Electrical controller for roofing apparatus

A controller for propelling a carriage along a plurality of purlins, and method of using same are disclosed. A plurality of carriage sections are joined to form a continuous carnage spanning a plurality of purlins. A plurality of puller assemblies are attached to selective ones of the carriage sections. A controller is connected to the plurality of puller assemblies. The controller can be actuated to a master control mode which simultaneously engages the plurality of puller assemblies, thereby propelling the carriage along the purlins. The controller can also be selectively actuated to a selective mode which engages one of the puller assemblies.

TECHNICAL FIELD AND INDUSTRIAL 
1. Applicability of the Invention 
This invention relates to the construction of an insulated metal roof 
structure for use in commercial and industrial buildings. 
2. Background of the Invention 
Metal roof structures typically comprise a series of parallel rafter beams 
extending across the building in one direction, and purlin beams parallel 
to each other mounted on top of the rafters extending in a direction 
normal to the rafters. Insulation material in long blankets is placed in 
the area between purlins. The blankets of insulation material can be laid 
along the length of the purlins or across the purlins in a direction 
normal to the purlins. If desired, the roof structure can have a first 
layer of insulation material which is laid along the length of the 
purlins, and a second layer of insulation material which is laid laterally 
across the purlins on top of the first layer on insulation. Hard roofing 
material such as metal decking is then attached on top of the purlins over 
the insulation material. Because the hard roofing material comes in long 
sheets and the roofs generally have two sloped sections, it is customary 
to construct the roof along the length of the structure from one end to 
the other. The workers stand on the previously laid section of roof to 
construct the next section. 
The insulation material is supported between the purlins beneath the hard 
roofing material. Various methods of supporting the insulation material 
have been used. Mounting straps or wire mesh which are attached to or 
draped over the purlins forming a lattice have been used. This is referred 
to as banding. A support sheet, typically made of vinyl and acting as a 
vapor barrier, is then rolled onto the lattice, and insulation material is 
placed between adjacent purlins and over the support sheet. If the 
installation of the lattice is done from underneath the roof structure, 
scaffolding or lifting equipment is typically required for installation. 
Since the lattice encompasses the entire roof, installation is costly and 
time consuming. Once the hard roofing material is mounted on the purlins, 
the support sheet can support the insulation material and the lattice no 
longer serves any useful purpose. 
Some systems dispense with the lattice and use the support sheet itself to 
support the insulation material. The support sheet is dispensed from a 
roll and draped from adjacent purlins. Insulation material is then placed 
on top of the support sheet. A carriage, such as that disclosed in U.S. 
Pat. No. 4,967,535 to Alderman, has been used to aid in the dispensing of 
the support sheet. The carriage is positioned on top of the purlins and 
travels along the length of the purlins during the roof construction. A 
roll of the support sheet material is mounted on the carriage and the 
support sheet is dispensed from the roll and placed on top of the purlins. 
As the carriage travels the length of the purlins, the support sheet is 
draped across the purlins. 
The carriage can be any length up to the width of the roof itself. For 
example, the carriage can be comprised of a plurality of carriage sections 
which are joined together so that they span the entire width of the roof. 
Each carriage section has a roll or a plurality of rolls of support sheet 
which are dispensed as the carriage travels along the purlins. Preferably, 
the support sheets are provided with a width appropriately sized so that 
the support sheet extends between two adjacent purlins. The carriage is 
then propelled along the length of the purlins so that the carriage 
sections move in unison. 
