Strapping machine

A strapping machine and method for applying flexible, heat sealable straps around objects in which the supply coil of strap and the feed rollers for a strap accumulating compartment are driven by a common rotatable drive for synchronous feeding. A strap feeding unit for feeding flexible strap in which a feed and pinch roller extend through opposed slots which intersect a strap carrying groove which totally confines the strap. A strap tensioning mechanism in which rough tensioning and final tensioning are achieved by the movement of a single mechanical plate. A cutting and sealing head in which feeding of a new strap around the object can occur simultaneously with the sealing of the previous strap. A track opening mechanism which is operated by components of the sealing and cutting head.

BACKGROUND OF THE INVENTION 
Field of the Invention 
This invention pertains to apparatus for wrapping objects with flexible, 
fusible strap. 
SUMMARY OF THE INVENTION 
The principal object of the invention is to provide a high speed strapping 
machine capable of strapping 80 straps a minute as compared to typical 
known strapping rates of 35 straps a minute. This is accomplished through 
simple mechanical movements, each combining several functions. 
It is another object of this invention to provide an improved flexible 
strap supply and accumulating device. Basically, this object is obtained 
by driving the reel or coil of strap for discharging strap synchronously 
with feed rolls for feeding the discharged strap into an accumulating 
compartment. In the preferred embodiment this common drive is a single 
common rotating rod. 
Another object of this invention is to provide an improved strap feeding 
unit for feeding flexible strap in a strapping machine. Basically, this 
object is obtained by confining the strap in an elongated transverse slot 
and bringing the powered and pinch rollers together through opposed 
grooves at right angles to the slot for driving the strap through the 
slot. 
It is another object of this invention to provide an improved strap 
tensioning mechanism. Basically, this object is obtained by providing 
first means for pulling the strap around the object with a first tension, 
providing a second means for drawing the strap tightly around the object 
at a second, greater tension, and actuating both of these means by a 
simple mechanical movement of a common plate. In the preferred embodiment 
the strap is anchored from the supply end until the first predetermined 
tension is reached, and then the anchor is overcome by the tension in the 
strap to provide removal of additional strap from the accumulator. 
Still another object of the invention is to provide a cutting and sealing 
head for a strapping apparatus in which a first strap can be sealed while 
a second strap is simultaneously being positioned around the object. 
Basically, this object is obtained by providing strap carrying slots in a 
platen and grippers which are acting on the first strap so that the strap 
can pass in a parallel path into the track. 
Still another object of this invention is to provide an improved track 
opening device for a strapping apparatus. Preferably this object is 
obtained by coupling the track opening mechanisms directly to movements of 
the members in the cutting and sealing heads so that a simple, single 
operation accomplishes opening of the track.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As best shown in FIG. 1 the strapping machine includes a strap track 10, a 
cutting and sealing head 12, a strap feed mechanism 14, a strap supply 16, 
a strap accumulator 18, a strap tensioning unit 20 and a cam control drive 
22. Basically, strap is fed through the strap feed mechanism 14 from the 
accumulator 18 through the tensioning unit 20. The strap feeds through the 
cutting and sealing head 12 around the track 10 and the free end of the 
strap hits an obstruction in the cutting and sealing head to stop its 
travel. Strap then builds up in the strap feed mechanism signaling to the 
cam control drive 22 to begin a cycle of sealing, cutting and tensioning. 
During this cycle the free end of the strap is held while the strap is 
first roughly tensioned by the tensioning unit 20 to pull the strap out of 
the track snugly around the object being wrapped. Secondly, the strap is 
then tightly tensioned around the object and the continuous end of the 
strap is clamped in the tensioned condition. Next the continuous end which 
underlies the free end, and the free end are pressed against a heating bar 
until the strap is melted and then the strap is pressed tightly together 
with the continuous end severed. After cooling the cutting and sealing 
head opens so that the strap can be removed with the object and a new 
cycle of feeding the strap around the track is begun. The machine and the 
method of strapping objects offer advantages over known prior art machines 
and methods which advantages will be discussed in more detail during the 
description of each of the sub-assemblies of the machine. 
