Paper dispenser dispensing mechanism

Abstract

The invention relates to a dispensing mechanism (10) for a paper dispenser, comprising: - a drive roller (15) rotatable about an axis of rotation (X1), said drive roller (15) being intended to support a paper strip (30), - a cutting blade (22) supported by the drive roller (15), said cutting blade (22) being able to move under the action of movement means (23, 25, 27) between a first position, called the rest position, in which the cutting blade (22) is housed entirely inside the drive roller (15), and a second position, called the cutting position, in which the cutting blade (22) can cut the paper strip (30), and - anti-reverse means (21) adapted to allow the rotation of the drive roller (15) in a first direction and to prevent the rotation of the drive roller (15) in a second direction opposite to the first direction. Figure 2

Description

Title of the invention: Dispensing mechanism for a paper dispenser

[0001] The present invention relates to the field of paper dispensers. More specifically, the present invention relates to a dispensing mechanism for a paper dispenser. The present invention also relates to a paper dispenser equipped with such a mechanism.

[0002] Paper dispensers comprising a dispensing mechanism with a drive roller, such as a dispensing drum, are well known in the field. A dispensing drum typically feeds and cuts a paper strip into sheets and can be operated in various ways, for example, manually using a rotary knob, with an electric motor, or by means of a spring-loaded mechanism activated by a user pulling on the paper strip. The dispensing drum contains a cutting blade that can move out of the drum, thus cutting the paper strip extending along the periphery of the drum. Conventionally, each revolution of the dispensing drum corresponds to the length of one sheet of paper, so the cutting blade is extended and retracted once for each revolution.The dispensing drum is often also a drive element, meaning that it extracts paper from the paper supply and then feeds it to a user.

[0003] Such types of paper dispensers are generally equipped with anti-return means which prevent the dispensing drum from moving in the opposite direction when cutting the paper, which could lead to incomplete cutting of the paper, or even to a complete winding of the paper strip around the dispensing drum, which could generate damage in the dispensing mechanism.

[0004] The anti-return means generally used consist of gear and ratchet type mechanisms, which are mounted at the bearing of the distribution drum.

[0005] The use of such anti-return means poses a number of problems.

[0006] On the one hand, their size is relatively large. This results in a difficulty in offering relatively compact paper dispensers.

[0007] On the other hand, when using the distribution mechanism, these anti-return means can generate relatively high noise levels, which may be deemed unacceptable to users.

[0008] An objective of the present invention is to solve the problems identified above associated with prior art paper dispensers by proposing a mechanism for distribution for a paper dispenser that is both compact and quiet.

[0009] To this end, according to a first aspect, the invention relates to a dispensing mechanism for a paper dispenser, comprising:

[0010] - a movable drive roller rotating about an axis of rotation, said drive roller intended to support a paper strip on an external surface and being provided with a shaft and a peripheral slot, said peripheral slot opening into an internal cavity of the drive roller,

[0011] - a cutting blade supported by the drive roller, said cutting blade capable of moving under the action of means of movement between a first position, called the rest position, in which the cutting blade is housed entirely inside the internal cavity of the drive roller, being positioned radially under the external surface of the drive roller, and a second position, called the cutting position, in which the cutting blade protrudes radially from said external surface at the level of the peripheral slot, and

[0012] - anti-reverse means suitable for allowing the rotation of the drive roller in a first direction and to prevent the rotation of the drive roller in a second direction opposite to the first direction,

[0013] wherein said anti-reverse means comprise at least one unidirectional ball bearing on which the shaft of the drive roller is mounted.

[0014] Thus configured, the distribution mechanism exhibits improved compactness due to the use of a unidirectional ball bearing with a reduced footprint. Furthermore, such a unidirectional ball bearing is also characterized by low noise levels during operation.

