Windscreen wiper control Field of the invention

Operating windscreen wipers today often involves using a knob with fixed positions which is incorporated in the flasher lever. This knob has limitations both in the number of degrees through which it can be turned (ergonomically) but also in that the possibility of implementing a larger number of positions/functions is limited, e.g. due to the need to be able to detect the voltage levels for the different positions.

Today's windscreen wiper controls have a number of fixed positions for operating them, e.g. off position, a number of separate positions for different sweep intervals and two different fixed speed positions. There are regulations (e.g. European Community directives) about the sweep rate for windscreen wipers. These regulations require at least two sweep rate positions, one of them to be 10-55 cycles per minute, the other at least 45 cycles per minute, and the difference between them to be at least 15 cycles per minute. Moreover, wiper blades have to respond to being switched off by automatically returning to their initial position.

US 6,114,640 gives examples of configurations of a lever for regulating windscreen wipers which comprises inter alia various knobs which can be rotated to alter the sweep rate. A further example of a lever for regulating windscreen wiper sweep rates appears in JP 10315919, involving rotation of part of the lever.

It has become increasingly common to use a rain sensor to control activation of windscreen wipers. This may for example involve measurement of moisture content on the windscreen, which may be done by using a capacitive or optical sensor. US 6,864,655 gives examples of windscreen wiper control based on a rain sensor, e.g. an optical rain sensor.

US 6,690,130 refers to a windscreen wiper system with blade speed controlled inter alia by optical monitoring of amounts of rain.

The object of the present invention is to propose a windscreen wiper control which is simple and intuitive to use, is of robust construction and is easy and therefore inexpensive to manufacture.

Summary of the invention

The above objects are achieved with the invention defined by the independent claim. Preferred embodiments are defined by the dependent claims.

The invention thus relates to a windscreen wiper control for regulating windscreen wipers which also operates in combination with rain sensor control of the function. This wiper control has three fixed positions and two resilient positions reached by rotating the lever, or parts of it, about its longitudinal axis. The wiper control according to the present invention thus has instead of many fixed positions two resilient positions, one up and one down, with a fixed neutral position between them. It has also two fixed positions beyond the upper resilient position, e.g. for "speed one" and "speed two" continuous windscreen wiping. The advantage of this solution is that it makes it possible to have more interval positions than is currently the case. This also results in the advantage of being able to use the same lever both for vehicles with rain sensors and for vehicles without rain sensors, thereby reducing the number of variants and the amount of spare parts stockholding, with consequently lower costs.

There is also a great advantage for the car industry, which often has this function on a lever which is situated to the right of the steering wheel and is dedicated to windscreen wiping and windscreen washing. If this knob is implemented on the lever, the up/down movement of the lever is eliminated, so the lever need be articulated in only one direction, resulting in less risk of mistakes and reduced cost. There is also an advantage in terms of less packing volume around the DCU (driver control unit), i.e. the control column, if lever movement is in only one direction. The reduction in the cost of such a lever for a car may be estimated at about 20%.

Brief description of drawings

Figure 1 is a schematic block diagram illustrating the present invention.

Figure 2 is a schematic diagram of a cross-section of a lever according to the present invention, illustrating various positions.

Figure 3 is a schematic diagram of an embodiment of the lever according to the invention. Figure 4 is a schematic diagram of a further embodiment of the lever according to the invention.

Detailed description of preferred embodiments of the invention

The invention will now be described in more detail with reference to the drawings.

Windscreen wiper control comprising an elongate lever 2 which has a longitudinal axis of rotation and is adapted to direct or indirect regulation of one or more windscreen wipers on a vehicle. The lever 2 is situated close to the vehicle's steering wheel (not depicted) and is fastened in a mounting device 8. In the mounting device there are sensors to monitor the position of the lever. The sensors are adapted to delivering sensor signals to a control unit 6 on the basis of monitored positions of the lever. The control unit 6 is adapted to delivering and receiving signals from a rain sensor 4, if such is provided, and to delivering control signals to one or more motors 10 which drive one or more windscreen wipers 12.

According to a variant of the windscreen wiper control, the whole lever is rotated about a longitudinal axis where the sensors are situated in the mounting device. An alternative is for only a portion of the lever, e.g. an outer portion, to be rotated. A further alternative is for a knob or turning cylinder to be fitted round the lever and be turnable with respect to the lever's longitudinal axis.