STRAP SUPPLY AND ACCUMULATOR 
The strap supply is best shown in FIGS. 1 and 2 and includes a coil 24 
containing strap S. The coil rests on a pair of shafts 25 and 26. Shaft 26 
is provided with a rubber friction cover beneath the coil and is provided 
with a larger diameter roller 26a at its end. Shaft 26 thus serves as a 
powered feed roll to pull the strap from the coil via guide or turning 
rollers 24a and 24b and push it into the accumulator 18. Shaft 26 is 
driven by a belt and pulley drive 27. A pinch roller 28 is spring-mounted 
to press against the powered roller 26a. 
The accumulator 18 includes a back plate 30 and a closely spaced clear 
plastic front plate 31 which forms a housing for the strap. The strap is 
pushed upwardly into the housing in accordion folds as best shown in FIG. 
1. A paddle 32 is pivotally mounted and protrudes down into the top of the 
housing. The paddle has a low switch operator surface 321 and a full 
switch operator surface 32f. As the accordion folds build up in the 
housing the paddle is raised until surface 32f closes a full switch FS to 
stop the feed. As strap leaves the accumulator the level of the folds 
drops deactivating the full switch and when the level drops sufficiently 
so that surface 321 energizes low switch LS the feed roller 26a is again 
put into motion to increase the supply of strap within the accumulator. An 
empty switch ES wil stop the machine if strap no longer is available due 
to an emtpy coil 24. 
In known plastic strap supplies and accumulators the feed rolls for the 
accumulator pull the strap from the coil by pulling directly on the strap. 
A brake is then used to stop the freely rotating coil. Using this 
technique the payoff speed is limited because the snap in the strap 
accelerates the coil and the coast of the coil reel at the end of feeding 
makes the braking action very critical. In the instant application the 
feed rolls for driving the coil and feeding the strap are advantageously 
very simple and require no separate brake for the coil. The drive on the 
powered shaft 26 operates through a clutch which brings the coil up to 
speed slowly and the coast at the end of feeding is not a concern since it 
merely adds a slight amount of additional strap to the accumulator. Using 
this unique technique the strapping machine is able to be run at higher 
speeds than in known strapping machines. A further advantage is that with 
known strap supplies a separate reel is needed to hold the coil whereas in 
the supply and accumulator of this invention the coil is merely set 
directly on the supporting shafts 25 and 26. Still further the strap 
leaves the coil at a constant linear speed regardless of changes in 
diameter of the roll. 
STRAP FEED MECHANISM 
The strap feed mechanism 14 is best shown in FIGS. 1 and 8. The feed 
mechanism includes a continuously rotating powered roller 34 which rotates 
in a counterclockwise direction. A spring pinch roller 35 actuated by 
solenoid 192 presses the strap against the powered roller. The rollers 34 
and 35 push the strap along a guide channel 36. As best shown in FIG. 7 
the guide channel is provided with a slot 36a and the peripheral surfaces 
of the rolls 34 and 35 are of reduced thickness which is less than the 
width of the slot 36a. The strap is thus contained at all times and is 
supported against buckling as it is driven by the rollers through the 
channel 36. This is an advantageous feature as buckling of the strap has 
been a problem with known strap-feeding mechanisms. Known strap-feeding 
mechanisms generally interrupt the strap guide or channel by breaking the 
channel upstream and downstream of the feed rollers. This necessitates 
chamfering the inlet to the downstream end of the track as the strap is 
fed from the feed rollers. It is in this area of the chamfer, however, 
where resistance to the movement of the strap causes the tendency to 
buckle. As is readily apparent in the instant invention of this 
application there is no chamfer nor interruption of the channel so that 
the buckling does not occur. 
The strap feed mechanism 14 also includes a compartment 38 having a paddle 
39 that forms a portion of the channel 36 as it passes over the 
compartment. The paddle is pivotally mounted and held by a light spring 40 
in the raised position. The paddle is provided with a cam 41 that engages 
a stop switch S. As strap is fed by the rollers 34 and 35 through the 
channel 36 the free end of the strap passes through the cutting and 
sealing head 12 around the track 10 and comes to rest again in the cutting 
and sealing head. When the free end of the strap is blocked the continuous 
end in the channel 36 begins to back up pushing the paddle 39 downwardly 
and activating the strap switch S. This de-energizes the solenoid 192 and 
allows a spring to move the pinch roller 35 away from the powered roller 
34 to discontinue feeding of the strap and energizes a trigger solenoid 43 
(FIG. 1) which pulls a trigger 44 away from a single revolution clutch 45 
which is the basic drive component for the cam control drive 22 to begin 
the rest of the cycling of the machine. 
