Patent Publication Number: US-11643861-B2

Title: Release mechanism for a door operator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a continuation-in-part of U.S. patent application Ser. No. 17/175,035 filed on Feb. 12, 2021, titled “Door Operator with Isolated Components,” which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to movable barrier opener systems for opening and closing garage doors, gates, and other movable barriers. 
     BACKGROUND 
     Movable barriers, such as upward-acting sectional or single panel garage doors, residential and commercial rollup doors, and slidable and swingable gates, are used to alternatively allow and restrict entry to building structures and property. These barriers are driven between their respective open and closed positions by motors or other motion-imparting mechanisms, which are themselves controlled by barrier moving units, sometimes referred to as “movable barrier operators,” and in the specific case of a door, as “door operators,” and in the even more specific case of a garage door, as “garage door operators.” Garage door operators are effective to cause the DC or AC motor, and accompanying motor drive assembly, to move the associated garage door, typically between its open and closed positions. 
     There are times that these barriers may need to be operated manually, such as in the event of a power outage. The force required to manually operate a barrier may be reduced by conventional release mechanisms. Generally, manual operation of a barrier is possible after disengaging the motor from the output shaft and/or engaging a hoist chain wheel. An example jackshaft operator may employ a mid-gear train style release mechanism that physically isolates the output shaft from the motor shaft. An example hoist operator may employ a series of levers to engage a chain wheel that is coupled to the output shaft. In both cases, the mechanisms are relatively complex with many moving parts leaving room for improvement. 
     This disclosure is directed to innovative and new release mechanism designs for operators including jackshaft and hoist operators that use fewer parts and improve the efficiency of the release mechanism. This may lead to lower manufacturing cost, increased reliability, fewer interfacing parts reducing friction noise, and/or greater customer satisfaction. 
     SUMMARY 
     It is to be understood that both the foregoing general description and the following drawings and detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following. One or more features of any embodiment or aspect may be combinable with one or more features of other embodiment or aspect. 
     In an aspect, a jackshaft operator release mechanism for manual operation of a movable barrier may include a motor mounted to a metal frame. The motor may have a brake assembly mounted to the metal frame such that a shaft of the motor is disposed through the brake assembly allowing the brake assembly to arrest rotation of the motor shaft. In an aspect, the brake assembly may include a brake release lever operable to disengage the brake assembly thereby allowing the motor shaft to freely rotate. In aspect a release bracket may be coupled to the metal frame and disposed over the brake release lever. A brake release cord may be coupled to the brake release lever and disposed through the release bracket providing with the release bracket providing the necessary leverage to move the brake release lever. With the brake assembly disengaged, manual operation of the barrier may be permitted, such as by lifting the barrier. 
     In another aspect, a hoist operator release mechanism for manual operation of a movable barrier may include a motor mounted to a metal frame. The motor may have a brake assembly mounted to the metal frame such that shaft of the motor is disposed through the brake assembly allowing the brake assembly to arrest the rotation of the motor shaft. In an aspect the brake assembly may include a brake release lever operable to disengage the brake assembly permitting the motor shaft to freely rotate. A transfer shaft may be operable for transfer rotation of the motor shaft to an output shaft to move the barrier. In an aspect, the transfer shaft may include a cross pin passing through the transfer shaft transverse to the axial direction of the transfer shaft. A spring may be disposed around the transfer shaft between the metal frame and the cross pin. A chain wheel, including pins, may be disposed around the transfer shaft adjacent the spring and between the spring and the metal frame. A release cam lever may be disposed around the transfer shaft adjacent the chain wheel and between the chain wheel and the metal frame. In an aspect, the release cam lever is operable to transfer a rotational movement provided by a release cord to a linear movement along the axial direction of the transfer shaft. The release cam lever may move the chain wheel away from the metal frame, compressing the spring, and the pins of the chain wheel engaging the cross pin. Additionally, the release cam lever may engage the brake release lever to disengage the brake assembly. With the chain wheel engaged and the brake assembly disengaged, a chain may be used to manually operate the barrier. 
     It is to be understood that both the foregoing general description and the following drawings and detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following. One or more features of any embodiment or aspect may be combinable with one or more features of other embodiment or aspect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate implementations of the systems, devices, and methods disclosed herein and together with the description, serve to explain the principles of the present disclosure. 
         FIG.  1    is an illustration of a conventional jackshaft operator mid-gear train disconnect mechanism enabling manual operation of a garage door. 
         FIG.  2    is an illustration of a conventional hoist operator chain wheel engagement mechanism enabling manual operation of a garage door. 
         FIG.  3    is a perspective illustration of material structural components of a jackshaft operator installed in a garage with a sectional type garage door, according to one example implementation. 
         FIG.  4    is a perspective illustration of a jackshaft motor drive assembly for moving a movable barrier, according to one example implementation. 
         FIG.  5    is an exploded perspective illustration of a brake assembly for an operator, such as a jackshaft or hoist operator, according to one example implementation. 
