Technical Field The invention relates to a device and a method for the packaging of coins in plastic bags. In particular, the invention is directed at a device and a method, which may be used and applied within or in direct connection to a coin handling machine, such as a machine for counting and/or sorting coins.

Background of the Invention Machines for handling a large amount of coins (such as counting and/or sorting the coins) are used in various applications, for instance in post and bank business, in shops, in lotteries, etc. Examples of known coin handling machines are given in W087/07742 and W097/07485.

After the coins have been counted and/or sorted, they are collected in coin bags, coin boxes, etc. These are emp- tied at appropriate intervals, wherein the coins will have to be provided in suitable packaging units. Today, coins are provided in packages by having an operator or a user removing the coin box, etc., from the coin handling machine and emptying the contents of the box in a separate packag- ing machine. Two different main principles are previously known when it comes to coin packaging. According to a first principle the coins are stacked in open tubes of paper or a similar material, wherein the tubes are sealed at their up- per, open ends after a certain number of coins have been received. According to an alternative to this principle a number of coins are first freely stacked on top of each other, and then the pile of coins is wrapped and, finally, the respective end is sealed on the wrapped pile of coins.

According to the second main principle the coins are instead packed in plastic bags. The plastic bags are formed

from a rectangular piece of plastic film (commonly polyeth- ylene film having a thickness of the order of 100 pm), which is fed and cut off from a roll of plastic film. The bag shape is then formed by folding the plastic film and welding it in its transversal direction (the bottom of the bag) as well as its longitudinal direction. When a correct number of coins have been placed in the coin bag, the bag is sealed by welding the upper opening of the bag in its transversal direction.

Even if the packaging principles described above are well tested and must be held to function properly as re- gards their main purpose, i. e. to provide a package of a number of coins in a functional way, these previously known methods have a common disadvantage in that the packaging machines are separate and occupy a large space.

In order to rationalize the handling of the coins it would be desirable to integrate a coin packaging device in a coin handling machine of the type described above. How- ever, this may not be done at a reasonable cost for any previously known coin packaging device.

Summary of the Invention Hence, an object of the present invention is to de- velop a coin packaging device, which will fit in a limited space and which also may be implemented at a limited cost.

The invention is particularly directed at allowing a coin packaging device to be integrated with a coin handling ma- chine, e. g. a coin counting or sorting machine.

The object above has been achieved through a device for the packaging of coins in plastic bags, comprising means for supporting a plastic tube, means for feeding a piece of the plastic tube to a position, where coins are supplied, means for sealing respective ends of said piece of plastic tube, and means for separating said piece from the rest of the plastic tube.

The object is also achieved through a method of pack- aging coins in plastic bags, where a number of coins are collected in a piece of a plastic tube, the ends of which are then sealed and separated from the rest of the plastic tube.

Other objects, advantages and features of the inven- tion will appear from the following detailed disclosure, from the appended patent claims and from the drawings.

Brief Description of the Drawings A preferred embodiment of the invention will be de- scribed in the following, reference being made to the ac- companying drawings, in which: FIG. 1 is a schematic perspective view, which illus- trates the device and the method according to the inven- tion, FIG. 2 is a perspective view, which illustrates a coin packaging device according to the preferred embodiment of the invention, FIG. 3 is a side view of the device shown in FIG. 2, when viewed from the front, FIG. 4 is a side view of the device shown in FIG. 2, when viewed from the rear, FIG. 5 is a side view of the device shown in FIG. 2, when viewed from the right, FIG. 6 is a top view of the device shown in FIG. 2, FIG. 7 is a detailed view of a bag holder and a com- pressed plastic tube, before the latter has been applied to the former, FIG. 8 illustrates the bag holder and the plastic tube, once the latter has been applied to the former, FIG. 9 is a perspective view of a welding and cutting unit comprised in the device, and

FIG. 10 illustrates a coin handling machine, in which a coin packaging device according to the invention advanta- geously may be used.