In the past, the carriage was manually pushed across the roof along the 
length of the purlins by means of push rods. The workers standing on a 
completed section of the roof structure would manually push the carriage 
sections to the desired position. Another method of advancing the carriage 
was by pulling the carriage across the roof by means of a relatively long 
cable and large winch fastened to the carriage. For a large number of 
carriage sections, multiple cables and winches were used. The cable was 
typically 200 feet long and had a conventional hook attached at the end of 
the cable. The cable was reeled out from the spool of the winch and then 
hooked to a flange of a rafter beam. If the roof structure was longer than 
200 feet, the cable was attached to the farthest rafter beam which the 
cable was able to reach. The winch was then manually operated to take up 
the cable about the spool of the winch so as to advance the carriage. It 
was preferred that the cable be as long as possible, so that the cable did 
not have to be re-attached to a different rafter beam often. Because the 
winch is attached to the carriage and moves over and across the rafter 
beams, the cable is laid across the tops of all the rafter beams between 
the carriage and the end of the roof structure. However, it can be 
difficult and time consuming to unroll the cable and pull the end of the 
cable across the rafter beams 200 feet away from the carriage. It is also 
difficult to initially attach the hook at the end of the roof structure 
since this requires a worker to climb to the top of the end of the roof 
structure. Since the cable is relatively long, the cable is relatively 
heavy and awkward to handle. Also, the size of the winch is relatively 
large and heavy to accommodate the length of the cable required to span 
across the roof structure. Further, the cable stringing and attaching 
process must be accomplished in a safe manner to protect the workers, and 
in an open rafter and purlin structure. This can require extensive safety 
measures. 
It would be desirable to have an apparatus and method for moving the 
carriage along the length of the purlins which is relatively simple, fast, 
and safe to perform. 
SUMMARY OF THE INVENTION 
The above objects as well as other objects not specifically enumerated are 
achieved by a method for propelling a plurality of carriage sections along 
a roof structure. The apparatus and method provides for a relatively 
simple and fast system for moving the carriage. 
The apparatus of the present invention provides is suitable for use on a 
roof structure of the type having a plurality of purlins spaced apart from 
one another in a parallel arrangement. The apparatus includes a plurality 
of carriage sections which are movable along the length of the purlins. 
The carriage sections are joined together to form a carriage spanning the 
purlins. A plurality of puller assemblies are attached to selective ones 
of the plurality of carriage sections. The puller assemblies are 
engageable to move the carriage along the purlins. A controller is 
electrically connected to a source of power and the puller assemblies. The 
controller is operable to a master control mode, wherein the plurality of 
puller assemblies are simultaneously engaged to move the carriage sections 
in unison. The controller is also operable to a selective mode, wherein 
one of the puller assemblies is selectively engaged to move the carriage 
section to which that puller assembly is attached. 
The method of the present invention includes first joining the plurality of 
carriage sections to form a continuous carriage spanning a plurality of 
purlins. The plurality of puller assemblies are then attached to selective 
ones of the carriage sections. The controller is also connected to the 
plurality of puller assemblies. The controller can be actuated to a master 
control mode which simultaneously engages the plurality of puller 
assemblies, thereby propelling the carriage along the purlins. The 
controller can also be selectively actuated to a selective mode which 
engages one of the puller assemblies. 
Various objects and advantages of this invention will become apparent to 
those skilled in the art from the following detailed description of the 
preferred embodiment, when read in light of the accompanying drawings.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION 
Referring to FIGS. 1 and 2, there is illustrated a partially completed 
building roof structure, indicated generally at 10. The roof structure is 
supported by a building framework which includes main rafter beams 12 
positioned parallel to each other. A plurality of purlins 18, spaced apart 
and arranged parallel to each other, is fastened on top of the rafters in 
a direction normal to the rafters. The building framework may have two 
sloped sections (not shown) which are joined together to form a peak. The 
spacing of the rafter beams is typically within the range of from about 25 
to about 30 feet (7.6 to about 9.1 meters) on centers. The spacing of the 
purlins is typically about 5 feet (1.52 m) on centers. As best shown in 
FIG. 2, the purlins typically have a generally Z-shaped cross-section, and 
include a horizontally extending upper portion 20, a vertically extending 
web 22, and a horizontally extending lower portion 24. Of course, the roof 
structures may be constructed from bar joists or trusses, and the 
invention as described herein will work equally well with purlins, bar 
joists or trusses. The use of the term "purlins" in this specification and 
claims includes not only traditional purlins, but also joists, trusses, 
and other suitable structural members for supporting the roof structure. 
