Title of Invention

HAND-HELD MACHINE TOOL

Abstract

The proposal is for a hand-held machine tool with a tool holder (20) and for an associated tool (16) with a push-in shank (17) which are designed in such a way that guide means (18) for the axial guidance of the tool shank (17), a rotary-drive region (21) and a holding section (24) are arranged in such a way as to be axially separated from one another. In this way, it is possible to achieve high accuracy of guidance in combination with simple construction and economy of production of the tool holder (20) and of the tool shank (17).

Full Text

The invention takes as its starting point a hand¬held machine tool in accordance with the precharacteriz-ing clause of Claim 1 and an associated tool in accord¬ance with the precharacterizing clause of Claim 13. A disclosure has already been made (DE 25 51 125 C2} of a hand-held machine tool which has a tool holder for the acceptance of a tool. The tool is driven in rotation by way of rotary-drive strips on the tool holder, which engage in corresponding rotary-drive grooves in the tool shank. The tool is secured in the axial direction by releasELble locking elements of the tool holder, which engage in corresponding recesses in the tool shank, the said recesses being closed axially at both ends. The means for driving the tool in rotation and the means for fixing the tool axially are arranged axially in the region of the receiving opening. Admittedly, this has the advantage that it is possible to achieve a tool holder which is relatively short in the axial direction and a correspondingly short tool shank. However, the axial overlap of the individual functional areas makes it necessary, for manufacturing reasons, to compromise on the properties of the tool shank. The requirement for a rotary-drive region which is robust and wear-resistant and therefore has to be hardened conflicts with the achievement of a guiding region which is narrowly toleranced and therefore has to be manufactured with very high dimensional accuracy to ensure good truth of r\in-ning. Jaw chucks are also known for the retention of a tool. To achieve good truth of running, the jaws must always accept the tool centrically with respect to the drill spindle, irrespective of the shank diaaeter of the said tool, and this requires a high outlay on manufac¬ture. The insertion of a tool in a jaw chuck is also relatively complex since the drill chuck must first of all be opened and the chuck jaws then jammed with the tool. Automatic push-in locking is not possible. Advantages of the invention In contrast, the tool holder according to the invention with the characterizing features of Claim 1 and the tool according to the invention with the characteriz¬ing features of Claim 13 have the advantage that high accuracy of guidance between the tool holder and the tool is made possible in combination with simple construction of the tool holder and the tool which is simple and economical to manufacture. The construction of the tool holder furthermore allows the provision of automatic axial locking upon insertion of the tool into the tool holder. Advantageous developments of the hand-held machine tool specified in Claim 1 and of the tool spec¬ified in Claim 13 are possible by means of the measures presented in the subclaims. Accordingly, the present invention provides a htnd-held machine tool, with associate tool, in particular for drilling, screwing, brushing, sanding or the like, with a tool holder, which has a socket as a guide means for the axial guidance of the tool, into which socket a guiding shank section of a tool shank of the tool can be inserted axially, and which is provided witii means for the rotary driving of the tool and with holding means for securing the tool axially, the holding means being arranged axially ahead of the guide means and being designed to cooperate witti a holding section of the tool shank, the said holding section being arraqged axially ahead of the guiding shank section, characterized in that the holding means have a socket region with a larger cross section dian the guide means. Drawing Five exemplary embodiments of the invention are illustrated in the drawing and explained in greater detail in the description which follows. Figure 1 shows a lon^tudinal section through a tool holder of a hand-held machine tool with a tool inserted therein. Figure 2 shows a longitudinal section trough a spring plate of the tool holder. Figure 3 shows an elevation of the spring plate. Figure 4 shows a longitudinal section tiurough a tool holder in accordance with a secondary exemplary embodiment. Figure 5 shows a longitudinal section through a tool holder in accordance with a third exemplary embodiment, figure 6 shows a longitudinal section througn a too± noiaer m accoraance with a xourcn exemplary