Note: Descriptions are shown in the official language in which they were submitted.
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WIRE MES~ STRAIGHTENING METHOD AND APPARATUS
Field of the Invention
This invention relates generally to construction power
equipment, and more particularly to a mobile apparatus for
automatically straightening rolled wire mesh of the type
used for concrete reinforcement of paved roadbeds.
Description of the Prior Art
Concrete pavement and decks often include a wire mesh
reinforcement material which is embedded within the
concrete at the time of pouring the concrete. To provide
maximum reinforcement, the reinforcing mesh should
preferably be evenly spaced from the ground when pouring
the concrete so as to be uniformly positioned when viewed
in cross section, generally near the center of the hardened
concrete. Uneven positioning of the reinforcing mesh
within the concrete can result in wide variations in the
strength of the concrete over the reinforced areas.
Such reinforcing mesh is typically shipped to the
construction site in large rolls, and must be ùnrolled and
positioned within the bed in which the concrete will be
poured or laid. Due to the wire resiliency and its
tendency to retain its "rolled" curvature, it has been very
difficult and often virtually impossible to get the
curvature out of the wire and to position such wire mesh
evenly and flat within the formed bed. Many man hours of
time and frustration are typically expended in unrolling
and partially straightening and pulling the wire prior to
pouring of the concrete. Even the best manual
straightening efforts generally leave a situation wherein
the wire extends in wave-like manner along its length. The
problem becomes even more acute as the thickness of the
wire increases and as the end of a wire roll is unwound,
since the radius of curvature of the wire decreases at its
"inside end," making the wire much more difficult to
straighten. It has become commonplace in the industry to
wastefully cut off and simply discard the last four to six
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feet of mesh near the end of a roll, rather than to expend
the time and efort in straightening the end of the roll.
The problem is further accentuated in colder weather
wherein the wire resiliency significantly decreases.
Heretofore, there have been no practical or economical
methods or apparatus for automatically straightening rolled
reinforcing mesh wire at the construction site. Attempts
at hand straightening, pulling and bending of such ~ire
have proven less than satisfactory, most often resulting in
uneven, over or under bending~ kinking and buckling of the
wire. It would be desirable, therefore, to have an
automated power operated straightening device that is
easily portable and usable at the construction site for
uniformly and rapidly straightening entire rolls of
reinforcing mesh wire. Such a device must above all, be
operator safe and incorporate fail-safe safety features
that allow a user to instantaneously stop or disengage
dangerous moving parts of the machine should an operator or
user get entangled with or otherwise drawn into the
apparatus processing the wire mesh.
One type of automated apparat~s known in the art
removed kinks and bends from wire mesh by compressing the
wire mesh between a pair of opposed driven rollers of the
type used in the agricultural industry for crushing hay.
While this technique represented a significant improvement
over prior hand straightening methods, it did not
incorporate the safety or convenience features required to
make it practical for use in the construction industry.
Further, the basic roller straightening technique did not
completely take the curvature out of a prerolled wire mesh
and did not provide adjustment compensation techniques for
rapidly adjusting to wire mesh thicknesses of varying
gauge. Such apparatus was also dangerous to the operator
who was required to manually assist in the feeding of the
wire mesh into the rollers, and did not incorporate fail-
safe safety features that enabled an operator to
immediately stop the rollers in the event he became
_ 3 _ ~ 31 7867
entangled or caught in the wire mesh or Eeed mechanism.
The present invention addresses and satisfies the
above noted prior art shortcomings and needs in the
industry for an automated mesh straightening apparatus by
providing a simple, reliable and effective mesh
straightenin~ apparatus that can be easily moved to the
desired construction location and safely operated by a
single person.
Summary of the Invention
The present invention provides a compact wire mesh
straightening apparatus particularly suitable for on-site
straightening of rolled wire mesh of the type used in
reinforcing concrete beds. Typically such mesh comes in
150 foot rolls in five-foot widths. Its applicability to
construction site use is provided in part by the fact that
the straighteninq apparatus is mounted on an axle and
wheels so as to be easily towed by a motor vehicle. It
also has a third caster wheel and handle assembly mounted
on a manually operable screw jack that enables the
apparatus to be rapidly iockeyed in dolly-like fashion into
the desired position at the construction site. The jack
also enables rapid leveling of the straightening apparatus.
In the event that heavier equipment such as cranes are
available at the construction site, the apparatus includes
a lifting bracket that enables the entire apparatus to be
lifted into, for example, a pickup truck or to other
elevated positions generally directly inaccessible by motor
vehicle. The apparatus further includes a brake locking
mechanism that is operable to prevent movement of the
apparatus once established in operative position.
Besides its mobility and compactness features, the
invention addresses operator safety. ~ fail-safe hydraulic
operating system is used that automatically removes power
from the straightening drive members in the event of
hydraulic failure and provides for a safety stop switch
mechanism that instantaneously stops the system drive
rollers in the unlikely event that a person were to be
_ 4 _ l 31 7~67
drawn toward the inlet of the apparatus. To further ensure
operator safety, the apparatus is designed to operated by a
single operator, and all of the controls needed to operate
the apparatus are located on the side of the apparatus in a
manner which ensures that the operator stands clear of the
advancing wire mesh and the moving parts of the apparatus.
