Patent Description:
Various packaging techniques have been used to build a load of unit products and subsequently wrap them for transportation, storage, containment and stabilization, protection and waterproofing. One system uses wrapping machines to stretch, dispense, and wrap packaging material, e.g., film, around a load. The packaging material may be pre-stretched before it is applied to the load. Wrapping can be performed as an inline, automated packaging technique that dispenses and wraps packaging material in a stretch condition around a load on a pallet to cover and contain the load. Stretch wrapping, whether accomplished by a turntable, rotating arm, vertical rotating ring, or horizontal rotating ring, typically covers the four vertical sides of the load with a stretchable packaging material such as polyethylene packaging material. In each of these arrangements, relative rotation is provided between the load and the packaging material dispenser to wrap packaging material about the sides of the load.

Film breaks are one of the most frequent and problematic sources of machine downtime and loss of "centerline" wrapper settings to a standard. Film breaks have many causes inherent to the wrapping process that can be mitigated, including, for example, irregularities or sharp points in the load or pallet, mechanical issues with rollers and clamps, electronic control issues around maintenance of film or packaging material tension during start, acceleration, and ending of a wrap operation or cycle, etc. These various causes of film breaks may be mitigated in many instances with more effective handling of the wrapping process.

However, film breaks are also impacted by fluctuations in the packaging material quality, where random and unpredictable changes in packaging material characteristics (often within a single packaging material roll) can cause a packaging material's resistance to film breaks to be reduced. Random flaws in a packaging material web such as gels, carbon particles, gauge band including shipping and handling damage to the packaging material roll remain problematic since they are generally difficult to sense or predict.

When film breaks occur from negative fluctuation in packaging material quality, many operators are left with the choice of tolerating the downtime and hassle of film breaks or lowering the packaging material tension until the film breaks are reduced to a tolerable level. The lowered packaging material tension either compromises the containment force and leaves loads more susceptible to damage during shipping, or requires additional layers (i.e., more packaging material) to maintain the desired containment force. Since there is generally no way for the operator to know when the packaging material quality fluctuations shift back more positive, the lowered packaging material tension effectively becomes the new normal, resulting in either increased occurrences of damaged loads or significantly wasted packaging material and longer cycle times.

<CIT> discloses a method controlling a load wrapping apparatus wherein some packaging material characteristics, indicating a change in packaging material quality, are sensed during the wrapping operation and, accounting for the sensed value of those characteristics associated with a risk of film breaks, wrapping parameters are changed.

The invention addresses these and other problems associated with the art by providing a method, apparatus and program product that utilize packaging material quality compensation to sense changes in certain characteristics of a packaging material that can be associated with increased risks of film breaks, and automatically make certain changes in machine settings to mitigate the impact of those enhanced risks.

Therefore, consistent with one aspect of the invention, a method of controlling a load wrapping apparatus of the type configured to wrap a load with packaging material dispensed from a packaging material dispenser through relative rotation between the packaging material dispenser and the load may include sensing one or more indications of changes in packaging material characteristics during one or more wrap operations, and changing one or more wrap parameters used to wrap the load in response to sensing the one or more indications.

In some embodiments, changing the one or more wrap parameters optimizes load wrapping apparatus performance and/or packaging material cost. In addition, in some embodiments changing the one or more wrap parameters reduces an incidence of film breaks.

According to the invention, the one or more indications includes a packaging material gel, a packaging material hole, an unwind force on a packaging material supply roll, and/or a visible packaging material roll surface. In some embodiments, the one or more indicators further include a force to pre-stretch at a given payout percentage and/or a tension at a payout percentage. Further, in some embodiments, the visible packaging material roll surface includes one or more of a wrinkle, air entrapment, edge feather, edge flaw, torn edge, nicked edge, die line, and/or gauge band.

In some embodiments, the one or more wrap parameters includes a payout percentage, a tension, a pre-stretch percentage, and/or a packaging material feed control, and in some embodiments, the one or more wrap parameters includes a roping mechanism parameter that controls roping or rolling of an edge of the packaging material. Some embodiments further include generating an alert to indicate to an operator an impact of any changes made.

In some embodiments, sensing the one or more indications is performed by a sensor array in a pre-stretch zone of the packaging material dispenser. In some embodiments, sensing the one or more indications includes sensing a gel on the packaging material with an image sensor directed at a web of the packaging material. In addition, in some embodiments, sensing the one or more indications includes sensing a hole in the packaging material with an ultrasonic sensor directed at a web of the packaging material, and in some embodiments, sensing the one or more indications includes sensing a force to pre-stretch at a given payout percentage with a force sensor coupled to an idle roller disposed between upstream and downstream dispensing rollers of a pre-stretch assembly. In some embodiments, sensing the one or more indications includes sensing a tension at a given payout percentage with a force sensor coupled to an idle roller disposed downstream of a pre-stretch assembly, and in some embodiments, sensing the one or more indications includes sensing an unwind force on a packaging material supply roll with a force sensor coupled upstream of a pre-stretch assembly. Further, in some embodiments, sensing the one or more indications includes sensing a visible packaging material roll surface with an image sensor.

Some embodiments also include sensing a cessation of the one or more indications of changes in packaging material characteristics, and changing the one or more wrap parameters in response to sensing the cessation. In addition, in some embodiments, changing the one or more wrap parameters in response to sensing the cessation includes restoring the one or more wrap parameters to original values.

In some embodiments, sensing the one or more indications of changes in packaging material characteristics is performed during a first wrap operation, and changing the one or more wrap parameters used to wrap the load in response to sensing the one or more indications is performed during a second wrap operation. In other embodiments, sensing the one or more indications of changes in packaging material characteristics and changing the one or more wrap parameters used to wrap the load in response to sensing the one or more indications are performed during the same wrap operation.

