Patent Publication Number: US-11378266-B2

Title: Low-noise light fixture reset structure and control method thereof

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of International Application No. PCT/CN2021/074037, filed on Jan. 28, 2021, which claims priorities from Chinese Patent Application No. 202010477381.8 filed on May 29, 2020, all of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to the technical field of stage light fixtures, and specifically relates to a low-noise light fixture reset structure and a control method thereof. 
     BACKGROUND 
     A stage light fixture generally includes a support arm rotatably connected to a base and a light head rotatably connected to the support arm. When the stage light fixture is power-on reset, both the light head and/or the support arm is required to zero to clarify an initial position, and a mechanical limiting structure is required in both clockwise and counterclockwise directions to prevent infinite rotation of the light fixture and twisting off of an electronic line therein. 
     When the support arm of the stage light fixture is reset, the support arm firstly rotates in a predetermined direction until the limiting structure is met to stop rotation. At this time, a driving motor shaft of the support arm cannot continue to rotate, and thus a feedback device cannot normally feed back signals, and a system cannot receive normal signals from the feedback device, so that it is determined that the light fixture has reached a limiting position of the limiting structure, which is defined as the initial position. 
     However, this reset method has a relatively large deficiency. That is, the support arm bounces back after collision with the limiting structure at a certain speed, and then collides with the limiting structure again under the drive of a drive motor and bounces back again. This process is repeated multiple times and noise like “click, click, click . . . ” is clearly generated. 
     SUMMARY 
     The present invention provides a low-noise light fixture reset structure that can avoid strongly collision with the limiting structure without noise generation when the light fixture is reset. 
     According to the present invention the low-noise light fixture reset structure includes a pivot shaft and a pivot member rotatably connected to the pivot shaft, in which the pivot member has a first rotation direction and a second rotation direction that are opposite in direction relative to the pivot shaft, the pivot shaft is connected with a relatively fixed drive wheel and is sleeved with a shifter lever that can freely rotate relative to the pivot shaft; 
     a first detection marker is provided on the shifter lever, and a first detector that detects the first detection marker is correspondingly provided on the pivot member; 
     a first limiting post that limits the shifter lever is also provided on the drive wheel, the pivot member is further provided with an elastic member capable of resisting against the shifter lever and a second limiting post that limits the shifter lever, an resisting end of the elastic member and the second limiting post are respectively located on two sides of the first detector, the second limiting post, the first detector, and the resisting end are sequentially provided in the first rotation direction, and the second limiting post, the elastic member and the first limiting post do not interfere with each other during a relative movement between the pivot member and the pivot shaft; and 
     when one side of the shifter lever is blocked by the first limiting post and the other side of the shifter lever squeezes the elastic member, the elastic member deforms to the second rotation direction to cause the first detector to detect the first detection marker on the shifter lever. 
     The first limiting post of the low-noise light fixture reset structure is fixed to the drive wheel on the pivot shaft, all the second limiting post, the first detector and the elastic member are fixed to the pivot member, the pivot member has the first rotation direction and the second rotation direction that are opposite in direction, the shifter lever is sleeved on the pivot shaft and can freely rotate relative to the pivot shaft. Since the second limiting post, the first detector, and the resisting end of the elastic member are sequentially provided in the first rotation direction, when the pivot member is rotated in the first rotation direction relative to the pivot shaft, the resisting end of the elastic member can push the shifter lever to rotate together upon touching the shifter lever until one side of the shifter lever is blocked by the first limiting post. As the pivot member continues to rotate in the first rotation direction relative to the pivot shaft, the elastic member deforms to the second rotation direction to cause the first detector to detect the first detection marker on the shifter lever and generate a first reset signal, and then this position is defined as a preliminary initial position, which is taken as a reset position. Since the second limiting post is not required to touch the shifter lever resisted against by the first limiting post, the pivot member do not bounce back under the action of a reaction force, thereby avoiding noise like “click, click, click . . . ” generated by multiple times of collision and creating a quieter reset process. 
