Strapping tool with energy release function

Abstract

The present disclosure provides a strapping tool with a sealing assembly including a die assembly and a camshaft. The camshaft includes a cam that engages a cam follower on the die assembly. The cam is shaped such that rotation of the camshaft during a sealing cycle causes the cam to force the die assembly to pivot from a home position to a sealing position to form interengaging notches in the overlapping strap portions. Continued rotation of the cam results in the die assembly pivoting back to its home position during an energy release phase and a return phase of the sealing cycle. During the energy release phase, the shape of the cam allows the die assembly to pivot a relatively small amount as potential energy is released. During the return phase after this energy is released, the shape of the cam allows the die assembly to pivot a relatively large amount.

Description

[Technical field]

[0001] Priority claim This patent application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 268,243, filed February 18, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a strapping tool, and more particularly to a strapping tool configured to tension a strap around a load and attach overlapping portions of the strap to one another via a cam-driven sealing assembly to form a taut strap loop around the load. [Background technology]

[0003] The strapping device is configured to tension the strap around a load and attach overlapping portions of the strap to one another to form a tensioned strap loop around the load. A battery-powered strapping tool is one type of strapping device. To form a taut strap loop around a load using one of these strapping tools, an operator first pulls a strap tip from a strap supply, wraps the strap around the load, and positions the strap tip under another portion of the strap. The operator then introduces one or more of these overlapped strap portions (depending on the type of strapping tool) into the strapping tool and actuates one or more buttons to initiate (1) a tensioning cycle in which the tensioning assembly pulls the strap around the load, and (2) a sealing cycle in which, after the tensioning cycle is complete, the sealing assembly attaches the overlapped strap portions to one another (thereby forming a taut strap loop around the load) and the separation assembly severs the strap from the strap supply.

[0004] The manner in which the strapping tool attaches the overlapping portions of the strap to one another during the sealing cycle depends on the type of strapping tool and the type of strap. Particular strapping tools configured for plastic straps (e.g., polypropylene straps or polyester straps) include friction welders, heated blades, or ultrasonic welders that attach the overlapping portions of the strap to one another. Some strapping tools that are configured for plastic or metal straps (e.g., steel straps) include jaws that attach the overlapping portions of the strap to one another by mechanically deforming (referred to in the strapping industry as "crimping") or cutting (referred to in the strapping industry as "notching") notches into a sealing element positioned around the overlapping portions of the strap. Other strapping tools that are configured for metal straps include punches and dies that are configured to form a set of mechanical interlocking notches in the overlapping portions of the strap to attach the overlapping portions of the strap to one another (referred to in the strapping industry as a "sealless" attachment).

[0005] In certain known sealless strapping tools, the die is attached to a die assembly that is lowered to force the overlapping portion of the strap against a punch, ultimately forming a notch that connects to the strap. After forming the notch, the strap and other mechanical components of the strapping tool store a large amount of potential energy that exerts a large force on the die assembly, which can cause problems when the die assembly moves back up and begins to release the strap. Summary of the Invention [Means for solving the problem]

[0006] Various embodiments of the present disclosure provide a strapping tool with a sealing assembly supported by a support and including a pivotable die assembly and a rotatable camshaft. The camshaft includes a cam having a cam surface of varying diameter that engages a cam follower on the die assembly. The cam surface is shaped such that rotation of the camshaft during a sealing cycle causes the cam to force the die assembly to pivot from a home position to a sealing position such that one or more dies of the die assembly cooperate with a punch on the support to form a notch that connects the two overlapping strap portions. Continued rotation of the cam results in the die assembly pivoting back to its home position during the energy release phase and return phase of the sealing cycle. During the energy release phase, the cam configuration allows the die assembly to pivot a relatively small amount as the potential energy stored in the strap and other components of the strapping tool is released, and during the return phase after this energy is released, the cam configuration allows the die assembly to rotate a relatively large amount back to the home position. [Brief description of the drawings]

[0007] [Figure 1A] FIG. 1 is a perspective view of an exemplary embodiment of a strapping tool of the present disclosure. [Figure 1B] FIG. 1 is a perspective view of an exemplary embodiment of a strapping tool of the present disclosure. [Figure 1C] FIG. 2 is a block diagram of certain components of the strapping tool of FIGS. 1A and 1B. [Figure 2A] FIG. 1C is a schematic diagram of the strapping tool of FIGS. 1A and 1B securing a load to a pallet. [Figure 2B] FIG. 1C is a schematic diagram of the strapping tool of FIGS. 1A and 1B securing a load to a pallet. [Figure 2C] FIG. 1C is a schematic diagram of the strapping tool of FIGS. 1A and 1B securing a load to a pallet. [Figure 2D] FIG. 1B is a perspective view of a sealless joint formed by the strapping tool of FIG. 1A to attach two overlapping portions of a strap. [Figure 3A]FIG. 2 is a perspective view of a working assembly of the strapping tool of FIGS. 1A and 1B. [Figure 3B] FIG. 2 is a perspective view of a working assembly of the strapping tool of FIGS. 1A and 1B. [Figure 3C] FIG. 3C is a partial side view of the working assembly of FIGS. 3A and 3B, showing upper and lower strap portions extending between the die assembly and the support, and between the tension wheel and the support, of the sealing assembly. [Figure 4A] FIG. 1C is a partial side view of the strapping tool of FIGS. 1A and 1B with a portion of the front housing section of the housing removed and the tensioning assembly in a strap tensioning position. [Figure 4B] FIG. 4B is a partial side view similar to FIG. 4A, but with the tensioning assembly in a strap insertion position. [Figure 5A] FIG. 3C is a perspective view of a tensioning assembly gear and tensioning wheel of the tensioning assembly of the working assembly of FIGS. 3A and 3B. [Figure 5B] 5B is a cross-sectional perspective view of the tensioning assembly gears and tensioning wheel of FIG. 5A taken along line 5B-5B of FIG. 5A. [Figure 5C] FIG. 5B is an exploded perspective view of the tensioning assembly gears and tensioning wheels of FIG. 5A. [Figure 6A] FIG. 3C is a perspective view of a disconnect assembly of the working assembly of FIGS. 3A and 3B. [Figure 6B] FIG. 6B is an exploded perspective view of the disconnect assembly of FIG. 6A. [Figure 6C] 6C is a cross-sectional perspective view of a portion of the actuation assembly of FIGS. 3A and 3B taken along line 6C-6C of FIG. 3B, extending through the disconnection assembly of FIG. 6A. [Figure 7A] FIG. 3C is a perspective view of a die assembly of the sealing assembly of the working assembly of FIGS. 3A and 3B. [Figure 7B] FIG. 3C is a perspective view of a die assembly of the sealing assembly of the working assembly of FIGS. 3A and 3B. [Figure 8]FIG. 3C is a perspective view of a camshaft, a first cam and a second cam, and a sealing assembly gearbox of the working assembly of FIGS. 3A and 3B. [Figure 9] FIG. 9 is an end view of the camshaft and the first and second cams of FIG. 8. [Figure 10] FIG. 3C is a perspective view of a motor assembly of the working assembly of FIGS. 3A and 3B. [Figure 11] 11 is a cross-sectional perspective view of the working assembly of FIGS. 3A and 3B taken along line 11-11 of FIG. 3B, extending through the motor assembly and transmission assembly of the working assembly of FIG. 10. [Figure 12A] FIG. 8 is a side view of the working assembly of FIGS. 3A and 3B with the first and second cams of FIG. 8 and the die assembly of FIGS. 7A and 7B in their home positions at the start of a sealing cycle. [Figure 12B] 12B is a side view corresponding to FIG. 12A, but after the strap engagement stage of the sealing cycle, with the die of the die assembly positioned just in contact with the upper strap portion. [Figure 12C] 12A and 12B, but with the die assembly in the sealing position after the strap cutting stage of the sealing cycle. [Figure 12D] FIG. 12C is a side view corresponding to FIGS. 12A-12C, but with the die assembly pivoted slightly back towards its home position after the energy release phase of the sealing cycle. [Figure 12E] 12A-12D, but with the first and second cams and die assembly returning to their home positions after the energy release phase of the sealing cycle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] While the systems, devices, and methods described herein may be embodied in various forms, the drawings show certain exemplary, non-limiting embodiments, and the specification describes these embodiments. Not all of the components shown in the drawings and described in the specification are required, and certain implementations may include additional, different, or fewer components. Changes may be made in the arrangement and type of components, the shape, size, and material of components, and the manner in which components are connected without departing from the spirit or scope of the claims. Unless otherwise indicated, any directions referenced in the specification reflect the orientation of the components shown in the corresponding drawings and do not limit the scope of the disclosure. Furthermore, terms referring to methods of attachment, such as, for example, attached, connected, etc., are not intended to be limited to direct attachment methods, but should be broadly interpreted to include the same attachment methods that are indirectly and operably attached and connected. This specification is intended to be viewed as a whole, interpreted in accordance with the principles of the present disclosure, and understood by those skilled in the art.

