The present invention relates to a windscreen wiper motor system, particularly for automobiles, for driving a windscreen wiper system, wherein the motor system comprises a drive shaft driven by a motor for driving a mounting head of said windscreen wiper system, wherein said mounting head is arranged to be connected to an elongated wiper blade to be placed in abutment with a windscreen to be wiped, wherein the drive shaft is arranged to oscillate the wiper blade to-and- from between a first reversal position and a second reversal position.

In the framework of the present invention, in the event that said wiper system is a rear windscreen wiper arm system with the drive shaft in a central position at a lower edge of the windscreen to be wiped, said first reversal position may be identified as a position, wherein the wiper blade or an arm member coupled thereto extends parallel to a windscreen to be wiped and is located near said lower edge of said windscreen to be wiped and left from said drive shaft, seen from behind of a vehicle. Also, said second reversal position may be formulated as a position, wherein the wiper blade extends also parallel to a windscreen to be wiped and is located also near said lower edge of said windscreen to be wiped, but right from said drive shaft, again seen from behind of the vehicle concerned. In other words, said first and said second reversal positions are located opposite each other in case the wiper blade is a rear windscreen wiper blade and the drive shaft is in the middle of the lower edge of the windscreen to be wiped.

The present invention also relates to a vehicle equipped with a windscreen wiper motor system for driving such a windscreen wiper system, as well as to a method for manufacturing a windscreen wiper arm.

It is noted that the present invention is not restricted to automobiles, but also refers to rail coaches, air or water crafts, and other (fast) vehicles.

A windscreen wiper motor system is generally known. Such a system may comprise a motor driving a drive shaft coupled to for instance an arm which is often pivotally connected to the mounting head by means of a pivot pin, for example in the form of a rivet. Coupled to the mounting head, for instance via the arm member, is a wiper blade. A spring is hooked with its first end on the mounting head and with its second end on to the arm member in order to ensure that the arm member and thus the wiper blade connected thereto is pressed onto a windscreen to be wiped. A wiper blade may also be coupled directly to a mounting head without the interposition of an intermediate arm. In use, the shaft rotates alternately in a clockwise and in a counter-clockwise sense carrying the mounting head into rotation also, which in turn draws the wiper blade into rotation and by means of a connecting device moves the wiper blade.

A disadvantage of the known windscreen wiper motor system is the following. In use said known windscreen wiper system comprises - coupled to the mounting head via for instance an arm and a connecting device or connector - a wiper blade equipped with a wiping lip. At each turning point of the oscillatory movement (“reversal position”) of the windscreen wiping arm, said wiping lip in abutment with a windscreen to be wiped is tumbled over. In practice, after a wiping cycle (to be understood as one or more finished oscillatory movement(s) of the windscreen wiper arm), the arm member and the wiper blade connected thereto rest in a reversal position with the wiping lip being in a tumbled over position, leading to stress in an elastomeric material of the wiping lip and thus to deformation of the elastomeric material. Said deformation is even worse in hot conditions (summer) and/or humid conditions (autumn and winter) and/or in case of a non-articulated arm member. This effect is also more pronounced for a windscreen wiper device wherein the attack angle of the drive shaft (that is the angle between the normal to the screen and the drive shaft) is lowered. To ensure proper reversal, in particular for systems with lowered attack angle, the rubber wiping lip needs to be perfectly symmetrical. Any deformation will thus adversely the wiping properties.

It is an object of the invention to obviate this disadvantage, in the sense that at minimum costs - without using complex machinery and additional tools - windscreen wiper motor systems are proposed, wherein the above-mentioned deformation of the elastomeric material of the wiping lip is minimized, so that the wiping properties are maintained at a high level and/or to generally improve the wiping properties.

Thereto, according to the invention, a windscreen wiper motor system mentioned in the preamble is characterized in that said motor system is arranged to stop and maintain said wiper blade at, or at least near, both the first and second reversal positions. By providing a motor system which is arranged, for instance programmed, to stop (rest or maintain) the wiper blade, for instance alternately, at either reversal position, the problem of deformation can be mitigated, while also the wiping properties can be improved. The motor system is thus preferably arranged to define two resting positions.

It is to be understood that with the term “maintain the wiper blade in a reversal position” in the context of this disclosure, it is meant that the wiper blade can be maintained at said position for a predetermined (non-zero) period of time and not just the stopping for reversal as in the prior art system. The period of time may be defined by the system. The motor, or a controller of the system, may be programmed to maintain the wiper blade at said position. Said predetermined period of time may be at least one second, more preferably at least two seconds, most preferably at least five seconds.

In a preferred embodiment, said wiper blade between said first and said second reversal positions is arranged to cover a wiping pattern in the form of a semi-circle. The drive shaft and motor are suitably equipped therefor.

Known windscreen wiper motor systems are provided with a motor and a transmission mechanism, for instance comprising gearing and/or linkage, for providing the to-and-from (in and out) motion of the wiper arm from a rotation motion of the motor in one direction. In other words, by driving the motor in a single direction, the drive shaft rotates in opposite directions for creating the to-and- from motion.

