Handheld strapping tool including an ultrasonic sealer

Abstract

Various embodiments of the present disclosure provide a handheld strapping tool including an ultrasonic sealer.

Description

HANDHELD STRAPPING TOOL INCLUDING AN ULTRASONIC SEALERPriority

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 515,712, filed July 26, 2023, the entire contents of which is incorporated herein by reference.Field

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

[0003] Strapping tools are configured to tension strap around a load and to attach overlapping layers of the strap to one another to form a tensioned strap loop around the load. Many strapping tools utilize friction welding to attach overlapping upper and lower strap layers to one another. 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 and presses a button to initiate a tensioning cycle during which a tensioning wheel rotates to move the upper strap layer over the lower strap layer and tension the strap around the load. After completion of the tensioning cycle, a sealing cycle is initiated. During the sealing cycle, a toothed weld shoe forces the strap layers against a toothed weld plate. A motor oscillates the weld shoe at a high frequency as the weld shoe exerts a welding force on the strap layers. The oscillating weld shoe oscillates 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 oscillating the weld shoe while the weld shoe continues to exert the welding force. The melted portions of theoverlapping strap layers join together and solidify as they cool, thereby attaching the upper and lower strap layers to form the tensioned strap loop.

[0004] One issue with these strapping tools is that the friction-weld process is noisy. Another issue with these strapping tools is that they are powered by a battery that adds weight to the tool. Since strapping-tool operators can use strapping tools hundreds of times each day, there is a continuing need to make the strapping devices as quiet and as light as possible to improve the operator experience.Summary

[0005] Various embodiments of the present disclosure provide a handheld strapping tool including an ultrasonic sealer.Brief Description of the Figures

[0006] Figure l is a perspective view of one example embodiment of a handheld strapping tool of the present disclosure.

[0007] Figure 2 is a side view of the strapping tool of Figure 1.

[0008] Figure 3 is a block diagram of certain components of the strapping tool ofFigure 1.

[0009] Figures 4A-4C are diagrammatic views of the strapping tool of Figure 1 securing a load to a pallet.

[0010] Figures 5 A and 5B are similar to Figure 2 but show the housing of the strapping tool partially removed to reveal certain internal components of the strapping tool.

[0011] Figures 6 and 7 are perspective and side-elevational views, respectively, of the anvil of the strapping tool of Figure 1.

[0012] Figure 8 is a perspective view of the ultrasonic sealer of the strapping tool of Figure 1.

[0013] Figure 9 is a front-el evational view of the sonotrode head of the sonotrode of the ultrasonic sealer of Figure 8.

[0014] Figures 10A and 10B are front-elevational views of the sonotrode head of Figure 9, the anvil of Figures 6 and 7, and upper and lower strap portions during a sealing cycle.

[0015] Figure 11 is a top-plan view of an example strap joint formed by the strapping tool of Figure 1.Detailed Description

[0016] 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.

[0017] Figures 1-10B show one example embodiment of a handheld strapping tool 50 of the present disclosure and certain assemblies and components thereof. As shown in Figures 4A-4C, the strapping tool 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 4A. The operator then introduces the overlapping 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 cycle. As shown in Figure 4B, a tensioning drive drives a tensioning wheel to carry out a tensioning cycle 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 inFigure 4C, an ultrasonic sealer is activated to carry out a sealing cycle during which the strapping tool 50 connects the upper and lower layers UL and LL of the strap S to one another via ultrasonic welding to form a strap joint SJ, shown in Figure 11, and cuts the strap S from the strap supply.

[0018] The strapping tool 50 includes a housing 100, a tensioning assembly, a sealing assembly, an opening device 700, one or more input devices 800, a display device 900, one or more sensors 1000, and a controller 1100.

