GB2071062A

GB2071062A - Conveying webs intermittently through transverse bias cutter

Info

Publication number: GB2071062A
Application number: GB8103601A
Authority: GB
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1980-02-09
Filing date: 1981-02-05
Publication date: 1981-09-16
Also published as: GB2071062B; FR2475512B3; BE887435A; FR2475512A1; DE3004894A1; DE3004894C2

Abstract

Web feed conveyor (1) reciprocates to open and close a bias cutting gap, which is occupied during the bias cutting process by the raisable and lowerable cutting support (3). The leading cut edge of the web is thereby prevented from entering the cutting gap between the feed conveyor (1) and the delivery conveyor (2). Vertically reciprocable clamps (4) hold the web during cutting. Conveyor (1) is reciprocated following engagement of clamp (14) on endless toothed belt (13). The apparatus is especially useful for cutting to length and supplying ply strips for pneumatic tyres. <IMAGE>

Description

SPECIFICATION Apparatus for separating plastically deformable fabric webs into individual sections The present invention relates to an apparatus for separating plastically deformable fabric webs into individual sections, comprising a feed conveyor and a delivery conveyor having a cutting device located therebetween, the cutting device extending over the width of the web and having a cutting blade which is displaceable relative to a cutting support and holding down members for the webs, more especially for cutting to length and supplying ply strips for pneumatic tyres to tyre building machines.

An important place within the framework of overall manufacture of, for example, pneumatic tyres, is occupied by the conveyor devices connected directly in front of the building drums for the rubberized reinforcing fabrics and other ply elements, together with the associated cutting devices, sincetheirfunction and mode of operation substantially determine the final state of the plies which are sensitive to mechanical influences on account of their plasticity, and hence also the quality of the finished tyre.The absolute requirement of careful handling or treatment of the plastically deformable material to be conveyed heretofore limited the general attempts made for possible extensive mechanisation of the conveying and cutting process, whereby the particular problem arose from the satisfactory, smooth transfer of the severed web sections or portions beyond the cutting gap without the risk of tipping and dipping of the leading cut edge into the gap, resulting in harmful distortions and displacements within the ply structure.

It is an object of the invention to at least minimise this problem and to provide the conditions of ensuring a satisfactory result by dispensing with manual incursions in the working cycle. In no way is the invention limited only to feed devices fortyre building machines; it also includes, moreover, the use in other technical fields in combination with intermittent conveying of relatively thin web-shaped articles such as, for example, webs of paper, plastic sheeting and the like.

According to the present invention there is provided apparatus for separating plastically deformable fabric webs into individual sections comprising a feed conveyor and a delivery conveyor having a cutting device located therebetween, the cutting device extending over the width of the web and having a cutting blade which is displaceable relative to a cutting support, and holding down members for the web, more especially for cutting to length and supplying ply strips for pneumatic tyres to tyre building machines, in which the feed conveyor for forming and closing a cutting gap, which is occupied during the cutting process by the raisable and lowerable cutting support, is adapted to be reciprocated relative to the delivery conveyor in synchronism with the supported fabric web.

In accordance with a preferred feature of the invention the feed conveyor is adapted to be driven, via a formlocking, preferably magnetically actuated, engageable and disengageable coupling or clutch, by the delivery conveyor in synchronism therewith.

When the feed conveyor is formed as a conveyor belt having an endless or a plurality of parallel traction means, in a preferred embodiment of the invention, means are fixedly mounted on the device for arresting the upper belt section during the reciprocating movement of the feed conveyor, whereby arresting or stopping means in the form of a clamp having a mutually adjustable looping drive are mounted either in the closing state of the upper belt section directly on an edge portion, or indirectly outside the conveying surface of the fabric web parallel to the feed conveyor and constantly coupled formlocking therewith, and having clamping jaws clamped around the endless belt. The arresting means are preferably electro-magnetically actuated in such a manner with mutual effectthat they are switched on in the disengaged state of the clutch or coupling.

The invention leads to a combined conveying and cutting device which on the one hand permits the desired separating cuts to be carried out transversely or diagonally over the whole width of the web in usual manner against the required cutting base or support located between the two conveyors, whilst on the other hand bridging the gap by periodically forwardly advancing the feed conveyor to pass the subsequent web section over a substantially closed conveyor surface through the cutting device. Any risk of the advancing leading edge striking against the edges of the gap is therefore impossible and, since the displacement movements of the feed conveyor are controlled in both directions in complete accordance with the movement state of the supported fabric web, this is not subjected to any mechanical influence whatsoever.By this means the web sections cut to length may be supplied, without displacement or distortion and in a satisfactory state, through the region of the cutting device and to the subsequently arranged building drum or any other processing position. The individual operating steps and movement cycles may be initiated by means of elements known in regulating and control technology, e.g. limit switches, photoelectric cells or the iike in mutual dependency, so that any manual interference is unnecessary.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawing, in which the single Figure schematically shows in plan view, the essential parts of a feed device for a tyre building machine.

The apparatus shown in the drawing comprises a feed conveyor 1 and a delivery or transfer conveyor 2 having a cutting device, including a cutting support 3, two holding down members 4 and a cutting blade, not shown further, arranged therebetween. The conveyors 1 and 2 are each assembled as endless conveyor belts from four individual belts 11 and 12 respectively, passed parallel to one another over guide rollers, whereby the effective conveying lengths of the belts are mutually stepped such that, in the cutting position shown, as a whole they form a diagonal gap corresponding to the angle of cut desired.The guide rollers leading in the direction of conveying of the delivery conveyor 2 are mounted on a common drive shaft 5 which is driven by a motor, not shown, and via a toothed belt 6, a chain or other appropriate driving means and a magnetic tooth coupling 7, having a cardanically connected telescopic shaft 8, acts on the common drive shaft 9 of the rear guide rollers of the feed conveyor 1. Thus, in the engaged state of the coupling 7, the two conveyors 1 and 2 are driven in the same direction and at the same conveying speed.

The rigid cutting base or support 3, adapted in contour to the stepped shape of the cutting gap, is vertically reciprocatable in the opposite direction to the holding down members 4. In its upper position of use, it is at the level of the conveyors 1 and 2 and almost fills the gap formed therebetween to present counter pressure to the cutting blade travelling downwards and being conducted over the width of the web. The simultaneously downwardly lowered holding down members 4 clamp the fabric web 10 during the cutting process, particularly in the endangered edge regions, securely against the base or support 3 to ensure a clean, straight cut.

An additional looping drive, in the shape of an endless toothed belt 13 passed over toothed discs, is provided parallel to the feed conveyor 1 and with lateral spacing therefrom. The rear toothed disc 15, acting as a driving disc, is non-rotatably mounted on the drive shaft 9 of the feed conveyor 1, so that the toothed belt 13 is driven constantly in synchronism with the individual belts 11 and in turn reacts formlocking thereon. The upper section of the toothed belt 13 is enclosed by a twin jaw clamp 14 electro-pneumatically actuated and fixedly mounted on the apparatus, whereby the arrangement is such that the toothed belt 13, depending upon the state of engagement of the magnetic tooth coupling 7, may be alternately securely clamped and released.

The fabric web 10 is supplied to the apparatus in the direction of the arrow I. Assuming that in the situation illustrated the drive (shaft 5) is cut off, a separating cut is carried out over the stationary fabric web. Whilst upon actuation of the subsequently tripped impulse whereby the cutting support 3 is lowered and the holding down member 4 is raised, the coupling is disengaged, so that with the restarting of the delivery or transfer conveyor 2 alone, the severed web section 10a is progressively conveyed.

Whilst the clamp 14 closes over the upper section of the toothed belt 13, the feed conveyor 1, subject to the action of lifting cylinders, not shown, advances relative to the delivery conveyor 2 until almost completely bridging the cutting gap exposed by the cutting support 3 and then comes to a halt. The individual belts 11 in the course of this movement, due to the formlocking connection with the clamp 14 are retained relative to the supported leading end section of the fabric web 10. Only after reaching its front end position is the coupling 7 engaged with simultaneous release of the clamp 14, and the feed conveyor supplies the subsequent web section over the closed cutting gap to the delivery conveyor 2.

When the fabric web 10 has been advanced by the desired linear measure, the conveyor drive at the shaft 5 is shut down. Whilst simultaneously engaging clamp 14 and disengaging coupling 7, the feed conveyor 1 - again with reference to the supported fabric web at rest - returns into the cutting position shown, and with the cutting support 3 moving upwards and simultaneous lowering of the holding down member 4 a new separating cut is instigated.

Claims

1. Apparatus for separating plastically deformable fabric webs into individual sections comprising a feed conveyor and a delivery conveyor having a cutting device located therebetween the cutting device extending over the width oftheweb and having a cutting blade which is displaceable relative to a cutting support, and holding down members for the web, more especially for cutting to length and supplying ply strips for pneumatic tyres to tyre building machines, in which the feed conveyor for forming and closing a cutting gap, which is occupied during the cutting process by the raisable and lowerable cutting support, is adapted to be reciprocated relative to the delivery conveyor in synchronism with the supported fabric web.

2. Apparatus as claimed in claim 1, in which the feed conveyor, by means of a formlocking engageable and disengageable coupling, is adapted to be driven by the delivery conveyor in synchronism therewith.

3. Apparatus as claimed in claim 2, in which the engageable and disengageable coupling is a magnetically actuated coupling.

4. Apparatus as claimed in claim 1, 2 or 3, in which the feed conveyor belt is formed by a plurality of parallel endless traction means, and including means fixedly mounted on the apparatus for arresting or stopping the upper belt section during the reciprocating movement of the delivery conveyor.

5. Apparatus as claimed in claim 4, in which the arresting or stopping means are formed in the manner of a clamp having clamping jaws which are mutually adjustable and which, in the closed position, clamp an edge portion of the upper section of the belt.

6. Apparatus as claimed in claim 4 or 5, in which the arresting or stopping means is electromagnetically or electro-pneumatically actuated and is switched on in the disengaged state of the coupling.

7. Apparatus as claimed in claim 4,5 or 6, in which a looping drive is mounted outside the conveying surface of the fabric web parallel to the feed conveyor and constantly coupled in formiocking manner therewith and provided with an endless belt, the upper section of which is in operational engagement with the arresting or stop means.

8. Apparatus as claimed in claim 7, in which the endless belt is a toothed belt.

9. Apparatus for separating plastically deformable fabric webs into individual sections substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.