U.S. patent application number 09/235990 was filed with the patent office on 2002-01-03 for pipe branch fitting.
Invention is credited to KUNSMAN, DONALD R..
Application Number | 20020000719 09/235990 |
Document ID | / |
Family ID | 22887684 |
Filed Date | 2002-01-03 |
United States Patent
Application |
20020000719 |
Kind Code |
A1 |
KUNSMAN, DONALD R. |
January 3, 2002 |
PIPE BRANCH FITTING
Abstract
A mechanical coupling is provided for connecting a branch pipe
to a main pipe at a hole through the main pipe. The coupling
includes an elastomeric sealing gasket which has a plurality of
generally parallel extending, but radially spaced, circumferential
seals to effect a secure sealing engagement between the main pipe
and the branch pipe in a minimal size coupling. Further, there is
increased retention of the gasket within the coupling during
on-site assembly which facilitates such assembly.
Inventors: |
KUNSMAN, DONALD R.;
(BETHLEHEM, PA) |
Correspondence
Address: |
ABELMAN FRAYNE & SCHWAB
150 EAST 42ND STREET
NEW YORK
NY
100175612
|
Family ID: |
22887684 |
Appl. No.: |
09/235990 |
Filed: |
January 22, 1999 |
Current U.S.
Class: |
285/197 |
Current CPC
Class: |
F16L 41/12 20130101 |
Class at
Publication: |
285/197 |
International
Class: |
F16L 005/00 |
Claims
I claim:
1. A mechanical coupling for connecting a branch pipe to a main
pipe at a hole through the wall of the main pipe, comprising two
opposed arcuate sections defining a cylindrical space therebetween
for embracing the wall of the main pipe; a first of said arcuate
sections including a concave saddle wall defining a portion of a
cylindrical surface having a radius generally corresponding to the
outer circumference of the main pipe, a radially extending branch
pipe opening within said first arcuate section dimensioned to
overlay the main pipe opening and communicate with said saddle
wall, and a spigot wall surrounding said branch pipe opening, and
terminating at said saddle wall; a radially extending gasket recess
surrounding said spigot wall, said gasket recess having a radially
inward open terminus at said saddle wall, and a radially outward
wall terminus in the direction of the branch pipe; and a gasket for
sealing engagement within said gasket recess and the main pipe,
said gasket including: a first generally circumferential sealing
surface at one radial end terminus of the gasket, positioned along
the radially inward open terminus of said gasket recess for
engagement with the outer circumference of the main pipe proximate
said spigot wall, and providing a continuation of the saddle wall,
a second generally circumferential sealing surface of the opposed
radial end terminus of the gasket, in engagement with the radially
outward wall terminus of the gasket recess, and a third generally
circumferential sealing surface, radially intermediate said first
and second generally circumferential sealing surfaces, in
engagement with said saddle wall, whereby said gasket provides
radially spaced first, second, and third generally circumferential
sealing surfaces.
2. A mechanical coupling in accordance with claim 1, wherein said
gasket includes a generally radial step between said second and
third sealing surfaces to provide a fourth generally radial sealing
surface, said fourth sealing surface in engagement with a generally
radial sealing surface of said gasket groove opposite said spigot
wall.
3. A mechanical coupling in accordance with claim 1, wherein said
first sealing surface has a circumferential area for engagement
with the outer circumference of the main pipe which generally
corresponds to the sum of the circumferential areas of said second
and third sealing surfaces.
4. A mechanical coupling in accordance with claim 2, wherein said
second sealing surface includes a radially extending annular
pressure slot to bifurcate said second sealing surface and provide
first and second radial wall surfaces, a first of said radial wall
surfaces opposing said spigot wall, and a second of said radial
wall surfaces forming the opposed radial wall of said fourth
sealing surface, and pressure transmission means for transmitting
the pressure from within the main pipe to said annular pressure
slot to urge said first and second radial wall surfaces in sealing
engagement with opposed wall surfaces of said spigot wall and
gasket groove.
5. A mechanical coupling in accordance with claim 4, wherein said
pressure transmission means includes at least one channel extending
between said first and second sealing surfaces.
6. A mechanical coupling in accordance with claim 1, wherein said
gasket includes a key projection and said gasket recess includes a
cooperating key recess for orienting said gasket within said gasket
recess.