Detailed Disclosure of the Preferred Embodiment A central idea with the invention is to use a plastic tube made of plastic film as starting material when produc- ing plastic bags, in which the coins are packed. By neither using finished plastic bags (which would be associated with cost drawbacks both as regards the packaging material and the required mechanics), nor using rolls of single plastic film (which is space-demanding, since the plastic must be welded both in the lateral direction and the longitudinal direction), the present invention allows coins to be packed in a both inexpensive and cost effective way. A preferred embodiment of the invention is given a basic illustration in FIG. 1. A bag holder 100 stores a plastic tube 110 by threading the latter on the former. An upper end of the plastic tube 100 advantageously connects to an outlet in any coin handling machine available on the market, so that coins which for instance have been sorted or counted by such a coin handling machine may be supplied to the bag holder 100. At the bottom of the bag holder 100 the plastic tube 110 has been sealed by means of a welding and cutting unit 140, which in a way described below may be moved in a vertical direction through a linear guide 120, a transmis- sion 130, an attachment block 150, a motor 160 for the welding and cutting unit 140 and a motor 170 for the trans- mission with an associated lock 180.

The device shown in FIG. 1 has a following basic op- erational cycle. In a first phase the welding and cutting unit has been moved to a lower position, where a pair of welding jaws (described below) have been brought together and wherein the plastic tube is squeezed between the jaws and is sealed through welding. During this first phase the

packaging device is consequently prepared to receive coins, when these fall through the bag holder 100 and are col- lected in the plastic tube 110.

When a predetermined number of coins have been col- lected in the plastic tube 110, the packaging device moves to a second phase, where the welding jaws are brought apart and the welding and cutting unit 140 is brought to an upper end position. Despite the downward-oriented force, which is applied on the plastic tube 110 by the weight of the coins that are present within the plastic tube, the plastic tube 110 will be maintained on the bag holder 100 by providing the latter with an appropriate design, as will be described in more detail with reference to FIGS. 7 and 8.

In a third phase the welding jaws of the welding and cutting unit 140 are brought together. The welding and cut- ting unit 140 is moved to its lower position, wherein a piece of the plastic tube 110 is drawn to the lower posi- tion through the clamping force of the welding jaws.

In a fourth phase the plastic tube is welded by the welding jaws at two adjacent positions. During a subsequent fifth phase the plastic tube is cut by the welding jaws be- tween aforesaid welding positions, wherein the ready-packed plastic bag will freely fall down into a collecting con- tainer not shown in the drawing. When the plastic bag has been separated from the plastic tube 110, the packaging de- vice will again be in phase 1, wherein the cycle is re- peated.

FIGS. 2-6 illustrate a possible implementation of the packaging device according to FIG. 1. The device is pro- vided in a frame 1, comprising square steel sections, which are welded together to form two rectangles la, lb. The rec- tangles la, lb are in turn screwed together by means of tubes lc. The linear guide 130 is responsible for guiding the attachment block 150 with its welding and cutting unit 140 up and down in a vertical direction during the opera-

tional cycle described above. The linear guide is imple- mented by means of a linear guide shaft 3 of type SKF LJM, having a length of 345 mm and a diameter of 12 mm. Moreo- ver, two ball bushings of type SKF LBBR 12 are used but are not shown in the drawings.

The transmission 120 is adapted to move the attach- ment block 150 and the welding and cutting unit 140 up and down according to the above and is implemented by a belt 38 with associated upper and lower gear wheels 29,23. The belt and gear wheels may advantageously be of type Bando.

The motor 170 of the transmission 120 is implemented by a 24 V direct current motor 22 of type Maxon 2140.987-231.

The bag holder 100, which is not shown in FIGS. 2-6 for clarity reasons, is implemented according to FIGS. 7 and 8 in the form of a steel pipe, which at its bottom is provided with two welded steel pins 102,104, the purpose of which is to stretch the plastic tube and to guide it correctly into the welding and cutting unit 140. The steel pins 102,104 are also responsible for engaging the plastic bag with its coins, when the welding bags during some of the phases of the operational cycle are brought apart from each other. Moreover, at its lower portion the bag holder is provided with two guiding elements 106,107, the purpose of which is to prevent the coins from getting stuck in the outlet of the bag holder without falling down into the coin bag below. Finally, the bag holder 100 has a bayonet joint 108 to be easily mounted at a coin outlet in the coin han- dling machine, in which the packaging device is preferably used.

