GB2271553A - Label feed pitch change-over mechanism for labeller - Google Patents

Abstract

A label feed pitch change-over mechanism for a labeller comprises a pitch change-over section 3 equipped with stops 6 and disposed at the bottom of the labeller to be slidable in the longitudinal direction thereof, a claw reciprocator 15 - 20 for engaging the backing strip (B) of a continuous label strip (T) and drawing the continuous label strip from a roll thereof, and gears 11, 12 mechanically linked with a hand-operated lever 8 for driving the claw reciprocator and provided with cams 13 engageable with the stops. The label feed pitch of the claw reciprocator can be switched between short and long states by sliding the pitch change-over section to bring the stops in and out of engagement with the cams. <IMAGE>

Description

LABEL FEED PITCH CHANGE-OVER MECHANISM FOR LABELLER The invention relates to a label feed pitch changeover mechanism for a labeller which can be loaded with label cassettes having label rolls containing labels that are of different lengths.

Japanese Utility Model Publication No. Hei-1(1989)13,053 discloses a labeller equipped with a mechanism for changing the pitch at which labels are fed during label printing. In that mechanism, a vertical positioning means (screw) located at the upper part of the labeller is operated to raise or lower a vertically movable triangular adjustment member for adjusting the label feed stroke. The stroke adjustment is achieved by controlling the relationship between a vertical positioning plate having an inclined surface and a link shaft attached to a drive member so as to limit the rotational angle of the drive member so as to limit the stroke of a reciprocating feed member.

The mechanism for adjusting the stroke of the feed member during label feeding in this prior art labeller is both complex in structure and troublesome to adjust before operating. Moreover, since the stroke adjustment it provides during label feeding is conducted steplessly in fine degrees, the mechanism is obviously intended for adjusting the labeller to compensate for errors in the positioning of feed cuts in the label backing sheet that occur during production of the label roll.

It is an object of the present invention to overcome or mitigate the above-mentioned problems and to provide a label feed pitch change-over mechanism for a labeller that is able to change the feed pitch of a roll-type continuous label strip as required in response to large changes in label size (length) between different continuous label strips, that is simple in structure and easy to operate, and that provides stepwise pitch change-over in two or more steps rather than continuous pitch change.

The present invention provides a label feed pitch change-over mechanism for a labeller, comprising stops that can be slid in the longitudinal direction of the bottom member of the labeller by operation of a movable change-over member for bringing the stops in and out of engagement with the cams of gears for operating a claw reciprocator to draw a backing strip so that labels provisionally attached thereto are peeled off by sharply reversing the direction of travel of the backing strip, the claw reciprocator being changed between long and short reciprocating strokes, and optionally also intermediate strokes, by the disengagement and engagement of the stops from and with the cams.

Preferably, when the label feed pitch is changed from long to short, the operating lever is squeezed and the change-over member is slid toward the rear of the labeller to cause the engagement projection to ride over the step and the stops to move into engagement with the underside of the cams, thus establishing the short label feed pitch.

One form of labeller incorporating a label feed pitch changeover mechanism according to the invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is an overall perspective view of a labeller unit loaded with a label cassette containing a roll of continuous label strip; Figure 2 is a view similar to Figure 1 showing the labeller unit and the label cassette in their separated state; Figure 3 is a perspective bottom view of the labeller unit of Figure 1 showing how the operation for changing the label feed pitch is conducted; Figure 4 is a simplified overall side sectional view of the labeller unit of Figure 1 showing one setting of the label feed pitch change-over mechanism; Figure 5 is view similar to Figure 4 showing the other setting of the label feed pitch change-over mechanism;; Figure 6 is an overall side sectional view of the labeller unit of Figure 1 with a label cassette loaded and the continuous label strip set in place for printing; Figure 7 is a front sectional view of the essential part of an excessive label projection prevention device employing a rubber ring; Figure 8 is a side sectional view of the essential part of an excessive label projection prevention device employing an elastic label presser member; Figure 9 is a top sectional view of the device shown in Figure 8; Figure 10 is an overall perspective view of the label cassette of the labeller of Figure 1 showing how a retainer for restricting lateral movement of the roll of continuous label strip is operated; Figure 11 is an exploded perspective view of a part of the retainer shown in Figure 10; and Figure 12 is an enlarged plan view of the essential part of the retainer shown in Figure 10.

Referring to the drawings, and initially to Figures 1 to 3, one form of labeller equipped with a mechanism for label feed pitch change-over constructed in accordance with the invention consists of a labeller unit 1 and a label cassette 2 loaded into the labeller unit 1.

