Tool holder for a hand-held power tool designed as a drill and / or chisel hammer

Abstract

Tool holder (100) for a hand-held power tool comprising an actuating sleeve (104), a tool receptacle (108) and a locking mechanism (114) operable via the actuating sleeve (104) for releasably locking an insert tool (102) received in the tool receptacle in a working position, wherein the tool receptacle (108) has an axial bore (112) on a tool-side end face (110) for receiving the insert tool (102) and at least one, preferably two, three or more radial recesses (132) for receiving fastening elements (138) in the connection area to an opposite end face, wherein the fastening elements (138) are radially secured in a mounted state by means of a flanged bushing (140) arranged on the tool receptacle (108), characterized in that a sealing lip (144) is arranged on the flanged bushing (140).which extends between the actuating sleeve (104) and the collar bushing (140) and essentially seals an internal locking chamber (115) against ingress of particles from the environment surrounding the tool holder (100).

Description

State of the art

[0001] The invention relates to a tool holder for a hand-held power tool designed as a drill and / or chisel hammer, comprising an actuating sleeve, a tool holder and a locking mechanism operable via the actuating sleeve for releasably locking an insert tool received in the tool holder in a usable position.

[0002] When working with rotary hammers and / or demolition hammers according to the state of the art, a protective or actuating sleeve is typically moved axially along a main dimension of the tool holder's tool receptacle to lock and unlock the insert tool in the tool holder. In this process, drilling dust can penetrate a locking chamber through an annular gap between the protective sleeve and a machine housing.

[0003] The tool holder's tool mount and an output spindle designed as a hammer tube for the drill and / or chisel hammer are usually connected to each other by a plurality of cylindrical rollers and radially secured by a ring or a flanged bushing.

[0004] The sealing of the locking chamber, specifically the area between the protective sleeve and the tool holder or the flanged bushing of the tool holder, is normally achieved by at least one sealing ring located in a seal holder. The sealing ring is usually an O-ring, but can also be a molded sealing ring. In a preferred embodiment, a first sealing ring located in an outer circumferential groove provides a seal between the protective sleeve and the seal holder, and an inner, second sealing ring provides a seal between the seal holder and the tool holder.

[0005] A similar solution is known, for example, from DE 197 24 532 A1. Due to the number of individual components and their sometimes small dimensions, the assembly or disassembly process during the assembly and / or maintenance of the hand-held power tool is rather complex and therefore costly.

[0006] From DE 93 05 463 U1, a tool holder for a hand-held power tool is also known, which has an axial bore on a tool-side end face for receiving the insert tool and in the connection area on an opposite end face a plurality of radial recesses for receiving fastening elements, wherein the fastening elements are radially secured in a mounted state by means of a flanged bushing arranged on the tool holder and a sealing lip is arranged on the flanged bushing, which extends between the actuating sleeve and the flanged bushing and essentially seals an internal locking chamber against ingress of particles from an environment surrounding the tool holder.

[0007] The object of the present invention is to enable a simplified assembly for locking a tool holder onto an output spindle of a drill and / or chisel hammer compared to the prior art. Advantages of the invention

[0008] To solve the above problem, it is provided that the fastening bodies of the tool holder engage in at least one, preferably two, three or more receiving recesses of the output spindle of the drill and / or chisel hammer during an assembly step to connect with the radial recesses of the tool holder.

[0009] The tool holder according to the invention, with the features of the main claim, offers the advantage of simplified locking of the tool holder to the output spindle during the assembly of the rotary hammer and / or chisel. Furthermore, functions previously implemented in separate components can be integrated into a smaller number of components. The inventive design of the tool holder preferably achieves the following functions: radial securing of the mounting elements in the assembled state (which refers in particular to the state after the hand-held power tool has been assembled), sealing of the locking chamber against ingress of particles, especially drilling dust or cuttings, and support of the spring element of the locking mechanism, all within a pre-assembled component consisting of a sealing lip and a flanged bushing. Overall, this advantageously reduces assembly time.

