Strapping tool

Abstract

This disclosure provides a strapping device including a welding plate; a welding arm movable between an initial position and a sealed position; a welding cam rotatable about a welding cam axis; and a motor configured to rotate the welding cam about the welding cam axis. The welding cam includes a cam surface with an actuating portion defined between a first point and a second point, the first point and the second point being separated by a first angular distance of at least 90 degrees. A radial distance between the welding cam axis and the cam surface increases along the actuating portion from a first radial distance at the first point to a second radial distance at the second point. The welding cam is operatively connected to the welding arm such that rotation of the welding cam forces the welding arm to move from its initial position to the sealed position.

Description

[Technical Field]

[0001] This disclosure relates to a strapping device, and more specifically to a strapping device configured to tension the strip around a load and to attach overlapping layers of the strip to each other to form a tensioned strip loop around the load. [Previous Technology]

[0002] The strapping device is configured to tension the strip around a load and attach overlapping layers of the strip to each other to form a tensioned strip loop around the load. Hand-held strapping tools are a common type of strapping device, and these hand-held strapping tools can be electric, pneumatic, or manual. Some strapping tools, such as those configured for use with plastic or paper strips, use friction welding to attach overlapping upper and lower strip layers to each other.

[0003] To use one of these strapping tools to form a tensioned strip loop around a load, the operator first pulls the front end of the strip from the strip supply, wraps the strip around the load, and positions the lower layer of the strip, including the front end, below the upper layer of the strip connected to the strip supply. The operator introduces the overlapping strip layers into the strapping tool such that these strip layers extend between the toothed tension wheel and toothed tension plate of the strapping tool and between the toothed welding shoe and toothed welding plate of the strapping tool. The tension wheel and tension plate are typically positioned near the front of the strapping tool, while the welding shoe and welding plate are positioned behind the tension wheel and tension plate and laterally aligned with them. A spring forces the tension wheel and tension plate together, clamping the strip layers in the middle, while initially the welding shoe does not contact the strip.

[0004] The operator presses a button to initiate the tensioning process, during which the tensioning wheel rotates to move the upper strip layer above the lower strip layer and tension the strip around the load. After the tensioning process is complete, the sealing process begins. During the sealing process, the welding shoe lowers to force the strip layer against the welding plate, while the self-strip supply cuts the upper strip layer. As the welding shoe applies welding force to the strip layer, it reciprocates at a high frequency. The reciprocating welding shoe causes the upper strip layer to reciprocate relative to the lower strip layer, which generates friction between the overlapping portions of the strip layers, causing these portions to partially melt. After a period of time, the welding shoe stops reciprocating but continues to apply welding force. The molten portions of the overlapping strip layers bond together and solidify upon cooling, thereby attaching the upper and lower strip layers to form a tensioned strip ring.

[0005] Some strapping tools use the same motor to lower the welding shoe and simultaneously reciprocate it. To perform both functions, these strapping tools include a transmission that: (a) transmits a high-speed, low-torque output from the motor output shaft to the welding shoe to reciprocate; and (b) uses a multi-stage planetary gear to convert the output from the motor output shaft into a low-speed, high-torque output sufficient to force a series of linkages to move, thereby lowering the welding shoe. This multi-stage planetary gear occupies space and increases the weight, complexity, and cost of the strapping tool. [Summary of the Invention]

[0006] Various embodiments of this disclosure provide a strapping device including a welding plate; a welding arm including a reciprocating welding shoe; a welding cam rotatable about a welding cam axis; and a motor operatively connected to and configured to rotate the welding cam about the welding cam axis. The welding arm is movable between an initial position and a sealed position. When the welding arm is in the sealed position, the welding shoe is closer to the welding plate than when the welding arm is in the initial position. The welding cam includes a cam surface including an actuating portion defined between a first point and a second point on the cam surface. The first point and the second point on the cam surface are separated by a first angular distance of at least 90 degrees. The radial distance between the welding cam axis and the cam surface increases along the actuating portion from a first radial distance at the first point to a second radial distance at the second point. The welding cam is operatively connected to the welding arm such that rotation of the welding cam about the welding cam axis causes the actuating portion of the cam surface to force the welding arm to move from the original position to the sealed position.

Implementation Method

[0017] Although the systems, apparatuses, and methods described herein may be embodied in various forms, the drawings and descriptions illustrate certain exemplary and non-limiting embodiments. Not all components shown in the drawings and described in the description may be required, and some implementations may include additional, different, or fewer components. Variations in the arrangement and type of components; the shape, size, and material of components; and the manner in which components are connected may occur without departing from the spirit or scope of the claims. Unless otherwise indicated, any orientation referred to in the description reflects the orientation of the components shown in the corresponding drawings and does not limit the scope of this disclosure. Furthermore, terms relating to installation methods, such as mounting and connection, are not intended to be limited to direct installation methods but should be broadly interpreted to include indirect and operative installation methods, connections, etc. This specification is intended to be viewed as a whole and interpreted in accordance with the principles of this disclosure and as understood by one of ordinary skill in the art.

