The present invention relates to a device for batch-dispensing a material from a container, such as pulverulent or granular material, for example dental powder such as glass ionomer, said device comprising at least one displaceable member being displaceable between a first position and a second position, and having at least one cavity being alternately emptied and filled from said container upon displacement of said displaceable member.
Many dispensing devices using a displaceable member are known in the art. For example, WO 02/064006 discloses a dispensing device for batch-dispensing a granular product. The principle of one example of such a dispensing device disclosed by WO 02/064006 is schematically shown in
U.S. Pat. No. 3,866,805 discloses a volumetric dispensing apparatus which is operated by rotating a portion of a cap about the axis of a container through about 90° back and forth, one path in each direction.
U.S. Pat. No. 4,560,092 discloses variable quantity dispensing device for granular material.
DE-A-100 23 971 discloses a screw-cap device for dispensing portions of coffee or tea etc. This screw-cap device includes a slide closure being spring-loaded in the closed position and having a dosing chamber open on both sides. The spring actions result from spring leaves formed from the same material as the slide closure. The free ends of the spring leaves are supported slidingly on slide faces which run onto each other on the push-in direction.
However, prior art dispensing devices as exemplified by these prior art documents are disadvantageous if they are used with certain materials, for example powders such as dental powders because such materials usually have to be stored encapsulated from environmental conditions, especially from moisture, which prior art dosing devices cannot ensure. Furthermore such special materials result in an immediate blocking of moveable parts of the dosing mechanism.
It is therefore an object of the present invention to provide an improved dispensing device. This object is solved with the features of the claims.
In its broad aspect, the present invention provides a device for dispensing a material from a container, comprising at least one displaceable member being displaceable between a first position and a second position and having at least cavity being alternately emptied and filled from said container upon displacement of said displaceable member. According to the present invention, the displaceable member is tightly sealed against the container.
Thus, the present invention provides a tight seal and/or a tight fitting between the moveable parts. This results in various advantages of the present dispensing device over the prior art. Firstly, the dispensing device according to the present invention is substantially moisture-proof. Secondly, the dispensing device of the present invention can be used to dispense very fine intractable materials, such as glass powder, i.e. an exact dosage of such material is possible with the dispensing device according to the present invention because a blocking of the moveable parts is prevented.
According to a first aspect of the present invention, the displaceable member is a moveable member.
Preferably, a displaceable member according to the first aspect of the present invention is moveably accommodated in a body member of the dispensing device, said body member being connectable to said container. The body member comprises a longitudinal axis, and the displaceable member is moveable along an axis being inclined with respect to said longitudinal axis of said body. In a preferred embodiment, the displaceable member is moveable in a direction transverse to said longitudinal axis of said body member. The displaceable member has an axis of movement, and said at least one cavity is inclined with respect to said axis of movement of said displaceable member. Preferably, the at least one cavity is arranged transverse to said axis of movement of said displaceable member.
The displaceable member of this embodiment extends along its axis of movement, and comprises at a first end thereof a circumferential sealing member for sealing said displaceable member against said body member once the displaceable member is fully accommodated in said body member. Preferably, the sealing member comprises a circumferential flange engaging a corresponding circumferential groove provided at said body member. More preferably, the circumferential flange is substantially L-shaped, and extends from that first end of the displaceable member along said axis of movement.
The dispensing device of this embodiment further comprises an activating element for moving said displaceable member. Preferably, the activating element is substantially U-shaped with the legs of the U being connected to said displaceable member. More preferably, the activating element is connected to said displaceable member such that said displaceable member is located between the two legs of the U-shaped activating element.
It is further preferred in this embodiment that the activating element and the displaceable member are integrally formed.
The displaceable member of this embodiment further comprises at a first end thereof a web element being arranged transverse to said axis of movement of said displaceable member. Preferably, the two ends of said web element extend beyond the circumference of the displaceable member, and the activating element is connected to said extending end portions of said web element. More preferably, the activating element is connected to said web element by means of a hinge.
