Strapping tool including a strap guide

Abstract

Various embodiments of the present disclosure provide a strapping tool including a support including a base, a strap manipulator supported by the support, a plate below the strap manipulator, a first strap guide including a first strap-contact surface, one or more first biasing elements biasing the first strap guide to a first home position, and a second strap guide comprising a second strap-contact surface. The first and second strap guides are positioned such that the first and second strap-contact surfaces are opposite one another and such that a strap path extending in a longitudinal direction is defined between the first and second strap-contact surfaces, below the strap manipulator, and above the plate. The first strap guide is movable from the first home position in a transverse direction to change a distance separating the first and second strap-contact surfaces. The transverse direction is transverse to the longitudinal direction.

Description

STRAPPING TOOL INCLUDING A STRAP GUIDEPriority

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 749,098, filed January 24, 2025, the entire contents of which is incorporated herein by reference.Field

[0002] The present disclosure relates to strapping tools, and more particularly to strapping tools 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] Handheld strapping tools 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. 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 tension 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 typically positioned rearward of and laterally aligned with the tensioning wheel and plate. The tensioning wheel is spring-biased to force the strap layers against the tension plate (or vice-versa), while initially the weld shoe does not contact the strap.

[0004] The operator presses a button to initiate a tensioning cycle 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 cycle, a sealing cycle is initiated.During the sealing cycle, 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 and solidify as they cool, thereby attaching the upper and lower strap layers to form the tensioned strap loop.

[0005] Certain strapping tools include inner and outer strap guides that define the width of the strap path, which is equal to or 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 cycle. 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 13-, 16-, or 19-millimeter strap will have three pairs of strap guides: one pair spaced apart slightly more than 13 millimeters when installed, another 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 when switching from one strap width to another.Summary

[0006] Various embodiments of the present disclosure provide a strapping tool including a support including a base, a strap manipulator supported by the support, a plate below the strap manipulator, a first strap guide including a first strap-contact surface, one or more first biasing elements biasing the first strap guide to a first home position, and a second strap guide comprising a second strap-contact surface. The first and second strap guides are positioned such that the first and second strap-contact surfaces are opposite one another and such that a strap path extending in a longitudinal direction is defined between the first and second strap-contact surfaces, below the strap manipulator, and above the plate. The first strap guide is movable fromthe first home position in a transverse direction to change a distance separating the first and second strap-contact surfaces. The transverse direction is transverse to the longitudinal direction.Brief Description of the Figures

[0007] Figure l is a perspective view of one example embodiment of a strapping tool of the present disclosure.

[0008] Figures 2A-2C are diagrammatic views of the strapping tool of Figure 1 carrying out a strapping cycle.

[0009] Figure 2D is a perspective view of a friction- weld strap joint formed by the strapping tool of Figure 1.

[0010] Figure 3 is a perspective view of the working assembly of the strapping tool of Figure 1.

[0011] Figure 4 is a perspective view of part of the support of the working assembly of Figure 3 and of the inner and outer strap guides of the strapping tool of Figure 1.

[0012] Figures 5A, 6A, 7A, 8A, 9A, and 10A are front elevational views of the inner and outer strap guides during the introduction of upper and lower strap layers between the inner and outer strap guides.

[0013] Figures 5B, 6B, 7B, 8B, 9B, and 10B are top plan views corresponding to Figures 5A, 6A, 7A, 8A, 9A, and 10A respectively.

[0014] Figure 11 is similar to Figure 4 but after upper and lower strap layers have been introduced between the inner and outer strap guides.

[0015] Figure 12 is a top plan view of part of the support of the working assembly of another embodiment of the strapping tool of the present disclosure including two pairs of inner and outer strap guides.

[0016] Figure 13 is a front elevational view of the inner and outer strap guides of another embodiment of the strapping tool of the present disclosure.

[0017] Figure 14 is a front elevational view of the inner and outer strap guides of another embodiment of the strapping tool of the present disclosure.Detailed Description

[0018] 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.

[0019] Figures 1-11 show one example embodiment of a strapping tool 10 of the present disclosure and certain subassemblies and components thereof. The strapping tool 10 is configured to carry out a strapping cycle to tension and seal strap (plastic strap in this example embodiment) drawn from a strap supply around a load on a pallet to form a tensioned strap loop that secures the load to the pallet. The strapping tool 10 is configured to cut the strap used to form the tensioned strap loop from the strap supply.

[0020] More specifically, an operator pulls strap S from a strap supply — such as a coil of strap on a strap dispenser — and wraps the strap around the load L and through the openings in the pallet P, as shown in Figure 2A. The operator then positions a lower strap layer LL of the strap S — which includes the leading end of the strap S — below an upper strap layer UL of the strap S and introduces the overlapping upper and lower strap layers into the strapping tool 10. The operator actuates a button to initiate the strapping cycle. As shown in Figure 2B, a motor drives a tensioning assembly to carry out a tensioning cycle during which the strapping tool 10 tensions strap S around the load L. Once a preset tension is reached in the strap S, the motor drives a sealing assembly to carry out a sealing cycle during which the strapping tool 10 connectsthe upper and lower strap layers UL and LI to one another via friction welding to form a strap joint SJ and a tensioned strap loop TSL as shown in Figures 2C and 2D. During the sealing cycle, the strapping tool 10 also cuts the tensioned strap loop TSL from the strap S remaining in the strap supply.

