Abstract:
A quick chuck for a hand power tool has an actuating element, at least one arresting element for receiving a clamping support force, a control device having at least one control unit for controlling the at least one arresting element, the arresting element controllable by the control device producing a form-locking connection for receiving the clamping support force.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a quick chuck.  
           [0002]    German patent document DE 101 08 490 A1 discloses a quick chuck for a hand power tool, which has a control device for controlling arresting means for receiving a clamping support force. The quick chuck has an axially displaceable actuating sleeve which is coupled with a turnably supported toggle of the control device. When the actuating sleeve is displaced rearwardly in an axial direction facing away from a receiving region of the quick chuck, the toggle is turned and thereby through a transmission means, a force transmitting connection for receiving the clamping support force is produced between the arresting means formed by plate springs and a base body of the fast chuck.  
         SUMMARY OF THE INVENTION  
         [0003]    Accordingly, it is an object of the present invention to provide a quick chuck, in particular for a hand power tool which avoids the disadvantages of the prior art.  
           [0004]    More particularly, it is an object of the present invention to provide a quick chuck, in particular for a hand power tool, with an actuating element and with a control device, which has at least one control means for controlling at least one arresting means for receiving a clamping support force.  
           [0005]    It is proposed in accordance with the present invention that through the arresting means controllable by the control device, a form locking connection (positive) connection for receiving the clamping support force is produced. An especially comfortable and simple to operate quick chuck can be provided in this manner. Great activation forces for force-transmitting fixing of the arresting means can be avoided, and a low wear of the arresting means over a longer service life can be provided. Also, a high percussion drilling strength can be obtained or a tool can be secured in the quick chuck with a higher clamping force which is suitable for a percussion drilling operation.  
           [0006]    Furthermore, a predetermined sequence of method steps can be guaranteed by the control device in a simple manner. Thereby a multi-part actuating device and/or a complicated operational sequence to be performed by an operator can be avoided.  
           [0007]    When the arresting means is supported movably in a radial direction, it can be integrated in a space-saving manner and structurally controlled simply through a control means, in particular through a control means which is turnable relative to the arresting means. The control means can be advantageously formed as a ring and arranged in a space-saving manner inside the arresting means. Basically, it is also possible that the arresting means, alternatively or additionally, can be formed so as to be supported movably in a circumferential and/or in an axial direction.  
           [0008]    In accordance with a further embodiment of the present invention the arresting means is loaded in at least one operational position by at least one spring element. An undesired jamming of the arresting means can be avoided and the arresting means in addition can be used advantageously for finding of preferable fixing positions. For this purpose one or several arresting means can be loaded radially outwardly, and/or one or several arresting means can be loaded radially inwardly.  
           [0009]    When the actuating element for clamping a tool is supported rotatably, structurally simple transmissions can be advantageously provided, in particular through thread connections, and is possible to obtain great clamping forces with small actuating forces. With the control device it is possible to turn the actuating element for clamping, preferably less than by 250°, so that a particularly comfortable clamping of a tool can be achieved. Basically it is also possible that instead of thread connections, lever mechanisms and the like are utilized.  
           [0010]    It is advantageous when the actuating element is supported displaceably in an axial direction. Thereby an axial actuation of a quick adjustment is provided and a simple, self-clearing operation can be obtained.  
           [0011]    It is further proposed to operationally uncouple the actuating element over at least one actuation region from the control means of the control device. Narrow tolerances and the resulting undesired consequences, such as high manufacturing costs, sensitivity to dirt, etc., can be avoided. It can be advantageous to first provide locking and then clamping. A structurally simple solution can be provided when the actuating element can be coupled to and uncoupled from the control means through a locking spring.  
           [0012]    The locking spring can be formed by springs of different types which are known to a person skilled in the art. For example, it can be formed as a helical spring and the like. When the locking spring has a substantially ring-shaped design, it can be integrated in an especially space-saving manner.  
