GB2486966A

GB2486966A - Saw Blade Clamping Device With Pivoting Clamping Elements

Info

Publication number: GB2486966A
Application number: GB1121799.9A
Authority: GB
Inventors: Tamas Farkas; Jozsef Knoblich
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-12-27
Filing date: 2011-12-16
Publication date: 2012-07-04
Anticipated expiration: 2031-12-16
Also published as: GB2486966B; GB201121799D0; CN102554345A; DE102010064206B4; DE102010064206A1; CN102554345B

Abstract

A device for clamping a saw blade has clamping elements 14, 16 pivotable under the action of a pivoting unit 24 (see Figure 3) to clamp the blade 18 against a clamping surface. The clamping elements may be rollers e.g. needle rollers ends of which are received in angled slots in the pivoting unit (62, 64, Figure 3). The pivoting unit slides in the direction of insertion of the blade (60, Figure 3) at which time the ends of the clamping elements move in the angled slots such that they pivot i.e. axes 92, 94 of the clamping elements become less parallel, as shown in Figure 5, and the clamping elements clamp the blade against the clamping surface on either side. The pivoting unit may be biased into the clamping position by a spring (34, Figure 3).

Description

Tool fastening device

Prior art

Tool fastening devices which have a clamping unit are already known. The clamping unit in these devices comprises a clamping element which, is provided to clamp, in a clamping position, a machining tool.

Disclosure of the invention

The invention starts from a tool fastening device, in particular from a sawing tool fastening device, with at least one clamping unit having at least one clamping element which is provided to clamp, at,least in a clamping position, at least one machining tool.

It is proposed that the clamping unit has a pivoting unit which is provided to pivot the clamping element relative to a clamping surface of the clamping unit. A "pivoting unit" here is to be understood, in particular, as a unit which is provided to clamp a machining tool for machining a workpiece by means of a form-fitting and/or force-fitting connection. The term "clamping element" here is intended to define, In particular, an element which is provided to secure at least one further element, in particular the machining tool, by means of a form-fitting and/or force-fitting connection in a position. Preferably, the machining tool is secured by the clamping element by means of a force-fitting connection in a position, in particular in a clamping position. The term "provided" here is intended to define, in particular, specially designed and/or specially configured. A "clamping position" here is to be understood, in particular, as a position of the machining tool relative to the clamping unit, in which a workpiece can be machined by means of the machining tool firmly clamped in the clamping unit, in particular by means of the machining tool driven by a drive unit of a portable machine tool. A "portable machine tool" here is to be understood, in particular, as a machine tool, in particular a hand-held machine tool, which can be transported by an operator without a transporting machine. The portable machine tool has, in particular, a mass less than 40 kg, preferably less than 10 kg andparticularly preferably less than 5 kg. In the clamping position, the machining tool is acted on with a clamping force, preferably by means of the clamping element, in the direction of a clamping surface. In the clamping position, the machining tool is thus preferably clamped between the clamping element and the clamping surface. Particularly preferably, the machining tool in this case lies, with a side facing away from the clamping element, against the clamping surface. A "clamping surface" here is to be understood, in particular, as a surface against which the machining tool lies in the clamping position and which is provided to firmly clamp the machining tool by means of an interaction with the clamping element. The term "pivoting unit" here is intended to define, in particular, a unit which is provided by means of a mechanism to pivot at least one element relative to at least one further element of the clamping unit. Preferably, the pivoting unit is provided to pivot the clamping element in a plane, running substantially perpendicularly to the clamping surface, relative to the clamping surface. In this case, a longitudinal axis of the clamping element is preferably inclined relative to the clamping surface. The longitudinal axis of the clamping element and the clamping surface enclose, in the clamping position, preferably an angle differing from 900. By means of the configuration of the tool fastening device according to the invention, an advantageous clamping of the machining tool can be achieved. Moreover, advantageously a high degree of operating convenience for an operator can be achieved.

Furthermore, it is proposed that the pivoting unit has a slotted-link guide which is provided to pivot the clamping element relative to the clamping surface in dependence on a translatory movement of the pivoting unit. A "slotted-link guide" here is to be understood, in particular, as a guide in which at least one component is guided in a restricted manner, and which is provided to convert a movement, in particular a movement of the pivoting unit relative to the component guided in a restricted manner, into a movement of the component guided in a restricted manner. The slotted-link guide is preferably formed by a recess, in particular by a slot, in which the clamping element engages. It is, however, also conceivable for the slotted-link guide to be designed as a projection, such as for example as a rib and/or web, which engages in a recess of the clamping element and thus guides and/or moves the clamping element.

