Segmented flange structure including a shim

A flange structure formed from a plurality of joined flange segments is provided. The joined flange segments form a generally circular opening for a conduit. The generally circular opening has a perimeter formed from a first surface segment having discrete teeth and extending in a direction generally perpendicular to the faces and a second surface segment tapered toward one of the faces. The flange structure can be connected to a substrate by fasteners extending through two oval shaped openings connecting the two forces. At least one shim is attached to the flange segments about the circular opening. The shim has an inner surface with essentially the same surface configuration as the generally circular opening of the flange segments.

BACKGROUND OF THE INVENTION 
This invention relates to a flange structure. More particularly, this 
invention relates to a flange structure utilized to replace damaged 
flanges such as flanges utilized to connect conduits. 
At the present time, it is common to connect conduits with a flange on each 
conduit together with means for securing the flanges to each other. 
Automobile exhaust systems are an example of a system of connected 
conduits which utilize connecting flanges. These exhaust systems include a 
plurality of connected modules such as pipes, a catalytic converter and an 
exhaust muffler. The modules are provided with flanges to effect 
connection with an adjacently positioned module such as with bolts 
extending through the flanges which are secured with nuts. 
As automobile exhaust systems are operated in a corrosive environment, 
particularly in winter conditions when the system is exposed to salt, 
moisture and sand, portions of the system, including the flanges become 
severely corroded to the extent that they become detached from an adjacent 
flange. When this condition occurs, repairs must be made so that 
connection of modules in the exhaust system can be reestablished in order 
to permit the system to function properly. 
Oftentimes, it is not possible to repair the flange, thereby necessitating 
replacement of the entire module to which the flange is attached. This 
damaged flange condition also requires unnecessary expense since the 
remaining portion of the module, such as the exhaust muffler or catalytic 
converter can be in acceptable working order. 
It has been proposed in U.S. Pat. 4,519,639 to provide a segmented hinged 
flange for a conduit. The flange segments are formed from laminated metal 
sheets which interleave with metal sheets of an adjacently positioned 
segment at the juncture points between segments. The segments surround a 
conduit to be attached to an adjacent conduit. The segments are joined by 
bolts extending through the laminated metal sheets at the juncture points. 
The joining bolts extend beyond the thickness of the segments and thus 
increase the effective thickness of the flange. This, in turn, limits the 
use of the flange to a relatively large volume of space to accommodate 
both the flange thickness and the added thickness of the added bolts. In 
addition, the interior size of the flange opening is not adjustable so 
that a wide size range of flange structures must be provided to 
accommodate a wide variety of conduit sizes. 
U.S. Pat. 5,203,593 discloses a flexible exhaust coupling utilizing 
resilient annular gasket means designed to permit related movement between 
adjacent joined conduits. 
U.S. Pat. 5,228,726 discloses an exhaust system clamp having flared flanges 
for connecting two conduits to permit axial expansion of the conduits 
during use. 
U.S. Pat. Des. 263,415 discloses a design for a pipe coupling flange. 
It would be desirable to provide a flange structure which can be attached 
to a conduit to accommodate conduits of varying sizes. It would also be 
desirable to provide such a flange structure including means for attaching 
the flange structure to a conduit, which occupies a minimum volume. In 
addition, it would be desirable to provide such a flange structure which 
can be secured to a slightly damaged conduit surface or to a conduit with 
a flared end while minimizing or preventing damage to the conduit 
SUMMARY OF THE INVENTION 
The present invention provides a flange structure formed from a plurality, 
usually two, mating flange segments, each having a means for connecting 
the segments together which can include one or more shims to accommodate 
varying size conduits. Each flange segment is provided with two generally 
flat faces and an opening connecting the flat faces for housing a means 
for connecting the flange structure to a substrate such as a second 
flange. Each flange segment is provided with a generally circular arc 
surface such as a semi-circular arc surface which when connected to at 
least one other flange segment forms a generally circular opening for 
housing a conduit or pipe having a generally circular outside surface. The 
means for connecting the segments comprises generally cylindrically shaped 
housings for accommodating a bolt or the like which extends between 
adjacent segments but does not extend through the generally flat faces. 
