Strapping tool with movable weld plate

Abstract

Various embodiments of the present disclosure provide a strapping device including a support, a tension wheel rotatable relative to the support about a tension-wheel axis, and a weld plate mounted to the support. The weld plate is positionable in one of a first position and a second position. The first and second positions are offset in a direction substantially parallel to the tension-wheel axis.

Description

STRAPPING TOOL WITH MOVABLE WELD PLATEPriority

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 616,865, filed January 2, 2024, the entire contents of which is incorporated herein by reference.Field

[0002] The present disclosure relates to strapping devices, and more particularly to strapping devices configured to tension strap around a load and to attach overlapping layers of the strap to one another to form a tensioned strap loop around the load.Background

[0003] Strapping devices are configured to tension strap around a load and to attach overlapping layers of the strap to one another to form a tensioned strap loop around the load. Handheld strapping tools, which can be electrically powered, pneumatically powered, or manually powered, are one common type of strapping device. Certain strapping tools, such as those configured for use with plastic or paper strap, use friction welding to attach overlapping upper and lower strap layers to one another.

[0004] To use one of these strapping tools to form a tensioned strap loop around a load, an operator pulls strap leading end first from a strap supply, wraps the strap around the load, and positions a lower layer of the strap including the leading end of the strap below an upper layer of the strap that is connected to the strap supply. The operator introduces the overlapped strap layers into the strapping tool so they extend between a toothed tensioning wheel and a toothed tensioning plate of the strapping tool and between a toothed weld shoe and a toothed weld plate of the strapping tool. The tensioning wheel and plate are typically positioned near the front of the strapping tool, while the weld shoe and plate are positioned rearward of and laterally aligned with the tensioning wheel and plate. The tensioning wheel is spring-biased toforce the strap layers against the tensioning plate, while initially the weld shoe does not contact the strap.

[0005] The operator presses a button to initiate a tensioning process during which the tensioning wheel rotates to move the upper strap layer over the lower strap layer and tension the strap around the load. After completion of the tensioning process, a sealing process is initiated. During the sealing process, the weld shoe forces the strap layers against the weld plate while simultaneously cutting the upper strap layer from the strap supply. A motor reciprocates the weld shoe at a high frequency as the weld shoe exerts a welding force on the strap layers. The reciprocating weld shoe reciprocates the upper strap layer relative to the lower strap layer, which generates friction between portions of the overlapping strap layers that locally melts them. The motor stops reciprocating the weld shoe while the weld shoe continues to exert the welding force. The melted portions of the overlapping strap layers join together and solidify as they cool, thereby attaching the upper and lower strap layers to form the tensioned strap loop.

[0006] Certain strapping tools include inner and outer strap guides positioned on opposite sides of the width of the strap path such that the space between the strap guides is slightly larger than the width of the strap. The strap guides prevent substantial movement of the strap from side to side (perpendicular to the longitudinal axis of the strap) during the strapping process. Certain strapping tools can be configured for use with strap of different widths. These strapping tools include swappable pairs of strap guides — one for each width. For instance, a strapping tool configured for use with 16 or 19 millimeter strap will have two pairs of strap guides: one pair spaced apart slightly more than 16 millimeters when installed and another spaced apart slightly more than 19 millimeters when installed. One issue with certain known strapping tools configured for use with strap of different widths is that the operator must keep track of unused strap guides and remember to swap them in when switching from one strap width to another.

[0007] Optimal friction-weld joint efficiency is achieved when the lateral centerline of the strap — i.e., the centerline in the width direction of the strap — is aligned with the lateral centerline of the weld plate. One issue with certain known strapping tools configured for use with strap of different widths is that the strap guides are configured such that the lateral centerline of the weld plate is not aligned with the lateral centerline of the strap for all strap widths. For instance, the lateral centerline of the strap may be aligned with the lateral centerlineof the weld plate for 16 millimeter strap but not 19 millimeter strap. This can result in inconsistent joint efficiency across all strap widths.Summary

[0008] Various embodiments of the present disclosure provide a strapping device including a support, a tension wheel rotatable relative to the support about a tension-wheel axis, and a weld plate mounted to the support. The weld plate is positionable in one of a first position and a second position. The first and second positions are offset in a direction substantially parallel to the tension-wheel axis.Brief Description of the Figures

[0009] Figure l is a perspective view of one example embodiment of a strapping device of the present disclosure.

[0010] Figure 2 is a block diagram of certain components of the strapping device of Figure 1.

[0011] Figures 3A-3C are diagrammatic views of the strapping device of Figure 1 securing a load to a pallet.

[0012] Figure 3D is a perspective view of a friction-weld strap joint formed by the strapping device of Figure 1 to attach two overlapping strap layers.

[0013] Figures 4A and 4B are perspective views of the working assembly of the strapping device of Figure 1.

[0014] Figures 5A-5C are side elevational views of part of one side of the working assembly of Figures 4A and 4B showing the tensioning assembly moving from a home position to a strap-insertion position and from the strap-insertion position to a tensioning position after strap is inserted into the strapping device. Certain components of the working assembly are not shown for clarity.

[0015] Figure 6A is a rear elevational view of the working assembly of Figures 4A and 4B showing the sealing assembly in a home configuration.

[0016] Figure 6B is similar to Figure 6A but shows the sealing assembly in a sealing configuration and forcing the overlapping upper and lower strap layers against the weld plate.

[0017] Figure 6C is similar to Figures 6 A and 6B but shows the sealing assembly in the sealing configuration and the weld shoe oscillating.

[0018] Figure 7 is a side elevational view of an outer strap guide of the strapping device of Figure 1.

