Electric hand tool having a discrete operating element

Abstract

An electric hand tool has an electric consumer, a movable operating element and a control unit for controlling a current flow between the energy store and the consumer on the basis of the position of the operating element. The control unit is constructed separately from the operating element and the mechanical position of the operating element is converted into an electrical control signal in the control unit.

Claims

1. An electric hand tool, comprising: an electrical consumer; an operating element having a first movable element for actuation by a user; and a control unit for controlling a current flow through the consumer on the basis of a position of the first movable element, wherein: the control unit is adapted to be separate from the operating element, and the position of the first movable element is converted into an electrical signal in the control unit but not in the operating element, wherein the first movable element is configured to require a predetermined operating force for a change in its position, wherein the operating element has a latching mechanism configured to counteract a movement of the first movable element between predetermined positions, wherein the predetermined operating force is independent from a force required to generate a corresponding electrical control signal.

2. The hand tool as recited in claim 1, wherein the latching mechanism is configured to mechanically generate a predetermined noise when there is movement of the first movable element into one of the predetermined positions.

3. The hand tool as recited in claim 2, wherein this noise is perceptible by a user acoustically or haptically via a structure-borne noise.

4. The hand tool as recited in claim 1, wherein: the operating element includes another movable element for operation by a user, and a movability of the other movable element is suppressed as long as the first movable element is in a predetermined position of the latching mechanism.

5. The hand tool as recited in claim 4, wherein the other movable element has an electrical contact for supplying an electrical signal indicating a position of the other movable element.

6. The hand tool as recited in claim 4, wherein the first movable element has connecting elements for a form-fitting attachment of the other movable element.

7. The hand tool as recited in claim 4, wherein a condition or a position of the additional movable element is locked.

8. The hand tool as recited in claim 1, wherein the first movable element is rotatable about an axis.

9. The hand tool as recited in claim 1, wherein: the consumer includes an electric motor, and the operating element is configured to control a direction of rotation of the electric motor.

10. The hand tool as recited in claim 1, wherein the first movable element includes connecting elements for form-fitting attachment of the control unit.

11. The hand tool as recited in claim 1, further comprising: a control unit configured for a differentiated analysis of the position of the first movable element.

12. The hand tool as recited in claim 1, wherein the first movable element can be moved to at least one position, in which the first movable element or any component coupled to the first movable element is not contacting a component of the control unit.

13. The hand tool as recited in claim 1, wherein the control unit has a microswitch, a spring contact, or a sliding switch provided to convert the mechanical position of the operating element into a control signal for triggering electronic modules of the control unit.

14. The hand tool as recited in claim 1, wherein the control unit has a reed contact or a Hall sensor provided to convert the mechanical position of the operating element into a control signal for triggering electronic modules of the control unit.

15. An electric hand tool, comprising: an electrical consumer; an operating element having a first movable element for actuation by a user; and a control unit for controlling a current flow through the consumer on the basis of a position of the first movable element, wherein: the control unit is adapted to be separate from the operating element, and the position of the first movable element is converted into an electrical signal in the control unit, wherein the first movable element is configured to require a predetermined operating force for a change in its position, wherein the first movable element is designed for a haptic feedback of a user regarding an operating force and without consideration of electrical activity or a conversion of a mechanical position into an electrical control signal or a mechanical behavior of an electrical component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an electric hand tool.

(2) FIG. 2 shows an operating element for the hand tool from FIG. 1.

(3) FIG. 3 shows the operating element from FIG. 2 in another perspective.

(4) FIG. 4 shows a force-path diagram of the operating element of one of FIGS. 1 through 3.

DETAILED DESCRIPTION

(5) FIG. 1 shows an electric hand tool 100. Hand tool 100 includes an energy store 105, an electrical consumer 110, an operating element 115 and a control unit 120. The exemplary specific embodiment shown here may be a battery-operated drill or screwdriver in the case of electric hand tool 100. Consumer 110 has an electric motor connected via a gear 122 to a mechanical tool holder 125. Tool holder 125 is configured in particular for accommodating a drill, a milling tool or a screwdriver.

(6) Operating element 115 has at least one first movable element 130. In the optional specific embodiment shown here a second movable element 135 is also provided. Operation of consumer 110 is controllable by control unit 120, which controls the current flow between energy store 105 and consumer 110. This control depends on the position of first movable element 130. The second movable element may be configured to control another function of hand tool 100.

