PORTABLE STRETCH WRAPPING MACHINE

Abstract

A portable stretch wrapping machine comprising a portable column having wheels for rolling on a surface, a cantilevered arm extending forwardly from a top of the portable column, a rotating arm depending from a distal end of the cantilevered arm, with the rotating arm including a stretch wrap holder with a roll of stretch wrap, wherein the rotating arm is spaced from the surface during wrapping of a product and no part of the portable stretch wrapping machine contacts the surface within any area defined by the area of rotation of the rotating arm, and wherein the portable stretch wrapping machine includes a counter balance extending rearwardly from a bottom of the portable column.

Description

CROSS REFERENCE TO RELATED APPLICATION

This claims the benefit of U.S. Provisional Application Ser. No. 62/101 081, filed Jan. 8, 2015, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention concerns stretch wrapping machines, and more particularly relates to a portable stretch wrapping machine.

BACKGROUND OF THE INVENTION

During the past several decades, considerable developments have been made in the field of wrapping a load with a stretched web of film. Most stretch wrapping machines are stationary.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first rear perspective view of a portable stretch wrapping machine of the present invention.

FIG. 2 is a second rear perspective view of the portable stretch wrapping machine of the present invention.

FIG. 3 is a first front perspective view of the portable stretch wrapping machine of the present invention.

FIG. 4 is a second front perspective view of the portable stretch wrapping machine of the present invention.

FIG. 5 is a side view of the portable stretch wrapping machine of the present invention.

FIG. 6 is a rear view of the portable stretch wrapping machine of the present invention.

FIG. 7 is a top view of the portable stretch wrapping machine of the present invention.

FIG. 8 is a bottom view of the portable stretch wrapping machine of the present invention.

FIG. 9 is a side view of the portable stretch wrapping machine of the present invention in a folded position.

FIG. 10 is a front view of a sensor panel of the portable stretch wrapping machine of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as orientated in FIG. 1. However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting.

The reference number 10 (FIGS. 1-8) generally designates a portable stretch wrapping machine of the present invention. The portable stretch wrapping machine 10 includes a movable base 12 having a wrapping column 14 mounted thereon. The wrapping column 14 includes a post assembly 18, a cantilevered arm 20 extending from a top of the post assembly 18 and an inverted L-shaped wrapping arm 22 depending downwardly from the cantilevered arm 20. A carriage 24 rides on the inverted L-shaped wrapping arm 22. Stretch wrap 26 is pulled from the carriage 24 to wrap a product 28 (see FIGS. 5-7) while the inverted L-shaped wrapping arm 22 rotates about the product 28. The portable stretch wrapping machine 10 is configured to be movable such that the portable stretch wrapping machine 10 can be moved to the product 28 and wrap the product 28 from a top 16 thereof to the floor 30 to thereby allow a pallet 32 under the product 28 to be wrapped.

In the illustrated example, the movable base 12 allows the portable stretch wrapping machine 10 to be moved to the product 28 to wrap the product 28 with the stretch wrap 26. The movable base 12 includes a support plate 34 supporting the wrapping column 14, an underframe 36 supporting the support plate 34 and a drive assembly 38 for moving the portable stretch wrapping machine 10. The support plate 34 is a substantially rectangular panel 40 that is made of material strong enough to support the wrapping column 14. The support plate 34 can also act as a counterweight to the wrapping column 14 to prevent the portable stretch wrapping machine 10 from becoming unbalanced. For example, the panel 40 can be formed to 0.5 inch thick steel. However, it is contemplated that further counterweights could be positioned on or connected to the panel 40. In the illustrated example, the panel 40 includes a pair of rear angled sections 42 to reduce weight and to allow the portable stretch wrapping machine 10 to turn easily.