     A second detection marker is provided on the drive wheel, and a second detector that detects the second detection marker is correspondingly provided on the pivot member. After the first detector detects that the first detection marker on the shifter lever generates the first reset signal, a system drives the pivot member to rotate in the second rotation direction relative to the pivot shaft, the resisting end of the elastic member resists against the shifter lever to cause the shifter lever to remain motionless, the first detector moves away from the first detection marker until the second detector detects the second detection marker on the drive wheel, then a second reset signal is generated, and this position is taken as a precise initial position. Due to the fact that the shifter lever is sleeved on the pivot shaft, the shifter lever may rotate with the pivot member relative to the pivot shaft because of a problem of friction force between the shifter lever and the pivot member, and that the reset is easy to deviate from a predetermined position if the preliminary initial position is taken as the reset position, thus the position at which the second detector generates the second reset signal for the first time is taken as the precise initial position, when, marked by the first reset signal, the pivot member rotates in the second rotation direction relative to the pivot shaft. When the precise initial position is taken as the reset position, the system is more stable without deviation, and the reset is more accurate. 
     On the pivot member, the second detector, the second limiting post, the first detector and the resisting end are sequentially provided in the first rotation direction, and on the drive wheel, the second detection marker and the first limiting post are also sequentially provided in the first rotation direction. 
     the second detection marker is a magnet, the second detector is a magnetic sensitive switch, and/or the first detection marker is a magnet, and the first detector is a magnetic sensitive switch. Magnetic induction is less susceptible to interference from acoustic, optical and non-magnetic material, which results in higher stability. 
     both the second detection marker and the second detector are located on one side of the drive wheel away from the shifter lever, and both the first detection marker and the first detector are located on one side of the shifter lever away from the drive wheel. In this manner, two detection systems are independent of each other to prevent the second detection marker from affecting the first detector and prevent the first detection marker from affecting the second detector. 
     A minimum distance between the second limiting post and a center of the pivot shaft, and a minimum distance between the elastic member and a center of the pivot shaft are greater than a maximum distance between the first limiting post and the center of the pivot shaft. Thus, when the second limiting post and the elastic member rotate together relative to the pivot shaft, the first limiting post cannot be touched, and relative rotation of the pivot member and the pivot shaft cannot be affected. 
     When the first detector detects the first detection marker, the second limiting post is not in contact with the shifter lever. That is, there is a distance between the second limiting post and the first detector such that the second limiting post cannot squeeze the shifter lever and emit collision noise when the first detector detects the first detection marker. 
     The pivot shaft is fixed to a position, and the pivot member self-rotates about the pivot shaft. The pivot member drives the second limiting post, the first detector and the elastic member that are provided on the pivot member to rotate together, while the pivot shaft and the drive wheel and the first limiting post that are provided on the pivot shaft remain motionless. 
     The pivot member is a support arm of a stage light fixture or a light head of a stage light fixture. A stage light fixture generally includes a support arm rotatably connected to a base and a light head rotatably connected to the support arm. The low-noise light fixture reset structure can be used on the reset structure of the support arm and on the reset structure of the light head. 
     The present invention also provides a control method of any of the low-noise light fixture reset structures described above, including the following steps: 
     S1, driving the pivot member to rotate in the first rotation direction relative to the pivot shaft such that the resisting end of the elastic member pushes the shifter lever to rotate together until one side of the shifter lever is blocked by the first limiting post; 
     S2, continuing to drive the pivot member to rotate in the first rotation direction relative to the pivot shaft, the other side of the shifter lever resisting against the resisting end to deform the elastic member to the second rotation direction, thereby causing the first detector to detect the first detection marker on the shifter lever and generate the first reset signal; and 
     S3, driving the pivot member to rotate in the second rotation direction relative to the pivot shaft, the resisting end of the elastic member resisting against the shifter lever to remain motionless, and the first detector moving away from the first detection marker to complete a reset. 
     Since the second limiting post is not required to touch the shifter lever resisted against by the first limiting post, the pivot member do not bounce back under the action of a reaction force, thereby avoiding noise like “click, click, click . . . ” generated by multiple times of collision and creating a quieter reset process. 