7. An elastomeric gasket for providing a multi-surface coupling
seal between a main pipe and a branch pipe, said gasket being a
unitary member having a generally saddle shape, and including at
least first, second, and third generally parallel extending, but
radially spaced, circumferential seals, said first and second seals
defining the opposed radially inward and outward termini of said
gasket, and said third seal being radially intermediate said first
and second seals.
8. A mechanical coupling in accordance with claim 7, wherein said
first seal has a circumferential area of sealing surface generally
corresponding to the sum of the circumferential areas of said
second and third seals.
9. A mechanical coupling in accordance with claim 7, further
including a generally radial step between said second and third
sealing surfaces to provide a fourth generally radial sealing
surface.
10. A mechanical coupling in accordance with claim 9, wherein said
first seal has a circumferential area of sealing surface generally
corresponding to the sum of the circumferential areas of said
second and third seals.
11. A mechanical coupling in accordance with claim 7, wherein said
second sealing surface includes a radially extending annular
pressure slot to bifurcate said second sealing surface to form
first and second pressure responsive radial wall surfaces, and
transmission means communicating between said first sealing surface
and said annular pressure slot.
12. A mechanical coupling in accordance with claim 11, wherein said
transmission means includes at least one channel extending between
circumferentially innermost locations of said first and second
sealing surfaces.
13. A mechanical coupling in accordance with claim 11, wherein said
annular slot effecting movement of said first and second radial
wall surfaces towards opposed coupling surfaces in response to a
predetermined input pressure to said annular slot.
Description
FIELD OF THE INVENTION
[0001] The invention relates to the interconnection of pipes, and
more particularly to a mechanical coupling for connecting a branch
pipe to a main pipe which includes an improved multi-surface
sealing gasket therebetween.
BACKGROUND OF THE INVENTION
[0002] It is known to connect branch pipes to a main pipe via an
opening in the main pipe, with a saddle type clamp providing an
effectively sealed, and mechanically secure connection
therebetween. Typical of such couplings are the style 920 and 921
outlet couplings available from Victaulic Company of America,
Easton, Pa., the Assignee of the present invention, and Blakeley
U.S. Pat. No. 3,999,785, whose teachings are incorporated by
reference herein. As shown in Blakeley U.S. Pat. No. 3,999,785, the
mechanical coupling for connecting the branch pipe through a hole
in the main pipe is comprised of two opposed arcuate sections which
define a cylindrical space therebetween for embracing the wall of
the main pipe about the hole. One of the arcuate sections, which is
intended to also receive the branch pipe, includes a concave saddle
wall opening which defines a portion of a cylindrical surface
having a radius generally corresponding to the outer circumference
of the main pipe. The branch pipe connecting portion of the arcuate
section includes a radially extending branch pipe opening which is
dimensioned to overlie the main pipe opening and communicate with
the saddle wall. A spigot wall surrounds the branch pipe opening,
terminating at the saddle wall about the perimeter of the main pipe
opening. A pressure sensitive elastomeric gasket is placed about
the connection between the coupling member and the opening within
the main pipe in order to provide an effective seal therebetween.
The gasket is typically placed within a gasket recess of the
coupling member, about the spigot wall. The gasket includes sealing
surfaces which are applied against the cylindrical surface of the
main pipe, spigot wall, and gasket recess. It has been determined
that a sufficiently large area of the main pipe proximate the hole
being connected to the branch pipe must be engaged by the gasket in
order to provide an effective seal. This seal area must be of a
size sufficient to compensate for possible irregularities in the
pipe surface which could be caused by such factors as welds during
manufacture, damage during shipment, or manufacturing tolerances.
The gasket construction shown in aforementioned U.S. Pat. No.
3,999,785, as well as that utilized in the Victaulic 920 and 921
outlet couplings has provided a safe and effective seal. However
the configuration of the seal has necessitated a significant
increase in the overall size of the coupling to accommodate the
greater sealing surface areas required with the coupling of larger
pipe sizes. Accordingly, it would be desirable to reconfigure the
coupling, and particularly the gasket construction and its
associated sealing surfaces, such that larger pipe sizes can be
connected without necessitating a significant increase in the size
of the coupling.
SUMMARY OF THE INVENTION
[0003] The present invention provides an improved gasket
construction, and associated sealing surfaces, which results in an
extremely reliable and effective seal within the coupling between
branch pipe and main pipe in a manner which maximizes the
circumferential sealing surface against the main pipe without
necessitating the heretofore requirement of substantially
increasing the size of the coupling. Furthermore, it has been
determined that the gasket construction of the present invention
modifies its associated gasket recess within the saddle of the
coupling member in a manner which advantageously simplifies the
manufacture of the coupling, as well as the on site assembly of the
gasket within the coupling.
