LABELS

This invention relates to apparatus for printing and dispensing .labels, for example hand-held apparatus for use with pricing labels.

Numerous apparatus are available for printing and dispensing labels and such apparatus incorporates one or more print heads which serve, prior to the dispensing of any given label, to apply indicia to that label. The indicia usually takes the form of a price and a stock code and experience has shown that it. is very important that the indicia should be so printed on the label that legibility is good even under poor lighting conditions.

The simplest form of printing involves a stamp impression but it is also very well-known in general to use rotary printing for high speed production and controlled printing quality.

In hand-held, manually-operable, apparatus, the problem of providing satisfactory indicia on labels has involved some complexity and cost which is clearly undesirable. In one such proposal a print-head is made to pivot while a label being printed is being moved forwardly simultaneously and although this gives good results inpractice, the apparatus is rather

complex, the more so when two print heads are incorporated i order to provide a two row printing facility. Furthermore, it is frequently desirable that the ink used for one row of printing should differ from that used in the other.

It follows that it is desirable that the print-heads should be operated by a simple mechanism but that nevertheles the quality of the printing should be consistently good and this necessitates that the operative print facets of the prin head or heads shall be adequately inked before each printing takes place.

According to the present invention,there is provided apparatus for printing and dispensing labels comprising a pri head mounted for pivotal movement between a rest position and printing position, means for actuating the print head to eff said movement, track means controlling the orientation of the print head during said movement, a rotatable inking roller positioned adjacent the path of movement of the print head so that during a first half of the operational cycle of the apparatus operative print facets of the head are inked by con with the roller and during the second half of the cycle the operative print facets move past the inking roller without contact, each inking action causing the roller to rotate so t during the next cycle a differnet portion of the roller periph is presented to ink the operative print facets.

Hand-held label printing and dispensing apparatus embody the invention will now be described, by way of example only, reference to the accompanying diagrammatic drawings, iτi which

Figures 1A and IB show the outline of an embodiment of apparatus in accordance with the invention with two print-hea assemblies at a rest and a printing configuration;

Figure 2 is an end elevation of one print-head assembly shown in Figures 1A and IB;

Figure 3 is a side elevation of a modification in which print-head assembly has provision for two lines of print in a single head; and

Figure 4 is a side elevation of a second modification of the print-head assembly of Figures 1 and 2.

Referring now to Figures 1 and 2, the hand-held label printing and dispensing apparatus as a whole comprises a body 10 rigid with a handle 12 and at the end of the handle remote from the main part of the body a trigger member 14 is pivotally mounted which serves to actuate any given operational cycle including label feed and dispensing and also printing.

The label storage and dispensing means includes a reel 16 of label web which incorporates both labels with a self-adhesive surface and a backing strip coated with silicone, and a wind-up reel 19 (Figures .3 and 4) for the spent backing strip after the labels havebeen dispensed. The wind-up reel is not illustrated in Figure 1.

The print-head assembly comprises two separate but co¬ operating print-heads 20, 22, both of which are pivotally mounted at 24 and 26 on a pair of arms 28 (only one shown in Figure 1) . The arms are shown in greater detail in Figure 4 together with actuating means therefor and provide a pivot axis external to the heads themselves. The pivots 24 and 26 provide internal pivot axes within the bounds. of the respective head.

Each print-head assembly carries a spigot 30, 32 at its end adjacent to the operative print facets 34, 36 thereof and actuation of the arms 28 supporting the print-heads 20, 22 controls, with the aid of the respective spigots 30, 32, the movement and orientation of the heads both while inking is taking place and during their travel towards a printing platen 38 on which a label to be printed is present. One or both of the heads may also incorporate a cliche 40 which is not adjustable as are the operative print facets 34, 36 which are mounted on print bands 41 (Figure 2) .

During movement of the print-heads under the action of the .arms 28 the spigots 30, 32 co-operate with respective cam tracks 42,44 and an intermediate track 46 lying between them which serves to prevent over-travel during the movement towards the printing

platen 38. The cam track 42 includes a stop portion 48 corres ponding to the rest position of the print-head 20, a concave inclined portion 50, and a rectilinear portion 52 extending normal to the working face of the platen 38. The cam track 44 has a stop portion 54 corresponding to the rest position o the head 22, a concave portion 56 extending generally at right angles to the rectilinear intermediate track 46, an inclined portion 58 and a rectilinear portion 60 extending normal to the working face of the platen 38. An inking roller 62, 64 co-operates with respective print-heads 20 and 22.

The arms 28 are actuated by the trigger member 14 through means, not shown in Figures 1A and IB, and not forming part of the present invention. One possible mechanism is illustrated in Figure 4 and in greater detail in our co-pending Applicatio No. ("Over Centre") .

