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»w 7, 1947.
Filed Feb. 28, 1944
Patented Jan. 7, i947
2,414,013 j
Thomas A. Bowers,y Mattapoisett, Mass.; Eliza
beth M. Bowers, adminîstratrix of said Thomas
A. Bowers, deceased, assignor ol' two-thirds to
Mum-oe H. Hamilton, Lexington, Mass.
Application February 28,V ¿1944, Serial No. 524,224
4 claims.
(ci. aos-a4)
This- invention relates to pistons and piston
rings, and its objects are to impr(- 'e devices of
this character and to provide means lfor more ef
liciently sealing a piston _in a cylinder, with a
view tov controlling cylinder and ring wear and
- sidey of the piston is a groove I0 and connecting
with the groove Ill` at separated points are oil
passages I_2. The head 8 of the piston is reduced
in diameter to an extent generally corresponding -
to the depth of the groove l0 and is tapered in
, to avoiding difliculties arising in connection with
wardly to form a beveled surface I8, as may be '
Íblowby and carbon deposits. Another object of
more clearly seen in Figs. 2 and 4 of the drawing'.
The reduced portion of the pistonhead occurs
in spaced relation to the groove I0 to'leave a
the invention is .to deal with the wear which `re
sults from a piston ring being free to move in
a piston groove, as for example hammeringof the
ring in the piston groove; “slap” of the piston 10 land or rib I4, and the upper side of the land l
I4 is formed with a ñat piston seating surface I8.
against vthe cylinder wall; tipping of a ring so
Mounted on the piston isa composite piston
that an edge is intermittently forced with fluc
‘tuatingpressures against the cylinder periphery,
ring member including an upper ring portion 20 _
and other causes. The invention further includes 15 and a lowerring portion 22 secured one to the
among its objects a decrease in- the number of
other by an annular web 24. Resilient character
piston rings required to seal a piston, reduction in '
is imparted to the web 24 by slots 26 which are cut
the size and weight lof pistons, and other changes - through the web ,and arranged in an irregular or '
directed generally to increasing the efficiency of `\o.\v,erlapping manner. The radial width Olathe ‘
internal combustion motors.
20 ring portions 20 and 22 exceeds the radial width
In the accompanying drawing:
`of the annular web 24 and the latter member
Fig. 1 is Aa plan view illustrating a piston and
is preferably arranged so that its outer peripheryl
piston ring- of the invention; coincides with’ the outer peripheries of the ring
Fig. 2 is a vertical >cross section taken on the
portions with the result that there is left a space
line 2--2 of Fig. 1 with the piston and ring being
or channel 28 between the ring portions. The
mounted in a cylinder;
Width of the channel 28, considered axially, is
Fig. 3 is a fragmentary perspective view of the ‘
normally less than th'e axialwidth of' the land
ring 'member of the invention; '
or rib I4. Due to thev expansible character of
Fig. 4 is a perspective view of a. piston similar ‘
the composite ring resulting from the resilient web
to that shown in Figs. 1 and 2; and
-30 24, the width of channel 28 may be increased by
Fig. 5 is an enlarged detail cross-sectional view.
stretching or springing the ring portions 20iand
The invention -generally includes a piston
22 apart, and in an extended position the ring
formed with a single seating surface, a piston
is snapped on over the land lt as .shown in Fig. 2.
ring member, and spring means for 'urging the
In» this position the ring develops an axial ten
ring member axially downward into continuously
sion which continually urges the seating surface
seated relation withrespectv to the piston seating
30 of ring 'portion 20 against the piston seat or
surface. The spring means is
especially arranged _
to exert a force acting in an axial direction away
from the head of the piston, and provides a light>
land surface i6 and provides a combustionV gas
seal of improveclcharacter.. Ai, the same time
the seating surface 32 of ring portion 22 is urged _“
tension which, while'maintaining the ring in seat 40 against the land surface 34 to provide a seal for
ed relation, permits the ring to flex radially and
excluding oil from passing up around the ring. ~
-to exert a definite wall pressure on a cylinder.
The .composite ring, including the top and vbot
In addition, the ring is mounted, at the top of
tom ring portions 20 and 22 -as well as the re
the piston so that it is subject tocombustion gasv
pressure, and its upper side lies directly in the 45 silient web 24, constitutes a split ring of the type
commonly referred to as a “C type” ring whose'
combustion chamber with the piston ring being
ends are normally spaced apart as shown in Fig._
free from contact or close proximity to any over
hanging surface onÀ which carbon may be de--4
Referring more in detail to the drawing, nu
meral 2 denotes acylinder having an yinner pe
ripheral surface 4. Mounted within the- cylinder
2, in spaced relation to the peripheral surface 4,
is a piston 6, secured-to a crank member and pre
The ring is mounted in a cylinder in a com
pacted position in which the ring tends to revert
to its normal position and thus exerts a' wall
50 pressule‘against-.the cylinder wall and provides '
radial flexibility.' The axial tension resulting
vfrom mounting the» ring on the land I4, with the.
radial web 24 in an extended position, is-of_ a
limited degree which always permits the ring *
senting a flat head 8. Extending around the outer 55
to-develop a suitable radial flexibility and Wall
pressure so that the ring periphery will constantly
adhere to the cylinder periphery.
