GB2141108A

GB2141108A - Continuous feeding tape

Info

Publication number: GB2141108A
Application number: GB08412266A
Authority: GB
Inventors: Kyouichi Yamashita
Original assignee: Koyo Jidoki Co Ltd; Koyo Automatic Machine Co Ltd
Current assignee: Koyo Jidoki Co Ltd; Koyo Automatic Machine Co Ltd
Priority date: 1983-05-17
Filing date: 1984-05-14
Publication date: 1984-12-12
Also published as: GB2141108B; FR2546146A1; DE3418221A1; FR2546146B1; GB8412266D0

Abstract

A first tape (T1) is fed to a cutting station (5, 6) in a bookbinding or other machine by a drive arrangement comprising a capstan (3) and a pressure roller (4). At the cutting station, sections of the tape of predetermined lengths are cut off for feeding to a next workstation of the machine. When exhaustion of the first tape (T1) is detected, a standby tape drive (3', 4') is energised, so that the leading end of the standby tape (T2) reaches the cutting station at the same instant as the trailing end of the last section of the first tape (T1). Due to this arrangement, no time is lost through exhaustion of the tape supply. The leading end of the now stationary exhausted tape is retracted back from the cutting station, eg by a deflecting pin or air jet, to prevent interference with the now advancing standby tape. <IMAGE>

Description

SPECIFICATION Continuous supply tape feeding method and apparatus This invention relates to a method and apparatus for continuously supplying tape to a work station by switching tape sources automatically and without interruption.

There are in existence machines which supply and cut tape at fixed lengths, for example labelling machines. However, recent advancements in the speed of these kinds of machines are quite remarkable. Tape sources are exhausted more rapidly and the replacement of tape reels becomes a time consuming problem.

There are two basic barriers to faster production. Firstly, each tape source has a finite amount of tape, and when it is exhausted it must be replaced. Secondly, the increase in speed means faster tape exhaustion and more frequent tape replacement.

The method used up to now of stopping the machinery and replacing the tape source by hand is not compatible with the new high speed machines. As a result, the time required for tape source replacement has a strong negative influence on the efficiency of the present tape supply devices. This tends to negate the innovations which produce greater speed, and has obvious inflationary effects on production costs.

An object of the present invention is to alleviate these problems, by employing multiple tape sources which act as operative and standby sources, automatically detecting tape source exhaustion, and automatically switching to the standby tape source when the operative source nears exhaustion.

It is intended that this method and apparatus be fully compatible with presently existing non-continuous supply machines.

According to one aspect of the invention, there is provided a method of feeding tape uninterruptedly to a workstation, comprising feeding tape from a first source; detecting the approach of exhaustion of the tape from the first source; halting the supply of tape from the first source; and simultaneously starting the supply of tape from a second source.

According to another aspect of the invention, there is provided apparatus for feeding tape uninterruptedly to a workstation, comprising first and second tape supply sources; means to feed tape from the first source to the workstation; means to detect the approach of exhaustion of tape from the first supply source, and tape feed control means responsive to the detection to arrest the feeding of the tape from the first supply source and to initiate the supply of tape from the second supply source.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which Figure 1 is a schematic diagram of apparatus in accordance with the invention, Figure 2 is a partially sectional view of a drive roller assembly of the apparatus, Figure 3 is a pictorial view showing a detail of the apparatus, Figure 4 is a schematic view of one form of tape end retraction mechanism for use in the apparatus, and Figure 5 is a schematic view of an alternative form of tape end retraction mechanism.

Referring to Figure 1 of the drawings a tape TI, for example a label tape, from a tape source reel 1 is fed between a capstan 3 and a pressure roller 4. A spring-loaded roller 2 prevents the tape from becoming slack. The roller 4 provides pressure to maintain the tape in contact with the capstan 3, which controls the speed of feeding of the tape at a desired level. The tape is fed at a high speed between a revolving cutter 5 and an opposing fixed cutter, by which it is cut into predetermined equal lengths. The cut lengths are fed to a next station which might be, for example, a printing machine, a bookbinding machine, a labelling machine, etc.

Parallel to the basic operative tape supply mechanism is a standby supply mechanism, which has parts 1'-4' which correspond to the parts 1-4 of the operative supply mechanism.

Both operative and standby supply mechanisms share the cutting assembly 5, 6. Between the driving rollers 3 and 3' and the cutting assembly 5, 6 are located a V-shaped tape guiding block 7 and two tape guiding walls 8 and 8', respectively. The tapes, coming from the respective sources 1 and 1' and driven by the rollers 3 and 3', pass through respective guide channels created between the guide block 7 and the guide walls 8 and 8' on either side.

For each tape source there is a device (not shown) for detecting the approach of tape exhaustion. At the tail end or near the tail end of each tape is a printed mark or a hole. A light sensor detects this mark or hole and indicates that the tape is exhausted. Alternatively, adjacent each tape reel there is a light source on one side of the reel and a receiver on the other side, such that the light path between the light source and the receiver lies close to the centre of the reel. When the tape reel is full. the signal is blocked, but when the amount of tape remaining becomes sufficiently low, the light reaches the receiver unobstructed, which signals tape exhaustion.

When the operative tape source is ex-hausted, the detector sends current to start/delay devices (not shown) of the operative and standby tape sources. If the start/delay device were to halt the supply of tape from the operative source immediately, it is likely that the cutting assembly 5, 6 would not cut the last length of tape at the proper place. If, for example, the tape supplies a printing ma chine, the last length of tape may carry half an image instead of a full printed image. To avoid misplaced cuts, it is therefore necessary that the last length of tape be fully advanced to the cutting assembly before the driving roller 3 halts.

It is also essential that the standby tape shall properly align with the last tape length of the operative supply, and that the feeding of tape from the standby source shall begin immediately upon the cessation of the ex hausted supply.

Referring to Figure 2, the tape driving rollers 3 and 3' are mounted over revolving gears 31 and 31' respectively. Solenoid-operated pins 32 and 32' extend into pin holes 33 and 33' to engage the rollers 3 and 3' to the respective gears 31 and 31', or retract to disengage them. The gears under the driving rollers are constantly turning, but the rollers themselves do not turn until engaged with their respective gears. The circumference of each roller is a fixed ratio to the desired tape section length R as shown in Figure 3. The roller reaches the appropriate point (this point being predetermined by the aforesaid ratio) and the cutting demarcation line of the last tape length is aligned with the leading end of the standby tape at a position less than one tape section length from the cutting assembly.

The gear 31' of the standby tape T2 has been constantly turning, disengaged from the pin 32', with its speed matched to that of the operational gear 31. The solenoid-operated pin 32' is activated just before the tapes align, and then at the instant the tapes come level the pin 32' drops down to engage the pin hole 33' and the standby tape T2 advances, together with the last length of the operative tape. As this last length reaches the cutting assembly, the solenoid pin 32 retracts, and the operative tape supply stops. The standby supply, already in motion, continues the supply of tape to the cutting assembly.

When the operative supply tape nears exhaustion, this fact is noted by the detection device which in turn sends current to the start/delay devices of both the operative and standby supplies. When the cutting demarcation line of the last label length of the exhausted tape comes level with the leading end of the standby tape, the standby tape advances together with the operative tape. This last segment of operative tape is cut and is fed to the next station and the operative supply is halted. The lead end of the standby tape advances to continue the supply of tape to the cutting device. At this point the change-over from the heretofore operative supply to the standby supply is complete.

It will be apparent that whilst the standby tape is being fed the original tape source can be replenished, and a change-over back to that tape source from the now operative source is effected, when the latter source is almost exhausted, in exactly the same way as described above.

When the tape supply is switched from the operative to the standby source, the lead end of the now exhausted tape can be automatically withdrawn to avoid entanglement with the newly operative tape supply source. As Figure 4 indicates, a slot is formed in the guide block 7, perpendicular to the direction of tape travel. Corresponding recesses 81 and 81' are formed in the guide walls 8 and 8'. A cylindrical pin 72, capable of left/right and right/left movement (relative to Figure 4) is located in the slot 71. When a tape supply change-over is made, the pin 72, with appropriate timing, is urged into the duct on the side of the exhausted tape, thus bending the tape and drawing the leading end of the tape back to prevent interference with the new tape.If this method of withdrawing the tape is linked to the aforementioned tape exhaustion detecting mechanism, the method and the timing by which the pin 32 or 32' is activated can be considered separately.

An alternative tape end withdrawal mechanism, as detailed in Figure 5, employs an air nozzle 9. The air nozzle is placed between the tension roller 2' and the drive roller assembly 3', 4' perpendicular to the direction of tape feed. When the exhaustion signal is activated, the pressure roller 4' is disengaged from the capstan 3', freeing the tape. At the same time, the nozzle projects air at the surface of the tape causing the tape to bend and thus withdrawing the leading end of the tape from the vicinity of the cutting assembly.

The method and apparatus of the present invention have the following advantages.

Since the present high speed tape supply machines do not incorporate an automatic tape source replacement capability, the duration of time during which the machine must be stopped while the necessary tape replacement is performed is excessive. With the present invention, the tape sources are switched over automatically and smoothly.

There is no need to halt the tape supply.

Notable increases in the production capacity of high speed tape supply machines thereby result. In addition, with the exhausted tape leading end withdrawal method, whereby the leading end of the exhausted tape is withdrawn from the cutting area when the changeover to the standby tape source is effected, the danger of the leading end of the exhausted tape becoming entangled with the new tape is nullified. Even with high speed machines, the tape can be withdrawn accurately and effectively.

The application of this method and device to paper and plastic label machines is apparent, but there are potentially numerous further applications to tapes made of fibres or sheet metal, as well as to other kinds of basic material supply machinery.

Claims

1. A method of feeding tape uninterruptedly to a workstation, comprising feeding tape from a first source; detecting the approach of exhaustion of the tape from the first source; halting the supply of tape from the first source; and simultaneously starting the supply of tape from a second source.

2. Apparatus for feeding tape uninterruptedly to a workstation, comprising first and second tape supply sources; means to feed tape from the first source to the workstation; means to detect the approach of exhaustion of tape from the first supply source, and tape feed control means responsive to the detection to arrest the feeding of the tape from the first supply source and to initiate the supply of tape from the second supply source.

3. Apparatus as claimed in claim 2, wherein the workstation comprises cutting means for cutting the tape into sections of predetermined length; and wherein, in response to detection of the approach of exhaustion of the first tape, the tape feed control means advances the final section of the tape from the first supply source to the cutting means and advances the leading end of the tape from the second supply source to the cutting means in alignment with the trailing end of the final section of the tape from the first supply source.

4. Apparatus as claimed in claim 3, further comprising means to retract the end of the arrested tape from the vicinity of the cutting means to prevent interference of said end with the advancing tape from the second supply source.

5. Apparatus as claimed in claim 4, wherein the retraction means comprises means to urge a portion of the arrested tape into a recess alongside its normal feeding path.

6. Apparatus as claimed in claim 4, wherein the retraction means comprises means to project a jet of air at a portion of the arrested tape to cause it to form a loop deviating from the normal feeding path.

7. A method as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.

8. Apparatus as claimed in claim 2, and substantially as hereinbefore described with reference to the accompanying drawings.