Patent Publication Number: US-2005127863-A1

Title: Door opener error-start prevention device

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to a door opener error-start prevention device, and particularly to a device which solves a jammed problem by itself, and which then makes the door opener reverse and then return back to its original position, when a door opener and a latch device are jammed, and rotation of a door opener is hindered, because of error-start.  
      2. Description of the Prior Art  
      Referring to  FIG. 1 , as an example illustration, for all rolling doors or sectional door or doors that move up and down in vertical direction, rolling doors that move in horizontal direction, sectional doors that moves in a manner that is parallel to the ground or other doors that are opened or closed in an electrical operation manner. For safety reason, a conventional door opener is usually provided with a latch device  2  on one side of the rolling door  1 , the purpose of which is to avoid being externally enforced opened either by a jack or by other means, after the door is closed. The latch device  2  of the rolling door  1  is locked from outside, after the door is closed. However, the latch device  2  must be unlocked at first, before the switch  3  for the rolling door  1  is switched on. In some cases, users often forget to unlock the latch device  2  before switching on the switch  3  for the rolling door  1 . As a result, the rolling door  1  is jammed with the latch pin of the latch device  2 , and this will result in switching on safety device and switching off the electrical power. In this case, neither can the rolling door  1  be opened, nor can the latch device  2  be unlocked. The only solution is to eliminate the jammed condition between the rolling door  1  and the latch device  2 , i.e., the rolling door  1  must return back to its original loose status and then the latch device  2  can be unlocked and the switch  3  of the door opener can be switched on again. Therefore the design of conventional rolling door  1  still has room for improvement.  
     SUMMARY OF THE INVENTION  
      In order to solve the jammed problem caused by error-starting of the conventional vertical, horizontal or parallel moving doors, the inventor of the present invention endeavored to think out that the door opener should have the function of self-restoration to avoid the jammed problem caused by the-error-start of the door. Therefore, the object of present invention is to provide a door opener error-start prevention device, in which a sensor device senses a backward movement caused by a sliding pin which is radially inserted into an output shaft of the door opener, and then the sensor device switches off the electrical power and temporarily supplies a reverse current, so as to make the door opener rotate in a reverse direction and then make the door return back to its original position.  
      The above object can be achieved by the door opener error-start prevention device of the present invention, comprising: a base; a door opener, one end of which has a mounting seat mounted on the base, the other end of which accommodates a power unit, and which transmits a power to an end gear; an output shaft, a first end of which has an axially central hole and is mounted at the center of the end gear, a second end of which extends into the base and is mounted in the base, and which is provided with a pair of sliding slots formed by penetrating the central hole; a sprocket assembly which is connected to the second end of the output shaft in a freely rotatable manner, one end of which comprises a sprocket that synchronously moves with a sprocket of a rolling shaft of the door through a chain, and the other end of which is integrally formed with a sleeve, a pair of V-shaped slots being formed, in respect to the sliding slots of the output shaft, in periphery of the sleeve; a sliding pin which is radially inserted into the sliding slots of the output shaft, and both ends of which are installed in the V-shaped slots of the sleeve; a compression spring which passes through and is installed in the central hole of the output shaft, one of which is mounted by means of an fastener, and the other end of which abuts against the sliding pin; a swaying plate which is installed beside of the sliding pin, one end of which is mounted on the base of the door opener, and the other end of which is a free end and can sway freely; a switch device which is installed beside of the free end of the swaying plate.  
      According to the present invention, the V-shaped slots on the sleeve of the sprocket assembly comprises a large end and a small end, in which the large end forms a gradually larger opening in an opposite direction of the compression spring. Generally speaking, both ends of the sliding pin respectively engages with the small end of the V-shaped slots, so as to drive the sprocket assembly. When the rolling door is jammed with the latch device, due to error-start, and rotation of the output of the door opener cannot drives the sprocket assembly, then torque of output shaft of the door opener will make the sliding pin have a force to resist pressure of the compression spring, and then move back toward the gradually larger opening of the large end of the V-shaped slots; moreover, when the sliding pin moves back, then the sliding pin will compress the swaying plate, and then trigger the switch device for switching off the electrical power for opening the door, and a reverse current is supplied through a prior circuit, so as to make the door opener rotate in a reverse direction, and then make the door return back to its original position. Therefore, the jammed condition can be eliminated, and then the door opener can be re-started again. 
    
