US3841029A

US3841029A - Apparatus for chamfering tablets

Info

Publication number: US3841029A
Application number: US00268106A
Authority: US
Inventors: H Saeki
Original assignee: Shionogi and Co Ltd
Current assignee: Shionogi and Co Ltd
Priority date: 1972-03-29
Filing date: 1972-06-30
Publication date: 1974-10-15
Anticipated expiration: 1991-10-15
Also published as: CA964862A; CH546574A; DE2226356A1; FR2177666A1; GB1345990A; JPS4899079A; FR2177666B1

Abstract

An apparatus for chamfering the sharp circumferential edges of tableted article. The apparatus has a rotating disk rotatably mounted on a stationary frame and having a grinding or abrading surface which is sufficiently hard and rough to scrape the tablets. A guiding member which is disposed above said surface, is composed of two end working segments and an intermediate segment having a plurality of grooved channels extending over the full length of the guiding member. The grooved channels are provided with inlets and outlets for the tablets at opposite ends of the channels, said channels being opened towards said grinding or abrading surface. Portions of each of said grooved channels which correspond to both of said working segments have a crosssection permitting unobstructed passage of the tablets while holding them oriented in a predominantly upright yet slightly inclined position with one of the sharp circular edges being directed towards the surface of the disk. A portion of each of said channels which corresponds to said intermediate segment is twisted in the direction of its length to change the orientation of the tablets from the position where one of its edges rests against the grinding or abrading surface to the position where the other edge rests against the grinding or abrading surface. These channels also have a somewhat narrowed but deepened and continuously changing cross-section to smoothly permit said change of tablet orientation.

Description

United States Patent 11"] Saeki 1 *Oct. 15, i974 Inventor: Haruji Saeki, Osaka, Japan Notice: The portion of the term of this patent subsequent to June 13, 1990, has been disclaimed.

[22] Filed: June 30, 1972 [21] Appl. No.: 268,106

[30] Foreign Application Priority Data Mar. 29, 1972 Japan 47-31353 [52] U5. El. 51/128, 29/76 [51] int. Cl B24b 7/00, 823d 67/00 [58] Field of Search 51/128, 129, 130, 110, 51/116,112, 210,215 E, 215 M, 289 S, 289 R; 29/76, 78

[56] References Cited UNITED STATES PATENTS 3,182,428 5/1965 Hannon 51/289 R X 3,348,338 10/1967 Messerschmidt 51/130 X 3,561,164 2/1971 Dunn t 51/116 3,668,751 6/1972 Saeki 51/128 X Primary Examiner-Al Lawrence Smith Assistant Examiner-Nicholas P. Godici Attorney, Agent, or Firm-Stewart and Kolasch, Ltd.

[57] ABSTRACT An apparatus for chamfering the sharp circumferential edges of tableted article. The apparatus has a rotating disk rotatably mounted on a stationary frame and having a grinding or abrading surface which is sufficiently hard and rough to scrape the tablets. A guiding member which is disposed above said surface, is composed of two end working segments and an intermediate segment having a plurality of grooved channels extending over the full length of the guiding member. The grooved channels are provided with inlets and outlets for the tablets at opposite ends of the channels, said channels being opened towards said grinding or abrading surface. Portions of each of said grooved channels which correspond to both of said working segments have a cross-section permitting unobstructed passage of the tablets while holding them. oriented in a predominantly upright yet slightly inclined position with one of the sharp circular edges being directed towards the surface of the disk. A portion of each of said channels which corresponds to said intermediate segment is twisted in the direction of its length to change the orientation of the tablets from the position where one of its edges rests against the grinding or abrading surface to the position where the other edge rests against the grinding or abrading surface. These channels also have a somewhat narrowed but deepened and continuously changing cross-section to smoothly permit said change of tablet orientation.

15 Claims, 7 Drawing Figures ii: i

1 APPARATUS FOR CHAMFERING TABLETS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an apparatus for preparatory treatment of tableted articles. More particularly, it concerns an apparatus for scraping sharp circumferential edges of the tablets formed by a tableting press as a thickset cylinder optionally with spherical ends, to improve the shape of such tablets so that they are more like ellipsoids or spheres.

Preferably, tablets, in general, are shaped such that each has an external form which resembles a sphere or an ellipsoid with a rounded sperical edge which facilitates coating with sugar or cellulosic material after they are molded.

