Abstract:
A snap-in device for connecting a window pane with a window regulator by using at least one pair of elastically expanding jaws wherein one of the jaws has at least one snap-in element in the form of a hook or pin pointing in the direction of the window pane and is associated with a hole in the pane. An insert guide device serves to expand the jaws when inserting the window pane into the snap-in device. In the engaged state of the window pane, the circumference of the snap-in element fills out the hole in the pane at least over a part of the width of the snap-in element.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a device for connecting a window pane to a window regulator. 
     European Patent No. 0 208 237 B1 describes a support element for connecting the window pane to a corresponding guide device which has several support wings to be mounted on either side of the lower edge of the window pane. One of the support wings supports a pin associated with a hole in the window pane. When the window pane is inserted between the elastic support wings, they bend outwards until the pin has locked in the hole in the pane. 
     In order to be able to insert the window pane between the two support wings, the top side of the pin is inclined to guide the bottom edge of the window pane past the pin during assembly. The drawback here however is the large amount of play associated therewith between the pin and the hole in the pane due to the reduced contact area between the pin and the hole on the circumference. Thus with a reversal of the stress direction, that is, the direction of movement of the window pane, often so-called reversal noises will occur. Furthermore, in the event of higher loads, particularly in the case of jammed window pane, the pin is likely to disengage from the hole in the pane whereby the window regulator becomes unusable. 
     A further snap-fitting coupling device between a window pane and window regulator is described in German Patent No. DE 31 08 244 A1. It consists of two interconnected channel-like profiled sections of which one encloses an area of the lower edge of the pane and is fixed thereto. The other downwardly open profiled section supports at its ends inwardly directed hooks which can engage projections of angled elements of the lift mechanism whereby a keyed connection is achieved. During assembly, the connecting elements are forced to snap together through the force of the window pane against the upper stop position whereby at the an automatic alignment of the pane in the frame structure takes place simultaneously, at which time additional manual adjustments are not required. 
     However, since the profile-like coupling element must be prefitted on the lower edge of the pane, the window assembly has a thick structure which makes insertion of the window pane in the door shaft difficult. Owing to the necessary lack of seals in this area, damage to the paintwork often occurs during assembly. A further problem can be produced by the close tolerances required in the snap-in area of the coupling elements in order to avoid reversal noises during operation of the window regulator. 
     Another type of snap-in pane fixing is described in Japanese Patent No. 6-135228. The elements fixed on the lower edge of the window pane have at their free ends conical barb-shaped elements each associated with a U-shaped connecting element of the window regulator. The U-shaped connecting elements also have inclined guide inserts with which the conical areas of the elements fixed on the window pane can engage. When bringing together the connecting elements the arms of the U-shaped connecting elements are elastically spread out. At the end of assembly (in the snapped-in position), inwardly directed hooks provided at the free ends of the U-shaped connecting elements engage over the projections of the conical barb-shaped elements. However, there is the disadvantage that the part of the connecting element fixed on the window pane and which angles away from the edge of the pane theoretically shortens the lift stroke. 
     The known snap-in connections between a window pane and the entrainment member of a window regulator use snap-in elements which engage in a hole in the pane and whose upper boundary faces are designed inclined as insert guides on the lower edge of the pane. As a result of this, a seating with a lot of play is automatically produced between the snap-in element engaged in the hole in the pane and the contour of the hole. This leads to reversal noises when changing the force direction engaging on the entrainment member. Furthermore, in the event of increased load conditions which arise when the window pane jams in the entrainment member, the large amount of play can lead to release of the connection. 
     SUMMARY OF THE INVENTION 
     According to one embodiment of the invention, a snap-in device for connecting a window pane with a window regulator is provided which includes at least one pair of elastically expanding jaws connected to the window regulator, wherein at least one of the jaws has at least one inwardly directed snap-in element in the form of a hook or pin or the like engages a hole in the pane in an engaged state and has a circumference which substantially fills the hole in the pane at least over a part of its width. An insert guide device is provided to spread out the jaws during insertion of the window pane in the snap-in device. The faces of the expanding jaws facing the window pane are convex and in their base area form an expansion area with a width greater than the thickness of the pane in which the free lower end of the window pane can swivel. 