embodiment, Figure 7 shows a partial section through a tool. Figure 8 shows a cross-section through the tool along the line VIII - VIII in Figure 7, and Figures 9 and 10 each show a longitudinal section through a tool holder in accordance with a fifth exemplary embodiment. Description of the exemplary- embodiments Figure 1 shows the tool-end part of a hand-held machine tool. The hand-held machine tool has a spindle 12 which can be driven in rotation about a longitudinal axis 11 and projects from a housing 13 of the hand-held machine tool. Located concentrically in the spindle 12 is an axial guide hole 14 which serves to accept and guide a cylindrical shank section 15 of a tool 16. In the case used as an example, the tool 16 is designed as a brush 16a. However, the tool concerned may be some other tool with a rotary working movement, e.g. a drilling, screwing or sanding tool. The guide hole 14 forms a guiding means 18 for the axial guidance of the shank section 15 and is part of a socket 19 of a tool holder 20 for holding the tool 16. The tool 16 is provided with a tool shank 17, which can be inserted into the socket 19. The shank section 15 is formed on an insertion end 22 of the tool 16. Adjoining the guide hole 14 axially at the tool end is a region 21 for the rotary driving of the tool 16, in which corre¬sponding means 23 for driving are formed. Seated on the spindle 12 is a sleeve 26, a rear section 26b of which is mounted on the spindle 12 and is connected to the latter in a manner which prevents relative rotation. The sleeve 26 projects beyond the spindle 12 at the tool end, a rotary-drive profile 25, e.g. toothing or a polygonal profile, being formeu on the inside of that part 26a of the sleeve 26 which projects beyond the spindle 12, the said profile interacting positively with a corresponding mating profile 25b on the tool shank 17. Axially adjoining the rotary-drive region 21 is a holding section 24 for the purpose of securing the tool 16 axially against falling out or inadvertently being pulled out of the guide hole 14. Acting as a holding means 28 in this holding section 24 is a spring plate 29 with an angled free end 29b, which lies obliquely relative to the longitudinal axis 11 and forms a jamming part 30. The jamming part 30 has an opening 31 through which their projects a cylindrical section of the tool shank 17. The jcuonming part 30 can be swivelled relative to the longitudinal axis 11, which simultaneously forms the axis of rotation of the tool 16. In this way, it is possible to alter the effective cross-section of the opening 31. One end 29a of the spring plate 29 is connected to the sleeve 26 in an axially fixed manner and in a manner which prevents relative rotation. The fixing of the spring plate 29 in a manner which prevents relative rotation is here accomplished by engagement in a longi¬tudinal groove 33 in the sleeve 26. The angled jaimning part 30 of the spring plate 29 is resiliently preloaded towards the longitudinal axis 11, so that the holding section 24 of the tool shank 17 jams with an edge 32 of the opening 31. If the tool 16 is pulled slightly out of the receiving opening 14 in the clamped position, the clamping force is increased further, i.e. there is self-locking. An actuating sleeve 36 surrounds the tool holder 20 and is supported in axially displaceable fashion relative to the spindle 12. When the actuating sleeve 36, which is preloaded towards the tool 16 by means of a spring 35, is pushed back, the front end 65 of the actuating sleeve 36 moves against the jamming part 30 and presses it resiliently into a position in which it lies more perpendicular to the longitudinal axis 11, in which case the opening 31 has a larger effective cross-section than the holding section 24, eliminating the jamming between the jamming part 30 and the tool 16. The tool shank 17 can then be removed from the socket 19. Figures 2 and 3 show the spring plate 29. As can be seen from the developed representation in Figure 3, circular lugs 38, 39 are integrally formed at each end of the spring plate 29. A first circular lug 38 forms the jamming part 30 interacting with the opening 31, while a second circular lug 39 is bent out perpendicularly to the longitudinal axis 11 at the rear end 29a of the spring plate 2 9 (Figure 2) and serves for the axial fixing of the spring plate 29 on the tool holder 20. A hole 40 for the spindle 12 is provided in this circular lug 39. In the case given as an example, the opening 31 4 is of cylindrical design with a larger radius than the radius of the tool shank 17 in the holding section 24. However, the opening 31 can also be of elliptical design. The cross-section of the opening 31, which is decisive for the jamming between the jamming part 30 and the tool 16, decreases in size with the cosine of a swivel angle a