In some embodiments, a method of controlling a load wrapping apparatus of the type configured to wrap a load on a load support with packaging material dispensed from a packaging material dispenser through relative rotation between the packaging material dispenser and the load support may include sensing one or more indications of changes in packaging material characteristics during one or more wrap operations and indicative of a decrease in quality in the packaging material, changing one or more wrap parameters used to wrap the load in response to sensing the one or more indications, thereafter sensing a cessation of the one or more indications of changes in packaging material characteristics, and changing the one or more wrap parameters in response to sensing the cessation.

In some embodiments, changing the one or more wrap parameters in response to sensing the cessation includes restoring the one or more wrap parameters to original values.

In some embodiments, an apparatus for wrapping a load with packaging material may include a packaging material dispenser for dispensing packaging material to the load, a rotational drive configured to generate relative rotation between the packaging material dispenser and the load about a center of rotation, and a controller coupled to the packaging material dispenser and the rotational drive and configured to sense one or more indications of changes in packaging material characteristics during one or more wrap operations, and change one or more wrap parameters used to wrap the load in response to sensing the one or more indications, and wrap the load using the changed one or more wrap parameters.

Some embodiments may also include an apparatus including a processor and program code configured upon execution by the processor to control a load wrapping apparatus of the type configured to wrap a load with packaging material dispensed from a packaging material dispenser through relative rotation between the packaging material dispenser and the load by performing any of the aforementioned operations, as well as a program product including a non-transitory computer readable medium and program code stored on the non-transitory computer readable medium and configured to control a load wrapping apparatus of the type configured to wrap a load with packaging material dispensed from a packaging material dispenser through relative rotation between the packaging material dispenser and the load by performing any of the aforementioned operations.

In some embodiments, the processor is in a controller of the load wrapping apparatus, and the apparatus further includes a packaging material dispenser for dispensing packaging material to the load, while in some embodiments, the processor is in a device external to the load wrapping apparatus. In some embodiments, the device is a mobile device, a single-user computer or a multi-user computer.

These and other advantages and features, which characterize the invention, are set forth in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there is described example embodiments of the invention.

Embodiments consistent with the invention may sense changes in certain characteristics of a packaging material that can be associated with increased risks of film breaks, and may automatically make certain changes in machine settings to mitigate the impact of those enhanced risks. Additionally, in some embodiments, changes in certain characteristics of packaging material that can be associated with reduced risk of film breaks may also be sensed and used to make certain changes in machine settings to benefit the wrap process in either cost or productivity. Prior to a further discussion of these techniques, however, a brief discussion of various types of wrapping apparatus within which the various techniques disclosed herein may be implemented is provided.

Various wrapping apparatus configurations may be used in various embodiments of the invention. For example, <FIG> illustrates a rotating arm-type wrapping apparatus <NUM>, which includes a roll carriage or elevator <NUM> mounted on a rotating arm <NUM>. Roll carriage <NUM> may include a packaging material dispenser <NUM>. Packaging material dispenser <NUM> may be configured to dispense packaging material <NUM> as rotating arm <NUM> rotates relative to a load <NUM> to be wrapped. In an example embodiment, packaging material dispenser <NUM> may be configured to dispense stretch wrap packaging material. As used herein, stretch wrap packaging material is defined as material having a high yield coefficient to allow the material a large amount of stretch during wrapping. However, it is possible that the apparatuses and methods disclosed herein may be practiced with packaging material that will not be pre-stretched prior to application to the load. Examples of such packaging material include netting, strapping, banding, tape, etc. The invention is therefore not limited to use with stretch wrap packaging material. In addition, as used herein, the terms "packaging material," "web," "film," "film web," and "packaging material web" may be used interchangeably. Moreover, the breakage of any of the aforementioned types of packaging materials will hereinafter be referred to as "film breaks," so the term should not be interpreted to imply that film breaks refer only to breakages occurring in film-type packaging material webs.

Packaging material dispenser <NUM> may include a pre-stretch assembly <NUM> configured to pre-stretch packaging material before it is applied to load <NUM> if pre-stretching is desired, or to dispense packaging material to load <NUM> without pre-stretching. Pre-stretch assembly <NUM> may include at least one packaging material dispensing roller, including, for example, an upstream dispensing roller <NUM> and a downstream dispensing roller <NUM>. It is contemplated that pre-stretch assembly <NUM> may include various configurations and numbers of pre-stretch rollers, drive or driven roller and idle rollers without departing from the scope of the invention as defined in the appended claims.

The terms "upstream" and "downstream," as used in this application, are intended to define positions and movement relative to the direction of flow of packaging material <NUM> as it moves from packaging material dispenser <NUM> to load <NUM>. Movement of an object toward packaging material dispenser <NUM>, away from load <NUM>, and thus, against the direction of flow of packaging material <NUM>, may be defined as "upstream. " Similarly, movement of an object away from packaging material dispenser <NUM>, toward load <NUM>, and thus, with the flow of packaging material <NUM>, may be defined as "downstream. " Also, positions relative to load <NUM> (or a load support surface <NUM>) and packaging material dispenser <NUM> may be described relative to the direction of packaging material flow. For example, when two pre-stretch rollers are present, the pre-stretch roller closer to packaging material dispenser <NUM> may be characterized as the "upstream" roller and the pre-stretch roller closer to load <NUM> (or load support <NUM>) and further from packaging material dispenser <NUM> may be characterized as the "downstream" roller.

A packaging material drive system <NUM>, including, for example, an electric motor <NUM>, may be used to drive dispensing rollers <NUM> and <NUM>. For example, electric motor <NUM> may rotate downstream dispensing roller <NUM>. Downstream dispensing roller <NUM> may be operatively coupled to upstream dispensing roller <NUM> by a chain and sprocket assembly, such that upstream dispensing roller <NUM> may be driven in rotation by downstream dispensing roller <NUM>. Other connections may be used to drive upstream roller <NUM> or, alternatively, a separate drive (not shown) may be provided to drive upstream roller <NUM>. Moreover, in some embodiments the roll of packaging material <NUM> may be undriven and may rotate freely, while in other embodiments the roll may be driven, e.g., by biasing a surface of the roll against upstream dispensing roller <NUM> or another driven roller, or by driving the roll directly.