TENSIONING UNIT 
The tensioning unit 20 is best shown in FIGS. 1, 3 and 4 and includes a 
plurality of freely rotating stationary take-up rolls 48 alternated with 
freely rotating movable take-up rolls 49. The strap feeds up and down the 
rolls 48 and 49 as shown in FIG. 3 and when the movable rolls 49 are 
shifted to the phantom line position in FIG. 3 it can be seen that a 
considerable amount of strap can be pulled back from the track 10 at the 
downstream end of the strap. The take-up rolls provide a rough or large 
retraction of the strap to pull it out of the track 10 and snugly around 
the object being wrapped. At this time, of course, the free end of the 
strap is clamped at the cutting and sealing head so that only the 
continuous end is retracted by the take-up rolls. The strap between the 
take-up rolls and the accumulator passes over a pair of flanged rollers 50 
in between which is fastened an anvil 51. The anvil has a smooth end 
surface 51a. A pair of spaced anchor arms 52 are pivoted on a plate 53 by 
pivot post 54. Pivotally mounted between the anchor arms is an anchor 
block 56 having a protruding wedge 56a. The anchor block has a surface 56b 
that rides against a pin 57. A spring 58 connects to the anchor arms at a 
point 58a and pulls the arms toward the anvil to pull the wedge 56a 
against the strap and press it against the smooth end surface 51a of the 
anvil. The strap is thus trapped and unable to move from the accumulator 
during rough tensioning. As the strap is drawn tight on the package, 
however, the tension increases so that the anchor block begins to rotate 
relative to the anchor arms and overcomes the force of the spring 58a. 
When the tension reaches a preset desired amount the anchor block swings 
over-center relative to the spring away from the strap and anvil. This 
frees the strap for movement from the accumulator as the rollers 49 
continue to move toward the right. The anchor arms are fixed to a lever 59 
that is engaged by a shoulder 60 that forms part of a T-shaped frame 61. 
The T-shaped frame is attached to a movable front plate 62 which carries 
the movable rollers 49 and reciprocates from left to right as shown in 
FIGS. 1 and 3. When the front plate 62 is to the left the lever 59 is 
rocked counterclockwise so that the anchor block is freed from the tape. 
As the front plate moves to the right, however, the spring 58 pulls the 
anchor arms 52 toward the anvil to bring the anchor block into engagement 
with the strap. 
The front plate 62 slides on ways 64 and is pulled to the left by a spring 
65 (FIG. 1). The upper end of the plate is supported by a roller 63 
running in a slot in a fixed bar 63a. The front plate is coupled to a 
tension arm 70 that is coupled to a bell crank 71. The free end of the 
bell crank is provided with a cam follower 72 that follows a cam 73 which 
is fixed to a cam shaft 76 that is coupled to the single revolution clutch 
45. Thus the tension arm begins to swing the front plate 62 to the right 
when the single revolution clutch is energized after the free end of the 
strap has completely encircled the object and has come to rest within the 
cutting and sealing head. 
Spaced just above the front plate 62 is a knurled tension roller 80 that is 
coupled to a slip clutch 82 (FIG. 4) such that the roller 80 is free in 
the counterclockwise direction as shown in FIG. 1 but will engage the 
clutch 82 when rotated clockwise and provide a drag to a predetermined 
desired amount. The strap is pinched against the tension roller 80 by an 
eccentrically mounted pinch roller 84. The pinch roller is connected to a 
tension lever 86 having a cam follower roller 87. The lever is pulled down 
by a spring 88. As the front plate 62 moves to the right during a 
tensioning cycle the cam roller 87 riding on the top of the plate keeps 
the pinch roller 84 away from the flanged tension roller 80 so that the 
strap can be freely drawn back by the rollers 49. The top surface of the 
plate 62 has a downward ramp 92 and an upward ramp 94. When the front 
plate moves to the right a distance sufficient to allow the roller 87 to 
move past the downward ramp 92 the tension lever 86 swings 
counterclockwise to engage the pinch roller 84 against the tension roller 
80. The strap is also pushed to the right (FIG. 3) by a roller which 
rotates on the movable frame 61 until the tension reaches the desired load 
on the slip clutch 82 and allows the strap to rotate the roller 80. 
