Патент USA US2127114

Aug. 16, 1938. '
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2,127,114
TWO-‘STROKE INTERNAL COMBUSTION ENGINE
Filed April 19, 1937
2 Sheets-Sheet 1 '
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Aug. 16, 1938.
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2,127,114
TWO-STROKE INTERNAL COMBUSTION. ENGINE
Filed April 19, 1957
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2 Sheets-Sheet 2
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Patented' Aug. 16, 1938 I'
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UNITED STATES-PATENT owl-let
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"2.121.114,
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wmteim Grab, 46mm»; in men, Germany"
- Application'Apl-il is. 1m. set-m No. ism-'14
In Germany?Nil
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. 1936
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,
(Cl. 128-59)
is actuated by the crank, II. -In the form or em
bodiment illustrated vin the.drawings,'the propor
The object o! the invention is a two-stroke
combustion engine with working cylinders which
are alternately charged by a feed pump, in such», tions .are so‘ selected that the- crank-shaft I.2,_
driven by the pair of gears II, II, rotates at twice‘.
a manner that the combustible charge supplleil
.5 'to the working cylinders by the feed pump. Piston‘ the speed‘ of the working crank-shaft 5, thatiits 5
is'always equal with respect to volume, provided stroke, however, is ‘only one half of the stroke of
that the pressure’ is held constant to the stroke the working pistons 4 and 4, that the piston
diameter is twice the diameter of the working
volume of the working » cylinder; whereas this
pistons, so that, in this way, the feed pump sup- .
4 chargeis introduced in a known manner from
plying alternately the working cylinders delivers 10
10 the top into the working cylinder; head, irrsuch.
ture is caused to follow aprogressive-movement
at each‘time to a working cylinder a charge cor
responding to the working ‘volume, the same pres
of helical direction from the top downwards, so
sure being'lprovfded- in .the feed pump and the I
as to secure a perfect scavenging'of' the working '
working cylinder.
j a manner that the entering current of gas mix
'
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,
.
The distribution oi! the feed pump is controlled’ 15
15 cylinders. .By means of this structure,v in view
of the known constructions, a larger output per _, by the sleeve valve I‘, which is driven‘ by the ‘
‘volume strokewill be obtained, so that for equal ‘working crank-shaft l, by means of the forked
output, smaller dimensions and a: reduced weight connecting rod It. At I1 is connected the tubu-_
'
of, the machine, maybe secured.
.
,
20 - In the drawings a two-'stroke-engine’is
2 lar conduit-starting from the carburetter and
‘
. mus-g I
.virom where the mixture-sis sucked through the 20
inlet port It oi the leev’e valve into the ‘charging
room above the p ton II of the feed pump II.
trated with two working cylinders, given by way
of exampleand in accordance with the invention,
The gas mixtin'e penetrates alternately through
the drawings comprising ?ve ?gures.
’ Fig. 1 is a longitudinal section of the engine the outlets is, in the inlet channel 20 of tne cyl
25 through the two working cylinders and the feed - inder I and the inlet channel 2| '_oi the cylinder 25
Pump?’
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2, both inlet channels conducting ‘through the
-
Fig.v 2 is‘ a slde'elevatiomoi the feed pump ‘in
longitudinal section;
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‘
Fig.3 illustrates the inlet- port for the fresh“
'30
gas mixture as seen from below; ’
p
_
Fig. 4 is a section through theinlet port for
' Ports I and "I.
"
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The speeds of the working piston and-oi the-H
supply piston are the same, as the reciprocating
movementoi the supply-piston isv as a whole equal 39
to the ‘single stroke of the working piston. (For
each stroke 01' the working piston, the supply- I
t. Fig. 5-isa section through the‘ head of a work " piston operates a suction ~stroke and a compres-'
‘sion stroke. 'I'he'sleeve valve has half the stroke
ing cylinder on line 13-1} of Fig. 1.' '
In b’oth working cylinders]. and 2, the'two of the working piston and half the speed of the "35
35. _
the mirture on line A'—B—C oi’ Fig.‘ 1;.
.
5 working pistons land 4, which are displaced 180°, ’ supply piston. ‘The adjustment of the feed pump ,
with respect to the working cylinders is such that.