According to a preferred embodiment, the motor however comprises a reversal motor. The motor is thus arranged, and preferably programmed, to rotate in opposite directions, thereby creating the movements between the first and second reversal positions. Stopping or resting the wiper blade at either reversal position can then be achieved efficiently. A compact system is obtained if the motor, preferably said reversal motor, is directly coupled to the drive shaft.

According to a preferred embodiment, the motor system is arranged to stop (maintain or rest) said wiper blade after a first wiping cycle in said first reversal position and to stop (maintain or rest) said wiper blade after a second wiping cycle in said second reversal position. In other words, in use of said windscreen wiper arm system, the wiper blade (and thus the wiping lip) is alternately put at rest in the first and the second reversal positions. Sometimes, for instance after use, the wiper blade is thus stopped at the left hand of the drive shaft, seen from behind of a car, and sometimes the wiper blade is thus stopped at the right hand of the drive shaft, seen from behind of a car. Hence, the pressure/stress exerted, for instance by the arm member, on the wiper blade/wiping lip is balanced in two directions due to the fact that after a first wiping cycle the wiper blade is stopped in the first reversal position and that after a second wiping cycle the wiper blade is stopped in the second reversal position. Experiments have shown that deformation of the wiping lip due to stress is significantly reduced thereby. Particularly, the windscreen wiper system comprises a windscreen wiper device of the “flat blade” type. Preferably, said windscreen wiper device comprises an elastic, elongated carrier element, as well as an elongated wiper blade of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade includes at least one longitudinal groove, in which groove a longitudinal strip of the carrier element is disposed, which windscreen wiper device comprises a connecting device (“connector”) for the windscreen wiper arm. The arm member is preferably made of metal. In the alternative, said arm member is preferably made of a plastic material.

In a further preferred embodiment, said first and said second wiping cycles are separated in time by at least one intermediate wiping cycle. The wiper blade may then be rested at alternating reversal positions after use, i.e. after turning of the wiper motor system. The motor system may thereto have a controller comprising a memory for storing the last resting position, wherein the motor system is arranged to rest the wiper blade based on the stored last resting position, for instance the other resting position, after use.

Additionally or alternatively, said first and said second wiping cycles follow each other in time without an intermediate wiping cycle. By proposing two stop (or rest) positions for the wiper blade at the locations of the first and the second reversal positions in the event of an intermittently moving wiper blade, the visibility for a driver is increased, as a time period in which the wiper blade is put at rest can be shortened. During use, for instance when the system receives a control signal, the wiper blade is then alternatively stopped and maintained at both reversal positions, preferably for a predetermined period of time of for instance at least one, preferably at least two seconds.

In a further preferred embodiment, said motor, or a controller thereof, is programmed to stop said wiper blade after said first wiping cycle in said first reversal position and to stop said wiper blade after said second wiping cycle in said second reversal position.

During use, for instance while a control signal is received for operation of the motor system, the motor may be programmed to stop and maintain said wiper blade after said first wiping cycle in said first reversal position and to stop said wiper blade after said second wiping cycle in said second reversal position directly following said first wiping cycle. This improves the visibility for the driver as mentioned above. After use, for instance when a control signal is received for stopping the operation of the motor system, the motor may be programmed to rest the wiper blade at alternating reversal positions after use. As mentioned above, a memory may thereto be provided. This reduces the deformation of the wiping lip due to stress, which also improves the wiping properties.

In a further preferred embodiment, said windscreen wiper arm is arranged as a rear windscreen wiper arm.

As indicated earlier, the present invention also refers to a vehicle provided with a windscreen wiper motor in accordance with the present invention.

Further, the present invention also refers to a method for manufacturing a windscreen wiper motor system according to the present invention, wherein said motor system is arranged to stop and maintain said wiper blade at both the first and second reversal positions

The invention will now be explained in more detail with reference to figures illustrated in a drawing, wherein: figure 1 is a schematic bottom view of a windscreen wiper arm (without a windscreen wiper blade), as well as a schematic side view thereof (without a windscreen wiper blade); figure 2 shows a schematic side view of the windscreen wiper arm of figure 1 ; figure 3 is a schematic cross-sectional view of the windscreen wiper blade of figure 1 at its two reversal positions; and figure 4 is a schematic perspective view of the rear of a vehicle equipped with a windscreen wiper arm of figure 1 in its two (opposite) stop positions.