In such position, the operator also has a clear line of
sight to both the inlet and the outlet portions of the
apparatus enabling him to safely operate the apparatus if
others are assisting him.
A preferred embodiment of the invention employs a
power lift feature for automatically lifting the roll of
wire mesh to be straightened, into a position such that the
wire naturally feeds into the inlet port of the
straightening apparatus. The mesh to be straightened is
unwound from the top of a roll which enables an automatic
self-releasing starting lever to engage and draw the mesh
toward the inlet port without operator intervention. The
wire mesh is drawn through a nip formecl by a pair of
rollers which compressively remove kinks and irregularities
generally across the plane of the mesh as it passes through
the nip. The compressive force at the nip as well as the
interroller spacing at the nip can be adjusted, and the
operator can entirely release pressure at the nip by
~5 lifting one of the rollers from the nip area by means of a
safety lever arrangement. The mesh is directed from the
nip toward a reaction surface, the angle of which can be
varied relative to the advancing wire, which bends the mesh
in a direction opposite to the curvature it has as it
leaves the roll. The adjustment features provided by the
invention enable a reverse curvature to be applled to the
roll which is exactly equal to its preexisting curvature,
such that the wire is completely straightened. The mesh
straightening apparatus of this invention enables the
entire wire mesh roll to be straightened, avoiding the
waste heretofore encountered with prior art straightening
techniques~
1 3 1 7867
-- 5 --
Therefore, according to one aspect of the invention
there is provided a wire mesh straightening apparatus for
automatically straightening rolled wire mesh at a construction
site which includes: (a) a chassis that is sized and configured
for ease of mobility to and at a constructio:n site; (b) a pair
of generally parallel rollers mounted to the chassis and
cooperatively aligned generally parallel to each other to form
a nip between their respective surface portions that lie closest
to one another, wherein the rollers are at least as wide as the
width of the wire mesh to be straightened; (c) means for
advancing the wire mesh to be straightened through the nip formed
by the rollers including hydraulic drive means operatively
connected to drive at least one of the rollers about its axis;
(d) reaction means connected to the chassis arranged and
configured to intercept the wire mesh passing through the nip for
continuously bending the mesh in a direction opposed to the
pree~isting curvature of the wire mesh as it leaves the nip,
whereby the wire mesh is uniformly straightened as it leaves the
reaction means; and (e) self-releasing starting means connected
to the chassis for retainably engaging the wire mesh to be
straightened and for guiding the mesh toward the nip.
According to another aspect of the invention there is
provided a method of straightening rolled wire mesh comprising
the steps of: (a) positioning a roll of wire mesh to be
straightened adjacent and in generally parallel manner to a pair
of generally horizontal rollers cooperatively arranged to form
a nip therebetween such that the wire unrolls from the top of the
roll; (b) lifting the roll of positioned wire mesh from the
1317867
- 5a -
ground and such that the wire leaving the roll is generally
aligned with said nip, without requiring bending of the wire to
enter the nip; (c) retainably engaging the wire mesh of the roll
by means of a self-releasing starting means and guiding the wire
mesh thereby toward the nip; (d) continuously advancing ths wire
through the nip by hydraulically rotating at least one of said
rollers; thereby removing kinks and irregularities therefrom; and
~e) continuously bending the wire advanced khrough said nip in
a direction opposed to the direction of travel of said wire from
said nip, thereby straightening said wire.
According to yet another aspect of the invention there
~PF
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is provided a method of automatically and continuously
straightening rolled wire mesh comprising the steps of:
~a) horizontally arranging a roll of wire mesh to be
straightened such that the wire will be unwound from the
top of the roll; (b) guiding the wire mesh unwound from the
roll through a nip formed by a pair of cooperatively
arranged rollers; (c) compressively engaging the wire mesh
between said rollers at said nip; (d) rotating at least one
of the rollers by means of a closed hydraulic power system
thereby advancing the wire mesh through the nip; (e)
directing the advancing wire mesh from said nip toward a
reaction surface; (f) continuously pushing said dixected
wire mesh against and along said reaction surface mounted
at a predetermined angle relative to the advancing wire
mesh, thereby imparting a reverse curvature to said wire
mesh generally opposite to that which it retained upon
removal from said roll; and (g) automatically stopping
rotation of said one roller upon a pressure failure in said
hydraulic system.
While the present invention will be described with
respect to its applicability to straightening reinforcing
wire mesh of the type used to reinforce concrete, it will
be understood that the invention is not limited to use with
such reinforcing wire mesh, but could be used to straighten
any type of rolled wire mesh product. Further, while the
invention will be described with respect to a particular
embodiment which has a uniquely looking form and shape,
such aesthetic features are not to be construed as limiting
to the invention. Further, the preferred embodiment of the
invention will be described with reference to particular
components and parts. It will be readily understood by
those skilled in the art that other components and parts or
variations thereof could equally well be used to achieve
the claimed functions. These and other variations in the
manner and technique of implementing the invention will
readily be recognized by those skilled in the art.
