Abstract:
The invention relates to a clamping chuck for a tool comprising a device for supplying a cooling agent and/or lubricants to a feeding channel of the tool maintained by the clamping chuck. The clamping chuck comprises a sleeve for coupling a feed pipe for supplying a cooling agent and/or lubricants, the sleeve provided with a tubular element and an adjusting screw which is arranged in such a way that it is displaceable with respect to the clamping chuck in the direction of the longitudinal axis thereof.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
   This application is a Continuation of International Application PCT/DE2004/000381, filed Feb. 20, 2004. This application claims the benefit of German Application DE 103 07 437.6, filed Feb. 20, 2003, and German Application DE 103 12 743.7, filed Mar. 21, 2003, the entireties of which are incorporated herein by reference. 

   FIELD OF THE INVENTION  
   The invention relates to a clamping chuck for a tool. 
   BACKGROUND OF THE INVENTION  
   From DE 199 35 960 A1, a clamping chuck for a tool comprising a device for supplying a coolant or lubricant from a spindle to a tool with a cooling channel is known. Furthermore, from TA 30 8243 01 of the company bielomatik LEUZE GmbH+Co, D-72637 Neuffen, such a clamping chuck is known. It can also be used as a clamping chuck for tools that have to be held in the clamping chuck at various depths and for this purpose are held by means of a shrink connection or by means of a hydro expansion chuck. Supplying a coolant or lubricant to the tool is by way of a sleeve that is firmly screwed to the chuck, to which sleeve lubricant is supplied by the spindle, wherein a tubular nozzle is pressed into this sleeve, which tubular nozzle conveys the lubricant onward to an adjusting screw. In this arrangement, the tubular nozzle or the tubular element is guided in the adjusting screw so as to be longitudinally slidable, and, by way of a rotary key, the adjusting screw is also longitudinally adjustable in the clamping chuck so that the adjusting screw can be rotated so as to contact the tool held in the clamping chuck. The adjusting screw is also used for manually setting the insertion depth of the tool, wherein for the purpose of rotating the adjusting screw, the tubular nozzle and the sleeve have to be deinstalled temporarily. Such temporary deinstallation is also necessary when the setting of the insertion depth takes place automatically with the use of a lance (see e.g. Inductive shrinking device GISS 3000 in the catalogue of the Gühring company: “Präzisions-Schneidwerkzeuge” (precision cutting tools) 2002 edition, page 958) in order to rotate the adjusting screw, following completion of the adjustment process, so that it contacts the tool so as to prevent turbulence in the coolant or lubricant flow in a free space between the adjusting screw and the tool. The state of the art is thus associated with a disadvantage in that the coolant supply arranged in the clamping chuck must be deinstalled and then reinstalled for each readjustment process that is required for the tool. 
   BRIEF SUMMARY OF THE INVENTION  
   It is thus the object of the invention to propose a clamping chuck which simplifies and reduces the steps required during initial and repeated adjustment of the insertion depth of a tool. 
   This object is met by the present invention. Advantageous and expedient improvements are also presented. 
   The clamping chuck according to one aspect of the invention comprises a tubular element that is longitudinally slidable in the sleeve; that can be activated at the end located in the sleeve by an adjusting tool; and that is connected, having positive or non-positive fit, to the adjusting screw. In this way, it is possible to rotate the adjusting screw, in particular if a suitable engagement shape is provided at the tubular element, directly by means of an adjusting tool that interacts by way of the sleeve with the engagement shape, with an in-line arrangement of the tubular element, without having to deinstall the tubular element and the sleeve to achieve such rotation. This means that after automated adjustment of the insertion depth of a tool, which adjustment is performed in a special device by means of a lance, the adjusting screw can be rotated so as to contact the tool without there being any need to deinstall the sleeve or the tubular element. Similarly, in the case of manual adjustment of the insertion depth of the tool, in which adjustment instead of the lance, the adjusting screw serves as the end stop for determining the insertion depth of the tool, it is possible to rotate the adjusting screw to the desired position using the adjusting tool without deinstalling the sleeve and the tubular element. These advantages are available to the user even in the case where the tool has to be readjusted as a result of wear, in other words where the tool has to be held in the clamping chuck at some other insertion depth. 
   Furthermore, in one aspect, the invention provides for the tubular element to be nonrotationally glued or screwed to the adjusting screw or to be nonrotationally connected by a corresponding contour. In this way tubular elements of different length and/or different design can quickly be combined with the adjusting screw. 