Downstream of downstream dispensing roller <NUM> may be provided one or more idle rollers <NUM>, <NUM> that redirect the web of packaging material, with the most downstream idle roller <NUM> effectively providing an exit point <NUM> from packaging material dispenser <NUM>, such that a portion <NUM> of packaging material <NUM> extends between exit point <NUM> and a contact point <NUM> where the packaging material engages load <NUM> (or alternatively contact point <NUM>' if load <NUM> is rotated in a counter-clockwise direction).

Wrapping apparatus <NUM> also includes a relative rotation assembly <NUM> configured to rotate rotating arm <NUM>, and thus, packaging material dispenser <NUM> mounted thereon, relative to load <NUM> as load <NUM> is supported on load support surface <NUM>. Relative rotation assembly <NUM> may include a rotational drive system <NUM>, including, for example, an electric motor <NUM>. It is contemplated that rotational drive system <NUM> and packaging material drive system <NUM> may run independently of one another. Thus, rotation of dispensing rollers <NUM> and <NUM> may be independent of the relative rotation of packaging material dispenser <NUM> relative to load <NUM>. This independence allows a length of packaging material <NUM> to be dispensed per a portion of relative revolution that is neither predetermined nor constant. Rather, the length may be adjusted periodically or continuously based on changing conditions. In other embodiments, however, packaging material dispenser <NUM> may be driven proportionally to the relative rotation, or alternatively, tension in the packaging material extending between the packaging material dispenser and the load may be used to drive the packaging material dispenser.

Wrapping apparatus <NUM> may further include a lift assembly <NUM>. Lift assembly <NUM> may be powered by a lift drive system <NUM>, including, for example, an electric motor <NUM>, that may be configured to move roll carriage <NUM> vertically relative to load <NUM>. Lift drive system <NUM> may drive roll carriage <NUM>, and thus packaging material dispenser <NUM>, generally in a direction parallel to an axis of rotation between the packaging material dispenser <NUM> and load <NUM> and load support surface <NUM>. For example, for wrapping apparatus <NUM>, lift drive system <NUM> may drive roll carriage <NUM> and packaging material dispenser <NUM> upwards and downwards vertically on rotating arm <NUM> while roll carriage <NUM> and packaging material dispenser <NUM> are rotated about load <NUM> by rotational drive system <NUM>, to wrap packaging material spirally about load <NUM>.

One or more of downstream dispensing roller <NUM>, idle roller <NUM> and idle roller <NUM> may include a corresponding sensor <NUM>, <NUM>, <NUM> to monitor rotation of the respective roller. In particular, rollers <NUM>, <NUM> and/or <NUM>, and/or packaging material <NUM> dispensed thereby, may be used to monitor a dispense rate of packaging material dispenser <NUM>, e.g., by monitoring the rotational speed of rollers <NUM>, <NUM> and/or <NUM>, the number of rotations undergone by such rollers, the amount and/or speed of packaging material dispensed by such rollers, and/or one or more performance parameters indicative of the operating state of packaging material drive system <NUM>, including, for example, a speed of packaging material drive system <NUM>. The monitored characteristics may also provide an indication of the amount of packaging material <NUM> being dispensed and wrapped onto load <NUM>. In addition, in some embodiments a sensor, e.g., sensor <NUM> or <NUM>, may be used to detect a break in the packaging material.

Wrapping apparatus also includes an angle sensor <NUM> for determining an angular relationship between load <NUM> and packaging material dispenser <NUM> about a center of rotation <NUM>. Angle sensor <NUM> may be implemented, for example, as a rotary encoder, or alternatively, using any number of alternate sensors or sensor arrays capable of providing an indication of the angular relationship and distinguishing from among multiple angles throughout the relative rotation, e.g., an array of proximity switches, optical encoders, magnetic encoders, electrical sensors, mechanical sensors, photodetectors, motion sensors, etc. The angular relationship may be represented in some embodiments in terms of degrees or fractions of degrees, while in other embodiments a lower resolution may be adequate. It will also be appreciated that an angle sensor consistent with the invention may also be disposed in other locations on wrapping apparatus <NUM>, e.g., about the periphery or mounted on arm <NUM> or roll carriage <NUM>. In addition, in some embodiments angular relationship may be represented and/or measured in units of time, based upon a known rotational speed of the load relative to the packaging material dispenser, from which a time to complete a full revolution may be derived such that segments of the revolution time would correspond to particular angular relationships. Other sensors may also be used to determine the height and/or other dimensions of a load, among other information.

Additional sensors, such as a load distance sensor <NUM> and/or a film angle sensor <NUM>, may also be provided on wrapping apparatus <NUM>. Load distance sensor <NUM> may be used to measure a distance from a reference point to a surface of load <NUM> as the load rotates relative to packaging material dispenser <NUM> and thereby determine a cross-sectional dimension of the load at a predetermined angular position relative to the packaging material dispenser. In one embodiment, load distance sensor <NUM> measures distance along a radial from center of rotation <NUM>, and based on the known, fixed distance between the sensor and the center of rotation, the dimension of the load may be determined by subtracting the sensed distance from this fixed distance. Sensor <NUM> may be implemented using various types of distance sensors, e.g., a photoeye, proximity detector, laser distance measurer, ultrasonic distance measurer, electronic rangefinder, and/or any other suitable distance measuring device. Exemplary distance measuring devices may include, for example, an IFM Effector 01D100 and a Sick UM30-<NUM> (<NUM>).