[0004] The gasket of the present invention utilizes a novel
plurality of sealing surfaces between the gasket recess within the
pipe coupling member and proximate surface of the main pipe about
the branch coupling hole in a manner which maximizes the effective
sealing areas, while minimizing the gasket radius and depth. More
specifically, the elastomeric gasket, which is of a generally
saddle shape corresponding to the outer circumference of the main
pipe includes three generally parallel extending, but radially
spaced, circumferential seals. The first circumferential sealing
surface is at the radially inward extent of the gasket, and is in
contact with the outer circumferential surface of the main pipe
proximate the branch pipe spigot. It provides a continuation of the
coupling saddle wall. The second generally circumferential sealing
surface is provided at the radially opposed outward end terminus of
the gasket which is in engagement with the outward wall terminus of
the gasket recess. A third generally circumferential sealing
surface is radially intermediate with the first and second
generally circumferential sealing surfaces and is in engagement
with the coupling saddle wall. A generally radial step is provided
between the second and third sealing surfaces to provide a fourth
generally radial sealing surface which is in engagement with a
generally radial sealing surface of the gasket recess opposite the
spigot wall. By virtue of this construction, the circumferential
sealing area of the first sealing surface, which is in engagement
with the main pipe outer circumference, will generally correspond
to the sum of the circumferential areas of the second and third
sealing surfaces. This configuration permits a maximizing of the
first circumferential sealing area with a minimal increase in both
the diameter and depth of the sealing gasket.
[0005] Since the sealing gasket must tightly fit within the
coupling gasket recess which surrounds the branch pipe spigot wall,
the present invention minimizes the size of the coupling to obtain
the requisite sealing area against the main pipe, as well as the
depth of the gasket groove.
[0006] Additional advantages are achieved by minimizing the depth
of the gasket groove. Specifically, since the coupling is typically
formed of a malleable iron casting, reducing the depth of the
gasket recess permits a reduction of mold draft along these
coupling walls. This facilitates the removal of the casting from
the mold.
[0007] As a further advantage, when the coupling is installed, the
on site worker typically lubricates the gasket before placing the
gasket within the gasket recess. The shape, dimensions, and mating
configuration of the gasket and gasket recess in accordance with
the present invention will experience less propensity of the gasket
to fall out of the gasket recess during its on site installation
within the coupling. Hence, in addition to providing a more compact
coupling and efficient gasket seal, the present invention enhances
both the manufacture of the coupling and its on site
installation.
[0008] In accordance with a further feature of a preferred
embodiment of the present invention, the gasket includes a radially
extending annular pressure slot without its second sealing surface,
(which is in engagement with the radially outward wall terminus of
the gasket recess), to bifurcate this surface and provide first and
second pressure responsive moveable radial wall surfaces. The first
of the radial wall surfaces opposes the spigot wall. The other
radial wall surface forms the opposed radial wall of the fourth
sealing surface (established by the radial step within the gasket).
A transmission means, which may preferably be in the form of a
plurality of radial channels, extends between the first and second
sealing surfaces for transmitting the pressure within the main pipe
to the annular pressure slot. Thus, the pressure transmitted to the
annular slot urges these first and second radial wall surfaces in
sealing engagement with the opposed wall surfaces of the spigot
wall and gasket groove to further optimize the effectiveness of the
seal provided by the gasket construction of the present
invention.
[0009] Accordingly, it is a primary object of the present invention
to provide an improved multi-surface gasket seal for utilization in
a coupling between a main pipe and branch pipe.
[0010] A further object is to provide such a gasket seal which
permits an increase in the circumferential sealing area against the
main pipe while minimizing the coupling size.
[0011] Another object of the present invention is to provide an
effectively sealed mechanical coupling between a main and branch
pipe, which is of compact size.
[0012] An additional object of the present invention is to provide
an elastomeric sealing gasket which is of a generally saddle shape
and includes three generally parallel extending, but radially
spaced, circumferential seals.
[0013] Yet a further object of the present invention is to provide
such an elastomeric gasket in which two of the circumferential
seals are at the opposed ends of the gasket, and a third seal is
radially intermediate the aforesaid seals, and is established by a
radial step therebetween.
