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Патент USA US2104892

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Jan. 1 l, 1938.
Filed Sept. 30, 1955
2 Sheets-Sheet 1
629071719 7/. 31611226}:
Jan. 11, 1938.
Filed Sept. 30, 1955
2 Sheets-Sheet 2
61307"; e 76.31%‘; ner:
QM” W5
Patented Jan. 11, 1938
-: ‘ i.
2,104,892 ’
George H. Blettner, Chicago, 111., assignor to
Renette Company, Chicago, Ill., a corporation
of Illinois
Aj'spiication September 30, 1935, Serial No. 42,776
1 Claim. (Cl. 123-193)
The present invention relates to internal com
bustion engine construction, and has to do more exhaust passages and above the positions oc
particularly with the provision of reliefs between
the pistons and cylinder walls adjacent the ex
5 haust passages of the engines, to accommodate
for the growth of the metal of the engine blocks
due to undissipated heat to which the portions
of the engines between the cylinder walls and
the cross passages are subjected.
It has been observed, in internal combustion
engines, that adjacent the exhaust ports or ex
haust passages of the engine blocks, because of
the excess metal there present, repeated starting
and stopping of the engines, causes growths of
15 metal adjacent such areas. Furthermore, there
being more metal adjacent the head ends of the
cylinder blocks, at the exhaust passages, than
opposite to the exhaust passages, a tendency
to how the cylinder has been observed. The
straight cylindrical surfaces of the cylinder have
been slightly bent so as to cause wedging action
between ‘the pistons and the upper or outer ends
of the cylinders whenever the pistons are moved
to such ends. Such wedging action has caused
the upper lands of the pistons to become crowd
ed to such an extent as to wear the lands ex
cessively and also to tilt the pistons to such an
extent as to press the pistons against the cylin
der walls opposite the exhaust valves with suf
30 ?cient pressure to cause rapid deterioration of
the cylinder walls and wear recesses in the walls
opposite the exhaust passages. Such action
causes abrasion of the surfaces of the upper ring
lands of the pistons and deforms the contour of
- the opposite sides of the pistons, causing bind
ing, collapse, scuffing and in a short time re
sulting in oil pumping and rattling of the pis
tons, thus calling for replacement of the parts.
The present invention has to do with the
.10 provision of reliefs at the upper or outer ends of
the cylinder blocks adjacent the ends thereof to
prevent the wedging of the pistons in the cylin
ders and thus prolong the lives of the engines
and pistons.
An object of the present invention is to pro
long the life and e?iciency of the pistons and
cylinder walls‘ of internal combustion engines
by affording additional clearance between the
pistons and cylinder walls in areas adjacent the
exhaust passages in the cylinder blocks, to ac
commodate for growth of the metal of the blocks,
at such areas, due to undissipated heat to which
such areas are subjected.
Another object of the present invention is to
provide reliefs on cylinder Walls adjacent the
cupied by the uppermost piston rings to pre
vent the cylinder walls, if distorted in this par
ticular area, from contacting the ring lands of
the pistons when the pistons reach their upper
most positions during use.
A further object of the present invention is
so to construct an internal combustion engine
that the distortion and enlargement localized
adjacent the exhaust passages in the engine 10
blocks cannot wedge or thrust the pistons against
the opposite sides of the cylinder walls while the
pistons are operating.
rfhe accompanying drawings illustrate an em
bodiment of the present invention, and the views
thereof are as follows:
Figure l is a fragmental axial sectional view
through a block of an internal combustion en
gine showing the cylinder, piston and, in dotted
lines, an exhaust passageway and valve for the
passageway. The piston is illustrated as having
the ring lands relieved to provide space for the
“growth” of a cylinder wall adjacent the ex
haust passageway.
Figure 2 is a view‘ similar to Figure 1, showing
a recess formed in the cylinder wall adjacent 25
the exhaust passageway for accommodating the
“growth” of metal occurring in this neighbor
Figure 3 is a fragmental top plan view of an
internal combustion engine block, showing the 30
lands of the pistons relieved to provide spaces ad
jacent the exhaust passages of the engine.
Figure 4 is a fragmental top plan view of an
engine block, showing a recess in the cylinder -
to provide relief space adjacent the exhaust pas
sage in the block.
Figure 5 is a view similar to Figures 1 and 2,
showing how an unrelieved piston is canted or
tilted in a cylinder, because of the presence of
a “growth” adjacent the exhaust passage of the 40
engine, and projecting into the cylinder. This
view shows, in dotted lines, the truly cylindrical
shape of the cylinder as originally fashioned and,
at the upper left, in full lines, the recess gouged
in the cylinder wall by the tilting of the piston
because of the presence of a “growth” adjacent
an exhaust passageway of the block.
The drawings will now be explained.
Figure 1 illustrates a fragmental portion of
an engine block casting having a cylinder 1, an 50
exhaust passageway 2, and water cooling com
partments 3 surrounding the cylinder for cool
ing purposes, as Well understood. Between the
exhaust passageway 2 and the cylinder 1, the
, “
in service, and therefore the consequent change of
casting is thickened at 4 by reason of the method size and shape of the straight cylindrical surface
of manufacture employed in casting such blocks. of the cylinder is su?icient to slightly how the cyl
Opposite to the thickened portions 4 of metal,' inder inwardly, thereby causing wedging of the
the section indicated at v5 is less, so that as ex
pansion and contraction takes place, due to the
stopping and starting of the engine, different
effects are created at these-points.