2. Description of the Prior Art The circumstances surrounding the well known prior art devices for tablet manufacture are very undesirable. Since tablets have hitherto been manufactured by the conventionally known tableting press of the punchand-die type, the shapes of the formed tablets are generally such that each is composed of a side cylindrical wall which corresponds to the internal wall of the die cavity and top and bottom convex end walls which correspond to the concave operative heads of the punches. The lines along which said cylindrical wall intersects with the sphereical end walls, constitute rather sharp terials as sugars subsequent to the compacting process,

manufacturers have been compelled to perform the coating operation by adding an additional thickness of the coating layer to fill up said groove between the banks. This operation requires excessive coating materials and prolongs processing time. Obviously, the above circumstances can equally be applicable to the case of film coating with, for example, cellulosic materials and the like.

It is therefore essential that the tablet which is to be coated has a shape wherein its sharp circular edges have been removed or at least the sharpness of the edge lines have been reduced. It order to fulfil these requirements there has hitherto been proposed a method wherein the shapes of the concave operative heads of the punches are modified so as to have a compound concave shape composed of a double or multiple sphere. According to this method, however, the construction of the punches become very complicated with a consequent high production and/or tooling cost of the punches and shortening of the sevice life of the punches.

SUMMARY OF THE INVENTION It is therefore the primary object of the present invention to provide an apparatus for removing or at least reducing the sharpness of the circumferential edges of the tableted articles as much as possible and allowing the shapes of such tablets to approach those of a sphere or an ellipsoid.

It is another object of the present invention to provide an apparatus for a preparative treatment interposed between a compacting process and a coating process in the tablet manufacture, which apparatus is capable of minimizing the thickness of the material utilized for coating the tablets.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of the present invention and attendant advantages thereof will be made apparent to those who are conversant with the art to which the present invention pertains by following the detailed disclosure of the specification and the appended claims, taken in conjunction with the accompanying drawings.

In the following paragraphs, description will be given in conjunction with the drawings wherein the parts or components having identical or corresponding functions are designated by the same or similar reference characters or numerals throughout the several views of the same apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, there is provided an apparatus for chamfering tableted articles comprising; a stationary frame, rotating disk rotatably mounted on said stationary frame and having a grinding or abrading surface which is sufficiently hard and rough to scrape the tablets, a means for driving said disk, and a guiding member disposed above said surface, being composed of two working segments with an intermediate segment disposed therebetwecn and having a plurality of grooved channels extending over the full length of the guiding member with inlets and outlets for the tablets at opposite ends of the channels and opened towards said grinding or abrading surface. Portions of each of said grooved channels which correspond to both of said working segments have a cross-section permitting unobstructed passage of the tablets while holding the tablets oriented in a predominantly upright yet slightly inclined position with one of the sharp edges of the tablet being directed towards the surface of the disk. A portion of each of said channels which corresponds to said intermediate segment is twisted in the direction of its length to change the orientation of the tablets from the position where one edge of the tablet rests against the grinding or abrading surface to the position where the other edge of the tablet rests against the grinding or abrading surface. The channels in the intermediate segment have a somewhat narrowed but deepened and continuously changing cross-section to smoothly permit said change of the orientation. A bracket is mounted on said stationary frame for holding said guiding member.

As the grinding or abrading surface of the present invention, grinding members, of hard stainless steel or tool steel treated with hard chrome plating, are generally preferred, although any roughened surfaces having sufficient hardness and ruggedness for scraping the circumferential edges of the compacted tablets can be employed.

The guiding member of the present invention is disposed closely above the grinding or abrading surface of the rotating disk, allowing a small clearance between them, which clearance is finely adjustable by a holding bracket fixedly mounted on the stationary frame. The guiding member is composed of an integral body of functionally differentiated three segments, Le, a first working segment, an intermediate segment and a second working segment.

Each of the grooved channels formed on the guiding member and opened towards the grinding or abrading surface is one which is capable of holding the tablet in a generally upright but somewhat inclined posture or status, or in other words, holding the tablet in a generally upright position with a moderate angle of inclination with respect to the grinding or abrading surface. Thus either one or the other of the circular edges of the tablets is always in good contact with said surface in both of its working segments.

