Patent Abstract:
The present invention relates to a tool holding clamp for a multiple change of tools for radial presses, where said presses comprise a plurality of radial jaws ( 12, 12′ ) onto which the tools ( 14 ) are mounted and where tools and jaws are provided with complementary coupling means, such as radial pins ( 15 ) and relative slots ( 16 ). The clamp presents centering devices, working together with the radial press to guarantee alignment of said complementary devices when the tools are mounted onto the jaws of the press. A tool holding rack for radial presses also constitutes the object of the invention, and is provided with devices adapted to interacting with the tool holding clamp for positioning the tools onto said clamp in the position of alignment with the jaws of the press.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates to both horizontal and vertical type radial presses, for example for connecting flexible tubes, and refers, in particular, to a tool holding clamp supplied with devices for centering the tools on these presses. 
   The invention also relates to a new tool holding rack for vertical radial presses configured to assist the improved clamp in question. 
   BACKGROUND OF THE INVENTION 
   As is known, in order to be able to perform the pressing of parts with various diameters, radial presses are supplied with an equal number of sets of interchangeable tools, which are essentially made up of circle sector section blocks, to be applied to respective radial jaws on the press. To assist and speed up operations of tool changing, a tool holding clamp is used, which is configured to take all of the tools at the same time from a tool holding rack, which are suitable for pressing a tube with a specific diameter; these are mounted onto-the press in just one operation and, inversely, dismounted from the press just as quickly, and placed back in the rack at the same time. 
   For this purpose, each tool is fitted with a radial pin to be inserted and locked in a respective slot provided in the radial jaws, once the clamp has been placed in the central opening of the machine, when these jaws are commanded to close on it. 
   At present, however, the positioning of the pressing tool pins level with the slots in the jaws is performed without the aid of any centering system, and consequently requires great care by the operator, so that when closing, the jaws do not cause the pins to break. This is a particular inconvenience in the case of vertical presses, which also require angular alignment of the tools in relation to the jaws, as for the horizontal presses, besides axial alignment. In fact, in this type of press, the tools, which have different lengths depending on the diameter of the flexible tube to be pressed, must nonetheless always be in the center of the press, and so it is not possible to perform axial centering simply by resting the tool holding clamp against the front surface of the press. 
   OBJECTS OF THE INVENTION 
   The object of the present invention is to remedy this inconvenience by proposing a tool holding clamp for radial presses as described below. 
   Another object of the invention is to resolve the problem of centering the tools on the respective jaws in the case of vertical radial presses, by proposing a clamp and a tool holding rack that are configured to interact as described further below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further details of the invention will, in any case, become clearer from the following description referring to the attached drawings, which are exemplary and not limiting, wherein: 
       FIGS. 1 and 2  show an axial section of a tool holding clamp according to the invention for vertical radial presses, with the magnet holder disc in a backward and forward position respectively; 
       FIG. 3  shows a transverse section of the clamp along line A-A in  FIG. 1 ; 
       FIGS. 4 and 4   a  show a side and front view of one of the tool holding shells of a tool holding rack according to the invention for vertical radial presses, in the tool locking position; 
       FIGS. 5 and 5   a  show views similar to the previous ones, but with the shell in the tool unlocking position; 
       FIG. 5   b  shows a transverse section of an enlarged detail of  FIG. 5   a;    
       FIG. 6  shows a section of part of a tool holding rack for vertical radial presses, where a clamp is inserted into each shell for removing the tools; 
       FIGS. 7 and 7   a  show an axial section and front view of the tool holding clamp during the assembly phase of the tools onto a vertical radial press; 
       FIG. 8  shows a view similar to the one in  FIG. 7 , but with the clamp carrying a set of tools of differing sizes; 
       FIG. 9  shows an axial section of a tool holding clamp for horizontal radial presses inserted into one of these presses; 
       FIG. 10  shows a front view of the clamp and press in  FIG. 9 ; and 
       FIGS. 11 and 12  show views similar to those in  FIGS. 9 and 10 , but with the clamp in an alternative embodiment. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the drawings, two vertical and horizontal presses  10 ,  11  are shown fully, provided with a plurality of radial jaws  12 ,  12 ′, respectively, marking a central opening  13  intended to receive the end of a piece of flexible tube to be connected. The jaws  12 ,  12 ′ can be moved between an open, inactive position and a closed position for pressing a connection onto the tube. In the case of vertical radial presses  10 , the closing/opening of the jaws  12  on the tube is carried out by a vertical movement, approaching/removing one block  10 ′ on the press in relation to another, whereas in the case of horizontal radial presses  11  the closing/opening of the jaws  12 ′ is controlled by a horizontally moveable piston  11 ′. The structure and working of these presses are, in any case, known and need no particular description herein. 