     A second detection marker is provided on the drive wheel, and a second detector that detects the second detection marker is correspondingly provided on the pivot member; and 
     in step S3, after the first detector is moved away from the first detection marker, the pivot member is continued to be driven to rotate in the second rotation direction relative to the pivot shaft until the second detector detects the second detection marker on the drive wheel, and then a second reset signal is generated to complete a reset. 
     Due to the fact that the shifter lever is sleeved on the pivot shaft, the shifter lever may rotate with the pivot member relative to the pivot shaft because of a problem of friction force between the shifter lever and the pivot member, and that the reset is easy to deviate from a predetermined position if the position of the first detection marker on the shifter lever detected by the first detector is taken as the reset position, thus the position at which the second detector generates the second reset signal for the first time is taken as the precise initial position, when, marked by the first reset signal, the pivot member rotates in the second rotation direction relative to the pivot shaft. When the precise initial position is taken as the reset position, the system is more stable without deviation, and the reset is more accurate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded structural schematic diagram of a low-noise light fixture reset structure according to the present invention. 
         FIG. 2  is an enlarged view of position A of  FIG. 1 . 
         FIG. 3  is an another exploded structural schematic diagram of the low-noise light fixture reset structure according to the present invention. 
         FIG. 4  is a partial cross-sectional view of the low-noise light fixture reset structure according to the present invention. 
         FIG. 5  is a schematic structural view when a pivot member is in a first position relative to a pivot shaft according to the present invention. 
         FIG. 6  is a schematic structural view when the pivot member is in a second position relative to the pivot shaft according to the present invention. 
         FIG. 7  is a schematic structural view when the pivot member is in a third position relative to the pivot shaft according to the present invention. 
         FIG. 8  is a schematic structural view when the pivot member is in a fourth position relative to the pivot shaft according to the present invention. 
         FIG. 9  a schematic structural view when the pivot member is in a fifth position relative to the pivot shaft according to the present invention. 
     
    
    
     REFERENCE NUMERALS 
       100 , pivot member;  110 , first detector;  120 , second limiting post;  130 , elastic member;  140 , second detector;  200 , pivot shaft;  210 , drive wheel;  220 , first limiting post;  230 , second detection marker;  300 , shifter lever;  310 , first detection marker;  320 , limiting tube. 
     DETAILED DESCRIPTION 
     The drawings are for illustration purpose only and are not intended to limit the present patent. Some components in the drawings may be omitted, enlarged or reduced for better illustrating the embodiments, and sizes of these components do not represent that of an actual product. For those skilled in the art, it will be understood that some known structures in the drawings and descriptions thereof may be omitted. The description of positional relationship in the drawings is for illustration purpose only and is not intended to limit the present patent. 
     As shown in  FIGS. 1 to 3 , a low-noise light fixture reset structure is provided including a pivot shaft  200  and a pivot member  100  rotatably connected to the pivot shaft  200 . The pivot member  100  has a first rotation direction and a second rotation direction that are opposite in direction relative to the pivot shaft  200 . The pivot shaft  200  is connected with a fixed drive wheel  210  relative to the pivot shaft  200  and is sleeved with a shifter lever  300  that can freely rotate relative to the pivot shaft  200 . 
     A first detection marker  310  is provided on the shifter lever  300 , and a first detector  110  configured to detect the first detection marker  310  is correspondingly provided on the pivot member  100 . 
     A first limiting post  220  configured to limit the shifter lever  300  is also provided on the drive wheel  210 . The pivot member  100  is further provided with an elastic member  130  capable of resisting against the shifter lever  300  and a second limiting post  120  that limits the shifter lever  300 . An resisting end of the elastic member  130  and the second limiting post  120  are respectively located on two sides of the first detector  110 , and the second limiting post  120 , the first detector  110  and the resisting end are sequentially provided in the first rotation direction. The second limiting post  120 , the elastic member  130 , and the first limiting post  220  do not interfere with each other during a relative movement between the pivot member  100  and the pivot shaft  200 . 
