VACUUM CLEANER WITH IMPROVED CABLE REWIND ACTIVITY

Description

[0001] In corded vacuum cleaners, the power cord (colloquially known as the cable) is typically wound up after use using a spring-loaded cable reel. The winding mechanism is usually triggered by pressing a switch on the vacuum cleaner (the so-called foot pedal). Some models only wind up the cord as long as the foot pedal is pressed; others completely rewind the cord after pressing the foot pedal once (a so-called comfort retraction).

[0002] It is usual for the user to go to the socket after vacuuming, pull out the power plug and then return to the vacuum cleaner - ideally with the power plug in their hand - to press the foot button and, if necessary, hold it down for the entire duration of the winding-up process. At the same time, the user must ensure that the cable does not become tangled, which would block the winding-up process. If the user does not take the power plug with them when vacuuming, the power plug will whip through the apartment with considerable force during the winding-up process. This could damage furniture or knock over objects, and the user or another person could be injured by the power plug. A vacuum cleaner according to the preamble of claim 1 is known, for example, from DE-A-10050555.

[0003] The invention therefore addresses the problem of improving the cable winding mechanism. According to the invention, this problem is solved by a vacuum cleaner having the features of patent claim 1. Advantageous embodiments and further developments of the invention are set forth in the following subclaims.

[0004] According to one aspect of the invention, there is provided a vacuum cleaner comprising: a connecting cable with at least a two-pole mains plug for connecting the electrical household appliance to a household socket; a cable receptacle configured to extend and retract the connecting cable; a sensor configured to detect a user touching at least one pole of the mains plug; and a triggering device configured to trigger the retraction of the extended connecting cable in response to the touching.

[0005] With this solution, the user can initiate the rewinding process immediately after unplugging the power cord from the socket, without having to return to the vacuum cleaner first. They no longer need to press the foot switch, which is usually out of reach when unplugging the power cord. The user can easily plug the power cord from one socket to the next without touching any plug contacts, without triggering the rewinding process.

[0006] According to one embodiment, the cable receptacle has a spring mechanism which is tensioned by pulling out the connecting cable in order to cause the connecting cable to be retracted, as well as a locking device which blocks the spring mechanism in the pulled-out state of the connecting cable, wherein the triggering device comprises an electrical actuator which is configured to release the locking device in order to trigger the retraction.

[0007] According to one embodiment, a single touch triggers complete retraction.

[0008] According to one embodiment, the triggered retraction is aborted by a further touch.

[0009] According to one embodiment, the retraction is performed only during touching.

[0010] The user can optionally interrupt the winding process by touching the plug contacts again. Alternatively, the winding process can be configured to continue only as long as the plug contacts are touched.

[0011] According to one embodiment, the sensor is a resistive sensor configured to detect a simultaneous touching of at least two poles of the power plug as the touching.

[0012] Touching the power plug can be detected, for example, by a high-resistance impedance measurement between the two plug pins. The plug pins must be touched or bridged simultaneously. After determining that there is no mains voltage, a finger contact resistance of preferably between 2 kOhm and 10 kOhm should be measured using a measuring voltage / low voltage. If detected, this should trigger one of the actions described above.

[0013] According to one embodiment, the sensor is a capacitive sensor.

[0014] In an alternative embodiment, instead of measuring the impedance across both plug pins, the capacitive change that occurs when a user's fingers / hand touch the power plug contacts is measured. The advantage is that simply touching one plug pin is sufficient for evaluation, eliminating the need to touch or bridge the plug pins simultaneously.

[0015] According to one embodiment, the household appliance further comprises a mechanical button for releasing the locking device.

[0016] The user can still use an existing foot switch (or other means of triggering the winding process). Touch triggering is also possible, as the actuator can release the locking device in parallel with the foot switch.

[0017] According to one embodiment, the household appliance comprises a sensor button for manually actuating the actuator.

[0018] In such a design, the mechanical foot switch can be omitted entirely, and the locking mechanism can be controlled solely by the electric actuator. An optional sensor panel can be used instead of a foot switch. This option allows for new designs and shapes for the household appliance.

[0019] In principle, the invention can be used in any non-stationary household appliance with a power cable, but it is preferably used in a vacuum cleaner.

[0020] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows Figure 1 shows a vacuum cleaner connected to the mains power supply; Figure 2 shows a vacuum cleaner with the power cord partially retracted; and Figure 3 shows a vacuum cleaner with the power cord fully retracted.