         FIG.  6    is a perspective illustration of a brake release mechanism in a disengaged position for an operator such as a jackshaft operator, according to one example implementation. 
         FIG.  7 A  is a perspective illustration of a brake release mechanism for an operator such as a hoist operator, according to one example implementation. 
         FIG.  7 B  is a perspective illustration of a brake release mechanism with the brake release not active for an operator such as a hoist operator, according to one example implementation. 
         FIG.  7 C  is a perspective illustration of a brake release mechanism with the brake release activated for an operator such as a hoist operator, according to one example implementation. 
     
    
    
     These Figures will be better understood by reference to the following Detailed Description. 
     DETAILED DESCRIPTION 
     For promoting an understanding of the principles of the present disclosure, reference will now be made to the implementations illustrated in the drawings and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In addition, this disclosure describes some elements or features in detail with respect to one or more implementations or Figures, when those same elements or features appear in subsequent Figures, without such a high level of detail. It is fully contemplated that the features, components, and/or steps described with respect to one or more implementations or Figures may be combined with the features, components, and/or steps described with respect to other implementations or Figures of the present disclosure. For simplicity, in some instances the same or similar reference numbers are used throughout the drawings to refer to the same or like parts. 
     With reference to  FIG.  1   , there is depicted an illustration of a conventional jackshaft operator having a mid-gear train disconnect mechanism  100  for manual operation of a garage door. In order to operate the garage door manually, a significant force is required to lift the weight of the door and back drive the motor (i.e. overcome the belt tension and pulley ratio between the motor and output shaft). While the torsion spring aids in lifting the weight of the door, the torsion spring must also provide the force that is required to back drive the motor. Generally, the solution to overcome this is to remove the motor from the system when manually operating a garage door. The most common method used to remove the motor is a mid-gear train disconnect. That is, disconnect the motor at the transfer shaft. 
     The mid-gear train disconnect mechanism  100  illustrated in  FIG.  1    includes a transfer shaft  102  operable to drive an output shaft. Transfer shaft  102  has a first plate  104  coupled to one end that contacts a second plate  106  and receives teeth  108  of the second plate  106 . The second plate  106  is coupled to a clutch shaft  110 . When the clutch shaft  110  rotates the teeth  108  engage with the first plate  104  causing the transfer shaft  102  to rotate. A rope may be attached to a corner of a release lever  112  operable to pivot the release lever  112 . When the rope is pulled, the release lever  112  rotates about a pivot point and pushes clutch shaft  110  which disengages the teeth  108  from the first plate  104 . This release mechanism physically separates the clutch shaft  110  on one side from the transfer shaft  102  on the other side. This separation disengages the motor shaft from the output shaft to avoid back driving the motor. 
       FIG.  2    depicts a conventional hoist operator chain wheel engagement mechanism  200  for manual operation of a garage door. A transfer shaft  202 , operable to drive an output shaft, is shown. A chain wheel  204  is coupled to an end of the transfer shaft  202 . A chain may be wrapped around the chain wheel for manually operating a garage door. A lever  206  is depicted where one end of the lever may be connected to a rope and the other end of the lever is disposed adjacent the chain wheel. When the rope is pulled, the lever  206  presses against, and moves, the chain wheel  204  which engages the chain wheel  204  with the transfer shaft  202 . In this manner, the chain may be pulled, rotating the chain wheel  204  that is now coupled to the transfer shaft  202 . The transfer shaft  202  rotates with the chain wheel  204  and drives the output shaft. 
     Persons of ordinary skill in the art will note the number of moving parts required for each of these conventional release mechanisms to function properly. The number of parts provides multiple points of failure within the release mechanism as well as added cost and weight to the operator. Additionally, the number of parts increases the potential points of vibration within the system, thereby increasing noise within the system. 
       FIG.  3    illustrates material structural components for moving a garage door according to some embodiments of the present disclosure. Depicted is an exemplary operator for moving a barrier. In this example, the operator is a operator  302 , including a chassis  304  and an electric box  305 , operable to move a barrier shown as a garage door  306  along guide rails  308  to open and close the garage door  306 . As depicted, the garage door  306  as a conventional upward acting sectional door being moved between open and closed positions along guide rails  308 . Other types of garage doors are contemplated such as single panel doors, rollup doors, etc. In some embodiments, the operator  302  may be a jackshaft operator. In some embodiments, the operator  302  may be a hoist operator, or other operator. 
     The chassis  304  encloses a jackshaft motor assembly. The electric box  305  encloses a door control module and an operator control module. The jackshaft motor assembly includes, among other components, (i) a motor adapted to move the garage door in the conventional manner known by one of ordinary skill in the industry, and (ii) an absolute position sensor that monitors or measures rotation of the output shaft of the unit and communicates signals based on the measurements indicative of, the extent and direction of rotation of the rotatable output shaft of the unit, and therefore indicative of the extent and direction of travel of the garage door  306  between travel limits. 