The generally circular opening surface at a central portion of the joined 
segments has a perimeter, a portion of which is flared outwardly away from 
a central axis of the generally circular opening and a portion of which 
extends in a generally parallel direction to the central axis of the 
opening. The portion of the opening which extends in a generally parallel 
direction to the central axis of the opening can be provided with discrete 
teeth which extend toward the central axis of the opening. One or more 
shim sections are connected to the generally circular opening to provide a 
means for reducing the diameter of the opening. The shims have an exposed 
surface having essentially the same shape as the opening surface.

DESCRIPTION OF SPECIFIC EMBODIMENTS 
The flange structure of this invention is formed by connecting a plurality, 
preferably two, flange segments with connecting means such as bolts or the 
like which extend between adjacent flange segments but which do not extend 
through the flat faces of the flange segments. Shim sections are provided 
which mate with the shape of a central opening formed by the flange 
segments. An exposed surface of the shim sections have essentially the 
same surface configuration as the surface of the central opening. By 
orienting the connecting means so that their central axis extends in a 
direction generally parallel to the planes of the flat flange segment 
surfaces rather than generally perpendicular to these planes, the 
connecting means do not increase the effective thickness of the flange 
structure. If the connecting means were oriented so that they passed 
through the flat flange segment surface, the heads of the bolts as well as 
the nuts connecting the bolts would extend past the flat flange segment 
surfaces, thereby effectively increasing the flange structure thickness. 
This increased effective thickness undesirably increases the minimum 
volume into which the flange structure can be positioned. 
Since the generally circular surface of the flange structure which 
surrounds a generally cylindrical conduit or pipe, has a tapered surface 
section and a generally cylindrical section, the flange structure of this 
invention can accommodate a wide variety of conduits or pipes. For 
example, conduits having a flared end can be fitted with the tapered 
surface section of the flange structure. In addition, conventional 
cylindrical conduits can be fitted with the cylindrical surface section. 
In addition, the cylindrical surface section can be provided with discrete 
teeth extending away from the cylindrical surface section. The shim 
sections which are secured to the generally circular surface of the flange 
structure has an exposed surface with a tapered surface section and a 
generally cylindrical surface having discrete teeth. The discrete teeth 
provide increased frictional force of the flange structure including one 
or more shims, each formed from a plurality of shim sections on the 
outside surface of the conduit, particularly when the outside conduit 
surface has become irregular due to mild corrosion or bending. In 
contrast, a continuous threaded surface would not provide such an 
increased frictional force, and, in fact, would promote undesirable 
rotation of the flange structure about the conduit. 
Referring to FIGS. 1, 2 and 3, the flange structure forming a part of the 
apparatus of this invention 10 is formed from two flange segments 12 and 
14, each having two relatively flat surfaces 16 and 18. The oval shaped 
openings 20 are shaped to accommodate a stem of a fastening device (not 
shown) such as a bolt, screw or the like. The oval openings are sized so 
that a conventional head (not shown) of the fastening device is sized to 
be positioned on surface 16 or 18 while the stem of the fastening device 
is sized to extend through oval openings 20 and be positioned along the 
length 22 of opening 20. The oval openings 20 permit adjustment of the 
position of flange segments 12 and 14 to permit positioning on a conduit 
having a range of diameters. Each flange segment 12 and 14 is provided 
with generally cylindrical openings 24 and 25 through which fit 
conventional fasteners such as bolts or the like in order to secure flange 
segments 12 and 14 together. 
Each flange segment 12 and 14 is provided with a generally circular arc 
surface 26 having a tapered surface section 28 and a generally cylindrical 
surface section 30. The cylindrical surface section 30 is provided with 
discrete teeth 32. The tapered section 28 of the flange segments 12 and 14 
permits the flange segments 12 and 14 to be positioned about a shim 11 a 
conduit 13 having a flared end 15. The cylindrical section 30 of flange 
segments 12 and 14 permits the flange segments 12 and 14 to be fit about a 
conduit having a generally cylindrical outside surface. The discrete teeth 
32 permit the flange segments 12 and 14 to be positioned about a 
nonuniform generally cylindrical conduit while preventing their rotation 
about the conduit due to frictional forces exerted by the teeth. In 
contrast, a continuous threaded surface does not provide the desired 
frictional retaining force and, in fact, promotes rotation of the flange 
about the conduit to which it is attached. 