[0010] A further advantage is that the functional integration achieved according to the invention allows for a reduction in the required installation space compared to a conventional design. In a preferred embodiment, the overall length of the tool holder according to the invention can be reduced, which advantageously leads to a reduction in the overall length of the hand-held power tool.

[0011] The measures listed in the dependent claims result in advantageous further developments and improvements of the features specified in the main claim.

[0012] A particularly easy-to-assemble solution is achieved by arranging the sealing lip essentially radially protruding from a cylindrical outer surface of the flanged bushing and by having a sealing edge of the sealing lip essentially opposite the outer surface.

[0013] A preferred embodiment is characterized by the fact that the sealing lip is held centrally by the flanged bushing. This advantageously ensures that the flanged bushing is centered in the assembled state.

[0014] If the sealing lip rests against a flanged surface of the bushing with its first flat side, the sealing lip can be advantageously protected against excessive deformation, for example by bending. This also has the advantage that the sealing lip can be made of a very soft material, such as soft rubber, sponge rubber, or very soft elastomers.

[0015] In a preferred embodiment, the sealing lip has a second flat surface which is essentially designed as a support surface for a spring element of the locking device, thereby particularly facilitating the assembly of the locking mechanism. Furthermore, the contact surface on this second flat surface also advantageously protects the sealing lip against deformation from this side.

[0016] When the sealing lip is pressed against the flanged surface of the flanged bushing by the spring element, the flanged bushing can be axially secured in a particularly simple way.

[0017] In a particularly preferred embodiment of the tool holder according to the invention, the actuating sleeve has a substantially cylindrical sealing surface which, in the assembled state, is opposite the sealing lip in every actuating position and with it substantially seals the locking chamber against penetrating particles from the environment surrounding the tool holder.

[0018] In another aspect, the invention relates to a drill and / or chisel hammer with an output spindle and a tool holder according to the invention, which can be advantageously more easily assembled, disassembled, manufactured and maintained due to the design according to the invention. Description of the drawings

[0019] An embodiment of the invention is illustrated in the drawings and explained in more detail in the following description. The drawings show: Fig. 1 a schematic drawing of a rotary and / or impact hammer with a tool holder according to the invention Fig. 2 a section through a tool holder according to the invention for a drill and / or impact hammer Description of the exemplary implementations

[0020] Fig. Figure 1 shows a schematic view of a rotary hammer and / or chisel 10 as an example of a hand-held power tool with a housing 12, a tool holder 100 according to the invention movably arranged on the housing 12 for the interchangeable receiving of an insert tool 102, and a drive device 22, comprising a drive unit 18 and a gear unit 20, which is received in the housing 12 and drives the insert tool 102. The tool holder 100 is preferably rotatably arranged on an end face 24 of the housing 12. On a side of the housing 12 opposite the end face 24 of the housing 12, in the example shown... Fig. 1. Furthermore, a handle device 26 is provided. In the present example, the handle device 26 comprises a main device switch 28 for starting up the drill and / or chisel hammer 10. Furthermore, an auxiliary handle device 30 is arranged on the housing 12 of the drill and / or chisel hammer 10, in particular arranged in an adjustable manner.

[0021] Fig. Figure 2 shows a sectional view through a tool holder 100 according to the invention for the detachable holding of an insert tool 102, which is not shown here.

[0022] Furthermore, the representation in Fig. 2. Note that the upper part of the image shows a view of the tool holder 100 in a first position of an actuating sleeve 104, while the lower part of the image shows a second position of the actuating sleeve 104 after actuation.