   In any case, a pressing tool  14  is to be mounted onto each jaw, which is basically constituted of a circle sector section block. In order for these to be coupled, the pressing tools  14  and the jaws  12 ,  12 ′ are provided with a radial pin  15  and a corresponding slot  16  respectively suitable for receiving said pin. A lock pin  17  is also inserted into each jaw perpendicularly to the slot  16 , which, stressed by a back spring  17 ′, tends to constrain the tool pin  15  to the jaw when it is fully inserted into the slot  16 . 
   For the purpose of mounting/dismounting all of the pressing tools  14  at the same time onto/from the respective jaws  12 ,  12 ′, tool holding clamps are provided, which are adapted to take the tools from a rack, move them and place them in the central opening  13  on the press, and vice versa, always keeping them in a circular position. In this way, when the clamp is inserted into the center of the press, the tools  14  are already in position to be hooked by the relative jaws when they are commanded to close. 
   In the case of vertical radial presses  10 , and with reference to  FIGS. 1-8 , the present invention proposes a tool holding clamp  18  and a tool holding rack  28  configured to guarantee angular and axial centering of the pressing tools  14  on the jaws  12  of these presses. 
   The tool holding clamp  18  has a grip handle  19  from which a fixed pin  20  comes out axially. A sliding pin  21  is placed around the fixed pin  20 , and a normal disc  22  is fixed with a ring of magnets on its distal end protruding from the handle  19 ; the tools  14  are attached to these magnets with the aid of a ring of pins  23 , extending from this disc to be inserted into corresponding holes  14 ′ made in the tools  14 . The sliding pin  21  with the magnet holder disc  22  is able to translate axially along the fixed pin  20  between two extreme positions, backwards, in which it finds itself completely contained in the handle  19 , and forwards, passing through a plurality of intermediate positions. The sliding pin  21  is pushed towards the forward position by a spring  23  located inside the handle  19  and can be stopped in the backward position and in each of the intermediate positions using the locking devices with which the manually operable clamp is fitted. In the form of embodiment described in  FIGS. 1-3 , the sliding pin  21  has a plurality of transverse grooves  21 ′ in each of which, selectively, it engages a small stop cylinder  24  set transversely in the handle  19  and stressed by a spring  24 ′. A button  25  is connected to the small cylinder  24  which releases it from the grooves  21 ′ when it is pressed, allowing the sliding pin  21  to slide onto the fixed one  20 . 
   A plate for angular centering  26  is also fixed on the distal end of the clamp handle  19 ; this plate is fitted, at the top, with a pair of mushroom pins  27  and, at the bottom, with a pair of pins  35 . This plate  26  is intended to rest on the front part of the press  10 , which will be described in further detail later on. 
   A plurality of tool holding shells  29  is located in the tool holding rack  28 , one for each sized tool  14 . Each shell  29  is made up, as is known, of a cylindrical cover, in which longitudinal splits  30  are made, and these are open at the front and terminate at the back with a slot  30 ′ that is inclined at 90° in relation to the splits  30 . When the tools are positioned in their relative shells  29 , the radial pins  15  are level with the slots  30 ′, so that the tools cannot be removed from the shell except after being rotated, which causes alignment of the pins  15  with the longitudinal splits  30 . According to the invention, the body of each shell  29  is crossed longitudinally and level with the two slots  30 ′ that are diametrically opposite a pair of cylindrical rods  31 , each of which presents a portion  31 ′ of reduced section, for example semi-cylindrical. The two rods  31  are connected at the back by a plate  32 , which is parallel to the back wall  33  of the rack. Normally, the rods  31  are held by relative springs  34 , situated between one of their heads  31 ″ protruding, at the front, from the shell  29 , and the shell itself, in a forward position where the plate  32  is detached from the back wall  33  of the rack and the reduced section portions  31 ′ are inside the body of the shell— FIGS. 4 ,  4   a . In this position, the tools cannot be rotated, since two pins  15  are locked in the relative slots  30 ′ by the rods  31 . 
