This invention relates to a dispenser by means of which arbitrary lengths may be severed and removed from one end of an elongate substrate. More particularly it relates to such a dispenser for cutting pieces from the end of a roll of pressurβ-sensitive-adhesive, or like, tape. In a particularly valuable embodiment it relates to such a dispenser for pigmented repositionable pressure-sensitive-adhesive transparent marker tape, as described in more detail below.

Pressure-sensitive-adhesive tapes are presented with the adhesive on one face of the tape and a release coating on the other so that the tape can be wound into a spiral roll and unwound progressively for use. Although the unwound position can be transversely severed with scissors for casual use, more repeated use conveniently involves the presence of a dispenser.

The most commonly-encountered dispenser comprises a heavy mounting, typically with rubber pads at the base so as to resist dislodgement in use, carrying a suitable roll over which the spiral of tape can rotate when the free end is pulled. The free end of the tape passes when pulled, over a transversely extending serrated edge, and if pulled downwards so that the points of the serrations enter the tape, is thereby provided with

progressively enlarging aligned openings until the free end is severed. At this time the adhesive face is at the underside, and typically adheres to a short leadface adjacent the serrations, until re-use.

A more recently available dispenser also uses a transverse serrated edge but is differently constructed. It is generally box-shaped, with the spiral roll of tape mounted around a suitable internal roll and the free end protruding from a transverse slot in an upper part of the box. Forward of the transverse slot is mounted a transverse blade with the serrated edge. In use the dispenser is picked up in one hand by the user and the free end of the tape is pulled from the slot to the extent desired, and severed over the serrated edge.

The remaining exposed length (i. e. extending from the slot to the blade) can if desired be folded back in the other direction to stick temporarily to the outside of the box on the other side of the slot, provided that the roll is so located that the adhesive side is uppermost when the tape is severed, as distinct from the case when a heavy desk dispenser is used. For this reason such a known dispenser is particularly useful for the recently available low-tack repositionable transparent luminous marking tapes. Such tapes can be lightly adhered to but are easily removable from paper surfaces, and

capable of use, more than once, as with repositionable memorandum pads, since they are similarly provided with a low-tack adhesive. They are also pigmented, transparent and luminous i. e. ' DAYGLO' , so that a length of tape can be located over a body of text as an emphasis, but removed later. Such tapes are particularly adapted to the ' box' type dispenser as described above since, in use, such a dispenser presents the adhesive face uppermost and gives an exposed length after cutting which is folded back and stuck to the box: in both these respects a low-tack face is preferably to a high-tack face.

The dispensers described above suffer from the same defect, in that the serrated edge, at all times presented for convenient use, is similarly a constant danger to the applicants. Minor lacerations to the hands and fingers are not uncommon. Moreover, the ' repositionable' tape dispenser is somewhat more dangerous than the original heavy dispenser because it is in constant use and located on the desk e. g. by the typewriter, and because it has particularly sharp teeth. This latter expedient is necessary because the teeth must permit clean uniform severance even of very short lengths of a relatively wider tape. Sometimes, indeed, the length severed is less than the width, so that the uniform appearance of the severed edges becomes proportionately of great importance. There is of

course much less of a burden of neat appearance at the severed ends of a longer, narrow tape used for packaging or the like purpose.

There have been proposals to provide a shield element, biassed to lie above the points of the serrations but depressible to expose the serrations for use. Hitherto it has been proposed that the tape flight itself should depress the shield element and expose the teeth. In practice however we find that such a shield element is also depressible by casual finger contact, again leading to lacerations. Indeed such a shield may increase the risk of laceration since it obscures teeth without adequately shielding them.

The present invention sets out to provide a safety shield element for the serrated edge of a box-type tape dispenser, which shield resists displacement to casual finger or like contact but is displaced upon handling of the box in normal use.

In one aspect the invention consists in a dispenser for severing lengths from an elongate substrate, comprising a box-like housing for the elongate substrate, an opening through which the substrate can be pulled, and a serrated blade extending transversely in relation to the path of the exposed substrate, with the teeth of which blade the substrate may be pulled into

contact to sever the desired length: characterized in that a safety shield is located adjacent the blade and is resiliently mounted in relation to the housing to be movable, from an outer position beyond and shielding the teeth of the serrated blade to an inner position exposing the said teeth for use, when the housing is gripped firmly to permit the substrate to be pulled through the opening.

