Abstract
A dispenser for a pasty material has a container, a cover and a handle. The dispenser is operable by twisting the cover and the handle relative to each other in a dispensing direction for dispensing material and, alternatively, in an opposite closing direction. The container having an outlet for the material and the cover having a dispensing opening. The container and the cover are arranged relative to each other for a rotation between a closed position, in which the cover closes the outlet, and an open position, in which the dispensing opening opens the outlet. A first engagement mechanism is provided for enabling the container and the handle to engage with each other in at least one angular position during twisting in the closing direction. The first engagement mechanism further forming a freewheel mechanism with respect to a rotation in the dispensing direction. The first engagement mechanism has a first snap-stop for providing the engagement between the handle and the container and for impeded disengagement when engaged. A second engagement mechanism is provided for enabling the rotation of the container and the cover in an angular range between the closed position and the open position and restricting a rotation outside that range. The second engagement mechanism has a second snap-stop for providing the restriction between the container and the cover with respect to a twisting toward the dispensing direction and providing for an impeded disengagement when engaged in the open position. The first snap-stop provides for an impeding force to be overcome for disengagement and the second snap-stop provides for a snap-in force to be overcome for engagement. The first and second snap-stop are configured such that the impeding force is greater than the snap-in force.
Claims
1. A dispenser for a pasty material comprising: a container for the material, a cover and a handle; the dispenser being operable by twisting the cover and the handle about a rotation axis relative to each other in a dispensing direction for dispensing material and, alternatively, in an opposite closing direction; the container having an outlet for the material and the cover having a dispensing opening, wherein the container and the cover are arranged relative to each other for a rotation between a closed position, in which the cover closes the outlet, and an open position, in which the dispensing opening opens the outlet; a first engagement mechanism being provided for enabling the container and the handle to engage with each other in at least one angular position during twisting in the closing direction, the first engagement mechanism further forming a freewheel mechanism with respect to a rotation in the dispensing direction; the first engagement mechanism comprising a first snap-stop for providing the engagement between the handle and the container and for impeded disengagement when engaged; a second engagement mechanism being provided for enabling the rotation of the container and the cover in an angular range between the closed position and the open position and restricting a rotation outside that range; the second engagement mechanism comprising a second snap-stop for providing the restriction between the container and the cover with respect to a twisting toward the dispensing direction and providing for an impeded disengagement when engaged in the open position; the first snap-stop providing for an impeding force to be overcome for disengagement and the second snap-stop providing for a snap-in force to be overcome for engagement; wherein the first and second snap-stop are configured such that the impeding force is greater than the snap-in force.
2. The dispenser of claim 1, wherein the first snap-stop comprises a pawl and a receptacle within which the pawl can be received in a pre-engaged position, in which further movement of the pawl into the receptacle is enabled, and an engaged position, in which the snap-stop is engaged and further movement of the pawl into the receptacle is prevented.
3. The dispenser of claim 2, wherein the pawl is formed by a partial circumferential wall of the container around the rotation axis, and wherein the receptacle is formed in at least a partial circumferential wall of the handle around the rotation axis.
4. The dispenser of claim 2, wherein the pawl is formed by the container and the receptacle is formed by the handle.
5. The dispenser of claim 2, wherein the pawl has a first retention element and the receptacle has a second retention element for engaging with each other to provide the impeding against disengagement of the first snap-stop.
6. The dispenser of claim 5, wherein the first and second retention element are configured for elastically yielding and resetting radially from the rotation axis for engaging and disengaging.
7. The dispenser of claim 6, wherein the cover has a cavity in a wall that faces the pawl, wherein the pawl is restricted against a radially outward movement by the wall in the closed position and such that the cavity provides a space for the pawl to radially outwardly move in the open position.
8. The dispenser of claim 2, wherein the pawl is elastically deflectable in a dimension transverse to the rotation axis.
9. The dispenser of claim 2, being provided with an audible click function, the click of the click function being triggered in at least one angular position during rotation of the handle and the container relative to each other in the dispensing direction.
10. The dispenser of claim 8, wherein the audible click function is provided by a baffle formed by the handle that cooperates with the pawl such that during the rotation of the handle and the container relative to each other the baffle and the pawl periodically meet, whereby the baffle elastically deflects the pawl radially inwardly and releases the pawl subsequently, wherein the click is generated in consequence of the pawl radially resetting when released.
11. The dispenser of claim 1, wherein the second engagement mechanism comprises a tappet and a detent for disengageable engagement with one another.
12. The dispenser of claim 1, further having a screw plunger, the screw plunger and the handle being anti-twist locked with each other but axially displaceable relative to each other.
13. The dispenser of claim 12, wherein the screw plunger at least with a front portion is received within the container, wherein further a screw connection is formed between the container and the screw plunger.
14. The dispenser of claim 1, wherein the cover and the handle are attached to one another and entirely enclose the container except for any portion of the container which is exposed by the dispensing opening.