Continued movement of the front plate 62 to the right draws the roller up 
the up ramp 94 allowing the dog 89 to seat beneath the notch at the end of 
the tension lever to hold the tension lever up and in an inactive position 
away from ramp 92 as the front plate is returned. When the front plate is 
returned to the left a pin 96 engages the dog 89 to release the tension 
levers so that the roller 87 returns to the top surface of the front plate 
62. An adjustment bar 67 is connected to plate 62 by screws and can be 
moved to the left to overlap ramp 92 with a second ramp 92a thus changing 
the starting time of the final tensioning. 
Known strapping machines usually employ two tensioning devices. The first 
draws the strap around the package more or less loosely. The second comes 
into action and draws the strap up to its final tension. In the instant 
application the invention performs both of these operations by a single 
mechanism requiring only a single timing sequence. This advantageously 
results in simplicity of manufacture and operation and greater strapping 
and tensioning speeds. 
CUTTING AND SEALING HEAD 
As best shown in FIGS. 1 and 8-14 the cutting and sealing head 12 is 
provided approximately centrally in the lower run of track 10 and forms a 
part thereof. The track includes a rectangular plastic strip 100 having a 
groove 102 for receiving the strap. The track is abutted against a cover 
104 by springs 105. The track is mounted on a pad 106 which slides on 
posts 107. Stripper pins 108 pass through the track and pass into the 
groove 102 as the track and pads are moved away from the cover. Thus the 
stripper pins eject the strap from the track groove to prevent binding. 
The track pads are connected to track bars 110 which are engaged by 
paddles 182 and 184 to be described to open the track during the desired 
timing sequence of the strapping cycle. 
The sections of track immediately adjacent the cutting and sealing head 12 
are best shown in FIGS. 12-14. FIG. 12 which is taken along the line 
12--12 of FIG. 1 shows the groove 102. FIG. 12 also shows groove 36a below 
the groove 102. This second groove is to allow the continuous strap to 
move in beneath the captured free end of the strap and for beginning the 
threading of a new strap during the sealing cycle. FIG. 13 illustrates 
only the groove 102 since at this location along the track there is only a 
single groove as the free end of the strap is stopped in the cutting and 
sealing head. 
The cutting and sealing head 12 is provided with a cover plate 116 that is 
movable transversely of the direction of strap movement. For clarity 
movements described as being transverse hereinafter will mean transverse 
to the path of the strap. Also in FIG. 10 which is a plan view of the 
cutting and sealing head it should be understood that the cover plate 116 
has been removed for clarity. The cover plate forms an anvil for gripping 
and sealing the strap as will be described. The cover plate 116 is 
reciprocated by a cam follower 118 which rides on a cover plate cam 119. A 
left hand gripper 120 pivotally mounted in a left hand yoke 120a which is 
pivotally mounted for vertical movement between an upper position as shown 
in FIG. 11 where it can clamp the continuous end of the strap to the cover 
plate. The left hand gripper is movable into a lower position as shown in 
phantom lines in which the free end of the strap engages a stop surface 
121 to stop the strap as it makes a loop around the track 10. The left 
hand gripper is provided with a track groove 122 which allows feeding of 
new strap while the gripper 120 is raised holding the previous loop of 
strap. The left hand gripper is free to move downwardly and is held in its 
raised position by a cam follower 124 that rides on a left hand cam 125. A 
spring 123 buffers the force between the gripper and the gripper yoke. 
A right hand gripper 128 is vertically reciprocally mounted and is moved 
down by a cam follower 130 that rides on a right hand gripper cam 131. The 
cam follower 130 pulls the right hand gripper down against the force of a 
set of Belleville springs 134. These springs when allowed to push the 
right hand gripper up press the gripper teeth of the right hand gripper 
against the strap to anchor the free end of the strap against the cover 
plate 116. The right hand gripper is provided with a track groove 136 
which provides a lower path for the strap as the free end of the strap 
passes between the cover plate and the upper surface of the right hand 
gripper on its way to the stop surface 121 on the left hand gripper. 
