Window lifter for a vehicle door

A vehicle window lifter includes first and second parallel guide rails, a connecting arm rigidly connecting the guide rails at a point along the rails between their ends, and cable returns defining a cable path along the rails and connecting arm. The connecting arm and guide rails form a cable path for a cable, protecting the cable while providing high rigidity and simple mounting on a vehicle door.

REFERENCE TO RELATED APPLICATIONS

The present invention claims priority to French Patent Application No. 02 07 566, filed Jun. 19, 2002.

1. Technical Field

The present invention relates to a window lifter, and more particularly to a vehicle door having such a window lifter.

2. Background of the Invention

Window lifters in vehicle doors are often difficult to mount. Several solutions have been proposed for mounting the window lifter in the door.

French patent 2,761,104 discloses a window lifter having two substantially parallel rails with cables in an X-configuration between the rails and sliding thereon. The window lifter also includes an X-shaped support joining the upper ends and enveloping the cables. The support provides rigidity for the window lifter, which can be mounted in a modular fashion in a large opening in the door. This window lifter suffers from the disadvantage of requiring large amounts of material for enveloping the cable over the whole length thereof between the rails, making the window lifter expensive to manufacture. Additionally, this type of window lifter cannot be installed into every type of vehicle door. Indeed, this type of window lifter must be installed via a large opening in the door, but certain doors may have small openings that limit access to the inside of the door. Additionally, the X-shaped crossing arrangement occupies a lot space inside the door, preventing other items of equipment being incorporated into the door.

U.S. Pat. No. 5,617,675 discloses a collapsible window lifter that is installed through openings that limit access to the inside of the door. This is achieved by incorporating a U-shape in the window lifter. The vertical arms of the slider-guiding U pivot at one of their ends on the base of the U. To introduce the window lifter through the opening, the vertical arms are folded down against the base of the U. Once the window lifter is in place, the vertical arms are unfolded inside the door and then secured thereto.

This window lifter nevertheless has the disadvantage of being highly complex and expensive to produce because of the pivoting arrangements. Unfolding the arms becomes increasingly complex as the opening in the door becomes narrower. Additionally, folding and unfolding the arms may degrade cable tension in the window lifter. Further, rigidity at the free end of the vertical arms is decreased, leading to the arms bending which is prejudicial to the securing of the window lifter. Also, when the door has a concave shape, the radius of curvature applied to the window lifter for matching the shape of the door prevents a complete folding of the window lifter; thus, introducing a window lifter into the door opening becomes more complex.

There is consequently a need for a window lifter that is less expensive to manufacture and that is flexible enough to be readily mounted on a vehicle door while still providing adequate protection for the cable.

SUMMARY OF THE INVENTION

The invention according to one embodiment is a window lifter comprising a first and a second parallel guide rail, a connecting arm rigidly connecting the said rails, the connecting arm being connected to the guide rails at a point along the rails between their ends, with cable returns defining a cable path along the said rails and said connecting arm.

According to one embodiment, the connecting arm extends at least in part outside a surface defined by the guide rails. Other embodiments incorporate details such as forming an angle of between 45° and 135° with respect to the connecting arm and one of the rails, and/or locating the connecting arm substantially at a half-way point along said rails.

According to one embodiment, the first and second guide rails carry a cable return at each of their ends and the connecting arm has a cable return at each one of its ends. One of the cable returns of the connecting arm may carry a motor and speed reduction gear.

According to one embodiment, the guide rails are of metal and the connecting arm is of plastic material. According to a further embodiment the guide rails each carry a projecting part extending towards the other rail, each of said projecting parts carrying a cable return directing the cable path along the connecting arm. The guide rails and the connecting arm may have supports for automobile fixtures.

The invention is also directed to a vehicle door having an inventive window lifter is also provided. According to one embodiment, the door includes a hollow section and openings for introducing the window lifter into the hollow section, the first and second rails extending inside the hollow section and the connecting arm being outside the hollow section.

