EP1595661B1 - Handle with safety device for a motorized handtool - Google Patents

Abstract

The handle has a pipe extending over a 3/4-circle, with a fuse switch, and a sensor extending spatially along from the outside of the pipe. The pipe is formed of two half shells (5, 6) with a laminar mounting plate element (10, 11) along the 0.75 circle. A laminar capacitive sensor extends over the range. Both half shells have a laminar mounting plate separated from each other with the sensors held on the plate. The mounting plate element has an oblong surface with pre-aged pins and the sensor formed as strips (25, 26) and wedged between the pins and the surface.

Description

The invention relates to a handle for a motor-driven hand tool according to the preamble of claim 1. Such a device is made US Pat. No. 4,493,377 A1 known .

Such handles with safety switches are usually provided on a second handle of such a motor-driven hand tool, so that the person handling the motor-driven hand tool, both hands securely on a handle - namely the first hand on the normally operated with the index finger ON / OFF switch on a first handle and the second hand on the second handle -, creating a safety switch is pressed. Only when the safety switch on the second handle is switched on, the switch-on is enabled on the ON / OFF switch on the first handle. Thus, it is ensured that while the operating engine is running and the tool (drill, knife or the like) is in operation, no hand of the operator is in a position where it can be injured.

A disadvantage of known, provided with a safety guard handles of this type is that they require a certain operating position of the "second" hand - namely the one that operates the safety switch - while for ergonomic reasons, it is often more convenient, if one of these second handle can touch another place.

A handle for a motor-driven tool according to the preamble of claim 1 is known from DE 93 08 698 U1 known. In this case, two mutually opposite parallel electrical contact conductors are provided, which come in contact with the compression of the plastic channel in which they are arranged and in turn in a groove (17) of the outside of a handle for a motor-driven tool, and trigger a safety switch , With this arrangement, it is quite possible that, although the grip is reliably grasped with one hand, it is not the case that the contacts are also actuated. In addition, the plastic tube surrounding the two contact conductors in a harsh environment is subject to a certain amount of wear and is possibly subject to damage.

From the DE 102 32 934 A1 is a handle with safety circuit has become known in the below a pressure-sensitive zone, a fluid chamber system is arranged, which communicates with a switching device designed as an on / off switch. When touched pressure is exerted on the pressure-sensitive zone and thus on the fluid, which then actuates the switch. This system is extremely expensive. The switch is located in the fluid. He may be subject to wear. There is a problem of reliable sealing of the fluid chamber system. This system is therefore complicated, expensive and unreliable.

From the DE 103 02 532 A1 a control for a hand tool is known in which contact surfaces are provided as touch sensors, which are connected via threshold switches with an integrated sensor circuit. For training along the full circumference of an approximately three-quarter circular handle this structure is too cumbersome. There is also the risk of pollution in harsh environments.

The object of the invention is therefore to provide a handle referred to in the preamble of claim 1 type such that these disadvantages are not met, in particular that you can touch this handle at any point and the contact is reliably closed.

This object is achieved by the means of the characterizing part of claim 1. Advantageous developments are defined in subclaims.

Figur 1

ein Ausführungsbeispiel;

Figur 2

eine Draufsicht auf das Ausführungsbeispiel;

Figur 3

eine Ansicht in Rechnung der Pfeile III-III in Figur 2;

Figur 4

eine Ansicht in Richtung der Pfeile IV-IV in Figur 2;

Figur 5

einen Schnitt in Richtung der Pfeile V-V in Figur 2; und

Figur 6

einen Schnitt in Richtung der Pfeile VI-VI in Figur 4.

An embodiment of the invention and its advantageous developments will be described below with reference to the accompanying drawings. They show:

FIG. 1

an embodiment;

FIG. 2

a plan view of the embodiment;

FIG. 3

a view in the bill of arrows III-III in Figure 2;

FIG. 4

a view in the direction of arrows IV-IV in Figure 2;

FIG. 5

a section in the direction of the arrows VV in Figure 2; and

FIG. 6

a section in the direction of the arrows VI-VI in Figure 4.

Figure 1 shows a handle 1, which is formed by a tube. The tube is approximately in the shape of a ¾ circle. With its mutually aligned end faces 2, it can be screwed to a motor-driven hand tool, for example a drill, a power saw, an angle grinder or a similar device. For this purpose, as can be seen from Figure 3 and Figure 6, the end faces 2 are provided with blind holes 3, which have an internal thread. A motor-driven hand tool of this type (not shown) has two handles, wherein the actual ON / OFF switch on a first handle (not shown) is mounted so that it can be operated with the forefinger, while the second switch a Safety switch is that serves to make the on / off on the first handle only take effect, although this second "safety" switch is actuated by the fact that the operator also holds the second handle.

To such a safety switch is here.

This is, as best seen in Figures 5 and 6, formed by a tube which is composed of two half-shells 5 and 6. The half-shell 5 has on the inside two spaced-apart, mutually parallel circular surfaces 10, 11. They arise at the interior of a ring 15, with which the half-shell 5 is inserted into the half-shell 6 or in a corresponding recess 7 provided in this.

Furthermore, pins 20 are provided on the half-shell 6 inside along the surfaces 10, 11 at a distance of 10 to 20 cm, which each have a distance of 0.5 to 1.0 mm from the associated surface 10 or 11. between these pins 20 and the surfaces 10 and 11, the actual designed as a film or board capacitive sensor elements or sensors 25, 26 are then clamped and supported by the lower surface 7 'of the recess 7. In the simplest case, the two capacitive sensors 25, 26 may be those in which a metal layer is applied flatly to a foil. Two sensors, such as the two sensors 25, 26, are provided for safety reasons. The capacity is then influenced by touching the tube at any point. Depending on this, a signal is then generated in an evaluation circuit. The sensors 25, 26 are provided with connecting wires 30, 31, which are guided through the connection opening 32 into a cable 33, which is connected to the control device of the tool, in which the said evaluation circuit is provided. The use of a strip-shaped foil makes it possible in a simple manner for the sensor to be distributed spatially over the entire area that can be touched on the outside.

Of course, other types of sensors are also possible. You only need to meet the requirement that the touch of an operator handle anywhere sufficient to result in a change of the output from the sensor signal and so to fulfill the said function as a safety switch. So there are also inductive sensors in question.

For easier handling, the outer surface of the handle is provided with grooves 40, which allow a non-slip touch.

Claims (5)

1. Handle for a motor driven handheld tool, especially a motor saw, made by a tube of a electrically nonconductive material, with a safety switch, released by a sensor, which extends in the space along the area of the tube, touchable from the outside and is arranged within said tube, characterized in that the tube is formed by two half shells (5, 6) fitted to each other, of which at least one contains flat holding element (10, 11), along which a flat capacitive sensor (25, 26) extending also along this area is positioned.
2. Handle according to claim 1 characterized in that both half shells (5, 6) in spaced relationship to each other each are provided with a flat holding element (10, 11) with sensors (25, 26) held in this position.
3. Handle in accordance to claim 1 or 2, characterized in that the holding element has an elongated surface (10, 11), in front of which at a certain distance pins (20) are positioned and that the sensor (25, 26) being provided as a strip is fitted between the pins and the surface (10, 11).
4. Handle in accordance to one of the claims 1, 2 or 3, characterized in that the tube is provided with two surfaces (2) adapted for a screw connection to a tool.
5. Handle in accordance to claim 4 or 5 characterized in that the half shells at a distance to said holding elements (10, 11) are provided with second holding elements (20), so that a sensor (25, 26) can be arranged between the first mentioned holding elements (10, 11) and the second mentioned holding elements (20).

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