The present disclosure relates to strapping tools, and more particularly to strapping tools configured to tension strap around a load and to attach overlapping portions of the strap to one another to form a tensioned strap loop around the load.
Strapping devices are configured to tension strap around a load and to attach overlapping portions of the strap to one another to form a tensioned strap loop around the load. Battery-powered strapping tools are one type of strapping device. 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 the leading end of the strap below another portion of the strap. The operator then introduces one or more (depending on the type of strapping tool) of these overlapped strap portions into the strapping tool and actuates one or more buttons to initiate: (1) a tensioning cycle during which a tensioning assembly tensions the strap around the load; and (2) after completion of the tensioning cycle, a sealing cycle during which a sealing assembly attaches the overlapped strap portions to one another (thereby forming a tensioned strap loop around the load) and during which a cutting assembly cuts the strap from the strap supply.
How the strapping tool attaches overlapping portions of the strap to one another during the sealing cycle depends on the type of strapping tool and the type of strap. Certain strapping tools configured for plastic strap (such as polypropylene strap or polyester strap) include friction welders, heated blades, or ultrasonic welders configured to attach the overlapping portions of the strap to one another. Some strapping tools configured for plastic strap or metal strap (such as steel strap) include jaws that mechanically deform (referred to as “crimping” in the strapping industry) or cut notches into (referred to as “notching” in the strapping industry) a seal element positioned around the overlapping portions of the strap to attach them to one another. Other strapping tools configured for metal strap include punches and dies configured to form a set of mechanically interlocking cuts in the overlapping portions of the strap to attach them to one another (referred to in the strapping industry as a “sealless” attachment).
Since strapping tool operators can use handheld strapping tools hundreds of times each day, there is a continuing need to make the strapping tools as light as possible (without sacrificing performance). One way to do so is to incorporate freewheels into the transmission of the strapping tool. These freewheels enable a single motor to drive different assemblies by rotating its output shaft in different rotational directions. One downside is that freewheels can impose drag torque that results in unintentional rotation of components of the transmission that in turn cause unintentional driving (or reverse driving) of different assemblies. This can interfere with the strapping cycle.
Various embodiments of the present disclosure provide a strapping tool including a tensioning assembly, a sealing assembly, a motor, and a transmission assembly. The transmission assembly operably connects the motor to the tensioning assembly and the sealing assembly. The motor can (via the transmission assembly) alternately drive the tensioning assembly to tension a loop of strap around a load and the sealing assembly to seal the strap to itself. The strapping tool also includes a locking assembly that prevents the motor from driving the sealing assembly via drag torque generated by the transmission assembly while the motor is driving the tensioning assembly.
While the systems, devices, and methods described herein may be embodied in various forms, the drawings show and the specification describes certain exemplary and non-limiting 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.
The strapping tool 50 includes a housing 100 (
The housing 100, which is best shown in
The working assembly 200, which is best shown in
The support 300, which is best shown in
The tensioning assembly 500, which is best shown in
The tensioning-assembly gearing 510 includes: a gearing support 512; a driven shaft 522; a tensioning-assembly-gearing freewheel 523; first planet gears 524a, 524b, 524c, and 524d; a carrier 525; a first ring gear 526; a bushing 527; a second ring gear 528; a tension-wheel mount 529; and second planet gears 530a, 530b, and 530c. Certain components of the tensioning-assembly gearing 510 are centered on and certain components of the tensioning-assembly gearing 510 are rotatable about a tension-wheel rotational axis A590. The gearing support 512 includes an annular support shaft 512a and a cover 512b extending radially outward from the support shaft 512a. The driven shaft 522 includes a shaft portion 522a and a first sun gear 522b at one end of the shaft portion 522a. The carrier 525 includes a first planet-gear carrier 525a to which the first planet gears 524a-524d are rotatably mounted (such as via respective bearings and mounting pins) and a second sun gear 525b rotatable with (and here integrally formed with) the planet-gear carrier 525a about the tension-wheel rotational axis A590. The first ring gear 526 includes internal teeth 526it and external teeth 526ot. The second ring gear 528 includes internal teeth 528it. The tension-wheel mount 529 includes a second planet-gear carrier 529a and a tension-wheel shaft 529b rotatable with (and here integrally formed with) the second planet-gear carrier 529a about the tension-wheel rotational axis A590. The second planet gears 530a-530c are rotatably mounted to the second planet-gear carrier 529a (such as via respective bearings and mounting pins). The tension-wheel shaft 529b includes a splined end 529s opposite the second planet-gear carrier 529a to enable the tension wheel 590 to be mounted thereon and fixed in rotation with the tension-wheel shaft 529.