     According to another embodiment of the invention, a device for connecting a window pane with a window regulator which is characterised by a structurally simplified design, easy to manufacture and simple to assemble is provided. The window pane requires no additional parts prior to its insertion in the door shaft, at least not those which lead to a significant increase in the thickness of the window pane. Furthermore an extensively play-free seating in the connecting device is ensured for the window pane in the entrainment member of the window regulator without impeding the production of the snap-in connection. 
     Another embodiment of the invention is based on the knowledge that the snap-in element of the entrainment member has to fill up as completely and as play-free as possible the associated pane hole in the assembled state in order to ensure a fixed keyed connection between the snap-in element and the hole in the pane and thus between the entrainment member and the window pane. However, the snap-in connection must be constructed so that this assembled state is separated from the assembly in which guide-in aids facilitate assembly and prevent damage to the parts to be fitted without the need for extra parts or assembly aids on the window pane. 
     According to another embodiment of the invention, both entrainment jaws are convex relative to the window pane and offer a widened or expanded area to house the lower edge of the pane in the lower base area. Thus the window pane can be moved a certain angle in the entrainment member and compensate for any manufacturing or assembly tolerances which may occur. This simultaneously prevents the jaws from expanding and the danger connected therewith of the connection being released between the window pane and entrainment member. The snap-in element is thereby preferably mounted in the area of the shortest distance between the opposing jaws rather than in the expanded area at the base. 
     In one embodiment, a chamfer is provided on the lower edge of the pane at least in the fixing area and, in conjunction with a comparatively short inclined insert cone on the end of the snap-in element, serves to expand the jaws of the entrainment member and thus guide in the window pane for the purpose of assembly. The incline directions of the chamfer of the lower pane edge and of the insert cone are complementary. Depending on the type of chamfer of the lower window pane edge, the insert cone of the snap-in element can be more or less narrow but is at most half as wide as the thickness of the window pane. The remaining area of the snap-in element substantially fills the hole in the pane so that no noticeable play can occur. So-called reversing noises are thereby avoided. 
     According to the invention, different embodiments of the chamfer of the lower pane edge can be used. Apart from the conventional wedge-shaped polishing of the glass edge there are further possibilities. For example a separate wedge element can be attached to the lower edge of the pane. When using a compound window pane of glass and plastic panes, a chamfer is preferably formed on the plastic pane and has a lateral wedged projection and preferably engages the entire width of the somewhat recessed glass pane. Even the recessed arrangement of the two window panes alone, that is, without a flat wedge shape, is suitable in compound structure to provide an edged contour according to the invention for facilitating the connecting process between window pane and entrainment member. 
     In a further embodiment, a further hole can be provided in the pane near the first hole which is allocated for a separate snap-in element. This second hole in the pane is located at a greater distance from the lower edge of the pane compared with the first hole. At the top free end of the jaw of the entrainment member which supports the snap-in element, the separate snap-in element, in the form of an expanding element, extends in the direction of the window pane and has an inclined insert guide dropping down in the assembly direction. 
     During the assembly process, first the lower edge of the pane enters into engagement with the inclined insert guide of the expanding element and presses the two jaws of the entrainment member apart. The necessary assembly gap is thus formed without having to act on the snap-in element in the normal way. As a result of this, it is not necessary to provide an inclined insert guide or similar element on the top side of the snap-in element. As a rule, a short conical end area is sufficient for problem-free insertion of the snap-in element in the associated hole in the pane when these come to align with each other. An extending base area of the snap-in element of this kind not only increases the load capacity of the connecting device, but also extensively fills out the hollow cavity of the hole in the pane whereby a lower amount of play occurs at the connection between the structural elements. The reversing noises which otherwise occur when changing over the load direction, for example, window raising and window lowering, can thus be extensively avoided. 