[0023] The tool holder 100 comprises, in addition to the actuating sleeve 104, a sealing cap 106 arranged on the tool side. The sealing cap 106 is, for example, mounted on a tool receptacle 108 via an internal collar 106a and locked in place by a preferably circumferential recess 108a provided in the tool-side end of the tool receptacle 108. The tool receptacle 108 further has an axial bore 112 on a tool-side end face 110 for receiving the insert tool 102. The sealing cap 106 also has a bore 106b for the insertion of the insert tool 102, which is substantially aligned with the axial bore 112. "Substantially aligned" means, in particular, that the axial bore 112 and the bore 106b are preferably coaxial and have substantially the same diameter. However, it can also be advantageous if the diameter of bore 106b is larger than the diameter of axial bore 112, e.g.when inserting tools 102 which have a working area whose diameter is larger than a shank area for insertion into the tool holder, or smaller than the diameter of the axial bore 112, e.g. when a sealing cap 102 is intended to prevent frontal penetration of particles into the tool holder.

[0024] The actuating sleeve 104 is shown in the example according to Fig. 2 is essentially cylindrical in construction, comprising an essentially cylindrical guide section 104a, a partly conical, partly cylindrical actuating section 104b, and a locking section 104c. The actuating sleeve 104 encloses a locking mechanism 114 arranged around the tool holder 108, which extends into an internal locking chamber 115.

[0025] In this example, the locking mechanism 114 comprises a spring element 116, a guide sleeve 118, a control element 120, and at least one locking body 122. The guide sleeve 118 serves to guide and radially outwardly support the locking body 122. The locking body 122 is designed such that a portion of it, directed radially toward the tool holder 108, can engage through a locking opening 124 in the tool holder 108. However, embodiments of locking mechanisms 114 are also known in which the at least one locking body 122 is designed as a simple locking ball or locking cylinder. Even with such locking mechanisms 114, the person skilled in the art can implement the inventive solution for sealing the locking chamber without having to inventively construct their own design.

[0026] The spring element 116 of the locking mechanism 114, designed here as a coil spring, is supported at one end by the control element 120, which in the example is shown below. Fig. 2 is designed as a control disc. In other embodiments, however, the control element 120 can also be designed as a control sleeve or control slide without this affecting the solution according to the invention. It can also be advantageous if the spring element 116 is designed as an elastomer element, rubber element and / or disc or leaf spring element.

[0027] The tool holder 100 is inserted into an output spindle 128, designed as a hammer tube 126 open at least on one side, with one end region of the tool receptacle 108 opposite the tool-side end face 110. For this purpose, a diameter of the outer surface of the tool receptacle 108 is preferably designed to match an inner diameter of the hammer tube 126, 128, so that the two preferably cylindrical sections of the tool receptacle 108 and the hammer tube 126, 128 can be joined with minimal play in this connection end region 130. In the tool receptacle 108, one, two, or preferably at least three radial recesses 132 are provided in the connection end region 130. In the connection end region 130 of the hammer tube 126, 128, one, two, or preferably at least three receiving recesses 134 are provided, which in the example are shown below. Fig. 2 are designed as essentially radially extending receiving bores 136. In a ready-to-assemble state, the receiving recesses 134, 136 and the radial recesses 132 are aligned with each other, so that fastening elements 138 can be inserted into the receiving recesses 134, 136 and engage through them into the radial recesses 132. In the example according to Fig. 2. The fastening elements 138 are preferably designed as substantially cylindrical fastening pins. However, the fastening elements 138 can also advantageously be spherical, conical and / or barrel-shaped.

[0028] To radially secure the fastening elements 138, after their insertion in the first assembly step, a flanged bushing 140 is arranged on the tool holder 108 in a second assembly step such that the flanged bushing 140 with a locking section 140a radially covers the fastening elements 138, the fastening elements 138 preferably bearing against an inner surface of the locking section 140a. In the preferred example according to Fig. 2 The flanged bushing 140 is designed as a stepped cylindrical bushing with a central bore, which can be slid axially onto the tool holder 108 towards the connection end region 130. On its tool-side end face, the flanged bushing 140 has a locking collar 140b, with which the flanged bushing 140 can finally be axially secured on the tool holder 108 by means of a locking device 142, such as a retaining ring or snap ring, at the end of the second assembly step.

