|Title of Invention||
A DEVICE FOR STRETCH WRAPPING ARTICLES WITH CLING FILM
|Abstract||This invention relates to a compact device having a table top for paoking articles with stretched cling film. The devioe consists of a feeder roller assembly, a stretching unit, consisting of a pair of rollers, pinching neans for pinching the film, width adjusting neans and cutting means. The article is packed nannually by wrapping the stretched film drawn through the stretching unit with more than one layer of the film of desired. The device is simple, can be noved from place to place and is econonioal.|
|Full Text||This invention relates to a device for stretch wrapping articles with cling film and is useful in packing articles like cassettes, printed circuit boards, cartons, books, nylon films, rope rolls and the like.
Articles are packed conventionally with wrapping materials such as, paper, foil, polyethylene bags, cloth and the like bags or pouches. These methods of packing are labour and cost intensive. Moreover the packed materials are to be sealed, vacummised and stapled to preserve and protect the contents therein. As the contents packed are not held intact but loosely within the packages, internal rubbing between the products occur. Conventional packing methods do not provide unitising of individual components which enhances internal friction between packed articles. Above all, packing non-uniform and irregular shapes is found to be a very cumbersome process.
The concept of stretch wrapping articles has been developed to overcome the drawbacks of conventional wrapping methods. Stretch wrapping is carried out by applying one or more layers of a film having cling property. When the film layers overlapp one over the other, bonding takes place between the two successive layers due to the clinging property exhibited by the film. Stretch wrapping prevents the entry of dust and moisture thereby protecting the contents. Such packing is unitised or
individual articles are packed separately thereoy preventing inter articles friction and internal rubbing of the contents. This method is also labour saving as stapling or sealing of individual packages becomes unnecessary. Moreover, irregular or non-uniform shapes can be packed very efficiently. It is also possible to increase the number of layers to provide extra protection or support to the packed article, if required. Stretch wrapping is also found to be economical and aesthetically appealing. The transparency of the cling film provides, easy see through facility for inspecting the goods packed without removing the wrapper. Films made from linear low density polyethylene are found to exhibit excellent cling property and are useful in stretch wrapping.
This device for stretch wrapping has been developed with the objectives of providing a simple and compact machine, which enables operators to perform smoothly and comfortably. The articles are packed on top of the table provided in the device. The mechanical and electrical controls of the machine are operable by hand or by foot.
The device for stretch wrapping according to this invention consists of a housing which may be made of sheet metal. The housing may also be custom made to suit the requirement of
individual oustomers. Hinged openings or doors are provided for the housing for easy accessibility inside to attend to any naintanance or repair work. The housing is provided with a feeder assembly consisting of holding neans to hold a roll of film and delivery means for delivery the film to a stretching unit mounted inside the housing. Holding means for holding the film roll is provided with brake means which applies brake force when the film is being pulled from it. Mechanical friction or electromagnetic types of brakes are preferred. The holding means is also provided with threaders for automatic treading of the film to the stretching unit. The stretching unit consists of two textured rollers which may be made of rubber or coated with polyurethane. These rollers are drivable by a motor having a variable speed drive for varying the stretch level according to user requirements. A second set of rollers preferably made of rubber and coated with polyurethane film functions as pinching means which prevents the film from going baok into the stretching rollers due to the resilient nature of the film. Dancing rollers oscillating between two sets of speeds are provided for dispersing the film as it is being pulled through the stretching unit. The stretching unit is also provided with width adjusting means which are a pair of skirting rollers connected to a rotatable hand wheel. The width of the film can be adjusted by rotating the hand wheel either in the clockwise or anti clockwise direction.
A film cutting unit is provided to cut the film after stretch wrapping the article. This unit may have an electrically heated cutting means, a mechanical or pneumatic cutter. The electrically operated cutter may be an impulse or constant heater which is capable of cutting the film. A foot cover activates a micro switch to supply power for a predetermined period to heat the cutting element of the impulse heated cutting means. Power supply is kept continuously on when a constant heat cutter is used to cut the film after wrapping the object. The cutting element may be a nickel chromium wire or a stainless steel blade which is protected by a flap like cover means which opens and closes as the foot lever is operated.
A control panel encloses the motor control card, overload relay for the motor, timer for adjusting the quantum of heat to the cutting unit and potentiometer for setting speed of the motor at the desired level. Power on and off switch as well as emergency stop means are also provided in the control panel. The housing has feet-in and feet-out counters for operating the device.
OPERATING PROCEDURE OF THE DEVICE
After turning on the power supply, the film loaded in the holding means is threaded to the rollers of the stretching unit,
and the tension of the film is adjusted. The width of the film is also adjusted by rotating hand wheel as to the requirenent of the article to be packed. If impulse heating is used to cut the film, tine and temperature adjustments may be made suitably. The film is then pulled and spread on the surface of the table, the product to be wrapped is kept on the film and the wrapping is carried out mannually by pulling the film through the stretching unit and rotating the product to pack it as required. Wrapping may be continued till the article is covered with the desired number of layers of the film. The foot lever is then actuated and the film is cut. The cut end of the film is wiped as to the article which clings to its surface.