Broadly stated, the roof structure is constructed by use of a carriage, 
indicated generally at 26, which rides on the upper portion 20 of the 
purlins and travels along the length of the purlins in a downstream 
direction, represented by an arrow 28, as shown in FIG. 1. Preferably, the 
carriage has rollers 30, rotatably mounted on the carriage, which roll 
along the upper portions of the purlins. As the carriage is moved, a 
support sheet 32 is payed out from rolls 34 and 42, as will be discussed 
below. The support sheet is draped on top of adjacent purlins so that the 
longitudinal edges of the support sheet depend from the upper portion of 
the purlins, as shown in FIG. 2. The support sheet supports a layer of 
insulation material 36 which is placed on top of the support sheet between 
the adjacent purlins. The insulation material is typically dispensed from 
a roll 38 but can be applied by any suitable manner, such as by applying 
elongated insulation batts on top of the support sheet. Alternatively, a 
layer of insulation may be placed laterally across the purlins. After the 
insulation material has been placed on the support sheet, long sheets of 
hard roofing material 40, such as metal roof decking, are then attached to 
the upper portion of the purlins over the support sheet and insulation. 
The hard roofing material can be fastened to the purlins in any suitable 
manner, such as by threaded fasteners or clips. The attachment of the hard 
roofing material presses down on the edges of the support sheet which are 
sandwiched between the upper portion 20 of the purlins and the hard 
roofing material 40, so that the support sheet supports the insulation 
between the purlins. 
Because the hard roofing material comes in long sheets, typically 30 to 35 
feet (9.1 to 10.7 m), and the roofs generally have two sloped roof sides, 
it is customary to construct a first section of the roof structure along 
the width of the sloped roof side and then proceed along the length of the 
structure from one end to the other. The workers stand on the previously 
attached first section of the roof structure to assemble the next section 
of roof. The carriage travels along the length of the purlins and is moved 
by the workers as each new section of roof is assembled. 
As best shown in FIG. 3, the carriage is comprised of a plurality of 
carriage sections 26a which are joined together. The carriage sections are 
joined at their respective ends 90 so that they are generally in alignment 
with each other, as shown in FIG. 3. The carriage sections can be joined 
together by any suitable manner, such as by being clamped or bolted 
together. Preferably, the carriage spans the entire width of the sloped 
section of the roof, but it can be any length up to the width of the roof 
itself. Note that in FIG. 3, the support sheets and insulation material 
are removed for clarity. 
To construct the roof structure 10, the carriage 26 is propelled across the 
purlins in the downstream direction 28. As the carriage moves along the 
length of the purlins, the ends of the support sheets 32 are draped across 
the upper portion of adjacent purlins. Preferably, the total width of the 
support sheet is wider than the distance between the purlins. Adjacent 
support sheet rolls may be positioned in a staggered and offset manner 
such that they are not co-linear with each other. Preferably, a carriage 
section 26a covers two purlin spans, as shown in FIG. 3. Each carriage 
section preferably has both a leading roll 34 and a trailing roll 42 of 
insulation support sheet, one roll for each of two adjacent purlin spans, 
as shown in FIG. 1. The edge of the support sheet from the trailing roll 
42 will be draped on top of the edge of the support sheet from the leading 
roll 34 as the carriage moves in the downstream direction. Multiple 
identical carriage sections having a leading and trailing roll can, 
therefore, be joined together, with every roll being staggered from an 
adjacent roll. 
The carriage 26 can be any suitable apparatus which moves along the top of 
the purlins and dispenses the support sheet. As seen from FIG. 1, the 
carriage preferably includes safety handrails 44 and a deck 46 for the 
workers to stand on while operating or moving the carriage. The rollers 30 
are mounted from the deck 46 of the carriage. Preferably, the carriage is 
equipped with two rollers (front and rear) for each purlin, as shown in 
FIG. 1. The carriage also includes a framework 48 for mounting the rolls 
34 and 42. Mounted on the framework are turning bars 50 which extend 
laterally across associated support sheets and are positioned slightly 
above the upper portions 20 of the purlins 18 so as to direct the support 
sheet to a generally horizontal position. 
