OUTSIDE REAR VIEW MIRROR

Abstract: An outside rear view mirror for cars wherein a mirror housing (10) which is formed independently of a base (20) is swingably supported by the base through a spindle member (140) and automatically swung toward the car body by re­ mote operation in the car room, and wherein when load is forcedly added to the mirror housing from outside, the mirror housing is swung toward the car body by a buffer mech­ anism, which is arranged between the base and the mirror housing, to thereby absorb the impact of the load added.

Description: The present invention relates to an outside rear view mirror for cars provided with a drive transmitting mechanism for electrically swinging its mirror housing relative to the base. The outside rear view mirrors have been widely used for cars and one of them is disclosed by U.S. Patent No. 4 213 675. Figs. 1 and 2 of this patent show the conventional outside rear view mirror, in which Fig. 1 is a vertically-sectioned view thereof and Fig. 2 a partially-sectioned view thereof. As shown in Figs. 1 and 2, the mirror housing (3) is swingably attached to the body (6) by means of a plate-like arm (17) and a screw (15) in the case of this conventional outside rear view mirror (4). The plate-like arm (17) is engaged with the boss of the mirror housing (3) by means of plural projections. The mirror housing (3), plate-like arm (17) and body (7) are held, pressed against one another, by a spring (38). In the case of this conventional outside rear view mirror (4), the mirror housing (3) is displaced forward or backward, taking the screw (15) as its center, when the handle (21) is moved forward or backward in Fig. 1. When the handle (21) is rotated, taking the center axis of the plate-like arm (17) as its center, the mirror housing (3) is displaced up and down. When excessive load is added to the mirror housing (3), the mirror housing (3) is released from the plate-like arm (17) and swung toward the door (2). The above-described conventional outside rear view mirror (4) is most suitable for use as a device whose range of vision can be adjusted by the handle (21). As apparent from Figs. 1 and 2, however, forward or backward displacement of the mirror housing (3) is determined by the amount of handle (21) operation carried out in the car room. This amount of handle (21) operation is limited to a range necessary to adjust the field of vision allowed by the mirror (4). When it is wanted that the mirror housing (3) which is projected outside the car body is swung over the range of adjusting the field of vision and displaced to contact with the car body at the time of transporting or garaging the car, the mirror housing must be forcedly swung against the spring (28) and released from the boss projections (16). Namely, the mirror housing must be brought under such state that impact has been artificially added to the mirror housing (3). It was therefore needed that the swing operation was carried out outside the car body. In addition, the swing operation was considerably difficult because it must be carried out against the spring which was pressed against the mirror housing (3) and body (7). US-A-3005384, (Baird) discloses a mirror housing (15), supported on a bracket (16). The bracket (16), comprises an axle pivot member (22) which is in rigid connection with the bracket (16). Furthermore, the housing (15), is supported on the bracket (16) by means of a pivot (23), as can be seen in Figure 1, of said application. The housing (15) further comprises a prime mover (28), whcih acts on an axle gear (36), supported on the axle pivot member (22). A clutch (45,46), is provided between the axle pivot member (22) and the axle gear (36) which is arranged to provide slippage between the axle gear(36) and the axle pivot when a predetermined torque is exerted. The pivot (23) acts as a second clutch between the housing (15) and the bracket (16). As described in column (4), lines 53 to 61, of said US-PS, the release force of the clutch comprising the pivot (23) is less than the release force required to overcome the clutch (45,46). Since the axle pivot member (22) is in rigid connection with the bracket (16), clutch (23) and clutch (45,46) have to be released when an external impact acts on the mirror housing (15). DE-U-7503867 refers to a mirror device comprising an axle (5), which is a rigid, non-rotatable connection with a car body. A mirror housing (1) supported on the axle (5) and rotatable with respect to the longitudinal axis of the axle (5) is provided. This rotatable movement can be achieved by activating a motor (9), which acts on a gear (13). The gear (13) is in non-rotatable connection with the axle (5) as long as there is no movement between clutch plates (14) and (15). Said clutch (14,15) is released upon exceeding a predetermined force in order to avoid damage of the motor (9). Furthermore, a