Although the angle of orientation of the tablet may not be specifically restricted and may be varied with the original shape of the tablet so long as the sharp circular edges of the tablets can effectively be scraped during the transferring through the grooved channel, an angle between about and 40, preferably. one between about 20 and 35, with respect to a line perpendicular to the grinding or abrading surface is desirable for effective production and convenience of toolmg.

Furthermore, the angle of orientation may be varied over the length of the channel to obtain a rounded edge. However, it is usually fixed for the convenience of tooling, and even in the case of a fixed orientation, a satisfactory result can be obtained because of the small clearance between the tablet and the side walls of the grooved channel.

Since such orientation must conform to the posture or status of the tablets in order to make the tablets follow the moving grinding or abrading surface, or in other words, to cause the tablets to be dragged by the surface, the inclination of the portion of each of the grooved channels which corresponds to the first working segmentof the guiding member must be opposite to that which corresponds to the second working segment.

Therefore. a portion of each of the grooved channel which corresponds to the intermediate segment must be twisted in the direction of its length and have a somewhat narrowed but deepened and continously changing cross-section so that the angle of orientation of the travelling tablet is reversed within this portion.

Portions of each of the grooved channels which correspond to the both working segments must be capable of transferring said tablets therethrough in a direction which intersects the derection of movement of the grinding or abrading surface at an angle other than a right angle. This angle of intersection is very important because it determines the component force due to the rotational movement of the grinding or abrading surface with which the tablets are in contact and exerted on the tablets. Therefore, an angle between about and 50, preferably one between about and 45 has been found to be particularly effective.

Furthermore, since the even transferring of the successively fed tablets is desirable from a production standpoint, this angle of intersection may preferably be constant over the full length of the grooved channel used for chamfering.

Therefore, each centerline of the grooved channels may preferably be spirally contoured so that they intersect, at every point which constitute the centerline, with tangents of the every circles which constitute the disk at a given angle, even through a simple straight line may optionally be used.

Usually, the apparatus of the present invention is used together with a tablet aligning means which is integrally annexed to the first working segment at the inlet portion of the grooved channels and including a plurality of twisted'tunnels. The purpose and/or function of this means is to feed the tablets into the grooved channels by first evenly aligning the randomly stuffed or scattered tablets and then errecting them during their travels within the twisted tunnels.

Moreover, these major components of the apparatus including the aligning means may preferably be tilted in order to insure the smooth transferring of the tablet through the grooved channels and tunnels, particularly through those within the aligning means and the intermediate segment of the guiding member. The angle of such tilting with respect to the horizontal plane may be larger than about 45, preferably larger than about In FIG. 1, wherein the essential components of the present invention are shown, rotating disk 1 is mounted on a stationary fame (F of FIG. 5) and has a grinding or abrading surface 12 disposed over the full surface thereof except on a mounting portion 11 of the core. The disk is rotatably driven in the direction of the arrow by a driving means (not shown).

A guiding member 5 is disposed above said grinding or abrading surface 12 and is held in this position by a bracket (not shown) which can be fixedly mounted on the stationary frame. The clearance between the member 5 and the surface 12 is adjustable by said bracket. The member 5 is an integral body of the functionally classifiable three segments; namely, a first working segment 51, an intermediate segment 52 and a second working segment 53.

The guiding member 5 also has five grooved channels 61, 62-65 (indicated generally by broken lines except the cut-out portions) which equally open toward said grinding or abrading surface 12 and run substantially parallel with each other, extending through the

respective segments

51, 52 and 53 from inlets for the tablets 71, 72-75 at the end of the first working segment 51 to outlets 81, 82-85 at the opposite end of the second working segment 53.

Each centerline of the grooved channels 61, 62-65 is preferably spirally contoured, within both of the working

segments

51 and 53, so that it intersects, at every point which constitutes the centerline, with the tangents of every circle which constitutes the disk at approximately 40. Although a portion of each centerline which corresponds to the intermediate segment 52 of the guiding member 5 may be a straight line for connecting both curved portions which correspond to working

segments

51 and 53, it may preferably be a gradual curve for smoothly connecting both of said curved portions as shown in the drawing.