The shaft portion 522a of the driven shaft 522 extends through and is engaged by the tensioning-assembly-gearing freewheel 523, which is itself supported by and positioned within a bore through the annular support shaft 512a of the gearing support 512. The tensioning-assembly-gearing freewheel 523 is configured to permit rotation of the driven shaft 522 relative to the gearing support 512 in a tensioning rotational direction—referred to as the tensioning direction T (
The tensioning-assembly gearing 510 is mounted to the tensioning-assembly support 505 via attaching the cover 512b of the gearing support 512 to the tensioning-assembly support 505. The second ring gear 528 is fixed in rotation about the tension-wheel rotational axis A590 relative to the tensioning-assembly support 505 (that is, the second ring gear 528 is not rotatable about the tension-wheel rotational axis A590 relative to the tensioning-assembly support 505). In this example embodiment, pins (not shown) are positioned between the outer surface of the second ring gear 528 and the tensioning-assembly support 505 to prevent relative rotation, though any suitable components (such as set screws, adhesive, high-friction components, or fasteners) may be used to do so. The decoupling assembly 1900 (except when actuated, as described below) fixes the first ring gear 526 in rotation about the tension-wheel rotational axis A590 relative to the tensioning-assembly support 505 so the first ring gear 526 cannot rotate about the tension-wheel rotational axis A590 relative to the tensioning-assembly support 505.
During the tensioning cycle, the motor assembly 900 and transmission assembly 800 drive the driven shaft 522 in the tensioning direction T, as described below. This causes the first sun gear 522b to rotate about the tension-wheel rotational axis A590 in the tensioning direction T. The first sun gear 522a drives the first set of planet gears 524a-524dc. Since the decoupling assembly 1900 prevents the first ring gear 526 from rotating about the tension-wheel rotational axis A590, rotation of the planet gears 524a-524d causes the carrier 525—including the second sun gear 525b—to rotate about the tension-wheel rotational axis A590 in the tensioning direction T. The second sun gear 525b drives the second set of planet gears 530a-530c. Since the second ring gear 528 cannot rotate about the tension-wheel rotational axis A590, rotation of the planet gears 530a-530c causes the tension-wheel mount 529 and the tension wheel 590 mounted thereto to rotate about the tension-wheel rotational axis A590 in the tensioning direction T. Accordingly, the tensioning-assembly gearing 510 operatively connects the motor assembly 900 and the transmission assembly 800 to the tension wheel 590 to rotate the tension wheel 590 about the tension-wheel rotational axis A590 in the tensioning direction T.
The tensioning assembly 500 is movably mounted to the mounting shaft 390 of the support 300 and configured to pivot relative to the support 300—and particularly relative to the base 310 of the support 300—under control of the rocker lever 700 (as described below) and about a tensioning-assembly-pivot axis A500 between a strap-tensioning position (
The decoupling assembly 1900, which is best shown in
The decoupling-assembly shaft 1910 includes a body 1912 having a first end 1912a having an irregular cross-section and second end 1912b having radially extending teeth around its circumference. A first support 1914 extends from the first end 1912a, and a second support 1916 extends from the second end 1912b. The first engageable element 1920 comprises a tubular bushing having a cylindrical outer surface and an interior surface having a perimeter that matches the perimeter of the first end 1912a of the body 1912 of the decoupling-assembly shaft 1910. The second engageable element 1930 includes a tubular body 1932 and an annular flange 1934 at one end of the body 1932. An opening 1934o is defined through the flange 1934. The expandable element 1940 includes a torsion spring having a first end 1940a and a second end 1940b.