Film angle sensor <NUM> may be used to determine a film angle for portion <NUM> of packaging material <NUM>, which may be relative, for example, to a radial (not shown in <FIG>) extending from center of rotation <NUM> to exit point <NUM> (although other reference lines may be used in the alternative). In one embodiment, film angle sensor <NUM> may be implemented using a distance sensor, e.g., a photoeye, proximity detector, laser distance measurer, ultrasonic distance measurer, electronic rangefinder, and/or any other suitable distance measuring device. In one embodiment, an IFM Effector 01D100 and a Sick UM30-<NUM> (<NUM>) may be used for film angle sensor <NUM>. In other embodiments, film angle sensor <NUM> may be implemented mechanically, e.g., using a cantilevered or rockered follower arm having a free end that rides along the surface of portion <NUM> of packaging material <NUM> such that movement of the follower arm tracks movement of the packaging material. In still other embodiments, a film angle sensor may be implemented by a force sensor that senses force changes resulting from movement of portion <NUM> through a range of film angles, or a sensor array (e.g., an image sensor) that is positioned above or below the plane of portion <NUM> to sense an edge of the packaging material.

In other embodiments, some or all of sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be omitted.

Wrapping apparatus <NUM> may also include additional components used in connection with other aspects of a wrapping operation. For example, a clamping device <NUM> may be used to grip the leading end of packaging material <NUM> between wrap operations or cycles. In addition, a conveyor (not shown) may be used to convey loads to and from wrapping apparatus <NUM>. Other components commonly used on a wrapping apparatus will be appreciated by one of ordinary skill in the art having the benefit of the instant disclosure.

An example schematic of a control system <NUM> for wrapping apparatus <NUM> is shown in <FIG>. Motor <NUM> of packaging material drive system <NUM>, motor <NUM> of rotational drive system <NUM>, and motor <NUM> of lift drive system <NUM> may communicate through one or more data links <NUM> with a rotational drive variable frequency drive ("VFD") <NUM>, a packaging material drive VFD <NUM>, and a lift drive VFD <NUM>, respectively. Rotational drive VFD <NUM>, packaging material drive VFD <NUM>, and lift drive VFD <NUM> may communicate with controller <NUM> through a data link <NUM>. It should be understood that rotational drive VFD <NUM>, packaging material drive VFD <NUM>, and lift drive VFD <NUM> may produce outputs to controller <NUM> that controller <NUM> may use as indicators of rotational movement.

Controller <NUM> in the embodiment illustrated in <FIG> is a local controller that is physically co-located with the packaging material drive system <NUM>, rotational drive system <NUM> and lift drive system <NUM>. Controller <NUM> may include hardware components and/or software program code that allow it to receive, process, and transmit data. It is contemplated that controller <NUM> may be implemented as a programmable logic controller (PLC), or may otherwise operate similar to a processor in a computer system. Controller <NUM> may communicate with an operator interface <NUM> via a data link <NUM>. Operator interface <NUM> may include a display or screen and controls that provide an operator with a way to monitor, program, and operate wrapping apparatus <NUM>. For example, an operator may use operator interface <NUM> to enter or change predetermined and/or desired settings and values, or to start, stop, or pause the wrap operation. Controller <NUM> may also communicate with one or more sensors, e.g., sensors <NUM> and <NUM>, among others, through a data link <NUM> to allow controller <NUM> to receive feedback and/or performance-related data during wrapping, such as roller and/or drive rotation speeds, load dimensional data, etc. It is contemplated that data links <NUM>, <NUM>, <NUM>, and <NUM> may include any suitable wired and/or wireless communications media known in the art.

For the purposes of the invention, controller <NUM> may represent practically any type of computer, computer system, controller, logic controller, or other programmable electronic device, and may in some embodiments be implemented using one or more networked computers or other electronic devices, whether located locally or remotely with respect to the various drive systems <NUM>, <NUM> and <NUM> of wrapping apparatus <NUM>.

Controller <NUM> typically includes a central processing unit including at least one microprocessor coupled to a memory, which may represent the random access memory (RAM) devices comprising the main storage of controller <NUM>, as well as any supplemental levels of memory, e.g., cache memories, non-volatile or backup memories (e.g., programmable or flash memories), read-only memories, etc. In addition, the memory may be considered to include memory storage physically located elsewhere in controller <NUM>, e.g., any cache memory in a processor in CPU <NUM>, as well as any storage capacity used as a virtual memory, e.g., as stored on a mass storage device or on another computer or electronic device coupled to controller <NUM>. Controller <NUM> may also include one or more mass storage devices, e.g., a floppy or other removable disk drive, a hard disk drive, a direct access storage device (DASD), an optical drive (e.g., a CD drive, a DVD drive, etc.), and/or a tape drive, among others. Furthermore, controller <NUM> may include an interface <NUM> with one or more networks <NUM> (e.g., a LAN, a WAN, a wireless network, and/or the Internet, among others) to permit the communication of information to the components in wrapping apparatus <NUM> as well as with other computers and electronic devices, e.g. computers such as a desktop computer or laptop computer <NUM>, mobile devices such as a mobile phone <NUM> or tablet <NUM>, multi-user computers such as servers or cloud resources, etc. Controller <NUM> operates under the control of an operating system, kernel and/or firmware and executes or otherwise relies upon various computer software applications, components, programs, objects, modules, data structures, etc. Moreover, various applications, components, programs, objects, modules, etc. may also execute on one or more processors in another computer coupled to controller <NUM>, e.g., in a distributed or client-server computing environment, whereby the processing required to implement the functions of a computer program may be allocated to multiple computers over a network.

In general, the routines executed to implement the embodiments of the invention, whether implemented as part of an operating system or a specific application, component, program, object, module or sequence of instructions, or even a subset thereof, will be referred to herein as "computer program code," or simply "program code. " Program code typically comprises one or more instructions that are resident at various times in various memory and storage devices in a computer, and that, when read and executed by one or more processors in a computer, cause that computer to perform the steps necessary to execute steps or elements embodying the various aspects of the invention. Moreover, while the invention has and hereinafter will be described in the context of fully functioning controllers, computers and computer systems, those skilled in the art will appreciate that the various embodiments of the invention are capable of being distributed as a program product in a variety of forms, and that the invention applies equally regardless of the particular type of computer readable media used to actually carry out the distribution.