[0019] The housing 100, best shown in Figures 1, 2, 5 A, and 5B, 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. The housing 100 includes a base section 110 and a handle 120. The base section 110 at least partially encloses and / or supports the rocker 300, the tensioning plate 420, the tensioning drive 490, the anvil 500, and the controller 1100. The handle 120 extends upward from the base section 110 and longitudinally along a handle axis A120. The handle axis A120 forms an angle relative to a vertical axis, as best shown in Figure 2. The angle 0 may be any suitable angle, such as an angle between 0 and 60 degrees and most preferably between 0 and 20 degrees (the angle may also be a negative angle). In other embodiments the angle 0 is 0 degrees such that the handle axis A120 is substantially vertical and substantially perpendicular to the longitudinal direction of the strap. The interior of the handle 120 defines a cavity sized and shaped to house at least part of the ultrasonic sealer 600 (and, in this example embodiment, the sealing drive 690). The exterior of the handle 120 is sized and shaped to be held by an operator of the strapping tool 50. 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.

[0020] The tensioning assembly is shown in Figures 5A and 5B and is configured to tension strap around a load during a tensioning cycle. The tensioning assembly includes a rocker 300, a toothed tensioning wheel 400, a tensioning plate 420, a tensioning drive 490, and tensioning gearing.

[0021] The tensioning wheel 400 is annular with a textured (such as toothed) outer surface and is rotatable to tension strap around a load. The tensioning drive 490, which is a rotary motor in this example embodiment but which may be any suitable type of device in otherembodiments, is operatively connected to the tensioning wheel 400 via the tensioning gearing and configured to rotate the tensioning wheel 400. The tensioning gearing may be any suitable gearing or combination of gearing configured to convert rotation of an output shaft of the tensioning drive 490 into rotation of the tensioning wheel 400. In certain embodiments, the tensioning gearing is configured to — such as via planetary gearing, eccentric gearing, evoloid gearing, bevel gearing, and the like — convert relatively low-torque, high-speed rotation of an output shaft of the tensioning drive 490 into relatively high-torque, low-speed rotation of the tensioning wheel 400.

[0022] The rocker 300 is movably connected to the base section 110 and configured to move relative to the base section 110. In certain embodiments, the rocker 300 is pivotable relative to the base section 110, while in other embodiments the rocker 300 is linearly movable relative to the base section 110. In this example embodiment, the tension wheel 400 is supported by the rocker 300 and the tension plate 420, which has a toothed upper surface, is supported by the base section 110 of the housing 100 beneath the tension wheel 400. In these embodiments, the rocker 300 is movable via actuation of the opening device 700 (described below) to move the rocker 300 — and the tension wheel 400 supported by the rocker 300 — away from the tension plate 420 to separate the tension wheel 400 and the tension plate 420 to make space for strap to be inserted between those components. In other embodiments, the tension plate 420 is supported by the rocker. In these embodiments, the rocker is movable via actuation of the opening device 700 to move the rocker — and the tension plate 420 supported by the rocker — away from the tension wheel 400 to separate the tension wheel 400 and the tension plate 420 to make space for strap to be inserted between those components. A spring or other suitable biasing element biases the rocker 300 such that the tension wheel 400 and the tension plate 420 are biased toward one another.

[0023] The sealing assembly is shown in Figures 5A-10B and is configured to attach overlapping layers of the strap to one another to form a tensioned strap loop around the load during a sealing cycle via ultrasonic welding. The sealing assembly includes an anvil 500, an ultrasonic sealer 600, and a sealing drive 690.

