US2127692A - Engine - Google Patents

Description

Aug. 23, 193s, M, OTHROP 2,127,692

' ENGINE Filed sept. so, 1955,

INVENTOR.

Patented Aug. 23, 1938 2,127,692

UNITED STATES PATNT @FFME ENGINE Marcus Lothrop, Berkeley, Calif. Application September 30V, 1935, Serial No. 42,754`

' 7 claims. (c1. 12s- 79) My invention relates to internal combustion 'I encompassed by a cooling water jacket 8. A engines and is especially concerned with a compiston 9 is adapted to reciprocate in the cylinder pression ignition engine of the single-valve type between a lower position and an upper positio-n as disclosed in the copending application of in which it forms the boundary of a combustion` Nathan C. Price et al., Serial No. 35,940, filed chamber II. 'Ihe combustion chamber is also 5V August 13, 1935, and entitled Engine partially bounded by a cylinder head I2, incor- The patent literature discloses many diierent porating a cooling water jacket I3, and formed forms of internal combustion engines in which to provide a conical seat I4 for a poppet valve I6.

a single valve, usually a poppet valve, controls This valve, in the customary fashion, has a relal communication between the combustion chamber tively flat head I'I and a rod-like stem I8. The 10- and the intake and exhaust ducts, .and likewise valve is guided by a bushing I9 pressed into the shows various arrangements for controlling flow head i2 and is preferably urged towards closed through such ducts. The present engine contemposition by a coil spring 2I interposed between plates the use of a single poppet valve at the comthe cylinder head i 2 and a washer 22 detachably l5 bustion chamber itself, arranged in series with secured to the Valve stem I8. A rocker arm 23, 15. a reciprocable distributor for controlling ow pivoted on a lay shaft 24, contacts the upper end through the intake and exhaust ducts. of the valve stem I8 and is subject to the action It is an object of my invention to provide such of a cam 26 rotatably driven in time with the an arrangement in Which lubrication is not operation of the engine by a cam shaft 21. needed. I The valve iii controls flow between the com- 20 Another object of my invention is tol provide bustion chamberv I I'and a pair of passages 3l such an engine in which the arrangement is very and 32 which together form a conduit merging like standard practice. with the combustion chamber at the seat I4 but Another object of my invention is to provide which are separated by an intervening wall 33 or SU-Ch an engine in Which the ngOing and OutgO- septum in `general bisecting the space to provide 25 ing 110W S conducive t0 a high volumetric eflitwo similar passageways. These turn to merge CenCy. through kopenings 34 and 36 with a cylindrical A further object of my invention is to provide bere si in the cylinder head l2. This bore at its such an engine in which scavenging is thorough. upper portion merges with a passage 38 emerging A11 Iadditional ObjeCt Of my invention S ISO` 1310- from the side of the cylinder head I2 and con- 30 Vide Suchv en engine in which the ingOing OW nected to any suitable type of air blower 39 prefand the outgoing ow can be denitely controlled. erabiy driven by the engine, whileat its lower The foregoing and Other Objects of the invenend the bore 3l preferably merges with a passage tion are attained in the embodiment illustrated 4I likewise emerging from the side of the head I2 in the drawing. in Which and connected by a suitable pipe 42 to exhaust. 35

Fie. 1 is a orossfseotion Showing semi-diagram- In order that new in the intake passage 3B and matieelly in DelSPeCtiVe e POTOD 0f the head the exhaust passage 4I can be properly controlled of an engine Constructed in aCCOIdanCe With my in conjunction with the general operation of the invention. l engine, `I preferably provide a distributor 46 to 40 Fis. 2 is a diagram showing the events of the operate in the eyundrieal bore 31. This distribu- 40 Operating Cycletor is in general like a poppet valve and is prot. In itslpeferreqnfrm theenrll Oftn'lrggen' vvided with a head il which is preferably a very lon me u es a S1 g e Popp e' a m` li ht, circular disc and a stem 48 merging with bustion chamber in series With a distributor which Slch disc. The Stem is reciprocably mounted a e a e e tween a plurality of positions to assist in conhe Cyimder head l2 The .sgemsls rmafuy trolling the inux and the eiux of working fluid. urged Into an uppermost p CS1 lon y a CO1 spr1-ng The enginealso preferably contemplates the use 53 Whlch enompasses the Stem an@ rests Wlth of means for establishing 'a positive-flow of Workone end agamst the Cage 52 and Wlth the other ing uid through the inlet and exhaust duc/5S` end against a washer 54 removably secured to As shown by the typical example i11ustrated in the valve stem d8. A rocker arm 56 1s at one end the drawing, the engine of my invention in its in Contact with the terminus of the stem d8 and major aspects is conventional and incorporates a at the other end is pivotally mounted von the lay 55, cylinder block 6in which there is a cylinder bore shaft 24. c A suitable cam 5'! is mounted on the '55,

cam shaft 21 to operate the rocker 56 and the distributor 35.