The illustrated movable base 12 includes the underframe 36 to provide support to the panel 40 of the support plate 34 and to allow the movable base 12 to move. The underframe 36 includes a front beam 46 connected to a bottom surface 48 of the panel 40 of the support plate 34 substantially under the wrapping column 14. The illustrated front beam 46 has a rectangular cross-sectional shape and extends beyond opposite side edges 50 of the support plate 34. A side leg 52 extends from each end 54 on the front beam 46. Each side leg 52 includes an angled beam 56 extending outwardly from the end 54 of the front beam 46 and away from the support plate 34. Each side leg 52 also includes an extension beam 58 extending from an end of the angled beam 56 opposite to the front beam 46. In the illustrated example, the extension beam 58 is substantially perpendicular to the front beam 46. As illustrated in FIGS. 6 and 7, a distance between the extension beams 58 is larger than a width of the product 28 and the pallet 32. Each extension beam 58 includes a roller wheel 60 connected to an end thereof opposite to the angled beam 56. In the illustrated example, each of the roller wheels 60 is fixed onto the end of the extension beam 58 and has an axis of rotation that is parallel to the front beam 46. However, it is contemplated that the roller wheels 60 could be able to be rotated about the end of the extension beams 58 about a vertical axis. The underframe 36 further includes a pair of parallel side beams 62 under side edges of the panel 40 of the support plate 34 and a pair of corner beams 64 under the rear angled sections 42 of the panel 40 of the support plate 34. A guard plate 66 is connected to and extends between the corner beams 64. The guard plate 66 guards a portion of the drive assembly 38 located under the support plate 34.

In the illustrated example, the drive assembly 38 moves and steers the movable base 12. The drive assembly 38 includes a driven wheel assembly 70 connected to a steering handle assembly 72. As illustrated in FIGS. 1-8, the drive assembly 38 includes a housing panel 74 connected to the support plate 34. The housing panel 74 has an inverted U-shape with a pair of side panels 76 with bottom flanges 78 connected to the panel 40 of the support plate 34 in a rear area thereof and a top panel 80 extending between the side panels 76. The housing panel 74 is located over an opening 82 in the rear of the panel 40 of the support plate 34. The opening 82 opens at the rear of the panel 40 of the support plate 34 and the guard plate 66 covers the rear of the opening 82 as illustrated in FIGS. 1 and 2. A battery housing 84 is located to the front of the housing panel 74. The battery housing 84 housing a battery for powering the drive assembly 38 to move the movable base 12 and for powering the wrapping column 14 to wrap the product 28.

The illustrated driven wheel assembly 70 is connected to the steering handle assembly 72 through the housing panel 74. As illustrated in FIGS. 1, 2, 5, 6, and 8, the driven wheel assembly 70 includes a wheel 85 that engages the floor 30 to move the movable base 12 along with an axle assembly 86 that engages the wheel 85. The axle assembly 86 includes an upper support portion 88 located above the wheel 85, a first fixed axle portion 90 on a first side of the wheel 85 and connected to the upper support portion 88, and a second fixed axle portion 92 on a second side of the wheel 85. The first fixed axle portion 90 and the second fixed axle portion 92 engage sides of the wheel 85 and maintain the wheel 85 in position relative to the upper support portion 88. An axle (not shown) driven by a motor powered by the battery rotates the wheel 85. The motor rotating the axle is located in the first fixed axle portion 90. The upper support portion 88 of the axle assembly 86 is connected to a vertical axle 94 (see FIG. 6) that extends through the housing panel 74. The vertical axle 94 is connected to the steering handle assembly 72 such that rotation of the steering handle assembly 72 about a vertical axis of the vertical axle 94 rotates the driven wheel assembly 70.

In the illustrated example, the steering handle assembly 72 actuates the driven wheel assembly 70 and steers the portable stretch wrapping machine 10. The steering handle assembly 72 includes a handle base panel 96 on top of the top panel 80 of the housing panel 74. The handle base panel 96 has an inverted U-shape with a pair of side panels 98 with bottom flanges 100 connected to the top panel 80 of the housing panel 74 and a top panel 102 extending between the side panels 98. The vertical axle 94 is connected to the driven wheel assembly 70, extends through the top panel 80 of the housing panel 74 and through the top panel 102 of the handle base panel 96. An upper bearing 104 surrounding the vertical axle 94 is connected to a bottom surface of the top panel 102 of the handle base panel 96 and a lower bearing 106 surrounding the vertical axle 94 is connected to a top surface of the top panel 80 of the housing panel 74. The upper bearing 104 and the lower bearing 106 maintain the position of the vertical axle 94 relative to the housing panel 74 and the handle base panel 96. As illustrated in FIG. 6, a wheel bearing 108 can be located between the upper support portion 88 of the axle assembly 86 and the bottom surface of the top panel 80 of the housing panel 74 to allow the driven wheel assembly 70 to easily rotate with the vertical axle 94.

