U.S. patent number 3,717,313 [Application Number 05/053,580] was granted by the patent office on 1973-02-20 for coil unreeler.
This patent grant is currently assigned to Interlake, Inc.. Invention is credited to Walter Q. Williams.
United States Patent |
3,717,313 |
Williams |
February 20, 1973 |
COIL UNREELER
Abstract
An unreeler for coils of a strapping material includes a coil
support rotatably driven by a reversible air motor in either an
unreeling or a reeling direction, two halves respectively
controlling the operation of the air motor in two opposite
directions, and a dancer arm having a home position and movable
therefrom in opposite directions as the tension in the unreeled
position of the strapping material varies above or below a
reference range of tension, the dancer arm engaging and actuating
the valves for actuating the motor in an unreeling or a reeling
direction, respectively, as the arm moves from the home position
thereof in response to increased or decreased strap tension; a coil
support brake responsive to the movement of the dancer arm is also
provided, the brake being applied when the dancer arm is in its
home position and being released when the dancer arm moves from its
home position.
Inventors: |
Williams; Walter Q. (Glenwood,
IL) |
Assignee: |
Interlake, Inc. (Chicago,
IL)
|
Family
ID: |
21985226 |
Appl.
No.: |
05/053,580 |
Filed: |
July 9, 1970 |
Current U.S.
Class: |
242/420;
242/421.6 |
Current CPC
Class: |
B65B
13/185 (20130101); B65H 49/34 (20130101); B65H
59/38 (20130101); B65H 2701/37 (20130101) |
Current International
Class: |
B65B
13/18 (20060101); B65H 49/00 (20060101); B65H
59/38 (20060101); B65H 49/34 (20060101); B65H
59/00 (20060101); B65h 025/32 (); B65h
025/04 () |
Field of
Search: |
;242/78.6,75.53,75.3,75,75.4,75.43,75.2,67.4,54R,75.5,75.51 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Mautz; George F.
Assistant Examiner: McCarthy; Edward J.
Claims
What is claimed is:
1. A coil unreeler for dispensing a continuous strip of strapping
material from a coil thereof, said unreeler comprising a coil
support for rotatably supporting an associated coil of strapping
material having an unreeled portion extending therefrom, a drive
motor coupled to said coil support for effecting rotation of the
associated coil in an unreeling direction, a brake coupled to said
coil support for retarding rotation of the associated coil, a
tension sensing device for sensing the tension in the unreeled
portion of the strapping material, and control apparatus responsive
to the sensing by said sensing device of a predetermined tension in
the unreeled portion of strapping material for releasing said brake
and thereafter actuating said drive motor to effect rotation of the
associated coil in an unreeling direction.
2. The coil unreeler set forth in claim 1, wherein said control
apparatus is responsive to the sensing by said sensing device of a
tension less than said predetermined tension in the unreeled
portion of strapping material for deactuating said drive motor and
applying said brake to retard the rotation of the associated
coil.
3. The coil unreeler set forth in claim 1, wherein said drive motor
comprises an air motor, and wherein said control apparatus includes
a valve for controlling the flow of air to said air motor, and a
mechanical linkage coupling said tension sensing device to said
brake.
4. The coil unreeler set forth in claim 1, and further including
means coupling said drive motor to said coil support and rotatable
therewith, said brake being engageable with said coupling means for
retarding rotation thereof.
5. A coil unreeler for dispensing a continuous strip of strapping
material from a coil thereof, said unreeler comprising a coil
support for rotatably supporting an associated coil of strapping
material having an unreeled portion extending therefrom, an air
motor coupled to said coil support and having a first condition for
effecting rotation of the associated coil in an unreeling direction
and a second condition for effecting rotation of the associated
coil in a reeling direction, a brake coupled to said coil support
for retarding rotation of the associated coil, a tension sensing
device for sensing the tension in the unreeled portion of the
strapping material both above and below a predetermined range of
tension therein, and control apparatus including a first valve for
controlling the flow of air to said air motor in the first
condition thereof and a second valve for controlling the flow of
air to said air motor in the second condition thereof and being
responsive to said sensing device for controlling said air motor
and said brake, said control apparatus being responsive to the
sensing by said sensing device of a tension above said
predetermined range of tension in the unreeled portion of strapping
material for releasing said brake and thereafter actuating said air
motor to the first condition thereof to effect rotation of the
associated coil in an unreeling direction, said control apparatus
being responsive to the sensing by said sensing device of a tension
in said predetermined range of tension in the unreeled portion of
strapping material for deactuating said air motor and applying said
brake to retard rotation of the associated coil, said control
apparatus being responsive to the sensing by said sensing device of
a tension below said predetermined range of tension in the unreeled
portion of strapping material for releasing said brake and
actuating said air motor to the second condition thereof for
effecting rotation of the associated coil in a reeling
direction.
6. The coil unreeler set forth in claim 5, and further including
means coupling said air motor to said coil support and rotatable
therewith, said brake being engageable with said coupling means for
retarding rotation thereof.
7. The coil unreeler set forth in claim 5, and further including a
sprocket plate coupled to said air motor and fixedly secured to
said coil support for rotation therewith, said brake including a
pair of brake shoes receiving said sprocket plate therebetween for
clamping engagement with said sprocket plate to retard the rotation
thereof.
8. A coil unreeler for dispensing a continuous strip of strapping
material from a coil thereof, said unreeler comprising a coil
support for rotatably supporting an associated coil of strapping
material having an unreeled portion extending therefrom, an air
motor coupled to said coil support for effecting rotation of the
associated coil in an unreeling direction, a rocker arm mounted for
pivotal movement about a predetermined axis between first and
second ranges of movement, bias means urging said rocker arm toward
said first range of movement and into engagement with the unreeled
portion of strapping material, application of a predetermined
tensional unreeling force to the unreeled portion of strapping
material beyond said rocker arm effecting pivotal movement thereof
from said first range of movement to said second range of movement,
and control apparatus including a valve having an actuator member
for controlling the flow of air to said air motor and being
responsive to the movement of said rocker arm from said first range
of movement to said second range of movement thereby to engage said
actuator member to actuate said air motor to effect rotation of the
associated coil in an unreeling direction.
