Patent Publication Number: US-2023133080-A1

Title: Door opener with adjustable screw rod

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a door opener and, more particularly, to a door opener automatically that controls pivotal opening and pivotal closing of a door. 
     An electric door opener currently available on the market is mounted on a door frame to which a door is mounted to pivot between an open position and a closed position. The electric door opener includes a linkage connected to the door. When a driving device of the electric door opener operates to actuate the linkage to pivot, the door can move to an open position or a closed position. Doors and door frames could be different in size and shape due to various types or various manufacturers. Conventional linkages could not or are difficult to adjust the length thereof and, thus, could not be applied to doors of different sizes and/or shapes. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the above drawbacks, the present invention provides a door opener adapted to be mounted to a frame, including:
         a driving device including a motor and a first transmission member configured to be driven by the motor, wherein the driving device is configured to be operatively connected to a door mounted to the frame;   a push rod connected to the first transmission member to move therewith; and   a pressing rod unit pivotably coupled to the push rod, wherein the pressing rod unit includes a coupling sleeve and first and second end pieces spaced from each other and coupled to the coupling sleeve, wherein the first end piece is coupled with a first pivotal member, wherein the second end piece includes an inner threading, wherein the pressing rod unit further includes an adjusting screw rod in threading connection with the inner threading of the second end piece, wherein an end of the adjusting screw rod is located outside of the coupling sleeve and is coupled with a second pivotal member, wherein the second pivotal member is pivotably connected to the push rod, wherein when the adjusting screw rod rotates, the adjusting screw rod moves in an axial direction of the coupling sleeve to change a length of a portion of the adjusting screw rod outside of the coupling sleeve, and wherein the first pivotal member is configured to couple with the door.       

     The portion of the adjusting screw rod of the pressing rod unit outside of the coupling sleeve can be adjusted, such that the second linkage can be applied to frames and doors of various sizes, and the installation is more convenient. 
     In an example, the door opener further includes a locking member in threading connection with the adjusting screw rod and located outside of the coupling sleeve. The adjusting screw rod is prevented from rotation when the locking member abuts against the second end piece. The adjusting screw rod is rotatable when the locking member is spaced from the second end piece. 
     In an example, the coupling sleeve includes a first outer end and a second outer end. Each of the first and second outer ends has an inner threading. The first end piece includes a first threaded portion in threading connection with the inner threading of the first outer end and a second threaded portion spaced from the first threaded portion. The second end piece includes an outer threaded portion in threading connection with the second outer end of the coupling sleeve. 
     In an example, the door opener further includes a limiting member including two coupling walls spaced from each other and a limiting wall extending between the two coupling walls. The limiting wall is at a non-parallel angle to the push rod. The second pivotal member is pivotably connected to the two coupling walls. The pressing rod unit permits the push rod to pivot until the second pivotal member abuts against one of the limiting wall and the push rod. 
     The limiting member cooperates with the second push rod to limit the relative pivotal angle between the second push rod and the pressing rod unit. Thus, the driving device is less likely to be damaged by excessive torque manually applied to the door. 
     In an example, the door opener further includes:
         a mounting seat including an end;   a first side cover fixed to the end of the mounting seat,   a mode switching device disposed on the first side cover and including an anti-theft control module;   a control device electrically connected to the mode switching device and the driving device, wherein the control device includes a control panel configured to operate the driving device, wherein the mode switching device is switchable to a wake-up mode only when the anti-theft control module is unlocked, and wherein the driving device is operable by the control panel only when the mode switching device is in the wake-up mode; and   an outer cover coupled to the first side cover and covering an outer side of the driving device and an outer side of the control device, wherein the outer cover includes a window, and wherein the control panel of the control device is exposed via the window to permit operation of the control panel.       

     The control panel of the control device is operable only when the mode switching device is switched to the wake-up mode. Furthermore, by the disposition of the anti-theft control module on the mode switching device, the mode switching device can be switched to the wake-up mode only when the anti-theft control module is unlocked. Thus, the control panel can be disposed to be exposed for pressing operation via the window. As a result, it is not necessary to detach the outer cover. Accordingly, the control panel can be directly operated after the mode switching device is switched to the wake-up mode, which provides both the anti-theft effect and convenience while proceeding with setting or changing the parameters of the door opener. 
     In an example, the mode switching device is configured to switch between the wake-up mode, an OFF mode, an ON mode, and a hold open mode while the anti-theft control module is unlocked. Power is not supplied to the driving device when the mode switching device is in the OFF mode. Power is supplied to the driving device when the mode switching device is in the ON mode or the wake-up mode. The door remains in the open position under operation of the driving device when the mode switching device is in the hold open mode. 
     After the anti-theft control module is unlocked, the mode switching device is switchable between the OFF mode, the ON mode, and the hold open mode. Thus, mode switching of the door opener can be conducted without detaching the outer cover, providing both the anti-theft function and convenience. 
     In an example, the driving device further includes:
         a casing coupled to the motor, wherein the first transmission member is rotatably mounted to the casing;   a sliding member slidably mounted to the casing, wherein the sliding member slides in a lateral direction when the first transmission member rotates;   a connecting rod coupled to the sliding member to move jointly, wherein the connecting rod includes a threaded portion;   a return spring mounted around the connecting rod and not movable in the lateral direction; and   an adjusting ring in threading connection with the threaded section  86  of the connecting rod and located outside of the casing, wherein when the first transmission member does not rotate, rotation of the adjusting ring causes displacement of the adjusting ring in the lateral direction to change an extent of pre-compression of the return spring, wherein when the first transmission member rotates in a first direction, the connecting rod and the adjusting ring together move in the lateral direction towards the first transmission member, and the return spring is compressed, and wherein when the first transmission member rotates in a second direction reverse to the first direction, the connecting rod and the adjusting ring together move in the lateral direction away from the first transmission member, and the return spring restores its length.       

     After the door is manually opened while the door opener is out of electricity, the driving device permits the door to automatically return to the closed position through the manual return module. Furthermore, the adjusting ring of the manual return module is located outside of the movable sleeve, permitting easy adjustment of the extent of pre-set compression of the return spring according to practical needs. 
     In an example, the driving device further includes:
         a fixing sleeve mounted around the return spring and not movable in the lateral direction, wherein an end of the return spring abuts against the fixing sleeve  88 ; a movable sleeve mounted around the return spring, wherein the movable sleeve is slidably coupled to the fixing sleeve and is slidable in the lateral direction, wherein another end of the return spring abuts against the movable sleeve, wherein when the first transmission member does not rotate and the adjusting ring rotates, the movable sleeve and the adjusting ring together displace in the lateral direction, wherein a length of a portion of the connecting rod outside of the movable sleeve becomes longer when the extent of pre-compression of the return spring is increased, and wherein when the first transmission member rotates, the connecting rod, the adjusting ring, and the fixing sleeve together move in the lateral direction.       

     The inner diameter of the movable sleeve is slightly longer than the outer diameter of the return spring, and the outer diameter of the inner tube is slightly smaller than the inner diameter of the return spring. Furthermore, the end of the movable sleeve distant to the abutting end is adjacent to an end of the inner tube. Thus, the return spring will not distort during compression. As a result, operation of the manual return module is smoother. 