[0015] According to other features, the distribution mechanism of the invention comprises one or more of the following optional features considered alone or in all possible combinations:

[0016] - the means of movement include a blade actuator mounted in such a pivoting on the drive roller around a pivot axis and on which the cutting blade is fixed, the blade actuator comprising a follower roller eccentric relative to the pivot axis and bearing against a cam, and a spring capable of causing a pivoting of the blade actuator when the follower roller is in an extreme position corresponding to the cutting position of the cutting blade.

[0017] - the cam has a closed contour having a first curved section extending in an arc around the axis of rotation of the drive roller between a first end edge and a second end edge, a second curved section extending from the first end edge of the first curved section to a pointed end edge corresponding to the extreme position of the roller follower, and a third curved section extending from said pointed end edge to the second end edge of the first curved section.

[0018] - the follower roller is close to or in contact with the first end edge of the first curved section of the cam when the cutting blade is in its rest position.

[0019] - the second curved section of the cam has a concavity facing towards the axis of rotation of the drive roller and the third curved section of the cam has a convexity turned towards the second curved section of the cam.

[0020] - the drive roller is provided with a series of annular grooves spaced the one of the others in the axial direction, at least one of said annular grooves housing at least partially a tooth protruding radially from a retaining bar disposed parallel to the drive roller, said tooth being configured to prevent the winding of the paper web around a peripheral portion of said drive roller which is situated downstream of said tooth in the direction of rotation of the drive roller.

[0021] - the distribution mechanism further comprises two guide rollers, respectively an upper guide roller and a lower guide roller, movable in rotation around axes of rotation parallel to the axis of rotation of the drive roller, said guide rollers being able to press the paper strip against the external surface of the drive roller.

[0022] - the distribution mechanism further includes a rotary knob coupled to the shaft of the drive roller, said rotary knob being manually operable so as to allow the rotation of the drive roller, in particular when introducing a new strip of paper into the dispensing mechanism.

[0023] - the rotary knob is provided with two cavities separated by a central segment, said cavities being suitable for receiving a user's fingers.

[0024] According to another aspect, the invention relates to a paper dispenser for distributing a strip of paper, comprising a distribution mechanism as defined above.

[0025] The invention will be more fully understood upon reading the following non-limiting description, made with reference to the figures attached hereto.

[0026] [Fig-1] represents a perspective view of a distribution mechanism according to a method of embodiment of the invention.

[0027] [Fig.2] represents a perspective view of the distribution mechanism of the [Fig.1].

[0028] [Fig.3] represents an exploded perspective view of the drive roller of the distribution mechanism of the [Fig.l].

[0029] [Fig.4] is a first cross-sectional view of the mechanism of [Fig.1], showing the position of the blade actuator in the rest position of the cutting blade.

[0030] [Fig.5a] is a second cross-sectional view of the mechanism of [Fig.l], showing the position of the cutting blade in the rest position of the cutting blade.

[0031] [Fig.5b] is a side view of the mechanism of [Fig.l], showing the position of the return spring in the rest position of the cutting blade.

[0032] [Fig.6a] is a view similar to [Fig.5a], with the cutting blade in its cutting position.

[0033] [Fig.6b] is a view similar to [Fig.5b], with the cutting blade in its cutting position.

[0034] [Fig.7a] is a view similar to [Fig.5a], the cutting blade being in an intermediate position between its cutting position and its resting position.

[0035] [Fig.7b] is a view similar to [Fig.5b], the cutting blade being in the intermediate position of [Fig.7a].

[0036] With reference to figures 1 and 2, a distribution mechanism is shown according to an embodiment of the invention.

