FR2631012A1 - DEVICE FOR UNWINDING AND CUTTING AN ADHESIVE TAPE - Google Patents

Abstract

Device for unwinding and cutting an adhesive tape wound on the outer face of a hollow hub, of the type comprising two side cheeks pivotably mounted at their lower ends about an axis parallel to the generatrices of said hub and joined at their ends upper by a transverse bar carrying a cutting blade, characterized in that said pivot axis of said lateral cheeks is distinct from the axis of the hub, such that as the said tape unwinds, said blade remains constantly at the same distance of the outer surface of the tape roll, thanks to the pivoting of said cheeks about their axis.

Description

The present invention relates to a device for unwinding and cutting

  of a roll of adhesive tape allowing permanent comfort of use whatever the thickness

  of the roller during use.

  Indeed, although this type of device is well known and spreads parallel to the multiple adhesive rollers of different sizes and uses, we are often faced with the same problem of convenience of use. This may be due, in particular, to the uneven qualities of the tapes which tear, form parasitic folds, so that it becomes difficult to operate a clean section if the device is not efficient. Quite often also, the latter is designed to last the time of a roll of self-adhesive tape, that is to say that it fulfills its function in an unsatisfactory manner resulting from a simplified design. extreme or even

  fragility of the materials used.

  Thus, the classic design of the unwinding devices. and cutting of adhesive rollers reveals a hub on which -two parallel cheeks, connected at their ends by the o .. sectioning knife, are sclidalised. The roller is free to 'rotate - on this hollow hub, so that it can be positioned so that the end of the strip to be cut is in the correct position. In some cases, means for gripping the severing appendage and the legs

  for guiding the tape towards the blade are also provided.

  However, regardless of the materials used, this classic design has multiple drawbacks and often proves to be difficult to use. The first design flaw concerns the connection between the hub and the sectioning appendage. They are self-contained, that is, their relative positions are immutable. However, the roller

  decreases in thickness as it is used.

  The relative positions of the cut-off member and the self-adhesive tape therefore change as time passes. This has the effect of changing the cutting angle and the direction of arrival of the ribbon and consequently the quality and ease of cutting. Indeed, it is easy to see that there is a preferred cutting angle for which the operation is easy and the result satisfactory, corresponding to a

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  certain roll thickness. As a first approximation, we can broaden these values by introducing them into intervals whose two limits define a correct range of use. Obviously, the external functionalities are only satisfactorily guaranteed and with sufficient guarantee only in this interval and this poses

the limits of the device.

  Second, there is no effective way to immobilize the cutting device relative to the roller at the precise moment of cutting. However, this is an essential characteristic of this type of device, allowing rapid and precise cutting of the end of the desired ribbon. Conversely, if this condition is not met, the ribbon

  sometimes slips and it becomes difficult to cut it.

  However, the rotation of the roller relative to the device, which causes this drawback, is strictly necessary for operation because it allows the length of ribbon to be cut to be chosen. However, it induces another drawback, immediately after cutting, in that a parasitic rotation in the opposite direction to that of normal unwinding causes the unrolled end of the ribbon to be glued to the

  roller, especially when it is almost finished.

  Indeed, the rigidity between the hub and the cutting appendage implies the establishment of a certain distance between them, so that a new thick roller can also be used. When the thickness decreases, the angle of arrival of the ribbon on the blade changes and it becomes very difficult to

  provide a way to prevent the tape from sticking to the roller.

  The device according to the invention overcomes these drawbacks and proposes a functional design allowing comfort of use without common measure with

  those found in the prior art.

  This design achieves an automatic mechanical control of the position of the sectioning appendage relative to the hub. Regardless of the residual thickness of the roll of self-adhesive tape, the relative positions of the roll and the cutting device are the same, and therefore the cutting angle is also invariable. Furthermore, the problem of the movement of the roller relative to the

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  disconnection device is also resolved because- the forcc-

  exerted at the precise moment of cutting is passed on to the roller, and blocks any possibility of rotation. Finally, the angle of arrival of the ribbon towards the blade being constant, or: a p; u design a precise guide of the ribbon preventing a possible recoiileen '. To this end, the device for unwinding and cutting a roll of adhesive tape of the invention, mounted freely in rotation on the outer face of a hollow hub, comprises two lateral cheeks mounted pixotarnts at their e.tremitis around an axis parallel to the generatrices of said hub and joined at their upper ends by an ersale trarns bar carrying a cutting blade. It is characterized in that said pivot axis of the lateral cheeks is distinct from the axis of the hub, in such a way that as it unwinds the ribbon, said blade remains constantly at the same distance from the external surface of the roller. % aubanri thanks to the pivoting of

cheeks around their axis.

  We will now describe the invention in more detail, with reference to the figures. anre-xeées, lice which: - Figure I is a '.ae front of the set of the device with a roll of adhesive tape, - Figure 2 gives a perspective,

  - Figure 3 shows the same exploded perspective.

  According to a configuration shown in Figure 1, the a: e pivot (1) of the side cheeks (2) is placed along a generatrix of the inner surface of the hub (3). The bar (4) supporting the cutting blade (5) has a spacer (6) determining a minimum constant distance between said blade (5) and the external surface of the ribbon roll (7). This wedge (6) also exerts pressure on said roller (7) each time the user presses the tape on the blade to cut it, so that any relative movement between the roller and the device is inhibited. The tangential effect resulting from the traction exerted by the user for the purpose of sectioning is in fact canceled out by the friction forces arising in contact with this wedge. This dist. constant minimum ance also represents l. length of the unwound tape remaining free after each cut, allowing each

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  new action gripping said ribbon.

  In the vicinity of its upper part, each of the lateral cheeks has a transverse tab (8) facing] a spacer (6). These tabs are part of the guide system, the ribbon passing between them and the spacer (6) before arriving at the cutting blade (5). After cutting, the adhesive side of the free length of unstuck tape

  of the roller comes to bear on these tabs (8).

  In order to allow the replacement of the roller (7) when the adhesive tape is exhausted, provision has been made to mount one of the cheeks so that it is removable. At one of its ends, a fixing lug (9) clicks into a corresponding orifice (10), while the part connected to the sleeve located on the internal face of the hub (3) has a system of analog fixing allowing simultaneous extraction

  on both sides of this side cheek.

  According to a possible improvement shown in Figure 3, the sleeve (11) in which pivots' - the cutting device is provided on its internal periphery with rock teeth. oriented in the direction of the unwinding of the ribbon; the lower end of at least one of the cheeks (2) connects the other by means of a cylinder (12 passing through this sleeve and comprising on its periphery hooks cooperating with said ratchet teeth, so as not to allow the pivoting of the cheeks (2) only in the direction of unwinding and prohibiting it in the other direction. In the case where only one of the cheeks is provided with such a system, the hook cylinder can for example have a length equal to half of

the thickness of the hub.

  The sleeve is provided with at least one slot along one of its generatrices, so that a slight expansion is

  possible to allow and facilitate pivoting.

  The device thus described is applicable whatever the dimensions of the rolls of adhesive tape, scotch tape, chatterton, wide strips for closing packages, etc. Its design offers ease of use which goes hand in hand with its efficiency: the sections made on all types of ribbons are sharp and burr-free thanks to the combination of

  blocking of the roller with the guidance and cutting system.

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  Of course, this description r.'LEt, 4u'il1ustrati \ e c!

  cannot be considered as limiting. The invention.

  on the contrary encompasses all possible variants.

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Claims (7)

  I. Device for unwinding and cutting a roll of adhesive tape, mounted to rotate freely on the external surface of a hollow hub, of the type comprising two lateral cheeks pivotally mounted at their lower ends about a parallel axis to the generatrices of said hub and joined at their upper ends by a transverse bar carrying a cutting blade, characterized in that said pivot axis of said lateral flanges is distinct from the axis of the hub, so that as the unwinding of said ribbon , said blade remains constantly at the same distance from the external surface of the ribbon roll, thanks to the pivoting said cheeks about their axis.   2. Device according to claim 1, characterized in that, under said blade, said strip carries a spacer block determining a minimum constant distance between said blade and the outer surface of the ribbon roll, this distance representing the length of unwound ribbon remaining free after each cut, and allowing the gripping of said ribbon.   3. Device according to claims 1 and 2, characterized   in that each of said cheeks has in the vicinity of its upper end a transverse tab facing said spacer and on which the adhesive face of said free length of tape comes to bear after each chopped off.   4; Device according to claims 1 to 3, characterized   In that the pivot axis of said cheeks is placed along   a generator of the inner surface of the hub.   5. Device according to claim 4, characterized in that said axis is materialized by a sleeve fixed along said generator and comprising on its inner periphery ratchet teeth oriented in the direction of unwinding of the ribbon, the lower ends of at least one of said cheeks being joined by a cylinder passing through this sleeve and comprising on its periphery hooks cooperating with 7 2631012   said ratchet teeth, so as to allow l1 pi-votemernt of said cheeks only in the direction of unwinding. vs   to ban it in the other direction.   6. Device according to claim 5, characterized in that said sleeve has at least one slot along one of   its generators, so that it can expand slightly. allowing said pivoting.   7. Device according to any one of claims 1 to   6, characterized in that one of said cheeks is removably mounted, by separation of its upper part from said bar on the one hand, and on the other hand by simultaneous extraction of the cylinder from said sleeve, so as to separate the device of the ribbon roll when it is used up