GB2390562A

GB2390562A - Connection device for a hand-held power tool

Info

Publication number: GB2390562A
Application number: GB0316103A
Authority: GB
Inventors: Thomas Apfel; Thomas Schomisch; Markus Heckmann; Harald Krondorfer; Albrecht Hofmann
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2002-07-11
Filing date: 2003-07-09
Publication date: 2004-01-14
Anticipated expiration: 2023-07-09
Also published as: DE10231249B4; FR2842451B1; GB0316103D0; DE10231249A1; GB2390562B; FR2842451A1

Abstract

A hand-held power tool, for example a hand held angle grinding machine comprising a housing 10, composed of at least one first housing unit and a second housing unit (12,14) that are connectable to one another via a connection device 16. The connection device 16 comprises first 18,20 and second clamping faces 22,24 and the second housing unit 14 is fastenable via the clamping faces 18,20,22,24 by a first wedge -type clamping action to the first housing unit.

Description

- Hand tool machine The invention proceeds from a hand tool machine

according 5 to the preamble of claim 1.

Single-handedly operated angle grinders are known, the housings of which are manufactured from two housing units.

Of the latter, the first housing unit is formed by a 10 tubular housing unit or by separate housing shells and the second housing unit Is formed by a separate gear case. The gear case is connected by a connection device to the first housing unit. Said connection device is formed by a radially outwardly directed collar that is formed on the 15 end of the gear case facing the first housing unit. The collar engages positively into a corresponding annular groove, which is formed in each case on the end of the first housing unit facing the gear case. The housing shells are braced together by means of screws, wherein the 20 gear case is braced in radial direction with the housing shells and is positively connected to the housing shells in longitudinal direction of the slngle- handedly operated angle grinder.

25 The invention proceeds from a hand tool machine, in particular from a hand-guided angle grinding machine, having a housing, which comprises at least one first and one second housing unit, which are connectable to one another by a connection device.

It is proposed that the connection device comprises at least one first and one second clamping face and the second housing unit is fastenable via the two clamping faces by a first wedge-type clamping action to the first housing unit.

The two clamping faces are designed as wedge faces or are clamping faces of a wedge segment, by means of which the wedge-type clamping action is achievable. The clamping faces are therefore disposed not parallel but at an angle 5 to one another, which is more than 0 and less than 180 .

In the present case, the two clamping faces may be formed on a single component or on a plurality of separate components. During connection of the two housing units the first and the second clamping face of the connection device 10 come into abutment with corresponding clamping faces of a housing unit. By said means the first wedge-type clamping action may be achieved, wherein an advantageous connection device for connecting the two housing units is achievable with a low amount of installation space. In the region of 15 a transition of the two housing units slim and harmonious external contours may therefore be achieved. The individual wedge faces themselves may be curved, such as e.g. in the case of a subsegment of a cylinder or truncated cone, flat, such as e.g. in the case of a sub 20 segment of any desired polyhedron, corrugated or of some other shape deemed appropriate by the person skilled in the art. With the clamping faces the two housing units may be aligned precisely and without play, and namely in the direction, in which a clamping direction of the wedge-type 25 clamping action acts. Furthermore, by means of the wedge-

type clamping action an advantageous and secure connection may be achieved, which presents a high degree of self-

locking. 30 When the first and the second clamping face are in each case flat clamping faces, they are constructionally easy and inexpensive to manufacture and a wedge-type clamping action with a large contact area is achievable.

In a further development of the invention it is proposed that the first housing unit comprises two separate housing shells, which are fastenable by the wedge-type clamping 5 action to the second housing unit, The hand tool machine may be manufactured as a so-called partial shell construction, wherein individual modules capable of preassembly, in particular the second housing unit, such as e.g. a gear case, may easily be fitted together. This 10 allows a reduction in assembly effort, assembly time and assembly costs. The two housing shells may be connected to one another by screwing, clamping or some other method deemed appropriate by the person skilled in the art.

Especially in the case of housing shells that are braceable 15 together by means of a connection device, a particularly advantageous alignment of the two housing units may be achieved in that, during bracing of the two housing shells, outer surfaces of the connection device or of the housing shells slide over the clamping faces lying at an angle to 20 one another, position the housing shells relative to one another and produce the wedgetype clamping action.

The connection device advantageously has at least one third clamping face, and the second housing unit is fastened via 25 the third clamping face by a second wedge-type clamping action to the first housing unit. Thus, the two housing units may advantageously be held and/or fixed relative to one another at two different points without play.