     In an example, the door opener further includes:
         a mounting seat including a bottom wall;   a reinforcing seat fixed to the bottom wall and including a plurality of coupling pegs protruding from an outer face thereof, wherein the driving device includes a plurality of lugs detachably coupled with the plurality of coupling pegs, wherein the driving device is configured to be operatively connected to the door for moving the door between an open position and a closed position;   a quick-release device including a quick-release seat fixed to the bottom wall, wherein the quick-release seat includes a first coupling portion, wherein the quick-release device further includes a movable member slidably coupled to the quick-release seat and slidable in a lateral direction, and wherein the movable member includes a movable coupling portion;   a control device including a protective housing and a control panel coupled to the protective housing, wherein the protective housing is detachably coupled with the first coupling portion and the movable coupling portion of the quick-release device, wherein the driving device is selectively mounted to make the motor face or face away from the control device; and   an outer cover covering an outer side of the driving device and an outer side of the control device, wherein the outer cover includes a window, and wherein the control panel of the control device is located in the window.       

     The four coupling pegs of the reinforcing seat and the four lugs of the casing permits easy installation and easy change in the direction of the driving device. Specifically, to simplify the installation, before using screws for tightening purposes, the driving device can be detachably coupled through the coupling between the four lugs and the four coupling pegs. This permits a worker to extend four screws (for fixing the driving device) into the four coupling pegs with two hands (namely, without the need of using a hand to hold the driving device). Since the four coupling pegs and the four lugs are arranged to be symmetric in the vertical and left/right directions, the assembling direction of the driving device can be easily changed in response to the open side or the opening direction of the door. 
     In an example, the door opener further includes a supporting device having a lining and a supporting member. The supporting member includes a first threaded portion and a second threaded portion. The supporting device further includes a fastener. The first threaded portion of the supporting member is in threading connection with lining. The fastener extends through the reinforcing seat and is in threading connection with the second threaded portion of the supporting member. When the supporting member rotates relative to the lining, the supporting member moves towards or away from the bottom wall. When the fastener rotates while the supporting and the lining do not rotate, the lining moves towards the bottom wall. 
     Each supporting device is mounted in the gap between the mounting seat and the frame to reinforce the overall coupling strength of the door opener installed on the frame. Furthermore, the lining and the supporting member of each supporting device can be rotated to adjust the length, so as to be applicable to frames of various sizes and shapes, thereby increasing the coupling strength between the door opener and the frame. 
     The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an exploded, perspective view of a door opener of an embodiment according to the present invention. 
         FIG.  2    is an exploded, perspective view of a driving device of the door opener of  FIG.  1   . 
         FIG.  3    is an exploded, perspective view of a mode switching device of the door opener of  FIG.  1   . 
         FIG.  4    is an exploded, perspective view of a mounting seat, a reinforcing seat, and a supporting device of the door opener of  FIG.  1   . 
         FIG.  5    is an exploded, perspective view of a quick-release device and a control device of the door opener of  FIG.  1   . 
         FIG.  6    is an exploded, perspective view of a first linkage and the door opener of  FIG.  1   . 
         FIG.  7    is an exploded, perspective view of the first linkage. 
         FIG.  8    is a diagrammatic perspective view illustrating mounting of the door opener of  FIG.  1    to a frame. 
         FIG.  9    is a portion of a cross sectional view taken along section line  9 - 9  of  FIG.  8   , illustrating the mode switching device. 
         FIG.  10    is a cross sectional view taken along section line  10 - 10  of  FIG.  9   . 
         FIG.  11    is another portion of the cross sectional view taken along section line  9 - 9  of  FIG.  8   , illustrating the control device and the quick-release device. 
         FIG.  12    is a cross sectional view taken along section line  12 - 12  of  FIG.  8   . 
         FIG.  13    is a cross sectional view taken along section line  13 - 13  of  FIG.  12   . 
         FIG.  14    is a cross sectional view taken along section line  14 - 14  of  FIG.  13   . 
         FIG.  15    is a cross sectional view taken along section line  15 - 15  of  FIG.  14   . 
         FIG.  16    is a view similar to  FIG.  15    with the door moved to an open position. 
         FIG.  17    is a cross sectional view taken along section line  17 - 17  of  FIG.  16   . 
         FIG.  18    is a view similar to  FIG.  14    with an adjusting ring rotated to change the extent of pre-compression of a return spring. 
         FIG.  19    is a view similar to  FIG.  18    with the door being pivoted from the closed position to the open position. 
         FIG.  20    is an exploded, perspective view illustrating mounting of the door opener on a second protrusive portion of the frame. 
         FIG.  21    is a perspective view of the door opener mounted on the second protrusive portion of the frame, illustrating a change in the assembling direction of the control device and the driving device. 
         FIG.  22    is an exploded, perspective view of a second linkage used by the door opener. 
         FIG.  23    is a perspective view of the door opener mounted on the second protrusive portion of the frame. 
         FIG.  24    is a cross sectional view taken along section line  24 - 24  of  FIG.  23   . 
         FIG.  25    is a cross sectional view taken along section line  25 - 25  of  FIG.  24   . 
         FIG.  26    is a cross sectional view illustrating a pressing rod unit of the second linkage pivoted to a position pressing against a limiting member. 
         FIG.  27    is a cross sectional view illustrating an adjusting screw rod of the second linkage adjusted to a position in which a larger portion of the adjusting screw rod is exposed outside of a coupling sleeve. 
     
    
    
     All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the embodiments will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood. 
     Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “lower”, “upper”, “inner”, “outer”, “side”, “end”, “portion”, “section”, “axial”, “lateral”, “vertical”, “spacing”, “length”, and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to a door opener mounted to an outer side of a door frame for opening and closing a door. The door opener provides power for pushing the door. With reference to  FIGS.  6  and  13   , the door opener  20  is mounted to a frame  717  including a first side  719  and a second side  731  parallel to and spaced from the first side  719 . The frame  717  further includes a first protrusive portion  733 A on the first side  719  and a second protrusive portion  733 B on the second side  731 . The first protrusive portion  733 A includes a first protrusive wall  735 A on an outer side of the first side  719 . The second protrusive portion  733 B includes a second protrusive wall  735 B on an outer side of the second side  731 . The first protrusive portion  733 A is pivotably connected to a door  737 . The door  737  includes a first surface  739  and a second surface  751  parallel to and spaced from the first surface  739 . The first surface  739  and the first side  719  are on the same side. The second surface  751  and the second surface  731  are on the same side. The first surface  739  is substantially aligned with the first protrusive wall  735 A. The second surface  751  is located between the second side  731  and the first surface  739 . 
     With reference to  FIGS.  1  and  3   , the door opener  20  includes a mounting seat  22  extending in a lateral direction. The mounting seat  22  has two ends  23  spaced from each other in the lateral direction. The mounting seat  22  further includes a bottom wall  24  extending between the two ends  23  and an upper edge  26  and a lower edge  27 , with each of the upper and lower edges  26  and  27  extending between the two ends  23  and extending perpendicular to the bottom wall  24 . The mounting seat  22  can be secured to the frame  717  by screws and can be optionally mounted on the first protrusive portion  733 A or the second protrusive portion  733 B. In the embodiment show in  FIGS.  1 - 19   , the mounting seat  22  is mounted on the first protrusive wall  735 A of the first protrusive portion  733 A. 
