Patent Application
20190021955
The present invention relates to a tablet cassette that contributes to automated supply of tablets in dispensing medicine in hospitals, pharmacies, and so forth.
A conventional tablet feeder will be described below with reference to the drawings. The tablet feeder includes a tablet cassette and a base serving as a drive portion that removably supports the cassette.
The tablet cassette 10 (see
The base 20 (see
A rotation transfer mechanism (see
Patent Document 1: JP 2002-279068 A
Patent Document 2: JP 2012-179127 A
Patent Document 3: JP 2012-120719 A
In the above-mentioned tablet cassette 10, the transfer mechanism which is constituted together with the base 20 having the drive portion is a rotation transfer mechanism of a so-called axial fitting type as discussed above. Thus, if there is displacement in tooth position between the inner tooth portion 18 and the outer tooth portion 25 after attachment of the tablet cassette 10 to the base 20, at the time of replacement with another cassette, or the like, the hollow rotary shaft 17 (the rotary body 16A of the rotor 16) may be rotated because of such displacement when the cassette is mounted, which may cause undesirable discharge operation beyond control. Thus, there is devised not only a scheme of suppressing or mitigating the effect of the displacement discussed above, but also a scheme of inhibiting shaft rotation beyond control when the shafts are fitted or meshed with each other, in order to take necessary measures (see Patent Document 3, for example).
However, such measures mainly address mounting of the cassette when undesirable discharge of tablets tends to occur, and involve modifications to both the rotary shaft (follower portion) of the tablet cassette 10 and the drive shaft 24 of the base 20. Therefore, the tablet cassette 10, to which the measures have been applied, can only be used for dispensing apparatuses etc. provided with the base 20, to which the corresponding measures have been applied. Thus it is not easy to apply such measures to the existing dispensing apparatuses etc. When handling the tablet cassette 10 detached from the base 20, in addition, care must be taken such that the hollow rotary shaft 17 and the rotor 16 which are not locked will not be rotated when carrying along the tablet cassette 10, replenishing the tablet cassette 10 with tablets, etc.
Thus, there is a technical challenge in achieving a tablet cassette configured to inhibit rotation of a rotary shaft of an axial fitting type independently when the tablet cassette is not mounted to a base.
An object of the present invention is to provide a tablet cassette capable of inhibiting rotation of a hollow rotary shaft when the tablet cassette is not mounted to a base.
A tablet cassette of the present invention includes a tablet container, a rotor, and a lock mechanism. The tablet container has a tablet containing space therein for containing a plurality of tablets in a random manner, and includes a bottom wall portion formed with a discharge port to allow the plurality of tablets in the tablet containing space to fall down one by one. The rotor includes a hollow rotary shaft and a rotary body. The hollow rotary shaft has an axial line extending in a direction orthogonal to the bottom wall portion, and has an opening portion on an opposite side to the tablet containing space. The rotary body is configured to rotate about the axial line together with the hollow rotary shaft in the tablet containing space of the tablet container, and has a plurality of tablet receiving portions provided in a peripheral portion of the rotary body at predetermined intervals in a circumferential direction to receive the tablets one by one and to allow the tablets to pass therethrough to the discharge port. The rotor is rotated when a motor is rotated with a drive shaft operable to be rotated by the motor being fitted with the hollow rotary shaft. The lock mechanism is configured to inhibit rotation of the hollow rotary shaft when the hollow rotary shaft is pulled off from the drive shaft, and to allow the hollow rotary shaft to rotate together with the drive shaft when the hollow rotary shaft is fitted with the drive shaft.
When the lock mechanism is provided as in the present invention in a state that the tablet cassette is not mounted to the base, namely, is freed from the base, movement of the hollow rotary shaft is inhibited, and rotation of the rotor with respect to the tablet containing space is accordingly stopped. Thus, rotation of the hollow rotary shaft and the rotary body is inhibited independently. When the tablet cassette is mounted to the base, the drive shaft is fitted into the hollow rotary shaft, and the hollow rotary shaft (or the rotor) can make axial rotation to allow the tablets to be sequentially discharged from the tablet containing space. As a result, the inherent function required for the tablet cassette is maintained.
