U.S. patent application number 09/770813 was filed with the patent office on 2002-08-01 for piston ring locator.
Invention is credited to Bloemers, James L., Ford, Elmer R., Hugg, Larry.
Application Number | 20020101039 09/770813 |
Document ID | / |
Family ID | 25089760 |
Filed Date | 2002-08-01 |
United States Patent
Application |
20020101039 |
Kind Code |
A1 |
Bloemers, James L. ; et
al. |
August 1, 2002 |
PISTON RING LOCATOR
Abstract
A piston and split piston ring assembly having a piston ring
locator to prevent substantial rotation of the piston ring in a
ring groove. A notch is provided in a wall of the ring groove and
an abutment pocket is formed by the ends of the split piston ring.
The piston ring locator is a flattened wire clip within the groove
between the piston ring and the wall of the groove. A segment of
the clip is displaced into the notch and another segment is
displaced into the pocket.
Inventors: |
Bloemers, James L.;
(Texarkana, TX) ; Hugg, Larry; (Texarkana, TX)
; Ford, Elmer R.; (Texarkana, TX) |
Correspondence
Address: |
PEARNE & GORDON LLP
526 SUPERIOR AVENUE EAST
SUITE 1200
CLEVELAND
OH
44114-1484
US
|
Family ID: |
25089760 |
Appl. No.: |
09/770813 |
Filed: |
January 26, 2001 |
Current U.S.
Class: |
277/435 |
Current CPC
Class: |
F16J 9/24 20130101 |
Class at
Publication: |
277/435 |
International
Class: |
F16J 009/00 |
Claims
What is claimed is:
1. A piston and piston ring assembly for an internal combustion
engine including a piston ring locator to prevent substantial
rotation of the piston ring in a ring groove comprising a piston
having a circumferential piston ring groove defined by an axially
extending circumferential bottom wall and spaced radially extending
annular sidewalls, a split piston ring in said groove, a piston
ring locator in said groove, said locator comprising a ring-shaped
clip having an annular body portion and first and second end
portions, a first segment of said clip being displaced and
extending substantially in a first axial direction, a second
segment of said clip being displaced and extending in a
substantially opposite second axial direction, a notch in one of
said sidewalls extending in one of said directions, and at least
one end of said split piston ring defining an abutment pocket
extending in another one of said directions, said first segment of
said clip being received in said notch and said second segment of
said clip being received in said abutment pocket to thereby lock
said ring against any substantial rotational movement relative to
said piston.
2. A piston and piston ring assembly according to claim 1 wherein
said first segment of said clip is the first of said end
portions.
3. A piston and piston ring assembly according to claim 1, wherein
said first segment of said clip is in said annular body
portion.
4. A piston according to claim 2 wherein said second segment of
said clip is the second of said end portions.
5. A piston and piston ring assembly according to claim 2 wherein
said second segment of said clip is in said annular body
portion.
6. A piston and piston ring assembly according to claim 3 wherein
said second segment of said clip is the first of said end
portions.
7. A piston and piston ring assembly according to claim 3 wherein
said second segment of said clip is in said annular body
portion.
8. A piston and piston ring assembly according to claim 1 wherein
another end of said split piston ring cooperates with said at least
one end of said piston ring to define said abutment pocket.
9. A piston and piston ring assembly according to claim 1 wherein
said ring-shaped clip is flattened.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to piston ring locators which are
intended to position a split piston ring so that the ring will not
rotate in the groove during operation of the engine.
[0002] It is important, particularly in two-stroke internal
combustion engines, to prevent the split piston ring from rotating
to a radial position where the ends of the ring are exposed to the
exhaust port or the transfer port. Such exposure permits one or
both of the ring ends to expand radially outwardly into the port
and to be broken off or jammed as the piston is driven from the
port.
[0003] A variety of techniques have been proposed to position the
ends of the split ring in a predetermined radial position on the
piston so that the ends will clear the exhaust and transfer ports.
