EP0317448B1 - Control device for the cutting plate of a distribution device, and for simultaneously cutting wound strip - Google Patents

Abstract

The control means for the cutting plate is noteworthy in that it consists of a rack-pinion device, with limited toothings, the pinion (1) being integral with a fixed part of the apparatus, with its axis of symmetry coincident with the axis of rotation of the drum, whilst the rack (2) is integral with the pivoting axis of the cutting-plate holder at a point located close to the periphery of the drum, with its toothing established opposite the said axis and according to a radius of curvature having, as centre, the said pivoting axis; the rack-pinion device being suitably sized and oriented in order to ensure the exit of the cutting plate outside the drum immediately after it passes behind the roll of material bearing on the drum, whilst the return of the said plate is achieved by an element complementing the device acting before its passage to the lower part of the apparatus. <IMAGE>

Description

The invention relates to a means for controlling the cutting blade for an apparatus for simultaneously distributing and cutting strips of wound material.

The object of the invention relates to the technical sector of the means for distributing the length of materials wound on reels. In particular, but not exclusively, the invention applies to apparatus for dispensing paper, wadding and similar wiping materials.

The apparatus is not limited to the type according to which the roll of material in service mounted with free rotation on a support, is applied by pressure directly to a drum with non-slip surface, so that by simple manual pulling on the strip of overflowing material under the apparatus, a strip is distributed and cut automatically, the length of which is substantially equal to the diameter of the drum, by a serrated cutting device associated with the drum and protruding from the drum when it is rotated by traction on the material, so as to penetrate the material thus stretched on either side of the cutting device. After cutting, the launched drum returns to its initial position through the action of various complementary members and a new strip of material overflows from the device.

Such a device has in particular been described in French Patent N. 2,332,215 and its Certificate of Addition N. 2,340,887 and also in European Patent No. 0.157.713 and in French Patent Applications N. 85.19447, N 85.02873, N. 86.18497 and N. 87.14068, in the name of the depositor.

It will be recalled that this type of device, as illustrated, mainly comprises, from a casing (not shown), a base plate (A) for wall mounting with wings (A1) (A2) receiving a drum for free rotation (B) in which is articulated at the side walls, a cutting blade holder (C) which is connected to means external to the drum to be controlled for cutting during the rotation of the latter.

A roller (F) of wiping material is mounted on a support bracket (G) articulated on the base plate and held resiliently in contact with the drum, the periphery of which is arranged to prevent slipping during traction on the overflowing strip. (F1). Thus, when pulling on said strip wound on the drum and protruding from the rear, the drum (B) is rotated and the cutting blade holder (C) associated with the control means, describes a curved path which makes it pass from a retracted position in the drum to an exit position (by a radial slot (B1) of the drum) where the serrated blade which is inclined in two orthogonal directions, can gradually penetrate into the material stretched on both sides 'other and thus detach a strip of length corresponding to the diameter of the drum that by the combined action of penetration and rotation.

At the end of traction, when the strip is detached, the drum which is connected on one side to an eccentric and spring lever mechanism (H), must return to the initial or armed position with a new strip of material overflowing under the device ready to be pulled, and no possibility to go back.

For this, various organs combined together and already described in the aforementioned Patents, are associated with the drum.

In particular, a part (J) called a parachute is freely articulated around a bearing secured to a wing of the base plate.

This parachute carries at its upper part and opposite the drum, a pawl (L) articulated elastically at (L1) to be constantly applied at its free end to a stop (J1) of the parachute. The wall of the drum carries near its periphery, a projection (B2) which is positioned and profiled to pass above the stop (J1) and raise the pawl (L) when, after cutting the material, the drum is launched by the eccentric lever (H). As soon as the projection (B2) has escaped from the pawl, the latter falls in abutment on the stop (J1).