[0019] Figures 8A and 8B are perspective and side elevational views, respectively, of the strapping device of Figure 1 with the tensioning assembly in the home position and the outer strap guide of Figure 7 in a lower position.

[0020] Figure 8C is a cross-sectional side elevational view of part of the strapping device of Figure 1 taken substantially along line 8C-8C of Figure 8A.

[0021] Figures 9A and 9B are assembled and exploded perspective views, respectively, of the weld-plate assembly of the strapping device of Figure 1 with the weld plate and the inner strap guide of the weld-plate assembly in respective first positions.

[0022] Figure 10 is similar to Figure 9A but shows the weld plate and the inner strap guide in respective second positions.

[0023] Figures 11A, 1 IB, 11C, and 1 ID are perspective, side elevational, rear elevational, and front elevational views of the weld-plate support of the weld-plate assembly of Figures 9A and 9B.

[0024] Figure 12A is a cross-sectional rear elevational view of the weld-plate assembly of Figures 9A and 9B taken substantially along line 12A-12A of Figure 9A. The weld plate is in the first position.

[0025] Figure 12B is a cross-sectional rear elevational view of the weld-plate assembly of Figures 9A and 9B taken substantially along line 12B-12B of Figure 10. The weld plate is in the second position.

[0026] Figure 13A is a rear elevational view of part of the strapping device of Figure 1 with the weld plate and the inner strap guide of the weld-plate assembly in their respective first positions.

[0027] Figure 13B is similar to Figure 13A but shows the weld plate and the inner strap guide in their respective second positions.

[0028] Figures 14A and 14B are similar to Figures 13A and 13B but show the upper and lower strap layers in cross-section.Detailed Description

[0029] While the systems, devices, and methods described herein may be embodied in various forms, the drawings show and the specification describes certain exemplary and nonlimiting embodiments. Not all of the components shown in the drawings and described in the specification may be required, and certain implementations may include additional, different, or fewer components. Variations in the arrangement and type of the components; the shapes, sizes, and materials of the components; and the manners of connections of the components may be made without departing from the spirit or scope of the claims. Unless otherwise indicated, any directions referred to in the specification reflect the orientations of the components shown in the corresponding drawings and do not limit the scope of the present disclosure. Further, terms that refer to mounting methods, such as mounted, connected, etc., are not intended to be limited to direct mounting methods but should be interpreted broadly to include indirect and operably mounted, connected, and like mounting methods. This specification is intended to be taken as a whole and interpreted in accordance with the principles of the present disclosure and as understood by one of ordinary skill in the art.

[0030] Figures 1-14B show one example embodiment of a strapping device of the present disclosure in the form of a battery-powered portable strapping device 50 and certain assemblies and components thereof. As shown in Figures 3A-3C, the strapping device 50 is configured to carry out a strapping cycle to tension and seal strap S (plastic strap in this example embodiment) around a load L on a pallet P to form a tensioned strap loop that secures the load L to the pallet P. An operator pulls strap S from a strap supply (not shown) and wraps the strap around the load L and through the openings in the pallet P until a lower layer LL of the strap S (which includes the leading end of the strap S) is positioned below an upper layer UL of the strap S, as shown in Figure 3A. The operator then introduces the overlapping upper and lower layers UL and LL of the strap S into the strapping device 50 and actuates one or more buttons to initiate the strapping cycle. As shown in Figure 3B, a motor drives a tensioning assembly to carry out a tensioning cycle during which the strapping device 50 tensions strap S around the load L. Once a preset tension is reached in the strap S, as shown in Figure 3C, the motor drives a sealing assembly to carry out a sealing cycle during which the strapping device 50 connects the upperand lower layers UL and LL of the strap S to one another via friction welding to form a strap joint SJ, as shown in Figure 3D, and cuts the strap S from the strap supply.

[0031] The strapping device 50 includes a housing 100, a working assembly 200, a outer strap guide 700, first and second pushbutton actuators 1410 and 1440, a display assembly 1490, a power supply 1500, a controller 1600, and one or more sensors 1700.

[0032] The housing 100, best shown in Figure 1, is formed from multiple components (not individually labeled) that collectively at least partially enclose and / or support some (or all) of the other assemblies and components of the strapping device 50. In this example embodiment, the housing 100 includes a front housing section 110, a cover 115, a rear housing section 120, a motor housing section 130, and a handle section 150. The front housing section 110 at least partially encloses and / or supports at least some of the components of the working assembly 200. The cover 115 at least partially encloses some of the components of the working assembly 200 — including the tension wheel 400w — and supports the outer strap guide 700 described below.

[0033] The rear housing section 120 at least partially encloses and / or supports at least some of the components of the display assembly 1490 and defines a receptacle sized, shaped, and otherwise configured to receive and at least partially enclose and / or support the power supply 1500 and the controller 1600. The motor housing section 130 extends between and connects the bottoms of the front and rear housing sections 110 and 120 and at least partially encloses and / or supports at least some of the components of the working assembly 200, including the motor 1100. The handle housing section 150 extends between and connects the tops of the front and rear housing sections 110 and 120 and defines a handle used by the operator. This is merely one example, and in other embodiments the components of the strapping device may be supported and / or enclosed by any suitable portion of the housing 100. The housing 100 may be formed from any suitable quantity of components joined together in any suitable manner. In this example embodiment, the housing 100 is formed from plastic, though it may be made from any other suitable material in other embodiments.

[0034] The working assembly 200, which is best shown in Figures 4A and 4B, includes the majority of the components of the strapping device 50 that are configured to carry out the strapping cycle to tension the strap around the load, attach the overlapping layers of the strap to one another, and cut the strap from the strap supply. The working assembly 200 includesa support 300, a tensioning assembly 400, a trigger 600, a weld-plate assembly 3000, a sealing assembly 900, a transmission 1000, and a motor 1100.