[0014] Yet another object of the present invention is to provide
such a gasket for utilization in a main pipe to branch pipe
coupling, which further includes an annular pressure slot to
enhance the sealing forces.
[0015] These as well as other objects of the present invention will
become apparent upon a consideration of the following detailed
description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a cross sectional view along the axis of the main
pipe of the assembled mechanical coupling of the instant
invention.
[0017] FIG. 2 illustrates the upper saddle arcuate section of the
coupling to show the gasket within the gasket recess, including
further details of the various sealing surfaces therebetween.
[0018] FIG. 3 is a top view of the arcuate section of the
mechanical coupling which includes the branch pipe opening and
gasket recess.
[0019] FIG. 4 is a cross sectional view of FIG. 3 as shown by the
arrow 4-4 and looking in the direction of the arrows.
[0020] FIG. 5 is a bottom view thereof.
[0021] FIG. 6 is a perspective view of the improved gasket
according to the present invention.
[0022] FIG. 7 is a top view of the gasket.
[0023] FIG. 8 is a cross sectional view of the gasket along the
line 8-8, as shown in FIG. 7 and looking in the direction of the
arrows.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] A mechanical outlet device of the general type shown in
aforementioned U.S. Pat. No. 3,999,785, but modified to include the
gasket construction of the present invention, is designated by the
reference numeral 10 shown in FIG. 1. It is secured around main
pipe section P for connection to the branch pipe B. The outlet
device 10 has a generally half-annular, continuous arcuate section
11 shown engaging the lower face of the pipe P and an arcuate
section 12 with an outwardly extending outlet portion 13 engaging
the upper face of the pipe P at the location of an outlet hole H
through the wall of the pipe P. The sections 11 and 12 of the
outlet device 10 can be metal castings, for example, castings of
malleable iron, ductile iron, aluminum or brass would be
satisfactory, but also other materials could be used including
plastic moldings.
[0025] The simpler half-annular section 11 is seen to be of the
appropriate size to engage the pipe P throughout its extent, and
thus serves to reinforce and support the pipe wall. At its ends 14
and 15 the section 11 has outwardly extending bolt pads 16 and 17.
The bolt pad has a channular shape with a central web portion and
legs 22. The legs 22 slant inwardly toward the pipe P at
substantially a 45.degree. angle with respect to the web portion
21.
[0026] The other bolt pad 16 of the section 11 is similar to the
bolt pad 17 in structure, as are the opposed bolt pads 26 and 27 of
the section 12 of the outlet device, the bolt pads 26 and 27 having
web portions 31 and slanting legs 32 (see FIGS. 4 and 5).
[0027] The sections 11 and 12 are secured together in place around
a pipe P by means of bolts 33 with nuts 34. The slanted legs 22, 32
of the opposed bolt pads permit the sections 11 and 12 to "hinge"
open and "swivel" with the removal of one bolt only. The other bolt
undisturbed in its pre-assembled position forms the pivot around
which the hinge/swivel action takes place. Subsequent placement of
the other bolt 33 through the bolt pads 16, 26 and tightening of
the nuts 34 secures the outlet device 10 in place. Since one bolt
33 can be left partially and loosely secured before assembly of the
outlet device 10 about a pipe, one worker can easily accomplish the
installation by holding the device with one hand and placing and
tightening the other bolt and nuts 33, 34 with the other hand. To
further facilitate installation of the mechanical outlet device 10,
the bolts 33 are preferably of the track head type, fitted through
oval holes 35 of the respective bolt pads 16, 26, 17 and 27. The
use of track head bolts 33 make it possible to assemble and tighten
the outlet device 10 in place with only one wrench.
[0028] The section 12 of the outlet device 10 shown atop the pipe P
in FIGS. 1 and 2 also embraces the wall of the pipe P throughout
substantially 180.degree. and reinforces the pipe P where
reinforcement is most important--at the location of the hole H
through the pipe wall. The hole H, as will be understood by those
familiar with the art, is slightly larger than the diameter of the
spigot 41 of the outlet device to accommodate the outlet device and
to permit passage through the outlet of the desired flow to the
branch pipe B. The hole H is round, i.e., the projection of a
circle on the pipe wall, and need not, as in some prior art
methods, be cut to exact tolerances, since the mechanical outlet of
the invention accommodates reasonable roughness and even variations
in diameter of the hole H which can result from the method of
cutting, for example in flame cutting of holes H.