Attached to the carriage is an optional plate 52 which extends from the 
carriage in an upstream direction opposite the downstream direction 28. 
The plate supports the payed out portion of the support sheet and 
insulation material so that the support sheet does not drape downwardly, 
thereby pulling the longitudinal edges of the support sheet off the upper 
portion of the purlins. If sufficiently built, the plate can be used for 
fall protection for the workers to prevent them from falling off the 
leading edge of the previously completed section of roof. The plate can be 
attached to the carriage by any suitable means. The plate follows the 
carriage as the carriage moves along the length of the purlins. 
Preferably, the plate has wheels 54 which also support the plate by 
rolling along the upper portion 20 of the purlins 18. However, it is not 
required that the payed out support sheet be supported by the plate. The 
carriage could be modified so that the support sheet is payed out in such 
a manner that the support sheet is underneath the plate. If desired, the 
roll 38 of insulation material 36 could be positioned on the plate 52 
above the support sheet. 
The space between the vertical webs 22 of adjacent purlins 18 generally 
defines an insulation cavity 58, as shown in FIG. 2. The insulation cavity 
has a generally rectangular cross-sectional shape. The support sheet 
supports the insulation material in the insulation cavity. The support 
sheet can also be used as a vapor barrier and/or for aesthetic purposes. 
The support sheet can be of any suitable material for the stated purposes, 
such as vinyl or foil faced paper. 
The carriage 26 is propelled or advanced along the length of the purlins in 
the downstream direction 28 by a plurality of puller assemblies 60. The 
puller assembly 60 can be any suitable apparatus which is attached to or 
mounted on a carriage section. For example, the puller assembly can 
include a motor 62 for driving a drive mechanism 64 which rotates a wheel 
66 frictionally engaging the purlin, as described in co-pending U.S. 
patent application Ser. No. 09/052,735 which is incorporated by reference 
herein. The rotation of the wheel causes the puller assembly and the 
carriage to move along the length of the purlins. The puller assembly 60 
can be attached to the carriage section by any suitable manner, such as by 
a cable 68, or can be mounted directly on the carriage section. 
When a relatively large number of carriage sections are used, multiple 
numbers of puller assemblies are used to move the carriage. If desired, a 
puller assembly 60 can be attached to each carriage section. However, it 
is preferred to use a fewer number of puller assemblies than the total 
number of joined carriage sections. For example, a puller assembly can be 
attached to every fourth carriage section, as shown in FIG. 3. Of course, 
any suitable number of puller assemblies can be used to move multiple 
joined carriage sections. 
When a plurality of puller assemblies is used, it is desirable to 
simultaneously control the plurality of puller assemblies so that the 
carriage sections will move in unison along the length of the purlins. The 
puller assemblies can be controlled by a single electrical controller 70, 
an embodiment of which is illustrated in FIG. 4. The controller is 
preferably mounted on one of the carriage sections, such as for example, 
on the handrail 44. The controller includes a housing 71 having a 
plurality of receptacles 72. The receptacles provide for electrical 
connection with each puller assembly via a cord 74, as shown in FIG. 1. In 
the embodiment of the controller 70 illustrated in FIG. 4, the controller 
70 includes three receptacles on each side thereof, to accommodate six 
puller assemblies (there are three shown, and three hidden in FIG. 4). Of 
course, the controller can include any suitable number of receptacles. The 
controller is connected to a source of power 76, such as a generator or 
battery, via a power conduit 78. Preferably, the controller controls the 
puller assemblies by directing electrical power from a single source to 
the plurality of puller assemblies. Of course, multiple power sources can 
be used. Each puller assembly can also be provided with its own source of 
power, wherein the controller controls every source of power. 