During this drum launching action, a stop (M) pivotally mounted inside said drum and having a part protruding from the wall by a large opening in an arc of a circle, has passed by gravity from a low position or close to the axis of the drum has a high position or away from said axis, in said opening. To stop the rotation of the drum as soon as the projection (B2) has escaped the pawl, provision has been made to keep this movable stop in the high position, despite its natural tendency to fall back when the drum approaches the area where it must stop. , so that said stop is pressed against the stop (J1) of the parachute which then oscillates against a spring (N) before returning by a projection (J2) in abutment against a stopper (A3) of the 'wing (A2).

For this, there is either a ramp (J3) judiciously oriented, dimensioned and associated with the parachute to force the movable stop to go up, or a lever freely articulated inside the drum at a point substantially diametrically opposite the point of articulation of the movable stopper and suitably sized to be naturally under said movable stopper, thereby retaining it in the high position so that it stops the drum when the drum is at the end of its travel, while said lever automatically retracts under the effect of the mobile stop rising when it comes into contact with the stop (J1), thus allowing the mobile stop (M) to return by gravity to the low position to reset the device.

This type of device gives users complete satisfaction, in particular by its simplicity of use and its reliability. However, it appeared necessary to further improve its performance, in particular in terms of safety, smoothness of operation, and economy of manufacture.

For this, and according to a first characteristic of the invention, the control means of the cutting blade is constituted by a device of the rack and pinion type with limited toothing, the pinion being integral with a fixed part of the apparatus situated opposite one of the walls of the drum and parallel to them, with its axis of symmetry coinciding with the axis of rotation of the drum, while the rack is integral with the pivot axis of the cutting blade holder at a point located near the periphery of the drum, with its teeth set opposite to said axis and along a radius of curvature having said pivot axis at its center; the rack and pinion device being suitably sized and oriented to ensure the exit of the cutting blade from the drum as soon as it passes behind the roll of material bearing on the drum, while the re-entry of said blade is obtained by a complementary member to the device acting before it passes to the lower part of the device.

These characteristics and others will emerge from the description which follows.

• La figure 1 est une vue de face, carter enlevé, d'un exemple de réalisation de l'appareil équipé du moyen de commande de lame selon l'invention.
• Les figures 2 à 5 montrent par des vues partielles en coupe considérées suivant la ligne 2-2 de la figure 1, les différentes phases de fonctionnement de la distribution et de la coupe avec le moyen de commande de la lame selon l'invention.
• La figure 6 est une vue partielle en coupe illustrant une variante de réalisation du moyen de commande de rentrée de la lame.

To fix the subject of the invention without however limiting it, in the appended drawings:

• Figure 1 is a front view, housing removed, of an exemplary embodiment of the apparatus equipped with the blade control means according to the invention.
• Figures 2 to 5 show by partial sectional views taken along line 2-2 of Figure 1, the different operating phases of the distribution and cutting with the blade control means according to the invention.
• Figure 6 is a partial sectional view illustrating an alternative embodiment of the blade reentry control means.

In order to make the object of the invention more concrete, it is now described in a nonlimiting manner with reference to the exemplary embodiments of the figures of the drawings.

The main known elements of the device having been stated in the preamble, we limit ourselves here to describing the control means of the cutting blade which is essentially constituted by a device of the rack and pinion type. limited teeth. The pinion element consists for example of a cylindrical seat (1) which is fixed to a re-entrant part (A4) of the wing (A1) of the base plate, on the opposite side of the drum (B), and which is crossed by the axis of rotation (D) of said drum carrying outside the eccentric lever and launching spring (H). On a part of its periphery, the cylindrical bearing surface (1) has teeth (1a), the number of which has been determined to obtain the output of the cutting blade from the drum in an arc of circle limited between the rear of the roller material to be dispensed which is applied to the drum and the bottom of the device.

The rack element consists of a sector (2) of generally triangular shape which is fixed, outside the drum and in the plane of the pinion (1), to the pivot axis (C1) of the blade holder ( C), near the periphery of the drum. Opposite the axis (C1), the sector (2) has, according to a curvature having the center of said axis, teeth (2a) with the same characteristics as the teeth (1a) and in equal number, in order to mesh together periodically.

Between the axis (C1) and the teeth (2a), the sector (2) carries a pin (2b) crossing with clearance an opening in an arc (B3) of the drum, in order to limit the stroke of the blade holder ( VS).

The pinion and the rack thus defined, are positioned and oriented suitably on their respective support to ensure the exit of the cutting blade according to the area indicated above, this with a very low tensile force on the overflowing strip, taking into account the reduced size of the pinion, and in addition, the large dimension of the sector.

One of the objects of the invention is also to ensure a rapid retraction of the blade into the drum after the material has been cut, so that it no longer projects when it reaches the level of the rollers (R1-R2) of guidance of the strip (B1) distributed, this to avoid any catching with possibly the user's fingers engaged between said rollers.

For this, an additional member has been provided which can be, as illustrated in FIG. 6, a spring (3) attached to the rear of the blade holder and to a point on the internal periphery of the drum; the spring being oriented to return the blade holder to the blade retraction position as soon as the rack no longer meshes with the pinion.

According to another embodiment illustrated in Figures 1 to 5, the complementary member is formed directly or in an attached manner, by a profiled shape (4) projecting from the re-entrant part (A4) of the wing (A1) and on which is fixed the pinion element (1).

This profiled shape (4) has a circular profile on a half-part (4a) of its surface with a radius less than that of the drum, the other half-part being on the side of the teeth (1a) of the pinion being delimited by a dish (4b) to authorize the tilting of the sector, as described below.

The toothed sector (2) of generally triangular shape, presents near one of its vertices a finger (2c) extending on the side of the profiled shape (4) and being able to rest on its contour as will be seen below. after.

Referring to Figures 2 to 6, the operation of the control means of the cutting blade thus produced is described.

When the apparatus is at rest (FIG. 2), with a strip (F1) of wiping material ready to be pulled, the drum is in the position illustrated, that is to say that the projection (B2) of the drum is in non-return support against the stop (J1) of the parachute (J), the mobile stop (M) is in the low position in its passage opening and the cutting blade (C) is in front of the roller (F) of material set back from the slot (B1). In this position, the sector (2) is kept apart from the pinion (1) by the finger (2c) resting on a circular part (4a) of the profiled shape (4).

When pulling the strip (F1) of material wound on the drum (Figure 3), it is rotated due to its non-slip surface. As soon as the cutting blade arrives behind the roller (F), the first tooth (2a) of the sector (2) bears against the first tooth (1a) of the pinion (1). The sector, taking into account its teeth and its axis of articulation (C1) to the blade holder, rocks around said axis, its teeth mesh by rolling on the teeth (1a). The cutting blade (C) protruding from the drum, then penetrates the tensioned material on either side of the blade until the strip (F1) is detached. At this moment, the last tooth (2a) of the sector escapes the last tooth (1a) of the pinion (figure 4) and, by the action of launching the drum due to the eccentric and spring lever (H), the finger ( 2c) of the sector comes to rest against the flat (4b) of the profiled shape (4). At the same time, the movable stop (M) of the drum is passed by gravity to the high position in the passage opening of the drum. As the drum continues to rotate, the sector (2) pivots on its axis (C1) because the finger (2c) slides on the flat (4b), thus bringing the blade holder into the retracted position in the drum (Figure 5 ) this before said blade reaches the level of the guide rollers (R1-R2) of the strip of material. The sector is then held in this position by sliding support of his finger (2c) on the circular profile (4a).

If the return spring (3) is used to return the blade holder to the retracted position, it is understood that this spring can act as soon as the sector (2) can tilt freely under the pinion (1).

At the end of the race, the projection (B2) passes under the pawl (L) and lifts it up against its return spring, to arrive above the stop (J1), while the ramp (J3) associated with the parachute (or the articulated lever) prevents the movable stop (M) from falling back into the low position in its passage opening. Then the movable stop (M) bears against the stop (J1), which causes the drum to stop. The parachute oscillates under the effect of the pressing force of the drum, then returns to its initial position by the action of its return spring (N). By reaction, the projection (B2) bears against the pawl (L) which has fallen on the stop (J1) thereby preventing the drum from going back. The device is then ready to cut a new strip of material.