9. The coil unreeler set forth in claim 8, wherein said control
apparatus is responsive to the movement of said rocker arm from
said second range of movement to said first range of movement for
deactuating said drive motor.
10. The coil unreeler set forth in claim 8, and further including a
fixed arm mounted for engagement with the unreeled portion of
strapping material and cooperating with said rocker arm to support
a reach of strapping material therebetween, the length of said
reach varying with the movement of said rocker arm.
11. The coil unreeler set forth in claim 8, and further including a
fixed arm, pulley assembles respectively mounted on said fixed arm
and said rocker arm for engagement with the unreeled portion of
strapping material and cooperating to support a reach of strapping
material therebetween, the length of said reach varying with the
movement of said rocker arm.
12. A coil unreeler for dispensing a continuous strip of strapping
material from a coil thereof, said unreeler comprising a coil
support for rotatably supporting an associated coil of strapping
material having an unreeled portion extending therefrom, a drive
motor coupled to said coil in an unreeling direction, a rocker arm
mounted for pivotal movement about a predetermined axis between
first and second ranges of movement, bias means urging said rocker
arm toward said first range of movement and into engagement with
the unreeled portion of strapping material, application of a
predetermined tensional unreeling force to the unreeled portion of
strapping material beyond said rocker arm effecting pivotal
movement thereof from said first range of movement to said second
range of movement, a brake plate coupled to said coil support and
rotatable therewith, a pair of brake shoes respectively mounted on
opposite sides of said brake plate and yieldably urged into
engagement therewith for retarding rotation thereof, releasing
mechanism coupled to said brake shoes for moving said brake shoes
out of engagement with said brake plate for accommodating free
rotation thereof, and control means responsive to the movement of
said rocker arm from said first range of movement to said second
range of movement for actuating said releasing mechanism and
actuating said drive motor to effect rotation of the associated
coil in an unreeling direction.
13. The coil unreeler set forth in claim 12, wherein said releasing
mechanism comprises a fixed cam member mounted between said brake
shoes, a pair of movable cam members respectively coupled to said
brake shoes and disposed on opposite sides of said fixed cam member
for camming engagement therewith, and means coupling said movable
cam members to said rocker arm for moving said movable cam members
in response to movement of said rocker arm, said movable cam
members being responsive to movement of said rocker arm from said
first range of movement to said second range of movement for urging
said brake shoe out of engagement with said brake plate.
14. A coil unreeler for dispensing a continuous strip of strapping
material from a coil thereof, said unreeler comprising a coil
support for rotatably supporting an associated coil of strapping
material having an unreeled portion extending therefrom, a drive
motor coupled to said coil support for effecting rotation of the
associated coil in an unreeling direction, a sprocket plate coupled
to said drive motor and fixedly secured to said coil support for
rotation therewith, a brake coupled to said coil support for
retarding rotation of the associated coil, said brake including a
pair of brake shoes receiving said sprocket plates therebetween for
clamping engagement with said sprocket plate to retard the rotation
thereof, a tension sensing device for sensing the tension in the
unreeled portion of the strapping material, and control apparatus
responsive to the sensing by said sensing device of a predetermined
tension in the unreeled portion of strapping material for releasing
said brake and thereafter actuating said drive motor to effect
rotation of the associated coil in an unreeling direction.
15. A coil unreeler for dispensing a continuous strip of strapping
material from a coil thereof, said unreeler comprising a coil
support for rotatably supporting an associated coil of strapping
material having an unreeled portion extending therefrom, an air
motor coupled to said coil support and having a first condition for
effecting rotation of the associated coil in an unreeling direction
and a second condition for effecting rotation of the associated
coil in a reeling direction, a tension sensing device for sensing
the tension in the unreeled portion of the strapping material, and
control apparatus including a first valve for controlling the flow
of air to said air motor in the first condition thereof, a second
valve for controlling the flow of air to said air motor in the
second condition thereof responsive to the sensing by said sensing
device of a first relatively high predetermined tension in the
unreeled portion of strapping material for actuating said air motor
to the first condition thereof to effect rotation of the associated
coil in an unreeling direction, said control apparatus being
responsive to the sensing by said sensing device of a second
relatively low predetermined tension in the unreeled portion of
strapping material for actuating said air motor to the second
condition thereof to effect rotation of the associated coil in a
reeling direction.
Description
This invention relates to coil unreelers and, in particular, to
unreelers for dispensing flexible strapping material such as steel
or plastic strapping and the like.
It is a general object of this invention to provide a coil unreeler
which does not rely upon the tensional unreeling force applied to
the strapping material by an associated strapping machine for
providing the rotational force to rotate the coil.
It is an important object of this invention to provide a coil
unreeler for dispensing a continuous strip of strapping material
from a coil thereof, the unreeler comprising a coil support for
rotatably supporting an associated coil of strapping material
having an unreeled portion extending therefrom, a drive motor
coupled to the coil support for effecting rotation of the
associated coil in an unreeling direction, a tension sensing device
for sensing the tension in the unreeled portion of the strapping
material, and control apparatus responsive to the sensing by the
sensing device of a predetermined tension in the unreeled portion
of strapping material for actuating the drive motor to effect
rotation of the associated coil in an unreeling direction.
It is a further object of this invention to provide a coil unreeler
of the type set forth which includes a brake coupled to the coil
support for retarding rotation of the associated coil, the brake
being released prior to actuation of the drive motor in response to
the sensing by the sensing device of the predetermined tension in
the unreeled portion of strapping material.