In other embodiments of the vehicle door, the connecting arm supports a window lifter motor and speed reduction gear and/or the vehicle door includes automobile fixtures secured on the connecting arm

Further characteristics and advantages of the invention will become clearer from the following description of some embodiments of the invention provided by way of non- and limiting example, and with reference to the attached drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A window lifter according to one embodiment of the invention comprises two parallel guide rails which are rigidly connected by a connecting arm. Generally, the connecting arm is connected to the guide rails between their ends, along the rails. Cable returns define a cable path along the rails and arm. This window lifter is more rigid at the free ends of the guide rails since the connecting arm is connected remotely from the ends of the rails. Moreover, because the rigidity of the window lifter is simply provided by one single connecting arm extending from one guide rail to the other, the window lifter saves on material while simultaneously ensuring the cable is protected as it runs along the rails.

FIG. 1shows one embodiment of the window lifter of the invention. The window lifter10comprises a first guide rail12and a second guide rail14. The rails12,14respectively guide linear movement of sliders11aand11b. The sliders11aand11bare secured to a window glass (not shown) of the vehicle. Incorporating two guide rails allows movement of the window glass at two points, ensuring that the glass will not swing while it is moving. The guide rails are rigidly connected together by a connecting arm16.

The connecting arm16has two ends16aand16bthrough which the connecting arm16is joined to the guide rails12,14at a point between the ends of the rails12,14. Cable returns18,20,22,24,26,28define a cable path along the rails12,14and the arm16. A cable13drives the sliders11aand11bwhile being protected from deterioration as the cable13runs close to the rigid rails12,14and connecting arm16.

The guide rails12,14may be made of, for example, metal or plastic material. The guide rails12,14can be manufactured by pressing or by molding. The guide rails12,14are preferably mutually parallel so that the sliders11a,11bare driven in parallel directions to allow the window glass to move without encumbrance. The guide rails12,14include fixing lugs30a,30b,30c,30dfor securing the window lifter10onto the vehicle door. For driving sliders11a,11bvia the cable, the guide rails12and14have respective cable returns18,20and26,28at each end. The cable returns can be, for example, pulleys. Cable tensioners can be provided on the pulleys, spreading the pulleys apart to lengthen the cable path.

In one embodiment, the connecting arm16is made of a metal or plastic material formed by pressing or molding. It can either be a member that is secured onto the guide rails or be integrally constructed with the guide rails. In the latter case, the connecting arm16can be obtained by cutting a metal plate which is then pressed, or it can be obtained by molding a complete rail and arm assembly.

In one embodiment, the guide rails12,14are made of metal and connecting arm16is made of plastic material. This allows cost and weight savings in the assembly. In one embodiment, the guide rails12,14each have a projecting part extending towards the other rail, and each projecting part carries a cable return22,24directing the cable path along the connecting arm16. The advantage is that the stresses set tip by operation of the cable returns22,24are taken up by the guide rails12,14, The connecting arm16is then preferably secured between these two projecting parts and their associated cable returns22,24.

The connecting arm16rigidly connects the guide rails12,14, allowing the cable to be tensioned while the window lifter is being assembled. Cable tension is thus preserved during handling and transport of the window lifter. Additionally, the rigidity of the window lifter allows more ready assembly on the vehicle door. Indeed, the upper ends of the guide rails12,14are firstly secured to the door. The rigidity of the window lifter then allows the lower ends of the rails12,14to come in blind fashion to the designed securing position on the door.

The connecting arm16is connected to the guide rails12,14between their ends, along the rails. For example, for a rail which is 450 cm long, the connecting arm16can be connected to the guide rails12,14at a point at least 30 cm from the end of a guide rail12,14. Compared to a U-shaped window lifter, the advantage of the connecting arm according to the invention is that the rails12,14are kept rigid, particularly at the free ends of the rails. The guide rails12,14of the invention are therefore connected together at regions that are closer to the center of the rails rather than at the ends of the rails, as is the case in a U-shaped window lifter. By connecting the middle portions, and not the ends, of the guide rails12,14, the invention limits deflection at each of the free ends of guide rails12,14.