clutch (17,18) is provided between the mirror housing (1) and the axle (5), which has to be released by the motor (9) upon activation of same in order to rotate or swing the mirror housing (1) with respect to the axle 5. In the case of external impact or force, both clutches (14,15) (17,18) have to be released. An outside rear view mirror in accordance with the preamble of claim 1 is disclosed in US-A-4 256 375. This document shows a rear view mirror that can be positioned to adjust the mirror viewing range by remote control. The rear view mirror has a mirror supporting post for attachment to a bracket and a driving unit which causes the mirror to be rotated about an axis. An electric motor is provided, being connected by a plurality of gears to a ring gear, coaxially mounted on said post. A slip clutch is provided within a gear casing and is formed between co-engaging annular surfaces on the ring gear and an annular flange of the post. The mirror housing can be rotated by this slip clutch in case of a shock. SUMMARY OF THE INVENTION The object of the present invention is to provide an outside rear view mirror which can be remotely operated in the car room to swing the mirror housing relative to the base and displace it toward the car body and which can be released upon an external impact to avoid damage of the mirror. The object is solved by the features of the main claim. In the following description, the invention will be further explained in connection with the drawings. Figs. 1 and 2 shows one of the conventional outside rear view mirrors; Fig. 1 is a vertically-sectioned view showing the mirror attached to the door of a car. Fig. 2 is a horizontally-sectioned view showing an adjustment means used for the mirror in Fig. 1. Fig. 3 shows an outside rear view mirror attached to the car. Fig. 4 is a front view showing the outside rear view mirror partially sectioned. Figs. 5 through 10 show an embodiment of the present invention. Fig. 5 is a plan view, partionally sectioned along the line A-A in Fig 4. Fig. 6 is an enlarged sectional view Fig. 7 is an exploded view showing main parts of the outside rear view mirror. Fig. 8 is a view similar to Fig. 5 and shows the mirror housing automatically swung. Fig. 9 is a view similar to Fig. 5 and shows the mirror housing forcedly swung backward as a result of an impact from the front side. Fig. 10 is a view similar to Fig. 5 and shows the mirror having forcedly swung forward as the result of an impact from the rear side. Figs. 3 through 10 show an embodiment of the present invention. As shown in detail in Figs. 3 through 10, an outside rear view mirror 1 comprises a mirror housing 10 for adjustably holding a mirror 50 in the opening thereof, a base 20 to which the mirror housing 10 is swingably attached through a spindle member 140, a drive transmitting mechanism 30 for swinging the mirror housing 10 relative to the base 20, and a buffer mechanism 60 located between the mirror housing 10 and the spindle member. As shown in Fig. 3, the outside rear view mirror 1 is attached to a car body 90 in such a way that it is projected only by distance ℓ outside the car body 90. As shown in Figs. 4 and 5, the mirror housing 10 is of the rectangular type, having longer horizontal sides, and formed different from the base 20. The mirror 50 is held in the opening of the mirror housing 10 to adjust the field of vision. The mirror housing 10 is swingably supported by the base 20 through the spindle member, and a buffer mechanism 60 which comprises springs 61 and 62 arranged between the mirror housing 10 and the base 20 and between the base 20 and the spindle member 140, respectively, serves to buffer such impact that is larger than a certain load. This impact buffering can be attained in such a way that the mirror housing 10 is swung round the base 20 against the springs 61 and 62 when the impact is added from outside to the mirror housing 10 of the outside rear view mirror which comprises the mirror housing 10, base 20 and spindle member 140 urged by the springs 61 and 62. The mirror housing 10 is swung round the spindle member 40 by remotely operating the drive transmitting mechanism 30 in the car room except the case where it is forcedly swung by the strong impact as described above. As shown in Figs. 6 and 7, to describe the arrangement of the mirror housing 10 in more detail, a base attaching portion 13 which is recessed inward a bottom wall 11 of the mirror housing 10 is formed at that portion of the bottom wall 11 of the mirror housing 10 which is located on the side of the base 20. A side wall 12 of the mirror housing 10 is arranged to have a curve portion. A mount 14 is projected from the base attaching portion 13 inward the mirror housing 10. The spindel member 140 passing through a through-hole 15 which is formed in the mount 14. The mount 14 includes a tapered circumference 15c, having