The disc-like head 41 of the distributor is preferably of somewhat smaller diameter than the bore 31 in order to provide a clearance space 58 therebetween. This space is shown in exaggeration in the drawing but in practice is several thousandths of an inch, in order that there will be no actual contact between the distributor disc 41 and the walls of the bore 31 but so that the leakage past such distributor disc 41 is a minimum amount.

The operation of the mechanism is described especially in connection with Fig. 2 which shows the events of the cycle since the cams 25 and 51 in Fig. 1 are illustrated diagrammatically. It isv assumed that the engine is in operation and that the blower 39 is inducing a current of air to flow into the passage 38 to leak around the disc of the distributor l1 and into the passages 34 and 36 wherein it leaks around the terminus of the dividing wall 33 kor septum and flows first in contact with the head l1 of the valve and thence outwardly through the passage il to the exhaust. rihis slight current of air is suflicient to maintain the parts som-ewhat cooler than they ordinarily would run, and likewise clears any pockets of residual exhaust gas and tends `to maintain flow `from the inlet toward the exhaust.

If it is assumed that the piston 9 is adjacent top dead center ready. for injection, then the injector 5i (of any standard type) introduces the charge of fuel into the combustion chamber li. The piston 9 begins its downward power stroke, and the valve IG and the distributor 36 remain in the positions shown in Fig. l until the piston has arrived within a few degrees of bottom dead center, at which time the cam 25 actuates the valve i6 sothat the .head l1 moves into the dotted line position 52 in Fig. 1 and permits the products of combustion to iiow outwardly from the combustion chamber l l around the valve I6, through the passages 3l and 32 on both sides of the dividing wall 33, and through the outlets 34 and 35 into the bore 31 wherein their upper progress into the intake duct 38 is blocked by the distributor disc 011 so that they flow through the passage 4l into the exhaust pipe 32. The full area of the passages 3! and 32, as well as of the passage lil,

f is thus available for quickly exhausting the products -of combustion, particularly when they are under an initial, relatively high pressure.

The exhaust continues preferably several degrees past bottom dead center position of the 1 piston, at which time the cam 51 moves the distributor dii into an intermediate position 53 (Fig. 1) wherein the distributor pauses so that air under pressure from the blower 39 enters the passage 33, flows downwardly through the upper half of the bore 3l', then is diverted through the opening 33 (reversing the previous direction of flow therein), and enters through the passage 3i into one side of the combustion chamber Ii. Flow still continues outwardly from the combustion chamber, through the passageway 32, and out the opening 36 and the exhaust passage lli. There is thus established a positive scavenging flow through the passage 3l to one side of the combustion chamber, across the top of the piston, and then out from the other side of the combustion chamber through the passage 32 to exhaust. This scavenging operation is considered important in the cycle of operation of the engine and is ccntinued for a considerable period. The scavenging air is relatively low in temperature and not only assists in cooling the moving parts but likewise reduces sensibly the temperature of the combustion chamber itself, so that upon a subsequent cycle the volumetric efliciency is somewhat increased due to the initially lower temperature.

The scavenging operation preferably continues until the piston 9 has again attained and passed top dead center position, at about which time the cam 51 causes further downward movement of the distributor 46 until the disc 41 assumes the dotted line position 64 in Fig. 1. In this position of the distributor disc there is no longer permitted communication between either the passage 3l or the passage 32 and the exhaust passage 4| (except possibly due to leakage), but the intake passage 38 is in communication through both of the openings 34 and 36 with the passages 3| and 32 so that fresh air is positively forced into the combustion chamber H through both of the passages 3l and 32, and the entire area of the valve i6 is useful for induction. Flow into the cylinder is assisted bythe downward movement of the piston 3, but considerable supercharging can be effected since the clearance 58 around the distributor disc is relatively small and the loss of high-pressure air directly into the exhaust line 4I around the distributor disc is insignificant.