In the preferred embodiment the plastic tube 110 is available from Christer Nojd AB, Balsta, Sweden, and is made of low-density polyethylene (LDPE). The plastic tube has a width of 100 mm and a thickness of 50 pm. As appears from FIGS. 7 and 8 the plastic tube 110 is adapted to be threaded onto the bag holder 100. By compressing the plas-

tic tube 110 on the bag holder 100 a plastic tube of at least 4 m may easily be stored on the bag holder 100.

Preferably, the attachment block 150 is made from aluminium so as to obtain a low weight. The attachment block is labelled 5 in FIGS. 2-6.

As previously mentioned, the welding and cutting unit 140 is responsible for squeezing the plastic early in the operational cycle and for pulling the plastic down by a certain distance. Moreover, the welding and cutting unit 140 is responsible for welding the plastic so as to seal the plastic bag and to provide a seam for separating the plastic bag from the rest of the plastic tube. According to the preferred embodiment the welding and cutting unit 140 is implemented by an arrangement shown in FIG. 9. The ar- rangement comprises first and second stationary jaws 11,12 and a third, movable jaw 13. A welding jaw 16 is mounted on the third jaw 13, whereas a welding bucket 17 is mounted on the second jaw 12. A motion screw 14 is responsible for moving the welding jaw 16 in relation to the welding bucket 17 through a spiral motion and to provide appropriate clamping force between these elements. The motion screw 14 is driven by an electric motor 8 (see FIGS. 2-6) as well as upper and lower belt wheels 15,9, which are connected through an O-ring not shown in the drawing. The electric motor 8 is driven in different directions in order to open and close the jaws.

The jaws 11,12,13 are preferably made from alumin- ium and are joined together by means of steel shafts. The center jaw is mounted with special bushings and may conse- quently slide between the outer jaws. A welding effect is obtained by means of a pair of resistive strips, comprising Kanthal wire with dimensions 1.25 x 0.15 mm. The resistive strips are provided with a protective Teflon tape in order to prevent the plastic tube from adhering to the resistive strips. The resistive strips, which are not shown in the

drawings, are mounted to the movable welding jaw 16, whereas the welding bucket 17 is provided with two thin rubber blocks (not shown), which press against the resis- tive strips and which also assist in fixing the plastic tube, when it is drawn downwards during a certain phase of the operational cycle. The resistive strips are driven in series by a voltage of 24 V and a current of 3 A, which give a sufficient welding effect for the plastic material in question.

The cutting effect is obtained through a resistive wire (not shown), which according to the preferred embodi- ment comprises a Nikrothal wire with a diameter of 0.25 mm.

The resistive wire is stretched between a cutting wire fas- tener 19 and a cutting wire spring 20 on the welding jaw 16 with such an adjustment, that the resistive wire is brought between the rubber blocks mounted on the welding bucket 17, when the welding jaw 16 is in contact with the welding bucket 17. In this way the resistive wire will reach con- tact with the plastic tube and will cut through the plas- tic, when the resistive wire is fed with 24 V and 3 A.

Since the cross-sectional area of the resistive wire is smaller than the cross-sectional area of the resistive strips, the wire will become hotter than the strips, wherein the cutting effect described above is achieved.

A measuring and locking disc 24 is arranged together with a solenoid 25 for locking the welding and cutting unit 140 in its respective operating positions. The lock 180 is achieved by guiding a pin on the solenoid 25 through one of the openings of the measuring and locking disc 24.

The measuring unit 190 is used for positioning the attachment block 150, which in turn is necessary in order to control the size of the plastic bag, which is to be formed from the plastic tube 110. The top position of the attachment block 150 is detected by means of a micro switch not shown in the drawings. The measuring and locking disc

24 is mounted to the drive shaft of the electric motor 22.

