Rotary-to-linear converter mechanism for a remotely controlled rearview mirror tilting device or the like

• US 4,494,420 A
• Filed: 02/01/1982
• Issued: 01/22/1985
• Est. Priority Date: 05/08/1981
• Status: Expired due to Term

• Current Assignee: Koito Seisakusho Company Limited
• Original Assignee: Koito Seisakusho Company Limited
• Inventors: Sakuma, Toranosuke
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Gonet, Michael J.
• Application Number:
  US06/344,477
• Time in Patent Office: 1,086 Days
• Field of Search: 74/89.15, 74/479, 74/424.8 R, 350/289, 248/487, 248/184, 248/185, 248/371
• US Class Current: 74/490.1
• CPC Class Codes: B60R 1/072 for adjusting the mirror relative to its housing
• CPC Class Codes: Y10T 74/2036 Pair of power elements

Abstract

A remotely controlled rearview mirror tilting device comprises two identical mechanisms, mounted within a housing, for converting the bidirectional rotation of motor-driven worms into rectilinear reciprocation of plungers in order to tilt a mirror holder relative to the housing about two orthogonal axes. Each rotary-to-linear converter mechanism comprises a hollow rotor integral with a worm wheel in mesh with one of the worms. The hollow rotor has an open end rotatably fitted in an opening in the housing and thereby restrained from axial displacement in one direction. For improved rainproofness and reduced frictional resistance the other end of the hollow rotor is closed and makes point contact with the housing via conical boss on either of the rotor and the housing. One of the plungers is mounted in the hollow rotor for simultaneous rotation therewith and for sliding motion in its axial direction. Projecting out of the open end of the rotor, one end of the plunger is coupled to the mirror holder via a ball-and-socket joint. The plunger is screw threaded and slidably engaged by a wire spring anchored to the housing, so that the bidirectional rotation of the rotor results in the rectilinear reciprocation of the plunger. An alternative embodiment is disclosed.

Claims

1. In a rearview mirror tilting device having a mirror holder (52) and a housing (50), said housing having housing open front and rear parts (62, 64), said housing being adapted and designed for accommodating motors and converter mechanisms, with a ball-and-socket joint (54) serving as the pivotal connection between the housing and the mirror holder, said ball-and-socket joint (54) including a ball (66) affixed approximately centrally on the mirror holder (52) and projecting rearward therefrom, a socket (68) to mate with the ball of said ball-and-socket joint, disposed in a corresponding position on the housing front part (62) so as to provide pivotal motion to the mirror holder (52) relative to the housing (50), in combination:

(a) first and second bidirectional motors (56, 56'"'"') within the housing (50), with output shafts, worms (76, 76'"'"') connected to said output shafts, meshing with worm wheels (78, 78'"'"'), and first and second converter mechanisms (60, 60'"'"') so arranged and disposed as to have the bidirectional rotation of the worms transformed into rectilinear reciprocation by the converter mechanisms, hollow rotor means (80) with front and rear parts, said front part being open, said hollow rotor means being formed integral with said worm wheels (78, 78'"'"'), said worm wheels being approximately midway between the opposite axial ends of said hollow rotors means (80), a wall rear part disposed at the hollow rotor means rear part perpendicular to its axis of rotation; and

,

(b) a boss (88) disposed between the hollow rotor means rear part and the housing rear part (64) said boss extending between said wall rear part and said housing rear part (64) being affixed to one of said rear parts and having a pointed tip in contact with the other of said rear parts, so that the closed end of the hollow rotor means (80) make rotatable point contact and is restrained from axial displacement in the rearward direction, said wall rear part (84) serving to waterproof the tilting device and makes frictionless contact between the hollow rotor means (80) and the pointed tip of the boss (88).

2. In a device as claimed in claim 1, including, one or more recesses (70) in the socket (88), arms (72) projecting radially outwardly from the ball (66) serving to connect the ball to the mirror holder (52), said arms (72) preventing rotation of the mirror holder about the ball-and-socket joint (54) without interfering with its tilting motion.

