JP4963614B2 - Wiper blade - Google Patents

Description

  The present invention relates to a wiper blade that swings on a windshield of a vehicle to wipe the windshield.

  2. Description of the Related Art Conventionally, a vehicle such as an automobile is provided with a wiper device for securing a driver's field of view by wiping off deposits such as rain and snow attached to a windshield and splashes of a front vehicle. Such a wiper device includes a wiper arm that is swingably driven via an electric motor, and a wiper blade that is attached to the distal end side of the wiper arm. The wiper blade is rotatable to the distal end side of the wiper arm. It has a blade holder to be mounted and a blade rubber held by the blade holder. The blade rubber is pressed against the windshield by a spring built in the wiper arm, and the blade rubber swings on the windshield by driving the wiper arm with an electric motor in this state. Exercise and wipe away.

  By the way, when the wiper blade is prevented from sticking to the windshield in cold weather or when the vehicle is washed, the user may wake up the wiper arm against the spring force. Depending on the case, the wiper blade may be gripped to raise the wiper arm, or the raised wiper arm may be tilted with the wiper blade rotating more than a predetermined angle with respect to the wiper arm.

Therefore, for example, Patent Document 1 discloses a wiper blade that makes it possible to easily raise the wiper arm by restricting the rotation of the wiper blade with respect to the wiper arm by a predetermined angle or more, and to correctly tilt the raised wiper arm. ing. The wiper blade described in Patent Document 1 is pivotably engaged with each other between a primary lever (blade holder) and a U-shaped spring member (arm mounting member) rotatably provided on the primary lever (blade holder). A restricting member (engagement protrusion and engagement hole) is provided, and the rotation restricting member prevents rotation of the wiper blade with respect to the wiper arm by a predetermined angle or more.
Japanese Utility Model Publication No. 02-129952 (FIGS. 1 and 2)

  However, according to the wiper blade described in Patent Document 1 described above, the rotation of the wiper blade with respect to the wiper arm is restricted with respect to the direction in which the engagement protrusion and the engagement hole constituting the rotation restriction member are separated from each other. I couldn't. Therefore, when the tip end of the blade holder is rotated to the windshield side with respect to the wiper arm, the wiper arm and the blade holder come into contact with each other. By repeating this contact operation, the paint on the wiper arm or the blade holder is peeled off and rusting occurs early. Or wiping performance may deteriorate at an early stage due to damage to both members.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wiper blade that restricts the rotation of a blade holder at a tip end side to a windshield side with respect to a wiper arm by a predetermined angle or more.

A wiper blade of the present invention is a wiper blade that is mounted on a wiper arm that is swingably provided on a vehicle and that swings on a windshield to wipe the windshield, and a blade rubber that contacts the windshield; A blade holder for holding the blade rubber, and a rotating shaft provided on the blade holder. The blade holder has a pair of facing portions along the longitudinal direction and a bridge portion formed between the pair of facing portions. An arm mounting member that is movably mounted, is mounted on the wiper arm, and has an engaging projection that engages with the bridge portion, and is provided on the facing portion, and protrudes from the blade holder toward the arm mounting member. a first engaging portion formed of convex portions, a portion facing the said blade holder of the arm mounting member, the lower end of the arm mounting member Are formed on, has the first engagement portion made of convex portion and the second engaging portion ing than recess engaging, the engaging projection and the elastic deformation of at least one of said bridge Watanabe Forming the first engaging portion and the second engaging portion, and restricting the rotation of the blade holder relative to the wiper arm by more than a predetermined angle toward the windshield side with respect to the wiper arm , The engagement between the engagement protrusion and the bridging portion restricts the rotation of the blade holder on the base end side of the blade holder to the windshield side by a predetermined angle or more with respect to the wiper arm. When the load is applied, the engagement between the engagement protrusion and the bridge portion is released, so that the base end side of the blade holder with respect to the wiper arm has a predetermined angle to the windshield side. Wherein the pivoting is allowed.