[0018] Figures 1 through 8C illustrate an exemplary embodiment of the strapping device of this disclosure in the form of a battery-powered portable strapping device 50, and certain assemblies and components thereof. As shown in Figures 3A through 3C, the strapping device 50 is configured to perform a strapping cycle to tension and seal a strip S (a plastic strip in this exemplary embodiment) around a load L on a tray P, forming a tensioned strip loop that secures the load L to the tray P. The operator pulls the strip S from the strip supply (not shown) and wraps the strip around the load L and through an opening in the tray P until the lower layer LL of the strip S (which includes the front end of the strip S) is positioned below the upper layer UL of the strip S, as shown in Figure 3A. The operator then introduces the overlapping upper layer UL and lower layer LL of the strip S into the strapping device 50 and actuates one or more buttons to initiate the strapping cycle. As shown in Figure 3B, the motor drives the tensioning assembly to perform a tensioning cycle, during which the strapping device 50 tensions the strip S around the load L. Once the preset tension is reached in the strip S, as shown in Figure 3C, the motor drives the sealing assembly to perform a sealing cycle, during which the strapping device 50 connects the upper UL and lower LL of the strip S to each other by friction welding to form a strip joint SJ, as shown in Figure 3D, and supplies the cut strip S from the strip.

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

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

[0021] The rear housing segment 120 at least partially surrounds and / or supports at least some of the components of the display assembly 1490 and defines a container that is sized, shaped, and otherwise configured to receive and at least partially surround and / or support the power supply 1500 and the controller 1600. The motor housing segment 130 extends between and connects the bottoms of the front housing segment 110 and the rear housing segment 120, and at least partially surrounds and / or supports at least some of the components of the operating assembly 200, including the motor 800. The handle housing segment 150 extends between and connects the tops of the front housing segment 110 and the rear housing segment 120, and defines a handle for operator use. This is only one example, and in other embodiments, components of the strapping device may be supported and / or surrounded by any suitable portion of the housing 100. The housing 100 may be formed from any suitable number of components joined together in any suitable manner. In this exemplary embodiment, the housing 100 is formed of plastic, but in other embodiments it may be made of any other suitable material.

[0022] The working assembly 200, best shown in Figures 4A and 4B, includes most of the components of the strapping device 50, which are configured to perform a strapping cycle to tension the strip around a load, attach overlapping layers of the strip to each other, and supply the strip for cutting. The working assembly 200 includes a support 300, a rocker arm 350, a tensioning assembly 400, a hand lever 600, a transmission device 700, a motor 800, and a sealing assembly 900.

[0023] The support member 300, best shown in Figures 4A and 4B, serves as a direct or indirect common mount for the rocker arm 350, tension assembly 400, trigger 600, sealing assembly 900, transmission device 700, and motor 800. The support member 300 includes a base 300b and a frame 300f extending from the base 300b. The base 300b supports the toothed welding plate 314 below the welding shoe 942 of the sealing assembly 900 (hereinafter described).

[0024] The rocker arm 350 is a bending assembly that supports the toothed tension plate 312 below the tension wheel 400w of the tension assembly 400 (hereinafter described). The rocker arm 350 is pivotally mounted to the frame 300f of the support 300 by a suitable shaft or pin. The rocker arm 350 is pivotable about the rocker arm pivot axis A350 by actuation of the hand lever 600 (hereinafter described) between a tensioned position (Figure 4A) where the tension plate 312 is adjacent to the tension wheel 400w to facilitate belt tensioning and a belt insertion position (not shown) spaced between the tension plate 312 and the tension wheel 400w to allow the overlapping upper and lower layers of the belt to be inserted between the tension plate 312 and the tension wheel 400w. A suitable rocker arm biasing element, such as a compression spring, biases the rocker arm 350 to the tensioned position.

[0025] The tensioning assembly 400 is operable by the motor 800 to tension the belt around the load during a tensioning cycle. The tensioning assembly 400 includes a tensioning assembly gear 400g and a tension wheel 400w. The tension wheel 400w is supported by the tensioning assembly gear 400g, which in turn is supported by the frame 300f of the support member 300. The tensioning assembly gear 400g is configured to rotate the tension wheel 400w about the tension wheel rotation axis A400w in the tensioning rotation direction to tension the belt around the load. When the rocker arm 350 is in the tensioned position and the overlapping belt layer is between the tension wheel 400w and the tension plate 312, the rocker arm biasing element forces the rocker arm 350 to move toward the tension wheel 400w, so that the upper and lower layers of the belt are sandwiched between the tension wheel 400w and the tension plate 312.