Figure 3 is a schematic diagram of an embodiment of the invention in which a portion of the lever 2, a so-called turning portion 14, can be rotated relative to the lever's stem portion 18 to reach the fixed and resilient positions.

Figure 4 is a schematic diagram of a further embodiment of the invention in which a portion of the lever 2, a so-called turning cylinder 16, surrounds, and can be rotated relative to, the lever's stem portion 18' to reach the fixed and resilient positions.

In the further description of the function, the term "lever" covers all of these variants.

Figure 2 is a schematic diagram of a cross-section of a lever with a longitudinal axis A according to the present invention, illustrating various positions.

According to the invention, said lever is adapted to reaching three distinct fixed positions by being rotated about its longitudinal axis, viz. a neutral position (N), a first fixed position (I) by rotation through a first angle vl from the neutral position, and a second fixed position (II) by rotation through a second angle v2 from the neutral position, vl being a smaller angle than v2.

Preferably, the angle vl is within the range 45-70 degrees and v2 within the range 60-100 degrees. According to an embodiment, vl is 60 degrees and v2 is 90 degrees. In its neutral position, the lever is adapted to allowing resilient rotary motion in two directions from the neutral position, viz. a first direction upwards to an upper resilient position (U) and a second direction downwards to a lower resilient position (L), which latter position is reached by the lever being rotated through a third angle v3 in each direction and then being released, v3 being a smaller angle than vl . The angle v3 is preferably within the range 20-50 degrees, e.g. 30 degrees. The resilient rotary motion is imparted by a spring force which brings the lever back from the respective upper and lower resilient positions to the neutral position, and said regulation of the windscreen wiper is effected entirely by rotation of the lever to either of said positions.

The control unit may be programmed to interpret the respective meanings of the lever being in the various positions.

According to an embodiment, the control unit is programmed so that the first and second fixed positions cause the windscreen wiper to operate at respective first and second wiping speeds, the second speed being faster than the first.

The windscreen wiper control according to the invention is particularly applicable to controlling a rain sensor. The control unit is then adapted to causing activation and deactivation of the rain sensor by rotating the lever to the resilient positions. Activating the sensor is done by rotating the lever to one of the resilient positions, holding it there for a predetermined first period of time and then releasing it, the period of time being for example within the range 0.1-0.4 s. Deactivation of the rain sensor is effected according to an embodiment by rotating the lever to the other resilient position and holding it there for a predetermined second period of time which is longer than the first period. The second period is preferably within the range 1-2 s. It is of course possible to adopt quite different values for the lengths of the aforesaid periods of time than those mentioned here, which values may be both longer and shorter, depending inter alia on the particular application.

According to an embodiment, the control unit may be programmed so that the sensitivity of the rain sensor is progressively increased or decreased by rotating the lever to the respective resilient position several times and holding it there for a predetermined first period of time before releasing it, said period being within the range 0.1-0.4 s. The rain sensor may be an optical or capacitive sensor and may for example be of the type described in any of the specifications cited above. The sensitivity of the sensor may be set by rotation upwards or downwards.

According to another embodiment, the length of the pauses in intermittent wiping is controlled by rotating the lever to the resilient positions and is shortened by rotating the lever repeatedly to one of the resilient positions and holding it there for a first

predetermined period of time within the range 0.1-0.4 s. The length of the pauses is lengthened by rotating the lever repeatedly to the other resilient position and holding it there for a first predetermined period of time within the range 0.1-0.4 s.

The control unit may easily be programmed to adapt the windscreen wiper control to the desired functionality. It is for example possible to adapt the system according to whether there is or is not a rain sensor.

If the vehicle is equipped with a rain sensor, the sensitivity of the sensor may be set by rotation to the resilient positions.

If there is no rain sensor, rotation to the resilient positions may instead regulate the pause length.

The neutral position serves as both initial position and off position (zero position). When the ignition is switched off, the rain sensor (if any) reverts to the off position to prevent its unintended operation. On vehicles which have to start and stop frequently, this function may be altered via parameter setting in the combination instrument. To switch the rain sensor off completely when the vehicle is in motion, or to zero the pause length, the lever may for example be rotated to its lower resilient position in a predetermined time within the range 1.0-2.0 s, i.e. a significantly longer period than a brief turn.

The present invention is not restricted to the preferred embodiments described above. Sundry alternatives, modifications and equivalents may be used. The above embodiments are therefore not to be regarded as limiting the invention's protective scope which is defined by the attached claims.