Yet another object of this invention is to provide a coil unreeler
of the type set forth wherein the drive motor has a first condition
for effecting rotation of the associated coil in an unreeling
direction and a second condition for effecting rotation of the
associated coil in a reeling direction, the control apparatus being
responsive to the sensing by the sensing device of a first
relatively high predetermined tension in the unreeled portion of
strapping material for actuating the drive motor to the first
condition thereof, the control apparatus being responsive to the
sensing by the sensing device of a second relatively low
predetermined tension in the unreeled portion of strapping material
for actuating the drive motor to the second condition thereof.
In connection with the foregoing object, it is another object of
this invention to provide a coil unreeler of the type set forth,
which further includes a brake coupled to the coil support for
retarding rotation of the associated coil, the tension sensing
device sensing the tension in the unreeled portion of the strapping
material both above and below a predetermined range of tension
therein, the brake being released prior to actuation of the drive
motor to either of the first and second conditions thereof in
response to sensing by the sensing device of tensions in the
unreeled portion of strapping material above or below the
predetermined range of tension, the control apparatus being
responsive to the sensing by the sensing device of a tension in the
predetermined range of tension in the unreeled portion of strapping
material for deactuating the drive motor and actuating the
brake.
It is another object of this invention to provide a coil unreeler
of the type set forth wherein the tension sensing device comprises
a rocker arm mounted for pivotal movement about a predetermined
axis between first and second ranges of movement, and bias means
urging the rocker arm toward the first range of movement and into
engagement with the unreeled portion of strapping material,
application of a predetermined tensional unreeling force to the
unreeled portion of strapping material beyond the rocker arm
effecting pivotal movement thereof from the first range of movement
to the second range of movement, the control apparatus being
responsive to movement of the rocker arm from the first range of
movement to the second range of movement for actuating the drive
motor.
In connection with the foregoing object, it is yet another object
of this invention to provide a coil unreeler of the type set forth
which further includes a brake plate coupled to the coil support
and rotatable therewith, a pair of brake shoes respectively mounted
on opposite sides of the brake plate and yieldably urged into
engagement therewith for retarding rotation thereof, and releasing
mechanism coupled to the brake shoes for moving the brake shoes out
of engagement with the brake plate for accommodating free rotation
thereof, the control means being responsive to the movement of the
rocker arm from the first range of movement to the second range of
movement for actuating the releasing mechanism.
Further features of the invention pertain to the particular
arrangement of the parts of the coil unreeler whereby the
above-outlined and additional operating features thereof are
attained.
The invention, both as to its organization and method of operation,
together with further objects and advantages thereof will best be
understood by reference to the following specification taken in
connection with the accompanying drawings, in which:
FIG. 1 is a front elevational view of a coil unreeler made in
accordance with and embodying the features of the present
invention;
FIG. 2 is a side elevational view of the coil unreeler of FIG. 1 as
viewed from the left-hand side thereof, with the fixed strap
supporting arm broken away to more clearly show the coil supporting
arrangement which is illustrated in partial section;
FIG. 3 is an enlarged fragmentary front elevational view of the
coil supporting assembly of the coil unreeler of FIG. 1;
FIG. 4 is a front elevational view of the coil unreeler of FIG. 1
with the coil supporting assembly removed to more clearly
illustrate the drive, brake and control assemblies, and
illustrating the various positions of the rocker arm;
FIG. 5 is an enlarged fragmentary front elevational view of the
brake assembly of the coil unreeler of this invention, illustrating
the various positions of the brake assembly and rocker arm;
FIG. 6 is a fragmentary sectional view of the brake assembly of
this invention taken along the line 6--6 in FIG. 5;
FIG. 7 is a further enlarged fragmentary front elevational view of
a portion of the brake assembly of FIG. 5;
FIG. 8 is a side elevational view of the portion of the brake
assembly illustrated in FIG. 7 as viewed from the right-hand side
thereof,
FIG. 9 is a top plan view of the portion of the brake assembly
illustrated in FIG. 7;
FIG. 10 is a further enlarged fragmentary view of the portion of
the brake assembly illustrated in FIG. 7, with the front brake arm
and cam member broken away to more clearly illustrate the internal
structure of the cam mechanism;
FIG. 11 is an enlarged fragmentary front elevational view of the
control valve apparatus of the present invention;
FIG. 12 is a side elevational view of the control valve apparatus
of FIG. 11 as viewed from the left-hand side thereof;
FIG. 13 is an enlarged, fragmentary perspective view of the pulley
blocks of the present invention;
FIG. 14 is a sectional view of one of the pulley blocks of this
invention taken along the line 14--14 of FIG. 1; and
FIG. 15 is a diagrammatical representation of the pneumatic circuit
utilized to power the coil unreeler of the present invention.
Referring now to the drawings and, in particular, to FIGS. 1 to 3
thereof, there is illustrated a coil unreeler constructed in
accordance with and embodying the features of the present
invention, and generally designated by the numeral 50. The coil
unreeler 50 is supported on a framework 51 which includes generally
horizontal interconnected frame members 52 provided with foot
plates 53 at spaced-apart points therealong for providing a stable
base for the coil unreeler 50. Extending upwardly from the
horizontal frame members 52 is a front stanchion 54 and a rear
stanchion 55 disposed substantially parallel to each other and
interconnected at the upper ends thereof by a flat substantially
horizontal mounting plate 56. For convenience, the portion of the
coil unreeler 50 disposed toward the right in FIG. 2 will
hereinafter be referred to as the front thereof, while the portion
disposed toward the left-hand side of FIG. 2 will be referred to as
the rear thereof. Coupled to the horizontal frame members 52 at the
right-hand side thereof, as viewed in FIG. 1, and extending
upwardly therefrom is a substantially rectangular anchor plate 57
for a purpose to be described more fully hereinafter. Extending
upwardly from the left-hand side of the framework 51 as viewed in
FIG. 1 is an upright post or fixed arm 58 braced adjacent to the
lower end thereof by a pair of struts 59 anchored to the framework
51.