According to the present invention, the first engaging portion is opposed to the arm mounting member of the blade holder, the opposing portion of the arm mounting member is opposed to the blade holder, and the second engaging portion is disposed at the lower end of the arm mounting member. Since the first and second engaging portions are respectively formed and the rotation of the blade holder at the tip side of the blade holder toward the windshield side with respect to the wiper arm is restricted by a predetermined angle or more, the wiper arm and the blade holder are Contact can be prevented. Therefore, it is possible to suppress rusting due to peeling of the paint on the wiper arm or the blade holder, deterioration of the wiping performance due to early damage to both members, and the like.

  According to the present invention, the first engaging part is formed by the convex part protruding from the blade holder toward the arm mounting member, and the second engaging part is formed by the concave part with which the convex part is engaged. By the engagement of the recess, the rotation of the blade holder at the tip end side to the windshield side with respect to the wiper arm can be restricted by a predetermined angle or more.

According to the present invention, the blade holder and the arm mounting member, each having a bridge Watanabe and engaging projection for restricting a predetermined angle or more rotation of the base end side of the windshield side of the blade holder engaged with each other Therefore, the blade holder can be rotated within a predetermined angle range with respect to the wiper arm. Therefore, the rotation of the wiper blade with respect to the wiper arm more than necessary with the wiper arm raised can be suppressed. Further, when a predetermined stress or more is applied to the blade holder, the engagement between the engagement protrusion and the bridge portion is released, so that the blade holder is more than a predetermined angle toward the windshield on the base end side of the blade holder with respect to the wiper arm. Therefore, the wiper blade can be prevented from being damaged when subjected to such a large stress that the engaging protrusion and the bridge portion are damaged.

  Hereinafter, an embodiment of a wiper blade according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram for explaining a wiper device mounted on a vehicle, FIG. 2 is an enlarged view showing the wiper blade of FIG. 1, FIG. 3 is a perspective view showing a blade holder, and FIG. 5 is a perspective view showing the arm support member, FIG. 6 is a sectional view taken along line AA in FIG. 2, and FIG. 7 is a sectional view taken along line BB in FIG. 8 is a partial cross-sectional view taken along the line CC of FIG. 2, FIGS. 9A and 9B are explanatory views for explaining a rotation range of the wiper blade with respect to the wiper arm, and FIG. 10 is a rotation restricting member. The partial expanded sectional view explaining the modification of each is represented.

  As shown in FIG. 1, a vehicle 10 has a wiper device for wiping off deposits such as rain and snow adhering to a windshield 11 serving as a windshield and splashes of a front vehicle to ensure the driver's view. 12 is mounted.

  The wiper device 12 includes a wiper motor 13 that is rotationally driven by operating a wiper switch (not shown) provided in a vehicle or the like, and a driver seat side and a passenger seat side wiper shaft 14a that are rotatably provided in the vehicle 10. 14b, the wiper shafts 14a and 14b are fixed to the wiper shafts 14a and 14b, and the front and rear wiper arms 15a and 15b are oscillating on the windshield 11. And a link mechanism 16 for converting into a swinging motion of 15b.

  Driver-side and passenger-side wiper blades 17a and 17b, which are formed in the same manner, are mounted on the front end sides of the wiper arms 15a and 15b so as to be rotatable with respect to the vertical direction of the windshield 11, respectively. The blades 17a and 17b are in elastic contact with the windshield 11 by springs (not shown) built in the wiper arms 15a and 15b. Then, by rotating the wiper motor 13, the wiping ranges 18a and 18b indicated by the two-dot chain line in the drawing on the windshield 11, that is, between the lower inversion position (wiper arm stop position) and the upper inversion position, The wiper blades 17a and 17b are in sliding contact.

  FIG. 2 shows a driver-side wiper blade. The driver-side wiper blade and the passenger-side wiper blade have the same configuration, so only the driver-side wiper blade will be described below. In the description of the wiper blade on the driver's seat, the suffix “swivel blade” etc. is not attached to the component parts but simply referred to as “wiper blade” etc. “A, b” is omitted.

  As shown in FIG. 2, the wiper blade 17 includes a blade holder 20, an arm attachment member 30 that is rotatably attached to a substantially central portion in the longitudinal direction of the blade holder 20, and a rotatably attachment to the arm attachment member 30. And an arm support member 40 that supports the distal end side of the wiper arm 15 with the arm mounting member 30.

  As shown in FIG. 3, a housing hole 21 for housing the arm mounting member 30 and the arm support member 40 (see FIGS. 4 and 5) penetrates in the vertical direction in the figure at a substantially central portion in the longitudinal direction of the blade holder 20. Is formed.