[0035] The support 300, which is best shown in Figures 4A and 4B, serves as a direct or indirect common mount for the tensioning assembly 400, the trigger 600, the weld-plate assembly 3000, the sealing assembly 900, the transmission 1000, and the motor 1100. The support 300 includes a base 300b and a frame 300f extending from the base 300b. The base 300b supports a toothed tension plate 312 below the tension wheel 400w of the tensioning assembly 400 (described below) and the weld-plate assembly 3000 below the weld shoe 942 of the sealing assembly 900 (described below).

[0036] The tensioning assembly 400 is operable via the motor 1100 to tension the strap around the load during the tensioning cycle. The tensioning assembly 400 includes a rocker 400r, tensioning-assembly gearing (not labeled), and a tension wheel 400w. The tension wheel 400w is supported by the tensioning-assembly gearing, which is in turn supported by the rocker 400r. The tensioning-assembly gearing is configured to rotate the tension wheel 400w about a tension-wheel rotational axis A400w in a tensioning rotational direction to tension the strap around the load. The tensioning assembly 400 is movably mounted to the support 300 via the rocker 400r and a tensioning-assembly mounting shaft 395 (Figures 4A and 4B) and configured to pivot relative to the support 300 — and particularly relative to the base 300b of the support 300 and the tension plate 312 — about a rocker-pivot axis A oor among a home position (Figure 5A), a strapinsertion position (Figure 5B), and a tensioning position (Figure 5C). When the tensioning assembly 400 is in the home position, the tension wheel 400w is adjacent to the tension plate 312 of the support 300. When the tensioning assembly 400 is in the strap-insertion position, the tension wheel 400w is spaced-apart from the tension plate 312 to enable the overlapping upper and lower layers of the strap to be inserted between the tension wheel 400w and the tension plate 312. When the tensioning assembly 400 is in the tensioning position and overlapping strap layers are between the tension wheel 400w and the tension plate 312, the tension wheel 400w engages the upper layer of strap and forces the strap layers onto the tension plate 312. The weight of the tensioning assembly 400 and one or more springs or other biasing elements (not shown) bias the tensioning assembly 400 to the home position.

[0037] The trigger 600 is operable (here, pivotable) to cause the tensioning assembly 400 to move from the home position to the strap-insertion position. In this example embodiment,when the trigger 600 is pulled it triggers a switch that causes the motor 1100 to cooperate with the tensioning assembly 400 to pivot the tensioning assembly 400 from the home position to the strap-insertion position. In other embodiments, the trigger 600 is operably connected to the tensioning assembly 400 via one or more mechanical linkages such that pulling the trigger 600 forces the tensioning assembly 400 to pivot from the home position to the strap-insertion position.

[0038] The outer strap guide 700, which is best shown in Figure 7, includes a body 710 and a neck 720 extending transversely from the body 710. The body 710 has opposing front and rear ends 712 and 714, respectively. The front end 712 includes a downwardly extending front guide 712f, and the rear end 714 includes a downwardly extending rear guide 714f. A vertical guide slot 710s is defined through the body 710 and the neck 720 and facilitates mounting the outer strap guide 700 to the cover 115. An opening 720o is defined through the neck 720 and facilitates mounting the outer strap guide 700 to the tensioning assembly 400, and particularly the rocker 400r of the tensioning assembly 400.

[0039] As best shown in Figure 8C, the outer strap guide 700 is mounted to the rocker 400r via a pin 700p extending through the opening 720o and a suitable opening (not shown) of the rocker 400r. The outer strap guide 700 is also mounted to the cover 115 via a pin 115p extending through the guide slot 710s and into a suitable opening (not shown) of the cover 115. The outer strap guide 700 is positioned so the front guide 712f is forward of the tension plate 312 and the rear guide 714f is rearward of the weld plate 3100 (described below).

[0040] The outer strap guide 700 is movable relative to various other components of the strapping device 50 — including the cover 115 and the support 300 — among between a lower position (Figures 8A-8C) and an upper position (not shown). The pin 700p operably connects the rocker 400r to the outer strap guide 700 such that the position of the rocker 400r controls the position of the outer strap guide 700. Specifically, when the tensioning assembly 400 (and thus the rocker 400r) is in the home position, the outer strap guide 700 is in the lower position; when the tensioning assembly 400 (and thus the rocker 400r) is in the strap-insertion position, the outer strap guide 700 is in the upper position; and when the tensioning assembly 400 (and thus the rocker 400r) is in the tensioning position, the outer strap guide 700 is in the tensioning position. Accordingly, movement of the rocker 400r as the tensioning assembly 400 moves among these positions causes the outer strap guide 700 to move among these positions.

[0041] When the outer strap guide 700 is in the lower position, as shown in Figures 8A-8C, the free end of the front guide 712f is received in a divot defined in the base 300b of the support 300 and the rear guide 714f extends below the upper surface of and behind the base 300b. When the outer strap guide 700 is in the upper position, the front and rear guides 712f and 714f are above the space between the tension wheel 400w and the tension plate 312 and the space between the weld shoe 942 and the weld plate 3100. When in the upper position, the outer strap guide 700 does not interfere with insertion of strap into those spaces. When the outer strap guide is in the lower position, the front and rear guides 712f and 714f extend below the lower layer LL of strap S to prevent the strap S from moving laterally out from beneath the tension wheel 400w and / or the weld shoe 942 (out of the page from the perspective shown in Figures 8B and 8C).

