The present invention relates to a clicking press for processing leather, hides, rubber and the like and in particular a turning arm clicking press (see for example
Turning arm clicking presses generally comprise a base on the top of which a working plane is arranged allowing to place a work piece and the tool or tools provided for the processing. The base is provided with a vertical support on which an arm is arranged supporting a pressing plane substantially parallel to the working plane. The support is movable in the vertical direction and driven by driving means arranged inside the base such as, for example, a hydraulic servomechanism, and the turning arm is rotatable relative to the base around a substantially vertical axis. In order to carry out a clicking operation, the arm is so rotated to place the pressing plane over the work piece and the tools arranged on the working plane, then the support is driven pressing with a given force the pressing plane on the tools and the work piece, and finally the support is driven in the opposite direction in order to move the working plane away and thus enable the rotation of the turning arm and the access to the working plane for the removal of the work piece.
Turning arm clicking presses are extremely practical and inexpensive machines, however they exhibit the drawback of having pressing planes of a much lower size with respect to the size of the working plane and such to not allow to exploit their whole area even by rotating the pressing plane in several positions by means of the turning arm. This results in a remarkable limit to the size of the pieces processable on this type of machines. In addition, the rotation of the turning arm in order to try to cover more zones of the working plane during the processing of a work piece often results in a low quality of the processing.
It is therefore an object of the present invention to provide a turning arm clicking press, which is free from said disadvantages. Said object is achieved with a turning arm clicking press, whose main features are disclosed in the first claim and other features are disclosed in the remaining claims.
The turning arm clicking press according to the present invention is provided with rotation blocking means that define a working position of the turning arm in which the pressing plane is substantially overlapped with the working plane. The pressing plane is longitudinally slidable relative to the turning arm and has a size substantially corresponding to the size of the working plane.
The main advantage of the clicking press according to the present invention is that through a single precise and repeatable positioning of the turning arm and a single driving of the pressing plane, it is possible to entirely cover the surface of the working plane, thus being able to process work pieces of a larger size with respect to the work pieces that can be processed on clicking presses of a similar size and to obtain processings with a high and uniform quality.
Further, the possibility of making the pressing plane slide relative to the turning arm makes it possible to access the working plane with neither the need of rotating each time the turning arm, nor the need of positioning it again for the subsequent processing, resulting in remarkable time savings, especially in the case of mass production.
The sliding of the pressing plane relative to the turning arm may be driven both manually and automatically, thus providing the user with the maximum ease of handling in any situation.
Further advantages and features of the turning arm clicking press according to the present invention will become clear to those skilled in the art from the following detailed and non-limiting description of an embodiment thereof with reference to the attached drawings, wherein:
Referring to
According to the present invention, the clicking press also includes blocking means of arm 4, comprising a first blocking element 7 arranged on base 1 and a second blocking element 8 arranged on arm 4. The first and the second blocking elements are suitable to engage one in the other, thus defining a working position of arm 4 wherein the pressing plane 5 is substantially overlapped with the working plane 2. In addition, the pressing plane 5 is longitudinally slidable relative to arm 4, in order to enable the access to the working plane 2 between one clicking operation and the following one.
As shown in the detail of
The pressing plane 5 has a size substantially corresponding to those of the working plane 2, for example typically 900x450 mm, 1000x500 mm or 1200x500 mm.
As shown in
In order to enable a correct pressing action, the pressing plane 5 is arranged under the longitudinal guides 9a, 9b, substantially contacting their lower surfaces. Thus, once the arm 4 has been blocked in the working position and the pressing plane 5 has been positioned, the pressing load is transmitted from arm 4 to the pressing plane 5 through the longitudinal guides 9a, 9b.
The sliding of the pressing plane 5 relative to arm 4 is limited between a first and a second stop arranged on the longitudinal guides 9a, 9b.
The pressing plane 5 preferably further comprises centering means 11 a, 11b arranged on the vertical supports 5a, 5b. and slidable on the lateral surfaces of the longitudinal guides 9a, 9b. The centering means 11a, 11b may comprise, for example, ball bearings urged against the longitudinal guides 9a, 9b by elastic means such as, for instance, Belleville springs, and serve to ensure the alignment of the pressing plane 5 with respect to the working plane 2 in the transverse direction.
The pressing plane 5 may be manually slid by acting upon pair of handles 12 arranged thereon and generally comprising the pressing drives of the clicking press. Alternatively, the sliding of the pressing plane may be automatically driven by means of a servomechanism such as, for example, a gearmotor and a worm.
As shown in
The drive of servomechanism 13, 14, 15 may be advantageously arranged in the driving handles 12 fixed on the pressing plane 5 and position sensors, suitable to automatically block the pressing plane 5, may be placed at the end-stroke locations.
Possible variants and/or additions may be made by those skilled in the art to the hereinabove disclosed and illustrated embodiment while remaining within the scope of the following claims. In particular, for example, the side walls 4a, 4b of arm 4 may be provided with a truss structure made up of struts and tie rods, which provides arm 4 with a high flexural rigidity while maintaining at the same time a low weight of the structure. Further, transverse reinforcing elements may be arranged between the side walls 4a, 4b, suitable to provide arm 4 with an improved torsional rigidity, thus enabling arm 4 to withstand, without being deformed, pressing loads being higher than those of known turning arm clicking presses and typical of clicking presses of larger size.
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