A coil support assembly, generally designated by the numeral 60, is
mounted on the mounting plate 56, the coil support assembly
including a pair of pillow blocks 61, respectively disposed
adjacent to the front and rear ends of the mounting plate 56 and
secured thereto by bolts 62. The pillow blocks 61 are disposed
substantially coaxially and respectively provide bearings in which
is journaled a shaft 63, the shaft 63 extending a substantial
distance forwardly of the front one of the pillow blocks 61, as is
best illustrated in FIG. 2. A reel, generally designated by the
numeral 65, is mounted on the shaft 63 immediately in front of the
front one of the pillow blocks 61, the reel 65 being provided with
an annular hub 64 which is fitted over the shaft 63 coaxial
therewith and is secured thereto by suitable means such as a roll
pin (not shown) so that the reel 65 rotates with the shaft 63. The
reel 65 includes a plurality of radially extending arms 66
equiangularly spaced therearound, and each provided adjacent to the
outer end thereof with a flange 66a extending laterally from the
opposite sides thereof, the arms 66 being interconnected
intermediate the ends thereof by a ring 67. The arms 66 are
preferably six in number, but other even numbers of arms 66 may be
provided if desired. Alternate ones of the radial arms 66 are
provided intermediate the ends thereof with a longitudinally
extending slot or groove 68 in the front surface thereof, the other
ones of the radial arms 66 each being provided intermediate the
ends thereof with a coil support arm 69 extending forwardly
therefrom substantially parallel to the axis of the reel 65.
A coil clamping assembly, generally designated by the numeral 70,
is provided adjacent to the front end of the shaft 63, the coil
clamping assembly 70 being provided with a hollow cylindrical hub
71, provided along the inner surface thereof with a hollow
cylindrical bushing 72 for being received over the front end of the
shaft 63, the hub 71 being provided at the front end thereof with a
generally rectangular hub block 73 for limiting the axial movement
of the hub 71 rearwardly of the shaft 63. Equiangularly spaced
about the hub 71 is a plurality of expanding pad assemblies,
generally designated by the numeral 75, preferably equal in number
to one half the number of radial arms 66 on the reel 65. The
expanding pad assemblies 75 are all identical and, therefore, only
one of the expanding pad assemblies 75 will be described in detail.
Each of the assemblies 75 includes an attachment flange 74
connected to the hub 71 and extending radially outwardly therefrom.
Pivotally connected to each of the attachment flanges 74 adjacent
to the front and rear ends thereof by pivot pins 77 is a pair of
linkage arms 76. Disposed radially outwardly of the attachment
flange 74 is a resilient, arcuate shoe or pad 78, the shoe 78 being
provided adjacent to one end thereof with a radially inwardly
extending attachment flange 79 pivotally connected by pivot pins 77
to the upper ends of the adjacent pair of linkage arms 76. The
linkage arms 76 are arranged substantially parallel to each other
so as to form a parallelogram linkage between the hub 71 and the
corresponding shoe 78. The shoe 78 is secured at the other end
thereof to one plate 81 of a hinge assembly 82, the other plate 83
of the hinge assembly 82 being secured to an adjacent one of the
coil support arms 69 (see FIG. 3). The rear edge of the shoe 78 is
received in the groove 68 in the adjacent one of the radial arms
66. Thus, the shoe 78 cooperates with the radial arm 66 and the
parallelogram linkage to produce a radial movement of the shoe 78
in response to an axial movement of the hub 71, this radial
movement of the shoe 78 being limited by the ends of the groove 68.
The grooves 68 are so positioned on the radial arms 66 that the
outer surfaces of the shoes 78 will be disposed for engagement with
the inner cylindrical surface of an associated coil 80, as will be
described in greater detail below.
Secured to each of the coil support arms 69 on the opposite side
thereof from the hinge assembly 82, is a mounting block 89 carrying
a toggle clamp mechanism 84 thereon for a purpose to be described
below. Extending axially outwardly of the front end of the shaft 63
is a threaded stud 85 which is received through a complementary
opening centrally disposed in the hub block 73 when the coil
clamping assembly 70 is inserted over the outer end of the shaft
63. A washer 87 and a thrust washer 88 are provided for cooperation
with an internally threaded speed handle 86, for securing the coil
clamping assembly 70 in position on the shaft 63. A reel cap plate,
generally designated by the numeral 90, is provided for attachment
to the coil support assembly 60 after the coil 80 has been
positioned thereon. The cap plate 90 comprises an outer ring 91
braced by an assembly of interconnected chord members 92 and radial
members 93 arranged in the pattern illustrated in FIG. 1.
Preferably, three of the chord members 92 are provided. Each of the
chord members 92 being positioned so that the central portion
thereof is disposed generally tangentially with respect to one of
the shoes 78. In use, the cap plate 90 is oriented so that the
chord members 92 are respectively disposed substantially normal to
the coil support arms 69, each of the chord members 92 being
provided inter-mediate the ends thereof with an attachment flange
94 for being clampingly engaged by the adjacent one of the toggle
clamp mechanisms 84, whereby the cap plate 90 is securely held in
position on the reel 65.