The cross-section of each of the grooved channels 61, 62-65, within the portions of the both working

segments

51 and 53, is so designed that it permit unobstructed passage of the tablet while holding the tablets oriented in a predominantly upright yet slightly inclined (about with respect to a line perpendicular to the grinding or abrading surface) position with one of its sharp edges inclined towards the surface 12 of the disk 1 as specifically shown in the sectional views of FIGS. 2 and 4, where the tablets are inclined in opposite directions.

As previously described, since that portion of each of the grooved channels 61, 62-65 which corresponds to the intermediate segment 52 of the guiding member 5 is designed to connect together those portions of said channels which correspond to the working

segments

51 and 53 and to have the ability of reversing the angle of orientation of the tablets with respect to the grinding or abrading surface 12 during their conveyance through this portion, said portion must be twisted in the direction of its length.

Therefore, this portion of each of the grooved channels 61, 62-65 is designed to have a somewhat narrowed but deepened and continuously changing crosssection. This facilitates errecting the tablets from their oriented postures and then inclining them from their upright postures to their oppositely oriented postures, as best shown in the sectional views of FIGS. 3a through Be.

A tablet aligning means 9 integrally annexed to the first working segment 51 of the guiding member 5, includes five twisted tunnels 91, 92-95, which run substantially parallel with each other and are adapted to communicate with the grooved channels 61, 62-65, re-

spectively when combined together. The tunnels 91,-

92-95 permit unobstructed passage of the tablet T introduced therein at inlets 101, 102-105 and provide for the smooth feeding ofthe tablet into the grooved channels 61, 62-65 in their substantially upright postures.

The tablet T introduced into the grooved channels 61, 62-65 at the inlets 71, 72-75, is transferred through the grooved channels which correspond to the first working segment 51 in the direction indicated by the arrow receiving a component force due to the rotational movement of the grinding or abrading surface 12 with which the tablet T is in contact, the particular circular edge ofthe tablet which is in contact with the surface 12 being scraped or bevelled during this transferring operation.

The tablet T is then pushed into the portion of each of the grooved channels which corresponds to the intermediate segment 52 where its angle of orientation is reversed. When the tablet T is switched from this portion to the next portion of each of the grooved channels which corresponds to the second working segment 53, its other circular edge is scraped while being transferred along this portion. Finally the tablet is expelled from one of the outlets 81, 82-85.

As can be appreciable from the perspective view of FIG. 5, a plane of the essential part of the apparatus including the annexed tablet aligning means 9 is actually tilted forward with respect to the horizontal plane at about a 60 angle. Therefore, the tablet can be even transferred smoothly by the aid of gravity through such portions as the tunnels of the aligning means and the portions of the grooved channels which correspond to the intermediate segment, where no component force due to the rotating movement of the grinding or abrading surface is exerted on the tablets.

The tablets processed and expelled from the outlet 81, 82-85 in the previously described manner, now have a shape which is more like an ellipsoid because the circular edges are evenly chamfered and smoothened. When a tablet has been treated as hereinabove described, any subsequent treatment of the tablet, such as for example a coating operation, will be extremely simplified.

The present invention may be embodied in other specitic forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims as well as the foregoing specification as indicating the scope of the invention.

What is claimed is:

1. An apparatus for chamfering the sharp edges of tableted articles, comprising; a stationary frame, a rotating disk rotatably mounted on said stationary frame and having a grinding or abrading surface which is sufficiently hard and rough to scrape the tablets; a means for driving said disk; a guiding member disposed above said surface, being composed of a working segment on each side of an intermediate segment and having a plurality of grooved channels extending over the full length of the guiding member with inlets and outlets for the tablets at opposite ends of the channels, said channels being opened towards said grinding or abrading surface, with portions of each of said grooved channels which correspond to both of said working segments having a cross-section permitting unobstructed passage of the tablets while holding the tablets oriented in a predominantly upright yet slightly inclined position with one of the sharp edges being directed towards the surface of the disk, and a portion of each of said channels which corresponds to said intermediate segment being twisted in the direction ofits length to change the orientation of the tablets from a position where one edge is disposed against the grinding or abrading surface to a position where the other edge is disposed against the surface, said intermediate segment having a somewhat narrowed but deepened and continuously changing cross-section to smoothly permit said change of orientation; and a bracket mounted on said stationary frame for holding said guiding member.