15. The dispenser of claim 1, wherein a notch is provided between the container and the cover, the notch extending over a distance in a dimension parallel the rotation axis and is arranged to be located between the outlet and the dispensing opening in the closed position.
16. The dispenser of claim 1, wherein a recessed area is provided in the container to provide a space between the container and the cover, the recessed area being located outside a ring-shaped seal around the outlet.
17. The dispenser of claim 1, wherein a third engagement mechanism is provided for impeding a rotation in the closing direction of the container and the cover relative to each other, when the dispenser is in the open position.
18. A method of dispensing a pasty material, comprising: providing a dispenser having a container for the material, a cover and a handle, the dispenser being operable by twisting the cover and the handle about a rotation axis relative to each other in a dispensing direction for dispensing material and, alternatively, in an opposite closing direction, the container having an outlet for the material and the cover having a dispensing opening, wherein the container and the cover are arranged relative to each other for a rotation between a closed position, in which the cover closes the outlet, and an open position, in which the dispensing opening opens the outlet; starting from the closed position, twisting the handle and the cover in the dispensing direction relative to each other and thereby entraining the container by the handle based on an engagement of the container and the handle with each other; further twisting the handle and the cover in the dispensing direction relative to each other and thereby reaching the open position in which the cover and the container are engaged for impeded disengagement; further twisting the handle and the cover in the dispensing direction relative to each other and causing the container and the handle to disengage from each other; further twisting the handle and the cover in the dispensing direction relative to each other and thereby dispensing the material; twisting the handle and the cover in the closing direction relative to each other whereby the handle and the container rotate relative to each other; further twisting the handle and the cover in the closing direction relative to each other and thereby causing the container and the handle to engage with each other; further twisting the handle and the cover in the closing direction relative to each other and thereby causing the container and the cover to disengage from each other; and further twisting the handle and the cover in the closing direction relative to each other and thereby reaching the closed position.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0066] FIG. 1 is a side view of a dispenser according to an embodiment of the invention;
[0067] FIG. 2 is a side view of the dispenser of FIG. 1 in use;
[0068] FIG. 3 is an exploded view of a dispenser according to an embodiment of the invention;
[0069] FIGS. 4-11 are schematic illustrations of the operation of a dispenser according to an embodiment of the invention;
[0070] FIG. 12 is a perspective partial cross-sectional view of a dispenser according to an embodiment of the invention;
[0071] FIGS. 13-19 are schematic illustrations of the function of the first engagement mechanism of a dispenser according to an embodiment of the invention;
[0072] FIG. 20 is a perspective partial cross-sectional view of a dispenser according to an embodiment of the invention;
[0073] FIG. 21-23 are schematic illustrations of the operation of a dispenser according to an embodiment of the invention;
[0074] FIG. 24 is a perspective partial view a dispenser according to an embodiment of the invention at one stage of operation;
[0075] FIG. 25 is a perspective partial view the dispenser shown in FIG. 24 at a further stage of operation; and
[0076] FIG. 26 is a perspective partial view the dispenser shown in FIG. 24 at still a further stage of operation.
DETAILED DESCRIPTION OF THE INVENTION
[0077] FIG. 1 shows an exemplary dispenser 1 for dispensing a pasty material as it may be used with the present invention. A similar dispenser is disclosed in further detail in WO 2014/179219 A1. The dispenser 1 has a cover 10 and a handle 80. The cover 10 and the handle 80 are rotatably connected to each other and form in combination a housing of the dispenser 1. The cover 10 forms a dispensing opening 11 of the dispenser 1. The dispensing opening 11 forms the only opening in the housing. In this regard any gap eventually formed by the rotatable interconnection between the cover 10 and the handle 80 is not regarded as a opening in the context of the present specification.
[0078] The operation of the dispenser 1 is illustrated in FIG. 2. The material stored within the dispenser 1 can be dispensed by rotating the cover 10 and the handle 80 in one direction relative to each other, which is further referred to as dispensing direction. The dispenser 1 additionally has an automatic opening function and a pressure relief function: A rotation of the cover 10 and the handle 80 in the dispensing direction relative to each other causes the initially closed dispenser to open first and only subsequently causes the material to be urged forward for dispensation upon further rotation in the same direction. The dispenser 1 can be closed again by rotating the cover 10 and the handle 80 in the opposite direction relative to each other, which is further referred to as closing direction. Thereby a rotation of the cover 10 and the handle 80 in the closing direction relative to each other first causes any pressure from dispensing the material to be relieved and only subsequently causes the dispenser 1 to close. Therefore, the dispenser is adapted such that it opens automatically before any material is urged forward for dispensing and such that any pressure in the material is relieved before the dispenser closes again. This functionality helps preventing unintentional urging of the material forward although the dispenser 1 is still closed and thus avoids leakage of any material beneath the cover 10 inside the dispenser 1. Further, this functionality helps preventing that a pressure in the material is captured within the closed dispenser and thus again avoids leakage of any material beneath the cover 10 as well as it avoids run-on or after-flow of the material prior to closing the dispenser 1.