     When the lower edge of the window pane has reached the base of the entrainment member at the completion of the assembly process, the snap-in element and the expanding element snap into the associated holes in the pane. 
     In another embodiment, the jaws have on their facing sides a convex contour so that the gap extending between the jaws either side of the snap-in element widens conically. Through this design a restricted swivelling of the window pane is possible without causing tension in the pane which could damage the entrainment member or lead to a release of the connecting device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be explained in further detail with reference to the embodiments shown in the drawings in which: 
     FIG. 1a shows a snap-in connecting device with a convex shaped clamping jaw as well as a compound window pane having a hole during the assembly, but prior to expanding the clamping jaws; 
     FIG. 1b shows the connecting device during the assembly, with a half-way expansion of the clamping jaws; 
     FIG. 1c shows the connecting device during assembly with a full expansion of the clamping jaws; 
     FIG. 1d shows the connecting device at the end of assembly; 
     FIG. 2 shows a snap-in connecting device according to the prior art with a jammed window pane; 
     FIG. 3 shows an entrainment member according to FIG. 1d, but with jammed window pane and free play of the lower end of the window pane and a free play of the upper end of the window pane; 
     FIG. 4 shows a lower edge of a window pane and a connecting device with an attached wedge; 
     FIG. 5 shows a compound window pane of a glass and a plastic pane with an integrated wedge; 
     FIG. 6 shows a compound window pane of a glass and a plastic pane with recessed, chamfered lower pane edges; 
     FIG. 7a shows another embodiment of the connecting device with an expanding element during assembly, but prior to expanding of the clamping jaws; 
     FIG. 7b shows the connecting device of FIG. 7a during assembly wherein the window pane engages the area of its lower edge with the expanding element; 
     FIG. 7c shows the connecting device of FIG. 7a during assembly wherein the window pane is in engagement with the snap-in element in the area of its lower edge; 
     FIG. 7d shows the connecting device of FIG. 7a at the end of assembly; 
     FIG. 8 shows the connecting device of FIG. 7a with a jammed window pane and free play of the lower end of the pane; 
     FIG. 9a shows a diagrammatic plan view of a window pane for use with a connecting device according to FIGS. 1a to 1d; 
     FIG. 9b shows a diagrammatic plan view of a window pane for use with a connecting device according to FIGS. 7a to 7d; and 
     FIG. 9c shows a diagrammatic illustration of a double-strand cable window regulator for use with the various embodiments of the invention. 
    
    
     DETAILED DESCRIPTION 
     FIGS. 1a to 1d show various phases of the assembly process of a compound window pane 1a on an entrainment member 3 wherein the window pane has a hole 10. The compound window pane 1a consists of a glass pane 11a and a glass pane 12a which are attached to each other, and their lower edges 110a, 120a are offset relative to each other. A wedge shape ledge is thereby produced which is formed as a chamfer in the sense of the invention. The entrainment member 3 consists of two opposing jaws 31, 32 which are connected together by a common base 33 and can be fixed by a fixing plate 34 on a window regulator. One of the elastically expanding jaws 32 supports a pin or bolt-like snap-in element 30 which is associated with the hole 10 in the pane 1a. The snap-in element has a substantially cylindrical shape 301 having a free end adjoined by a guide-in cone 302 having an inclined sleeve face 303. The path of the incline of the sleeve face 303 corresponds to the inclined direction of the stepped, wedge-shaped off-set lower edges 110a, 120a of the pane, that is, the chamfer of the compound window pane 1a. 
     The illustrated embodiment of the entrainment member 3 represents a preferred embodiment of the invention with an expanded area 35 provided in the area of the base 33 of the jaws 31, 32 formed by the convex inner contour of the jaws 31, 32. The expanded area 35 ensures a tension-free seating of the pane in the entrainment member which will be explained in more detail further on. 
