Automatic Measuring, Cutting And Rolling Machine For Webs Of Paper Or The Like

Abstract

An automatic web-measuring, cutting and rolling-up machine of the type having cutting mechanism disposed transversely of the web during its passage from one to the other of two pairs of driven rollers, the second of which pairs delivers said web to deliver said mechanism including a roller-carrying gate adapted for automatic displacement as the diameter of the roll of web increases and for subsequent positive displacement to discharge the finished roll, is characterized in that the winding speed of the machine and the operation of the cutting mechanism are automatically controlled through the medium of a measuring unit driven directly or indirectly by the incoming web, and preferably including cam-operated switches which respectively control electromagnetic clutch means for driving the first and second pairs of rollers and electrical means for causing actuation of the cutting and gate-opening mechanism during each operating cycle of the machine.

Description

This invention relates to machines for automatically measuring, cutting-off and rolling-up predetermined lengths of a paper or like web, and has particular, though not exclusive, application to machines used for producing standardized rolls of wallpaper from a bulk supply.

It is usual in such machines for the web to be drawn over a measuring roller, and thence to pass through a transverse cutting device to the gap between a pair of horizontal rollers which are continuously rotated in the same sense about fixed axes, a similar pair of rollers being urged towards the first pair by a movable gate and cooperating therewith in such manner that the incoming web is progressively rolled-up between the two pairs of rollers. After a predetermined number of revolutions of the measuring roller engaging the web, the delivery of the latter is momentarily checked whilst the cutting device severs it, and when the rest of the cutoff length has been rolled up, the gate is positively retracted to allow the resultant roll to fall clear.

The object of the present invention is to provide an improved machine which will be capable of cutting paper and like webs indefinitely to a precise predetermined length irrespective of variations in the tension of the web or its weight per unit length, as well as being readily adjustable to suit other characteristics of such web, and in which the positive opening movement of the gate is unaffected by the size of roll being wound.

According to this invention, an automatic web-measuring, cutting and rolling-up machine of the type having cutting mechanism disposed transversely of the web during its passage from one to the other of two pairs of driven rollers, the second of which pairs delivers said web to rolling-up mechanism including a roller-carrying gate adapted for automatic displacement as the diameter of the roll of web increases and for subsequent positive displacement to discharge the finished roll, is characterized in that the winding speed of the machine and the operation of the cutting mechanism are automatically controlled through the medium of a measuring unit driven directly or indirectly by the incoming web, and preferably including cam operated switches which respectively control electromagnetic clutch means for driving the first and second pairs of rollers and electrical means for causing actuation of the cutting and gate-opening mechanism during each operating cycle of the machine.

Conveniently the two electromagnetic clutches aforesaid are energized in turn so that the pair of rollers remote from the gate are driven at high and low speeds alternately, the second pair of rollers being normally driven from the first pair through a freewheel device but also having a driving connection to the cutting mechanism whereby, during each period of low speed rotation, they are momentarily accelerated immediately following severance of the web, such cutting mechanism including a rotary knife adapted to make a single revolution at low speed when released by the electrical means aforesaid.

The measuring unit may include a shaft indirectly friction-driven from one of the first pair of rollers and carrying two cams, one such cam being adjustable in length to control the period for which the first pair of rollers is driven at low speed in each cycle of operations, and the second cam being angularly adjustable relative thereto to control the instant at which the rotary knife is set in motion.

The positive opening of the gate may be effected through the medium of a housing connected thereto and containing two coacting wedge-blocks, one of these being constantly urged towards the other which is periodically advanced a predetermined amount by means of an eccentric in timed relation to the operation of the cutting mechanism, the positive movement of the housing produced by wedging of the two blocks within it being thus unaffected by the extent to which it has already been displaced by expansion of the roll being formed.

The web may be advanced to the machine from a constantly braked stock reel by means of an independently driven band conveyor, or alternatively a substantially constant tension may be applied to the entering web by passing the same between a series of rollers which are alternately mounted in a fixed frame and in a second frame pivoted at one end, the angular position of this second frame being dependent upon the rate of intake of the machine and controlling the rate at which the web is unwound from the stock reel.

In the accompanying drawing:

FIG. 1 is a schematic sectional side elevation of a machine embodying the present invention;

FIG. 2 is a schematic side elevation showing the drive means for the several moving parts;

FIG. 3 is a schematic fragmentary plan view;

FIGS. 4 & 5 are enlarged side and end elevations, respectively, of a detail of the machine;

FIG. 6 is a fragmentary section on the line 4-4 of FIG. 1;

FIGS. 7 & 8 are an enlarged side elevation and part-sectional plan view, respectively, of another detail;

FIG. 9 is an exploded perspective view of a measuring unit shown in FIGS. 1 and 3;

FIG. 10 is an electrical wiring diagram;

FIG. 11 is a side elevation of a paper supply system for use with the machine aforesaid;

FIG. 12 is a schematic side elevation of an alternative supply system.

In the example illustrated, the frame of the improved machine comprises two vertical side-plates 1, 2 fixed parallel to one another by suitably placed cross-members.

Bolted inside the left-hand side-plate 1 is an electric motor 3 connected, by external `V` belts 4, to a fast-drive shaft 5 which is journaled upon both side-plates near the rear end of the machine.

Above this, and connected thereto through twin link-belts 6 and a reduction gearbox 7, is a parallel slow-drive shaft 8, the two drive shafts 5, 8 being respectively connected by further link-belt drives 9, 10 to the input elements of two electromagnetic clutches 11, 12 whose output elements are keyed to a third parallel shaft 13.

The lower of two superposed feed rollers 14 near the rear end of the machine is driven from this clutch-shaft 13 by a toothed belt 15 outside the right-hand side-plate 2, a similar drive 16 outside the left-hand side-plate 1 connecting the other end of this roller to the lower of two superposed web-driving rollers 17 near the front of the machine.

The upper of each pair or rollers 14, 17 is journaled in vertically-movable slide-blocks 18, the upper web-driving roller 17 merely resting upon its mate whilst the upper feed roller 14, which is rubber-covered, is urged towards the lower one by adjustable spring pressure means 19, provision (such as a cam 20 and rocking-lever 21) being made for positively manually raising it to facilitate threading of the web 22 through the machine.

In front of the web-driving rollers 17 is a rolling-up mechanism of generally known form; that is to say, it comprises one pair of superposed horizontal friction rollers 23 journaled at fixed positions in the side-plates 1, 2 and a second pair of similarly superposed friction rollers 24 journaled in the side members of a gate 25 which can rock in a fore-and-aft direction about a horizontal shaft 26 parallel to the several roller axes.

Each of the four friction rollers 23, 24 is circumferentially grooved or comprises a plurality of axially-spaced sections arranged opposite the gaps between those of its mate, an adjustable counterweight 27 and springs 28 tending to hold the gate rollers 24 engaged with the rear pair 23.

The upper and lower of each pair of friction rollers 23, 24 are connected by a chain 29 for rotation in the same sense, the upper roller 23 being connected to the lower web-driving roller 17 through a train of spur gears 30, 31, 32 at the right-hand side of the machine, and also to the lower movable roller 24 by means of toothed belts 33, 34 which engage an idle multiple pulley 35 on the gate rock-shaft 26.

Thus all four friction rollers 23, 24 rotate in the same direction so as to rollup the leading end of the web 22 when the latter is advanced between the rollers 23 by the web-driving rollers 17.

As rolling-up proceeds the gate 25 is pushed forwards against its gravity- and spring-loading due to the increasing diameter of the roll 22a being formed, and after severance of the web 22 in a manner hereinafter described, the gate automatically receives a further positive movement which allows the completed roll 22a to fall clear into a collecting trough 36. The return stroke of the gate 25 is cushioned by an adjustable hydraulic damper 37.

Before reaching the feed rollers 14 the web 22 passes under two further rollers 38 behind and somewhat below the latter, and one such further roller may be mounted on swinging arms 39 so that it can be skewed slightly with reference to the feed rollers 14 to enable the entering web 22 to run truly at right angles to the axes of the latter.

After leaving the nip between the feed rollers 14 the web 22 passes over two successive supporting plates 40 and beneath an intervening transverse rail 41 to whose front edge a blade 42 is fixed, this rail being angularly adjustable about its longitudinal axis.

This stationary blade 42 cooperates with the serrated or longitudinally-inclined edge of a knife 43 secured to a substantially radial seating 44 on a part-cylindrical roller 45 which is journaled in the side-plates 1, 2 between the feed and web-driving rollers 14, 17.

The left-hand end of this knife roller 45 is driven from the slow-drive shaft 8 through the medium of twin roller-chains 46 outside the adjacent side-plate 1 and a roller-ratchet clutch 47 (FIGS. 4 and 5) which, when released as hereinafter described, causes its output element to rotate the knife roller 45 through one revolution and then to turn freely relative thereto.

A chain-drive 48, outside the right-hand side-plate 2, connects the adjacent end of the knife roller 45 to that of the lower web-driving roller 17, the driven sprocket on the latter incorporating a freewheel device 49 (FIG. 6) similar to one provided at 50 in the driven pulley at its other end. The web-driving rollers 17, whilst normally driven from the feed rollers 14, are thus automatically rotated at increased speed by the knife roller 45 during each intermittent revolution of the latter, so as to wind in the tail of the cut web.

Such web, on passage beyond the rollers 17, is controlled by guide plates 51 having fingers 52 which project between the sections of the upper roller 23.

A further chain-drive 53 connects the right-hand end of the knife roller 45 to an eccentric 54 (FIGS. 7 and 8) mounted on a stub shaft 55, the strap 56 of such eccentric being fixed to a wedge block 57 slidable along a boxlike housing 58 whose outer end is pivoted to a crank arm 59 on the gate shaft 26.

The upper inclined face of this wedge block 57 cooperates, through the medium of an interposed roller-bearing pad 60, with the underside of a complementary spring-loaded wedge 61 also slidable along the housing 58 but only to the extent allowed by a slot 62 in the latter through which projects a lateral peg 63 on the upper wedge 61.

During the automatic forward movement of the gate 26 through the angle A by the expanding roll 22a, the slot 62 allows the upper wedge 61 to maintain its original relation with the lower wedge 57 despite the advancement of the housing 58, but, when the operation of the rotary knife 43 to sever the web 22 against the stationary blade 42 causes the eccentric 54 to turn, the lower wedge 57 is advanced within the housing 58 and cooperates with the upper wedge 61 so that such housing is frictionally locked to the eccentric strap 56.

The eccentric 54 then effects the previously-mentioned positive movement of the gate 26 through the angle B, which releases the roll 22a and whose amplitude is constant whatever the diameter of the latter.

The length of web 22 forming each roll 22a and whose amplitude is constant whatever the diameter of the latter.

The length of web 22 forming each roll 22a is determined by a measuring unit 64 (FIGS. 1, 3 and 9) pivoted on a crossbar 65 so that two friction wheels 66 mounted on a common shaft 67 therein engage the periphery of the upper feed roller 14, this shaft 67 being connected, through worm-gearing 68 and a freewheel device 69, to a short spindle 70 upon which are two cams 71, 72 for operating microswitches 73, 74, within the unit 64.

The lower cam 71, which controls the high- and low-speed operation of the machine as hereinafter described, is split so that its operative portion can be expanded or contracted to vary the amount of time for which the machine is held on slow speed. The upper cam 72 is angularly adjustable relative thereto and controls the timing of the knife 43.

As shown in FIG. 10, the machine is operated with single-phase current fed to a conventional transformer/rectifier power pack 75 whose DC output is smoothed by a condenser 76.

Assuming that the web 22 has already been fed in, switching-on of the motor 3 is accompanied by energization of the fast-drive clutch 11, so that the web is run through at high speed until the first microswitch 73 in the measuring unit operates.

This energizes a relay 77 whereby the fast-drive clutch 11 is released and the slow-drive clutch 12 engaged, the machine thereafter operating at low speed until the second microswitch 74 is actuated and energizes two further relays 78, 79 one of which allows a condenser 80 to discharge through the other relay 79 whilst the latter is passing an AC pulse to a solenoid 81 to thereby release (by retraction of a pawl 81a ) the single-revolution clutch 47 controlling the knife roller 45, the period of energization of the solenoid 81 being sufficiently short to ensure that it has reset before such knife roller can complete its one revolution.

As previously described, the cutting of the web 22 is followed by a momentary acceleration of the web-driving rollers 17 to wind in the tail of the roll 22a, the low-speed operation of such rollers thereafter continuing until the leading end of the next length of web 22 has entered the gate 26 and the microswitch 73 is changed over by the action of its cam 71, whereupon the machine reverts to high-speed operation, the resetting of the microswitch 74 causing the condenser 80 to be recharged through the appropriate relay 79.

The fact that rolling-up is commenced at a low speed enables the machine to handle very lightweight webs and webs of relatively stiff and heavy material with equal ease.

With materials which have a tendency to curl, however, it may be preferable to set the measuring-unit cam 71 so that the machine reverts to high speed before the leading end of the web 22 reaches the web-driving rollers 17 and to reduce the nip pressure of the feed rollers 14 so that the latter will slip at the instant of acceleration, the driving rollers 17 thus momentarily having a peripheral speed higher than the speed of the web 22.

During normal operation of the machine the web 22 is advanced to the nip between the feed rollers 14 by any suitable supply mechanism, and in this connection it will usually be found satisfactory to employ a band conveyor 82 (FIG. 11) onto which the web is delivered in loose folds from a constantly-braked stock reel 83 by means of a pair of unwind nip rollers 84 driven from a separate motor 85 which also operates the band conveyor 82. The several bands of the conveyor 82 form the base of a trough 86 in which a reserve of web is maintained ready for acceptance by the machine.

From the trough 86 the web 22 passes into the machine over an arched support, on which it is in full view of the operator. This support (FIGS. 1 and 3) comprises a pair of laterally spaced davitlike members 87 carrying a pivoted tensioning frame 88 through which the web is threaded, and also a curved inspection plate 89.

In an alternative supply system (FIG. 12) suitable for lightweight paper webs which may tend to become airborne if unwound from the stock reel 83 at high speed, the web 22 leaving the unwind nip rollers 84 is led between two sets of parallel rollers, the rollers 90 rotating about fixed axes in a horizontal frame 91, whilst the rollers 92 alternated therewith are mounted in a second frame 93 which is pivoted at the end adjacent the unwind rollers 84.

When a latch 94 temporarily holding it is released, the weight of this pivoted frame 93 pulls the web 22 into a zigzag formation to provide a reserve on which the machine can draw. As this reserve is taken up, the resultant rising movement of the frame 93 operates the speed control of an infinitely-variable gearbox (not shown) whose output shaft is connected to the unwind nip rollers 84, the latter therefore accelerating the stock reel 83 to full speed before the frame 93 can reach a horizontal position.

When the machine decelerates during the cutting of the web 22 as aforesaid, the weight of the raised roller frame 93 enables it to take in a fresh supply of web from the stock reel 83, and as such frame sinks the unwind nip rollers 84 are automatically slowed to a standstill simultaneously with stoppage of the stock reel 83 under the influence of its brake.

The tension in the web 22, being dependent solely on the weight of the swinging frame 93, is thus substantially constant at all times.

Should a faulty section of web 22 be seen entering the machine, resetting of the measuring unit pointer 96 to zero after stoppage of the machine will cause the web to be severed immediately the machine is restarted, the short roll being released from the gate 26 and the next roll produced accurately to length.

Claims

I claim:

1. A machine for automatically measuring, cutting-off and rolling-up predetermined lengths of web material, comprising first and second pairs of driven rollers successively engaging said web so as respectively to wind in and carry forward the same measuring means driven by the incoming web, cutting means disposed transversely of said web between said first and second rollers, means for rolling-up each cut length of web delivered thereto by said second rollers and automatically discharging the finished roll, said measuring means controlling the winding speed of the machine and the operation of said cutting means, electromagnetic clutches for driving said first and second pairs of rollers, electrical means for causing actuation of said cutting means and for discharging a roll from said rolling-up means during each operating cycle of the machine, and cam operated switches operated by said measuring means for controlling said clutches and electrical means.

2. A machine as claimed in claim 1, wherein said electromagnetic clutches for driving said first and second pairs of rollers and energized in turn so that said first pair of rollers are driven at high and low speeds respectively, and including a freewheel device through which said second pair of rollers is normally driven from said first pair, and a driving connection between said second pair and said cutting means whereby, during each period of low-speed rotation, said second pair are momentarily accelerated immediately after severance of said web by said cutting means, the latter including a rotary knife adapted to make a single revolution at low speed when released by said electrical means.

3. A machine as claimed in claim 1, wherein said measuring means includes a shaft indirectly friction-driven from one of said first pair of rollers, and two cams mounted on said shaft for operating said switches, one such cam being adjustable in length to control the period for which said first pair of rollers is driven at low speed in each cycle of operations, and the other such cam being angularly adjustable relative to said one cam to control the instant of operation of said cutting means.

4. A machine as claimed in claim 1, and wherein the rolling-up mechanism comprises two coacting sets of rollers, a movable gate carrying one such set and serving continuously to urge them towards said other set, a housing connected to said gate, two acting wedge-blocks contained in said housing, one such wedge-block being continuously urged towards the other, and an eccentric for periodically advancing the other such wedge-block in timed relation to the operation of said cutting means, the positive movement of said housing produced by wedging of said blocks within it causing release of a roll of web formed between said sets of rollers and being unaffected by the extent to which said housing has already been displaced by expansion of said roll.

5. A machine as claimed in claim 1, in combination with web-supply means comprising a fixed frame, a second frame pivoted at one end about an axis transverse to the direction of web movement towards said machine, a first set of equally-spaced rollers mounted transversely of said fixed frame, a second set of equally spaced rollers mounted transversely of said pivoted frame at such positions as to be capable of movement between and above the rollers of said first set, said web being passed between said sets of rollers during disposal of the same as aforesaid and being subjected to substantially constant tension when supporting the weight of said pivoted frame, whose angular position depends upon the winding speed of said machine.