     With reference to  FIGS.  1 ,  3 ,  9 , and  10   , the door opener  20  further includes first and second side covers  593  and  716  mounted to the mounting seat  22 . The first side cover  593  includes a first mounting portion  597  having three coaxial holes having different inner diameters. The first mounting portion  597  is stepped in cross section. The first side cover  593  further includes a second mounting portion  598  on an outer side of and adjacent to the first mounting portion  597 . The second mounting portion  598  can be in the form of a peg with a screw hole. The first side cover  593  includes a fixing portion  595  on a bottom end thereof. The second side cover  716  also includes a fixing portion (not shown). 
     The first side cover  593  and the second side cover  716  are mounted to two sides of the mounting seat  22 , respectively. As shown in  FIGS.  1  and  3   , the first side cover  593  is mounted to one of the two ends  23  of the mounting seat  23  by two screws extending through the fixing portion  595  and is substantially perpendicular to the bottom wall  24 . The second side cover  716  is mounted to another end  23  of the mounting seat  22  in a way similar to the first side cover  593 . 
     With reference to  FIGS.  3 ,  9 , and  10   , a mode switching device  592  is disposed on the first side cover  593  and includes an anti-theft control module  599  fixed to the first mounting portion  597  and a switching module  713  fixed on the second mounting portion  598 . The mode switching device  592  further includes a control module  715  fixed in the first side cover  593 . The control module  715  is electrically connected to the switching module  713  which is used to switch the mode of the control module  715 . In the form shown, the anti-theft control module  599  is a lock cylinder that can be operated only after unlocking by a metal key. The anti-theft control module  599  in the form of a lock cylinder includes a pivotable actuating piece  711  on an outer side of the lock cylinder. 
     The switching module  713  cooperates with the anti-theft control module  599  in the form of a lock cylinder and includes a push rod  718  that can displace physically to achieve the switching function of the switching module  713 . As shown in  FIG.  10   , the actuating piece  711  is adjacent to the switching module  713 . When a key is used to unlock the anti-theft control module  599  in the form of a lock cylinder, the actuating piece  711  pushes the switching module  713  to switch the operation mode of the door opener  20 . Note that the physical displacement achieving the switching function of the switching module  713  includes four positions corresponding to four different modes, respectively. In an embodiment, the four positions of the switching module  713  corresponds to a non-conductive (OFF) mode, a conductive (ON) mode, a wake-up (W/U) mode, and a hold open (H/O) mode of the control module  715 . 
     Alternatively, the anti-theft control module  599  can be a mechanism other than a lock cylinder. For example, the anti-theft control module  599  can be a Bluetooth control module. The switching module  713  is an electric programmable control unit. For example, after a smart mobile device of a user is connected to the anti-theft control module  599  in the form of a Bluetooth control module (the anti-theft control module  599  is unlocked), the switching module  713  in the form of an electric programmable control unit controls switching of the mode of the door opener  20 . Accordingly, it can be appreciated that the anti-theft control module  599  can also be comprised of a remote control module. 
     It is noted that unlocking refers to the anti-theft control module  599  in a state in connection with a Bluetooth device when the anti-theft control module  599  is a Bluetooth control module. Alternatively, in a case that the anti-theft control module  599  is a remote control module, unlocking refers to the anti-theft control module  599  in a state capable of receiving a signal. 
     With reference to  FIGS.  1 ,  3 ,  5 , and  11   , the door opener  20  further includes q quick-release device  197  fixed to the mounting seat  22  and a control device  175  detachably coupled to the quick-release device  197 . The control device  175  is in electrical connection with the control module  715 . The quick-release device  197  includes a quick-release seat  199 . The quick-release device  197  includes a first coupling portion  317  on an end thereof and a first assembling portion  311  opposite to the first coupling portion  317 . The first assembling portion  311  includes a sliding groove  313  in a central portion thereof and extending in a lateral direction and two protrusions  315  on two sides thereof and extending in the lateral direction. The quick-release seat  199  further includes two second coupling portions  319  between the first coupling portion  317  and the assembling portion  311 . The quick-release seat  199  is screwed by screws to the mounting seat  22  at a position adjacent to the first side cover  593 . 
     The quick-release device  197  further includes a movable member  331  slidably coupled to the quick-release seat  199 . The movable member  331  includes a movable coupling portion  335  on a distal end thereof. The movable member  331  further includes an ear  337  on a bottom side thereof and two sliding blocks  333  spaced from and on two sides of the ear  337 . The movable member  331  can be slidably coupled with the assembling portion  311  of the quick-release seat  199 . The ear  337  of the movable member  331  is received in the sliding groove  313 . The two sliding blocks  333  and the two protrusions  315  can be slidably coupled. Thus, the movable member  331  can slide relative to the assembling portion  311  in the lateral direction. Furthermore, a biasing spring  339  is disposed between an end wall of the sliding groove  313  and the ear  337 . The biasing spring  339  biases the movable member  331  towards the first coupling portion  317 . It can be appreciated that when the movable member  331  moves in the lateral direction to compress the biasing spring  339 , the spacing between the first coupling portion  317  and the movable coupling portion  335  increases. 
     The control device  175  includes a protective housing  177  and a control panel  178  coupled to an end of the protective housing  177 . An electronic module required for operation of the door opener  20  is disposed in the protective housing  177 . The door opener  20  can be operated or set through use of the control panel  178 . The protective housing  177  includes two lateral sides  179  spaced from each other and a bottom side  193  extending between an end of one of the two lateral sides  179  and an end of another of the two lateral sides  179 . A first side coupling slot  191  and a second side coupling slot  195  are disposed on the two lateral sides  179 , respectively. The bottom side  193  includes two bottom coupling slots  192 . The first and second side coupling slots  191  and  195  are symmetric to each other. 
     When the movable member  331  of the quick-release device  197  is biased by the biasing spring  339  to a biased position, the spacing between the first coupling portion  317  and the movable member  339  in the lateral direction is smaller than a spacing between the first and second side coupling slots  191  and  195  of the control device  175  in the lateral direction. 
     During installation of the control device  175 , the movable member  331  is moved in a direction compressing the biasing spring  339  until the movable member  331  reaches a position in which the spacing between the first coupling portion  317  and the movable member  339  in the lateral direction is larger than the spacing between the first and second side coupling slots  191  and  195  of the control device  175  in the lateral direction. Thus, the bottom side  193  of the protective housing  177  of the control device  175  abuts against a surface of the quick-release seat  199 . The two second coupling portions  319  are respectively coupled with the two bottom coupling slots  192  of the bottom side  193  of the protective housing  177 , assuring the installation angle of the control device  175  is correct. Furthermore, the first coupling portion  317  is coupled with the first side coupling slot  191 , and the movable member  331  is released and moves towards the first coupling portion  317 . The movable coupling portion  335  of the movable member  331  is coupled with the second side coupling slot  195 . Thus, the control device  175  can be positioned in the correct position. 
     Thus, when it is desired to detach the control device  175 , the movable member  331  can be simply moved toward the direction compressing the biasing spring  339 , permitting easy detachment of the control device  175  from the quick-release device  197 . Such an arrangement permits rapid assembly or detachment of the control device  175  during maintenance of the control device  175  or changing the assembling orientation of the door opener  20 . 
     With reference to  FIGS.  1 ,  4 ,  12 , and  13   , the door opener  20  further includes a reinforcing seat  137  coupled to the mounting seat  22 . The reinforcing seat  137  can be made of a metal sheet. The reinforcing seat  137  includes four coupling pegs  139  protruding from an outer face thereof. The four coupling pegs  139  are arranged to be symmetric in the vertical direction and left/right direction. 