[0037] This distribution mechanism 10 includes, in particular, an external frame formed of a lower panel 11, an upper panel 12, a right side panel 13, and a left side panel 14. The external frame surrounds a drive roller 15 mounted to rotate about an axis of rotation XI on the right side panel 13 and the left side panel 14, respectively. Each side panel is formed of two interconnected parts, for example by clipping, namely a bearing panel, 13a and 14a respectively, and a cover plate, 13b and 14b respectively. The cover plate 13b of the right side panel 13 advantageously has a circular arc 131 contour designed to conform to the external shape of a rotary knob 31 coupled to a shaft of the drive roller 15.The rotary knob 31 is equipped in particular with two cavities 311, 312 separated by a central segment 313, said cavities 311, 312 being suitable for receiving a user's fingers. Thus configured, the rotary knob 31 can be turned manually by a user so as to allow the rotation of the drive roller 15. Such an operation will be carried out in particular when introducing a new strip of paper into the dispensing mechanism.

[0038] The distribution mechanism 10 further comprises two guide rollers 16, 17, respectively an upper guide roller 16 and a lower guide roller 17, which are rotatable respectively about axes of rotation X3, X4 parallel to the axis of rotation XI of the drive roller 15. As explained in detail in the following paragraphs, the guide rollers 16, 17 have the function to press the paper strip against the external surface of the drive roller 15, allowing for better paper distribution.

[0039] Furthermore, the distribution mechanism 10 is equipped with a retaining bar 18 which is arranged parallel to the drive roller 15. This retaining bar 18 has several teeth 181 which project radially from an outer face that faces the drive roller 15. Each of these teeth 181 is aligned with an annular groove 153 formed on the outer periphery of the drive roller 15. As shown in [Fig. 2], the drive roller 15 may be provided with a series of such annular grooves 153 along its outer surface, said grooves being spaced from each other axially. In the normal operation of the distribution mechanism, each of the teeth 181 is housed at least partially inside the corresponding annular groove 153.Thus configured, the teeth 181 will prevent the paper strip from wrapping around a peripheral portion of said drive roller 15 which is located downstream of said teeth in the direction of rotation of the drive roller 15. This will prevent damage to the dispensing mechanism in the event that a partially cut paper strip creates a jam inside the mechanism.

[0040] As shown in [Fig. 2], the guide rollers 16 and 17 are advantageously equipped at each end with hubs having bidirectional ball bearings 19 so as to allow bidirectional rotation of the guide rollers 16, 17 around their respective axes X3 and X4. In contrast, the drive roller 15 is equipped at one of its ends with a hub having a bidirectional ball bearing 19 and at its opposite end with a hub having a unidirectional ball bearing 21. This unidirectional ball bearing 21 acts as a backstop which will allow the rotation of the drive roller 15 in a first direction, namely clockwise in the embodiment shown, and prevent the rotation of the drive roller 15 in a second direction opposite to the first direction, namely counterclockwise in the embodiment shown.This unidirectional 21 ball bearing has the advantage of being both compact and quiet.

[0041] With reference to [Fig. 3], an exploded view of the drive roller 15 shown in [Fig. 2] is shown. This drive roller 15 is formed of a lower part 151 and an upper part 152, said lower and upper parts fitting one inside the other. Each of the parts 151, 152 is defined by two left and right end walls in the shape of a half-disc, respectively 151a, 151b and 152a, 152b, connected by a longitudinal wall of substantially semi-cylindrical shape, respectively 151c, 152c. The longitudinal walls 151c, 152c are covered with several strips of rough material 156 intended to improve adhesion of the paper strip upon contact with the drive roller 15. The lower portion 151 incorporates a left hub 154 projecting axially from the left end wall 151a and a right hub 155 projecting axially from the right end wall 151b. These hubs 154, 155 fit into corresponding notches 152e in the end walls 152a, 152b. In an alternative embodiment of the invention (not shown), these hubs 154, 155 may form the two ends of a single shaft passing through the drive roller 15. As explained previously, the left hub 154 will be mounted on the left side panel 14 via the bidirectional ball bearing 19 and the right hub 155 will be mounted on the right side panel 13 via the unidirectional ball bearing 21.The longitudinal wall 151c of the lower part 151 is notably delimited by an end edge 15Id which faces an end edge 152d of the longitudinal wall 152c of the upper part 152. The end edges 15Id and 152d are angularly offset so that they define a slot or opening 159a at the periphery of the drive roller 15. This peripheral slot 159a opens into an internal cavity 159b of the drive roller 15. This internal cavity 159b is notably configured to fully house a cutting blade 22 in a rest, or non-operating, position of the cutting blade 22 (as illustrated in [Fig. 5a]).The cutting blade 22 is provided with several cutting portions 221, 222, 223 separated by grooves 224, 225 oriented radially with respect to the axis of rotation XL. The cutting portions 221-223 have a serrated cutting edge designed to cut the paper strip when it comes into contact with it in a cutting position of the cutting blade (as illustrated in [Fig. 6a]). Once cut, the paper strip will then present a series of three pre-cut segments connected by material bridges that can easily break when the user pulls on the paper.