     When one side of the shifter lever  300  is blocked by the first limiting post  220  and the other side of the shifter lever  300  squeezes the elastic member  130 , the elastic member  130  deforms to the second rotation direction (i.e., a direction close to the second limiting post  120 ) to cause the first detector  110  to detect the first detection marker  310  on the shifter lever  300 . 
     According to the present invention, the first limiting post  220  of the low-noise light fixture reset structure is fixed to the drive wheel  210  on the pivot shaft  200 , the second limiting post  120 , the first detector  110  and the elastic member  130  are all fixed to the pivot member  100 , the pivot member  100  has the first rotation direction and the second rotation direction that are opposite in direction relative to the pivot shaft  200 , and the shifter lever  300  is sleeved on the pivot shaft  200  and can freely rotate relative to the pivot shaft  200 . Since the second limiting post  120 , the first detector  110 , and the resisting end of the elastic member  130  are sequentially provided in the first rotation direction, when the pivot member  100  is rotated in the first rotation direction relative to the pivot shaft  200  (as shown in  FIG. 5 ), the resisting end of the elastic member  130  can push the shifter lever  300  to rotate together upon touching the shifter lever  300  until one side of the shifter lever  300  is blocked by the first limiting post  220  (as shown in  FIG. 6 ). As the pivot member  100  continues to rotate in the first rotation direction relative to the pivot shaft  200 , the elastic member  130  deforms to the second rotation direction to cause the first detector  110  to detect the first detection marker  310  on the shifter lever  300  (as shown in  FIG. 7 ) to generate a first reset signal, and this position is defined as a preliminary initial position, which is taken as a reset position. Since the second limiting post  120  is not required to touch the shifter lever  300  resisted against by the first limiting post  220 , the pivot member  100  do not bounce back under the action of a reaction force, thereby avoiding noise like “click, click, click . . . ” generated by multiple times of collision and creating a quieter reset process. 
     If the pivot member  100  continues to rotate in the first rotation direction relative to the pivot shaft  200 , the second limiting post  120  may resist against the shifter lever  300 . In addition, due to the fact that the other side of the shifter lever  300  is blocked by the first limiting post  220 , the pivot member  100  cannot continue to rotate relative to the pivot shaft  200 , at which time a minimum relative rotation angle is reached. 
     Optionally, the first rotation direction refers to a counterclockwise direction, and the second rotation direction refers to a clockwise direction. 
     Optionally, the drive wheel  210  is a synchronizing wheel and is driven by a synchronous belt. 
     Optionally, the elastic member  130  is an end-bent elastic piece, and a bent portion forms the resisting end. 
     Optionally, as shown in  FIG. 4 , the shifter lever  300  is sleeved on a limiting tube  320  having blocking portions at two ends that prevents the shifter lever  300  from swaying along a length direction of the limiting tube  320 , in which the limiting tube  320  is sleeved on the pivot shaft  200 . 
     In a preferred embodiment of the present invention, a second detection marker  230  is provided on the drive wheel  210 , and a second detector  140  configured to detect the second detection marker  230  is correspondingly provided on the pivot member  100 . After the first detector  110  detects that the first detection marker  310  on the shifter lever  300  generates the first reset signal (as shown in  FIG. 7 ), the system drives the pivot member  100  to rotate in the second rotation direction relative to the pivot shaft  200 , the resisting end of the elastic member  130  resists against the shifter lever  300  to cause the shifter lever  300  to remain motionless, the first detector  110  moves away from the first detection marker  310  until the second detector  140  detects the second detection marker  230  on the drive wheel  210  (as shown in  FIG. 8 ), then a second reset signal is generated, and this position is taken as a precise initial position. Due to the fact that the shifter lever  300  is sleeved on the pivot shaft  200 , the shifter lever  300  may rotate with the pivot member  100  relative to the pivot shaft  200  because of a problem of friction force between the shifter lever  300  and the pivot member  100 , and that the reset is easy to deviate from a predetermined position if the preliminary initial position is taken as the reset position, thus the position at which the second detector  140  generates the second reset signal for the first time is taken as the precise initial position, when, marked by the first reset signal, the pivot member  100  rotates in the second rotation direction relative to the pivot shaft  200 . When the precise initial position is taken as the reset position, the system will be more stable without deviation, and the reset is more accurate. 