'Ihe introduction of air continues until the piston 9 has again approximated bottom dead center position, at which time the cam 2B is effective to permit the spring 2l again to position the valve i6 with the head l1 in contact with the valve seat Ml. The combustion chamber Il is then isolated from the passages 3l and 32. Shortly after the piston passes bottom deadcent/er position and begins the compression stroke, the cam 51 releases the rocker 55 so that the Vspring 53 is effective relatively quickly to move the disc 41 from its dotted line position 54 to the. fullline position in Fig. 1. Since this return movement of the -distributor i3 is relatively rapid, there is a minimum loss of air from the inlet passage 38 into the exhaust passage lll. The parts have then all returned to their original positions and the cycle is repeated indefinitely during the operation of the engine.

If thorough scavenging is unimportant, the distributor can be moved between exhaust position and inlet position directly without any intermediate pause at scavenging position. vIn this event the dividing wall 33 or septum can likewise be omitted.

I claim:

1. An engine comprising means forming a combustion chamber, means `forming a cylindrical bore, an inlet duct communicating with one end of said bore, an exhaust duct communicating with the other end of said bore, a pair of passageways separately communicating with said bore and jointly communicating with said combustion chamber, a valve for controlling communication between said passageways and said combustion chamber, a distributor reciprocable in said bore for controlling communication between said passageways and said inlet duct and said exhaust duct, means operating in time with said engine for periodically positioning said distributor to aord separate communication between one of said ducts and one of said passageways, and n ieans for enforcing air ow throughv said inlet duct and out said exhaust duct when said distributor is so positioned.

2. An engine comprising means forming a combustion chamben'an inlet duct, an exhaust duct, means forming a cylindrical bore communicating at opposite ends with said inlet duct and said exhaust duct, means establishing separate cornmunication between axially spaced parts of said bore and said combustion chamber, a Valve for controlling communication between said combustion chamber and said establishing means, a distributor reciprocable in said bore and movable into a position between said axially spaced parts of said bore for controlling separate communication through said establishing means between said inlet duct and said exhaust duct, and means for forcing air to flow first through said inlet duct and then through said exhaust duct when said distributor is in said position.

3. An engine comprising means forming a com-- bustion chamber, a conduit having twoI separate passages merging with said combustion chamber, a poppet valve controlling ow between said conduit and said combustion chamber, an exhaust duct, an inlet duct, reciprocable means for selec-- tively connecting both of the passages of said conduit to said exhaust duct or said inlet duct and for connecting one of said passages to said inlet duct and the other of said passages to said exhaust duct, and means for forcing an air flow through said inlet duct and then through said exhaust duct.

4. An engine comprising means forming a combustion chamber, a single conduit having separate passages merging with said combustion chamber, a reciprocable valve for controlling flow between said conduit and said combustionv chamber, a plurality of ducts merging with said conduit, means :for` establishing periodically during the operation of said engine communication between each of the passages of said conduit and said ducts, and means for forcing an air ilow when said communication is established from one of said ducts through one of said passages into said combustion chamber thence through the other of said passages and the other of said ducts.

5. An engine comprising means forming a combustion chamber, a single lconduit having a plurality of passageways merging with said combustion chamber, a valve for controlling flow between said conduit and said combustion chamber,

a plurality of ducts merging with said conduit, reciprocable means eiective periodically 'during operation of the engine for selectively blocking communicaton between individual ones of said ducts and individual ones of said passageways, and means effective periodically during operation oi the engine to establish air ow into said combustion chamber through one of said ducts and passageways and out from said combustion chamber through the other of said ducts and passageways.

6. An engine comprising means forming a combustion chamber, a single conduit merging with said combustion chamber and divided into two passageways, a poppet valve for controlling now between said conduit and said combustion charnber, an inlet duct merging with said conduit, means for forcing ow through said inlet duct, an exhaust duct merging with said conduit, and reciprocable means including a disc out of rubbing contact with the walls of said conduit and said ducts adapted when in one position periodically during operation of the engine partially but not entirely to prevent communication between one of the passageways in said conduit and said inlet duct andthe other of the passageways in said conduit and said exhaust duct.

'7. An engine comprising means forming a combustion chamber, means forming a bore, a conduit merging with said combustion chamber and communicating with said bore, a septum extending between said combustion chamber and said bore and dividing said conduit into an inlet passageway and an exhaust passageway, means defining an exhaust passage communicating with said bore, means defining an inlet passage communicating with said bore, a distributor reciprocable in said bore, means operating in time with said engine for moving said distributor to register with said septum, and means for establishing an air now into said inlet passageway through said combustion chamber and out said exhaust passageway when said distributor registers with said septum.

MARCUS LOTHROP.

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