[0024] The anvil 500, best shown in Figures 6 and 7, acts as a clamping surface against which the ultrasonic sealer 600 clamps the overlapping strap layers during the sealing cycle. The anvil 500 includes an anvil body 510 and multiple elongated anvil teeth 520 formedon the upper surface of the anvil body 510. This example anvil 500 includes six anvil teeth, though it may include any other suitable quantity of teeth in other embodiments. Each anvil tooth 520 has a substantially triangular cross-section and includes opposing planar, angled side surfaces 520a and 520b and a substantially planar contact surface 520c connecting the side surfaces 520a and 520b. The anvil defines an anvil contact plane P500 that forms the angle 0 relative to a horizontal plane. The horizontal plane in this instance corresponds to the longitudinal direction of the strap path (and strap in the strap path). In this example embodiment, the anvil contact plane P500 is defined by the substantially coplanar contact surfaces 520c of the anvil teeth 520. The side surfaces of adjacent anvil teeth 520 are separated by an angle a (which is which is 90 degrees in this example embodiment but may be any suitable angle in other embodiments) such that substantially V-shaped grooves are formed between adjacent anvil teeth. The cross-section of these grooves (and thus the cross-section of the anvil teeth that form the grooves) is substantially constant along their entire length. The base of each anvil tooth 520 has a width DI, and the contact surface 520c of each anvil tooth 520 has a width D2 that is less than DI. Each anvil tooth 520 has a height D3. In this example embodiment, DI is 0.5 millimeters, D2 is 2 millimeters, and D3 is 0.75 millimeters (though these dimensions may differ in other embodiments). The anvil teeth extend substantially parallel to the strap path and the longitudinal direction of the strap (into and out of the page from the perspective shown in Figures 6 and 7) and have a length that is greater than or equal to the length of the sonotrode teeth (described below) in this example embodiment.

[0025] As shown in Figures 5A and 5B, the anvil 500 is supported by the base section 110 of the housing 100 such that the anvil teeth 520 face the ultrasonic sealer 600 (described below). In this example embodiment, the anvil 500 is removably attached to the base section 110 (such as via fasteners) to enable an operator to replace the anvil 500 when the anvil teeth 520 have become too worn to operate properly.

[0026] The ultrasonic sealer 600, best shown in Figures 8 and 9, is configured to impart ultrasonic vibrations to two overlapping layers of strap to attach them to one another to form a strap joint. The ultrasonic sealer 600 includes a sonotrode 610 and an ultrasonic transducer 640 and extends longitudinally along an ultrasonic-sealer axis Aeoo. The sonotrode 610 includes a sonotrode body 615, a sonotrode neck 620 connected to (and here integrally formed with) the sonotrode body 615, and a sonotrode head 630 connected to (and hereintegrally formed with) the sonotrode neck 620. The sonotrode head 630 includes a tooth support 632. Multiple elongated sonotrode teeth 634 are formed on the top surface of the tooth support 632. This example sonotrode includes seven sonotrode teeth, though it may include any other suitable quantity of teeth in other embodiments. Each sonotrode tooth 634 has a substantially triangular cross-section and includes opposing planar, angled side surfaces 634a and 634b and a substantially planar contact surface 634c connecting the side surfaces 634a and 634b. The sonotrode head 630 defines a sonotrode contact plane Peso. Specifically, in this example embodiment, the sonotrode contact plane Peso is defined by the substantially coplanar contact surfaces 634c of the sonotrode teeth 634. The sonotrode contact plane Peso is substantially perpendicular to the ultrasonic-sealer axis Aeoo (though their orientation may differ in other embodiments). The side surfaces of adjacent sonotrode teeth 634 are separated by the angle a such that substantially V-shaped grooves are formed between adjacent sonotrode teeth. The cross-section of these grooves (and thus the cross-section of the sonotrode teeth that form the grooves) is substantially constant along their entire length. The base of each sonotrode tooth 634 has the width DI, and the contact surface 634c of each sonotrode tooth 634 has the width D2. Each sonotrode tooth 634 has the height D3. The sonotrode teeth extend substantially parallel to the strap path and the longitudinal direction of the strap (as well as the anvil teeth) and have a length that is less than or equal to the length of the anvil teeth in this example embodiment. In other words, the sonotrode teeth 634 are sized, shaped, oriented, and otherwise configured substantially identically to the anvil teeth 520 (though they may differ in other embodiments).