The device for stretch wrapping articles with cling film according to this invention comprising a housing provided with a table top, the said housing having a feeder assembly for holding and delivering the film to a stretching unit consisting of a pair of driven rollers, film pinching and width adjustments means of the said stretching unit being mounted on the table top, cutting means for cutting the desired length of film and control means for controlling the operation of the device.
This invention will now be described with reference to the plan view and elevation of the device shown in figures I and II respectively in the accompanying drawings.
In the plan view dipicted by figure I, referebce letters TT indicate the table top of the device which has article A to be wrapped placed thereon. Different parts of the stretching unit are indicated by the following reference letters. P represents the film pinching means, DR stand for the dancing rollers which control the speed of the film. WR show the width reducing means and CM the cutting means for cutting the film. Reference letter H indicates the hand wheel which is rotatable to adjust the width of the film as required.
Fig II represents the elevation of the device wherein SU stand for the stretching unit having different parts as indicated in fig. I but not separately shown in Fig. II. Letter C stands for the control panel which houses the electrical system and connections for operation of the device. FA indicate the feeder assembly having a film roll mounted therein. Letter R stands for rollers on which the table top housing is mounted for ensuring mobility of the unit. FP represent the foot pedal for operting the device.
Though the device has been described herein above with reference to a preferred embodiments, alterations and modifications obvious to persons skilled in the art are within the scope of this invention and the appended claims.
WE CLAIM :
1. A device for stretch wrapping articles with cling film comprising a housing provided with a table top, the said housing having a feeder assembly for holding and delivering the film to a stretching unit consisting of a pair of driven rollers, film pinching and width adjustments means, the said stretching unit being mounted on the table top, cutting means for cutting the desired length of film and control means for controlling the operation of the device.
2. The device as claimed in claim 1, wherein the housing has hingedly connected openings.
3. The device as claimed in claims 1 and 2, wherein the housing is mounted on rollers.
4. The device as claimed in any one of the preceding claims, wherein the feeder assembly consists of holding means, delivery means and brake means.
5. The device as claimed in claim 4, wherein the brake means is electromagnetic or mechanical.
6. The device as clained in claim 1 to 5, wherein the holding
means is provided with threaders for feeding film to the
7. The device as claimed in claim 1, wherein the driven rollers
of the stretching units are textured and polyurethane coated.
8. The device as claimed in claims 1 and 7, wherein dancing
rollers are provided for varying the speed of the driven rollers.
9. The device as claimed in claim 1, wherein the film pinching
means consists of a pair of rollers for preventing the stretched
film from going back to its original form.
10. The device as claimed in claim 1, wherein the width adjusting means consists of a pair of skirting rollers connected to a rotatable hand wheel.
11. The device as claimed in claim 1, wherein dancing rollers are provided on the stretching unit to disperse the film at the desired speed.
12. The device as claimed in claim 1, wherein the cutting means is selected from an electrical, mechanical or pneumatic cutter.
13. The device as claimed in claim 12, wherein the cutting means is an impulse cutting means and has a micro switch connected to a foot cover for energising the same.
14. The device as claimed in claim 12, wherein the cutting means is a nickel-chromium or stainless steel cutting blade.
15. The device as claimed in claims 1 and 14, wherein the cutting means is a blade kept heated constantly by electricity.
16. The device as claimed in claims 12 to 15, wherein a flap like cover means is provided for the cutting means.
17. The device as claimed in claim 16, wherein the said flap like cover is connected to the foot lever for opening and closing the same.
18. The device as claimed in claim 1, wherein the control panel houses the electrical connections, over load relay, timer for adjusting the quantum of heat to be supplied to the cutter blades and a potentiometer for controlling the speed of the motor.
19. The device as claimed in claims 1 and 18, wherein the said control panel has power ON and OFF switches, as well as emergency STOP switch.
20. The device as claimed in any one of the preceding claims, wherein
feet in and feet out stations are provided on the control base of panel.
21. A device for stretch wrapping articles with cling film, substantially as
hereinabove described and illustrated with reference to the
|Indian Patent Application Number||1783/MAS/1996|
|PG Journal Number||30/2009|
|Date of Filing||08-Oct-1996|
|Name of Patentee||ITW SIGNODE INDIA LIMITED|
|Applicant Address||5, S.P. ROAD, BEGUMPET, HYDERABAD-500 016|
|PCT International Classification Number||B65B11/00|
|PCT International Application Number||N/A|
|PCT International Filing date|