ANNULAR CLAMPING FLANGE

BRIDE DE SERRAGE ANNULAIRE

English Abstract

An annular clamping flange for use in clamping a first pipe end
portion to a second pipe end portion in an engine exhaust system includes a first
arcuate flange portion and a second arcuate flange portion co-operable therewith to
form a pipe receiving aperture. Each flange portion has at least one clamping bolt
receiving aperture having a longitudinal axis parallel to the longitudinal axis of the
pipe receiving aperture. Each flange portion also has opposite ends each having a
connecting bolt receiving tubular lug on the laterally outer side thereof, the tubular
lug having a longitudinal axis substantially tangential to the pipe receiving aperture.
The two flange portions can be positioned around a first pipe end portion and
connected together by connecting bolts passing through respective pairs of adjacent
tubular lugs on the first and second flange portions, and the annular flange can then
be secured to a second pipe end portion by clamping bolts passing through the
clamping bolt receiving apertures.

Claims

I CLAIM:


1. An annular clamping flange for use in clamping a first pipe end
portion to a second pipe end portion in an engine exhaust system, said annular
flange comprising:
a first arcuate flange portion and a second arcuate flange portion co-
operable therewith to form a pipe receiving aperture, each flange portion having at
least one clamping bolt receiving aperture having a longitudinal axis parallel to the
longitudinal axis of the pipe receiving aperture,
each flange portion having opposite ends each having a connecting bolt
receiving tubular lug on the laterally outer side thereof, said tubular lug having a
longitudinal axis substantially tangential to the pipe receiving aperture,
whereby the two flange portions can be positioned around a first pipe
end portion and connected together by connecting bolts passing through respective
pairs of adjacent tubular lugs on the first and second flange portions, and the annular
flange can then be secured to a second pipe end portion by clamping bolts passing
through the clamping bolt receiving apertures.




2. An annular clamping flange according to claim 1 wherein the first
flange portion is identical to the second flange portion.




3. An annular clamping flange according to claim 2 wherein one pair of
adjacent tubular lugs has a longitudinal axis parallel to the longitudinal axis of the



other pair of adjacent tubular lugs.




4. An annular clamping flange according to claim 3 wherein each flange
portion has a single clamping bolt receiving aperture equi-spaced from the tubular
lugs thereof.




5. An annular clamping flange according to claim 1 wherein one pair of
adjacent tubular lugs has a longitudinal axis inclined to the longitudinal axis of the
other pair of adjacent tubular lugs, whereby the tubular lugs of one flange portion
are closer to each other than the tubular lugs of the other flange portion.




6. An annular clamping flange according to claim 5 wherein the flange
portion with the closer tubular lugs has a single clamping bolt receiving aperture
equi-spaced from the lugs, and the second flange portion has a pair of clamping bolt
receiving apertures each adjacent a respective lug thereof.




7. An annular clamping flange according to claim 1 wherein each flange
portion has a generally U-shaped cross-section.




8. An annular clamping flange according to claim 1 wherein the tubular
lugs are welded to the arcuate flange portions.




9. An engine exhaust system comprising a first pipe end portion clamped

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to a second pipe end portion by a clamp including an annular clamping flange as
claimed in claim 1,
the flange portions of the annular clamping flange being connected
around the first pipe end portion by connecting bolts passing through respective
pairs of adjacent tubular lugs on the first and second flange portions, the second pipe
end portion having a further clamping flange with connecting bolt receiving
apertures, and
the annular clamping flange being secured to the further clamping
flange by clamping bolts passing through the clamping bolt receiving apertures of
the annular clamping flange and the further clamping flange.




10. An engine exhaust system according to claim 9 wherein the first flange
portion of the annular clamping flange is identical to the second flange portion
thereof.




11. An engine exhaust system according to claim 10 wherein one pair of
adjacent tubular lugs of the annular clamping flange has a longitudinal axis parallel
to the longitudinal axis of the other pair of adjacent tubular lugs thereof.




12. An engine exhaust system according to claim 11 wherein each flange
portion of the annular clamping flange has a single clamping bolt receiving aperture
equi-spaced from the tubular lugs thereof.