The illustrated steering handle assembly 72 further includes a handle 110 coupled to the vertical axle 94 for rotating the vertical axle 94. The handle 110 includes an axle connection plate 112, a pivot assembly 114, a post 116 and a grip 118. The axle connection plate 112 is connected to a top of the vertical axle 94 extending through the top panel 102 of the handle base panel 96. The axle connection plate 112 is fixed to the vertical axle 94 and rotates therewith. The pivot assembly 114 includes a pair of vertical plates 120 connected to and extending upwardly from the axle connection plate 112. An inverted U-shaped plate 124 at a bottom end of the post 116 is located between the vertical plates 120 and is pivotally connected thereto by a horizontal axle 122 adjacent a first side of the inverted U-shaped plate 124. A spring 126 biases a second side of the inverted U-shaped plate 124 upward to maintain the post 116 in a vertical position (via a pivot pin 128 as illustrated in FIG. 6). The post 116 can be lowered about the horizontal axle 122 against the bias of the spring 126 to allow for easy rotation of the steering handle assembly 72 about the vertical axis of the vertical axle 94 to thereby steer the movable base 12 by rotating the vertical axle. The grip 118 is located at the top of the post 116 and allows for easy movement of the handle 110. The grip 118 includes buttons and/or a lever 131 for moving the wheel 85 in a first direction and/or a second direction for easily moving the movable base 12. The grip 118 can also include a brake lever 132 for stopping rotation of the wheel 85.

In the illustrated example, the movable base 12 is used to bring the wrapping column 14 to the product 28 for wrapping the product 28 (and the pallet 32 if desired). The post assembly 18 of the wrapping column 14 is connected to a top of the panel 40 of the support plate 34 adjacent the front beam 46. The post assembly 18 includes a pair of spaced parallel vertically extending posts 134. The posts 134 can have braces 136 extending between side surfaces thereof and the top of the panel 40 of the support plate 34 to provide for extra stability for the post assembly 18. A folding assembly 138 is connected to the top of the posts 134. As discussed in more detail below, the folding assembly 138 allows for a top of the wrapping column 14 to be folded to a horizontal position (see FIG. 9). The folding assembly 138 includes a pair of pillars 140 at the top of the posts 134. Each pillar 140 is connected to one of the posts 134 by a hinge 142. The folding assembly 138 also includes a lower cross brace 144 extending between a bottom of the pillars 140 and an upper cross brace 146 parallel to the lower cross brace 144 connected to a top of the pillars 140. A centrally located pole 148 extends upwardly from a top surface of the upper cross brace 146 at a location substantially equally spaced from the pillars 140. L-shaped braces 150 can be connected to opposite side surfaces of the pole 148 and a top surface of the upper cross brace 146 for added stability.

The illustrated cantilevered arm 20 extends forwardly from the top of the pole 148 of the folding assembly 138 of the post assembly 18. The cantilevered arm 20 of the illustrated embodiment is beam 152 having a rectangular cross sectional shape. An angled brace 154 can extend between a bottom surface of the beam 152 and a side surface of the pole 148 of the folding assembly 138 of the post assembly 18 for added stability. A first motor assembly 156 is connected to the beam 152 of the cantilevered arm 20 at a distal end thereof opposite the pole 148 of the folding assembly 138 of the post assembly 18. The first motor assembly 156 is powered by the battery on the movable base 12 and rotates the inverted L-shaped wrapping arm 22. The first motor assembly 156 includes a motor base 158 having a first motor 160 connected thereto. The first motor 160 rotates a first pulley wheel 162 connected to the motor base 158. A second pulley wheel 164 is located on top of the beam 152 of the cantilevered arm 20 at a distal end thereof. An endless link 167 surrounds the first pulley wheel 162 and the second pulley wheel 164 such that rotation of the first pulley wheel 162 by the first motor 160 causes the second pulley wheel 164 to rotate. A wrapping axle 166 is connected to the second pulley wheel 164 and rotates with the second pulley wheel 164. The inverted L-shaped wrapping arm 22 is also connected to the wrapping axle 166 and rotates with the wrapping axle 166. As illustrated in FIGS. 5 and 6, the wrapping axle 166 has a first bearing 170 located under the beam 152 of the cantilevered arm 20, a second bearing 172 located within the beam 152 of the cantilevered arm 20 and a third bearing 174 on top of the beam 152 of the cantilevered arm 20. The first bearing 170, the second bearing 172 and the third bearing 174 maintain a position of the wrapping axle 166 on the beam 152 of the cantilevered arm 20. The cantilevered arm 20 can also include an upper wrapping axle support (not shown) connected to an upper end of the wrapping axle 166 within an axle housing 176 to provide further support for the wrapping axle 166.