     The pivot member  100  is continued to be driven to rotate in the second rotation direction relative to the pivot shaft  200 . After the pivot member  100  is rotated approximately 360° in the second rotation direction relative to the pivot shaft  200 , the second limiting post  120  can push the shifter lever  300  to rotate together, and finally the shifter lever  300  can be blocked by the first limiting post  220  (as shown in  FIG. 9 ), thereby limiting the pivot member  100  to continue rotation relative to the pivot shaft  200 , at which time a maximum relative rotation angle is reached. 
     In a preferred embodiment of the present invention, on the second detector  140 , the pivot member  100 , the second limiting post  120 , the first detector  110  and the resisting end are sequentially provided in the first rotation direction, and on the drive wheel  210 , the second detection marker  230  and the first limiting post  220  are also sequentially provided in the first rotation direction. At this time, a sector central angle centered on a center of the pivot shaft  200  from the second detection marker  230  to the first limiting post  220  in the first rotation direction is less than 180°. 
     Further, taking the center of the pivot shaft  200  as a center, a sector central angle from the second detection marker  230  to the first limiting post  220  in the first rotation direction is less than 120° and preferably 60°, and when the first detection marker  310  on the shifter lever  300  is detected by the first detector  110 , the central angle between the second detection marker  230  and the first detector  110  is greater than that between the second detector  140  and the first detector  110 . Thus, after the first detector  110  detects that the first detection marker  310  on the shifter lever  300  generates the first reset signal, the pivot member  100  is only required to rotate a smaller angle relative to the pivot shaft  200  in the second rotation direction to achieve detection of the second detection marker  230 , so that the reset is quicker. 
     In a preferred embodiment of the present invention, the second detection marker  230  is a magnet, the second detector  140  is a magnetic sensitive switch, and/or the first detection marker  310  is a magnet, and the first detector  110  is a magnetic sensitive switch. Magnetic induction is less susceptible to interference from acoustic, optical and non-magnetic material, which results in higher stability. 
     In other embodiments, the second detection marker  230  and/or the first detection marker  310  can also be a color marker, a touch point, or the like, and the second detector  140  and/or the first detector  110  can correspond to a light intensity sensor, a touch switch light, or the like. 
     When the second detection marker  230  and the first detection marker  310  are both magnets while the second detector  140  and the first detector  110  are both magnetic sensitive switches, the second detection marker  230  and the first detection marker  310  have different spacings from the center of the pivot shaft  200  to avoid interaction between each other. When the second detection marker  230  and the first detection marker  310  are of different types, the second detection marker  230 , the first detection marker  310  can have the same spacing from the center of the pivot shaft  200 . 
     In a preferred embodiment of the present invention, both the second detection marker  230  and the second detector  140  are located on one side of the drive wheel  210  away from the shifter lever  300 , and both the first detection marker  310  and the first detector  110  are located on one side of the shifter lever  300  away from the drive wheel  210 . In this manner, two detection systems are independent of each other to prevent the second detection marker  230  from affecting the first detector  110  and prevent the first detection marker  310  from affecting the second detector  140 . 
     In a preferred embodiment of the present invention, a minimum distance between the second limiting post  120  and the center of the pivot shaft  200 , and a minimum distance between the elastic member  130  and the center of the pivot shaft  200  are greater than a maximum distance between the first limiting post  220  and the center of the pivot shaft  200 . Thus, when the second limiting post  120  and the elastic member  130  rotate together relative to the pivot shaft  200 , the first limiting post  220  cannot be touched, and relative rotation of the pivot member  100  and the pivot shaft  200  cannot be affected. In other embodiments, a minimum distance between the first limiting post  220  and the center of the pivot shaft  200  is greater than a maximum distance between the second limiting post  120  and the center of the pivot shaft  200 . 
