.

Like reference numerals The transfer port or passage 10 leads from the upper part of the crank chamber '11 to the upper or intake cylinder 12, al-

though not necessarily from the highest point of the crank chamber, as the highest pointunight be so, situated as to collect lubricating oil thrown from the moving parts. By arranging the passage 10 in the upper part of the crank chamber the sepa ration of oil by gravity'is facilitated, and by suitably choosing the disposition of the transfer port with regard tot-he moving parts in the crank chamber, it is possible to ensure thatoil cannot be thrown directly into the port. Any oil OIBXCGSS fuel which may however pass through this transfer pas sage into thev intake cylinder 12 readily gravitates through the intake cylinder into the exhaust cylinder 13, and thence out of the exhaust port 14 which is, in engines constructed according to this invention, situate in the lower side of the exhaust cylinder. The force of gravity is assisted by the intermittent rush of the gases passingthrough from the intake portto the exhaustport.

Four cylinder engines constructed according to'this invention consist conveniently of two two- cylinder units 15 and 16 arranged side by side so that the axes of the two intake cylinders 12 and 17 are substantially in a horizontal plane above another horizontal plane containing-the axes'of the exhaust cylinders 13 and 18.' The inlet pipe or passage 19 from the carburettor may pass indicate like parts throughoutthe drawings.

Cit

in a substantially horizontal direction and about equidistant from the axes of all the cylinders into a chamber containing ports 21 leading into the crank chamberg the ports being controlled by the skirt endsof the exhaust pistons.

The passage from the"carburett(n' to the crank chamber is constructed so as to be free froin'pocltet's in which liquid'can collect,

lLllClSO'tllElt' any oil which may deposit drains down intothe'cran-k chamber, and by disposmg the inlet 131136, or passage 19-1ntlre manner above cle'scr1becl,"-tl1'e "carburetted mix- 'ture be'comes heat e'dby reason of its proxnor'do 'they require -de-carbonizing. "Hence the difficulty experienced with mosttwostroke engines; of obtaining sparking plugs which can both resist oil and the'high tom-- peratures associated with such engines, is eliminated! 1. In a two-stroke"cycle internal-combusnon, engine of the three-port type. having crank-case "compression of the combustible mixture the combination of a casing having a compres's on chamber in' the form of a crank-case -"there'in;an inta ke cylinder having a transfer port anclan exhaust cylinder having an exhaust port within said casing,

bothof which cylinders open atone end into the-said crank-case, a combustion cham- ,be1' "comfmon-'to both cylinders at the end 'thereofremote' from thecrank case,'the exhaust cylinder*haviug an inlet port at the side/of itsexhaust portremote from the combustion chamben'a conduit connected to said inlet "port" ifo'r supplying. combustible mi'xtu're thereto, a transfer passage putting the said transfer port in open communication w'iththe-crankcase, a crank-shaft in said crank 'caseyand pistons operable one in each cylinder and operatively connected to "said "crank-shaftand arranged to control said portsywhi'ch saidiports are so situated and the engine parts'r provided with said ports are'so constructed =thatthe combustible cha'rgeus compelled to flow to and through thepinlet' port to the transfer port along a path which dra'ins' downwardlytowards the bottomofthe crank-caSe'aWay from the said conduit, and the. whole of said combustion space in all positions of the pistons drains down from the transfer port to the exhaust port withoutencountering a liquid-collecting pocket.

2. In two-stroke cycle internal-combustion engine 'of'the three-port type having crankcase compression of the combustible mixture, the combination of a casing having a compression chamber in the form of a crankcase therein, an intake cylinder having a transfer port and an exhaust cylinder having an exhaustport within said casing, both of'which cylinders open atone end into the said crank-case, a combustion chamber common to both cylinders at the end thereof remote' from the crank-case, the exhaust cylinder having an inlet port at the sideof its exhaust port remote from the combustion chamber, a transfer passage putting the said transfer port in open communication with i the crank-case, 'a crankshaft in said crankcase; and-pistons operable one in each cylinder and opera'tively' connected to said crankshaft and arranged to control said ports,

which said ports are 'sosituated, and-the engine parts'provided with said ports are so constructed that the combustible charge is compelled to flow upwards in the crankcase from the inlet port tothe-transfer port along a path which drains downwardly to Wards thebottom'ofthe crank-case away from thcsaid inlet and transfer ports, and the'wvhole of said combustionspace in all positions of the pistons drains down -to the exhaust port withoutencountering a liquidcolleeting pocket.