In the illustrated example, the inverted L-shaped wrapping arm 22 rotates about the product 28 to wrap the product 28 with the stretch wrap 26. The inverted L-shaped wrapping arm 22 includes a horizontal portion 180 and a vertical portion 182. The carriage 24 is connected to the vertical portion 182 and is configured to move vertically along the vertical portion 182 of the inverted L-shaped wrapping arm 22. An inner end of the horizontal portion 180 of the inverted L-shaped wrapping arm 22 is connected to a bottom of the wrapping axle 166 and rotates with the wrapping axle 166. A second motor assembly 184 is located at the inner end of the horizontal portion 180 of the inverted L-shaped wrapping arm 22. The second motor assembly 184 includes a motor 186 powered by the battery on the movable base 12. The second motor assembly 184 includes a spool 188 that is rotated by the motor 186. A cable 190 is configured to be selectively pulled and wrapped onto the spool 188 or unwound from the spool 188 to raise and lower the carriage 24. As illustrated in FIG. 6, the cable 190 is guided over a first guide wheel 192 connected to a pivot pin 194 connected to a pair of plates 196 extending downwardly from the horizontal portion 180 of the inverted L-shaped wrapping arm 22 adjacent the second motor assembly 184. The first guide wheel 192 includes a circular channel 198 for locating the cable 190 in a center of the first guide wheel 192 as the cable 190 rolls on the first guide wheel 192.

The illustrated inverted L-shaped wrapping arm 22 includes a pair of braces 200 connecting the horizontal portion 180 of the inverted L-shaped wrapping arm 22 to the vertical portion 182 of the inverted L-shaped wrapping arm 22. A second guide wheel 202 is connected to a pivot pin 204 extending between the braces 200. The second guide wheel 202 allows the cable 190 to change from a horizontal position along a bottom of the horizontal portion 180 of the inverted L-shaped wrapping arm 22 to a vertical positon along a side of the vertical portion 182 of the inverted L-shaped wrapping arm 22. A bottom end of the cable 190 is connected to the carriage 24, which runs vertically along a track of the vertical portion 182 of the inverted L-shaped wrapping arm 22.

The illustrated carriage 24 includes a roll of the stretch wrap 26 used to wrap the product 28. The carriage 24 preferably prestretches the stretch wrap 26 in order to lengthen the stretch wrap 26 in a manner known to those skilled in the art. During use, a free end of the stretch wrap 26 extending from the carriage 24 is positioned on the product 28. The inverted L-shaped wrapping arm 22 then rotates about the product 28 with the carriage 24 moving up and down along the vertical portion 182 of the inverted L-shaped wrapping arm 22 by being pulled upward by the cable 190 (via the second motor assembly 184) and by being allowed to lower through the force of gravity to a selected position by the cable 190 (via the second motor assembly 184). The carriage 24 is allowed to move to a position slightly above the floor 30 to be able to position the stretch wrap 26 about the bottom of the product 28 and a portion of the pallet 32, if desired. Because of the weight of the movable base 12, the carriage 24 and the inverted L-shaped wrapping arm 22 never need to touch the floor 30 to be able to wrap the bottom of the product 28 and a portion of the pallet 32.

