Strapping tool with resilient member

Abstract

A strapping device including a weld plate, a weld arm including a weld shoe, a link movable from a first position to a second position, and a resilient member between the weld arm and the link. The weld arm is movable between a home and sealing positions. The weld shoe is closer to the weld plate when the weld arm is in the sealing position than when the weld arm is in the home position. The link is movable from the first to second positions to cause the resilient member to move to force the weld arm to move from the home position to the sealing position. The resilient member exerts a first force on the weld arm and a second force on the link when the link is in the second position to maintain the weld arm in the sealing position and the link in the second position.

Description

STRAPPING TOOL WITH RESILIENT MEMBERPriority

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 617,875, filed January 5, 2024, the entire contents of which is incorporated herein by reference.Field

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

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

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

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

[0006] Various embodiments of the present disclosure provide a strapping device including a weld plate, a weld arm including a weld shoe, a link movable from a first position to a second position, and a resilient member between the weld arm and the link. The weld arm is movable between a home position and a sealing position. The weld shoe is closer to the weld plate when the weld arm is in the sealing position than when the weld arm is in the home position. The link is movable from the first position to the second position to cause the resilient member to move to force the weld arm to move from the home position to the sealing position. The resilient member is configured to exert a first force on the weld arm and a second force on the link when the link is in the second position to maintain the weld arm in the sealing position and the link in the second position.Brief Description of the Figures

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

[0008] Figure 2 is a block diagram of certain components of the strapping device of Figure 1.

[0009] Figures 3A-3C are diagrammatic views of the strapping device of Figure 1 securing a load to a pallet.

[0010] Figure 3D is a perspective view of a friction- weld strap joint formed by the strapping device of Figure 1 to attach two overlapping strap layers.

[0011] Figures 4A and 4B are perspective views of the working assembly of the strapping device of Figure 1.

[0012] Figures 5A-5C are side elevational views of part of one side of the working assembly of Figures 4A and 4B showing the tensioning assembly moving from a home position to a strap-insertion position and from the strap-insertion position to a tensioning position after strap is inserted into the strapping device. Certain components of the working assembly are not shown for clarity.

[0013] Figure 6A is a rear elevational view of the working assembly of Figures 4A and 4B showing the sealing assembly in a home configuration.

[0014] Figure 6B is similar to Figure 6A but shows the sealing assembly in a sealing configuration and forcing the overlapping upper and lower strap layers against the weld plate.

[0015] Figure 6C is similar to Figures 6A and 6B but shows the sealing assembly in the sealing configuration and the weld shoe oscillating.

[0016] Figure 7 is a perspective view of the resilient member of the sealing assembly.Detailed Description

[0017] 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, anydirections 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.

[0018] Figures 1-7 show one example embodiment of a strapping device of the present disclosure in the form of a battery-powered portable strapping device 50 and certain assemblies and components thereof. As shown in Figures 3A-3C, the strapping device 50 is configured to carry out a strapping cycle to tension and seal strap S (plastic strap in this example embodiment) around a load L on a pallet P to form a tensioned strap loop that secures the load L to the pallet P. An operator pulls strap S from a strap supply (not shown) and wraps the strap around the load L and through the openings in the pallet P until a lower layer LL of the strap S (which includes the leading end of the strap S) is positioned below an upper layer UL of the strap S, as shown in Figure 3A. The operator then introduces the overlapping upper and lower layers UL and LL of the strap S into the strapping device 50 and actuates one or more buttons to initiate the strapping cycle. As shown in Figure 3B, a motor drives a tensioning assembly to carry out a tensioning cycle during which the strapping device 50 tensions strap S around the load L. Once a preset tension is reached in the strap S, as shown in Figure 3C, the motor drives a sealing assembly to carry out a sealing cycle during which the strapping device 50 connects the 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 3D, and cuts the strap S from the strap supply.

[0019] The strapping device 50 includes a housing 100, a working assembly 200, first and second pushbutton actuators 1410 and 1440, a display assembly 1490, a power supply 1500, a controller 1600, and one or more sensors 1700.