Such computer readable media may include computer readable storage media and communication media. Computer readable storage media is non-transitory in nature, and may include volatile and non-volatile, and removable and non-removable media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules or other data. Computer readable storage media may further include RAM, ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other solid state memory technology, CD-ROM, digital versatile disks (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and which can be accessed by controller <NUM>. Communication media may embody computer readable instructions, data structures or other program modules. By way of example, and not limitation, communication media may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above may also be included within the scope of computer readable media.

Various program code described hereinafter may be identified based upon the application within which it is implemented in a specific embodiment of the invention. However, it should be appreciated that any particular program nomenclature that follows is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature. Furthermore, given the typically endless number of manners in which computer programs may be organized into routines, procedures, methods, modules, objects, and the like, as well as the various manners in which program functionality may be allocated among various software layers that are resident within a typical computer (e.g., operating systems, libraries, API's, applications, applets, etc.), it should be appreciated that the invention is not limited to the specific organization and allocation of program functionality described herein.

In the discussion hereinafter, the hardware and software used to control wrapping apparatus <NUM> is assumed to be incorporated wholly within components that are local to wrapping apparatus <NUM> illustrated in <FIG>, e.g., within components <NUM>-<NUM> described above. It will be appreciated, however, that in other embodiments, at least a portion of the functionality incorporated into a wrapping apparatus may be implemented in hardware and/or software that is external to the aforementioned components. For example, in some embodiments, some user interaction may be performed using an external device such as a networked computer or mobile device, with the external device converting user or other input into control variables that are used to control a wrapping operation. In other embodiments, user interaction may be implemented using a web-type interface, and the conversion of user input may be performed by a server or a local controller for the wrapping apparatus, and thus external to a networked computer or mobile device. In still other embodiments, a central server may be coupled to multiple wrapping stations to control the wrapping of loads at the different stations. As such, the operations of receiving user or other input, converting the input into control variables for controlling a wrap operation, initiating and implementing a wrap operation based upon the control variables, providing feedback to a user, etc., may be implemented by various local and/or remote components and combinations thereof in different embodiments. In some embodiments, for example, an external device such as a mobile device, a networked computer, a server, a cloud service, etc. may generate a wrap model that defines the control variables for controlling a wrap operation for a particular load, and that wrap model may then be communicated to a wrapping apparatus and used by a controller therefor to control a dispense rate during a wrap operation. As such, the invention is not limited to the particular allocation of functionality described herein.

Now turning to <FIG>, a rotating ring-type wrapping apparatus <NUM> is illustrated. Wrapping apparatus <NUM> may include elements similar to those shown in relation to wrapping apparatus <NUM> of <FIG>, including, for example, a roll carriage or elevator <NUM> including a packaging material dispenser <NUM> configured to dispense packaging material <NUM> during relative rotation between roll carriage <NUM> and a load <NUM> disposed on a load support <NUM>. However, a rotating ring <NUM> is used in wrapping apparatus <NUM> in place of rotating arm <NUM> of wrapping apparatus <NUM>. In many other respects, however, wrapping apparatus <NUM> may operate in a manner similar to that described above with respect to wrapping apparatus <NUM>.

Packaging material dispenser <NUM> may include a pre-stretch assembly <NUM> including an upstream dispensing roller <NUM> and a downstream dispensing roller <NUM>, and a packaging material drive system <NUM>, including, for example, an electric motor <NUM>, may be used to drive dispensing rollers <NUM> and <NUM>. Downstream of downstream dispensing roller <NUM> may be provided one or more idle rollers <NUM>, <NUM>, with the most downstream idle roller <NUM> effectively providing an exit point <NUM> from packaging material dispenser <NUM>, such that a portion <NUM> of packaging material <NUM> extends between exit point <NUM> and a contact point <NUM> where the packaging material engages load <NUM>.

Wrapping apparatus <NUM> also includes a relative rotation assembly <NUM> configured to rotate rotating ring <NUM>, and thus, packaging material dispenser <NUM> mounted thereon, relative to load <NUM> as load <NUM> is supported on load support surface <NUM>. Relative rotation assembly <NUM> may include a rotational drive system <NUM>, including, for example, an electric motor <NUM>. Wrapping apparatus <NUM> may further include a lift assembly <NUM>, which may be powered by a lift drive system <NUM>, including, for example, an electric motor <NUM>, that may be configured to move rotating ring <NUM> and roll carriage <NUM> vertically relative to load <NUM>.

In addition, similar to wrapping apparatus <NUM>, wrapping apparatus <NUM> may include sensors <NUM>, <NUM>, <NUM> on one or more of downstream dispensing roller <NUM>, idle roller <NUM> and idle roller <NUM>. Furthermore, an angle sensor <NUM> may be provided for determining an angular relationship between load <NUM> and packaging material dispenser <NUM> about a center of rotation <NUM>, and in some embodiments, one or both of a load distance sensor <NUM> and a film angle sensor <NUM> may also be provided. Sensor <NUM> may be positioned proximate center of rotation <NUM>, or alternatively, may be positioned at other locations, such as proximate rotating ring <NUM>. Wrapping apparatus <NUM> may also include additional components used in connection with other aspects of a wrapping operation, e.g., a clamping device <NUM> may be used to grip the leading end of packaging material <NUM> between cycles.