Brief Description of the Drawin~
~ 7 ~ I 3 1 7 ~ 67
Referring to the Figures, wherein like numbers
represent like parts throughout the several views:
Fig. l is a perspective view of a mesh straightening
apparatus constructed according to the principles of this
invention viewed from the front, top and right end thereof;
Fig. 2 is a right end elevational view of the mesh
straightening apparatus of Fig. l;
Fig. 3 is a left end elevational view of the mesh
straightening apparatus of Fig. l;
Fig. 4 is an enlarged fragmentary perspective view of
the left portion of the emergency stop panel of the
apparatus shown in Fig. 1 illustrating the apparatus for
actuating the primary safety stop switch;
Fig. 5 is a cross sectional view generally taken along
the Line 5-5 of Fig. l;
Fig. 6 is an enlarged fractional view of the caster
wheel and brake portion of the apparatus of E'ig. l; and
Fig. 7 is a hydraulic schematic diagram illustrating
the hydraulic operating system oE the mesh straightening
apparatus of Fig. 1.
Description of the Preferred Embodiment
The Drawing illustrates one preferred embodiment of a
wire mesh straightening apparatus constructed according to
the principles of this invention. Referring to Figs. 1~ 2
and 3 there is generally shown at 10 a mesh straightening
apparatus having an upper chassis structure 12 mounted to a
lower support framework, generally designated at 14. The
lower support frame 14 is mounted by means of a pair of
springs 15 in a manner well-known in the art to a primary
axle 16, the ends of which operatively carry a pair of
wheels and tires, generally designated at 17. One end of
the frame (Fig. 3~ forms a tongue and conventional trailer
hitch connector, generally designated at 20, which enables
the entire apparatus to be towed by a motor vehicle in
conventional manner.
The forward end of the chassis also includes a
mounting bracket 21 to which is connected a caster wheel
- ~ - 1 3 1 7 ~ 67
support jack 22. The caster support jack 22 has a movable
internal sleeve member 22a telescopically inserted and
threadably secured within the external housing oE the jack
22 so as to be vertically raised and lowered in response to
rotation of a crank handle 23 disposed at the upper end of
the jack 22, in a manner well-known in the art. The lower
end of the vertically movable jack member 22a is pivotally
connected to an axle support assembly, generally
illustrated at 24 ~Fig. 6) for rotatable caster-like motion
about the axis of the support jack 22. A second axle 26
and caster wheel and tire 27 are operatively mounted to the
caster support bracket 24. When the mesh straightening
apparatus lO is not connected to a towing vehicle by means
of the trailer hitch assembly 20, the caster wheel 27 can
be lowered by means of the caster wheel support jack 22 to
provide support and leveling action for the forward end of
the apparatus. When the apparatus 10 is being towed, the
caster wheel 27 is simply lifted off of the ground by means
of the jack assembly 22.
In the preferred embodiment, the caster wheel 27 is
generally aligned with one of the primary wheels 17 as is
best illustrated in Figs. 2 and 3. A handle 28 is
pivotally connected to the caster bracket member 24
adjacent its forward end (as best illustrated in Figs. 1
and 5) to enable ease o~ movement of the mesh straightening
apparatus in wagon or dolly-like fashion at a construction
site. When the handle 28 is extended in a forward manner
such as illustrated in dashed lines in Fig. l, the caster
tire 27 i5 free to rotate and move along the ground or
support surface upon which the caster wheel 27 and primary
wheel 17 rest. The lower end of the handle has a rigid
extension bar 28a ~Fig. 6) which pivots about the
horizontal connection axis of the handle 28 with the caster
support bracket 24 in a manner such that when the handle 28
is "lowered" as shown in dashed lines in Fig. l, the rigid
extension bar pivots in an upward direction away from the
tread of the caster wheel 27. ~owever, when the handle 28
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is lifted to an upright or vertical position, as shown in
solid lines in Figs. l and 6, the rigid extension bar 28a
pivots downwardly into frictional engagement with the tread
of the caster wheel 27, to prevent the caster wheel from
turning, thereby acting as a locking brake for the caster
wheel. The handle 28 is positioned in such brake-lock
position during operative use of the Mesh straightening
apparatus, as hereinafter described in more detail. A
handle lock or clamp, generally designated at 29 secures
the handle 28 in an upright position. The locking clamp 29
has a U-shaped channel mounted to the outer housing of the
support jack 22 which forms a seat for the elongate handle
portion of the handle 28, and a retaining spring-biased pin
29a which is disposed across and closes the open end of the
U-shaped channel. The handle 28 is locked or released from
locked position in the clamp by simply operating the
sprin~-blased pin 29a.
The input or wire feed side of the apparatus,
generally designated as the "front" side, is illustrated in
Fig. 1. A first front panel 30 protectively shields a
drive roller 50, hereinafter described~ n more detail, and
is securely mounted to the support framework 14. The panel
30 has a lower generally vertical portion 30a, a first
upper portion 30b inclined inwardly and upwardly toward the
drive roller 50, and a second upper portion 30c which
extends from the first upper portion 30b and extends
inwardly and downward toward the drive roller 50. The
inclined surfaces 30b and 30c form an input guide surface
for the wire mesh to be straightened. The upper inclined
guide surface 30c terminates at an inlet feed port,
generally designated at 32, for directing ~ire mesh between
the lower drive roller 50 and an upper roller 55, to be
described in more detail hereinafter. A pair of outer
guide rollers 3~ and 36 vertically mounted at each end of
the inclined guide surface 3Qc are rotatable about
generally vertical axes and function to guide and contain
wire mesh fed into the input feed port 32 from lateral
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shifting movement. Each of the guide rollers 34 and 36 has
in the preferred embodiment a grease fitting at its upper
end for lubricating the rollers.