of the jamming part 30, the said angle being measured from the perpendicular lib to the longitudinal axis 11. As soon as the effective cross-section of the opening 31, said cross-section being measured transversely to the longitudinal axis 11, corresponds to the diameter of the holding section 24, jamming occurs between the edge 32 of the opening 31 and the tool 16. Jeunming on the right-hand side of the shank 17 only may also be sufficient. Figure 4 shows a second exemplary embodiment of a tool holder 20. Parts which are the seune and have the sarnie action are, as in all the other exemplary embodi¬ments, indicated by the same reference numerals. The essential difference with respect to the preceding first exemplary embodiment is that a disc 50 is provided instead of a spring plate with a jamming part. The disc 50 is connected in a hinged manner on one side to a projection 51 on the sleeve 26. The disc 50 likewise has an opening 31, the effective cross-section of which can be altered by swivelling the disc 50. A compression spring 52 is clsunped between the sleeve 26 and the disc 50 concentrically to the tool shank 17. Because of the hinged movmting of the disc 50, the compression spring 52 effects swivelling of the disc 50 towards the tool 16 so as to reduce the effective cross-section of the opening 31, thereby jamming the disc 50 with the holding section 24 of the tool 16. By means of a rearward axial displacement of the actuating sleeve 36, the disc 50 is raised by the end 65 of the actuating sleeve 36. In the process, the effective cross-section of the opening 31 increases, thus axially releasing the tool 16 by releasing the jaxoming with the disc 50. In order to prevent unintentional release of the tool 16, a part of the actuating sleeve 3 6 designed as a push button 54 must first of all be pressed radially inwards, thus releasing a blocking surface 55. Only then can the actuating sleeve 36 be displaced axially rear¬wards. The push button 54, for its part, can only be moved inwards when a tooth 56 lies opposite a correspon¬ding groove 57 in the sleeve 2 6 (left-hand half of the section in Figure 5} in such a way that it can engage in the groove 57. In the position in which it is not depressed, the actuating sleeve 36 is axially non-displaceable, so that the actuating sleeve 36 at the same time fulfils the function of a housing part. Figure 5 shows a third exemplary embodiment of a tool holder 20. Compared with the second exemplary embodiment shown in Figure 4, this tool holder 20 differs only as regards the holding means 28, which comprise a jamming disc 60 which, on one side, rests on a hanger 61. The hanger 61 is connected in an axially fixed manner and in a manner which prevents relative rotation to the sleeve 26. It has an angled holding part 61b which is provided with a through opening 63 for the holding section 24 of the tool shank 17, which projects through the through opening 63 with a large clearance. The jamming disc 60 is provided with the opening 31 which, when the jamming disc 60 is set obliquely, effects the axial fixing of the tool 16. The jamming disc 60 is pressed against the holding part 61b of the hanger 61 by a spring 64. By virtue of the slope of the holding part 61b relative to the longitudinal axis 11, the jamming disc 60 rests against the holding part 61b on one side. A free end 60a of the jamming disc 60 is then pressed by the spring 64 towards the jamming position of the j aimning disc 60 with the tool 16. Here, too, the jamming can be eliminated if the actuating sleeve 36 is displaced axially rearwards. This is possible when the tooth 56 engages in the groove 57 by virtue of the pushing in of the push button 54, and the blocking surface 55 is released in relation to the ^ housing 13. A driver part 65a on the front end 65 of the actuating sleeve 36 then - as in the embodiments described above - effects the swivelling of the jeunming disc 60 so as to release the jamming between the jaunming disc 60 and the tool 16. When the actuating sleeve 36 is pushed back, the driver part 65a first of all comes to rest against the holding part 61b, which is of resilient design. As the actuating sleeve 36 is pushed back further, the holding part 61b takes up a more perpen¬dicular position relative to the longitudinal axis 11, and the jamming disc 60 pressed against the holding part 61b by the spring 64 is likewise raised, with the jamming with the tool 16 being released. Common to all three exemplary embodiments is the automatic locking of the tool 16 upon insertion into the tool holder 20. During the insertion of the tool 16, the holding section 15 is first of all inserted by a certain distance into the guide hole 14. The rotary-drive profile 25 is then moved into the correct rotational position, so that the tool shank 17 can be inserted