           [0013]    In accordance with a further embodiment of the present invention it is proposed that the quick chuck has at least one clamping jaw which is loadable in an axial direction by a spring element in at least one operating position. An automatic closing of the quick chuck to a predetermined degree can be provided, and the comfort can be increased.  
           [0014]    When the quick chuck has at least one clamping jaw which is loadable in at least one operating position through a means in a radial direction, in particular in a radial direction inwardly, an undesired jamming of the clamping jaw can be reliably avoided.  
           [0015]    The means can be formed by a transmission means with an inclined surface and/or by a spring means, etc.  
           [0016]    The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a view showing an impact drilling power tool with a quick chuck in accordance with the present invention;  
         [0018]    [0018]FIG. 2 is a view showing a longitudinal section through the inventive quick chuck inclinedly from above with a tool having a small diameter.  
         [0019]    [0019]FIG. 3 is a view showing the quick chuck of FIG. 2 with a tool having a great diameter;  
         [0020]    [0020]FIG. 4 is a view showing a clamping jaw of the quick chuck illustrated separately, in accordance with the present invention;  
         [0021]    [0021]FIG. 5 is a view showing a control wing of the quick chuck illustrated separately, in accordance with the present invention;  
         [0022]    [0022]FIG. 6 is a view showing a longitudinal section through an alternative quick chuck with an actuating sleeve uncoupled from a control ring;  
         [0023]    [0023]FIG. 7 is a view showing a transverse cross-section through the quick chuck of FIG. 6 taken along the line VII-VII;  
         [0024]    [0024]FIG. 8 is a view showing a section through the quick chuck of FIG. 6 taken along the line VIII-VIII; and  
         [0025]    [0025]FIG. 9 is a view showing a cross-section through the quick chuck of FIG. 6 taken along the line IX-IX.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    [0026]FIG. 1 shows a impact drilling power tool with an inventive quick chuck. The quick chuck has a base body  33   a , and three clamping jaws  26   a  which are uniformly distributed over a circumference and displaceably supported in recesses which are inclined radially inwardly toward a free end, as shown in FIGS. 2-4. With an actuating sleeve  20   a  which is supported rotatably and axially displaceably, tools  34   a ,  34   a′  with different diameters can be clamped via the clamping jaws  26   a.    
         [0027]    The actuating sleeve  20   a  is composed of plastic and is connected with a control device  10   a  for joint rotation therewith through an inner toothing and also through an outer toothing of a control ring  16   a  arranged radially inwardly of the actuating sleeve  20   a . Control cams  38   a  are formed on the inner periphery on the control ring  16   a . The arresting means  12   a  for receiving a clamping support force are distributed radially inwardly of the control ring  16   a  over a periphery and displaceably supported in a fixing sleeve  36   a  in a radial direction. The arresting means  12   a  are controllable by the control cams  30   a  of the control ring  16   a.    
         [0028]    When the actuating sleeve  20   a  is located in direction toward a free end in a defined end position associated with an opening position counterclockwise, the control ;ring  16   a  is located with first partial portions  40   a  of the control curves  38   a  over the arresting means  12   a , in which the control ring  16   a  has a relatively great inner diameter, so that the arresting means  12   a  are movable outwardly.  
         [0029]    When a tool  34   a  is introduced into the quick chuck, the actuating sleeve  20   a  is pulled axially rearwardly in the direction facing away from the free end. Thereby the clamping jaws  26   a  which are coupled through a guiding sleeve  42   a  in axial direction form-lockingly with the actuating sleeve  20   a,  are guided rearwardly in a direction facing away from the free end and radially outwardly.  
         [0030]    The guiding sleeve  42   a  is supported axially displaceably on the base body  32   a  and is connected for joint rotation with the base body  32   a  through a not shown form-locking connection. Basically the guiding sleeve  42   a  can be however supported also rotatably relative to the base body  32   a . Instead of pulling back the actuating sleeve  20   a  rearwardly, also the free end of the clamping jaw  26   a  can be pressed with the tool  34   a  and the clamping jaw  26   a  can be inserted in the axial direction into the quick chuck until the tool  34   a  can be inserted between the clamping jaws  26   a.    