     The reinforcing seat  137  abuts against an inner face of the bottom wall  24  of the mounting seat  22  and is adjacent to an end of the second side cover  716 . The reinforcing seat  137  is fixed by a plurality of screws extending through the reinforcing seat  137  and the bottom wall  24  and in threading connection with the first protrusive portion  733 A of the frame  717 , such that the mounting seat  22  is fixed to the frame  717  and that the reinforcing seat  137  tightly abuts against the inner face of the bottom wall  24 . Furthermore, the plurality of coupling pegs  139  of the reinforcing seat  137  protrudes away from the bottom wall  24 . 
     With reference to  FIGS.  1 ,  2 ,  12 ,  14 , and  15   , the door opener  20  further includes a driving device  28  coupled with the reinforcing seat  137 . The driving device  28  includes a casing  30  having four lugs  40  on an outer side thereof for respectively coupling with the four coupling pegs  139  of the reinforcing seat  137 . The four lugs  40  are also arranged to be symmetric in the vertical direction and left/right direction. The casing  30  further includes a first mounting side  32  and the second mounting side  34  spaced from the first mounting side  32 . The casing  30  further includes two first pivotal portions  36  and the two second pivotal portions  38 . Each of the two first pivotal portions  36  is located between an associated one of the two second pivotal portions  38  and the second mounting side  34  in the lateral direction. Each of the second pivotal portions  38  is located between an associated one of the first pivotal portions  36  and the first mounting side  34  in the lateral direction. 
     The four lugs  40  of the casing  30  are coupled with the four coupling pegs  139 , and four screws are used to threadedly coupled with the four coupling pegs  139 . The casing  30  is, thus, fixed to the reinforcing seat  137 . Furthermore, when the mounting seat  22  is mounted to the first protrusive wall  735 A of the first protrusive portion  733 A, the casing  30  is so mounted that the first mounting side  32  faces the first side cover  593 , and the second mounting side  34  faces the second side cover  716 . 
     The two first pivotal portions  36  of the casing  30  rotatably receives a first transmission member  52 . The first transmission member  52  includes a first gear  58  and a second gear  60  larger than the first gear  58 . The first and second gears  58  and  60  are coaxial and rotate synchronously. The first transmission member  52  further includes first and second mounting ends  54  and  56  which extend beyond the two first pivotal portions  36  and which have non-circular cross sections. 
     The two second pivotal portions  38  of the casing  30  rotatably receive a second transmission member  62 . The second transmission member  62  includes a third gear  66  meshed with the second gear  60  and a follower gear  64  larger than the third gear  66 . The follower gear  64  and the third gear  66  are coaxial and rotate synchronously. The follower gear  64  can be a bevel gear. 
     A cap  42  is fixed to a first mounting side  32  of the casing  30 . A motor  44  is mounted to the cap  42  and includes a shaft extending into the casing  30  and jointly rotatable with a driving gear  45 . The motor  44  is located between the casing  30  and the first side cover  593  in the lateral direction. The driving gear  45  can be a bevel gar and meshes with the follower gear  64 . When the motor  44  operates, the driving gear  45  drives the second transmission member  62  to rotate, and the second transmission member  62  drives the first transmission member  52  to rotate. Furthermore, the driving device  28  is electrically connected to the control device  175 . Thus, the control module  715  can control the OFF mode, ON mode, the wake-up (W/U) mode, and the hold open (H/O) mode through cooperation of the control device  175  and the motor  44 . 
     A detection unit  68  is mounted to the casing  30  and includes a pinion meshed with the second gear  60 . When the second gear  60  rotates, the detection unit  68  detects operation of the motor  44  as well as the operating time of the motor  44 . 
     A supporting sleeve  46  is disposed on the second mounting seat  34  of the casing  30 . The supporting sleeve  46  includes a sliding groove  48  extending in the lateral direction to an outer end face  47  of the supporting sleeve  46 . The supporting sleeve  46  further includes a roller  50  spaced from the sliding groove  48 . The roller  50  is at an inner side of the casing  30 . The outer end face  47  of the supporting sleeve  46  is at an outer side of the casing  30 . 
     The driving device  28  further includes a sliding member  70  slidably coupled to the supporting sleeve  46 . The sliding member  70  includes a coupling portion  72  and a tail  73 . The sliding member  70  further includes an abutting face  74  extending from the tail  73  to the coupling portion  72  and a rack  71  extending between the coupling portion  72  and the tail  73 . The coupling portion  72  can be in the form of a hole. The sliding member  70  is slidably coupled with the sliding groove  48  of the supporting sleeve  46 . The abutting face  74  abuts the roller  50 . The rack  71  of the sliding member  70  meshes with the first gear  58  of the first transmission member  52 , and the coupling portion  72  faces the outer end face  47 . When the motor  44  operates, the sliding member  70  displaces in the lateral direction. Furthermore, since the tail  73  is free of rack, after the rack  71  of the sliding member  70  meshes with the first gear  58 , the sliding member  70  can only displace within the extent of the rack  71  in the lateral direction. Namely, when the sliding member  70  displaces in the lateral direction, the rack  71  cannot disengage from the first gear  58 . 
     The driving device  28  further includes a manual return module  77  coupled to the sliding member  70 . The manual return module  77  is located between the casing  30  and the second side cover  716  in the lateral direction. The manual return module  77  includes a connecting rod  78  having an inner end  80  and an outer end  82  spaced from the inner end  80 . The connecting rod  78  further includes a threaded section  86  extending from the outer end  82  towards but spaced from the inner end  80 . The inner end  80  of the connecting rod  78  is coupled with the coupling portion  72  of the sliding member  70  by a locking pin  84 . Thus, the connecting rod  78  and the sliding member  70  displace synchronously in the lateral direction. 
     The manual return module  77  further includes a fixing sleeve  88 , a movable sleeve  90 , and a return spring  94 . The return spring  94  is mounted around the connecting rod  78 . The fixing sleeve  88  is mounted around the return spring  94 . An end of the fixing sleeve  88  abuts against the outer end face  47  of the supporting sleeve  46 . An end of the return spring  94  abuts against the fixing sleeve  88 . Namely, the end of the fixing sleeve  88  is located between the outer end face  47  of the supporting sleeve  46  and the end of the return spring  94 . 
     The movable sleeve  90  is mounted around the return spring  94 . An end of the movable sleeve  90  is at an inner side of the fixing sleeve  88 . Another end of the movable sleeve  90  is abutted by another end of the return spring  94 . Since an outer diameter of the movable sleeve  90  is slightly smaller than an inner diameter of the fixing sleeve  88 , the movable sleeve  90  can displace in the lateral direction relative to the fixing sleeve  88 . Furthermore, an inner diameter of the movable sleeve  90  is slightly larger than an outer diameter of the return spring  94 , such that when the return spring  94  is compressed, the movable sleeve  90  avoids the return spring  94  from distorting. 
     The manual return module  77  further includes an inner tube  96  mounted between the connecting rod  78  and the return spring  94  and located adjacent to the inner end  80  of the connecting rod  78 . An outer diameter of the inner tube  96  is slightly smaller than an inner diameter of the return spring  94 . Thus, when the return spring  94  is compressed, the inner tube  96  cooperates with the movable sleeve  90  to assure that the return spring  94  will not distort. 
