Abstract:
Screwing tool ( 1 ) having a grip ( 2 ) and a shank ( 3 ), which is received removably in a cavity ( 4 ) open toward an end of the grip ( 2 ) and which at its free end has an actuating portion ( 5 ). The shank ( 3 ) is retained in a position of use such that it is fixed in terms of rotation on the grip, to avoid sliding in the axial direction, by a retaining element ( 14 ) associated with the grip ( 2 ). The retaining element ( 14 ) can be displaced into a removal position by displacement of an actuating member ( 6 ) in order for the shank to be removed from the grip ( 2 ). In a storage position, a large part of the shank ( 3 ) is located in the cavity ( 4 ), where it is held by a holding element (H). The holding element (H) is releasable, so that part of the shank ( 3 ) can be moved out.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
   The invention relates to a screwing tool having a grip and a shank which is received removably by a chuck associated with the grip and at its free end has an actuating portion. 
   Screwing tools of this type are known from the prior art. Screwing tools of this type usually have exchangeable blades. The grip has a central cavity, into which a clamping portion of the blade can be slid. There, on the side of the cavity opening, it is possible to provide a clamping chuck which has clamping jaws that can be moved radially onto the blade in order to hold the blade retained in the axial direction. The blade can be used with different lengths by means of a chuck of this type. Although this solution has the advantage of a stepless length adjustment, if the clamping jaws are not pressed onto the shank with sufficient force, the shank can slip into the grip in the event of a corresponding axial load being applied to the grip. 
   Furthermore, the prior art has disclosed clamping chucks for holding bits. Clamping chucks for bits are shown, for example, in DE-U1 85 02 308, DE-U1 201 06 986.5 and DE-U1 90 00 245.8. 
   Screwdrivers with exchangeable blades are known from DE 44 01 335 C2 and DE-U1 90 02 085. 
   SUMMARY OF THE INVENTION 
   The invention is based on the object of further developing the screwing tool of the generic type in a way which is advantageous for use. 
   The object is achieved by the invention given in the claims. 
   The invention provides firstly and substantially that the removable shank can also be moved into a storage position, in which a large part of the shank is located in a rear part of the cavity, where it is held by means of holding means, which holding means are releasable, so that that part of the shank which is located within the cavity, apart from a holding portion of the shank associated with the fixed end of the shank, can be moved out of the cavity into a position of use onto a stop by the application of force, in which position of use the holding portion is retained in the axial direction and in the direction of rotation by the chuck. This retaining can be released in order shank can be displaced outward with respect to the grip by the compression spring, but before it has reached the release position of the blocking ball, which captures the shank on reaching its outwardly displaced position. This refinement has the advantage that the actuator initially only displaces the actuating sleeve sufficiently far for the shank to be the subject of preliminary displacement. The further displacement into the release position of the blocking ball has to be deliberate. It is particularly advantageous if the resistance is audibly overcome. For example, it is provided that the bush which defines the cavity for receiving the shank has an annular groove, in which a circlip is located. An inwardly directed collar of the actuating sleeve comes into contact with this circlip. This produces the perceptible resistance. The depth of the groove is such that the circlip can yield into it. Therefore, it has to be compressed if the collar is to be lifted over the circlip. Moreover, this is associated with an audible click. In a further configuration of the invention, it is provided that the actuating sleeve has a link guide. This link guide comprises a longitudinal slot in which a guide pin engages. The longitudinal slot has an obtuse-angled extension into which the guide pin engages when the actuating sleeve is rotated. Rotation of the actuating sleeve is required in order to release the blocking ball. 
   The invention of the latching mechanism is of stand-alone inventive importance even independently of the removability of the shank which was primarily outlined above. 
