PISTON RING WITH TONGUE AND GROOVE JOINT

SEGMENT DE PISTON A JOINT EN BOUVET

English Abstract

ABSTRACT OF THE DISCLOSURE
A piston ring comprises an elongated one-piece element having
a cylinder contact surface, a side surface and a pair of relatively movable
ends. One end has a groove with a pair of opposed parallel walls disposed
at an angle less than 90° with respect to the ring side surface. The other
end is receivable in the groove to prevent relative motion between the ends
of the ring in directions normal to the side surface.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A piston ring comprising an elongated one-piece element having a
cylinder contact surface, and a side surface, a pair of relatively movable
ends, including a first end and a second end, said first end having a groove
including a pair of generally opposed walls disposed at an angle less than
90° with respect to said ring side surface, and the second end being
receivable in said groove to prevent relative motion between the ends of
the ring in directions normal to said side surface.
2. A piston ring comprising an elongated one-piece element having a
cylinder contact surface, a side surface extending the length of said element
and a pair of relatively movable ends including a first end and a second end,
said first end having a groove including a pair of generally opposed walls,
said walls being planar and parallel with respect one to the other and being
disposed at an angle of about 45° with respect to said ring side surface,
the second end being receivable in said groove to prevent relative motion
between the ends of the ring in directions normal to said side surface.
3. A piston ring comprising an elongated one-piece element having a
cylinder contact surface, a side surface extending the length of said element,
and a pair of relatively movable ends including a first end and a second end,
said first end having a groove including a pair of generally opposed walls,
said walls being planar and parallel with respect one to the other and being
disposed at an angle less than 90° with respect to said ring side surface,
the second end being receivable in said groove to prevent relative motion
between the ends of the ring in directions normal to said side surface, said
element having a generally rectangular cross-section and one of said groove
parallel walls extending diagonally from one of the corners of said cross-
section to the opposite corner thereof.
4. A piston ring comprising an elongated one-piece element having a

cylinder contact surface, and a side surface extending the length of said
element, and a pair of relatively movable ends, including a first end and a
second end, said first end having a groove including a pair of generally
opposed walls, said walls being planar and parallel with respect one to the
other and being disposed at an angle less than 90° with respect to said
ring side surface, the second end being receivable in said groove to prevent
relative motion between the ends of the ring in directions normal to said
side surface, said element having a generally rectangular cross-section and
the parallel walls of said groove being spaced on opposite sides of a pair
of nonadjacent corners of said cross-section.
5. A piston ring as defined in claim 2, 3 or 4, in which the second
end of the ring is slidably receivable within the parallel walls of said
groove.
6. A piston ring as defined in claim 2, 3, or 4, in which the second
end of the ring has a reduced thickness defining a pair of planar parallel
walls on opposite sides of said reduced end such that the second end is
slidably receivable within the parallel walls of said first end.
7. A piston ring as defined in claim 2, 3, or 4, in which the piston
ring is receivable within the slot of a piston, said slot having opposed
sidewalls, the side surface of said ring being engageable with one of the
sidewalls of said piston slot and the second end of the ring has a reduced
thickness forming a pair of planar parallel surfaces slidably receivable
between the opposed sidewalls of the first end.
8. A piston ring comprising an elongated one-piece element having a
cylinder contact surface, a side surface extending the length of said
element, and a pair of relatively movable ends, including a first end and a
second end, said first end having a groove including a pair of generally
opposed walls, said groove having ends opening in opposite sides of said

