Title of Invention

ROTATING DEVICE FOR QUICK CUTTING OF LABELS, WHICH ARE FED AS AN ENDLESS LOOP

Abstract

The invention comprises of a device for defined cutting of labels which are fed as endless loop. It consists of a disc (2) rotating at constant rotating speed, with one or several knives (5) which can be moved between a rest position and a cutting position. Each knife (5) is connected with a part made of soft magnetic material and several electromagnets are arranged around the rotating cutting disc (2), which can exercise forces on the soft iron parts connected to the knives (5) and thus can move the knives (5) between are rest position and a cutting position. The knives are brought back to the initial position either by a spring (4) or by the centrifugal force.

Full Text

Rotating device for quick cutting of labels, which are fed as an endless loop Description For marking rotation-symmetric containers like bottles or cans, among other types of things also labels are used, which are fed to the labelling device in the form of an endless loop of thin elastic synthetic substance This loop :s initially rolled as flat joined band on a roller. Before fixing on to the container to me marked, the label loop has to be expanded into a circular shape and then cut off according to the label length. For this, the cutting device rotates around the label loop drawn on a circular mandrel and separates one lable a t a time, whereas the fed loop stands still for a short period of time. The cut-off label is then drawn over the container with the help of suitable devices, e.g. a stocking, and then adheres tightly to the jacket surface on account of its elasticity. Modern label devices process several tens of thousands units per hour Therefore, for cutting off a label, including all related transportation and positioning sequences, only very little time of less than 100 milli-seconds is available Known cutting devices work with an arrangement, which consists of a circular disc rotating around the label loop which has several movable knives The knives are equipped with an additional mass as well as a return spring, The rotation speed of the disc is varied between two values by the drive device - a lower value at which the cutting knives do not touch the lable loop (rest position), and a higher value at which the knives are swivelled into the cutting position. The masses connected to the knives and the spring forces are thereby dimensioned in such a way, that at the lower rotation speed the spring force weighs more and holds the knife in rest position, and at the higher rotation speed the centrifugal force of the mass connected to the knife weighs more and the knife gets swung into the cutting position The disadvantages of this device are the high periodic forces which are required for accelerating and retarding the entire mass of the knife-holder with the knives between the two rotation speeds as well as the time required for these acceleration sequences The device as per the invention avoids these disadvantages, in that the knife holder rotates with constant rotation speed and the movement of the knives can be executed much more easily without the additional masses for generation of defined centrifugal forces. Fig. 1 shows the principle A disc 2 rotating at constant rotating speed and made of non-ferromagnetic material, e.g. aluminium or plastic, carries the knife 5. In the figure, only one knife is shown. For further reducing the cutting time and for reducing the bearing load, a symmetric arrangement of several knives would be sensible. The knife can be rotated around the axis 7 and is held in rest position by the spring 4. The knife axis 7 is fixed on to the rotating holding disc 2. The rotation point of the knife is selected in such a way, that the centrifugal forces on both sides of the rotation axis are approx. equal. In this way, a momentum around the rotation axis of the knife on account of centrifugal force can be avoided. Along the periphery the knife carries a vane 3 made of soft magnetic material. Concentrically around the rotating knife holder ring, a ring 1 made of soft magnetic material with U-shaped cross-section is arranged, into which the ring spool 6 is embedded. In order to avoid dirtying, the spool is cast or locked by a plastic ring. The soft magnetic ring along with the ring spool 6 and the vane 3 forms an electromagnet. In the rest position of the knife, the longitudinal axis of the vane 3 is not parallel to the tangent 8 at the cutting point with the soft iron ring. If a current flows through the spool, then the generated field forces try to reduce the volume of the air gap between the vane 3 and the ring 1. This means, that the knife 5 rotates, reduces the angle between the longitudinal axis of the vane 3 and the tangent 8 and thus swings into the cutting position. The outer radius of the vane towards the ring magnet is selected in such a way, that in the cutting position a parallel air gap of a few tenths of a millimetre occurs. After the spool current is switched off, the knife, on account of the tensed spring 4 in this position, swings back to rest position. Instead of a spring 4, also by means of mass distribution around the rotation axis of the knife, it can be achieved that the centrifugal force present during rotation generates a momentum which brings back the knife to rest position. The range of movement at both ends can be limited by means of mechanical stops. The advantages of the device as per the invention are given by the constant rotation speed of the knife holder 2 and the low power that is required for moving the knife, • The constant rotation speed of the knife holder 2 can be selected higher in the device as per the invention, than in the case of the already described known arrangement. • The times for acceleration and retardation of the knife disc are not required. • The light knife in the device as per the invention can be moved very quickly. • The ring magnet can swing several knives simultaneously into the cutting position. In all, a significantly higher cutting frequency is thereby possible, than in the case of the described known arrangement. Rotating device for quick cutting of levels, which are fed as an endless loop Figure 1 (For figure see original) Section A - B WE CLAIM 1. Device for defined cutting of labels which are fed as endless loop, consisting of a rotating disc with one or several knives, which can be respectively moved between rest position and a cutting position, in which each knife is connected to part made of light-magnetic substance and one or several electro-magnets are arranged around the rotating cutting disc, which exercise forces on the soft-iron parts connected to the knives and can thus move the knives 2 Device as per claim 1, in which a concentric ring made of light-magnetic material is arranged around the cutting disc as electro-magnet, which has a spoof in its U-shaped cross- section 3. Device as per claim 1, in which the knives are moved into cutting position on account of the magnetic force generated by the current-conducting electro-magnets. 4. Device as per claim 1, in which when there is no current in the electro-magnets, the knives are moved back into rest position by a spring 5. Device as per claim 1, in which when there is no current in the electro-magnets, the knives are moved back into rest position on account of the cenrifugal force. 6. Device as per claim 1. in which the cutting disc rotates with constant rotation speed The invention comprises of a device for defined cutting of labels which are fed as endless loop. It consists of a disc (2) rotating at constant rotating speed, with one or several knives (5) which can be moved between a rest position and a cutting position. Each knife (5) is connected with a part made of soft magnetic material and several electromagnets are arranged around the rotating cutting disc (2), which can exercise forces on the soft iron parts connected to the knives (5) and thus can move the knives (5) between are rest position and a cutting position. The knives are brought back to the initial position either by a spring (4) or by the centrifugal force.

Documents:

96-kol-2004-granted-abstract.pdf

96-kol-2004-granted-claims.pdf

96-kol-2004-granted-correspondence.pdf

96-kol-2004-granted-description (complete).pdf

96-kol-2004-granted-drawings.pdf

96-kol-2004-granted-examination report.pdf

96-kol-2004-granted-form 1.pdf

96-kol-2004-granted-form 18.pdf

96-kol-2004-granted-form 2.pdf

96-kol-2004-granted-form 26.pdf

96-kol-2004-granted-form 3.pdf

96-kol-2004-granted-form 5.pdf

96-kol-2004-granted-priority document.pdf

96-kol-2004-granted-reply to examination report.pdf

96-kol-2004-granted-translated copy of priority document.pdf