Strapping device with a linearly movable tensioning-and-welding plate

Abstract

Various embodiments of the present disclosure provide a strapping device including a rotatable tensioning wheel, a tensioning-and-welding plate linearly movable relative to the tensioning wheel, and a rotary-to-linear converter operably connected to the tensioning-and-welding plate and configured to convert rotational movement into linear reciprocating movement of the tensioning-and-welding plate relative to the tensioning wheel.

Description

STRAPPING DEVICE WITH A LINEARLY MOVABLE TENSIONING- AND-WELDING PLATEPriority

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 583,674, filed September 19, 2023, 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 via friction welding 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. 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 aligned with the tensioning wheel and plate in the longitudinal direction of the strap. The tensioning wheel is spring-biased to force 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. 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] One problem with certain known strapping tools that use friction welding to attach the strap layers to one another is that they include separate assemblies — and sometimes even separate motors — for tensioning and sealing the strap. This can make these devices relatively heavy. Since strapping tool operators can use handheld strapping tools hundreds of times each day, there is a need to make the strapping tools as light as possible without sacrificing performance.

[0007] Another problem with certain known strapping tools is the size of their base plate. The base plate separates the tensioning and weld plates from the load and rests on the load during operation. Since the weld plate is rearward of and aligned with the tensioning plate, the base plate is relatively long. This prevents operators from using the strapping tool to strap curved loads with relatively small radii, such as small bundles of metal pipes, because the length of the base plate prevents the strap from retaining adequate tension after the strapping tool is removed from the load. Since this limits the potential applications of these strapping tools, there is a need for strapping tools with shorter base plates.Summary

[0008] Various embodiments of the present disclosure provide a strapping device including a rotatable tensioning wheel, a tensioning-and-welding plate linearly movable relative to the tensioning wheel, and a rotary-to-linear converter operably connected to the tensioning-and-welding plate and configured to convert rotational movement into linear reciprocating movement of the tensioning-and-welding plate relative to the tensioning wheel.Brief Description of the Figures

[0009] Figure 1 A is a perspective view of one example embodiment of a strapping tool of the present disclosure.

[0010] Figure IB is a block diagram of certain components of the strapping tool of Figure 1A.

[0011] Figures 2A-2C are diagrammatic views of the strapping tool of Figure 1A securing a load to a pallet.

[0012] Figure 2D is a perspective view of a friction-weld strap joint formed by the strapping device of Figures 1A and IB.

[0013] Figure 3 A is a perspective view of the working assembly of the strapping tool of Figure 1A.

[0014] Figure 3B is a perspective view of the working assembly of Figure 3A with the first frame of the support of the working assembly removed.

[0015] Figure 4 is a perspective view of the transmission of the working assembly of Figure 3 A.

[0016] Figure 5 A is a perspective view of the tensioning assembly of the working assembly of Figure 3 A.

[0017] Figure 5B is an exploded perspective view of the tensioning assembly of Figure 5A.

[0018] Figure 5C is a cross-sectional perspective view of the tensioning assembly of Figure 5 A taken along line 5C-5C of Figure 5 A.

[0019] Figure 6A is a side elevational view of the working assembly of Figure 3 A with the tensioning assembly of Figure 5 A in the tensioning-and-welding position.

[0020] Figure 6B is a side elevational view of the working assembly of Figure 3 A with the tensioning assembly of Figure 5 A is the strap-insertion position after strap has been inserted into the strapping tool.

[0021] Figure 7 is a perspective view of the rotary-to-linear converter of the working assembly of Figure 3 A and the base of the support of the working assembly.

[0022] Figures 8A and 8B are perspective and bottom plan views, respectively, of the driven shaft of the rotary-to-linear converter of Figure 7.

[0023] Figures 9A-9E are cross-sectional top plan views of part of the rotary-to- linear converter of Figure 7 taken along line 9A-9A of Figure 7 that show the reciprocating linear movement of the tensioning-and-welding plate during a complete rotation of the driven shaft of Figure 8 A.

[0024] Figure 10 is similar to Figure 9A but shows part of a rotary-to-linear converter of an alternative embodiment of the strapping tool of the present disclosure.

[0025] Figure 11 is similar to Figure 9A but shows part of a rotary-to-linear converter of an alternative embodiment of the strapping tool of the present disclosure.

[0026] Figure 12 is similar to Figure 9A but shows part of an alternative embodiment of the strapping tool of the present disclosure.Detailed Description

[0027] 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.

[0028] Figures 1 A-9E show one example embodiment of a strapping device of the present disclosure in the form of a battery-powered handheld strapping tool 50 and certain assemblies and components thereof. As shown in Figures 2A-2C, the strapping tool 50 is configured to carry out a strapping process 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 2A. The operator then introduces the overlapped upper and lower layers UL and LL of the strap S into the strapping tool 50 and actuates one or more buttons to initiate the strapping process. As shown in Figure 2B, the strapping tool 50 first carries out a tensioning process during which the strapping tool 50 tensions strap S around the load L. Once a preset tension is reached in the strap S, as shown in Figure 2C, the strapping tool 50 carries out a sealing process during which the strapping tool 50 connects the upper and 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 2D, and cuts the strap S from the strap supply.

[0029] The strapping tool 50 includes a housing 100, a working assembly 200, a display assembly 1300, an actuating assembly 1400, a power supply, a controller 1600, and one or more sensors 1700.