[0079] Accordingly, although the dispenser 1 can be operated by only two operations (rotating in the dispensing direction and rotation in the closing direction) the dispenser is adapted to perform four different functions in a predetermined sequence. Exemplary structures for providing these functions are described in further detail in the following.
[0080] FIG. 3 shows an exploded view of the dispenser 1. The dispenser 1 has a container 40 within which a screw plunger 70 is received. The container 40 forms a material chamber 41 within which the material (not shown) is received. Further, the container 40 has an outlet 42 through which the material can be dispensed by screwing the screw plunger 70 into the container 40. The screw connection between the container 40 and the screw plunger 70 may be implemented based on the concepts disclosed in co-pending European patent application no. EP15177972.5. The screw connection between the container 40 and the screw plunger 70 is such that a rotation of the container 40 and the screw plunger 70 relative to each other in the dispensing direction causes the screw plunger 70 to move into the container 40 and a rotation of the container 40 and the screw plunger 70 relative to each other in the closing direction causes the screw plunger 70 to retract. The rotation of the container 40 and the screw plunger 70 relative to each other in the dispensing direction thus causes the material stored in the container 40 to be pressurized and therefore to be urged forward for dispensation. The rotation of the container 40 and the screw plunger 70 relative to each other in the closing direction however relieves any pressure from the material. As explained in further detail below the dispenser 1 is adapted such that the rotation of the container 40 and the screw plunger 70 relative to each other in the closing direction is limited to a predetermined retraction stroke which is sufficient to relieve any pressure in the material but insufficient to cause any air to be sucked into the container 40.
[0081] The screw plunger 70 and the handle 80 are anti-twist locked (against a rotation about rotation axis A) but axially movable (along rotation axis A) with each other. The anti-twist lock between the screw plunger 70 and the handle 80 is bidirectional (in both directions of rotation). Therefore, any rotation of the handle 80 relative to the container 40 also causes the same rotation of the screw plunger 70 relative to the container 40. However, due to the screw connection between the container 40 and the screw plunger 70 the rotation of the handle 80 relative to the container 40 also causes the screw plunger 70 to axially move relative to the container 40. In the example, the anti-twist lock is formed by an elongated rectangular groove along the rotation axis in the handle 80 within which a corresponding rectangular portion 71 of the screw plunger 70 is axially slidably received.
[0082] For dispensing the material the opening 11 can be selectively brought in alignment with the outlet 42 by rotation of the cover 10 relative to the container 40. For closing the dispenser 1 the cover 10 and the container 40 can be rotated to misalign the opening 11 and the outlet 42 so that a wall of the cover 10 blocks the outlet 42. Accordingly, the cover 10 and the container 40 form a rotary slide valve in combination.
[0083] For opening and dispensation, the dispenser 1 can be operated by rotating the handle 80 and the cover 10 in the dispensing direction relative to each other. The dispenser 1 has a sequence control mechanism (described in detail further below) which provides for a controlled coupling interaction between the handle 80 and the cover 10 via the container 40. In particular, the sequence control mechanism is configured such that, starting with the dispenser when it is closed, a rotation of the handle 80 and the cover 10 in the dispensing direction relative to each other causes the handle 80 to entrain the container 40 due to an engagement between the handle 80 and the container 40. Upon reaching a position in which the outlet 42 and the opening 11 are aligned a stop provided between the cover 10 and the container 40 prevents further relative movement between the cover 10 and the container 40. The engagement between the handle 80 and the container 40 is configured such that further rotation of the handle 80 and the cover 10 in the dispensing direction relative to each other causes the engagement to disengage so that the handle 80 can freely rotate relative to the container 40 but with the container 40 and the cover 10 fixed (not rotating) relative to each other. As described above the rotation of the handle 80 and the container 40 relative to each other causes material to be dispensed.
[0084] The sequence control mechanism is further configured such that, starting with the dispenser 1 when it is open, a rotation of the cover 10 and the container 40 in the closing direction relative to each other is impeded by a further engagement so that the handle 80 and the container 40 initially rotate relative to each other in the closing direction while the cover 10 and the container 40 not yet rotate (being still fixed) relative to each other. Upon reaching a position in which the outlet 42 and the opening 11 are fully misaligned a stop provided between the handle 80 and the container 40 prevents further relative movement between the handle 80 and the container 40. A further urging of the handle 80 and the container 40 relative to each other therefore causes the handle 80 to entrain the container 40 so that both, the handle 80 and the container 40 rotate together. The impeding engagement between the cover 10 and the container 40 is configured such that further rotation of the handle 80 and the cover 10 in the closing direction causes the cover 10 and the container to disengage in consequence of the handle 80 entraining the container 40. Thus, the cover 10 and the container 40 rotate relative to each other so that the dispenser 1 closes.