30 A particularly reliable positioning and a constructionally simple fixing of the housing units relative to one another may be achieved in that the clamping direction of the second wedge-type clamping action differs from the clamping

direction of the first wedge-type clamping action, and namely particularly in that the two clamping directions are at an angle of 90 to one another. In the present case, the clamping direction of the first wedge-type clamping 5 action may be in assembly direction and the clamping direction of the second wedge-type clamping action may be at right angles to the clamping direction of the first wedge-type clamping action. In a hand tool machine, which presents an assembly direction of the housing units in 10 longitudinal extension of the hand tool machine, the housing units are fixed and held without play relative to one another in longitudinal extension and in a direction at right angles to the longitudinal extension. The clamping directions may however be at any other angle to one another 15 that the person skilled in the art deems appropriate.

It is further proposed that the connection device comprises at least one clamping element, on which at least one fixing element is disposed. A connection device of a simple 20 design is achievable for locking the second housing unit to the first housing unit. The fixing element in the present case may be formed by a separate component to the clamping element or may be formed on the clamping element. The fixing element may lock the two housing units against one 25 another by e.g. engaging positively into a corresponding recess of a housing unit. This may be effected by means of a locking face, which is formed by the fixing element and which engages behind a corresponding clamping face on the housing unit. Thus, the two housing units are braced 30 together by means of the clamping element and are additionally held or braced together once more advantageously In the other direction by means of the fixing element. When the corresponding clamping face is

formed on an existing component of the two housing units, the latter may be advantageously utilized and additional components for locking the housing units are avoidable.

5 When the clamping element is constructed integrally with one of the housing units, the clamping element may be formed on the appropriate housing unit e.g. in the course of an injection moulding process, or some other process deemed appropriate by the person skilled in the art, and 10 additional components and assembly effort may be spared.

When the housing shells are positively connectable to one another by at least one connection element, the housing shells may be advantageously in a constructionally simple 15 manner releasably connected to one another and easy assembly of the hand tool machine is achievable. The connection element in the present case may be formed by a plug-in element, which engages positively into a corresponding element, by a detent element, by a screw 20 element or by some other connection element deemed appropriate by the person skilled lo the art. When the clamping face corresponding to the locking face and/or the clamping faces corresponding to the clamping faces of the connection device are formed onto the connection element, 25 existing components may be jointly utilized and installation space may be spared.

In a further development of the invention it is proposed that a connection screw, which generates the force for the 30 wedge-type clamping action, engages through the connection element. A space-saving device is achievable, by means of which a high force for a reliable and lasting wedge-type clamping action may be achieved. The force for the wedge

type clamping action may be transmitted directly by the connection element to the clamping element. An additional transmission of force, a lever action or a clamping action by means of a deformable housing shell for generating the 5 force for the wedge-type clamping action is avoidable. A secure seat of the wedge-type clamping action may be achieved. When the housing parts are positively connectable to one 10 another with the aid of a locking element, a simply designed anti- rotation element may advantageously be achieved between the two housing parts. The locking element may be designed separately or as part of the connection device. It is however particularly advantageous 15 when the locking element is formed by a separate part. The locking element may have dimensions and a configuration purposefully adapted to its function.

Further advantages arise from the following description of

20 the drawings. In the drawings an embodiment of the invention IS illustrated. The drawings, the description

and the claims contain numerous features in combination.

The person skilled in the art will practically consider the features also individually and combine them into meaningful 25 further combinations.

The drawings show: Fig. 1 an exploded drawing of a housing of a 30 singlehandedly operated angle grinder of a partial shell construction in side view, Fig. 2 a partial section through the angle grinder and

Fig. 3 a section along the line III-III in Fig. 2.

Fig. 1 shows an exploded view of a housing 10 of a single-

handedly operated angle grinder in side view. The 5 housing 10 comprises a first housing unit 12 and a second housing unit 14, which are connectable to one another by a connection device 16. The housing 10 is manufactured as a so-called partial shell construction, wherein the first housing unit 12 is formed by two housing shells 30, 32 made 10 of plastics material and the second housing unit 14 is formed by a gear case made of metal. The first housing unit 12 at its end remote from the second housing unit 14 has a receiving area (not shown in detail) for a power supply unit such as e.g. a battery pack (not shown in 15 detail).