The dispensing device of this embodiment further comprises a retaining element for urging said displaceable member back to its fully accommodated position. Preferably, the retaining element is a substantially U-shaped retaining or part-circular-shaped spring element. Alternatively, the retaining element is an O-ring or elastic band. Preferably, the retaining element is connected to said displaceable member in the area of its first end, and surrounds said body member.
The dispensing device further preferably comprises a locking element for releasable locking the displaceable member to said body and for generating a contact force between the sealing member and said body in its accommodated position in order to achieve a tight sealing during storage of the container.
According to a second aspect of the present invention, the displaceable member is a rotatable member. The dispensing device of the second aspect of the present invention comprises a body member, and a fixing member, said displaceable member being a rotor, said fixing member being provided for fixing said rotor to said body member such that said rotor is freely rotatable. Preferably, the body member comprises an upper end and a bottom end connected by a circumferential wall, said bottom end being adapted to be mounted on said container, said upper end comprising a radially extending ring shaped portion and an axially extending center post, said ring shaped portion and said center post being connected by a ring shaped recess forming a ring shaped chamber around said center post. The bottom of said ring shaped recess comprises an opening for forming a passage to the interior of said container. Preferably, the rotor comprises a disk-shaped plate portion comprising a center hole for alignment with said center post of said body member, and an axially extending circumferential wall. The plate portion of said rotor comprises a plurality of cavities, preferably three, being at one end thereof alignable with said opening in said ring shaped recess of said body member.
The fixing member of the present dispensing device comprises a central fixing element for twist locked fixing said fixing member to said body member through said center hole of said rotor. Preferably, the fixing element provides for a snap connection to the center rod and generates a contact pressure upon the rotor, thus causing a tight seal between the movable and non-movable parts of the device.
Preferably, the fixing member comprises at least one eccentric aperture. The fixing element is arranged such that a cavity of said rotor being aligned with said opening in said body member is at that time covered by said fixing member. The aperture allows a cavity not being aligned with said opening in said body member to be exposed to the exterior of said device.
Preferably, the fixing member comprises two apertures spaced from each other at a angle of 120°.
With the dispensing device of the second aspect of the present invention, the cavities are filled and emptied sequentially while said rotor is turned.
The body member further preferably comprises at least one positioning detent for defining a dosing position of said rotor.
Preferably, the body member is glue molded to said container.
An alternative dispensing device according to the second aspect of the present invention comprises a body member, said displaceable member being a rotor, said rotor being centrically or eccentrically accommodated in said body member. In this alternative embodiment, the body member comprises a bottom portion and an upper portion being spaced from each other by a side wall portion for forming a space for accommodating said rotor between said bottom portion and said upper portion. The bottom portion comprises an opening for forming a passage from the interior of said container to said accommodating space. Preferably, the rotor comprises two cavities being alternately alignable with said opening, said cavities extending through said rotor. In this alternative dispensing device, the upper portion of said body member covers said rotor such that the cavity being aligned at one end thereof with said opening in said body portion is at its open end closed by said upper portion.
Preferably, the rotor is moveable in said body member in clockwise or anticlockwise direction.
Preferably, the rotor is press-fit into said body member in such a way that a contact pressure between the moveable and non-movable parts is generated in order to achieve a tight sealing of the container but at the same the movable parts are still displaceable by manual operation.
A further alternative design of a dispensing device according to the second aspect of the present invention comprises a displaceable member being essentially circular shaped and comprising a plurality of segments, each defining a cavity. The circular displaceable member is arranged such that, at one time, one cavity is aligned with the interior of said container and another cavity is exposed to the exterior of the dispensing device. Preferably, the circular displaceable member is arranged such that said cavities defined in the plurality of segments are filled from said container essentially in radial direction, and said cavities defined in said plurality of segments are emptied to the exterior of said device substantially in radial direction.