[0042] The front and rear guides 712f and 714f are each sized, shaped, oriented, positioned, and otherwise configured to prevent the tension wheel 400w from tensioning the strap if the strap is misaligned such that it is sandwiched between either of the front and rear guides 712f and 714f and the base 300b of the support 300. In this example embodiment, the bottom ends of the front and rear guides 712f and 714f are below the tension wheel 400w, meaning that the tension wheel 400w does not engage (or if the strap is curved, slightly engages) the upper layer UL of the strap S. In any event, the tension wheel 400w does not exert enough pressure on the strap S to force the strap S against the tension plate 312 such that the tension wheel 400w tensions the strap when rotated. In other words, if the tensioning process is initiated with the strap trapped between one or both of the front and rear guides and the base of the support, the strapping device will not tension the strap.

[0043] The weld-plate assembly 3000, which is best shown in Figures 9A-14B, is configured to support the lower layer of strap during the friction-welding process and to, along with the outer strap guide 700, prevent undesired lateral movement of the upper layer of strap during the strapping process. The weld-plate assembly 3000 includes a weld plate 3100, a weldplate support 3200, an inner strap guide 3300, and a fastener 3400 (which is a screw in this example embodiment but may be any other suitable component in other embodiments).

[0044] The weld plate 3100 includes a T-shaped body 3110 including a rectangular and substantially planar weld surface 3112 including multiple teeth 3112t. A circular bore 3114is defined through the body 3110 and has a central axis substantially aligned with a lateral center of the weld surface 3112.

[0045] The weld-plate support 3200 serves as a support for the weld plate 3100 and also controls the position of the weld plate 3100 and the inner strap guide 3300. The weld-plate support 3200 includes a cylindrical support mounting shaft 3210, a cylindrical weld-plate mounting shaft 3220, an oblong positioner 3230, and a cylindrical inner-strap-guide mount 3240. The weld-plate mounting shaft 3220 is positioned between and connected to the support mounting shaft 3210 and the positioner 3230, and the positioner 3230 is positioned between and connected to the weld-plate mounting shaft 3220 and the inner-strap-guide mount 3240. As best shown in Figures 1 IB and 1 ID, the weld-plate support 3200 has a longitudinal axis A3200 that is coaxial with the longitudinal axis of the support mounting shaft 3210, and the weld-plate mounting shaft 3220 has a longitudinal axis A3220 that is substantially parallel to — but offset from — the axis A3200. This means that the weld-plate mounting shaft 3220 is eccentric relative to the support mounting shaft 3210. Similarly, although not shown, the inner-strap-guide mount 3240 has a longitudinal axis that is substantially parallel to — but offset from — the axis A3200, meaning the inner-strap-guide mount 3240 is eccentric relative to the support mounting shaft 3210.

[0046] The inner strap guide 3300 includes an L-shaped body 3310 having a mounting portion 3312 and a guiding portion 3314 transverse to the mounting portion 3312 and having an inner guiding surface 3314s. First, second, and third bores 3312a, 3312b, and 3312c are defined through the mounting portion 3312. The first bore 3312a is sized and shaped to receive the inner- strap-guide mount 3240 of the weld-plate support 3200, and the second and third bores 3312b and 3312c are sized and shaped such that the fastener 3340 can extend through them to facilitate attaching the inner strap guide 3300 to the support 300.

[0047] The weld plate 3100 is positioned within a cavity 300c defined in the base 300b of the support 300. The support mounting shaft 3210 of the weld-plate support 3200 is received in a suitably sized and shaped bore 300b 1 defined in the base 300b of the support 300. The weld-plate mounting shaft 3220 extends through the bore 3114 of the body 3110 of the weld plate 3100. The positioner 3230 is received in a suitably sized and shaped positioner-receiving opening 300b2 defined in the base 300b of the support 300. The inner-strap-guide mount 3240 isreceived in the first bore 3312a of the inner strap guide 3300, and the fastener 3400 secures the inner strap guide 3300 to the base 300b of the support 300.

[0048] The weld plate 3100 can be mounted to the support 300 via the weld-plate support 3200 in a first position (Figures 9A, 12A, 13A, and 14A) or a second position (Figures 10, 12B, 13B, and 14B). When the weld plate 3100 is in the first position, as shown in Figures 13A and 14A, the lateral center of the weld plate 3100 is a first distance DI from a guiding surface 700g of the outer strap guide 700, and the tops of the teeth 3112t of the welding surface 3112 are a first height Hl from the underside of the cover 115. When the weld plate 3100 is in the second position, as shown in Figures 13B and 14B, the lateral center of the weld plate 3100 is a second distance D2 from the guiding surface 700g of the outer strap guide 700, and the tops of the teeth 3112t of the welding surface 3112 are a second height H2 from the underside of the cover 115. The second distance D2 is less than the first distance DI, and the second height H2 is less than the first distance D2. Thus, moving the weld plate 3100 from the first position to the second position moves the lateral center of the weld plate 3100 closer to the guiding surface 700g of the outer strap guide 700 and closer to the underside of the cover 115.

[0049] Similarly, the inner strap guide 3300 can be mounted to the support 300 via the weld-plate support 3200 in a first position (Figures 9A, 12A, 13A, and 14A) or a second position (Figures 10, 12B, 13B, and 14B). When the inner strap guide 3300 is in the first position, as shown in Figures 13A and 14A, the inner guiding surface 3314s is a third distance D3 from the guiding surface 700g of the outer strap guide 700. When the inner strap guide 3300 is in the second position, as shown in Figures 13B and 14B, the inner guiding surface 3314s is a fourth distance D4 from the guiding surface 700g of the outer strap guide 700. The fourth distance D4 is less than the third distance D3. Thus, moving the inner strap guide 3300 from the first position to the second position moves the inner guiding surface 3314s closer to the guiding surface 700g of the outer strap guide 700.