an upper small-diameter portion 15a and a lower large-diameter portion 15b. The base 20 has a vertical wall 27 provided with a curve portion which corresponds to the side wall 12 of the mirror housing 10, and a support 21 which extends horizontally from the vertical wall 27 toward the mirror housing 10. A conical bearing 22 is projected from the support 21. A spring attaching portion 24 is formed on the underside of the bearing 22 and a through-hole 23 through which a cylindrical shaft 141 of the spindle member 140 passes is formed in the bearing 22, extending from the bottom of the spring attaching portion 24 to the upper side of the bearing 22. A cord 70 which is connected to a drive motor 31 for the drive transmitting mechanism 30 is inserted through a hollow portion 49 of the cylindrical shaft 141. The drive transmitting mechanism 30 comprises the spur gear 35, another spur gear 34 which is engaged with the spur gear 35, fixed to a motor shaft 33 of the drive motor 31, and located on the movable side, the drive motor for rotating the spur gear 34, and a speed reducer 32. The buffer mechanism 60 comprises the spring 61 which is compressed between the engagement recess 46 located on the upper end side of the cylindrical shaft 141 and the upper face of a cover 80 by means of two washers 63 and a clip 65, and the spring 62 which is compressed in the spring attaching portion 24 of the base 20 by means of the clip 66 and two washers 64, said clip 66 being fitted into the engagement recess 47 located on the lower end side of the cylindrical shaft 141. The cover 80 serves to seal the two spur gears 34 and 35 of the drive transmitting mechanism 30, and includes a through-hole 84 for the cylindrical shaft 41, a through-hole 85 for the motor shaft 31, and a bearing 82 for the spur gear 34. The mirror housing, base, spindle member drive transmitting mechanism and cover are assembled one another as follows. The spindle member 140 is attached to the bearing 22 projected from the support 21 of the base 20. The cylindrical shaft 141 of the spindle member 40 is passed through the through-hole 23 in the bearing 22 of the base 20 and the spring attaching protion 24 and projected below the base 20 under this state. The mirror housing 10 is then attached to the spindle member 140 which has been set to the base 20. At this time, the upper end portion of the cylindrical shaft 141 is projected inward the mirror housing 10. The spur gear 34 located on the movable side is set on the mount 14 to engage the spur gear 35 and these are sealed by the cover 80. The cylindrical shaft 41 is projected through the through-hole 84 in the cover inward the mirror housing 10, and the motor shaft 33 of the drive motor 31 on the top of the cover 80 is passed through the through-hole 85, with the speed reducer 32 interposed, into the hollow portion 81 in the cover 80 to fit into the spur gear 34. A shaft 34a of this spur gear 34 is supported by the bearing 82 of the cover 80. The cover 80 is fixed on the mount 14 by means of a screw 83. The drive motor 31 and speed reducer 32 are attached to the top of the cover 80, and the cord 70 is introduced outside through the hollow portion 49 in the cylindrical shaft 41. The buffer mechanism 60 is attached to the assembly thus obtained. More specifically, the spring 61 which is interposed between the two washers 63 is fitted onto the cylindrical shaft 41 projected from the top of the cover 80 and compressed and fixed by the clip 65 fitted onto the engagement recess 46. The spring 62 which is interposed between the two washers 64 is similarly attached to the lower end of the cylindrical shaft 41 projected at the spring attaching portion 24 of the base 20 and it is compressed and fixed by the clip 66 fitted onto the engagement recess 47. When arranged as described above, the mirror housing can be easily swung by remote operation in the car room to become parallel to the outside of the car body at the time of transporting the car to which the outside rear view mirrors are attached or garaging it, thereby enabling car transportation space to be made smaller and preventing the mirror housings from becoming obstacles at the time of garaging the car. Further, the buffer mechanism is arranged between the mirror housing and the base. Therefore, the mirror housing is swung to buffer impact even when the impact is added to the mirror housing, thereby preventing reducing the damage of human beings and the outside rear view mirror 1. Furthermore, the mirror housing 10, base 20 and spindle member 140 are contacted with one another at their respective faces. Therefore, the outside rear view mirror 1 is excellent in stability and it hardly happens that the field of vision is made worse by the vibration of the mirror 50. As shown in Fig. 7, the through-hole 23 in the bearing 22 of the base 20 is provided with a pair of key grooves 123. The