[0030] The housing 100, which is shown in Figure 1 A, is formed from multiple components that collectively at least partially enclose and / or support some or all of the other assemblies and components of the strapping tool 50. In this example embodiment, the housing 100 includes a front housing section 110, a rear housing section 120, 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 and the actuating assembly 1400. The rear housing section 120 at least partially encloses and / or supports at least some of the components of the display assembly 1300 and defines a receptacle 122 sized, shaped, and otherwise configured to receive and at least partially enclose and / or support the power supply and the controller 1600. The handle housing section 150 extends between and connects the tops bottoms of the front and rear housing sections 110 and 120 and defines a handle usable by the operator. This is merely one example, and in other embodiments the components of the strapping tool may be supportedand / or enclosed by any suitable portion of the housing 100. The housing 100 may take any suitable shape and 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.

[0031] The working assembly 200, which is best shown in Figures 1 A, 3A, and 3B, includes the majority of the components of the strapping tool 50 that are configured to carry out the strapping process to tension the strap around the load and attach the overlapping layers of the strap to one another. The working assembly 200 includes a support 300, a tensioning-and- welding plate 390, a motor 400, a transmission 500, a tensioning assembly 600, a rotary-to-linear converter 700, and a hand lever 800.

[0032] The support 300, which is best shown in Figures 3A and 3B, serves as a direct or indirect common mount for the tensioning-and-welding plate 390, the motor 400, the transmission 500, the tensioning assembly 600, and the rotary-to-linear converter 700. The support 300 includes a base 310, a first frame 320, a second frame 322, and a rail 325. The base 310 is substantially planar, generally rectangular, and extends longitudinally in a transverse direction DI. As best shown in Figures 3 A, 6A, and 9A, the transverse direction DI refers to the transverse direction of the strap when received in the strapping tool 50, and the longitudinal direction D2 refers to the longitudinal direction of the strap when received in the strapping tool 50. In this example embodiment, the transverse direction DI is perpendicular to the longitudinal direction D2, though they may be transverse but not perpendicular to one another in other embodiments. The rail 325 — which serves as a mount for the tensioning-and-welding plate 390 and certain components of the rotary-to-linear converter 700 as described below — is mounted to the base 310 in any suitable manner (such as via fasteners) and extends in the transverse direction DI . The first frame 320 extends upward from the base 310 and serves as a mount for the motor 400, the transmission 500, and certain components of the rotary-to-linear converter 700, as described below. The second frame 322 extends upward from the base 310 and serves as a mount for the tensioning assembly 600. This is merely one example configuration of the support 300, and other embodiments may be configured differently.

[0033] The tensioning-and-welding plate 390, best shown in Figure 7, includes a toothed surface 392 and is slidably mounted to the rail 325 of the support 390 beneath the tensioning assembly 600 such that it can move in a linear reciprocating manner relative to thetensioning assembly 600 in the transverse direction DI under control of the rotary -to-linear converter 700. As described below, the tensioning-and-welding plate 390 serves two functions. First, during the tensioning process, the tensioning-and-welding plate 390 is held stationary in the transverse direction DI and serves as a counter-pressure plate as the strap is tensioned. Second, during the sealing process, the tensioning-and-welding plate 390 is reciprocated in the transverse direction DI to locally melt the strap.

[0034] The motor 400, which is best shown in Figures 3A and 3B, is mounted to the first frame 310 and includes a motor housing 400h and a rotatable motor output shaft 400s extending from the motor housing 400h. A motor drive gear 450 is fixedly attached to the motor output shaft 400s such that the motor drive gear 450 rotates with the motor output shaft 400s. The motor drive gear 450 is a bevel pinion gear in this example embodiment but may be any other suitable component in other embodiments. As shown in Figure 3B, the motor 400 is configured to rotate the motor output shaft 400s in opposing first and second rotational directions R1 and R2 to carry out the tensioning and sealing processes, respectively, as explained below. The motor 400 includes an electric motor in this example embodiment but may include any suitable motor or other actuator in other embodiments.

[0035] The transmission 500, which is best shown in Figures 3A-4, is driven by the motor 400 and is operably connected to: (1) the tensioning assembly 600 and configured to cause the tensioning assembly 600 to tension the strap around the load during the tensioning process; and (2) the rotary -to-linear converter 700 and configured to cause the rotary -to-linear converter 700 to reciprocate the tensioning-and-welding plate 390 to locally melt the strap via friction welding during the sealing process. To do so, the transmission 500 is configured to: (1) transmit output from the motor 400 to the tensioning assembly 600 but not to the rotary -to-linear converter 700 when the motor 400 rotates the motor output shaft 410s in the first rotational direction Rl; and (2) to the rotary -to-linear converter 700 but not to the tensioning assembly 600 when the motor 400 rotates the motor output shaft 410s in the second rotational direction R2. The transmission 500 includes a first shaft 505, an input gear 510, a sealing-assembly freewheel 515, a sealing-assembly-drive gear 520, a tensioning-assembly freewheel 525, a first intermediate gear 530, a second shaft 540, a second intermediate gear 545, a tensioningassembly-drive gear 550, and a connector 555.