   The shank is rotationally fixedly connected to the grip in the position of use. In the storage position, rotationally fixed connection with respect to the shank is not required. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments of the invention are explained below with reference to the drawings, in which: 
       FIG. 1  shows a perspective illustration of the grip of the screwing tool with associable shank; 
       FIG. 2  shows a view toward the screwing tool in a position of use; 
       FIG. 3  shows a view corresponding to  FIG. 2  rotated through 90°; 
       FIG. 4  shows a rear view of  FIG. 2  rotated through 90°; 
       FIG. 5  shows a section on line V-V in  FIG. 2 , but in a released position of the shank; 
       FIG. 6  shows the section on line VI-VI in  FIG. 3 , but relating to the position illustrated in  FIG. 5 ; 
       FIG. 7  shows the follow-up illustration to  FIG. 5 , but in a position of use of the shank; 
       FIG. 8  shows a follow-up illustration to  FIG. 6 , but in the position of use; 
       FIG. 9  shows a follow-up illustration to  FIG. 7 , but in a storage position of the shank; 
       FIG. 10  shows a follow-up illustration to  FIG. 8 , but in the storage position; 
       FIG. 11  shows a sectional view on line XI-XI in  FIG. 5 ; 
       FIG. 12  shows a sectional view on line XII-XII in  FIG. 7 ; 
       FIG. 13  shows a sectional view on line XIII-XIII in  FIG. 6 ; 
       FIG. 14  shows a sectional view on line XIV-XIV in  FIG. 8 ; 
       FIG. 15  shows a sectional illustration of a further exemplary embodiment of the invention in the region of the chuck with locked actuating sleeve; 
       FIG. 16  shows the exemplary embodiment in accordance with  FIG. 15 , with the actuating sleeve  6  having been displaced into the release position of the latching ball  13 ; 
       FIG. 17  shows the exemplary embodiment in accordance with  FIG. 15 , with the actuating sleeve having been displaced into the release position of the blocking ball; 
       FIG. 18  shows a further exemplary embodiment in plan view; 
       FIG. 19  shows a sectional illustration of the exemplary embodiment in accordance with  FIG. 18  with the actuating sleeve locked; 
       FIG. 20  shows an illustration in accordance with  FIG. 19 , with the actuating sleeve having been displaced into the release position of the latching ball, and 
       FIG. 21  shows an illustration in accordance with  FIG. 19 , with the actuating sleeve having been displaced into the release position of the blocking ball. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Reference numeral  1  denotes a screwing tool which is composed of a grip  2  and a polygonal shank  3 . The hexagonal shank  3  can be fitted into an axially disposed cavity  4  in the grip  2 . The free end of the polygonal shank  3  has an actuating portion in the form of a clamping chuck  5 . An axially displaceable actuating sleeve  6  is associated with the grip  2  to the rear of the opening of the cavity  4 . Furthermore, the grip  2  is in the shape and form of a screwdriver handle. 
   The grip cavity  4  which has already been mentioned above is formed by a tube  7  which receives the shank  3 . Approximately half of the body length of the tube  7  is seated in a rotationally fixed manner in an axially disposed opening  8  in the grip  2 , the opening  8  extending further toward the inside of the grip. In the insertion region, the cavity  4  is in part shaped as a polygonal cavity  9 . Furthermore, at its free end which projects beyond the grip  2 , the tube  7  has an engagement shoulder  10  of larger diameter. Furthermore, the tube  7  has window-like apertures  11  and  12  which have been formed in the radial direction and are located axially offset, with three windows  11  located in a first plane being disposed at an angle of 120° with respect to one another and the two windows  12  located in the second plane, which is offset toward the rear, being disposed diametrically opposite one another. Latching balls  13  are disposed in the windows  11  such that they are retained in terms of movement, and blocking balls  14  are disposed in the windows  12  such that they are retained in terms of movement. Furthermore, the diameters of the latching balls  13  are smaller than the diameters of the blocking balls  14  (cf. in particular the illustrations in  FIGS. 11 and 13 ). 
   Beyond the stop shoulder  10 , i.e. directed toward the inside of the grip, the axially slidable actuating sleeve  6  slides on a portion  7 ′ of wider diameter of the tube  7 . A locking sleeve  15  is associated with the actuating sleeve  6  to the rear. The same locking sleeve  15  likewise slides on the portion  7 ′ of larger diameter of the tube  7 . Both the actuating sleeve  6  and the locking sleeve  15  are spring-loaded outward in the axial direction by springs  16  and  17 . In this context, spring  16  is associated with the actuating sleeve  6  and spring  17  is associated with the actuating sleeve  15 . Both springs  16  and  17  are likewise disposed in axially oriented manner on the portion  7 ′ of the tube  7 . Two annular collars  18  and  19  serve as the necessary abutment for the springs  16  and  17 , the annular collars  18  and  19  each being located radially in circumferential grooves of the tube  7 . In this context, the annular collar  18  is associated with the spring  16  and the annular collar  19  is associated with the spring  17 . While one side of the spring  17  is supported on the end face  15 ′ of the locking sleeve  15 , the spring  16  has an annular portion  20  of the actuating sleeve  6  engaging over it, which annular portion  20  defines a cavity  21 , one side of the spring  16  being supported on the base of the cavity  21 . 