As best shown in
As best shown in
The decoupling assembly 1900 is actuatable (such as by the rocker 700 as described below) to eliminate the connection between the torsion spring 1940 and the first engageable element 1920 such that the first engageable element 1920 and the decoupling-assembly shaft 1910 may rotate relative to the second engageable element 1930 about the decoupling-assembly rotational axis A1900. As explained above, the second engageable element 1930 and the second end 1940b of the expandable element 1940 (that is received in the opening 1934o of the flange 1934 of the second engageable element 1930) are fixed in rotation relative to the tensioning-assembly support 505. To eliminate the connection between the torsion spring 1940 and the first engageable element 1920, the first end 1940a of the torsion spring 1940 is rotated decoupling-assembly rotational axis A1900 relative to the tensioning-assembly support 505, the second end 1940b of the torsion spring 1940, and the second engageable element 1930 (such as via moving the rocker lever 700 from the home position to the intermediate position). As this occurs, the inner diameter of the torsion spring 1940 near its first end 1940a begins expanding, and eventually expands enough (thereby reducing the compression force or eliminating it altogether) to enable the first engageable element 1920 and the decoupling-assembly shaft 1910 to rotate decoupling-assembly rotational axis A1900 relative to the second engageable element 1930 (and the torsion spring 1940).
Upon completion of the tensioning cycle, the tension wheel 590 holds a significant amount of tension in the strap, and the strap exerts a counteracting force (or torque) on the tension wheel 590 in the release direction TREV. Actuation of the decoupling assembly 1900 enables the tension wheel 590 to rotate in the release direction TREV to release that tension in a controlled manner. Specifically, upon completion of the tensioning cycle, the decoupling-assembly shaft 1910 (via the intermediary gear 1990) continues to prevent the first ring gear 526 of the tensioning-assembly gearing 510 from rotating about the tension-wheel rotational axis A590, which prevents the tension wheel 590 from rotating in the release direction TREV T. As the first end 1940a of the torsion spring 1940 is rotated about the decoupling-assembly rotational axis A1900, the inner diameter of the torsion spring 1940 near its first end 1940a begins expanding. Eventually, the force the first ring gear 526 exerts on the decoupling-assembly shaft 1910 exceeds the compression force the torsion spring 1940 exerts on the first engageable element 1920. When this occurs, the first ring gear 526 rotates in the release direction TREV about the tension-wheel rotational axis A590. Since the tensioning-assembly-gearing freewheel 523 prevents the driven shaft 522—including the first sun gear 522b—from rotating in the release direction TREV, this causes the first planetary gears 524a-524d to rotate in the release direction TREV about the tension-wheel rotational axis A590. This (as explained above) causes the tension wheel 590 to rotate in the release direction TREV about the tension-wheel rotational axis A590.
In other embodiments, the second end of the body of the decoupling-assembly shaft directly meshes with the outer teeth of the first ring gear (rather than via one or more intermediary gears).
The rocker lever 700, which is best shown in
The mounting head 710 is pivotably mounted to the mounting shaft 390 of the support 300 such that the rocker lever 700 is pivotable relative to the support 300 about a rocker-lever pivot axis A700 (which in this example embodiment is the same as the tensioning-assembly-pivot axis A500). The rocker lever 700 is also mounted to the tensioning-assembly 500 via pin 700p that extends through the tensioning-assembly support 505 and a slot (not shown) defined through the body 720 of the rocker lever 700. The slot is sized, shaped, and oriented such that the rocker lever 700 is pivotable about the tensioning-assembly-pivot axis A500: (1) relative to the support 300, the tensioning assembly 500, and the decoupling assembly 1900 from a home position (
More specifically, when the rocker lever 700 is in the home position, as shown in
The sealing assembly 600, which is best shown in
In operation, the motor assembly 900 and the transmission assembly 800 drive the camshaft 620 and the cams 622 and 624 thereon to rotate about a camshaft rotational axis A620 (which in this example embodiment is the same as the tensioning-assembly and rocker-lever pivot axes A500 and A700) in a sealing rotational direction S—referred to herein as the sealing direction S (
The transmission assembly 800, which is best shown in
The first transmission-gear assembly 810 includes a first driven gear 812 (which is a bevel gear in this example embodiment but may be any suitable gear) having teeth 812t, a second-gear-assembly drive gear 814 (which is a spur gear in this example embodiment but may be any suitable gear) having teeth 814t, and a first transmission freewheel 816. The first transmission freewheel 816 is mounted to, engages, and circumscribes the shaft portion 522a of the driven shaft 522 of the tensioning-assembly gearing 510 of the tensioning assembly 500. The first driven gear 812 and the second-gear-assembly drive gear 814 are fixed in rotation with one another (so they rotate together) and are mounted to, engage, and circumscribe the first transmission freewheel 816. The first transmission freewheel 816 is configured to: (1) transmit rotational movement of the first driven gear 812 and the second-gear-assembly drive gear 814 in the tensioning direction T to the driven shaft 522 such that the first driven gear 812, the second-gear-assembly drive gear 814, and the driven shaft 522 rotate together in the tensioning direction T about the tension-wheel rotational axis A590; and (2) not transmit rotational movement of the first driven gear 812 and the second-gear-assembly drive gear 814 in the release direction TREV to the driven shaft 522 such that the first driven gear 812 and the second-gear-assembly drive gear 814 rotate about the tensioning rotational axis A590 in the release direction TREV relative to and around the first transmission freewheel 816 and the driven shaft 522.