[0036] The first shaft 505 is rotatably supported by the first frame 320 of the support 300 in any suitable manner, such as via bearings fit onto opposite ends of the first shaft 505 and into suitable bores in the first frame 320. As shown in Figure 4, the first shaft 505 is rotatable relative to the support 300 in a tensioning rotational direction T and an opposing sealing rotational direction S. The input gear 510 is fixedly attached to or otherwise mounted to one end of the first shaft 505 such that the input gear 510 and the first shaft 505 rotate together. The input gear 510 is a bevel pinion gear in this example embodiment but may be any other suitable component in other embodiments. The motor drive gear 450 is drivingly engaged to the input gear 510 via the teeth of the motor drive gear 450 meshing with the teeth of the input gear 510. Specifically, the motor 400 is (via this driving engagement) operably connected to the first shaft 505 and configured to rotate the first shaft 505 in the tensioning rotational direction T (via rotation of the motor output shaft 400s in the first rotational direction Rl) and in the sealing rotational direction S (via rotation of the motor output shaft 400s in the second rotational direction R2).

[0037] The sealing-assembly freewheel 515 is mounted to, engages, and circumscribes the first shaft 505. The sealing-assembly-drive gear 520 is mounted to, engages, and circumscribes the sealing-assembly freewheel 515. The sealing-assembly-drive gear is a bevel gear in this example embodiment but may be any other suitable component in other embodiments. The sealing-assembly freewheel 515 is configured to: (1) transmit rotational movement of the first shaft 505 in the sealing rotational direction S to the sealing-assembly-drive gear 520 so the sealing-assembly-drive gear 520 and the first shaft 505 rotate together in the sealing rotational direction S; and (2) not transmit rotational movement of the first shaft 505 in the tensioning rotational direction T to the sealing-assembly-drive gear 520 so the first shaft 505 rotates in the tensioning rotational direction T relative the sealing-assembly-drive gear 520.

[0038] The tensioning-assembly freewheel 525 is mounted to, engages, and circumscribes the first shaft 505 and is positioned such that the sealing-assembly freewheel 515 is between the tensioning-assembly freewheel 525 and the input gear 510. The first intermediate gear 530 is mounted to, engages, and circumscribes the tensioning-assembly freewheel 525. The first intermediate gear is a gear pulley in this example embodiment but may be any other suitable component in other embodiments. The tensioning-assembly freewheel 525 is configured to: (1) transmit rotational movement of the first shaft 505 in the tensioning rotational direction T to thefirst intermediate gear 530 so the first intermediate gear 530 and the first shaft 505 rotate together in the tensioning rotational direction T; and (2) not transmit rotational movement of the first shaft 505 in the sealing rotational direction S to the first intermediate gear 530 so the first shaft 505 rotates in the sealing rotational direction S relative the first intermediate gear 530.

[0039] The second shaft 540 is rotatably supported by the first frame 320 of the support 300 in any suitable manner, such as via bearings fit onto opposite ends of the second shaft 540 and into suitable bores in the first frame 320. The second shaft 540 is spaced-apart from the first shaft 505 in the longitudinal direction D2. The second intermediate gear 545 is fixedly attached to or otherwise mounted to the second shaft 540 such that the second intermediate gear 545 and the second shaft 540 rotate together. The second intermediate gear 545 is a gear pulley in this example embodiment but may be any other suitable component in other embodiments. The tensioning-assembly-drive gear 550 is fixedly attached to or otherwise mounted to one end of the second shaft 540 such that the tensioning-assembly-drive gear 550 and the second shaft 540 rotate together. The tensioning-assembly-drive gear 550 is a gear pulley in this example embodiment but may be any other suitable component in other embodiments.

[0040] The connector 555, which is a toothed belt in this example embodiment but may be any suitable connector in other embodiments, operably connects the first intermediate gear 530 and the second intermediate gear 545.

[0041] When the motor 400 rotates the motor output shaft 400s in the first rotational direction Rl, the first shaft 505 rotates in the tensioning rotational direction T. The sealingassembly freewheel 515 does not transmit this rotational movement to the sealing-assembly- drive gear 520, which remains stationary. On the other hand, the tensioning-assembly freewheel 525 transmits this rotational movement to the first intermediate gear 530, which rotates with the first shaft 505 in the tensioning rotational direction T. The connector 555 transmits this rotational movement to the second intermediate gear 545, which begins rotating and causes the second shaft 540 and the tensioning-assembly-drive gear 550 to rotate with it.

[0042] When the motor 400 rotates the motor output shaft 400s in the second rotational direction R2, the first shaft 505 rotates in the sealing rotational direction S. The sealing-assembly freewheel 515 transmits this rotational movement to the sealing-assembly- drive gear 520, which rotates with the first shaft 505 in the sealing rotational direction S. On theother hand, the tensioning-assembly freewheel 525 does not transmit this rotational movement to the first intermediate gear 530, which remains stationary.

[0043] The tensioning assembly 600, which is best shown in Figures 5A-6B, is configured to tension the strap around the load during the tensioning process. The tensioning assembly 600 includes first, second, and third tensioning-assembly supports 614, 618, and 650; tensioning-assembly gearing; a tensioning wheel 640 driven by the tensioning-assembly gearing; a cover 652; and bearings 600b 1, 600b2, and 600b3. The tensioning wheel 640 is supported by the tensioning-assembly gearing, which is in turn supported by the first, second, and third tensioning-assembly supports 614, 618, and 650.