Operation of the trigger member 14 will cause the twin arms 28 to pivot from the position shown in Figure 1A progress ively to the position shown in Figure IB. During the first pa of the operational cycle inking will take place and provided t an inking roller 62, 64 is present, t.he spigots 30, 32 do not contact the track portions 50, 56 and the motions of the print heads are controlled by interaction with the inking rollers 62 64 themselves. Excessive pressure by the heads on the rollers is prevented by an arrangement illustrated in and described by an arrangement illustrated in and described with reference to Figure 2. The spigots 30, 32 co-operate with the track portio 50, 56 respectively in the absence of inking rollers in order prevent damage to the mechanism. Spring means (not shown) lightly bias the heads ^" to the open configuration of Figure 1A. Continued movement of the support arms 28 results in the heads 20, 22 disengaging from the inking rollers and the respective spigots 30, 32 then move down the portions 52 and 58, 60 of th cam tracks and any tendency to over-travel and thus interferen between the two print-heads is prevented by the intermediate track 46 lying between the cam tracks 42 and 44. The movemen of the inking rollers 62, 64 ensures that during each successi

operation of the apparatus a different part of the ink pad periphery will be contacted, so that re-inking of the surface from the interior of the inking roller can take place ready for the next contact with the operative print facets. Locii of the spigots 30, 32 are indicated at 30A, 32A, 30B, 32B and so on in Figure 1A.

At the printing position of the two heads as shown in Figure IB, the spigots 30, 32 are closely confined by the cam tracks 42, 44 and the intermediate track so that lateral move¬ ment relative to the label on the platen 38 is positively prevented.

The return half of the operational cycle is substantially the same as the first half but the operative facets do not contact their respective ink rollers on the return half of the cycle. This is ensured because the upward (as shown) move¬ ment of the arms does not press the operative print facets towards the inking rollers 62, ^' 64 and reset stops 66, 68 provided adjacent the upper edge of each print head in its rest position are not contacted until movement of the arms 28 has been substantially completed. Thus undesired ink transfer during the operational cycle is prevented and in the rest position the operative print facets do not contact the inking rollers 62, 64.

In a modification, each inking roller 62, 64 is mounted in the apparatus by quick-release means such as illustrated in our co-pending Application No. and in outline in Figure 2.

Figure 2 shows an end view of one print-head 20 or 22 and the corresponding inking roller 62 or 64 and the pair of pivotal arms 28 which support both print-heads. For the pur¬ pose of renewal of the inking rollers 62, 64 they may be readily

removable by mounting a spindle 70 of the roller in a bearing 72 integral with one wall of the casing 10 and a second spind 74 in a knob 76 which is a snap-fit in another wall of the casing 10. As will also be apparent from Figure 2, end plat 80 of the print head engage during the first part of the opera tional cycle against corresponding flanges 82 at each end of t inking roller 62 or 64 and this engagement ensures that during the inking operation the operative print facets 34 to not dig too deeply into the spongy rubber material forming the outer face of the inking roller 62 or 64. The inking roller is readily removable and replaceable by axial movement, indicate by double-headed arrow 63.

.Turning now to the modification illustrated in Figure 3, the apparatus as a whole is generally similar to that of the first embodiment illustrated in*Figures 1 and 2 but the print- heads are coupled and mounted about a single pivot 100 and a single spigot 102 co-operates with a single cam track 104 to control movement of the print-head both in relation to the single inking roller 106 and in relation to the printing plate 108. The cam track 104 includes an end stop 110, a portion 1 corresponding to the inking part of the operational cycle, a portion 114 inclined in relation to the printing platen surfac and a portion 116 normal to the platen surface. A second tra 118 serves the same purpose as the intermediate track 46 of the first embodiment, namely to ensure freedom from lateral movement of the print-head at the instant of printing (broken lines). Spring means (not shown) bias the head to the full line position. In this embodiment, the inking roller can be removed in the direction of the arrow E or alternatively as indicated in the embodiment of Figures 1 and 2. The roller

removal arrangement of Figure 3 can also be applied to the embodiments of Figures 1 and 2.

The manner of operation of the embodiment of Figure 3 is generally similar to that of Figures 1 and 2 except that only one head assembly is moved. Two line printing is again possible but may not provide as high quality as the first embodiment since any slight misalignment of the single pivotal head cannot be as readily accommodated.

In the embodiment of Figure 4 the construction of the apparatus as a whole is generally similar to that disclosed . in our co-pending Application No ("Over Centre") and the single print head 120 is arranged to co-operate by means of a spigot with a single cam track 104 as in the embodi¬ ment of Figure 3. The print-head 120 provides only a single line of print but otherwise the construction of the printing mechanism is generally the same as that of the embodiment of Figure 3 and like parts have been given the same reference numerals. In the operational cycle the retraction of the print-head 120 effected by the spring means 122 causes, .as in the first embodiment, the operative print facets to return to their rest position without contacting the inking roller 106. Again as in the embodiment of Figure 3 the inking roller can be removed either laterally as indicated by the arrow B or axially as in the embodiment illustrated in Figure 2.