   In order to unlock the tools, it is necessary for the tool holding clamp  18  to be inserted fully into the shells  29  until the fixed pin  20  pushes the plate  32  so that it touches the back wall  33  of the rack. Then, the reduced section portions  31 ′ of the rods are level with the slots  30 ′ allowing the tool pins  15  to rotate— FIGS. 5 ,  5   a  and  5   b . At this point, when the button  25  on the clamp handle  19  is pressed, the magnet holder disc  22  comes into close contact with the tools, which can then be rotated and removed from the shell. 
   As may be seen from  FIG. 6 , the two states of the fixed pin  20 , pushed against the back wall  33  of the rack and magnet holder disc  22  touching the tools  14 , guarantees that the X distance between the clamp centering plate  26  and the radial pins  15 , which coincides with the distance between the front plane of the press, where the clamp, and its center is touching, is always the same regardless of the size of the tools. In this way, axial centering of the tool pins, whatever their length, is always achieved in relation to the slots  16  in the jaws. 
   As for angular centering, the upper block  10 ′ of the vertical press is supplied with a pair of “U” guides  34  where the mushroom pins  27  of the centering plate  26  are to be inserted. The guides  34 , therefore, determine the exact angular position of the tool holding clamp, when this is resting on the front part of the press, thus constraining this position, also when the upper block  10 ′ is lowered towards the lower block and contributes to supporting the weight of the clamp with the tools. The guides  34  are also configured complementarily with the mushroom pins  27 , so that the clamp can only be released from the guides by lifting it but not by removing it axially, thus avoiding any risk of the clamp falling forwards towards the operator. Moreover, the support of the pins  35  against the lower block of the press guarantees stability and also that the clamp always stays perpendicular to the press, contributing to making operations of tool assembly/disassembly safe and easy. 
     FIGS. 7-8  illustrate two examples of application of the tools  14  to a vertical press  10 , where the tools are of differing sizes. In these Figures it is possible to observe that, in the case of longer tools, the sliding pin  21  is in a backward position, and fully contained inside the handle  19 , whereas for shorter tools, the sliding pin is in a forward position, so that the X height between the centering plate and the median plane of the press, where the slots of the jaws rest, is always constant. 
   In the case of horizontal radial presses  11 , and with reference to  FIGS. 9-12 , the proposed tool holding clamp  118  is provided only with the usual magnet holder disc  122  and an angular centering plate  126 , which is integral at the distal end of the handle  119  and designed to rest against a front surface of the horizontal press  11 , when the clamp is inserted into the central opening  13  of the press. 
   In particular, in a first example of embodiment illustrated in  FIGS. 9 and 10 , the diameter of the centering plate  126  is such as to rest against the front flange  11 ′ of the press and is fitted with a pair of pins  127  to be inserted in corresponding holes  127 ′ in said flange  11 ′. 
   In a second embodiment, shown in  FIGS. 11 and 12 , the centering of the tool holding clamp exploits the front plane of the jaws  12 ′ and the guide dowels  17 ″ of the lock pins  17 , these protruding from the front plane. For this purpose, a plurality of radial slots  128  is made in the centering plate  126 . The guide dowels  17 ″ of the lock pins  17  are inserted in the slots and are free to slide in the slots when the plate  126  is resting against the front plane of the jaws  12 ′. 
   In the case of horizontal presses, it is possible to use a normal tool holding shell, since axial centering is not required.

Technology Classification (CPC): 8