[0026] The hand lever 600 is actuable (here, pivotable) to move the rocker arm 350 from the tensioned position to the strip insertion position. In this exemplary embodiment, a mechanical linkage operatively connects the hand lever 600 to the rocker arm 350 such that when the hand lever 600 is pulled, the mechanical linkage forces the rocker arm 350 to move to the strip insertion position. Other embodiments of the strapping device include any suitable actuator, such as a trigger, rather than the illustrated hand lever. In some such embodiments, the actuator's actuation triggers a switch that causes a motor to operate to pivot the rocker arm from the tensioned position to the strip insertion position.

[0027] The transmission device 700, best shown in Figures 5A to 6B, is driven by a motor 800. This transmission device is operatively connected to the tensioning assembly 400 and configured to rotate the tension wheel 400w in the tensioning direction to tension the belt. It is also operatively connected to the sealing assembly 900 and configured to attach overlapping portions of the belt to each other. The transmission device 700 includes a transmission support 705; first, second, and third planetary gears 710, 711, and 712; a welding cam 720; a sun gear 730; a tubular collar 740; a first one-way bearing 750; a welding shoe gear 760; a second one-way bearing 770; a tensioning assembly drive gear 780 with teeth 780t; and bearings 700b1, 700b2, and 700b3.

[0028] The welding cam 720, best shown in Figures 5A to 6B, includes an annular body 722 having an outer cam surface 722s, an internal tooth 724, and a welding cam axis A 720 (the welding cam axis being the central axis of the welding cam 720). The cam surface 722s includes a base portion 722s1, an actuating portion 722s2, and a return portion 722s3. In this exemplary embodiment, each of these portions is curved. The base portion 722s1 is defined between a starting point P1 and a transition point P2 of the cam surface 722s. The actuating portion 722s2 is defined between the transition point P2 and a vertex P3 of the cam surface 722s. The return portion 722s3 is defined between the vertex P3 and the starting point P1. In this exemplary embodiment, a first angular distance α separates the starting point P1 and the transition point P2, a second angular distance β separates the transition point P2 and the vertex P3, and a third angular distance θ separates the vertex P3 and the starting point P1. In various embodiments, the second angular distance β is greater than the first angular distance α, which is greater than the third angular distance θ. For example, in this exemplary embodiment, the first angular distance α is approximately 90 degrees, the second angular distance β is approximately 263 degrees, and the third angular distance θ is approximately 7 degrees; however, this angular distance may be any other suitable value in other embodiments. In some embodiments, the first angular distance α is greater than or equal to the third angular distance θ. In various embodiments, the first angular distance α is 0 to 270 degrees, the second angular distance β is 90 to 355 degrees, and the third angular distance θ is 5 to 10 degrees. In other words, in some of these embodiments, the first angular distance α is omitted.

[0029] In this exemplary embodiment, the radial distance of the cam surface 722s from the welding cam axis A720 is: (a) substantially constant along the base portion 722s1 (however, this radial distance may not be substantially constant in other embodiments); (b) increases along the actuation portion 722s2 moving from the transition point P2 to the apex P3; and (c) decreases along the return portion 722s3 moving from the apex P3 to the starting point P1. In this exemplary embodiment, the radial distance increases along the actuation portion 722s2 at a substantially constant rate of approximately 0.007 mm per degree, however, this rate may not be substantially constant in other embodiments. In this exemplary embodiment, the average rate at which the radial distance increases along the actuation portion 722s2 is less than the average rate at which the radial distance decreases along the return portion 722s3.

[0030] Motor 800 is operatively connected (via transmission 700) to tension assembly 400 and sealing assembly 900, and is configured to drive those assemblies as explained herein. Motor 800 includes a motor housing 800h and a motor output shaft 800s, which is rotatable about a motor shaft axis A800. Motor 800 includes an electric motor in this exemplary embodiment, but may be any suitable motor.

[0031] The motor housing 800h is fixedly mounted to one side of the transmission support 705, such that the motor output shaft 800s extends through a suitably sized hole defined by the transmission support 705. The first, second, and third planetary gears 710, 711, and 712 are rotatably mounted to the transmission support 705, such that they surround the motor output shaft 800s. The welding cam 720 is rotatably mounted to the transmission support 705 via a bearing 700b1, such that the welding cam axis A720 is coaxial with the motor shaft axis A800. The teeth of the first, second, and third planetary gears 710, 711, and 712 mesh with the internal teeth 724 of the welding cam 720, such that the first, second, and third planetary gears 710, 711, and 712 drively engage the welding cam 720. The teeth of the sun gear 730 mesh with the first, second, and third planetary gears 710, 711, and 712, thereby drivingly engaging the first, second, and third planetary gears 710, 711, and 712. The sun gear 730 is fixedly mounted to the motor output shaft 800s and rotates together with the motor output shaft 800 about the motor shaft axis A800.