When the ring is compacted in a cylinder, the
ends are brought closer to one another but there
still remains a gap or opening which it is desir
able to close and for this purpose I have provided
a gap-sealing member 36 which may consist of
some suitable closure device as a right angularly
piston land surface tends to prevent the piston
from assuming an angular position, or one in‘
which its axis is out of alinement with the axis
of the cylinder, such as commonly occurs at the
instant of change of direction of the piston
stroke. Contact of the piston against the inner
periphery of _the ring, while the piston is in an
shaped piece of metal, adapted to overlie the two
angularly disposed position, either results in
slightly tipping one side of the ring itself or in
causing an upper edge of the ring to bear non
ends of the ring and close the space at both the 10 uniformly against the cylinder periphery and in
top sides and inner sides of the ring.
either case excessive cylinder wear occurs. The
In operation, the axial or vertical tension by
effect of the axial tension of the ring on the
which the upper and lower ring portions 20 and
piston tends to keepl the piston from assuming
22 are tightly clamped against the land i4, main
an angular position and tipping the ring. In this
tains the seating surface 30 of the ring in con 15 way, wear is also r'educed at those points' where
tinuously sealed relation with respect tothe seat
the skirt of the piston strikes against the cylin
ing surface I6 of the land or rib portion. At the
der wall.
same time, the ring is free to fiex in a radial direc
A very substantial degree of protection for the
tion, with the ring seating surface 30 sliding in
surface 30 and the land surface i6 is afforded
and out on the piston seating surface I6 and 20 ring
by preventing wear in the' several respects noted.
thus allowing the ring to conform tova'ny irregu
As a result I. obtain an exceedingly efficient seal
larity which may be present in the periphery 4, l between the two surfaces and the seal is charac
of the cylinder. The arrangement of the ring
terized by long life and dependability to a point
-at the top of the piston results in the upper
ring portion 20 having its top surface 38 and its 25 where it beco V espraotical to rely on a single ring
in place of- fg or five rings as are convention
inner peripheral surface 40 lying directly in the
combustion chamber. Combustion gas pressure
of the ring at the top of' the
is thus allowed to act on the ring to seal it tightly
referred to in connection
against the land surface i6 in a very 'efficient
manner while a vertical tension is maintained 30 with allowing combustion gases to act on the ring
and provide for a tight seal. The same arrange
which is developed from points lower in the
ment is also designed tohprovide a means of con
piston. The ring and piston thus work in com
, bination with one
another to provide a means
trolling carbon deposits, a substance which is
formed from combustion gases and which may
tive to the piston and yet permitting ‘the ring -to 35 destroy the seal between a ring and its seat, or
which may`iam the ring in a piston groove. In
move radially and to be subject to combustion gas
conventional ring installations, the ring being
pressure for sealing purposes.
free to slap in a pistonl grooveI continually shakes
The continuously seated relation of the ring
itself free of carbon deposits and this is a prin
. with respect to the piston operates to advantage
40 cipal reason for allowing the ring to “slapff In
especially at
the ring of the invention, there are only two sides
changes the direction of its stroke at the top of
the cylinder. In ordinary ring installations, a
'on- which carbon may be deposited, i. e. the top
side 38 and the inner periphery 40. Since there
ring at the time a piston changes its strokemay.
is no piston groove present there is no oppor- ,
due to its momentum, leave its seat in the piston
tnnity for carbon to jam at the top of the ring.
groove and come to rest with a definite impact
To take care of the inner periphery of the
against the other side of the groove. The ring
of the inyention resists such displacement, and
ring, the piston has been cut away to form the
bevel surface i8. As the ring reciprocates in a
in so doing eliminates a'series of impacts, often
of preventing axial displacement of the ring rela
termed "hammering,” which may appreciably
cylinder, it moves radially in and out on its seat
wear the surface of the -piston. seat or the ring .
Aand any carbon which is deposited between the
inner periphery of the ring and the beveled sur
face is broken up‘and forced upward on to the
itself, and make it impossible to maintain a tight
seal to exclude gas pressure. Only a very little
wear is necessary to create a tiny crack or space '
into which hot `combustion gases can enter and
burn the lubricant on the seating surfaces. Once
' top of the piston where 1t is blown out with ex
haust gases. The sharp edge of the ring lying
on the seat i6, under tension, acts like a chisel
which continually cuts away any carbon deposit
on the'seat i8, and the tension prevents the'ring
fromsliding over carbon deposits without cutting
the lubricant is burned, wear _proceeds at a great
ly accelerated pace.