         [0031]    When the tool  34   a  is inserted between the clamping jaws  36   a  and the actuating sleeve  20   a  is released by the operator, it is displaced through a helical pressure spring  24   a  in direction to the free end of the quick chuck. The helical pressure spring  24   a  is supported against a cover sleeve  58   a  and acts through a holding ring  44   a , which is provided for securing the arresting means  12   a  in the fixing sleeve  36   a  in the axial direction facing away from the free end, on the actuating sleeve  20   a  which acts with an axial force on the clamping jaws  26   a  through the guiding sleeve  42   a . During turning over of the control ring  16   a  or in other words with a turning angle greater than 120°, the holding ring  44   a  comes to use. The arresting means  12   a  are held in engagement by the holding ring  44   a . The clamping jaws  26  can be guided radially inwardly along the inclined surfaces of the recesses in the base body  32   a  by the axial force, and thereby can secure the tool  34   a  with a small clamping force.  
         [0032]    For manual clamping of the tool  34   a  with the clamping force applied for the operation, the actuating sleeve  20   a , when considered in direction toward the free end is turned in clockwise direction. Basically the tool  34   a  is clamped with a rotary movement opposite to the clockwise direction, for example with a left thread. The control ring  16   a  which is connected with the actuating sleeve  20   a  for joint rotation therewith, is turned relative to the arresting means  12   a  and to the fixing sleeve  36   a , which is axially displaceably supported on the base body  32   a  and coupled with the base body  32   a  for joint rotation therewith through a not shown form-locking connection. With the relative movement between the control ring  16   a  and the arresting means  12   a , the control cams  38   a  come to a position with second partial portions  46   a  through the arresting means  12   a , in which the control ring  16   a  has a relatively small inner diameter. The arresting means  12   a  are pressed through the control ring  16   a  with its radially inwardly extending, injection molded ends, in a toothing  48   a  which is formed on an outer periphery of the base body  32   a.    
         [0033]    Through the arresting means  12   a  controllable by the control device  10   a  a form-locking connection  14   a  for receiving the clamping support forces is produced, and in particular in an axial direction between the arresting means  12   a  and the base body  32   a.    
         [0034]    With the rotary movement of the actuating sleeve  20   a , in addition a clamping sleeve  54 , which is coupled for joint rotation with the actuating sleeve  20   a , is turned relative to the fixing sleeve  36   a . The clamping sleeve  54   a  is coupled with the fixing sleeve  36   a  through an inner thread  50   a  formed on it and through an outer thread  52   a  of the fixing sleeve  36   a.    
         [0035]    The rotary movement of the clamping sleeve  54 , due to the thread  50   a ,  52   a  leads to an axial movement of the clamping sleeve  54   a , and it acts with an axial force through an axial bearing  56   a  and through the guiding sleeve  42   a  on the clamping jaws  26   a  which are pressed radially inwardly along the inclined surfaces of the recesses in the base body  32   a  and clamp the tool  34   a.    
         [0036]    For releasing the quick chuck, the actuating sleeve  20   a , when considered in direction toward the free end of the quick chuck, is turned opposite to the clockwise direction. The clamping sleeve  54   a  is guided in the direction facing away from the free end, and the clamping force is lifted until the clamping force which is caused by the helical pressure spring  24   a . Furthermore, the first partial portions  40   a  of the control cams  38   a  are guided over the arresting means  12   a , and the arresting means  12   a  are released in the radial direction outwardly.  
         [0037]    The actuating sleeve  20   a  can be pulled axially rearwardly in the direction facing away from the free end and the quick chuck can be completely open. The radially inwardly facing, injection molded ends of the arresting means  12   a  can be determined with respect to the toothing  48   a  so that they overlatch during rearward pulling of the actuating sleeve  20   a.    