[0032] A collar 740 is fixedly mounted to the outer race of a first one-way bearing 750, such that the collar and the first one-way bearing rotate together about the motor shaft axis A800. The first one-way bearing 750 is fixedly mounted to a motor output shaft 800s and rotates together with the motor output shaft 800s about the motor shaft axis A800. A sun gear 730 is fixedly attached to one end of the collar 740 and a welded shoe gear 760 is fixedly attached to the other end of the collar 740, such that the sun gear 730, collar 740, and welded shoe gear 760 rotate together. A second one-way bearing 770 is fixedly mounted to the motor output shaft 800s and rotates together with the motor output shaft 800s about the motor shaft axis A800. A tensioning assembly drive gear 780 is fixedly mounted to the outer race of the second one-way bearing 770, such that the tensioning assembly drive gear and the second one-way bearing rotate together about the motor shaft axis A800. The teeth 780t of the tensioning assembly drive gear 780 drive and engage with the tensioning assembly gear 400g.

[0033] When the motor output shaft 800s rotates along the welding rotation direction W, the first one-way bearing 750 transmits the rotational movement of the motor output shaft 800s to the collar 740. However, when the motor output shaft 800s rotates along the tensioning rotation direction T, which is opposite to the welding rotation direction W, the first one-way bearing does not transmit the rotational movement of the motor output shaft 800s to the collar 740. When the motor output shaft 800s rotates along the tensioning rotation direction T, the second one-way bearing 770 transmits the rotational movement of the motor output shaft 800s to the tensioning assembly drive gear 780. However, when the motor output shaft 800s rotates along the welding direction W, the second one-way bearing does not transmit the rotational movement of the motor output shaft 800s to the tensioning assembly drive gear 780.

[0034] Therefore, the use of these two one-way bearings enables the strapping device 50 to perform different functions by rotating the motor output shaft 800s in different directions. Rotation of the motor output shaft 800s in the tensioning rotation direction T causes the second one-way bearing 770 to rotate the tensioning assembly drive gear 780 in the tensioning rotation direction T and drive the tensioning assembly gear 400g, which in turn causes the tensioning wheel 400w to rotate. When this occurs, the first one-way bearing 750 does not transmit the rotation of the motor output shaft 800s to the collar 740, meaning that the collar 740, sun gear 730, welding shoe gear 760, welding cam 720, and first, second, and third planetary gears 710, 711, and 712 do not rotate. Rotation of the motor output shaft 800s in the welding direction W causes the first one-way bearing 750 to rotate the collar 740 in the welding rotation direction W. The collar 740 drives the welding shoe gear 760 to rotate in the welding rotation direction W, causing the welding shoe to reciprocate as described below. The collar 740 also drives the sun gear 730 to rotate in the welding rotation direction W. The sun gear 730 drives the first, second, and third planetary gears 710, 711, and 712, which in turn drive the welding cam 720, which rotates about the motor shaft axis A800 to lower the welding arm as described below. When this occurs, the second one-way bearing 770 does not transmit the rotation of the motor output shaft 800s to the transmission assembly drive gear 780, meaning that the transmission assembly drive gear does not rotate. Therefore, the transmission device 700 is driven by the motor 800 and, depending on the drive direction of the motor output shaft 800s, drives the tensioning assembly 400 or the sealing assembly 900.

[0035] In other embodiments, the welding cam may be directly driven by a motor, rather than via gears. For example, in some of these embodiments, the welding cam is mounted to the motor output shaft via a one-way bearing, such that rotation of the motor output shaft in the welding rotation direction causes the one-way bearing and the welding cam to rotate.

[0036] The sealing assembly 900, best shown in Figures 7 to 8C, is configured to operate together with the welding plate 314 to attach overlapping portions of the strip to each other, thereby forming a tensioned strip ring around the load by friction welding during sealing cycles. The sealing assembly 900 includes a first link 905, a second link 910 including a cam follower 910a, a variable length link assembly 920, a spring 930, a welding arm 940, a welding shoe 942, a cutter 944, an eccentric shaft 950, and a collar 960.

[0037] The linkage assembly 920 includes a first head 922, a second head 924, and a shaft 926. The first and second heads are mounted to opposite ends of the shaft 926 and are translatable along the shaft 926. A spring 930 extends around the shaft 926 between the first head 922 and the second head 924. The spring 930 is compressed such that it exerts opposing forces on the first head 922 and the second head 924, thereby forcing them to move toward opposite ends of the shaft 926. The welding shoe 942 includes a body 942b, a toothed head 942h located at one end of the body 942b, and a bending frame 942m located at the other end of the body 942b.