   Furthermore, it is provided that the latching balls  13  interact with the actuating sleeve  6  and the blocking balls  14  interact with the locking sleeve  15 . 
   Whereas the actuating sleeve  6  is only partly engaged over by the grip  2 , which has an opening  22  which at the end is matched to the diameter of the actuating sleeve  6  in order to ensure axial slidability, the locking sleeve  15  is completely received in an axial opening  23  which is made in the base of the opening  22  and is of reduced diameter compared to the opening  22 . In this context, the spring  16  and the annular collar  18  are associated with the opening  22  and the spring  17  and the annular collar  19  are associated with the opening  23  of the grip  2 . 
   The positioning of the latching balls  13  and of the blocking balls  14  is such that the latching balls  13  are located in that portion of the tube  7  which projects beyond the grip  2  and the blocking balls  14  are located in that portion of the tube  7  which the grip  2  engages over, in the region of the step between the openings  22  and  23 . 
   The opening  8  which is formed in the axial direction and has already been mentioned above opens into the base of the opening  23 . One side of a spring  24  may be adhesively bonded or injection-molded to the base of the opening  8 . Furthermore, the spring  24  is wound around a peg  25  of the grip  2 , which peg  25  is identical in terms of materials to the grip  2 . The free end of the spring  24  penetrates into the cavity  4 . The spring  24  is guided by the inner wall  4  of the tube  7 . The diameter of the spring  24  is slightly smaller than the diameter of the cavity  4 . 
   The mode of action will now be explained in more detail with reference to the illustrations in  FIGS. 5 and 6 : 
   To move the screwing tool  1  into a position of use, the actuating sleeve  6  has to be displaced inward with respect to the grip counter to the spring force of the spring  16 . This is associated with the end face  20 ′ of the annular portion  20  of the actuating sleeve  6  acting on the end face  15 ″ of the locking sleeve  15 , causing the same locking sleeve  15  to move inward with respect to the grip counter to the spring force of the spring  17 . 
   This displacement of the actuating sleeve  6  and of the locking sleeve  15  into a release position means that the latching balls  13  and the blocking balls  14  are now in a position to move radially outward. In the process, the latching balls  13  partially pass through the windows  11  in the tube  7  and then, in segmented fashion, enter a cavity  27  in the actuating sleeve  6 . The blocking balls  14  likewise move partially through the windows  12  in the tube  7  and then in segmented fashion enter the cavity  21  in the annular portion  20  of the actuating sleeve  6 . Depending on the position of the screwing tool  1 , the latching balls  13  and the blocking balls  14  can move radially outward of their own accord in this situation as illustrated. 
   To produce a locking position of the screwing tool, the situation as illustrated in  FIGS. 7 and 8  is established. For this purpose, the shank  3  has to be fitted into the cavity  4  in the insertion direction x through the polygonal cavity  9 . This is associated with a radially outward displacement by the run-up slope  3 ′ of the shank  3  of both the latching balls  13  and the blocking balls  14 . As the shank  3  slides in further, the latching balls  13  and the blocking balls  14  move with it on the outer lateral surface of the shank  3 . The shank  3  is introduced into the cavity  4  until the blocking balls  14  move into the annular neck  31 . 
   After the actuating sleeve  6  has been released, both the actuating sleeve  6  and the locking sleeve  15  are displaced outward with respect to the grip by the prestressed springs  16  and  17 , the outward displacement of the actuating sleeve  6  being limited by the stop shoulder  10 . The annular collar  18  prevents further axially outward displacement of the locking sleeve  15 , with the end face  15 ″ of the locking sleeve  15  acting on the underside of the annular collar  18 . 