[0042] To move from its rest position to its cutting position, the cutting blade 22 is pivotally connected to the drive roller 15 around a rotation axis X2 which is parallel to the rotation axis XL. For this purpose, it is fixed at a left end to a left connecting element 24 and at a right end to a right connecting element 23. The left connecting element 24 has a substantially cylindrical shape and is intended to fit inside semi-circular notches 157a, 158a formed respectively in the left end walls 151a, 152a so that the left connecting element 24 can pivot around the rotation axis X2. The right-hand connecting element 23 comprises, at a first end, a cylindrical portion 231 on which the cutting blade 22 is fixed and which is axially aligned with the left-hand connecting element 24, and at a second end, which is radially distant from the first end, A cylindrical follower roller 233 is oriented towards the right-hand side panel 13. The cylindrical portion 231 and the follower roller 233 are connected to each other by means of a radially oriented arm 232. The cylindrical portion 231 is designed to fit inside semicircular notches 157b and 158b formed respectively in the right-hand end walls 151b and 152b, so that the right-hand connecting element 23 can pivot about the axis of rotation X2.

[0043] As shown in [Fig.4], the bearing panel 13a is provided on its inner face with a rib 29 against which the follower roller 233 rests during the rotation of the drive roller 15 around the axis of rotation XL. The rib 29 thus forms a cam track for the follower roller 233.This cam track has a closed contour having several sections, respectively a first curved section Cl extending in an arc around the axis of rotation XI of the drive roller 15 between a first end edge El, corresponding substantially to a so-called rest position (represented in solid lines) of the follower roller 233, and a second end edge E2, a second curved section C2 extending from the first end edge El of the first curved section Cl to a pointed end edge E3 corresponding to an extreme position PC (represented in dashed lines) of the follower roller 233, and a third curved section C3 extending from said pointed end edge E3 to the second end edge E2 of the first curved section Cl, along which the follower roller 233 can be in a so-called return position PR (represented in dashed lines). As shown in [Fig.4], the second curved section C2 has a concavity facing the axis of rotation XI of the drive roller 15 and the third curved section C3 has a convexity facing the second curved section C2. Each position of the follower roller 233 along the cam path defined by the rib 29 will generate a particular orientation of the arm 232 of the right connecting element 23 with respect to the plane defined by the axes of rotation XI and X2, and, consequently, a particular orientation of the cutting blade 22 with respect to said plane.As described below, the movement of the follower roller 233 along the cam 29 will occur successively, along the second curved section C2, due to the movement of the paper strip under the action of the traction exerted by the user, and, along the third and first curved sections C3 and C1, under the action of a return spring 25 connected, on the one hand, to the left side panel 14, and, on the other hand, to an articulated lever 27 coupled to the left connecting element 24 (shown in particular in [Fig. 2]). The combined action of the return spring 25 and this lever 27 will thus return the cutting blade 22 from its cutting position PC to its rest position, once the paper strip has been completely cut.

[0044] The operation of the distribution mechanism 10 will be described below in relation to figures 5a, 5b, 6a, 6b, 7a and 7b.

