Connection member of a windshield wiper system

Abstract

The present invention relates to a connection member (10) for a windscreen wiper system (100) comprising a head portion (12) and a shaft portion (14). The shaft portion (14) is configured to be assembled between an output shaft (30) and a transmission housing (20) of the windscreen wiper system (100) to adjust the position of the output shaft within the transmission housing. Additionally, an outer periphery (16) of the shaft portion (14) includes a plurality of laser engraved longitudinal patterns (40) having at least one groove (42) engraved in an axial direction of the shaft portion (14). The plurality of laser engraved longitudinal patterns (40) further includes a plurality of micro-gripping structures (46) formed along a perimeter (44) of the at least one groove (42).

Description

Technical Field

[0001] The present invention relates to a connecting member of a windscreen wiper, and more particularly to a connecting member that provides optimal frictional performance for connecting the output shaft of a wiper motor.

Background Art

[0002] Automobile vehicles are provided with at least one windscreen wiper for cleaning the windscreen. These windscreen wipers generally include a wiper arm having a wiper blade that moves on the surface of the windscreen to clean contaminants on the windscreen. The wiper motor generally drives the wiper arm via a linkage. The motor typically has a worm gear device for transmitting the movement of the motor to drive the wiper arm.

[0003] In these types of motors, it is necessary to adjust the axial distance between the worm wheel and the worm gear in order to minimize play. In order to maintain an appropriate spacing between the worm wheel and the worm gear, the output shaft of the wiper motor is usually attached to a connecting member such as an eccentric bushing. By rotating the eccentric bushing in its seat, the position of the worm wheel relative to the output shaft is accurately controlled.

[0004] Conventionally, a connecting member such as an eccentric bush is fitted into the motor housing by applying force and is usually held in a fixed position by friction. The fitting functions without problems under normal working conditions. However, under heavy load conditions such as in the case of snow or ice accumulation, the bush may slip. The slip can further affect the functionality of the output shaft and thus may lead to motor failure. Furthermore, if the friction is too high, it may cause damage to wiper motor parts such as the housing and the output shaft. In addition, increased pressure may be required to increase the power necessary to operate the wiper motor and transmit power to the wiper arm.

[0005] Therefore, there is a need to provide a connecting member that can provide the necessary frictional resistance between wiper motor parts without causing damage to the motor housing.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present invention is to solve the above-mentioned drawbacks of known connecting members of windscreen wiper systems. In particular, the present invention provides a connecting member for accurately positioning an output shaft within a housing. More specifically, the object of the present invention is to provide a connecting member that increases the resistance torque between the output shaft and the connecting member to prevent rotation of the connecting member without increasing the clamping force of the connecting member.

Means for Solving the Problems

[0007] According to an embodiment of the present invention, there is provided a connecting member for a windscreen wiper comprising a head portion and a shaft portion, the shaft portion being assembled between an output shaft of a windscreen wiper system and a transmission housing and configured to adjust the position of the output shaft within the transmission housing.

[0008] According to the present invention, the outer periphery of the shaft portion includes a plurality of laser-engraved longitudinal patterns having at least one groove engraved in the axial direction of the shaft portion, and the plurality of laser-engraved longitudinal patterns further include a plurality of fine gripping structures formed along the boundary of the at least one groove.

[0009] At least one longitudinal pattern is engraved using a controlled laser engraving process to achieve optimal frictional performance while minimizing process time and cost. The pattern including the groove creates a resistive torque between the connecting member and the housing. The additional longitudinal grooves provide optimal clamping and avoid the need to increase the clamping force that could compromise the structural integrity of the housing.

[0010] Furthermore, at least one fine gripping structure is configured to hold on the surface and thus increase friction and provide the resistive torque necessary to avoid slippage.

[0011] In one embodiment of the present invention, the fine gripping structure is formed perpendicular to the at least one groove. The fine gripping structure perpendicular to the groove can provide an increased resistance to the movement of the connecting member. Furthermore, the fine gripping structure can provide a gripping force for holding the surface of the housing.

[0012] In an alternative embodiment of the present invention, the fine gripping structure is formed at an angle oblique to the at least one groove. The oblique angle can provide for easy assembly of the connecting member. Furthermore, the oblique angle can provide the friction necessary to prevent slippage of the connecting member and at the same time reduce wear and tear of the parts by maintaining the correct coefficient of friction.