[0085] FIGS. 4 to 11 illustrate the function dispenser 1 and the sequence control mechanism of the dispenser 1 at different stages. In these Figures the dispenser 1 is illustrated strongly abstracted and in particular with the cover 10, the container 40 and the handle 80 being presented in an unwound view. This means that, for better explanation purposes only, the walls of the cover 10, the container 40 and the handle 80 each are illustrated planar (unwound) although these walls are circular circumferential walls in reality. Further, some details of the cover 10, the container 40 and the handle 80 are omitted and the scale is purely schematic.
[0086] In FIG. 4 the dispenser 1 is illustrated in an initial stage. In the initial stage the dispenser 1 is closed. A new dispenser 1 is for example typically provided by the manufacturer in the initial stage. In this initial stage the dispensing opening 11 is displaced from the outlet 42 so that the dispensing opening 11 and the outlet 42 do not overlap. Further, the container 40 is in contact with the dispensing opening 11, whereas the cover 10 is in contact with the outlet 42. Thus, the cover 10 closes or seals the outlet 42. As shown in this example, in an area 30 formed between the cover 10 and the container and between the outlet 42 and the dispensing opening 11 the container 40 and the cover 10 are in sliding contact with each other.
[0087] In FIG. 5 the cover 10 and the handle 80 are moved (in reality rotated) in the dispensing direction as indicated by the arrows D1. The force for causing the movement of the cover 10 and the handle 80 relative to each other is only applied to the cover 10 and the handle 80, whereas the container 40 is entrained by either the cover 10 or the handle 80 as the control mechanism provides for. Without the control mechanism the container 40 would be entrained by either the cover 10 and/or the handle 80 depending on the friction between the cover 10 and the container 40 and the handle 80 and the container 40 so that the movement of the container 40 would be arbitrary. However, at the stage shown the control mechanism provides for the container 40 to be entrained by the handle 80 so that there is no relative movement between the container 40 and the handle 80, while the cover 10 and the container 40 move relative to each other. This is achieved by a first engagement mechanism comprising a first snap-stop 50. The first snap-stop 50 provides for an engagement between the handle 80 and the container 40. Further the first snap-stop 50, when engaged, prohibits a relative movement between the handle 80 and the container 40 in a direction opposite of the dispensing direction D1, but just impedes a disengagement when the handle 80 and the container 40 are urged relative to each other toward the dispensing direction D1. Accordingly, at this stage during moving the handle 80 and the cover 10 relative to each other in the dispensing direction D1, there is a friction force between the cover 10 and the container 40 as well as a friction force between the handle 80 and the container 40 plus an impeding force provided by the first snap-stop. The friction force and the impeding force between the handle 80 and the container 40 together form a total pulling force. It is noted that the friction force may include forces that result from a friction between the screw plunger and the container and/or the screw plunger and the material with which the screw plunger is in touch. The first snap-stop 50 is configured such that the pulling force between the handle 80 and the container 40 is sufficient to prevail over the friction force between the cover 10 and the container 40. The total pulling force further preferably accounts for any tolerances of the friction force, for example as they may be caused by dirt or pasty material getting between the cover 10 and the container 40. In the example, the first snap-stop 50 comprises a pawl 51 and a recess 52 for receiving the pawl 51. The recess 52 resembles the shape of a garage for the free end of the pawl 51 and therefore is further referred to as garage herein. The garage 52 is provided at the handle 80, whereas the pawl 51 is provided at the container 40. In more particular, the pawl 52 can enter the garage 52 from only one side and is stopped by a garage end wall 53 upon further movement. Further, the pawl 51 can be disengaged from the garage 52. However, a retention element 54 in the garage 52 (at the handle 80) impedes the disengagement. Upon engaging the garage 52 the pawl 51 further snaps behind the retention element 54.
[0088] At the stage shown the dispensing opening 11 and the outlet 42 are not yet overlapping so that the dispenser 1 is not yet open. Due to the fact, that there is no relative movement between the container 40 and the handle 80 up to this stage, the screw plunger 70 has not displaced axially yet. Therefore the pasty material 100 is not yet urged toward the cover 10. This prevents the pasty material from being urged between the cover 10 and the container 40.
[0089] In FIG. 6 the dispensing opening 11 and the outlet 42 are fully aligned so that the dispenser 1 is open. Further, the dispenser 1 has a second engagement mechanism which comprises a second snap-stop 20. The second snap-stop 20 comprises a tappet 21 provided at the container 40 and a recess 22 provided in the cover 10. The tappet 21 is restricted for a movement only within the recess 22. This is because end walls 23a, 23b block the tappet from any movement outside the recess 22. Therefore the second engagement mechanism enables the movement (rotation) of the container 40 and the cover 10 in an angular range and restricts or prohibits a movement (rotation) outside that range. The second engagement mechanism further has a detent 24 behind which the tappet has snapped. The detent 24 impedes the tapped so that a movement of the cover 10 and the container 40 in the opposite direction of the dispensing direction is also impeded.