[0021] The strapping tool 10 includes a housing 20, a working assembly 30, an inner strap guide 100, an outer strap guide 200, one or more input devices, a power supply, and a controller.

[0022] The housing 20, 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 subassemblies and components of the strapping tool 10. In this example embodiment, the housing 20 includes a front housing section that at least partially encloses the working assembly 30, a rear housing section that at least partially encloses and that supports the power supply and the controller, and a handle extending between and connecting the front and rear housing sections. The handle is held by the operator during operation of the strapping tool 10. The housing 20 may be formed from any suitable quantity of components joined together in any suitable manner. In this example embodiment, the housing 20 is formed from plastic, though it may be made from any other suitable material in other embodiments.

[0023] The working assembly 30, which is shown in Figure 3, includes most of the subassemblies and components of the strapping tool 10 that are configured to carry out the strapping cycle to tension the strap around the load and attach the overlapping layers of the strap to one another. The working assembly 30 includes a support 40, a first strap manipulator in the form of a tensioning assembly 50, a second strap manipulator in the form of a sealing assembly 60, a trigger 70, a transmission 80, and a motor M.

[0024] The support 40 serves as a direct or indirect common mount for the tensioning assembly 50, the sealing assembly 60, the trigger 70, the transmission 80, and the motor M. The support 40 includes a base 41 that supports a toothed tension plate 42 and a toothed weld plate 49. The weld plate 49 is positioned rearward of the tension plate 42 in a longitudinal strap direction LONG identified in Figure 3. The centers of the tension plate 42 and the weld plate 49 are aligned in a transverse strap direction TR, which is perpendicular to the longitudinal strap direction LONG. A strap path SP (Figure 5A) is defined above and extends across the tension plate 42, the weld plate 49, and the strap-guiding surface 41s. A strap-pathcenterline CLSP extends in the longitudinal strap direction LONG and through the centers of the tension plate 42 and the weld plate 49. The base 41 includes a planar strap-guiding surface 41s that extends between the tension plate 42 and the weld plate 49.

[0025] The tensioning assembly 50 is operable via the motor M to tension the strap around the load during the tensioning cycle. The tensioning assembly 50 includes a rocker, tensioning-assembly gearing, and a tension wheel 52. The rocker supports the tensioningassembly gearing. The tensioning-assembly gearing supports the tension wheel 52, operably connects the transmission 80 to the tension wheel 52, and is configured to rotate the tension wheel 52 about an axis A52 in a tensioning rotational direction to tension the strap around the load. The tensioning assembly 50 is pivotably mounted to the support 40 via the rocker and a suitable shaft such that the tension wheel 52 is above and adjacent to the tension plate 42. The tensioning assembly 50 is configured to pivot relative to the support 40 to increase the distance between the tension wheel 52 and the tension plate 42. The weight of the tensioning assembly 50 and one or more springs bias the tensioning assembly 50 toward the tension plate 42.

[0026] The trigger 70 is operable (here, pivotable) to raise the tensioning assembly 50 to separate the tension wheel 52 from the tension plate 42. In this example embodiment, when the trigger 70 is pulled it activates a switch that causes the motor M to cooperate with the tensioning assembly 50 to pivot the tensioning assembly 50 upwards. In other embodiments, the trigger 70 is operably connected to the tensioning assembly 50 via one or more mechanical linkages such that pulling the trigger 70 forces the tensioning assembly 50 to pivot upwards. When the trigger is released, the tensioning assembly 50 lowers back down to its initial position.

[0027] The sealing assembly 60 is operable via the motor M 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 60 includes a weld arm 61, a weld shoe 62, and a cutter 63. The weld arm 61 is pivotably mounted to the support 40. The weld shoe 62 includes downwardly extending teeth and is mounted to the weld arm 61 and positioned so the teeth are above and adjacent to the weld plate 49. The weld shoe 62 is movably mounted to the weld arm such that the weld shoe 62 can oscillate in the transverse strap direction TR during the sealing cycle to form the strap joint. The cutter 63 includes downwardly extending teeth and is removably attached to the weld arm 61 rearward of the weld shoe 62.

[0028] The weld arm 61 is pivotable between home and connecting positions to: (a) move the weld shoe 62 toward and away from the weld plate 49 to engage and disengage the upper strap layer UL during and after the sealing cycle; and (b) move the cutter 63 toward the upper strap layer UL so the teeth can engage and cut the upper strap layer UL from the strap supply during the sealing cycle. In this example embodiment, the sealing assembly includes a linkage operably connecting the transmission 80 to the weld arm 61 to pivot the weld arm 61. The sealing assembly also includes an eccentric shaft operably connecting the transmission 80 to the weld shoe 62 to oscillate the weld shoe 62.