[0027] The ultrasonic transducer 640 is configured to convert high-frequency electrical signals received from a power source into high-frequency mechanical vibrations in the ultrasonic range, such as 20-100 kilohertz. In certain embodiments, the ultrasonic transducer 640 is configured to generate vibrations in the range of 20 to 40 kilohertz. In other embodiments, the ultrasonic transducer 640 is configured to generate vibrations in the range of 34 to 36 kilohertz. In further embodiments, the ultrasonic transducer 640 is configured to generate vibrations in the range of 35 kilohertz. The ultrasonic transducer 640 is connected to the sonotrode body 615 of the sonotrode 610 such that the mechanical vibrations generated by the ultrasonic transducer 640 are transmitted to the sonotrode 600, and the sonotrode 600 is sized, shaped, oriented, and otherwise configured such that these vibrations are transmitted to the sonotrode head 630, including the sonotrode teeth 634. Accordingly, the ultrasonic transducer 640 is configured toconvert high-frequency electrical signals into mechanical vibration of the sonotrode teeth 634 at ultrasonic frequencies.

[0028] The ultrasonic sealer 600 is mounted within the handle 120 of the housing 100 such that the sonotrode teeth 634 face the anvil teeth 520 of the anvil 500. The ultrasonic sealer 600 is oriented such that the sonotrode contact plane Peao is substantially parallel to the anvil contact plane Psoo and transverse to the longitudinal direction of the strap. In this example embodiment, the ultrasonic sealer 600 is mounted within the handle 120 such that the ultrasonicsealer axis Aeoo is substantially parallel to — and in this example embodiment is coaxial with — the handle axis Ano, as shown in Figures 5A and 5B, such that the ultrasonic-sealer axis Aeoo forms the angle 0 relative to a vertical axis. As used herein, “coaxial” is a subset of “parallel” when referring to the orientation of the handle and ultrasonic-sealer axes. In certain embodiments, the ultrasonic-sealer axis Aeoo is substantially perpendicular to the longitudinal direction of the strap. The sealing drive 690, which is a linear actuator in this example embodiment but may be any other suitable drive, is operatively connected to the ultrasonic sealer 600 and configured to move the ultrasonic sealer 600 within the handle 120 and toward and away from the anvil 500.

[0029] Figures 10A and 10B show the ultrasonic sealer 600 attaching overlapping upper and lower layers UP and LP of strap S to one another. Initially, as shown in Figure 10A, the ultrasonic sealer 600 is positioned such that the sonotrode head 630 is spaced-apart from the anvil 500 to make room for the strap. Once the upper and lower layers UP and UP of strap S are positioned between the sonotrode head 630 and the anvil 500, the sealing drive 690 moves the ultrasonic sealer 600 towards the anvil 500. As this occurs, the sonotrode teeth 634 engage the upper layer UL and force it toward the anvil 500, thereby forcing the lower layer UU against the anvil teeth 520. As shown in Figure 10B, because the anvil teeth 520 and the sonotrode teeth 634 are in a meshing arrangement with one another (i.e., the teeth of one component are positioned opposite respective grooves between the teeth of the other component), the upper and lower strap layers UL and LL bend and assume a substantially wavy profile (including alternating peaks and valleys) in the transverse direction of the strap (horizontal from the perspective shown in Figures 10A and 10B). The ultrasonic transducer 640 is activated for a designated period while the ultrasonic sealer 600 and the anvil 500 sandwich the upper and lower layers UL and UL of the strap S. As explained above, this results in the sonotrode teeth 634 vibrating at an ultrasonicfrequency that causes the upper and lower layers UL and LL of the strap S to locally melt together to form a strap joint. Figure 11 shows such a strap joint SJ having a width D4 — which corresponds to the length of the sonotrode teeth — extending in the longitudinal direction of the strap (horizontal from the perspective shown in Figure 11), which is perpendicular to the transverse direction of the strap (vertical from the perspective shown in Figure 11). The width D4 is 14 millimeters in this example embodiment, though it may be any other suitable value in other embodiments (such as 5 to 32 millimeters). As shown in Figure 10B, the cross-section of the strap joint SJ has a wavy profile with several alternating peaks WP and valleys WV formed by the offset anvil and sonotrode teeth.