[0090] At the stage shown the tappet 21 and the wall 23b of the recess 22 are in contact and prohibit a further relative movement of the container 40 and the cover 10 in the dispensing direction D1. Upon, however, further urging the handle 80 and the cover 10 in the dispensing direction the first engagement mechanism disengages.
[0091] This is illustrated in FIG. 7. As shown, the pawl 51 has overcome the retention element 54 and is retracted from the garage 52. Because in the open position of the dispenser 1 as shown any relative movement in the dispensing direction D1 between the cover 10 and the container 40 is blocked, urging the handle 80 and the cover 10 relative to each other in the dispensing direction D1 causes the handle 80 and the container 40 to move relative to each other in the dispensing direction D1. Therefore, also the screw plunger 70 is moved relative to the container 40 in the dispensing direction D1 and thus screws into the container and urging the material 100 toward the dispensing opening 11.
[0092] In FIG. 8 the dispenser 1 is operated further in the dispensing direction D1 so that a strand 101 of material 100 is dispensed from the dispensing opening 11. The pawl 51 is entirely removed from the garage 52 and accommodated in a space 55 provided at the container 40. As can be seen from the illustration, the handle 80 and the container 40 can be freely rotated in the dispensing direction D1 without the first engagement mechanism re-engaging. Therefore, a user can dispense any desired amount of pasty material.
[0093] FIG. 9 illustrates a stage in which no further material is dispensed and in which the cover 10 and the handle 80 are moved relative to each other in the closing direction D2. At this stage the dispenser 1 is still in the open position and the cover 10 and the container 40 are impeded against a relative movement in the closing direction D2. This is provided by the detent 24 which hinders the tappet 21 in moving away from the wall 23b. During a movement of the handle 80 and the cover 10 relative to each other in the closing direction the second engagement mechanism provides for the container 40 to be entrained by the cover 10 while the container 40 and the handle 80 move relative to each other until the first engagement mechanism engages. At the stage shown the pawl 51 is just about to enter the garage 52 but is not yet snapped behind the retention element 54. Due to the garage 52 having a length L along which the pawl 51 travels to engage, the garage 52 provides for a minimum pre-determined distance at which the container 40 and the handle 80 can be moved relative to each other in the closing direction D2 at any position of the container 40 and the handle 80 relative to each other in the open position of the dispenser 1. This movement of the container 40 and the handle 80 relative to each other in the closing direction D2 further causes the screw plunger 70 to be retracted in a direction away from the dispensing opening 11. Thus any pressure in the material that may exist from dispensing can be relieved while the dispenser is in the open position. Any residual pressure in the dispenser 1 can thus be minimized. Further, any leakage of the material, for example in the area between the cover 10 and the container 40, can be minimized.
[0094] FIG. 10 shows the dispenser 1 at a stage in which the pawl 51 is snapped behind the retention element 54 so that the first engagement mechanism is engaged. During a movement from the stage shown in FIG. 9 to the stage shown in FIG. 10 the pawl 51 overcomes the retention element 54. The associated snap-in force required for the pawl 51 to snap over the retention element 54 is transmitted via the second engagement mechanism, in particular via the detent 24 that impedes the tappet 21. The associated impeding force to be overcome so that the tappet 21 disengages from the detent is greater than the snap-in force. This is provided by the shape and dimensioning of the detent 24 and tappet 21, on the one hand, and by the shape and dimensioning of the engagement element 54 and the pawl, on the other hand. In the example, the detent 24 has a flank to be overcome by the tappet that is steeper than a flank of the retention element 54 to be overcome by the paw1 21. Other possibilities exist to provide a pre-determined difference between the impeding force of the second engagement mechanism and the snap-in force of the first engagement mechanism. Once the first engagement mechanism is engaged a further movement of the container 40 and the handle 80 in the closing direction is prohibited so that such a further movement causes the second engagement mechanism to disengage. At this stage the screw plunger 70 is retracted over at least minimum pre-determined distance so that the pressure in the dispenser 1 is minimized.
[0095] Upon disengagement of the second engagement mechanism and a further movement of the handle 80 and the cover 10 relative to each other in the closing direction D2, the dispenser 1 is brought in the closed position as illustrated in FIG. 11. Thereby the container 40 is entrained by the handle 80.
[0096] FIG. 12 shows a portion of the dispenser 1 with the snap-stop 50 and the pawl 51 and the garage 52 in more detail. In contrast to the schematic illustrations of FIGS. 4 to 11 the pawl 51 of the real embodiment moves radially relative to the rotation axis A for engaging with and disengaging from the garage 52 and/or the retention element (not visible in this view). The skilled person will however recognize that the pawl may likewise function based on an axial movement with respect to the rotation axis A as illustrated in FIGS. 4 to 11. It has however been found that the radial movement allows for a design of the pawl 51 in which the magnitude of the movement can be minimized while the strength of the stop function of the snap-stop 50 is maintained. This minimizes further the mechanical stress the pawl is exposed to and therefore helps maximizing the reliability of the dispenser 1. In the example, the snap-stop 50 has a first retention element 54a and a second retention element 54b, as further described in the following.
