Patent Publication Number: US-2018027979-A1

Title: Anti-pinch headrest regulating mechanism

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to the technical field of manufacturing motorized furniture, and more particularly, to an anti-pinch headrest regulating mechanism. 
     BACKGROUND OF THE INVENTION 
     A luxury sofa, chair or bed is usually equipped with a headrest at the upper part of the backrest, which is used to support and comfort a user&#39;s head. To achieve an ideal supporting effect, the headrest needs to be regulated according to the physical difference between the user and the real-time demand of the user&#39;s body. In the prior art, when the user or anyone else carelessly places his hand between the headrest part and the backrest part, which is hinged to the headrest part, the headrest regulating mechanism may easily pinch and hurt his hand during the reset process. In conclusion, the shortcomings of the traditional headrest regulating mechanism are urgent problems that need to be solved for those skilled in this field. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is to provide a safe and reliable anti-pinch headrest regulating mechanism having a reasonable and simple structure. 
     To achieve the above purpose, the present invention adopts the following technical solution: 
     The anti-pinch headrest regulating mechanism comprises a headrest part, a backrest part, a pushrod motor having a unidirectional push force, a hinge device and two tension springs. The headrest part is rotatably hinged to the backrest part through the hinge device. The base end of the pushrod motor is rotatably connected to the backrest. The pushrod of the pushrod motor is rotatably connected to the headrest part. The tension springs impose a reset force on the headrest part and the backrest part when the pushrod is propelled by the pushrod motor to extend to push the headrest part far from the backrest part. 
     In another aspect of the present invention, the hinge device comprises a hinge, which is fixedly connected to the headrest part, and a hinge, which is fixedly connected to the backrest part. The hinge, which is fixedly connected to the headrest part, is slidably coupled to the hinge, which is fixedly connected to the backrest part. The hinge, which is fixedly connected to the headrest part and the hinge, which is fixedly connected to the backrest part, can slide toward each other and form an arc-shaped sliding path. 
     In another aspect of the present invention, an arc-shaped slot is disposed on the hinge, which is fixedly connected to the headrest part, and a guide post is disposed on the hinge, which is fixedly connected to the backrest part. The guide post can penetrate into the arc-shaped slot. 
     In another aspect of the present invention, one end of the tension spring is connected to the backrest part, and the other end of the tension spring is connected to the headrest part. 
     In another aspect of the present invention, one end of the tension spring is connected to the backrest part, and the other end of the tension spring is connected to the hinge, which is fixedly connected to the headrest part. 
     In another aspect of the present invention, the anti-pinch headrest regulating mechanism further comprises a horizontal rod. The headrest part is rotatably hinged to the backrest part through at least two hinge devices. The hinges, which are fixedly connected to the headrest part, are disposed at the two ends of the horizontal rod, and fixedly connected to the two ends of the horizontal rod. 
     In another aspect of the present invention, one end of the tension spring is connected to the backrest part, and the other end of the tension spring is connected to the horizontal rod. 
     In another aspect of the present invention, the base end of the pushrod motor is rotatably connected to the backrest part, and the pushrod of the pushrod motor is rotatably connected to the horizontal rod. 
     In another aspect of the present invention, the pushrod motor comprises a motor, a lead screw, a stretchable rod, a thread sleeve and a housing. The thread sleeve is a tubular hollow structure, and the inner wall of the thread sleeve is provided with the inner threads. The thread sleeve, which is disposed at the outside of the lead screw, is connected to the lead screw through the threads. The lead screw is propelled by the motor to rotate, enabling the thread sleeve to move through the transmission of the lead screw. A chamber, in which the stretchable rod is installed, is disposed in the housing. The stretchable rod, which can slide in the housing, is disposed on the moving path of the thread sleeve. The thread sleeve can push the stretchable rod to move in the housing. The outer surface of the thread sleeve and the stretchable rod are not in threaded connection. 
     In another aspect of the present invention, the transmission way, which enables the motor to propel the lead screw to rotate, is a worm gear transmission or driving belt transmission. 
     Compared with the prior art, the present invention has the following advantages: The structure of the present invention is simple and reasonable, which can effectively protect the users from being pinched and hurt by the hinge between the headrest part and the backrest part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To clearly expound the present invention or technical solution, the drawings and embodiments are hereinafter combined to illustrate the present invention. Obviously, the drawings are merely some embodiments of the present invention, and those skilled in the art can associate themselves with other drawings without paying creative labor. 
         FIG. 1  is a structure diagram of the present invention. 
         FIG. 2  is a structure diagram of another viewing angle of the present invention. 
         FIG. 3  is an enlarged structure diagram of part A in  FIG. 2 . 
         FIG. 4  is a structure diagram of the pushrod motor of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Drawings and detailed embodiments are combined hereinafter to elaborate the technical principles of the present invention. 
     Embodiment 1 
     As shown in  FIGS. 1 and 3 , the anti-pinch headrest regulating mechanism comprises a headrest part  1 , a backrest part  2 , a pushrod motor  3  having a unidirectional push force, a hinge device  4  and two tension springs  5 . The headrest part  1  is rotatably hinged to the backrest part  2  through the hinge device  4 . The base end of the pushrod motor  3  is rotatably connected to the backrest  2 . The pushrod of the pushrod motor  3  is rotatably connected to the headrest part  1 . The tension springs  5  impose a reset force on the headrest part  1  and the backrest part  2  when the pushrod is propelled by the pushrod motor  3  to extend to push the headrest part  1  far from the backrest part  2 . The headrest part  1  is pushed by the pushrod motor  3  to rotate, so as to be far from the backrest part  2 . The headrest part  1  can be reset by the acting force of the tension springs  5 . 