     The manual return module  77  includes an end cover  98 , an adjusting ring  113 , and an end cap  133 . The end cover  98  includes two positioning grooves  111  on an end face thereof. The end cover  98  is mounted to the outer end  82  of the connecting rod  78  and abuts an end of the movable sleeve  90 . The adjusting ring  113  has a non-circular outer periphery. The adjusting ring  113  further includes two receiving holes  117  corresponding to the two positioning grooves  111  and a central screw hole  115  spaced from the two receiving holes  117 . Each of the two receiving holes  117  receives a positioning spring  131  and a positioning member  119 . Each positioning spring  131  biases an associated positioning member  119  towards an associated positioning groove  111 . The screw hole  115  of the adjusting ring  113  is in threading connection with the threaded section  86  of the connecting rod  78 , such that the adjusting ring  113  moves in the lateral direction when the adjusting ring  113  rotates. When the two receiving holes  117  are aligned with the two positioning grooves  111 , the positioning members  119  are coupled with the positioning grooves  111 , preventing undesired self-rotation of the adjusting ring  113 . 
     The end cover  133  is mounted to the end face of the outer end  82  of the connecting rod  78  and is fixed to the outer end  82  of the connecting rod  78  via threading connection using a fastener  135 . The end cap  133  is used to prevent the adjusting ring  113  from disengaging from the connecting rod  78  in the lateral direction when the adjusting ring  113  rotates. 
     The door opener  20  further includes a linkage connected between the driving device  28  and the door  737 . According to an example shown in  FIGS.  6 ,  7 , and  15   , the linkage is a first linkage  355  including a first push rod  357 A having a first end  359 A and a second end  371 A. The first end  359 A of the first push rod  357 A has a non-circular hole. The second end  371 A includes three through-holes arranged in a triangular pattern. 
     The first linkage  355  includes a first connecting member  373 A having a first engaging end  375 A associated with the first mounting end  54  of the first transmission member  52  and a second engaging end  377 A associated with the second mounting end  56  of the first transmission member  52 . The first engaging end  375 A has a non-circular hole. The second engaging end  377 A has an outer periphery matched with the non-circular hole of the first end  359 A of the first push rod  357 A. The second engaging end  377 A of the first engaging member  373 A and the first end  359 A of the first push rod  357 A engage with each other to rotate jointly. A screw extends through the first connecting member  373 A to threadedly engage with the first mounting end  54  or the second mounting end  56  of the first transmission member  52 . The first engaging portion  375 A of the first connecting member  373 A engages with the first mounting end  54  or the second mounting end  56  of the first transmission member  52  to rotate jointly. According to the form shown, the first engaging portion  375 A of the first connecting member  373 A engages with the first mounting end  54  of the first transmission member  52 . Thus, the first connecting member  373 A is sandwiched between the first push rod  357 A and the first transmission member  52 . According to the form shown in  FIG.  15   , the screw is in threading connection with the first mounting end  54 , such that the first connecting member  373 A and the first mounting end  54  are coupled together to rotate jointly. Thus, the first transmission member  52  pushes the first push rod  357 A to pivot when the motor  44  operates. 
     The first linkage  355  further includes a guiding wheel member  379  coupled to the second end  371 A. The guiding wheel member  379  includes an enlarged portion  391  and a narrower portion  392  which tapers away from the enlarged portion  391 . A guiding wheel  393  is rotatably mounted on the narrower portion  392 . The enlarged portion  391  of the guiding wheel member  379  is associated with the second end  371 A of the first push rod  357 A. In this embodiment, three screws extend through the three through-holes of the second end  371 A of the first push rod  357 A to be in threading connection with screw holes in the enlarged portion  391 . Thus, the guiding wheel member  379  is securely coupled with the first push rod  357 A. 
     The first linkage  355  further includes a track member  395  (see  FIGS.  6 ,  13   , and  15 ) mounted to an upper end of the first surface  739  of the door  737 . The track member  395  includes a track  397  extending in the lateral direction. Two coupling pegs  399  extend through the second surface  751  towards but spaced from the first surface  739  of the door  737 . Two bolts  511  extend through two ends of the track member  395  and threadedly engage with the two coupling pegs  399 . Thus, the track member  395  is fixed to the first surface  739  of the door  737 . The narrower portion  392  of the guiding wheel member  379  and the guiding wheel  393  are received in the track  397  of the track member  395 . 
     With reference to  FIGS.  1 ,  13 ,  15 , and  18   , the pivoting direction of the door  737  pivoting from the closed direction to the open position and the assembling direction of the door opener  20  are at the same side, such that the door opener  20  can only be mounted above the top end of the door  737 , avoiding the door opener  20  from interfering with pivotal movement of the door opener  20  towards the open position. Thus, a portion of the mounting seat  22  of the door opener  20  will protrude outside of the first protrusive portion  733 A. As a result, two supporting devices  153  ( FIG.  4   ) are mounted to an outer side of the mounting seat  22  to securely fix the mounting seat  22  to the frame  717 . 
     Each of the two supporting devices  153  includes a lining  155  in the form of a cylinder and a supporting member  159  in threading connection with the lining  155 . Each lining  155  includes a screw hole  157  with an inner threading. Each supporting member  159  includes a first threaded portion  171  having an outer threading for threading connection with the screw hole  157  and a second threaded portion  173  in the form of a screw hole formed in an end face of the first threaded portion  171 . Each supporting member  159  further includes a head  174  formed at an end of the first threaded portion  171  and located opposite to an open end of the second threaded portion  173  in the form of a screw hole. The first threaded portion  171  of each of the two supporting members  159  is in threading connection with the screw hole  157  of an associated one of the linings  155 . When relative rotation occurs between the two supporting members  159  and the two linings  155 , the two supporting members  159  move towards or away from the bottom wall  24 . 
     Each supporting device  153  is disposed on an outer face of the bottom wall  24  of the mounting seat  22  and is located between the bottom wall  24  and the first side  719 . Since the perpendicular distance between the first side  719  and the first protrusive wall  735 A may change, each supporting device  153  can be used to permit relative rotation between each supporting member  159  and the associated lining  155 , such that the supporting device  153  may extend or shorten to span between and abut against the bottom wall  24  of the mounting seat  22  and the first side  719  of the frame  717 . In this embodiment, an end of each lining  155  abuts against the bottom wall  24  of the mounting seat  22 , and the head  174  abuts against the first side  719  of the frame  717 . 
     Each supporting device  153  further includes two fasteners  151  extending through the reinforcing seat  137  and the bottom wall  24  and in threading connection with the second threaded portions  173  of the two supporting members  159 . When the two fasteners  151  are tightened while the two supporting members  159  and the two linings  155  are not rotated, the two linings  155  and the two supporting members  159  move toward the bottom wall  24 , such that an end of each of the two linings  155  abuts against the wall  24 . Furthermore, the head  174  of each of the two supporting member  159  abuts against the first side  719  of the frame  717 . Furthermore, the lower edge  27  of the mounting seat  22  abuts against the first protrusive wall  735 A of the first protrusive portion  733 A, securing fixing the whole door opener  20  to the frame  717 . 
     The door opener  20  further includes an outer cover  351  having a window  353 . The outer cover  351  is fixed between the first side cover  593  and the second side cover  716 . The control panel  178  of the control device  175  is located in the window  353  and is, thus, exposed for pressing purposes. 