[0020] The housing 100, best shown in Figure 1, is formed from multiple components (not individually labeled) that collectively at least partially enclose and / or support some (or all) of the other assemblies and components of the strapping device 50. In this example embodiment, the housing 100 includes a front housing section 110, a cover 115, a rear housing section 120, a motor housing section 130, and a handle section 150. The front housing section110 at least partially encloses and / or supports at least some of the components of the working assembly 200. The cover 115 at least partially encloses some of the components of the working assembly 200, including the tension wheel 400w.

[0021] The rear housing section 120 at least partially encloses and / or supports at least some of the components of the display assembly 1490 and defines a receptacle sized, shaped, and otherwise configured to receive and at least partially enclose and / or support the power supply 1500 and the controller 1600. The motor housing section 130 extends between and connects the bottoms of the front and rear housing sections 110 and 120 and at least partially encloses and / or supports at least some of the components of the working assembly 200, including the motor 1100. The handle housing section 150 extends between and connects the tops of the front and rear housing sections 110 and 120 and defines a handle used by the operator. This is merely one example, and in other embodiments the components of the strapping device may be supported and / or enclosed by any suitable portion of the housing 100. The housing 100 may be formed from any suitable quantity of components joined together in any suitable manner. In this example embodiment, the housing 100 is formed from plastic, though it may be made from any other suitable material in other embodiments.

[0022] The working assembly 200, which is best shown in Figures 4A and 4B, includes the majority of the components of the strapping device 50 that are configured to carry out the strapping cycle to tension the strap around the load, attach the overlapping layers of the strap to one another, and cut the strap from the strap supply. The working assembly 200 includes a support 300, a tensioning assembly 400, a trigger 600, a sealing assembly 900, a transmission 1000, and a motor 1100.

[0023] The support 300, which is best shown in Figures 4A and 4B, serves as a direct or indirect common mount for the tensioning assembly 400, the trigger 600, the sealing assembly 900, the transmission 1000, and the motor 1100. The support 300 includes a base 300b and a frame 300f extending from the base 300b. The base 300b supports a toothed tension plate 312 below the tension wheel 400w of the tensioning assembly 400 (described below) and a toothed weld plate 314 below the weld shoe 942 of the sealing assembly 900 (described below).

[0024] The tensioning assembly 400 is operable via the motor 1100 to tension the strap around the load during the tensioning cycle. The tensioning assembly 400 includes a rocker 400r, tensioning-assembly gearing (not labeled), and a tension wheel 400w. The tension wheel400w is supported by the tensioning-assembly gearing, which is in turn supported by the rocker 400r. The tensioning-assembly gearing is configured to rotate the tension wheel 400w about a tension-wheel rotational axis Aww in a tensioning rotational direction to tension the strap around the load. The tensioning assembly 400 is movably mounted to the support 300 via the rocker 400r and a tensioning-assembly mounting shaft 395 (Figures 4A and 4B) and configured to pivot relative to the support 300 — and particularly relative to the base 300b of the support 300 and the tension plate 312 — about a rocker-pivot axis A4ooramong a home position (Figure 5A), a strapinsertion position (Figure 5B), and a tensioning position (Figure 5C). When the tensioning assembly 400 is in the home position, the tension wheel 400w is adjacent to the tension plate 312 of the support 300. When the tensioning assembly 400 is in the strap-insertion position, the tension wheel 400w is spaced-apart from the tension plate 312 to enable the overlapping upper and lower layers of the strap to be inserted between the tension wheel 400w and the tension plate 312. When the tensioning assembly 400 is in the tensioning position and overlapping strap layers are between the tension wheel 400w and the tension plate 312, the tension wheel 400w engages the upper layer of strap and forces the strap layers onto the tension plate 312. The weight of the tensioning assembly 400 and one or more springs or other biasing elements (not shown) bias the tensioning assembly 400 to the home position.

[0025] The trigger 600 is operable (here, pivotable) to cause the tensioning assembly 400 to move from the home position to the strap-insertion position. In this example embodiment, when the trigger 600 is pulled it triggers a switch that causes the motor 1100 to cooperate with the tensioning assembly 400 to pivot the tensioning assembly 400 from the home position to the strap-insertion position. In other embodiments, the trigger 600 is operably connected to the tensioning assembly 400 via one or more mechanical linkages such that pulling the trigger 600 forces the tensioning assembly 400 to pivot from the home position to the strap-insertion position.