The label cassette 2 comprises a spool 30 for holding a roll of continuous label strip T consisting of a number of preprinted labels L releasably attached at regular intervals to a backing strip B. When an operating lever 8 of the labeller unit 1 is squeezed towards a grip 7 of the labeller unit, one of the labels L is peeled off the backing strip B and made ready for attachment to the object to be labelled.

The roll of continuous label strip T is available in different types in which the labels L are of different lengths, and consequently the label pitch (which is usually equal to the label length plus a narrow gap between labels) is different. The labeller unit 1 is provided with the label feed pitch change-over mechanism according to the present invention so as to be able to use the different types of continuous label strip T. When the continuous label strip T is changed from one type to another, the label feed pitch change-over mechanism is operated to change the label feed pitch to that suitable for the pitch of the labels of the new continuous label strip T.

As shown in Figure 3, the change-over between label feed pitches is carried out by operating a pitch changeover section 3, specifically by sliding a change-over member 5 thereof provided on a bottom member 4. In the present embodiment, two label feed pitch settings are possible: when the change-over member 5 is slid in the direction of arrow a the shorter feed pitch setting (28 mm) is selected and when it is slid in the direction of arrow b the longer pitch setting (38.1 mm, 43 mm, or 50.8 mm) is selected . (The reason for the longer setting being able to provide three pitches will be explained later.) The label feed pitch change-over mechanism will now be explained in detail with reference to Figures 4 and 5.

The pitch change-over section 3 comprises a change-over member 5, which is a moulded cylinder of synthetic resin having an engagement section 5a including an elastic engagement projection 5b on its bottom side. The pitch change-over section 3 is provided at the bottom of the labeller unit 1 so that the label feed pitch can be changed over by the engagement projection 5b riding over a step 4a extending in the lateral direction of the bottom member 4.

A stop 6 is bonded to or formed integrally with either lateral side of the change-over member 5. The pair of stops 6 move together with the change-over member 5 to be slidable in the longitudinal direction of the bottom member 4, which is also the longitudinal direction of the backing strip B.

A pair of sector gears 12 having respective cams 13 engageable with the stops 6 are rotatably mounted on either end of a shaft 14 supported by the opposite lateral walls of the labeller unit 1. Each sector gear 12 is also engaged with the gear portion of one of a pair of geared arms 11. The geared arms 11 are rotatably mounted on a shaft 10 and connected with the operating lever 8 so as to be rotated counterclockwise against the force of a spring 9 (as shown in Figure 6) when the grip 7 and the operating lever 8 are squeeqed together.

An operating arm 15 iS mounted on each end of the shaft 14 outside the sector gear 12 mounted thereon. The other end of each operating arm 15 is linked with a claw arm 17 via a link pin 16. The other ends of the claw arms 17 are rotatably attached to a shaft 19 of a slider 20.

The movement of the operating arm 15 is thus transmitted to the slider 20 to cause the shaft 19 of the slider 20 to slide along guide rails 21 provided to extend in the longitudinal direction of the bottom member 4. The shaft 19 of the slider 20 has a pair of claws 18 which engage with and pull feed flaps (not shown) of the backing strip B. The operating arm 15, claw arm 17, slider 20 and claw 18 on each side together constitute a claw reciprocator 22.

Figure 6 shows a side sectional view of the labeller unit loaded with a label cassette 2 having a roll of continuous label strip T on its spool 30.

The tip of the continuous label strip T is paid out from the label cassette 2 and passed under a presser roller 31 and to a deflection pin 32 provided in the label cassette 2, where the backing strip B is turned sharply back to peel off the labels L. On the other hand, as mentioned earlier, the backing strip B from which the labels L have been peeled is drawn in the direction of the arrow a by the claws 18. As will be explained later, on the return stroke the claws 18 disengage from the backing strip B and move in the opposite direction from the arrow a to resume their initial positions.

The reciprocal motion of the claws 18 is produced via the geared arms 11, the sector gears 12 and the claw reciprocator 22 by squeezing the operating lever 8 towards the grip 7 against the force of the spring 9 and by releasing the operating lever 8 to allow the spring 9 to return it to its normal position.

Each claw 18 is further biased by a coil spring 23 wound about the shaft 19. Thus, after the claws have engaged with the feed flaps of the backing strip B and drawn the backing strip B a prescribed distance (the label feed pitch), the action of the coil springs 23 enables the claws 18 to disengage from the feed flaps and, while maintaining a light pressure on the undersurface of the backing strip B, to return to their original positions for engagement with the next pair of feed flaps.