[0030] The opening device 700, best shown in Figures 1, 2, 5A, and 5B, is operatively connected to the rocker 300 and configured to move the rocker 300 to separate the tensioning wheel 400 and the tensioning plate 420. In this example embodiment, the opening device 700 is formed as a trigger that is pivotably connected to and partially extends from the front of the handle 120. The trigger is sized, shaped, positioned, oriented, and otherwise configured to be actuated (pulled) by an index finger of the operator while the operator is holding the handle 120. In certain embodiments, the strapping tool 50 includes one or more mechanical linkages operatively connecting the rocker 300 to the opening device 700 such that actuating the opening device 700 forces the rocker 300 to move. In other embodiments, the strapping tool 50 includes a suitable drive operatively connected to the rocker 300 and configured to move the rocker 300 responsive to a switch being triggered when the opening device 700 is actuated.

[0031] The one or more input devices 800 are suitable mechanical or electromechanical devices, such as pushbuttons, scroll wheels, dials, and the like, configured to receive inputs from the operator. In this example embodiment of the strapping tool 50, the one or more input devices 800 include a first pushbutton actuator 810, a second pushbutton actuator 820, and a scroll wheel 830 supported on an upper surface of the handle 120 of the housing 100. The first and second pushbutton actuators 810 and 820 are operable to initiate the tensioning and / or sealing cycles as described below. The scroll wheel 830 is operable to change various settings of the strapping tool 50, such as the tension level, weld time, or operating mode. In this example embodiment, the input devices are sized, shaped, positioned, oriented, and otherwise configured to be operated by the thumb of the operator while the operator is holding the handle 120.

[0032] The display device 900 is configured to display information regarding the strapping tool 50. In this example embodiment, the display device 900 is supported by the upper surface of the handle 120 of the housing 100 and is adjacent the input devices 810, 820, and 830.

[0033] In certain embodiments, the strapping tool 50 includes one or more output devices, such as lights. In one such embodiment, the output device is a light that borders the display device 900 and that can be activated in one of three different colors: green, yellow, and red. In one example embodiment, the light is activated in green to indicate a successful seal, in yellow to indicate that service is required, and in red to indicate an unsuccessful seal.

[0034] The sensors 1000 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 1100. The sensors 1000 may include, for instance: a sensor configured to detect when the tensioning wheel 400 and the tensioning plate 420 are separated, a sensor configured to detect when the opening device 700 is actuated, and sensors configured to detect actuation of the first and second pushbutton actuators 810 and 830.

[0035] The controller 1100, shown in Figure 3, 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 1100 is communicatively and operably connected to the tensioning drive 490, the ultrasonic transducer 640, the sealing drive 690, the input devices 800, the display device 900, and the sensor(s) 1000 and is configured to receive signals from and to control those components. The controller 1100 may also be communicativelyconnectable (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.

[0036] The controller 1100 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 1100 operates the tensioning drive 490 to rotate the tension wheel 400 responsive to the first pushbutton actuator 810 being actuated and maintained in its actuated state. The controller 1100 operates the sealing drive 690 to move the ultrasonic sealer 600 toward the anvil 500 and activates the ultrasonic transducer 640 to form the seal joint as explained above to carry out the sealing cycle responsive to the second pushbutton actuator 820 being actuated. In the semi-automatic operating mode, the controller 1100 operates the tensioning drive 490 to rotate the tensioning wheel 400 responsive to the first pushbutton actuator 810 being actuated and maintained in its actuated state. Once the controller 1100 determines that the tension in the strap reaches the (preset) desired strap tension, the controller 1100 automatically operates the sealing drive 690 to move the ultrasonic sealer 600 toward the anvil 500 and activates the ultrasonic transducer 640 to form the seal joint as explained above to carry out the sealing cycle (without requiring additional input from the operator). In the automatic operating mode, the controller 1100 operates the tensioning drive 490 to rotate the tensioning wheel 400 responsive to the first pushbutton actuator 810 being actuated. Once the controller 1100 determines that the tension in the strap reaches the (preset) desired strap tension, the controller 1100 automatically operates the sealing drive 690 to move the ultrasonic sealer 600 toward the anvil 500 and activates the ultrasonic transducer 640 to form the seal joint as explained above to carry out the sealing cycle (without requiring additional input from the operator).