[0044] The tensioning-assembly gearing includes: a driven shaft 610 having a first sun gear 610a at one end; a driven gear 612; a freewheel 616; a ring gear 620 having internal teeth 620it; a carrier 622; a first set of planet gears 624a, 624b, and 624c; a gear mount 630; and a second set of planet gears 634a, 634b, and 634. Certain components of the tensioning-assembly gearing are centered on, and certain components of the tensioning-assembly gearing are rotatable about, a tensioning-wheel rotational axis A640, which is substantially parallel to the transverse direction DI. The driven gear 612 is fixedly attached to or otherwise mounted to the driven shaft 610 such that the driven gear 612 rotates with the driven shaft 610. In this example embodiment, the driven gear is a gear pulley, though it may be any other suitable component in other embodiments. The carrier 622 includes a planet-gear carrier 622a to which the first set of planet gears 624a-624c are rotatably mounted (such as via respective bearings and mounting pins) and a second sun gear 622b rotatable with (and here integrally formed with) the planet-gear carrier 622a about the tensioning-wheel rotational axis A640. The second set of planet gears 634a-634c are rotatably mounted to the gear carrier 630 (such as via respective bearings and mounting pins). The tensioning wheel 640 includes an annular body having internal teeth 642 and a toothed outer surface 644.

[0045] The driven shaft 610 extends through and is engaged by the freewheel 616, which is itself supported by and fit into a bore defined through the second tensioning-assembly support 618. The freewheel 616 is configured to prevent back-driving of the driven shaft 610. The free end of the driven shaft 610 is rotatably supported by the first tensioning-assembly support 614. Specifically, that end is fit into the bearing 600bl, which is in turn fit into a suitable bore defined in the first tensioning-assembly support 614. The first sun gear 610a of the drivenshaft 610 meshes with and drivingly engages the first set of planet gears 624a-624c. The first set of planet gears 624a-624c mesh with the internal teeth 620it of the ring gear 620, which is itself supported by the gear support 630. The second sun gear 622b of the carrier 622 extends through part of the gear support 630 and meshes with and drivingly engages the second set of planet gears 634a-634c. The gear support 630 is attached to the second and third tensioning-assembly supports 618 and 650, such as via suitable fasteners. The tensioning wheel 640 is rotatably mounted to the gear support 630 via the bearing 600b2 such that the second set of planet gears 634a-634c mesh with the internal teeth 642 of the tensioning wheel 640 and therefore drivingly engage the tensioning wheel 640. The tensioning wheel 640 is also rotatably mounted to the cover 652 via the bearing 600b3, and the cover 653 is attached to the gear support 630 in any suitable manner such as via fasteners.

[0046] The tensioning-assembly-drive gear 550 of the transmission 500 is operably connected to the driven shaft 610 to rotate the driven shaft 610. In particular, a toothed belt 500b operably connects the tensioning-assembly-drive gear 550 and the driven gear 612. In operation, when the motor 400 rotates the motor output shaft 400s in the first rotational direction Rl, the transmission 500 converts that rotational movement into rotation of the tensioning-assembly- drive gear 550 as explained above. This results in rotation of the driven gear 612 and, therefore, rotation of the driven shaft 610 and the first sun gear 610a about the tensioning-wheel rotational axis A640. The first sun gear 610a drives the first set of planet gears 624a-624c. Since the ring gear 620 is fixed in rotation by a suitable decoupling assembly or other component (not shown), rotation of the first set of planet gears 624a-624c causes the carrier 622 — including the second sun gear 622b — to rotate about the tensioning-wheel rotational axis A640. The second sun gear 622b drives the second set of planet gears 634a-634c, which causes the tensioning wheel 640 to rotate about the tensioning-wheel rotational axis A640. Accordingly, the tensioning-assembly gearing operatively connects the transmission 500 to the tensioning wheel 640 to rotate the tensioning wheel 640.

[0047] The tensioning assembly 600 is movably mounted to the second frame 322 of the support 300 via the second and third tensioning-assembly supports 618 and 650. Specifically, a shaft extends through aligned bores defined in the second and third tensioning-assembly supports 618 and 650 and a bore defined through the second frame 322 such that the tensioning assembly 600 is configured to pivot relative to the support 300 about a pivot axis Aeoo between atensioning-and-welding position (Figure 6A) and a strap-insertion position (Figure 6B). When the tensioning assembly 600 is in the tensioning-and-welding position, the tensioning wheel 640 is adjacent to the tensioning-and-welding plate 390. When the tensioning assembly 600 is in the strap-insertion position, the tensioning wheel 640 is spaced-apart from the tensioning-and- welding plate 390 to enable the overlapping upper and lower layers UL and LL of the strap S to be inserted between the tensioning wheel 640 and the tensioning-and-welding plate 390, as shown in Figure 6B. The weight of the tensioning assembly 600 and one or more springs or other biasing elements, such as a leaf spring 600s shown in Figures 3A and 3B, bias the tensioning assembly 600 to the tensioning-and-welding position.

[0048] The hand lever 800, which is shown in Figure 1 A, is operably connected to the tensioning assembly 600 — directly or via suitable linkages, gearing, and / or other components — and configured to move the tensioning assembly 600 relative to the support 300 from the tensioning-and-welding position to the strap-insertion position. Specifically, the hand lever 800 is pivotable from a home position (shown in Figure 1 A) spaced-apart from the handle section 150 of the housing 100 of the strapping tool 50 to an actuated position (not shown) closer to the handle section 150 to move the tensioning assembly 600 from the tensioning-and-welding position to the strap-insertion position. In other embodiments, the motor is operably connected — via suitable gearing, linkages, and / or other components — to the tensioning assembly and configured to pivot the tensioning assembly from the tensioning-and-welding position to the strap-insertion position. In these embodiments, the strapping tool includes a suitable input device, such as a hand lever, a trigger, or a button, supported by the handle portion of the housing and actuatable to cause the motor to pivot the tensioning assembly from the tensioning- and-welding position to the strap-insertion position.