[0050] Since the weld plate 3100 and the inner strap guide 3300 are both mounted to the weld-plate support 3200 in this example embodiment, the strap guide 3300 is in its first position when the weld plate 3100 is in its first position, and the strap guide 3300 is in its second position when the weld plate 3100 is in its second position. The positioner 3230 — and particularly the rotational position of the positioner 3230 — controls the positioning of the weld plate 3100 and the strap guide 3300. Specifically, the positioner 3230 and its correspondingpositioner-receiving opening 300b2 in the base 300b of the support 300 are sized and shaped such that the positioner 3230 can be received in the positioner-receiving opening 300b2 in either a first rotational position or a second rotational position. When the positioner 3230 is in the first rotational position shown in Figures 9A, 12A, 13A, and 14A, the weld-plate mounting shaft 3220 and the inner-strap-guide mount 3240 are positioned such that the weld plate 3100 and the inner strap guide 3300 are in their respective first positions. Conversely, when the positioner 3230 is in the second rotational position shown in Figures 10, 12B, 13B, and 14B, the weld-plate mounting shaft 3220 and the inner-strap-guide mount 3240 are positioned such that the weld plate 3100 and the inner strap guide 3300 are in their respective second positions.

[0051] The positioner-receiving opening 300b2 is sized and shaped to substantially prevent rotation of the positioner 3230 — and, therefore, to substantially prevent rotation of the weld-plate support 3200 — relative to the support 300 when the positioner 3230 is received in the positioner-receiving opening 300b2. Accordingly, to switch the weld plate 3100 and the inner strap guide 3300 from their first positions to their second positions (or from their second positions to their first positions), the operator: (1) removes the fastener 3400 from the base 300b of the support 300; (2) removes the inner strap guide 3300 from the inner-strap-guide mount 3240 of the weld-plate support 3200; (3) pulls the weld-plate support 3200 out of the base 300b of the support 300 until the positioner 3230 is removed from the positioner-receiving opening 300b2; (4) rotates the positioner 3230 from the first rotational position to the second rotational position (or from the second rotational position to the first rotational position); (5) pushes the positioner 3230 back into the positioner-receiving opening 300b2; (6) mounts the inner strap guide 3300 back onto the inner-strap-guide mount 3240 of the weld-plate support 3200; and (7) fastens the inner strap guide 3300 to the base 300b of the support 300 via passing the fastener 3400 through the third bore 3312c (or the second bore 3312b) of the mounting portion 3312 of the inner strap guide 3300.

[0052] In other embodiments, the positioner is cylindrical and simply rotatable to change the lateral position of the weld plate. A locking device, such as a fastener, could be used to lock the positioner in place.

[0053] The strapping device 50 of the present disclosure is configured for use with strap of two different widths: a first width shown in Figure 14A and a second width shown in Figure 14B. The first width is slightly less than the third distance D3, and the second width isslightly less than the fourth distance D4. Accordingly, the weld plate 3100 and the inner strap guide 3300 should be in their respective first positions when the strapping device 50 is used with strap of the first width and in their respective second positions when the strapping device 50 is used with strap of the second width. The weld-pad assembly 3000 of the present disclosure — and particularly the configuration of the weld-pad support 3200 — enables the operator to reposition the weld plate 3100 and the inner strap guide 3300 when switching between the first and second strap widths.

[0054] The sealing assembly 900, which is best shown in Figures 6A-6C, is configured to operate with the weld-pad assembly 3000 to attach overlapping portions of the strap to one another to form a tensioned strap loop around the load during the sealing cycle via friction welding. The sealing assembly 900 includes a first link arm 910, a second link arm 920, a first sealing-assembly biasing element 930, a second sealing-assembly biasing element 932, a weld arm 940, a weld shoe 942, a cutter 944, and an eccentric shaft (not shown). The weld shoe 942 is slidably mounted to the weld arm 940 such that the weld shoe 942 can oscillate relative to the weld arm 940 in the transverse direction of the strap (left and right from the perspective of Figures 6A-6C). The eccentric shaft is operably connected to the weld shoe 942 and configured to, when rotated, cause the weld shoe 942 to oscillate. A toothed belt 900b operably connects the transmission 1000 to the eccentric shaft. The cutter 944 is removably mounted to the weld arm 940.

[0055] The weld arm 940 is pivotably mounted to the support 300 and is pivotable relative to the support 300 and the weld plate 3100 about a weld-arm axis A940 between a home position (Figures 4A and 6A) in which the weld shoe 942 is spaced-apart from the weld plate 3100 and a sealing position (Figure 6C) in which the weld shoe 942 is adjacent to the weld plate 3100 and positioned to weld the strap. The first and second link arms 910 and 920 operably connect the transmission 1000 to the weld arm 940 such that the transmission 1000 can move the weld arm 940 from the home position to the sealing position. The first link arm 910 is pivotably mounted to the support 300 via a first pivot 900pl (such as a pivot pin). The second link arm 920 links the first link arm 910 to the weld arm 940. Specifically, one end of the second link arm 920 is pivotably connected to one end of the first link arm 910 via a second pivot 900p2 (such as a pivot pin), and the other end of the second link arm 920 is pivotably connected to the weld arm 940 via a third pivot 900p3 (such as a pivot pin). The first sealing-assembly biasing element 930circumscribes the second link arm 920 and, as explained below, biases the sealing assembly 900 to its sealing configuration. The second sealing-assembly biasing element 932 biases the sealing assembly to its home configuration.