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13. An engine exhaust system according to claim 9 wherein one pair of
adjacent tubular lugs of the annular clamping flange has a longitudinal axis inclined
to the longitudinal axis of the other pair of adjacent tubular lugs thereof, whereby
the tubular lugs of one flange portion are closer to each other than the tubular lugs
of the other flange portion.


14. An engine exhaust system according to claim 13 wherein the flange
portion with the closer tubular lugs has a single clamping bolt receiving aperture
equi-spaced from the lugs, and the second flange portion has a pair of clamping bolt
receiving apertures each adjacent a respective lug thereof.


15. An engine exhaust system according to claim 9 wherein each flange
portion of the annular clamping flange has a generally U-shaped cross-section.


16. An engine exhaust system according to claim 9 wherein the tubular
lugs of the annular clamping flange are welded to the arcuate flange portions.


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Description

~ 2112837
ANNULAR CLAMPING FLANGE


This invention relates to annular clamping flanges for use in clamping
a first pipe end portion to a second pipe end portion in an engine exhaust
system, for example an exhaust system for a motor vehicle.
5When one or more parts of an engine exhaust system have to be
replaced, problems often arise when a pipe end portion of a new part has to
be clamped to the pipe end portion of an existing part, especially if the
existing part has been damaged by long time use or for other reasons.
It is therefore an object of the invention to provide an annular
10clamping flange which is useful in such circumstances.
According to the invention, an annular clamping flange comprises a
first arcuate flange portion and a second arcuate flange portion co-operable
therewith to form a pipe receiving aperture, each flange portion having at
least one clamping bolt receiving aperture having a longitudinal axis parallel
15to the longitudinal axis of the pipe receiving aperture, each flange portion
having opposite ends each having a connecting bolt receiving tubular lug on
the laterally outer side thereof, said tubular lug having a longitudinal axis
subst~nti~lly tangentially to the pipe receiving aperture, whereby the two
flange portions can be positioned around a first pipe end portion and
20connected together by connecting bolts passing through respective pairs of
adjacent tubular lugs on the first and second flange portions, and the annular
flange can then be secured to a second pipe end portion by clamping bolts

~ 2112837

passing through the clamping bolt receiving apertures.
The first flange portion may be identical to the second flange portion.
One pair of adjacent tubular lugs may have a longitudinal axis parallel to the
longitudinal axis of the other pair of adjacent tubular lugs, and each flange
5 portion may have a single clamping bolt receiving aperture equi-spaced from
the tubular lugs thereof.
One pair of adjacent tubular lugs may have a longitudinal axis inclined
to the longitudinal axis of the other pair of adjacent tubular lugs, whereby the
tubular lugs of one flange portion are closer to each other than the tubular
10 lugs of the other flange portion. The flange portion with the closer tubular
lugs may have a single clamping bolt receiving aperture equi-spaced from the
lugs, and the second flange portion may a have a pair of clamping bolt
receiving apertures each adjacent a respective lug thereof.
Each flange portion may have a generally U-shaped cross-section, and
15 the tubular lugs may be welded to the arcuate ~lange portions.
The invention also provides an engine exhaust system comprising a
first pipe end portion clamped to a second pipe end portion by a clamp
including an annular clamping flange as defined above.
Embodiments of the invention will now be described, by way of
20 example with reference to the accompanying drawings, in which;
Fig. 1 is an exploded perspective view of an engine exhaust system
having two pipe end portions clamped together by a clamp including an