[0049] The rotary-to-linear converter 700, which is best shown in Figures 7-9E, is configured to convert rotational movement of the transmission 500 into linear reciprocating movement of the tensioning-and-welding pad 390 during the sealing process. The rotary-to- linear converter 700 includes a driven shaft 710, a slider 720, a drive block 730, and a link 750.

[0050] As best shown in Figures 8 A and 8B, the driven shaft 710 includes a cylindrical shaft portion 712, a driven gear 714 at one end of the shaft portion 712, and a discshaped eccentric 716 at the other end of the shaft portion 712. The driven gear 714 is a bevel gear in this example embodiment, though it may be any other suitable component in otherembodiments. The driven shaft 710 has an axis of rotation A710, referred to herein as the driven- shaft axis A710, that is coaxial with the axes of symmetry and rotation of the shaft portion 712 and the driven gear 714. As best shown in Figure 8B, the eccentric 716 has an axis of symmetry A716 that is parallel to — but offset from — the driven-shaft axis A710. This results in the axis of symmetry A716 of the eccentric 716 — and the eccentric 716 itself — rotating around the driven- shaft axis A710 as the driven shaft 710 rotates about the driven-shaft axis A710. Figure 8B shows positions of the eccentric 716 that correspond to different rotational positions of the driven shaft 710 in dashed lines.

[0051] The driven shaft 710 is rotatably supported — such as via a bearing — by the first frame 320 and oriented such that the driven-shaft axis A710 is transverse to, and here perpendicular to, the transverse and longitudinal directions DI and D2 and the first and second shafts 505 and 540 of the transmission 500. The sealing-assembly-drive gear 520 drivingly engages the driven gear 714 of the driven shaft 710 via meshing of the teeth of the sealingassembly-drive gear 520 and the teeth of the driven gear 714. The slider 720 defines a slot 720s that extends in the longitudinal direction D2 and is supported by the base 310 of the support 300 substantially beneath the driven shaft 710. The slider 720 is slidably mounted to the rail 325 and movable along the rail in the transverse direction DI (though in other embodiments the slider 720 is not mounted to the rail). The drive block 730 is positioned within and movable within the slot 720s of the slider 730. The drive block 730 defines a bore in which the eccentric 716 is received. The link 750 connects the slider 720 to the tensioning-and-welding plate 390.

[0052] The position of the tensioning-and-welding plate 390 in the transverse direction is controlled by the rotational position of the eccentric 716. As explained above, as the driven shaft 710 rotates about the driven-shaft axis A710, the eccentric 716 rotates around the driven-shaft axis A710 in a circular path. The eccentric 716 moves in the transverse and longitudinal directions DI and D2 as it follows its circular path around the driven-shaft axis A710. As this occurs, the eccentric 716 exerts forces on the drive block 730 in both the transverse and longitudinal directions DI and D2. The forces in the transverse direction DI are transferred from the drive block 730 to the slider 720, from the slider 720 to the link 750, and from the link 750 to the tensioning-and-welding plate 390, resulting in the tensioning-and-welding plate 390 sliding along the rail 325. The forces in the longitudinal direction D2 result in the drive block 730 sliding within the slot 720s of the slider 720.

[0053] Figures 9A-9E illustrate this via one example rotation of the driven shaft 710 about the driven-shaft axis A710. Directions referenced in this paragraph refer to directions relative to the perspective shown in Figures 9A-9E. Figure 9 A shows the driven shaft 710 in a rotational position at which the axis of symmetry A716 of the eccentric 716 is directly to the left of the driven-shaft axis A710. This corresponds to the rotational position of the driven shaft 710 at which the tensioning-and-welding plate 390 is closest to the driven shaft 710. Figure 9B shows the components after the driven shaft 710 has rotated 90 degrees counterclockwise. The eccentric 716 has rotated and forced the drive block 730 to move toward the bottom end of the slot 720s of the slider 720 and has (via the slider 720 and the link 750) forced the tensioning-and-welding plate 390 to move away from the driven shaft 710 in the transverse direction DI. Figure 9C shows the components after the driven shaft 710 has rotated another 90 degrees counterclockwise. The eccentric 716 has rotated and forced the drive block 730 to move toward the center of the slot 720s of the slider 720 and has (via the slider 720 and the link 750) forced the tensioning-and-welding plate 390 to move away from the driven shaft 710 in the transverse direction DI. At this point, the driven shaft 710 is in a rotational position at which the tensioning-and-welding plate 390 is furthest from the driven shaft 710. Figure 9D shows the components after the driven shaft has rotated another 90 degrees counterclockwise. The eccentric 716 has rotated and forced the drive block 730 to move toward the upper end of the slot 720s of the slider 720 and has (via the slider 720 and the link 750) forced the tensioning-and-welding plate 390 to move back toward the driven shaft 710 in the transverse direction DI. Figure 9E shows the components after the driven shaft has rotated another 90 degrees counterclockwise to return to the rotational position shown in Figure 9 A. The eccentric 716 has rotated and forced the drive block 730 to move back toward the center of the slot 720s of the slider 720 and has (via the slider 720 and the link 750) forced the tensioning-and-welding plate 390 to move back toward the driven shaft 710 in the transverse direction DI.