(7) First movable element 130 is movable by a user of hand tool 100. Movable element 130 may be displaceable along one direction of movement or may be rotatable or pivotable about an axis of movement. As explained in greater detail below, operating element 115 is preferably configured to enable the movement of the movable element 130 in such a way that actuation and resistance forces, actuation paths or noises associated with actuations are suitable for imparting haptic feedback and optionally also acoustic feedback about an operating procedure. The situation is similar for second movable element 135, elements 130 and 135 controlling different aspects of the current flow between energy store 105 and consumer 110 and which may be configured accordingly to deliver variable haptic feedback to a user. In the specific embodiment depicted here, first movable element 130 may control, for example, a direction of rotation of electric motor 110 and second movable element 135 may control the rotational speed of electric motor 110.

(8) It is essential for control unit 120 to be constructed separately from operating element 115. This means that operating element 115 may be a fully mechanical component which does not have any directly scanned electrical properties such as a resistance or a switching function. Instead, the position or movement supplied by operating element 115 is converted into an electrical signal by control unit 120.

(9) In a simple specific embodiment, control unit 120 may include only one switch, which may be operated by operating element 115.

(10) In another specific embodiment, control unit 120 may include, for example, a differentiated electronic control unit, conversion of the mechanical position of operating element 115 into a control signal for triggering electronic modules of control unit 120 being carried out by a scanning unit 140 of control unit 120 provided specifically for this purpose. Scanning unit 140 may be, for example, a microswitch, a spring contact, a sliding switch, a reed contact, a Hall sensor, a photoelectric barrier or some other suitable device for scanning operating element 115.

(11) In one specific embodiment, the electric elements for converting the position of second movable element 135 into an electrical signal or an electrically scannable property may also be included by operating element 115, in particular by second movable element 135.

(12) FIG. 2 shows operating element 115 for hand tool 100 from FIG. 1 in an exemplary specific embodiment. The diagram in FIG. 2 shows operating element 115, which may be assembled from a top section 205 and a bottom section 210, preferably using a locking connection, in particular a releasable locking connection. Top section 205 includes first movable element 130 and may also include a number of additional elements, which define or ensure movability of first element 130 in top section 205. Such elements may include in particular a spring, a spring-loaded ball, a lever or an axis. In the specific embodiment shown here, an axis of rotation 215 about which first element 130 is movable is provided.

(13) Bottom section 210 includes second movable element 135 and optional elements for defining the movability of second element 135 and/or the movability characteristics. In the preferred specific embodiment shown here, a switch or potentiometer is additionally installed, an electrical terminal 220 being provided for electrical contacting of such components. For the operability of top section 205, bottom section 210 and in particular the presence of scanning device 140 are not necessary.

(14) Top section 205 and bottom section 210 may preferably be brought together. In the specific embodiment shown here, a snap connection 225 is provided for this purpose.

(15) FIG. 3 shows operating element 115 from FIG. 2 in a perspective top view. In the specific embodiment shown here, a connecting element 305 is provided for connecting control unit 120 or its scanning unit 140 to operating element 115.

(16) FIG. 4 shows a force-path diagram 400 of operating element 115 of one of FIGS. 1 through 3. Diagram 400 relates to a peripheral path of first movable element 130 about its assigned axis of rotation 215. This path s is plotted horizontally, while the corresponding force is plotted vertically. The units given are merely examples.

(17) At a path s of 0 mm, movable element 130 is in a middle position, where the movability of second element 135 may be prevented, limited or impeded mechanically. This position of first movable element 130 is therefore also known as locking position 405. In the −3 mm position, there is a running position 410 at the left, and at a position of +3 mm, there is a running position 415 at the right. Running positions 410, 415 correspond to the left and right direction of rotation, respectively, of electric motor 110 of exemplary hand tool 100 from FIG. 1.

(18) A first curve 420 shows a relationship between path s and the force. A second curve 425 shows a maximal deviation from a first curve 420. It is apparent that first curve 420 is designed to be symmetrical with locking position 405 along path s. To go from locking position 405 to one of running positions 410, 415, an actuating force is exerted, increasing to 8 N in the present example with an increase in deflection from locking position 405. From there the operating force drops again, reaching approximately 0 N at the corresponding running position 410, 415.