TUBE HANDLING LINE TECHNICAL FIELD The invention relates to a tube handling line or machine intended to in-line process empty packaging tubes to form closed tubes filled with product.

STATE OF THE ART Machines or machine lines of said general type have long been used for various types of products which can be packaged in tubes or tube-like packagings, for example cosmetic products, pharmaceutical products, food products etc. Stringent requirements apply for the machines with regard to operational safety, hygiene, reasonable maintenance costs and often also format-adjustability. A tube filling machine conventionally comprises some form of intermittently driven, endless conveyor, and a number of processing stations are arranged along this conveyor so as to deliver filled and closed tubes at the exit from the machine. The number of stations may vary depending on the type of tube or type of material but, usually, a feeding-in station for empty tubes, a filling station, a station for orienting the design on the tubes, a station for closing the tube ends and also a station for feeding out filled tubes are required.

The number of filled tubes that can be produced per unit of time in the machines can, within certain limits, be adapted to the current requirement.

In some cases, for example, it is possible to double up certain stations but the upper limit for the number of tubes produced per unit of time will still be limited by the slowest station in the production chain, namely the filling station.

One way of improving productivity would be to drive the endless conveyor at a continuous rate and make use of a continuously operating filler. The implementation of such a method would mean, however, that the station for closing the tube ends would not have time to perform its function and would thus take over the production-limiting role of the intermittent filling station.

In order to achieve productivity corresponding to continuous operation of the conveyor, it would therefore at first appearance be necessary to in some way convert conventional, reliable closing stations into closing tools operating synchronously with the conveyor.

Such an arrangement would, however, add greatly to the complexity and the cost of the machine and would moreover be very difficult to implement in applications in which hot-air closing is used in the closing station or stations.

THE OBJECT OF THE INVENTION The object of the invention is to improve tube handling lines and machines so that the rate of production of filled and closed tubes is increased while at least retaining the specification requirements referred to in the introduction.

THE INVENTION The object of the invention is achieved by a tube handling line or machine according to Patent Claim 1 and further developments and alternative embodiments emerge from the subclaims.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows diagrammatically a first embodiment of a tube handling line or machine according to the invention. Fig. 2 shows a section along the line A-A in Fig. 1, and Fig. 3 shows diagrammatically a second embodiment of a tube handling line or machine according to the invention.

Fig. 1 shows diagrammatically a line comprising a delivery station 10 for empty packaging tubes, a first transfer arrangement 11 in the form of a robot for transferring tubes intended for filling to a filler 12 and also a second transfer arrangement 13, likewise in the form of a robot, for transferring filled tubes to an endless conveyor 14. Located along this conveyor, which in the exemplary embodiment shown is driven intermittently, has rectilinear conveyor sections 15,16 and is provided with tube holders 17, are a number of stations 18-23 for processing the tubes carried in the tube holders 17.

In the embodiment shown, the station 18 is a station for orienting the design on the tubes, the station 19 is a station for end closing using hot air, the station 20 is a station for coding, the station 21 is a station for trimming, the station 22 is a station for ejecting defective tubes, and the station 23 is a station for feeding out finished, filled tubes.

In the exemplary embodiment in Fig. 1, the filling station 12 is a stationary station comprising a number of filling nozzles 24 arranged in a straight line above a filling beam 25 provided with holders 26 for tubes intended for filling. The filling beam 27 is vertically adjustable in the direction of the double arrow 25.

The delivery station 10 for empty tubes comprises a feed-in conveyor 28 for transport packages 29 filled with tubes 30 positioned rectilinearly in rows. A feed-out conveyor 31 for emptied transport packages follows at right angles to the feed-in conveyor 28.

The robot 11 operates between the delivery station 10 and the filling station 12 and has on its arm 32 a gripper 33 which, as has been indicated by the arrow 34, performs a reciprocating movement between the delivery station 10 and the filling station 12. The gripper 33 is provided with a number of tube holders corresponding to the number of tubes required in the filling station.

On the arm 35 of the robot 13, there is a gripper 36 which is similar to the gripper 33 and is intended to perform a reciprocating movement in the direction of the double arrow 37 so as to transfer filled tubes from the filling station 12 to the endless conveyor 14.

During operation of the line, the gripper 33 of the robot 11 loads the filling beam 25 at the same time as the robot 13 loads the endless conveyor 14 by delivering filled tubes to the rectilinear conveyor section 15 by means of the gripper 36 for further processing in the stations 18-23.

After the gripper 33 has loaded the filling beam 25, the latter is raised, with the empty tubes arranged in it, to the filling position below the nozzles 24.

The gripper 33 then performs a movement (shown diagrammatically by the arrow 34) so as to grip a new row of tubes 30 in the transport package 29 and remove them. At the same time, the gripper 36 performs a movement (shown diagrammatically by the arrow 37) so as to remove filled tubes from the filling beam 25. If, for example, twenty filling nozzles are used and there is adequate capacity in the closing station 19 (for example double hot-air nozzles), the programmable robots 11,13 make possible a production rate of up to 400 tubes per minute.

The embodiment of the tube handling line or machine shown in Fig. 3 differs from the embodiment in Fig. 1 in that a filling station 12'with continuously rotating filling nozzles has been included instead of a stationary filling station. The robot arrangement is otherwise identical. Instead of the filling beam 25 in Fig. 1, use is made of an endless conveyor which is driven continuously and synchronously with the filling nozzles in the filling station 12'and comprises a rectilinear filler section 25 entering the filling station and a likewise rectilinear filler section 25'leaving the station.

In Fig. 3, as in Fig. 1, a cartoning station 38 is also shown at the exit from the tube handling line or machine.

Although only two embodiments of the invention have been described, it is clear that the invention is limited only by the contents of the appended patent claims.