[0013] In one embodiment of the present invention, the gripping structure is formed as a hook embedded in the boundary. The hook creates a "gecko's foot" effect between the components, thus improving the frictional performance of the connecting member and maintaining the play necessary for assembly to avoid structural damage.

[0014] In one embodiment of the present invention, a plurality of laser engraving longitudinal patterns are formed as a plurality of straight stripes engraved adjacent to each other. The straight stripes provide uniform friction across the shaft portion, and thus, by more uniformly dispersing the acting force, enable the connecting member to provide better structural integrity.

[0015] In one embodiment of the present invention, the boundaries of consecutive straight stripes coincide to form a ridgeline portion. The ridgeline portion may be configured to contact the housing in order to resist the movement of the connecting member to avoid slipping.

[0016] In one embodiment of the present invention, each of at least one longitudinal pattern is formed at the same angular interval. At least one longitudinal pattern formed at the same interval improves the friction performance because the friction caused by the longitudinal pattern is uniformly distributed along the surface of the connecting member.

[0017] In a particular embodiment, each of at least one longitudinal pattern is formed at an angular interval of 60° from each other. Engraving too many longitudinal patterns damages the inner bore of the motor housing and ultimately reduces effectiveness, so the longitudinal patterns formed at an angular interval of 60° from each other provide optimal friction performance and at the same time prevent damage to the connecting member.

[0018] In an alternative embodiment of the present invention, at least one longitudinal pattern consists of at least one cross-hatching pattern formed on the outer periphery of the shaft portion. The cross-hatching pattern is configured to provide friction between the connecting member and the housing to prevent rotational and linear movement between the components, and thus improve the optimal friction performance of the connecting member.

[0019] In an alternative embodiment of the present invention, at least one longitudinal pattern consists of a helical pattern formed on the outer periphery of the shaft portion. The patterns of helix and cross-hatching have the additional advantage that they are particularly quick and easy to produce on a rotary engraving machine tool.

[0020] In one embodiment of the present invention, at least one longitudinal pattern is formed as a continuous pattern on the circumference of the outer periphery of the shaft portion. The continuous pattern allows for a simple and easy engraving process such that the pattern can be formed in one movement along the entire length of the connecting member.

[0021] In one embodiment of the present invention, at least one longitudinal pattern formed in the first cross-section is different from at least one longitudinal pattern formed in the second cross-section. The discontinuous patterns different in the first and second cross-sections make it possible to provide an optimal number of longitudinal patterns on the connecting member according to the parameters of the particular application in question. The optimal number of patterns provides optimal frictional performance without causing damage to the connecting member of the housing of the windscreen wiper system.

[0022] In one embodiment of the present invention, the shaft portion includes at least one set of laser-engraved longitudinal patterns formed proximal to the head portion and at least one set of laser-engraved longitudinal patterns formed distal to the head portion. Thus, the two sets of longitudinal patterns provide a resistive torque distributed over the length of the connecting member. Further, the two sets of longitudinal patterns can reduce structural damage to the connecting member and the housing.

[0023] In one embodiment of the present invention, at least one longitudinal pattern in the first cross-section is formed at 60° intervals and at least one longitudinal pattern in the second cross-section is formed at 30° intervals.

[0024] In one embodiment of the present invention, the controlled laser engraving for forming at least one longitudinal pattern includes controlling the intensity and size of the laser beam. By controlling the intensity and size of the laser beam, it becomes possible to remove an optimal amount of material from the surface of the connecting member during the engraving process. The amount of material removed is important for maintaining the optimal frictional performance of the shaft and is also important for preventing damage that may be contrary to the purpose of the connecting member having the longitudinal pattern.

[0025] In one embodiment of the present invention, the connecting member is an eccentric bush. In a windshield wiper system, by rotating the eccentric bushing, the position of the worm wheel relative to the shaft is accurately controlled.

[0026] In one embodiment of the present invention, the connecting member is made of sintered metal.

Brief Description of the Drawings

[0027] To complete the description and provide a better understanding of the present invention, a set of drawings is provided. The said drawings form an essential part of the description, illustrate an embodiment of the present invention, which should not be construed as limiting the scope of the present invention, but should be construed only as an example of how the present invention can be implemented. The drawings include the following features.