[0029] The transmission 80 is driven by the motor M, is operably connected to the tensioning assembly 50 and configured to cause the tension wheel 52 to rotate in the tensioning rotational direction to tension the strap, and is operably connected to the sealing assembly 60 and configured to cause the sealing assembly 60 to attach the overlapping portions of the strap to one another. The transmission 80 includes transmission gearing supported by the support 40. The transmission gearing includes suitable components (such as gears, bearings, and freewheels) that transmit rotational movement of the output shaft of the motor M: (a) in a first drive direction to the tensioning-assembly gearing of the tensioning assembly 50, which in turn rotates the tension wheel 52; and (b) in a second drive direction opposite the first drive direction to the sealing assembly 60 to force the linkage to pivot the weld arm 61 to move the weld shoe 62 and the cutter 63 toward the weld plate 49 and to drive the eccentric shaft to oscillate the weld shoe 62. This is merely one example transmission assembly, and the strapping tool may include any suitable transmission assembly or assemblies operably connecting one or more motors to the tensioning and sealing assemblies to drive those assemblies.

[0030] The motor M is operably connected to (via the transmission 80) the tensioning assembly 50 and the sealing assembly 60 and is configured to drive those assemblies as explained herein. The motor M includes the output shaft (not shown) referenced above. The motor M is an electric motor in this example embodiment but may be any suitable motor.

[0031] The inner (or first) strap guide 100 and the outer (or second) strap guide 200, which are shown in Figures 4-11, cooperate to automatically center the upper and lower strap layers UL and LL of the strap S on the strap-path centerline CLSP regardless of the width of the strap S. In this example embodiment, the inner and outer strap guides 100 and 200 are positioned on opposite sides of the strap-path centerline CLSP and extend between the tension plate 42 andthe weld plate 49. The strap path SP is also defined between the inner and outer strap guides 100 and 200. The inner and outer strap guides 100 and 200 are positioned and oriented such that they extend between the tension plate 42 and the weld plate 49 and are adjacent to opposite sides of the strap-guiding surface 41s.

[0032] The inner strap guide 100 includes a rectangular body 110 having a planar strap-contact surface 110s, a first finger 120 extending from a first side of the body 110, a second finger 130 extending from a second side of the body 110 opposite the first side of the body 110, a third finger 140 extending from a lower end of the body 110, and tubular first and second spring retainers 150a and 150b extending from a surface of the body 110 opposite the strap-contact surface 110s and spaced apart in the longitudinal strap direction LONG. The first, second, and third fingers 120, 130, and 140 extend from the body 110 in the same direction and at substantially the same angle, though the angles may differ in other embodiments. In further embodiments, the inner strap guide does not include one or more of the first, second, and third fingers.

[0033] The inner strap guide 100 is movably mounted to the support 40 such that the inner strap guide 100 can move relative to the support 40 in the transverse strap direction TR. Specifically, the inner strap guide 100 is movably mounted to an upstanding wall 41w of the base 41 of the support 40 via first and second inner-guide spring 190a and 190b such that the strap-contact surface 110s extends substantially parallel to the longitudinal strap direction LONG (and, in this example embodiment, the strap-path centerline CLSP). The wall 41w is offset from the strap-guiding surface 41s of the base 41 of the support 40 in the transverse strap direction TR. One end of the first inner-guide spring 190a is received in a bore defined within the first spring retainer 150a of the inner strap guide 100 and an opposing end of the first inner-guide spring 190a is received in a corresponding bore (not labeled) defined in the wall 41w such that the first inner-guide spring 190a extends between the bores. Similarly, one end of the second inner-guide spring 190b is received in a bore defined within the second spring retainer 150b of the inner strap guide 100 and an opposing end of the second inner-guide spring 190b is received in a corresponding bore (not labeled) defined in the wall 41 w such that the second inner-guide spring 190b extends between the bores. The first and second inner-guide springs 190a and 190b bias the inner strap guide 100 to a home position shown in Figures 4-9B.

[0034] The outer strap guide 200 includes a rectangular body 210 having a planar strap-contact surface 210s, a first finger 220 extending from a first side of the body 210, a second finger 230 extending from a second side of the body 210 opposite the first side of the body 210, a third finger 240 extending from a lower end of the body 210, and tubular first and second spring retainers 250a and 250b extending from a surface of the body 210 opposite the strap-contact surface 210s and spaced apart in the longitudinal strap direction LONG. The first, second, and third fingers 220, 230, and 240 extend from the body 210 in the same direction and at substantially the same angle, though the angles may differ in other embodiments. In further embodiments, the outer strap guide does not include one or more of the first, second, and third fingers.