FIG. 2shows a window lifter according to another embodiment of the invention. This embodiment maximizes the rigidity in the window lifter. The amount of deflection at a point on the guide rail is proportional to the distance between this point and another point at which the guide rail and the connecting arm join. Thus, the smallest simultaneous deflection at the free ends12a,12b,14a,14bof the rails12,14is obtained when the connecting arm is substantially at half the length of the guide rails and substantially perpendicular to the guide rails12,14. In this embodiment, the window lifter generally has an H-shape.

In one embodiment, the connecting arm16and guide rails12,14can include supports for automobile fixtures. For example, the supports may be designed to carry a loudspeaker, door lock, armrest, or other fixtures. The rigidity of the window lifter provides support for the fixtures as well as forces occurring during use of the door. For example, when a passenger closes the door using the armrest, the window lifter can take up the forces resulting from the door closing. The window lifter can therefore help limit sagging of the door.

The inclination and position of fixing the connecting arm along the guide rails allows the window lifter to be adapted to securing automobile fixtures. The connecting arm offers numerous possible positions for fastening the fixtures, depending on the height and length of the door. Thus, the connecting arm can form an angle α between 45° and 135° with respect to one of the guide rails12,14. InFIG. 1, the connecting arm16makes an angle α of about 45° with respect to guide rail14. Thus, the connecting arm16passes through a central region of the door allowing, for example, the handle for closing the door to be secured to points32and34on the connecting arm16, along with the armrest in the region identified by reference numeral36(FIG. 1).

Another advantage of the connecting arm16is that it can be adapted as a function of door geometry to allow components of the door to be fitted. Currently known X-shaped window lifters cannot be adapted to door geometry.

The cable13returns18,20,22,24,26,28define a cable path along the rails12,14and the connecting arm16. The cable13follows the rigid rails12,14, and the connecting arm16, allowing it to be protected from deterioration. Further, the connecting arm16reduces the amount of material needed to protect the cable13, particularly when compared to an X-shaped window lifter.

In the embodiment shown inFIG. 1, the first rail12and the second rail14have a cable return18,20,26,28at each of their free ends allowing the cable to extend along the rails for driving the sliders11aand11b. The cable returns can be, for example, pulleys. The connecting arm16also has cable returns22,24, which allow the cable to be guided and protected along arm16.

FIG. 3is a section view of the window lifter ofFIG. 2taken along line A—A. The cable return22can be seen more clearly inFIG. 2. InFIG. 3, it can be seen that cable return22has two parts22aand22bto drive cable13twice, as can be seen inFIG. 2. InFIG. 3, the two parts22aand22bof the cable return22are rotatably mounted independently of each other so that the cable13is rotatably driven in two different directions. The cable return22is, for example, composed of two pulleys22aand22bsharing a common axis of rotation. The pulleys may also be arranged side by side with non-common axes of rotation. The cable return24has the same structure as cable return22.

FIG. 3shows a guide rail12having a curved shape to allow it to be adapted to a vehicle door having a curved profile. Of course, the other guide rail14(not shown inFIG. 3) will also have a curved shape to accommodate the profile of the door.

The cable13is driven by a motor having a speed reduction gear (not shown), which can be secured at any point along the cable path except on the path of the sliders. In one alternative embodiment, one of the cable returns22,24guiding the cable13along the connecting arm16carries the motor and speed reduction gear. As shown inFIG. 3, one of the cable returns22,24of the connecting arm16carries a motor and speed reduction gear. The speed reduction gear can take the place of the cable return part22band have a part22afixed thereon, using a common axis with the speed reduction gear. This reduces the number of cable returns in the system and allows the stresses on the motor and speed reduction gear and cable return part22ato be taken up on a common axis.