[0038] The first link 905 is pivotally mounted to the frame 300f of the support 300 via a first pivot pin 900p1. The second link 910 is pivotally mounted to the first link 905 via a second pivot pin 900p2. The first link 905 is pivotally mounted to the first head 922 of the link assembly 920 via a third pivot pin 900p3. The second head 924 of the link assembly 920 is pivotally mounted to the welding arm 940 via a fourth pivot pin 900p4. The welding arm 940 is pivotally mounted to the support 300 in any suitable manner. The eccentric shaft 950 is housed within a collar 960 and rotatably mounted to the support 300. The frame 942m of welding shoe 942 is mounted to collar 960, and the head 942h of welding shoe 924 is slidably mounted to welding arm 940, allowing welding shoe 942 to swing relative to welding arm 940 in the transverse direction of the belt (left and right angles from Figures 8A to 8C). Cutter 944 is removably mounted to welding arm 940. Toothed belt 900b connects welding shoe gear 960 to eccentric shaft 950.

[0039] The welding arm 940 is pivotable relative to the support 300 and the welding plate 314 between its original position (Figure 8A) where the head 942h of the welding shoe 942 is spaced apart from the welding plate 314, and between its sealing position (Figure 8C) where the head 942h of the welding shoe 942 is adjacent to the welding plate 314 and positioned to weld the strip. The first link 905, the second link 910, and the link assembly 920 operably connect the welding cam 720 of the transmission device 700 to the welding arm 940, such that rotation of the welding cam 920 moves the welding arm 940 from its original position to its sealing position. When the sealing assembly 900 is in the original configuration shown in Figure 8A with the welding arm 940 in its original position, the first link 905 (specifically, the line between the first pivot pin 900p1 and the third pivot pin 900p2) and the link group 920 (specifically, the line between the third pivot pin 900p3 and the fourth pivot pin 900p4) form an angle greater than 0 degrees and less than 180 degrees (i.e., an acute or obtuse angle). When the sealing assembly 900 is in the sealing configuration shown in Figure 8C with the welding arm 940 in its sealed position, the first link 905 (specifically, the line between the first pivot pin 900p1 and the third pivot pin 900p2) and the link group 920 (specifically, the line between the third pivot pin 900p3 and the fourth pivot pin 900p4) form an angle greater than 180 degrees and less than 360 degrees (i.e., a reflection angle).

[0040] The components of the transmission device 700 transmit the rotational movement of the motor output shaft 800s along the welding rotation direction to the sealing assembly 900, thereby switching the sealing assembly 900 from its original configuration to its sealing configuration, and driving the toothed belt 900b to rotate the eccentric shaft 950 and oscillate the welding shoe 942. As shown in Figure 8A, when the sealing assembly 900 is in the initial configuration, the cam follower 910a of the second link 910 engages the base portion 722s1 of the cam surface 722s of the welding cam 720. As explained above, the rotation of the motor output shaft 800s along the welding rotation direction W causes the welding cam 720 to rotate. As shown in the progression of Figures 8A to 8C, as the welding cam 720 rotates, the increased radial distance between the cam surface 722s and the welding cam axis A720 causes the welding cam 720 to force the second link 910 to pivot. When the second link 910 pivots, it engages the first link 905 and causes the first link 905 to pivot. As the first link 905 pivots, it forces the welding arm 940 to pivot toward the sealing position. Once the apex P3 of the cam surface 922s reaches the cam follower 910a of the second link 910, the pivoting of the second link 910 ends, at which point the welding arm 940 has reached the sealing position (and the sealing assembly 900 has reached the sealing configuration).

[0041] The display assembly 1490 shown in Figures 1 and 2 includes a suitable display screen 1492 having a touch panel 1494. The display screen 1492 is configured to display information about the strapping device 50 (at least in this embodiment), and the touch screen 1494 is configured to receive operator input, such as the desired operating mode (described below), the desired strip tension, and the desired welding time. A display controller (not shown) controls the display screen 1492 and the touch panel 1494, and in these embodiments, the display controller is communicatively connected to the controller 1600 to send signals to and receive signals from the controller 1600. Other embodiments of the strapping device do not include a touch panel. Other embodiments of the strapping device do not include a display assembly. Some embodiments of the strapping device include a separate button panel instead of a touch panel located below or integrated with the display screen.

[0042] The first and second button actuators 1410 and 1440 are operable to initiate a tensioning and / or sealing cycle as described below. Other embodiments of the strapping device 50 do not have button actuators but instead incorporate the functionality of button actuators into the display assembly 1490. For example, in one embodiment of these embodiments, two areas of the touch panel define virtual buttons that function the same as mechanical button actuators.

[0043] The controller 1600 shown in Figure 2 includes a processing device (or multiple devices) communicatively connected to a memory device (or multiple devices). 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 state machines. The memory device may include any suitable memory device, such as, but not limited to, read-only memory, random access memory, one or more digital registers, cache memory, one or more semiconductor memory devices, magnetic media such as integrated hard disk drives and / or removable memory, magneto-optical media and / or optical media. The memory device stores instructions executable by the processing device to control the operation of the strapping device 50. The controller 1600 is communicatively and operatively connected to the motor 800, display assembly 1490, push-button actuators 1410 and 1440, and sensor 1700, and is configured to receive signals from and control those components. The controller 1600 may also communicatively connect (e.g., via Wi-Fi, Bluetooth, NFC, or other suitable wireless communication protocols) to an external device such as a computing device to send and receive information from that external device.

