HAND-HELD STRAPPING DEVICE AND METHOD OF OPERATION THEREOF

Priority

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/365,798, filed June 3, 2022, the entire contents of which is incorporated herein by reference.

Field

[0002] The present disclosure relates to a hand-held strapping device and method of operation thereof.

Background

[0003] Strapping devices are used to form a tensioned loop of plastic strap (such as polyethylene or polypropylene strap), metal strap (such as steel strap), or paper strap around a load, such as a palletized load of boxed products or a large bundle of stacked lumber. Hand-held strapping tools and larger, standalone strapping machines are two types of strapping devices.

[0004] To use a strapping tool to form a tensioned strap loop around a load, an operator pulls strap leading end first from a strap supply, wraps the strap around the load, and positions the leading end of the strap below another portion of the strap. The operator then introduces one or more (depending on the type of strapping tool) of these overlapped strap portions into the strapping tool and actuates one or more buttons to initiate: (1) a tensioning cycle during which a tensioning assembly tensions the strap around the load; and (2) after completion of the tensioning cycle, a sealing cycle during which a sealing assembly attaches the overlapped strap portions to one another (thereby forming a tensioned strap loop around the load) and during which a cutting assembly cuts the strap from the strap supply.

[0005] How the strapping tool attaches overlapping portions of the strap to one another during the sealing cycle depends on the type of strapping tool and the type of strap. Certain strapping tools configured for plastic strap (such as polypropylene strap or polyester strap) include friction welders, heated blades, or ultrasonic welders configured to attach the overlapping portions of the strap to one another Certain strapping tools configured for plastic strap or metal strap (such as steel strap) include jaws that mechanically deform (referred to as “crimping” in the strapping industry) or cut notches into (referred to as “notching” in the strapping industry) a seal element positioned around the overlapping portions of the strap to attach them to one another. Certain strapping tools configured for metal strap include punches and dies configured to form a set of mechanically interlocking cuts in the overlapping portions of the strap to attach them to one another (referred to in the strapping industry as a “sealless” attachment).

[0006] A typical strapping machine includes a support surface (such as a raised tabletop for smaller machines or large-scale conveyors for larger machines) that supports the load, a strap chute that circumscribes the support surface, a strapping head that forms the strap loop, a controller that controls the strapping head to strap the load, and a frame that supports these components. A typical strapping head includes a strap-feeding assembly for feeding strap from a strap supply into and around the strap chute and for retracting the strap so it exits the strap chute and moves radially inwardly into contact with the load, a strap-tensioning assembly for tensioning the strap around the load, and a strap-sealing assembly for cutting the strap from the strap supply and attaching two areas of the strap together to form the strap loop. The strapping head includes several guides that define strap channels that the strap passes through as it moves between the various assemblies of the strapping head. The strap channels and the strap chute together define a strap path that the strap moves through.

[0007] To strap the load, the strapping machine carries out a strapping cycle including a strap-feeding cycle, a strap-retraction cycle, a strap-tensioning cycle, and a strapsealing cycle. The strapping machine first carries out the strap-feeding cycle during which the strap-feeding assembly feeds strap (with the leading strap end first) from the strap supply through the strap-tensioning assembly, through the strap-sealing assembly, and into and around the strap chute until the leading strap end returns to the strap-sealing assembly. The strapping machine then carries out the strap-retraction cycle during which the strap-sealing assembly holds the leading strap end while the strap-feeding assembly retracts the strap to pull the strap out of the strap chute and onto and around the load. The strapping machine then carries out the straptensioning cycle during which the strap-tensioning assembly tensions the strap to a designated strap tension. The strapping machine then carries out the strap-sealing cycle during which the strap-sealing assembly either (1) cuts the strap from the strap supply to form a trailing strap end and attaches the leading and trailing strap ends to one another in one of the manners described above, or (2) attaches the leading end to a portion of the strap that becomes the trailing strap end and then cuts the strap from the strap supply, thereby forming a tensioned strap loop around the load and completing the strapping cycle.

Summary

[0008] Various embodiments of the present disclosure provide a hand-held strapping device and method of operation thereof.