3. In a horizontal, two-stroke cycle, internal-combustion engine 'of the three port type havingcrank-case compression of the combustible mixture; the combination of a casing having a compression chamber in the form of a crank-case therein, a pair of parallel substantially horizontal cylinders within said casing, whereof one cylinder is arranged above the other and both open at one end'into saidacran-k case, a conibustion chamber conunonto bot-h cylinders atthe end thereof remote from the crank-case, the lower cylinder haa 'ing only in its upper part an'inlet port and "havingatthe side of the inlet port remote'from the crank-case an exhaust port, the upper cylinder having a transfer port which communicates with the upper part of'the crank-case,- pistons operable one in each cylinder and arranged'to control saidports a crank-shaft in said crank-case, and means operatively connecting said' pistonswitlrthe crankshaft, whereby the charge is compelled to flowfrom the inlet: port to 'theitransfer port along a path which drains downwardly towards the bottom ofthe' crank-case1away from the said inlet and transfer ports, and'liquid-collectin'gi pockets are "obviated, substantially as described;

4. Ina horizontal,two-stroke cycle, internal-combustion engine of the three-port type having crank-case compression of the combustible mixture, the combination of a casing having a compression chamber in the form of a crank-case therein, a' pair of parallel horizontal cylinders within said'casing, whereof one cylinder is arranged vertically above the other, and both open at one end into said crank-case, a combustion chamber common to both cylinders at the end thereof remote from the crank-case, the lower cylinder having an inlet port and at the side thereof remote from the crankcase an exhaust port, the upper cylinder having in its upper part a transfer port and a transfer conduit which communicates with the upper part of the crank-case, pistons operable one in each cylinder and arranged to control said ports, and means for controlling said pistons in unison, whereby the charge is compelled to enter the compression chamber at a part thereof situated below the crankcase end of the transfer conduit, and the exhaust from the upper cylinder is compelled to pass through a part of the lower cylinder on its way to the exhaust port without encountering liquid-collecting pockets, substantially as described.

5. In a horizontal, four-cylinder, twostroke cycle internal-combustion engine of the three-port type having crank-case compression of the combustible mixture, the combination of a casing having two compression chambers each constituting a crankcase therein, two pairs of parallel horizontal cylinders arranged side by side within said casing, whereof the one cylinder of. one pair is arranged above the other cylinder of the same pair and both cylinders of a pair open at one end into one of said crank-cases, two combustion-chambers, one common to each pair of cylinders, at the end of the casing remote from the crank-case, the \lower cylinder of each pair having only in its upper part a fuel-inlet port and in its lower part at the side thereof remote from the crank-case an exhaust port, the upper cylinder of each pair havinga transfer port which communicates, with the upper part of the allotted crank-case, pistons operable one in each cylinder and arranged to control said ports, means for controlling said pistons, a supply chamber for combustible mixture situated between said cylinders and opening directly into said inlet ports, and a horizontal supply conduit for combustible mixture substantially parallel to the axes of the four cylinders and free from pockets lying between said cylinders and opening into said supply chamber, substantially as described. s

6. In a horizontal, four-cylinder twostroke cycle, internal-combustion engine of the three-port type having crankcase compression with the combustible mixture, the combination of a casing havingtwo compression chambers each constituting a crankcase therein, two pairs of parallel horizontal cylinders arranged side by side within said casing, whereof the one cylinder of one pair is arranged above the other cylinder of the same pair and both cylinders of a pair open at one end into one of said crank-- cases, two combustion chambers, one common to each pair of cylinders, at the end of the casing remote from the crank-case, the lower cylinder of each pair having only in its upper part an inlet port and in its lower part at the side of said inlet port remote from the crank-case an exhaust port, the upper cylinder of each pair having a transfer port which communicates with the upper part of the allotted crank-case, pistons operable one in each cylinder and arranged to control said ports, means for controlling said pistons, a supply chamber for combustible mixture situated between said cylinders and opening directly into said inlet ports, the wall of which supplychamber is constituted in part by parts of the walls of said cylinders, and a supply conduit for comliustible mixture free from pockets lying between said cylinders and opening into said supply chamber, whereby the combustible mixture will be heated by the cylinders on its way to the latter, substantially as described. a

In testimony whereof I affix 'my signature.

LESLIE HAYWOOD HOUNSFIELD.

Images