[0035] The outer strap guide 200 is movably mounted to an outer-strap-guide support 300 — shown in Figures 4-11 — such that the outer strap guide 200 can move relative to the outer-strap-guide support 300 in the transverse strap direction TR. Specifically, the outer strap guide 200 is movably mounted to the outer-strap-guide support 300 via first and second outer-guide spring 290a and 290b such that the strap-contact surface 210s extends substantially parallel to the longitudinal strap direction LONG (and, in this example embodiment, the strappath centerline CLSP) and substantially parallel to the strap-contact surface 110s of the inner strap guide 100. The outer-strap-guide support 300 is offset from the strap-guiding surface 41s of the base 41 of the support 40 in the transverse strap direction TR. One end of the first outerguide spring 290a is received in a bore defined within the first spring retainer 250a of the outer strap guide 200 and an opposing end of the first outer-guide spring 290b is received in a corresponding bore (not labeled) defined in the outer-strap-guide support 300 such that the first outer-guide spring 290a extends between the bores. Similarly, one end of the second outer-guide spring 290b is received in a bore defined within the second spring retainer 250b of the outer strap guide 200 and an opposing end of the second outer-guide spring 290b is received in corresponding bore (not labeled) defined in the outer-strap-guide support 300 such that the second outer-guide spring 290b extends between the bores. The first and second outer-guide springs 290a and 290b bias the outer strap guide 200 to a home position shown in Figures 4-9B.

[0036] The outer-strap-guide support 300 is vertically movable between a lower position shown in Figures 4, 5 A, 9A, 10A, and 11 and an upper position shown in Figures 6A and 7A. The outer strap guide 200 is movable with the outer-strap-guide support 300 between thelower and upper positions. In this example embodiment, the tensioning assembly 50 is operably connected to the outer- strap-guide support 300 — such as via a pin or a suitable linkage — such the outer-strap-guide support 300 moves from the lower position to the upper position when the tensioning assembly 50 pivots upward and such that the outer-strap-guide support 300 moves from the upper position to the lower position when the tensioning assembly 50 pivots back downward. When the outer-strap-guide support 300 and the outer strap guide 200 attached to it are in the lower position, the strap-contact surfaces 110s and 210s of the inner and outer strap guides 100 and 200 are substantially aligned with one another in the vertical direction from the perspective shown in Figure 5A and in the longitudinal strap direction LONG as shown in Figure 5B. When the outer-strap-guide support 300 and the outer strap guide 200 attached to it are in the upper position, the lower end of the third finger 240 of the outer strap guide 200 and the strapguiding surface 41s of the base 41 are separated by a vertical distance H as shown in Figures 6A and 7A. The vertical distance H is greater than the thickness of the upper and lower strap layers UL and LL — as shown in Figure 7A — to enable these strap layers to be introduced between the inner and outer strap guides 100 and 200.

[0037] In this example embodiment, when the inner and outer strap guides 100 and 200 are in their respective home positions, as shown in Figure 5A, their respective strap-contact surfaces 110s and 210s separated in the transverse strap direction TR by a home distance Du. In this example embodiment, the home distance DH is less than the width of any strap used by the strapping tool 10.

[0038] In this example embodiment, the first and second inner guide springs 190a and 190b and the first and second outer guide springs 290a and 290b are identical (i.e., they have the same length, the same quantity of turns, are made from the same material, have the same spring constant, and the like). Additionally, the first and second inner guide springs 190a and 190b and the first and second outer guide springs 290a and 290b are compressed the same amount when the inner and outer strap guides 100 and 200 are in their respective home positions. Accordingly, the pair of first and second inner guide springs 190a and 190b and the pair of first and second outer guide springs 290a and 290b are configured to exert the same force per unit of deflection of the inner strap guide 100 and the outer strap guide 200, respectively, away from their respective home positions in the transverse strap direction TR.

[0039] Due to this configuration of the guide springs, when strap is introduced between the first and second strap guides 100 and 200, the first and second strap guides 100 and 200 automatically center the strap between them. Figures 7A-10B show this phenomenon. Figures 7A and 7B show the outer strap guide 200 in the upper position, a lower strap layer LL of strap S atop the strap-guiding surface 41s, and an upper strap layer UL of the strap S atop the lower strap layer LL. A side edge of each of the upper strap layer UL and the lower strap layer LL engages the strap-contact surface 110s of the inner strap guide 110 such that the upper and lower strap layers UL and LL are aligned in the transverse strap direction TR. The strap S has a width W that is greater than the home distance DH. Accordingly, the opposite side edges of the upper and lower strap layers UL and LL are positioned below the third finger 240 of the outer strap guide 200, and the centerline CLs of the strap S in the transverse strap direction TR is laterally offset from the strap-path centerline CLSP. Specifically, a first distance DI separates the centerline CLs of the strap S from the strap-contact surface 210s in the transverse strap direction TR and a second distance D2 separates the centerline CLs of the strap S from the strap-contact surface 110s in the transverse strap direction TR. The second distance D2 is greater than the first distance DI.

[0040] As the outer strap guide 200 moves back to its lower position, the angled surface of the third finger 240 engages the upper surface and / or the side edge of the upper strap layer UL below it, as shown in Figure 8A. Continued movement of the outer strap guide 200 to the lower position results in the outer strap guide 200 moving away from the home position and compressing the first and second outer guide springs 290a and 290b as shown in Figures 9A and 9B. Eventually the force exerted by the outer strap guide 200 (via the first and second outer guide springs 290a and 290b) on the upper and lower strap layers UL and LL overcomes the force exerted by the inner strap guide 100 (via the first and second inner guide springs 190a and 190b). This results in the outer strap guide 200 moving back toward its home position, thereby forcing the upper and lower strap layers UL and LL to force the inner strap guide 100 to move away from its home position. The movement stops once the inner and outer strap guides 100 and 200 exert the same force F on the strap S, which is shown in Figures 10A and 10B. Due to the above-described configuration of the inner and outer guide springs, this results in the strap S being centered between the inner and outer strap guides 100 and 200 such that the centerline CLsof the strap S is aligned with the strap-path centerline C SP in the transverse strap direction, as also shown in Figures 10A and 10B.

