GB2048804A - Rear view mirror assembly - Google Patents

Abstract

A rear view mirror assembly has a head 10 mounted on a base member 54 by means of two arms 14 and 16. The arm 14 is coupled by a universal joint to a knob 68 and has a screw-threaded portion 32 which engages in a nut 30 on the mirror head 10. Thus rotation of the knob 68 moves the mirror head 10 about a vertical axis. The base member 54 is rotatably mounted on the shaft 48 and held stationary by friction pads 56. If the knob 68 is pressed to the left (as viewed in the drawing) it engages, via friction pads 72, with the end of a stem 44 on which the base member 54 is mounted. Further depression of the knob 68 disengages the friction pads 56 so that rotation of the knob 68 then causes rotation of the base member 54 to move the mirror head 10 about a horizontal axis. <IMAGE>

Description

SPECIFICATION Rear view mirror assembly This invention relates to a remotely adjustable rear view mirror assembly for a vehicle.

Our U.K. Application No. 48960/77 (Serial No.

1578950) is concerned with a rear view mirror assembly in which the mirror head is connected to a mounting bracket by first and second arms, rotary movement of the mounting bracket causing movement of the mirror about a first axis and sliding movement of one end of one of the arms relative to the corresponding end of the other arm, causing angular movement of the mirror head about a second axis perpendicular. To enable a control member inside a vehicle to initiate such sliding movement, it is necessary to cut an elongate slot in the side of the vehicle. The present invention is concerned with the provision of a rear view mirror assembly in which the mirror can be adjusted about mutually perpendicular axes without such sliding movement.

According to the present invention, a rear view mirror assembly comprises a head including a reflective member, a mounting bracket having a shaft projecting therethrough so as to be anguiarly moveable about a first axis, a base member pivotally mounted on said shaft, a first arm connected at one end to the base member and having its other end pivotally connected to the mirror head for angular movement about a second axis perpendicular to the first axis, a second arm coupled at one end to the shaft and at the other end to the mirror head, the second arm having a screw-threaded portion for engagement with a complementary screw-threaded element on the mirror head, whereby rotation of the second arm varies the distance between its point of attachment to the base member and its point of attachment to the mirror head, and control means operative in a first manner to cause angular movement of the shaft and second arm relative to the base member and operative in a second manner to cause angular movement of the base member relative to the mouriting bracket.

Preferably the control means comprises coupling means operative in a first state to permit angular movement of the shaft and the second arm while holding the base member stationary relative to the mounting bracket and operative in a second state to permit angular movement of the base member relative to the mounting bracket while inhibiting relative angular movement between the base member and the shaft.

In the accompanying drawings:- Figure 1 is a plan view, partly in section, of a rear view mirror assembly in accordance with the invention, and Figure 2 is a side sectional view taken on the line Il-Il in Figure 1.

Referring to the drawings, a rear view mirror assembly comprises a head 10, a mounting bracket 12, and arms 14, 16 and 1 8 fqr supporting the head 10 from the bracket 12. The bracket 12 is shown mounted on a structural member 20, for example a door panel, of a vehicle (not shown).

The mirror head 10 includes a casing 22 having a resilient bead 24 for supporting a reflective member or sheet of mirror glass 26. A U-shaped bracket 28 is secured to the inside of the casing 10 and attached to the arms 1 6 and 1 8. A nut 30 is pivotally mounted between the limbs of the bracket 28 for angular movement about an axis parallel to but spaced from the axis of pivotal attachment of the arms 1 6 and 1 8. The arm 20 has a screvv-threaded end portion 32 which engages in the nut 30.

The mounting bracket 12 includes a base portion 34 and a cylindrical portion 36 extending through the structural member 20 into the vehicle, with a locking ring 38 screwed onto its inner end.

The cylindrical portion 36 has a bore 40 extending therethrough, with a shoulder 42 formed at the outer end thereof. Rotatably located in the bore 40 is a coaxical shaft assembly comprising an outer shaft 44 and an inner shaft in the form of two shaft portions 46 and 48 coupled for simultaneous angular movement, by a telescopic coupling which allows relative axial movement.

The outer shaft 44 has, on its inner end, a shoulder 50 which engages with the surface of the bore 40, the outer end of the outer shaft being supported by the shoulder 42. A base member 54 is secured fast with the outer end of the outer shaft 44 and has the arms 1 6 and 1 8 attached thereto. A high-friction rubber washer 56 is located on guide pegs 58 between a face of the base member 54 and a confronting face of the base portion 34. A spring 60 engages between the shoulder 42, on the one hand, and, via a thrust washer 62 and steel balls 64, the shoulder 50 on the other. Thus the above-mentioned confronting faces are urged towards one another to engage with the washer 56, thereby to inhibit angular movement of the base member 54 relative to the base member 34.