2. An apparatus as claimed in claim 1, wherein the cross-section of the portions of each grooved channel which correspond to the working segments are formed so that the angle of said orientation of the tablets held by said grooved channel is from about 20 to about 40 with respect to a line perpendicular to the grinding or abrading surface.

3. An apparatus as claimed in claim 2, wherein said angle of orientation has a fixed value between about 20 and 40.

4. An apparatus as claimed in claim 2, wherein said angle of orientation is continuously changing along its length within the range between about 20 and 40.

5. An apparatus as claimed in claim 2, wherein said angle of said orientation has a fixed value between about 25 and 35.

6. An apparatus as claimed in claim 2, wherein said angle of orientation is continuously changing along its length within the range between about 25 and 35.

7. An apparatus as claimed in claim 1, wherein each center line of the grooved channel is spirally contoured within the working segments so that it intersect, at all the points which constitute the center line, with tangents of all the circles which constitute the disk at a substantially constant angle other than a right angle.

8. An apparatus as claimed in claim 7, wherein said constant angle of intersection is selected from an angle between about 30 and about 50.

9. An apparatus as claimed in claim 7, wherein said constant angle of intersection is selected from an angle 13. An apparatus as claimed in claim 1, wherein said plurality of the grooved channels run substantially parallel with each other throughout the guiding member.

14. An apparatus as claimed in claim 1, wherein the apparatus is used together with a tablet aligning means which is integrally annexed to the first working segment at the inlet portion of the grooved channels and which comprises a plurality of twisted tunnels which are capable of feeding the tablets into the grooved channels by first evenly aligning the randomly stuffed or scattered tablets and then errecting them during their travels within the twisted tunnels.

15. An apparatus as claimed in claim 1, wherein said bracket for holding said guiding member is capable of adjusting the clearance between the guiding member and the abrading surface or the disk.

Claims

1. An apparatus for chamfering the sharp edges of tableted articles, comprising; a stationary frame, a rotating disk rotatably mounted on said stationary frame and having a grinding or abrading surface which is sufficiently hard and rough to scrape the tablets; a means for driving said disk; a guiding member disposed above said surface, being composed of a working segment on each side of an intermediate segment and having a plurality of grooved channels extending over the full length of the guiding member with inlets and outlets for the tablets at opposite ends of the channels, said channels being openEd towards said grinding or abrading surface, with portions of each of said grooved channels which correspond to both of said working segments having a cross-section permitting unobstructed passage of the tablets while holding the tablets oriented in a predominantly upright yet slightly inclined position with one of the sharp edges being directed towards the surface of the disk, and a portion of each of said channels which corresponds to said intermediate segment being twisted in the direction of its length to change the orientation of the tablets from a position where one edge is disposed against the grinding or abrading surface to a position where the other edge is disposed against the surface, said intermediate segment having a somewhat narrowed but deepened and continuously changing cross-section to smoothly permit said change of orientation; and a bracket mounted on said stationary frame for holding said guiding member.

2. An apparatus as claimed in claim 1, wherein the cross-section of the portions of each grooved channel which correspond to the working segments are formed so that the angle of said orientation of the tablets held by said grooved channel is from about 20* to about 40* with respect to a line perpendicular to the grinding or abrading surface.

3. An apparatus as claimed in claim 2, wherein said angle of orientation has a fixed value between about 20* and 40*.

4. An apparatus as claimed in claim 2, wherein said angle of orientation is continuously changing along its length within the range between about 20* and 40*.

5. An apparatus as claimed in claim 2, wherein said angle of said orientation has a fixed value between about 25* and 35*.

6. An apparatus as claimed in claim 2, wherein said angle of orientation is continuously changing along its length within the range between about 25* and 35*.

8. An apparatus as claimed in claim 7, wherein said constant angle of intersection is selected from an angle between about 30* and about 50*.

9. An apparatus as claimed in claim 7, wherein said constant angle of intersection is selected from an angle between about 35* and about 45*.

10. An apparatus as claimed in claim 1, wherein a plane including the rotating disk and the guiding member is tilted forward with respect to the horizontal plane.

11. An apparatus as claimed in claim 10, wherein said angle of tilting is greater than about 45*.

12. An apparatus as claimed in claim 10, wherein said angle of tilting is greater than about 55*.

13. An apparatus as claimed in claim 1, wherein said plurality of the grooved channels run substantially parallel with each other throughout the guiding member.