deeper into the tool holder 20. The guide hole 14 has a balance opening 58 which facilitates the establishment of a pressure balance during the insertion and removal of the tool 16. As the tool shank 17 is inserted further, the jamming member 3 0 is swivelled by the shank section 24 towards its release position, in which the decisive crosL>-section of the opening 31 is larger, with the result that the holding means 28 do not lock. The fourth exemplary embodiment, which is illus¬trated in Figure 6, differs from the first three exem¬plary embodiments essentially as regards the aucial securing of the tool shank 17. In Figure 6, it is poss¬ible to see the spindle 12, into which the shank section 15 of the tool 16 is inserted. The tool end of the spindle 12 is surrounded by the sleeve 26, which is provided with the rotary-drive profile 25b in the form of four grooves uniformly distributed around the circum¬ference. The axial securing of the tool 16 in the tool holder 20 is effected by means of hinged jaws 70, 71, each of which engages by means of a holding projection 72, 73 in an annular groove 80 in the holding section 24 of the tool shank 17. The hinged jaws 70, 71 serving as holding means 28 are here urged by a spring 74 into their locking position by means of an axially displaceeQsle taper sleeve 75. The hinged jaws 70, 71 are mounted on the sleeve 26 in such a way that they can be swivelled radially about pivots 76, 77. To unlock the tool shank 16, the actuating sleeve 36 is displaced axially rearwards counter to the force of the springs 74 and 35, a driving collar 78 on the actuat¬ing sleeve 36 driving the taper sleeve 75 by way of a corresponding catch projection 79 and releasing the hinged jaws 70, 71. During the subsequent removal of the tool shank 16 in the direction of an arrow 79 in Figure 6, the hinged jaws 70, 71 can swivel radially outwards, allowing the tool shank 17 to be removed from the tool holder 20. Figure 7 shows the tool shank 17 of the tool 16. The regions, arranged axially in series, of the shank section 15 for axial guidance, the rotary-drive region 21 and the holding section 24 can be seen. Like the holding section 24, the guiding shank section 15 is cylindrically shaped. According to the fourth exemplary embodiment, the holding section 24 can, if appropriate, also be provided with depressions, e.g. the annular groove 80. In Figure 7, the tool shank 17 is designed as an adaptor 84, to which the tool 16 in Figure 1 can be releasibly attached by means of a thread 85. The mating profile 25b of the rotary-drive region 21 can be seen in Figure 8. A total of four projections 82 distributed around the outer circumference are pro¬vided and these can be inserted into grooves formed in a complementary fashion in the sleeve 26. In Figures 9 and 10, a fifth exemplary embodiment of the invention is shown. It differs from the embodiment shown in Figure 4 in that the disc 50 can be locked in its release position (see Figure 9) with the aid of a locking member 34 for the jam-free insertion or removal of the tool 16. The locking member 34 comprises a hanger 37, which is attached at one end 41 to the sleeve 26 of the tool holder 20. Approximately at its centre, the hanger 37 forms an offset 34a, by means of which it engages behind the disc 50 and holds it approximately at right angles to the longitudinal axis 11. The free end 42 of the hanger 37 is supported on the shank 17 of the tool 16 to be inserted into the socket 19. The shank 17 is of stepped design suid, at the end, has a section 17a of smaller dieuneter and, adjoining the latter, a section 17b of larger disuneter. As soon as the free end 32 of the hanger 37 is supported against the first section 17a as the tool 16 is inserted, the disc 50 remains locked in its open position. As soon as the tool 16 has been inserted completely into the socket 19, the free end 42 is pushed outwards by the second section 17b, and the hanger 37 releases the disc 50 (see Figure 10). The disc 50 is then slanted by the compression spring 52 and in this way jammed with the shank 17. To release the tool 16, the push button 54 is pushed in in a manner similar to that in the second exemplary embodiment shown in Fig. 4, allowing the actuating sleeve to be displaced axially rearwards. The push button 54 is here coupled to the actuating sleeve 3 6 by a hinge 90. The disc 50 can be raised into its open position by means of a projection (not shown specifically in Figures 9 and 10) on the actuating sleeve. The offset 34a of the hanger 37, which is preloaded inwards, engages in the open position in front of the disc 50 and locks WE CLAIM; 1. A hand-held machine tool, with associated tool (16), in particular for drilling, screwing, brushing, sanding or the like, with a tool holder (20), which has a socket (19) as a guide means (18) for the axial guidance of the tool (16), into which socket a guiding shank section (15) of a tool shank (17) of the tool (16) can be inserted axially, and which is provided with means (23) for the rotary driving of the tool (16) and with holding means (28) for securing die tool (16) axially, the holding means (28) being arranged axially ahead of the guide means (18) and beii^ designed to cooperate with a holding section (24) of the tool shank (17), the said holding section being arranged axially ahead of the guiding shank section (15), characterized in that the holding means (28) have a socket region with a larger cross section than the guide means (18). 