2112837

annular clamping flange in accordance with one embodiment of the
invention, the front of the annular clamping flange being shown,
Fig. 2 is a sectional view along the line 2-2 of Fig. 1 but showing the
two pipe end portions clamped together, and
Fig. 3 is a perspective rear view of an annular clamping flange in
accordance with another embodiment of the invention.
Referring to the drawings, Figs. 1 and 2 show an annular clamping
flange 12 in accordance with one embodiment of the invention fitted on a
first pipe end portion 14 and secured to a clamping flange 16 on a second pipe
end portion 18 of a motor vehicle engine exhaust system to clamp the two
pipe end portions 14, 18 together. In this embo~iment, the first pipe end
portion 14 is an existing part extending rearwardly from an engine (not
shown) and a second pipe end portion 18 P7~t~n-1s forwardly from a new
catalytic converter or muffler which is to be attached to the first pipe end
portion 14.
The annular clamping flange 12 comprises identical first and second
arcuate flange portions 20, 22 of generally U-shaped cross-section co-operable
with one another to form a pipe recei~ing aperture 24 to receive the pipe end
portion 14. Each flange portion 20, 22 has a single clamping bolt receiving
aperture 26 and two connecting bolt receiving tubular lugs 28, 30. The
tubular lugs 28, 30 are welded to opposite ends of the respective flange
portions 20, 22 on the laterally outer sides thereof.

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.



The tubular lugs 28, 30 extend substantially tangentially to the pipe
receiving aperture 24, the longitudinal axis of one pair of adjacent tubular lugs
28 being parallel to the other pair of adjacent tubular lugs 30. The clamping
bolt receiving aperture 26 of each flange portion 20, 22 is equi-spaced from
5 the tubular lugs 28,30 thereof.
The end of the pipe end portion 14 has a flange 31 formed thereon
which mates with one side of an annular sealing ring 32 flange 34 on the end
of pipe end portion 18 mates with the other side of sealing ring 32 in known
manner.
In use, the two clamping flange portions 20,22 are positioned around
the pipe end portion 14, as in~ic~te~l in Fig. 1, and are connected together by
connecting bolts 36 passing through respective pairs of adjacent tubular lugs
28,30 respectively from the first and second flange portions 20,22, the bolts
36 having washers 38 and nuts 40. The assembled clamping flange 12 is a
loose fit on the pipe end portion 14.
After the sealing ring 32 has been placed in position, the annular
clamping flange 12 is secured to the clamping flange 16 by clamping bolts 42
which pass through the clamping bolt receiving apertures 26 in the flange
portions 20, 22 and through clamping bolt receiving apertures 44 in the
clamping flange 16 to draw the flanges 31,34 tightly into engagement with
the sealing ring 32, the clamping bolts 42 having washers 46 and nuts 48.
Fig. 3 shows an annular clamping flange 50 in accordance with another

2112~37
.



embo~iment of the invention comprising first and second annular flange
portions 52, 54 of generally U-shaped cross-section and co-operable with one
another to form a pipe receiving aperture 56. The flange portion 52 has a
single clamping bolt receiving aperture 58 equi-spaced from two connecting
bolt receiving tubular lugs 60 welded to opposite ends of the flange portion
52 on laterally outer sides thereof and .o~ten~ing tangentially to the pipe
receiving aperture 56. The flange portion 54 has two clamping bolt receiving
apertures 62 and two connecting bolt receiving tubular lugs 64 welded to
opposite sides of the flange portion 54 on laterally outer sides thereof and
~rten~ling tangentially to the pipe receiving aperture 56.
The tubular lugs 60, 64 on one side of the clamping flange 50 have a
longitudinal axis inclined to the longitudinal axis of the tubular lugs 60, 64 on
the other side thereof, the tubular lug 60 on the flange portion 52 being closerto one another than the tubular lug 64 on the flange portion 54. The two
clamping bolt receiving apertures 62 on the flange portion 54 are each
adjacent a respective lug 64.
The clamping flange 50 is provided with two clamping bolts 66 which
pass through respective pairs of tubular lugs 60, 64, the clamping bolts 66
having washers 68 and nuts 70.
The manner in which annular clamping flange 50 of Fig. 3 is used will
be readily apparent to a person skilled in the art from the foregoing
description of the manner of use of the embodiment shown in Figs. 1 and 2.

21I2837
.



The clamping flange on the other pipe end portion will of course be provided
with three clamping bolt receiving apertures to receive clamping bolts passing
through the three clamping bolt receiving apertures 58 of annular clamping
flange 50.
Other embo~imçnt~ of the invention will also be readily apparent to
a person skilled in the art, the scope of the invention being defined in the
appended claims.:

Representative Drawing