[0041] The strap guides of the present disclosure improve upon the above-described individual strap guides because they automatically adjust to strap of different widths. This eliminates the need for operators to keep track of different strap guides tied to distinct strap widths and to swap strap guides when switching to different width strap. The fact that the strap guides of the present also automatically center the strap — regardless of its width — increases the repeatability of the strapping process.

[0042] The one or more input devices of the strapping tool 10 are operable to initiate the tensioning and / or sealing cycles. They may include pushbutton actuators, a touch screen, or any other suitable input device.

[0043] The controller of the strapping tool 10 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 tool 10. The controller is communicatively and operably connected to the motor M and the one or more input devices and is configured to receive signals from and to control those components. The controller 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.

[0044] The controller is configured to operate the strapping tool 10 in one of three operating modes to carry out the strapping cycle: (1) a manual operating mode; (2) a semi-automatic operating mode; and (3) an automatic operating mode. In the manual operating mode, the controller operates the motor M to cause the tension wheel 52 to rotate responsive to a first of the one or more input devices being actuated and maintained in its actuated state. The controller operates the motor M to cause the sealing assembly 60 to carry out the sealing cycle responsive to a second of the one or more input devices being actuated. In the semi-automatic operating mode, the controller operates the motor M to cause the tension wheel 52 to rotate responsive to the first input device being actuated and maintained in its actuated state. Once the controller determines that the tension in the strap reaches the (preset) desired strap tension, the controller automatically operates the motor M to cause the sealing assembly 60 to carry out the sealing cycle (without requiring additional input from the operator). In the automatic operating mode, the controller operates the motor M to cause the tension wheel 52 to rotate responsive to the first input device being actuated. Once the controller determines that the tension in the strap reaches the (preset) desired strap tension, the controller automatically operates the motor M to cause the sealing assembly 60 to carry out the sealing cycle (without requiring additional input from the operator).

[0045] The power supply is electrically connected to (via suitable wiring and other components) and configured to power several components of the strapping tool 10, including the motor M and the controller. The power supply 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.

[0046] Use of the strapping tool 10 to carry out a strapping cycle to form a tensioned strap loop around a load is now described below. The strapping tool 10 is in the automatic mode for the purposes of this example.

[0047] The operator pulls the strap S leading-end first from a strap supply, wraps the strap S around the load, and positions the lower strap layer LL including the leading end LE of the strap S below the upper strap layer UL of the strap S. The operator then pulls the trigger 70 to lift the tensioning assembly 50 and separate the tension wheel 52 from the tension plate 42, which in turn lifts the outer strap guide 200 to its upper position. While continuing to pull the trigger 70, the operator introduces the overlapping upper and lower strap layers UL and LL of the strap S between the tension wheel 52 and the tension plate 42 and between the weld shoe 62 and the weld plate 49 as shown in Figures 7A and 7B . The operator then releases the trigger 70,enabling the appropriate biasing elements to force the outer strap guide 200 to its lower position to center the strap S as shown in Figures 10A and 10B and to force the tensioning assembly 50 descend and sandwich the overlapping upper and lower strap layers UL and LL between the tension wheel 52 and the tension plate 42.

[0048] The operator then actuates the first input device, and in response the controller starts the tensioning cycle by controlling the motor M to rotate the output shaft in the first drive direction. As explained above, the transmission 80 transmits this rotational movement of the output shaft to the tensioning-assembly gearing which, in turn, rotates the tension wheel 52 in the tensioning rotational direction. As the tension wheel 52 rotates, it pulls the upper strap layer UL of the strap S over the lower strap layer LL of the strap S in the longitudinal strap direction LONG, thereby tensioning the strap S around the load. Throughout the tensioning cycle, the controller monitors the current drawn by the motor M. When this current reaches a preset value that is correlated with the (preset) desired strap tension for this strapping cycle, the controller stops the motor M, thereby terminating the tensioning cycle.

[0049] After completion of the tensioning cycle, the controller automatically starts the sealing cycle by controlling the motor M to begin rotating the output shaft in the second drive direction. This causes the transmission 80 to begin oscillating the weld shoe 62 and to pivot the weld arm to the connecting position to cause the weld shoe 62 to move downward to force the overlapping upper and lower strap layers UL and LL against the weld plate 49. The oscillation of the weld shoe 62 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. As the weld arm 61 reaches the connecting position, the cutter 63 cuts the upper strap layer UL from the strap supply to form a new leading end of the strap. The controller controls the motor M to stop rotating the output shaft, completing the sealing cycle.

[0050] Figure 12 shows part of another embodiment of the strapping tool of the present disclosure. In this embodiment, rather the include a single inner strap guide and a single outer strap guide extending between the tension plate 42 and the weld plate 49, the strapping tool includes a pair of inner strap guides — one forward of the tension plate 42 and one rearward of the weld plate 49 — and a pair of outer strap guides — one forward of the tension plate 42 and one rearward of the weld plate 49. Specifically, in this example embodiment, the strapping toolincludes a first inner strap guide 1100a, a second inner strap guide 1100b, a first outer strap guide 1200a, and a second outer strap guide 1200b.

[0051] The first inner strap guide 1100a includes a rectangular body 1110a having a planar strap-contact surface 11 lOas, a first finger 1120a extending from a first side of the body 1110a, a second finger 1130a extending from a second side of the body 1110a opposite the first side of the body 1110a, a third finger 1140a extending from a lower end of the body 1110a, and a tubular retainer 1150a extending from a surface of the body 1110a opposite the strap-contact surface 11 lOas. The first, second, and third fingers 1120a, 1130a, and 1140a extend from the body 1110a in the same direction and at substantially the same angle, though the angles may differ in other embodiments. In further embodiments, the inner strap guide does not include one or more of the first, second, and third fingers.

[0052] The second inner strap guide 1100b includes a rectangular body 1110b having a planar strap-contact surface 11 lObs, a first finger 1120b extending from a first side of the body 1110b, a second finger 1130b extending from a second side of the body 1110b opposite the first side of the body 1110b, a third finger 1140b extending from a lower end of the body 1110b, and a tubular retainer 1150b extending from a surface of the body 1110b opposite the strap-contact surface 11 lObs. The first, second, and third fingers 1120b, 1130b, and 1140b extend from the body 1110b in the same direction and at substantially the same angle, though the angles may differ in other embodiments. In further embodiments, the inner strap guide does not include one or more of the first, second, and third fingers.

[0053] The first inner strap guide 1100a is movably mounted to the support 40 such that the first inner strap guide 1100a can move relative to the support 40 in the transverse strap direction TR. Specifically, the first inner strap guide 1100a is movably mounted to an upstanding first wall 41wl of the base 41 of the support 40 via a first inner-guide spring 1190a such that the strap-contact surface 11 lOas extends substantially parallel to the longitudinal strap direction LONG (and, in this example embodiment, the strap-path centerline CLSP). The first wall 41wl is forward of the tension plate 42 in the longitudinal strap direction LONG and is offset from the strap-path centerline CLSP in the transverse strap direction TR. One end of the first inner-guide spring 1190a is received in a bore defined within the spring retainer 1150a of the first inner strap guide 1100a and an opposing end of the first inner-guide spring 1190a is received in a corresponding bore (not labeled) defined in the first wall 41wl such that the first inner-guidespring 1190a extends between the bores. The first inner-guide spring 1190a biases the inner strap guide 1100a to a home position.

[0054] The second inner strap guide 1100b is movably mounted to the support 40 such that the second inner strap guide 1100b can move relative to the support 40 in the transverse strap direction TR. Specifically, the second inner strap guide 1100b is movably mounted to an upstanding second wall 41w2 of the base 41 of the support 40 via a second inner-guide spring 1190b such that the strap-contact surface 11 lObs extends substantially parallel to the longitudinal strap direction LONG (and, in this example embodiment, the strap-path centerline CLSP). The second wall 41w2 is rearward of the weld plate 49 in the longitudinal strap direction LONG and is offset from the strap-path centerline CLSP in the transverse strap direction TR such that the first and second inner strap guides 1100a and 1100b flank the tension and weld plates 42 and 49. One end of the second inner-guide spring 1190b is received in a bore defined within the spring retainer 1150b of the second inner strap guide 1100b and an opposing end of the second inner-guide spring 1190b is received in a corresponding bore (not labeled) defined in the second wall 41w2 such that the second inner-guide spring 1190b extends between the bores. The second inner-guide spring 1190b biases the second inner strap guide 1100b to a home position.

[0055] The first outer strap guide 1200a includes a rectangular body 1210a having a planar strap-contact surface 1210as, a first finger 1220a extending from a first side of the body 1210a, a second finger 1230a extending from a second side of the body 1210a opposite the first side of the body 1210a, a third finger 1240a extending from a lower end of the body 1210a, and a tubular retainer 1250a extending from a surface of the body 1210a opposite the strap-contact surface 1210as. The first, second, and third fingers 1220a, 1230a, and 1240a extend from the body 1210a in the same direction and at substantially the same angle, though the angles may differ in other embodiments. In further embodiments, the inner strap guide does not include one or more of the first, second, and third fingers.

[0056] The second outer strap guide 1200b includes a rectangular body 1210b having a planar strap-contact surface 1210bs, a first finger 1220b extending from a first side of the body 1210b, a second finger 1230b extending from a second side of the body 1210b opposite the first side of the body 1210b, a third finger 1240b extending from a lower end of the body 1210b, and a tubular retainer 1250b extending from a surface of the body 1210b opposite the strap-contact surface 1210bs. The first, second, and third fingers 1220b, 1230b, and 1240bextend from the body 1210b in the same direction and at substantially the same angle, though the angles may differ in other embodiments. In further embodiments, the inner strap guide does not include one or more of the first, second, and third fingers.

