US2768690A - Severing means in web feeding machines - Google Patents

Description

1956 G. R. ROBERTS ET AL 2,7 ,6

SEVERING MEANS IN WEB FEEDING MACHINES Filed July 6, 1954 5 Sheets-Sheet l g a s Q66 4; i W W 0 MM W Oct. 30, 1956 G. R. ROBERTS ET AL 2,7

SEVERING MEANS IN was FEEDING MACHINES Filed July 6, 1954 a Sheets-Sheet 2 %6ML7QM 33% Wm m Oct. 30, 1956 G. R. ROBERTS El'AL 2,768,590 7 SEVERING MEANS IN WEB FEEDING MACHINES Filed July 6, 1954 3 Sheets-Sheet 3 United States Patent SEVERING MEANS 1N WEB FEEDING MACHINES George Richard Roberts, New Barn, Longfield, Kent, Ronald Thomas Heathcote, Dartford, Kent, and Ernest James Lister, Orpington, Kent, England, assignors to Bowaters Development and Research Limited, London, England, a company of Great Britain Application July ti, 1954, Serial No. 441,497

Claims priority, application Great Britain July 14, 195B 14 Claims. (Cl. 164-4 8) This invention comprises improvements in web feeding machines wherein the Web is drawn from a supply and is cutinto pre-determined lengths by a pair of rotary shearing drums.

It is known to incorporate in web feeding machines a pair of rotary shearing drums equipped with resilient segments on their surfaces so that the web is gripped during the cutting operation.

The object of this invention is to provide an improved control of the cutting operation and of the continued web feeding after cutting has taken place.

According to the invention, in a web feeding machine comprising means for drawing the web from a supply and a pair of co-operating rotary shearing drums between which the Web passes .in the course of its travel and by which it is cut when a predetermined length ha passed, the rotary shearing drums and the actuating means therefor are so arranged that the Web has normally free passage between the drums, but when the web is to be cut the drums are displaced out of their normal disposition to grip the web and to be rotated thereby until the web is cut, a positive drive being then applied to the drums to feed forward the web behind the cut for engagement with the web drawing means, after which feeding operation the drums are restored to their normal disposition.

The actuating means for the drums are preferably such as to produce a rotary displacement, the drum surfaces being such that portions thereof are brought together to grip and cut the web when said displacement is effected. These portions of the drum may be elements hinged about axes parallel to the drum axes and spring-urged outwardly.

A spring loaded member may be provided to actuate the rotary displacement of the drums, means being provided for automatically releasing the spring loaded member when the predetermined length of web has passed between the drums. Thus, for example, the two drums are geared together and the spring loading operates on a toothed rack which co-acts with a toothed quadrant fixed to one drum.

The aforesaid positive drive may be applied to the drums by a driving motor connected to the drums through engageable and disengageable unidirectional transmission elements adapted to be automatically put into engagement when the Web is cut, the motor being adapted to drive the drums at a speed substantially lower than that due to the draw of the web before the cutting takes place.

Means may be provided for reducing the take-off of the web from a supply when the drums are rotating at the lower speed. These means preferably comprise a roll about which the web is entrained and which is displaceable according to the tension of the web, and brake means acting at the web supply and actuated by displacement of said roll.

The present invention may be used in a convolute drum winder comprising the features described in any of our co-pending applications Serial Nos. 441,452 and 441,495, filed July 6, 1954.

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An embodiment of the invention as applied to a convolute drum winder will now be described with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic side elevation of a convolute drum winder;

Figure 2 is a detail of part of Figure 1 on a larger scale and in vertical section and Figure 3 is a schematic diagram of the drum winder shown in Figure 1 diagrammatically represented.

Referring now to Figure 1 a web of paper W in its normal course of travel is drawn from an unwinding reel 1, over a fixed roll 2, a compensator roll 3 and a further [fixed roll 4; thence between guillotine drums 5 and 6 and over a glue roll 7 to a winding mandrel 8. The web W is maintained in contact with the glue roll by a pressure bar 9.