[0009] 1A-12E illustrate one example embodiment of a strapping device of the present invention in the form of a strapping tool 50 (sometimes referred to as a “tool” in the detailed description for the sake of brevity), illustrating certain assemblies and components thereof. As shown in FIGS. 2A-2C, the strapping tool 50 performs a strap cycle to tension and seal a strap S (metal strap in this embodiment) around a load L on a pallet P and form a tensioned strap loop to secure the load L to the pallet P. An operator draws a strap S from a strap supply (not shown) and wraps the strap around the load L and through an opening in the pallet P until the lower portion LP of the strap S (including the tip of the strap S) is located under the upper portion UP of the strap S, as shown in FIG. 2A. The operator then inserts the overlapping upper portion UP and lower portion LP of the strap S into the strapping tool 50 and operates one or more buttons to initiate the strap cycle. As shown in FIG. 2B, a motor drives a tensioning assembly to perform a tensioning cycle during which the strapping tool 50 tensions the strap S around the load L. Once the strap S reaches a predetermined tension, as shown in Figure 2C, a motor drives the sealing assembly to perform a sealing cycle during which the strapping tool 50 cuts keys K into the upper UP and lower LP portions of the strap S to sever the strap S from the strap supply, as shown in Figure 2D. Because the strap S is under tension, severing the strap from the strap supply causes the upper portion UP to slide relative to the lower portion LP, mechanically interlocking keys K to form a sealless strap joint J, as shown in Figure 2D.

[0010] The strapping tool 50 includes a housing 100 (FIGS. 1A and 1B), a working assembly 200 (FIGS. 3A-3C), a display assembly 1300 (FIGS. 1A-2), an actuation assembly 1400 (FIGS. 1A-1C), a power source (not shown), a controller 1600 (FIG. 1C), and one or more sensors 1700 (FIG. 1C).

[0011] The housing 100 is best seen in FIGS. 1A and 1B and is formed from a number of components (not individually labeled) that at least partially enclose and / or support some (or all) of the other assemblies and components of the strapping tool 50. In this embodiment, the housing 100 includes a front housing portion 110, a rear housing portion 120, a motor housing portion 130, and a handle housing portion 150. The front housing portion 110 at least partially surrounds and / or supports at least some of the components of the working assembly 200 and the actuation assembly 1400. The rear housing portion 120 at least partially surrounds and / or supports at least some of the components of the display assembly 1300 and defines a receptacle 122 that is sized, shaped, and otherwise configured to receive and at least partially surround and / or support a power supply and controller 1600. The motor housing portion 130 extends between and connects the bottoms of the front and rear housing portions 110, 20 and at least partially encloses and / or supports at least some of the components of the working assembly 200 (particularly the motor assembly 900, as described further below). The handle housing portion 150 extends between and connects the tops of the front and rear housing portions 110, 120 and defines a handle for use by an operator. This is by way of example only, and in other embodiments, the strapping tool components may be supported and / or enclosed by any suitable portion of the housing 100. The housing 100 may be formed from any suitable amount of components joined together in any suitable manner. In this exemplary embodiment, the housing 100 is formed from plastic, but in other embodiments, the housing 100 may be made from any other suitable material.

[0012] 3A, 3B, and 8-9C, the working assembly 200 includes most of the components of the strapping tool 50, which is configured to perform a strapping cycle to pull the strap around a load, attach overlapping portions of the strap to one another, and sever the strap from the strap supplier. Specifically, the working assembly 200 includes a support 300, a tensioning assembly 500, a sealing assembly 600, a rocker lever 700, a transmission assembly 800, a motor assembly 900, and a disconnect assembly 1900.

[0013] The support 300, best seen in Figures 3A-4B, serves as a direct or indirect common mounting point for the tensioning assembly 500, the sealing assembly 600, the rocker lever 700, the transmission assembly 800, the motor assembly 900, and the decoupling assembly 1900. The support 300 includes a base 310, first and second support ears 320, 330 extending upwardly from the base 310, a die assembly mounting ear (not shown) extending forwardly from the base 310, and a mounting shaft 390 extending through and rotatably supported by the support ears 320, 330. The base 310 supports a tension plate 312 below a tension wheel 590 of a tension assembly 500 (described below) and a punch 314 below a die 614 of a die assembly 610 (described below).

[0014] 5A-5C, tensioning assembly 500 is configured to tension a strap around a load during a tensioning cycle. Tensioning assembly 500 includes a tensioning assembly support 505, tensioning assembly gearing 510, and a tensioning wheel 590 driven by tensioning assembly gearing 510.

[0015] The tensioning assembly gearing 510 includes a gearing support 512, a driven shaft 522, a tensioning assembly gearing freewheel 523, first planetary gears 524a, 524b, 524c, 524d, a carrier 525, a first ring gear 526, a bushing 527, a second ring gear 528, a tensioning wheel mount 529, and second planetary gears 530a, 530b, 530c. Certain components of the tensioning assembly gearing 510 are centralized and are rotatable about a tensioning wheel axis of rotation A 590. 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 planetary gear carrier 525a to which the first planetary gears 524a-524d are rotatably mounted (e.g., via respective bearings and mounting pins) and a second sun gear 525b that is rotatable with the planetary gear carrier 525a (here integrally formed) about the tensioning wheel rotation axis A 590. The first ring gear 526 includes internal teeth 526it and external teeth 526ot. The second ring gear 528 includes internal teeth 528it. The tensioning wheel mounting portion 529 includes a second planet gear carrier 529a and a tensioning wheel shaft 529b rotatable (here integrally formed) with the second planet gear carrier 529a about a tensioning wheel rotation axis A 590. The second planet gears 530a-530c are rotatably mounted (via respective bearings and mounting pins) to the second planet gear carrier 529a. The tensioning wheel shaft 529b has a splined end 529s facing the second planet gear carrier 529a, and a tensioning wheel 590 can be mounted on the splined end 529s and rotatably fixed to the tensioning wheel shaft 529.

[0016] The shaft portion 522a of the driven shaft 522 is engaged through a freewheel 523 of the tensioning assembly gearing, which is itself supported by and located within a bore through the annular support shaft 512a of the gearing support 512. The tensioning assembly gearing freewheel 523 allows rotation of the driven shaft 522 relative to the gearing support 512 in a tensioning rotational direction - referred to as the tensioning direction T (FIG. 5A) - and in a rotational direction opposite to the tensioning direction T - the release direction T REV (FIG. 5A) is configured to prevent rotation of driven shaft 522 in the A first sun gear 522b of driven shaft 522 meshes and drivingly engages first planetary gears 524a-524d. The first planetary gears 524a-524d mesh with internal teeth 526 of a first ring gear 526. A bushing 527 rotatably supports the first ring gear 526 and separates the first ring gear 526 from a second ring gear 528. The second sun gear 525b meshes and drivingly engages the second planetary gears 530a-530c, which mesh with the internal teeth 528 of the second ring gear 528. The tensioning wheel 590 is attached to the splined end 529s of the tensioning wheel shaft 529b and is held in place longitudinally via a suitable retainer such that the tensioning wheel shaft 529b and the tensioning wheel 590 rotate together about the tensioning wheel axis of rotation A 590. Any other suitable method, such as a key, may be used to rotatably secure the tensioning wheel to the tensioning wheel shaft.