[0009] Various embodiments of the present disclosure provide a strapping device for forming a loop of strap around a load, wherein the strapping device includes: a housing configured to support a supply of strap; a jaw assembly comprising a first jaw and a second jaw, wherein the first jaw is movable relative to the second jaw, the jaw assembly extending from the housing and at least partially defining a strap chute circumscribing a load-receiving area; a strapfeeding assembly configured to feed strap from the supply through the strap chute and retract the strap from the strap chute; and a sealer-cutter assembly configured seal two portions of the strap together and to cut the strap from the supply to form the loop of strap.

[0010] Various embodiments of the present disclosure provide a method of operating a strapping device, wherein the method includes: moving at least one of two jaws of a jaw assembly to an open position; positioning a load between the two jaws; moving at least one of the two jaws to a closed position; activating a strap-feeding assembly to feed strap through a strap chute defined by the jaws and around the load; applying tension to the strap; sealing the strap; and cutting the strap.

Brief Description of the Figures

[0011] Figure 1 is a perspective view of one example embodiment of a hand-held strapping device of the present disclosure with a front cover of the housing thereof removed to show various internal components.

[0012] Figure 2 is a block diagram showing certain of the components of the handheld strapping device of Figure 1. [0013] Figure 3 is a diagrammatic view showing certain of the components of the hand-held strapping device of Figure 1.

[0014] Figures 4A-4I are perspective views of an example method of operation of the hand-held strapping device of Figure 1 to strap a load including a bundle of separate objects.

Detailed Description

[0015] While the systems, devices, and methods described herein may be embodied in various forms, the drawings show and the specification describes certain exemplary and nonlimiting embodiments. Not all of the components shown in the drawings and described in the specification may be required, and certain implementations may include additional, different, or fewer components. Variations in the arrangement and type of the components; the shapes, sizes, and materials of the components; and the manners of connections of the components may be made without departing from the spirit or scope of the claims. Unless otherwise indicated, any directions referred to in the specification reflect the orientations of the components shown in the corresponding drawings and do not limit the scope of the present disclosure. Further, terms that refer to mounting methods, such as mounted, connected, etc., are not intended to be limited to direct mounting methods but should be interpreted broadly to include indirect and operably mounted, connected, and like mounting methods. This specification is intended to be taken as a whole and interpreted in accordance with the principles of the present disclosure and as understood by one of ordinary skill in the art.

[0016] Various embodiments of the present disclosure provide a hand-held strapping device. Figures 1-3 show one example embodiment of a hand-held strapping device 10 of the present disclosure and components thereof.

[0017] The strapping device 10 is configured to form a loop of strap S drawn from a removable strap supply 1000 around a load (such as but not limited to a bundle of objects). The strapping device 10 includes a housing 100; a jaw assembly 200; a strap-feeding assembly 300; a sealer-cutter assembly 400; a controller 500; a power source 600; and a strapping-initiation device 700. The strapping device 10 is configured to receive and hold removable strap supplies such as strap supply 1000 [0018] The housing 100 supports the various components of the hand-held strapping device 10 and can be formed of any suitable components arranged in any suitable configuration. The jaw assembly 200, the strap-feeding assembly 300, the sealer-cutter assembly 400, the controller 500, the power source 600, and the strapping-initiation device 700 are supported by the housing 100 and are sized, shaped, positioned, oriented, and otherwise configured to cooperate to form loops of the strap S from the strap supply 1000 around loads — such as the example load 50 shown in Figures 4A-4I. The housing 100 can be shaped to fit in a user’s hand and can include suitable cavities, posts, tabs, or other features that enable the housing 100 to engage and hold the various components within the housing 100.