     In a preferred embodiment of the present invention, when the first detector  110  detects the first detection marker  310 , the second limiting post  120  is not in contact with the shifter lever  300 . That is, there is a distance between the second limiting post  120  and the first detector  110  such that the second limiting post  120  cannot squeeze the shifter lever  300  and emit collision noise when the first detector  110  detects the first detection marker  310 . In the present embodiment, the second limiting post  120  is in close proximity to the first detector  110 . 
     In a preferred embodiment of the present invention, the pivot shaft  200  is fixed to a position, and the pivot member  100  self-rotates about the pivot shaft  200 . The pivot member  100  drives the second limiting post  120 , the first detector  110 , and the elastic member  130  that are provided on the pivot member  100  to rotate together, while the pivot shaft  200  and the drive wheel  210  and the first limiting post  220  that are provided on the pivot shaft  200  remain motionless. In other embodiments, the pivot member  100  can remain motionless while the pivot shaft  200  drives the drive wheel  210  and the first limiting post  220  to rotate. 
     In a preferred embodiment of the present invention, the pivot member  100  is a support arm of a stage light fixture or a light head of a stage light fixture. A stage light fixture generally includes a support arm rotatably connected to a base and a light head rotatably connected to the support arm. The low-noise light fixture reset structure can be used on the reset structure of the support arm and on the reset structure of the light head. 
     The present invention also provides a control method of any of the low-noise light fixture reset structures described above, including the following steps: 
     S1, driving the pivot member  100  to rotate in the first rotation direction relative to the pivot shaft  200  such that the resisting end of the elastic member  130  pushes the shifter lever  300  to rotate together until one side of the shifter lever  300  is blocked by the first limiting post  220 ; 
     S2, continuing to drive the pivot member  100  to rotate in the first rotation direction relative to the pivot shaft  200 , the other side of the shifter lever  300  resisting against the resisting end to deform the elastic member  130  to the second rotation direction, thereby causing the first detector  110  to detect the first detection marker on the shifter lever  300  and generate the first reset signal; and 
     S3, driving the pivot member  100  to rotate in the second rotation direction relative to the pivot shaft  200 , the resisting end of the elastic member  130  resists against the shifter lever  300  to remain motionless, and the first detector  110  moving away from the first detection marker  310  to complete a reset. 
     Since the second limiting post  120  is not required to touch the shifter lever  300  resisted against by the first limiting post  220 , the pivot member  100  do not bounce back under the action of a reaction force, thereby avoiding noise like “click, click, click . . . ” generated by multiple times of collision and creating a quieter reset process. 
     In a preferred embodiment of the present invention, a second detection marker  230  is provided on the drive wheel  210 , and a second detector  140  that detects the second detection marker  230  is correspondingly provided on the pivot member  100 ; and 
     in step S3, after the first detector  110  is moved away from the first detection marker  310 , the pivot member  100  is continued to be driven to rotate in the second rotation direction relative to the pivot shaft  200  until the second detector  140  detects the second detection marker  230  on the drive wheel  210 , and then a second reset signal is generated to complete a reset. 
     Due to the fact that the shifter lever  300  is sleeved on the pivot shaft  200 , the shifter lever  300  may rotate with the pivot member  100  relative to the pivot shaft  200  because of a problem of friction force between the shifter lever  300  and the pivot member  100 , and that the reset is easy to deviate from a predetermined position if the position of the first detection marker  310  on the shifter lever  300  detected by the first detector  110  is taken as the reset position, thus the position at which the second detector  140  generates the second reset signal for the first time is taken as the precise initial position, when, marked by the first reset signal, the pivot member  100  rotates in the second rotation direction relative to the pivot shaft  200 . When the precise initial position is taken as the reset position, the system is more stable without deviation, and the reset is more accurate. 
     Obviously, the above embodiments of the invention are merely examples for clear illustration of the invention, and are not intended to limit the implementation of the invention. For those skilled in the art, modifications or changes in other forms can also be made on the basis of the above description. It is unnecessary and impossible to exhaust all implementations herein. Any modification, equivalent substitution, improvement or the like within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.