   The following occurs during the axially outward displacement of the actuating sleeve  6  and of the locking sleeve  15 : 
   By means of an axially oriented oblique flank  28 , the actuating sleeve  6  acts on the latching balls  13  and causes them to partially pass through the windows  11  in the tube  7  and then to engage in corner cutouts  29  of the shank  3 . In this context, the positioning of the corner cutouts  29  is selected in such a manner that they are disposed transversely with respect to the position in which the shank  3  extends. A radially oriented oblique boundary edge  30  of the locking sleeve  15  acts on the blocking balls  14  and causes them to partially pass through the windows  12  in the tube  7  in order then to engage in an annular neck  31  of the shank  3 . In this context, the axial length of the annular neck  31  is greater than the diameter of the blocking balls. Therefore, the screwing tool  1  is located in a latch-secured position of use, with the latching balls  13  forming an axial securing feature for the shank  3  in the grip  2  (cf. in particular the illustrations in  FIGS. 7 and 8 ). The blocking balls  14  are located in a positively locking manner beneath the cylindrical wall of the cavity  26 . 
   Furthermore, the latching balls  13  perform the function of a holding means H. The blocking balls  14  perform the function of a stop A in order to define the insertion position of the shank  3  in the position of use. 
   With regard to the mode of operation of the holding means H, reference is made to DE-U1 90 00 245, in the name of the present Applicant. According to this, with the shank  3  inserted, each of the corner cutouts  29  is aligned with a latching ball  13 , which through the released actuating sleeve  6  comes into two-point contact with the surfaces, which are in a prism-like relationship with respect to one another, of the corner cutouts  29 . 
   As shown in the illustrations presented in  FIGS. 9  and  10 , it is also possible for the shank  3 , which includes the clamping chuck  5 , to be moved into a so-called storage position, i.e. for virtually the entire length of the shank  3  to be slid into the cavity  4  in the grip  2 . For this purpose, the actuating sleeve  6  and the corresponding locking sleeve  15  have to be displaced inward with respect to the grip, so that the inclined flank  28  of the actuating sleeve  6  releases the latching balls  13 . This is associated with the boundary edge  30  of the locking sleeve  15  releasing the blocking balls  14 . If the shank  3  is then displaced further inward with respect to the grip, counter to the spring force of the spring  24 , the latching balls  13  and the blocking balls  14  are also displaced radially outward as a result of this sliding-in motion. The blocking balls  14  are supported against the slopes  30 . Since the blocking balls  14  cannot penetrate radially inward, but rather rest against the shank  3 , the locking sleeve  15  remains in its rear position. 
   The axial spacing which can be seen in  FIGS. 7 and 8  and in principle allows a certain preliminary displacement of the actuating sleeve  6  before it drags the locking sleeve  15  with it is greater in the storage position illustrated in  FIGS. 9 and 10 . 
   During further displacement of the shank  3  which includes the clamping chuck  5 , the spring  24  is prestressed. To allow the shank to be held in this storage position inside the grip  2 , the shank  3  has further axially offset corner cutouts  29 ′, into which the latching balls  13  once again move in a blocking manner after the storage position has been reached. Releasing the actuating sleeve  6  secures this position, with only the latching balls  13  entering the corner cutouts  29  of the shank  3 . The blocking balls  14  which form the stop A are only supported on the outer surfaces of the polygonal shank (cf. in particular the illustration in  FIG. 10 ). In the storage position, the blocking ball  14  is pressed onto the shank by the oblique boundary edge  30  of the locking sleeve  15 . This effects a certain frictional moment. 
   If, starting from the storage position illustrated in  FIGS. 9 and 10 , the actuating sleeve  6  is displaced slightly inward with respect to the grip, the cavity  27  moves over the latching balls  13 , so that the latching balls  13  can move radially out of their associated corner cutouts  29 ′. In this intermediate position, the rear boundary edge  20 ′ of the actuating sleeve  6  does not yet need to have come into contact with the boundary edge  30  of the locking sleeve  15 . If the force of the spring  24  is greater than the above-described frictional force of the blocking ball  14  on the shank  3 , the shank  3  is moved out of the cavity  8  solely by the force of the spring  24 . The spring  17  which loads the locking sleeve  15  at the rear ensures that the blocking ball  14  can enter the annular neck  31  when the latter is located beneath the blocking ball  14 . As a result, the outward movement of the shank  3  is stopped. When the actuating sleeve is released again, the latching ball  13  enters the corner cutout  29 , so that the position of use illustrated in  FIGS. 7 and 8  is reached. 