     The structural features of the present invention and the first assembly mode thereof have been set forth. To assist in understanding the technical features of the first assembly mode of the present invention, operation of the embodiment of the present invention will be set forth in association with corresponding drawings. Firstly, it is assumed that the door  737  is in a closed position ( FIGS.  8  and  13   ), and the mode switching device  592  is set to the ON mode. In this state, a tooth of the first gear  58  abuts against the tail  73  of the sliding member  70 , the adjusting ring  113  of the manual return module  77  abuts the end cap  133 , and the spacing between the abutting end  92  of the movable sleeve  90  and the outer end face  47  of the supporting sleeve  46  in the lateral direction is maximal ( FIG.  14   ). 
     With reference to  FIGS.  15 - 17   , when the motor  44  operates, the driving gear  45  drives the second transmission member  62  to rotate, and the second transmission member  62  drives the first transmission member  52  to rotate. The first gear  58  of the first transmission member  52  pushes the sliding member  70  to slide in the lateral direction. Furthermore, the sliding member  70  actuate the connecting rod  78  and the end cap  133  to move in the lateral direction. Thus, the connecting rod  78  actuates the connecting ring  113  and the end cover  98  to press against the movable sleeve  90 , which, in turn, moves in the lateral direction towards the first transmission member  52 , and the return spring  94  is compressed by the movable sleeve  90 . 
     Furthermore, during rotation of the first transmission member  52 , the first mounting end  54  drives the first connecting member  373 A to pivot, and the first connecting member  373 A drives the first push rod  357 A to pivot. The guiding wheel member  379  presses against the track member  395  to push the door  737  to pivot in the opening direction (see  FIG.  16   ). The guiding wheel  393  of the guiding wheel member  379  slides along the track  397  of the track member  395 . 
     Furthermore, when the first transmission member  52  rotates, the second gear  60  drives the gear of the detection unit  68  to rotate. Thus, the detection unit  68  can identify the operation status of the motor  44 , such as the operation time or rounds. Thus, the detection unit  68  can control the opening angle of the door  737 . 
     Given the mode switching device  592  set to the ON mode, the pivotal movement of the door  737  from the open position to the closed position is achieved by reversing operation of the motor  44 . Specifically, assuming that the motor  44  rotates in a forward position to pivot the door  737  from the closed position to the open position, after a person passes through the door  737  or after a pre-determined period of time (such as a couple of seconds) has expired, the motor  44  rotates in a reverse direction to push the first connecting member  373 A by the first transmission member  52 . The push rod  357 A actuates the guiding wheel member  379  to press against the track member  395 , which, in turn, pushes the door  737  to pivot towards the closed position. The second gear  60  drives the pinion of the detection unit  68  to rotate. Thus, how long or how many turns the motor rotates for pivoting the door  737  from the open position to the closed position can be precisely detected. Furthermore, during the pivotal movement of the door  737  from the open position to the closed position, the movable sleeve  90 , the end cover  98 , the adjusting ring  113 , and the end cap  133  move away from the first transmission member  52  in the lateral direction, such that the return spring  94  restores its pre-set length. 
     It can be appreciated that with the mode switching device  592  set to the ON mode, opening or closing of the door  737  is achieved through operation of the driving device  28  of the door opener  20 . 
     When the mode switching device  592  is set to the OFF mode, only manual operation for opening the door is allowed. Specifically, with the mode switching device  592  set to the OFF mode, when a person pushes or pulls the door  737  to pivot, the track member  395  actuates the guiding wheel member  379  to pivot, and the guiding wheel member  379  actuates the first push rod  357 A, which, in turn, drives the first connecting member  373 A to pivot. The first connecting member  373 A drives the first transmission member  52  to pivot through transmission of the first mounting end  54 . The second gear  60  of the first transmission member  52  pushes the sliding member  70  to slide in the lateral direction. Thus, the connecting rod  78 , the movable sleeve  90 , the end cover  98 , the adjusting ring  113 , and the end cap  133  move together in the lateral direction towards the supporting sleeve  46  and compresses the return spring  94  (see  FIG.  17   ). 
     When the person releases the door  737 , the return spring  94  moves away from the first transmission member  52  to press against the abutting end  92  of the movable sleeve  90 . Thus, the sliding member  70 , the connecting rod  78 , the movable sleeve  90 , the end cover  98 , the adjusting ring  113 , and the end cap  133  move together in the lateral direction away from the first transmission member  52  until one of the teeth of the second gear  60  abuts against the tail  73  of the sliding member  70 , and the door  737  reaches the closed position when one of the teeth of the second gear  60  abuts against the tail  73  of the sliding member  70  ( FIGS.  14  and  15   ). 
     When the mode switching mode  592  switches to the hold open mode (H/O mode), the door opener  20  retains the door  737  in the open position through operation of the motor  44 . Specifically, since the door  737  is in the open position, the return spring  94  of the manual return module  77  is compressed. Thus, the motor  44  must keep outputting a force when it is intended to retain the door  737  in the open position, such that the door  737  will not pivot from the open position to the open position under the action of the return spring  94 . The hold open mode is suitable to retain the door  737  in the open position for a longer period of time, such as in a case for moving goods. 
     Note that the control panel  178  of the control device  175  of the door opener  20  is exposed to the outer side of the outer cover  351 , to prevent the control panel  178  from being operated in an undesired manner, the control panel  178  is inoperable when the mode switching device  592  is set to the ON, OFF, or hold open (H/O) mode. Namely, pressing of the control panel  178  will not cause any change in operation or control of the door opener  20 . When it is desired to use the control panel  178  to operate or set the door opener  20  (such as adjusting the open angle of the door  737 ), the mode switching device  592  is set to the wake-up mode, such that the control panel  178  is in an operable state, permitting use of the control panel  178  to operate or set the door opener  20 . 
     Furthermore, according to the form shown, the switching between the ON, OFF, hold open, and wake up modes requires a key to unlock the anti-theft control module  599 . Namely, the switching between the ON, OFF, hold open, and wake up modes can be operated only after the anti-theft control module  599  is in an unlocked state, and the control panel  178  can be operated only when the control device  175  is waken up (the wake up mode). 
     It is worth noting that the manual return module  77  allows adjustment of the extent of pre-compression of the return spring  94  to thereby adjust the pivoting speed of the door  737  moving from the open position to the closed position. 
     Specifically, with reference to  FIG.  14   , the adjusting ring  113  is at the outer end  82  of the connecting rod  78 . In this state, the extent of pre-compression of the return spring  94  is minimal. The length of a portion of the threaded section  86  of the connecting rod  78  outside of the movable sleeve  90  in the lateral direction is shortest. Thus, when the door  737  is manually opened, the pivotal speed of the door  737  from the open position to the closed position is slowest. With reference to  FIG.  18   , the rotating adjusting ring  113  moves in the lateral direction. Thus, when the adjusting ring  113  rotates, the adjusting ring  113  also moves towards the first transmission member  52 , such that the adjusting ring  113  presses against and actuates the end cover  98  and the movable sleeve  90  to move in the lateral direction towards the supporting sleeve  46 . The return spring  94  is compressed during the movement of the movable sleeve  90  in the lateral direction towards the supporting sleeve  46 . Thus, the larger the extent of pre-compression of the return spring  94 , the larger the length of the portion of threaded section  86  of the connecting rod  78  outside of the movable sleeve  90  in the lateral direction. Thus, the extent of pre-compression of the return spring  84  can be adjusted according to practical needs, such as the weight of the door. Furthermore, the extent of pre-compression of the return spring  94  can be judged by the length of the portion of the threaded section  86  of the connecting rod  78  outside of the movable sleeve  90  in the lateral direction. 