[0029] Besides the in Fig. In the embodiment shown in Figure 2, where the tool holder 104 engages in the hammer tube 126 or output spindle 128 at the connection end 130, it can be particularly advantageous for output spindles 128 with a smaller diameter to reverse the radial arrangement at the connection end 130. In such an embodiment, not shown here, the tool holder 108 encompasses the corresponding section of the output spindle 128 at the connection end 130. For axial fastening, the one, two, or preferably at least three radial recesses 132 in the tool holder 108 are designed as radial bores. The receiving recesses 134, in turn, are preferably designed as countersinks in the output spindle 128.This allows, in a first step of the first assembly step, the tool holder 108 to be placed onto the output spindle 128 such that the radial bores are aligned with the receiving recesses 134, and in a second step of the first assembly step, the fastening elements 138 to be inserted from the outside through the radial bores so that they engage radially in their respective receiving recesses 134. In a second assembly step, the flanged bushing 140 according to the invention can then be arranged on the tool holder 104, so that the fastening elements 138 are radially secured.

[0030] The flange bushing 140 according to the invention has in the example according to Fig. 2 a sealing lip 144. The sealing lip 144 is essentially disc-shaped, preferably circular, and is arranged projecting substantially radially from a cylindrical intermediate section 140c of the flanged bushing 140. The sealing lip 144 can simply be pushed onto the intermediate section 140c and / or otherwise attached there. In particular, the sealing lip 144 can be bonded, welded, wedged, and / or snapped to the flanged bushing 140, so that the flanged bushing 140 with the sealing lip 144 can be supplied as an advantageously pre-assembled unit for the assembly of the tool holder 100 according to the invention.

[0031] In the preferred version according to Fig. 2. The sealing lip 144 also rests with a first flat side 144a against a flanged surface 140d of the flanged bushing 140. However, it can also be advantageous for the sealing lip 144 to alternatively or additionally rest against the one in Fig. 2 shown fastening of the sealing lip 144 with this plan side 144a to the flange surface 140d on the intermediate section 140c, wherein the sealing lip 144 may be glued, welded, wedged and / or snapped to the flange surface 140d.

[0032] In the preferred embodiment, the sealing lip 144 projects beyond Fig. 2 radially beyond the flanged bushing 140, in particular beyond the locking section 140a. In particular, the flanged bushing 140 extends radially to an inner surface 104d of the locking area 104c of the actuating sleeve 104, so that the sealing lip 104 forms a sealing edge 146 upon contact with the inner surface 104d. The sealing lip 104, together with the sealing edge 146, closes the locking chamber 115 formed by the actuating sleeve 104, so that the ingress of particles, in particular dust particles, drilling dust and / or drill cuttings, from the vicinity of the tool holder into the locking chamber 115 can be, if not completely prevented, then at least significantly reduced. The inner surface 115 forms a cylindrical sealing surface.is designed as such, which in the assembled state is opposite the sealing lip in every actuation position and with it essentially seals the locking chamber against penetrating particles from the environment surrounding the tool holder.

[0033] On a second plan page 144b, according to Fig. 2. The spring element 116 is deformed with its second end, which is substantially opposite the first end of the spring element 116, such that the control element 120, which rests axially against the actuating sleeve 104, is biased into a first position, the rest position, in the opposite direction of insertion of the insert tool 102 into the axial bore 112 towards the tool-side end of the tool holder 100, together with the actuating sleeve 104 (see upper partial image of Fig. 2) Even in this first position of the actuating sleeve 104, the sealing edge 146 closes off the locking chamber 115.

[0034] To remove an inserted tool 102 from the tool holder 100 according to the invention, the user pulls the actuating sleeve axially backward toward the tool-side end. This causes the sealing lip 144 to shift axially along the inner surface 104d, so that the sealing edge 146 is axially closer to the control element 120. This reduces the volume of the locking chamber 115, but prevents dust from entering the locking chamber via the sealing edge 146 (see lower partial image of...). Fig. 2).