element, the second end being receivable in said groove to prevent relative
motion between the ends of the rings in directions normal to said side
surface and being movable through each of the ends of said groove in a
direction of about 45° with respect to said ring side surface,
9. A piston ring comprising an elongated one-piece element having a
cylinder contact surface, a side surface extending the length of said element
adjacent said cylinder contact surface, a pair of relatively movable ends
including a first end and a second end, said first end having a groove, the
second end having a tongue defined by a pair of planar parallel sides
disposed at an angle less than 90° but greater than 0° with respect to said
ring side surface, said tongue being receivable in said groove to prevent
relative motion between the ends of the ring in directions normal to said
side surface.
10. A piston ring as defined in claim 9, in which the parallel sides
of said tongue are disposed at an angle of about 45° with respect to said
ring side surface.
11. A piston ring as defined in claim 9, in which said element has a
generally rectangular cross-section and one of the parallel sides of said
tongue extends diagonally from one of the corners of said cross-section to
the opposite corner thereof.
12. A piston ring as defined in claim 9, in which the ring has a
generally rectangular cross-section and the parallel sides of said tongue
are spaced on opposite sides of a pair of nonadjacent corners of said cross-
section.
13. A piston ring as defined in claim 9, in which said tongue is
slidably received within said groove.
14. A piston ring as defined in claim 9, in which said groove has a

pair of opposed spaced parallel sidewalls slidably receiving said tongue.
15. A piston ring comprising an elongated one-piece element having a
cylinder contact surface, a side surface extending the length of said
element, and a pair of relatively movable ends including a first end and
a second end, said first end having a groove including a pair of generally
opposed walls, said walls being planar and parallel with respect to one
another, but nonparallel with respect to said ring side surface, said groove
having ends opening in opposite sides of said element, the second end having
a tongue receivable in said groove to prevent relative motion between the
ends of the ring in directions normal to said side surface, said tongue being
movable through both ends of said groove in directions forming an angle
greater than 0° but less than 90° with respect to said ring side surface.

Description

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Background of the Invention
This invention is related to piston rings, and more particularly,
to a one-piece piston ring having one end slidably received between a pair
of opposed walls in the other end to minimize the blow-by of fluids or gases.
Piston rings are employed in a variety of engines and machines,
such as internal combustion engines, steam engines, compressors, pumps, and
the like, usually where a piston is movable according to pressure variations
at t~e head of the piston. A conventional piston ring comprises an elongated
spring-like element having spaced ends. When the ring is mounted on the
piston in a cylinder liner, the ends are moved toward one another to form a
joint. One problem with a conventional piston ring is that as the ring
and the piston are heated up, the joint ends tend to separate during a
portion of the stroke thereby permitting blow-by of the gases or fluid. This
pressure loss reduces the efficiency of the device in which the piston is
mounted.
Another problem with conventional piston rings is that relative
motion betwen piston ends, as the piston is being reciprocated, causes the
cylinder walls to wear and thereby reduce the life of the cylinder liner.
Summary of the Invention
According to the present invention there is provided a piston ring
comprising an elongated one-piece element having a cylinder contact surface,
and a side surface, a pair of relatively movable ends, including a first
end and a second end~ said first end having a groove incl~ding a pair of
generally opposed walls disposed at an angle less than 90 with respect to
said ring side surface, and the second end being receivable in said groove
to prevent relative motion between the ends of the ring in directions normal
to said side surface.
With this arrangement, the second end of the ring is slidably
engaged with at least one of the walls of the groove depending upon the
direction of motion of the piston.
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Description of the Draw ngs
The description refers to the accompanying
drawings in which like reference characters refer to like
parts throughout the several views, and in which:
FIGU~E 1 is a fragmentary sec~ional view of a
piston mounted in a cylinder showing the manner in which a
preferred ring is mounted;
FIGURE 2 is a perspective view of the preferred
ring;
FIGURE 3 is a view as seen along lines 3-3 of
Figure 2;
FIGURE 4 is a view as seen along lines 4-4 of
Figure 2;
FIGURE 5 is a fragmentary perspective view of
the ends of another embodiment of the invention;
FIGURE 6 is a view as seen along lines 6-6 of
Figure 5;
FIGURE 7 is a view as seen along lines 7-7 of
Figure 5;
FIGURE 8 is a perspective view of still another
embodiment of the invention;
FIGURE 9 is a view as taken along lines 9-9 of
Figure 8;
FIGURE lO is a view as seen along lines 10-lO
of Figure 8;
FIGURE ll is a view of still another embodiment
of the invention;
FIGURE 12 is a view as seen along lines 12-12
of Figure 11;
FIGURE 13 is a view as seen along lines 13-13
of Figure 11;
FIGURE 14 is a perspective view of still another
embodiment of the invention;