In the illustrated example, the portable stretch wrapping machine 10 is configured to have positioning sensors to allow an operator of the portable stretch wrapping machine 10 to positon the portable stretch wrapping machine 10 adjacent the product 28 and the pallet 32 to allow for the carriage 24 to rotate about the product 28 and the pallet 32 at a position slightly above the floor 30. Therefore, the pallet 32 and the product 28 must be centrally located about the wrapping axle 166. The sensors include a pair of first sensors 250 connected to outer sides of the vertically extending posts 134 of the post assembly 18. As illustrated in FIG. 7, the first sensors 250 sense a distance of the product 28 from the first sensors 250 along line 252. It is contemplated that the first sensors 250 could be any sensor that can sense the distance of the product 28 from the first sensors 250 (e.g., ultrasonic sensors). It is contemplated that the grip 118 of the handle 110 could include a panel 244 (see FIG. 10) that includes a first pair of lights 256 and a second pair of lights 258. The first pair of lights 256 can include a green light 260 that is illuminated when the left first sensor 250 senses that the product 28 is in the proper position for wrapping and a red light 262 that is illuminated when the left first sensor 250 senses that the product 28 is not in the proper position. The second pair of lights 258 can include a green light 264 that is illuminated when the right first sensor 250 senses that the product 28 is in the proper position for wrapping and a red light 266 that is illuminated when the right first sensor 250 senses that the product 28 is not in the proper position.

The illustrated positioning sensors can also include a pair of second sensors 270 that ensure that the product 28 and the pallet 32 are located between the side legs 52. The pair of second sensors 270 are located on top of the angled beams 56 of the under frame 36 of the movable base 12. As illustrated in FIG. 7, the second sensors 270 sense sides of the product 28 along line 272. It is contemplated that the second sensors 270 could be any sensor that can sense the product 28 (e.g., ultrasonic sensors). The panel 254 (see FIG. 10) can include a third pair of lights 276 and a fourth pair of lights 278. The third pair of lights 276 can include a green light 280 that is illuminated when the left second sensor 270 does not sense the product 28 (i.e., that the carriage 24 can pass by the left side of the product 28) and a red light 282 that is illuminated when the left second sensor 270 senses the product 28 (such that the carriage 24 would run into the product 28 if there was an attempt to wrap the product 28). The fourth pair of lights 278 can include a green light 290 that is illuminated when the right second sensor 270 does not sense the product 28 (i.e., that the carriage 24 can pass by the right side of the product) and a red light 292 that is illuminated when the right second sensor 270 senses the product 28 (such that the carriage 24 would run into the product 28 if there was an attempt to wrap the product 28).

Once all of the green lights are illuminates, a button or switch can be activated to start the wrapping process by revolving the inverted L-shaped wrapping arm 22 about the product 24 and moving the carriage 24 up and down.

FIG. 9 illustrates the portable stretch wrapping machine 10 in a folded position to allow the portable stretch wrapping machine 10 to be moved through locations with small clearances (e.g., into trailers of semi-trucks). In the folded position, the folding assembly 138, and thereby the cantilevered arm 20, the inverted L-shaped wrapping arm 22 and the carriage 24, are folded about the hinges 142. The post assembly 18 can have a lock member 1000 extending between each post 134 and pillar 140 to keep the portable stretch wrapping machine 10 in the unfolded position until the lock member 1000 is disengaged, thereby allowing the portable stretch wrapping machine 10 to move to the unfolded position. It is contemplated that the wiring extending through the post assembly 18, the cantilevered arm 20 and the inverted L-shaped wrapping arm 22 to power the first motor assembly 156 and the second motor assembly 184 could be located within tubing 300 to protect the wiring as the portable stretch wrapping machine 10 is moved between the folded position and the upright position.

The above description is considered that of the one embodiment only. Modification of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiment shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the invention.

Claims

1. A portable stretch wrapping machine comprising:

a portable column having wheels for rolling on a surface;

a cantilevered arm extending forwardly from a top of the portable column; and

a rotating arm depending from a distal end of the cantilevered arm, with the rotating arm including a stretch wrap holder with a roll of stretch wrap;

wherein the rotating arm is spaced from the surface during wrapping of a product and no part of the portable stretch wrapping machine contacts the surface within any area defined by an area of rotation of the rotating arm, and wherein the portable stretch wrapping machine includes a counter balance extending rearwardly from a bottom of the portable column.