[0057] The first outer strap guide 1200a is movably mounted to an outer-strap-guide support 1300 — which is identical to the outer-strap-guide support 300 in this example embodiment — such that the first outer strap guide 1200a can move relative to the outer-strapguide support 1300 in the transverse strap direction TR. Specifically, the first outer strap guide 1200a is movably mounted to the outer-strap-guide support 1300 via a first outer-guide spring 1290a such that the strap-contact surface 1210as extends substantially parallel to the longitudinal strap direction LONG (and, in this example embodiment, the strap-path centerline CLSP) and substantially parallel to the strap-contact surface 11 as of the first inner strap guide 1100a. The first outer strap guide 1200a is positioned opposite the first inner strap guide 1100a. One end of the first outer-guide spring 1290a is received in a bore defined within the spring retainer 1250a of the first outer strap guide 1200a and the opposing end is received in a corresponding bore (not labeled) defined in the outer-strap-guide support 1300 such that the first outer-guide spring 1290a extends between the bores. The first outer-guide spring 1290a biases the first outer strap guide 1200a to a home position.

[0058] The second outer strap guide 1200b is movably mounted to the outer-strapguide support 1300 such that the second outer strap guide 1200b can move relative to the outer-strap-guide support 1300 in the transverse strap direction TR. Specifically, the second outer strap guide 1200b is movably mounted to the outer-strap-guide support 1300 via a second outer-guide spring 1290b such that the strap-contact surface 1210bs extends substantially parallel to the longitudinal strap direction LONG (and, in this example embodiment, the strap-path centerline CLSP) and substantially parallel to the strap-contact surface 11 lObs of the second inner strap guide 1100b. The second outer strap guide 1200b is positioned opposite the second inner strap guide 1100b. One end of the second outer-guide spring 1290b is received in a bore defined within the spring retainer 1250b of the second outer strap guide 1200b and the opposing end is received in a corresponding bore (not labeled) defined in the outer-strap-guide support 1300 such that the second outer-guide spring 1290b extends between the bores. The second outer-guide spring 1290b biases the second outer strap guide 1200b to a home position.

[0059] The outer-strap-guide support 1300 is vertically movable between a lower position and an upper position as explained above with respect to the outer-strap-guide support 300.

[0060] In this example embodiment, the first inner and outer strap guides 1100a and 1200a operate similar to the strap guides 100 and 200 described above except that they engage a first portion of the upper and lower strap layers forward of the tension plate 42 in the longitudinal strap direction LONG. Similarly, the second inner and outer strap guides 1100b and 1200b operate similar to the strap guides 100 and 200 described above except that they engage a second portion of the upper and lower strap layers rearward of the weld plate 49 in the longitudinal strap direction LONG.

[0061] Figure 13 shows another embodiment of the strapping tool of the present disclosure that is identical to the strapping tool 10 except that the outer strap guide 200 is fixedly mounted to the outer-strap-guide support 300 such that the outer strap guide 200 is not movable in the transverse strap direction TR. Figure 14 shows another embodiment of the strapping tool of the present disclosure that is identical to the strapping tool 10 except that the inner strap guide 100 is fixedly mounted to the wall 41w such that the inner strap guide 100 is not movable in the transverse strap direction TR.

[0062] In other embodiments, the inner and outer strap guides are mechanically linked together such that they move the same distance in the transverse direction.

[0063] The above-described example embodiment of the strapping tool includes a single motor configured to drive both the tensioning assembly and the sealing assembly. In other embodiments, the strapping tool includes separate motors configured to drive the respective tensioning and sealing assemblies and may include separate transmissions for each motor.

[0064] Other embodiments of the strapping tool may include fewer assemblies, components, and / or features than those included in the strapping tool 10 described above and shown in the Figures. In other words, while the strapping tool 10 includes all of the assemblies, components, and features described above, they are independent of one another and may be independently included in other strapping tools.

[0065] While the strapping tool described above is a handheld strapping tool, the strapping tool may be any other suitable strapping tool in other embodiments, such as a standalone automatic or semi-automatic strapping machine.

[0066] In the strapping tool described above, the movable rocker supports the tension wheel and moves the tension wheel relative to the stationary tension plate. 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.

Claims

Claims1. A strapping tool comprising:a support comprising a base;a strap manipulator supported by the support;a plate below the strap manipulator;a first strap guide comprising a first strap-contact surface;one or more first biasing elements biasing the first strap guide to a first home position; anda second strap guide comprising a second strap-contact surface,wherein the first and second strap guides are positioned such that the first and second strap-contact surfaces are opposite one another and such that a strap path extending in a longitudinal direction is defined between the first and second strap-contact surfaces, below the strap manipulator, and above the plate, andwherein the first strap guide is movable from the first home position in a transverse direction to change a distance separating the first and second strap-contact surfaces, wherein the transverse direction is transverse to the longitudinal direction.

2. The strapping tool of claim 1, further comprising one or more second biasing elements biasing the second strap guide to a second home position, wherein the second strap guide is movable from the second home position in the transverse direction to change the distance separating the first and second strap-contact surfaces.

