Product wrapping machine

Abstract

A film wrapping machine comprising a film supply reel (2) and rollers (3, 4) for conducting film from the supply reel to a delivery point from where the film can be engaged with a product to be wrapped, in use, the delivery point and the product being movable relative to each other to wrap the film on to the product, includes a monitoring system comprising: a central control unit (5) attached to the machine, the control unit including a processor and data storage means and a battery, and a plurality of sensors (6-8) attached to the machine and each configured to measure rotation of a respective one of the rollers, the sensors being in communication with the central control unit.

Description

PRODUCT WRAPPING MACHINEField of the Invention

[0001] This invention relates to a film wrapping machine including apparatus for monitoring the operation thereof.Background to the Invention

[0002] Product wrapping machines are employed to wrap a stretchable plastics film around a product or collection of products, typically on a pallet, to secure and protect the products during transportation. In one form of wrapping machine, a large mobile wrapping head is moved around a ring surrounded the object to be wrapped and is configured to dispense the wrapping film under tension to hold the products being wrapped as the film layers adhere to one another.

[0003] In order to make efficient use of the wrapping film, while ensuring that the wrapping meets the desired specification, it is desirable to monitor the amount of film used and the tension applied, as well as detecting the occurrence of snapping of the film. It is especially desirable to be able to provide this monitoring function for existing wrapping machines without the need for costly modification of the machine.Summary of the Invention

[0004] Accordingly, a film wrapping machine comprises a film supply reel and rollers for conducting film from the supply reel to a delivery point from where the film can be engaged with a product to be wrapped, in use, the delivery point and the product being movable relative to each other to wrap the film on to the product, and a monitoring system comprising: a central control unit attached to the machine, the control unit including a processor and data storage means and a battery, and a plurality of low power Hall Effect sensors attached to the machine and each configured to detect passage of a magnet attached to a respective one of the rollers whereby to detect and measure rotation of the roller, the sensors being in communication with the central control unit.

[0005] Further features of the invention are set out in the claims.Brief Description of the Drawing

[0006] The drawing is a diagrammatic representation of a film wrapping machine with the monitoring system installed in accordance with an exemplary embodiment of the invention.Detailed Description of the Illustrated Embodiment

[0007] Referring to the drawing, a film wrapping machine can operate in one of two ways: the products to be wrapped are held on a stationary surface and the film supply rollers revolve around the products, for example being mounted on a ring or a rotary arm; or the products are placed on a turntable which is rotated relative to a stationary film-feed. In the drawing, the rotary portion of the machine, either the turntable or the ring, is represented as a simple rotary member 1. The film supply reel 2 feeds the stretchable film, typically known as stretch wrap or pallet wrap, to primary and secondary stretch rollers 3 and 4 to control the feeding of the film, the degree of stretch being controlled by the relative movement of the wrapper and the object being wrapped.

[0008] The monitoring apparatus comprises a central control unit 5 linked by cables to sensors 6, 7 and 8 configured to monitor rotation of the rotary member 1 , and the stretch rollers 3 and 4, respectively. Each sensor 6, 7 and 8 suitably includes a Hall effect device mounted adjacent to the rotary member or roller, at least one target magnet being mounted on the rotary member and each roller so that, rotation causes the magnet to move into and out of proximity to the sensor on each rotation, generating a differential signal which is transmitted to the central control unit 5, where the differential signals are translated into digital pulse signals that are readable by an ultra-low power processor in the unit 5.

[0009] While reference is made to “at least one magnet”, in practice multiple target magnets are placed at regularly angled intervals to provide more resolution on the rotations. Currently these are simply neodymium magnets which are placed on, but custom targets may be developed in the future to maximise sensor resolution. The number of targets is configured and accounted for in the software, which may be in the cloud, i.e. on a remote server.

[0010] The control unit 5 includes electrical power storage, typically a rechargeable battery, and a wireless charging coil 9 is provided, connected to the battery, and located where it can be coupled to a wireless power supply 10 on a stationary part of the machine when the charging coil 9 is brought into proximity thereto. In this way, power can be supplied to the control unit 5 when it is mounted on a rotating part of the machine when the machine is briefly at rest at the end of each wrapping cycle.