The connection device 16 comprises clamping faces 18, 20, 22, 24, via which the second housing unit 14 is fastened by a first wedge-type clamping action to the first housing 20 unit 12 in the assembled state, wherein the clamping faces 18, 20, 22, 24 are flat clamping faces (Fig. 3) . The clamping faces 18, 20 are formed in each case on a first clamping element 44 of the connection device 16 and the clamping faces 22, 24 are formed in each case on a second 25 clamping element 46 of the connection device 16. The clamping elements 44, 46 extend in longitudinal extension 60 of the housing 10 in the direction of the first housing unit 12 and are constructed integrally with the second housing unit 14 (Fig. 1). The clamping faces 18, 20 and/or 30 22, 24 are disposed at an obtuse angle to one another. The clamping faces 18 and 22 are disposed not parallel but at an angle of 5 to one another and therefore together form a

wedge segment. The same applies to the clamping faces 20 and 24.

The clamping elements 44, 46 each have an end, which is 5 directed towards the first housing unit 12 and on which in each case a fixing element 38, 48 is disposed. The fixing elements 38, 48 extend outwards in radial direction and in the present case comprise clamping faces 34, 36 extending outwards in radial direction (Fig. 1).

The second housing unit 14 on its end facing the first housing unit 12 has additional tab-shaped locking elements 58. The locking elements 58 engage positively into recesses 86, which are formed in the housing shells 30, 32.

The two housing shells 30, 32 of the first housing unit 12 are connectable to one another by connection elements 50, 52, 54, 56, 62, 64, 66, 68, 70, 72, which are formed integrally on the housing shells 30, 32 (Fig. 1). The 20 housing shells 30, 32 in a front area facing the housing part 14 have the connection elements 50, 52, 54, 56. The web-like connection elements 52, 56 on their ends directed towards the housing shell 32 have a positioning collar (Fig. 2 and Fig. 3). The connection elements 50, 54 of the 25 housing shell 32, which correspond to the connection elements 52, 56, are likewise of a web-like construction, wherein the ends of the connection elements 50, 54 facing the housing shell 30 have in each case a positioning hole.

In the assembled state of the housing shells 30, 32, the 30 positioning collars of the connection elements 52, 56 engage positively into the positioning holes of the connection elements 50, 54. The connection elements 50, 52, 54, 56 in the direction of extension of their web have

a substantially wedge-shaped longitudinal section, wherein external contours of the connection elements 50, 52, 54, 56 have flat clamping faces 78, 80, 82, 84, 26, 28, which form clamping faces corresponding to the clamping faces 18, 20, 5 22, 24, 34, 36 (Fig. 2 and Fig. 3).

In order to fit the second housing unit 14 and the first housing unit 12 together, the second housing unit 14 is inserted into the housing shell 30. In so doing, the 10 fixing elements 38, 48 of the clamping elements 44, 46 engage behind the connection elements 52, 56 of the housing shell 30. The clamping faces 20, 24, 36 of the clamping elements 44, 46 come into abutment with the corresponding clamping faces 80, 84, 28 of the connection elements 15 52, 56. At the same time, the locking element 58 of the second housing unit 14 engages into the corresponding recess of the first housing unit 12.

In a next step, the second housing shell 32 of the first 20 housing unit 12 is screw-connected to the first housing shell 30. The connection elements 50, 54, 62, 64, 66, 68 of the housing shell 32 engage positively with their cup-

shaped ends into the pin-shaped ends of the connection elements 52, 56, 70, 72 of the housing shell 30. The 25 fixing elements 38, 48 of the clamping elements 44, 46 engage behind the connection elements 50, 54 of the housing shell 32 and the clamping faces 18, 22 of the clamping elements 44, 46 as well as the clamping face 34 of the fixing element 48 come into abutment with the corresponding 30 clamping faces 78, 82 and 26 of the connection elements 50, 54. At the same time, the locking element 58 of the second housing unit 14 engages positively into the corresponding recess 86 of the first housing unit 12.