The second transmission-gear assembly 820 includes a second driven gear 822 (which is a spur gear in this example embodiment but may be any suitable gear) having teeth 822t, a second transmission freewheel 824, a sealing-assembly drive shaft 826, a washer 827, and a bushing 828. The sealing-assembly drive shaft 826 includes a freewheel-mounting portion 826a and a bushing-mounting portion 826b on either side of a sealing-assembly drive gear 826g (which is a spur gear in this example embodiment but may be any suitable gear) having teeth 826t. A locking-assembly mounting portion 826c extends from the bushing-mounting portion 826b. The second transmission freewheel 824 is mounted to, engages, and circumscribes the freewheel-mounting portion 826a of the sealing-assembly drive shaft 826. The second driven gear 822 is mounted to, engages, and circumscribes the second transmission freewheel 824. The second transmission freewheel 824 is configured to: (1) transmit rotational movement of the second driven gear 822 in a transmission rotational direction TR—referred to herein as the transmission direction TR (
As best shown in
The locking assembly 840 includes a locking-assembly freewheel 842 and an annular locking ring 844 defining circumferentially spaced openings 844o therethrough. The locking-assembly freewheel 842 is positioned within the bore 505b defined in the tensioning-assembly support 505 and is mounted to, engages, and circumscribes the locking-assembly mounting portion 826c of the sealing-assembly drive shaft 826. The locking ring 844 is mounted to, engages, and circumscribes the locking-assembly freewheel 842 within the bore 505b defined in the tensioning-assembly support 505.
As best shown in
The connector 830, which is a toothed belt in this example embodiment but may be any suitable connector, operably connects the second-gear-assembly drive gear 814 of the first transmission-gear assembly 810 and the second driven gear 822 of the second transmission-gear assembly 820.
Although the second transmission freewheel 824 is configured not to transmit rotational movement of the second driven gear 822 in the non-transmission direction TRREV to the sealing-assembly drive shaft 826, the second transmission freewheel 824 can impose a drag torque on the sealing-assembly drive shaft 826 in the non-transmission direction TRREV. If not prevented, this drag torque could result in the sealing-assembly drive gear 826g of the sealing-assembly drive shaft 826 driving the driven gear 632 of the sealing assembly 630 in a rotational direction opposite the sealing direction S—referred to herein as the reverse sealing direction SREV—while the tensioning cycle is ongoing, which could interfere with the strapping cycle and/or damage various components of the tool. The locking assembly 840 is operably connected to the sealing-assembly drive shaft 826 to prevent this drag torque from causing the sealing-assembly drive shaft 826 from rotating in the non-transmission direction TRREV.
Specifically, the locking-assembly freewheel 842 is configured to permit rotation of the sealing-assembly drive shaft 826 relative to the locking-assembly freewheel 842 and the locking ring 844 in the transmission direction TR and to transmit rotational movement of the sealing-assembly drive shaft 826 in the non-transmission direction TRREV to the locking ring 844. The biasing force applied by the nose-biasing element 898 of the locking-ring retainer 890 to the locking ring 844 is great enough to prevent any drag torque applied to the sealing-assembly drive shaft 826 in the non-transmission direction TRREV from causing the locking ring 844 and the sealing-assembly drive shaft 826 from rotating in the non-transmission direction TRREV.