The lock mechanism may be configured to include a slit, a swing member, an engaged portion, and an urging member, for example. The slit is formed in the hollow rotary shaft to penetrate the hollow rotary shaft in a radial direction, and extends in an axial direction. The swing member is supported with respect to the hollow rotary shaft so as to be swingable about a support point of swing motion provided in the slit. The swing member includes a follower portion located in an internal space of the hollow rotary shaft, and an engaging portion located outside the hollow rotary shaft. The engaged portion is provided on the bottom wall portion of the tablet container, and spaced from the hollow rotary shaft to surround the hollow rotary shaft. The urging member is operable to urge the swing member such that the engaging portion is moved toward the engaged portion and the follower portion is moved into the hollow rotary shaft. In this case, the swing member is swung in one direction by an urging force of the urging member to cause the engaging portion to engage with the engaged portion when the hollow rotary shaft is pulled off from the drive shaft. When the hollow rotary shaft is fitted with the drive shaft, the follower portion is pushed by the drive shaft radially outward to cause the swing member to swing in the other direction, thereby cancelling engagement between the engaging portion and the engaged portion.
With the tablet cassette according to the present invention, in a state that the tablet cassette is not mounted to the base, namely, is freed from the base, the engaging portion of the swing member is urged by the urging member to abut against and engage with the engaged portion. Thus, movement of the swing member and hence the hollow rotary shaft with respect to the engaged portion is inhibited. As a result, rotation of the rotor with respect to the tablet containing space is stopped. Thus, rotation of the hollow rotary shaft (or the rotor) is accordingly inhibited independently. When the tablet cassette is mounted to the base, the drive shaft on the base side is fitted into the hollow rotary shaft. In this event, the follower portion of the swing member is pushed out of the slit by the drive shaft. Thus, the swing member is swung against the urging force, and the engaging portion of the swing member is accordingly disengaged from the engaged portion. As a result, in a state that the base is mounted to the cassette, the hollow rotary shaft (or the rotor) can make axial rotation to allow the tablets to be sequentially discharged from the tablet containing space.
Moreover, the hollow rotary shaft is formed with the slit, the support points of swing motion and the middle portion of the swing member are disposed in the slit, and the engaged portion is provided on the bottom wall portion of the tablet containing space to surround the hollow rotary shaft. Consequently, the lock mechanism including the engaged portion and the swing member can be made compact. Thus, according to the present invention, it is possible to achieve a compact tablet cassette configured to inhibit rotation of the hollow rotary shaft of an axial fitting type independently when the tablet cassette is not mounted to the base.
Another lock mechanism includes a slit, a linear moving member, an engaged portion, and an urging member. The slit is formed in the hollow rotary shaft to penetrate the hollow rotary shaft in a radial direction, and extends in an axial direction. The linear moving member is provided in the slit so as to be linearly movable in the slit. The linear moving member includes a follower portion located in an internal space of the hollow rotary shaft, and an engaging portion located outside the hollow rotary shaft. The engaged portion is provided on the bottom wall portion of the tablet container, and spaced from the hollow rotary shaft to surround the hollow rotary shaft. The urging member is operable to urge the linear moving member such that the engaging portion is moved toward the engaged portion and the follower portion is linearly moved toward the bottom wall portion. In this case, the linear moving member is moved toward the bottom wall portion by an urging force of the urging member to cause the engaging portion to engage with the engaged portion when the hollow rotary shaft is pulled off from the drive shaft. When the hollow rotary shaft is fitted with the drive shaft, the follower portion is pushed by the drive shaft to cause the linear moving member to move in the slit away from the bottom wall portion, thereby cancelling engagement between the engaging portion and the engaged portion. Also with this structure, it is possible to achieve a compact tablet cassette configured to inhibit rotation of the hollow rotary shaft of an axial fitting type independently when the tablet cassette is not mounted to the base.
The engagement between the engaging portion and the engaged portion may be achieved by fitting between at least one projection and at least one recess. Here, preferably, the engaged portion includes a plurality of recesses provided at predetermined intervals in the circumferential direction when the engaging portion includes the at least one projection, and the engaged portion includes a plurality of projections provided at predetermined intervals in the circumferential direction when the engaging portion includes the at least one recess. The engagement can be maintained by achieving engagement between the engaging portion and the engaged portion through fitting between the projection and the recess.
Preferably, the engaged portion has an annular wall surface that extends along the hollow rotary shaft; the annular wall surface is formed with the plurality of recesses or the plurality of projections that extend along the hollow rotary shaft; and the engaging portion is formed with the at least one projection or the at least one recess so as not to inhibit swing motion of the swing member.
Preferably, a plurality of grooves that extend in the axial direction are formed at constant intervals in the circumferential direction in a portion of an inner peripheral portion of the hollow rotary shaft excluding a portion in which the slit is formed; and a plurality of protrusions that extend in the axial direction are provided at constant intervals in the circumferential direction on an outer peripheral portion of the drive shaft to be fitted in the plurality of grooves.