spindle member 140 has a cylindrical shaft 141. Two projection 142 and a conical slide-contact wall 144 spaced therefrom are farmed integrally to the cylindrical shaft 141. A portion between the projections 142 and the conical slide-contact wall 144 is a spur gear attaching portion for attaching a spur gear 135. The conical slide-contact wall 144 is enlarged upward and the spur gear 135 being located on the fixed side. The drive transmitting mechanism 30 is substantially same in arrangement as in the first embodiment, but a tapered recess 36 is formed on the upper portion of the through-hole 37, of the spur gear 135 located on the fixed side. Further, a pair of grooves 137 are formed on the inner wall of the through-hole 37. The projections 142 on the cylindrical shaft 141 are passed through the grooves 137, respectively. As shown in Figs. 5 and 6, these base, mirror housing, spindle member and drive transmitting mechanism are assembled one another as follows. The through-hole 15 of the mirror housing 10 is fitted onto the bearing 22 of the base 20 to locate the mirror housing 10 on the base 20, the spur gear 135 is positioned on bearing 22, and the cylindrical shaft 141 of the spindle member 40 is then inserted into the assembly from above. The projections 142 on the cylindrical shaft 141 are passed through the paired grooves 137 which are formed on the inner face of through-hole 37 of the spur gear 135 located on the fixed side, and they are fitted, movable up and down, into the key grooves in the bearing 22 of the base 20. The spur gear 34 located on the movable side is then engaged with the spur gear 135 located on the fixed side and the cover 80 seals these spur gears of the drive transmitting mechanism 30. The mirror housing 10 is pressed against the base 20, using the springs 61, 62,clips 65, 66 and washers 63, 64 which form the buffer mechanism 60. Referring to Fig. 8 it will be described how the mirror housing 10 is swung by remote operation. In a case where the mirror housing 10 is swung backward, for example, the drive motor 31 is rotated, and its rotation is reduced by the speed reducer 32 and transmitted to the spur gear 34. Since the spur gear 34 is engaged with the spur gear 135 located on the fixed side, the rotation is transmitted to the spur gear 135 to rotate it, but the spur gear 135 located on the fixed side is slide-contacted with the tapered face between the recess 36 and the slide-contact wall 144 on the cylindrical shaft 141 and compressive force is applied to the tapered slide-contact face by means of the springs 61 and 62, thereby keeping the spur gear 135 not rotated. Therefore, the spur gear 34 moves round the spur gear 135 and on its axis, and the mirror housing 10 is thus swung backward. In a case where the mirror housing 10 is swung forward, the drive motor 31 is reversely rotated to reversely rotate the spur gear 34. Fig. 9 shows a state under which the mirror housing 10 is swung backward by external force P added thereto from front. When the external force P is added to the mirror housing 10, as shown in Fig. 9, the spur gears 34 and 135 become locked and the mirror housing 10 becomes unrotatable together with the spindle member 140 if the load which is added to the mirror housing 10 is smaller than the certain load. When the impact of the external force P is strong, however, the spur gear 135 is rotated relative to the spindle member 140, exceeding frictional force between the spindle member 140 and the spur gear 135 located on the fixed side. This is because the frictional force between the slide-contact wall 144 on the spindle member 140 and the recess 36 on the spur gear 135 is caused by the springs 61 and 62, because the spindle member 140 cannot rotate but move only up and down since it is engaged with the key grooves 123, and because the spindle member 140 is moved upward and released from its frictional engagement with the spur gear 135 when the external force P is stronger than the urging force of the springs 61 and 62. Fig. 10 shows a state under which the mirror housing 10 is swung forward by the external force P added thereto from back. As seen in Fig. 9, the mirror housing 10 is swung forward in relation to the spindle member 140 by the rotation of the spur gear 135 located on the fixed side, thereby buffering the impact of the external force P. When the mirror housing 10 is swung to its final positon in relation to the base and the rotation force of the drive motor is still added to the spur gear 135 located on the fixed side in the case of this second embodiment, the frictional engagement between the slide-contact wall 144 of spindle member 140 and the spur gear 135 located on the fixed side is released, as shown in Figs. 7 and 8, thereby preventing excessive load from being added to the drive motor 31. The above functioning can be summarized as follows: The spindle member (140) is supported on the base (20) in such a manner that it is not possible to rotate the spindle member (140) with respect to the base (20). This is caused by the key grooves (123) provided on the base (20) and the projections (142) provided on the spindle member (140). Therefore, a relative movement between the mirror housing (10) and the base (20) always leads to a relative movement between the spindle member (140) and the mirror housing (10). A friction clutch (36,144) provided between the gear (135) and the spindle member (140) prevents a relative movement between the gear (135) and the spindle member (140) during the activation of the drive transmitting mechanism (30). A swinging or turning movement of the mirror housing (10) with respect to the base (20) caused by an activation of the drive transmitting mechanism (30) leads to a release of the friction clutch formed by the bearing (22) of base (20) and the through hole (15) of housing (10). Both above-mentioned clutches, namely the clutch acting between the gear (134) and the spindle member (140), (36 144) and the clutch between the mirror housing (10) and the base (20), (15,22) are released upon an external impact or force acting on the mirror housing (10). Since the gear (34) of the drive transmitting mechanism (30) cannot be rotated without activating the drive transmitting mechanism (30), the gear (135), which meshes the gear (34), also remains without movement with respect to the mirror housing (10) when an external impact or force acts on the mirror housing (10). Therefore, in this case, both clutches are releasable in order to allow a rotation of the mirror housing (10). In the case of this second embodiment arranged as described above, excessive load can be prevented from being added to the drive motor, in addition to same effects as those already described.

Claims: An outside rear view mirror comprising a mirror housing (10), a base (20), supporting the mirror housing (10) in a swingable manner, a driving mechanism (30), provided with a drive motor (31), supported on the mirror housing (10) for producing a driving torque to rotate the mirror housing (10) in relation to the base (20) and a clutch mechanism provided between the mirror housing (10) and the base (20) so as to release the driving torque when a large external impact is applied to the mirror housing (10), characterized in that the clutch mechanism comprises a spindle member (140) which is under normal operation conditions non-rotatable with respect to the base (20), a spur gear (135) connected to the driving mechanism (30) and disposed coaxially with and in engagement with said spindle member (140), a coil spring (62), biasing the spindle member (140) to the base (20), whereby the engagement between the spindle (140) and the spur gear (135) is released by an axial movement of the spindle member against the biasing force of the coil spring (62) upon receiving an external torque imposed on the mirror housing (19). An outside rear view mirror according to claim 1, wherein said base (20) has a vertical wall (27) provided with a support (21), which extends horizontally from the vertical wall (27) towards said mirror housing (10), and a bearing (22), projecting from the support (21) with a through-hole (23), receiving a cylindrical shaft (141) of said spindle member (140). An outside rear view mirror according to claim 2, wherein said through-hole of said bearing (22) is conical, opening to the lower end of the spindle (140). An outside rear view mirror according to claim 1 or claim 2, wherein said coil spring (62) is located on the lower end side of the cylindrical shaft (141) of said spindle (140) and wherein a second spring (61) is provided, on the upper end side of the cylindrical shaft (141) of said spindle (140). An outside rear view mirror according to claim 1, wherein said spindle member (140) has a pair of projections (142) engaging a pair of grooves (137) located in the through-hole (37) of said spur gear (135). An outside rear view mirror according to claim 1, wherein a second spur gear (34) is provided meshing with said first spur gear (135), secured on the drive shaft (33) of said drive motor (31) and wherein for rotation of the mirror housing (10) by remote operation, the drive motor (31) is rotated with the second spur gear (34), whereas the spur gear (134) is held unrotatable by the friction force, exerted by the coil spring (61) and the second coil spring (62) so that the second spur gear (34) is rotated around the axis of the spur gear (135). An outside rear view mirror according to one of claims 1 to 6, wherein the spindle member (140) is provided with an axial through-hole (49) for receiving electric wires (70) for providing the drive motor (31) with energy.

Inventors: MASAO, ENOMOTO
Applicants: ICHIKOH INDUSTRIES LIMITED
Application year: 1984
Main classification: B60R1
IPC codes: B60R1