[0029] The body of section 12 is not just a semi-annular band like
that of section 11, but rather has a middle portion 40 widened to
the form of a saddle. The outlet portion 13 extends centrally
outward from this widened portion 40 of the section 12 and a spigot
41 extends inwardly. The spigot 41 is sized to be received within
the hole H with some clearance, and is accordingly also formed as
the projection of a circle with a tapered lip 42 that follows the
curvature of the hole H. The spigot 41, by fitting within the hole
H, accurately locates the section 12 on the pipe P, and prevents
dislodgement of the outlet device 10 in service.
[0030] Surrounding the spigot 41 there is a gasket-receiving recess
43 within the middle portion 40 of the section 12. The gasket
receiving recess 43, follows the circumferential curvature of the
outer diameter of the pipe P, and is bounded at its inner side by
the lip 42 of the spigot 41.
[0031] The gasket receiving recess 43 is configured to contain
gasket 50. Gasket 50 can be of rubber, or preferably some synthetic
elastomer material such as chlorinated butyl or ethylene propylene
dienemonomer. In accordance with the present invention, the gasket
50 includes a novel plurality of sealing surfaces, as shown in the
cross sectional view of FIGS. 2 and 8. These include a first
circumferential sealing surface 52 which is at the inward radial
end of the gasket 50 and is adapted to overlie the outer
circumferential surface of the main pipe section P about the spigot
lip 42. At the opposite, outward radial extent of the gasket 50, a
second generally circumferential sealing surface 54 is provided.
Sealing surface 54 is configured to be in engagement with the
radially outward terminus 55 of the gasket recess 43. A generally
radial step 56 is provided in the gasket, circumferentially outward
of the circumferential sealing surface 54, to establish a third
generally circumferential sealing surface 58. Sealing surface 58
will be in engagement with a portion of the saddle wall 60
immediately outward of gasket recess 43. Thus, the gasket includes
three generally parallel extending, but radially spaced,
circumferential sealing surfaces 52, 54, and 58. Further, step 56
provides an additional radial sealing surface which will be in
engagement with gasket recess wall 62. Also, the opposed radial
wall 64 of the gasket will oppose radial wall 67 of the gasket
recess.
[0032] The gasket preferably also includes diametrically opposed
key projections 71 which mate with coupling recesses 69 to properly
orient the gasket 50 within the gasket recess 43.
[0033] By virtue of the configuration of the gasket 50, the
circumferential sealing surface 52 will generally correspond to the
sum of the circumferential sealing surfaces 54, 58. This results in
an increase in the sealing area provided by cylindrical seal 52
against the main pipe P, to advantageously accommodate for
irregularities within the pipe surface while assuring an effective
seal, without necessitating a correspondingly large increase in
overall circumferential extent or depth of gasket 50. This, in
turn, allows the coupling 10 to accommodate larger size branch
pipes within the outlet portion 13 without requiring a substantial
increase in the overall size of coupling 10. As a further advantage
resulting from the present gasket construction, by minimizing the
depth of gasket recess 43, the draft along the generally radial
walls 62 and 66 is reduced. This eases the removal of the casting
from its mold. Further, the gasket configuration facilitates the
retention of the gasket 50 within the gasket recess 43 during the
on site installation of the coupling 10.
[0034] According to a further feature of the preferred embodiment
of the gasket, an annular pressure slot 166 is provided about
sealing surface 54. Pressure slot 166 bifurcates sealing surface 54
to form a pair of pressure responsive wall surfaces 168, 170. The
pressure from within pipe P is transmitted to the annular pressure
slot by a transmission means which includes communicating channels
72, 74. As increased pressure is applied to the annular pressure
slot 166, wall section 168 will be urged towards the spigot lip 42,
while wall section 170 will be urged into enhanced sealing
engagement with the gasket recess wall 62.
[0035] Thus, the configuration of gasket 50, and the plurality of
circumferential seals provided thereby, against the main pipe P,
gasket recess 43, and the associated concave saddle wall of
coupling arcuate section 12, provide an improved seal within a
minimal size coupling.
[0036] Numerous modifications, applications, and substitutions of
material will suggest themselves to those familiar with the piping
arts, and such alterations are considered to be within the spirit
and scope of the invention. For example, arcuate section 11 of the
coupling may be similar to member 12, so as to permit two branch
pipes to be connected to opposed diametrical openings within the
main pipe P. Accordingly, it is intended that the invention be
described by the following claims.
* * * * *