[0044] The controller 1600 is configured to operate the strapping device in one of three operating modes to perform a strapping cycle: (1) manual operation mode; (2) semi-automatic operation mode; and (3) automatic operation mode. In manual operation mode, the controller 1600 operates the motor 800 to rotate the tension wheel 400w in response to the actuation of the first button actuator 1410 and maintain its actuated state. The controller 1600 operates the motor 800 to perform a sealing cycle by actuating the sealing assembly 900 in response to the actuation of the second button actuator 1440. In semi-automatic operation mode, the controller 1600 operates the motor 800 to rotate the tension wheel 400w in response to the actuation of the first button actuator 1410 and maintain its actuated state. Once the controller 1600 determines that the tension in the strap has reached the (preset) desired strap tension, the controller 1600 automatically operates the motor 800 to perform a sealing cycle by the sealing assembly 900 (without requiring additional input from the operator). In automatic operation mode, controller 1600 operates motor 800 to cause tension wheel 400w to rotate in response to the first button actuator 1410. Once controller 1600 determines that the tension in the belt has reached the (preset) desired belt tension, controller 1600 automatically operates motor 800 to cause sealing assembly 900 to perform sealing cycle (without requiring additional input from the operator).

[0045] Sensor 1700 includes any suitable sensor, such as a microswitch, optical sensor, ultrasonic sensor, magnetic position sensor, and the like, which is configured to detect the position of certain components of the strapping device 50 and send appropriate signals to controller 1600. Sensor 1700 may include, for example: one or more tension assembly position sensors configured to detect when tension assembly 400 is in its original position and / or its strip insertion position; one or more trigger position sensors configured to detect when trigger 600 is pulled; and one or more actuation assembly sensors configured to detect actuation of the first and second button actuators 1410 and 1440.

[0046] Power supply 1500 is electrically connected (via suitable wiring and other components) to and configured to supply power to several components of strapping device 50, including motor 800, display assembly 1490, controller 1600, and sensor 1700. In this exemplary embodiment, power supply 1500 includes a rechargeable battery (such as a lithium-ion or nickel-cadmium battery), but in other embodiments, the power supply may be any other suitable power supply. Power supply 1500 is sized, shaped, and otherwise configured to be housed in a container defined by housing segment 120 after housing 100. Strapping device 50 includes one or more power supply fastening devices (not shown) to releasably lock the power supply 1500 in place when housed in the container. Actuation of the strapping device 50 or a release device of power supply 1500 unlocks power supply 1500 from housing 100 and allows an operator to remove power supply 1500 from the container.

[0047] The following describes the use of the strapping device 50 to perform a strapping cycle to form a tensioned strip loop around the load. Initially, the tensioning assembly 400 is in its original position and the sealing assembly 900 is in its original configuration, as shown in Figures 5A and 6A. For the purposes of this embodiment, the strapping device 50 is in automatic mode.

[0048] The operator first pulls out the front end of the strip S from the strip supply (not shown), wraps the strip S around the load, and positions the lower layer LL, including the front end of the strip S, below the upper layer UL of the strip S. The operator then pulls the trigger 600 to raise the tensioning assembly 400 to its strip insertion position, as shown in Figure 5B. With the tensioning assembly 400 in its strip insertion position and while the trigger 600 is being pulled, the operator introduces the overlapping upper and lower layers UL and LL of the strip S between the tension wheel 400w and the tension plate 312 and between the welding shoe 942 and the welding plate 314, as shown in Figure 5B. The operator then releases the trigger 600, thereby allowing the appropriate offset element to force the tensioning assembly 400 to pivot to its tensioned position to clamp the overlapping upper and lower strip layers UL and LL between the tension wheel 400w and the tension plate 312, as shown in Figure 5C.

[0049] The operator then actuates the first button actuator 1410. Once one of the sensors 1700 detects the actuation of the first button actuator 1410, the controller 1600 initiates the tensioning cycle by controlling the motor 800 to rotate the output shaft in the first drive direction. As explained above, the transmission 700 transmits this rotational movement of the output shaft to the tensioning assembly gear, which in turn causes the tension wheel 400w to rotate about the tension wheel rotation axis A400w in the tensioning direction. As the tension wheel 400w rotates in the tensioning direction, it pulls the upper layer UL of the strip S above the lower layer LL of the strip S, thereby tensioning the strip S around the load. Throughout the tensioning cycle, the controller 1600 monitors the current consumed by the motor 800. When this current reaches a preset value related to the (preset) desired strip tension for this strapping cycle, the controller 1600 stops the motor 800, thereby terminating the tensioning cycle.