[0026] The sealing assembly 900, which is best shown in Figures 6A-7, is configured to operate with the weld plate 314 to attach overlapping portions of the strap to one another to form a tensioned strap loop around the load during the sealing cycle via friction welding. The sealing assembly 900 includes a link 910, a resilient member 930, a sealingassembly biasing element 932, a weld arm 940, a weld shoe 942, a cutter 944, and an eccentric shaft (not shown). The weld shoe 942 is slidably mounted to the weld arm 940 such that the weldshoe 942 can oscillate relative to the weld arm 940 in the transverse direction of the strap (left and right from the perspective of Figures 6A-6C). The eccentric shaft is operably connected to the weld shoe 942 and configured to, when rotated, cause the weld shoe 942 to oscillate. A toothed belt 900b operably connects the transmission 1000 to the eccentric shaft. The cutter 944 is removably mounted to the weld arm 940.

[0027] The resilient member 930, which is best shown in Figure 7, includes a curved body 930a with a first end including first and second eyelets 930b and 930c and an opposing second end including third and fourth eyelets 930d and 930e. In this example embodiment, the eyelets are integrally formed with the body such that the resilient member 930 is formed from a single piece of material, though in other embodiments the resilient member is formed from multiple components connected to one another. In this example embodiment, the resilient member 930 is formed from a resilient material having a stiffness that enables the resilient member 930 — and particularly the body 930a — to deform (and specifically, flex) from its resting configuration when subjected to a suitably large force and then automatically return to that resting configuration when the force is removed. Put differently, the resilient member 930 is formed such that it is biased to return to its resting configuration. In this example embodiment, the resilient material includes spring steel, though any other suitable resilient material may be employed in other embodiments. In this example embodiment, the thickness of the resilient member is substantially constant, while in other embodiments it varies (e g., is thicker in the center of the body than near the eyelets). In this example embodiment, the resilient member includes a leaf spring.

[0028] The weld arm 940 is pivotably mounted to the support 300 and is pivotable relative to the support 300 and the weld plate 314 about a weld-arm axis A940 between a home position (Figures 4A and 6A) in which the weld shoe 942 is spaced-apart from the weld plate 314 and a sealing position (Figure 6C) in which the weld shoe 942 is adjacent to the weld plate 314 and positioned to weld the strap. The link 910 and the resilient member 930 operably connect the transmission 1000 to the weld arm 940 such that the transmission 1000 can move the weld arm 940 from the home position to the sealing position. Specifically, the link 910 is pivotably mounted to the support 300 via a first pivot 900pl (such as a pivot pin). The resilient member 930 operably connects (and in this example embodiment, physically connects) the link 910 to the weld arm 940. In particular, the first end of the resilient member 930 — specifically,the first and second eyelets 930b and 930c — are pivotably connected to one end of the link 910 via a second pivot 900p2 (such as a pivot pin), and the other end of the resilient member 930 — specifically, the third and fourth eyelets 93 Od and 93 Oe — are pivotably connected to the weld arm 940 via a third pivot 900p3 (such as a pivot pin). The sealing-assembly biasing element 932, which is a compression spring in this example embodiment but may be any other suitable component in other embodiments, biases the sealing assembly to a home configuration.

[0029] When the sealing assembly 900 is in the home configuration in which the weld arm 940 is in the home position — shown in Figure 6A — the link 910 and the resilient member 930 form an angle greater than 0 degrees and less than 180 degrees (i.e., an acute or obtuse angle), and a first distance DI separates the first and second ends of the resilient member 930. In this example embodiment, the first distance DI is less than the distance separating the first and second ends of the resilient member 930 when the resilient member 930 is in the resting configuration such that the resilient member 930 is slightly flexed and thus exerts a force on both the link 910 and the weld arm 940.