[0037] The strapping tool 50 is configured to be powered by a power supply external to the strapping tool 50. For instance, the strapping tool 50 includes a power cord electrically connectable to a power supply external to the strapping tool 50. In certain embodiments, the power supply is part of a strap dispenser carrying strap coil from which the strapping tool 50 draws strap. In other embodiments, the strapping tool 50 includes an onboard power supply, such as a rechargeable battery.

[0038] One example use of the strapping tool 50 to form a tensioned strap loop around a load is described below. The strapping tool 50 is in the automatic mode for the purposes of this example. 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 actuates the opening device 700 to move the rocker 300 to separate the tensioning wheel 400 and the tensioning plate 420. While continuing to actuate the opening device 700 to hold the rocker 300 in position, the operator introduces the overlapping upper and lower layers of the strap between the tensioning wheel 400 and the tensioning plate 420 and between the sonotrode teeth 634 and the anvil teeth 520. The operator then releases the opening device 700, enabling the appropriate biasing elements to force the rocker 300 back toward the tensioning plate 420.

[0039] The operator then actuates the first pushbutton actuator 810. Once one of the sensors 1000 detects the actuation of the first pushbutton actuator 810, the controller 1100 initiates the strapping process. The controller 1100 operates the tensioning drive 490 to rotate the tensioning wheel 400. As the tensioning wheel 400 rotates, it pulls the upper layer of the strap S over the lower layer of the strap S, thereby tensioning the strap S around the load. Throughout the tensioning process, the controller 1100 monitors the current drawn by the tensioning drive 490. When this current reaches a preset value that is correlated with the (preset) desired strap tension for this strapping process, the controller 1100 stops the tensioning drive 490, thereby terminating the tensioning process.

[0040] After completion of the tensioning process, the controller 1100 automatically starts the sealing process by controlling the sealing drive 690 to move the ultrasonic sealer 600 toward the anvil 500 and activating the ultrasonic transducer 640. Once the sonotrode head 630 forces the overlapping upper and lower layers of strap against the anvil 500, the ultrasonic mechanical vibration of the sonotrode head 630 locally melts portions of the upper and lower strap layers together. After a preset period, the controller 1100 controls the ultrasonic transducer 640 to stop. After a cooling period expires, the controller 1100 controls the sealing drive 690 to move the ultrasonic sealer 600 away from the anvil 500 to release the now-sealed strap, completing the sealing process.

Claims

Claims1. A handheld strapping tool comprising: a tensioning plate; a rotatable tensioning wheel adjacent to the tensioning plate, wherein one of the tensioning wheel and the tensioning plate is movable relative to the other of the tensioning wheel and the tensioning plate to separate the tensioning wheel and the tensioning plate; an anvil comprising multiple anvil teeth and defining an anvil contact plane; and an ultrasonic sealer extending longitudinally along an ultrasonic-sealer axis that is transverse to the anvil contact plane, wherein one of the ultrasonic sealer and the anvil is movable toward and away from the other of the ultrasonic sealer and the anvil, the ultrasonic sealer comprising: a sonotrode comprising multiple sonotrode teeth and defining a sonotrode contact plane that is substantially parallel to the anvil contact plane; and an ultrasonic transducer configured to generate mechanical vibrations at an ultrasonic frequency and to transmit the mechanical vibrations to the sonotrode.

2. The handheld strapping tool of claim 1, further comprising one or more drives operatively connected to the tensioning wheel and configured to rotate the tensioning wheel and operatively connected to the one of the ultrasonic sealer and the anvil and configured to move the one of the ultrasonic sealer and the anvil toward or away from the other of the ultrasonic sealer and the anvil.