<FIG> likewise shows a turntable-type wrapping apparatus <NUM>, which may also include elements similar to those shown in relation to wrapping apparatus <NUM> of <FIG>. However, instead of a roll carriage or elevator <NUM> that rotates around a fixed load <NUM> using a rotating arm <NUM>, as in <FIG>, wrapping apparatus <NUM> includes a rotating turntable <NUM> functioning as a load support <NUM> and configured to rotate load <NUM> about a center of rotation <NUM> (through which projects an axis of rotation that is perpendicular to the view illustrated in <FIG>) while a packaging material dispenser <NUM> disposed on a roll carriage or elevator <NUM> remains in a fixed location about center of rotation <NUM> while dispensing packaging material <NUM>. In many other respects, however, wrapping apparatus <NUM> may operate in a manner similar to that described above with respect to wrapping apparatus <NUM>.

Packaging material dispenser <NUM> may include a pre-stretch assembly <NUM> including an upstream dispensing roller <NUM> and a downstream dispensing roller <NUM>, and a packaging material drive system <NUM>, including, for example, an electric motor <NUM>, may be used to drive dispensing rollers <NUM> and <NUM>, and downstream of downstream dispensing roller <NUM> may be provided one or more idle rollers <NUM>, <NUM>, with the most downstream idle roller <NUM> effectively providing an exit point <NUM> from packaging material dispenser <NUM>, such that a portion <NUM> of packaging material <NUM> extends between exit point <NUM> and a contact point <NUM> (or alternatively contact point <NUM>' if load <NUM> is rotated in a counter-clockwise direction) where the packaging material engages load <NUM>.

Wrapping apparatus <NUM> also includes a relative rotation assembly <NUM> configured to rotate turntable <NUM>, and thus, load <NUM> supported thereon, relative to packaging material dispenser <NUM>. Relative rotation assembly <NUM> may include a rotational drive system <NUM>, including, for example, an electric motor <NUM>. Wrapping apparatus <NUM> may further include a lift assembly <NUM>, which may be powered by a lift drive system <NUM>, including, for example, an electric motor <NUM>, that may be configured to move roll carriage or elevator <NUM> and packaging material dispenser <NUM> vertically relative to load <NUM>.

In addition, similar to wrapping apparatus <NUM>, wrapping apparatus <NUM> may include sensors <NUM>, <NUM>, <NUM> on one or more of downstream dispensing roller <NUM>, idle roller <NUM> and idle roller <NUM>. Furthermore, an angle sensor <NUM> may be provided for determining an angular relationship between load <NUM> and packaging material dispenser <NUM> about a center of rotation <NUM>, and in some embodiments, one or both of a load distance sensor <NUM> and a film angle sensor <NUM> may also be provided. Sensor <NUM> may be positioned proximate center of rotation <NUM>, or alternatively, may be positioned at other locations, such as proximate the edge of turntable <NUM>. Wrapping apparatus <NUM> may also include additional components used in connection with other aspects of a wrapping operation, e.g., a clamping device <NUM> may be used to grip the leading end of packaging material <NUM> between cycles.

Each of wrapping apparatus <NUM> of <FIG> and wrapping apparatus <NUM> of <FIG> may also include a controller (not shown) similar to controller <NUM> of <FIG>, and receive signals from one or more of the aforementioned sensors and control packaging material drive system <NUM>, <NUM> during relative rotation between load <NUM>, <NUM> and packaging material dispenser <NUM>, <NUM>.

Those skilled in the art will recognize that the example environments illustrated in <FIG> are not intended to limit the present invention. Indeed, those skilled in the art will recognize that other alternative environments may be used without departing from the scope of the invention as defined in the appended claims.

In some embodiments, characteristics of packaging material that are associated with increased and/or reduced risks of film breaks may be sensed and used to change the settings of a load wrapping apparatus to improve the operation of the load wrapping apparatus, e.g., to mitigate the impact of risks and/or benefit the wrap process in either cost or productivity. In particular, it has been found that relationships exist between certain characteristics of packaging material and increased film breaks. Consistent with the invention, various mitigating strategies may be employed for each of these characteristics that may be initiated when changes to packaging material characteristics are sensed.

In some embodiments, for example, it has been found that certain changes in packaging material characteristics may be impactful, including: packaging material "gels" as measured with a high speed video camera, packaging material holes as measured by an ultrasonic sensor (e.g., a Sick Ultrasonic UC4-<NUM><NUM> film sensor), force to pre-stretch the packaging material at a given payout percentage, e.g., as measured by a load cell on an intermediate idle roller, packaging material tension at a specific payout percentage, e.g., as measured by a load cell on a downstream idle roller, unwind force on packaging material from a supply roll, and visible packaging material roll surface (e.g., wrinkles, air entrapment, edge feather, gauge bands, etc.), among others. These packaging material characteristics in some instances may be considered to be packaging material quality characteristics as they are indicative of the relative quality of a packaging material as compared to that packaging material's regular specifications.

Consistent with some embodiments of the invention, changes may be made to mitigate specific combinations of packaging material changes as sensed in the manner discussed above, including: change in payout percentage or packaging material tension, change in pre-stretch percentage, and/or change in packaging material feed control. In addition, in some embodiments, an alert notification (e.g., an alert banner) may be generated to indicate to an operator the impact of the changes made.

In some embodiments, for example, a sensor array may be provided in a pre-stretch or other zone of a film delivery system or packaging material dispenser, and in response to detecting one or more changes in packaging material characteristics, automatic adjustments may be made to mitigate these changes in packaging material characteristics and potentially decrease the incidence of film breaks during wrapping. It will be appreciated that in some embodiments, a control system of a wrapping apparatus may receive one or more indications of changes in packaging material characteristics and may, in response, react to such indications with changes to one or more wrapping apparatus settings to optimize machine performance and/or packaging material cost.