[0030] When the sealing assembly 900 is in a sealing configuration in which the weld arm 940 is in the sealing position — shown in Figure 6C — the link 910 and the resilient member 930 form an angle greater than 180 degrees and less than 360 degrees (i.e., a reflex angle), and a third distance D3 separates the first and second ends of the resilient member 930. In this example embodiment, the third distance D3 is less than the distance separating the first and second ends of the resilient member 930 when the resilient member 930 is in the resting configuration such that the resilient member 930 is slightly flexed and exerts a first force on the link 910 and a second force on the weld arm 940 to retain the link 910 in the second position and the weld arm 940 in the sealing position.

[0031] As described below, the transmission 1000 is configured to switch the sealing assembly 900 from its home configuration to its sealing configuration by manipulating the orientation of the link 910 and the resilient member 930. At one point during transition of the sealing assembly 900 from the home configuration to the sealing configuration, the link 910 and the resilient member are substantially aligned, as shown in Figure 6B. At this point, a second distance D2 separates the first and second ends of the resilient member 930. In this example embodiment, the second distance D2 is less than the first distance DI and the third distance D3, and the third distance D3 is less than the first distance DI .

[0032] The transmission 1000, which is best shown in Figures 4A and 4B, is driven by the motor 1100, is operably connected to the tensioning assembly 400 and configured to cause the tension wheel 400w to rotate in the tensioning direction to tension the strap and is operably connected to the sealing assembly 900 and configured to cause the sealing assembly 900 to attach the overlapping portions of the strap to one another. The transmission 1000 includes transmission gearing including a drive gear 1012 (which is a bevel pinion gear in this example embodiment) and a variable offset coupling 800. The transmission gearing and the variable offset coupling 800 are mounted to the support 300 such that the drive gear 1012 is configured to drive the variable offset coupling 800.

[0033] The transmission gearing includes suitable components (such as gears, bearings, and freewheels) that transmit rotational movement of the output shaft of the motor 1100 in a first drive direction to the drive gear 1012 to rotate the drive gear 1012 (but not to drive any components of the sealing assembly 900 in this example embodiment). The drive gear 1012 drives the variable offset coupling 800, which transmits the rotational movement of the drive gear 1012 to the tensioning-assembly gearing to rotate the tension wheel 400w.

[0034] The components of the transmission gearing transmit rotational movement of the output shaft of the motor 1100 in a second drive direction opposite the first drive direction to the sealing assembly 900 to switch the sealing assembly 900 from its home configuration to its sealing configuration and to drive the toothed belt 900b to rotate the eccentric shaft and cause the weld shoe 942 to oscillate (but not to drive the drive gear 1012 in this example embodiment). More specifically, the transmission gearing includes a cam 1010c (Figure 6A) driven in rotation by the output shaft of the motor 1100 when the output shaft is rotated in the second drive direction. The cam 1010c engages the free end (not shown) of the link 910 of the sealing assembly 900, which causes the link 910 of the sealing assembly 900 to rotate clockwise about the first pivot 900pl (from the viewpoint shown in Figures 6A-6C) to raise the second pivot 900p2 — and the first end of the resilient member 930 connected to it — and switch the sealing assembly 900 to the sealing configuration, thereby moving the weld arm 940 into its sealing position.

[0035] This is merely one example transmission assembly, and the strapping device may include any suitable transmission assembly or assemblies operably connecting one or more motors to the tensioning and sealing assemblies to drive those assemblies.

[0036] The motor 1100, which is best shown in Figures 4A and 4B, is operably connected to (via the transmission 1000) the tensioning assembly 400 and the sealing assembly 900 and is configured to drive those assemblies as explained herein. The motor 1100 includes the output shaft (not shown) referenced above. The motor 1100 is an electric motor in this example embodiment but may be any suitable motor.

[0037] The display assembly 1490, which is shown in Figures 1 and 2, includes a suitable display screen 1492 with a touch panel 1494. The display screen 1492 is configured to display information regarding the strapping device 50 (at least in this embodiment), and the touch screen 1494 is configured to receive operator inputs such as the desired operating mode (described below), a desired strap tension, and a desired weld cooling time. A display controller (not shown) may control the display screen 1492 and the touch panel 1494 and, in these embodiments, is communicatively connected to the controller 1600 to send signals to the controller 1600 and to receive signals from the controller 1600. Other embodiments of the strapping device do not include a touch panel. Still other embodiments of the strapping device do not include a display assembly. Certain embodiments of the strapping device include a separate pushbutton panel instead of a touch panel beneath or integrated with the display screen.