A platen 138 is pivotally mounted on a platen yoke 138a. The platen yoke 
is pivotally mounted for movement between the left hand and right hand 
grippers and between an upper position as shown in solid lines in FIG. 11 
in which it presses the lower continuous end of the strap against the 
upper free end of the strap and against the stop plate 116 to squeeze the 
straps together after melting. The platen is provided with a lower groove 
140 for allowing the continuous end of the strap to be moved beneath the 
sealed loop of strap for starting a new feeding cycle. A cam follower 142 
follows a platen cam 143 to move the platen upwardly from the phantom line 
lower position to the solid line position shown in FIG. 11. A spring 189 
presses the platen with a small force during heating and Belleville 
springs 190 press the platen with a greater force for bonding the melted 
ends. 
A heater bar 147 is mounted for transverse movement by a cam follower 148 
that follows a heater bar cam 149. The heater bar moves between the two 
runs of strap and melts the strap as the platen presses the straps 
together by spring 189 and then is removed prior to final pressing of the 
straps together by the platen through springs 190. The left hand gripper 
yoke 120a and the platen yoke 138a are pivotally mounted on an innerslide 
160 that is reciprocally mounted for transverse movement. Springs 162 urge 
the left hand gripper and platen to seat against their respective yokes. 
The inner slide is reciprocated by a follower 163 that rides between cam 
surfaces on an inner slide cam 164 and the back of cover plate cam 119. 
Thus while the platen and left hand gripper can move up and down they also 
are moved transversely by the inner slide. Springs 170 move the cover 
plate to the left and the cam follower 118 moves it transversely to the 
right. 
OPERATION 
The operation of the cutting and sealing head 12 is best described with a 
complete overall operation of the machine. In the start condition the 
strap S has been loaded in the machine and fed around the track 10. The 
main drive motor M is running. The position of all elements of the machine 
are shown as in the drawings. At a signal to apply a strap the trigger 
solenoid 43 energizes and pulls the trigger away from the single 
revolution clutch 45. This releases the clutch and engages the drive with 
a cam shaft 180 on which all of the various cams are mounted. The cam 
shaft begins to rotate and releases the right hand gripper 128. The right 
hand gripper is driven upward by the Belleville springs 134 and anchors 
the free end of the strap (in from its terminal edge) against the cover 
plate 116. Continued rotation of the cam shaft causes the inner slide 160 
to move transversely to the right away from the strap. Since the platen 
138 and the left hand gripper 120 are mounted on the inner slide they also 
are pulled away from the strap to clear the strap area for tensioning. The 
retraction of the inner slide also opens the strap guide track 10. This 
occurs by paddles 182 and 184 which are on the platen and left hand 
gripper, respectively, and which engage the track bars 110. Motion of the 
track pads 106 causes the stripper pins 108 to push the strap free of the 
track groove 102. Once the platen and left hand gripper are clear of the 
strap and the track is open the tension cam 73 drives the tension arm 70 
in a counterclockwise direction (as viewed in FIG. 1) and pushes the front 
plate 62 to the right to begin tensioning. 
The first motion of the front plate allows the anchor block 56 to be swung 
down and clamp the strap to the anvil 51. Continued motion of the front 
plate 62 causes the strap to be drawn from the track down on the package. 
The strap is drawn by the alternate sets of moving and fixed rollers 49 
and 48. When the strap is around the package and no more strap can be 
drawn from the track the tension in the strap increases and trips the 
anchor which releases and allows the strap to be drawn from the 
accumulator so that the front plate can complete its stroke. Toward the 
end of the front plate movement the tension lever roller 86 falls down the 
ramp 92 and allows the tension rolls 84 and 80 to close on the strap. The 
strap is then drawn to the final tension by the remainder of the front 
plate movement. 
At the beginning of the tensioning, after the inner slide is retracted, the 
left hand gripper 120 and the platen 138 drop downward in response to the 
platen and left hand gripper cams. Near the end of tensioning, the inner 
slide 160 moves back to its initial position. During this motion the 
platen and left hand gripper, now in the lower position, come back 
underneath the just tensioned strap. This motion also allows the track to 
close. Thus at this moment the continuous run of the strap is confronting 
the trapped free end of the strap. The left hand gripper is then raised to 
the up position by its cam and clamps the continuous end of the strap 
against the cover plate. 
