GB2135928A

GB2135928A - Case-making machinery

Info

Publication number: GB2135928A
Application number: GB08305363A
Authority: GB
Inventors: John Arthur Moss; Keith Antony Mander
Original assignee: CORRTRONIC
Current assignee: CORRTRONIC
Priority date: 1983-02-25
Filing date: 1983-02-25
Publication date: 1984-09-12
Also published as: GB2135928B; GB8305363D0

Abstract

A rotary shear comprising a shaft (10) carrying a cut-off knife (12) driven by a reversible electric motor (16) adapted to accelerate the knife from a parked position to sever board over an arc of some 270 DEG or so to decelerate the knife over the same arc after cutting the board and to drive the knife in reverse direction to its initial parked position in readiness for the next cutting cycle. <IMAGE>

Description

SPECIFICATION Case-making machinery This invention concerns case-making machinery and more particularly the rotary shear customarily provided between the machinery provided for the production of corrugated paper board and the machinery provided for conversion of that board into formed but collapsed cases, and which is adapted to sever the corrugated board whenever there is an order change to enable a change of slitter-scorer heads and so on to be effected. Such a rotary shear will be referred to hereinafter as a rotary shear of the kind referred to.

One known kind of rotary shear of the kind referred to comprises upper and lower shafts carrying cutting knives which can be brought to board travel speed gradually and well in advance of each cutting operation and arranged above and below the path of board travel respectively and adapted to be closed against the travelling board by means of hydraulic or pneumatic actuators. Such a shear is generally of heavy construction and very costly.

Another known kind of rotary shear of the kind referred to comprises upper and lower shafts disposed in fixed positions above and below the path of board travel and carrying a knife and anvil respectively. With this kind of shear, the knife will normally be parked in a position disposed 1800 from the travelling board. Motor means is provided to rotate the shaft and accelerate the knife to board speed through an arc of some 1800 and brake itto its initial position again through an arc of some 1800. In a typical installation a motor of 22 kw power is required for this operation.

The present invention is based on an appreciation of the possibility of utilising the whole of the arc available from the position of knife engagement and disengagement with and from the path of board travel for acceleration and braking thus requiring a motor of greatly reduced power.

According to the present invention there is provided a rotary shear of the kind referred to comprising a rotatable shaft carrying a cut-off knife adapted to be parked at a position just clear of the path of board travel in the downstream direction thereof, means for accelerating the shaft and hence the knife to strike the board at a position upstream from said parked position to sever the board, means to decelerate the shaft and knife after severing the board to bring it to rest at a position just clear of the path of board travel in the upstream direction and means to drive the shaft and hence knife in the reverse direction to return it to said parked position.

The invention will be further apparent from the following description, with reference to and as illustrated by the several Figures of the accompanying drawing, which show, by way of example only one form of rotary shear embodying the invention.

Of the drawing:- Figure 1 shows an end elevation of the rotary shear; Figure 2 shows a cross-section through the upper shaft of the shear of Figure 1 illustrating diagrammatically the knife movements effected in accordance with the invention; and Figure 3 shows a cross-section similar to that of Figure 2 but illustrating prior art knife movements forthe purpose of comparison.

Referring now to the drawing, and more particularly Figure 1, it will be seen that the rotary shear comprises, in known manner, upper and lower shafts 10 and 11 carrying a cut-off knife 12 and anvil 13 respectively and connected by gears 14 and 15 driven by a motor 16 through a reduction gear box 17.

Turning now to Figure 3, it will be seen that in the prior art arrangement the knife 12 is normally parked diametrically opposite the path of board travel.

When it is desired to sever the board B the motor 16 is required to accelerate the knife 12 from rest to the speed of board travel over the arc P, an angular displacement which is somewhat less than 1800 and to decelerate the knife from the speed of board travel over the arc Q, again an angular displacement somewhat less than 1800. These requirements necessitate an extremely powerful motor 16 typically one of22 kw.

Turning now to Figure 2 it will be seen that in accordance with the invention the knife 12 is normally parked just clear of the path of board travel on the downstream side of the shaft 10. When it is desired to sever the board B the motor 16 operates to accelerate the knife from rest to the speed of board travel over the arc R, an angular displacement of some 270". The knife 12 is decelerated over the same arc R after severing the board to come to rest at a position shown in dotted lines just clear of the path of board travel on the upstream side of the shaft 10.

The direction of rotation of the shaft 10 is then reversed to return the knife 12 to its initial parked position in readiness for the next cutting cycle.

In this way the power of the motor 16 can be reduced to 9 kw or so or even 4.5 kw as overheating can be tolerated in view of the substantial intervals of time which can be expected between successive cutting operations.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope therof as defined by the appended claims.

1. A rotary shear of the kind referred to comprising a rotary shear of the kind referred to comprising a rotatable shaft carrying a cut-off knife adapted to be parked at a position just clear of the path of board travel in the downstream direction thereof, means for accelerating the shaft and hence the knife to strike the board at a position upstream from said parked position to sever the board, means to decelerate the shaft and knife after severing the board to bring it to rest at a position just clear of the path of board travel the upstream direction and means to drive the shaft and hence knife in the reverse direction to return itto said parked position.

2. A rotary shear according to claim 1, wherein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Case-making machinery This invention concerns case-making machinery and more particularly the rotary shear customarily provided between the machinery provided for the production of corrugated paper board and the machinery provided for conversion of that board into formed but collapsed cases, and which is adapted to sever the corrugated board whenever there is an order change to enable a change of slitter-scorer heads and so on to be effected. Such a rotary shear will be referred to hereinafter as a rotary shear of the kind referred to. One known kind of rotary shear of the kind referred to comprises upper and lower shafts carrying cutting knives which can be brought to board travel speed gradually and well in advance of each cutting operation and arranged above and below the path of board travel respectively and adapted to be closed against the travelling board by means of hydraulic or pneumatic actuators. Such a shear is generally of heavy construction and very costly. Another known kind of rotary shear of the kind referred to comprises upper and lower shafts disposed in fixed positions above and below the path of board travel and carrying a knife and anvil respectively. With this kind of shear, the knife will normally be parked in a position disposed 1800 from the travelling board. Motor means is provided to rotate the shaft and accelerate the knife to board speed through an arc of some 1800 and brake itto its initial position again through an arc of some 1800. In a typical installation a motor of 22 kw power is required for this operation. The present invention is based on an appreciation of the possibility of utilising the whole of the arc available from the position of knife engagement and disengagement with and from the path of board travel for acceleration and braking thus requiring a motor of greatly reduced power. According to the present invention there is provided a rotary shear of the kind referred to comprising a rotatable shaft carrying a cut-off knife adapted to be parked at a position just clear of the path of board travel in the downstream direction thereof, means for accelerating the shaft and hence the knife to strike the board at a position upstream from said parked position to sever the board, means to decelerate the shaft and knife after severing the board to bring it to rest at a position just clear of the path of board travel in the upstream direction and means to drive the shaft and hence knife in the reverse direction to return it to said parked position. The invention will be further apparent from the following description, with reference to and as illustrated by the several Figures of the accompanying drawing, which show, by way of example only one form of rotary shear embodying the invention. Of the drawing:- Figure 1 shows an end elevation of the rotary shear; Figure 2 shows a cross-section through the upper shaft of the shear of Figure 1 illustrating diagrammatically the knife movements effected in accordance with the invention; and Figure 3 shows a cross-section similar to that of Figure 2 but illustrating prior art knife movements forthe purpose of comparison. Referring now to the drawing, and more particularly Figure 1, it will be seen that the rotary shear comprises, in known manner, upper and lower shafts 10 and 11 carrying a cut-off knife 12 and anvil 13 respectively and connected by gears 14 and 15 driven by a motor 16 through a reduction gear box 17. Turning now to Figure 3, it will be seen that in the prior art arrangement the knife 12 is normally parked diametrically opposite the path of board travel. When it is desired to sever the board B the motor 16 is required to accelerate the knife 12 from rest to the speed of board travel over the arc P, an angular displacement which is somewhat less than 1800 and to decelerate the knife from the speed of board travel over the arc Q, again an angular displacement somewhat less than 1800. These requirements necessitate an extremely powerful motor 16 typically one of22 kw. Turning now to Figure 2 it will be seen that in accordance with the invention the knife 12 is normally parked just clear of the path of board travel on the downstream side of the shaft 10. When it is desired to sever the board B the motor 16 operates to accelerate the knife from rest to the speed of board travel over the arc R, an angular displacement of some 270". The knife 12 is decelerated over the same arc R after severing the board to come to rest at a position shown in dotted lines just clear of the path of board travel on the upstream side of the shaft 10. The direction of rotation of the shaft 10 is then reversed to return the knife 12 to its initial parked position in readiness for the next cutting cycle. In this way the power of the motor 16 can be reduced to 9 kw or so or even 4.5 kw as overheating can be tolerated in view of the substantial intervals of time which can be expected between successive cutting operations. It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope therof as defined by the appended claims. CLAIMS

2. A rotary shear according to claim 1, wherein said means for accelerating and decelerating said shaft comprises a reversible electric motor.

3. A rotary shear according to claim 2, wherein said electric motor is drivingly connected to said shaft through a reduction gear box.

4. A rotary shear according to claim 2 or claim 3, wherein said motor has a power not exceeding 9kw.

5. A rotary shear according to claim 4, wherein said motor has a power not exceeding 4.5 kw.

6. A rotary shear of the kind referred to constructed and adapted to operate substantially as described herein with reference to and as illustrated by Figures 1 and 2 of the accompanying drawing.