     FIG. 1a shows the compound window pane 1a immediately before its assembly on the entrainment member 3. The thickness of the individual panes 11a, 12a corresponds substantially to the width B of the guide-in cone 302. In order to ensure a secure assembly, the width B of the inclined sleeve face 303 of the guide-in cone 302 corresponds at least to the thickness of the pane lla which first contacts the sleeve face 303 during assembly. In the present example only the edges of the end faces 110a, 120a of the individual panes 11a, 12a are ground so that roughly the thickness of the pane 11a approximates the required width B of the guide-in cone. 
     FIG. 1b shows the entrainment member 3 in a half-expanded position wherein the pane 11a has been pushed between the left jaw 31 and the end face of the snap-in element 30 and the lower edge 120a of the adjoining pane 12a is in contact with the sleeve face 303 of the guide-in cone 302. With further penetration of the compound window pane 1a in the entrainment member 3, the jaws 31, 32 spread out to a maximum (FIG. 1c). The assembly process is completed by the snap-in element 30 engaging in the hole 10 in the pane. As shown in FIG. 1d, the lower edge 110a of the pane 11a thereby stands on the base 33 of the entrainment member 3. 
     FIG. 2 shows a snap-in pane connection according to the prior art. It consists of two expanding jaws 31&#39;, 32&#39; which are connected by a common base 33&#39; and are connectable by means of a fixing plate 34&#39; to a window regulator. The snap-in element 30&#39; is molded in one piece on the jaw 31&#39; and is associated with the hole 10&#39; in the window pane 1b. The lower edge 110b of the pane is formed substantially flat and only its edges are ground. 
     The illustration of FIG. 2 shows a critical state of the connecting device with a jammed window pane 1b lying in the entrainment member 3&#39;. Such a state can occur for example in the case of extreme load conditions (e.g., a jammed window pane). This not only leads to high tensions in the connecting device, which can also lead to breakages, particularly in very low temperatures, but also to at least a partial loss of the positive engagement between the hole 10&#39; in the pane 1b and the snap-in element 30&#39;. There is thus a greater danger of the connection between the pane 1b and entrainment member 3&#39; becoming loose. 
     In another embodiment according to the invention, shown in FIG. 3, such negative tensions cannot occur. Since there exists a free expanded space both above and below the snap-in element 30, swivel movements of the window pane 1c about an apparent swivel point P in the area of the hole 10 may be carried out freely. Thus, there is no danger of the connection becoming loose. 
     FIG. 4 shows the combination of a conventional window pane with a substantially planar lower pane edge with an assembly aid 2 placed thereon. It consists of a wedge 21 with a chamfer, inclined insert guide 22, and a side web 20 for accommodating an adhesive connection with the window pane 1b. This assembly aid 2 is preferably designed as a plastic part. 
     FIG. 5 shows a compound window pane 1d, consisting of a plastic window pane 11d and a glass window pane 12d wherein the plastics pane 11d projects with a wedged lower end 110d over a lower pane edge 120d of the glass pane 12d. The inclined lower edge 110d of the pane completely covers the lower edge 120d of the pane with a wedge shape projection 111. A wedge tip 112 has a very small diameter so that the width B of the insert guide cone can be made very short. The cylindrical area 301 of the snap-in element may then be made longer, thereby improving the bearing load of the connecting device. 
     According to another embodiment, a compound window pane 1e shown in FIG. 6 consists of two glass panes 11e, 12e attached to each other with their respective lower edges 110e, 120e arranged off-set relative to each other. These lower pane edges are strongly rounded and have substantially the contour of a semicircle. Width B of the guide-in cone 302 of the snap-in element 30 requires a minimum width which corresponds to only half the thickness of a pane 11e, 12c. Thus a problem-free insertion of the window pane 1e into the gap between the jaws 31, 32 of an entrainment member according to the invention is guaranteed. 
     FIGS. 7a to 7d show various phases of the assembly process of a window pane 1 on the entrainment member 3 of a window regulator. The entrainment member 3 consists of two opposing jaws 31, 32 which are connected by a common base 33 and are fixed by a fixing plate 34 on a window regulator (not shown). On one of the two jaws 32 is formed the snap-in element 30 and a wedge-shaped expanding element 4 which lies in an internal spacing A2 above the snap-in element 30. A separate hole 10, 13 in the window pane 1 is associated with each of these inwardly projecting parts 30, 4. 
     FIG. 7a shows the first phase of the assembly process wherein the lower pane edge 100 contacts the inclined insert guide 40 of the expanding element 4. With further displacement of the window pane 1 in the direction of the entrainment member 3, the jaws 31, 32 spread out whereby at the same time the snap-in element 30 is lifted from the opposite jaw 31 and releases an insert gap (FIG. 7b). 
     Preferably, the length L of the expanding element 4 approximates the length of the snap-in element 30, or is even slightly longer. However, should the length L of the expanding element 4 be shorter than the length of the snap-in element 30, then a sufficiently large conical area 302 has to be selected so that the projecting lower pane edge 100 does not become blocked on the cylindrical area 301 of the snap-in element. 
     FIG. 7c shows an assembly phase wherein the lower pane edge 100 of the window pane 1 has already penetrated up to the end face of the snap-in element 30. To prevent the expanding element 4 from engaging hole 10 as it passes by the hole, the internal distance A2 between the expanding element 4 and the snap-in element 30 should be smaller than the distance A1 between the lower edge area of the hole 10 and the lower edge 100 of the pane. Otherwise a further penetration of the window pane 1 could be blocked by the snap-in element 30 as a result of the engaged expanding element 4. Alternatively, a comparatively large conical area 302 is provided on the snap-in element 30. In a further embodiment, the expanding element 4 and the snap-in element 30 are arranged laterally off-set from each other. Accordingly, the arrangement of the holes 10 and 13 in the pane must also be offset in an analogous arrangement. 
     FIG. 7d shows the connecting device at the end of the assembly process with the snap-in element 30 and expanding element 4 engaged in the respective associated hole 10, 13 of the pane. 
     Another embodiment of the invention provides the use of convex expanding jaws 31, 32 wherein on either side of the snap-in element 30, an expanded area 35 is formed in the assembly direction for the window pane 1. In the event of the action of lateral forces on the window pane 1 (shown in FIG. 8) and which lead to tilting in the entrainment member 3, no tensions occur which could lead to breakage or release of the connecting device. The window pane 1 can swivel in the entrainment member 3 in a comparatively large angular area wherein the expansion area 35 is provided for the freedom of movement for the lower pane edge 100 in the area of the base 33 of the entrainment member 3. 
     The connecting devices according to the invention can be used with particular advantage in cable window regulators as shown in FIGS. 9a to 9c through diagrammatic views of two window panes for use with a double-strand cable window regulator. 
     FIG. 9a shows a window pane 1 with recesses 92 provided in the fixing areas 90 wherein the recesses are defined by lateral conical guide faces 91 for engaging the entrainment member 3. The holes 10 in the pane contact the cylindrical area 301 of the pin or bolt like snap-in element 30 in the assembled state. This window pane is particularly suitable for the embodiment of the snap-in device shown in FIGS. 1a to 1d. 
     FIG. 9b shows a window pane 1 having fixing areas including holes 10 and 13 for holding the snap-in elements 30 and wedge shaped expanding element 4, respectively. This window pane is particularly suitable for the embodiment of the snap-in device shown in FIGS. 7a to 7d. 
     The window regulator shown in FIG. 9c consists of two parallel guide rails 8 on each of which an entrainment member 3 is displaceably mounted and is connected through nipples of the cable 5 in a nipple chambers 50 to a drive unit 7 consisting of a cable drum 71 and a motor 72. Cable rollers 6 serve to guide the cable 5 between the guide rails 8 and the drive unit 7.