         [0038]    For avoiding tilting of the clamping jaws  26   a  in the recesses of the base body  32   a , they can be loaded in a radial direction inwardly by one or several means  28   a ,  30   a . For example, they can be loaded by one or several means  30   a  formed by spring elements, or by one means  28   a  formed by an incline of the guiding sleeve  42   a  and/or by one means formed by an incline on the clamping jaws  26   a , as schematically shown in FIG. 3.  
         [0039]    [0039]FIGS. 6-9 shown an alternative quick chuck in accordance with the present invention. In these embodiments the components which are substantially the same are identified with the same reference numerals. In order to distinguish between embodiments, the letters “a” and “b” are introduced. Furthermore, the same features and functions are not repeatedly described but instead they correspond to the description of the embodiments shown in FIGS. 1-5.  
         [0040]    The quick chuck has an actuating sleeve  20   b , which is operatively uncouplable over one actuating region by a control ring  16   b  of a control device  10   b . In particular, it is uncoupled through a locking spring  22   b  which is formed by a band-shaped spring steel, has a substantial ring-shaped design and is arranged in a peripheral groove of the control ring  16   b.    
         [0041]    When the actuating sleeve  20   b , as considered in direction facing the free end, is located in a defined end position associated with an opening position and opposite to the clockwise direction, the control ring  16   b  is located with a first partial portion  40   b  of the control cam  38   b  over the arresting means  12   b , in which the control ring  16   b  has a relatively great inner diameter, so that the arresting means  12   b  are movable outwardly. Three arresting means  12   b  are arranged so that they are offset in a circumferential direction approximately over 120°.  
         [0042]    When a tool  34   b  must be inserted in the quick chuck, the actuating sleeve  20   b  is pulled axially rearwardly in the direction facing away from the free end. Thereby the clamping jaws  26   b  which are coupled through a guiding sleeve  42   b  in an axial direction form-lockingly with the actuating sleeve  20   b , are guided rearwardly and radially outwardly in the direction facing away from the free end. The guiding sleeve  42   b  is supported axially displaceably on the base body  32   b , and is connected for joint rotation with the base body  32   b  through a key-groove connection  80   b . In addition to the key-groove connection  80   b  another connection which is known to a person skilled in the art can be used as well.  
         [0043]    When the tool  34   b  is inserted between the clamping jaws  26   b  and the actuating sleeve  20   b  is released by the operator, it is displaced by a helical pressure spring  20   b  in direction to the free end of the quick chuck. The helical pressure spring  24   b  is supported against a cover sleeve  58   b  and acts through a holding ring  44   b  on the actuating sleeve  20   b , which acts with an axial force through an axial bearing  56   b  and through the guiding sleeve  42   b , on the clamping jaws  26   b . By the axial force, the clamping jaws  26   b  are guided radially inwardly along the inclined surfaces of the recesses in a base body  32   b  and secure the tool  34   b  with a small clamping force.  
         [0044]    For manual clamping of the tool  34   b  with a clamping force provided for the operation, the actuating sleeve  20   b , when considered in direction to the free end, is turned in clockwise direction. With the actuating sleeve  20   b  the control ring  16   b , which is coupled through a recess  66   b , the locking spring  22   b  and through a recess  60   b  on the inner periphery of the actuating sleeve  20   b  with the same, is turned relative to the arresting means  12   b  and relative to a fixing sleeve  36   b , which is axially displaceably supported on the base body  32   b  and coupled through a key-groove connection  62   b  non-rotatably with the base body  32   b.    
         [0045]    With the relative movement between the control ring  16   b  and the arresting means  12   b , the control cams  38   b  come to location with the second partial portion  14   b  over the arresting means  12   b , in which the control ring  16   a  has a relatively small inner diameter. The arresting means  12   b  are pressed through the control ring  16   b  with its radially inwardly facing ends in a toothing  48   b  formed on an outer periphery of the base body  32   b . Three toothings  48   b  which are offset approximately by 120° in a peripheral direction, are formed on the base body  32   b . The base body  32   b  forms guiding surfaces for the guiding sleeve  42   b  and the fixing sleeve  36   b  between the toothings  48   b  in the peripheral direction. Through the arresting means  12   b  controllable by the control device  10   b , a form-locking connection  14   b  is produced for receiving the clamping support force, and in particular in an axial direction between the arresting means  12   b  and the base body  32   b.    
