Pipe fitter's combination instrument

An adjustable instrument, capable of several functions, is provided for use by a pipe fitter. The primary use of the instrument is for positioning pipe sections and pipe fittings for joining, and it may also be employed to locate certain points on the exterior surface of a pipe length or fitting in preparation for a joining operation. The instrument is intended particularly for onsite use in accurately positioning tubular pipes and connections which are joined by application of annular weld beads. The instrument comprises a rigid squaring tool having a slidable carriage means movable on its major bar portion, and a rigid adjustable leg projecting from the carriage means in parallel relation to the fix leg of the squaring tool. The carriage means is provided with a releasable locking means to permit selective readjustment of its position along the major bar portion on which it is mounted. The carriage means also includes a spacer block section adapted to project outwardly a specific minimum distance from an edge of the major bar portion. Both the adjustable leg and the squaring tool are provided with calibrated scale graduations enabling rapid adjustment of the instrument during use. One embodiment of the instrument includes leveling means and magnetic means carried on the carriage means to further increase the versatility of the instrument.

BACKGROUND OF THE INVENTION 
In the fabrication and installation of metal pipe and fittings of 
comparatively large diameter, the shear size and weight of the pipe 
lengths and the various transitional connections make it impractical to 
provide threaded ends which can be joined and sealed by rotation, as is 
common with relatively small diameter iron or steel pipes and fittings. It 
is therefore customary to position such pipe lengths and fittings 
successively in mating alignment and then apply annular weld beads to 
unitize the installation. In smaller pipe sizes it is often necessary to 
utilize a welding procedure to join the pipe components either because the 
material composition of the components is resistant to the provision of 
threaded ends which may be joined by rotation or because welding jointure 
requirements are dictated by the intended special use and are mandatory in 
the specifications for the installation. 
The time required for preparing each jointure by pipe fitters in order to 
complete a predetermined layout is often tedious and cumbersome, 
particularly when the work is being performed insitu. The use of holding 
fixtures, as are normally available in a workshop environment, is not 
practical, and the careful positioning and temporary retention of each 
successive workpiece and the application of successive weld beads is a 
laborious process. It is common for at least two workmen to be involved in 
such pipe fitting practice. The steps they must perform for each jointure 
include positioning the workpieces by visual approximation, tack welding 
the workpieces along the intended line of jointure whereby some limited 
angular movement between the workpieces can still be effected, completing 
final accurate alignment of the work pieces relative to each other through 
the use of several large carpenter squares, and then applying an annular 
weld bead along the jointure line to firmly unitize and seal the joint. 
This procedure is repeated successively with the addition of each pipe 
length and fitting, and is particularly cumbersome because of the 
difficulties associated with manipulation of the squaring tools to 
properly position the workpieces. 
The aforementioned fitting and welding procedure may be simplified and 
expedited through the provision and use of a specially designed locating 
and positioning instrument to replace the several carpenter's squares 
normally employed. A device for this purpose which has some obvious 
advantages to the pipe fitter has been previously disclosed in Canadian 
Pat. No. 697,863. There remains, however, a need for an improved, more 
versatile pipe fitter's instrument to expedite the weld jointure of 
diverse special purpose fittings in the arrangements which confront pipe 
fitters. 
SUMMARY OF THE INVENTION 
The present invention comprehends an improved combination instrument for 
use by a pipe fitter in various job-related applications but primarily as 
a tool for positioning and aligning pipe lengths and fittings prior to 
welding them into a unitized structure in accordance with a preconceived 
layout or plan. 