[0017] The tensioning assembly gear set 510 is attached to the tensioning assembly support 505 via attaching the cover 512b of the gear set support 512 to the tensioning assembly support 505. The second ring gear 528 is rotationally fixed about the tensioning wheel axis of rotation A 590 relative to the tensioning assembly support 505 (i.e., the second ring gear 528 is not rotatable about the tensioning wheel axis of rotation A 590 relative to the tensioning assembly support 505). In this embodiment, a pin (not shown) is disposed between the outer surface of the second ring gear 528 and the tensioning assembly support 505 to prevent relative rotation, although any suitable component (e.g., set screws, adhesives, high friction components, or fasteners) may be used. The decoupling assembly 1900 (except when operated as described below) rotationally fixes the first ring gear 526 about the tensioning wheel axis of rotation A590 relative to the tensioning assembly support 505 such that the first ring gear 526 cannot rotate about the tensioning wheel axis of rotation A590 relative to the tensioning assembly support 505.

[0018] During a tensioning cycle, the motor assembly 900 and the transmission assembly 800 drive the driven shaft 522 in a tensioning direction T, as described below. This allows the first sun gear 522b to rotate in the tensioning direction T about the tensioning wheel axis of rotation A 590. The first sun gear 522b drives the first set of planetary gears 524a-524dc. The decoupling assembly 1900 prevents the first ring gear 526 from rotating about the tensioning wheel axis of rotation A 590, so that rotation of the planetary gears 524a-524d causes the carrier 525 (including the second sun gear 525b) to rotate in the tensioning direction T about the tensioning wheel axis of rotation A 590. The second sun gear 525b drives the second set of planetary gears 530a-530c. Because the second ring gear 528 is unable to rotate about the tensioning wheel axis of rotation A 590, rotation of the planetary gears 530a-530c causes the tensioning wheel mount 529 and the tensioning wheel 590 mounted to the tensioning wheel mount 529 to rotate in the tensioning direction T about the tensioning wheel axis of rotation A 590. Thus, the tensioning assembly gearing 510 operatively connects the motor assembly 900 and the transmission assembly 800 to the tensioning wheel 590 to rotate the tensioning wheel 590 in the tensioning direction T about the tensioning wheel axis of rotation A 590.

[0019] The tensioning assembly 500 is movably mounted on the mounting shaft 390 of the support 300 and is configured to pivot relative to the support 300, and in particular relative to the base 310 of the support 300, between a strap tensioning position (FIG. 4A) and a strap insertion position (FIG. 4B) about the tensioning assembly pivot axis A500 under the control of the rocker lever 700 (as described below). When the tensioning assembly 500 is in the strap tensioning position, the tensioning wheel 590 is adjacent to the tensioning plate 312 of the support 300 (or a top surface of the top of the strap when the strap is inserted into the strapping tool 50). When the tensioning assembly 500 is in the strap insertion position, the tensioning wheel 590 is spaced apart from the tensioning plate 312 to allow for insertion of overlapping upper and lower portions of the strap between the tensioning wheel 590 and the tensioning plate 312. One or more springs or other biasing elements (not shown) bias the tensioning assembly 500 into the strap tensioning position.

[0020] 6A-6C, the decoupling assembly 1900 includes a tensioning wheel 590 that (when actuated) rotates in a release direction T about a tensioning wheel axis of rotation A 590. REV , i.e., in a rotational sense opposite to the tensioning direction T, to allow tension in the strap to be released after completion of the tensioning cycle but prior to completion of the sealing cycle. The disconnect assembly 1900 includes a disconnect assembly shaft 1910 , a first engageable element 1920 , a second engageable element 1930 , an expandable element 1940 , a retainer 1950 , a washer 1960 , and a threaded fastener 1970 .

[0021] The uncoupling assembly shaft 1910 includes a body 1912 having a first end 1912a with an irregular cross-section and a second end 1912b with teeth extending radially 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 inner surface having a periphery that matches the periphery of the first end 1912a of the body 1912 of the uncoupling 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.

[0022] 6A and 6C, the first engageable element 1920 is attached to a first end 1912a of the body 1912 of the decoupling assembly shaft 1910 and rotates therewith about the decoupling assembly axis of rotation A 1900. The second engageable element 1930 surrounds the first support 1914 of the body 1912 of the decoupling assembly shaft 1910 and is positioned such that the body 1932 is adjacent to and coaxial with the first engageable element 1920. An expandable element 1940, which in this exemplary embodiment is a torsion spring, surrounds the first engageable element 1920 and the body 1932 of the second engageable element 1930. The outer diameter of the body 1932 of the first engageable element 1920 and the second engageable element 1930 is substantially the same as, greater than or the same as, the rest inner diameter of the torsion spring 1940. This means that the torsion spring 1940 exerts a compressive force on the body 1932 of the first engageable element 1920 and the second engageable element 1930, preventing these components (and the decoupling assembly shaft 1910) from rotating relative to one another about the decoupling assembly axis of rotation A 1900. The second end 1940b of the expandable element 1940 is received within an opening 1934o defined through the flange 1934 of the second engageable element 1930.

[0023] 6C , the decoupling assembly 1900 is attached to the tensioning assembly support 505 and operatively connected to the tensioning assembly gearing 510. More specifically, the decoupling assembly 1900 is attached to the tensioning assembly support 505 via a fastener 1970 that rotationally fixes the second engageable element 1930 relative to the tensioning assembly support 505 such that the second engageable element 1930 and the second end 1940b of the expandable element 1940 received in the opening 1934o of the flange 1934 of the second engageable element 1930 cannot rotate relative to the tensioning assembly support 505 about the decoupling assembly axis of rotation A 1900. A retainer 1950 and a washer 1960 separate the first engageable element 1920 from the tensioning assembly support 505. An intermediate gear 1990 attached to (and freely rotatable relative to) the tensioning assembly support 505 operatively connects the body 1912 of the decoupling assembly shaft 1910 to the first ring gear 526 of the tensioning assembly gear set 510. Specifically, the teeth on the second end 1912b of the body 1912 of the decoupling assembly shaft 1910 mesh with the teeth of the intermediate gear 1990, which also mesh with the outer teeth 526ot of the first ring gear 526 of the tensioning assembly gear set 510 of the tensioning assembly 500. Because the body 1932 is rotationally fixed relative to the tensioning assembly support 505 and the decoupling assembly shaft 1910 is rotationally fixed with the first engageable element 1920, the decoupling assembly shaft 1910 - and therefore the intermediate gear 1990 - is rotationally fixed relative to the tensioning assembly support 505. Because the intermediate gear 1990 meshes with the external teeth 526ot of the first ring gear 526 of the tensioning assembly gear train 510, the decoupling assembly 1900 prevents the first ring gear 526 from rotating about the tensioning wheel rotation axis A 590.

[0024] The decoupling assembly 1900 is actuable (such as by rocker lever 700, described below) to remove the coupling between the torsion spring 1940 and the first engageable element 1920, thereby allowing the first engageable element 1920 and the decoupling assembly shaft 1910 to rotate relative to the second engageable element 1930 about the decoupling assembly axis of rotation A 1900. As described above, the second engageable element 1930 and the second end 1940b of the expandable element 1940 (received in an opening 1934o in a flange 1934 of the second engageable element 1930) are rotationally fixed relative to the tensioning assembly support 505. To remove the coupling between the torsion spring 1940 and the first engageable element 1920, the first end 1940a of the torsion spring 1940 is rotated about the decoupling assembly axis of rotation A1900 relative to the tensioning assembly support 505, the second end 1940b of the torsion spring 1940, and the second engageable element 1930 (e.g., via moving the rocker lever 700 from a home position to an intermediate position). As this occurs, the inner diameter of the torsion spring 1940 begins to expand near its first end 1940a, and eventually expands sufficiently (thereby reducing or eliminating the compressive force entirely) to allow the first engageable element 1920 and the decoupling assembly shaft 1910 to rotate the decoupling assembly axis of rotation A1900 relative to the second engageable element 1930 (and the torsion spring 1940).