The flange segments, when utilized without one or more shims, are secured 
about a conduit by virtue of forces exerted by fastening means such as a 
bolt and nut extending through the generally cylindrical openings 24 and 
25. The flange segments 12 and 14 need not contact each other so that the 
diameter of the central opening 36 formed by the flange segments 12 and 14 
can be adjusted to accommodate conduits of varying diameter. The opening 
36 has a central axis 35 which extends generally parallel to the width 37 
of the cylindrical surface section 30. 
Since fastening means extend through generally cylindrical opening 24 and 
25, the fastening means (not shown) do not increase or significantly 
increase the effective thickness 38 of the flange segments 12 and 14. 
Thus, the formed flange structure can be positioned within a volume having 
a maximum thickness as small as the thickness 38 of the flange structure 
10. In contrast, the flange of the prior art (FIG. 4) having fastening 
means extending through the generally flat surfaces 52 and 54 have an 
increased effective thickness defined by the increased length added by the 
fastener 50 including washer 56 and nuts 58. In addition, the inner 
surfaces 60 of the flange segments 62 and 64 each a tapered section and a 
cylindrical section so that it is not practical for use with a conduit 
having a variety of outside surface shapes. 
Referring to FIG. 5, the flange structure portion of this invention 9 is 
formed from two flange segments 12 and 14, each having two relatively flat 
surfaces 16 and 18. The oval shaped openings 20 are shaped to accommodate 
a stem of a fastening device (not shown) such as a bolt, screw or the 
like. The oval openings are sized so that a conventional head (not shown) 
of the fastening device is sized to be positioned on surface 16 or 18 
while the stem of the fastening device is sized to extend through oval 
openings 20 and be positioned along the length 22 of opening 20. The oval 
openings 20 permit adjustment of the position of flange segments 12 and 14 
to permit positioning on a conduit having a range of diameters. Each 
flange segment 12 and 14 is provided with generally cylindrical openings 
24 and 25 through which fit conventional fasteners such as bolts or the 
like in order to secure flange segments 12 and 14 together. 
Each flange segment 12 and 14 is provided with a generally circular arc 
surface 26 having a tapered surface section 28 and a generally cylindrical 
surface section 30. The generally cylindrical surface section 30 is 
provided with discrete teeth 32. The shim sections 11, like the flange 
segments 12 and 14 include a flared segment 15 and a generally cylindrical 
surface section 17 provided with teeth 19. Likewise, the shims section 13 
include a flared segment 21 and a generally cylindrical surface section 23 
having teeth 25. The shim sections 11 include a flange 27 to permit them 
to fit about the flange segments 12 and 14. The shim sections 13 include a 
flange 29 to permit them to fit about the shim sections 11. The tapered 
sections 21 and 15 of the shim segments 11 and 13 permits the flange 
structure 9 and 14 to be positioned about a conduit having a flared end. 
The cylindrical sections 30, 17 and 23 permit the flange segments 12 and 
14 and shim sections 11 and 13 to be fit about a conduit having a 
generally cylindrical outside surface. The discrete teeth 25 of the 
innermost shim sections 13 permit the flange structures 9 to be positioned 
about a nonuniform generally cylindrical conduit while preventing its 
rotation about the conduit due to frictional forces exerted by the teeth. 
In contrast, a continuous threaded surface or a smooth surface does not 
provide the desired frictional retaining force and, in fact, promotes 
rotation of the flange about the conduit to which it is attached. 
The flange structure 9 is secured about a conduit by virtue of forces 
exerted by fastening means such as a bolt and nut extending through the 
generally cylindrical openings 24 and 25. The flange segments 12 and 14 
need not contact each other so that the diameter of the central opening 40 
formed by the flange segments 12 and 14 can be adjusted to accommodate 
conduits of varying diameter. The opening 46 has a central axis 42 which 
extends generally parallel to the width of the cylindrical surface section 
23. 
As shown in FIG. 5, a plurality of shim sections 11 and 13 to form a 
plurality of shims can be utilized. It is convenient to form the shims 
sections having 1/16 inch thick so that a shim layer reduces the diameter 
of opening 40 by 1/8 inch from that of the joined flange segments 12 and 
14. It is convenient to utilize from one to three shims for a flange 
structure 10 of a given diameter. Typically, the diameter of the central 
hole of the flange structure with shims can range from about 1 inch to 
about 5 inches to accommodate a wide variety of conduit diameters.