GB2428992A

GB2428992A - Electric hand tool with pot housing part and shell housing part

Info

Publication number: GB2428992A
Application number: GB0615637A
Authority: GB
Inventors: Robert Simm; Cornelis Van Der Schans; Markus Weber
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2005-08-08
Filing date: 2006-08-04
Publication date: 2007-02-14
Anticipated expiration: 2026-08-04
Also published as: GB2428992B; GB0615637D0; DE102005037255A1; US20070193760A1; CN1911604A; CN1911604B

Abstract

An electric hand tool comprises a plurality of separable housing parts, with at least two mutually associated housing-side shell elements 10 and a housing-side pot element 11. A housing part 20b of the pot element 11 at least partially externally encompasses a housing part 20a of the shell elements 10. Preferably an extension 12 of the shell elements 10 tightly surrounds gear wheels 15 of a gear unit 13, and the pot element 11 may form a termination for a grease region (14, fig 1a) disposed in the extension 12.

Description

Electric hand tool 2428992

Background art

The invention proceeds from an electric hand tool according to the preamble of claim 1.

According to the background art, electric hand tools are known, which are designed either as shell-type machines or as pot-like machines. Shelltype machines comprise a housing-side shell element, which surrounds corresponding functional modules in a shell-like manner. In the case of a pot-type machine, the functional modules of the electric hand tool are disposed in a housing-side pot element.

Electric hand tools having a plurality of separable housing parts are also known, wherein at least one housing-side shell element and one housing-side pot element are formed, which are separate from one another.

Advantages of the invention In the electric hand tool according to the invention, a housing part of a pot element at least partially externally encompasses a housing part of a shell element. In this case, for example two mutually associated shell elements surround the interior of the electric hand tool in the corresponding housing part. The shell elements have a dividing seam in axial direction. A pot element, on the other hand, has a division at right angles to the axial direction. Advantageously, according to the invention the pot element is designed circumferentially larger than the shell element, thereby allowing improved lubrication of the gear unit. This is because the circumferential region, in which the pot element encompasses the shell element, is of a double-walled design. A grease compartment disposed in the shell part is therefore restricted to only less room than in electric hand tools, in which the grease compartment is disposed up to the single-walled housing part. The lubricant and/or grease therefore advantageously remains in the vicinity of the components to be supplied, for example of a gear unit, and so the lubrication may be improved and in particular rapid running-dry of the gear unit may be prevented. This advantageously leads also to a longer life of the components, for example gear wheels, without the design being adversely affected thereby.

In a preferred manner, the region of the shell element encompassed by the pot element engages as an extension of the shell element into the pot element, wherein the shell element and the pot element are strung axially together.

The extension is advantageously no longer visible from the outside. The extension of the shell element therefore advantageously has to meet only the technical requirements, without a designer appearance having to be taken into account. In the interior, on the other hand, an optimum amount of overall space is achieved. In the visible part, on the other hand, i.e. in the pot element discernible from the outside, the electric hand tool may satisfy ergonomic requirements and have a designer appearance.

Preferentially, a gear unit is disposed in the shell element, wherein the extension delimits a grease region of the shell element that is disposed in the gear unit. In particular, the extension may tightly surround gear wheels of the gear unit. In a particularly preferred embodiment, a termination for the grease region disposed in the extension may be disposed in the pot element, wherein the grease region is workingly Connected to the extension. The working connection arises by virtue of the grease remaining in the immediate vicinity of the gear wheels, this having the initially mentioned positive effects upon the lubrication.

In an advaftageous development, the shell element and the pot element may be connectable to one another without a tool, for example by means of a bayonet-catch_j connection, a plug-in connection or a locking device, wherein the housing parts of the shell element and of the pot element are locked against mutual rotation.

Drawings Further embodiments, aspects and advantages of the invention arise also independently of their grouping in claims, without restricting the generality, from embodiments of the invention that are represented below by way of drawings.

The drawings show: Figs. la,b,c a view of a shell part of an embodiment of an electric hand tool in a side view (Fig. la), a front view (Fig. ic) and a perspective view laterally from above (Fig. ib); and Figs. 2a,b a view of a pot part in the embodiment according to Fig. 1 in a side view (Fig. 2a) and a front view (Fig. 2b)

Description of the embodiment

Figs. la, b, c show in various perspectives a shell element 10 of an electric hand tool according to the invention, in the housing part 20a of which a drive unit 16 that is not visible in Fig. 1, for example an electric motor, and a gear unit 13 are disposed. Figs. 2a, b show in each case a pot element 11 in various perspectives, the housing part 20b of which comprises supports and/or bearings for a drive shaft (not shown) The shell element 10 and the pot element 11 in the assembled state are strung axially together and non- positively and/or positively connectable to one another, wherein assembly is effected preferentially without a tool, for example by means of a bayonet-like catch, or requires only a single assembly tool. In the assembled state, which is not shown in the drawings, the housing parts 20a, 20b have a substantially cylindrical cross section. According to the invention, in this case a housing part 20a of the pot element 11 at least partially externally encompasses a housing part 20b of the shell element 10. The region of the shell element 10 encompassed by the pot element 11 in said case engages as an extension 12 of the shell element 10 into the pot element 11. The extension 12 is outlined by a dashed line in Fig. la and is part of the shell element 10. The extension 12 is in particular of a circumferentially smaller design than the housing part 20b of the pot element 11 that encompasses the extension 12. A projection 17 on the upper circumference of the housing part 20a of the shell element 10 is so disposed that, when the pot element 11 is pushed on, it overlaps the pot element 11 in the region 18. A secure connection is therefore established between the shell element 10 and the pot element 11.

Because the extension 12 in the assembled state is not visible from the outside, it does not have to meet any designer requirements. Rather, the design of the extension 12 may be adapted to the technical requirements.

The extension 12 delimits in particular a grease region 14 of the shell element 10 that is disposed in the gear unit 13. The extension 12 surrounds gear wheels 15 of the gear unit 13 as tightly as possible. The pot element 11 therefore forms a termination for the grease region 14 disposed in the extension 12. The grease region 14 is therefore of smaller dimensions than in the known electric hand tools. Because of this dimensioning of the grease region 14, the grease therefore remains in the vicinity of the gear wheels 15, thereby preventing the gear unit 13 from rapidly running dry.

Claims

Claims 1. Electric hand tool having a plurality of separable housing

parts, comprising at least two mutually associated housing-side shell elements (10) and a housing-side pot element (11), characterized in that a housing part (20a) of the pot element (11) at least partially externally encompasses a housing part (20b) of the shell element (10)
2. Electric hand tool according to claim 1, characterized in that the region of the shell element (10) encompassed by the pot element (11) engages as an extension (12) of the shell element (10) into the pot element (11)
3. Electric hand tool according to claim 1 or 2, characterized in that a gear unit (13) is disposed in the shell element (10)
4. Electric hand tool according to one of claims 2 or 3, characterized in that the extension (12) delimits a grease region (14) of the shell element (10) that is disposed in the gear unit (13)
5. Electric hand tool according to one of claims 2 to 4, characterized in that the extension (12) tightly surrounds gear wheels (15) of the gear unit (13)
6. Electric hand tool according to one of claims 4 or 5, characterized in that the pot element (11) forms a termination for the grease region (14) disposed in the extension (12)
7. Electric hand tool according to one of claims 4 to 6, characterized in that the grease region (14) is so disposed that it is workingly connected to the extension (12)
8. Electric hand tool according to one of the preceding claims, characterized in that the shell element (10) and the pot element (11) are Connectable to one another without a tool.
9. An electric hand tool substantially as herein described with reference to the accompanying drawings.