The upper roller 55 and the upper portion of the
chassis 12 is enclosed by an emergency stop panel 40 and a
top cover 44. The emergency stop panel 40 is pivotally
mounted to an upper cross bar support 41 transversely
extending between the forward and trailing ends of the
apparatus. The emergency stop panel 40 downwardly hangs
from its support member 41 in protective fashion in front
of the upper roller 55, with its lower edge being bent
slightly inward toward the roller 55 and defining the upper
boundary of the inlet feed port 32. The emergency stop
plate 40 defines a rectangular opening 40a near its center,
and further has a laterally projecting lever arm 40b
extending from its left edge (as viewed in ~igs. 1 and 6)
for engaging an emergency stop valve 110, hereinafter
described in more detail. The top cover panel 44 extends
backwardly from the support bar 41 to prevent access to the
rollers 50 and 55 from the front and top of the apparatus,
except through the inlet feed port 32.
Referring to Fig. 3~ the forward end of the mesh
straightening apparatus 10 is closed by means of an end
plate member generally designated at 46. The trailing end
of the apparatus, illustrated in Fig. 2, is similarly
closed by an end plate member 48. End plates 46 and 48 are
appropriately secured to the framework 14 and also support
and are fastened to the top cover 44. The upper cross bar
support 41 extends between and is mounted to the opposed
end plates 46 and 48. While a matter of design choice as
dictated by the width of wire to be straightened, in the
preferred embodiment, the width of the inlet port is sized
to accommodate a wire mesh roll five feet wide. The
primary drive roller 50 is transversely mounted to extend
across the inlet feed port 32. The axle 50a of roller S0
is mounted at the trailing end to the end plate 48 by means
of a bearing assembly generally illustrated at 49 and to
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the forward end plate 46 by means of a similar bearing
assembly (not illustrated)~ The axle 50a o~ drive roller
50 projects through the bearing assembly of the forward end
plate 46 and is operatively coupled to and for movement
with the drive shaft of a hydraulic motor 11~, illustrated
in phantom in end view in Fig. 3, which is protected by a
plate member 47. A second cross bar support shaft 56
extends between and is securely mounted to the end plates
46 and 48 and is aligned parallel to the axis 50a of the
drive roller 50. The respective ends of the support shaft
56 project through and extend slightly beyond the outer
surfaces respectively of end plates 46 and 48. End plates
46 and 48 respectively define elongate openings 46a and
48a, arcuately shaped relative to the central axis o~
support shaft 56.
First and second roller mounting levers 60 and 64
respectively, are pivotally mounted to the projecting end
portions at opposite ends of the support shaft 56, as
illustrated in Figs. 2 and 3, for pivotal rotation about
the axis of support shaft 56 adjacent the outwardly
directed surfaces of the end plates 46 and 48. The
mounting levers 60 and 64 are secured to the support shaft
56 by an appropriate bearing and nut arrangement. Those
en~ portions of the roller support lever members 60 and 64
disposed toward the front or wire mesh feed side of the
apparatus 10 have roller bearing support members 61 and 65
respectively secured thereto for mounting the upper roller
55 in a manner such that the ends of the central support
axle 55a of the roller 55 freely pass through the elongated
slots 46a and 48a in the end plates 46 and 48 when the
roller support levers 60 and 64 are pivoted, and such tha~
the roller axis 55a is aligned parallel with the axis 50a
of the drive roller 50.
As illustrated in Figs. 2, 3 and 5, the position of
the upper roller 55 can be pivotally adjusted relative to
the primary drive roller 50 by pivoting of the roller
support levers 60 and 64 about their common pivot axis 56.
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Depending upon the thickness or gauge of -he wire mesh
being handled, the pivotal position of the lever support
arms 60 and 6~ may be adjusted such that the respective
surfaces of rollers 50 and 55 actually engage one another,
or, preferabl~ are spaced slightly apart from one another.
A pair of adjustable stop members 62 and 66 are
respectively mounted to the end plates 46 and 48 and are
positioned to engage the upper surfaces of the roller
support levers 60 and 64 respectively so as to adjust the
minimum interroller spacing at the nip formed by the
cooperating rollers 50 and 55.
A pair of springs 63 and 67 are respectively secured
to the nonroller-supporting ends of the levers 60 and 64
for cooperatively biasing the lever members about their
pivot axis 56 and toward engagement with the adjustable
stop members 62 and 66 respectively. The springs 63 and 67
cooperatively provide a downward biasing force through the
lever arms 60 and 64 to the upper roller 55 to counteract
any forces imparted to the roller 55 which would tend to
lift the roller in an upward direction. The upper ends of
the springs 63 and 67 are respectively secured to a pair o~
eccentric cam plates 70 and 71 which are rotatably mounted
for common movement with a shaft 73 laterally extending
across the chassis 12 and secured through the end plates 46
and 48. The cam members 71 and 73 and sha~ft 73 are rotated
by means of an operating lever 74 which is directly
connected to the cam 70. As illustrated in Fig. 3, when
the operating lever 74 is rotated in the clockwise
direction, the cams 70 and 71 move in an upward direction
to stretch the springs 63 and 67, thereby exerting a
downward biasing force on the upper roller 55 through the
respective lever arms 60 and 64. Conversely, when the
operating lever 74 is moved in a counterclockwise direction
(as viewed in Fig. 3), the springs 63 and 67 relax,
thereby relieving tension and enabling the upper roller 55
to move out of engagement and in an upward direction away
from engagement with the lower roller 50.