     In can be appreciated that with the return spring  94  having a larger extent of pre-compression, the return spring  94  is further compressed when the door  737  pivots from the closed position to the open position, such that the return spring  94  provides a larger elastic force for moving the movable sleeve  90  to actuate the connecting rod  78  for moving the first transmission member  52  in the reverse direction. Thus, the door  737  pivots faster from the open position to the closed position, or a heavier door can be pushed to pivot from the open position to the closed position. Furthermore, the force for retaining the door  737  in the closed position is larger when the return spring  94  has a larger extent of pre-compression. 
     Furthermore, after reaching a suitable position, minor adjustment of the adjusting ring  113  is carried out to couple the two positioning members  119  with the two positioning grooves  111 , reliably preventing undesired rotation of the adjusting ring  113  while avoiding unpredictable change in the extent of pre-compression of the return spring  94 . 
     In addition to the first assembly mode in which the door opener  20  is mounted to the first protrusive portion  733 A at the same side as the open position of the door  737 , the door opener  20  can be mounted to the second protrusive portion  733 B (at the same side as the closed position of the door  737 ) of the frame  717 , which is the second assembly mode. Specifically, the door opener  20  is pivoted 180° about a lateral axis extending in the lateral direction, and the mounting seat  22  and the frame  717  are screwed to the second protrusive portion  733 B of the door opener  20 . Furthermore, the change also makes the control panel  178  of the control device  175  of the door opener  20  upside down, which requires further adjustment in the assembling direction of the control device  175 . This only requires simple operation including detachment of the outer cover  351  of the door opener  20  and then manually pushing the movable member  331  of the quick-release device  197  until the movable coupling portion  335  of the movable member  331  disengages from the second side coupling slot  195  of the protective housing  177  of the control device  175 . Thus, the control device  175  is detached from the quick-release device  197 . Next, the control device  175  is turned to couple the first side coupling slot  191  with the movable coupling portion  335  and to couple the second side coupling slot  195  with the first coupling portion  317 . The two second coupling portions  319  are coupled with the two bottom coupling slots  192 . As shown in  FIGS.  20  and  21   , the orientation of the control panel  178  is correct after mounting of the control device  175 . 
     It is worth noting that the assembling direction of the driving device  28  can be rapidly changed according to the open side of the door  737 . As shown in  FIGS.  21 ,  23 , and  24   , since the door opener  20  pivots 180° about the lateral axis and since the open side of the door  737  (the door is opened from the left side or right side thereof) is not changed, the assembling direction of the driving device  28  must also be changed, such that the first mounting end  54  of the first transmission member  52  faces the ground. 
     The driving device  28  can be detached from the reinforcing seat  137  by removing the four screws in threading connection with the four coupling pegs  139 . Then, the driving device  28  is rotated to the correct assembling direction, such that the four lugs  40  couple with the four coupling pegs  139  of the reinforcing seat  137 . Next, the four screws are threadedly connected to the four coupling pegs  139  to secure the driving device  28 . In this state, the driving device  28  is so assembled that the motor  44  is located between the casing  30  and the second side cover  716  in the lateral direction. Furthermore, the manual return module  77  is located between the casing  30  and the control device  175  in the lateral direction. Thus, the first mounting end  54  of the first transmission member  52  faces the ground (as shown in  FIG.  24   ). 
     In addition to the first linkage  355  shown in  FIG.  7   , the door opener  20  can use a linkage in another form. According to the form shown in  FIGS.  20 ,  22 ,  24 , and  25   , the door opener  20  uses a second linkage  513  including a second push rod  357 B having a first end  359 B and a second end  371 B. The first end  359 B of the second push rod  357 B has a non-circular hole. 
     The second linkage  513  further includes a limiting member  515  coupled with the second end  371 B of the second push rod  357 B. The limiting member  515  includes two coupling walls  517  symmetric to and spaced from each other and a limiting wall  519  extending between an end of one of the two coupling walls  517  and an end of another of the two coupling walls  517 . The two coupling walls  517  abut against a surface of the second push rod  3578  and is fixed to the second end  371 B by riveting, such that the limiting member  515  cannot pivot relative to the second push rod  357 B. Furthermore, the limiting wall  519  is at an angle of about 110°-135° to the length direction of the second push rod  358 B. 
     The first end  359 B of the second push rod  357 B is securely connected to a second connecting member  373 B. The second connecting member  373 B includes a first engaging end  375 B and a second engaging end  377 B. The second engaging end  377 B has a shape matching with the non-circular hole of the first end  359 B. The second engaging end  377 B of the second connecting member  373 B is non-rotatably coupled to the first end  3598  of the second push rod  357 B. The first engaging end  375 B of the second connecting member  373 B is coupled with the first mounting end  54  of the first transmission member  52  to rotate jointly (see  FIG.  24   ). Thus, when the first transmission member  52  rotates, the first transmission member  52  drives the second push rod  357 B to pivot jointly. 
     The second linkage  513  further includes a pressing rod unit  531 . The pressing rod unit  531  includes a coupling sleeve  533 , a first end piece  539 , and a second end piece  555 . The coupling sleeve  533  includes a first outer end  535  and a second outer end  537 . Each of the first outer end  535  and the second outer end  537  has an inner threading. The first end piece  555  includes a first threaded portion  551  having an outer threading and a second threaded portion  553  having an outer threading. The second end piece  555  includes an outer threaded portion  559  having an outer threading and an inner threaded portion  557  having an inner threading. The outer threaded portion  559  of the second end piece  555  is in threading connection with the second outer end  537  of the coupling sleeve  533 . 
     The pressing rod unit  531  further includes a first pivotal member  571 , a second pivotal member  577 , an adjusting rod  575 , and a locking member  573 . The adjusting screw rod  575  has an outer threading on an outer periphery thereof and is in threading connection with the inner threaded portion  557  of the second end piece  555 . An end of the adjusting screw rod  575  is outside of the coupling sleeve  533 , and another end of the adjusting screw rod  575  is inside of the coupling sleeve  533 . Rotation of the adjusting screw rod  575  can adjust the length of a portion of the adjusting screw rod  575  outside of the coupling sleeve  533 . The locking member  573  is threadedly coupled on the adjusting screw rod  575 . When the locking member  573  abuts against a surface of the second end piece  555 , the adjusting screw rod  575  cannot rotate (see  FIG.  25   ). Thus, the length of the portion of the adjusting screw rod  575  exposed outside of the coupling sleeve  533  is fixed. When the locking member  573  rotates and is, thus, spaced from the second end piece  555  (see  FIG.  27   ), the adjusting screw rod  575  can rotate to increase or reduce the length of the portion of the adjusting screw rod  575  exposed outside of the coupling sleeve  533 . 
     An end of the first pivotal member  571  is in threading connection with the second threaded portion  553  of the first end piece  539 . An end of the second pivotal member  577  is in threading connection with an end of the adjusting screw rod  575  outside of the coupling sleeve  533 . Another end of the second pivotal member  577  is pivotably disposed between the two coupling walls  517  of the limiting member  515  and is spaced from the second end  371 B of the second push rod  357 B. 