Typically, the elongated substrate is a spiral roll of pressure-sensitive-adhesive tape, and in particular a roll of repositionable low-tack transparent luminous (i.e. day-luminous) pigmented marker tape. The opening will thus typically be a slot through which the tape issues. The blade is typically moreover a flat serrated blade with its edge parallel to and spaced from the slot, to that side such that the adhesive face is uppermost when the tape is severed, whereby the exposed but unsevered length can be folded back for low-tack adhesion to the other side of the slot, which may be configured to assist this temporary adhesion for retrieval at the next instance of use.

The shield is preferably a flat strip or plate with a straight edge located movably about the general level of the teeth on the blade. For instance, it may be such a strip or plate located in the same slot, or a further slot just adjacent the blade, and oveable in and out of the slot to achieve the purpose set forth above (for

convenience, the same slot may serve as a blade mounting and communicate with a blade-holding channel or like structure inside the housing).

To achieve the necessary movement the shield strip or plate may be mounted on, or be an integral part of, an internally mounted resilient framework. For instance, the strip or plate can be carried on a yoke by two parallel arms terminating, beyond a journalling shaft located parallel to the shield strip, in a resilient leaf engageable to press against the inside of the housing inwardly of the shield slot and thereby providing for resilient movement into and out of the desired positions. Actuation could be effected by flexure of the housing walls e. g. to bring the front and back faces together, but more preferably the framework itself comprises an actuation member e. g. a plate, bar or button, which protrudes from a suitable orifice in the housing to be actuated when the housing is grasped.

The dispenser in accordance with the present invention can be fabricated as a throwaway unit or (with a removable housing portion) as a refillable unit.

The invention will be further described with reference to the accompanying drawings, in which:

Fig. 1 is an exploded view of the dispenser prior to

assembly, with the blade omitted,

Fig. 2 is a median section of the dispenser with all parts assembled including the blade; and

Fig. 3 shows the blade/shield interaction.

The dispenser is formed as a box portion 1 and a removable side wall 2. It includes a shield unit 3 and a serrated blade 4 (Figs. 2 and 2a).

Box portion 1 has a front wall 5, back wall 6, base 7, top 8 and side wall 9.

Front wall 5 has an orifice 10 towards its upper edge, and a channel shaped formation 11 with shaped inner surfaces 12 and 13, at the top inner margin. Externally, at the top edge 14, it is angled inwards. Back wall 6 has externally directed parallel ribs 15.

Base 7 is generally plane, with finger slot 18 to facilitate dismantling.

Top 8 slopes downwards to a front edge 19, defining a slot 20 with edge 14 of the front. Tape exit slot 21 is defined between inwardly directed tongues 22, 23 towards the rear of the top face.

Side wall 9 carries a spindle 24 for a roll of tape, and defines at 25 a side wall for the top 8. It also carries a collar, not shown, to receive the shaft of

the shield unit, as described below.

Removable side wall 2 fits parallel to side wall 9. It comprises a split cylinder 26 for engagement with the spindle 24 and various fixing lugs 27, 28, 19, 30 for friction engagement with the box portion 1. It also carries a collar 31 for the shield unit shaft.

Shield unit 3 comprises the shaft 32, held in collar 31 and its counterpart collar, not shown. Forwardly, there is an operating button 33, protruding through orifice 10 in use. Parallel arms 34, integral with shaft 32, and further integral resilient leaf 35, ensure that when the button 33 is pressed it can move inwards against a bias and be thereafter pressed firmly out again.

Attached to or integral with the arms 34 is a blade shield 36 which in use protrudes from the slot 20 if the button 33 is undepressed. If the button is depressed, the shield is retracted within slot 20, but is resiliently presented again (by virtue of the resilience in members 32, 34, 35) when the button is released.

Blade 4, serrated at 38 and angled as shown about line 39 is held in channel shaped formation 11 between shaped inner surfaces 12 and 13 (see Figs. 2 and 2a). The line of sharp serrations 38 lies beneath the upper

shield edge position 40 but below the position of the shield edge 41, shown in dotted lines, when the button

32 is released.

The use of the dispenser is readily comprehended. The user picks up the box, and in so doing depresses button

33 to expose the sharp serrations 38. The end of the tape is detached from ribs 15, brought forward over the top 8 between guide walls 25 and pulled down over the serrations 38 to give a clean separation. The tape is then folded back over serrations 38.

Casual touching, or like impact, at the blade region is not enough to force down the shield 36 past serrations 38 to cause an accident.