[0056] When the sealing assembly 900 is in the home configuration in which the weld arm 940 is in the home position — shown in Figures 3A and 6A — the first and second link arms 910 and 920 are oriented such that they form an angle greater than 0 degrees and less than 180 degrees (i.e., an acute or obtuse angle). When the sealing assembly 900 is in the sealing configuration in which the weld arm 940 is in the sealing position — shown in Figure 6C — the first and second link arms 910 and 920 form an angle greater than 180 degrees and less than 360 degrees (i.e., a reflex angle). As described in detail below, the transmission 1000 is configured to switch the sealing assembly 900 from its home configuration to its sealing configuration by manipulating the orientation of the first and second link arms 910 and 920.

[0057] The transmission 1000, which is best shown in Figures 4A and 4B, is driven by the motor 1100, is operably connected to the tensioning assembly 400 and configured to cause the tension wheel 400w to rotate in the tensioning direction to tension the strap and is operably connected to the sealing assembly 900 and configured to cause the sealing assembly 900 to attach the overlapping portions of the strap to one another. The transmission 1000 includes transmission gearing including a drive gear 1012 (which is a bevel pinion gear in this example embodiment) and a variable offset coupling 800. The transmission gearing and the variable offset coupling 800 are mounted to the support 300 such that the drive gear 1012 is configured to drive the variable offset coupling 800.

[0058] The transmission gearing includes suitable components (such as gears, bearings, and freewheels) that transmit rotational movement of the output shaft of the motor 1100 in a first drive direction to the drive gear 1012 to rotate the drive gear 1012 (but not to drive any components of the sealing assembly 900 in this example embodiment). The drive gear 1012 drives the variable offset coupling 800, which transmits the rotational movement of the drive gear 1012 to the tensioning-assembly gearing to rotate the tension wheel 400w.

[0059] The components of the transmission gearing transmit rotational movement of the output shaft of the motor 1100 in a second drive direction opposite the first drive direction to the sealing assembly 900 to switch the sealing assembly 900 from its home configuration to its sealing configuration and to drive the toothed belt 900b to rotate the eccentric shaft and cause theweld shoe 942 to oscillate (but not to drive the drive gear 1012 in this example embodiment). More specifically, the transmission gearing includes a cam 1010c (Figure 6A) driven in rotation by the output shaft of the motor 1100 when the output shaft is rotated in the second drive direction. The cam 1010c engages the free end (not shown) of the first link arm 910 of the sealing assembly 900, which causes the first link arm 910 of the sealing assembly 900 to rotate clockwise about the first pivot 900pl (from the viewpoint shown in Figures 6A-6C) to raise the second pivot 900p2 and switch the sealing assembly 900 to the sealing configuration, thereby moving the weld arm 940 into its sealing position.

[0060] This is merely one example transmission assembly, and the strapping device may include any suitable transmission assembly or assemblies operably connecting one or more motors to the tensioning and sealing assemblies to drive those assemblies.

[0061] The motor 1100, which is best shown in Figures 4A and 4B, is operably connected to (via the transmission 1000) the tensioning assembly 400 and the sealing assembly 900 and is configured to drive those assemblies as explained herein. The motor 1100 includes the output shaft (not shown) referenced above. The motor 1100 is an electric motor in this example embodiment but may be any suitable motor.

[0062] The display assembly 1490, which is shown in Figures 1 and 2, includes a suitable display screen 1492 with a touch panel 1494. The display screen 1492 is configured to display information regarding the strapping device 50 (at least in this embodiment), and the touch screen 1494 is configured to receive operator inputs such as the desired operating mode (described below), a desired strap tension, and a desired weld cooling time. A display controller (not shown) may control the display screen 1492 and the touch panel 1494 and, in these embodiments, is communicatively connected to the controller 1600 to send signals to the controller 1600 and to receive signals from the controller 1600. Other embodiments of the strapping device do not include a touch panel. Still other embodiments of the strapping device do not include a display assembly. Certain embodiments of the strapping device include a separate pushbutton panel instead of a touch panel beneath or integrated with the display screen.

[0063] The first and second pushbutton actuators 1410 and 1440 are operable to initiate the tensioning and / or sealing cycles as described below. Other embodiments of the strapping device 50 do not have pushbutton actuators and instead incorporate their functionalityinto the display assembly 1490. For instance, in one of these embodiments two areas of the touch panel define virtual buttons that have the same functionality as mechanical pushbutton actuators.

[0064] The controller 1600, which is shown in Figure 2, includes a processing device (or devices) communicatively connected to a memory device (or devices). For instance, the controller may be a programmable logic controller. The processing device may include any suitable processing device such as, but not limited to, a general-purpose processor, a specialpurpose processor, a digital-signal processor, one or more microprocessors, one or more microprocessors in association with a digital-signal processor core, one or more applicationspecific integrated circuits, one or more field-programmable gate array circuits, one or more integrated circuits, and / or a state machine. The memory device may include any suitable memory device such as, but not limited to, read-only memory, random-access memory, one or more digital registers, cache memory, one or more semiconductor memory devices, magnetic media such as integrated hard disks and / or removable memory, magneto-optical media, and / or optical media. The memory device stores instructions executable by the processing device to control operation of the strapping device 50. The controller 1600 is communicatively and operably connected to the motor 1100, the display assembly 1490, the pushbutton actuators 1410 and 1440, and the sensor(s) 1700 and configured to receive signals from and to control those components. The controller 1600 may also be communicatively connectable (such as via Wi-Fi, Bluetooth, near-field communication, or other suitable wireless communications protocol) to an external device, such as a computing device, to send information to and receive information from that external device.