[0054] The display assembly 1300, which is shown in Figures 1A and IB, includes a suitable display screen 1310 with a touch panel 1320. The display screen 1310 is configured to display information regarding the strapping tool 50 (at least in this embodiment), and the touch screen 1320 is configured to receive operator inputs such as a desired strap tension and desired weld cooling time. A display controller (not shown) may control the display screen 1310 and the touch panel 1320 and, in these embodiments, is communicatively connected to the controller1600 to send signals to the controller 1600 and to receive signals from the controller 1600. Other embodiments of the strapping tool do not include a touch panel. Still other embodiments of the strapping tool do not include a display assembly. Certain embodiments of the strapping tool include a separate pushbutton panel instead of a touch panel beneath or integrated with the display screen.

[0055] The actuating assembly 1400, which is shown in Figures 1A and IB, is configured to receive operator input to start operation of the tensioning and sealing processes. In this example embodiment, the actuating assembly 1400 includes first and second pushbutton actuators 1410 and 1420 that, depending on the operating mode of the strapping tool 50, initiate the tensioning and / or sealing processes as described below. Other embodiments of the strapping tool 50 do not have an actuating assembly 1400 and instead incorporate its functionality into the display assembly 1300. 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.

[0056] The controller 1600, which is shown in Figure IB, 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 50. The controller 1600 is communicatively and operably connected to the motor 400, the display assembly 1300, the actuating assembly 1400, 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, nearfield 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.

[0057] The controller 1600 is configured to operate the strapping tool in one of three operating modes (as set by the operator): (1) a manual operating mode; (2) a semi-automatic operating mode; and (3) an automatic operating mode. In the manual operating mode, the controller 1600 operates the motor 400 to cause the tensioning 640 to rotate responsive to the first pushbutton actuator 1410 being actuated and maintained in its actuated state. The controller 1600 operates the motor 400 to cause the tensioning-and-welding plate 390 to reciprocate in the transverse direction DI to carry out the sealing process responsive to the second pushbutton actuator 1420 being actuated. In the semi-automatic operating mode, the controller 1600 operates the motor 400 to cause the tensioning wheel 640 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 strap reaches the (preset) desired strap tension, the controller 1600 automatically operates the motor 400 to cause the tensioning-and-welding plate 390 to reciprocate in the transverse direction DI to carry out the sealing process (without requiring additional input from the operator). In the automatic operating mode, the controller 1600 operates the motor 400 to cause the tensioning wheel 640 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 400 to cause the tensioning-and-welding plate 390 to reciprocate in the transverse direction to carry out the sealing process (without requiring additional input from the operator).

[0058] 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 tool 50 and to send appropriate signals to the controller 1600. The sensors 1700 may include, for instance, one or more rocker-position sensors configured to detect when the tensioning assembly 600 is in its tensioning-and-welding position and / or its strap-insertion position and one or more actuating-assembly sensors configured to detect actuation of the first and second pushbutton actuators 1410 and 1420.

[0059] The power supply is electrically connected to (via suitable wiring and other components) and configured to power several components of the strapping tool 50, including the motor 400, the display assembly 1300, the actuating assembly 1400, the controller 1600, and thesensor(s) 1700. The power supply is 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 is sized, shaped, and otherwise configured to be received in the receptacle 122 defined by the rear housing section 120 of the housing 100. The strapping tool 50 includes one or more battery-securing devices (not shown) to releasably lock the power supply in place upon receipt in the receptacle. Actuation of a release device of the strapping tool 50 or the power supply unlocks the power supply from the housing 100 and enables an operator to remove the power supply from the receptacle 122.

[0060] Use of the strapping tool 50 to carry out a strapping process including: (1) a tensioning process in which the strapping tool 50 tensions strap around a load; and (2) a sealing process in which the strapping tool 50 attaches two overlapping portions of the strap to one another via friction welding is described below. The strapping tool 50 is in the automatic mode for the purposes of this example.

[0061] The operator pulls the strap leading-end first from a strap supply (not shown), wraps the strap around the load, and positions the leading end of the strap S below another layer of the strap to form upper and lower layers of strap. The operator then pulls the hand lever 800 and in doing so moves the tensioning assembly 600 from its tensioning-and-welding position to its strap-insertion position. With the tensioning assembly 600 in its strap-insertion position and while continuing to pull the hand lever 800, the operator introduces the overlapping upper and lower layers of the strap between the tensioning wheel 640 and the tensioning-and-welding plate 390. The operator then releases the hand lever 800, which enables the tensioning-assembly biasing element 600s to force the tensioning assembly 600 back toward its tensioning-and- welding position. Eventually, the outer surface 644 of the tensioning wheel 640 engages the top surface of the upper layer of the strap and force the bottom surface of the lower layer of strap against the toothed surface 392 of the tensioning-and-welding plate 390.