[0019] The jaw assembly 200 includes a first jaw 210, a second jaw 220, a jawbiasing mechanism (not shown), and a jaw actuator 240. The jaw assembly 200 is sized, shaped, positioned, oriented, and otherwise configured to direct strap drawn from the strap supply 1000 around the load positioned in a load-receiving area 20 defined between the first jaw 210, the second jaw 220, and the housing 100. The first and second jaws 210 and 220 are mirror images of each other in this example, so for brevity only the first jaw 210 is described. The first jaw 210 includes a base end 212 and a free end 216. In the illustrated embodiment, the jaws 210 and 220 extend from the housing 100 away from each other, each jaw including at least one bend in the respective middle section thereof, and such that the free ends extend toward each other. In the illustrated embodiment, the first jaw 210 and the second jaw 220 are pivotably connected to the housing and configured to pivot between respective closed positions (shown in Figure 4A) and open positions (shown in Figure 4B). When in their closed positions, the free ends of the first and second jaws 210 and 220 can be slightly spaced-apart or can contact each other to close a loop formed by the first jaw 210, the second jaw 220, and the housing 100. In other alternative embodiments, the free end of the first jaw 210 can overlap the free end of the second jaw 220, or vice versa. In other embodiments, the first jaw 210 and the second jaw 220 are pivotable independently from each other. In other embodiments, the first jaw 210 or the second jaw 220 can be stationary, while the other of the first jaw 210 or the second jaw 220 can be pivotable between an open position and a closed position.

[0020] In certain embodiments, the jaws 210 and 220 include inner walls or blocking members (not shown) positioned to prevent strap from prematurely falling inward and out of the strap chute 250 (described below) during the strap feeding process. The inner walls can be stationary, only partially covering the inner side of the jaws. Alternatively, the inner walls can be pivotable and can be held in a closed position by spring(s), such that tension must be applied to the strap to move the inner walls to an open position and enable the strap to be pulled out of the strap chute.

[0021] The jaw-biasing mechanism of the jaw assembly 200 biases the jaws 210 and 220 to the closed position. In this embodiment, the jaw-biasing mechanism includes a spring (not shown). In other embodiments, the jaw-biasing mechanism can be otherwise configured to bias the jaws 210 and 220 to their respective closed positions or open positions depending on the particular configuration. In certain embodiments, the jaw-biasing mechanism acts directly on the first and second jaws (such as on their respective base ends) to bias them to their respective closed positions. In other embodiments, the jaw-biasing mechanism acts on another component, such as the jaw actuator or part of a mechanical linkage operably connecting the jaw actuator to the jaws, to bias the jaws to their respective closed positions.

[0022] The jaw actuator 240 extends from the housing 100 and is actuatable by a user to move the jaws 210 and 220 from the closed positions to the open positions. The jaw actuator 240 can be a mechanical lever or button. The jaw actuator 240 can be coupled to the jaws 210 and 220 via one or more linking members (not shown). Alternatively, the jaw actuator 240 can be operably connected to a motor that moves the jaws between the open and closed positions.

[0023] The first and second jaws 210 and 220 partially define a strap chute 250. The strap chute 250 defines a strap path that the strap follows when fed through the strap chute 250 and from which the strap is removed when retracted. A leading-end sensor can be positioned and configured to detect the leading end of the strap when the leading end has traversed and reached the end of the strap chute 250 adjacent the sealer-cutter assembly 400.

[0024] The strap-feeding assembly 300 includes a drive roller 320, a drive-roller actuator 322, and one or more guide rollers or strap guides (not shown). The strap-feeding assembly 300 is configured to feed strap from the strap supply 1000 into and through the strap chute 250 and to, after the leading-end sensor senses the leading end of the strap and the sealercutter assembly 400 holds the leading end, retract the strap so it exits the strap chute 250 and contacts the load 50. One or more of the components of the strap-feeding assembly 300 can be sized, shaped, positioned, oriented, and otherwise configured. [0025] The drive roller 320 is cylindrical and is mounted to the housing 100 such that the drive roller 320 is rotatable relative to the housing 100 about a drive-roller rotational axis. In certain embodiments, at least part of the external cylindrical surface of the drive roller 320 is knurled or coated with a friction-enhancing coating to facilitate engaging and dispensing the strap. The drive-roller actuator 322 is mounted to the housing 100 and is operably connected to the drive roller 320 and configured to drive the drive roller 320 in opposing feed and retract rotational directions. The drive-roller actuator 322 can be operably connected to the drive roller 320 in any suitable manner, such as via a keyed or splined connection and/or via a suitable drive train.

[0026] Guide rollers or strap guides (not shown) can extend between the various components of the strapping device 10 and are configured to guide the strap as it moves between those components.