[0035] When a tool 102 is inserted into the tool holder 108, the actuating sleeve 104 returns to its first position, whereby particles that have settled on the previously exposed section of the inner surface 104d are wiped off by the passing sealing edge 146, so that they are essentially unable to penetrate into the increasing volume of the locking chamber 115.

[0036] To the person skilled in the art, compared to the tool holder 100 shown here as an example on a rotary and / or impact hammer, there are 10 other hand-held power tools with tool holders which, on the one hand, have a locking mechanism that, in turn, can be subject to increased wear, particularly due to particle exposure, and in which, on the other hand, the simplified sealing concept proposed here, with a sealing lip on a flanged bushing of the tool holder, can be successfully and obviously used to suppress dust. For example, the chuck of a screwdriver, impact wrench, drill, or hammer drill can be protected from penetrating particles in the same way.

Claims

[1] Tool holder (100) for a hand-held power tool comprising an actuating sleeve (104), a tool holder (108) and a locking mechanism (114) operable via the actuating sleeve (104) for releasably locking an insert tool (102) received in the tool holder in a working position, wherein the tool holder (108) has an axial bore (112) on a tool-side end face (110) for receiving the insert tool (102) and at least one, preferably two, three or more radial recesses (132) for receiving fastening elements (138) in the connection area to an opposite end face, wherein the fastening elements (138) are radially secured in a mounted state by means of a flanged bushing (140) arranged on the tool holder (108), characterized by, that a sealing lip (144) is arranged on the collar bushing (140), which extends between the actuating sleeve (104) and the collar bushing (140) and essentially seals an internal locking chamber (115) against ingress of particles from an environment surrounding the tool holder (100). [2] Tool holder (100) according to claim 1, characterized by , that the sealing lip (144) is arranged substantially radially projecting from a cylindrical outer surface (140c) of the flanged bushing and a sealing edge (146) of the sealing lip (144) is substantially opposite the outer surface (140c). [3] Tool holder (100) according to claim 1 or 2, characterized by , that the sealing lip (144) is held centrally by the flanged bushing (140). [4] Tool holder according to any one of claims 1 to 3, characterized by , that the sealing lip (144) rests with a first plan side (144a) against a flanged surface (140d) of the flanged bushing (140). [5] Tool holder (100) according to one of claims 1 to 4, characterized by , that the sealing lip (144) has a second flat surface (144b) which is essentially designed as a support surface for a spring element (116) of the locking device (114). [6] Tool holder according to claims 4 and 5, characterized by , that the sealing lip (144) is pressed against the flange surface (140d) of the flange bushing (140) by the spring element (116). [7] Tool holder (100) according to any one of the preceding claims, characterized by , that the actuating sleeve (104) has a substantially cylindrical sealing surface (104d) which, in the assembled state, is opposite the sealing lip (144) in every actuating position and with this seals the locking chamber (115) against the environment surrounding the tool holder (100) against penetrating particles. [8] Tool holder according to any one of the preceding claims, characterized by, that the sealing lip (144) is made of an elastic material, in particular soft rubber. [9] Hand-held power tool, in particular a drill and / or impact hammer (10), with an output spindle (126, 128) for driving a tool holder (100) according to one of the preceding claims, characterized by , that the output spindle (126, 128) has at least one, preferably two, three or more receiving recesses (134) into which, during an assembly step with the tool holder (100) axially mounted, the fastening elements (138) can engage for connection with the radial recesses (132) of the tool holder (108). [10] Hand-held power tool (100) according to claim 9, characterized by, that the output spindle (126, 128) radially encompasses the tool holder (108), and the receiving recesses (134) are designed as receiving bores (136) through which the fastening bodies (138) can pass and into which they can engage the radial recesses (132) of the tool holder (108). [11] Hand-held power tool (100) according to claim 9, characterized by , that the tool holder (108) with a connecting end area (130) substantially radially encompasses the output spindle (126, 128), and the radial recesses (132) are designed as radial bores through which the fastening elements (138) can pass and into which they can engage the receiving recesses (134) of the output spindle (126, 128).

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