The combination instrument of the present invention comprises a rigid 
squaring tool with an elongated straight-edged major bar portion and a 
fixed leg portion extending perpendicularly from one end of the major bar 
portion. The fixed leg also has parallel straight longitudinal edges 
therealong. A rigid auxiliary leg is adapted for slidable securement to 
the major bar portion in an orientation which is parallel to the fixed leg 
of the squaring tool. A carriage means arrangement attaches the distal end 
of the auxiliary leg to the major bar portion of the squaring tool whereby 
the auxiliary leg may be selectively slid and repositioned along the bar 
portion to adjust the distance between the adjustable leg and the fixed 
leg portion. The structure of the carriage means relative to the bar 
portion is such that it permits selective removal and reinstallation of 
the auxiliary leg in a reverse orientation wherein the auxiliary leg is 
moved from a first position of extension which is coextensive with the 
fixed leg portion, to a second position of extension from the opposite 
edge of the major bar portion, to facilitate use of the instrument 
relative to different positioning applications. A spacer block section is 
provided as an integral part of the carriage means and projects outwardly 
from the edge of the major bar portion of the squaring tool, at 
180.degree. to the auxiliary leg. The spacer block section serves as a 
means of properly locating the instrument in a spaced orientation from the 
side wall of a pipe length in certain pipe joining operations, and as a 
support base for the entire instrument in other operations. A manually 
operable releasable locking means is provided on the carriage means to 
retain the auxiliary leg in a predetermined position on the squaring tool. 
In certain alternate embodiments of the invention, provision is made for 
magnetic holding means on the spacer block section whereby the instrument 
can be temporarily retained in a predetermined position on iron or steel 
pipe and thus free the hands of the pipe fitter. The invention also 
comprehends the provision of leveling means as an integral part of the 
instrument, and the provision of removable means of extending the 
effective length of the fixed leg portion of the squaring tool to thereby 
adapt the instrument for certain specialized uses.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIGS. 1 through 4 illustrate a pipefitter's combination instrument 2 
comprising a rigid squaring tool (FIG. 2) having an elongated flat major 
bar portion 4 with straight oppositely disposed longitudinal marginal 
edges 6 and 8. Projecting from one end of the major bar portion 4 is a 
fixed leg portion 10 having oppositely disposed straight longitudinal 
edges 12 and 14. The edge 14 of the fixed leg portion 10 forms a 
90.degree. angle with the edge 8 of the major bar portion 4. 
As shown in FIG. 1, an auxiliary leg 16 is mounted for slidable, 
longitudinal movement on the major bar portion 4. The auxiliary leg 16 is 
a rigid flat bar similar in configuration to the fixed leg 10, and has 
oppositely disposed longitudinal straight edges 18 and 20. The distal end 
of the auxiliary leg 16 is firmly anchored in a block 22 which serves as a 
carriage means to permit the auxiliary leg 16 to be slidably adjusted to 
any desired position along the length of the major bar portion 4. 
As shown in FIG. 3, the block 22 may be formed from a solid piece which is 
provided with a groove or opening 24 and a transverse bore 26. As 
illustrated in FIG. 4, a relatively smaller bore or hole 28 extends from 
the sidewall defining bore 26 to the opening 24 and is threaded to 
accommodate a thumb screw 30 having a knurled head 32 contained within the 
bore 26. FIG. 4 also illustrates that the opening 24 is partially defined 
by the termination of the distal end of the auxiliary leg 16, and that the 
auxiliary leg 16 is firmly fastened in position to the block 22 by rivets 
34. 
It is preferred that all of the parts of the instrument heretofore 
described be formed from metal such as steel or aluminum so the instrument 
will withstand the wear and normal abuse which is normally encountered in 
the pipe-fitter's work environment. The major bar portion 4 and its fixed 
leg 10 constitute a squaring tool which may be stamped from metal stock of 
appropriate thickness. The auxiliary leg 16 may be similarly formed. The 
block 22 can be formed and machined from a solid piece, or alternatively, 
can be formed from stamped sidewall blanks laminated over a central blank 
to provide the configuration shown. 
The opening 24 through the block 22 is appropriately dimensioned to 
accommodate the extension therethrough of the major bar portion 4 of the 
squaring tool in a reasonably snug slip-fit arrangement whereby the shank 
end of the thumb screw 30 will firmly engage against the adjacent straight 
longitudinal edge of the major bar portion 4, when the thumb screw is 
manually rotated. The described arrangement thus acts as a releaseable 
locking means to selectively fix the position of the adjustable leg 16 
along the major bar portion 4. 