[0065] The controller 1600 is configured to operate the strapping device in one of three operating modes to carry out the strapping cycle: (1) a manual operating mode; (2) a semiautomatic operating mode; and (3) an automatic operating mode. In the manual operating mode, the controller 1600 operates the motor 1100 to cause the tension wheel 400w to rotate responsive to the first pushbutton actuator 1410 being actuated and maintained in its actuated state. The controller 1600 operates the motor 1100 to cause the sealing assembly 900 to carry out the sealing cycle responsive to the second pushbutton actuator 1440 being actuated. In the semiautomatic operating mode, the controller 1600 operates the motor 1100 to cause the tension wheel 400w to rotate responsive to the first pushbutton actuator 1410 being actuated and maintained in its actuated state. Once the controller 1600 determines that the tension in the strapreaches the (preset) desired strap tension, the controller 1600 automatically operates the motor 1100 to cause the sealing assembly 900 to carry out the sealing cycle (without requiring additional input from the operator). In the automatic operating mode, the controller 1600 operates the motor 1100 to cause the tension wheel 400w to rotate responsive to the first pushbutton actuator 1410 being actuated. Once the controller 1600 determines that the tension in the strap reaches the (preset) desired strap tension, the controller 1600 automatically operates the motor 1100 to cause the sealing assembly 900 to carry out the sealing cycle (without requiring additional input from the operator).

[0066] The sensors 1700 include any suitable sensors, such as microswitches, optical sensors, ultrasonic sensors, magnetic position sensors, and the like, configured to detect the position of certain components of the strapping device 50 and to send appropriate signals to the controller 1600. The sensors 1700 may include, for instance: one or more tensioning-assembly- position sensors configured to detect when the tensioning assembly 400 is in its home position and / or its strap-insertion position; one or more trigger-position sensors configured to detect when the trigger 600 is pulled; and one or more actuating assembly sensors configured to detect actuation of the first and second pushbutton actuators 1410 and 1440.

[0067] The power supply 1500 is electrically connected to (via suitable wiring and other components) and configured to power several components of the strapping device 50, including the motor 1100, the display assembly 1490, the controller 1600, and the sensor(s) 1700. The power supply 1500 includes a rechargeable battery (such as a lithium-ion or nickel cadmium battery) in this example embodiment, though it may be any other suitable electric power supply in other embodiments. The power supply 1500 is sized, shaped, and otherwise configured to be received in the receptacle defined by the rear housing section 120 of the housing 100. The strapping device 50 includes one or more power-supply-securing devices (not shown) to releasably lock the power supply 1500 in place upon receipt in the receptacle. Actuation of a release device of the strapping device 50 or the power supply 1500 unlocks the power supply 1500 from the housing 100 and enables an operator to remove the power supply 1500 from the receptacle.

[0068] Use of the strapping device 50 to carry out a strapping cycle to form a tensioned strap loop around a load is now described below. Initially, the tensioning assembly 400 is in its home position and the sealing assembly 900 is in its home configuration, as shown inFigures 5A and 6A. The strapping device 50 is in the automatic mode for the purposes of this example.

[0069] The operator pulls the strap S leading-end first from a strap supply (not shown), wraps the strap S around the load, and positions a lower layer LL including the leading end of the strap S below an upper layer UL of the strap S. The operator then pulls the trigger 600 to lift the tensioning assembly 400 to its strap-insertion position, as shown in Figure 5B. With the tensioning assembly 400 in its strap-insertion position and while continuing to pull the trigger 600, the operator introduces the overlapping upper and lower layers UL and LL of the strap S between the tension wheel 400w and the tension plate 312 and between the weld shoe 942 and the weld plate 3100, as shown in Figure 5B. The operator then releases the trigger 600, enabling the appropriate biasing elements to force the tensioning assembly 400 pivot to its tensioning position to sandwich the overlapping upper and lower strap layers UL and LL between the tension wheel 400w and the tension plate 312, as shown in Figure 5C.

[0070] The operator then actuates the first pushbutton actuator 1410. Once one of the sensors 1700 detects the actuation of the first pushbutton actuator 1410, the controller 1600 starts the tensioning cycle by controlling the motor 1100 to rotate the output shaft in the first drive direction. As explained above, the transmission 1000 transmits this rotational movement of the output shaft to the tensioning-assembly gearing which, in turn, rotates the tension wheel 400w about the tension-wheel rotational axis A oow in the tensioning direction. As the tension wheel 400w rotates in the tensioning direction, it pulls the upper layer UL of the strap S over the lower layer LL of the strap S, thereby tensioning the strap S around the load. Throughout the tensioning cycle, the controller 1600 monitors the current drawn by the motor 1100. When this current reaches a preset value that is correlated with the (preset) desired strap tension for this strapping cycle, the controller 1600 stops the motor 1100, thereby terminating the tensioning cycle.

[0071] In this example embodiment, after completion of the tensioning cycle, the controller 1600 automatically starts the sealing cycle by controlling the motor 1100 to begin rotating the output shaft in the second drive direction. This causes the transmission 1000 to drive the toothed belt 900b to begin rotating the eccentric shaft and oscillating the weld shoe 942 and to switch the sealing assembly 900 from its home configuration to its sealing configuration, and in doing so pivot the weld arm 940 to its sealing position. As the weld arm 940 reaches the sealing position, the weld shoe 942 forces the overlapping upper and lower layers of strap ULand LL against the weld plate 3100 while the cutter 944 cuts the upper strap layer UL from the strap supply. Figures 6B and 6C show this movement of the weld arm 940 and oscillation of the weld shoe 942. As explained above, the oscillation of the weld shoe 942 is fast enough to generate friction and heat substantial enough to locally melt and join the portions of the overlapping strap layers, thereby attaching the upper and lower strap layers UL and LL to form the tensioned strap loop. The controller 1600 controls the motor 1100 to stop rotating the output shaft, completing the sealing cycle. The operator can then pull the trigger 600 to raise the tensioning assembly 400 and to switch the sealing assembly 900 back to its home configuration to release the tensioned strap loop.