3. The strapping tool of claim 2, wherein the first and second strap guides are movable independently of one another in the transverse direction.

4. The strapping tool of claim 3, wherein the second strap guide is vertically movable relative to the first strap guide between a lower position and an upper position.

5. The strapping tool of claim 4, wherein when the first strap guide is in the first home position and the second strap guide is in the lower position and the second home position, a first distance separates the first and second strap-contact surfaces.

6. The strapping tool of claim 5, wherein when the first strap guide is in the first home position, the second strap guide is in the lower position and the second home position, andoverlapping upper and lower strap layers are positioned in the strap path between the first and second strap-contact surfaces, a second distance separates the first and second contact surfaces, wherein the second distance is greater than the first distance.

7. The strapping tool of claim 6, wherein when the first strap guide is in the first home position, the second strap guide is in the lower position and the second home position, and overlapping upper and lower strap layers are positioned in the strap path between the first and second strap-contact surfaces, the first strap guide is not at the first home position and the second strap guide is not at the second home position.

8. The strapping tool of claim 7, wherein when the first strap guide is in the first home position, the second strap guide is in the lower position and the second home position, and overlapping upper and lower strap layers are positioned in the strap path between the first and second strap-contact surfaces, the first strap guide exerts a first force against a first side of the upper and lower strap layers and the second guide exerts a second force against a second side of the upper and lower strap layers, wherein the first force and the second force are equal.

9. The strapping tool of claim 8, wherein when the first strap guide is in the first home position, the second strap guide is in the upper position and the second home position, and overlapping upper and lower strap layers are positioned in the strap path, part of the overlapping upper and lower strap layers extend beneath the second strap guide such that, as the second strap guide moves to the lower position, the second strap guide contacts the upper and lower strap layers, thereby forcing the upper and lower strap layers, the second strap guide, and the first strap guide to move in the transverse direction until the first strap guide exerts the first force against the first side of the upper and lower strap layers and the second strap guide exerts the second force against the second side of the upper and lower strap layers.

10. The strapping tool of claim 9, wherein a strap-path centerline is defined at a center of the strap path in the transverse direction, wherein the strap-path centerline extends in the longitudinal direction, wherein when the first strap guide is in the first home position, the second strap guide is in the lower position and the second home position, and overlapping upper and lower strap layers are positioned in the strap path between the first and second strap-contactsurfaces, a strap centerline of the overlapping upper and lower strap layers is aligned with the strap-path centerline.

11. The strapping tool of claim 6, further comprising a tensioner supported by the support and a tension plate below the tensioner, wherein the strap manipulator comprises a strap connector and the plate comprises a connector plate, wherein the tensioner and the strap connector are spaced apart in the longitudinal direction, wherein the tension plate and the connector plate are spaced apart in the longitudinal direction, wherein the first and second strap guides are positioned between the tension plate and the connector plate.

12. The strapping tool of claim 6, further comprising a tensioner supported by the support and a tension plate below the tensioner, wherein the strap manipulator comprises a strap connector and the plate comprises a connector plate, wherein the tensioner and the strap connector are spaced apart in the longitudinal direction, wherein the tension plate and the connector plate are spaced apart in the longitudinal direction, wherein the first and second strap guides are positioned forward of the tension plate in the longitudinal direction.

13. The strapping tool of claim 12, further comprising:a third strap guide comprising a third strap-contact surface;one or more third biasing elements biasing the third strap guide to a third home position; anda fourth strap guide comprising a fourth strap-contact surface; andone or more fourth biasing elements biasing the fourth strap guide to a fourth home position,wherein the third and fourth strap guides are positioned such that the third and fourth strap-contact surfaces are opposite one another and such that the strap path is further defined between the third and fourth strap-contact surfaces,wherein the third strap guide is movable from the third home position in the transverse direction to change a distance separating the third and fourth strap-contact surfaces, wherein the fourth strap guide is movable from the fourth home position in the transverse direction to change the distance separating the third and fourth strap-contact surfaces, and wherein the third and fourth strap guides are positioned rearward of the connector plate in the longitudinal direction.

14. The strapping tool of claim 1 , wherein the second strap guide is vertically movable relative to the first strap guide between a lower position and an upper position, wherein when the first strap guide is in the first home position and the second strap guide is in the lower position, a first distance separates the first and second strap-contact surfaces, wherein when the first strap guide is in the first home position, the second strap guide is in the lower position, and overlapping upper and lower strap layers are positioned in the strap path between the first and second strap-contact surfaces, a second distance separates the first and second contact surfaces, wherein the second distance is greater than the first distance.

15. The strapping tool of claim 1, wherein the first strap guide is vertically movable relative to the second strap guide between a lower position and an upper position, wherein when the first strap guide is in the lower position and the first home position, a first distance separates the first and second strap-contact surfaces, wherein when the first strap guide is in the lower position and the first home position and overlapping upper and lower strap layers are positioned in the strap path between the first and second strap-contact surfaces, a second distance separates the first and second contact surfaces, wherein the second distance is greater than the first distance.

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