The controller includes a single master control switch 80. The master 
control switch 80 is operable to a master control mode which 
simultaneously engages the puller assemblies so that the carriage sections 
26a are propelled along the purlins in unison. Preferably, the master 
control switch 80 is a two-position switch for permitting or preventing 
electrical communication between the source of power 76 and the motors 62 
of the puller assemblies. The controller preferably includes a control 
overload relay 82 to help protect the electrical circuitry within the 
controller. The control overload relay can be any suitable circuitry which 
disrupts electrical communication between the source of power 76 and the 
electrical circuitry within the controller when an undesirable electrical 
current or voltage is detected which may cause harm to the electrical 
components. For example, the control overload relay 82 can be a thermal 
protection relay triggered by an electrical power drain. The control 
overload relay 82 can be reset automatically, such as by a time delay 
circuit, or manually reset, such as by a reset switch 84. 
In addition to controlling the plurality of puller assemblies 
simultaneously with the master control switch, the controller 70 can also 
be actuated to control or engage individual puller assemblies. For 
example, it may be desirable to control a single puller assembly if the 
carriage section to which it is attached is misaligned with the other 
carriage section, as will be described in further detail below. As shown 
in FIG. 4, the controller 70 includes a plurality of operator switches 86 
and a plurality of associated overload relays 88. The overload relays 88 
can be any suitable circuitry to help protect the controller 70, the 
motors 62, and the source of power 76. Preferably, the overload relays 88 
are configured so that they can be reset automatically, such as by a time 
delay circuit, or manually reset, such as by associated reset switches 90. 
In the embodiment shown in FIG. 4, the controller includes six operator 
switches, relays, and reset switches corresponding to the six receptacles 
72. Preferably, the operator switches are two position switches for 
preventing or permitting electrical communication between the source of 
power and the plurality of puller assemblies. The master control switch 80 
and the operator switches may include an indicator light (not shown) to 
indicate the position of the switch. 
The method of propelling the carriage 26 along the purlins in the 
downstream direction 28 will now be described. If the carriage sections 
26a are in alignment in a direction normal to the length of the purlins, 
as illustrated in FIG. 3 with solid lines, an operator actuates the master 
control switch 80 so that the plurality of puller assemblies move the 
carriage section 26a in unison. Preferably, the carriage is moved a 
relatively short distance so that one or two panels of hard roofing 
material 40 can be fastened to the purlins. This process is repeated to 
complete the roof structure. 
Under certain circumstances, the carriage sections can become misaligned. 
For example, a carriage section can be prevented from moving because of an 
obstruction, such as fasteners extending upward from the upper portions of 
the purlins. When a carriage section confronts the obstruction, the 
remaining carriage sections may continue to be propelled in the downstream 
direction before being prevented from further movement, thereby causing a 
misalignment of the carriage. There is illustrated in FIG. 3, an example 
of the carriage 26 being misaligned such that a pair of carriage sections 
26a', shown in phantom lines, are shifted with respect to the remaining 
carriage sections 26a. When the carriage becomes misaligned, the 
controller 70 is actuated to a stop mode to prevent the puller assemblies 
from moving the carriage. The controller is then actuated to a selective 
mode, wherein one or more of the puller assemblies are engaged to align 
the carriage. For example, the puller assembly 60 associated with the 
misaligned carriage section 26a', as illustrated in FIG. 3, can be 
actuated to move the carriage sections 26a' from their misaligned 
positions, as indicated by the phantom lines 26a', to an aligned position, 
as indicated by the solid lines 26a. The misaligned carriage section 26a' 
can be moved by actuating the associated operator switch 86 to provide 
power to the associated puller assembly. After the carriage 26 has been 
realigned, the operator can then actuate the master control switch 80 to 
move the carriage sections in unison. 
Although the carriage has been described as being propelled in the 
downstream direction 28, the puller assemblies can be configured to propel 
the carriage in a direction opposite the downstream direction, such as by 
back driving the motors 62 of the puller assemblies 60. If desired, the 
controller 70 can have additional controls to actuate the puller 
assemblies in both directions. 
The principle and mode of operation of this invention have been described 
in its preferred embodiments. However, it should be noted that this 
invention may be practiced otherwise than as specifically illustrated and 
described without departing from its scope.