[0097] FIGS. 13-18 illustrate in a cross-sectional view (as indicated in FIG. 12) a rotation of the handle 80 and the container 40 relative to each other in the dispensing direction.
[0098] FIG. 13 illustrates the dispenser in the open position (compare to FIG. 6). In particular, at the stage shown the pawl 51 of the container 40 (only the pawl 51 of the container 40 being visible) is snapped with the first retention element 54a of the pawl 51 behind the second retention element 54b of the handle 80. At this stage a twisting of the handle 80 and the cover 10 relative of each other in the dispensing direction causes the first engagement mechanism 50 to disengage as illustrated in FIG. 14. This is because the second engagement system (provided between the cover 10 and the container 40 and being not visible) causes the container 40 to be entrained by the cover 10 (compare to FIG. 7). The disengagement of the first and second retention element 54a, 54b is enabled by the cavity 12 formed on the inside of the cover 10. The cavity 12 is sized to extend over only a part of the circumference of an inner wall of the cover 10 about the rotation axis. In the open position of the dispenser 1 the cover 10 and the container 40 are positioned such that the cavity 12 is located to enable the pawl 51 to move into the cavity 12. The pawl 51 in the example particularly has a protrusion 51a which can move into the cavity 12.
[0099] At the stage shown in FIG. 15 the retention elements 54a, 54b are fully disengaged. Further twisting of the handle 80 and the cover 10 relative of each other in the dispensing direction therefore causes the pawl 51 to be deflected radially inwardly by a baffle 81 formed by a wall of the handle 80.
[0100] This is shown in FIG. 16. The baffle 81 is formed partly circumferentially about the rotation axis A (extending perpendicular to the area of the Figure), and also comprises the recess 52 of the first engagement mechanism 50. As the handle 80 and the cover 10 are further twisted relative to each other in the dispensing direction (compare to FIG. 8) the pawl 51 is maintained deflected and under a pretension while the handle 80 and the container 40 rotate relative to each other. The container 40 thereby is prevented from rotating relative to the cover 10 by the second engagement mechanism (not shown). Accordingly, twisting the handle 80 and the cover 10 relative to each other in the dispensing direction causes material to be dispensed.
[0101] As shown in FIG. 17 the baffle 81 extends circumferentially but leaves a window 82 into which the pawl 51 snaps back radially outwardly. At the illustrated stage due to the pretension, the pawl 51 makes a noise (audible as a click) as it runs over the edge 81a of the baffle 80 to snap into the window 82. It has been found that the edge 81a should be formed as a sharp edge rather than a rounded edge to maximize the level of the sound. Further, a corresponding edge 51c of the pawl 51, which cooperates with the edge 81a for generating the sound, is likewise sharp rather than rounded. In the example the audible click occurs once per round (per 360 degrees rotation angle) in a rotation of the handle 80 and the container 40 relative to each other in the dispensing direction. In another example the audible click occurs twice per round (per 180 degrees rotation angle) in a rotation of the handle 80 and the container 40 relative to each other in the dispensing direction. In such an example the baffle leaves two windows, although only one first snap-stop may be provided. Because, the angle of rotation of the handle 80 and the container 40 relative to each other is proportional (due to the screw plunger being directly rotated by the handle 80) to an amount of material dispensed from the dispenser a user can meter the amount by help of the number of clicks that occur during dispensation.
[0102] FIG. 18 illustrates a stage at whichrelative to the situation shown in FIG. 17the pawl 51 is snapped into the window 82. This stage corresponds to the stage shown in FIG. 15. At this stage it is possible to dispense further material by twisting the handle 80 and the cover 10 relative to each other in the dispensing direction (as illustrated in FIGS. 16 and 17). Alternatively, at this stage the handle 80 and the cover 10 can be twisted relative to each other in the closing direction for discontinuing dispensation and for re-closing the dispenser 1. Further, at this stage the protrusion 51a extends into the cavity 12 and a cavity edge 12a engages the protrusion 51a. Thus, a third engagement mechanism is provided. This third engagement mechanism impedes a rotation of the container 40 and the cover 10 relative to each other in a particular angular position of the container 40 and the cover 10 to each other. Therefore, twisting the handle 80 and the cover 10 relative to each other in the closing direction causes the container 40 to be entrained by the cover 10 via the cavity edge 12a engaging the protrusion 51a. This engagement is in addition to the engagement provided between the cover 10 and the container 40 via the second engagement mechanism (see FIGS. 9 and 10). The redundant engagement of the cover 10 and the container 40 with each other by independent engagement means provides for a reliable re-engaging of the first engagement mechanism. The re-engaging of the first engagement mechanism is particularly important so that the dispenser 1 automatically re-opens when the dispenser is used for dispensing material the next time.