[0025] Upon completion of the tensioning cycle, the tensioning wheel 590 holds substantial tension in the strap, and the strap is pulled in the release direction T REV 19. The actuation of the decoupling assembly 1900 exerts a reaction force (or torque) on the tensioning wheel 590. REVSpecifically, upon completion of the tensioning cycle, the decoupling assembly shaft 1910 (via the intermediate gear 1990) continues to prevent the first ring gear 526 of the tensioning assembly gear train 510 from rotating about the tensioning wheel axis of rotation A 590, which in turn prevents the tensioning wheel 590 from rotating in the release direction T REV As the first end 1940a of the torsion spring 1940 rotates about the uncoupling assembly axis of rotation A 1900, the inner diameter of the torsion spring 1940 near its first end 1940a begins to expand. Eventually, the force that the first ring gear 526 exerts on the uncoupling assembly shaft 1910 exceeds the compressive force that the torsion spring 1940 exerts on the first engageable element 1920. When this occurs, the first ring gear 526 rotates in the release direction T about the tensioning wheel axis of rotation A 590. REV The freewheel 523 of the tensioning assembly gearing rotates in the release direction T REV This prevents the first planetary gears 524a-524d from rotating in the release direction T about the tensioning wheel rotation axis A 590. REV This causes the tensioning wheel 590 to rotate in the release direction T about the tensioning wheel axis of rotation A 590 (as described above). REV Rotate to.

[0026] In other embodiments, the second end of the body of the shaft of the decoupling assembly directly meshes with the external teeth of the first ring gear (rather than through one or more intermediate gears).

[0027] 3A-4B, rocker lever 700 is operatively connected to (1) tensioning assembly 500 and configured to move tensioning assembly 500 from a strap tensioning position to a strap insertion position relative to support 300, and (2) decoupling assembly 1900 and configured to drive the decoupling assembly such that tensioning wheel 590 is moved in release direction T REV to allow it to rotate. Rocker lever 700 includes a mounting head 710 , a body 720 coupled to mounting head 710 , and a disconnect assembly actuator 730 (in this embodiment, a pin) extending laterally from body 720 .

[0028] The mounting head 710 is pivotally 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 exemplary embodiment is the same as the tensioning assembly pivot axis A500). The rocker lever 700 is also attached to the tensioning assembly 500 via a pin 700p, which extends through a slot (not shown) defined through the tensioning assembly support 505 and the body 720 of the rocker lever 700. The slot is sized, shaped, and oriented such that the rocker lever 700 is pivotable about tensioning assembly pivot axis A500 such that the rocker lever 700 is (1) pivotable relative to the support 300, tensioning assembly 500, and decoupling assembly 1900 from a home position (FIGS. 3A-4A) to an intermediate position (FIGS. 3A-4A) to actuate the decoupling assembly 1900, and (2) pivotable relative to the support 300 from an intermediate position (not shown) to an actuated position (FIG. 4B). A rocker lever biasing element (not shown), such as a spring, biases the rocker lever to the home position.

[0029] 3A-4A, when the rocker lever 700 is in the home position, the tensioning assembly 500 is in its strap tensioning position. When the rocker lever 700 moves to an intermediate position relative to the support 300, the tensioning assembly 500, and the disconnection assembly 1900, the disconnection assembly actuator 730 engages a first end 1940a of a torsion spring 1940 of the disconnection assembly 1900 and rotates the first end 1940a relative to the tensioning assembly support 505, the second end 1940b of the torsion spring 1940, and the first and second engageable elements 1920 and 1930. As this occurs, the inner diameter of the torsion spring 1940 near its first end 1940a begins to expand, eventually expanding sufficiently to allow the first engageable element 1920 and the decoupling assembly shaft 1910 to rotate relative to the second engageable element 1930 and the torsion spring 1940 (thereby reducing or completely eliminating the compressive force). After the rocker lever 700 reaches the intermediate position, continued movement towards the actuated position of the rocker lever 700 begins to pivot the tensioning assembly 500 along with the rocker lever 700, eventually causing the rocker lever 700 to reach its actuated position and the tensioning assembly 500 to reach its strap insertion position.

[0030] The sealing assembly 600, best shown in Figures 3A-3B and 7A-9, is configured to connect overlapping portions of the strap to one another during a sealing cycle by forming a series of mechanically interlocking notches in the overlapping portions of the strap to connect the straps to one another, thereby forming a tensioned strap loop around the load. The sealing assembly 600 includes a die assembly 610 , a camshaft 620 including a first cam 622 and a second cam 624 , and a sealing assembly gear set 630 .

[0031] 7A and 7B, the die assembly 610 is movable to engage the strap and cooperate with a punch 314 on the support 300 to form a notch (or key) that interlocks with overlapping portions of the strap. The die assembly 610 includes a body 611 including two spaced apart mounting ears 611e1 and 611e2, a first cam follower 612 mounted on an upper surface of the body 611, a mounting arm 613 extending from the body 611 and supporting a second cam follower 613f that curves over the first cam follower 612, two spaced apart dies 614 on the underside of the body 611, and a cutter 616 supported behind the body 611 of the dies 614. The die assembly 610 is attached to the support 300 via (1) a mounting pin 605 that extends through mounting ears 611e1 and 611e1 and the die assembly mounting ear of the support 300, and (2) a mounting pin (not numbered) that connects the mounting arm 613 to a first mounting ear 320 of the support 300. This mounting configuration allows the die assembly 610 to pivot about a die assembly pivot axis A 610 between a home position (FIGS. 3A and 12A) and a sealing position (FIG. 12C) under the control of first and second cams 622, 624 of a camshaft 620 relative to the support 300, and in particular, relative to the base 310 of the support 300, as described in more detail below. A die assembly biasing element (not shown) biases the die assembly 610 to its home position.

[0032] A camshaft 620, best seen in Figures 8 and 9, controls the position of the die assembly 610 during the sealing cycle. In this embodiment, the total angular displacement of the camshaft 620 is 360 degrees (i.e., one revolution) in a single sealing cycle. The camshaft 620 is elongated and has first and second cams 622 and 624 near one end and a splined end 620s opposite the first and second cams 622 and 624 that allows the camshaft 620 to be rotationally fixedly attached to a planet gear carrier 634 (described below) of the sealing assembly gearing 630.

[0033] The first cam 622 has a cam surface 622s of varying radius (measured from the camshaft axis of rotation A 620) that is divided into four angular sections 622s1, 622s2, 622s3, and 622s4 that correspond to four stages of the sealing cycle and different positions of the die assembly 610, as described below. The four stages of the sealing cycle are (1) a strap engagement (first) stage in which the camshaft (and first cam) rotates a first cam angular displacement Φ1 (FIG. 9) and the die assembly 610 pivots a first die assembly angular displacement from its home position toward its sealing position until the die 614 contacts the upper strap portion; and (2) a strap-cutting (second) stage in which the camshaft (and first cam) rotates a second cam angular displacement Φ2 (FIG. 9) and the die assembly 610 pivots a second die assembly angular displacement to its sealing position, at which point the die 614 cooperates with the punch 314 of the support 300 to cut the strap and the cutter 616 cuts the strap. (3) an energy release (third) phase in which the camshaft (and first cam) rotates a third cam angular displacement Φ (FIG. 9) and the die assembly biasing elements, straps, and other mechanical components of the sealing assembly 600 gradually rotate the die assembly 610 upwardly toward the home position a third die assembly angular displacement, releasing the large potential energy; and (4) a return (fourth) phase in which the camshaft (and first cam) rotates a fourth cam angular displacement Φ (FIG. 9) and the die assembly biasing elements rapidly pivot the die assembly 610 a fourth die assembly angular displacement to complete the return to the home position.