The compensator roll 3 is rotatably mounted on an arm 10 pivoted to the machine frame (not shown) at 11. An extension 12 of the arm 10 is pivotally connected at 13 to a rod 14, the other end of which is pivotally connected at 15 to a bell crank 16. The latter is pivoted to the machine frame at 17. A tension spring 18 is connected to the arm 10 on one end and anchored to the machine frame at the other.

The unwinding reel 1 is provided with a brake band 19 anchored at one end 20 and connected at the other end 21 to a pivoted arm 22. The end 23 of the latter is pivotally connected to a rod 24 provided with a fixed collar 25.

Referring now to Figure 2 the construction of each of the guillotine drums 5 and 6 is generally similar, and although for clarity some parts are shown only on one drum, they are common to both with the exception of the knives as will hereinafter be described. The structure of each drum comprises a plurality of polygonal frames 26 spaced along the length of the drum. The structure also comprises a channelled member 27 in which is secured an angle bracket 28 for the mounting of a knife 29 or 30. The knife 30 is bolted directly to the angle bracket 28 and is set with it cutting edge along a line parallel to the axis of the drum.

The length of the knife 29 is in two halves set slightly divergently from one another so that their junction in the middle is a little behind a line, parallel to the axis of the drum, joining their outer ends. The setting of this knife is controlled by bolts 31 and lock nuts 32.

The mandrel 3 is rotated by a shaft 79 which may be driven by any suitable means (not shown). A bevel gear wheel is carried by the shaft 79 and meshes with another bevelled gear wheel 81 mounted on the end of a shaft 82. The shaft 82 extends into a switch box 83 and carries two earns 84 and 35. The cam 84 is adapted to trip a counter mechanism (not shown) connected to a selector switch 86, and the cam is adapted to actuate a switch (not shown) to close an electrical circuit between the selector 86 and solenoid 78. An electrical source 87 is connected to the selector 86 and solenoid 78. The selector switch 86 is of the type which may be pre-set by hand, such that after a predetermined number of operations of the counter mechanism, the switch is made to close an electrical circuit or part of an electrical circuit.

Two portions 33 and 34 of the drums shellsare pivoted at 35 and 36 respectively to the structure frames 26. These portions are biassed away from the drum centre by springs, one of which is shown at 37. This is mounted in a sleeve 38 having a cap 39 engaging a cradle 40 carried on the pivoted portion 33. The position of the spring 37 may be adjusted by a threaded pin 41 passing through a yoke piece 42, keyed to the shaft 43 of the drum. Also carried by the yoke piece 42 is a rod 44 pivotally connected at 45 to the pivoted portion 33, the

3 rod being threaded at its other end to receive a lock nut 46 serving to limit the outward position of the pivoted portion 33.

The remainder of the drum shell comprises segments 47 bolted tothe frames 26 and all but a segment 48 is covered with a layer of rubber 49.

Returning now to Figure 1 the rotary shearing drums are geared together and are driven from a motor 50 through a worm 51 on a shaft 52. Meshing with the worm 51 is a worm wheel 53, connected to a ratchet wheel 54, both being free on the shaft 55 of the rotary shearing drum 6. Keyed to the shaft 55 is a plate 56 which on one side carries a pivoted lever 57 and on .its other side a pawl 58 connected to the lever. The plate 56 is also provided with a recess 59 engageable by a spring loaded catch 68. A cam plate 61 is fixed to the frame of the machine and so arranged that it forms a riding surface 'for the lever 57.

The rotary shearing drum is fixed to its shaft 43, and freely mounted on this shaft is a disc formed with a toothed segment 62 and provided with a notch 63. Keyed to the shaft 43 is a cam plate 64 having a cam surface 65 and carrying a catch 66.

Fixed to the machine frame above the rotary shearing drum 5 is a toothed rack 67 carried in a closed guide 68 and an open guide 69. A compression spring 70 is provided between one end of the toothed rack and the closed end of the guide 68; fixed to the rack 67 is a collar 71 provided with two pegs, one of which is shown at 72. A yoke piece 73 is pivoted to the frame of the machine at 74, its end 75 being in contact with the pegs 72 and the other end carrying a roller 76. A pivoted catch 77 is provided adapted to engage the collar 71 and to be controlled by a solenoid 78.

In operation, during the winding of the web W on to the mandrel 8, the components are disposed as shown in Figure l, the web W passes from the unwinding reel 1, over the fixed roll 2, around the compensator roll 3, over the fixed roll 4 and between the rotary shearing drums 5, 6, remaining out of contact therewith due to the uncovered segments 48 of their surfaces; it then passes over the glue roll 7 and on to the winding mandrel 8. The motor 50 is running and driving the worm wheel 53 and ratchet wheel 54 through the worm 51. The drums are stationary, the plate 56 .is held against displacement by the spring loaded catch 68 and the pawl 58 is free of the ratchet wheel 54.

When a predetermined length of the paper has been wound on the mandrel 8, the solenoid 78 is operated as hereinbefore described to lift the catch 77. When the catch is raised the spring 70 pushes the toothed rack 6'7 to the right. The rack engages with the toothed segment 62 and the cam plate 64 is rotated through the notch 63 and catch 66, thus rotating the drums. The spring loaded catch 60 is forced out of the detent 58 and the drums move to the extent that the hinged members 33 grip the web W. The web in its travel towards the left then rotates the drums until it is sheared by the co-operating knives 29 and 30.

That portion of the web behind the cut is gripped by the pivoted members 34 and by this time the lever 57 has cleared the bulge of the cam plate 61 so that the pawl 58 is riding on the ratchet wheel 54. A soon as the speed of rotation of the drums falls below that of the ratchet wheel 54- they will be driven by the motor 59 through the pawl 58 and the ratchet 54. By this time the catch 66 has cleared the notch 63 on the plate 62. As the drums are driven by the motor 50 they feed the uncut portion of the web W forward in preparation for a further winding.

The driving speed of rotation of the drums 5 and 6 is substantially slower than the speed of rotation when they are drawn by the web W and therefore the unwinding reel must be slowed down. As the web is cut the tension in that portion of the web behind the cut falls.

This allows the arm 10 carrying the compensator roll 3 to fall under the action of the spring 18. As it falls the bell crank 16 engages the collar 25 and so applies the brake to the unwinding reel 1 through the rod 24 and the pivoted lever 22. As soon as the unwinding reel slows down the tension in the Web will increase, the arm 1%) will rise against the tension in the spring 18 and the bell crank 16 will be moved to the position shown in Figure 1, thus releasing the brake on the unwinding reel.

As the rotary shearing drums continue to rotate the portion 65 of the cam plate 64 will engage the roller 76 and through the yoke piece 73 will push the toothed rack 67 to the left until the collar 71 is caught by the catch 77. On further rotation the lever 57 will ride on the bulge of the cam plate 61 and raise the pawl 58 from the ratchet wheel 54, and the spring loaded catch 60 will enter the detent 59 to hold the drums in the position shown in Figure 1 until the solenoid 78 is operated and the cycle repeated.

As the mandrel 8 and shaft 79 rotate, the shaft 82 and cams 84 and 85 rotate in unison therewith through the gear wheels and 81, and upon each rotation of the cam 84 it trips the counter mechanism to advance the selector switch 86 one stop. The selector switch 86 has been pre-set by hand to suit the number of revolutions of the mandrel 8 to give the required number of laminations on the drum being wound. When the selector switch 86 has reached its pre-set position, the electrical circuit from the source 87 to the switch operated by the cam i complete, so that the next time the cam 85 closes the switch associated thereto, the electrical circuit of the solenoid '78 is complete and the solenoid is thus momentarily energized. Upon the next revolution of the mandrel, the selector mechanism is advanced one stop thus disconnecting the solenoid circuit so that, when the cam 85 actuates its associated switch, the solenoid .is not energized.

What is claimed is:

l. In a web feeding machine having means for drawing said web from a supply, web severing means comprising a pair of rotatable drums between which said web passes in the course of its travel, cooperable shearing means carried by said drums for cutting said web when a predetermined length has passed, said drums normally having a disposition such that said web has free passage between said drums, actuating means for displacing said drums from their normal disposition when said web is to be cut so that they grip said web and are rotated thereby to cause said cooperable shearing means to out said web, and means for applying a positive drive to said drums for causing said drums to feed forward the portion of said web behind the cut for engagement of said portion with said web drawing means.

2. Web severing means according to claim 1 in which the displacement of said drums is rotary and in which the surfaces of said drums are such that portions thereof are brought together by rotation of said drums to grip said web when said displacement is effected.

3. Web severing means according to claim 2 in which said actuating means includes a spring loaded member, and means for automatically releasing said spring loaded member when said predetermined length of web has passed between said drums.

4. Web severing means according to claim 3 including a toothed quadrant fixed to one of said drums and a toothed rack constituting said spring loaded member and coacting with said quadrant, and means connecting said drums for conjoint rotation.

5. Web severing means according to claim 1 in which said means for applying said positive drive include a driving motor, engageable and disengageable transmission elements connecting said motor to said drums and means for automatically engaging said transmission elements when said web is cut.

6. Web severing means according to claim 5 in which the drive engagement between said transmission elements is unidirectional.

7. Web severing means according to claim 2 in which a surface portion of at least one of said drums is provided by a displaceable section of the drum, and in which spring means are provided to urge said section away from the centre of said drum.

8. Web severing means according to claim 2 in which each of said drums comprises a section hinged about an axis parallel to its axis, and in which spring means are provided for urging the ends of said sections remote from their hinges away from the centres of said drums.

9. Web severing means according to claim 1 in which said positive drive means is adapted to rotate said drums at a speed which is substantially lower than the speed of said web drawing means.

10. A web feeding machine having web severing means according to claim 9 and including means for automatically reducing the takeoff of the web from said supply when said drums are rotating at said lower speed.

11. A web feeding machine according to claim 10 in which said means for automatically reducing said takeoff of said Web includes a roll about which said web is entrained and which is displaceable according to the tension of said web and brake means acting at said web supply and actuated by displacement of said roll.

12. Web severing means including a pair of rotatable drums mounted adjacent to one another with their axes parallel, cooperable web shearing means carried by said drums, said drums having a normal disposition such that 3 a web is capable of free passage therebetween, actuating means for causing a rotary displacement of said drums when a web between said drums is to be cut, and gripping portions 011 each of said drums adapted when said drums are displaced to grip said web, each of said portions including a section hinged about an axis parallel to the axes of said drums, and each of said sections having spring means for urging the end of said section remote from its hinge away from the centre of its supporting drum.

13. Web severing means including a pair of rotatable drums mounted adjacent to one another with their axes parallel and having a normal disposition such that a web is capable of free passage therebetween, actuating means for causing rotary displacement of said drums when a web between said drums is to be cut, gripping portions on each of said drums adapted when said drums are displaced to grip said web, each of said portions including two sections hinged about axes parallel to the axes of said drums, each of said sections having spring means for urging the end of each section remote from its hinge away from the centre of its supporting drum and a knife mounted longitudinally of each of said drums between said sections cooperate with each other to cut said Web.

147 Web severing means according to claim 13 including adjustable stops for controlling the outward movement of said hinged sections.

References Cited in the file of this patent UNITED STATES PATENTS 100,367 Bullock Mar. 1, 1870 2,193,259 Sheperdson Mar. 12, 1940 FOREIGN PATENTS 475,512 Germany Apr. 27, 1929

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