[0103] FIG. 19 illustrates a stage at which the handle 80 and the cover 10 are further rotated toward the closing direction and at which the pawl 51 is (re-)engaged in the recess 52. At this stage also the first and second retention elements 54a, 54b are engaged with each other. In addition, the cavity 12 is displaced from the pawl 51 so that a wall of the cover 10 restricts a movement of the pawl 51 radially outwardly. This restriction of the movement of the pawl 51 locks the first and second retention elements 54a, 54b against disengagement from each other at positions outside the open position of the dispenser 1. Accordingly, a premature disengagement of the first and second retention elements 54a, 54b is prevented during opening of the dispenser until the dispenser is fully opened. This prevents dispensation of material in case the dispenser 1 is closed or only partially open.
[0104] FIG. 20 shows a front portion of each the container 40 and the cover 10. The container 40 has a generally ball-shaped or bullet-shaped outer front end 43 which matches with a corresponding ball-shaped or bullet-shaped inner surface 13 of the cover 10. In the example, the outer front end 43 is recessed outside a ring-shaped seal 44 around the outlet 42. The recessed area 45 provides for a space between the cover 10 and the container 40 when the cover 10 and the container 40 are assembled with the seal 44 abutting the inner surface 13 of the cover 10. Therefore, any material that unintentionally builds up or reaches between the cover 10 and the container 40 can be at least partially absorbed in the recessed area 45. Thus, any areas between the cover 10 and the container 40 that are in direct contact with each other and that are contaminated by material can be minimized. This further helps minimizing the force required to rotate the container 40 and the cover 10 relative to each other, even with contamination of areas between the cover 10 and the container 40. Because the forces required to rotate the container 40 and the cover 10 relative to each other can affect the operation of the dispenser, in particular in connection with the impeding and/or snap-in force of the first engagement mechanism, this further helps maximizing the reliability of the dispenser.
[0105] The outer front end 43 of the container further has a notch 46 which extends from a location adjacent the front end 43 past the outlet 11 toward a rear end (opposite of the front end 43 but not visible in this view). The notch 46 is located in the container such that it extends between the outlet 42 and the dispensing opening 11 when the dispenser 1 is in the closed position. In the closed position the outlet 42 and the dispensing opening 11 are offset and spaced relative to each other and the notch 46 is arranged in the container 40 so that it is positioned in the space between the outlet 42 and the dispensing opening 11. The notch 46 thus interrupts a path between the outlet 42 and the dispensing opening 11 on which a liquid could creep (for example due to capillary effects) from the dispensing opening 11 toward the outlet 42 where the liquid may contaminate the material stored in the container 40. Such a liquid may for example include a disinfectant used for cleaning the closed device. The notch 46 may be connected to a volume that is provided between the cover 10 and the container 40 further toward the rear end of the container. Thus a relatively great amount of liquid may be guided away from the outlet 42 and absorbed in the volume.
[0106] FIG. 21 shows a dispenser 1 which is identical to the embodiment illustrated in FIGS. 4 to 11 except that the second engagement mechanism is modified as described in the following. It is noted that all other features and functions of the embodiment shown in FIGS. 21-23 are identical to the embodiment illustrated in FIGS. 4 to 11 and therefore for the description of the other features and functions of the embodiment in FIGS. 21-23 the description about FIGS. 4 to 11 can be referred to without change.
[0107] In the embodiment shown in FIGS. 21-23 there is no detent (as designated by numeral 24 in FIGS. 4 to 11). The second engagement mechanism instead has a spring cam 47. The spring cam 47 is attached at the container 40 resiliently urged toward the cover 10. It is noted that the example is very schematic for illustrating the principle features and operation of the modified second engagement mechanism. One implementation into reality is described in FIGS. 24 to 26.
[0108] In the example of FIGS. 21-23 the spring cam 47 is radially (in the Figure vertically) movable against spring force, but fixed relative to the container 40 against a movement in a circumferential direction (in the Figure horizontally). The cover 10 has a first engagement groove 18a into which the spring cam 47 engages. Accordingly, the cover 10 and the container 40 are retained against relative movement to each other. By urging the handle 80 and the cover 10 in the dispensing direction relative to each other the spring cam 47 is urged out of the first engagement groove 18a and thus disengages from the first engagement groove 18a as shown in FIG. 22. This is enabled in the example by an inclined structure, for example a chamfer or cone provided on the portion of the spring cam 47 which extends into the engagement groove 18a. Due to the inclined structure the spring cam 47 is urged radially in a direction out of the engagement groove 18a as a force in the circumferential direction is exerted on the inclined structure.
[0109] The handle 80 (or a part that is fixedly connected with the handle 80) has a second engagement groove 88. As shown in FIG. 22 the spring cam 47 moves into the second engagement groove 88 in a situation in which the snap stop 50 of the first engagement mechanism is engaged. Thereby the handle 80 and the container 40 are locked with each other against relative movement to each other. Because the spring cam 47 at the portion which extends into the engagement groove 88 does not have an inclined structure no radial force occurs upon a force in the circumferential direction is exerted by the handle 80 on the spring cam 47. This prevents that the container 40 and the handle 80 move relative to each other as long as the cover 10 is in an intermediate position between positions in which the dispenser 1 is closed or open. This further prevents situation in which material is extruded although the dispenser is not fully open.
[0110] As shown in FIG. 23 the cover 10 has a third engagement groove 18b. Upon reaching a position in which the dispenser is open the spring cam 47 snaps into the third engagement groove 18b, thus retracting from the second engagement groove 88. Accordingly, once the dispenser 1 is open the container 40 and the handle 80 are unlocked from each other and enabled for a relative movement to each other. Further, if the dispenser 1 is open the cover 10 and the container 40 are retained relative to each other via the spring cam 47 engaging the second engagement groove 18b. Like described for the retention between the spring cam 47 and the first engagement groove 18a, due to the inclined structure the retention can be overcome by urging the cover 10 relative to the container 40 in the circumferential direction. Upon closing the dispenser 1 therefore the spring cam 47 is caused to disengage from the second retention groove 18b in consequence of urging the container 40 and the cover 10 in the circumferential direction to each other.
[0111] FIGS. 24-26 illustrate an implementation of the principle described in FIGS. 21-23. FIGS. 24-26 correspond to the dispenser shown in FIG. 12 (for example) except that the second engagement mechanism is modified as described in the following. FIG. 24 shows the dispenser 1, having a cover 10, a container 40 and a handle 80. The dispenser 1 is generally operable as described in FIG. 3. Further, the dispenser has a spring cam 47 which in the situation shown engages a third engagement groove 18b. In the situation shown the dispenser 1 is open. Therefore, the situation shown corresponds to the situation illustrated in FIG. 23. When the dispenser is closed (not shown) the dispenser engages a first engagement groove 18a.
[0112] From this situation a rotation of the handle 80 and the cover 10 relative to each other in the dispensing direction causes pasty material stored in the dispenser 1 to be dispensed, as described in FIG. 7. Thereby the handle 80 and the container 40 move relative to each other so that also the screw plunger (no. 70 in FIGS. 25 and 26) moves relative to the container 40. In the example, the dispenser has a washer 70a which is slotted and therefore forms a second engagement groove 88. The washer in the example is mounted on the screw plunger 70 and is rotationally fixed thereon. However in another embodiment the washer 70a may be integrally molded with the screw plunger 70.
[0113] In the situation shown the spring cam 47 is enabled for a movement into the second engagement groove 88, for example in case the dispenser 1 would be closed. However, because the spring cam 47 is resiliently urged toward the cover 10, the spring cam 47 remains disengaged from the second engagement groove 88 as long as the spring cam 47 can engage into the third engagement groove 18b (or into the first engagement groove 18a). Hence, a rotation of the handle 80 and the container 40 in the dispensing direction is enabled and after a slight rotation the situation shown in FIG. 25 is reached. In the situation shown in FIG. 25 the spring cam 47 is prevented by the washer 70a from moving out of the third engagement groove 18b. Accordingly, as long as the second engagement groove 88 and the spring cam 47 are misaligned from each other, the spring cam 47 locks the cover 10 in place. Therefore, when the second engagement groove 88 and the spring cam 47 are misaligned from each other, the cover 10 and the container 40 cannot be rotated relative to each other. This prevents that during dispensing the pasty material the dispenser 1 cannot be closed before the screw plunger 70 has somewhat retracted from the container 40. Thus, inadvertent closing the dispenser while the pasty material is still under pressure during dispensing is prevented.
[0114] There are situations in which the second engagement groove 88 and the spring cam 47 are almost aligned with each other but still slightly misaligned. During a rotation a situation may occur as illustrated in FIG. 26. In this situation the washer 70a still restricts the movement of the spring cam 47 toward the second engagement groove 88, however, due to the tongue-like design of the spring cam 47 the spring cam 47 may itself deform upon being urged toward the second engagement groove 88. Accordingly, in such a situation the cover 10 would be become rotatable relative to the container 40, which is undesired. Therefore, the container 4 has a locking mechanism 48 which locks the cover 10 in situations in which the second engagement groove 88 and the spring cam 47 are almost aligned with each other but in which they are still slightly misaligned. The locking mechanism 48 comprises a rocker 48a which is configured so that it can engage the first engagement groove 18a. The rocker 48a is movable by a circumferential control portion 89 of the handle 80 between a locking position in which the rocker 48a engages with the first engagement groove 18a and a release position in which the rocker 48a disengages from the first engagement groove 18a. In the example, the rocker 48a is set up to resiliently retract from cover 10 toward the release position. The circumferential control portion 89 of the handle 80 is configured such that the control portion 89 pushes the rocker 48a into the locking position in angular positions of the handle 80 and the container 40 in which the second engagement groove 88 and the spring cam 47 are almost aligned with each other but in which they are still slightly misaligned. The circumferential control portion 89 of the handle 80 is further configured such that the control portion 89 releases the rocker toward the release position in the other angular positions.