   Should the frictional force which the blocking ball  14  exerts on the shank  3  be greater than the force of the spring  24 , which is not desired, the blocking ball  14  can nevertheless perform its stop function if the shank  3  is moved out of the cavity  4  under the force of gravity or by a pulling action on the clamping chuck  5 . 
   If it is desired for the shank  3  which has the clamping chuck to be completely removed, the actuating sleeve  6  and the corresponding locking sleeve  15  have to be displaced inward with respect to the grip. This allows the spring  24  to exert its prestressed force, so that the shank  3  is displaced outward with respect to the grip. This is also associated with the latching balls  13  and the blocking balls  14  being displaced radially outward, so that they can in turn move into the cavities  27  in the actuating sleeve  6  and  21  in the annular portion  20 . Consequently, the shank  3  which includes the clamping chuck can be separated from the grip  2  in order if appropriate for a shank  3  which has a different actuating portion to be fitted in. 
   It is considered particularly advantageous for the shank  3  at its end to have an annular neck  31  which is at a spacing from the end of the shank  3  such that the hexagonal shank can be fitted into a standard chuck of an electric screwdriver or the like. A chuck of this type may, for example, be configured as described in DE 199 32 369.0. 
   Therefore, the tool according to the invention is suitable for use with a power screwdriver and at the same time for being driven by a manually actuable grip. If it is used as a manual screwdriver, it has proven advantageous for the grip to perform the function of a storage chamber into which the shank can be fitted. By snapping the shank out of the cavity in the grip, it is possible to produce a practical screwdriver with a suitably long blade. 
   In the exemplary embodiments illustrated in  FIGS. 15 to 21 , the actuating sleeve  6  can initially be displaced into a release position for the latching ball  13 . In this release position, the shank  3 , which is located in the storage position, can undergo preliminary displacement into the position of use. This is effected by means of the compression spring  24 . In this position, the blocking ball  15  is still subject to the action of its associated locking sleeve  15 . Therefore, when the position of use is reached, the blocking ball  14  latches into its associated annular neck  31  of the shank  3 . 
   In the two exemplary embodiments, this position of the actuating sleeve can only be passed by overcoming a resistance. In the exemplary embodiment illustrated in  FIGS. 15 to 17 , the resistance is provided by a radially inwardly directed collar  34  of the actuating sleeve  6 , which butts against a radially protruding portion of a circlip  32  located in an annular groove  33 . In this exemplary embodiment, the actuating sleeve  6  is in two parts. It comprises a tubular core  6  and an actuating portion  6 ′ which is applied to the core  6  and consists of plastic. The collar  34  is associated with the core  6 . 
   The annular groove  33  is associated with the tube denoted by reference numeral  7 . The circlip  32 , which consists of spring steel, is located in this annular groove with radial play. The depth of the annular groove  33  is such that the ring  32  can be completely recessed into it when it is acted on by the boundary edge of the collar  34 . This takes place with an audible click. It is then possible to reach the operating position illustrated in  FIG. 16 , in which the actuating sleeve  6  has displaced the locking sleeve  15  to the rear in such a manner that the blocking ball  14  can move out of the annular neck  31 . 
   In the exemplary embodiment illustrated in  FIGS. 18 to 20 , the actuating sleeve  6 , during displacement out of the locking position, encounters a resistance, likewise before the release position of the blocking ball  14  is reached. In this exemplary embodiment, a guide pin  36 , which is fixedly connected to the grip, projects into a link guide  35  associated with the actuating sleeve  6 . The link guide  35  has a slot portion  35 ′ running in the axial direction and a portion  35 ″ which adjoins the portion  35 ′ at an obtuse angle. During displacement of the actuating sleeve from the locking position into the release position of the latching ball  13 , the guide pin  36  slides in the axial slot portion  35 ′. As a result of subsequent turning of the actuating sleeve, the guide pin  36  moves within the obtuse-angled portion  35 ′ of the link guide  35 , with the result that the actuating sleeve  6  is displaced further inward with respect to the grip until it displaces the locking sleeve  15  into the release position of the blocking ball  14 . 
   All features disclosed are (inherently) pertinent to the invention. The disclosure content of the associated/appended priority documents (copy of the prior application) is hereby incorporated in its entirety in the disclosure of the application, partly with a view to incorporating features of these documents in claims of the present application.