Preferably, a portion of the rotary body that faces the bottom wall portion is formed with an annular recessed portion that opens toward the bottom wall portion and that surrounds the hollow rotary shaft; and the annular recessed portion receives a part or entirety of the engaged member and a part or entirety of the engaging portion. With such a configuration, even if the desired lock mechanism includes the engaged portion and the engaging portion, the tablet containing space in the tablet container is not occupied significantly by the engaged portion and the engaging portion since a large part of the engaged portion and the engaging portion is received in the annular recessed portion of the rotary body. Moreover, the lock mechanism can be built in the cassette without increasing the size of the other members. Thus, the entire cassette can be made compact.
The urging member is preferably received in the internal space of the hollow rotary shaft. With such a structure, the drive shaft and the hollow rotary shaft can be reliably coupled to each other. With the urging member received inside the hollow rotary shaft, a space for the urging member is not required, and the size of the other members is not increased. Thus, the entire cassette can be made compact.
When the first tapered surface is formed at an inner circumferential portion of the opening portion of the hollow rotary shaft and the second tapered surface is formed at an outer circumferential portion at a distal end of the drive shaft, the dimensions are determined as follows. That is, a distance between a start position of following motion, at which the follower portion starts following motion, in the internal space of the hollow rotary shaft and the opening portion of the hollow rotary shaft is larger than a sum of an axial length of the first tapered surface of the hollow rotary shaft and an axial length of the second tapered surface of the drive shaft, and the start position of following motion is located more inside the internal space from the opening portion. If one or both of the opening portion of the hollow rotary shaft and the distal end portion of the drive shaft of the base to which the tablet cassette is mounted are chamfered, the hollow rotary shaft and the drive shaft can be smoothly fitted with each other. The transfer of rotary motion from the rotary shaft to the hollow rotary shaft can be established only when the hollow rotary shaft and the drive shaft are fitted with each other deeply over a length more than the sum of the axial length of the first tapered surface of the hollow rotary shaft and the axial length of the second tapered surface at the distal end of the drive shaft.
Under such preconditions, further requirements for the state of supporting the swing member by the hollow rotary shaft are imposed on the tablet cassette according to the present invention. That is, the distance between the start position of following motion, at which the follower portion of the swing member starts following motion in the hollow rotary shaft and the opening portion of the hollow rotary shaft is larger than the sum described above. To be exact, as seen from the opening end of the hollow rotary shaft, the start position of following motion, which is the position of a portion of the follower portion of the swing member to be first contacted by the drive shaft fitted into the hollow rotary shaft, is larger than the above-mentioned sum, and is located more inside the internal space of the hollow rotary shaft. Therefore, when the hollow rotary shaft and the drive shaft are fitted with each other, the first tapered surface and the second tapered surface start being fitted with each other smoothly, but in such a manner that rotation is not fully transferred. Next, the hollow rotary shaft and the drive shaft are fitted deeply with each other after fitting of the first tapered surface and the second tapered surface, at the point of which rotation transfer between the hollow rotary shaft and the drive shaft is established. After that, the drive shaft and the swing member abut against each other. Consequently, engagement between the swing member and the engaged portion is cancelled after the rotation transfer is established. As a result, even if there is displacement in tooth position etc. between the hollow rotary shaft and the drive shaft, priority is given to rotation and fixation of the hollow rotary shaft, followed by rotation of the drive shaft, thereby establishing the rotation transfer and furthermore adequately preventing undesirable discharge of the tablets beyond control when mounting the cassette.
A tablet cassette according to a plurality of embodiments of the present invention will be described below with reference to the drawings.
In
A specific configuration of a tablet cassette according to a first embodiment of the present invention will be described with reference to the drawings.
The tablet cassette 10′ (see
The rotor 16′ is different from the rotor 16′ discussed already in that a lock mechanism housing space 51 is formed to surround a root portion of the hollow rotary shaft 17′, that a portion of a peripheral wall portion 17′A of the hollow rotary shaft 17′ is cut out in the axial direction to form a slit 52, and that a pair of support points of swing motion 53 are provided to project into the slit 52, as illustrated in
As illustrated in
The pair of support points of swing motion 53 are formed by protrusions unitarily formed respectively with a pair of facing wall portions of the slit 52 to project from the facing wall portions toward each other. The pair of support points of swing motion 53 swingably support the swing member 70 at the swing center of the swing member 70 as discussed later, of the lock mechanisms 60 to 80. The swing member 70 is formed with a pair of recesses (not illustrated), with which the pair of support points of swing motion 53 are fitted. When the swing member 70 is fitted into the slit 52, the hollow rotary shaft 17′ is deformed such that the slit 52 is widened in the width direction, or the swing member 70 is deformed to be compressed in the width direction.