[0072] The above-described example embodiment of the strapping device includes a single motor configured to drive both the tensioning assembly and the sealing assembly. In other embodiments, the strapping device includes separate motors configured to drive the respective tensioning and sealing assemblies and may include separate transmissions for each motor.

[0073] Other embodiments of the strapping device may include fewer assemblies, components, and / or features than those included in the strapping device 50 described above and shown in the Figures. In other words, while the strapping device 50 includes all of the assemblies, components, and features described above, they are independent of one another and may be independently included in other strapping devices.

[0074] While the strapping device described above is a handheld strapping device, the strapping device may be any other suitable strapping device in other embodiments, such as a standalone automatic or semi-automatic strapping machine.

[0075] In the strapping device described above, the movable rocker supports the tension wheel and moves the tension wheel relative to the stationary tension plate as the rocker pivots among the home, strap-insertion, and tensioning positions. In other embodiments, the movable rocker supports the tension plate, and the support of the working assembly supports the tension wheel. In these embodiments, the movable rocker moves the tension plate relative to the stationary tension wheel as the rocker pivots among the home, strap-insertion, and tensioning positions.

Claims

Claims1. A strapping device comprising: a support; a tension wheel rotatable relative to the support about a tension-wheel axis; and a weld plate mountable to the support one of a first position and a second position, wherein the first and second positions are offset in a direction substantially parallel to the tension-wheel axis.

2. The strapping device of claim 1, wherein the first and second positions are vertically offset.

3. The strapping device of claim 1, further comprising a strap guide comprising a guiding surface, wherein the weld plate comprises a welding surface, wherein a center of the welding surface is laterally spaced apart a first distance from the guiding surface when the weld plate is in the first position and laterally spaced apart a second distance from the guiding surface when the weld plate is in the second position, wherein the first distance is greater than the second distance.

4. The strapping device of claim 1, further comprising a weld-plate support to which the weld plate is removably mounted, wherein the weld plate support is removably mounted to the support.

5. The strapping device of claim 4, wherein the weld-plate support comprises a weld-plate mounting shaft and a positioner, wherein the weld plate is removably mounted to the weld-plate mounting shaft.

6. The strapping device of claim 5, wherein the support defines a positionerreceiving opening, wherein the positioner of the weld-plate support and the positioner-receiving opening are sized and shaped such that the positioner-receiving opening can receive the positioner in a first positioner orientation and a second positioner orientation, wherein the first positioner orientation corresponds to the first position of the weld plate and the second positioner orientation corresponds to the second position of the weld plate.

7. The strapping device of claim 6, further comprising a strap guide comprising a guiding surface, wherein the weld-plate mounting shaft of the weld-plate support comprises a first longitudinal axis, wherein the first longitudinal axis is further from the guiding surface when the positioner is in the first positioner orientation than when the positioner is in the second positioner orientation.

8. The strapping device of claim 6, wherein the positioner-receiving opening of the support is sized and shaped to substantially prevent rotation of the positioner relative to the support when the positioner is received in the positioner-receiving opening.

9. The strapping device of claim 8, wherein the weld-plate support is rotatable about a second longitudinal axis when the positioner is removed from the positioner-receiving opening to move the positioner between the first and second positioner orientations, wherein the first longitudinal axis is offset from and substantially parallel to the second longitudinal axis.

10. The strapping device of claim 9, wherein the positioner has an oblong shape.

11. The strapping device of claim 9, further comprising a movable strap guide positionable in one of an outer position and an inner position, wherein the movable strap guide is in the outer position when the weld plate is in the first position and in the inner position when the weld plate is in the second position.

12. The strapping device of claim 11, wherein the weld-plate support further comprises an inner-strap-guide mount to which the outer strap guide is mounted.

13. The strapping device of claim 12, wherein the inner-strap-guide mount of the weld-plate support comprises a third longitudinal axis offset from and substantially parallel to the first and second longitudinal axes.

14. The strapping device of claim 6, further comprising a movable strap guide positionable in one of an outer position and an inner position, wherein the movable strap guide is in the outer position when the weld plate is in the first position and in the inner position when the weld plate is in the second position.

15. The strapping device of claim 14, further comprising a second strap guide comprising a guiding surface, wherein the movable strap guide is closer to the second strap guide when in the inner position than when in the outer position.

16. The strapping device of claim 1, further comprising an eccentric weld-plate mounting shaft having a first longitudinal axis, wherein the weld plate is mounted to the support via the weld-plate mounting shaft.

17. The strapping device of claim 16, wherein the weld plate is in the first position when the weld-plate mounting shaft is in a first rotational position, wherein the weld plate is in the second position when the weld-plate mounting shaft is in a second rotational position.

18. The strapping device of claim 17, further comprising a positioner connected to the weld-plate mounting shaft and having a second longitudinal axis offset from and substantially parallel to the first longitudinal axis, wherein the positioner is rotatable about the second longitudinal axis to move the weld-plate mounting shaft between the first and second rotational positions.

19. The strapping device of claim 18, wherein the positioner is receivable in a positioner-receiving opening defined in the support to substantially prevent rotation of the weldplate mounting shaft.

20. The strapping device of claim 19, further comprising a strap guide mounted to the positioner.

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