[0062] The operator then actuates the first pushbutton actuator 1410 to initiate the strapping process. In response, the controller 1600 starts the tensioning process by controlling the motor 400 to begin rotating the motor output shaft 400s in the first rotational direction Rl. As explained above, the transmission 500 transmits this rotational movement to the tensioning assembly 600, which converts this rotational movement into rotation of the tensioning wheel 640 via the tensioning-assembly gearing. As the tensioning wheel 640 rotates, it pulls the upper layerof the strap over the lower layer of the strap, thereby tensioning the strap around the load. The transmission 500 does not transmit rotational movement of the motor output shaft 400s to the rotary- to-linear converter 700 as this occurs. Throughout the tensioning process, the controller 1600 monitors the current drawn by the motor 400. When this current reaches a preset value that is correlated with the preset desired strap tension for this strapping process, the controller 1600 stops the motor 400, thereby completing the tensioning process.

[0063] The controller 1600 then automatically starts the sealing process by controlling the motor 400 to begin rotating the motor output shaft 400s in the second rotational direction R2. As explained in detail above, the transmission 500 transmits this rotational movement to the rotary-to-linear converter 700, which converts this rotational movement into linear reciprocation of the tensioning-and-welding plate 390 in the transverse direction DI via the driven shaft 710, the slider 720, the drive block 730, and the link 750. The combination of the downward pressure the tensioning wheel 640 exerts on the strap and the rapid reciprocation of the tensioning-and-welding plate 390 locally melts the portions of the upper and lower strap layers together. After a preset period of time or a preset quantity of rotations of the motor output shaft 400s, the controller 1600 controls the motor 400 to stop rotating the motor output shaft, completing the sealing process, melts the two overlapping portions of the strap and fuses them together. After a certain period of time elapses, the controller 1600 stops the motor 400, thereby completing the sealing process. 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.

[0064] The strapping tool of the present disclosure solves the above problems. First, moving the tensioning-and-welding plate to weld the strap eliminates the need for separate tensioning and welding assemblies (and in some embodiments separate tensioning and welding motors), which renders the tool lighter and easier to use for prolonged periods of time compared to traditional strapping tools with distinct assemblies. Second, elimination of the separate welding assembly enables the base of the support to be shorter in the longitudinal direction than the bases of traditional strapping tools, which enables the strapping tool of the present disclosure to be used for more applications (such as to strap curved loads with relatively small radii) than many traditional strapping tools.

[0065] In the example embodiment described above, only one motor is used to drive the tensioning and sealing assemblies during the tensioning and sealing processes. In other embodiments, the strapping tool includes separate tensioning and sealing motors. In these embodiments, the tensioning motor is operably connected to the tensioning assembly to rotate the tensioning wheel during the tensioning process, and the sealing motor is operably connected to the rotary-to-linear converter and configured to (via rotation of the driven shaft) reciprocate the tensioning-and-welding plate during the sealing process.

[0066] Figure 10 shows certain components of an alternative embodiment of the rotary-to-linear converter. In this embodiment, a cam 1716 is formed on or attached to the end of the shaft portion 712 of the driven shaft 710 and fixed in rotation with the driven shaft 710 such that the cam 1716 rotates with the driven shaft 710. The cam 1716 replaces the eccentric 716, and the slider 720 and the drive block 730 are not included in this embodiment. A cam follower 1745 is attached to the end of the link 750 and is biased by a spring or other suitable biasing element (not shown) into contact with the cam 1716. The outer profile of the cam 1716 is shaped such that rotation of the cam 1716 (via rotation of the driven shaft 710) causes the tensioning- and-welding plate 390 to reciprocate in the transverse direction DI as described above.

[0067] Figure 11 shows certain components of another alternative embodiment of the rotary-to-linear converter. In this embodiment, a rigid connector 1745 connects the eccentric 716 and the link 750. The slider 720 and the drive block 730 are not included in this embodiment. In this embodiment, rotation of the eccentric 716 (via rotation of the driven shaft 710) results in the connector 1745 forcing the tensioning-and-welding plate 390 to reciprocate in the transverse direction DI as described above.

[0068] In other embodiments, the rotary-to-linear converter includes a rack-and- pinion mechanism. In these embodiments, the pinion is drivingly engaged to the toothed rack, which is movable in the transverse direction. The toothed rack is operably connected to the tensioning-and-welding plate such that the tensioning-and-welding plate is movable with the toothed rack in the transverse direction. Here, the pinion is rotated by a suitable motor is opposite directions to cause the toothed rack and the tensioning-and-welding plate to reciprocate in the transverse direction. In certain variations, the toothed rack and pinion is replaced with a worm gear driven by the motor.

[0069] Figure 12 shows certain components of an alternative embodiment of the strapping device. In this embodiment, the strapping device does not include a rotary-to-linear converter to convert rotary movement of a component into linear movement of the tensioning- and-welding plate. Rather, this embodiment includes a linear actuator 1790 operably connected to the tensioning-and-welding plate 390 via the link 750 (though it may be directly connected to the tensioning-and-welding plate in other embodiments). Here, the linear actuator 1790 is operable to reciprocate the tensioning-and-welding plate 390 in the transverse direction DI as described above. In certain embodiments, the linear actuator actively moves the tensioning-and- welding plate 390 in both directions. In other embodiments, a spring return is provided so the linear actuator actively moves the tensioning-and-welding plate 390 in one direction with the spring return forcing the tensioning-and-welding plate 390 to move in the opposite direction. In one example embodiment, the linear actuator includes a voice coil.