The reason why three pitches (38.1 mm, 43 mm, and 50.8 mm) can be obtained at the longer setting is that, when the pitch of the feed flaps is shorter than the stroke of the claws 18, the claws (which are held in contact with the backing strip B by the pressure of the coil springs 23) will slip until they reach and engage with a pair of feed flaps. On the other hand, on the return stroke the claws 18 overcome the force of the coil springs 23 to separate from and go past the next pair of feed flaps, with which they will engage on the following stroke.

Although in the labeller shown in the drawings the gears 12 provided with cams 13 for engaging with and disengaging from the stops 6 are sector-shaped, it is possible to use circular gears instead, provided that they are formed at an appropriate portion thereof with cams for engaging with the stops 6.

It is also possible to form the cams 13 on the side surfaces of the gears 12 or to form them independently of the gears 12.

In addition, label feed pitch change-over mechanisms with strokes suitable for use with continuous label strips T of various label pitches can be made available by equipping them with stop cams 13 of differing thickness.

The operation of the label feed pitch change-over mechanism according to the present invention will now be explained with reference to Figures 4 and 5. When it is desired to change-over from the long pitch setting (Figure 4) to the short pitch setting (Figure 5), the change-over member 5 is slid from the position shown in Figure 4 in the direction of the arrow a so as to cause the engagement projection 5b to ride over the step 4a and assume the position shown in Figure 5. When the changeover member 5 is slid in this manner, the stops 6 also move by the same distance in the direction of the arrow a and, as a result, come into engagement with the cams 13 of the sector gears 12.

This engagement of the stops 6 with the cams 13 requires the operating lever 8 to be squeezed slightly.

This is because the force of the spring 9 acts to rotate the sector gears 12 counterclockwise and hold the cams 13 at a level where they will be struck by the stops 6 when they are slid in the direction of the arrow a. The operating lever 8 is therefore squeezed to rotate the cams 13 of the sector gears 12 by a small amount, specifically to a position higher than the stops 6, after which the stops 6 can pass under and engage with the cams 13. The operating lever 8 can then be released.

The engagement of the stops 6 and the cams 13 of the sector gears 12 shortens the arc through which the sector gears 12 can rotate, and thus shortens the stroke of the claw reciprocator 22 from S1 to S2, so that the claws 18 thereafter reciprocate for drawing the backing strip B at a shorter stroke S2.

The operation for changing the label feed pitch from short to long, which is the reverse of that just explained, increases the stroke of the claw reciprocator 22 from S2 to S1, after which the claws 18 reciprocate for drawing the backing strip B at a longer stroke sl.

Reference symbol 2b in the drawings designates a guide surface for the backing strip B of the label cassette 2 and corresponds to the bottom of the cassette, 33 designates a backing sheet presser foot, and 34 designates a cutter for severing the backing strip B into appropriate lengths.

In the label feed pitch change-over mechanism disclosed in the present application, the labeller unit 1 is equipped on both sides with the sector gears 12, the cams 13, the claw reciprocator 22 and the stops 6 engageable with the Cams 13. Differently from the onesided arrangement of the prior art labeller (Japanese Utility Model Publication No. Hei 1(1989)-13,053), this two-sided arrangement eliminates label feed position shift and ensures stable label conveyance.

Another aspect of the invention provides an excessive label projection prevention device for preventing excessive projection of the continuous label strip T.

In the labeller 1, the labels L releasably attached to the backing strip B are peeled off the backing strip B and made ready for application to the object to be labelled by sharply reversing the direction of travel of the backing strip B. The label excessive projection prevention device according to this invention serves to prevent the peeled-off labels from projecting further than a prescribed amount from a labelling roller 24 at the label supply port of the labeller.

The label excessive projection prevention device is shown in Figure 2 and Figures 6 to 9. It is an improvement of the presser roller 31 portion located at the forward end of the label cassette 2 (Figure 6) for holding down the paid out continuous label strip T and will be explained mainly with reference to the embodiment shown in Figure 7.

The label cassette 2 is equipped with a rotary label presser section 36 for holding down the continuous label strip T. The rotary label presser section 36 comprises a pair of support projections 37 that are pivotably supported by the opposite side walls 2a, 2a of the label cassette 2 so as to accommodate the rotary label presser section 36 inside the label cassette 2.

More specifically, as shown in Figures 6 and 7, the leading end of the roll of continuous label strip T is drawn out and, with the rotary label presser section 36 opened upward, turned back at the deflection pin 32 and set in a rotary backing sheet presser section at the rear of the label cassette 2.

The presser roller 31 for guiding the continuous label strip T is provided at the forward end of the rotary label presser section 36. The rotary label presser section 36 is preferably divided into a plurality of sections so as to be able to cope with labels of different widths and configurations. As shown in Figure 7, it is divided into two roller sections 31a and 31b.