2. The hand-held machine tool according to claim 1, wherein the means (23) for the rotary driving of the tool (16) and the holding means (28) for securing tiie tool (16) axially are arranged axially one behind the other. 3. The hand-held machine tool according to claim 1 or 2, wherein the holding means (28) for tiieir part are arranged axially ahead of the means (23) for rotary driving. 4. The hand-held machine tool according to claim 3, wherein the means (23) for rotary driving are formed on a sleeve (26), the rear section (26b) of which is mounted on the spindle (12) and is connected to the latter in a manner which prevents relative rotation. 5. The hand-held machine tool according to any one of the preceding claims, wherein the guide means (18) are formed by a guide hole (14) arranged coaxially in a spindle (12) which can be driven in rotation. 6. The hand-held machine tool according to any one of the preceding claims, wherein the holding means (28) have a jamming part (30) which can be swivelled out of an open position approximately perpendicular to the longitudinal axis (11) of the tool holder (20) and has an opening (31) for the passage of the tool (16), it being possible, by swivelling the jamming part (30) towards the longitudinal axis (II), to reduce the size of an effective cross-section of the opening (31) in such a way that the jamming part (30) and ttie tool (16) jam together. 7. The hand-held machine tool according to claim 6, wherein the jamming part (30) is formed on a spring plate (29), one end (29a) of which is attached to the tool holder (20) i and the other end (29b) of which is angled obliquely to the longitudinal axis (11) and preloaded resiliently towards its jamming position. 8. The hand-held machine tool according to claim 6, wherein the jamming part (30) is formed by a disc (30) which is connected in a hinged manner to a projection (51) formed on the sleeve (26) and its acted upon by a compression spring (52) towards its jamming position. 9. The hand-held machine tool according to claim 4, wherein the jamming part (30) is designed as a jamming disc (60) which is urged by a spring (64) against a flexible holding part (61a) of an axially fixed hanger (61), the said holding part lying obliquely to the longitudinal axis (11). 10. The hand-held machine tool according to any one of claims 6 to 9, wherein a locking member (34) is provided which locks the jamming part (30) in an unlocked position to allow insertion and removal of the tool (16). 11. The hand-held machine tool according to any one of claims 1 to 3, wherein the holding means (28) are formed by hinged jaws (70, 71) which are mounted in such a way that they can swivel relative to the tool holder (20), radially with respect to the longitudinal axis (11) of the said tool holder on the sleeve (26) of the latter, about pivots (76, 77) and can be pressed radially towards the tool shank (17) by axial displacement of a taper sleeve (75) preloaded by spring force (74). 12. The hand-held machine tool according to any one of claims 6 to 11, v herein the holding means (28) can be swivelled out of its jamming position into its release position by means of a part (65) which can be displaced axially counter to a restoring source. 13. The hand-held machine tool according to claim 12, wherein the part (65) is formed on an actuating sleeve (36) which is provided with at least one moveable push button (54), which interacts with a locking surface in such a way that the actuating sleeve (36) can be displaced axially only after actuation of the push button (54). 14. A hand-held machine tool, substantially as herein described with reference to the accompanying drawings.

Documents:

1895-mas-1996 abstract duplicate.pdf

1895-mas-1996 abstract.pdf

1895-mas-1996 claims duplicate.pdf

1895-mas-1996 claims.pdf

1895-mas-1996 correspondence others.pdf

1895-mas-1996 correspondence po.pdf

1895-mas-1996 description (complete) duplicate.pdf

1895-mas-1996 description (complete).pdf

1895-mas-1996 drawings duplicate.pdf

1895-mas-1996 drawings.pdf

1895-mas-1996 form-1.pdf

1895-mas-1996 form-26.pdf

1895-mas-1996 form-4.pdf

1895-mas-1996 petition.pdf