   The invention provides for aspects in which the tubular element and the adjusting screw to be designed in one piece, e.g., as a lathed part. A one-piece design of the tubular element and the adjusting screw makes it particularly easy to handle the components; moreover, the transition between the channel arranged in the tubular element and the borehole of the adjusting screw can be designed so as to be optimal from the point of view of fluid technology. 
   It is advantageous if the adjusting tool reaches through a channel in the sleeve into the engagement shape of the tubular element and is thus rotatable in the channel. This makes it possible to easily adjust the adjusting screw. 
   One variant of an embodiment according to the invention provides for the tubular element to be held in the sleeve and/or in the adjusting screw so as to be longitudinally adjustable, and for the adjusting screw to be designed for operation by an adjusting tool, wherein the adjusting tool can be brought into engagement from the end opposite the tool through the sleeve and the tubular element and wherein it is freely rotatable in relation to the sleeve and the tubular element. In this way too the already described advantages are achieved. Furthermore, direct interaction between the adjusting tool and the adjusting screw makes it possible to achieve a torque transfer that does not subject the tubular element to any loads so that said tubular element can be designed to be weaker and thus more cost-effective. To this effect the adjusting screw may comprise, for example, an engagement shape for the adjusting tool. 
   Furthermore, the variant of the embodiment described provides for an aspect in which the sleeve and the tubular element can be designed in one piece so as to reduce the number of hardware components and so as to facilitate the handling or installation of the hardware components. 
   An expedient design of the subject of the invention provides for the tubular nozzle to be sealed off from the sleeve. This prevents undesirable leakage of coolant or lubricant into the free spaces between the device and the clamping chuck. 
   For example, the tubular element can be sealed off from the sleeve by means of a contact seal, lip seal or at least an O-ring, wherein the O-ring is held in the sleeve and/or on the tubular element. Such a seal supports longitudinal sliding of the tubular element in the sleeve, as well as repeated decoupling and coupling of the components for maintenance purposes. 
   The invention provides aspects in which the tubular element or the adjusting screw can comprise an engagement shape, e.g., designed to accommodate a box spanner, such as a hexagonal spanner. In this way, the adjusting tool can interact directly with the tubular element or with the adjusting screw. A box spanner is a particularly slim adjusting tool which can be inserted unerringly through the sleeve. 
   Furthermore, the invention provides aspects in which the sleeve can be of an internal diameter which at least in sections tapers off toward the tubular element. In this way, the coolant flow or lubricant flow is fed to the tubular element in a nozzle-like way so as to prevent eddies from occurring. 
   An advantageous embodiment of the subject of the invention provides for the sleeve to be screwed to the clamping chuck by means of a threaded bush or a union nut. In this way, a safe and yet simply disconnectable connection is created which makes it possible to service all the components in an easy way. 
   Furthermore, the sleeve can be sealed off from the clamping chuck by means of a ring seal. In this way, an effective seal is achieved with very simple means. 
   The invention also provides aspects in which a through borehole is provided for the adjusting screw to open up in a funnel shape towards the tool. Such a funnel-shaped opening towards the tool makes possible optimum flow and supply of coolant or lubricant to the channels arranged in the tool. 
   The invention also provides aspects in which the sleeve, the tubular element and the adjusting screw can be made from plastic and/or metal and/or ceramics, and aspects in which the sleeve and/or the tubular element and/or the adjusting screw can be coated. This makes it possible to design the individual components so that they are optimal in view of the requirements they have to meet. 
   The invention provides aspects in which the sleeve, the tubular element and the adjusting screw can be designed so that they can be penetrated by the adjusting pin of an automatic device for adjusting the position of the tool, wherein the adjusting pin is slidable in the direction of the longitudinal axis of the clamping chuck, e.g. for positioning a tool. 
   Moreover, the invention provides aspects in which the tubular element can be rotated directly or indirectly by means of the adjusting tool. Direct adjustment makes it possible to directly engage the adjusting tool in the tubular element and thus provides precise adjustability of the tubular element because there is only little play between the interacting components. The use of an adapter between the adjusting tool makes it possible to provide a special engagement shape in the tubular element, while at the same time standard tools can be used as adjusting tools. 
   The aspects which include a multi-part design of the tubular element from sub-elements made from different materials make it possible to optimally adapt the tubular element to various requirements. For example, in the region of the engagement shape for the adjusting tool the tubular element can be constructed from a torsion-resistant material such as metal, while the region of the face of the tubular element, which face rests against the tool during operation, can be made from a plastic material in order to achieve a particularly good seal toward the tool. 