[0028]

Figure 1

Figure 2

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Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0030] FIG. 1 shows an isometric view of a windscreen wiper system comprising a connecting member of the present invention. FIG. 1, which is an exploded view of the assembly of the wiper system 100, shows an output shaft 30 assembled to a housing 20 by a connecting member 10 which is an eccentric bushing as known in the art. In order to maintain an appropriate spacing between the worm wheel and the worm gear, the output shaft 30 of the wiper motor is typically attached to the connecting member 10 of the present invention. Thus, by rotating the connecting member 10, the position of the worm wheel relative to the output shaft is accurately controlled.

[0031] Hereinafter, the connecting member 10 of the windscreen wiper system according to the first embodiment of the present invention will be described.

[0032] As shown in FIG. 2, the connecting member 10 includes a head portion 12 and a shaft portion 14, and the shaft portion 14 is assembled between the output shaft 30 of the windshield wiper system 100 and the transmission housing 20, and can be configured to adjust the position of the output shaft within the transmission housing 20 (shown in FIG. 4) of the windshield wiper system 100. Further, the head portion 12 may be configured to abut against the housing 20, or may be configured to fit flush within the cavity 22 of the housing 20. Further, as shown in FIGS. 2 and 3 showing the outer periphery 16 of the shaft portion 14, the shaft portion 14 includes a plurality of laser engraved longitudinal patterns 40 having at least one groove 42 engraved in the axial direction of the shaft portion 14. Further, the plurality of laser engraved longitudinal patterns 40 further include a plurality of fine gripping structures 46 formed along the boundary 44 of at least one groove 42.

[0033] The connecting member 10 may be configured to position the output shaft within the housing such that the axial position of the worm gear is adjusted. The connecting member 10 may be arranged such that the outer periphery 16 of the shaft portion 14 of the connecting member contacts the housing and the inner periphery of the shaft portion 14 of the connecting member contacts the output shaft. Further, the connecting member may be configured to allow the output shaft to rotate about an axis, and in addition, the connecting member 10 may be connected to the housing and configured to avoid slippage while operating the wiper system.

[0034] According to one embodiment of the present invention shown in FIG. 2, the connecting member 10 includes at least one longitudinal pattern 40 formed on the outer periphery 16 of the shaft portion 14 using a controlled laser engraving process. The at least one longitudinal pattern 40 engraved on the connecting member includes at least one groove 42 having at least one edge 44. In one embodiment, a plurality of grooves 42 may be engraved adjacent to each other. Further, the grooves 42 and the edges 44 can form a profile including alternately formed valleys and peaks.

[0035] At least one longitudinal pattern can be engraved using a laser engraving process in order to enable easy workability and because the process is relatively cost-effective. The engraving process can include controlling various parameters related to the engraving process, such as the intensity of the laser beam and the depth and profile of the longitudinal pattern. To create at least one longitudinal pattern, the laser beam from the laser engraving tool may be projected onto the outer circumference 16 of the shaft portion 14. Further, the laser beam can be moved across the outer circumference 16 to create at least the longitudinal pattern 40. Additionally, the laser tool may be configured to make multiple passes in order to create the profile of the pattern according to requirements. Laser engraving further enables the removal of an exact amount of metal from the metal, and thus creates a longitudinal profile having a pattern that provides the necessary friction between components to create optimal working efficiency.

[0036] As shown in FIG. 4, at least one longitudinal pattern 40 further includes at least one fine gripping structure 46 formed along the boundary 44 of at least one groove 42. The at least one fine gripping structure 46 can be configured to increase the friction between the connecting member 10 and the housing 20 and thus prevent relative movement. In a preferred embodiment, the fine gripping structure 46 can be formed perpendicular to the at least one groove 42. Alternatively, the fine gripping structure 46 may be formed at an oblique angle with respect to the at least one groove 42. The fine gripping structure 46 can be configured to provide a gripping effect such as a gecko gripping structure. Thereby, the resistance torque between the components can be further increased. Further, the fine gripping structure 46 may be formed as a hook embedded in the boundary 44 of the at least one groove 42. The relative angle formed between the fine gripping structure and the at least one groove, together with the hook, allows an increase in the coefficient of friction and thus a better fit of the connecting member within the housing. The fine gripping structure 46 may be formed at the boundary 44 while engraving a pattern on the outer periphery 16 by laser engraving. They may be formed as burrs along the engraved surface.