The presser roller 31 is mounted on a roller shaft 38 and is provided on its periphery with a large number of peripheral projections 39 for promoting smooth guidance of the continuous label strip T. A plurality of rubber rings 40a serving as excessive label projection prevention members are fitted over the presser roller 31 at positions between the peripheral projections 39.

The rubber rings 40a provided on the periphery of the presser roller 31 elastically retain the continuous label strip T as it passes through the narrow gap G between the presser roller 31 and the bottom 2b of the label cassette 2. The peeled off labels L are thus prevented from projecting more than the prescribed amount.

A second embodiment of the excessive label projection prevention device will now be explained with reference to Figures 8 and 9. In the second embodiment, the roller shaft 38 at the forward end of the rotary label presser section 36 of the label cassette 2 is fitted with a presser roller 31 consisting of three roller sections 31a, 31b, and 31c. Elastic label presser members 40b made of synthetic resin and formed integrally with the rotary label presser section 36 are located between adjacent roller sections 31a and 31b and between adjacent roller sections 31b and 31c.

The elastic label presser members 40b serving as the excessive label projection prevention members apply an elastic force on the deflection pin 32 located at the bottom front of the label cassette 2 and this force prevents the labels L peeled off the backing strip B and projected forward from being projected more than the prescribed amount.

The labeller unit 1 is provided with a label receiver 25 for receiving the peeled off labels L, an auxiliary pin 26 for guiding the peeled off labels L, and the labelling roller 24 for applying the labels L to the individual objects to be labelled.

Another aspect of the invention provides a retainer for restricting lateral movement of the roll of continuous label strip. This retainer is an improvement on the label lateral guide device for a label cassette disclosed in the assignee's Japanese laid-open Patent Application No. Hei. 2(1990)-4630. In accordance with this aspect of the invention, there is provided a retainer which ensures that the continuous label strip can be paid out smoothly irrespective of differences in width between different types of label strip rolls.

The retainer is shown in Figures 2, 6 to 10, and 12.

Referring first to Figures 2 and 10, which show perspective views of the label cassette 2, the label cassette is provided at its forward end with a label lateral restriction section 50 which comprises a retainer plate 52 linked with a grip 51 slidable along a guide slit 54 in a dial 53 of the rotary label presser section 36 for restraining the side surface of the roll of continuous label strip T.

As shown in Figure 11, the grip 51, and accordingly the retainer plate 52, are held in the selected position by engagement of elastic projections 55 on the retainer plate 52 with one of a plurality of pairs of engagement holes 56.

The retainer plate 52 and the elastic projections 55 thereon are integrally moulded of synthetic resin. Three pairs of engagement holes 56 are provided, one each for restricting 48 mm, 40 mm and 36 mm wide rolls. The members of each pair are vertically aligned above and below the guide slit 54.

As described in the foregoing, the label feed pitch change-over mechanism for a labeller according to the present invention is constituted such that by operating the change-over member 5 of the pitch change-over section 3 at the bottom of the labeller unit 1 so as to cause the longitudinally slidable stops 6 to engage/disengage with/from the cams 13 of the sector gears 12 linked with the reciprocating claw reciprocator 22, the stroke of the claw reciprocator 22 can be controlled for simply and accurately changing the label feed pitch.

Claims (6)

Claims:

1. A label feed pitch change-over mechanism for a labeller, comprising: a pitch change-over section equipped with stops and arranged to be disposed at the bottom of the labeller to be slidable in the longitudinal direction thereof; a claw reciprocator for engaging a backing strip of a continuous label strip and drawing the continuous label strip from a roll thereof; and gears for driving the claw reciprocator and provided with cams engageable with the stops; the label feed pitch of the claw reciprocator being changeable between at least a short and a long state by sliding the pitch change-over section to bring the stops in and out of engagement with the cams.

2. A label feed pitch changeover mechanism substantially as hereinbefore described with reference to, and as shown in, Figures 2 to 6 of the accompanying drawings.

3. A labeller incorporating a label feed pitch changeover mechanism as claimed in claim 1 or claim 2.

4. A labeller substantially as hereinbefore described with reference to, and as shown in, Figures 1 to 6 of the accompanying drawings.

5. A labeller as slaimed in claim 4, modified substantially as hereinbefore described with reference to, and as shown in, Figures 7, 11, and 12, or Figures 8 and 9, of the accompanying drawings.

6. A label cassette substantially as hereinbefore described with reference to, and as shown in, Figures 1, 2, 6, and 10 of the accompanying drawings.