   Finally, the invention provides aspects in which the tubular element and the sleeve can be coupled in order to transfer a rotary movement, introduced into the sleeve with the adjusting tool, to the tubular element. This arrangement provides for the tubular element to be longitudinally slidable in relation to the sleeve, while the rotary movement of the sleeve is transferred to the tubular element. Such a design of the two components provides in particular for these two components to be made from different materials, thus optimally adapting them to their respective functions. For example, the sleeve can be made of metal in order to ensure optimum interaction with the adjusting tool, while the tubular element can be made from plastic in order to obtain an optimally sealed connection to the tool. For the purpose of torque transfer, carriers and guide slots in the sleeve or in the tubular element are preferably dimensioned in accordance with the materials characteristics. 
   Further details of the invention are described below with reference to diagrammatically shown exemplary embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     The invention may be more fully understood with reference to the accompanying drawings and the following detailed description of the invention. 
       FIG. 1 : a section of a clamping chuck in which the tubular nozzle and the adjusting screw are made in one part; and 
       FIG. 2 : a section of the clamping chuck shown in  FIG. 1 , comprising a tubular nozzle which is glued to an adjusting screw. 
   

   DETAILED DESCRIPTION OF THE INVENTION  
     FIG. 1  shows a section of a clamping chuck  1 . The clamping chuck  1  comprises a longitudinal axis  1 . Along the longitudinal axis  1 , a borehole  2  passes through the clamping chuck  1 , wherein the diameter of said borehole  2  differs in some sections. The clamping chuck  1  comprises a clamping section  3 , a middle section  4  and a coupling section  5 . The clamping section  3  is designed to accommodate a tool  6  (indicated by dashed lines) which comprises feeding channels  7  for conveying coolant or lubricant to a tool tip (not shown), which feeding channels  7  lead to a bottom surface  8 . Arranged in the middle section  4  in the borehole  2  is a device  9  for supplying a coolant or lubricant to the feeding channels  7  of the tool  6 . By way of the coupling section  5 , the clamping chuck  1  is coupled to a spindle (not shown) of a machine tool (not shown), wherein the coolant or lubricant is supplied by the spindle to the device  9  by way of a line  10  (shown by a dashed line). The clamping chuck  1  is a so-called hydro expansion chuck in which the tool  6  is hydraulically clamped, wherein the pressure acting on the tool  6  is generated by way of a ring channel  11  positioned in the clamping section  3  of the clamping chuck  1 . Increasing and decreasing the pressure is by way of an adjusting screw (not shown) which is arranged in a borehole  12 . The device  9  essentially comprises a sleeve  13 , a tubular section  14  and an adjusting screw  15 , wherein the tubular element  14  and the adjusting screw  15  are made in a single piece as a tube screw  16 . The sleeve  13  comprises a through borehole  17 . In an end region  18  facing the tool  6 , the sleeve  13  comprises a ring-shaped step  19  and in the region of the through borehole  17  comprises an O-ring seal  20 . By means of a threaded bush  21  with an external thread G 21 , the sleeve  13  is screwed to the clamping chuck  1 , wherein the sleeve  13  is pushed against a wall  22  of the clamping chuck  1  by the threaded bush  21 . In this arrangement, the threaded bush  21  exerts pressure on the step  19  of the sleeve  13 , while the step  19  is supported by the wall  22  by way of an O-ring seal  23 . On a further end section  24 , which faces the spindle (not shown), the line  10  leads into the sleeve  13 . However, this connection between the sleeve  13  and the line  10  only exists if the clamping chuck  1  is coupled to the spindle. The tubular element  14  is partially inserted into the sleeve  13  and is sealed off from the sleeve  13  by the O-ring seal  20  which is held in the sleeve. On a first end section  25 , which faces away from the tool  6 , there is a channel  26 , formed by the tubular element  14 , which serves as an engagement shape  27  for an adjusting tool (not shown). In an end section  28  facing in the direction of the tool  6 , the channel  26  of the tubular element  14  gradually changes to a channel  29  which passes through the adjusting screw  15 , made in one piece with the tubular element  14 , in the direction of the tool  6 . The adjusting screw  15  is adjustably guided by an external thread G 15  in an internal thread G 2  of the borehole  2  which leads through the clamping chuck  1 . From the position shown in  FIG. 1 , the tube screw  16  is adjustable in the direction of the arrow z toward the tool  6 . This adjustment or longitudinal displacement is carried out by means of the adjusting tool (not shown), which interacts with the receptacle, formed by the engagement shape  27 , for a box spanner and rotates the tube screw  16  in relation to the clamping chuck  1  in a direction of rotation w on the longitudinal axis  1 . During this movement, the adjusting screw  15  slowly pulls the tubular element  14  of the tube screw  16  into the direction of the arrow x from the sleeve  13 , and the adjusting screw  15  slowly moves toward the bottom surface  8  of the tool  6 . Readjustment of the adjusting screw  15  or of the tubular element  14  is completed when a face  30  of the adjusting screw  15  closes off so as to provide a seal to the tool  6 . After completion of this adjustment movement, the tube screw  16  has been displaced in the direction z by the dimension a so that the tubular element  14  is no longer inserted so deeply in the sleeve  13 . The extension required for readjusting the device  1  thus takes place by pulling the sleeve  13  some distance out of the tubular element  14 . Rotating the box spanner in the engagement shape  27  in the direction opposite to the direction of rotation w results in withdrawal of the adjusting screw  15  in the direction of the arrow z′ and in the device  9  being pushed together or shortened, which takes place by inserting the tubular element  14  deeper into the sleeve  13 . In other words, the tube screw  16  is arranged in the sleeve  13  and in the thread G 2  so as to be slidable relative to the clamping chuck  1 . 