     The pressing rod unit  531  further includes a fixing member  579  and two pins  591 . The fixing member  579  abuts the second surface  571  of the door  737  at a position adjacent to an upper end of the second surface  571 . The two pins  591  extend from the first surface  739  of the door  737  through the door  737 . Then, two bolts  511  are threadedly coupled with the two pins  591  to securely fix the fixing member  579  to the second surface  751  of the door  737 . Another end of the first pivotal end  571  is pivotably connected to the fixing member  579  (see  FIGS.  23 - 25   ). 
     When the motor  44  of the door opener  20  runs, the first transmission member  52  pushes the second push rod  357 B to pivot, such that the push rod unit  531  pushes the door  737  to pivot from the closed position to open position or from the open position to the closed position. It can be appreciated that the return spring  94  of the manual return module  77  is compressed when the door  737  pivots towards the open position and that the return spring  94  restores its length when the door  737  pivots towards the closed position. When the door  737  is manually pushed open, the pressing rod unit  531  pushes the second push rod  357 B to pivot, such that the first transmission member  52  pivots to actuate the manual return module  77 , thereby compressing the return spring  94 . Thus, after the door  737  is released, the return spring  94  returns the door  737  to the closed position. 
     The limiting wall  519  of the limiting member  515  of the second linkage  513  prevents excessive pivotal angle of the door  737 . Specifically, when the door  737  pivots from the closed position towards the open position, the pressing rod unit  531  pivots relative to the limiting member  515 . When the pressing rod unit  531  pivots to a position in which the second pivotal member  577  abuts against the limiting wall  519  of the limiting member  515  (see  FIG.  26   ), the door  737  cannot pivot further towards the open position. Nevertheless, the door  737  in this state can pivot towards the closed position. Thus, the limiting member  515  can prevent excessive pivotal angle of the door  737 . 
     The pressing rod unit  531  has a function of minor adjustment of the length to match with doors and frames of different sizes. With reference to  FIGS.  25  and  27   , when it is desired to adjust the pressing rod unit  531 , the locking member  573  is rotated first, moving the locking member  573  away from the second end piece  555 , thereby permitting rotation of the adjusting screw rod  575  to change the length of the portion of the adjusting screw rod  575  outside of the coupling sleeve  533 . Specifically, when the adjusting screw rod  575  rotates, the adjusting screw rod  575  also moves in the axial direction of the coupling sleeve  533  to change the length of the portion of the adjusting screw rod  575  outside of the coupling sleeve  533 . Thus, when the length of the portion of the adjusting screw rod  575  outside of the coupling sleeve  533  increases, the spacing between the first pivotal member  571  and the second pivotal member  577  also increases. On the other hand, when the length of the portion of the adjusting screw rod  575  outside of the coupling sleeve  533  decreases, the spacing between the first pivotal member  571  and the second pivotal member  577  is reduced. 
     Note that since the door opener  20  is mounted on the second protrusive portion  733 B of the frame  717 , the mounting position of the door opener  20  will not interference with the pivotal movement of the door  737  from the closed position to the open position. Furthermore, the mounting position of the door opener  20  on the second protrusive portion  733 B can be lower than the mounting position of the first protrusive portion  733 A (compare the respective mounting position of the door opener  20  in  FIGS.  13  and  24   ). As shown in  FIG.  24   , when the door opener  20  is mounted to the second protrusive portion  733 B, the door opener  20  will not protrude too much above the second protrusive portion  733 B. This permits the door opener  20  to securely couple with the second protrusive portion  733 B of the frame  717  without using the two supporting devices  153 . 
     The portion of the adjusting screw rod  575  of the pressing rod unit  531  outside of the coupling sleeve  533  can be adjusted, such that the second linkage  513  can be applied to frames  717  and doors  737  of various sizes, and the installation is more convenient. 
     The limiting member  515  cooperates with the second push rod  357 B to limit the relative pivotal angle between the second push rod  357 B and the pressing rod unit  531 . Thus, the driving device  28  is less likely to be damaged by excessive torque manually applied to the door  737 . 
     The reinforcing seat  137  abuts against and is securely screwed to the bottom wall  24  of the mounting seat  22  to increase the structural strength of the mounting seat  22 , such that the mounting seat  22  is less likely to distort and deform even though a heavier driving device  28  is disposed. Furthermore, the reinforcing seat  137  and the mounting seat  22  are in threading connection with the frame  717  by screws, providing the mounting seat  22  with excellent coupling strength. 
     The four coupling pegs  139  of the reinforcing seat  137  and the four lugs  40  of the casing  30  permit easy installation and easy change in the direction of the driving device  28 . Specifically, to simplify the installation, before using screws for tightening purposes, the driving device  28  can be detachably coupled through the coupling between the four lugs  40  and the four coupling pegs  139 . This permits a worker to extend four screws (for fixing the driving device  28 ) into the four coupling pegs  139  with two hands (namely, without the need of using a hand to hold the driving device  28 ). Since the four coupling pegs  139  and the four lugs  40  are arranged to be symmetric in the vertical and left/right directions, the assembling direction of the driving device  28  can be easily changed in response to the open side or the opening direction of the door  737 . 
     Each supporting device  153  is mounted in the gap between the mounting seat  22  and the frame  717  to reinforce the overall coupling strength of the door opener  20  installed on the frame  717 . Furthermore, the lining  155  and the supporting member  159  of each supporting device  153  can be rotated to adjust the length, so as to be applicable to frames of various sizes and shapes, thereby increasing the coupling strength between the door opener  20  and the frame  717 . 
     After the door  737  is manually opened while the door opener  20  is out of electricity, the driving device  28  permits the door  737  to automatically return to the closed position through the manual return module  77 . Furthermore, the adjusting ring  113  of the manual return module  77  is located outside of the movable sleeve  90 , permitting easy adjustment of the extent of pre-set compression of the return spring  94  according to practical needs. 
     The inner diameter of the movable sleeve  90  is slightly longer than the outer diameter of the return spring  94 , and the outer diameter of the inner tube  96  is slightly smaller than the inner diameter of the return spring  94 . Furthermore, the end of the movable sleeve  90  distant to the abutting end  92  is adjacent to an end of the inner tube  96 . Thus, the return spring  94  will not distort during compression. As a result, operation of the manual return module  77  is smoother. 
     The control panel  178  of the control device  175  is operable only when the mode switching device  592  is switched to the wake-up mode. Furthermore, by the disposition of the anti-theft control module  599  on the mode switching device  592 , the mode switching device  592  can be switched to the wake-up mode only when the anti-theft control module  599  is unlocked. Thus, the control panel  178  can be disposed to be exposed for pressing operation via the window  353 . As a result, it is not necessary to detach the outer cover  351 . Accordingly, the control panel  178  can be directly operated after the mode switching device  592  is switched to the wake-up mode, which provides both the anti-theft effect and convenience while proceeding with setting or changing the parameters of the door opener  20 . 
     After the anti-theft control module  599  is unlocked, the mode switching device  592  is switchable between the OFF mode, the ON mode, and the hold open mode. Thus, mode switching of the door opener  20  can be conducted without detaching the outer cover  351 , providing both the anti-theft function and convenience. 
     Now that the basic teachings of the present invention have been explained, many extensions and variations will be obvious to one having ordinary skill in the art. For example, the manual return module  77  does not have to include the end cap  133  and the fasteners  135 . In this case, the threading connection between the adjusting ring  113  and the connecting rod  78  can still avoid undesired detachment from the connecting rod  78 . 
     Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.