[0034] In this exemplary embodiment, the angular displacement of the first die assembly is approximately 4 degrees, the angular displacement of the second die assembly is approximately 5 degrees, the angular displacement of the third die assembly is approximately 1.4 degrees, and the angular displacement of the fourth die assembly is approximately 7.6 degrees, although these values ​​may vary in other embodiments. Thus, the first die assembly angular displacement is less than the second die assembly angular displacement, and the third die assembly angular displacement is less than the fourth die assembly angular displacement.

[0035] In this embodiment, the first cam angle displacement is approximately 55 degrees, the second cam angle displacement is approximately 166 degrees, the third cam angle displacement is approximately 78 degrees, and the fourth cam angle displacement is approximately 61 degrees, although these values ​​may vary in other embodiments. Thus, the second cam angle displacement is greater than the first and third cam angle displacements, and the third cam angle displacement is greater than the fourth cam angle displacement.

[0036] The first angular section 622s1 corresponds to the strap engagement phase and the first cam angular displacement and is characterized by an increase in radius moving in the sealing direction S from R1 to R2. In this illustrated embodiment, R2 is approximately 1.5×R1, which in combination with the relatively short first cam angular displacement makes this a relatively sharp increase. The second angular section 622s2 corresponds to the strap cutting phase and the second cam angular displacement and is characterized by an increase in radius moving in the sealing direction S from R2 to R3. In this illustrated embodiment, R3 is approximately 1.4×R2, which in combination with the relatively large second cam angular displacement makes this a relatively gradual increase. The third angular section 622s3 corresponds to the energy release phase and the third cam angular displacement and is characterized by a decrease in radius moving in the sealing direction S from R3 to R4. In this illustrated embodiment, R4 is approximately 0.9×R3, which in combination with the relatively large third cam angular displacement makes this a relatively gradual decrease. The fourth angle section 622s4 corresponds to the return phase and the fourth cam angular displacement and is characterized by a decrease in radius moving in the sealing direction S from R4 to R1. In this illustrated embodiment, R1 is approximately 0.5×R4, which, combined with the relatively short fourth cam angular displacement, makes this a relatively sharp decrease. The radius multiples are merely examples and may be any other suitable multiples in other embodiments.

[0037] Thus, during a sealing cycle (i.e., 360 degree rotation of the camshaft 620), (1) the angular displacement of the first cam 622 during the strap engagement phase (when the first angular portion 622s1 contacts the first cam follower 612) is a first cam angular displacement of approximately 60 degrees; (2) the angular displacement of the first cam 622 during the strap cutting phase (when the second angular portion 622s2 contacts the first cam follower 612) is a second cam angular displacement of approximately 150 degrees; and (3) the angular displacement of the first cam 622 during the energy release phase (when the third angular portion 622s3 contacts the first cam follower 612) is a third cam angular displacement of approximately 90 degrees. and (4) the angular displacement of the first cam 622 during the return phase (when the fourth angular portion 622s4 contacts the first cam follower 612) is a fourth cam angular displacement of approximately 60 degrees. In other words, in this embodiment, the second cam angular displacement is greater than the first cam angular displacement, and the third cam angular displacement is greater than the fourth cam angular displacement. And, in this embodiment, the second cam angular displacement is greater than the third cam angular displacement (although not required in other embodiments), and the first and fourth cam angular displacements are the same (although not required in other embodiments).

[0038] In this exemplary embodiment, the motor assembly 900 drives the camshaft 620 at a substantially constant torque speed during the sealing cycle. A strap engagement phase time elapses during the strap engagement phase, a strap cutting phase time elapses during the strap cutting phase, an energy release phase time elapses during the energy release phase, and a return phase time elapses during the return phase. In this exemplary embodiment, the energy release phase time is longer than the return phase time even though the third die assembly angular displacement of the die assembly 610 during the energy release phase is smaller than the fourth die assembly angular displacement of the die assembly 610 during the return phase. Additionally, in this exemplary embodiment, the strap cutting phase time is shorter than the strap engagement phase time and longer than the energy release phase time. Also, the strap engagement phase time and the return phase time are approximately the same.

[0039] The second cam 624 has a radially extending lobe 624l and a cam surface 624s.

[0040] The cam shaft 620 generally extends through the mounting shaft 390 of the support 300 and is supported by bearings or other suitable components. As best shown in Figures 12A-12E, the cam shaft 620 is positioned, oriented, or configured such that the die assembly biasing element biases the first cam follower 612 of the die assembly 610 into engagement with the cam surface 622s of the first cam 622.

[0041] The sealing assembly gearing 630, best shown in FIG. 8, operatively connects the transmission assembly 800 and the motor assembly 900 to the camshaft 620 to rotate the camshaft 620 (and the first and second cams 622 and 624 thereon) in a sealing direction S. The sealing assembly gearing 630 includes a driven gear 632 having teeth 632t, a sun gear (not shown) rotationally fixed to the driven gear 632, a planet gear carrier 634, a plurality of planet gears 636, and a ring gear (not shown). The planet gears 636 are rotatably mounted to the planet gear carrier 634 (such as via respective bearings and mounting pins). The sun gears mesh and drivingly engage the planet gears 636. The planet gears 636 mesh with the teeth of the rotationally fixed ring gear (not shown). The splined end 620s of the camshaft 620 is received in a suitably shaped opening in the planetary gear carrier 634, thereby rotationally fixing the camshaft 620 and the planetary gear carrier 634. Most of the components of the sealing assembly gear train 630 reside within the mounting shaft 390 of the support 300 and are supported by bearings or other suitable components.

[0042] Generally, in operation, the motor assembly 900 and the transmission assembly 800 drive the driven gear 632 in a sealing direction S, which causes the sun gear to rotate with the driven gear 632 in the sealing direction S. The sun gear drives the planet gears 636. Because the ring gear is rotationally fixed, rotation of the planet gears 636 rotates the planet gear carrier 634 and the camshaft 620 (which is rotationally fixed to the planet gear carrier 634 via a splined connection) in the sealing direction S via the first and second cams 622 and 624 to control the position of the die assembly 610. Thus, the sealing assembly gearing 630 operatively connects the motor assembly 900 and the transmission assembly 800 to the die assembly 610 (via the camshaft 620) and orbits the die assembly 610 (via the rotation of the camshaft 620).

[0043] More specifically, as described above, the cam surface 622s of the first cam 622 is divided into four angles 622s1, 622s2, 622s3, and 622s4 that correspond to the four stages of the sealing cycle and different positions of the die assembly 610. FIG. 12A shows the first cam 622, the second cam 624, and the die assembly 610 in their respective home positions. When the first cam 622 is in its home position, the first cam follower 612 engages the first cam 622 at the junction between the first and fourth angles 622s1 and 622s4 of the cam surface 622s. When the second cam 624 is in its home position, the lobe 624l engages the second cam follower 613s of the mounting arm 613 of the die assembly 610. A second cam 624 operates in conjunction with the die assembly biasing element to hold the die assembly 610 in the home position.

[0044] 12B shows the strapping tool 50 after the strap engagement phase of the sealing cycle has been completed and the motor assembly 900 has rotated the first cam 622 in the sealing direction S by a first cam angular displacement Φ1 from its home position to the strap engagement position. During this rotation, the first angled portion 622s1 of the cam surface 622s of the first cam 622 engages the follower 612, causing the abrupt increase in the radius of the cam surface 622s from R1 to R2 to quickly pivot downward by the angular displacement of the first die assembly until the die 614 contacts the upper strap portion (not shown for clarity).

[0045] FIG. 12C shows the strapping tool 50 after the strap-cutting stage of the sealing cycle has been completed and the motor assembly 900 has further rotated the first cam 622 in the sealing direction S by a second cam angular displacement Φ2 from the strap-engaging position to the strap-cutting position. During this rotation, the second angle 622S2 of the cam surface 622S of the first cam 622 engages the follower 612, and the gradual increase in the radius of the cam surface 622S from R2 to R3 causes the die assembly 610 to slowly pivot downwards by a second die assembly angular displacement until the die assembly 610 reaches its strap-cutting position, where the die 614 cooperates with the punch 314 of the support 300 to cut the strap (not shown), and the cutter 616 cuts the strap from a strap supply (not shown). This gradual cutting process (which took longer than the process of contacting the die assembly with the strap) has several advantages over a rapid cutting process, including lower power requirements (leading to an increased number of strapping cycles per battery charge) and less strain on the mechanical components of the sealing assembly, transmission assembly, and motor assembly 600, 800, and 900 (prolonging the life of the components).

[0046] When the die assembly 610 is in the sealing position, the die assembly biasing elements, straps, and other mechanical components of the sealing assembly 600 store a large potential energy that exerts a large force on the die assembly 610, which tends to force the die assembly 610 back to its home position. If this energy is not gradually released, the first cam 622 may rotate in the sealing rotation direction S independently of the motor assembly 900, causing the first cam 622 to rotate past its home position. If this occurs, the first cam 622 will remain in the wrong position (ie, any position except its home position) for the next tensioning cycle.

[0047] The third angle 622S3 of the cam surface 622S allows for the gradual release of this potential energy. Figure 12D shows the strapping tool 50 after the energy release phase of the sealing cycle is completed and the motor assembly 900 has rotated the first cam 622 an additional third cam angular displacement Φ3 in the sealing direction S from its strap cut position to its energy release position. During this rotation, the third angle 622S3 of the cam surface 622S of the first cam 622 engages the follower 612, and the gradual reduction in the radius of the cam surface 622S from R3 to R4 allows the die assembly biasing element, strap, and other mechanical components of the sealing assembly 600 to gradually pivot the die assembly 610 upwards the third die assembly angular displacement. By gradually raising the die assembly 610 in this manner (taking as long as the cutting process), the forces these components apply to the die assembly 610 are reduced to a level where they are unable to rotate the first cam 622 independently of the motor assembly 900.

[0048] 12E shows the strapping tool 50 after the return phase of the sealing cycle is completed and the motor assembly 900 has rotated the first cam 622 an additional fourth cam angular displacement Φ4 in the sealing direction S from its energy release position to its home position. During this rotation, the fourth angled portion 622S4 of the cam surface 622S of the first cam 622 engages the first cam follower 612, and the rapid reduction in radius from R4 to R1 allows the die assembly biasing element to rapidly pivot the die assembly 610 upwards the fourth die assembly angular displacement to its home position. Additionally, during this rotation, the lobe 6241 of the second cam 624 engages the second cam follower 613f, pushing the mounting arm 613 and the remainder of the die assembly 610 upwards to its home position.

[0049] In other embodiments, the die assembly is vertically (rather than pivotally) movable relative to the support between its home and sealing positions, in these embodiments, the vertical displacement of the die assembly varies during different stages of the sealing cycle.

[0050] Although a single cam controls movement of the die assembly through the four stages of the sealing cycle in the embodiment described above, in other embodiments multiple cams control movement of the die assembly through the four stages, for example one cam is shaped to engage a cam follower and control movement of the die assembly during the strap engagement and strap cut stages, while a different cam is shaped to engage a different cam follower and control movement of the die assembly during the energy release and return stages.

[0051] 10, the transmission assembly 800 is driven by a motor assembly 900 and operably connected to the tensioning assembly 500 and configured to rotate the tensioning wheel 590 in a tensioning direction T to tension the strap, and the transmission assembly 800 is operably connected to the sealing assembly 600 and configured to attach overlapping portions of the strap to one another. The transmission assembly 800 includes a first transmission-gear assembly 810, a second transmission-gear assembly 820, and a connector 830.

[0052] The first transmission-gear assembly 810 includes a first driven gear 812 (which is a bevel gear in this example, but may be any suitable gear), a second gear assembly drive gear 814 (which is a spur gear in this example, but may be any suitable gear), and a first transmission freewheel 816. The first transmission freewheel 816 is attached to, engages, and surrounds the shaft portion 522a of the driven shaft 522 of the tensioning assembly gearbox 510 of the tensioning assembly 500. The first driven gear 812 and the second gear assembly drive gear 814 are rotationally fixed to one another (and therefore rotate together) and are attached to, engage, and circumscribe the first transmission freewheel 816. The first transmission freewheel 816 is configured to (1) transmit the rotational motion of the first driven gear 812 and the second gear assembly drive gear 814 in a tensioning direction T to the driven shaft 522, so 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 tensioning wheel rotation axis A 590, and (2) transmit the rotational motion of the first driven gear 812 and the second gear assembly drive gear 814 in a release direction T REV to the driven shaft 522, and the first driven gear 812 and the second gear assembly drive gear 814 rotate relative to and around the first transmission freewheel 816 and the driven shaft 522 in a release direction T about the tensioning wheel rotation axis A 590. REV The rotating shaft is configured to rotate in a clockwise direction.

[0053] The second transmission-gear assembly 820 includes a second driven gear 822 (which in this embodiment is a spur gear but may be any suitable gear), a second transmission freewheel 824, and a sealing assembly drive gear 826 having a long shaft (which in this embodiment is a spur gear but may be any suitable gear). The second transmission freewheel 824 is mounted on, engages and circumscribes the long shaft of the sealing assembly drive gear 826. The second driven gear 822 is mounted on, engages and surrounds the second transmission freewheel 824. The second transmission freewheel 824 is configured to (1) transmit the rotational motion of the second driven gear 822 in a transmission rotational direction TR - here referred to as the transmission direction TR (FIG. 8) - to the sealing assembly drive gear 826, so that the second driven gear 822 and the sealing assembly drive gear 826 rotate together in the transmission direction TR, and (2) transmit the rotational motion of the second driven gear 822 in a rotational direction opposite to the transmission direction TR of the second driven gear 822 - here referred to as the non-transmitting direction TR. REV 8)—to the sealing assembly drive gear 826, and the second driven gear 822 rotates relative to and around the second transmission freewheel 824 and the sealing assembly drive gear 826 in a non-transmitting direction TR REV The rotating shaft is configured to rotate in a clockwise direction. Although not shown, the sealing assembly drive gear 826 is operably connected to the sealing assembly gear set 630 and configured to drive the sealing assembly gear set 630 to rotate the camshaft 620 in the sealing direction S.

[0054] A connector 830, which in this embodiment is a toothed belt 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.

[0055] This is just one example transmission assembly, and the strapping tool may include any suitable transmission assembly that operably connects one or more motors to the tensioning assembly and sealing assembly to drive those assemblies.

[0056] A connector 830, which in this embodiment is a toothed belt 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.

[0057] In operation, the motor assembly 900 rotates the first driven gear 812 of the first transfer gear assembly 810 of the transfer assembly 800 in a tensioning direction T or a release direction T REV It can be driven in either When the motor assembly 900 drives the first driven gear 812 in a 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 tensioning wheel rotation axis A 590. The connector 830 transfers the rotation of the second gear assembly drive gear 814 to the second driven gear 822 of the second transfer gear assembly 820, which rotates around the second transfer freewheel 824 in a non-transmitting direction TR. REV 13, which does not transmit this rotational motion to the sealing assembly drive gear 826. On the other hand, the motor assembly 900 rotates the first driven gear 812 in the release direction T REV When driven in the direction of the arrow A, the first driven gear 812 and the second gear assembly driving gear 814 rotate around the first transmission freewheel 816 in the release direction T REV5 and does not transmit this rotational motion 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 to rotate in the transmission direction TR. The second transmission freewheel 824 transmits this rotational motion to the sealing assembly drive gear 826, which rotates in the transmission direction TR and drives the sealing assembly gear set 630 to rotate the camshaft 620 in the sealing direction S.

[0058] 7 and 8, motor assembly 900 is operatively connected (via transmission assembly 800) to and configured to drive tensioning assembly 500 and sealing assembly 600. Motor assembly 900 includes a motor 910, a drive gear 920, a motor mount 930, and a motor biasing element 940 (although other embodiments may not include motor biasing element 940).

[0059] As best shown in FIG. 7, the motor 910, which in this embodiment is an electric motor but may be any suitable motor, includes a motor housing 910b and a rotatable output shaft 910s extending from the motor housing 910b. A drive gear 920, which in this exemplary embodiment is a bevel gear but may be any other suitable gear, is fixedly attached to the end of the output shaft 910s opposite the motor housing 910b, and the drive gear 920 and the output shaft 910s are fixed in rotation (i.e., rotate together) about the motor axis of rotation A 910. Specifically, the motor 910 is configured to rotate the output shaft 910s and the drive gear 920 in opposite first and second drive directions D1 and D2 (FIG. 8) to perform tensioning and sealing cycles, respectively. The motor mount 930 includes a tubular body 932 and a head 934 at one end of the body 932. The head 934 includes a base 934b and first and second spaced apart mounting ears 934e1 and 934e2 extending from the base 934b. The body 932 is fixedly mounted (via suitable fasteners) to the motor housing 910b, with the output shaft 910s extending through the body 932 and the drive gear 920 being between the mounting ears 934e1 and 934e2. A motor biasing element 940, which in this embodiment is a compression spring but may be any suitable biasing element, surrounds the body 932 of the motor mounting portion 930 and is constrained at both ends by the motor housing 910b and the base 934b of the head 934 of the motor mounting portion 930.

[0060] As shown in FIG. 8 , the motor assembly 900 is pivotally attached at one end to the tensioning assembly 500 and at the other end is housed within the motor housing portion 130 of the housing 100 of the strapping tool 50 such that the motor 910 can move relative to the housing 100 and the tensioning assembly 500. The motor assembly 900 is mounted such that the drive gear 920 is configured to mesh with, and thus drivingly engage, the first driven gear 812 of the first transfer gear assembly 810 of the transfer assembly 800. As described in more detail below, the motor assembly 900 is mounted such that the motor 910 can move relative to the housing 100 and the tensioning assembly 500 (and in this example, both pivot and move longitudinally) as the tensioning assembly 500 pivots between the strap tensioning position and the strap insertion position, such that the drive gear 920 maintains driving engagement with the first driven gear 812.

[0061] Specifically, a first mounting ear 934e1 of a head 934 of a motor mount 930 of the motor assembly 900 is attached (via suitable bearings not labeled) to a driven shaft 522 of the tensioning assembly gear set 510 of the tensioning assembly 500, and a second mounting ear 934e2 of the head 934 is attached (via suitable bearings not labeled) to a support shaft 512a of the gear set support 512 of the tensioning assembly gear set 510, such that the motor assembly 900 is rotatable relative to the tensioning assembly 500 about the tensioning wheel axis of rotation A 590. The motor housing portion 130 defines one or more internal chambers that house the motor mount 930, the motor 910, and the motor biasing element 940.

[0062] 1A-1C includes a suitable display screen 1310 with a touch panel 1320. The display screen 1310 is configured (at least in this embodiment) to display information related to the strapping tool 50, and the touch panel 1320 is configured to receive operator inputs such as desired strap tension, desired weld cooling time, etc., as is known in the art. A display controller (not shown) may control the display screen 1310 and the touch panel 1320, and in these embodiments is communicatively connected to the controller 1600 to send signals to and receive signals from the controller 1600. Other embodiments of the strapping tool do not include a touch panel. Still other embodiments of the strapping tool do not include a display assembly. Certain embodiments of the strapping tool include a separate push button panel instead of a touch panel below or integrated with the display screen.

[0063] The actuation assembly 1400 shown in FIGS. 1A-1C is configured to accept operator input to initiate actuation of the tensioning and sealing cycles. In this embodiment, the actuation assembly 1400 includes first and second push button actuators 1410 and 1420 that initiate tensioning and / or sealing cycles as described below depending on the operational mode of the strapping tool 50. Other embodiments of the strapping tool 50 do not have the actuation assembly 1400, instead incorporating its functionality into the display assembly 1300. For example, in one of these embodiments, two regions of the touch panel define virtual buttons that have the same functionality as the mechanical push button actuators.

[0064] The controller 1600 shown in FIG. 1C includes a processing device(s) communicatively coupled to a memory device(s). For example, 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 special purpose processor, a digital signal processor, one or more microprocessors, one or more microprocessors associated with a digital signal processor core, one or more application specific 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, a read-only memory, a random access memory, one or more digital registers, a cache memory, one or more semiconductor memory devices, a magnetic medium such as an integrated hard disk and / or a removable memory, a magneto-optical medium, and / or an optical medium. The memory device stores instructions executable by the processing device to control the operation of the strapping tool 50. The controller 1600 is communicatively and operably coupled to the motor 910, the display assembly 1300, the actuation assembly 1400, and the sensor 1700 and is configured to receive signals from and control those components. The controller 1600 may also be communicatively connected to an external device, such as a computing device (via Wi-Fi, Bluetooth, near field communication, or other suitable wireless communication protocol) to send information to and receive information from the external device.

[0065] 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 rotate the tensioning wheel 590 in response to the first push button actuator 1410 being actuated and maintained in an actuated state. The controller 1600 actuates the motor 910 to cause the sealing assembly 600 to perform a sealing cycle in response to the second push button actuator 1420 being actuated. In the semi-automatic mode of operation, the controller 1600 operates the motor 910 to rotate the tensioning wheel 590 in response to the first push button actuator 1410 being actuated and maintained in its actuated state. Once the controller 1600 determines that the tension in the strap has reached the desired (pre-set) strap tension, the controller 1600 automatically actuates the motor 910 to cause the sealing assembly 600 to perform a sealing cycle (without further input from the operator). In the automatic mode of operation, the controller 1600 operates the motor 910 to rotate the tensioning wheel 590 in response to actuation of the first push button actuator 1410. Once the controller 1600 determines that the tension in the strap has reached the desired (pre-set) strap tension, the controller 1600 automatically actuates the motor 910 to cause the sealing assembly 600 to perform a sealing cycle (without requiring further input from the operator).

[0066] The sensors 1700 may include any suitable sensors, such as microswitches, optical sensors, ultrasonic sensors, magnetic position sensors, etc., configured to detect the position of particular components of the strapping tool 50 and send appropriate signals to the controller 1600. The sensors 1700 may include, for example, 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, in particular whether the camshaft 620 is in its 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 actuation assembly sensors configured to detect actuation of the first and second push button actuators 1410 and 1420.

[0067] The power source is electrically connected (via appropriate wiring and other components) to and configured to power several components of the strapping tool 50, including the motor 910, the display assembly 1300, the actuation assembly 1400, the controller 1600, and the sensor(s) 1700. The power source is a rechargeable battery (such as a lithium-ion or nickel-cadmium battery) in this embodiment, although in other embodiments it may be any other suitable power source. The power source is sized, shaped, and otherwise configured to be received within a receptacle 122 defined by the rear housing portion 120 of the housing 100. The strapping tool 50 includes one or more battery retaining devices (not shown) for releasably locking the power source in place when the power source is received in the receptacle. Actuation of a release device of the strapping tool 50 or the power source unlocks the power source from the housing 100 and allows the operator to remove the power source from the receptacle 122.

[0068] Performing a strapping cycle using the strapping tool 50 includes (1) a tensioning cycle in which the strapping tool 50 pulls the strap around a load, and (2) a sealing cycle in which the strapping tool 50 attaches the overlapping upper and lower portions of the strap to one another via a sealless strap joint, as 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 purposes of this example.