[0037] According to an embodiment of the present invention, the connecting member 10 can be made of a sintered metal that can be engraved using a controlled laser engraving process. Sintered metal parts made using powder metallurgy are usually hard and strong, but still relatively inexpensive to manufacture. These sintered parts are difficult to engrave using conventional engraving processes, however, controlled laser engraving makes it possible to produce a pattern on the parts without introducing defects. As described above, by passing a laser beam over a predetermined area of the connecting member 10, a predetermined amount and layer of metal is removed. Multiple passes of the laser beam can be performed over the predetermined area to obtain the predetermined pattern on the connecting member 10.

[0038] In one embodiment of the present invention, at least one longitudinal pattern 40 consists of a plurality (i.e., at least two) of straight stripes distributed adjacent to each other. As shown in FIG. 4, a plurality of laser engraved longitudinal patterns 40 are formed as a plurality of straight stripes engraved adjacent to each other. Further, the boundaries 44 of the continuous straight stripes coincide to form a ridgeline portion. FIG. 4 shows an enlarged view of at least one longitudinal pattern displaying this ridgeline portion. In FIG. 4, three continuous stripes are shown, but the number of stripes or patterns engraved on the outer periphery 16 can be changed as necessary, for example, according to the outer diameter of the bushing or the desired holding strength.

[0039] Therefore, generally speaking, the number of longitudinal patterns 40 that need to be engraved on the outer surface 16 can be calculated based on the torque and load state requirements of the windshield wiper system 100.

[0040] In a preferred embodiment of the present invention, the distance between the continuous boundaries 44 and / or the width of the groove 42 may be in the range of 0.08 mm to 0.12 mm, and the depth of the groove 42 may be in the range of 0.02 mm to 0.03 mm. The above dimensions of the longitudinal pattern 40 provide an optimal gripping effect. However, it is possible to engrave the longitudinal pattern 40 with different dimensions without departing from the scope of the present invention.

[0041] In one embodiment of the present invention, the shaft portion 14 of the connecting member 10 may be configured to have a variable cross-section. Further, the variable cross-section can be obtained such that the shaft portion 14 of the connecting member 10 includes a first cross-section 16a and a second cross-section 16b. The two cross-sections may be provided such that the second cross-section 16b is different from the first cross-section 16a. The cross-sections may be provided such that the perimeter of either the first cross-section 16a or the second cross-section 16b is larger than the other cross-section.

[0042] Furthermore, the first cross-section 16a and the second cross-section 16b may be connected by a third cross-section that may include a transition portion, for example, in the form of a tapered profile. The profile disclosed above is shown in FIG. 2, where a stepped profile of the shaft portion 14 connected by a tapered portion can be seen. In another embodiment of the present invention, the perimeters of the first cross-section 16a and the second cross-section 16b are the same. In this embodiment, the shaft portion 14 may have a single cross-section extending axially from the head portion 12 to the connecting member 10.

[0043] As previously disclosed, the position and number of the longitudinal patterns can be calculated based on the torque and load state requirements of the windshield wiper system. In addition to the depth and width of the grooves as previously disclosed, the position of the longitudinal pattern 40 also plays an important role in gripping and subsequent increase in torque resistance.

[0044] To obtain an appropriate resistance torque between the connecting member and the housing 20, it is most important that at least one longitudinal direction is engraved in an appropriate and suitable portion of the outer periphery 16. Furthermore, the number of longitudinal patterns also plays an equally important role in obtaining an appropriate resistance torque.

[0045] The spacing between the longitudinal patterns 40 can be calculated according to the size of the connecting member 10 in order to provide optimal friction between the connecting member 10 and the housing 20.

[0046] In one embodiment of the present invention, each of the at least one longitudinal pattern 40 may be formed at the same angular interval on the outer periphery 16. In a preferred embodiment of the present invention, each of the at least one longitudinal pattern 40 is formed at an angular interval of 60° from each other. The longitudinal patterns 40 formed at the said intervals make it possible to create six longitudinal patterns distributed equidistantly from each other.

[0047] Alternatively, the shaft portion 14 can include at least one set of laser engraved longitudinal patterns 40 formed near the head portion 12 and at least one set of laser engraved longitudinal patterns 40 formed away from the head portion (12). Further, the longitudinal patterns may also be formed with different angular intervals, for example, at intervals of 45° or 30°. Alternatively, the longitudinal patterns may also be formed at irregular intervals, which can be particularly advantageous when an increase in retention is required at specific angular positions.