The lock mechanisms 60 to 80 include the engaged portion 60, the swing member 70, and the urging member 80 in order to inhibit axial rotation of the rotor 16′ and the hollow rotary shaft 17′ when the tablet cassette 10′ is detached from the base 20 to be in a free state.
The engaged portion 60 is an annular member with an inside diameter that is larger than the outside diameter of the hollow rotary shaft 17′, and is spaced from the hollow rotary shaft 17′ to surround entirely the circumference of the hollow rotary shaft 17′. The engaged portion 60 is fixed to the upper surface of the bottom wall portion 12 of the lower portion 13 (tablet containing space), or unitarily formed with the bottom wall portion 12, to be substantially entirely received in the lock mechanism housing space 51 discussed above. An inner tooth portion 61 to mesh or engage with the engaging portion 72 of the swing member 70 is formed over the circumference of an inner peripheral portion, for example, of the engaged portion 60. The inner tooth portion 61 is shaped such that a plurality of projections and a plurality of recesses alternately appear in the circumferential direction.
The swing member 70 is supported in the slit 52 discussed above by the support points of swing motion 53 so as to be swingable, and includes the follower portion 71 which is swung near the lower end of the hollow rotary shaft 17′, the engaging portion 72 which is provided outside the hollow rotary shaft 17′ to be swung near the inner tooth portion 61 of the engaged portion 60, and a portion on which the urging member 80 acts (a portion to which one end of a coil spring, as the urging member 80, is fixed). The engaging portion 72 is formed with at least one projection or at least one recess that is to be engaged with at least one recess or at least one projection that constitutes the inner tooth portion 61 provided on the engaged portion 60.
The follower portion 71 and the engaging portion 72 are provided on different sides of the support points of swing motion 53, and the engaging portion 72 and its root portion are received in the lock mechanism housing space 51. When the follower portion 71 is moved into a bottomed hole 17′a of the hollow rotary shaft 17′, the engaging portion 72 engages with the inner tooth portion 61 to inhibit axial rotation of the hollow rotary shaft 17′ (or the rotor 16′). In contrast, when the follower portion 71 is moved into the slit 52 from the internal space of the hollow rotary shaft 17′, the engaging portion 72 is spaced away from the inner tooth portion 61 to allow axial rotation of the hollow rotary shaft 17′ (or the rotor 16′).
As illustrated in
The follower portion 71 is configured such that the axial position (A) of a portion of the follower portion 71 that is first contacted by the drive shaft 24 when fitting the drive shaft into the hollow rotary shaft 17′ is larger than the sum (B+C) of the axial lengths of the first tapered surface 19′ and the second tapered surface 26, and is closer to the bottom side (upper side in the drawing) of the bottomed hole 17a.
The urging member 80 (see
The use and operation of the tablet cassette 10′ according to the first embodiment will be described with reference to the drawings discussed above.
In order to use the tablet cassette 10′, the tablet cassette 10′ must be replenished with tablets in advance. Thus, the tablet cassette 10′ is detached from the base 20 into a free state (see
When the tablet cassette 10′ is moved down toward the base 20 located below, the fitting frame 11 of the tablet cassette 10′ is fitted with a fitting portion 23 of the base 20 so that the tablet cassette 10′ and the base 20 are generally aligned with each other in the horizontal and transverse directions, and the first tapered surface 19′ of the lower-end opening of the bottomed hole 17a of the hollow rotary shaft 17′ of the tablet cassette 10′ and the second tapered surface 26 at the upper end of the outer tooth portion 25 of the drive shaft 24 of the base 20 contact (or are fitted with) each other. Such tapered surfaces are smoothly fitted with each other in a free fitting state in a contacting stage. When the tablet cassette 10′ is moved further downward, fitting between the hollow rotary shaft 17′ of the tablet cassette 10′ and the drive shaft 24 of the base 20 proceeds to a subsequent meshing state, in which the lower portion of the inner tooth portion 18′ of the hollow rotary shaft 17′ of the tablet cassette 10′ and the upper portion of the outer tooth portion 25 of the drive shaft 24 of the base 20 are fitted with each other to establish meshing between the inner tooth portion 18 and the drive shaft 24.
