DE3316111A1 - Electrical hand tool having a controller for various functions - Google Patents

Description

10.156

Description;

The present invention relates to an electric hand tool according to the preamble of claim 1. The invention relates specifically to electric drills and similar electric hand tools that perform various functions such as "slapping", "multi-speed", "reversibility" and "electronic clutch". the The present invention aims at a control for an electric hand tool having two or more such functions, so that the functions can be selectively combined.

Well known and commercially available are electric drills, which with the usual function "drilling" the functions "hammering", "reversing" and "electronic coupling" combine. Electric drills are also known which employ multi-speed gear assemblies are equipped so that the drill operated at different, preset speeds can be.

The main purpose of the "Strike" function is to use particularly resistant materials, such as concrete, to be able to drill, which hardly yield to the actual drilling (turning) effect.

A reverse function enables the drill to be turned counterclockwise to make the drill easier, for example be able to pull it out of a drilled hole or loosen a screw. Such work is expediently carried out at a speed lower than the drilling speed sometimes required.

The "electronic coupling" function enables the motor to be automatically switched off from the energy supply, when the torque acting on the armature shaft of the motor exceeds a specified maximum value.

Some of the functions mentioned above, such as the "Hit" and "Reverse" functions, should be in the Operation must not be present at the same time in order to avoid damage to the drill. Also is it is sometimes preferable to override the "electronic clutch" function for certain work, so that avoids the clutch stopping the engine and making certain work impossible is done, for example, certain impact drilling work carried out at high speed and high torque .

The invention is based on the object of an electric hand tool, in particular an electric drill, with a control that allows the operator allows to select the desired and correct combination of functions without the possibility is to make a mistake.

In order to obtain some of the mentioned functions it is necessary to have one or more internal components of the electric drill to move mechanically. For example, if on a multi-speed gear arrangement the gear (i.e. the speed) is changed, one or more gears become mechanical postponed. In addition, when changing from a "hammering" operating mode to a "drilling only" operating mode or vice versa, usually a movement-limiting stop for the clamping chuck spindle mechanically

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turns. In contrast, in order to activate other functions, electrical circuit parts must be influenced; this applies E.g. when an electronic coupling is made ready for operation or put in a non-functional state will.

The above object is achieved according to the invention by the In the invention characterized in claim 1 solved.

Further developments of the invention are given in the subclaims. The control device is preferably a Slide with which a shaft-like member is connected inside the tool housing, which the or the electrical switches operated.

The slider can be mechanically operated in a multi-speed gear box provided movable gear be coupled, with the movement of the slide selects the transmission ratio of the gear case.

As an alternative or in addition, the slide can have an operating mode switchover mechanism move to switch from a "hammering" operating mode to a "drilling only" operating mode, and vice versa.

One of the electrical switches can control a reverse function, while another switch has an electronic clutch function controls. There can also be one switch at the same time for both the reverse and the electronic clutch function steer.

The slide has three positions on a hammer drill with reversing and electronic clutch function take in. In a first position of the slide, hitting is excluded and there are two switches operated to activate both the reversing and the electronic

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activate clutch function. In a second slider position, hammer operation is possible, during the
Reversing switch deactivated and the electronic clutch switch activated. In the third slide position, hammer operation is possible, but the two switches mentioned are deactivated.

Preferably, a rod-like member connected to the slide extends parallel to the axis of rotation of the Motor, and it has one or more sections of insulating material. These sections are between one or more Pairs of elastic electrical contacts can be pushed in to open one or more electrical switches. With a multi-speed drill,

at the front end of the rod-like link one
Gear shift fork be attached.

In the following, embodiments of the invention are explained in more detail with reference to the drawing. Show it:
20th

Figure 1 is a block diagram of one for one embodiment

the invention provided control of a hammer drill with reversing and electronic clutch function;
25th

Fig. 2 is a side view of the front part of another embodiment of the invention applied to a drill equipped with two gears, with the Housing is partially broken away;

3 shows a detail of the drilling machine shown in FIG. 2, the alignment of some parts being recorded and a part of the two-speed transmission is shown; and

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FIG. 4 shows a sectional view along the line IV-IV in FIG. 2.