  The accommodation hole 21 is formed by opposing wall portions (opposing portions) 21a and 21b along the longitudinal direction of the blade holder 20 and bridging portions 22a and 22b formed between the opposing wall portions 21a and 21b. Yes. A rotation pin (rotation shaft) 23 on which the arm mounting member 30 is rotatably mounted is provided between the opposing wall portions 21a and 21b. In addition, a pair of convex portions 24a and 24b as first engaging portions are formed in the vicinity of the rotation pins 23 of the opposing wall portions 21a and 21b so as to protrude inwardly. .

  As shown in FIG. 4, the arm mounting member 30 includes a main body portion 31 covered by the distal end side of the wiper arm 15 and arm portions 32 a and 32 b formed integrally with the main body portion 31 and paired in the vertical direction in the figure. And have. The main body 31 is formed with a concave groove 33 that is rotatably mounted on a rotation pin 23 (broken line in the figure) provided on the blade holder 20, and the distal end side (left side in the figure) of each arm part 32a, 32b. ), A pair of pins 34a and 34b to which the arm support member 40 is rotatably mounted are formed so as to protrude toward the inside.

  Each arm portion 32a, 32b is formed such that the thickness dimension in the vertical direction in the figure gradually decreases as it moves away from the concave groove 33 attached to the rotation pin 23, that is, from the rotation pin 23 in the figure. It is formed so that the dimension of the gap S between the blade rubber 50 (broken line in the figure) increases as it moves away to the left. Rubber contact portions 35a and 35b that can contact the back side (upper side in the drawing) of the blade rubber 50 are formed on the lower end sides of the arm portions 32a and 32b in the drawing.

  The main body 31 of the arm mounting member 30 is integrally formed with an engagement protrusion 36 as a rotation restricting portion of the present invention so as to extend to the right side in the figure. It is possible to engage with a bridging portion 22a (see FIG. 3) that forms 20 accommodation holes 21.

Each of the wall portions (opposing portions) 31a and 31b of the main body portion 31 of the arm mounting member 30, and a pair of recesses as a second engaging portion in the lower end portion of the arm mounting member 30 close to the engaging protrusion 36 37a and 37b are formed. Each of the recesses 37a and 37b is formed in a cutout shape having an opening on the lower side in the figure, and the projections 24a and 24b of the blade holder 20 enter from the openings, whereby the recesses 37a and 37b and the projections 24a. , 24b can be engaged with each other.

  As shown in FIG. 5, the arm support member 40 is mounted on a mounting cylinder 41 that is rotatably mounted on pins 34 a and 34 b (broken lines in the drawing) formed on the arms 32 a and 32 b of the arm mounting member 30. And a main body 42 formed integrally with the mounting cylinder 41 and a support 43 formed integrally with the main body 42 and elastically deformable in the left-right direction in the figure. The support part 43 is formed to be thinner than the main body part 42, whereby the support part 43 is elastically deformed in the left-right direction in the figure.

  The blade holder 20 is formed in a substantially hollow shape as shown in FIGS. 6 and 7, and a blade rubber 50 is held inside thereof. A pair of guide protrusions 25a and 25b are integrally formed in the longitudinal direction inside the blade holder 20 so as to face each other, and each guide protrusion 25a and 25b is attached to the blade holder 20 of the blade rubber 50. Is to guide you.

  A pair of holding claws 26a and 26b projecting inward from the respective guide projections 25a and 25b are formed at portions further inside the respective guide projections 25a and 25b corresponding to the line BB in FIG. The retaining claws 26a and 26b prevent the blade rubber 50 from coming off from the blade holder 20. Each of the holding claws 26a and 26b is provided in a portion corresponding to the line BB in FIG. 2, and is also provided in a portion opposite to the center line AA. The blade rubber 50 is supported at two points by the blade holder 20.

  As shown in FIG. 7, contact protrusions 27 that contact the back side of the blade rubber 50 are integrally formed on the portions of the blade holder 20 corresponding to the holding claws 26a and 26b. The protrusion 27 abuts on the back side of the blade rubber 50, so that excessive inclination of the blade rubber 50 with respect to the blade holder 20 during wiping is suppressed.