The measuring and locking disc 24, which is provided with openings, does not only serve as a locking means according to the above but will also co-operate with a measuring fork 26, which detects the number of openings, that the measur- ing and locking disc 24 has been turned through the rota- tion of the electric motor 22. Under control of a control- ler not shown in the drawings the welding and cutting unit 140 may be positioned with enough accuracy in its vertical direction by reading output signals from the measuring fork 26.

The controller referred to above is preferably imple- mented by means of any electronic controller, which is al- ready used in the coin handling machine, in which the coin packaging device advantageously is used. Alternatively, the controller may be implemented by any hardware and/or soft- ware, such as a commercially available personal computer with associated control software. Other alternatives in- volve a dedicated hardware solution with a micro-processor arrangement, an ASIC circuit or similar. To design and con- nect such a controller, having the components described above, in the packaging device must be regarded to fall within the normal knowledge of a man skilled in the art and is consequently not described in more detail herein.

According to an alternative embodiment of the inven- tion the top-mounted bag holder 100 is replaced by a plas- tic tube storage in the form of a roller, on which the plastic tube is rolled, and an associated feeding arrange- ment for positioning a piece of the plastic tube at a cor- rect location in the packaging device with respect to the welding and cutting unit.

In FIG. 10 there is shown an example of a coin han- dling machine 200 in the form of a coin counter/sorter for self-service purposes. The overall design of the coin han- dling machine 200 is previously known in essential details.

The machine has a cabinet 232 with a hinged upper casing 248 and a hinged lower door 250. Behind the casing 248, which during the normal use will assume a closed position and will therefore hide and protect the internal parts of the machine, a counting and/or sorting device 216 is pro- vided.

Preferably, the machine 200 is used on a self-service basis. A user of the machine (such as a bank customer or a visitor in a supermarket) will deposit an amount of mixed coins (for instance originating from a wallet, a coat pocket or a money box) in a coin intake 234 on top of the machine 200. By for instance pressing a start button not shown in the drawing the user will initiate the coin count- ing/sorting. The counting and/or sorting 216 will identify, count and sort the individual coins, which are supplied through coin outlets to different coin containers 252. The coin containers will be locked behind the door 250 during normal use but may be removed, by means of handles 254, and be emptied by authorized personnel. Once all coins have been processed by the machine 200, a receipt will be printed by a printer 236. The total counted amount will be specified on the receipt, and the user may subsequently re- ceive for instance shop articles in exchange of the re- ceipt. Alternatively, the user may deposit the amount on a bank account. Coins which have not been accepted by the ma- chine 200 are returned in a return box 246.

The coin packaging device according to the present invention may advantageously be integrated in a coin han- dling machine 200 according to FIG. 10 or alternatively in any other coin handling machine available on the market.

The frame 1 is given such external dimensions, that the coin packaging device may replace one or several coin con- tainers 252, wherein only insignificant modifications are required for the coin handling machine 200.

The invention has been described above with reference to a preferred embodiment. The scope of the invention, as defined by the independent patent claims, does however also cover many other opportunities, which should be apparent to a man skilled in the art. Choice of material and detailed design of components must of course be changed depending on a practical application.

List of components for the preferred embodiment ac- cording to FIGS. 2-6 Reference nu-Specification meral 1 Frame 2 Shaft support 3 Shaft 4 Shaft support 5 Attachment block 6 Motor support 7 Spacer 8 Electric motor 9 Belt wheel 10 Shaft 11 Jaw 12 Jaw 13 Jaw 14 Motion screw 15 Belt wheel 16 welding jaw 17 Welding bucker 18 Threading insert 19 Cutting wire fastener 20 Cutting wire spring 21 Motor and solenoid support 22 Electric motor 23 Gear wheel 24 Measuring and locking disc 25 Solenoid 26 Measuring fork 27 Guide plate 28 Gear wheel shaft 29 Gear wheel 30 Breaker bucker 31 Breaker support 32 Breaker 33 Breaker support 34 Breaker bucker 35 Breaker support 36 Spring 37 Spring screw 38 Belt 39 Belt lock