The configuration of the locking assembly 840 does, however, enable an operator to manually rotate the sealing-assembly drive shaft 826 in the non-transmission direction TRREV in certain situations, such as to fix a tool jam. To do so, the operator must apply enough torque to the sealing-assembly drive shaft 826 in the non-transmission direction TRREV to overcome the biasing force of the nose-biasing element 898 and thus rotate the sealing-assembly drive shaft 826 and the locking ring 844 relative to the tensioning-assembly support 505 in the non-transmission direction TRREV. Alternatively, the operator can remove the locking-ring retainer 890 from the tensioning-assembly support 505, which would enable the sealing-assembly drive shaft 826 and the locking ring 844 to rotate in the non-transmission direction TRREV without impediment. The locking assembly 840 of the present disclosure thus prevents the motor 910 from driving the sealing assembly 600 via drag torque while the motor 910 is driving the tensioning assembly 500 while enabling the operator to manually override the locking function in certain scenarios.
In other embodiments, the nose of the locking-ring retainer is fixed in place such that the operator must remove the locking-ring retainer from the locking ring to rotate the sealing-assembly drive shaft in the non-transmission direction TRREV.
In operation, the motor assembly 900 can drive the first driven gear 812 of the first transmission-gear assembly 810 of the transmission assembly 800 in either the tensioning direction T or the release direction TREV. When the motor assembly 900 drives the first driven gear 812 in the tensioning direction T, the first driven gear 812, the second-gear-assembly drive gear 814 and the driven shaft 522 rotate together in the tensioning direction T about the tension-wheel rotational axis A590. The connector 830 transmits the rotation of the second-gear-assembly drive gear 814 to the second driven gear 822 of the second transmission-gear assembly 820, causing it to rotate in the non-transmission direction TRREV around the second transmission freewheel 824, which does not transmit this rotational movement to the sealing-assembly drive shaft 826 (though it may transmit drag torque to the sealing-assembly drive shaft 826). On the other hand, when the motor assembly 900 drives the first driven gear 812 in the release direction TREV, the first driven gear 812 and the second-gear-assembly drive gear 814 rotate in the release direction TREV around the first transmission freewheel 816, which does not transmit this rotational movement to the driven shaft 522. The connector 830 transmits the rotation of the second-gear-assembly drive gear 814 to the second driven gear 822 of the second transmission-gear assembly 820, causing it to rotate in the transmission direction TR. The second transmission freewheel 824 transmits this rotational movement to the sealing-assembly drive shaft 826, which rotates in the transmission direction TR (
The motor assembly 900, which is best shown in
As best shown in
As shown in
Specifically, the first mounting ear 934e1 of the head 934 of the motor housing 930 of the motor assembly 900 is mounted (via a suitable bearing, not labeled) to the driven shaft 522 of the tensioning-assembly gearing 510 of the tensioning assembly 500, and the second mounting ear 934e2 of the head 934 is mounted (via a suitable bearing, not labeled) to the support shaft 512a of the support 512 of the tensioning-assembly gearing 510 such that the motor assembly 900 is pivotable relative to the tensioning assembly 500 about the tension-wheel rotational axis A590. The motor housing section 130 defines one or more internal chambers that house the motor mount 930, the motor 910, and the motor biasing element 940.
The display assembly 1300, which is shown in
The actuating assembly 1400, which is shown in
The controller 1600, which is shown in
The controller 1600 is configured to operate the strapping tool in one of three operating modes: (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 910 to cause the tension wheel 590 to rotate responsive to the first pushbutton actuator 1410 being actuated and maintained in its actuated state. The controller 1600 operates the motor 910 to cause the sealing assembly 600 to carry out the sealing cycle responsive to the second pushbutton actuator 1420 being actuated. In the semi-automatic operating mode, the controller 1600 operates the motor 910 to cause the tension wheel 590 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 910 to cause the sealing assembly 600 to carry out the sealing cycle (without requiring additional input from the operator). In the automatic operating mode, the controller 1600 operates the motor 910 to cause the tension wheel 590 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 910 to cause the sealing assembly 600 to carry out the sealing cycle (without requiring additional input from the operator).