  A pair of covers 28 are attached to the left and right sides of the blade holder 20 in FIG. 2 so as to cover the blade rubber 50, and claw portions 28 a formed integrally with the covers 28 are provided inside the blade holder 20. Each cover 28 is prevented from being detached from the blade holder 20 by being fitted into the formed contact protrusions 27. As shown in FIG. 7, a steel cored bar 28b is inserted into the claw portion 28a of the cover 28 by insert molding or the like, thereby giving the claw portion 28a flexibility and repeated elastic deformation. Improves durability.

  The blade holder 20 and each cover 28 are integrally formed with fins 29 along the longitudinal direction of the blade holder 20, and the fins 29 generate traveling wind when the vehicle 10 travels at a high speed or the like. By receiving, the blade rubber 50 is prevented from being lifted from the windshield 11, and the wiping performance of the wiper blade 17 is prevented from being lowered.

  The blade rubber 50 is formed by using a material such as natural rubber or chloroprene rubber and pouring the molten material into a mold. As shown in FIGS. 6 and 7, the blade rubber 50 has a main body 52 on which a pair of vertebras 51 as plate springs made of steel are mounted. Each vertebra 51 is formed in an arc shape so as to bend with a radius of curvature smaller than the radius of curvature of the windshield 11, whereby the pressing force against the windshield 11 in the entire longitudinal direction of the blade rubber 50 is made substantially uniform. It is trying to become.

  On the lower side of the main body portion 52 of the blade rubber 50 in the figure, a body portion 53 that is opposed to the guide projections 25a and 25b and the holding claws 26a and 26b of the blade holder 20 is integrally formed. A lip portion 54 that contacts the windshield 11 is integrally formed on the lower side of the body portion 53 in the drawing, and the lip portion 54 and the body portion 53 are the windshield of the lip portion 54 at the time of wiping. 11 are connected to each other by a neck portion 55 for smoothly performing a tilting operation (reversing operation) with respect to 11.

  As shown in FIG. 8, the wiper blade 17 employs a so-called U-hook connection method in which the wiper blade 17 is connected to the U-shaped portion 19 formed on the distal end side of the wiper arm 15 via the arm mounting member 30. Yes. The inner side of the U-shaped portion 19 of the wiper arm 15 is in contact with the arm mounting member 30 so as to cover the main body portion 31 of the arm mounting member 30 from the vertical direction in the figure, and the outer side of the U-shaped portion 19 is the arm It is in contact with the support portion 43 of the support member 40. In this way, the U-shaped portion 19 of the wiper arm 15 is sandwiched between the arm mounting member 30 and the arm support member 40, that is, the U-shaped portion 19 is supported by the elastic force of the support portion 43, thereby providing a wiper blade. 17 is attached to the wiper arm 15.

  When the wiper blade 17 is removed from the wiper arm 15, as shown by a broken line in FIG. 8, the arm support member 40 is rotated so as to stand up about the central axis C1 (the pins 34a and 34b), and the support portion The wiper blade 17 can be removed from the wiper arm 15 by releasing the elastic force applied to the U-shaped portion 19 by 43 and sliding the wiper blade 17 with respect to the wiper arm 15.

  Here, FIG. 8 shows a state where the wiper arm 15 is tilted toward the windshield 11, that is, a wiping operation state (reference state) of the wiper blade 17. In this reference state, the engaging protrusion 36 is separated from the bridging portion 22a and is not engaged with the bridging portion 22a, and the convex portion 24a is separated from the concave portion 37a and not in the concave portion 37a. In the engaged state. Therefore, when the wiper blade 17 is in the reference state, the wiper blade 17 can rotate with respect to the wiper arm 15 within a predetermined angle range.

  Next, the case where the wiper blade 17 rotates in one direction or the other direction with respect to the wiper arm 15 from the reference state shown in FIG. 8 will be described with reference to FIG. 9A shows a state in which the distal end side (left side in the figure) of the wiper blade 17 is rotated to the windshield 11 side, and FIG. 9B shows the base end side (right side in the figure) of the wiper blade 17. 1) represents the state of rotating toward the windshield 11.

