Patent Publication Number: US-2020282870-A1

Title: Electric drive mechanism of seat rail

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The technical field relates to a slide rail, and more particularly to an electric drive mechanism of a seat rail capable of preventing the production of abnormal sounds effectively. 
     2. Description of Related Art 
     To adjust the position of a seat in a car, a seat rail is usually installed between the seat and a car body and capable of sliding back and forth. The seat rail comprises two parallel side rails with an interval apart from each other, and each slide rail includes an outer rail fixed to the car body and an inner rail slidably coupled to the outer rail, and the seat is mounted onto the inner rail. 
     To control the inner rail to slide with respect to the outer rail, an electric rail has been introduced to the market, wherein a driver is used to drive the inner rail to slide and move with respect to the outer rail. 
     However, when the conventional electric rail drives the inner rail to slide to a dead point of a stroke, a tall and big user may slide the seat all the way to the bottom towards the rear of the car, and a knocking sound may occur since adjacent objects may collide with each other, and this issue has been criticized for a long time, especially when such abnormal sound occurs in a high-end luxury car. 
     SUMMARY OF THE INVENTION 
     Therefore, it is a primary object of this disclosure to overcome the drawbacks of the prior art by providing an electric drive mechanism of a seat rail capable of preventing the production of abnormal sounds effectively. 
     To achieve the aforementioned and other objectives, this disclosure provides an electric drive mechanism of a seat rail, and the electric drive mechanism is installed between an inner rail and an outer rail of the slide rail and driven by a driving device, and the electric drive mechanism comprises: a front frame and a rear frame, disposed apart from each other and fixed to the outer rail; a lead screw, fixed and spanned between the front frame and the rear frame; a gear assembly, fixed to the inner rail and driven by the driving device, and engaged to the lead screw; and a bumper, selectively installed at one of the gear assembly and the rear frame; wherein, the bumper provides a buffering effect between the gear assembly and the rear frame to prevent the production of abnormal sounds. 
     Compared with the prior art, this disclosure has the following effect. An adjustment of sliding the slide rail all the way to the bottom can be made to prevent the production of abnormal sounds. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a seat rail and an electric drive mechanism of the seat rail of this disclosure; 
         FIG. 2  is a partial perspective view of  FIG. 1 ; 
         FIG. 3  is a partial exploded view of  FIG. 1 ; 
         FIG. 4  is an exploded view showing a bumper and a rear frame of this disclosure; 
         FIG. 5  is a cross-sectional view of  FIG. 1 ; 
         FIG. 6  is a partial blowup view of  FIG. 5 ; 
         FIG. 7  is another cross-sectional view of  FIG. 1 ; and 
         FIG. 8  is a partial blowup view of  FIG. 7 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The technical contents of this disclosure will become apparent with the detailed description of preferred embodiments accompanied with the illustration of related drawings as follows. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive. 
     With reference to  FIG. 1  for an electric drive mechanism of a seat rail in accordance with an embodiment of this disclosure, the seat rail of this embodiment is an automobile seat rail. The seat rail comprises two parallel slide rails  800  with an interval apart from each other, and each slide rail  800  includes an outer rail  8   b  fixed to a car body and an inner rail  8   a  slidably coupled to the outer rail  8   b . The driving device  7  drives the inner rail  8   a  of each slide rail  800  to slide with respect to the outer rail  8   b . The seat (not shown in the figure) is fixed onto the inner rail  8   a.    
     With reference to  FIGS. 1 to 3 and 5 to 8  for an electric drive mechanism  100  of this disclosure, the electric drive mechanism  100  comprises: a front frame  1   b , a rear frame, a bumper  2 , a lead screw  3  and a gear assembly  5 , and preferably further comprises a mount  4 , a plurality of fixing frames  6  and a connection frame H. 
     The front frame  1   b  and the rear frame are disposed with an interval apart from each other and fixed to an inner bottom wall of the outer rail  8   b . In  FIG. 4 , the rear frame preferably comprises a bottom plate  11  and two parallel sidewalls  12  coupled to both sides of the bottom plate  11  respectively, so as to form a substantially U-shaped structure. In addition, the rear frame further comprises a fixing plate  13 , and the rear frame is fixed to the outer rail  8   b  by the fixing plate  13 . Wherein, the fixing plate  13  may further be coupled to the two sidewalls  12  in addition to its connection with the bottom plate  11  to provide a better structural strength. 