Another feature in the operation of the ring,
running in continuously seated relation, is con
trol of piston “slap” against the cylinder or
against the inner periphery of the ring and thus
indirectly against the cylinder. The axial ten
sion of the ringcreates a friction between the
it away.
ring'seating surface and thelpiston seating sur
face and in order for the piston to slap, it must
overcome this friction force. The result is that
' downward on the piston seat, also serves as an
the ring functions as a brake or cushion which
is effective in converting the side thrust of the
piston from a sharp impact intoA a rapidly in
creasing pressure and the Wear of such piston
movement is largely overcome.
In-coniunction with its braking or cushioning
function, the continuously seated ring also serves
to reduce wear from piston slap in another way. 75
The axial tension of the ring portions on the
A further factor in the control of car
bon deposit' isthe efficient seal between the ring
and piston at all times which keeps oil from
passing up around the ring and becoming burned.
The ring- portion 22 which is clamped at the
under land surface 34, in addition to functioning
as a clamping member for holding the ring
oil scraping ring, and to facilitate this action as
an oil scraping or oil scavenging member, the
oil passages I2 have been formed -to connect with
the groove i0 in the `manner shown. There is
thus obtained in one piston ring, compression
sealing means (the ring portion 2li) , and oil seal
ing means, since the tension atthe under land
surface 34 provides for the ring sealing at this_
point and thus preventing oil from escaping
around the ring.
It will be >noted that the groove l0 is of a sum
cient >depth to provide a slight clearance I2 be
tween itself and the ring portion 22. This space
provides a reservoir in which oil is constantly
being collected. The body of oil occurring all ,
the way around the piston in back of the ring
tion to being made shorter. may also be of lighter
construction. owing to the fact that reinforced
portions commonly required to provide for pis
ton ring grooves may be eliminated.
While I have shown a preferred vembodiment `
ot my invention, it
various changes and should be understood that
may be made,
in keeping'with the modifications
spirit oi' the invention as
thrust, and this ‘
outlined in the appended
I claim:
with the cushioning action which is obtained from
l. A piston ring structure comprising opposed
the continuously seated relation of the ring on
the land surface I6. ‘
sealing members connected by an intervening
The ring portions 20
slotted metallic web, said structure being adapted
web may be formed of several dlßerent materials 15' to be clamped about an extending rib on a pis
ton and resiliently to grip oppósitely disposed
surfaces of said rib.
and 22‘of cast iron and the resilient web 24 of
steel. Other types of spring~devices maybe uti
2. In combination, a cylinder, a piston mount
ed in said cylinder carrying a circumferentially
lized to secure the two rings together and to
extending rib, and a piston ring structure com
ring under tension on a piston seating
surface. The several ring elements may be se 20 prising opposed sealing members connected by an
cured together in some suitable manner such
intervening slotted metallic web, said structure
being adapted to be clamped about an extending
as welding, or I may desire to form the ring out
of a single length of material.
rib on said piston and resiliently to grip opposite
ly disposed surfaces of said rib.
3. In combination a piston carrying a circum
.ferentially extending rib, a piston ring structure
comprising opposed sealing
ton land surface I6 is appreciably protected from
wear and a true seating surface is-'preserved
throughout ,the life oi the ring, against which
the seating surface 3U of the ring may be square
ly held and a more emcient seal obtained. Re-l
duction of wear from preventing the ring’s be
ing tipped is also accomplished and “blowby"
is greatly minimized. By providing c. seal which
of several and.
time, the cost of forming a piston with a plurality
of piston ring grooves ‘may be eliminated. The
by metallic spring means, said piston ring struc
ture being adapted to be clamped about the ex
tending. rib on said piston and resiliently to grip
oppositely disposed surfaces of said rib, said con
necting means i'or the opposed sealing members
occurring in spaced relation to the outer periph
eral edge of the extending piston rib to provide
an oil reservoir, said connecting means being
formed with openings for permitting passage of
oil into -and out of the said reservoir.
4. In combination. a hollow piston carrying ,a
circumferentially extending rib, a piston ring
structure comprising opposed sealing members
connected by metallic spring means, said piston
ring structure being adapted to be clamped about
the extending rib on said piston and resiliently to
piston itself may be decreased inlen‘gth since the 45 grip oppositely disposed surfaces of said rib, said
connecting means occurring in radially spacedv
space in which the ring grooves are commonly
,formed is no longer
relation to the piston rib, Vsaid piston having oil
required. By thus shorten
passages formed therein,`
ing the length of the piston, it is possibley to de
oil passages ex
tending through the piston said
crease the height of the cylinder block and thus
wall at a point direct
to decrease the total weight of a motor. with an 50 ly below the said piston ring structure.
increase in eiilciency. The piston itself, in addi
'moi/ias A. BOWERS.
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