The function block 1 shown in Fig. 1 represents a manually operable one Control member, preferably a slide, with which the "hitting" function of a hammer drill can be activated or deactivated. The control member 1 is manually between three different positions movable, and depending on the selected position it generates different commands A, B and C for a cooperating with the motor 3 of the drill control circuit 2. The function block 4 provides the The "hitting" function of the drilling machine represents. The function block 5 represents the reverse function of the motor 3, through which the direction of rotation of the motor can be reversed. The function block 6 provides an electronic clutch function of the motor 3, by means of which the motor is automatically switched off from the energy supply, when the torque acting on the armature shaft of the motor exceeds a predetermined value.

The control member designed as a slide 1 causes in a first position that the drive spindle of the Drill is held in a position in which a pair of impact pawls are axially spaced from each other are held and therefore generate no axially reciprocating impact movement of the chuck spindle can. In the other two positions of the slide 1, the drive spindle is not related axial movement locked, and the impact pawls can interact with each other relative to each other Rotate to create an impact on the drive screw. This impact then occurs when the operator presses the drill against a workpiece, i.e. a base, so that the

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Chuck spindle in a known manner against the action of a weak spring axially in the drill is shifted to engage the two ratchet pawls.

In addition to its impact function, the slide 1 opens and closes two sets of electrical contacts or Switches in different combinations, depending on which of the three positions of the slide 1 occupies. The slide is releasably held in the selected position by a latching device.

In the first position of the slide 1, the command A is given to the control circuit 2. In this position both switches or sets of contacts are closed, so that the reverse function 5 and the electronic coupling function 6 in the control circuit 2 are released. The drill can then be operated in a "Only Drilling "work, the impact effect is switched off, while by actuating a reverse switch however, operation in the opposite direction of rotation of the spindle is possible. In addition, in the case of a If the drilling machine is overloaded, switch off the electronic coupling of motor 3. In other words: the command A excludes the "impact" function, but enables the "reverse" and "electronic clutch" functions.

In the second position of the slide 1, the command B is given to the control unit 2. In this case it will the striking is enabled, the switch assigned to the reverse function is open, but that of the electronic clutch function is open assigned switch still closed. The drill works with command B. so with impact effect and the function "electronic clutch", but can not work in reverse operation, i.e.,

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the reverse function is blocked.

In the third position of the slide 1, the command C is given to the control circuit 2. In this position the drill is still working in the "hammering" operating mode, but both the reverse function and the electronic coupling function assigned switch open. Accordingly, the command C causes the drill to do the same To work with the impact effect, combined with turning the drill, while the "reverse" functions and "Electronic clutch" switched off.

Although in the embodiment described above, the switches for switching off or deactivating the functions are opened, the circuit can of course be designed so that the switch can be deactivated of the functions can be closed and opened to activate the functions.

The embodiment shown in Fig. 1 can, without departing from the basic idea of the invention, in different ways Modified manner depending on the functions intended for a particular hand tool.

For example, command B could be omitted so that the slider only switches between two positions to generate of command A or command C would be moved. This would mean that in the "Only Drilling "both reverse and coupling function would be activated, but that in the operating mode" hammering " both of these functions would be turned off.

The hammer drill can also have a multi-speed gear box so that the commands B and C have different speeds of rotation of the input

• Control the chuck spindles.

In another embodiment, the drill only have one operating mode "Drilling only" without impact drilling being possible. In such a case

the function block 4 could represent the "high speed" function. Then with command A the Rotate the drill at low speed, with the "reverse" and "clutch" functions possible 'Would be 0. With command C, however, the drill would rotate at high speed while the reverse and clutch functions are disabled.

Fig. 2 shows a two-speed drill with a than

^ 5 command slide 11 trained, manually operated selection device 10 for shifting gears for the purpose of changing gears, i.e. changing speed. A depressible one Push button 12 locks the slide 11 in the selected position. The one shown in the drawing The position of the slide corresponds to the position for low speed. By pressing down the Push button 12 and by moving the slide 11 to the left in the direction of arrow 23 high speed is selected. A shaft 14 is with the slide 11 connected and moves with him. The rear The end of the shaft 14 has a tip 17 made of insulating material, for example a suitable plastic material. In the position shown for low speed, the insulating tip 17 is between a pair of resilient metal contacts 21 which are separated from the tip. When the slider is 11 in Is shifted in the direction of the arrow, the tip 17 is released from the electrical contacts 21, which are thereby close and change a function in the control circuit 22. The control circuit 22 consists of one

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• Printed circuit board mounted directly under the top of the drill press housing. on Various electrical components are mounted on the printed circuit board. The control circuit 22 provides various operating functions of the drill, such as speed control a selected speed, an electronic clutch function to protect the electric motor of the drill, and a reverse function, which is switched to '0 operation if the direction of rotation of the motor is reversed will.