The telescopic coupling between the two portions 46 and 48 of the inner shaft is of noncircular cross-section so as to constrain the two portions to rotate together. The free end of the portion 48 is coupled by a universal joint 66 to the arm 14 and is mounted within the outer shaft 44 by means (not shown) inhibiting relative axial movement. The portion 46 has a knob 68 mounted on its free end and is resiliently biased by a spring 70 so as to maximise the length of the inner telescopic shaft. A second high-friction rubber washer 72 is disposed between the knob 68 and the adjacent end of the outer shaft 44 but the spring 70 urges the knob 68 out of engagement therewith.

In use, mere rotation of the knob 68 causes corresponding rotation of the arm 14, thus screwing the threaded end 32 of the latter into or out of the nut 30. This causes angular movement of the mirror head 10 about a vertical axis, namely the axis of pivotal attachment of the arms 16 and 1 8 to the bracket 28.

In order to move the mirror head 10 about an axis perpendicular to the said vertical axis, the knob 68 is turned while being held depressed against the springs 60 and 70. Initial depression of the knob 68 brings it into frictional engagement, via the washer 72, with the outer shaft 44. Further depression of the knob 68 causes corresponding axial movement of the shaft 44 and, with it the base member 54 thereby disengaging the latter from the washer 56. Angular movement of the knob 68 now causes corresponding angular movement of the mirror head 10 about the axis of the shaft 44. Since the arm 14 and the nut 30 are subject to the same angular movement, this does not cause interference with adjustment of the mirror about the above-mentioned axis of pivoted attachment of the arms 16 and 18 to the bracket 28.

In order to provide a so-called "break-out'- facility, the arms 14, 16 and 18 are pivotally mounted on the base member 54 for anvular movement about an axis through the universal joint 66, as can be seen in Figure 2. The arms 16 and 1 8 are normally biased away from each other, by their inherent resilience, when fitted to the base bracket 54. This enables the head 10 to be held in a predetermined position by means of a detent or detents such as a pair of protrusions 74 (only one of which can be seen in Figure 2) on the base member 54. These protrusions may define a Vshaped, or U-shaped notch in which the arm 1 8 rests in its normally extended position. If the mirror head 10 is subjected to an impact, the arm 18 rides out of the notch thereby enabling the head to be folded backwards or forwards towards the side of the vehicle.

A bell-shaped elastomeric sleeve 76 houses the pivotal connection of arms 14, 1 6 and 1 8 and is fitted, at one end into a peripheral groove 78 in the base member 34. The other end of sleeve 76 is received in the casing of the mirror head 10. The sleeve 76 acts as a weather seal to prevent the entry of rain and dust to the assembly.

Claims (7)

1. A rear view mirror asembly comprising a head including a reflective member, a mounting bracket having a shaft projecting therethrough so as to be angularly moveable about a first axis, a base member pivotally mounted on said shaft, a first arm connected at one end to the base member and having its other end pivotally connected to the mirror head for angular movement about a second axis perpendicular to the first axis, a second arm coupled at one end to the shaft and at the other end to the mirror head, the second arm having a screw-threaded portion for engagement with a complementary screwthreaded element on the mirror head, whereby rotation of the second arm varies the distance between its point of attachment to the base member and its point of attachment to the mirror head, and control means operative in a first manner to cause angular movement of the shaft and second arm relative to the base member and operative in a second manner to cause angular movement of the base member relative to the mounting bracket.

2. A rear view mirror assembly according to claim 1, wherein the control means comprises coupling means operative in a first state to permit angular movement of the shaft and the second arm while holding the base member stationary relative to the mounting bracket and operative in a second state to permit angular movement of the base member relative to the mounting bracket while inhibiting relative angular movement between the base member and the shaft.

3. A rear view mirror assembly according to claim 2, wherein the coupling means includes a first clutch assembly arranged to couple the base member to the mounting bracket in the first state of the coupling means and a second clutch assembly arranged to couple the base member to the shaft in the second state of the coupling means.

4. A rear view mirror assembly according to claim 3, wherein the first clutch assembly is resiliently biased into its engaged position, the second clutch assembly is resiliently biased into its released position and the means for transmitting force to release the first clutch assembly includes the second clutch assembly so that, as the coupling means changes from one state to the other state, release of one of the clutch assemblies does not commence until after the other clutch assembly has engaged.

5. A rear view mirror assembly according to claim 2, 3 or 4, wherein the shaft comprises first and second co-axial shaft portions which are movable axially relative to one another but coupled for simultaneous angular movement about their axis, the second arm being connected to the free end of the first shaft portion and a manually operable control member being fitted to the free end of the second shaft portion, axial displacement of the second shaft portion relative to the first shaft portion being operative to change the coupling means between its first and second states.

6. A rear view mirror assembly according to any preceding claim, wherein the base member includes a hollow cylindrical stem extending therefrom on the opposite side from the first arm and co-axially surrounding the shaft, the control means being adapted to engage with the free end of the stem so as to impart angular movement thereto when operating in said second manner.

7. A rear view mirror assembly substantially as hereinbefore described with reference to the accompanying drawings.