3. In a device as claimed in claim 2, including a front side to said worm wheels, a step (82) formed in said front side, the outer surface (83) of the hollow rotor means (80) between its front part and the step (82) being of cylindrical shape, a circular opening (86) in the front part (62) of said housing, receiving the front part of the hollow rotor means (80), with an edge on said front part (62) of said housing, in contact with the step (82) so that the hollow rotor means (80) is restrained from axial displacement in the forward direction.

4. In a device as claimed in claim 3, including, a reciprocator plunger (90) at least partly screw threaded, said plunger (90) having a front and rear end, the front end being pivotally coupled to said mirror holder (52) via said ball-and-socket joint, slider flanges (94) of square or polygonal shape spaced from each other in the axial direction of the plunger at said rear end, said slider flanges (94) being slidably fitted in the hollow (96) of the hollow rotor means (80) with the plunger partly projecting forwardly of the hollow rotor means through its open end, the cross sectional shape of the hollow (96) corresponding to the shape of the slide flanges (94) so that the slider flanges allow the plunger (90) both to rotate coaxially with the hollow rotor means and to reciprocate axially relative to the same.

5. In a device as claimed in claim 4, including, spring means (104, 106) coupled to the front housing part (62) and engaging the threads of said reciprocator plunger (90).

6. In a device as claimed in claim 5, including having said first and second converter mechanisms (60, 60'"'"') pivotally coupled to said mirror holder (52) at points angularly spaced 90°

from each other about the axis of the ball-and-joint socket.

7. In a remotely controlled rearview mirror tilting device or the like, a mechanism for converting bidirectional rotation into rectilinear reciprocation, comprising:

(a) stationary means having a circular opening defined therein;

(b) a hollow rotor open at one end and closed at the other, the open end of the rotor being rotatably engaged in the opening in the stationary means and thereby restrained from axial displacement in a first direction;

(c) point contact means for providing point contact between the stationary means and the closed end of the rotor, the closed end of the rotor being rotatably held against the stationary means via the point contact means and thus restrained from axial displacement in a second direction opposite to the first direction;

(d) a reciprocator mounted in the hollow rotor for sliding motion in its axial direction, the reciprocator being at least partly screw threaded; and

,

(e) means rotatable relative to the reciprocator and slidably engaged in its screw threaded part to cause its rectilinear reciprocation in response to the bidirectional rotation of the hollow rotor.

8. A converter mechanism as claimed in claim 7, wherein the point contact means comprises a boss formed on either of the stationary means and the closed end of the rotor and having a pointed tip for point contact with the other stationary means and the closed end of the rotor.

9. A converter mechanism as claimed in claim 8, wherein the boss is cone shaped.

10. A remotely controlled rearview mirror tilting device comprising:

(a) a housing;

(b) a mirror holder pivotally mounted on the housing for tilting motion about two orthogonal axes;

(c) two bidirectional motors mounted within the housing;

(d) two worms driven one by each motor

(e) two worm wheels in mesh one with each worm; and

,

(f) two rotary-to-linear converter mechanisms for translating the bidirectional rotation of the respective worm wheels into rectilinear reciprocation in order to tilt the mirror holder about the two orthogonal axes relative to the housing, each rotary-to-linear converter mechanism comprising;

(1) a hollow motor rotatable with one of the worm wheels, the rotor being open at one end and closed at the other, the open end of the rotor being rotatably engaged in an opening in the housing and thereby restrained from axial displacement in a first direction;

(2) point contact means for providing point contact between the housing and the closed end of the rotor, the closed end of the rotor being rotatably held against the housing via the point contact means and thus restrained from axial displacement in a second direction opposite to the first direction;

(3) a plunger mounted in the rotor for sliding motion in its axial direction and having one end projecting from its open end, the projecting end of the plunger being pivotally coupled to the mirror holder at a point on one of the two orthogonal axes, the plunger being screw threaded; and

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(4) means rotatable relative to the plunger and slidably engaged in its screw threads to cause its rectilinear reciprocation in response to the bidirectional rotation of the rotor.

11. The rearview mirror tilting device as claimed in claim 10, wherein the point contact means of each rotary-to-linear converter mechanism comprises a boss formed on either of the housing and the closed end of the rotor and having a pointed tip for point contact with the other of the housing and the closed end of the rotor.

12. The rearview mirror tilting device as claimed in claim 11, wherein the boss is cone shaped.