When the adjustable auxiliary leg 16 is in its operative mounted position 
on the major bar portion 4, as shown in FIG. 1, the part of the block 22 
wherein the set screw 30 is contained constitutes a spacer block section 
36 having an outer end face 37 which is parallel to the longitudinal 
straight edge 6 of the major bar portion 4, as illustrated in FIG. 1. 
Specifically, the spacer block section 36 is that portion of the block 22 
which, in FIG. 1, projects upwardly from edge 6 of major bar portion 4 and 
terminates in the flat end face or base 37. The spacer block section 36 
has oppositely disposed side faces 38 and 39, each of which forms a right 
angle relative to the edge 6 of the major bar portion 4. 
The embodiment of the invention shown in FIGS. 1-4 is designed and intended 
for use by a pipefitter in various pipefitting applications. One such 
application is shown in FIG. 5 which illustrates the disposition of the 
instrument 2 and the orientation of its parts to effect a connection 
between a pipe length A and a neck flange fitting C. In understanding FIG. 
5 it should be assumed that pipe length A has been previously installed in 
a permanent fixed intended position, and that the instrument 2 is being 
utilized to properly locate the neck flange C for coaxial connection to 
the end of the pipe length A. The connecting procedure includes the steps 
of placing the neck flange C with its narrow lip against the end rim of 
the pipe length A, placing one or more spaced apart tack welds on the 
annular line of abutment between the pipe length A and the neck flange C, 
disposing the auxiliary leg 16 in the general disposition shown in FIG. 5 
whereby the spacer block section 36 projects from the inside straight edge 
8 of the major bar portion 4, and utilizing the inside edge 14 of the 
fixed leg 10 to "square" the wide-faced end of the neck flange C with the 
sidewall of the pipe length A. 
It should be noted that the linear dimension of the spacer block section 36 
taken from the pipe A sidewall to the edge 8 of the major bar portion 4 
must be of a specific minimum magnitude. It is essential that the distance 
"d" shown by the arrows in FIG. 5, be at least equal to and preferably 
slightly greater than the widest radius of any part of any fitting 
normally used with a given size of pipe. Accordingly, the height dimension 
"h" of the spacer block section 36 (see FIG. 4) must be at least equal and 
preferably greater than the difference obtained by subtracting the radius 
of pipe A from the radius taken at the widest point of the widest normal 
fitting. The widest normal fitting generally would be the widest common 
transitional neck flange used with any pipe size. Having established the 
critical range for the dimension "h", it should then be recognized that 
the length of the inside edge 14 of the fixed leg 10 must at least equal 
to the diameter of the neck flange C taken along its wide forward face, 
plus the linear distance from edge 8 of the bar portion 4 to the nearest 
circumferential surface of neck flange C. This assures full face contact 
of the edge 14 of the fixed leg 10 in properly aligning the neck flange C 
to pipe length A following the tack welding step and prior to completion 
of the annular bead weld which permanently joins neck flange C to pipe 
length A. 
FIG. 6 demonstrates the use of the instrument of the present invention 
wwherein the pipe length A is a relatively short nipple, and the neck 
flange C has already been welded permanently into position pursuant to the 
arrangement shown in FIG. 5. Where, as shown in FIG. 6, it is desired to 
place a slip flange D (or any other fitting having oppossite end parallel 
bases which are perpendicular to the axis of the fitting) on a pipe nipple 
A and at a position a relatively short distance from an already installed 
fitting such as neck flange C, the components of the instrument 2 are 
oriented as shown in FIG. 6 whereby the auxiliary leg 16 is coextensive 
with the fixed leg 10. The installation steps include visually aligning 
the slip flange D in its intended position and retaining it there by one 
or more tack welds and then placing the instrument 2 into position with 
the inner edge 14 of the fixed leg 10 firmly against the base of the neck 
flange C. Then, the auxiliary leg 16 is adjustably moved along the major 
bar portion 4 whereby its inward edge 18 abuts with the wide face of the 
slip flange D. Slight manual repositioning of the slip flange D relative 
to the pipe length may then be accomplished as the instrument 2 is 
rotatively repositioned about the pipe-fitting assembly to several 
successively different planes in order to obtain true coaxial orientation 
of the slip flange with the pipe. This use of the tool in FIG. 6 aptly 
demonstrates a need, not previously mentioned herein, for the length of 
the auxiliary leg 16 to be the same, along its edge 18, as the length of 
the fixed leg 10 along it inside edge 14. Then, when the instrument 2 is 
used in an orientation similar to that illustrated in FIG. 6, large 
diameter fittings can be successively aligned and welded when they are in 
close proximity to each other. 