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In the preferred embodiment, the lower drive roller 55
is made of steel and is coated with 0.5 inches of rubber,
and has an overall diameter of nine inches. ~he upper
roller 55 is also made of steel and has a diameter of six
inches. The vertical dimension "A" of Fig. 5 between the
respective axes 50a and 55a is seven inches, and the
horizontal interaxis spacing (dimension "B" in Fig. 5~ is
three and one-half inches. The offset positioning of the
upper roller axis 55a, rearward with respect to the axis
50a of the lower roller (Fig. 5) causes wire mesh engaged
at the nip of the rollers to curve downward from the nip to
the shelf or plate 79 (as hereinafter described in more
detail). Placement of the upper roller 55 by the support
lever arms 60 and 64 preferably is such so as to leave a
one-eighth inch spacing between the respective surfaces of
the rollers 50 and 55 at their nip line ("C" in Fig. 5).
A fourth support shaft 78 transversely extends between
and is mounted to the end plates 46 and 48 and is generally
aligned in parallel with the axes of the upper and lower
rollers 50 and 55 and lies proximate to the lower roller
50. One end of a shelf or plate 79 isi pivotally secured to
~ the support rod 7~ proximate the drive roller 50, as shown
; in Fig. 5, such that the upper surface of the plate 79 is
generally at the same vertical height as the axis 50a of
the dri~e roller 50. The opposite, distal end of the shelf
or plate 79 is supported by another transversely extending
support rod 80, the ends of which are carried by to a pair
of adjustable bracket members 81 and 82 which are connected
respectively to the end plates 46 and 48 for ad~usting the
3n vertical position of the distal end of the plate member 79.
The upper surface of the plate 79 forms a reaction or
bending surface for intercepting wire mesh passing between
the rollers 50 and 55.
The anchor positions of the springs 63 and 67 on the
cams 70 and 71 are off-center or eccentric in nature such
that the operating lever 74 has a "rest" position either in
its upright position or in its lowermost position. 3etween
- 14 - 1 3 1 7~67
the two "rest" positions there is a spring tension from the
springs 63 and 67 transmitted through -the lever 74 which
must be overcome by the operator. Therefore, before the
upper roller 55 can be placed in operative (nip forming)
S position adjacent the lower roller 50, the operator must
make a conscious decision, and must actually place roller
in operative position by moving lever 74 to its
uppermost "rest" position. Placing lever 74 Oll the side of
the apparatus provides another degree of safety in that the
operator is forced to move away from the front or wire mesh
"feed" side of the machine when he operates lever 74. The
spring/lever arrangement of the arms 60, 64 and springs 63,
67 is designed in the preferred embodiment to place
approximately 1000-1400 pounds of pressure on the upper
roller 55 for straightening wire at the nip line. This
force has been found to be more than adequate to remove
bends and kinks from wire mesh typically used for concrete
reinforcement purposes, at a typical processing speed of
two lineal feet per second.
The handle portion 84 of a wire engaging and feed arm
apparatus projects through the opening 40a formed in the
emergency stop panel 40. The lower portion of the handle
~4a is bent toward the wire mesh input feed port 32 and
forms a self-releasing hook for engaging the wire mesh to
be straightened by the apparatus 10. The handle 84 is
connected to an elongate inner tubular portion 85a which
cooperatively slides within an outer sleeve member 85b,
mounted within the chassis 12 above the upper roller 55. A
spring 86 housed within the tubular members 85a and 85b
connects the handle 84 and inner tube 85a to the rear of
the chassis 12 so as to provide bias to the handle 84 in a
direction which tends to retract the handle back toward the
opening 40a when pulled outwardly therefrom.
The preferred embodiment of the invention also
includes a power lift feature for automatically raising a
roll of wire mesh to be straightened from the ground such
that the top of the wire roll from which the mesh is being
- 15 - l 3 1 7 8 6 7
unwound generally aligns with the input feed port 32 of the
wire straightening apparatus ~as illustrated in Figs. 2 and
3). It will be understood by those skilled in the art that
since the wire feed to the inlet port 32 comes from the
"top" of the roll (Figs. 1-3), the wire roll does not have
to be lifted very far from the ground and could also easily
be performed manually by an operator who could load the
wire roll onto the unwinding dowel or spool by lifting the
loaded spool into position, one end at a time. The mesh
lifting apparatus includes a first pair of lifting arms 87
and 88 pivotally mounted to a pair of support brackets 90
and 91 which are respectively welded to the end plates 46
and 48. The free end of each of the wiring lifting arms 87
and 88 defines an upwardly facing "U-shaped" bracket sized
to accommodate a spool member 162 that can be inserted
through the center of a wire mesh roll 160, for lifting the
roll. The back surfaces 87a and 88a of the li~ting arms
define cam su~faces, hereinafter described in more detail.
The lifting arms 87 and 88 may be manually pivoted upwardly
such that the support arms 87 and 88 engage the upper
portion of the chassis 12 wherein they are out of the way
for storage purposes or when the mesh straightening
apparatus is being towed or otherwise moved.
The lifting arms 87 and 88 are operatively movable,
under hydraulic power, between a wire feed position
(illustrated in bold lines in Fig. 5) and a loading
position (illustrated by phantom lines in Fig. 5), by means
of a pair of cam members 92 and 93, which engage and move
the lifting arms 87 and 88 respectively by forces exerted
on the cam surfaces 87a and 88a respect~vely. The movable
cam members 92 and 93 are secured to a rotatable shaft 94
which is operatively mounted to the frame 14 below the
lower panel 30, as illustrated in Fig. 5. The shaft 94 is
rotated about its axis by means of a lever arm 95 which is
driven by a hydraulic piston 116. The piston 116 is
secured to the frame 14 such that when the piston is
operated so as to move its piston arm 116a, the lever arm
- 16 - l 3 1 7 ~ 67
95 moves so as to rotate the shaft 94 and its associated
cams 92 and 93 so as to appropriately raise or lower the
wire lifting arms 87 and 88.
As described above the emergency stop panel 40
S pivotally hangs from its support bar 41. An enlarged view
of the let side of the emergency stop panel 40 is shown in
Fig. 4. Referring thereto, the lateral:Ly projecting lever
arm 40b has an opening therein through which an operating
lever llOa of an emergency stop switch llO projects. The
emergency stop switch is secured to the chassis 12 at a
position generally above the guide roller 34. The
emergency stop switch comprises a hydraulic safety control
valve, hereinafter described in more detail, that is
operable in a "run" condition when its operator lever llOa
is pulled out as illustrated in Fig. 5, to operatively
circulate hydraulic fluid within the closed hydraulic
system to the motor 118 that rotates drive roller 50, and
in a "stop" or "safe" condition, when its operator lever
llOa is pushed in, to divert hydraulic fluid from the drive
motor 118 for roller 50, causing roller 50 to stop. The
operating lever arm llOa has an enlarged pad member llOb
secured to it which is aligned with the lever arm 40b of
the emergency stop panel such that the lever arm 40b will
engage and apply force to the pad llOb so as to activate
the emergency stop switch llO to its "stop" mode of
operation by pushing in the operating lever arm llOa, when
the emergency stop panel 40 is pushed inwardly in the
direction of the arrow "S" in Fig. 4. The emergency stop
panel 40 is maintained at a position as limited by a
retaining clip 40c (see Fig. 1) by a spring 97 (Fig. 5)
such that the lever arm 40b lies adjacent to but does not
touch the pad llOb of the emergency stop switch llO when
the operating lever llOa is pulled fully out to its "run"
condition. When the emer~ency stop panel 40 is pushed,
causing the operator lever llOa to activate switch 110 in
its "stop" or "safe" mode, switch llO will remain in such
"safe" mode until the safety switch 110 is manually reset
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by pulling the operator lever llOa outward (Fig. 5) by the
operator reset knob llOc.
The primary power source for the wire straightening
device is an internal combustion engine generally
designated at 100 (Fig. 3). In the preferred embodiment,
the engine used is a eight horsepower internal combustion
engine manufactured by Honda Corporation which operates at
an average speed of 3400 rpm. The engine 100 is
mechanically coupled to and drives a hydraulic pump 1~6
which hydraulically controls the entire operation of the
wire straightening apparatus in a fail-safe manner~ If the
hydraulic pressure should fail, or if the emergency stop
safety switch is activated, the drive roller 50
instantaneously stops rotating.
A schematic diagram of the hydraulic circuit of the
wire mesh straightening apparatus of the preferred
embodiment is illustrated in more detail in Fig. 7.
Referring thereto, the internal combustion engine 100
operatively drives the pneumatic pump 106 by means of a
mechanical coupling illustrated by the dashed line 120. In
the preferred embodiment, the pump I05``is a type lP-3020-
CPSJB hydraulic gear pump manufactured by Dowty Industrial
Corporation that is operable to pump hydraulic fluid from
its inlet port to its outlet port proportionately with the
speed of its mechanical drive from the engine lO0. The
pump 106 pumps hydraulic fluid from a hydraulic fluid
reservoir 102 through a strainer 103 and a hydraulic line
121. The reservoir 102 is also illustrated in the
schematic as having a filler port 104 and a return defuser
element 105 that receives return flow from the closed
hydraulic system through a filter 108 and a h~draulic line
122. In the preferred embodiment the filter 108 is of a
type F4E030#3 manufactured by Purolator Inc.
The pump 106 pumps hydraulic fluid from the reservoir
102 in proportion to the drive speed of the motor 100, and
provides hydraulic fluid to the safety control valve 110 by
means of a hydraulic line 123. In the preferred
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embodiment, the safety control valve 110 is a ball check
type MV-04 selector valve manufactured by Metro Hydraulics
which is operable, as described above, in either a "run" or
"safe" position. In its "run" positisn as illustrated in
the schematic diagram of Fig. 7, switch 110 directs
hydraulic oil received from line 123 at its input port to
hydraulic line 124. ~hen activated, as described above, to
its "safe" mode or position, the switch's internal spool
redirects the incoming hydraulic fluid to the hydraulic
line 125 which returns the fluid back to the reservoir 102
through the filter 1~8.
The pump 106 also provides hydraulic ~luid to the
inlet port of a hydraulic pressure relief valve 107. In
the preferred embodiment, the relief valve ls a type RL-
50-1500PSI valve manufactured by Brand Hydraulics and is
operable to sense the pressure at its inlet port. Valve
107 is normally "closed" to enable pump 106 to direct fluid
flow through line 123 to the safety switch 110 and is
operable to "open" in the event that its input pressure
exceeds a predetermined value, to return hydraulic fluid
back to the reservoir 102 by means o~ the hydraulic line
126. In the preferred embodiment, the relief valve 107 is
designed to maintain the hydraulic line pressure at a
maximum of 1500 psi. The typical line pressure within the
system of the preferred embodiment varies between 1000 and
1300 psi.
When normally operative in a "run" mode the safety
switch 110 directs hydraulic fluid by means of the
hydraulic line 124 to the inlet port of a hydraulic control
valve 112. In the preferred embodiment, the control valve
112 is a four-way pressure compensated flow control valve
manufactured by Brand Hydraulics and is of a type SDCF-
755-TM6-4LS. The valve 112 has an operator lever,
generally designated at 112a that is spring-centered and
has a neutral center position and is operable to
selectively direct hydraulic fluid received at its inlet
port from hydraulic line 124 to either the hydraulic line
:~
- 19 - 1 3 1 7 8 6 7
126 or the hydraulic line 127, with the other of the two
serving as the return line for the closed system. The
spring-centered feature returns the valve spool to a
neutral position whenever the operating lever is released.
The hydraulic lines 126 and 127 are connected to the
hydraulic piston 116 which powers the wire roll lifting
feature previously described. The hydraulic cylinder 116
is power driven in both directions to raise or lower the
lifting arms ~7 and 88 through the camming structure
previously described. When the operating lever 112a of
valve 112 is not actuated so as to direct fluid flow to the
lines 126 and 127, fluid applied to the inlet port of valve
11~ is automatically directed by means of the hydraulic
line 128 to the inlet port of a second hydraulic valve 114.
Hydraulic control valve 114 is in the preferred
embodiment identical to valve 112, and is operable to
selectively direct hydraulic fluid applied to its inlet
port to either the hydraulic line 129 or the hydraulic line
130, with the second of the two lines serving as the return
path for the hydraulic fluid, which is directed by valve
114 back to the reservoir 102 by means of the return line
131. The hydraulic lines 129 and 130 are connected to
selectively energize the hydraulic motor 118 in either of
two directions, depending upon the operator selection
provided by means o~ the valve operating lever 114a. The
hydraulic motor 118 is, in the preferred embodiment, a
general purpose low speed high torque hydraulic motor
manufactured by Eaton Corporation under its Char-Lynn~
trademark and is a type 101-1040 motor. An operator would
normally move the valve lever 114a in a direction so as to
cause the drive roller 50 to rotate in a clockwise
direction as viewed in Fig. 5, so as to advance wire mesh
through the wire straightening apparatus. The "reverse"
feature, however, enables rotation of the drive roller S0
3~ to be reversed in case of emergency or should a malfunction
or jamming of the straightening apparatus occur.
Referring to Fig. 1, the reservoir 102 is generally
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illustrated as mounted near the top of the apparatus
adjacent the pump 106 and the motor 100. The filter 108 is
mounted to the side o~ the reservoir 102. As previously
described, the safety switch 110 is mounted near the left
side of the emergency stop panel 40. The pressure relief
valve 107 is not physically illustrated in the figures, but
lies adjacent to the pump 106. Referring to Fig. 3, most
of the operator controls are positioned so as to be
controlled by an operator while he is standing adjacent the
forward end of the apparatus as illustrated in Fig. 3 where
he is safely out of the way of the advancing wire mesh
being drawn into the inlet port 32 and where he can clearly
view the wire feeding process as well as the wire leaving
the apparatus. As previously described, the operator lever
74 for controlling positioning of the upper roller 55 is
located adjacent the left side of the forward end as
addressed by an operator. The engine 100 is mounted to the
chassis near the top thereof so as to be in mechanical
alignment with the pump 106 and close to the reservoir 102.
The control valves 112 and 11~ and their associated
operator levers 112a and ll~a are mounted adjacent the
engine 100 for ease of operation of all three, as well as
the lever 74, by an operator standing at one position which
is remote from the inlet feed port of the apparatus.
The entire apparatus is fairly compact and, as
previously described, can be towed by a motor vehicle and
maneuvered in dolly or wagon-like fashion by an operator at
the construction site by means of the caster wheel
assembly. When not in use, the entire apparatus can be
lifted if so desired by a crane into the bed of a pickup
truck by means of a lifting bracket 150, illustrated best
in Fig. 1.
The entire wire straightening apparatus can be
operated by one person. A roll of wire mesh 160 to be
straightened is positioned between the lifting arms 87 and
88, with the free end of the wire roll positioned near the
"top" of the roll so as to address the inlet feed port 32
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of the apparatus/ as illustrated in Fig. 1. A dowel or bar
162 is then slid through the center opening of the wire
mesh roll 160 and is positioned within the U-shaped end
portions of the li~ting arms 87 and 88, as illustrated in
Fig. 1. The operator then grasps the handle 84 of the wire
engaging and feed mechanism and pulls the handle out
against the bias of spring 86, and lowers the handle and
tubular arm 85a to engage the lower hook ~4a or the handle
84 with the wire mesh to be straightened. As the operator
releases tension on the lever 84, the spring 86 will pull
the mesh toward the inlet feed port 32 and maintain the
pressure on the engaged wire mesh roll to automatically
urge the wire mesh roll toward the inlet feed port and the
drive roller 50 without further operator intervention.
Once the wire mesh feed lever is thus engaged, the operator
can walk around to the front or forward end of the
apparatus without fear of becoming entangled with or
engaged by the wire mesh to be straightened. He can start
the engine 100, and raise the engine to its desired rpm
operating level, which automatically pressurizes the
hydraulic system of the apparatus by means of the pump 106.
By appropriately operating the lever 112a of the control
valve 112, the hydraulic cylinder 116 can be selectively
energized to raise the lifting arms 87 and 88 and the
attached wire mesh roll to an operating level such as
illustrated in Figs. 2 and 3. The apparatus is now ready
for activation of the roller structure.
By raising the lever 74, the opera-tor places the upper
roller 55 into proximity with the lower roller 50, forming
a nip line therebetween. The separation distance between
the surfaces of the upper and lower rollers is established
by preadjustment of the adjustment brackets 62 and 66 as
described above. Once the lever 74 is set in its upper
"rest" position, it is generally left in that position for
an entire straightening project which may involve a
plurality of mesh rolls. The handle 74 would typically
only be "tripped" to its lowered position in the event of
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an emergency that required immediate lifting of the upper
roller 55. By moving the control lever ll~a of the control
valve 11~, the operator energizes the hydraulic ~otor 118,
causing the drive roller 50 to rotate in the direction
indicated in Fig. 5. As urged by the engaged feed lever
84, the end of the wire mesh is forced toward the nip,
engages the rubberi~ed surface of the feed roller 50 and is
pulled between and flattened by the nip formed by the drive
roller 50 and the upper roller 55. The upright guide
rollers 34 and 3~ safeguard against lateral shifting of the
wire mesh being fed to the inlet port 32. As the wire mesh
is drawn into the straightening apparatus, the automatic
feed lever apparatus 84, 85 is pulled by means of the
spring 86 back into its retracted position illustrated in
Fig. 5, and the hook member 84a automatically releases from
the engaged mesh as the engaged portion thereof advances
into the inlet port 32 of the apparatus. The pressure
applied by the upper roller against the wire mesh as it
proceeds through the nip area between the rollers, flattens
any kinks or bends in the lateral plane of the wire as it
passes through the nip area. Once the wire mesh passes
through the nip area, it engages the upper surface of the
shel~ or plate member 79 (as illustrated in ~ig. 2) and is
bent upward in a direction opposite to the curvature of the
wire as it leaves the roll 160, thereby straightening the
wire. The angle of the reaction force applied to the wire
mesh by the plate member 79 can be controlled by adjusting
the vertical support brackets 81 and 82 so as to raise or
lower the distal end of the plate 79 as desired. This
adjustment is typically mcde in advance of operating the
apparatus, based upon predetermined knowledge as to the
proper height of the distal end that is needed to achieve
the desired bend in the wire beiny handled so as to
completely straighten the wire. The straightened wire
simply drops by gravity to the construction bed where it is
to be used as it exits from the straightening apparatus,
and can be advanced along the ground if needed by a second
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operator. The straightening apparatus of thls invention
provides for straightening of an entire roll of wire mesh,
including the very end of the roll which heretoEore has
been typically discarded as waste.
In the unlikely event that a foreign object or perhaps
second person (other than the control operator) were to get
entangled in the wire mesh being fed into the inlet port of
the machine, the endangered person can "immediately" stop
the drive roller 50 by simply pushing the emergency stop
panel at the inlet port 32 inward, to activate the
emergency stop switch 110. Once activated, the emergency
stop switch 110 will not allow the drive roller 50 to
receive power from the motor 118 until the emergency stop
switch 110 as been manually reset. The "hydraulic" nature
of the system provides for "instantaneous" reaction oE the
safety stop feature, that is not easily attained with
nonhydraulic mechanisms that use mechanical spring or
throw-out mechanisms. Alsor a hydraulic type of system is
generally more liable than mechanical counterparts over
extended periods of use. If the operator desires to
reverse operation of the roller 50a for any reason, he can
do so by simply toggling the lever arm 114a in the opposite
direction so as energize the hydraulic motor 118 in
reverse, thus reversing the direction of rotation of the
drive roller 50. Further, any failure, leak or malfunction
in the closed hydraulic system used to power the system
will automatically result in a fail-safe condition that is
safe to the operator.
While a preferred embodiment of the invention has been
described which clearly illustrates the principles and
concepts of this invention, it will be understood by those
skilled in the art that many other variatlons of the
invention and the use of other components and parts or
designs therefor may be employed without departing from the
spirit and scope of this invention. As an example, but not
by way of limitation, a wire cutting apparatus could
readily be installed on the apparatus for automatically
- 24 - 1 31 7 ~ 67
cutting the straightened wire to desired len~ths. The
above-described preferred embodiment has been provided to
illustrate one example of a possible embodiment that
incorporates and practices the principl.es oE the present
invention. Other modifications and alterations thereof are
well within the knowledge of those skilled in the art and
are to be included within ~he broad scope of the appended
claims.