    
     A BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic view of a conventional rolling door;  
       FIG. 2  is a schematic view of an embodiment of the door opener error-start prevention device of the present invention in which some component parts are omitted;  
       FIG. 2   a  is an another schematic view of a sprocket in the  FIG. 2 ;  
       FIG. 3  is a perspective view of the embodiment of the  FIG. 2  in which some component parts are omitted.  
       FIG. 4  is a front view of the embodiment of the door opener error-start prevention device of the present invention;  
       FIG. 5  is a sectional view taken along with  5 - 5  line in the  FIG. 4 , in which some component parts are omitted.  
       FIG. 5   a  is an enlarged view of  5   a  portion in the  FIG. 5 ;  
       FIG. 6  is an enlarged view of the  FIG. 5 , in which a sprocket assembly is sectional, and shows that a sliding pin is in a normal drive position;  
       FIG. 6   a  is an enlarged view of  6   a  portion in the  FIG. 6 :  
       FIG. 7  is a view showing a backward movement caused by the sliding movement, when rotation of an output shaft in the  FIG. 6  is hindered;  
       FIG. 7   a  is an enlarged view of  7   a  portion in the  FIG. 7 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION (PREFERRED EMBODIMENTS)  
      The technological features and advantages of present invention will be further understood with the description of a preferred embodiment of present invention, which is considered to be illustrative purpose only and should not be regarded as limitative, in reference to accompanied drawings.  
      First, referring to FIGS.  2  to  5 , a door opener error-start prevention device  10  of the present invention comprises: 
          a base  4  which is provided at a lateral side of an accommodating chamber  6  of an upper-side rolling shaft  5  of a rolling door  1  (the same as reference numerals of a conventional door opener as shown in  FIG. 1 );     a door opener  20  which comprises a housing  20   a , one end of which has a mounting seat  21  that is mounted on the base  4 , and the other end of which accommodates a power unit  22 , the power of the power unit being transmitted to an end gear  23  through a gear assembly;     an output shaft  24 , a first end  24   a  of which is mounted at center of the end gear  23 , and a second end  24   b  of which extends into the base, and is mounted in the base, the center of the first end  24   a  having an axially central hole  241 ; moreover, a pair of axial sliding slots  242  being formed in a manner that passes through the central hole  241 ;     a sprocket assembly  25  which is connected to the second end  24   b  of the output shaft  24  in a freely rotatable manner, the outer side of the sprocket assembly  25  comprising a sprocket  251 , the sprocket assembly  25  synchronously moving with a sprocket  51  on a rolling shaft  5  of the rolling door through a chain  26 , an inner side of the sprocket assembly  25  being integrally formed with a sleeve  252 , a gear  254  being mounted on the sleeve  252  and synchronously moving with a limitation switch (not shown), a pair of V-shaped slots  253  being formed, in respect to sliding slots  242  on the output shaft  24 , in periphery of the sleeve  252 ;     a sliding pin  27  which is radially inserted into the sliding slots  242  of the output shaft  24 , and both ends of which extend into and are respectively mounted in the pair of V-shaped slots  253  of the sleeve  252 , so as to drive the sprocket assembly  25 , a positioning bump  271  being formed in the middle of the sliding pin  27  in a vertical direction;     a spring  28  which passes through and is installed in the central hole  241  of the output shaft  24 , one end of which is mounted at a first end  24   a  of the output shaft  24  by a fastener  29 , and the other end of which is mounted on the positioning bump  271  of middle of the sliding pin  27 , the spring being intended to push the sliding pin  27  toward the second end  24   b;       a swaying plate  30  which is installed beside of the sliding pin  27 , and is in a position where the swaying plate is not in contact with the sliding pin  27 , one end  30   a  of which is mounted on a mounting seat  21  of the door opener  20 , and the other end  30   b  of which is a free end and can sway; and     a switch device  31  which is installed beside the free end  30   b  of the swaying plate  30 , and which is used to detect whether the sliding pin  27  is in a normal drive position or not, in which the switch device  31  can be, for example, a touch-type micro switch or an optical-type sensor (not shown); however, in the preferred embodiment of the present invention, only the touch-type micro switch is represented for illustrative purpose.        

      Referring to  FIGS. 6 and 6   a , according to the present invention, pressure that the compression spring  28  abuts against the sliding pin  27  is selected either based on weight of the door and on strength of the sliding pin  27  for choosing the compression spring  28  having an appropriate pressure, or based on sensitivity by adjusting the pressure of the compression spring  28  through the fastener  29 , which compression spring abuts, with a pressure that is in response to weight of the rolling door, against the sliding pin  27 . As shown in  FIGS. 2   a  and  5   a , the slots  253  on the sleeve  252  of the sprocket assembly  25  comprises a small end  253   a  in a direction of pressure of the compression spring  28 , and comprises a large end  253   b  having a gradually larger opening in an opposite direction of the compression spring  28 . Generally, the compression spring  28  pushes the sliding pin  27  toward the second end  24   b  of the output shaft  24 , and thus abuts against the small end  253   a  of the slots  253 , so as to drive the sprocket assembly  25 .  
      Again, as shown in  FIGS. 7 and 7   a , when the rolling door and the latch device are jammed, because of error-start and rotation of the output shaft  24  of the door opener  20  cannot drive the sprocket assembly  25 , then the torque of the output  24  will make the sliding pin  27  have a force to resist the pressure of the compression spring  28 , and then move back toward the gradually larger opening  253   b  of the large end of the slots  253 ; moreover, when the sliding pin  27  moves back, then the sliding pin  27  will compress the swaying plate  30  for making the free end  30   b  sway, and then trigger an arm  31   a  of the switch device  31  for switching off the electrical power for rising the rolling door. According to the present invention, as shown in a prior circuit, normal close (NC) contact of the switch device  31  is electrically connected to a circuit for opening the door; on the contrary, normal open (NO) contact is electrically connected to a circuit for closing the door. Therefore, when the free end  30   b  of the swaying plate  30  is in contact with the arm  31   a  of the switch device  31 , then electrical power for the circuit for opening the door opener is switched off, and a reverse current provided by the prior circuit can make the door opener  20  rotate in the reverse direction, and make the door opener return back to its original position. Therefore, the jammed condition can be eliminated, and then the door opener can be re-started again.  
      The above-mentioned door opener of the door opener error-start prevention device can be used as the conventional electrical doors, for example, rolling doors or sectional doors that move up and down in vertical direction, rolling doors that move in horizontal direction, sectional doors that moves in a manner that is parallel to the ground, or other doors that is opened or closed by an electrical manner. Therefore, the aforesaid preferred embodiment of the present invention for illustrative purpose only, and it should not be considered as a limitative to present invention. Any equivalent modifications and variations are considered to be within the range of present invention without departing from the spirit and scope of the appended claims.  
      Based on the foregoing, the door opener error-start prevention device of the present invention has the function of self-restoration even at low cost and at low expenses, even when the door opener is jammed with the latch pin due to error-start; Therefore, this invention is novel in design, and, has inventive steps comparing to convention device and potential feasibility in industrial application.