Referring now to FIGS. 2 and 4 of the drawings, there is
illustrated a drive assembly, generally designated by the numeral
100, for the reel 65. The drive assembly 100 includes a generally
rectangular mounting plate 101 secured by means of suitable
fasteners 102 to the front stanchion 54 and extending outwardly
beyond the left-hand edge thereof, as viewed in FIG. 4. Secured to
the mounting plate 101 adjacent to the outer end thereof by means
of fasteners 104 is a reversible air motor 105, the air motor 105
extending through a complementary opening in mounting plate 101
substantially normal thereto and being provided at the front end
thereof with an output drive shaft 106. Secured to the output shaft
106 is a relatively small sprocket wheel 107 which is coupled by
means of a riveted chain 108 to a large sprocket wheel 109 disposed
coaxially with the shaft 63 and secured to the rear end of the hub
65 by means of a plurality of circumferentially spaced bolts 109a.
Thus, it will be seen that the rotation of the sprocket plate 109
effected by the drive motor 105 serves to rotate the reel 65 and
the shaft 63.
The coil unreeler 50 is also provided with a dancer arm, generally
designated by the numeral 110, and comprising upper and lower
straight portions 111 and 112, respectively, disposed at an obtuse
angle to each other. The lower portion 112 of the dancer arm 110 is
fixedly secured to a shaft 113 which is journaled at the opposite
ends thereof in complementary openings in a pair of bearing plates
114, respectively disposed on the upper ends of the anchor plates
57 (see FIG. 5), for accommodating pivotal movement of the dancer
arm 110. The dancer arm 110 is of such a length that the upper end
of the upper portion 111 thereof is disposed generally in
horizontal alignment with the upper end of the fixed arm 58. The
lower end of the lower portion 112 of the dancer arm 110 extends
downwardly below the shaft 113 to a point adjacent to the frame
members 52 and has connected thereto one end of a tension spring
115, the other end of the tension spring 115 being connected to one
of the struts 59 for biasing the dancer arm 110 in a clockwise
direction about the shaft 113, as viewed in FIG. 4. Referring to
FIGS. 11 and 12 of the drawings, an actuator plate 116 is attached
by means of suitable fasteners 117 to the rear surface of the lower
portion 112 of the dancer arm 110, the actuator plate being
provided adjacent to the upper and lower ends thereof,
respectively, with two generally V-shaped actuator members 118 and
119 extending rearwardly therefrom substantially normal thereto,
with the apexes of the V-shaped members 118 and 119 being disposed
toward each other. The function of the actuator members 118 and 119
will be described more fully below.
The fixed arm 58 and the dancer arm 110 are each provided adjacent
to the upper end thereof with a pulley block, generally designated
by the numeral 120. Each of the pulley blocks 120 comprises a
plurality of pulleys 122 arranged coaxially on a shaft 121 which is
secured by a bolt 123 to the upper end of the associated arm 58 or
110. Preferably, each of the pulley blocks 120 comprises three
pulleys, the axis of the shaft 121 for the pulley block 120 on the
dancer arm 110 being disposed substantially normal thereto, while
the axis of the shaft 121 for the pulley block 120 on the fixed arm
58 is inclined upwardly at a slight angle thereto, as illustrated
in FIG. 2. This angled arrangement of the pulley blocks 120 is to
accommodate the camber in the strap web 95 to be dispensed from the
coil 80. Each of the pulley blocks 120 is provided with a retainer
125 mounted at one end thereof by a hinge assembly 126 to the
adjacent end of the associated arm and provided at the other end
thereof with a plurality of retaining lugs 127, respectively
received in the channels of the pulleys 122 for retaining the strap
web 95 therein. The hinge assembly 126 for the retainer 125 on the
fixed arm 58 is attached directly to the upper end thereof, while
the hinge 126 for the retainer 125 on the dancer arm 110 is
attached to the upper end thereof by means of a mounting block
128.
In use, the leading end of the strap web 95 fed from the coil 80 is
threaded through the pulley blocks 120 in the manner illustrated in
FIG. 13 and is then fed to associated equipment, such as a strap
straightener and a strapping machine for securing the strap web 95
about an associated bundle or package in a well-known manner. Such
strapping machines are provided with strap drive apparatus which
serves to pull the strap web 95 from the supply coil 80 thereof. It
will be appreciated from FIG. 4 that under the urging of the
tension spring 115, the dancer arm 110 is normally biased toward
the right-hand positions thereof illustrated in phantom in FIGS. 4,
5 and 11, in which positions a substantial length of strap web 95
is accommodated between the pulley blocks 120. As the leading end
of the strap web 95 is pulled by the associated strapping machine,
the length of strap web 95 extending between the pulley blocks 120
will be taken up by the strapping machine, thereby urging the
dancer arm 110 toward the fixed arm 58, i.e., toward the left as
viewed in FIG. 4, all in a well-known manner.
A valve assembly, generally designated by the numeral 130, is also
provided for controlling the operation of the air motor 105. A
mounting plate 131 extends upwardly from the right-hand side of the
framework 151, as viewed in FIG. 4, two valves 132 and 133 being
secured to the front surface of the mounting plate 131 adjacent to
the upper end thereof by means of bolts 132a and 133a,
respectively. Referring to FIGS. 11 and 12, the valves 132 and 133
are identical in construction, each of the valves 132 and 133 being
provided with a plunger or actuator rod 135 extending
longitudinally therethrough and outwardly beyond the opposite ends
thereof, each plunger 135 being provided at the upper end thereof
with a roller 138 and being provided at the lower end thereof with
a roller 139. The valves 132 and 133 are spaced apart on the
mounting plate 131 and are so positioned with respect to the dancer
arm 110 that the rollers 138 and 139 are engaged by the actuator
members 118 and 119, respectively, on the actuator plate 116 as the
dancer arm 110 moves between the extreme left-hand and right-hand
positions thereof illustrated in FIGS. 4, 5 and 11. More
particularly, the valves 132 and 133 are so oriented with respect
to the dancer arm 110 that, as the dancer arm 110 moves in a
counterclockwise direction as viewed in FIG. 11, with the plungers
135 in their downward positions, illustrated in solid line in FIG.