At this point, the drive shaft 24 of the base 20 has not reached the follower portion 71 of the swing member 70 of the tablet cassette 10′ yet, and axial rotation of the hollow rotary shaft 17′ and the rotor 16′ is inhibited by the lock mechanisms 60 to 80. Thus, if there is displacement in tooth position between the inner tooth portion 18′ of the tablet cassette 10′ and the outer tooth portion 25 of the base 20, the drive shaft 24 of the base 20 receives a component of fitting thrust to make axial rotation for half a tooth or less, absorbing the displacement.
Therefore, the tablets are not discharged from the discharge port of the tablet cassette 10′ in an undesirable manner even when the tablet cassette 10′ is mounted to the base 20.
When the tablet cassette 10′ is moved further downward (see
In this way, now that the lock mechanisms 60 to 80 has finished its role, accompanying the mounting of the tablet cassette 10′ to the base 20, the hollow rotary shaft 17′ (or the rotary body 16′A of the rotor 16′) can make axial rotation together with the drive shaft 24 of the base 20. Therefore, the tablet cassette 10′ operates in the same manner as that (10) according to the related art after being mounted to the base 20. That is, each time the base 20 follows the control to activate the motor to rotate the drive shaft 24, the hollow rotary shaft 17′ makes axial rotation, thereby accordingly rotating the rotor 16′ axially. Thus, the tablets which are aligned are allowed to fall down one by one from the discharge port H of the lower portion 13 of the tablet container.
In the embodiment described above, the respective numbers of teeth of the inner tooth portion 18′ of the hollow rotary shaft 17′ of the tablet cassette 10′ and the outer tooth portion 25 of the drive shaft 24 of the base 20 are large. However, the numbers of teeth may be small as long as the numbers correspond to each other (see Patent Document 3, for example).
In the embodiment described above, the hollow rotary shaft 17′ and the rotary body 16′A of the rotor 16′ are directly coupled to each other. However, the hollow rotary shaft 17′ and the rotary body 16′A of the rotor 16′ may be separate and operable in conjunction with each other via a coupling structure (see Patent Document 4, for example).
A modification of the first embodiment described above will be described with reference to
In the present modification, a coil spring of the urging member 80′ is disposed in a direction orthogonal to the axis of the hollow rotary shaft 17′. One end 80′A of the urging member 80′ is engaged with the swing member 70′, and the other end 80′B of the urging member 80′ abuts against the inner wall surface of the bottomed hole 17′a of the hollow rotary shaft 17′.
Adopting this structure facilitates assembly of the swing member 70′ into the hollow rotary shaft 17′, and facilitates assembly of the urging member 80′ with the swing member 70′.
In addition, an engaging portion 72′ of the swing member 70′ is formed with three projections 72′A and two recesses 72′B that extend in the axial direction. If the respective numbers of projections 72′A and recesses 72′B are large, the engagement between the engaging portion 72′ and the inner tooth portion 61 of the engaged portion 60 can be further secured.
The linear moving member 70″ is moved toward the bottom wall portion 12 by an urging force of the urging member 80′ to cause the engaging portion 72″ to engage with the engaged portion 60 when the hollow rotary shaft 17″ is pulled off from the drive shaft 24. When the hollow rotary shaft 17″ is fitted with the drive shaft 24, the follower portion 71″ is pushed by the drive shaft 24 to cause the linear moving member 70″ to move in the slit away from the bottom wall portion 12, thereby cancelling engagement between the engaging portion 72″ and the engaged portion 60.
As a matter of course, the structure of the lock mechanism may be different from the structures according to the first and second embodiments as long as the lock mechanism is configured to inhibit rotation of the hollow rotary shaft when the hollow rotary shaft is pulled off from the drive shaft, and to allow the hollow rotary shaft to rotate together with the drive shaft when the hollow rotary shaft is fitted with the drive shaft.
The tablet cassette according to the present invention is applicable not only to the tablet dispensing apparatuses and the tablet splitting apparatuses discussed already, but also to other medicine dispensers such as bottling apparatuses, as long as such apparatuses include a drive portion for a tablet cassette that can be mounted thereon.
The tablet cassette according to the present invention can be used not only for fully automated medicine dispensers, but also for semi-automatic medicine dispensers etc. operable to process tablets one by one upon each manual operation, for example.
The tablet cassette according to the present invention can be used to contain in a random manner and sequentially discharge not only typical tablets such round tablets, but also capsules etc.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-009939 | Jan 2016 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/001960 | 1/20/2017 | WO | 00 |