[0045] With reference to [Fig. 5a], the cutting blade 22 is shown in its rest position, as illustrated in [Fig. 4]. In this position, the cutting blade 22 is entirely located inside the internal cavity 159b of the drive roller 15, positioned below the peripheral slot 159a. Thus, it is not in contact with a strip of paper 30 that passes through the distribution mechanism 10, being wound successively around the upper guide roller 16, the drive roller 15, and the lower guide roller 17.

[0046] This rest position of the cutting blade 22, as shown in [Fig. 5b], corresponds to a specific angular positioning of the rotation axis X2 relative to the rotation axis XL. In this specific angular positioning, the articulated lever 27 has a specific configuration in which a first arm 271 of said lever 27, which can pivot about the rotation axis XI, is oriented downwards and is substantially perpendicular to a second arm 272 of said lever 27, which can pivot about the rotation axis X2. A free end of the second arm 272 is connected to the return spring 25 at a first end 251, the return spring 25 being connected to the left side panel 14 at a second end 252. In this specific configuration of the articulated lever 27, the return spring 25 is not subjected to an extension of its length at rest and does not exert a restoring force.

[0047] With reference to [Fig. 6a], the cutting blade 22 is shown in its cutting position PC, as illustrated in [Fig. 4]. In this position, the cutting blade 22 is partially positioned outside the internal cavity 159b of the drive roller 15, being positioned at least partially above the peripheral slot 159a. Thus, it comes into contact with the paper strip 30. The transition from the rest position to the cutting position results from the displacement D of the paper strip 30 under the effect of the traction exerted by the user. Due to its contact with the external surface 156 of the drive roller 15, the paper strip 30 has generated a rotation of said drive roller 15 around the axis of rotation XI in a clockwise direction.

[0048] At this cutting position of the cutting blade 22, and as shown in [Fig. 6b], there corresponds to a specific angular positioning of the rotation axis X2 relative to the rotation axis XL. In this specific angular positioning, the articulated lever 27 has a specific configuration in which the first arm 271 is oriented obliquely downwards and is substantially aligned with the second arm 272. In this specific configuration of the articulated lever 27, the length of the return spring 25 between its ends 251, 252 is at its maximum: the spring of reminder 25 therefore exerts a restoring force tending to bring the articulated lever 27 back into its specific position shown in [Fig.5b].

[0049] With reference to [Fig. 7a], the cutting blade 22 is shown in its return position PR, as illustrated in [Fig. 4]. In this position, the cutting blade 22 is again arranged inside the internal cavity 159b of the drive roller 15, positioned below the peripheral slot 159a. Thus, it is no longer in contact with the paper strip 30. The transition from the cutting position to the return position results from the complete cutting of the paper strip 30 under the action exerted by the user, which has produced a tear in the material bridges. Due to the restoring force exerted by the spring 25, the drive roller 15 has moved around the axis of rotation XI in a clockwise direction. It should be noted that this rotation of the drive roller 15 cannot be counterclockwise due to the presence of the unidirectional ball bearing 21.

[0050] At this return position of the cutting blade 22, and as shown in [Fig. 7b], there corresponds a specific angular positioning of the axis of rotation X2 relative to the axis of rotation XL. In this specific angular positioning, the articulated lever 27 has a specific configuration in which the first arm 271 is oriented obliquely upwards and is substantially perpendicular to the second arm 272. In this specific configuration of the articulated lever 27, the length of the return spring 25 between its ends 251, 252 is slightly greater than that at rest: the return spring 25 therefore exerts a restoring force tending to return the articulated lever 27 to its specific position shown in [Fig. 5b].