Fig. 3 shows how the slide 11 by means of a triangular arm 13 which extends from the rear end of the slide

• 5 bers 11 protrudes inward and formed in one piece with this is firmly connected to the shaft 14. The shaft 14 has where it penetrates the arm 13, a threaded section, by means of which the axial position of the shaft 14 with respect to the arm 13 during assembly of the tool is set. One recognizes the control circuit 22, from which the elastic contacts 21 protrude, held apart by the insulating tip 17 will. The control circuit has lines, of which a line 24 is shown, through which it is electrically connected to the actuation switch of the drill and its electric motor. Fig. 4, the A view from the rear end of the drill clearly illustrates how the contacts 21 elastic metal strips at the ends

^ v forms, which initially extend from the printed circuit board of the control circuit 22 downwards, to then laterally to the position of the axis of the insulating material tip 17 to extend. According to Fig. 3, the shaft 14 extends through one in the gearbox wall

^ formed cylindrical seat 15 forward, wherein

the shaft 14 is slidably mounted in the seat 15. At the front end of the shaft 14 is a rigid itself Fork lever 16 extending at right angles to the shaft is attached. The forks of the lever 16 engage in an annular groove 18, which is in the hub of a first gear 19 slidably mounted on the chuck spindle 20 is trained. The gear 19 and the spindle 20 have mutually meshing axial gears, and the spindle 20 is driven by the gear 19. One on the armature shaft of the drill motor Seated pinion meshes with a gear 25 mounted on a countershaft 26 and drives it. In the position shown in Fig. 3 is the drive group of another seated on the countershaft Gear 27 completed, which meshes with gear 19, and here the drill works with lower Speed. It can be seen that the slide 11 is in a rear position. When the slider is 11 in Is pushed forward in the direction of arrow 23, the forked lever 16 pushes the gear 19 along the spindle forward, disengaging from gear 27 and under the action of a dog clutch with another Gear (not shown) comes into engagement, which is fixedly mounted on the chuck spindle 20 is. This gear meshes with another gear (not shown) on the countershaft 26 and completes it a second drive group by which the chuck spindle 20 rotates at high speed will. During this forward movement of the shaft 14, the insulating material tip 17 is held by the slider pulled out of the contact pair 21 so that the contact pieces close.

When the contacts 21 are open, the reverse and electronic coupling functions of the control circuit 22 are free.

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given. If the contacts 21 are closed, the Reversing and the electronic clutch function disabled.

If in operation according to the illustrated in Fig. 3 » When the drill is working at low speed, the electric motor is powered by dit Ilek = Electronic coupling protected against overload, and the direction of rotation of the clamping chuck shaft can be controlled manually a reversing switch (not shown) to = to be turned around. Details of such an arrangement are known to the person skilled in the art. Then when the slide 11 is used in its front position, you are working High speed drill, where the Il @ k <= electronic clutch is switched off and the drill cannot be driven in the opposite direction »Follow» Can be borrowed for operation with low and high rotation Torque the drill up to ^ u a v © rg © g © » be operated in one direction or the other. When drilling at high speed, however, the drilling machine works © hn © üntsrbr © - ting through torque limitation and only in the n © rma = len direction.

Depending on the special application the contacts 21 could also be connected in such a way that they only have the electronic coupling = Control the function or just the reverse function.