[0027] In certain embodiments, the strap-feeding assembly 300 can also include a pinch roller (not shown) mounted to the housing 100 such that the pinch roller is freely rotatable relative to the housing 100 about a pinch-roller rotational axis. In certain embodiments, at least part of the external cylindrical surface of the pinch roller is knurled or coated with a frictionenhancing coating to facilitate engaging and dispensing the strap. The drive roller and the pinch roller are sized, shaped, positioned, oriented, and otherwise configured such that their respective rotational axes and are generally parallel and coplanar. In this example embodiment, during the strap-feeding cycle, the pinch roller is forced toward and against the drive roller 320 such that the strap passes between the nip formed between the two rollers.

[0028] The sealer-cutter assembly 400 receives and holds the leading end of the strap, seals two overlapping portions of the strap to one another after tensioning, and cuts the strap from the strap supply 1000. The sealer-cutter assembly 400 includes a strap holder 410, a strap sealer-cutter 420, and a sealer-cutter actuator 430. The strap holder 410 is configured to receive the leading of the strap and hold the leading end while the drive roller 320 reverses direction to retract the strap from the strap chute and onto the load. The strap sealer-cutter 420 is configured to seal and cut the strap to form the strap loop. The manner of attaching the leading and trailing strap ends to one another will depend on the type of strap. If the strapping device is configured for plastic or paper strap, it can include a strap-sealing assembly with a friction welder, a heated blade, or an ultrasonic welder configured to attach the leading and trailing strap ends to one another. If the strapping device is configured for plastic strap or metal strap, it can include a strap-sealing assembly with jaws that mechanically deform (referred to as “crimping” in the industry) or cut notches into (referred to as “notching” in the industry) a seal element positioned around the leading and trailing strap ends to attach them to one another. Alternatively, if the strapping device is configured for metal strap it can include a strap-sealing assembly with punches and dies configured to form a set of mechanically interlocking cuts in the leading and trailing strap ends to attach them to one another (referred to in the strapping industry as a “sealless” attachment). Alternatively, if the strapping device is configured for metal strap it can include a strap-sealing assembly with spot, inert-gas, or other welders configured to weld the leading and trailing strap ends to one another. The sealer-cutter actuator 430 is operably connected to the strap holder 410 and the strap sealer-cutter 420. In this example embodiment, the strap holder 410, strap sealer-cutter 420, and sealer-cutter actuator 430 are supported by the housing 100.

[0029] The jaw assembly 200, the strap-feeding assembly 300, and the sealer-cutter assembly 400 operate together to form a loop of strap from the strap supply around the load 50 by feeding the strap through the strap chute 250 in a feed direction, holding the leading strap end while retracting the strap in the retract direction to remove it from the strap chute 250 so it contacts the load 50, tensioning the strap around the load 50, cutting the strap from the strap supply to form a trailing strap end, and connecting the leading strap end and the trailing strap end to one another.

[0030] The controller 500 includes a processing device (or devices) communicatively connected to a memory device (or devices). For instance, the controller can be a programmable logic controller. The processing device can 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 in association 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 can include any suitable memory device such as, but not limited to, read-only memory, random-access memory, one or more digital registers, cache memory, one or more semiconductor memory devices, magnetic media such as integrated hard disks and/or removable memory, magneto-optical media, and/or optical media. The memory device stores instructions executable by the processing device to control operation of the strapping device 10, such as to carry out the strap-feeding process described below in connection with Figures 4A-4I.

[0031] The power source 600 is connected to the controller 500, the drive roller actuator 322, the leading end sensor, the strap holder 410, the strap sealer-cutter 420, and the sealer-cutter actuator 430 to supply power to enable these components to operate. The power source 600 can be a battery or other electric power source, or can be some other type of power storage and can be removable from the housing 100.

[0032] The strapping-initiation device 700 is connected to the controller 500 to enable an operator of the strapping device 10 to begin the strapping process. In this example embodiment, the strapping-initiation device 700 includes a physical button and a sensor, such as an electromechanical switch, that senses when the button is pressed. The strapping-initiation device 700 is communicatively connected to the controller 500 to communicate to the controller 500 when the button is pressed.