One such arrangement is disclosed in U.S. Pat. No. 5,664,536 to
Bigsby. In that patent, the piston ring groove is machined so that
a recess extends radially inward from a portion of the groove. A
split piston ring is located in the groove and the ring is provided
with a tab which extends radially inward and is received within the
recess, thereby preventing rotation of the ring relative to the
piston.
[0004] Other piston ring locating techniques are demonstrated in
U.S. Pat. Nos. 2,481,552 and 2,481,553 to Williams. Both of these
patents provide an annular channel machined into the piston ring
groove. A wire locking clip is placed in the channel so that it is
located inwardly of the piston ring. In both patents, one end of
the wire clip is bent radially outwardly and cooperates with a hole
drilled through the ends of the split piston ring. The piston ring
is anchored in position according to the teachings of the '552
patent by frictional engagement of the wire within the channel. The
piston is anchored in position according to the teachings of the
'553 patent by an in-turned end portion of the wire which comprises
an anchoring stud. The anchoring stud is received in a hole drilled
radially into the piston.
[0005] A common technique for locking a split piston ring against
rotation is to drill and ream a small hole radially into the bottom
of the piston ring groove. A steel pin is press fitted into the
hole. An abutment pocket is formed at the ends of the split piston
ring and the pin is received in the pocket to prevent rotation of
the ring.
[0006] These prior art techniques add to the cost of the piston
because of the additional precision machining operations on the
piston and/or piston ring. Further, stop pins embedded in the
piston tend to loosen or break during prolonged operation.
SUMMARY OF THE INVENTION
[0007] This invention overcomes many of these prior art problems by
providing a piston and piston ring assembly having a low-cost
piston ring locator which is reliable and which does not require
costly modifications to the piston and/or piston ring.
[0008] According to the invention, the assembly includes a piston
having a circumferential piston ring groove defined by an axially
extending circumferential bottom wall and spaced radially extending
annular sidewalls. A split piston ring is located in the groove
together with a piston ring locator. The locator is a flattened
steel wire in the form of a ring-shaped clip having an annular body
portion and first and second end portions. The clip is sandwiched
between the piston ring and one of the groove sidewalls. A first
segment of the clip is displaced and extends substantially in a
first axial direction. A second segment of the clip is displaced
and extends substantially in a second axial direction. A notch is
provided in one of the groove sidewalls and extends in one of the
axial directions and the ends of the split ring form an abutment
pocket extending in another one of the axial directions. The first
segment of the clip is received in the notch and the second segment
of the clip is received in the abutment pocket to thereby lock the
ring against any substantial movement relative to the piston.
[0009] According to one aspect of this invention, the first segment
of the clip is the first of the end portions and the second segment
of the clip is in the annular body portion.
[0010] According to a further aspect of this invention, the first
segment of the clip is the first of the end portions and the second
segment of the clip is the second of the end portions.
[0011] According to another aspect of this invention, the first
segment of the clip is in the annular body portion and the second
segment of the clip is in the annular body portion.
[0012] According to a still further aspect of this invention, the
first segment of the clip is in the annular body portion and the
second segment of the clip is the second of the end portions.
[0013] It will become apparent that this invention does not involve
precision machining or forming operations on the piston and/or the
piston ring, nor the placement of a stud or pin in the piston to
restrain rotation of the ring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an elevational view of a piston and piston ring
assembly according to this invention;
[0015] FIG. 2 is an enlarged fragmentary portion of the assembly
shown in FIG. 1;
[0016] FIG. 3 is an enlarged fragmentary portion of the assembly
shown in FIG. 1;
[0017] FIG. 4 is an enlarged fragmentary portion of a piston and
piston ring assembly according to another aspect of this
invention;
[0018] FIG. 5 is an enlarged fragmentary portion of a piston and
piston ring according to another aspect of this invention;
[0019] FIG. 6 is an enlarged fragmentary portion of the piston and
piston ring assembly as shown in FIG. 5;
[0020] FIG. 7 is an enlarged fragmentary portion of a piston and
piston ring assembly according to a still further aspect of this
invention;
[0021] FIG. 8 is an enlarged fragmentary portion of the piston and
piston ring assembly as shown in FIG. 7; and
[0022] FIG. 9 is a sectional view, the plane of the section being
indicated by the line 9--9 in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring now to the drawings, and particularly, to FIGS.