   Furthermore, the device  9  for automatically adjusting the clamping depth of the tool  6  makes it possible for a lance  31  (only indicated by a dot-dash line) of an automatic tool adjustment device (not shown) to be inserted through the sleeve  13 , the tubular element  14  and the adjusting screw  15  so that the latter serves as an end stop for the tool  6 . In other words, in the relaxed state of the hydro expansion chuck  1 , the tool  6  is moved to the lance  31  and then clamped in the hydro expansion chuck  1  so that it is held at the clamping depth predefined by the lance. Subsequently, the device  9  is adjusted such that the adjusting screw  15  contacts the tool  6 . 
     FIG. 2  again shows the clamping chuck  1  shown in  FIG. 1 , wherein the tube screw  16  is made in two parts. In  FIG. 2 , the tube screw  16  comprises a tubular element  14 , one end section  28  of which is inserted in a channel  29  of an adjusting screw  15  and is glued to said adjusting screw  15 . The tubular element  14  and the adjusting screw  15  are thus interconnected so as to be non-rotating. Rotating a box spanner, which interacts with an engagement shape  27  of the tubular element  14 , causes the tubular element  14  and the adjusting screw  15  to rotate and slide together. In a way that additionally differs from the design of the coolant or lubricant transfer set  9  shown in  FIG. 1 , the tubular element  14  comprises an O-ring seal  32  with which said tubular element  14  can be moved in the through borehole  17  of the sleeve  15 . 
   One embodiment variant (not shown) provides for a box spanner to engage the adjusting screw, and for the channel of the tubular element and the through hole of the sleeve to be dimensioned such that the box spanner can interact through these with the engagement shape. 
   The invention is not limited to the embodiments shown or described. Instead, it covers improvements of the invention within the scope of the claims for protective rights. In particular it is provided, in the case of a multi-part design of the adjusting screw and the tubular element, to use tubular elements of various lengths in order to design clamping chucks with different dimensions according to the invention. In the case of a single-part design of the adjusting screw and the clamping chuck, accordingly, components of different length are provided. 
   LIST OF REFERENCE CHARACTERS  
   
       
         1  Clamping chuck 
         2  Borehole in  2   
         3  Clamping section of  1   
         4  Middle section of  1   
         5  Coupling section of  1   
         6  Tool 
         7  Feeding channel in  6   
         8  Bottom surface of  6   
         9  Device 
         10  Line (from the spindle) 
         11  Ring channel in  1   
         12  Borehole in  1   
         13  Sleeve 
         14  Tubular element 
         15  Adjusting screw 
         16  Tube screw 
         17  Through borehole in  13   
         18  End region of  13   
         19  Step on  13   
         20  O-ring seal of  13   
         21  Threaded bush 
         22  Wall 
         23  O-ring seal between  13  and  1   
         24  End section of  13   
         25  End section of  14   
         26  Channel of  14   
         27  Engagement shape for adjusting tool in  13   
         28  End section of  14   
         29  Channel of  15   
         30  Face of  15   
         31  Lance 
         32  O-ring seal on  14   
         1  Longitudinal axis of  1   
       G 2 , G 15 , G 21  Thread