FIG. 7 demonstrates the use of the instrument 2 in an operation to connect 
two successive fittings, one to the pipe A and one to the first connected 
fitting. Specifically, FIG. 7 shows an eccentric reducer B after bead weld 
"w" has been applied to permanently join the large end of the reducer B to 
the end of the pipe length A. A neck flange C has been tack welded into 
position for final alignment, through the use of the instrument 2, prior 
to the application of an annular weld bead at the abutment line between 
the two fittings B and C. In the performance of the steps required to 
obtain the pipe component arrangement shown in FIG. 7, the instrument 2 
was utilized first to properly align the eccentric reducer B. In the use 
of the instrument for such an alignment, the spacer block section 36 would 
have been located relative to the fixed leg 10 approximately the same as 
the distance shown in FIG. 5, after which it would be manually adjusted a 
greater distance along the major bar portion 4 to the position shown in 
FIG. 7 for use in positioning the neck flange C. 
FIG. 8 illustrates the use of the instrument 2 in positioning a three part 
union E for welding to the end of the pipe length A. The connection 
between the pipe length A and the union E could be made, with the use of 
the instrument 2, by using only that part of the union which is actually 
connected to the end of the pipe length A and thereafter assembling the 
union to continue the installation. FIG. 8, however, shows the use of the 
instrument 2 as it is employed for positioning the assembled union E. Such 
use is effective so long as the parts of the union are substantially 
firmly joined by rotating of the central section of the union into firm 
threaded position so that the outer face of the union will occupy a plane 
which is perpendicular to the axis of the union. Then, when the instrument 
2 is used for aligning the union relative to the pipe length A, prior to 
application of the final weld bead, coaxial alignment of the union E to 
the pipe length A is assured. 
FIG. 9 illustrates the use of the instrument 2, with its components 
oriented substantially the same as in FIG. 8, for aligning a neck flange C 
into an aligned position on the laterally projecting lip of a tee 
connection F. The tee F has already been aligned and permanently welded in 
an interposed position between two pipe lengths A. In this illustration, 
the instrument 2 serves to align the wide face end of the neck flange C 
into parallel orientation with the side wall surface of pipe length A. 
FIG. 10 illustrates the use of the instrument 2 as a means of aligning 
successive pipe lengths A in an exact right angle orientation with each 
other. In the arrangement shown in FIG. 10, assuming the horizontal pipe 
length A is the fixed stationary member prior to the permanent coupling 
thereto of the elbow G, the instrument 2 would be utilized in the manner 
and orientation shown in FIG. 9 to align the elbow G to the horizontal 
pipe length A. Then, once the annualar weld bead is applied to permanently 
join the elbow G into position to the horizontal pipe length A, the 
components of the instrument 2 would be rearranged to the orientation 
shown in FIG. 10 to enable the alignment of vertical pipe length A with 
horizontal pipe length A, as shown. 
FIG. 11 illustrates an alternate embodiment of the present invention 
wherein the instrument 2 utilizes a pair of spacer block sections 36 to 
effectively bridge a union E in aligning two vertically successive pipe 
lengths A with the union E interposed therebetween. Obviously, the 
instrument 2 could be utilized with a single spacer block section 36 if 
the pipe fitter elected to fully complete each jointure from the elbow H 
upwardly, before proceeding with the next upwardly sucessive connection. 