Now turning to <FIG>, this figure functionally illustrates an example load wrapping apparatus <NUM> consistent with some embodiments of the invention. Apparatus <NUM> may include a packaging material dispenser that dispenses a web of packaging material <NUM> from a roll <NUM> and past upstream and downstream dispensing rollers <NUM>, <NUM> of a pre-stretch assembly, as well as between upstream and downstream idle rollers <NUM>, <NUM> that are respectively disposed upstream and downstream of downstream dispensing roller <NUM>. A controller <NUM> controls a dispense rate of the packaging material dispenser by controlling a packaging material drive <NUM> coupled to downstream dispensing roller <NUM>. In addition, while in some embodiments dispensing rollers <NUM> and <NUM> may be mechanically coupled to one another to rotate at a fixed or adjustable ratio relative to one another to provide a fixed or adjustable pre-stretch, in other embodiments, and as illustrated in <FIG>, dispensing roller <NUM> may be driven by a separate pre-stretch drive <NUM> that enables the pre-stretch ratio to be controlled electronically, and in some instances, dynamically during a wrap operation.

In addition, while in some embodiments, roll <NUM> may be unpowered, in other embodiments, including as shown in <FIG>, the roll may be driven by a drive <NUM>, which in some embodiments may be configured as an electronic brake.

During a wrap operation, controller <NUM> may control drives <NUM>, <NUM> and <NUM> to control the dispensation of packaging material from roll <NUM> to a load, which when coupled with control over a rotational drive <NUM> that controls relative rotation between the packaging material dispenser and the load, wraps packaging material around the load in a controlled manner. It will be appreciated that additional aspects of controlling load wrapping apparatus <NUM>, including, for example, carriage control and various sensors used to detect various aspects of a wrap operation, may also be incorporated into load wrapping apparatus <NUM> but are not illustrated in <FIG>.

A suite of sensors <NUM>-<NUM> may be used in some embodiments to sense various characteristics of the packaging material that are associated with increased risk of film breaks, and controller <NUM> may be configured to alter one or more wrap parameters in response to these sensed characteristics, e.g., in response to detected changes in packaging material characteristics. It will be appreciated, however, that in other embodiments, different combinations of these sensors <NUM>-<NUM> may be used, and that some of such sensors may be used alone in some embodiments. Furthermore, the placement of these sensors can vary in different embodiments, so the various placements illustrated in <FIG> are not exclusive, and the invention is therefore not limited to the particular sensor placements illustrated herein. In particular, various locations within a pre-stretch or other zone of a packaging material dispenser, or within a film delivery system, may be used in different embodiments.

One type of sensor that may be used, for example, is an image sensor <NUM>, e.g., a high speed video camera or other suitable image sensor, which can be used to sense the presence of packaging material "gels" formed on the surface of the packaging material. Gels are generally unmelted plastic in a packaging material web that can cause breaks towards the center of the packaging material, and may be detectable from image data collected by image sensor <NUM>, e.g., when positioned between upstream dispensing roller <NUM> and upstream idle roller <NUM>, or in another suitable location.

Another type of sensor that may be used, for example, is an ultrasonic sensor <NUM>, e.g., a Sick Ultrasonic UC4-<NUM><NUM> film sensor, which can be used to sense holes in the packaging material web. Sensor <NUM> may be positioned between downstream idle roller <NUM> and downstream dispensing roller <NUM>, or in other suitable locations. In some embodiments, positioning sensor <NUM> within the pre-stretch assembly or downstream of the pre-stretch assembly may be beneficial due to the fact that pre-stretching can enlarge holes in some instances, thereby making holes easier to detect.

Another type of sensor that may be used is force sensor <NUM>, e.g., a load cell mechanically coupled to upstream idle roller <NUM> or another suitable arrangement for measuring tension (e.g., a dancer bar), to sense the tension in the packaging material between the upstream and downstream dispensing rollers <NUM>, <NUM>. Such a sensor may be used, for example, to sense the force required to pre-stretch the packaging material at a given payout percentage or other wrap force parameter.

Still another type of sensor that may be used is force sensor <NUM>, e.g., a load cell mechanically coupled to downstream idle roller <NUM> or another suitable arrangement for measuring tension (e.g., a dancer bar), to sense the tension in the packaging material between the downstream dispensing roller <NUM> and the load. Such a sensor may be used, for example, to sense packaging material tension at a given payout percentage or other wrap force parameter.

Another type of sensor that may be used is force sensor <NUM>, e.g., a load cell mechanically coupled to dancer bar <NUM>, or alternatively an idle roller, to sense the tension in the packaging material between the roll <NUM> and upstream dispensing roller <NUM>, which is indicative of an unwind force on the packaging material from the roll.

Still another type of sensor that may be used is an image sensor <NUM>, e.g., a high speed video camera or other suitable image sensor, which can be used to sense the presence of defects on the surface of roll <NUM> and/or in the packaging material web <NUM> as it exits the roll, e.g., wrinkles, air entrapment, edge feather, gauge bands, die lines, nicked or torn edges, etc..

In response to the outputs of any of sensors <NUM>-<NUM>, controller <NUM> may detect one or more characteristics of the packaging material associated with increased incidence of film breaks, and in response thereto, mitigate the risks by modifying one or more wrap parameters, e.g., to change a payout percentage, tension or other wrap force parameter (e.g., to vary the dispense rate controlled by packaging material drive <NUM> relative to the relative rotation rate controlled by rotational drive <NUM>), to change a pre-stretch ratio or percentage (e.g., to vary the relative rates of rotation controlled by drives <NUM>, <NUM>), to change a packaging material feed control (e.g., to vary the drive or braking of roll <NUM> by drive <NUM>), or various combinations thereof. In addition, other aspects of a wrap operation, e.g., the carriage speed, the number of layers of packaging material, etc., may also be varied in some embodiments, e.g., to maintain containment force by compensating for decreases in payout percentage or wrap force by wrapping the load with additional layers of packaging material. As another alternative, a parameter of a roping mechanism <NUM>, which rolls or otherwise forms a rope along an edge of the packaging material web <NUM>, may also be modified, e.g., to engage or disengage the mechanism, or to control an extent to which the edge of the web of packaging material is roped or rolled.