At the end of the tension front plate 62 movement the tension lever 86 
rolls up the ramp 94 and separates the tension rollers 80 and 84. Just as 
the left hand gripper comes up to press the strap against the cover plate 
and thus against the underside of the free end of the strap the heater 
blade 147 moves in between the straps at the seal area. Once the heater 
blade is in place the platen 138 rises to an intermediate position and 
presses against the strap by the spring 189. During this time a cutter 186 
on the surface of the right hand gripper 128 shears the continuous end of 
the strap to separate it from the supply. At the intermediate position the 
platen presses the bottom strap, heater and top strap together so that the 
strap is melted for sealing. The press force is determined by a spring and 
plunger between the platen and the platen lever which is pivoted on the 
axis 168. 
At this time a switch 200 is actuated by cam 201. The activation of this 
switch energizes a feed solenoid 192 that draws the pinch roller 35 
against the powered feed roller 34 by a lever 193. Because the strap is 
pressed between the rolls it is fed and passes through the channel 36, the 
groove 112 in track 10, the groove 136 in right hand gripper 128, the 
groove 140 in platen 138, the groove 122 in the left hand gripper 120, the 
groove 102 in the track 110 as it leaves the cutting and sealing head. 
When the melting of the strap is complete the heater blade is pulled back 
by the heater cam 149. When the heater bar is clear of the strap the 
platen cam 143 drives the platen up hard against the overlapping ends of 
the straps and presses the melted sections together. The Belleville 
springs 190 between the platen and the platen lever overcome the spring 
189 and determine the pressing force. These springs 190 do not affect the 
heating force from spring 189, however, since they do not contact the 
bottom of the platen until the cam forces the platen up into its final 
press. After the melted plastic has hardened the left hand gripper 120, 
the platen 138, and the right hand gripper 128 move down to their initial 
positions in response to their respective cams. After the grippers and 
platen have started down the cover plate 116 is retracted by its cam 119 
against the force of springs 170 to allow the sealed strap to leave the 
sealing head. The cover plate immediately returns to the initial position 
after the strap is free. 
After the tensioning part of the cycle the front tension plate 62 is 
returned by its cam 73 so that at the end of the cam shaft rotation the 
front plate is back to its initial position and has moved the dog 89 out 
from under the tension lever 86 and has retracted the anchor block 56. 
Ready for the next cycle. At the end of the cam shaft rotation the trigger 
44 engages the single revolution clutch 45 which then disconnects the 
drive from the cam shaft. 
Just after the cover plate 116 closes, the end of the new feeding strap 
enters the sealing head and strikes the stop surface 121. Feeding then 
stops when the strap backs up into the compartment 38. This completes the 
cycle of operation. 
Known strapping machines start the strap feeding part of the cycle only 
after the seal has been made and after the strap has been ejected from the 
machine. As described above, in the invention of this application feeding 
of the new strap occurs during the sealing operation thus shortening the 
total cycle time. Known strapping machines also use separate actuators 
such as air cylinders or solenoids to provide the opening force for the 
track. In the invention of this application the motion of the gripper and 
platen in the sealing and cutting unit provide this opening force and is 
much simpler in construction and operation and far more reliable. Known 
strapping machines rely on the lateral stiffness of the strap to keep the 
straps aligned with each other in the seal area. Since the slides and 
guides employed in known stapping machines and always the heater blade are 
moving sideways relative to the strap, there is a tendency in the known 
strapping machines for the straps to be moved out of alignment thus 
producing misaligned seals. In the invention of this application a 
stripper bar 203 is advantageously provided to keep the two straps aligned 
rather than solely relying on lateral stiffness of the strap. In known 
strapping machines the gripper for holding the free end of the strap prior 
to tensioning is generally done either by separate triggering mechanisms 
such as cylinders or solenoid or by the technique of coupling the gripper 
with motion of the seal head then stopping the head for tensioning and 
finally restarting the head to complete the seal after tensioning is 
complete. In the invention of this application the initial gripper is 
applied, tensioning and sealing are all accomplished with one revolution 
of a cam shaft giving simplicity, reliability and a very high speed 
machine. 
While the preferred embodiment of the invention has been illustrated and 
described and the known advantages apparent have been discussed, it should 
be understood that variations and other advantages will be apparent to one 
skilled in the art without departing from the principles herein. 
Accordingly the invention is not to be limited to the specific embodiment 
illustrated in the drawings.