Figure 1 shows a preferred variant of a windscreen wiper motor system 100 according to the invention for driving a windscreen wiper arm 1. As illustrated in figure 1 , a windscreen wiper arm 1 comprises a mounting head 2 which can be fixed for rotation to a shaft 3 driven by a small motor 101. In this example, the motor 101 is a reversible electromotor 101, wherein the draft shaft 3 is directly coupled to the output axle of said motor 101. In the alternative a mechanism may be provided between the motor 101 and the drive shaft 3. The motor system 100 further comprises a controller, schematically indicated with 102, which is arranged to control the motor 101 functions. The motor system 100 is arranged to receive control signals, in this example illustrated with line 103 entering controller 102. Said windscreen wiper arm 1 further comprises an arm member 4 supported by the mounting head 2, wherein said arm member 4 in turn supports a schematically depicted rubber wiper blade 5 with the help of a connecting device (not shown). The arm member 4 is pivotally connected to the mounting head 2 by means of a pivot pin 6, for example in the form of a rivet. A spring (not shown) is hooked with its first end on the mounting head 2 and with its second end on to the arm member 4 in order to ensure that the arm member 4 and thus the wiper blade connected thereto is pressed onto a windscreen to be wiped. In use, the shaft 3 rotates alternately in a clockwise and in a counter-clockwise sense carrying the mounting head 2 into rotation also, which in turn draws the arm member 4 into rotation and by means of the connecting device moves the wiper blade 5. Said mounting head 2 and/or said arm member 4 could be made of a plastic, metal or composite material.

As illustrated, the arm member 4 has a substantially U-shaped cross-section near said pivot pin 6 comprising two side walls 7,8, wherein said side walls 7,8 extend between a part of the mounting head 2 and beyond said pivot pin 6. Said part of the mounting head 2 is provided with opposite surfaces 9,10.

The arm member 4 is pivotally connected to the mounting head 2 by means of the pivot pin 6, wherein the arm member 4 can be pivoted between a wiping position (or “working position”), wherein the arm member 4 extends parallel to a windscreen to be wiped, and an elevated or upright position (or “service position”), wherein the arm member 4 and/or a windscreen wiper blade 5 to be attached thereto can be repaired or replaced.

With reference to figure 3 the wiper blade 5 is equipped (in one piece therewith) with a wiping lip 11. At each turning point of the oscillatory movement (“reversal position”) of the windscreen wiping arm 1, said wiping lip 11 being in abutment with a windscreen 12 to be wiped is tumbled over. Figure 3 shows the wiper blade 5 in its two reversal positions (left and right). The wiping lip 11 being in a tumbled over position, is exposed to stress resulting in deformation of the rubber. If the windscreen wiper arm 1 after each wiping cycle would be stopped by the motor of the drive shaft 3 in only one of its reversal positions, the wiping lip 11 would ultimately be deformed in its reversal position on the left or on the right in figure 3.

Figure 4 schematically shows the rear of a vehicle 13 equipped with a windscreen wiper motor system 100 of figure 1, arranged as a rear wiper arm 1. As depicted, the wiper blade 5 extends parallel to the windscreen 12 to be wiped. In its two stop positions the wiper blade 5 is positioned left or right from said drive shaft 3 near a lower edge 14 of said windscreen 12 to be wiped, seen from behind of the vehicle 13. In other words, in use of said windscreen wiper arm 1, the wiper blade 5 (and thus the wiping lip 11) is alternately put at rest in the first or the second reversal position. Sometimes the wiper blade 5 is thus stopped at the left hand of the drive shaft 3 (shown in dotted lines in figure 4), seen from behind of the vehicle 13, and sometimes wiper blade 5 is thus stopped at the right hand of the drive shaft 3, seen from behind of the vehicle 13. Hence, the pressure/stress exerted by the arm member 4 on the wiper blade 5/wiping lip 11 is balanced in two directions due to the fact that the arm member 4 after a wiping cycle is stopped alternately on the left or on the right of the drive shaft 3. The controller 102 of the motor 102 may be programmed to this end.

As an example, upon receipt of a control signal 103 to start the wiping operation, the controller 102 may control the motor to intermittently rotate the drive shaft 3. To improve the visibility, upon reaching the reversal positions (as indicated in figure 4), the wiper blade 5 may be stopped and maintained at these positions for a predetermined time, for instance 3 or 5 seconds. The controller may thus control the motor to rotate the drive shaft to move the wiper blade towards a first reversal position and to maintain the wiper blade at said position for a predetermined period of time. Thereafter, the controller may control the motor to rotate the drive shaft to move the wiper blade back towards a second reversal position. The wiper blade may again be maintained at said position for the predetermined period of time. Each wiping action is thus followed by a pause, thereby improving the cleaning action compared to a wiping action wherein the wiper blade is returned immediately at the first reversal position and maintained only at the second position.

When a control signal 103 is received to stop the wiping operation, the controller may stop and maintain the wiper blade 5 at a resting position different from the resting position after the previous use. The motor 101, for instance the controller 102 thereof, may thereto be provided with a memory or counter for storing the previous resting position(s). It may for instance be the case that the resting position may be alternated after each use, i.e. upon receipt of a signal to stop operation. The controller may also be arranged to alternate the resting position after a predetermined number of uses, for instance after 5 or 10 uses of the wiper system. A counter may also be provided for counting the number of stops, i.e. after use, at each resting position. The controller may then be arranged to maintain the wiper blade at the resting position having the lowest count. Additionally or alternatively, a timer may be provided for timing the amount of time the wiper blade is in each resting position, wherein the controller may be arranged to maintain the wiper blade in the resting position having the lowest amount of time associated therewith.

The invention is not restricted to the embodiment shown, but extends also to other embodiments falling within the scope of the appended claims.