The advantages are apparent from the description. The softness of traction obtained by the pinion-rack assembly, the safety at the level of the guide rollers, is also emphasized, due to the rapid retraction of the cutting blade in the drum.

Claims (6)

1. Control means of the cutting blade for an apparatus for the simultaneous dispensing and cutting of rolled up webs of material of the type according to which the roll (F) of material mounted for free rotation on a wall support (A) is placed under pressure directly on a drum (B) with non skid surface, so that by mere manual pull on the web (F1) of material protruding out under the apparatus, there will be dispensed and separated automatically a web the length of which is approximately equal to the diameter of the drum, by means of a serrated cutting device (C) associated with the drum and co-operating with means outside the drum in order to project out from the drum in an arched manner when said drum is driven for rotation by pulling on the material and to penetrate through the material so stretched on either side of the cutting device, the drum actuated by an eccentric lever (H) coming back after the cutting operation has been performed to the initial position thereof through the intermediary of the action of various various additional organs such as parachute (J), pawl (L), nearing faces (M, J1, B2) disposed on the drum and on the wall support, and a fresh web of material projecting out automatically under the apparatus after the cutting operation, the apparatus being characterized in that the control means of the cutting blade consists of a device of the rack and pinion type with limited toothings, the pinion (1) being in interdependance with a fixed portion of the apparatus situated in front of one of the walls of the drum and parallel to same, with the symmetry axis thereof merging into the axis of rotation of the drum, while the racl (2) is in interdependence with the pivotal axis of the cutting blade holder at a location situated adjacent the periphery of the drum, and with the toothing of the rack established opposite said axis and according a radius of curvature having for its centre said pivotal axis, the rack and pinion device being suitably dimensioned and oriented to allow for the projection of the cutting blade out of the drum immediately after the passage thereof behind the roll of material resting on the drum, while the return of said cutting blade is obtained by means of an organ complementary to the device, becoming active before the passage thereof under the lower portion of the apparatus.

2. Cutting blade control means as claimed in Claim 1, characterized in that the retraction of the cutting blade in a collapsed position within the drum is obtained bi means of a spring (3) secured to the blade holder (C) at a predetermined location of the inside periphery of drum (B), in order to permit the rocking of the rack (2) as soon as the last teeth (2a) thereof is released from the last tooth (1a) of the pinion (1).

3. Cutting blade control means as claimed in Claim 1, characterized in that the retraction of the cutting blade in the position collapsed within the drum is obtained by means of a contoured portion (4) in interdependence with a fixed portion of the apparatus, and by means of the pinion (1) co-operating with a finger (2a) established on the rack at a pre-determined location in order to permit the various movements of the rack.

4. Cutting blade control means as claimed in Claim 1, characterized in that the piston (1) and the rack (2) have each one an identical toothing (1a-2a), the number of teeth of which has been so determined, that by slidable meshing and pivotal motion of the rack about the linking axis (C1) thereof, the development of the cutting blade out of the drum will be permitted along a sector of limited circumference between the rear part of the roll of material (F) and the guide rollers (R1-R2).

5. Cutting blade control means as claimed in Claim 3, characterized in that the contoured portion (4) has successively a circular part (4a) the radius of which is smaller than the radius of drum (B), for the abutment of the finger (2c) of the rack (2) when the latter must be held back in the collapsed position of the cutting blade, and a tapering part delimited by a face (4b) on the side of the teeth of the pinion (1) secured on said contoured portion, in order to permit at first the rocking of the rack and of the finger thereof when the teeth are meshing, for the projection of the cutting blade, and then the collapse of said blade by slidable abutment of the finger (2c) on the face (4b) when the cutting operation has been completed.

6. Cutting blade control means as claimed in Claim 1, characterized in that the piston (1), in order to decrease as much as possible the pulling effort on the protruding web (F1) of material, is of a smaller size, while the rack (2), complementarily, is of a large size.

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