[0033] In the example embodiment shown in Figures 4A-4I, the controller 500 is operably connected to the drive-roller actuator 322 and is configured to control the output of the drive-roller actuator 322 — and therefore the rotation of the drive roller 320 of the strap-feeding assembly 300 — in accordance with one or more actuator control instructions and in response to actuation of the strapping-initiation device 700. The actuator control instructions can include but are not limited to: actuator drive speed (e.g., the rotational speed of the actuator output shaft); actuator drive direction (e.g., feed or retract direction); and actuator drive torque.

[0034] An example method of operation of the strapping device is now described with reference to Figures 4A-4I. As an initial step, the hand-held strapping device 10 is brought near a load 50 (which in this example is a bundle of objects) that the operator seeks to strap together.

[0035] The operator then depresses the jaw actuator 240, causing each of the jaws 210 and 220 to move from its closed position to its open position as shown in Figure 4B.

[0036] The operator then moves either the load 50 or the hand-held strapping device 10 such that the load 50 is positioned within the jaws and particularly the load-receiving area, as shown in Figure 4C. [0037] The operator then releases the jaw actuator 240 as shown in Figure 4D, enabling each of the jaws 210 and 220 to be biased and to move back to its respective closed position, while the load 50 remains positioned in the load-receiving area between the jaws 210 and 220. The operator can then press the strapping-initiation device 700 to begin the strapfeeding cycle, and enable the controller 500 to automatically carry out the next steps to strap the load 50.

[0038] After initiation of the strap-feeding cycle via activation of the strappinginitiation device 700, the controller 500 drives the drive-roller actuator 322 in accordance with the actuator control instructions to drive the drive roller 320 in a strap-feeding direction to feed the strap around the strap chute 250. The strap S is fed in a counterclockwise direction as shown in Figure 4E. When the strap S has been fed all the way around the strap chute 250, a leading end sensor senses the strap. Responsive to the leading-end sensor sensing the leading end of the strap S, the controller 500 stops driving the drive-roller actuator 322 to stop the drive roller 320 and complete the strap-feeding cycle.

[0039] The strap holder 410 then engages and holds the leading end of the strap S that has been fed through the strap chute 250. The controller 500 controls the drive-roller actuator 322 to rotate the drive roller 320 in the retract direction, to pull the strap S out of the strap chute 250 and around the load 50, as shown in Figure 4F.

[0040] The controller 500 continues to control the drive actuator 322 to cause the drive roller 320 to retract the strap S, such that tension is applied to the strap S and the load 50 begin to be bundled together. In some cases, the optimal shape of the load when bundled is not possible while the jaws 210 and 220 are in the closed position. This is due to the load running into the base ends of the jaws 210 and 220 as the load moves when tension is applied to the strap S.

[0041] The jaws 210 and 220 are movable to the open position when tension is applied to the strap S, as shown in Figure 4H. This enables the load 50 to be more compactly bundled in its optimal shape, which is circular in the illustrated embodiment.

[0042] When the predetermined tension is met, the strap sealer-cutter 420 seals or affixes the strap S together around the load, and cuts the strap S. The jaws 210 and 220 can then be opened (if they are not already) and the strapped load removed from the strapping device 10, as shown in Figure 41. [0043] Tn certain embodiments, the strap supply 1000 is positionable on a spool holder (not labeled). The strap supply 1000 is removably positioned within the housing 100 and is positioned to rotate to supply strap as needed. The spool holder engages and enables rotation of the strap supply 1000. The spool holder can be formed as a part of the housing 100, or alternatively can be separately formed and affixed to the housing 100. A strap-supply actuator 316 can engage the strap supply 1000 and/or spool holder to rotate the strap supply 1000 in a retract direction to retract excess strap. The controller 500 can be operably engaged to the strapsupply actuator 316 to control the output of the strap-supply actuator 316 — and therefore the rotation of the strap supply 1000 — in accordance with one or more actuator control instructions.

[0044] In alternative embodiments, the components of the strapping device can be alternatively configured such that the strap can be fed in a clockwise direction instead of a counterclockwise directions.