         [0046]    When the fixing sleeve  36   b  is fixed through the arresting means  12   b  in an axial direction form-lockingly on the base body  32   b , the locking spring  22   b  comes to a position with a radially inwardly facing end over a depression  64   b  of the fixing sleeve  36   b . It is arrested in it and can travel over the inclined surface  68   b  which is formed on the actuating sleeve  20   b  and follows the recess  60   b . The inclined surface  68   b  corresponds to the inclined surface  74   b  formed on the locking spring  22   b  as shown in FIG. 8. The actuating sleeve  20   b  and the control ring  16   b  are operatively uncoupled.  
         [0047]    Substantially when the actuating sleeve  20   b  is uncoupled from the control ring  16   b , the actuating sleeve  20   b  comes to abutment against the abutment surfaces  72   b ,  72   b′  of a clamping sleeve  54   b  through radially inwardly facing projections  70   b ,  70   b′  formed on the inner periphery. Thereby it is coupled with them in a rotary direction, when considered in direction toward the free end, in the clockwise direction as shown in FIG. 9.  
         [0048]    After this, by the rotary movement of the actuating sleeve  20   b , the clamping sleeve  54   b  is then turned relative to the fixing sleeve  36   b , and clamping sleeve  54   b  is coupled with the fixing sleeve  36   b  through an inner thread  50   b  formed on the clamping sleeve  54  and through an outer thread  52   b  of the fixing sleeve  36   b.    
         [0049]    The rotary movement of the clamping sleeve  54   b , because of the threads  50   b ,  52   b , leads to an axial movement of the clamping sleeve  54   b . It acts with an axial force through the axial bearing  56   b  and through the guiding sleeve  42   b , on the clamping jaws  26   b  which are pressed radially inwardly along the inclined surfaces of the recesses in the base body  32   b  and clamp the tool  34   b.    
         [0050]    For releasing the quick chuck, the actuating sleeve  20   b , when considered in direction to the free end of the quick chuck, is turned opposite to the clockwise direction. The clamping sleeve  54   b  is guided in the direction which faces away from the free end, and the clamping force is lifted until the clamping force caused by the helical pressure spring  24   b.    
         [0051]    Furthermore, the actuating sleeve  20   b  comes to abutment against an abutment surface  70   b  of the locking spring  22   b , with its abutment surface  76   b  which is formed on its inner periphery and follows the recess  60   b , and guides it from the depression  64   b , and in particular by a pre-tensioning of the locking spring  22  which acts outwardly in a radial direction outwardly.  
         [0052]    The control ring  16   b  is coupled with the actuating sleeve  20   b  through the locking spring  22   b , the first partial portion  40   b  of the control cams  38   b  is guided through the arresting means  12   b , and the arresting means  12   b  are released in the radial direction outwardly.  
         [0053]    The actuating sleeve  20   b  can be pulled axially rearwardly in the direction facing away from the free end, and the quick chuck can be opened completely. The radially inwardly facing, injection molded ends of the arresting means  12   b  are determined with respect to the toothing  48   b  so that during pulling rearwardly of the actuating sleeve  20   b  they are overlatched. Two arresting means  12   b  are loaded outwardly in a radial direction through bracket-shaped spring elements  18   b  with a spring force, and one of the arresting means  12   b  is loaded radially inwardly with a spring force through a bracket-shaped spring element  18   b.    
         [0054]    Instead of the individual spring elements  18   b , several arresting means  12   b  can be loaded with spring forces by a single spring element, for example a ring-shaped wire spring.  
         [0055]    It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.  
         [0056]    While the invention has been illustrated and described as embodied in a quick chuck, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.  
         [0057]    Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.