The execution shown in Figs. 2, 3 and 4 §f © rm can be modified by sewing the shaft 14 rear is extended to at the rear Varlän = a second point or a second cut made of insulating material, whereby this awsit © Ab = cut a second pair to control circuit 22

connected electrical contacts actuated. This second pair of contacts can be a function of the control circuit Activate or deactivate 22 while the contacts 21 control another puncture. The slider 11 can be arranged to have three of the push button 11 lockable positions can take. In the position corresponding to the command A according to FIG. 1 both contact pairs open. In the second position corresponding to command B in FIG. 1, the contacts would be of the second pair of contacts closed while the contacts 21 would still be open. Finally would be in the third position according to command C both contact pairs closed.

in a further modification of the exemplary embodiments described above The drill could have a pair arranged around the chuck spindle 20 and interacting more closely Impact pawls can be equipped with a mode changing device for the single chuck spindle to hold in a forward position or the chuck spindle a limited axial To allow back and forth movement, as is known per se. A position of the mode changing device causes the drill to operate in one mode of "drilling only" mode, in the other position (or some other range of positions) the drill is actuated simultaneously with the drilling operation to work in a "hammering" mode. The slide 11 could be arranged in this way by mechanical connecting means be that he operates the mode changing device. Thus, the drill could be under the Command A operate at a given speed in the "Drilling Only" mode while the functions "Reverse" and "Electronic coupling" are available. Then under the command B the drill could be used

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work at the same speed in the "impact" operating mode, with the "electronic clutch" function being available would stand, but the "Reverse" function would be excluded. Eventually the drill would be under the command C work with a different speed in the operating mode "impact", whereby both the function "electronic clutch" as well as the "Invert" function would be excluded.

According to the invention, the slide is used to change a mechanical arrangement of the hand tool, wherein at the same time other functions in the control circuit are automatically enabled or disabled. Thus can the operator in an extremely convenient manner according to the type of work to be performed the combination of operating conditions without the risk of mistakenly combining a number of functions, which could damage the tool or cause the tool to malfunction.

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Claims (10)

Electric hand tool with control for various functions Claims (i .) Electric hand tool, with an electric motor, a control circuit for controlling the motor functions, and a hand-operated control device with which different operating modes of the hand tool can be mechanically selected, characterized in that the control device (10) also has one or more electrical switches (21) actuated, which deactivates or activates one or more of the motor functions (5, 6) controlled by the control circuit. 2. Electric hand tool according to claim 1, characterized in that a gear arrangement is provided is so that the hand tool can operate at two different speeds, and that the control device (10) is mechanically coupled to a movable gear (19) provided in the gear arrangement, wherein a movement of the control device (10) the transmission ratio the gear arrangement selects. 3. Electric hand tool according to claim 1 or 2, characterized in that the control device (10) has a slide (11) with which the or Redecfcestraße 43 8000 Munich 60 Telephone (089) 883603/88 36CK Telex 52123T3 Telegrams Patenlconsult the electrical switch (21) actuating member (14) is connected. 4. Electric hand tool according to claim 3, characterized in that g e - indicates that the member (14) is wave-like and parallel to the axis of rotation of the Motor extends, and that the member (14) has one or more sections (17) of insulating material, the or which can be brought between one or more pairs of elastic electrical contact pieces (21), around the or to open the switch (21). 5. Electric hand tool according to claim 4, characterized in that on the shaft-like member (14) a gear shift fork (16) is attached which protrudes from the member (14). 6. Electric hand tool according to one of the preceding claims, characterized in that one An impact mechanism is assigned to the chuck spindle (20) of the hand tool, through which the hand tool is in an operating mode "percussion" (4) is operable, and that the hand-operated control device (10) with a Mode change mechanism is linked to the Select the "Hammering" operating mode or an "Drilling only" operating mode. 7. Electric hand tool according to one of the preceding claims, characterized in that the control circuit (22) has a reverse function (5) which is deactivated by moving the control device (10) or is activated. 8. Electric hand tool according to one of the preceding claims, characterized in that the control circuit (22) has an electronic coupling function (6), which by moving the control device (10) deactivated or activated. 9. Electric hand tool according to claim 1, characterized in that the operating modes "strike" (4) and "Drilling only" are provided so that the motor functions can be deactivated by separate slide-in switches (21) and activatable reverse and electronic clutch functions (5, 6) comprise that the control device (10) a slide (11) is able to occupy three positions that in the first position of the slide (11) the "Drilling only" mode can be executed, and the two slide-in switches (21) are actuated to activate the reverse and electronic clutch functions (5, 6) that in the second position the operating mode "impact" (4) can be carried out, whereby the reverse switch is deactivated and the electronic clutch switch is activated, and that in the third position the operating mode "impact" (4) can be carried out, but both slide-in switches (21) are deactivated. 10. Electric hand tool according to claim 9, characterized in that the slide (11) also the Carries out gear shifting in a gear arrangement designed for multiple speeds.