[0038] The first and second pushbutton actuators 1410 and 1440 are operable to initiate the tensioning and / or sealing cycles as described below. Other embodiments of the strapping device 50 do not have pushbutton actuators and instead incorporate their functionality into the display assembly 1490. For instance, in one of these embodiments two areas of the touch panel define virtual buttons that have the same functionality as mechanical pushbutton actuators.

[0039] The controller 1600, which is shown in Figure 2, includes a processing device (or devices) communicatively connected to a memory device (or devices). For instance, the controller may be a programmable logic controller. The processing device may include any suitable processing device such as, but not limited to, a general-purpose processor, a specialpurpose processor, a digital-signal processor, one or more microprocessors, one or more microprocessors in association with a digital-signal processor core, one or more applicationspecific integrated circuits, one or more field-programmable gate array circuits, one or more integrated circuits, and / or a state machine. The memory device may include any suitable memory device such as, but not limited to, read-only memory, random-access memory, one or more digital registers, cache memory, one or more semiconductor memory devices, magnetic mediasuch as integrated hard disks and / or removable memory, magneto-optical media, and / or optical media. The memory device stores instructions executable by the processing device to control operation of the strapping device 50. The controller 1600 is communicatively and operably connected to the motor 1100, the display assembly 1490, the pushbutton actuators 1410 and 1440, and the sensor(s) 1700 and configured to receive signals from and to control those components. The controller 1600 may also be communicatively connectable (such as via Wi-Fi, Bluetooth, near-field communication, or other suitable wireless communications protocol) to an external device, such as a computing device, to send information to and receive information from that external device.

[0040] The controller 1600 is configured to operate the strapping device in one of three operating modes to carry out the strapping cycle: (1) a manual operating mode; (2) a semiautomatic operating mode; and (3) an automatic operating mode. In the manual operating mode, the controller 1600 operates the motor 1100 to cause the tension wheel 400w to rotate responsive to the first pushbutton actuator 1410 being actuated and maintained in its actuated state. The controller 1600 operates the motor 1100 to cause the sealing assembly 900 to carry out the sealing cycle responsive to the second pushbutton actuator 1440 being actuated. In the semiautomatic operating mode, the controller 1600 operates the motor 1100 to cause the tension wheel 400w to rotate responsive to the first pushbutton actuator 1410 being actuated and maintained in its actuated state. Once the controller 1600 determines that the tension in the strap reaches the (preset) desired strap tension, the controller 1600 automatically operates the motor 1100 to cause the sealing assembly 900 to carry out the sealing cycle (without requiring additional input from the operator). In the automatic operating mode, the controller 1600 operates the motor 1100 to cause the tension wheel 400w to rotate responsive to the first pushbutton actuator 1410 being actuated. Once the controller 1600 determines that the tension in the strap reaches the (preset) desired strap tension, the controller 1600 automatically operates the motor 1100 to cause the sealing assembly 900 to carry out the sealing cycle (without requiring additional input from the operator).

[0041] The sensors 1700 include any suitable sensors, such as microswitches, optical sensors, ultrasonic sensors, magnetic position sensors, and the like, configured to detect the position of certain components of the strapping device 50 and to send appropriate signals to the controller 1600. The sensors 1700 may include, for instance: one or more tensioning-assembly-position sensors configured to detect when the tensioning assembly 400 is in its home position and / or its strap-insertion position; one or more trigger-position sensors configured to detect when the trigger 600 is pulled; and one or more actuating assembly sensors configured to detect actuation of the first and second pushbutton actuators 1410 and 1440.

