Apparatus for establishing the junction contour for intersecting pipes

A simulator in the form of a tubular pantograph mechanism is adjustable in diameter, and has circumferentially spaced elongated rods mounted on the inner wall in parallel relation with the axis. These rods define the inner diameter of the simulator and when the simultor is compressed on a lateral, define the outer diameter of the lateral. These rods are movable axially with frictional restraint. A guide includes a base to be placed on the surface of the main in alignment with the axis of the main, and a linear guide arm pivotally mounted on the base in a manner to be clamped in a selected position aligned with the projected axis of the lateral to be joined to the main. The simulator includes coacting support brackets to mount the simulator on the guide arm; and the simulator rods are then moved axially into engagement with the surface of the main. The points of engagement of the rod ends define the contour of the joint opening to be cut in the main. When the simulator is again placed over the lateral, the points at the ends of the rods define the mating contour for the end of the lateral to be joined to the main.

This invention relates to the joining of a pipe lateral to a linear pipe 
main; and more particularly to ascertaining the mating junction contours 
where a pipe lateral is to be joined to a pipe main usually of larger 
diameter. 
When a lateral is to be joined to a main in the field, it is desirable to 
be able to ascertain quite accurately the contour of the opening for the 
joint which must be formed in a main, and the contour of the mating joint 
end face of the lateral. The accuracy of these contours is important 
particularly for the joining of steel pipe where the joint is to be a 
welded joint; and these accurate contours must be ascertained regardless 
of the angle of intersection and regardless of whether or not the axes of 
the two pipes are actually intersecting or are offset. 
An object of this invention is to provide a novel apparatus for 
ascertaining the junction contour of a main and lateral to be joined. 
Another object of this invention is to provide such novel apparatus which 
may be employed in the field where the intersecting angle of the pipes and 
possible offset cannot be precalculated. 
A further object of this invention is to provide such novel apparatus to 
enable the immediate marking of the junction contours of the two pipes, 
and to enable the immediate cutting and joining of the two pipes. 
Still another object of this invention is to provide such novel apparatus 
which is effective and accurate regardless of the angle of intersection of 
the pipes and regardless of any offset of the pipe axes. 
These objects are accomplished in apparatus which includes broadly an 
adjustable simulator having circumferentially spaced, axially-slidable 
rods for defining the outer diameter of the lateral; wherein the rods are 
movable into engagement with the surface of the main to establish the 
contour. More particularly, the simulator comprises an endless pantograph 
mechanism formed to a tubular configuration, with the rods being mounted 
on the inner wall to define the inner diameter thereof. Still more 
particularly, the apparatus includes, in combination, means for guiding 
the simulator adjacent to the main with its longitudinal axis along the 
projected axis of the lateral. 
The novel features and the advantages of the invention, as well as 
additional objects thereof, will be understood more fully from the 
following description when read in connection with the accompanying 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
While the invention may be utilized for the joining of two pipes of the 
same size, and may be utilized for the joining of pipes having a 
cross-section other than circular, the invention is illustrated and 
described by way of example with respect to the joining of a smaller 
diameter cylindrical lateral to a larger diameter cylindrical main. The 
designation "main" and "lateral" are used only as descriptive examples of 
two pipes to be joined. 
FIGS. 1 to 3 of the drawing illustrate a pipe joint of the type to which 
the invention is directed, wherein a lateral 12 is joined to a main 11, 
wherein the lateral intersects the main at an acute angle, and where the 
axes of the lateral and main do not intersect but, rather, are offset. 
The apparatus of the invention consists of two basic components which are 
referred to as a simulator 20 and a guide 30. The simulator is so named 
because it functions to simulate the outer diameter of the pipe lateral 
and also the junction contour at the end of the pipe lateral which is to 
be joined to the body of the main 11. The guide 30 is an apparatus to be 
oriented with the axis of the main, and which functions to guide the 
positioning of the simulator 20 in relation to the main for the simulating 
of the intersection of the lateral with the main. 
As seen in the drawings, the simulator 20 consists of an adjustable 
pantograph mechanism which consists of a plurality of links 21, which are 
elongated flat strips of a suitable material, which links are of uniform 
length and are joined together in a parallelogram arrangement. In this 
parallelogram arrangement, the links 21 are connected together at their 
respective ends and also at the midpoints between the respective ends. 
This mechanism is an endless pantograph mechanism, formed into a 
cylindrical configuration; and the mechanism therefore forms a tubular 
member which is adjustable to different diameters. 
A plurality of elongated rods 24 are mounted on the inner wall of the 
simulator 20 by means of brackets 25; and the rods are supported on the 
simulator wall to be disposed parallel to the central axis of the tubular 
simulator and in uniform circumferentially spaced relation around the 
simulator. The rod brackets are so configured that when the simulator is 
compressed on a pipe section corresponding in size to a pipe lateral 12, 
the inner faces of the rods will essentially engage the pipe surface and 
will therefore define a diameter which corresponds to the outer diameter 
of the lateral 12. The pivot joints 22 of the simulator provide sufficient 
friction that the simulator will retain a diameter to which it is 
adjusted; after removal from the pipe section. 
Preferably the rod brackets 25 are pivotally attached to the simulator at 
each of the end pivots of the links 21; and the brackets themselves are 
rotatable relative to these pivots to allow the simulator to be compressed 
and expanded. Each of the rods 24 then is slidably supported in a pair of 
rod brackets 25 which are attached to axially aligned pivots 22. The rod 
brackets may be fabricated from a suitable material to allow the rods to 
be moved axially but with frictional restraint so that the rods will 
remain in a selected axial position relative to the pantograph mechanism. 
In order to align and guide the simulator at a desired angle relative to a 
main 11, the simulator is provided with a pair of axially aligned mounting 
brackets 27. These brackets are mounted on a pair of axially aligned end 
pivots 22, on the exterior of the simulator, and extend laterally relative 
to the simulator axis. Each of the brackets is provided with a hole 28 
adjacent to its distal end, which holes are aligned parallel to the 
simulator axis and configured to receive an elongated guide bar of a guide 
to be described. 
The guide 30 includes a base 31 which is an elongated channel-shaped 
member, with the edges of this member defining parallel runners which may 
be engaged with the cylindrical surface of a pipe main to orient the guide 
with the pipe. The guide then has a longitudinal axis which, when so 
oriented with the main, is disposed parallel to the axis of the main. The 
guide 30 further includes a turret 33, mounted for rotation about an axis 
perpendicular to the longitudinal axis of the base (and the axis of the 
main 11), the turret consisting of a base wall and upright ears 34. The 
turret base is rotatably secured to the base 31 by means of a suitable 
bolt-nut assembly 35 which defines the pivot mounting for the turret. This 
pivot mounting is designed to be tightened in order to lock the turret in 
a selected rotative position relative to the base 31. The ears 34 are 
provided with aligned holes which define a pivot axis perpendicular to the 
pivot axis of the turret mount 35. 
A guide arm 41 consists of an elongated shaft having a transverse tubular 
base 42, the base 42 having a transverse bore which is perpendicular to 
the longitudinal axis of the guide arm and defines a pivot axis for the 
guide arm. The tubular base is received within the ears of the turret; and 
the guide arm is pivotally mounted to the turret by means of a suitable 
nut-bolt assembly 43 which extends through the holes in the ears 34 and 
the bore of the tubular base 42. This pivot mounting assembly 43 may be 
tightened to clamp the tubular base the ears and lock the guide arm in a 
selected rotative position relative to the turret. 
For certain applications of the apparatus of the invention, the guide 30 
may be appropriately oriented with the main 11 and a linear marking then 
applied to the main to identify the position of the guide 30 relative to 
the circumference of the main, and the guide arm 41 is then aligned 
parallel with the axis of the lateral to be joined to the main. The pivot 
mounts 35 and 43 would then be tightened to lock the respective positions 
of the turret and the guide arm. The guide arm may then be used to guide 
the simulator, as will be described presently, to ascertain the contours 
of the hole to be formed within the main and the contour to be cut on the 
end of the lateral. 
For certain joint configurations, it may be possible to predetermine the 
angle of elevation of the lateral relative to the axis of the main, and 
the lateral angle of the lateral relative to a vertical plane coincident 
with the axis of the main 11; and where this is possible it may be 
desirable to preset these predetermined angles in a guide 30. For this 
purpose the top of the base 31 may be provided with an angle indicia 37 to 
indicate an angle of rotation of the turret 33 relative to the base; and 
the turret may be provided with a pointer 38 for coaction with the indicia 
37. Similarly, the turret may be provided with an angular indicia 45 to 
indicate the angle of the guide arm 41 relative to a plane coincident with 
both the turret axis and the guide arm axis; and the guide arm may be 
provided with a pointer 46 coacting with the indicia 45. For use of the 
guide 30 with predetermined angles locked in, the guide 30 would 
preferably be oriented on the main with the turret axis disposed in a 
vertical plane passing through the axis of the main. 
In use of the apparatus of the invention, for the orienting of the guide 
arm parallel to the axis of the lateral 12 and for the locking of the two 
pivot mounts, the guide is either held or secured to the main 11 in any 
suitable manner. The simulator, which has been compressed around a section 
of pipe to simulate the diameter of the lateral 12, is then placed on the 
guide 30 in the manner indicated in FIG. 10. The guide 30 and simulator 20 
may then be moved along the main, without any circumferential movement of 
the guide, to position the axis of the simulator in alignment with the 
axis of the lateral. Each of the rods 24 is then moved axially to a point 
just touching the surface of the main; and the points where these rods 
touch identify the outline of the hole contour. These points may be marked 
with a suitable marker and, after removal of the simulator and guide from 
the main, a continous line may be drawn through these marked points which 
line will represent the contour of the hole to be cut in the main. 
The simulator 20 is then placed over the section of pipe lateral which is 
to be actually joined to the main, (FIG. 11) after the desired length of 
that section has been ascertained, and the ends of the simulator rods 24 
will identify the contour of the end cut of this pipe section. Again 
suitable marks may be placed on the pipe corresponding to the ends of the 
rods 24, and, after the simulator is removed, these marked points are 
connected by a continuous line to identify the contour of the cut to be 
made. 
As an alternative procedure, after the simulator rods 24 have been 
positioned relative to the surface of the main 11 as described above, the 
simulator and guide are removed from the main without marking the main, 
but only marking the lateral as has been described. Then, after the 
lateral has been cut along the indicated contour, the lateral is fitted in 
place contiguous to the main, and the contour of the hole to be formed in 
the main is marked using the lateral itself as a guide or template for 
producing this contour. 
Operation and Method 
While the operation of the apparatus has been described to some extent, the 
entire operation will be clear from the following description of the 
method of the invention. 
The method of the invention involves first the ascertaining of the axis of 
the lateral and the point where this axis will intersect the main. This 
lateral axis may be ascertained, in the field, when the last full section 
of the lateral is laid, by projecting the axis of that last section to the 
point of intersection with the main which point should be marked. Possibly 
a string might be connected between the main and last section of the 
lateral to identify this axis. 
Desirably a line should be marked along the surface of the main, parallel 
to its axis, as a guide line for subsequent movement of the guide 30 along 
the main without accompanying circumferential movement. Next, the guide 30 
is placed on the main, aligned with the main and in a selected relation to 
the above mentioned guide line; and the turret 33 and the guide arm 41 are 
appropriately adjusted to align the guide arm parallel to the projected 
axis of the lateral. The turret and guide arm are then clamped in the 
respective adjusted positions. 
Next, the simulator 20 is placed over a section of pipe for the lateral 12 
and is compressed to bring its rods 24 into engagement with the pipe 
surface whereby the rods define the outer diameter of the lateral. The 
simulator then slipped off the pipe section and joined to the guide 30 by 
slipping the mounting brackets 27 over the guide arm 41. 
The guide 30 is then held in the same selected position relative to the 
above mentioned guide mark, and possibly moved longitudinally along the 
main 11 to position the axis of the simulator in coincident alignment with 
the projected lateral axis. The above mentioned string would be removed 
prior to this step. 
Then holding the guide 30 and the simulator 20 in these positions, the rods 
24 are moved axially to place the adjacent ends in engagement with the 
surface of the main 11. Since these rods 24 simulate the outer diameter of 
the lateral, the points where these rods engage the main define a contour 
on the main which is a projection of the outer surface of the lateral. 
These contact points may be marked on the main and, after removal of the 
guide and simulator, these marks may be connected with a continuous line 
to establish that contour. That contour, then, is the outer limit of a 
hole to be formed in the main 11 for the junction with the lateral. 
FIG. 10 of the drawing illustrates, in part, the steps described in this 
paragraph. 
Next, the simulator is separated from the guide and slipped over a section 
of pipe which is to form the last section of the lateral joined to the 
main. Depending on the type of pipe used, it may be necessary first to 
establish the length of this last pipe section. The simulator 20 is then 
used, as indicated in FIG. 11, to establish the contour of the end cut 
which contour is defined by the ends of the rods 24. These end points of 
the rods may be marked on the lateral and, after removal of the simulator, 
these points connected with a continuous line to establish the contour to 
be cut. 
If the contour of the opening in the main 11 has not been established as 
described above, the cut end of the lateral may be placed in aligned 
relation with the main, and end of the lateral itself used as a template 
to establish the contour on the surface of the main. 
Where the pipes to be joined are fabricated from steel, the cuts will 
likely be made with a cutting torch; and the surfaces of the cuts will 
likely be beveled, as illustrated in FIG. 3, so that the hole in the main 
11 provides a seat for the lateral 12. With this seating relationship 
established, the completing of the joint by means of exterior weld bead is 
facilitated. 
What has been described are a unique apparatus and a unique method for the 
joining of a lateral to a main in the field. 
A particular feature and advantage of the apparatus and method of the 
invention is that they may be employed by the field personnel making such 
a joint to establish, with minimum expenditure of time and with 
considerable precision, the contours of the opening in the main and the 
mating end cut for the lateral, to accomplish a successful completion of 
the joint. 
A related feature and advantage of the invention is that the joint contours 
are accurate regardless of the angle of intersection of the pipes and 
regardless of whether or not the axes of the pipes are intersecting or are 
offset. 
While the preferred embodiments of the invention have been illustrated and 
described, it will be understood by those skilled in the art that changes 
and modifications may be resorted to without departing from the spirit and 
scope of the invention.