However, provision of the additional spacer block section 36 enables the 
entire vertical portion of the pipe assembly to be tack welded and then 
permanently aligned before applying any of the full annular weld beads to 
render the assembly permanent. 
The instrument 2 is preferably provided with calibrated scale indicia such 
as shown along the inside margins of the major bar portion 4, the fixed 
leg 10, and the auxiliary leg 16, in FIG. 12. These calibrated markings 
serve several different functions. For example, the number of typical 
different types of pipe fittings is limited, as is the number of different 
common pipe sizes. Therefore, most pipe fitting situations or arrangements 
are repetitive such that the pipe fitter, in using the instrument 2, will 
quickly begin to associate and memorize certain pipe fitting operations 
with the required component orientation and specific adjustment setting of 
the instrument 2. By use of the calibrated scale the pipe fitter may 
quickly position the auxiliary leg 16 at a desired point along the edge 8 
of the major bar portion 4 to obtain a setting which is commensurate with 
aligning a particular fitting arrangement. 
This invention also contemplates the provision of a specific 
special-purpose scale along the inside edges of the major bar portion 4, 
the fixed portion 10, and also along the inward edge 18 of the auxiliary 
leg 16. The numbers set forth on the instrument in FIG. 12 which appear in 
circles coincide with the radius of standard pipe sizes whereby use of the 
instrument 2, as shown, in a "caliper" orientation about any given pipe 
length, enables the pipe fitter to accurately segment the pipe surface 
into quadrants. The ability to lay out such quarter markings is important 
to the pipe fitter when, for example, it is desired to make a saddle-type 
connection along the length of a pipe without the use of a fitting. This 
involves cutting a "fish mouth" opening in the pipe side wall, and a 
complimentary shape on the pipe end to be welded thereto. Such an opening 
is made by first inscribing a pattern for the cut line which can only be 
done if the pipe fitter first has specific reference points on the pipe 
surface from which to begin. Such reference points are provided by 
locating circumferentially spaced marks about the pipe in an annular 
arrangement which can be accomplished by the means shown in FIG. 12. 
The primary purpose of the instrument 2, as heretofore described in various 
operations, is to facilitate angular alignment of successive pipe lengths 
and fittings. A distinct advantage in obtaining such angular alignment 
between a fixed or stationary pipe length and a successive pipe length or 
fitting to be coupled thereto is that force or pressure of the instrument 
to hold it in proper position during use is only against the stationary 
workpiece and then only through contact of one component of the instrument 
with the stationary workpiece. This obviates the need, as required in 
prior art methods of alignment, of being certain that more than one 
component or point of an alignment tool is in abutting contact with the 
surface of the stationary workpiece. In every common connecting operation, 
either the spacer block section 36 or the fixed leg portion 10 or the 
auxiliary leg 16 is firmly held against the surface of the stationary 
workpiece whereby the workpieces to be connected to the stationary 
workpiece can be moved into alignment with the other guiding surfaces of 
the instrument 2. Accordingly, in most instances of its use, the 
instrument 2 is held stationary against a stationary workpiece so that no 
force need be asserted against the next successive fitting or pipe length 
brought into position for connection. 
The form of the instrument 2 as heretofore described may be further 
sophisticated in its manufacture to enhance its versatility for the pipe 
fitter. A more sophisticated embodiment of the instrument 2 is shown in 
FIG. 13 wherein a large opening 40 is provided through the spacer block 
section 36 to facilitate the installation therein of level means which is 
preferably a plurality of spirit levels 42, 44, and 46. Level 42 is 
installed to extend parallel to the end surface of spacer block section 
36. Level 46 is installed to extend exactly perpendicular to level 42. 
Level 44 is installed to extend at 45.degree. to level 42. The 
aforementioned arrangement enables the pipe fitter to visually ascertain 
the position of any pipe length, during installation, relative to true 
horizontal or vertical and make appropriate adjustments as required. In 
any use of the tool herein described, one of the levels 42, 44, or 46 will 
be oriented to serve as a means for the pipe fitter to visually check 
either the horizontal or vertical positioning of a pipe workpiece. 