[0069] The operator first pulls the strap leading end from a strap supply (not shown) and wraps the strap around the load, positioning the leading end of strap S under another portion of the strap to form an upper and lower portion of the strap. The operator then pulls rocker lever 700 from its home position to its actuated position, raising tensioning assembly 500 from its strap tensioning position to its strap insertion position. While holding rocker lever 700 in its actuated position, the operator introduces overlapping upper and lower portions of the strap between punch 314 (on base 310 of support 300) and die 614 (of die assembly 610 of sealing assembly 600), and between tensioning plate 312 (on base 310 of support 300) and tensioning wheel 590 (of tensioning assembly 500), as shown in FIG. 3C. The operator then releases the rocker lever 700, which causes various biasing elements to force the rocker lever 700 back to its home position and the tensioning assembly 500 to return to its strap tensioning position, causing the tensioning wheel 590 to engage the top surface of the upper portion of the strap and force the bottom surface of the lower portion of the strap against the tensioning plate 312.

[0070] The operator then actuates the first push button actuator 1410 to initiate a strapping cycle. In response, the controller 1600 initiates a tensioning cycle by controlling the motor 910 to begin rotating the motor output shaft 910s in a first drive direction D1, thereby driving the first driven gear 812 of the transmission assembly 800 in a tensioning direction T. As explained in detail above, this causes the tensioning wheel 590 to begin rotating in the tensioning direction T, pulling on the top of the strap, thereby pulling 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 correlates with the (preset) desired strap tension for this strapping cycle, the controller 1600 stops the motor 910, thereby ending the tensioning cycle.

[0071] Then, the controller 1600 controls the motor 910 to start rotating the motor output shaft 910s in the second driving direction D2 and rotate the first driven gear 812 in the release direction T REV 300。 As described in detail above, this rotates the camshaft 620 in the sealing direction S, which rotates the die assembly 610 into a sealing position where the die 614 engages the upper portion of the strap and forces the lower portion of the strap against the punch 314 in the base 310 of the support 300, ultimately cutting a key into the overlapping upper and lower portions of the strap to join them. Meanwhile, the cutter 616 of the die assembly 610 severs the strap from the strap supply. Once the cutter 616 has severed the strap from the strap supply, the top of the strap slides against the bottom of the strap, which causes the keys to interlock and form a sealless strap joint. Continuing to rotate the camshaft 620 in the sealing direction S reverses this motion, returning the die assembly 610 to the home position. After the sealing cycle is complete, the operator again pulls the rocker lever 700 to raise the tensioning assembly 500 and remove the strapping tool 50 from the tensioned strap loop.

[0072] Although the sealing assembly in the above-described exemplary embodiment of the strapping tool comprises a punch and die configured for a sealless connection in the strap, in other embodiments, the sealing assembly can comprise other sealing mechanisms (such as a notching jaw assembly, a crimping jaw assembly, a friction welding assembly, an ultrasonic welding assembly, or a hot knife assembly) configured to seal any suitable type of strap (such as a metal, plastic, or paper strap).

[0073] The above-described exemplary embodiments of the strapping tool include a single motor configured to drive both the tensioning assembly and the sealing assembly. In other embodiments, the strapping tool includes separate motors configured to drive the respective tensioning and sealing assemblies. In these embodiments, either or both motors can be moved relative to the housing of the strapping tool to ensure that the respective drive gears remain drivingly engaged with the respective driven gears configured to drive the assemblies.

[0074] 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 illustrated in the figures. In other words, the strapping tool 50 includes all of the assemblies, components, and features described above, but which are independent of one another and may be included independently in other strapping tools.

[0075] Although the strapping tool described above is a handheld strapping tool, the strapping tool may have other embodiments, for example any other suitable strapping tool, such as a stand-alone automatic or semi-automatic strapping tool.

Claims

1. 1. A strapping device comprising: A support including a punch; a die assembly movable relative to the support between a home position and a sealing position, the die assembly including a body and a die supported by the body, and a sealing assembly including a camshaft rotatable relative to the support and including one or more cams; a motor operatively connected to the camshaft to rotate the camshaft in a sealing rotational direction to perform a sealing cycle; one or more cams are formed such that during first and second stages of the sealing cycle, the cams urge the die assembly from the home position to the sealing position, and during third and fourth stages of the sealing cycle, the cams urge the die assembly from the sealing position to the home position; the angular displacement of at least one of the one or more cams during the third stage is a third cam angular displacement, and the displacement of the die assembly during the third stage is a third die assembly displacement; the angular displacement of at least one of the one or more cams during the fourth stage is a fourth cam angular displacement, and the displacement of the die assembly during the fourth stage is a fourth die assembly displacement; The strapping apparatus, wherein the fourth die assembly displacement is greater than the third die assembly displacement.

2. 2. The strapping apparatus of claim 1, wherein the die assembly further comprises a cam follower supported by the body, the one or more cams comprising a first cam having a cam surface of varying radius, the cam surface shaped such that during the first and second stages of the sealing cycle, the first cam urges the die assembly from the home position to the sealing position, and during the third and fourth stages of the sealing cycle, the first cam moves the die assembly from the sealing position to the home position.

3. 3. The strapping device of claim 2, wherein the third cam angular displacement is greater than the fourth cam angular displacement.

4. 3. The strapping apparatus of claim 2, wherein the die assembly is pivotable between a home position and a sealing position relative to the support, and the third and fourth die assembly displacements include third and fourth die assembly angular displacements.

5. The strapping device of claim 2 , further comprising a die assembly biasing element biasing the cam follower into contact with the first cam.

6. 6. The strapping apparatus of claim 5, wherein the die assembly biasing element urges the die assembly partially from the sealing position to the home position during third and fourth stages of the sealing cycle.

7. 3. The strapping apparatus of claim 2, wherein the first stage comprises a strap engaging stage in which the die assembly moves toward the sealing position until the die contacts an upper portion of two overlapping strap portions located between the die and the punch, the second stage comprises a strap cutting stage in which the die assembly moves to the sealing position and the die and punch cooperate to cut the overlapping strap portions, the third stage comprises an energy releasing stage in which the die assembly moves back toward the home position, and the fourth stage comprises a return stage in which the die assembly reaches the home position.

8. 8. The strapping device of claim 7, wherein the third stage takes a longer time than the fourth stage.

9. 8. The strapping apparatus of claim 7, wherein an angular displacement of the first cam in the strap engaging step is a first cam angular displacement, a displacement of the die assembly in the first step is a first die assembly displacement, an angular displacement of the first cam in the strap cutting step is a second cam angular displacement, and a displacement of the die assembly in the second step is a second die assembly displacement, the second cam angular displacement being greater than the first cam angular displacement.

10. 10. The strapping device of claim 9, wherein the second stage is longer than the first stage.

11. The strapping apparatus of claim 9 , wherein the first die assembly displacement is greater than the second die assembly displacement.

12. The strapping apparatus of claim 11 , wherein the fourth die assembly angular displacement is greater than the first die assembly angular displacement.

13. The strapping apparatus of claim 12 , wherein the fourth die assembly displacement is greater than the first die assembly displacement.

14. 3. The strapping apparatus of claim 2, wherein the camshaft comprises a second cam having a lobe, the die assembly comprises a second cam follower, the lobe being positioned such that the lobe engages the second cam follower, and wherein the die assembly is forced to move to a home position during a fourth stage of the sealing cycle.

15. 1. A strapping device comprising: A support including a punch; A sealing assembly comprising a die assembly, a camshaft, and a die assembly biasing element, the die assembly is movable relative to the support between a home position and a sealing position and includes a body, a cam follower supported by the body, and a die supported by the body; the camshaft is rotatable relative to a support and includes a cam having a cam surface of varying radius; The die assembly biasing element includes a sealing assembly that biases a cam follower into contact with a cam surface of a cam; a motor operatively connected to the camshaft to rotate the camshaft in a sealing rotational direction to perform a sealing cycle; a cam surface of the cam is formed such that in the first and second stages of the sealing cycle, the cam urges the die assembly from the home position to the sealing position, and in the third and fourth stages of the sealing cycle, the cam can move the die assembly from the sealing position to the home position; The strapping device, wherein the cam rotates more in the third stage than in the fourth stage, and the die assembly moves more in the fourth stage than in the third stage.

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