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 tensioning-assembly-position sensors configured to detect when the tensioning assembly 500 is in its strap-tensioning position and/or its strap-insertion position; one or more camshaft-position sensors configured to detect the rotational position of the camshaft 620 and, specifically, whether the camshaft 620 is in a home rotational position; one or more rocker-lever-position sensors configured to detect when the rocker lever 700 is in its home position, its intermediate position, and/or its actuated position; and one or more actuating assembly sensors configured to detect actuation of the first and second pushbutton actuators 1410 and 1420.
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 910, the display assembly 1300, the actuating assembly 1400, the controller 1600, and the sensor(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.
Use of the strapping tool 50 to carry out a strapping cycle including: (1) a tensioning cycle in which the strapping tool 50 tensions strap around a load; and (2) a sealing cycle in which the strapping tool 50 attaches overlapping upper and lower portions of the strap to one another via a sealless strap joint is described below. Initially, the rocker lever 700 is in its home position, the tensioning assembly 500 is in its strap-tensioning position, and the die assembly 610 is in its home position. 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 portion of the strap to form upper and lower portions of strap. The operator then pulls the rocker lever 700 from its home position to its actuated position to raise the tensioning assembly 500 from its strap-tensioning position to its strap-insertion position. While holding the rocker lever 700 in its actuated position, the operator introduces the overlapping upper and lower portions of the strap between the punch 314 (on the base 310 of the support 300) and the die 614 (of the die assembly 610 of the sealing assembly 600) and between the tensioning plate 312 (on the base 310 of the support 300) and the tension wheel 590 (of the tensioning assembly 500), as shown in
The operator then actuates the first pushbutton actuator 1410 to initiate the strapping cycle. In response the controller 1600 starts the tensioning cycle by controlling the motor 910 to begin rotating the motor output shaft 910s in the first drive direction D1, which drives the first driven gear 812 of the transmission assembly 800 in the tensioning direction T. As explained in detail above, this causes the tension wheel 590 to begin rotating in the tensioning direction T and pull on the upper portion of the strap, thereby tensioning the strap around the load. Throughout the tensioning cycle, the controller 1600 monitors the current drawn by the motor 910. 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 910, thereby terminating the tensioning cycle.
The controller 1600 then automatically starts the sealing cycle by controlling the motor 910 to begin rotating the motor output shaft 910s in the second drive direction D2, which drives the first driven gear 812 in the release direction TREV. As explained in detail above, this causes the camshaft 620 and to rotate in the sealing direction S, which pivots the die assembly 610 to its sealing position such that the dies 614 engage engage the upper portion of strap and force the lower portion of strap against the punch 314 of the base 310 of the support 300, eventually combining to cut keys in the overlapping upper and lower portions of strap. Meanwhile, the cutter 616 of the die assembly 610 cuts the strap from the strap supply. Once the cutter 616 cuts the strap from the strap supply, the upper portion of the strap slides relative to the lower portion of the strap, which causes the keys to interlock and form the sealless strap joint. Continued rotation of the camshaft 620 in the sealing direction S reverses this movement to return the die assembly 610 to its home position. After the sealing cycle is complete, the operator again pulls the rocker lever 700 to raise the tensioning assembly 500 and removes the strapping tool 50 from the tensioned strap loop.
Although the sealing assembly of the above-described example embodiment of the strapping tool comprises a punch and die configured to for a sealless connection in the strap, the sealing assembly may comprise other sealing mechanisms (such as notching jaw assembly, a crimping jaw assembly, a friction-welding assembly, an ultrasonic welding assembly, or a hot-knife assembly) in other embodiments configured to seal any suitable type of strap (such as metal, plastic, or paper strap).
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.
While the strapping device described above is a handheld strapping tool, the strapping device may be any other suitable strapping device in other embodiments, such as a standalone automatic or semi-automatic strapping machine.
This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/268,084, filed Feb. 16, 2022, the entire contents of which is incorporated hereby by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US2023/062184 | 2/8/2023 | WO |
Number | Date | Country | |
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63268084 | Feb 2022 | US |