FIGURE 15 is a view as seen along lines 15-15
of Figure 14; and
FIGURE 16 is a view as seen along lines 16~16
of Figure 14.
Description of the Preferred Embodiments
Referring to the drawings, Figure 1 is a f~agmentary
view of a piston 10 reciprocally mounted in a cylinder 12.
Piston 10 has a conventional cylindrical wall formed about
an axis 14 which coincides with the longitudinal a~is of the
cylinder wall.
Piston 10 has a circumerential slot 16. A ring 18
is mounted in slot 16 so as to be carried with the piston,
slidably engaged with the wall of cylinder 12.
Referring to Figure 2, ring 18 is formed of metal,
preferably of cast iron, however, it can be formed of a
variety of suitable materials. The ring is resilient and
split to form spaced ends 20 and 22. Ring 16 has a cylinder
contact surface 22A and a side surface 22B generally parallel
to the piston top. The spaced ends of the ring permit the
user to assemble the ring in piston slot 16.
Ring 18 is formed about an axis of curvature 24
which coincides with cylinder axis 14 when the piston and
ring are mounted in the cylinder.
Referring to Figures 3 and 4, end 26 of the
ring has a tongue 26, and end 20 has a groove 28. Groove 28
has a pair of spaced~ parallel, opposed walls 30 and 32
formed at an angle of approximately 45 with respect to side
surface 22B. Tongue 26 is also formed at a similar angle so
as to be slidably receivable between walls 30 and 32.
Normally, the variable pressure at the head of
piston 10, coupled with the piston motion within the cylinder,
tends to cause relative motion between the ring ends. The
opposed walls of groove 28 are such that if the piston is

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being moved in one direction, tongue 26 will be slidably
engaged with wall 30, and if the piston is being move~ in
the opposite direction, the tongue will be slidably engaged
with the opposite wall thereby providing a joint minimizing
blow-by.
Figures 5-7 show another embodiment of the
invention comprising a ring 100, having an axis of
curvature and a diameter identical to that of ring 16,
but with the ends formed in a different configuration.
One end of ring 100 has a tongue 10~., and the opposite end
has a groove 104. In this case, one wall o groove 104
extends between opposite corners of the ring cross-section
whereas in the embodiment of Figures 1-4, the groove walls
are on opposite sides of the corners. Tongue 110 is slidably
receivable within groove 104 with both the tongue and
groove being disposed at ~n angle of 45 with respect to
ring side surface 105.
Figure 8 shows another embodiment comprising
ring 200 having an axis of curvature and a diameter identical
to that of ring 16. In this embodiment of the invention,
tongue 202 has a V-shaped cross-section receivable within
opposed walls o~ groove 204 which convergc toward:one
another.
Figure 11 shows another embodiment of the
invention comprising ring 300 which also has an axis of
curvature and a diameter identical to that of ring 16.
The ends of ring 300 are formed with a tongue 302 and a
groove 304. Groove 304 has a pair o~ spaced, opposed walls
306 and 308 which are parallel to one another for receiving
tongue 302 such that the tongue is slidably engaged with
walls 306 and 308. In this embodiment of the invention,
walls 306 and 308 are parallel to ring side surface 310.
Figure 14 illustrates piston 400 having an axis
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of curvature and a diameter idèntical to that of ring 16.
One end of ring 400 has a tongue 402 and its opposite end
having a groove 404. In this embodiment of the invention,
the groove sidewalls are curvilinear, and the tongue has a
shape complemen~ary to the groove so that it is slidably
receivable between the groove walls when the ring is
mounted in the cylinder.
Having described my invention, I claim: