CA2224761A1

CA2224761A1 - Printed markers

Info

Publication number: CA2224761A1
Application number: CA002224761A
Authority: CA
Inventors: Timothy Mathias; Dominic Roger Meech
Original assignee: Bowthorpe PLC
Current assignee: Bowthorpe PLC
Priority date: 1996-12-11
Filing date: 1997-12-12
Publication date: 1999-06-12
Also published as: EP0847864A2; ATE224303T1; DE69715574T2; DE69715574D1; GB9724862D0; GB2320225B; GB2320225A; EP0847864A3; EP0847864B1

Abstract

Printed markers for identifying electrical cables are formed by winding an elongate strip or flattened length of tubing 19 onto a reel 30, which is then mounted for rotation to a thermal transfer printer 25. The printer then prints markings onto the strip or tubing 19 as it advances past a print head 36 of the printer. The strip or tubing 19 may be formed with transverse lines of weakness at intervals along its length, to define successive markers.

Description

Printed ~arkers The present inv~ntion relates to print~d markers for identifyi~g electric cables, for exa~ple.
It is a common practice to provide tubular printed mark~rs which a~e slipped on~o indi~idual cables. These 5 tubular markers may be heatshrinkable or non-heatshrinkable.
It is also common to provide markers as flat ytrips, which are atta~hable to indi~idual cables. The kno~n types o~ markers are ~uppli~d either support~d on a ladder-type o~ bandoli~r or on a paper backing, and axe fed through the printer 10 transversely: the markers are accordingly restricted to p~edetermined lengths.
we ha~re now devised arrang~ments w~ich of~er signif icant advantages rela~ve to the arrangements which have been provided hitherto.
I5 In accordance with the present invention, there is provided a thermal transfer printer arranged to receive a wound length of elongate strip or flattened tubing, the printer ~a~ing a thermal transfer print head and means for guiding the strip or tubing past the print head, the guiding means being 20 arranged to constrain the strip or tubing against lateral displacement as it advances ~hrough the print head.
Preferably the printer ls arranged to recei~e a wound l~ngth of strip or tubing of selected width Prefer~bly the printer ls arrang~d to receive two or more wound lengt~s of 25 strip or tu~in~, side-by-side.
The strip or tubing may be ~ound onto a reel, which is then mounted for rotation. The guiding means in this case co~prises a pair of elonga~e guides which extend from the ree].
towards the print head, the elongat~ guides having inwardly-facing edges which are formed with longitudinal grooves inwhich the opposite ed~es o~ the strip or tubing are slidably r~ceived. These elongate guides may comprise two separate mem~ers which can be engaged, either side o~ the reel, onto a spindle on which the r~l is fitted. Instead, the el~ngate 35 guides may be mounted to the reel, so that the reel and guides form a single ~ni~ ~o~ fitting into the printer. The strip or tubing may ~e printed on one side, and rewound onto the same or dif~erent reel, which is inserted into the printer for printing onto the opposite side of the ~trip or tubing In an another embodiment, the elongate strip or tubing 5 may be wound within a cassette, having an exit slot through w~ich the ~eedstock passes. In this case, pref erably the cassette i~cludes a portion which projects radially outwardly and includes the exit slot at its outer end, so that opposite side walls of this projectin~ portion constrain the strip or lC tubing against transverse displacement as it ad~ances towards the print head. Pre~erably the cassette is arranged so that it can be ~eversed, to ena~l~ the strip or tubing to be printed on either side: in particular, the strip or tu~ing can be printed on one side, then re~ound into the cassette, for ehe 15 cassette thcn to be turned over to enable printing on the opposite slde of the strip or tubing Pre~erably therefore, the cassette is symmetrical about a plane which contains its exit slo~ and the axis around which the strip or tubing is wound.
Also in accorda~ce with the presen~ inv~ntion, there is provided a thermal transfer printer in combination with a length o~ elongate strip or flattened tubing, the printer havi~g a thermal transfer print head and means for guiding the strip or tubing past the print head, the guiding means being arranged to constrain the strip or tubing against lateral displacement as it advances throu~ the print head.
The strip or tubing is prefera~ly pre~ormed with transverse lines of weakness at intervals along its length, to de~i~e successive markers The iines of weakness may be 30 provided by a line of perforations or by a partial cut through thc thickness of the material: however, the lines o~ weakness may be ~ormed at any desired intervals, so ~orming mar~ers o~
any desired lengths.
Pre~era~ly, the strip is semi-rigi~. Preferably, the 35 str~p eomprises an adhesive backing.
In use, as the strip or tubing advances through the printer, the position of the p~r~orations or lines o~ weakness between successive markers needs to ~e determined, so that the printer ca~ determine where to positio~ each successive print on each succesQive marker.
Thus, in accordance ~ith this in~ention, there is pro~ided a printer in combination with a length o~ ~longate strip or flattened tubing, formed with transverse lines o~
5 w~akness at i~tervals along its length to define successive markers, da~um markings being formed at regular intervals along the strip or tubing, the spacing between each marking being related to the length of each markex, the printer compri3ing a sensor arranged to sense the position of each marker as the 10 strip or tubing is advanced through the printer and control ~eans arranged to control the po~ition at which successive prints are formed on successive ~arkers o~ the strip or tubing, in accordance with the output of the sensor.
In usc, the sensor d~t~cts the position of the datum 15 markings, so that the printer kno~s whcn it can start printing each suc~essi~e marker.
Prefera~ly a datum marking is provided on each o~ the successi~e ~arkers. However, it is envisa~ed that datum markings may not ~c provided on e~ery marker, in which case the 20 printer is preferably arra~ged to calculate the position a~
which each successive mark¢r is to be print~d.
Preferably the markings are transparent and thus do not af fect the appearance of the markers on which they are provided.
25Preferably the markings are formed of a Uv reflective ~aterial such as ink.
Preferably, the printer compri~es a W light source which irradiates the strip or tubing, the sensor being arranged to detect said ~ light re~lected ~rom ~h~ datum markings.
30A disadvantage of cut~ing or tearing markers ~rom a length o~ markers is that the length of markers beco~es fragmented, with the result that ~ome markers can become lost.
This is a particular problem ~rhere is each marker i3 princed differently and selected markers ar~ then cut at random from 35 the length.
In order to overco~e ~his problem, the strip or tubing i5 preferably joined to an axially extending carrier which keeps the remaining markers together once ~arkers h~e been cut or torn from the length In one em~odiment, the edge o~ the strip or tubing is connected to the edge o~ the carrier. Preferably, t~o lengths of strip or tubing are mounted side-by-side to respective oppo~ite side edges of the carrier. Preferably, the or each length o~ ~trip or tubin~ is frangibly connected to the carrier In an alternati~e embodiment, the strip or tu~ing is ~ounted on an elongate carrier of sheet ~aterial such as paper, the strip or tubing being disposcd between opposite side edges lo of the carrier. Pre~erably, a plurality o~ strips and l~ngths o~ tu~ing coextend along the carrier.: Thi~ format aids alignment, since the carrier can be tractor-fed, Qay by means of perforations extending along the length of the c~rrier.
Also in accordance with the present in~ention, there is 15 provided a method of formin~ printed markers, comprising advancing an elongate strip or length of flattened tubing longitudinally of itself through a thermal transfer printer and printing indicia at successive longitudinal interval~ onto said strip or tubing.
Thc strip or tubin~ may be formed ~ith transverse lines of weakness after it has been printed.
Further in accordance with thc pre~ent invention, there is pro~ided feedstock for forming individual mark~rs, co~prising an elongate strip or a flattened length o~ tubing, formed wit~ transverse lines of weakness at intervals along its leng~h, to define successi~e markers.
~ et further in accordance with the present invention, there is provided a series of ma~kers ~ormed on an elongate strip or length of flattened tubing, said ~trip or tubing being formed with trans~erse ~ines of weakness at intervals and carrying printed indicia ~etween the adjacent pairs of lines of weakness.
Embodiments of the present invcntion will now be described by way cxamples only and with reference to th~
accompanying drawings, in which:
FIG~E l is a plan view of a ~irst embodiment of fe~dstock in the form of flattened tubing;
FIGURE 2 is sectional view through a second embodiment o~ feedstock in the for~ of two lengths o~ tubing mounted side-' CA 02224761 1997-12-12 by-side to a carrier:
FIG~RE 3 is a plan view of thc feedstock o~ Figure 2;
FIGURE 4 is a plan ~fiew of a third embodiment of ~eedstock in the form of lengths of strip or ~lattened tubing 5 mounted on a carrier;
FIGURE S a plan vie~ oi~ a fourth e~r~odiment o~
feedstock in the form of elongate strip;
FIGURE: 6 is a schematic side view of an em~odiment of thex~al transfer printer in zccordance ~ith th~ invention;
FIGURE 7 is a plan view of a ~ui~e arrangement of the printer;
FI&URE 8 is a view of a cassette in ac~ordance with the in~ention;
FIGURE 9 is a view of the cassette fitted into the thermal trans~er printer o~ ~igure 6;
FIGURE 10 is a schematic section~l view of a portion o~
an alternative embodiment of th~rmal trans~er printer in accordance with the invention.
Re~erring to Figure 1, there is s~own a portion of a 20 length of tubing 10 which has been flattened by ~eing passed between a pair of rollers under ~oderate heat. ~he tubing may be heatshrinkable or non-heatshrink~ble, and comprises a plastics material e.g. PVC or a polyole~in. The tubing is semi-sever~d across its width at periodic intervals, ~s indicated 25 at 12, so that individual markers, once printed, can be torn from it, as indicated at 14.
Referring to Figures 2 an~ 3 of the drawings, two lengths of flattened tubing lOa,lOb are arranged side-by-sid~
and are interconnected by a solid carrier 11. I'h~ lengths of tubing lOa,lOb can be pri~ted simultaneously using a single printer.
Once printed, the l~ngths o~ tubing lOa,lOb can be detached from the carrier ll using a simple tearing action.
Both lengths of tubing lOa,'Ob a~e se~i-se~ered across their 35 width at periodic i~te~valj~ as indicated a~ 13, so that selected individual ~arkers can be detachcd from various points along the prin~ed length: the carrier 11 k~eps th~ remaining portions of the tubing lOa,lOb together, so that they do not get lost and so that further individual markers can easily be selected.
Referring to Figure 4 of the drawings, one or more lengths o~ strip and/or tubing 1~ can be supplied adhered to a paper carrier 16 and prese~ted on a roll. The carrier 16 comprises a longitudinally extending series o~ perforations 17 w~ich can be engaged by a toothed dri~e wheel on the printer, so as to ad~rance the carrier and strip or tubi~g through the printer. The lengths of strip or tubing are scvered across their width, as indicated at 18, so that indi~idual printed lo markers can be selected at random from the carrier 16, whilst keeping the remaining markers co~veniently together.
Figure 5 shows a portion of a length of flat strip 20 which is also semi-se~ered at int~rvals along its length, as indicated at 22, to definc successive markers. ~he strip is 15 pre-punched to form each such marker wi~h a pair of rectangular apertures 24 tor alternatively with a single aperture) adjacent each of its oppositc ends, for attaching the marker, typically using ~able ties, to a cable etc. to be marked.
Feedstock 19 of any of the types shown in ~igures 1 to 5 may ~e wound onto a reel 30, which is then ~itted into a thermal transfer printer 25 as shown in ~igures 6 and ~, for the feedstock 19 to pass the print hcad 36, where it is printed on as required. The printer 25 co~prises a spindle 32 projecting from a side wall of the apparatus, and the reel 30 i~ r~ceived on this spindle. The feedstock 19 passes from the reel 30, through a pair o~ closely-spaced guide plates 34, then over a roller 3S which is positioned under the thermal p~int head 36, and finally out through a slot 37 in the ~ront of the pri~er. A printer ribbon 38 is advanced past the thermal 30 print head, over the feedstock 19, from a reel 39 to a reel ~o In order to prevent the feedstock 19 wandering sideways as it passes from its reel 3~ to the print head 36, a guide arrangemcnt is provided, comprising a pair of elongate guide members 42. At one end, the guide members 42 engage over the 3S spindle 32 either side of the recl 30 and ~re secured in position b~ ~ightening respect screws 43: at their opposite ends, the guide ~embers 42 engage in a slot 34a in a downwardly-bent rear portion of the lower guide plate 3~. A~
shown in Figure 7, there is a gap between the t~o guide ~embers 42: the inwardly facing edges of the two guide members 42 are formed with longitudinally-extending groov~s (one of which is shown at 42a in ~igure 6). The opposite edges o~ the feedstock 19 are received in the longitudinal grooves 42a of the two 5 guide me~bers 42.
In the example shown in Figure9 6 and 7, the two guide members 42 are s~parate from the reel 30 and indep~ndently fitted in place, at one end in the slot 34a of t~e lower guide plate 34 and at the othcr end on the spindle 32. Instead, ~h~
two guide members 42 may be mounted to the reel 30, enabling the reel and guide members to be fitted as a single unit into the printer 25: for example, the two guide melT~ers 42 may fit together through the centre op~ning in the reel.
Two or more reels 30, with ~heir respective guide 15 members, may be mounted side-by-side on the spindle 32, such that their feedstock advance side-by-side past the print head 36. In this way, the correspon~in~ number o~ ~eedstock (~u~es or strip) may be printed simultaneously.
The feedstock used .in thc printer ma~ be of a wide 20 range of di~ferent widths, the reel 30 being o~ correspond.ing width. Where the fccdstock is preformed with transverse lines o~ weakness at regular inter~als along its length, then use is mad~ o~ a graduated support 44 projecting from the front of the printer 25: thus, the feedstock is pulled through un~il its 25 leading end is aligned with one o~ the graduations, appropriate for the distance between the succes~ive lines o~ weakness of that particular feedstock; this ensures that the printing process will ~e synchronised to the successive markers.
The feedstock may be formed to a profile in cross-section, inst~ad o~ being ~lat. In this case, the guide plates34 and roller 36 ma~ be ~ormed with a correspondingly profiled cross-section.
Instead of being wound on a reel, the feeds~ock may be wound in~o a cassette as shown in Figures 8 and 9. The 35 cassette comprises a body part S0 having a flat base formed with an upstanding peripheral ~all 51 and with ~n upstanding core 52: the cassette further compris~s a ~lat cover 53 which fits across the open top o~ the ~ody part 50 and is secured i~
place by a screw 54 which passes through the cover 53 and into the core 52. ~he cassette comprises a generally circular main portion, with the core 52 at its centre, from whlch a tapered portion projects: the end of the latter portion is provided with a slot 55. The feeds~ock 19 is wound around the core 52 5 within the cassette and its free end passes outwardly throug~
the slot 55. The core 52 a~d ~astening screw 54 are ~ormed ~th a through-hol~ so that the cassette can be mounted on the spindle 3Z of the print.er, alongsi~ one or more additional cassettes. In passing to the print head, the ~eedstock 19 is 10 guided by t~e opposite sides o~ the cassette and so prevented fro~ ~andering side~ays. ~s shown in Figure 9, when the cass~tte is fitted into the printer, its tapered end terminates a short distsnc~ from the entrance to the passagewa~ between the two guid~ plates 34: the cassette r~mains free to turn on 15 the spindle 32, a~d to adopt its own position as the feedstock is drawn past the print head.
It will be noted that the casset~e is s~mmetrical in shape about a plane which contains the exit slot 55 and the axis o~ the core 52. Thus, its ~eedstock 19 can be printed on 20 one side, then rewound into the cas~ette, and the cassette can ~en be turned over for the feed~tock to be printed on its opposite side.
It ~ill be apprecia~ed that the printer can print any desired indicia on the fe~dstock: the printing may run either lengthwise or transversely of the feedstock. The printing may also include graphics. Further, the printing may b~ ~ormed to any selected colour, ~y appropriate choic~ o~ the p~inter ribbon. The feedstock can be of any desired colour, and the printing may be white lo~ other light colours) onto black (or 30 other dark colour) feeds~ock.
The printer may be adapted to ~ccepted large-diameter r~els of feedstock, carried on a spindle mounted outside the printer casing. The feedstock may then enter the printer through it9 rear wall, pass over the spindle 3;2 of the printer 35 and then be guided by a pair of guide members 42 (as previously described) to the passageway between the guide plates 34.
The ~lattened tubing feedstock 10 of ~igure l may be pre~ormed ~ith its successive transverse lines o~ weakness 12 prior to printing, as sho~n: alternati~ely, these lines of weakness may be ~ormed subsequent to the printing. Similarly, the strip 2~ of Figure 5 ~ay bc formed with its transverse lines o~ ~eakness 22 and fi~ing apertures 24 prior to printi~g, or ~ubsequent to the printing. Alternatlvely, the feedstock (particularly the strip 20 of Figure 5~ may be supplied in it~
printed form, ~ithout its trans~erse lines of weakness, for the user to cut indi~idual markers from it In embodiments wherc the strip or tubing is preformed with transverse lines of weakness defining successl~e markers, the lines of weakness may be overprinted with a band of transparent UV ink, in order to de~ine datum marks 90, as ohown in Figures 1, 3 and 5.
Referring to Figure 10, the printer is arranged to detect these datum marks ~0 be~ween successive markers, so that it ~an determine where to form the prints on successive markers. In order to achie~e this, the printer comprises a UV
light source 91 which illuminates the strip or tubing 10/20 with W light through a window 93 ~7 light is re~lected from the strip or tubing 10~20 through a window 94 onto a W sensor 92 disposed adjacent the light source 91.
The output of the senQor 92 is connected to a print control unit via a le~el detector. In use, a great~r amount o~ UV light is reflec~ed by the strip or tubing 10/20 when the datum marks 90 pass the seno.or 92. The level de~ector is 25 arranged to de~ect the increased output l~vel of the sensor 92 and in this manner the pxi~t control circuit can control the position of successi~e prints to correspond with the position of the successive markers as the strip or tubing advances through the printer.
A particular advantage of using a thermal transfer printer is that the print formed on the feedstock i8 resi~tant to touch (in contrast to the print formed by dot matrix printers, which requires "fixing", for example under W light).
Further, the prin~ is itself resistant to W li~ht, and will 3S therefore no~ fade over time.
It will ~urther be appreciated that the printer avoids ~astage. The reels and cassettes can be re-used. Further, the ~cedstock is free o~ contamination: the reels o~ dstock can be enclosed in a ~rapper until use, whilst the cassettes are ~nclosed and ensure protection for the feed-qtock.

Claims

1) An assembly comprising a thermal transfer printer in combination with a length of elongate strip or flattened tubing, the printer having a thermal transfer print head and means for guiding the strip or tubing past the print head, the guiding means being arranged to constrain the strip or tubing against lateral displacement as it advances through the print head.

2) An assembly as claimed in claim 1, in which the strip or tubing is preformed with transverse lines of weakness at intervals along its length, to define successive markers.

3) An assembly as claimed in claim 2, in which the lines of weakness may be provided by a line of perforations through the thickness of the material.

4) An assembly as claimed in claim 2, in which the lines of weakness may be provided by a partial cut through the thickness of the material.

5) An assembly as claimed in claim 1, in which the strip is semi-rigid.

6) An assembly as claimed in claim 1, in which the strip comprises an adhesive backing.

7) An assembly as claimed in claim 1, in which the strip or tubing is joined to an axially extending carrier.

8) An assembly as claimed in claim 7, in which the edge of the strip or tubing is connected to the edge of the carrier.

9) An assembly as claimed in claim 8, in which two lengths of strip or tubing are mounted side-by-side to respective opposite side edges of the carrier.

10) An assembly as claimed in claim 8, in which the or each length of strip or tubing is frangibly connected to the carrier.

11) An assembly as claimed in claim 7, in which the strip or tubing is mounted on an elongate carrier of sheet material, the strip or tubing being disposed between opposite side edges of the carrier.

12) An assembly as claimed in claim 11, in which a plurality of strips and/or lengths of tubing coextend along the carrier.

13) An assembly as claimed in claim 1, in which the strip or tubing is wound onto a reel, which is mounted for rotation.

14) An assembly as claimed in claim 13, in which the guiding means comprises a pair of elongate guides which extend from the reel towards the print head, the elongate guides having inwardly-facing edges which are formed with longitudinal grooves in which the opposite edges of the strip or tubing are slidably received.

15) An assembly as claimed in claim 14, in which the elongate guides comprise two separate members which are engaged, either side of the reel, onto a spindle on which the reel is fitted.

16) An assembly as claimed in claim 14, in which the elongate guides are mounted to the reel, so that the reel and guides form a single unit for fitting into the printer.

17) An assembly as claimed in claim 14, in which the elongate strip or tubing is wound within a cassette, having an exit slot through which the feedstock passes.

18) An assembly as claimed in claim 17, in which the cassette includes a portion which projects radially outwardly and includes the exit slot at its outer end, opposite side walls of the projecting portion being arranged to constrain the strip or tubing against transverse displacement as it advances towards the print head.

19) An assembly as claimed in claim 17, in which the cassette is arranged so that it can be reversed.

20) An assembly as claimed in claim 19, in which the cassette is symmetrical about a plane which contains its exit slot and the axis around which the strip or tubing is wound.

21) A thermal transfer printer arranged to receive a wound length of elongate strip or flattened tubing, the printer having a thermal transfer print head and means for guiding the strip or tubing past the print head, the guiding means being arranged to constrain the strip or tubing against lateral displacement as it advances through the print head.

22) A thermal transfer printer as claimed in claim 21, arranged to receive a wound length of strip of tubing of selected width.

23) A thermal transfer printer as claimed in claim 22, arranged to receive two or more wound lengths of strip or tubing, side-by-side.

24) A method of forming printed markers, comprising advancing an elongate strip or length of flattened tubing longitudinally of itself through a thermal transfer printer and printing indicia at successive longitudinal intervals onto said strip or tubing.

25) A method as claimed in claim 24, in which the strip or tubing is formed with transverse lines of weakness after it has been printed.

26) A method as claimed in claim 24, in which the strip or tubing is printed on one side, and rewound onto the same or different reel, which is then inserted into the printer for printing onto the opposite side of the strip or tubing.

27) Feedstock for forming individual markers, the feedstock comprising an elongate strip or a flattened length of tubing, formed with transverse lines of weakness at intervals along its length, to define successive markers.

28) A series of markers formed on an elongate strip or length of flattened tubing, said strip or tubing being formed with transverse lines of weakness at intervals and carrying printed indicia between the adjacent pairs of lines of weakness.

29) An assembly comprising a thermal transfer printer in combination with a length of elongate strip or flattened tubing, formed with transverse lines of weakness at intervals along its length to define successive markers, datum markings being formed at regular intervals along the strip or tubing, the spacing between each marking being related to the length of each marker, the printer comprising a sensor arranged to sense the position of each marker as the strip or tubing is advanced through the printer and control means arranged to control the position at which successive prints are formed on successive markers of the strip or tubing, in accordance with the output of the sensor.

30) An assembly as claimed in claim 29, in which a datum marking is provided on each of the successive markers.

31) An assembly as claimed in claim 29, in which datum markings are not be provided on every marker, the printer being arranged to calculate the position at which each successive marker is to be printed.

32) An assembly as claimed in claim 29, in which the markings are transparent.

33) An assembly as claimed in claim 32, in which the markings are formed of a UV reflective material.

34) An assembly as claimed in claim 33, in which the printer comprises a UV light source which irradiates the strip or tubing, the sensor being arranged to detect said UV light reflected from the datum markings.