[0042] The power supply 1500 is electrically connected to (via suitable wiring and other components) and configured to power several components of the strapping device 50, including the motor 1100, the display assembly 1490, the controller 1600, and the sensor(s) 1700. The power supply 1500 includes a rechargeable battery (such as a lithium-ion or nickel cadmium battery) in this example embodiment, though it may be any other suitable electric power supply in other embodiments. The power supply 1500 is sized, shaped, and otherwise configured to be received in the receptacle defined by the rear housing section 120 of the housing 100. The strapping device 50 includes one or more power-supply-securing devices (not shown) to releasably lock the power supply 1500 in place upon receipt in the receptacle. Actuation of a release device of the strapping device 50 or the power supply 1500 unlocks the power supply 1500 from the housing 100 and enables an operator to remove the power supply 1500 from the receptacle.

[0043] Use of the strapping device 50 to carry out a strapping cycle to form a tensioned strap loop around a load is now described below. Initially, the tensioning assembly 400 is in its home position and the sealing assembly 900 is in its home configuration, as shown in Figures 5A and 6A. The strapping device 50 is in the automatic mode for the purposes of this example.

[0044] The operator pulls the strap S leading-end first from a strap supply (not shown), wraps the strap S around the load, and positions a lower layer LL including the leading end of the strap S below an upper layer UL of the strap S. The operator then pulls the trigger 600 to lift the tensioning assembly 400 to its strap-insertion position, as shown in Figure 5B. With the tensioning assembly 400 in its strap-insertion position and while continuing to pull the trigger 600, the operator introduces the overlapping upper and lower layers UL and LL of the strap S between the tension wheel 400w and the tension plate 312 and between the weld shoe 942 and the weld plate 314, as shown in Figure 5B. The operator then releases the trigger 600, enabling the appropriate biasing elements to force the tensioning assembly 400 pivot to its tensioningposition to sandwich the overlapping upper and lower strap layers UL and LL between the tension wheel 400w and the tension plate 312, as shown in Figure 5C.

[0045] The operator then actuates the first pushbutton actuator 1410. Once one of the sensors 1700 detects the actuation of the first pushbutton actuator 1410, the controller 1600 starts the tensioning cycle by controlling the motor 1100 to rotate the output shaft in the first drive direction. As explained above, the transmission 1000 transmits this rotational movement of the output shaft to the tensioning-assembly gearing which, in turn, rotates the tension wheel 400w about the tension-wheel rotational axis A oow in the tensioning direction. As the tension wheel 400w rotates in the tensioning direction, it pulls the upper layer UL of the strap S over the lower layer LL of the strap S, thereby tensioning the strap S around the load. Throughout the tensioning cycle, the controller 1600 monitors the current drawn by the motor 1100. When this current reaches a preset value that is correlated with the (preset) desired strap tension for this strapping cycle, the controller 1600 stops the motor 1100, thereby terminating the tensioning cycle.

[0046] In this example embodiment, after completion of the tensioning cycle, the controller 1600 automatically starts the sealing cycle by controlling the motor 1100 to begin rotating the output shaft in the second drive direction. This causes the transmission 1000 to drive the toothed belt 900b to begin rotating the eccentric shaft and oscillating the weld shoe 942 and to switch the sealing assembly 900 from its home configuration to its sealing configuration, and in doing so pivot the weld arm 940 to its sealing position. As the weld arm 940 reaches the sealing position, the weld shoe 942 forces the overlapping upper and lower layers of strap UL and LL against the weld plate 314 while the cutter 944 cuts the upper strap layer UL from the strap supply. Figures 6B and 6C show this movement of the weld arm 940 and oscillation of the weld shoe 942. As explained above, the oscillation of the weld shoe 942 is fast enough to generate friction and heat substantial enough to locally melt and join the portions of the overlapping strap layers, thereby attaching the upper and lower strap layers UL and LL to form the tensioned strap loop. The controller 1600 controls the motor 1100 to stop rotating the output shaft, completing the sealing cycle. The operator can then pull the trigger 600 to raise the tensioning assembly 400 and to switch the sealing assembly 900 back to its home configuration to release the tensioned strap loop.

[0047] The above-described example embodiment of the strapping device includes a single motor configured to drive both the tensioning assembly and the sealing assembly. In otherembodiments, the strapping device includes separate motors configured to drive the respective tensioning and sealing assemblies and may include separate transmissions for each motor.