[0011] The control unit 5 uses an ultra-low-power processor to record information on pallets and is programmed to decide when a pallet has finished, and then waking up a main processor and pass the data to it for further processing, storage, and upload, as hereinafter described. The use of wireless charging coils and a power-optimised device (the whole main unit and sensors are optimised for very low power consumption) allows the monitoring apparatus on a mobile head to complete its functions on battery power and then recharge on docking. A battery life of ~1 week may be achieved, which allows continued operation even in charging system failure or poor machine docking, and reports on the battery condition so that the issue has plenty of time to be resolved whilst still providing continuous coverage and uptime

[0012] The control unit 5 is also provided with wireless communication with a remote monitoring station 11 , for example cloud-based servers, for processing recording and display of the date collected by the monitoring system.

[0013] In use, as a new pallet starts wrapping, the sensors located at the primary and secondary rollers and the turntable send pulses as differential signals as they detect the targets. The differential signals are received by the main circuit board in the central control unit 5 and are translated into digital pulse signals that are directly readable by the ultra-low-power processor. The ultra-low- power processor is configured to record the start time of the new pallet, and then subsequently count pulses from each of the independent sensors, applying basic digital filters to ensure that the data received is accurate and robust. When the ultra-low-power-processor determines from the sensor signals that the pallet has finished wrapping, it is programmed to send a ‘wake up’ signal tothe main microprocessor. The main microprocessor is configured to then retrieve the pulse counts for each different sensor, the start and end times for the pallet, and whether or not the pallet is believed to have had a snap, and bundle them into a ‘pallet’ object. The microprocessor is also configured to note its cur- rent battery conditions and other relevant system information. The pallet object and system information is then saved to local storage on the device and flagged as not-yet-sent-to-cloud. The microprocessor is programmed to determine the best time to send all of the queued pallet objects and system info to the servers in the cloud for processing, recording and display. Once this data has been transmitted, the microprocessor will go back to sleep and the main board will remain in low power mode until the device has finished receiving a new pallet.

[0014] When a new pallet object is received by the server, it uses the user- configured settings to calculate a number of outputs, for example:

Claims

CLAIMS1 . A film wrapping machine, comprising a film supply reel and rollers for conducting film from the supply reel to a delivery point from where the film can be engaged with a product to be wrapped, in use, the delivery point and the product being movable relative to each other to wrap the film on to the product, and a monitoring system comprising: a central control unit attached to the machine, the control unit including a processor and data storage means and a battery, and a plurality of low power Hall Effect sensors attached to the machine and each configured to detect passage of a magnet attached to a respective one of the rollers whereby to detect and measure rotation of the roller, the sensors being in communication with the central control unit.

2. A film wrapping machine according to Claim 1 , herein the battery is a rechargeable battery, the monitoring system is mounted on a rotatable part of the film wrapping machine, and a contactless charging station for the battery is mounted on a fixed part of the wrapping machine such that, when the rotatable part of the machine is at a rest position, the central control unit is positioned in close proximity to the charging station whereby electrical energy is transferred to the battery.

3. A film wrapping machine according to Claim 1 or 2, wherein the central control unit includes a wireless data transmitter for transmitting stored data to a remote monitoring station.

4. A film wrapping machine according to Claim 3, wherein the remote monitoring station is configured to store and display data relating to each wrapping operation of the wrapping machine.

5. A film wrapping machine according to Claim 3 or 4, wherein the remote monitoring station is also configured to communicate with a control system for controlling the operation of the wrapping machine and / or for collecting further data relating to the operation of the machine.

6. A film wrapping machine according to any preceding claim, wherein each said sensor includes a plurality of magnets attached to the roller and uniformly spaced therearound.

7. A film wrapping device according to any preceding claim, including at least one additional sensor connected to the central control unit and configured to measure a respective one of temperature, film thickness, force and vertical movement of the film.

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