' act on thecrank-shait I. The ‘charge is intro
duced'fin the working cylinders each' time from‘ when the working cylinder pistons have opened.‘
' the top into the cylinder head at 8 and ‘I, and at . the exhaust slit for half the height‘ during the
J40 this inlet, the‘ entering mixture is caused to new ) downward movement, the supply of fresh gas mix-‘ 40
along a helical sloping face starting from the top fture by the i'eedpump is started in the working
cylinder, as itisillustrated-in Fig; 1. The work- m'ay be seen in Fig. 3,- it may be observed that, . ing piston, in its .iiurther-‘downward movement,
on the one hand, the charge is more readily intro-' completely frees the exhaust’ slitsuntil the stroke
at the inlet-port and directed’downwards. vAs‘
45
duced into the workingwcylinder, while, on they
other hand,- a progressive helical movement is
~imparted to the mixture, so that thereby a rapid
and perfect scavenging issecured, by the fact.
that the remaining spent gases from the last
50 \working stroke will be caught by this turbulent
end and starts closing ‘the same again‘ slowly when 45
itsv upward movement begins. As soon as‘ the
exhaust (ports are closed, the teed pump, in‘ ac
cordance with the selected dimensions cited by
- way of example, has pressed in the-cylinders 3/4
a‘ of the stroke volume of the saidcylinders, which 50
movement to be expelled downwards, through the . ‘corresponds, with‘ the working cylinder volume
exhaust slits 8v and 9 provided in the working cyl irom the upperv edge ofv the ‘exhaust portsvto the >
"start of thestroke from above. -The remaining- ' '
inders at the end of the stroke.
Between the two working cylinders I and I is. stroke of 25% of the feed pump piston corre- .
55 arranged the feed pump I II, the piston I I oi’ which Y sponds to the volume content of the part of the 5 (.
2
2,127,114
I . backward stroke made by the working piston from
the starting ‘end of, the stroke from below. Dur
ing cylinders through said outlet and inlet ports;
2. In a two-stroke internal combustion engine
ing the last fourth part of the movement of the
comprising two working cylinders, working pis
supply piston, said feed pump will act as .a com
tons therein, piston rods and a common crank
pressor, which supplies to the working cylinder,
shaft, an inlet port in each working cylinder 5
close to the cylinder head, an inner helical slope
extending tangentially from the inlet port inside
the working cylinder, exhaust ports in the cylin
‘under pressure, a gas volume corresponding to‘
the height of the exhaust ports. This auxiliary
charge prevents the loss of. volume in the work
ing cylinders,‘ which may be observediin known
10 constructions of combustion motors having ex
haust ports in the working cylinders, said loss
corresponding to the height of the exhaust ports.
‘ I claim:
.
1. In a two-stroke internal combustion engine
comprising two working cylinders, working pis
der walls, a pump cylinder located between and
in alinement with the working cylinders, a pump
piston therein, an auxiliary crank-shaft connect
ed to said pump piston, a two to one ratio driving
gear between both crank-shafts, an inlet port in
the pump cylinder, oppositely arranged outlet
ports in the pump cylinder forming direct com 15
_munications with the inlet ports of the working
tons therein, piston rods and a common crank
shaft, an inlet port in each working cylinder ‘cylinders respectively,‘ a sleeve-valve’ located be
close to the cylinder head, exhaust ports in the tween the pump cylinder and its piston, and an
cylinder walls, a pump cylinder located between eccentric'driving connection between the com
and in alinement with the working cylinders, mon crank-shaft and the sleeve-valve for con 20
a pump piston therein, an auxiliary crank-shaft
connected to said pump piston, a two to one
'ratio driving gear between both‘crank-shafts, an
inlet port in the pump cylinder, oppositely ar
ranged outlet ports in the pump cylinder forming
direct communications with the inlet ports of the
working cylinders'respectively, a sleeve-valve lo
cated between the pump cylinder and its piston,
and an eccentric driving connection between the
_common crank-shaft and the sleeve-valve for
controlling the supply of gas mixture to the work
trolling the supply of gas mixture to the working
cylinders through said outlet and inlet ports, the
arrangement being such that the mixture is sup
plied to the ‘working cylinders without compres
sion during the main part of the charging stroke
of the pump piston, a ?nal supply being made
under pressure during the remaining part of said
charging stroke which corresponds to that part
of the return stroke of the working piston neces
sary for closing the exhaust ports.
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WILHELM GRAB.
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