[0048] Other embodiments of the strapping device may include fewer assemblies, components, and / or features than those included in the strapping device 50 described above and shown in the Figures. In other words, while the strapping device 50 includes all of the assemblies, components, and features described above, they are independent of one another and may be independently included in other strapping devices.

[0049] While the strapping device described above is a handheld strapping device, the strapping device may be any other suitable strapping device in other embodiments, such as a standalone automatic or semi-automatic strapping machine.

[0050] In the strapping device described above, the movable rocker supports the tension wheel and moves the tension wheel relative to the stationary tension plate as the rocker pivots among the home, strap-insertion, and tensioning positions. In other embodiments, the movable rocker supports the tension plate, and the support of the working assembly supports the tension wheel. In these embodiments, the movable rocker moves the tension plate relative to the stationary tension wheel as the rocker pivots among the home, strap-insertion, and tensioning positions.

Claims

Claims1. A strapping device comprising: a weld plate; a weld arm comprising a weld shoe, the weld arm movable between a home position and a sealing position, wherein the weld shoe is closer to the weld plate when the weld arm is in the sealing position than when the weld arm is in the home position; a link movable from a first position to a second position; and a resilient member operably connecting the weld arm and the link, wherein the link is movable from the first position to the second position to cause the resilient member to move to force the weld arm to move from the home position to the sealing position, wherein the resilient member is configured to flex to exert a first force on the weld arm and a second force on the link when the link is in the second position to maintain the weld arm in the sealing position and the link in the second position.

2. The strapping device of claim 1, wherein the resilient member comprises a first end, a second end, and a curved body connected to and extending between the first end and the second end.

3. The strapping device of claim 2, wherein the first end, the second end, and the curved body of the resilient member are integrally formed such that the resilient member is formed from a single piece of material.

4. The strapping device of claim 3, wherein the resilient member is formed from a resilient material.

5. The strapping device of claim 4, wherein the resilient material comprises spring steel.

6. The strapping device of claim 2, wherein the first end of the resilient member is connected to the link and the second end of the resilient member is connected to the weld arm.

7. The strapping device of claim 6, wherein the first end of the resilient member is pivotably connected to the link and the second end of the resilient member is pivotably connected to the weld arm.

8. The strapping device of claim 7, wherein a first distance separates the first and second ends of the resilient member when the link is in the first position, wherein a second distance separates the first and second ends of the resilient member when the link is in the second position, wherein a third distance separates the first and second ends of the resilient member when the link is between the first and second positions, wherein the third distance is less than the first and second distances, wherein the resilient member is flexed when the link is in the second position.

9. The strapping device of claim 8, wherein the second distance is less than the first distance.

10. The strapping device of claim 8, further comprising a first pivot pin and a second pivot pin, wherein the first end of the resilient member is pivotably connected to the link via the first pivot pin, wherein the second end of the resilient member is pivotably connected to the weld arm via the second pivot pin.

11. The strapping device of claim 10, wherein the resilient member is removably connected to the link and the weld arm.

12. The strapping device of claim 11, wherein the first end, the second end, and the curved body of the resilient member are integrally formed such that the resilient member is formed from a single piece of material.

13. The strapping device of claim 12, wherein the resilient member is formed from a resilient material.

14. The strapping device of claim 13, wherein the resilient material comprises spring steel.

15. The strapping device of claim 2, further comprising a rotatable cam positioned such that, when the link is in the first position, rotation of the cam causes the cam to move the link from the first position to the second position.

16. The strapping device of claim 15, further comprising a motor operably connected to the cam to rotate the cam.

17. The strapping device of claim 16, wherein the motor is operably connected to the weld shoe to oscillate the weld shoe.

18. The strapping device of claim 16, further comprising a rotatable tensioning wheel, wherein the motor is operably connected to the tensioning wheel to rotate the tensioning wheel.

19. The strapping device of claim 18, wherein the first end, the second end, and the curved body of the resilient member are integrally formed such that the resilient member is formed from a single piece of material, wherein the resilient member is formed from a resilient material.

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