The window lifter can be secured inside a door having openings that limit access to the inside of the door. For this purpose, the connecting arm16is offset with respect to the guide rails12,14. InFIG. 3, the connecting arm16extends at least partially outside the surface defined by the guide rails12,14. The central portion16aof the connecting arm16(visible inFIG. 2) lies in a surface that is offset with respect to the surface defined by the guide rails. The central portion16asupports the cable returns22and24. The offset is, for example, provided by giving connecting arm16a U-shape, the central portion of the U being the portion16aof the connecting arm16. The connecting arm is for example obtained by pressing or molding. The connecting arm16then carries lugs16d, shown inFIG. 3, at both sides of the central portion16a, allowing the central portion16ato be joined to the guide rails12,14. In another embodiment, the central portion16ais joined to the cable rails12,14by bracing members16bto which, for example, central portion16ais welded.

FIG. 4shows a door23of the vehicle carrying the window lifter ofFIG. 2and exhibiting offset of the connecting arm16. The door shown inFIG. 4can incorporate a window lifter either with or without cable returns. To reinforce vehicle door rigidity, automobile manufacturers limit access to the inside of the door. The openings provided in the door allow equipment and fixtures to be introduced inside the door. InFIG. 4, the door23has a hollow section37and openings38,40that allow equipment and fixtures to be introduced into the door23. The openings38,40allow the window lifter10to be placed into the hollow section37. The openings38,40are separated by a support portion39ensuring rigidity of the door23. The hollow section37delimits a damp and dry region, one inside the hollow section and the other outside, towards the inside of the vehicle.

As shown inFIG. 4, the first guide rail12and second guide rail14are inside the hollow section37and the connecting arm16is the outside hollow section37. The window lifter10can be arranged in the door by, for example, first introducing the upper ends12aand14aof the guide rails12,14into the openings38,40. The ends12aand14aare then inserted more deeply into hollow section37toward the top of the door until the lower ends12b,14bof the guide rails12,14can be introduced via openings38,40into hollow section37. The connection between the connecting arm16and the guide rails12,14at a point between their ends allows such a maneuver.

The window lifter10is then lowered towards the bottom of the door and then secured in position by, for example, using the fixing lugs30aand30d(FIG. 1). Securing the window lifter may be conducted by, for example, first fixing the upper ends12a,14ato the door23. The rigidity of the window lifter10will allow the lower ends12b,14b, to move into position. Note that the order in which the ends of the window lifter10are introduced into the door23is not limited to the discussion above.

The shape of the connecting arm16outside the surface defined by the guide rails12,14allows the connecting arm to rest on the support portion39, outside the hollow section37, while the guide rails12,14remain inside the hollow section. Having the connecting arm16outside the hollow section37allows the motor and speed reduction gear to be arranged on the arm16and kept in the dry region of the door.

According to another embodiment, the support portion39of the door23has a concave shape, which is pushed in toward the inside of hollow section37. This allows the window lifter10to be arranged inside the hollow section37without any portion of the connecting arm16being disposed outside the surface defined by the guide rails. This facilitates manufacture of window lifter10. The invention also concerns the door23of the vehicle carrying the window lifter described.

Obviously, the present invention is not limited to the embodiments described above by way of example. For example, the embodiment where at least one part of the connecting arm16is disposed outside the surface defined by guide rails12and14is not limited to a window lifter10with an H-shape and the connecting arm inclined with respect to the guide rails; the offset can also be obtained with a window lifter10having generally a U-shape. Further, the invention is not limited to a door having two openings38,40as shown inFIG. 4; the door can, for example, have a longitudinal opening running in the direction of movement of the vehicle, or with a length slightly greater than the width of the window lifter. It can also be arranged to provide the window lifter described in the bodywork of a hatchback vehicle, at the height of the rear seat passengers.

It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby.