Patent Publication Number: US-5838507-A

Title: Mirror assembly with friction drive

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to rearview mirror assemblies and more particularly to rearview mirror assemblies of the type adapted to be mounted on an exterior side of a motor vehicle so as to be viewed by a driver within the vehicle. 
     2. Description of the Related Art 
     The specific example of a vehicle mirror assembly to which the present invention relates is disclosed in U.S. Pat. No. 5,467,230, which issued Nov. 14, 1995, for a Dual Pivoted Member Mount for Mirror. The mirror assembly disclosed in the &#39;230 patent has been demonstrated to function very well as a vehicle mirror assembly. However, there is an ever present need in the automotive parts supply business to be more cost-effective. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a vehicle mirror assembly of the type disclosed in the &#39;230 patent which is more cost-effective. In accordance with the principles of the present invention, this objective is obtained by providing a rearview mirror assembly which comprises a mirror unit, a mirror unit support, a central connection between the mirror unit and the support mounting the mirror unit on the support for pivotal movement about first and second generally intersecting perpendicular axes. A first arm is mounted on the support for pivotal movement between limits with respect to the support about the first axis and connected with the mirror unit to enable limited pivotal movement of the mirror unit with respect to the first arm about the second axis at a position spaced from the first axis. A second arm is mounted on the support for pivotal movement between limits with respect to the support about the second axis and connected with the mirror unit to enable compound movement of the mirror unit with respect to the first arm at a position spaced from the second axis which compound movement includes limited lateral movement with respect to the first axis and pivotal movement about an axis which is either coincident with or slightly angularly related with the first axis depending upon the position of relative lateral movement. A remotely controlled power-operated mechanism is carried in part by the support for effecting a desired movement of the mirror unit together with a corresponding movement of either one or both of the first and second arms with respect to the support in response to a remote manual movement by a user. The remote controlled power-operated mechanism includes first and second power-transmitting surfaces on the first and second arms respectively arcuate about the first and second axis respectively and first and second power-operated rotary members having circular peripheries engaged respectively with the first and second power-transmitting surfaces. The first and second power-operated rotary members are constructed and arranged with respect to first and second power-transmitting surfaces respectively (1) to move under power in peripheral rolling contact therewith to effect movement of the first and second arms respectively and (2) to move under power in peripheral sliding relation therewith in the event that movement of the first and second arms respectively is otherwise prevented. 
     Another object of the present invention is the provision of a rearview mirror assembly of the type described which is simple in construction, effective in operation, and economical to manufacture. 
     These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims. 
     The invention may best be understood with reference to the accompanying drawings wherein an illustrative embodiment is shown. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevational view looking forward at the rear of a mirror assembly embodying the principles of the present invention, with parts broken away for purposes of clear illustration; 
     FIG. 2 is an enlarged sectional view taken along the line 2--2 of FIG. 1; 
     FIG. 3 is a enlarged sectional view taken along the line 3--3 of FIG. 1; 
     FIG. 4 is an enlarged sectional view taken along the line 4--4 of FIG. 1; 
     FIG. 5 is an enlarged sectional view taken along the line 5--5 of FIG. 1; 
     FIG. 6 is a schematic view of a potentiometer circuit of the memory system; and 
     FIG. 7 is a view similar to FIG. 3 showing the modifications of a modified form of mirror assembly embodying the principles of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now more particularly to the drawings, there is shown in FIGS. 1-5 thereof a rearview mirror assembly, generally indicated at 10, which embodies the principles of the present invention. The rearview mirror assembly 10 includes a mirror unit, generally indicated at 12, and a mirror unit support, generally indicated at 14. The support 14 is in the form of a casing assembly which, in turn, is mounted on a shell-like support member 16 which is suitably fixed to the side of a motor vehicle (not shown) as, for example, to the forward central portion of a front door thereof. The support member 16 can be of any conventional construction and need not be a fixed support but could be a spring-biased foldaway support assembly of any well-known construction. 
     The present invention is more particularly concerned with the manner in which the mirror unit 12 is mounted on and moved with respect to the mirror unit support 14 rather than with the configuration and construction of the support member 16 and its connection with the mirror unit support 14, all of which may be conventional. The mirror unit 12 has a mirror side which is defined by a mirror 18 and an opposite side which is defined by a mirror holder 20 within which the mirror 18 is mounted in fixed relation. In the preferred embodiment of the rearview mirror assembly 10, shown in FIGS. 1-6, the casing assembly support 14 is preferably formed of first and second cooperating housing parts 22 and 24. The second housing part 24 is disposed in facing relation with the opposite side of the mirror unit 12 and the first housing part 22 cooperates with the second housing part 24 to define a housing space therein. 
     A central connection formed by two connecting structures 26 and 28 is disposed between the opposite side of the mirror unit 12 and the support 14. As shown, the connecting structure 26 forms an integral part of the second housing part 24 whereas the connecting structure 28 forms an integral part of the mirror holder 20. It will be understood, however, that the two connecting structures 26 and 28 can be reversed if desired. The connecting structures 26 and 28 are of the snap-in type and are adapted to establish a pivotal interconnection between the support 14 and the mirror unit 12 which provides for pivotal movement about first and second generally intersecting perpendicular axes. The connecting structures 26 and 28 may be of any configuration suitable to establish the aforesaid pivotal movements of the mirror unit 12 with respect to the support 14. However, as shown, they are preferably constructed in the manner of U.S. Pat. No. 4,915,493, the disclosure of which is hereby incorporated by reference into the present specification. 
     As shown, the integral connecting structure 26 on the support 14 includes a projecting base portion 30 having an enlarged portion 32 on a projecting end of the base portion 30. The enlarged portion 32 has a first convex connecting surface 34 which is disposed within a first spherical plane having a first pair of truncations one of which is defined by an intersection with the base portion 30. In the embodiment shown, the surface 34 is a dual truncated spherical surface extending throughout the first dual truncated spherical plane. It will be understood that portions of the surface 34 within the plane may be omitted. 
     The enlarged portion 32 also has a first concave connecting surface 36 facing away from the base portion 30 which is disposed within a first spherical segmental plane having (1) a center coincident with the center of the first truncated spherical plane and (2) a radius smaller than the radius of the first truncated spherical plane. As before, surface 36 is a segmental spherical surface extending throughout the plane. Portions may be omitted however. An annular wall surface 38 which preferably is conical extends from the spherical segmental surface 36 to the truncated spherical surface 34 in outwardly diverging relation. 
     The integral connecting structure 28 on the mirror holder 20 comprises a projecting annular wall 40 having a second concave connecting surface 42 disposed within a second spherical plane having (1) a radius generally equal to the radius of the first spherical plane and (2) a second pair of parallel truncations. Surface 42 as shown is a dual truncated spherical surface extending throughout the second dual truncated spherical plane although portions thereof may be omitted. 
     The integral connecting structure 28 also includes a projecting central portion 44 within the annular wall 40 which is in the form of a cone having its apex formed with a second convex connecting surface 46 facing in the direction of the projection oft he annular wall disposed within a second spherical segmental plane having (1) a center coincident with the center of the second truncated spherical plane and (2) a radius equal to the radius of the first spherical plane segmental plane. Surface 46, as shown, is a spherical segmental surface extending throughout the second spherical segmental plane although portions thereof may be omitted. 
     It will be noted that both the first and second housing part 22 and 24 of the casing assembly support 14 are molded of plastic material and that similarly the mirror holder 20 is molded of plastic material as well. The nature of the plastic material utilized, as, for example, Delrin® or the like, and the construction of the annular wall 40 is such that the annular wall is operable in response to the movement of the enlarged portion 32 therein to resiliently yield and resiliently return to bring the first convex connecting surface 34 of the enlarged portion 32 into engagement with the second concave connecting surface 42 of the annular wall 40 so as to retain the first and second integral connecting structures 26 and 28 against movement in a direction away from one another and the first concave connecting surface 36 of the enlarged portion 32 into engagement with the second concave connecting surface 46 of the projecting central portion 44 so as to limit the movements of the first and second connecting structures 26 and 28 in a direction toward one another. The engagement of the connecting surfaces permits relative sliding movement therebetween so as to retain the members in cooperating relation in a multiplicity of different positions of pivotal movement of the mirror holding member with respect to the support member along the aforesaid two intersecting perpendicular axes. It will be noted that such pivotal movements are limited by the extent of the truncated surfaces 34 and 42 and that the differences in the angles of divergence of the conical surface of the portion 46 with respect to the conical surface 38 of the portion 32 accommodate such movements. 
     In addition to the central connection 26-28, the mirror unit 12 is mounted on the mirror unit support 14 by first and second mounting members 48 and 50 mounted on the support for pivotal movement between limits with respect to the support 14 about the first and second generally intersecting perpendicular axes respectively provided by the central connection 26-28. The first mounting member 48 includes a first pair of spaced arms 52 and 54 which extend from the support 14 toward the mirror unit 12 and are connected on the opposite side of the mirror unit at positions spaced in opposite directions from the first axis for limited pivotal movement with respect to the mirror unit 10 about the second axis. The second member 50 includes a second pair of arms 56 and 58 extending from the support 14 toward the mirror unit 12 and connected with the opposite side of the mirror unit 12 for compound movement with respect thereto at positions spaced in opposite directions from the second axis. The compound movement includes limited lateral movement with respect to the first axis and pivotal movement about an axis which is either coincident with or slightly angularly related with the first axis depending upon the position of relative lateral movement. 
     Referring now more particularly to FIGS. 1 and 2, the first mounting member 48 includes a central portion 60 between the first pair of arms 52 and 54 which has a pair of arcuate flanges 62 extending from opposite sides thereof. The first pair of flanges 62 are arcuate about the first axis. The first housing part 22 has a first arcuately spaced pair of first parallel rail sections 64 fixed therein within the aforesaid interior space having first arcuate concave surfaces 66 on the free edges thereof slidably engaging convex surfaces of the first pair of arcuate flanges 62. The second housing part 24 has a first arcuately spaced pair of second parallel rail sections 68 fixed therein within the interior housing space having first radially spaced arcuate convex surfaces 70 on the free edges thereof slidably engaging concave surfaces of the first arcuate flanges 62 respectively. It can be seen that, when the first and second housing parts 22 and 24 are moved into engagement so that the aforesaid arcuate surfaces 66 and 70 of the parallel rail sections 64 and 68 engage the arcuate flanges 62 and the two housing parts are secured in cooperating relation as by threaded fasteners or the like, the engagement of the arcuate surfaces 66 and 70 on opposite sides of the arcuate flanges 62 will serve to mount the first member 48 within the interior housing space provided by the first and second housing parts for pivotal movement between the limits with respect to the support 14 about the first axis. 
     Referring now more particularly to FIGS. 1 and 3, it can be seen that the second mounting member 50 includes a central portion 72 between the second pair of arms 58 and 60 thereof which has a pair of arcuate flanges 74 extending outwardly therefrom. The flanges 74 are arcuate about the second axis. As before, the first housing part 22 includes a second arcuately spaced pair of first parallel rail sections 76 fixed therein within the interior space which have second arcuate concave surfaces 78 on the free edges thereof, spaced radially from the first concave surfaces 66, which slidably engage the convex surfaces of the second pair of arcuate flanges 74. Also, as before, the second housing part 24 includes a second arcuately spaced pair of second parallel rail sections 80 therein within the interior housing space and having convex surfaces 82 on the free edges thereof, spaced radially from the first convex surfaces 70, which slidably engage the concave surfaces of the second arcuate flanges 74. In this way, the second mounting member 50 is pivotally mounted within the housing space between the two housing parts 22 and 24 when they are moved together and fixed in cooperating relation with one another. The mounting enables the second member 50 to pivot within limits with respect to the support 14 about the second axis. It will be noted that the second housing part 24 includes openings through which the first and second pairs of arms 52-58 are enabled to extend from the support 14 toward the mirror unit 12. 
     It will be noted that all of the arms 52-58 are of uniform cross-sectional configuration except for their free ends which are used to connect the arms to the mirror unit 12. The openings closely surround the arms with a minimum clearance space which is substantially constant throughout the movement of the arms. The free ends of the arms are of a size to pass through the openings. It is preferable to apply a small amount of grease around each opening which serves as an effective seal to prevent dirt entrained in air from being moved into the interior space between the housing parts 22 and 24. 
     The connection between the ends of the first pair of arms 52 and 54 and the mirror unit 12 is also preferably a snap-action type connection and, as shown, there is formed on the end of each of the first pair of arms 52 and 54 a first cylindrical connecting element 84 having an axis which is aligned with the second axis. The mirror holder 20 is formed with surfaces 86 which rotatably receive an outer peripheral portion of each first cylindrical connecting element 84 and a pair of cantilevered arcuate walls 88 for rotatably engaging on opposite sides of an inner peripheral portion of each first cylindrical connecting element 84. The flexure of the cantilever mount of the walls 88 allows the elements 84 to be snapped into engagement with the surfaces 86 and the engaging surfaces of the walls 88. In this way, the first cylindrical connecting elements 84 are captured so that they can only be moved pivotally in opposite directions between limits relative to the mirror holder 20 about the second axis. 
     The connection between the second pair of arms 56 and 58 and the mirror unit 12 includes a second cylindrical connecting element 90 on the outer end of each of the second pair of arms 56 and 58. The mirror holder 20 is formed with surfaces 92 which slidably receives an outer peripheral portion of each second cylindrical connecting element 90 for limited lateral movement and a pair of flexible cantilevered walls 94, one of which is L-shaped, for engaging opposite ends of an inner peripheral portion of each second cylindrical connecting element 90. As shown, the outer end of each second cylindrical connecting element 90 may be formed into a conical shape. A similar conical end shape can be provided on each first cylindrical connecting element 84. Here, again, the cantilever mount of the L-shaped walls 94 allow the elements 90 to be mapped into engagement with the surfaces 92 and the engaging surfaces of the walls 94. In this way, the second cylindrical connecting elements 90 are captured so that they are capable of a compound movement with respect to the mirror holder 20. The compound movement includes lateral sliding movement along the engaging surfaces 92 with respect to the mirror holder 20 and a limited pivoted movement about an axis which is either coincident with or slightly angularly related with the first axis. 
     In accordance with the principles of the present invention, it is preferable to provide a remotely controlled power-operated assembly, generally indicated at 96, for effecting the pivotal movement of each of the first and second mounting members 48 and 50 respectively. Each power-operated assembly 96 includes a reversible electric motor 98 carried within the housing space between the housing parts 22 and 24 in an appropriate position with respect to the associated mounting member. Each electric motor 98 is connected as by a yieldable gear train with the associated mounting member. 
     Referring now more particularly to FIGS. 1, 4 and 5, each yieldable gear train includes a worm 100 fixed to the output shaft of the electric motor 98. Worm 100 is disposed in meshing engagement with a worm pinion 102 suitably journalled on a shaft 104 extending between the housing parts 22 and 24 as best shown in FIG. 5. Fixed to rotate with the worm pinion 102 is a spiral gear 106 which is disposed in meshing relation with a toothed wheel 108. The toothed wheel 108 is preferably molded of a suitable plastic material integrally with a shaft 110. The ends of the shaft are suitably rotatably mounted between the housing parts 22 and 24 as best shown in FIG. 4. Mounted on the shaft 110 in side-by-side relation to the toothed wheel 108 is a rotary member 112. Each rotary member 112 constitutes a cylinder of a plastic material or of rubber. A preferred material is polyurethane. As can be appreciated from the Figures, the rotary members 112 have substantially smooth peripheral surfaces. Each rotary member 112 is suitably fixed on the shaft 110 and has a circular exterior periphery. The rotary member 112 of the power-operated assembly 96 associated with the first mounting member 48 is disposed in engagement with a power-transmitting surface 120 arcuate about the first axis formed along the outer edge of the arm 52. As can also be appreciated from the Figures, the power transmitting surfaces 120 are also substantially smooth. Likewise, the rotary member 112 of the power-operated assembly 96 associated with the second mounting member 50 is disposed in engagement with a power-transmitting surface 122 arcuate about the second axis formed along the outer edge of the arm 56 of the second mounting member 50. 
     It will be understood that the electric motors 98 are under the control of a control lever (not shown) which is mounted in a position of access to the driver so that a remote manual movement of the control lever will serve to energize one or both of the electric motors in the desired direction to movement the mirror unit 12 with respect to the mirror unit support 14 into a desired operating position to be viewed by the driver through the associated door window. The control lever is such that the direction of movement of the control lever determines the direction of movement of the motor or motors which are energized. When each electric motor 98 is energized, the associated worm 100 is turned which, in turn, will rotate the associated worm pinion 102 about the axis of its shaft 104. The associated spiral gear 106 turns with the worm pinion 102 in the same direction and the meshing engagement of the spiral gear 106 with the associated toothed wheel 108 will cause a corresponding rotational movement of the toothed wheel 108 and shaft 110 about the axis of the shaft 110. The rotation of the shaft 110 carries with it the rotary member 112 fixed thereon. The rotation of the rotary member 112 in engaging relation with the power-transmitting surfaces 120 or 122 on the associated arm 52 or 56 of the associated mounting member 48 or 50 will effect a corresponding pivotal movement of the associated mounting member about its pivotal axis with respect to the support 14. In the event that the mirror unit is moved under power into a limiting position, continued energization of the motor will result in the associated rotary member 112 turning with its periphery sliding with respect to the associated power-transmitting surface 120 or 122. 
     In the case where the second mounting member 50 is moved, the connections of the pair of arms 52 and 54 of the first member 48 with the rear holder 20 serve to restrict the pivotal movement of the mirror unit 12 about the second axis. It is noted that the spacing of the connecting elements 84 in opposite directions from the first axis is sufficient to prevent movement about the first axis and a third axis intersecting the first and second axes. In the case where the first mounting member 48 is moved, the connections of the pair of arms 56 and 58 of the second member 50 restrict the movement of the mirror unit about the first axis but the compound movement allowed by the connecting elements 90 permit the first axis to shift laterally at each connection to accommodate diagonal tilting when present. The central connection assures that the first axis will extend through the pivot point provided between the connecting structures 26 and 28. The spacing of the connecting elements 90 in opposite directions from the second axis is sufficient to prevent movement about the aforesaid third axis. 
     As previously indicated, the pivotal mounting of the mounting members 48 and 50 with respect to the support 14 is such as to render the present subject matter easily susceptible to having a memory function applied thereto. Moreover, the memory function can be provided by a position-sensing arrangement operatively connected between the support 14 and each of the mounting members 48 and 50 to determine the pivotal position of each of the mounting members. While any suitable means may be provided, a preferred sensing means is in the form of a potentiometer similar to the potentiometer disclosed in U.S. Pat. No. 4,678,295, the disclosure of which is hereby incorporated by reference into the present specification. As best shown in FIG. 1, the housing part 22 is provided with first and second pairs of guides 124 which receive first and second circuit boards 126. As best shown in FIG. 6, mounted on each circuit board 126 is a pair of arcuate electric resistance elements 128 and 130. A brush 132 is operatively associated with each pair of arcuate resistance elements 128 and 130. Each brush 132 has two slides connected by a cross piece. The cross piece of one brush 132 is mounted in the arm 54 of the first mounting member 48 so that the spaced slides extend therefrom into sliding engagement with the arcuate resistance elements 128-130 of circuit board 126 mounted in the associated pair of guides 124. A second brush 132 is similarly mounted in arm 58 of the second mounting member 50 to extend therefrom in sliding engagement with the arcuate resistance elements 182-130 of the associated circuit board 126. 
     As best shown in FIG. 6, the conductive resistance element 128 of each circuit board 126 is connected to a voltage source 134 such as the vehicle battery. As each mounting member is pivoted, the brush 130 carried thereby moves along both arcuate conducting surfaces of the associated elements 128-130. This movement creates a variable electrical resistance on element 128 which generates an electrical signal proportionally responsive to the position of the mirror unit 12. This signal is carried by the brush 132 to where it is received by the conductive element 130. A wire 136 attached to conductive element 130 carries a signal to a microprocessor 138. 
     In operation, the vehicle operator adjusts the mirror unit 12 to a desired position by using the manual switches 140 to actuate the associated motor 98. The adjustment of the mirror unit 12 generates an electrical signal across the linear arcuate potentiometer which is then received by the microprocessor 138. Once the desired adjustment is obtained, the operator pushes a set button 142, whereupon the microprocessor 138 records the signal received. 
     If the position of the mirror unit 12 is thereafter changed, all the vehicle operator has to do to return the mirror unit to the original position selected is to press the actuator button 144. The microprocessor 138 then starts the associated motor 96 of the associated power-operated assembly 96 which pivots the associated mounting member 48 or 50 to reposition the mirror unit 12. The motor or motors 96 continue to run as the linear potentiometers sense the signal changes across elements 128. The signal changes are continually received by the microprocessor 138 through element 130 and wire 136. The microprocessor 138 compares the received signals with the recorded signal. When the linear potentiometers reach the position having the identical signal as the recorded signal, the microprocessor 138 immediately stops the associated motor 96. The mirror unit is now readjusted to the desired pre-set position. 
     It will be understood, in accordance with the principles of the present invention, that, while the potentiometer is mounted with respect to the arm of each mounting member which does not have the arcuate power-transmitting surface 120 or 122 thereon that it would be nevertheless within the contemplation of the present invention to provide the potentiometer on the same arm. Moreover, it is possible in accordance with the principles of the present invention to eliminate one of the arms of each of the mounting members so that there is only a single connection of a single arm to the mirror holder for each member. The spacing of the single arms is sufficient to restrict the pivotal movements of the mirror unit in the manner previously indicated. The provision of a pair of arms is preferred because of the greater stability provided thereby. 
     Referring now more particularly to FIG. 7, there is shown therein modifications to the rearview mirror assembly 10 which are clearly contemplated by the present invention. Specifically, in this embodiment, wherein the same reference numerals are utilized to designate the same parts as previously recited, the elements of the connecting structures 26 and 28 forming the center connection are eliminated. This can be done by eliminating either one or both of the connecting structures, as shown. The connections of the first pair of arms 52 and 54 of the first mounting member 48 to the mirror unit 12 are the same, but the connections of the second pair of arms 56 and 58 of the second mounting member 50 are modified from the connections, such as shown in FIG. 3, to connections similar to that made for the arms 52 and 54. Thus, the mirror holder 20 includes surfaces 146 similar to the surfaces 86 and flexible walls 148 similar to the flexible walls 88. In this way, the second mounting member 50 is connected with the mirror unit 12 for pivotal connection only about the first axis. With the connections as shown in FIG. 7, the adjusting movement of the mirror unit 12 will take place in the same way as previously described except that the tilting movement in the diagonal direction is accommodated by the omission of the center connection so that, when a diagonal tilting movement is involved, as, for example, a tilting movement in both directions, the lack of a center connection will accommodate the diagonal tilting movement so that the mirror unit 12 does not at all times pivot about a single point as is the case with the first embodiment which includes a center connection with the diagonal tilting being accommodated by the compound movement afforded by the connecting elements 90. 
     The provision of cylindrical connecting elements 84 and 90 is preferred because of ease of molding. However, it will be understood that spherical connecting elements could be utilized in conjunction with corresponding shaped surfaces and walls. 
     It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing preferred specific embodiment has been shown and described for the purpose of this invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.