WO2005120996A1

WO2005120996A1 - Roll drive arm for converting and slitting machine

Info

Publication number: WO2005120996A1
Application number: PCT/GB2005/050088
Authority: WO
Inventors: Lee Fenney; Arthur Chilcott; Adrian Hazelwood
Original assignee: Tibble, Mary
Priority date: 2004-06-12
Filing date: 2005-06-13
Publication date: 2005-12-22
Also published as: GB0413125D0

Abstract

A roll drive arm for a converting and slitting machine comprises a hollow body (1) carrying in an upper part thereof a rotatable support (7) for supporting one end of a roll, the body enclosing an electric motor (3, 4) and transmission means (6) operatively linking the motor to the rotatable support.

Description

Description ROLL DRIVE ARM FOR CONVERTING AND SLITTING MACHINE Technical Field

[001] This invention relates to a roll drive arm for use with a converting and slitting machine for converting wide rolls of flexible sheet material into narrower rolls, and to a machine incorporating such roll drive arms. Background Art

[002] Converting and slitting machines are used to convert wide rolls of flexible sheet material, such as paper, plastics film, card or aluminium foil, into narrower rolls, for example for further processing or for retail sale. This is achieved by unwinding the wide roll of material, passing it across one or more fixed knives to slit it along its length, and then rewinding the material on to multiple narrower rolls. Each roll is mounted between two drive arms, either or both of which have electric motors mounted on them and mechanical transmission systems to couple the motors to the rolls to rotate them. A controller and drive circuit are used to power and control the motors so that the motions of all the rolls are synchronised.

[003] Such drive arms have two characteristics that significantly limit the performance of the machine: 1. The pitch, or thickness, of the arm. This is the distance from the edge of the driven product roll to the opposing end face of the complete drive arm assembly. This defines the minimum distance apart that the rolls can be mounted, since the rolls must be separated by two arm assemblies. A small pitch, or thickness, allows additional rolls of material to be converted on the same machine bed. 2. The asymmetry of the coupling between the roll and the arm. Rolls of material can only be mounted on one side of the arm, which restricts the operational flexibility of the machine because separate left- or right-handed arms must be used.

[004] An object of this invention is to provide a roll drive arm with a very small pitch and a symmetrical roll coupling, allowing more product rolls to be mounted linearly on each machine bed and eliminating the need for left- and right-handed arms. Disclosure of Invention

[005] Accordingly, this invention provides a roll drive arm for a converting and slitting machine, the arm comprising a hollow body carrying in an upper part thereof a rotatable support for supporting one end of a roll, the body enclosing an electric motor and transmission means operatively linking the motor to the rotatable support.

[006] The body preferably comprises an integrally-formed internal moulding which conforms closely with a substantial part of the external shape of the motor, to ensure efficient transfer of waste heat from the motor to the body, and from there to the surrounding air, in order to stabilise the motor temperature.

[007] Preferably the body of the arm is made of metal, for example aluminium or an aluminium alloy, to maximise heat conduction from the motor within it, but it may instead be made from plastic or polymer material, or from a combination of these materials.

[008] The transmission means may comprise a chain, or preferably a belt, with the motor being set with its shaft parallel to the roll axis in use. Alternatively, the transmission means may be a gear drive, permitting the motor to be set with its shaft substantially normal to the roll axis, if desired.

[009] The rotatable support is preferably arranged to be accessible to support a roll on two opposed sides of the body.

[010] The electric motor is preferably an AC servo motor.

[011] The invention also provides a converting and slitting machine for converting wide rolls of flexible sheet material into narrower rolls, comprising a support for a roll of material to be slit, a plurality of roll drive arms according to the invention, and slitting knives between the support and the roll drive arms for slitting the material.

[012] The narrow form of the roll drive arms permits converting and slitting machines incorporating them to operate more efficiently, with more product rolls across the width of the machine and less wastage of material. Larger diameter product rolls could be accommodated, because the projecting motors are eliminated. Brief Description of the Drawings

[013] In the drawings, which illustrate exemplary embodiments of the invention:

[014] Figure 1 shows an external perspective view of the assembled drive arm according to one embodiment of the invention; [015] Figure 2 is an exploded perspective view of the arm shown in Figure 1, illustrating the internal elements of the drive arm, including the motor, the mechanical transmission system and the two roll couplings; [016] Figure 3 shows an external perspective view of the drive arm according to a second embodiment of the invention; and [017] Figure 4 is an exploded perspective view of the drive arm illustrated in Figure 3, illustrating the elements of the drive motor, the mechanical transmission system and the two roll couplings. Best Mode for Carrying Out the Invention [018] Referring first to Figure 1, the drive arm consists of a hollow body or outer framework 1 which is to be mounted onto the converting machine. The framework has a roll coupling 2 at its upper end, extending through the body so as to allow the product roll to be mounted on either side of the arm. It will be seen that the body has no external projections, the motor being mounted wholly within the body, as may be seen from Figure 2, which shows that the electric drive motor, consisting of rotor 3 and stator 4, is mounted inside the body 1, with cooling fins mounted around the outside of the stator 4 contacting the inside of inner motor casing 4a so as to transmit heat via the casing 4a to the hollow body, which serves as a heat sink, maintaining the operating temperature of the motor within acceptable limits. The rotor is held in place by bearings 5 and is coupled at its upper end to a bevel gear 6. The bevel gear is coupled to a pinion shaft 7 inside a symmetrical roll coupling housing 8, on which the roll of product is to be mounted. Applying electrical power to the motor causes it to rotate. This rotation is transmitted through the bevel gear to the pinion shaft, causing the roll of product to rotate with the motor.

[019] Referring to Figures 3 and 4, a second embodiment of the invention will now be described in which the drive motor is mounted parallel to the roll of material and an alternative mechanical transmission system configuration is employed. In this configuration, as shown in Figure 3, this drive arm configuration also consists of a hollow body or outer framework 21 which is to be mounted onto the converting machine, with a roll coupling 22 at its upper end, allowing the product roll to be mounted on either side of the arm.

[020] Figure 4 shows that the drive arm motor 23 is mounted inside the outer framework parallel to a pinion shaft 27, and hence parallel to the product roll. The motor 23 is held in place in a closely-conforming enclosure 24, moulded into the body 21, by bearings 25 mounted in motor carrier plates 26 and is coupled to a set of reduction gears 29. The output of the reduction gears is coupled to a pulley 30 for a drive belt 31. The drive belt drives a second pulley 32 connected to the pinion shaft 27 inside the symmetrical roll coupling housing 28. The roll of product is mounted on the roll couplings 22 at the ends of the pinion 27.

[021] The enclosure 24 serves to transmit waste heat from the motor to the casing or body 21, permitting it to act as a heat sink for the motor to maintain a satisfactory working temperature. The heat is conducted through the body and is dissipated therefrom to the environment by a combination of radiation and heat transfer to air surrounding the body.

[022] Applying electrical power to the motor 23 causes it to rotate. This rotation is transmitted through the reduction gears 29 to the drive pulley 30 and the drive belt 31. This causes the upper drive pulley 32 and the pinion shaft 27 to rotate, causing the roll of product to rotate with the motor. Embedding the drive motor within an outer framework 21 allows the arm to be constructed with a small pitch dimension. The roll couplings allow the roll of material to be mounted on either side of the arm.

Claims

[001] A roll drive arm for a converting and slitting machine, the arm comprising a hollow body carrying in an upper part thereof a rotatable support for supporting one end of a roll, the body enclosing an electric motor and transmission means operatively linking the motor to the rotatable support.

[002] A roll drive arm according to Claim 1, wherein the body is formed from a heat conductive material and the motor is mounted within the body in such a manner that heat is conducted away from the motor by the body.

[003] A roll drive arm according to Claim 2, wherein the body comprises an integrally- formed internal moulding which conforms closely with a substantial part of the external shape of the motor.

[004] A roll drive arm according to Claim 2 or 3, wherein the body is formed of aluminium or an alloy thereof.

[005] A roll drive arm according to any of Claims 1 to 4, wherein the transmission means comprises a belt or chain.

[006] A roll drive arm according to Claim 5, wherein the motor is arranged with the drive shaft thereof parallel to the axis of rotation of the rotatable support.

[007] A roll drive arm according to any of Claims 1 to 4, wherein the transmission means comprises a gear drive.

[008] A roll drive arm according to Claim 7, wherein the motor is arranged with the drive shaft thereof normal to the axis of rotation of the rotatable support.

[009] A roll drive arm according to any preceding claim, wherein the rotatable support is accessible to support a roll on two opposed sides of the body.

[010] A roll drive arm according to any preceding claim, wherein the electric motor is an AC servo motor.

[011] A converting and slitting machine for converting wide rolls of flexible sheet material into narrower rolls, comprising a support for a roll of material to be slit, a plurality of roll drive arms according to any preceding claim, and slitting knives between the support and the roll drive arms for slitting the material.