A pivoting movement of the clamping element for clamping the machining tool in the clamping position can be achieved in a constructionally simple manner.

Advantageously, the clamping element is designed as a rolling body. A low friction between the slotted-link guide and the clamping element during a movement of the clamping element in the slotted-link guide can thus advantageously be achieved.

Preferably, the clamping element is designed as a needle roller. It is, however, also conceivable for the clamping element to have another configuration which appears appropriate to a person skilled in the art, such as for example a sphere, a cylinder etc. Particularly advantageously, a compact arrangement of the clamping element in the clamping unit can be achieved. Installation space can thus advantageously be saved.

Furthermore, it is proposed that the clamping unit has at least one spring element which is provided to prestress the pivoting unit. A "spring element" is to be understood, in particular, as a macroscopic element which has at least one extent which, in a normal operating state, is elastically variable by at least 10%, in particular by at least 20%, preferably by at least 30% and particularly advantageously by at least 50%, and which generates, in particular, an opposed force which is dependent on a variation of the extent and preferably proportional to the variation, and which counteracts the variation. An "extent" of an element is to be understood, in particular, as a maximum distance between two points of a perpendicular projection of the element onto a plane. A "macroscopic element" is to be understood, in particular, as an element with an extent of at least 1 mm, in particular of at least 5 mm and preferably of at least 10 ruin. Preferably, the spring element is designed as a compression spring. It is, however, also conceivable for the spring element to be configured in another way which appears appropriate to a person skilled in the art, such as for example as a tension -spring, torsion spring, volute spring, pneumatic spring, etc. Advantageously, a spring force can be utilised to position the pivoting unit.

Advantageously, the spring element is operatively arranged between a securing element of the clamping unit and the pivoting unit. The term "operatively" here is intended to define, in particular, an arrangement of the spring element in which the spring element can exert a spring force on two components. Preferably, the spring element is arranged, when viewed along the tool introducing direction, between the pivoting unit and the securing element. Preferably, the spring element is supported, with one.end, on the securing element and the spring element is supported, with a further end, on the pivoting unit. A "securing element" here is to be understood, in particular, as an element which is provided to prevent a movement of at least one movably mounted component relative to a further component in at least one operating state. A movement of the securing element dependent on a movement of the pivoting unit can advantageously be achieved.

In addition, it is proposed that the clamping unit has at least one securing element which is provided, in at least one operating state, to retain the clamping element in at least one tool introducing position. A "tool introducing position" here is to be understood, in particular, as a position of components of the clamping unit relative to one another, in which an introduction of the machining tool into the clamping unit for firmly clamping the machining tool is possible. By means of the configuration according to the invention, the tool fastening device can be retained in the tool introducing position advantageously and in a constructionally simple manner. Moreover, a convenient introduction of the machining tool into the clamping unit can thus be achieved. Furthermore, a single-handed operation of the tool fastening device can advantageously be achieved.

Preferably, the securing element has at least one actuating leg which is actuable by means of the machining tool to initiate a clamping process of the clamping unit. A "clamping process" is to be understood, in particular, as a process in which the machining tool is fastened, starting from an unfastened state. An initiation of the clamping process can be achieved in a constructionally simple manner during an introduction of the machining tool into the clamping unit. The machining tool is thus advantageously firmly clamped, in a manner uncoupled from an additional actuation of an actuating element, upon an introduOtion into the clamping unit. A convenient firm clamping of the machining tool can advantageously be achieved.

Furthermore, it is proposed that the clamping unit has at least one further clamping element which is pivotable relative to the clamping surface by means of the pivoting unit in order to clamp the machining tool. Advantageously, a high clamping force can be generated which acts on the machining tool at at least two points. The machining tool can thus be advantageously firmly clamped.

Machine tool, in particular jigsaw and/or sabre saw, with at least one tool fastening device according to the invention. The machine tool is preferably designed as a portable machine tool. Particularly preferably, the portable machine tool is designed as a jigsaw and/or sabre saw. It is, however, conceivable for the portable machine tool to be formed by another portable machine tool which appears appropriate to a person skilled in the art. By means of the configuration of the machine tool according to the invention, a high degree of operating convenience for an operator of the machine tool can advantageously be achieved.