Figure‘ 1 illustrates at 6 a “growth” which has
accumulated on the interior of the cylinder wall
pistons in the upper or outer ends of the cylinders.
It has been observed that this wedging action
has, in some instances, been such as to so tightly
wedge the upper ends of pistons in the upper ends
of cylinders as to result in a tearing‘ apart of the
10 adjacent the exhaust passageway, and which has
pistons when the direction of travel of the pistons
was reversed by the crank shaft.
cylindrical surface of the cylinder I. The dotted
lines 1 indicate the cylindrical portion of the cyl
“growt ” 6 or by a slightly bowed effect of the
become a permanent deforma ion within the truly "
inder wall.’
The obstructional deformation formed by the
cylinder due to the heat abovementio-necl is suffi
cient, unless provision'is made to overcome it, to
In order to enable the piston 8 to reach its up
alwaysv press the pistons against the cylinder walls
per or outward limit of movement adjacent the I
opposite to the exhaust valves with suf?cient pres
head end of the block, the lands 9 and 10 are re
duced or ?attened to provide a space between the
sure to cause rapid deterioration of the cylinder
walls and as well abrade the surfaces of the upper
piston and cylinder wall at its upper end to ac- I
"ring lands ’ of the. pistons adjacent the exhaust
20 commodate the “growt ” 6, and: thus prevent" the
passageway and deforming the contours of the op- .
wedging or jamming of the piston in the cylinder
at the upper limit of its stroke; a
Figure 3 shows piston 3 relieved as indicated‘ by
the line I l, the cylinder'being shown as truly cir
cular. Exhaust valves l2 control exhaust pas
sages in the engine block communicating with the
cylinders shown in this ?gure. The inlet valves
!3 are arranged as is common practice and func
tion in a manner well understood.
FigureZ shows the cylinder casting as having a
recess or relief space it formed in‘ the wall of the
cylinder l adjacent the exhaust passageway‘ 2, the
truly cylindrical surface of the cylinder being in
dicated by the dotted line l5. With the provision
of this recess ill, the accumulation of metal or
“growth” at this area would therefore not cause
wedging or binding of the piston 8 on reaching its
uppermost or outermost limit of travel in service.
Figure 5 shows what happens in an internal
'40 combustion engine when metal “growth” J6 oc
curs on an area of the cylinder wall adjacent the
exhaust passageway 2‘, and no relief is provided to
accommodate for this “growth”. It willbe ob
served that the piston I1 has been tilted or‘ canted
to the left, and by reason of the travel of-the pis
ton in the cylinder has worn a recess IS in the
wall of the cylinder opposite to the exhaust pas
sageway 2, that is, opposite tothe “growth” l6‘.
In forming the recess i8,a slight ledge 19 remains
50 which lies within the cylindrical contour‘ of the
original shape of the cylinder. The dotted. line 20
' of this figure shows the original cylindrical con
tour of the cylinder prior to the formation of the
recess i8 therein by the canting or tilting of the
piston I? in service.
It is to eliminate the trouble illustrated in Fig
ure 5 that the‘ relief, such as illustrated in Fig
ures 1 and 2, has been provided. Because of the
fact that the thicker portion 4 of the engine block
60 casting'is between the exhaust passageway 2 and‘
the cylinder, this portion becomes unduly heated
posite thrust sides of the pistons, causing bind
ing, collapse, scuffing or otherdamage.
The provision of reliefs on the pistons by flat
tening the ring lands is caused preferably by ta- "
pering off the‘ heads of the pistons along the areas
which will be adjacent theexhaust passageways
when the pistons are assembled in the engines.
'The “growths” heretofore mentioned in the
neighborhood of the exhaust passageways result -
from intermittent operations of the engines and
eventually become permanently fixed obstructions
in the cylinders and are'contacted by the pistons‘
for every revolution of the crank shafts. .
It may be stated, by way of example, that in one I
internal combustion engine inspected, a growth of
as much as .018 inch was observed in 31/2 inch
cylinders, after a sustained operation of the en
gine while the engine was in a heated condition.
I am aware that many changes may be'made 40
and numerous detailsof construction may be var
ied through a wide range without departing from
the principles of this invention, and I, therefore,
do not purpose limiting the patent granted here
on otherwise than is necessitated by the prior art.
The invention is claimed asfollows:
In an internal combustion engine including an
‘engine ‘block casting having therein a cylinder, ‘a
piston reciprocally mounted in said cylinder, and
an exhaust passage, the: upper portion of the ,
block between said passage and adjacent upper
cylinder wall being relatively thicker than the
portion of said block on the opposite side of said
cylinder, localized clearance being. provided be
tween said upper cylinder wall portion and that
portion of said piston which overrides said wall
portion in its travel, whereby any growth of said
wall portion is-compensated for and tilting of the
piston is prevented.
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