3. The handheld strapping tool of claim 2, wherein the one or more drives comprise: a tensioning drive operatively connected to the tensioning wheel and configured to rotate the tensioning wheel; and a sealing drive operatively connected to the one of the ultrasonic sealer and the anvil and configured to move the one of the ultrasonic sealer and the anvil toward or away from the other of the ultrasonic sealer and the anvil.

4. The handheld strapping tool of claim 3, wherein the tensioning drive comprises a rotary motor and the sealing drive comprises a linear actuator.

5. The handheld strapping tool of claim 2, wherein the one or more drives comprise a single drive operatively connected to the tensioning wheel and configured to rotate the tensioning wheel and operatively connected to the one of the ultrasonic sealer and the anvil and configured to move the one of the ultrasonic sealer and the anvil toward or away from the other of the ultrasonic sealer and the anvil.

6. The handheld strapping tool of claim 2, further comprising tensioning gearing operatively connecting the one or more drives to the tensioning wheel.

7. The handheld strapping tool of claim 1, further comprising a movable rocker on which the one of the tensioning wheel and the tensioning plate is mounted.

8. The handheld strapping tool of claim 7, further comprising an opening device operatively connected to the rocker such that actuation of the opening device causes the rocker to move to separate the tensioning wheel and the tensioning plate.

9. The handheld strapping tool of claim 8, further comprising a housing comprising a handle extending longitudinally along a handle axis, wherein the handle is sized and shaped to be held by an operator of the strapping tool, wherein the ultrasonic sealer is at least partially enclosed within the handle.

10. The handheld strapping tool of claim 9, wherein the opening device is supported by the handle.

11. The handheld strapping tool of claim 10, wherein the ultrasonic-sealer axis is substantially parallel to the handle axis.

12. The handheld strapping tool of claim 11, wherein the ultrasonic-sealer axis and the handle axis are coaxial.

13. The handheld strapping tool of claim 11, wherein the handle axis and the ultrasonic-sealer axis are substantially perpendicular to the anvil contact plane.

14. The handheld strapping tool of claim 13, further comprising: one or more drives operatively connected to the tensioning wheel and configured to rotate the tensioning wheel and operatively connected to the one of the ultrasonic sealer and the anvil and configured to move the one of the ultrasonic sealer and the anvil toward or away from the other of the ultrasonic sealer and the anvil; and an input device supported by the handle and actuatable to cause the one or more drives to operate.

15. The handheld strapping tool of claim 14, further comprising a controller configured to, responsive to actuation of the input device: control the one or more drives to rotate the tensioning wheel to tension a loop of strap around an object until a designated tension is reached in the strap; control the one or more drives to move the one of the ultrasonic sealer and the anvil toward the other of the ultrasonic sealer and the anvil such that two overlapping layers of the strap are sandwiched between the sonotrode teeth and the anvil teeth; and activate the ultrasonic transducer to cause the sonotrode teeth to vibrate and attach the overlapping layers of the strap to one another.

16. The handheld strapping tool of claim 15, wherein the one or more drives and the controller are electrically connectable to a power source remote from the handheld strapping tool.

17. The handheld strapping tool of claim 15, wherein the input device is supported by an upper surface of the handle.

18. The handheld strapping tool of claim 1, further comprising a housing comprising a handle extending longitudinally along a handle axis, wherein the handle is sized and shaped to be held by an operator of the strapping tool, wherein the ultrasonic sealer is at least partially enclosed within the handle.

19. The handheld strapping tool of claim 17, wherein the ultrasonic- seal er axis is substantially parallel to the handle axis.

20. The handheld strapping tool of claim 19, wherein the ultrasonic-sealer axis and the handle axis are coaxial.

21. The handheld strapping tool of claim 19, wherein the handle axis and the ultrasonic-sealer axis are substantially perpendicular to the anvil contact plane.

22. The handheld strapping tool of claim 21, further comprising an input device supported by the handle and actuatable to cause the one or more drives to operate.

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