The two housing shells 30, 32, the connection elements 50, 52, 54, 56, 62, 64, 66, 68, 70, 72 of which are penetrated by connection screws 74, 76, are screw-connected to one 5 another and braced by the connection screws 74, 76. The connection screws 74, 76 during tightening generate a force for wedge-type clamping actions in clamping directions 40a, 40b, 42a, 42b for the play-free connection of the housing units 12, 14. During tightening of the connection screws 10 74, 76 the clamping elements 44, 46 slide with their clamping faces 18, 20, 22, 29, 34, 36 along the corresponding clamping faces 78, 80, 82, 84, 26, 28 of the connection elements 50, 52, 54, 56. In the present case the clamping element 44, with its clamping faces 18, 20 via l5 the clamping faces 78, 80 of the connection elements 50, 52, and the clamping element 46, with its clamping faces 22, 24 via the clamping faces 82, 84 of the connection elements 54, 56, produce the wedge-type clamping actions in the clamping direction 40a and 40b respectively.

20 The clamping faces 34, 36 of the fixing elements 38, 48 via the corresponding clamping faces 26, 28 of the connection elements 50, 52 and 54, 56 respectively produce the wedge-

type clamping actions in the clamping direction 42a, 42b, wherein the clamping directions 40a and 40b are situated at 25 right angles to the clamping directions 42a and 42b. With the wedge-type clamping actions in direction 42a and 42b the second housing unit 14 is pressed against the first housing unit 12, while with the wedge-type clamping actions in direction 40a and 40b the two housing units 12, 14 are 30 positioned in radial direction precisely relative to one another. The wedge-type clamping actions effect a jamming of the connection elements 50, 52, 54, 56 with the clamping elements 44, 46, i.e. a self-locking occurs, which prevents

independent loosening of the wedge-type clamping action.

In addition, a permanent bias arises as a result of an elastic deformation of the two housing shells 30, 32 made of plastics material. The housing units 12, 14 are 5 connected to one another precisely and without play.

03.07.02

5 ROBERT BOSCH GMBH; D-70442 Stuttgart Reference characters 10 housing 56 connection element 12 housing unit 58 locking element 14 housing unit 60 longitudinal extension 16 connection device 62 connection element 18 clamping face 64 connection element 20 clamping face 66 connection element 22 clamping face 68 connection element 24 clamping face 70 connection element 26 clamping face 72 connection element 28 clamping face 74 connection screw 30 housing shells 76 connection screw 32 housing shells 78 clamping face 34 clamping face 80 clamping face 36 clamping face 82 clamping face 38 fixing element 84 clamping face 40 clamping direction 86 recess 42 clamping direction 44 clamping element 46 clamping element 48 fixing element 50 connection element 52 connection element 54 connection element

Claims

1. Hand tool machine, in particular a hand-guided angle grinding machine, having a housing (10), which comprises at least one first and one second housing unit (12, 14), which are connectable to one another by 10 a connection device (16), characterized in that the connection device (16) comprises at least one first and one second clamping face (18, 20, 22, 24) and the second housing unit (14) is fastenable via the clamping faces (18, 20, 22, 24) by a first wedge-type 15 clamping action to the first housing unit (12).

2. Hand tool machine according to claim 1, characterized n that the first and the second clamping face (18, 20, 22, 24) are in each case flat clamping faces.

3. Hand tool machine according to claim 1 or 2, characterized in that the first housing unit (12) comprises two separate housing shells (30, 32), which are fastenable by the wedge-type clamping action to 25 the second housing unit (14).

4. Hand tool machine according to one of the preceding claims, characterized in that the connection device (16) comprises at least one third clamping face 30 (34, 36) and the second housing unit (14) is fastenable via the third clamping face (34, 36) by a second wedge-type clamping action to the first housing

unit (12).

5. Hand tool machine according to claim 4, characterized in that the clamplog direction (40) of the second 5 wedge-type clamping action differs from the clamping direction (42) of the first wedge-type clamping action.

6. Hand tool machine according to one of the preceding 10 claims, characterized in that the connection device (16) comprises at least one clamping element (94, 46), on which at least one fixing element (38, 48) is disposed.

15

7. Hand tool machine according to claim 6, characterized in that the clamping element (44, 46) is constructed lotegrally with one of the housing units (14).

8. Hand tool machine according to claim 3, characterized 20 in that the housing shells (30, 32) are positively connectable to one another by at least one connection element (50, 52, 54, 56).

9. Hand tool machine according to claim 8, characterized 25 in that a connection screw (74, 76), which generates the force for the wedge-type clamping action, engages through the connection elements (50, 52, 54, 56).

10. Hand tool machine according to one of the preceding 30 claims, characterized in that the housing units (12, 14) are positively connectable to one another with the aid of a locking element (S8).

A hand tool machine substantially as herein described with reference to the accompanying drawings.