[0050] In this exemplary embodiment, after the tensioning cycle is completed, the controller 1600 automatically initiates the sealing cycle by controlling the motor 800 to begin rotating the output shaft in the second drive direction. This causes the transmission 700 to drive the toothed belt 900b to begin rotating the eccentric shaft and causing the welding shoe 942 to swing, switching the sealing assembly 900 from its original configuration to its sealing configuration, and in doing so, pivoting the welding arm 940 to its sealing position. When the welding arm 940 reaches the sealing position, the welding shoe 942 forces the overlapping upper and lower layers UL and LL of the strip against the welding plate 314, while the cutter 944 supplies the strip itself to cut the upper strip layer UL. Figures 6B and 6C illustrate this movement of the welding arm 940 and the swinging of the welding shoe 942. As explained above, the oscillation of the welding shoe 942 is fast enough to generate friction and heat, which is generally sufficient to locally melt and bond portions of the overlapping strip layers, thereby attaching the upper and lower strip layers UL and LL to form a tensioned strip ring. The controller 1600 controls the motor 800 to stop rotating the output shaft, thus completing the sealing cycle. The operator can then pull the trigger 600 to raise the tensioning assembly 400 and switch the sealing assembly 900 back to its original configuration to release the tensioned strip ring.

[0051] The above exemplary embodiment of the strapping device includes a single motor configured to drive both the tension assembly and the sealing assembly. In other embodiments, the strapping device includes separate motors configured to drive separate tension assemblies and sealing assemblies and may include separate transmissions for each motor.

[0052] In some embodiments, the controller is configured to stop the rotation of the motor output shaft in the welding rotation direction only when the welding cam is in a rotating position, in which the base portion of the cam surface of the welding cam is adjacent to the cam follower of the second link, such that movement of the sealing assembly back to its original configuration causes the cam follower to contact the base portion of the cam surface. The controller may do this in any suitable manner. For example, a sensor may be positioned and otherwise configured to detect when the base portion is adjacent to the cam follower.

[0053] Other embodiments of the strapping device may include fewer assemblies, components, and / or features than those included in the strapping device 50 described above and shown in the figures. In other words, while the strapping device 50 includes all of the assemblies, components, and features described above, such assemblies, components, and features are independent of each other and may be independently included in other strapping devices.

[0054] Although the above-described strapping device is a handheld strapping device, in other embodiments, the strapping device may be any other suitable strapping device, such as a stand-alone automatic or semi-automatic strapping machine.

[0055] In the above-described strapping device, when the rocker arm pivots between the original position, the strip insertion position, and the tension position, the movable rocker arm supports the tension wheel and causes the tension wheel to move relative to the fixed tension plate. In other embodiments, the movable rocker arm supports the tension plate, and a support member of the working assembly supports the tension wheel. In these embodiments, when the rocker arm pivots between the original position, the strip insertion position, and the tension position, the movable rocker arm causes the tension plate to move relative to the fixed tension wheel. [Simplified Explanation of the Diagram]

[0007] Figure 1 is a perspective view of an exemplary embodiment of the binding device disclosed herein.

[0008] Figure 2 is a block diagram of some components of the binding device in Figure 1.

[0009] Figures 3A to 3C are schematic views of the strapping device for securing the load to the pallet as shown in Figure 1.

[0010] Figure 3D is a perspective view of a friction-welded strip joint formed by the binding device in Figure 1 to attach two overlapping strip layers.

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

[0012] Figure 5A is an exploded perspective view of the transmission device and motor of the working assembly shown in Figures 4A and 4B.

[0013] Figure 5B is a cross-sectional side elevation view of the working assembly of Figures 4A and 4B, generally taken along line 5B-5B of Figure 4B—and more specifically, the transmission device and motor of Figure 5A.

[0014] Figures 6A and 6B are perspective views and front elevation views of the welding cam of the transmission device in Figure 5A, respectively.

[0015] Figure 7 is a perspective view of the sealing assembly of the working assembly in Figures 4A and 4B.

[0016] Figures 8A to 8C are cross-sectional front elevation views of the working assembly in Figures 4A and 4B, generally taken along line 8A-8A of Figure 7. Figure 8A shows the sealing assembly in its original configuration, Figure 8B shows the sealing assembly between the original and sealed configurations, and Figure 8C shows the sealing assembly in its sealed configuration. [Biomaterial Storage]

[0057] Domestic Deposit Information (Please note in order of deposit institution, date, and number) None

[0058] Overseas Deposit Information (Please note in the order of deposit country, institution, date, and number) None

Claims

1. A strapping device comprising: a welding plate; a welding arm including a welding shoe, the welding arm being movable between an initial position and a sealed position, wherein the welding shoe is closer to the welding plate when the welding arm is in the sealed position than when the welding arm is in the initial position; A welding cam, rotatable about a welding cam axis and including a cam surface, the cam surface including an actuating portion defined between a first point and a second point on the cam surface, wherein the first point and the second point are separated by a first angular distance of at least 90 degrees, wherein a radial distance between the welding cam axis and the cam surface increases along the actuating portion from a first radial distance at the first point to a second radial distance at the second point, wherein the welding cam is operatively connected to a welding arm such that rotation of the welding cam about the welding cam axis causes the actuating portion of the cam surface to force the welding arm to move from the original position to the sealed position; and a motor operatively connected to the welding cam and configured to rotate the welding cam about the welding cam axis.