FIG. 13 also illustrates a further sophistication of the instrument 2 which 
is the provision, on the outer end surface of spacer block section 36, of 
a rectangular permanent magnet 48. Inasmuch as a significant number of the 
typical installation arrangements encountered by the pipe fitter are those 
wherein a spacer block section is in contact with a pipe length (see, for 
example, FIGS. 5, 7, and 8), the instrument 2 can be rendered self 
supporting through the attraction of the magnet 48 to the pipe length 
surface. Accordingly, the provision of the magnet 48 permanently fixed to 
the outer end surface of the spacer block section 36 provides a further 
useful characteristic to the instrument 2, particularly in the 
installation of common iron or steel pipe lengths or fittings. 
Most pipe installations require either 90.degree. or 180.degree. 
orientation of successive workpieces. That is, most connection operations 
involve placing the next fitting on a pipe length whereby the successive 
pipe length to be installed after installation of the fitting will extend 
coaxial to the stationary pipe length in a 180.degree. orientation, or 
perpendicular to the axis of the stationary pipe length in a 90.degree. 
orientation. Fewer in number are those connections which require 
orientation of a successive pipe length at some other angle such as 
45.degree. or 30.degree. to the preceding stationary pipe length. When 
special angle orientations are required, an additional longitudinal plate 
or edge extender 50 is used as part of the combination of the instrument 
2, as shown in FIG. 14. The edge extender 50 is a rigid elongated bar 
similar to a long straight edge. The edge extender 50 preferably has a 
longitudinally extending integral skirt portion or ridge 52 which defines 
one of the long edges of the extender 50. The use of the extender 50 may 
be further facilitated by the provision of resilient plastic magnetic 
strips 54 and 56 extending longitudinally on one flat surface of the 
extended 50, in a spaced apart relation whereby the strip 54 is adjacent 
the under surface of the ridge 52, and the strip 56 extends along the 
straight edge 58 of the extended 50, as shown in FIG. 15. 
The components of the instrument 2, as shown in FIG. 14, are utilized to 
align fittings, such as 30.degree. and 45.degree. elbows, to a pipe lengt, 
prior to completion of the permanent weld operation. Proper orientation of 
the instrument 2 is obtained by presetting the long side edge of the 
carriage means to align it with the 45.degree. mark on the major bar 
portion 4. The adjacent corners 60 and 62 of the major bar portion and the 
spacer block section, respectively, become a base which, when in contact 
with the pipe length, dispose the edge 14 of the fixed leg portion 10 at 
the appropriate selected angle relative to the axis of the pipe length. 
The extender 50 is then placed in position on the fixed leg 10 whereby its 
edge 58 coincides with edge 14 of fixed leg portion 10 and serves as an 
accurate linear extension against which to align the outer face of the 
45.degree. elbow I shown in FIG. 14. The ridge 52 of extender 50 enables 
rapid firm contact and alignment of the extender 50 with the fixed leg 
portion 10, and the magnetic strips 54 and 56 serve to hold the extender 
in position during use. Obviously, for use of the magnetic strips 54 and 
56, it is necessary that the instrument 2 be of an iron or steel 
composition to enable the magnetic attraction and temporary holding of the 
extender 50 in position on the fixed leg portion 10. Alternatively, the 
magnetic strips 54 and 56 could be eliminated in favor of embedded 
discrete magnets spaced along the body of the extender 50. Such 
modification would better withstand the conditions and normal abuse to 
which the instrument 2 will be subjected. It is also contemplated that the 
entire extender 50 could be a magnetized bar to enable it to be 
temporarily magnetically locked into position against the fixed leg 
portion 10. 
While certain presently preferred forms of the invention have been 
heretofore described and shown, other equivalent variations may occur to 
thos skilled in the art in light of the above teachings. It should be 
understood that the appended claims are intended to cover all such 
variations coming within the spirit and scope of the present invention.