  As shown in FIG. 9A, the wiper blade 17 is rotated in one direction around the rotation pin 23 (rotated counterclockwise) by gripping the wiper arm 15, and the rotation range is predetermined. When the angle is reached, the convex portion 24a enters the concave portion 37a, and the convex portion 24a and the concave portion 37a are engaged. Accordingly, the engagement between the convex portion 24a and the concave portion 37a restricts further rotation of the wiper blade 17 with respect to the wiper arm 15, and as shown in FIG. 9A, the wiper arm 15 contacts the wiper blade 17. Can be avoided. In FIG. 9A, only the convex portion 24a and the concave portion 37a are shown, but the convex portion 24b and the concave portion 37b are similarly engaged.

  As shown in FIG. 9B, the wiper blade 17 rotates in the other direction (rotates clockwise) around the rotation pin 23 by gripping the tip end side of the wiper blade 17, and the rotation is performed. When the range reaches a predetermined angle, the engagement protrusion 36 is now engaged with the bridge portion 22a. Therefore, the further rotation of the wiper blade 17 relative to the wiper arm 15 can be restricted by the engagement between the engagement protrusion 36 and the bridge portion 22a.

As described above in detail, according to the wiper blade 17 according to the present embodiment, the convex portions 24 a and 24 b are formed on the opposed portion of the blade holder 20 to the arm mounting member 30, and the blade holder 20 of the arm mounting member 30. The front glass on the tip side of the wiper blade 17 with respect to the wiper arm 15 is formed by forming concave portions 37a and 37b at the lower end portion of the arm mounting member 30 and engaging the convex portions 24a and 24b with the concave portions 37a and 37b. Since the rotation to the 11 side by a predetermined angle or more is restricted, the contact between the wiper arm 15 and the wiper blade 17 can be prevented. Accordingly, it is possible to suppress rusting due to the peeling of the paint on the wiper arm 15 or the wiper blade 17 and early deterioration of both members and deterioration of the wiping performance.

  Further, according to the wiper blade 17 according to the present embodiment, the arm mounting member 30 has the engagement protrusion 36 that restricts the rotation of the wiper blade 17 toward the windshield 11 on the base end side by a predetermined angle or more. Therefore, the wiper blade 17 can be rotated with respect to the wiper arm 15 within a predetermined angle range. Therefore, the rotation of the wiper blade 17 with respect to the wiper arm 15 can be suppressed more than necessary under the state where the wiper arm 15 is raised (lockback state).

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the rotation of the wiper blade 17 relative to the wiper arm 15 is restricted by the engagement between the engagement protrusion 36 and the bridge portion 22a. Not only this but the engagement protrusion 36 can also be comprised as shown in FIG.

  That is, the base end side (main body portion 31 side) of the engagement protrusion 36 is formed to be relatively thin, and the engagement protrusion 36 is formed so as to be elastically deformable in the direction of the arrow in the drawing, It is also possible to configure so that the engagement between the engagement protrusion 36 and the bridging portion 22a is released when a predetermined stress or more is applied. In this case, when the engagement protrusion 36 and the bridge portion 22a are subjected to such a large stress as to be damaged, the wiper blade 17 is rotated by a predetermined angle or more with respect to the wiper arm 15 to prevent the wiper blade 17 from being damaged. Is possible. However, the bridging portion 22a may be formed to be elastically deformable without forming the engaging projection 36 to be elastically deformable, or both the engaging projection 36 and the bridging portion 22a may be formed to be elastically deformable. It doesn't matter.

  Moreover, in the said embodiment, while forming each convex part 24a, 24b in the blade holder 20 as a 1st engaging part, forming each recessed part 37a, 37b in the arm mounting member 30 as a 2nd engaging part However, the present invention is not limited to this, and a slit as a first engaging portion is formed in the blade holder 20, and a convex as a second engaging portion that slidably enters the arm mounting member 30 into the slit. A part may be formed.

  In this case, the sliding range of the convex portion, that is, the rotation range of the wiper blade 17 relative to the wiper arm 15 can be set by appropriately setting the length of the slit.

  Further, in the above-described embodiment, the recesses 37a and 37b are formed in the arm mounting member 30 as the second engagement portion. However, the present invention is not limited to this, and the recesses 37a and 37b are omitted. You can also. That is, the lower ends of the arm mounting member 30 may be engaged with the convex portions 24 a and 24 b of the blade holder 20, and in this case, the engagement with the convex portions 24 a and 24 b at the lower end of the arm mounting member 30. The joint portion becomes the second engaging portion.