Preferably, the dispensing device of this alternative further comprises an activator for stepwise rotational movement for said displaceable member.
According to a further alternative design, the second aspect of the present invention comprises a displaceable member being a bevel wheel, comprising at its conical surface at least one cavity. The at least one cavity is arranged such that at one position of said bevel wheel the cavity is exposed to the interior of said container, and at a second position that cavity is exposed to the exterior of said device.
According to a third aspect of the present invention, the dispensing device comprises a first moveable member comprising a first cavity and a second moveable member comprising a second cavity, and a connecting element connecting said first and second moveable members, such that movement of said first moveable member is transferred to said second moveable member. Preferably, said connecting member is a baffle. With the present dispensing device, in a first position of said device, said first cavity of said first moveable member is aligned with a first through-hole to the interior of the container, and said second cavity of said second moveable is exposed to the exterior of said device, and wherein, in a second position of said device, said first cavity of said first moveable member is exposed to the exterior of said device, and said second cavity of said second moveable member is aligned with a second through-hole to the interior of said container. Preferably, a press-fit is provided between said moveable members and the housing of said device.
According to a fourth aspect of the present invention, the displaceable member is pivotable. Preferably, the displaceable member is disk-shaped, comprising a first surface and an opposing second surface, and comprising at least one cavity provided at the lateral side of said displaceable member. The displaceable member is alternately pivotable between two end positions, wherein in one end position said at least one cavity is exposed to the interior of said container, and in the other end position, the at least one cavity is exposed to the exterior of the device. Preferably, the displaceable member further comprises a second cavity being provided laterally opposite to said first cavity, wherein in each end position of the pivotable displaceable member, one cavity is exposed to the interior of said container, and the other cavity is exposed to the exterior of the device.
The dispensing device further comprises a body member accommodating said displaceable member, said displaceable member being press-fit to said body member.
The dispensing device according to the present invention is particularly usable with pulverulent or granular materials, like glass ionomers (e.g., glass ionomer cements), resin modified glass ionomers, composite materials, epoxide materials, chelate cements, carboxylate cements, alginate materials, biochemical granules, or granules used in biochemical products. Typical grain sizes in the present invention are in the range of d50=20-130 μm. d50 means that 50% of the particles have a grain size smaller or equal said value.
These and other features and advantages of the present invention will become more apparent from a detailed consideration of the invention when taken in conjunction with the drawings in which:
a, b show a second embodiment of the invention having a rotatable displaceable member;
a-c show a third embodiment of the present invention having a pivotable displaceable member;
a-d show a fifth embodiment of the present invention having a rotatable displaceable member being rotatable clockwise or anticlockwise;
a, b show a sixth embodiment of the present invention wherein the displaceable member comprises a body member, a rotatable rotor and a fixing member;
The displaceable member 16 is accommodated in the body member of the dispensing device 19 by means of a press-fit. In other words, a tight seal and/or a tight fitting is provided between the displaceable member and the container. The effect of such a tight seal/tight fitting is that, on the one hand, the material contained in the container can only enter the cavities of the displaceable member but cannot enter a potential space between the displaceable member and the surrounding body member, so that a blocking of the movement of the displaceable member is prevented. On the other hand, the container is closed in an air-tight manner so that no moisture can enter the container through the dispensing device. However, the press-fit still allows movement of the displaceable member.
a and 2b show a second preferred embodiment of a dispensing device of the present invention. In this embodiment, the displaceable member 22 of the dispensing device 20 is provided in the form of a circular element comprising a plurality of segments, each defining a cavity 231, 232 . . . 23n-1, 23n. The circular displaceable member is held in a body member 21 of the dispensing device 20 such that the circular displaceable member is rotatable about its center axis. Preferably, the circular displaceable member 22 is rotatable in a stepwise manner. Furthermore, the circular rotatable displaceable member 22 is arranged in the dispensing device such that material to be dispensed enters the displaceable member 22 through a passage 24 from a container substantially in radial direction. If the displaceable member is rotated in clockwise or anticlockwise direction, each cavity 23i filled through passage 24 rotates to a position where the cavity is exposed to the exterior of the dispensing device 20, and the cavity is emptied again. The emptying of the cavities also takes place in a substantially radial manner. This radial filling and radial emptying has the advantage that the dispensing device of the second preferred embodiment can be made very compact, and the displaceable member 22 can be tightly sealed against the container or tightly fitted into the body member of the displaceable member, respectively. Apart from the two cavities being filled and emptied at one time, all cavities, in particular all filled cavities, are tightly sealed against the body member of the displaceable member, and also the empty cavities are tightly sealed against the body member 21 so that no material entering the dispensing device from the container through passage 24 can reach a location where it would block movement of the displaceable members. Any material is only allowed to enter the cavity being in alignment with passage 24.
Preferably, the dispensing device 20 of this preferred embodiment is provided with an actuator, for example a lever that activates the displaceable member, for example by means of a ratchet mechanism, and thus provides a stepwise rotation of the displaceable member in one direction only. It is preferred in this embodiment that the stepwise rotation is possible in one direction only (i.e., either clockwise or anticlockwise) because this further enhances the tight seal.
a through 3c show a third preferred embodiment of the dispensing device of the present invention. This preferred embodiment comprises a pivotable displaceable member 31.
The body member 39 of the dispensing device 30 of this embodiment comprises a wall portion 36 and a holding portion 37. The holding portion 37 holds the displaceable member 31 in its position. Again, like in the other embodiments of the present invention, the displaceable member is tightly held by the holding member 37, and is thus tightly sealed against the interior of the container. Nevertheless, the tight seal allows the pivotional movement of the displaceable member. The holding member 37 is designed such that in a first end position of the alternately pivotable displaceable member as shown in
A fifth preferred embodiment of a dispensing device 50 of the present invention is shown in
The rotor 52 is sized and shaped to fit into the space formed by the body member. Furthermore, the rotor 52 comprises two cavities 551 and 552 that have a cross-section that is substantially identical to the cross-section of opening 54 provided in the body member 51. Furthermore, the rotor 52 comprises two activating portions 591 and 592 which can be pushed by the user to provide a rotational movement of the rotor in clockwise or anticlockwise direction.
c and 5d show the entire assembly of the body member and rotor. The rotor is press-fit to the body member in order to provide a tight seal so that material to be dispensed can be dispensed only through the opening 54 and the cavities 551 and 552 of the rotor. Due to the tight seal, no material can enter any space between the body member and the rotor, for example at the side wall portion 57 of the body member. This prevents a blocking of the movement of the rotor and also prevents that moisture enters the container through the dispensing device.
In the first position of the rotor 52 shown in
The rotor can either be accommodated in the body member in an eccentric or centric manner.
The body member 61 comprises a central rod 68. Furthermore, the rotor 62 comprises a central hole 67. Finally, the fixing member 63 comprises a fixing element (provided at the underside of the fixing member and thus not shown in
Preferably, the fixing member 63 comprises two apertures that are spaced from each other at an angle of 120°. This allows the rotor to be rotated clockwise or anticlockwise without having idle positions within the movement of the rotor.
Preferably, the fixing member is snapped into the central rod 68 of body member 61.
The rotor is axially held on the body member by the fixing member in order to provide a tight seal between movable and non-movable parts.
Preferably, body member 61 comprises a positioning detent 69 that defines a dosing position of the rotor. Preferably, three detents are provided and spaced from each other at an angle of 120° (if three cavities are present). Due to these sprag clutches, the rotor snaps in at each of the (preferably) three dosing positions. As an advantageous side effect, due to the vibration of the snap mechanism, the material to be dispensed easily flows into the cavity at the filling position of the rotor.
It is preferred that the positioning detents do not prevent rotation in the opposite direction. Rotation of the rotor in two directions is particularly advantageous if the fixing member comprises two apertures. In this case, material can be dispensed by rotating the rotor back and forth from a first to a second position.