1-3, there is illustrated a piston and piston ring assembly 10 for
an internal combustion engine. The assembly 10 includes a piston 12
having a circumferential split piston ring 14 located in a
circumferential piston ring groove 16. As may be seen most clearly
in FIG. 9, the ring groove 16 is defined by an axially extending
circumferential bottom wall 18 and spaced radially extending
annular sidewalls 20 and 22.
[0024] A piston ring locator 24 is positioned in the groove 16
between the piston ring 14 and the annular sidewall 20. The locator
24 is a flattened ring-shaped clip having an annular body portion
26 and first and second end portions 28 and 30. A notch 32 is
formed in the sidewall 20 and extends in a first axial direction.
The split ring has ends 34 and 36 (FIG. 3) which are formed to
provide a pocket 38 extending in a second axial direction.
[0025] A first segment of the ring locator 24 is displaced and
extends in the first axial direction and a second segment of the
ring locator 24 is displaced and extends in the substantially
opposite second axial direction. In the embodiment shown in FIGS.
1-3, the first end portion 28 comprises the first segment of the
ring locator 24 and it is displaced upwardly into the notch 32
while a portion 40 of the annular body portion 26 is displaced
downwardly into the pocket 38 to comprise the second segment of the
ring locator 24.
[0026] The position of the notch 32 and the arcuate extent of the
body portion 26 between the displaced portion 40 and the displaced
first end portion 28 determines a substantially is fixed location
for the split ends 34 and 36 of the piston ring 14. This position
is selected so that the ring ends 34 and 36 are located in a radial
position on the piston that is adapted to clear the exhaust and
transfer ports.
[0027] A piston and piston ring assembly according to a further
aspect of this invention is illustrated in FIG. 4. A first segment
of the ring locator 24 is displaced and extends in the first axial
direction and a second segment of the ring locator 24 is displaced
and extends in the substantially opposite second direction.
According to this aspect of the invention, the first end portion 28
comprises the first segment of the ring locator 24 and is displaced
upwardly into the notch 32. The second end portion 30 comprises the
second segment of the ring locator 24 and is displaced downwardly
into the pocket 38.
[0028] A piston and piston ring assembly according to another
aspect of this invention is illustrated in FIGS. 5 and 6. A first
segment of the ring locator 24 is displaced and extends in the
first axial direction and a second segment of the ring locator 24
is displaced and extends in the substantially opposite second
direction. According to this aspect of the invention, a portion 42
of the annular body portion 26 is displaced upwardly into the notch
32 to god comprise the first segment of the ring locator, while
another portion 44 of the annular body portion is displaced
downwardly into the pocket 38 to comprise the second segment of the
ring locator 24.
[0029] A piston and piston ring assembly according to a still
further aspect of this invention is illustrated in FIGS. 7 and 8. A
first segment of the ring locator 24 is displaced and extends in a
first axial direction and a second segment of the ring locator 24
is displaced and extends in the substantially opposite second
direction. According to this aspect of the invention, a portion 42
of the annular body portion 26 is displaced upwardly into the notch
32 to comprise the first segment of the ring locator 24 while the
first end portion 28 is displaced downwardly into the pocket 38 to
comprise the second segment of the ring locator 24.
[0030] While the invention has been shown and described with
respect to particular embodiments thereof, those embodiments are
for the purpose of illustration rather than limitation, and other
variations and modifications of the specific embodiments herein
described will be apparent to those skilled in the art, all within
the intended spirit and scope of the invention. Accordingly, the
invention is not to be limited in scope and effect to the specific
embodiments herein described, nor in any other way that is
inconsistent with the extent to which the progress in the art has
been advanced by the invention.
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