     The hinge device  4  in this embodiment comprises a hinge  41 , which is fixedly connected to the headrest part, and a hinge  42 , which is fixedly connected to the backrest part. The hinge  41 , which is fixedly connected to the headrest part, is slidably coupled to the hinge  42 , which is fixedly connected to the backrest part. The hinge  41 , which is fixedly connected to the headrest part and the hinge  42 , which is fixedly connected to the backrest part, can slide toward each other and form an arc-shaped sliding path. The hinge  41 , which is fixedly connected to the headrest part  1  can be exchanged to connect the backrest part  2 ; and, the hinge  42 , which is fixedly connected to the backrest part  2 , can be exchanged to connect the headrest part  1 , which is a commonly used technical solution for those skilled in the art. 
     An arc-shaped slot  410  is disposed on the hinge  41 , which is fixedly connected to the headrest part, and a guide post  421  is disposed on the hinge  42 , which is fixedly connected to the backrest part. The guide post  421  can penetrate into the arc-shaped slot  410 . The guide post  421  is limited by the arc-shaped slot  410  to move along the path of the arc-shaped slot  410 . 
     One installation method of the tension spring  5  in this embodiment is that one end of the tension spring  5  is connected to the backrest part, and the other end of the tension spring  5  is connected to the hinge  41 , which is fixedly connected to the headrest part  1 . In such case, the hinge  41  and the tension springs  5  are distributed at the two sides without occupying the space in the middle part. Another installation method of the tension spring  5  involves connecting one end of the tension spring  5  to the backrest part  2 , and connecting the other end of the tension spring  5  to the headrest part  1 . In this way, the headrest part  1  is located at a relative upper part, and the tension spring  5  can be extended through changing the installation site of the other end of the tension spring  5 . According to this arrangement, the reset force imposed on the headrest part  1  can be regulated, which is beneficial when the elastic force of the tension spring  5  decreases due to long-term use. 
     As shown in  FIG. 4 , the pushrod motor  3 , which only has a unidirectional push force, comprises a motor  31 , a lead screw  32 , a stretchable rod  33 , a thread sleeve  34 , and a housing  35 . The thread sleeve  34  is a tubular hollow structure, and the inner wall of the thread sleeve is provided with the inner threads. The thread sleeve  34 , which is disposed at the outside of the lead screw  32 , is connected to the lead screw  32  through the threads. The lead screw  32  is propelled by the motor  31  to rotate, enabling the thread sleeve  34  to move through the transmission of the lead screw  32 . A chamber  33 , in which the stretchable rod is installed, is disposed in the housing  35 . The stretchable rod  33 , which can slide in the housing, is disposed on the moving path of the thread sleeve  34 . The thread sleeve  34  can push the stretchable rod  33  to move in the housing  35 . The outer surface of the thread sleeve  34  and the stretchable rod  33  are not in threaded connection. However, a traditional pushrod motor  31  has a contracting force, with the outer surface of the thread sleeve  34  being connected to the stretchable rod  33  through the threads—which arrangement is the major difference between the pushrod motor of the present invention and the traditional motor having a contracting force. 
     The transmission way, which enables the motor  31  to propel the lead screw  32  to rotate, is a worm gear transmission or driving belt transmission. 
     This embodiment further comprises a horizontal rod  6 . The headrest part is rotatably connected to the backrest part through at least two hinge devices. The hinges, which are fixedly connected to the headrest part, are disposed at the two ends of the horizontal rod  6 , and fixedly connected to the two ends of the horizontal rod  6 . The horizontal rod  6  is used to improve the stability of the present invention. 
     After installing the horizontal rod  6 , another installation method of the tension spring  5  is that one end of the tension spring  5  is connected to the backrest part  2 , and the other end of the tension spring  5  is connected to the horizontal rod  6 , which makes the present invention more stable. In this way, the convenience and stability can be achieved during assembly. 
     The base end of the pushrod motor  3  is rotatably connected to the backrest part  2 , and the pushrod of the pushrod motor  3  is rotatably connected to the horizontal rod  6 . 
     The pushrod motor  3  in this embodiment merely has a unidirectional push force. Namely, the pushrod motor  3  has a push force when the pushrod is extended. An opposing acting force to the push force must be imposed from the outside during the reset process of the motor. During the operation of the present invention, the headrest part can be raised through the extension of the pushrod of the pushrod motor  3 . The pushrod of the pushrod motor  3  can overcome the pulling force of the tension spring  5  and the acting force of the headrest part  1 . The headrest part  1  can be reset according to the pulling force of the spring  5 . When the headrest part  1  moves to the end, the acting force maintained between the headrest part  1  and the backrest part  2  (where a hand may be pinched and hurt) is merely the acting force of the tension springs  5 . At this moment, the tension springs  5  are completely compressed so that the acting force becomes very tiny, significantly reducing the risk of injury. 
     The previous descriptions are of preferred examples for implementing the invention, and the scope of the invention should not necessarily be limited by this description. The scope of the present invention is defined by the claims.