Improved hand tool

Abstract: The invention provides a key pad (6) for the on/off switch for a powered hand tool (2) in which the on/off switch is of the rocker type in which the switch mechanism is actuated by a rocker member (16) comprising two rocker components (18,20) pivoted about a pivot point (22) and is switched by applying pressure selectively to one of the two rocker components (18,20). The key pad (6) forms a sealed cover for the rocker switch (16) and is moulded from a resilient material, and comprises a pair of actuator pads (8,10), each of which actuator pads (8,10) is associated with a corresponding rocker component (18,20) of the rocker switch (16) and is moulded as a relatively thick pad section (8,10) linked to the key pad wall (12) by a relatively thin deformable circumferential linking section (14) and can be selectively switched between a first stable position and a selectively position in which the actuator pad (8,10) is depressed relative to the first stable position.

Description: The present invention relates to a combination of an as per the preamble of claim 1 improved key pad and on/off switch for a powered hand tool as per the preamble of claim 1, and is particularly suitable for a key pad and on/off switch for a tool which is to be used in a dust-laden or dirty environment, for example a powered sander, planer or jigsaw. An example of such a combination is disclosed in DE-A-1 490 050. A number of designs are known for the on/off switches for powered hand tools, and these fall broadly into one of two types. The first type comprise switches of the slider type which have good appearance from an aesthetic point of view but which are not acceptable from the point of view of dust ingress as they are not sealed. The second type of known switches comprise rocker switches, which have to be sealed with a seal made, for example, of rubber, for use in a dust-laden or dirty environment. While these switches have the advantage that they are sealed against the ingress of dust or other dirt, they have the disadvantage that they are difficult to operate, switch disposition can be difficult to ascertain prior to applying power to the unit and the switches are of poor aesthetic appearance. DE-A-1 490 050 discloses a switch suitable for the on/off switch suitable for a power hand tool, in which the on/off switch is of the rocker type in which the switch mechanism is actuated by a rocker member (7) comprising a single rocker component, is switched by applying pressure selectively to one of the two ends of the switch and is moulded from a waterproof material. DE-A-1 490 050 further discloses, as an alternative embodiment, a switch suitable for the on/off switch suitable for a power hand tool, in which the on/off switch comprises two separate non-pivoted components and is switched by applying pressure selectively to one of the two non-pivoted components, wherein the switch is provided with a sealed cover moulded from a waterproof material, and comprising a pair of actuator pads (8'), each of which actuator pads (8') is attached to a corresponding non-pivoted component of the switch and is formed as a relative thick pad section (8') and relatively thick side wall section (26'), linked to the second actuator pad (8') by a relatively thin deformable circumferential linking section (20',28) and can be selectively switched between a first and a second position in which the actuator pad is depressed relative to the first position. It is an object of the present invention to provide a combination of a key pad and an on/off switch for a powered hand tool in which the above disadvantages are reduced or substantially obviated. The present invention provides a combination of a key pad and an on/off switch for a powered hand tool in which the on/off switch is of the rocker type in which the switch mechanism is actuated by a rocker member comprising two rocker components pivoted about a pivot point and is switched by applying pressure selectively to one of the two rocker components, wherein the key pad forms a sealed cover for the rocker switch, is moulded from a resilient material, and comprises a pair of actuator pads, characterised in that each of which actuator pads is associated with a corresponding rocker component of the rocker switch, is moulded as a relatively thick pad section linked to the key pad wall by a relatively thin deformable circumferential linking section and can be selectively switched between a first stable position and a second stable position in which the actuator pad is depressed relative to the first stable position. In a preferred embodiment of the combination of a key pad and an on/off switch according to the invention, in the first stable position, the actuator pad is substantially coplanar with the surrounding key pad wall and in the second stable position the actuator pad is depressed relative to the surrounding key pad wall. In a particularly preferred embodiment of the combination of a key pad and an on/off switch according to the invention, each of the actuator pads is provided with identifying marking. In order to correspond with international guidelines , the actuator pad which is in the relatively depressed position when the switch is in the 'ON' configuration should be marked 'I' and the actuator pad which is in the relatively depressed position when the switch is in the 'OFF' configuration should be marked 'O'. It is a particularly advantageous feature of the combination of a key pad and an on/off switch according to the invention that the switch disposition can be easily and reliably ascertained prior to applying power to the unit. The invention will now be described with reference to the accompanying drawings, in which Figure 1 is a perspective view of an embodiment of a combination of a key pad and an on/off switch according to the invention, shown in situ in the housing of a powered hand tool, the scale of the key pad being enlarged relative to that of the hand tool; Figure 2 is a section on the line II-II of Figure 1, showing the first actuator pad in the first stable position and the second actuator pad in the second stable position and Figure 3 is a similar view to that of Figure 3 showing the first actuator pad in the second stable position and the second actuator pad in the first stable position. As can be seen from Figure 1, a powered sander shown generally at 2 includes a handle portion 4. A key pad 6 is located in the handle portion 4 and comprises first and second actuator pads 8,10 and a surrounding key pad wall 12. A deformable section 14 surrounds each of the actuator pads 8,10, linking the actuator pad 8,10 with the key pad wall 12. The first actuator pad 8 is marked with the symbol 'O' and the second actuator pad 10 is marked with the symbol 'I'. Figure 2 shows the key pad 6 with an associated rocker member 16, in the 'ON' configuration. The rocker member 16 which is of known design, comprises first and second rocker elements 18,20 pivoted about a pivot point 22. The first rocker element 18, which is associated with the first actuator pad 8 is shown in a relatively raised disposition and the second rocker element 20, which is associated with the second actuator pad 10 is shown in a relatively depressed disposition. Figure 3 shows the key pad 6 with an associated rocker member 16, in the 'OFF' configuration. The rocker member 16 comprises first and second rocker elements 18,20 pivoted about a pivot point 22. The first rocker element 18, which is associated with the first actuator pad 8 is shown in a relatively depressed disposition and the second rocker element 20, which is associated with the second actuator pad 10 is shown in a relatively raised disposition. As can be seen from Figures 2 and 3, in each of the stable switched positions, i.e. in both the 'ON' and the 'OFF' configurations, there is no contact between either of the rocker elements 18,20 and their corresponding actuator pads 8,10. Wear on the actuator pads 8,10 is thus reduced, as is the risk of unintentional switching of the tool. In order to switch the powered tool from the 'ON' configuration shown in Figure 2 to the 'OFF' configuration shown in Figure 3, pressure is applied to the relatively raised first actuator pad 8 which is then depressed so that the pressure is applied through the material of the pad 8 to the first rocker element 18. This rocker element 18 is then displaced into its depressed position (as shown in Figure 3) and the actuator pad 8 also is displaced into its second position. By pivoting about the pivot point 22, the second rocker element 20 is displaced from its relatively depressed position into its relatively raised position. During this displacement, the second rocker element 20 contacts the undersurface of the second actuator pad 10 and displaces it from its second, relatively depressed, position to its first, relatively elevated position (as shown in Figure 3).

Claims: A combination of a key pad (6) and an on/off switch for a powered hand tool (2) in which the on/off switch is of the rocker type in which the switch mechanism is actuated by a rocker member (16) comprising two rocker components (18,20) pivoted about a pivot point (22) and is switched by applying pressure selectively to one of the two rocker components (18,20), wherein the key pad (6) forms a sealed cover for the rocker switch (16), is moulded from a resilient material and comprises a pair of actuator pads (8,10), characterised in that each of the actuator pads (8,10) is associated with a corresponding rocker component (18,20) of the rocker switch (16), is moulded as a relatively thick pad section (8,10) linked to a surrounding key pad wall (12) by a relatively thin deformable circumferential linking section (14) and can be selectively switched between a first stable position and a second stable position in which the actuator pad (8,10) is depressed relative to the first stable position. A combination of a key pad and an on/off switch according to claim 1 characterised in that both actuator pads (8,10) are substantially coplanar with the surrounding key pad wall (12) in their respective first stable positions and depressed relative to the surrounding key pad wall (12) in their respective second stable positions. A combination of a key pad and an on/off switch according to claim 1 or claim 2 characterised in that each of the actuator pads (8,10) is provided with identifying marking. A combination of a key pad and an on/off switch according to claim 3 characterised in that one of the actuator pads is marked '0' and the other actuator pad is marked 'I'.

Inventors: COOPER VINCE, COOPER, VINCE
Applicants: BLACK & DECKER INC, BLACK & DECKER INC.
Application year: 1995
Main classification: H01H23
IPC codes: B25F5, H01H23, H01H9