2. The portable stretch wrapping machine of claim 1, wherein:

a motor powers rotation of at least one of the wheels.

3. The portable stretch wrapping machine of claim 1, wherein:

the portable column includes a base having the wheels connected thereto and an upright extending upwardly from the base, with the cantilevered arm extending from the upright.

4. The portable stretch wrapping machine of claim 3, wherein:

the base comprises a platform and a pair of side legs extending forwardly from the platform, with the upright extending upwardly from the platform;

each of the pair of side legs includes a forward end, with a line between the forward end of the pair of side legs extending through the area of rotation of the rotating arm.

5. The portable stretch wrapping machine of claim 4, wherein:

each of the pair of side legs includes at least one of the wheels.

6. The portable stretch wrapping machine of claim 5, wherein:

the platform also includes at least one of the wheels.

7. The portable stretch wrapping machine of claim 6, wherein:

a motor powers rotation of the at least one of the wheels of the platform.

8. The portable stretch wrapping machine of claim 6, wherein:

the portable column further includes a steering handle assembly rotatably connected to the platform, the steering handle assembly be fixedly connected to the at least one of the wheels of the platform for pivoting the at least one of the wheels of the platform during rotation of the steering handle assembly relative to the platform.

9. The portable stretch wrapping machine of claim 4, wherein:

the upright includes a pair of first sensors for sensing a distance of the product to the upright.

10. The portable stretch wrapping machine of claim 9, wherein:

the pair of side legs each include a second sensor for sensing a location of the product.

11. The portable stretch wrapping machine of claim 1, wherein:

the cantilevered arm includes a rotating motor for rotating the rotating arm.

12. The portable stretch wrapping machine of claim 11, wherein:

the rotating arm includes a horizontal portion rotatably connected to the cantilevered arm and a vertical portion holding the stretch wrap holder; and

the rotating arm includes a holder motor for raising and lowering the stretch wrap holder on the vertical portion of the rotating arm.

13. A portable stretch wrapping machine comprising:

a portable column including a base having wheels for rolling on a surface and an upright extending upwardly from the base;

a cantilevered arm extending forwardly from a top of the portable column; and

a rotating arm depending from a distal end of the cantilevered arm, with the rotating arm including a stretch wrap holder with a roll of stretch wrap, the rotating arm including a horizontal portion rotatably connected to the cantilevered arm and a vertical portion holding the stretch wrap holder;

the cantilevered arm including a rotating motor for rotating the rotating arm; and

the rotating arm including a holder motor for raising and lowering the stretch wrap holder on the vertical portion of the rotating arm;

wherein the rotating arm is spaced from the surface during wrapping of a product and no part of the portable stretch wrapping machine contacts the surface within any area defined by an area of rotation of the rotating arm, and wherein the portable stretch wrapping machine includes a counter balance extending rearwardly from a bottom of the portable column.

14. The portable stretch wrapping machine of claim 13, wherein:

the base comprises a platform and a pair of side legs extending forwardly from the platform, with the upright extending upwardly from the platform;

each of the pair of side legs includes a forward end, with a line between the forward end of the pair of side legs extending through the area of rotation of the rotating arm.

15. The portable stretch wrapping machine of claim 14, wherein:

each of the pair of side legs includes at least one of the wheels.

16. The portable stretch wrapping machine of claim 15, wherein:

the platform also includes at least one of the wheels.

17. The portable stretch wrapping machine of claim 16, wherein:

a wheel motor powers rotation of the at least one of the wheels of the platform.

18. The portable stretch wrapping machine of claim 16, wherein:

the portable column further includes a steering handle assembly rotatably connected to the platform, the steering handle assembly be fixedly connected to the at least one of the wheels of the platform for pivoting the at least one of the wheels of the platform during rotation of the steering handle assembly relative to the platform.

19. The portable stretch wrapping machine of claim 14, wherein:

the upright includes a pair of first sensors for sensing a distance of the product to the upright.

20. The portable stretch wrapping machine of claim 19, wherein:

the pair of side legs each include a second sensor for sensing a location of the product.