Drawing Further advantages emerge from the following description of the drawing. In the d±awing, an exemplary embodiment of the invention is illustrated. The drawing, the description and the claims contain numerous features in combination. A person skilled in the art will also consider the features, expediently, individually and combine them to form appropriate further combinations.

In the drawing: Fig. 1 shows a portable machine tool according to the invention with a tool fastening device according to the invention, in a schematic illustration, Fig. 2 shows a detail view of the tool fastening device according to the invention with a machining tool inserted in the tool fastening device according to the invention, in a schematic illustration, Fig. 3 shows a detail view of the tool fastening device according to the invention in a clamping position, in a schematic illustration, Fig. 4 shows a sectional view of the tool fastening device according to the invention in a clamping position, along the line IV-IV from Figure 2, in a schematic illustration, Fig. 5 shows a sectional view of the tool fastening device according to the invention in a clamping position, along the line V-V from Figure 2, in a schematic illustration, Fig. 6 shows a sectional view of the tool fastening device according to the invention in a tool introducing position, analogous to the section along the line IV-IV from Figure 2, in a schematic illustration, and Fig. 7 shows a sectional view of the tool fastening device according to the invention in a tool introducing position, analogous to the section along the line V-V from Figure 2, in a schematic illustration.

Description of the exemplary embodiment

Figure 1 shows a portable machine tool 42, designed as a jigsaw 44, having a tool fastening device 10. The portable machine tOol 42 has a machine tool housing 46 which encloses a drive unit 48 of the machine tool 42 and a gear unit 50 of the machine tool 42. The drive unit 48 and the gear unit 50 are provided to drive a machining tool 18, clamped in the tool fastening device 10, in an oscillating manner. In this case, the machining tool 18 is driven in a manner oscillating substantially perpendicularly to a machining direction. The machining tool 18 is designed as a jigsaw blade 58. It is, however, also conceivable for the machining tool 18 to be formed by another machining tool which appears appropriate to a person skilled in the art.

The gear unit 50 has, for this purpose, an output element 54 designed as a reciprocating rod 52. The reciprocating rod 52 extends, with a partial region, into the tool fastening device 10 (Figure 2). The reciprocating rod 52 thus forms part of the tool fastening device 10. The tool fastening device 10 is provided to couple the machining tool 18 to the reciprocating rod 52.

Figure 2 shows the tool fastening device 10 with the machining tool lEinserted in the tool fastening device 10.

The tool fastening device. 10 comprises an actuating housing 56. The actuating housing 56 can be actuated by an operator to clamp and/or release the machining tool 18 in the tool fastening device 10. Furthermore, the tool fastening device comprises a clamping unit 12 which has a first clamping element 14 and a second clamping element 16 (Figure 3) . The clamping elements 14, 16 are provided to clamp, in a clamping position, the machining tool 18.

Figure 3 shows the clamping unit 12 in a clamping position.

The machining tool 18 is in this case coupled to the reciprocating rod 52 by means of an interaction of the clamping elements 14, 16 and a clamping surface 22 of the reciprocating rod 52. The clamping elements 14, 16 act on the machining tool 18 with a clamping force in the direction of the clamping surface 22 (Figure 4). The machining tool 18 is thus clamped between the clamping elements 14, 16 and the clamping surface 22. Furthermore, in the clamping position, retaining elements 96, 98 of the machining tool 18 are supported on the clamping elements 14, 16. When viewed along the tool introducing direction 60, the retaining elements 96, 98 of the machining tool 18 are arranged, in the clamping position, behind the clamping elements 14, 16. The machining tool 18 is thus secured in the clamping position, along a direction running opposite to a tool introducing direction 60, by means of the clamping unit 12.

Furthermore, the clamping unit 12 has a pivoting unit 20 which is provided to pivot the clamping elements 14, 16 relative to the clamping surface 22 of the clamping unit 12. The pivoting unit 20 has a slotted-link guide 24 which is provided to pivot the clamping elements 14, 16 relative to the clamping surface 22 in dependence on a translatory movement of the pivoting unit 20 along the tool introducing direction 60. The clamping elements 14, 16 are designethas rolling bodies 26, 28. In this case, the clamping elements 14, 16 are designed as needle rollers 30, 32. The clamping elements 14, 16 thus each'have an axis of rotation 92, 94.