Claims

Demands

1. Dispensing mechanism (10) for a paper dispenser, comprising: - a drive roller (15) rotatable about an axis of rotation (XI), said drive roller (15) being intended to support a paper strip (30) on an external surface (156) and being provided with a shaft (155) and a peripheral slot (159a), said peripheral slot (159a) opening into an internal cavity (159b) of the drive roller (15), - a cutting blade (22) supported by the drive roller (15), said cutting blade (22) being able to move under the action of movement means (23, 25, 27) from a first position, called the rest position, in which the cutting blade (22) is housed entirely inside the internal cavity (159b) of the drive roller (15), being positioned radially under the surface external (156) of the drive roller, and a second position, called the cutting position,in which the cutting blade (22) protrudes radially from said external surface (156) at the level of the peripheral slot (159a), and - anti-reverse means (21) capable of permitting the rotation of the drive roller (15) in a first direction and preventing the rotation of the drive roller (15) in a second direction opposite to the first direction, characterized in that said anti-reverse means comprise at least one unidirectional ball bearing (21) on which the shaft (155) of the drive roller (15) is mounted.

2. Distribution mechanism (10) according to claim 1, characterized in that the movement means comprise a blade actuator (23) pivotally mounted on the drive roller (15) about a pivot axis (X2) and on which the cutting blade (22) is fixed, the blade actuator (23) comprising a follower roller (233) eccentric with respect to the pivot axis (X2) and bearing against a cam (29), and a return spring (25) capable of causing a pivoting of the blade actuator (23) when the follower roller (233) is in an extreme position (PC) corresponding to the cutting position of the cutting blade (22).

3. Distribution mechanism (10) according to claim 2, characterized in that the cam (29) has a closed contour having a first curved section (Cl) extending in an arc around the axis of rotation (XI) of the drive roller (15) between a first end edge (El) and a second end edge (E2), a second curved section (C2) extending from the first end edge (El) of the first curved section (Cl) to a pointed end edge (E3) corresponding to the extreme position (PC) of the follower roller (233), and a third curved section (C3) extending from said pointed end edge (E3) to the second end edge (E2) of the first curved section (Cl).

4. Distribution mechanism (10) according to claim 3, characterized in that the follower roller (233) is close to or in contact with the first end edge (El) of the first curved section (Cl) of the cam (29) when the cutting blade (22) is in its rest position.

5. Distribution mechanism (10) according to any one of claims 3 and 4, characterized in that the second curved section (C2) of the cam (29) has a concavity facing towards the axis of rotation (XI) of the drive roller (15) and the third curved section (C3) of the cam (29) has a convexity facing towards the second curved section (C2) of the cam (29).

6. Dispensing mechanism (10) according to any one of the preceding claims, characterized in that the drive roller (15) is provided with a series of annular grooves (153) spaced apart axially, at least one of said annular grooves (153) housing at least partially a tooth (181) protruding radially from a retaining bar (18) disposed parallel to the drive roller (15), said tooth (181) being configured to prevent the winding of the paper web (30) around a peripheral portion of said drive roller (15) which is located downstream of said tooth (181) in the direction of rotation of the drive roller (15).

7. Distribution mechanism (10) according to any one of the preceding claims, characterized in that it further comprises two guide rollers (16, 17), respectively an upper guide roller (16) and a lower guide roller (17), movable in rotation about axes of rotation (X3, X4) parallel to the axis of rotation (XI) of the drive roller (15), said guide rollers (16, 17) being able to press the paper strip (30) against the external surface (156) of the drive roller (15).

8. Dispensing mechanism (10) according to any one of the preceding claims, characterized in that it further comprises a rotary knob (31) coupled to the shaft (154) of the drive roller (15), said rotary knob (31) being manually actuable such that it allows the rotation of the drive roller (15), in particular when introducing a new strip of paper (30) into the dispensing mechanism.

9. Dispensing mechanism (10) according to claim 8, characterized in that the rotary button (31) is provided with two cavities (311, 312) separated by a central segment (313), said cavities (311, 312) being suitable for receiving the fingers of a user.

10. Paper dispenser for dispensing a strip of paper (30), comprising a dispensing mechanism (10) according to any one of the preceding claims.

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