It is preferred that the body member is connected to the container 64 by means of a glue molding process. This is advantageous because this eliminates the necessity of a threaded mold core which would increase the cycle time of the molding process.
There is a press-fit between the two moveable members and the housing of the dispensing device 70 accommodating the two moveable members 71 so that a tight seal or tight fitting is provided in order to avoid that moisture enters the container or that material blocks movement of the moveable members.
The baffle 72 is preferably provided in the form of a plastic stripe that is guided along a cylindrical wall 76 in order to transfer the force applied on one moveable member to the other moveable member.
The advantage of the embodiment shown in
The dispensing device 80 of this embodiment further comprises an activating element 82, for example a pusher, for moving the displaceable member between its two end positions. As shown in
In this embodiment of the present invention, the displaceable member is loosely accommodated in the bore 95 of body element 81. A tight seal against the interior of the container is in this embodiment provided by a sealing member 91. The sealing member 91 is provided at the first end 85 of the displaceable member 83, and is circumferentially provided. In the embodiment shown in
Preferably, in order to provide an inexpensive solution for injecting molding, the retain spring 89 is made as in integral part of the pusher 82. And an advantage of such a retain spring is that the “compression” characteristic is constant over the travel of the displaceable member instead of being progressive (common springs have progressive characteristics). The separate locking member 90 is provided to ensure that the displaceable member 83 is held in the closed position during storage of the container. The spring member 90 is arranged so that it is only in operation when the displaceable member is close to its final filling position.
In order to avoid relaxation of the springs during storage, and in order to enable an assembly of the dispensing device of this embodiment, the pusher 82 is connected to the web element 86 by means of hinges 87 which makes it possible to disengage the displaceable member from the body member.
The seal as used in this embodiment is further advantageous since the seal is loaded and unloaded in direction of movement of the displaceable member. In case the seal would act in radial direction between the displaceable member and the body member, multiple use and displacement of the displaceable member would result in a wear of the seal.
As shown in
FIGS. 13 to 15 show an alternative design of the eighth embodiment of the present invention. In particular, FIGS. 13 to 15 show dispensing device 80′. In this alternative design, the displaceable member 83′ is not moveable transverse to the longitudinal axis of the body member; rather, the direction of movement is inclined to the longitudinal axis of the body member. The displaceable member 83′ comprises a cavity 84′ that is inclined to the axis of movement of the displaceable member 83′, and also with respect to the longitudinal axis of the entire dispensing device 80′. The displaceable member 83′ comprises a pusher 82′ that is integrally formed with the displaceable member 83′. In use, the displaceable member 83′ is basically pushed by the pusher 82′ parallel to the axis of movement of the displaceable member so that the displaceable member is moved from its filling position (shown in
The inclined arrangement of the displaceable member 83′ is advantageous in that it facilitates the transport of the material during the dosing operation and also provides a more ergonomic operation of the dispensing device.
The embodiments of FIGS. 9 to 15 are advantageous since the displaceable member 83, 83′ of these embodiments comprises the minimum number of openings, namely two openings, i.e., the passage to the container and the dispensing opening. Thus, merely one opening needs to be sealed, i.e., the opening 95 which is the only way moisture can enter into the container.
Opening 95″ is sealed against the displaceable member 83″ for example by means of a tight fit. Alternatively, in its closed position, displaceable member 83″ is jammed like a stopper into opening 95″. Further alternatively, displaceable member 83″ comprises a sealing flange like sealing member 91 shown in
A cap 99″ is preferably provided which can particularly cover the dispensing device 80″ in order to avoid any contamination of the material to be dispensed by the environment when the device is not used. In
The embodiment shown in
In the alternative design shown in
In the alternative shown in
Number | Date | Country | Kind |
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03016542.7 | Jul 2003 | EP | regional |
This application claims priority from patent application No. 03016542.7, filed Jul. 23, 2003.