BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows the functional diagram of a rotary press as a developed view of the pitch circle diameter.
FIG. 2 shows an embodiment of a charging cam according to the invention in a side view.
FIG. 3 shows a plan view of the charging cam of FIG. 2.
FIG. 4 shows a side view similar to FIG. 2, but in a minimal filling position.
FIG. 5 shows a plan view of the charging cam of FIG. 4.
FIG. 6 shows the sections through FIGS. 2 and 5 at the indicated positions.
FIG. 7 shows a side view of a second embodiment of a charging cam according to the invention at a maximal filling depth.
FIG. 8 shows a side view similar to FIG. 7, but at a minimal filling depth.
FIG. 9 shows a plan view of the charging cam of FIGS. 7 and 8.
FIG. 10 shows the aforementioned section through the representation of FIG. 9 at different filling depths.
FIG. 12 shows the aforementioned section through the representation of FIG. 9 at different filling depths.
DETAILED DESCRIPTION OF THE INVENTION
While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated.
FIG. 1 shows a rotor 10 for a tablet rotary press as a developed view. The rotor has a die-plate 12 with bores 14 with which pairs of upper rams 16 and lower rams 18 interact. A filling device 20 charges the powder requiring compaction into the bores 14 if they pass along the filling device 20. The lower rams 18 then have a position which predetermines the filling volume. During the charging procedure, the lower rams make their heads 22 move along a charging cam 24 which has a downward inclination. What then follows is a proportioning cam 26 by which the lower rams 18 are raised again a little bit in order to batch the volume in the bores The batched-out volume is received by the filling device 20. The powder is compacted in the bores 14 at two successive compression stations having pre-compression rollers 28, 30 and main compression rollers 32, 34. The upper rams 16 gradually are moved out of the bores 14 and the lower rams expel the compacts, which are designated by 36, from the bores 14. For this purpose, the lower rams 18 are moved upwards by an ejector cam 38. Thus, the ejector cam 38 is followed by the charging cam 24 in the direction of production, which is from left to right in FIG. 1.
The charging cam 24 alone will be discussed below,
FIGS. 2 to 6 allow to identify a bearing component (lower cam carrier) 40 which is disposed in a press-mounted relationship. It carries a press-mounted first cam element 42 having a first charging cam 46. The outside of the press-mounted first charging-cam element 42 has fixed thereon a second charging-cam element 48. The cam elements 42, 48 engage each other via a groove and spring-type joint which has a predetermined upward slope oblique to the horizontal as ensues from FIGS. 2 and 4. The position relative to each other is fixed by a screw 50. The second cam element 48 has a second charging cam 52 (FIG. 6—Section E-E). The cam elements 42, 48 further, have third charging-cam portions 54 (FIG. 6—Section D-D) which act together and extend along a helically shaped path. The groove and spring-type guide has the same upward slope so that if there is a relative displacement between the cam elements, which is both vertical and horizontal, the common charging-cam portions 54 always are oriented towards each other and guide the heads of the lower rams together as is illustrated in FIG. 6. In the first charging-cam element 42, the heads 22 are guided only in the first cam portion 46 on the side facing the rotor axis while the other side of the heads 22 is vacant (FIG. 6—Section F-F). In the second cam element of FIG. 6—Section E-E, guidance is performed exclusively by the second charging-cam portion 52.
No matter what the relative position of the cam element 48 is towards the cam element 42, a permanent transition exists from the inner charging-cam portion 46 to the charging-cam portion 54 and, thence, to the charging-cam portion 52. However, a different relative position will result in a different position of the end of the charging-cam portion 52. In the positions of FIG. 2, the lower rams 18 are moved down at a maximum within the displacement path of the second charging-cam element 48. Hence, the filling depth of the bores 14 is maximal as is also indicated by tmax in FIG. 2 In FIG. 4, the filling depth of the lower ram 18 is minimal as is indicated by tmin. If the filling depth is a maximum the second charging-cam element 48 is displaced to the right maximally with respect to the fixed charging-cam element 42, which is indicated by ?max. If the filling depth is a minimum the displaceable charging-cam element 48 is pivoted through the least path with respect to the fixed charging-cam element 42 as is shown by ?min in FIG. 5.
FIGS. 2 and 4 suggest that the displacement of the displaceable charging-cam element is performed by four steps since a fixation via the screw 50 is only possible by four steps. It is understood that a continuous shift between minimum and maximum filling depths is possible as well. Furthermore, such displacement may be made via a motor.
The same reference numbers are used as far as the components shown in FIGS. 7 to 12 are identical to those of FIG. 1.
Referring to FIGS. 7 to 12, the bearing component (lower cam carrier) 40 has arranged thereon a charging-cam element 60 which is movable in height. At its underside, the element has two guide pins 62, 64 which are guided to be movable in height inside bores of a plate 66 of the bearing component 40. The plate 66 is engaged from below by an adjusting screw 68 the shank end of which bears against the underside of the block-like charging-cam element 60. The charging-cam element 60 may be adjusted in height, depending on the position of the adjusting screw 68. The stroke h is outlined in FIG. 7. This allows a variation of the filling depth between tmax and tmin as per FIG. 7 and FIG. 8 via the charging-cam portions in the charging-cam element 60, reference to which will be made at once.
The charging-cam element 60 has three charging-cam portions which follow each other in the sense of rotation, i.e. a first charging-cam portion 70, a second charging-cam portion 72, and a third charging-cam portion 74. The charging-cam portions 70, 74 are horizontal, but are offset from each other in height. The second charging-cam portion 72 has a gradient by which the lower rams 18 are pulled to a lower level which matches the desired filling depth. The first charging-cam portion 70 has a relatively large entry height and, thus, enables the heads 22 of the lower rams 18 to enter irrespective of the adjustable height position of the charging-cam element 60. This can be recognized in FIG. 10. In the left-hand representation of FIG. 10, the charging-cam element 60 is lowered to a maximum and the head 22 enters in the upper region of the first charging-cam portion. In the right-hand representation of FIG. 10, the charging-cam element 60 is raised to a maximum so that the head 22 enters in the lower region of the first charging-cam portion.
Referring to FIGS. 11 and 12, the maximum filling depth is always indicated at left and the minimum filling depth is indicated at light.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
Patent Application
20070257411