[0070] In the example embodiments described above, the tensioning assembly is movable, and in particular pivotable, relative to the tensioning-and-welding plate to make space for strap insertion. In other embodiments, the tensioning assembly is stationary and the tensioning-and-welding plate is movable (such as pivotable) away from the tensioning assembly to make space for strap insertion.

[0071] Other embodiments of the strapping tool may include fewer assemblies, components, and / or features than those included in the strapping tool 50 described above and shown in the Figures. In other words, while the strapping tool 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 tools.

[0072] In the example embodiments described above, the working assembly is employed as part of a portable handheld strapping tool. The working assembly may be incorporated into any other type of strapping device, such as a general-purpose strapping machine or the strapping head of a special-purpose strapping machine.

Claims

Claims1. A strapping device comprising: a rotatable tensioning wheel; a tensioning-and-welding plate linearly movable relative to the tensioning wheel; and a rotary-to-linear converter operably connected to the tensioning-and-welding plate and configured to convert rotational movement into linear reciprocating movement of the tensioning- and-welding plate relative to the tensioning wheel.

2. The strapping device of claim 1, further comprising a motor comprising a motor output shaft operably connected to the rotary-to-linear converter to provide the rotational movement to the rotary-to-linear converter.

3. The strapping device of claim 2, further comprising a transmission operably connecting the motor output shaft to the rotary-to-linear converter and configured to transmit the rotational movement from the motor output shaft to the rotary-to-linear converter.

4. The strapping device of claim 3, wherein the motor output shaft is rotatable in a first rotational direction and in a second rotational direction opposite the first rotational direction, wherein the transmission is configured to transmit the rotational movement of the motor output shaft in the first rotational direction to the rotary-to-linear converter.

5. The strapping device of claim 4, further comprising tensioning-assembly gearing operably connected to the tensioning wheel to rotate the tensioning wheel, wherein the transmission is operably connected to the tensioning assembly gearing and configured to drive the tensioning assembly gearing to rotate the tensioning wheel when the motor output shaft rotates in the second rotational direction.

6. The strapping device of claim 1, wherein the rotary-to-linear converter comprises: a link operably connected to the tensioning-and-welding plate; anda driven shaft rotatable about a driven-shaft axis and operably connected to the link such that rotation of the driven shaft about the driven-shaft axis causes the link to linearly move the tensioning-and-welding plate in a reciprocating manner.

7. The strapping device of claim 6, wherein the driven shaft comprises an eccentric offset from the driven-shaft axis, wherein the driven shaft is operably connected to the link via the eccentric.

8. The strapping device of claim 7, wherein the rotary -to-linear converter further comprises a slider connected to the link, wherein the link is connected to the tensioning-and- welding plate, wherein the slider and the link are linearly movable in a reciprocating manner, wherein the driven shaft is operably connected to the slider via the eccentric such that rotation of the driven shaft about the driven-shaft axis causes the slider and the link to linearly move in a reciprocating manner.

9. The strapping device of claim 8, wherein the rotary-to-linear converter further comprises a drive block defining an opening, wherein the eccentric is received in the opening, wherein the drive block is slidably received in a slot defined in the slider such that the drive block linearly moves within the slot in a reciprocating manner as the driven shaft rotates.

10. The strapping device of claim 9, wherein the slider, the link, and the tensioning- and-welding plate are linearly movable in a first direction transverse to the driven-shaft axis, wherein the drive block is linearly movable within the slot in a second direction transverse to the first direction and to the driven-shaft axis.

11. The strapping device of claim 10, wherein the tensioning wheel is rotatable about a tensioning-wheel axis that is substantially parallel to the first direction.

12. The strapping device of claim 7, wherein the rotary-to-linear converter further comprises a rigid connector connecting the eccentric and the link, wherein the link is connected to the tensioning-and-welding plate, wherein the driven shaft is operably connected to the link via the eccentric and the rigid connector such that rotation of the driven shaft about the driven-shaft axis causes the rigid connector to force the link to linearly move the tensioning-and- welding plate in a reciprocating manner.

13. The strapping device of claim 6, wherein the driven shaft comprises a cam, wherein the link comprises a cam follower biased into contact with the cam, wherein the cam comprises an outer profile shaped such that rotation of the driven shaft about the driven-shaft axis causes the cam follower to force the link to linearly move the tensioning-and-welding plate in a reciprocating manner.14.. The strapping device of claim 1, wherein the tensioning wheel is rotatable about a tensioning-wheel axis, wherein the tensioning-and-welding plate is linearly movable substantially parallel to the tensioning-wheel axis.

15. The strapping device of claim 1, further comprising a first motor comprising a motor output shaft operably connected to the rotary-to-linear converter to provide the rotational movement to the rotary-to-linear converter and a second motor operably connected to the tensioning wheel to rotate the tensioning wheel.

16. A strapping device comprising: a rotatable tensioning wheel; a tensioning-and-welding plate linearly movable relative to the tensioning wheel; a motor; and means for converting rotational movement provided by the motor into linear reciprocating movement of the tensioning-and-welding plate relative to the tensioning wheel.

17. The strapping device of claim 16, wherein the tensioning wheel is rotatable about a tensioning-wheel axis, wherein the tensioning-and-welding plate is linearly movable substantially parallel to the tensioning-wheel axis.

18. The strapping device of claim 17, wherein the rotational movement comprises first rotational movement, the strapping device further comprising means for converting secondrotational movement provided by the motor into rotation of the tensioning wheel, wherein the first rotational movement is different from the second rotational movement.

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