Moreover, whenever the outputs of any of sensors <NUM>-<NUM> indicate that any previously-sensed characteristics of the packaging material are no longer being detected (i.e., a positive change in packaging material characteristics, or a cessation in detecting indications of changes in packaging material characteristics indicative of a decrease in packaging material quality), controller <NUM> may restore any previously-modified wrap parameters to their original values, or otherwise modify the wrap parameters from the values selected when attempting to mitigate the incidence of film breaks. As one example, if a number of gels are detected along a length of the packaging material web, one or more wrap parameters may be modified from their original settings to decrease the likelihood of film breaks, and if later no gels are detected, the wrap parameters may be modified once again, but potentially to intermediate values that are not equal to the original values, but are still modified relative to those used when the gels were detected to accommodate the relatively higher risk that gels could be encountered on the same roll in the future.

In addition, in some embodiments, one or more alerts may be generated on an operator interface <NUM>, e.g., via an audible alert, a visual alert (e.g., a banner) on a display mounted to the load wrapping apparatus, a visual alert on a mobile or other external device in communication with the load wrapping apparatus, a text or email alert communicated to a mobile or other external device in communication with the load wrapping apparatus, or other notifications as will be apparent to those of ordinary skill having the benefit of the instant disclosure.

<FIG>, for example, illustrates an example sequence of operations <NUM> suitable for execution by controller <NUM> of load wrapping apparatus <NUM> when performing a wrap operation. In block <NUM>, the wrap operation is initiated using various selected parameters, e.g., payout percentage or wrap force, number of layers, tension, carriage speed, roping/no roping, etc. The selected parameters may be provided, for example, in a wrap profile retrieved by an operation, via manual input through the operator interface, or in other suitable manners.

Next, in block <NUM>, the various sensors utilized in load wrapping apparatus <NUM> may be monitored to detect the packaging material quality during the wrap operation, i.e., to attempt to detect one or more characteristics of the packaging material that are associated with increased incidences of film breaks. Block <NUM> determines whether a negative change in packaging material quality has been detected, e.g., in response to sensing one or more characteristics exhibiting a greater risk of film breaks. If not, control passes to block <NUM> to determine whether a positive change in packaging material quality has been detected, e.g., in response to no longer sensing one or more characteristics exhibiting a greater risk of film breaks. If no changes have been detected in packaging material quality, block <NUM> passes control to block <NUM>, which, so long as the wrap operation is not complete, passes control to block <NUM> to continue the wrap operation while continuing to monitor packaging material quality.

Returning to block <NUM>, if a negative change in packaging material quality is detected, control passes to block <NUM> to change or modify one or more wrap parameters to mitigate the risk of film breaks, and then to block <NUM> to continue with the wrap operation using the modified wrap parameters. As an example, it may be determined that gels have been detected on the roll, and as a result it may be desirable to lower the payout percentage <NUM>%, and potentially add another layer of packaging material to the load when wrapping.

Likewise, if a positive change in packaging material quality is detected, block <NUM> passes control to block <NUM> to restore one or more wrap parameters based upon the reduced risk of film breaks, and then to block <NUM> to continue with the wrap operation using the restored wrap parameters. It will be appreciated that in some embodiments, block <NUM> may simply restore original wrap parameters based upon a cessation of sensed indications of changes in packaging material characteristics. In other embodiments, however, block <NUM> may modify wrap parameters relative to those used to mitigate film breaks, while still using values that are different from the original wrap parameters.

In addition, while <FIG> illustrates a single wrap operation, in some embodiments, monitoring of packaging material quality may be performed over multiple wrap operations such that sensed indications of changes in one wrap operation may be used to vary one or more wrap parameters used in another wrap operation. It will be appreciated, in particular, that a single roll of packaging material may be used to wrap multiple loads, so if a quality issue is detected in the roll during one wrap operation, that quality issue will likely exist for subsequent wrap operations.

<FIG>, for example, illustrates another example sequence of operations <NUM> suitable for execution by controller <NUM> of load wrapping apparatus <NUM> when performing a wrap operation. In block <NUM>, the selected wrap parameters for the current wrap operation are obtained, and in block <NUM>, a determination of whether any packaging material quality modifications are currently active, e.g., based upon the last wrap operation. If so, any active packaging material quality modifications are applied to the selected wrap parameters, e.g., to modify one or more of the selected wrap parameters to mitigate film break risks, and the wrap operation is initiated in block <NUM>. As an example, from a prior wrap operation it may be determined that gels have been detected on the roll, and as a result it may be desirable to lower the payout percentage <NUM>%, and potentially add another layer of packaging material to the load when wrapping. If no modifications are active, however, block <NUM> may bypass block <NUM>, and proceed with the wrap operation using the selected wrap parameters.

Thereafter, as illustrated by blocks <NUM>-<NUM>, wrapping proceeds in a similar manner to blocks <NUM>-<NUM> of <FIG>. However, upon completion of the wrap operation, block <NUM> passes control to block <NUM> to store any active packaging material quality modification(s) for use in subsequent wrap operations (e.g., as described above in connection with blocks <NUM> and <NUM>). As such, monitoring of packaging material quality and mitigation of film break risks may occur over the course of multiple wrap operations in some embodiments.

Claim 1:
A method of controlling a load wrapping apparatus (<NUM>) of the type configured to wrap a load (<NUM>) with packaging material dispensed from a packaging material dispenser (<NUM>) through relative rotation between the packaging material dispenser (<NUM>) and the load (<NUM>), the method comprising:
sensing one or more indications of changes in packaging material characteristics during one or more wrap operations, wherein the one or more indications of changes in packaging material characteristics are indicative of a change in packaging material quality associated with a risk of film breaks, and wherein the one or more indications includes a packaging material gel, a packaging material hole, an unwind force on a packaging material supply roll, and/or a visible packaging material roll surface; and
changing one or more wrap parameters used to wrap the load in response to sensing the one or more indications.