     The lead screw  3  is fixed and spanned between the front frame  1   b  and the rear frame. To prevent the lead screw  3  from rotating with respect to the rear frame, the lead screw  3  is clamped between the two sidewalls  12 . In this embodiment, the lead screw  3  has a non-circular section  31  (for example, at least one cross-section is formed at the outer periphery of the lead screw  3 ). Therefore, the two sidewalls  12  of the rear frame can be clamped at the non-circular section  31  of the lead screw  3 . Particularly, a planar inner wall of the sidewall  12  is clamped at a planar outer cross-section of the non-circular section  31  to prevent the lead screw  3  from rotating with respect to the rear frame. It is noteworthy that a plugging space  14  is formed among the bottom plate  11 , two sidewalls  12  and the lead screw  3  (as shown in  FIG. 8 ). 
     The gear assembly  5  is fixed to an inner top wall of the inner rail  8   a  and driven by the driving device  7 . Specifically, a driving rod  71  of the driving device  7  is plugged into a first plug hole  51  of the gear assembly  5 , and the driving rod  71  is used for driving the gear assembly  5 . The gear assembly  5  is screwed to the lead screw  3  and capable of moving with respect to the lead screw  3 . Specifically, the lead screw  3  is plugged into a second plug hole  52  of the gear assembly  5 , so that the gear assembly  5  is engaged to the lead screw  3 , and the gear assembly  5  can be driven to move with respect to the lead screw  3 . Preferably, the gear assembly  5  has the mount  4 , and the gear assembly  5  is fixed to an inner top wall of the inner rail  8   a  by the mount  4 . 
     In  FIGS. 3 and 8 , the gear assembly  5  may comprise a gear assembly body (not labeled in the figure) and a mount  4 , wherein the gear assembly body is fixed into the mount  4 . In another embodiment, the gear assembly body may have the mount  4  protruding therefrom. 
     The bumper  2  is installed at the rear frame or the gear assembly  5 , and this disclosure is not limited to the aforementioned arrangements. In this embodiment, the bumper  2  is installed at the rear frame. The bumper  2  is made of a buffer material, but this disclosure is not limited by such material only. In this embodiment, the bumper  2  is made of rubber. 
     In  FIGS. 4 and 8 , the bumper  5  preferably comprises a buffer body  21  with a purlicue  211 , and the bumper  2  is clamped at the lead screw  3  by the purlicue  211 , so that the clamped bumper  2  can be situated at any position between the gear assembly  5  and the rear frame (for example, the clamped bumper  2  abuts against the rear frame or the gear assembly  5 ) to facilitate the buffering operation. The bumper  5  may also comprise a buffer body  21  and a convex body  22 , wherein the convex body  22  is protruded from the buffer body  21 , so that the bumper  2  can be plugged into the plugging space  14  by the convex body  22  in order to fix the bumper  2  to the rear frame. In the meantime, the buffer body  21  can be situated between the gear assembly  5  and the rear frame to facilitate the buffering operation. Of course, the bumper  2  preferably has both purlicue  211  and convex body  22  to provide the best fixing effect and prevent the bumper  2  from falling off from the rear frame. 
     In  FIGS. 7 and 8 , when a user adjusts the seat and moves the gear assembly  5  all the way to the bottom towards the rear of the car, the gear assembly  5  originally would hit the rear frame directly to produce a knocking sound will hit the buffer body  21  of the bumper  2  instead, since the bumper  2  exists between the gear assembly  5  and the rear frame. Therefore, no abnormal sound will be produced. In short, the electric drive mechanism  100  of this disclosure can effectively prevent the gear assembly  5  from hitting the rear frame directly, and thus having the function of preventing the production of abnormal sounds. 
     In  FIGS. 1, 5 and 6 , the two fixing frames  6  are fixed onto the inner rails  8   a  of the two slide rails  800  respectively, and the connection frame H is detachably spanned between the two fixing frames  6 , and the driving device  7  is fixed to the connection frame H. When it is necessary to perform a strength test of the slide rail  800 , the connection frame H together with the driving device  7   a  can be removed easily. In other words, the driving device  7  and the connection frame H are modularized, and users simply need to remove the connection frame H from the two fixing frames  6 , such that the whole module together with the driving device  7   a  can be removed without the need of removing the driving component (such as a motor), a driving shaft (such as a motor shaft) and a carrier frame (such as a frame for mounting the motor) and related components one by one. Therefore, this disclosure has a quick installation/removal effect. 
     In summation of the description above, this disclosure can surely achieve the expected effects and overcome the drawbacks of the prior art, and this disclosure also complies with patent application requirements, and thus is duly filed for patent application. 
     While this disclosure has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of this disclosure set forth in the claims.