2. The binding device as claimed in claim 1, wherein the first point includes a transition point and the second point includes a vertex, wherein the radial distance between the welding cam axis and the cam surface is not less than the first radial distance at any point along the actuating portion of the cam surface.

3. The binding device as claimed in claim 2, wherein the cam surface further includes a base portion defined between a starting point and the transition point, wherein a second angular distance less than the first angular distance separates the starting point and the transition point, wherein the radial distance between the welding cam axis and the cam surface is substantially constant along the base portion.

4. The binding device as claimed in claim 3, wherein the cam surface further includes a return portion defined between the vertex and the starting point, wherein a third angular distance less than the second angular distance separates the vertex and the starting point, wherein the radial distance between the welding cam axis and the cam surface decreases along the return portion from the second radial distance at the vertex to the first radial distance at the starting point.

5. The binding device as claimed in claim 1, wherein no point on the cam surface is closer to the welding cam axis than the first point.

6. The binding device as claimed in claim 1, wherein the radial distance between the welding cam axis and the cam surface increases at a substantially constant rate along the actuating portion from the first point to the second point.

7. The binding device as claimed in claim 6, wherein the first point includes a transition point and the second point includes a vertex, wherein the cam surface further includes a base portion defined between a starting point and the transition point, wherein a second angular distance less than the first angular distance separates the starting point and the transition point, wherein the radial distance between the welding cam axis and the cam surface is substantially constant along the base portion.

8. The binding device as claimed in claim 1, further comprising a link movable from a first position to a second position to move the welding arm from the original position to the sealed position, wherein the welding cam is operatively connected to the welding arm by the link such that rotation of the welding cam about the welding cam axis causes the actuating portion of the cam surface to force the link to move from the first position to the second position.

9. The binding device as claimed in claim 8, wherein the link includes a follower that engages the cam surface when the link is in the first position.

10. The binding device as claimed in claim 9, wherein when the welding cam rotates as the follower engages the cam surface, the actuating portion of the cam surface of the welding cam forces the follower away from the welding cam axis, thereby pivoting the link.

11. The strapping device as claimed in claim 1 further includes a planetary gear set that operatively connects the motor to the welding cam.

12. The strapping device as claimed in claim 11, wherein the motor includes a motor output shaft, wherein the planetary gear set is configured to convert a first rotational speed of the motor output shaft and a first torque of the motor output shaft into a second rotational speed of the welding cam and a second torque of the welding cam, wherein the second rotational speed is less than the first rotational speed, and wherein the second torque is greater than the first torque.

13. The binding device as claimed in claim 12, wherein the planetary gear set is a single-stage planetary gear set.

14. The strapping device as claimed in claim 13, wherein the planetary gear set is the only planetary gear set that operatively connects the motor to the welding cam.

15. The binding device as claimed in claim 13, wherein the welding cam includes internal teeth, wherein the planetary gear set includes a sun gear and a plurality of planetary gears, wherein the sun gear includes teeth that mesh with teeth of each of the planetary gears such that the sun gear drivesly engages the planetary gears, wherein the teeth of the planetary gears mesh with the internal teeth of the welding cam such that the planetary gears drively engage the welding cam.

16. The strapping device as claimed in claim 15, wherein the motor output shaft is operatively connected to the sun gear and configured to rotate the sun gear.

17. The binding device as claimed in claim 16, wherein the motor is operatively connected to the welding boot and configured to cause the welding boot to reciprocate.

18. The strapping device as claimed in claim 17, wherein the first point includes a transition point and the second point includes a vertex, wherein the radial distance between the welding cam axis and the cam surface along the actuating portion of the cam surface is not less than the first radial distance.

19. The binding device as claimed in claim 18, wherein the cam surface further includes a base portion defined between a starting point and the transition point, wherein a second angular distance less than the first angular distance separates the starting point and the transition point, wherein the radial distance between the welding cam axis and the cam surface is substantially constant along the base portion.

20. The strapping device as claimed in claim 19, wherein the cam surface further includes a return portion defined between the vertex and the starting point, wherein a third angular distance less than the second angular distance separates the vertex and the starting point, wherein the radial distance between the welding cam axis and the cam surface decreases along the return portion from the second radial distance at the vertex to the first radial distance at the starting point.

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