11, the upper actuator member 118 will move past and clear the
upper roller 138 on each valve, after which the lower actuator
member 119 will engage the lower roller 139 on that valve for
urging the plunger 135 to the upward position thereof illustrated
in phantom in FIG. 11. Similarly, with the plungers 135 in their
upward positions, as the dancer arm moves in a clockwise direction,
as viewed in FIG. 11, the lower actuator member 119 will move past
and clear the lower roller 139 on each valve, after which the upper
actuator member 118 will engage the upper roller 138 on that valve
for moving the plunger 135 to its downward position. Preferably,
the valves 132 and 133 are so connected to a suitable source of
pressurized air that, when the plungers 135 are in their downward
positions, the valves 132 and 133 are closed while, when the
plungers 135 are in their upward positions, the valves 132 and 133
are open to permit the passage of air therethrough from the
associated source to the air motor 105, as will be described in
greater detail below.
Referring now to FIGS. 1, 2 and 4 of the drawings, the coil
unreeler 50 is also provided with a shock absorber, generally
designated by the numeral 140, for cushioning the clockwise
movement of the dancer arm 110. The shock absorber 140 includes a
cylinder 141 having a pivot coupling 142 at one end thereof
pivotally connected by means of a bolt 143 to a mounting plate 144
secured to the front stanchion 54. The shock absorber is also
provided with a piston 145 slidably received within the cylinder
141 and provided at the free end thereof with a pivot coupling 146
pivotally connected by means of a pivot pin 147 to the lower
portion 112 of the dancer arm 110. In use, shock absorber 140 will
serve to cushion the sudden clockwise movement of the dancer arm
110, as viewed in FIG. 4, when the supply coil 80 is exhausted or
in the event that the strap web 95 breaks.
Referring now to FIGS. 4 to 10 of the drawings, the coil unreeler
50 is provided with a brake assembly, generally designated by the
numeral 150, for retarding the rotation of the reel 65 and the coil
80 carried thereon. The brake assembly 150 includes a pair of
substantially parallel brake arms 151 and 152, the front brake arm
151 being substantially straight, while the rear brake arm 152 has
an offset portion 153 at the upper end thereof, whereby the brake
arms 151 and 152 are arranged back-to-back in engagement with each
other at the lower ends thereof, while the offset portion 153 at
the upper end of the brake arm 152 is spaced a predetermined
distance from the adjacent upper end of the brake arm 151. The
brake arms 151 and 152 are pivotally mounted adjacent to the lower
ends thereof on the shaft 113 forwardly of the bearing plates 114.
Respectively attached to the brake arms 151 and 152 at the upper
ends thereof by means of bolts 154 are two brake pads or shoes 155
respectively disposed on the inner surfaces of the brake arms 151
and 152 in facing relationship. The brake arms 151 and 152 are
disposed substantially along a radial line extending between the
axes of the shafts 63 and 113, with the brake shoes 155 being
respectively disposed on opposite sides of the sprocket plate 109 a
very slight distance radially inwardly from the outer edge thereof.
Fixedly secured to the shaft 113 forwardly of the brake arm 151, as
by welding, is a substantially rectangular pivot plate 156 having a
pivot pin 157 adjacent to the outer end thereof for pivotally
connecting the pivot plate 156 to a brake actuator arm 158. The
actuator arm 158 is shaped complementary to the brake arm 153 and
is disposed substantially parallel thereto, the actuator arm 158
having an offset upper portion 159 which is disposed between the
upper ends of the brake arms 151 and 152.
A mounting block 160 is secured by means of bolts 160a to the front
stanchion 54 adjacent to the periphery of the sprocket plate 109,
the mounting block 160 having a cylindrical bore 161 extending
therethrough substantially normal to the front stanchion 54.
Received in the bore 161 is a cylindrical shaft 162 secured to the
block 160 by means of set screws 163, the front end of the shaft
162 being received through complementary openings in the upper ends
of the brake arms 151 and 152. Extending diametrically through the
shaft 162 and fixedly secured thereto between the brake arms 151
and 152 is a generally cylindrical dowel or pin 164, with the
opposite ends thereof extending a slight distance beyond the
periphery of the shaft 162. Respectively secured to the inner
surfaces of the brake arms 151 and 152 are a pair of cam plates
165, each of the cam plates 165 receiving the shaft 162 through a
complementary opening therein, whereby the cam plates 165 are
pivotally movable with respect to the shaft 162. The cam plates 165
are each pivotally connected at one end thereof to the upper end of
the actuator arm 158 by means of a bolt 166 and nut 167. Each of
the cam plates 165 has formed in the inner surface thereof an
elongated channel or groove 168 shaped complementary to the pin 164
and normally receiving the pin 164 therein.
Extending through complementary openings in the brake arms 151 and
152 a slight distance below the shaft 162 is a bolt 170, the rear
end of the bolt 170 having a compression spring 171 disposed
therearound and held in place by a backing washer 172 and a nut
173. The nut 173 is adjusted to compress the spring 171 so as to
urge the brake arms 151 and 152 toward each other, the compression
in the spring 170 being preferably set so that the brake shoes 155
are normally held in engagement with the opposite surfaces of the
sprocket plate 109 for braking or retarding the rotation of both
the sprocket plate 109 and the reel 65 connected thereto. When the
brake assembly 150 is in this normally applied or braking
condition, the pin 164 is disposed in the grooves 168 and in firm
engagement therewith. It will be appreciated that, when the
actuator arm 158 is moved either upwardly or downwardly, it will
effect a corresponding pivotal movement of the cam plates 165,
whereby the grooves 168 will be moved out of alignment with the pin
164. Thus, the camming action between the cam plates 165 and the
pin 164 will move the cam plates 165 and the brake arms 151 and 152
apart from each other in an obvious manner, for releasing the brake
assembly 150 by disengaging the brake shoes 155 from the sprocket
plate 109 to permit free rotation thereof.