The axes of rotation 92, 94 of the clamping elements 14, 16 designed as needle rollers 30, 32 are pivoted by means of the slotted-link guide 24 relative to the clamping surface 22, in a plane running perpendicularly to the clamping surface 22. In the process, the axes of rotation 92, 94 are pivoted relative to one another.

The slotted-link guide 24 is arranged in a guide element 78 of the pivoting unit 20. The guide element 78 is arranged inside the actuating housing 56 of the tool fastening device 10. Furthermore, outer walls of the guide element 78 lie against inner walls of the actuating housing 56. Thus, a movement of the actuating housing 56 can be transmitted to the guide element 78. Furthermore, the slotted-link guide 24 comprises two guide paths 66, 68 designed as slots 62, 64. The slots 62, 64 have an angled course, differing from a 90° angle, relative to the tool introducing direction 60. The course may be of arcuate form and/or be formed by a rectilinear course angled with respect to the tool introducing direction 60.

The clamping elements 14, 16 are each guided by means of one end 70, 72 in the slots 62, 64. Furthermore, ends 74, 76 of the clamping elements 14, 16 facing away from the ends 70, 72 guided in the slots 62, 64 are each movably arranged in recesses 80,. 82 of the clamping unit 12. Upon a translatory movement of the pivoting unit 20, starting from the clamping position, opposite to the tool introducing direction 60, the clamping elements 14, 16 are moved away from the clamping surface 22 by the guidance in the slots 62, 64. Upon a movement of the pivoting unit 20, the clamping elements 14, 16 can roll along edge regions of the pivoting unit 20 bounding the slots 62, 64.

The clamping unit 12 furthermore has a spring element 34 which is provided to prestress the pivoting unit 20. In the clamping position, the pivoting unit 20 is acted on by means of the spring element 34 along the tool introducing direction 60 with a spring force of the spring element 34.

Thus, the clamping elements 14, 16 are acted on with a retaining force in the direction of the clamping surface 22 by means of an interaction of the spring element 34 and the slots 62, 64 of the slotted-link guide 24. The spring element 34 is designed as a compression spring 84. The spring element 34 is in this case operatively arranged between a securing element 36 of the clamping unit 12 and the guide element 78 of the pivoting unit 20. One end 86 of the spring element 34 is supported on the securing element 36. A further end 88 of the spring element 34 is supported on the securing element 36 (Figure 4) . The securing element 36 is provided, in one operating state, to retain the clamping elements 14, 16 in a tool introducing position (Figure 7).

The securing element 36 has two actuating legs 38, 40 which are actuable by means of the machining tool 18 to initiate a clamping process of the clamping unit 12. The actuating legs 38, 40 extend along the tool introducing direction 60 parallel to an extent of the spring element 34.

Furthermore, respectively one of the two actuating legs 38, 40 is arranged on one side of the spring element 34. Thus, when viewed along a direction running perpendicularly to the tool introducing direction 60, the spring element 34 is arranged between the actuating legs 38, 40 (Figures 5 and 7). The actuating legs 38, 40 each have an arcuate partial section which is curved in the direction of the clamping surface 22. Upon introduction along the tool introducing direction 60, the machining tool 18 actuates, with a conically running actuating section 90, the securing element 36 by means of the actuating legs 38, 40. Upon the introduction of the machining tool 18, the conically running actuating section 90 comes into contact with the arcuate partial sections of the actuating legs 38, 40.

Starting from the clamping position of the clamping unit 12 shown in Figures 4 and 5, an operator can transfer the clamping unit 12 into a tool introducing position by movement of the actuating housing 56 of the tool fastening device 10. In this case, starting from the clamping position, the machining tool 18 can be removed from the tool fastening device 10. The actuating housing 56 is in this case moved by the operator in a direction opposite to the tool introducing directioi2 60. The guide element 78 is thus likewise moved in the direction opposite to the tool introducing direction 60. The spring element 34 is compressed and acts on the securing element 36 with a force in the direction of the clamping elements 14, 16. Owing to the movement of the guide element 78, the clamping elements 14, 16 are moved away from the clamping surface 22 by means of the slots 62, 64 of the slotted-link guide 24. Owing to the movement in the slots 62, 64, the clamping elements 14, J6 are pivoted relative to the clamping surface 22 until the axes of rotation 92, 94 of the clamping elements 14, 16 are oriented substantially perpendicularly to the clamping surface 22.