[0021] In Figure 1a corded vacuum cleaner 1 is shown as an example of an electrical household appliance (suction tube, floor nozzle, etc. not shown here) in which the present invention can be used. The assumption here is a vacuum cleaner 1 with a (preferably) internal cable receptacle 2 (indicated here by dashed lines) for a power cable 2, in which the power cable 3 can be stored internally in the vacuum cleaner 1 when retracted. The cable receptacle 2 is equipped with an automatic cable retractor, for example in the form of a cable drum, in which a spring is tensioned when the cable is pulled out. In the pulled out state, this spring is mechanically blocked by a locking device so that the power cable is not immediately retracted again.

[0022] This spring tension can in turn be used by releasing the blockage, for example by means of a foot switch, to retract the power cable 3.

[0023] As shown here, the power cable 3 can be pulled out and connected to a household socket 4. This allows the vacuum cleaner 1 to be supplied with power and used for vacuuming.

[0024] After completing a vacuuming operation, the extended power cable 3 should be regularly retracted into the internal cable receptacle 2, for example, to store the vacuum cleaner in a cupboard. The present invention provides an alternative solution for triggering the known cable retraction.

[0025] In Figure 2 an embodiment of a vacuum cleaner 1 is shown, with all elements as already shown in Figure 1 described, but here with the power cable 3 partially retracted. The power cable 3 has a power plug 5 with two poles or plug contacts 6a and 6b.

[0026] The vacuum cleaner 1 has a triggering device 7 (which can, for example, be part of a control unit of the vacuum cleaner, symbolized here by the rotary control), which, by means of a sensor (not shown), can detect a user touching at least one pole 6a and / or 6b of the power plug. If such a touch is detected, the triggering device 7 triggers the retraction of the power cable 3.

[0027] According to one embodiment (not shown), an additional actuator in the form of an electromagnet is provided, which acts on the locking device. When de-energized, the actuator is only applied to the locking device. The actuator is preferably powered by a supercapacitor or a rechargeable battery to provide sufficient energy for operation after the power cable is disconnected. The same energy source can also be used to ensure potential-free measurement via the plug contacts.

[0028] A foot switch 8 is provided to trigger the retraction of the power cable 3 into the cable receptacle 2 by a user on the vacuum cleaner 1 itself. The foot switch 8 can act purely mechanically on the cable receptacle 2 or its locking device; alternatively, the foot switch can also be designed as a pure sensor switch that acts on an electrical actuator as described above.

[0029] Touch measurement can be performed resistively, requiring both plug contacts 6a and 6b to be touched. Alternatively, touch measurement can also be performed capacitively, which advantageously allows only one of the plug contacts 6a or 6b to be touched. With capacitive measurement, a parallel triggering of the cable retraction is possible by touching these surfaces using an additional electrically conductive contact on a surface of the vacuum cleaner, for example, in the area of ​​the foot switch. For this purpose, inexpensive microcontrollers (MC) with capacitive measurement inputs (touch-read input) already provided in the hardware are suitable. These microcontrollers are also recommended due to their capability for extended logic functions such as improved detection and scanning.

[0030] Figure 3 shows another representation of the vacuum cleaner 1 of the Figure 2, with the same elements, but here with the power cable fully retracted.

Claims

1. Vacuum cleaner (1), comprising: a connecting cable (3) having an at least two-pole mains plug (5) for connecting the electrical domestic appliance to a domestic socket (4); a cable receptacle (2) which is designed for pulling out and retracting the connecting cable (3); characterised in that the vacuum cleaner (1) comprises: a sensor which is designed to detect a user touching at least one pole (6a, 6b) of the power plug (5); and a triggering device (7) which is designed to trigger the retraction of the pulled-out connection cable (3) in response to the touch.

2. Vacuum cleaner (1) according to claim 1, wherein the cable receptacle (2) has a spring mechanism which is tensioned by pulling out the connecting cable (3) in order to cause the connecting cable (3) to be retracted, and a locking device which blocks the spring mechanism when the connecting cable (3) is in the pulled-out state, wherein the triggering device (7) comprises an electrical actuator which is designed to release the locking device in order to trigger the retraction.

3. Vacuum cleaner (1) according to any of the preceding claims, wherein complete retraction is triggered by a single touch.

4. Vacuum cleaner (1) according to claim 3, wherein the triggered retraction is cancelled by a second touch.

5. Vacuum cleaner (1) according to any of claims 1 to 3, wherein the retraction is carried out only during the touching.

6. Vacuum cleaner (1) according to any of the preceding claims, wherein the sensor is a resistive sensor which is designed to detect simultaneous touching of at least two poles (6a, 6b) of the power plug as the touching.

7. Vacuum cleaner (1) according to any of claims 1 to 5, wherein the sensor is a capacitive sensor.

8. Vacuum cleaner (1) according to any of claims 2-7, further comprising a mechanical button for releasing the locking device.

9. Vacuum cleaner (1) according to any of claims 2-8, further comprising a sensor button for releasing the locking device.