The operation of the coil unreeler 50 will now be described in
detail. When it is desired to mount a coil 80 of strapping material
on the coil unreeler 50, the cap plate 90 is first removed from the
coil support assembly 60 by means of releasing the toggle clamps
94. The speed handle 86 is then rotated so that it moves axially
outwardly of the stud 85. This will accommodate a corresponding
axial outward movement of the hub 71 of the coil clamping assembly
70 whereby, through the action of the parallelogram linkage, the
ends of the shoes 78 connected thereto will move radially inwardly
along the slots 68 to the inner ends thereof. This will assure
sufficient clearance between the shoes 78 and the cylindrical inner
surface of the coil 80. The coil 80 is then mounted on the reel 65
with the coil support arms 69 extending through the central opening
in the coil 80, and with the rear surface of the coil 80 flush
against the front edges of the radial arms 66. The speed handle 86
is then rotated so that it moves axially inwardly of the stud 85,
thereby moving the hub 71 axially inwardly and expanding the shoes
78 radially outwardly through the action of the parallelogram
linkage until the shoes 78 are firmly in engagement with the inner
cylindrical surface of the coil 80. In this manner the coil 80 is
securely locked in position on the reel 65 for rotation therewith.
The cap plate 90 is then replaced on the reel 65 flush against the
outer side surface of the coil 80, whereby the cap plate 90
cooperates with the radial arms 66 for preventing any axial
movement of the coil 80 with respect to the coil support assembly
60.
The leading end of the strap web 95 is then fed from the coil 80
upwardly through the pulley blocks 120 in the manner illustrated in
FIG. 13, and is then fed to the associated strap tightening
apparatus and strapping machine in a standard fashion. A sufficient
length of the strap web 95 will be unreeled from the coil 80 to
permit the dancer arm 110 to rest in a home or reference position
midway between the valves 132 and 133, the dancer arm 110 being
balanced in this home position by the cooperating action of the
tension spring 115 and the holding force exerted on the free end of
the strap 95 by the strapping machine. It will be noted that the
valves 132 and 133 are so coupled to the air motor 105 that, when
the valve 132 is opened, the air motor 105 will be driven in a
first direction so as to rotate the shaft 63 in a clockwise or
unreeling direction, as viewed in FIG. 4, and when the valve 133 is
open the air motor 105 will be driven in a second direction so as
to effect rotation of the shaft 63 in a counterclockwise or reeling
direction, as viewed in FIG. 4.
When the associated strapping machine is operated, it will exert a
tensional force on the free end of the strapping web 95 in the
direction of the arrow in FIG. 4, thereby pulling the dancer arm
110 toward the left as viewed in FIG. 4 and simultaneously drawing
strapping material from the length of the strap web 95 extending
between the pulley blocks 120. As noted above, when the dancer arm
110 is in its home position between the valves 132 and 133, the
brake assembly 150 will be in its braking condition, i.e., with the
pin 164 recessed in the grooves 168 in the cam plates 165 and with
the brake shoes 155 in braking engagement with the sprocket plate
109. As the dancer arm 110 moves in a counterclockwise direction
from its home position, the pivot plate 156 is also rotated
counterclockwise, thereby pulling the actuator arm 158 downwardly
and pivoting the cam plates 165 in a counterclockwise direction for
separating the brake shoes 155 and releasing them from engagement
with the sprocket plate 109 for accommodating free rotation of coil
80. As the dancer arm 110 moves further toward the left under the
action of the pulling force exerted by the strapping machine on the
strap web 95, actuator member 119 will engage the lower roller 139
on the valve 132 for moving the plunger 135 to its upward position,
thereby opening the valve 132. The opening of the valve 132 admits
air under pressure to the air motor 105 for driving the motor 105
and the coil 80 in an unreeling direction, as described above, for
dispensing strapping material from the coil 80. The motor 105 will
continue rotating the coil 80 in an unreeling direction and
dispensing the strapping material therefrom at a fixed
predetermined rate which is preferably greater than the rate at
which the strapping material is consumed by the strapping machine.
Accordingly, the length of material accommodated between the pulley
blocks 120 will be permitted to increase, thereby allowing the
dancer arm 110 to move back to the right in a clockwise direction,
as viewed in FIG. 4, under the urging of the tension spring 115.
This clockwise movement of the dancer arm 110 will continue until
it passes back over the valve 132, whereupon the actuator member
118 will engage the roller 138 for moving the plunger 135 to its
downward position and closing the valve 132, thereby deactuating
the air motor 105. As the dancer arm 110 continues its clockwise
movement into its home position, the pivot plate 156 is rotated in
a clockwise direction, thereby rotating the cam plates 165
clockwise under the action of the actuator arm 158 until the
grooves 168 are again in alignment with the pin 164, whereupon the
compression spring 171 will urge the brake shoes 155 back into
engagement with the sprocket 109 for exerting a braking force
thereon. The rotation of the coil 80 will, thus, be gradually
slowed by the brake assembly 150 until it has completely
stopped.
In the operation of the standard strapping machine, after the strap
has been wrapped around the object to be bound, the supply end of
the strap is pulled to a tensioned condition therearound, thereby
creating a certain amount of slack in the strap web 95 extending
between the strapping machine and the coil unreeler 50. This slack
will permit the dancer arm 110 to move further in a clockwise
direction under the urging of the tension spring 115, thereby
creating an excessive length of strap web 95 to be stored between
the pulley blocks 120. For this reason the valve 133 is provided to
control the air motor 105 for restoring the dancer arm 110 to its
equilibrium or home position.