Owing to the spring force of the spring element 34, the securing element 36 is moved between the clamping elements 14, 16 (Figures 6 and 7) until a shoulder (not illustrated specifically here) of the securing element 36 lies against the clamping elements 14, 16. Owing to the movement of the securing element 36 by the spring force of the spring element 34, the machining tool 18 is at least partially thrown out of the clamping unit 12 by means of the arcuate partial sections of the actuating legs 38, 40. The guide element 78 is acted on with a spring force by the spring element 34 along the tool introducing directiOn 60. A movement of the guide element 78 along the tool introducing direction 60 is prevented by means of the securing element 36 arranged between the clamping elements 14, 16. The securing element 36 is clamped between the clamping elements 14, 16. In this case, the securing element 60 is acted on by means of a spring force of the spring element 34 in a direction running opposite to the tool introducing direction 60. A movement of the clamping elements 14, 16 along the slots 62, 64 of the slotted-link guide 24 is thus prevented. Furthermore, a pivoting movement of the clamping elements 14, 16 relative to the clamping surface 22 is prevented. The clamping unit 12 is thus in the tool introducing position, in which the machining tool 18 can be introduced into the clamping unit 12 by an operator.

Upon introduction of the machining tool 18 into the tool fastening device 10 and/or into the clamping unit 12 along the tool introducing direction 60, the securing element 36 is pushed out between the clamping elements 14, 16 along the tool introducing direction 60 by means of the machining tool 18. The conical region of the machining tool 18 is brought into contact with the arcuate partial sections of

the actuating legs 38, 40 upon introduction of the

*machining tool 18. The movement of the machining tool 18 is thus transmitted to the securing element 36. Owing to the movement ofthe securing element 36 along the tool introducing direction 60, the spring element 34 is compressed. The guide element 78 is consequently acted on with a spring force of the spring element 34 along the tool introducing direction 60. Thus,the guide element 78 together with the actuating housing 56 is moved along the tool introducing direction 60. The clamping elements 14, 16 are pivoted towards one another and relative to the clamping surface 22 by means of the slots 62, 64 of the slotted-link guide 24. In this case, the axes of rotation 92, 94 of the clamping elements 14, 16 are pivoted along a direction running perpendicularly to the tool introducing direction 60 and parallel to the clamping surface 22. The machining tool 18 is firmly clamped after the pivoting movement of the clamping elements 14, 16. The machining tool 18 is clamped between the clamping elements 14, 16 and the clamping surface 22. As a result, the machining tool 18 is coupled to the reciprocating rod 52. The retaining elements 96, 98 of the machining tool 18 are supported on the clamping elements 14, 16. The clamping unit 12 is thus in a clamping position, in which a workpiece can be machined by means of the clamped machining tool 18.

Claims

Claims 1. A tool fastening device, in particular sawing tool fastening device, with at least one clamping unit having at least one clamping element which is provided to clamp, at least in a clamping position, at least one machining tool, wherein the clamping unit has a pivoting unit which is provided to pivot the clamping element relative to a clamping surface of the clamping unit.
2. The tool fastening device according to Claim 1, wherein the pivoting unit has a slotted-link guide which is provided to pivot the clamping element relative to the clamping surface in dependence on a translätory movement of the pivoting unit.
3. The tool fastening device according to any of the preceding claims, wherein the clamping element is designed as a rolling body.
4. The tool fastening device according to Claim 3, wherein the clamping element is designed as a needle roller.
5. The tool fastening device according to any of the preceding claims, wherein the clamping unit has at least one spring element which is provided to prestress the pivoting unit.
6. The tool fastening device according to Claim 5, wherein the spring element is operatively arranged between a securing element of the clamping unit (12) and the pivoting unit.
7. The tool fastening device according to any of the preceding claims, wherein the clamping unit has at least one securing element which is provided, in at least one operating state, to retain the clamping element in at least one tool introducing position.
8. The tool fastening device acoording to Claim 7, wherein the securing element has at least one actuating leg which is actuable by means of the machining tool to initiate a clamping process of the clamping unit.
9. The tool fastening device according to any of the preceding claims, wherein the clamping unit has at least one further clamping element which is pivotable relative to the clamping surface by means of the pivoting unit in order to clamp the machining tool.
10. A machine tool, in particular jigsaw and/or sabre saw, with at least one tool fastening device according to any of the preceding claims.
11. A tool fastening device substantially as herein described with reference to the accompanying drawings.V
12. A machine tool substantially as herein described with reference to the accompanying drawings.