[0048] In an alternative embodiment, at least one set of laser engraved longitudinal patterns 40 near the head portion may be formed at 60° intervals, and at least one set of laser engraved longitudinal patterns 40 away from the head portion may be formed at 30° intervals. This is to ensure that an optimal coefficient of friction is obtained without affecting the functionality of the connecting member 10. Alternatively, if necessary, the longitudinal pattern 40 may also extend along the entire length of the connecting member 10.

[0049] The preferred embodiment of the present invention disclosed above includes a longitudinal pattern 40 (seen in FIG. 4) formed in the shape of a straight stripe. Alternatively, at least one longitudinal pattern 40 formed on the connecting member 10 consists of at least one cross-hatching pattern formed on the outer periphery 16 of the shaft portion 14. In another embodiment, at least one longitudinal pattern 40 consists of a spiral pattern formed on the outer periphery 16 of the shaft portion 14. These and / or other patterns can be used based on the resistance torque and design requirements.

[0050] FIG. 5 shows a windshield wiper housing 20 adapted to accommodate the connecting member 10 of the present invention. The housing 20 includes a cavity 22 (as shown in FIG. 6), and the connecting member 10 is screwed into the cavity to enable the assembly of the windshield wiper system 100.

[0051] This disclosure refers to the drawings, but all the embodiments shown in the drawings are not intended to limit the present invention. Instead, they are intended to illustrate the preferred embodiments of the present invention by way of example. Preferred embodiments of the present invention are disclosed. However, it will be apparent to those skilled in the art that certain modifications fall within the scope of the teachings of the present invention and that various changes or modifications can be made in this disclosure without departing from the principles and spirit of the disclosure. These changes or modifications are intended to be encompassed by the present invention as long as they are within the scope defined by the claims and their equivalents.

Claims

1. A connecting member (10) of a windshield wiper system (100), comprising: a head portion (12); a shaft portion (14) assembled between an output shaft (30) of the windshield wiper system (100) and a transmission housing (20) and configured to adjust the position of the output shaft within the transmission housing; and a connecting member (10), characterized in that an outer periphery (16) of the shaft portion (14) comprises a plurality of laser-engraved longitudinal patterns (40) having at least one groove (42) engraved axially of the shaft portion (14). The plurality of laser-engraved longitudinal patterns (40) further includes a plurality of fine gripping structures (46) formed along a boundary (44) of the at least one groove (42). The plurality of fine gripping structures (46) hold a surface of the transmission housing (20).

2. The connecting member (10) according to claim 1, wherein the fine gripping structures (46) are formed perpendicular to the at least one groove (42) or at an angle oblique to the at least one groove (42).

3. The connecting member (10) according to claim 1, wherein the fine gripping structures (46) are formed as hooks embedded in the boundary (44).

4. The connecting member (10) according to claim 1, wherein the plurality of laser-engraved longitudinal patterns (40) are formed as a plurality of straight stripes engraved adjacent to each other.

5. The connecting member (10) according to claim 4, wherein boundaries (44) of consecutive straight stripes coincide to form a ridgeline portion.

6. The connecting member (10) according to claim 1, wherein the plurality of laser-engraved longitudinal patterns (40) are formed as at least one cross-hatching pattern or spiral pattern on the outer periphery (16) of the shaft portion (14).

7. The connecting member (10) according to claim 1, wherein the plurality of longitudinal patterns are formed at the same angular intervals.

8. The connecting member (10) according to claim 1, wherein the plurality of laser-engraved longitudinal patterns (40) are formed as a continuous pattern extending over the entire length of the shaft portion (14).

9. The connecting member (10) according to claim 1, wherein the plurality of laser engraving longitudinal patterns (40) are formed as discontinuous patterns distributed along the length of the shaft portion (14).

10. The connecting member (10) according to claim 9, wherein the shaft portion (14) includes at least one set of laser engraving longitudinal patterns (40) proximal to the head portion (12) and at least one set of laser engraving longitudinal patterns (40) formed distal to the head portion (12).

11. The connecting member (10) according to claim 10, wherein the at least one set of laser engraving longitudinal patterns (40) proximal to the head portion are formed at 60° intervals, and the at least one set of laser engraving longitudinal patterns (40) distal to the head portion are formed at 30° intervals.

12. The connecting member (10) according to claim 1, which is an eccentric bush.

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