  Further, in the above-described embodiment, the first engaging portion forms the pair of convex portions 24a and 24b in the blade holder 20, and the arm mounting member 30 has the pair of concave portions 37a and 37b as the second engaging portion. Although what was formed was shown, this invention is not restricted to this, Either one set can also be abbreviate | omitted among the set of the convex part 24a and the recessed part 37a, or the set of the convex part 24b and the recessed part 37b.

  Further, in the above embodiment, the wiper blade is applied to a wiper device for wiping the windshield as a windshield. However, the present invention is not limited to this, and the wiper for wiping the rear glass as a windshield is shown. It can also be applied to a device.

It is explanatory drawing explaining the wiper apparatus with which the vehicle was mounted | worn. FIG. 2 is an enlarged view showing the wiper blade of FIG. 1 in an enlarged manner. It is a perspective view which shows a blade holder. It is a perspective view which shows an arm mounting member. It is a perspective view which shows an arm support member. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is a fragmentary sectional view which follows the CC line of FIG. (A), (b) is explanatory drawing explaining the rotation range with respect to the wiper arm of a wiper blade. It is a partial expanded sectional view explaining the modification of a rotation control member.

Explanation of symbols

10 Vehicle 11 Windshield (windshield)
12 Wiper device 13 Wiper motor 14a Driver side wiper shaft 14b Passenger side wiper shaft 15a Driver seat side wiper arm (wiper arm)
15b Front passenger side wiper arm (wiper arm)
16 Link mechanism 17a Wiper blade on the driver's seat (wiper blade)
17b Passenger side wiper blade (wiper blade)
18a, 18b Wiping range 19 U-shaped part 20 Blade holder 21 Accommodating hole 21a, 21b Opposing wall (opposing part)
22a, 22b Bridge 23 Rotating pin (Rotating shaft)
24a, 24b Convex part (first engaging part)
25a, 25b Guide projection 26a, 26b Holding claw 27 Abutting projection 28 Cover 28a Claw portion 28b Core metal 29 Fin 30 Arm mounting member 31 Main body portion 31a, 31b Wall portion (opposing portion)
32a, 32b Arm part 33 Groove 34a, 34b Pin 35a, 35b Rubber contact part 36 Engagement protrusion (rotation restriction part)
37a, 37b Recessed part (second engaging part)
40 Arm support member 41 Installation cylinder part 42 Main body part 43 Support part 50 Blade rubber 51 Vertibra 52 Main body part 53 Body part 54 Lip part 55 Neck part

Claims (1)

A wiper blade that is mounted on a wiper arm that is swingably provided on a vehicle and that swings on a windshield to wipe the windshield,
A blade rubber in contact with the windshield;
A blade holder having a pair of facing portions along the longitudinal direction and a bridging portion formed between the pair of facing portions, and holding the blade rubber;
An arm mounting member that is rotatably mounted on a rotating shaft provided in the blade holder, is mounted on the wiper arm, and has an engaging projection that engages with the bridge portion ;
A first engagement portion provided on the facing portion and made of a convex portion protruding from the blade holder toward the arm mounting member;
An opposing portion between the blade holder of the arm mounting member, the formed at the lower end portion of the arm mounting member, and the second engaging portion ing from the recess in which the first engaging portion made of protrusion is engaged Have
Forming at least one of the engagement protrusion and the bridge portion so as to be elastically deformable;
By the engagement between the first engagement portion and the second engagement portion, the rotation of the blade holder on the tip side of the blade holder with respect to the wiper arm is restricted from turning more than a predetermined angle ,
With the engagement between the engagement protrusion and the bridging portion, the rotation of the blade holder on the base end side of the blade holder with respect to the wiper arm by more than a predetermined angle is restricted, and
When the blade holder is subjected to a stress of a predetermined level or more, the engagement between the engagement protrusion and the bridge portion is released, so that the blade shield is moved to the windshield side on the proximal end side of the blade holder with respect to the wiper arm. The wiper blade is characterized in that it is allowed to rotate more than a predetermined angle .

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