More particularly, as the dancer arm 110 moves from its home
position in a clockwise direction, the pivot plate 156 will also be
rotated in a clockwise direction, thereby moving the actuator arm
158 upwardly and pivoting the cam plates 165 in a clockwise
direction, so that the grooves 168 therein are moved out of
alignment with the pins 164. Thus, the pin 164 and the cam plates
165 coact to separate the brake shoes 155 and move them out of
engagement with the sprocket plate 109, thereby releasing the brake
assembly 150. As the dancer arm 110 continues its clockwise
movement past the valve 133, the actuator member 119 will engage
the roller 139, for moving the plunger 135 to its upward position
and opening the valve 133. Thus, a supply of air under pressure
will be provided to air motor 105 for effecting operation thereof
in a reeling direction for taking up the excess slack in the strap
web 95 onto the coil 80. As this excess slack is taken up on the
coil 80, the dancer arm 110 will be pulled back in a
counterclockwise direction toward its home position. As the dancer
arm 110 passes back over the valve 133, the actuator member 118
will engage the roller 138 for moving the plunger 135 to its
downward position and closing the valve 133, thereby deactuating
the air motor 105. As the dancer arm 110 moves into its home
position, the pivot plate 156 and the cam plates 165 will be moved
in a counterclockwise direction back into their braking
configuration wherein the grooves 168 are again in alignment with
the pin 164. Thus, the brake shoes 155 will again be urged into
engagement with the sprocket plate 109 for braking the rotation of
the coil 80, as described above.
It will be seen that the action of the air motor 105 and the
control valves 133 and 134 therefor will serve to maintain the
dancer arm 110 in its home position, and thereby serve to maintain
a predetermined range of tension in the unreeled portion of strap
web 95 and to maintain a predetermined length of strap web 95
between the pulley blocks 120. Thus, it will be appreciated that
the dancer arm 110 serves as a sensing device for sensing the
tension in the unreeled portion of the strap web 95 stored between
the pulley blocks 120. When the length of this portion of the strap
web 95 drops below a predetermined amount as a result of the
tension increasing above a reference range of tension, the drive
motor 105 is actuated for rotating the coil 80 in an unreeling
direction and dispensing additional strap web therefrom to relieve
the tension in the strap web 95 and increase the length thereof
between the pulley blocks 120. The air motor 105 is deactuated and
the rotation of the coil 80 is braked when the tension in the strap
web 95 is again in the reference range and the dancer arm 110 has
returned to its home position. Similarly, if the length of strap
web 95 between the pulley blocks 120 becomes too great as a result
of the strap tension dropping below the reference range, the dancer
arm 110 cooperates with the valve 133 to actuate the air motor 105
for rotating the coil 80 in a reeling direction and taking up slack
thereonto to increase the tension in the strap web 95 and decrease
the length thereof between the pulley blocks 120. The air motor 105
is deactuated and the rotation of the coil 80 is braked when the
tension in the strap web 95 is again in the predetermined range and
the dancer arm 110 has returned to its home position.
Thus, it will be noted that the tensional unreeling force applied
to the strap web 95 by the associated strapping machine serves only
to move the dancer arm 110, this movement being greatly facilitated
by the mechanical advantage afforded by the pulley blocks 120.
Accordingly, very little tension is built up in the strap web 95 in
moving the dancer arm 110. More importantly, the driving force for
rotating the coil 80 is supplied solely by the air motor 105, no
portion of this drive force being supplied by the pulling action of
the associated strapping machine on the strap web 95. This is
extremely important when certain types of plastic strap, such as
polypropylene strap, are utilized, since these plastic straps
generally lack the tensile strength of steel strapping and would be
likely to deform or break if the normally extremely heavy supply
coil 80 were driven directly by the pulling force exerted on the
strap web 95 by the strapping machine.
It will be noted that in the preferred embodiment, two pulleys 122
have been provided on the fixed arm 58 and three pulleys 122 have
been provided on the dancer arm 110. However, it will be
appreciated that any desired number of pulleys 122 may be provided
depending upon the length of strap web 95 to be accommodated
between the pulley blocks 120. Ideally, the length of strap web 95
accommodated between the pulley blocks 120 will be substantially
equal to the length of strap web 95 consumed during each strapping
operation of the associated strapping machine. Thus, only one
unreeling operation of the coil unreeler 50 would be required for
each strapping operation, thereby minimizing wear on the coil
unreeler 50. While this ideal situation may be difficult or
impossible to achieve where objects of widely differing sizes are
being strapped by the strapping machine, the automatic
tension-sensing action of the coil unreeler 50 will nevertheless
always provide smooth dispensing of the strap web 95 while
preventing the buildup of harmfully excessive tension therein.
From the foregoing, it will be observed that there has been
provided an improved coil unreeler which is particularly suitable
for use in dispensing plastic strapping material or other strapping
material having relatively low tensile strength, as well as in
dispensing steel strapping from unusually heavy coils thereof. More
particularly, there has been provided a coil unreeler wherein the
coil is rotated by a drive motor completely independently of the
force exerted on the strap web by the associated strapping
machine.
There has also been provided a motor-driven coil unreeler wherein
the drive motor is an air motor controlled by air valves, whereby
the control system for the coil unreeler is completely
pneumatic.
In addition, there has been provided a motor-driven coil unreeler
provided with a reversible drive motor for driving the coil in
either an unreeling or a reeling direction for either dispensing
strapping material from the coil or taking up slack strapping
material onto the coil.
Finally, there has been provided an improved brake assembly for a
motor-driven coil unreeler for retarding the rotation of the coil
when the drive motor is deactuated.
While there has been described what is at present considered to be
the preferred embodiment of the invention, it will be understood
that various modifications may be made therein, and it is intended
to cover in the appended claims all such modifications as fall
within the true spirit and scope of the invention.
* * * * *