     The motor is operatively coupled to a drive assembly  310 . The motor and drive assembly  310  are effective to impart movement to the garage door  306  in accordance with door commands remotely and/or proximately transmitted to operator control module and thereafter to the motor. The drive assembly  310  may be any of the standard and conventional drive assemblies available on the market that are suitable to move the garage door  306  in response to the motor. In the example described herein, the drive assembly  310  is a part of a jackshaft drive assembly. 
     The operator  302  is installed adjacent a garage door  306  and operable to open and close the garage door. The chassis  304  of the operator  302  is shown adjacent the drive assembly  310  which may include a torsion tube  312  and one or more cable drums  314  rigidly affixed to the torsion tube  312 . These may be rotatably driven by the operator  302 . One or more cables  316  may be wound about the cable drums  314  and have their free ends  318  attached at or adjacent a bottom edge  320  of the garage door  306 . In some embodiments, the torsion tube  312  forms a part of or is coaxial with the output shaft of the operator  302 . In other embodiments, the torsion tube  312  may be laterally offset from the output shaft of the operator  302  and use a chain and sprockets to couple the operator  302  to the torsion tube  312 . Rotation of the output shaft of the operator  302  rotates the torsion tube  312  and the cable drums  314 . Rotation in a direction to wind the cable around the cable drums  314  results in the garage door  306  being raised to the open position. 
     In this embodiment, the torsion tube  312  of the drive assembly  310  extends horizontally and is directly coupled to, and adapted to be rotatably driven by, the operator  302  in either a clockwise or counterclockwise direction. A torsion spring  322  extends around the torsion tube  312 . 
     When the operator  302  is instructed by a controller to open the garage door  306 , the torsion tube  312  and the connected cable drums  314  are rotated by the operator  302  in a direction so as to wind the cable(s)  316  onto the cable drum(s)  314 , thereby lifting the garage door  306  to its open position. When the operator  302  is instructed by the controller to close the garage door  306 , the torsion tube  312  and connected cable drums  314  are rotated by the operator  302  in the opposite direction so that cable(s)  316  may be payed out, thereby permitting the garage door  306  to be closed. The torsion spring  322  provides a counterbalance to aid in the door  306  being moved to its closed position. 
       FIG.  4    depicts a perspective view of an exemplary operator  400  according to some embodiments of the present disclosure. The operator  400  may be the operator  302  in  FIG.  3   . In the depicted embodiment, the operator  400  is a jackshaft operator. In some embodiments, the operator  400  may be a hoist operator or other operator. In the depicted embodiment, the operator  400  includes a chassis  401  including side panels  402  for mounting the various components of a motor assembly and an electric box  404  mounted to side panels  402 . In some embodiments, side panels  402  may be metal panels including mounting points and holes configured to receive the different components of the operator  400 . In some embodiments, the side panels  402  may be sheet metal. The motor assembly may include a motor having a motor shaft (not visible in FIG.  4 ), a transfer shaft  410 , and an output shaft  412 . In some embodiments, the motor may have dual motor shafts. The output shaft  412  may be coupled to torsion tube  312  ( FIG.  3   ) for operating the garage door  306 . In some embodiments, the output shaft  412  may directly connected to torsion tube  312 . In some embodiments, the output shaft  412  may be coupled to torsion tube  312  by a chain or belt mechanism. The motor is mounted between bottom portions of the side panels  402 . A motor belt pulley is coupled to one of the motor shafts of the motor. A brake  416  is coupled to the motor shaft of motor. A brake release mechanism  417  may be connected to the brake  416  operable to release the brake to allow for manual operation of the door. In some embodiments, the motor belt pulley may be mounted one side of the operator  400 , such as for example the left side. In some embodiments, the motor belt pulley may be mounted on the other side of the operator  400 , such as for example the right side. The side on which the motor belt pulley is installed may be determined by where the operator  400  is installed. In some embodiments, an anti-rotation stud may prevent the motor from rotating within the chassis during operation of the operator  400 . Some implementations of the operator  400  may include features described in U.S. patent application Ser. No. 17/175,035, filed Feb. 12, 2021, incorporated herein by reference. 
     With reference to  FIG.  5    there is depicted an exploded perspective illustration of an exemplary brake assembly for use in a jackshaft or hoist type operator. As illustrated, the brake assembly  500  includes a mounting plate  502  including a first spacer  504 , standoffs  506 , and a brake release lever  508 . Standoffs  506  may be threaded to receive a fastener, such as for example a screw, bolt, etc. In some embodiments, standoffs  506  may be smooth allowing for a fastener to pass through to be secured on a backside of the mounting plate  502 . Brake release lever  508  includes a notch feature  510  which may be a depression, a slot, or other indentation. The brake assembly  500  further includes a collar  512  having a central opening  514  and a base  516  having a non-circular perimeter, a friction pad  518  having an opening  520  that is non-circular and matches the perimeter shape of the base  516 , an armature plate  522  having tabs  524  and cutouts  526 , a spring  528 , and a second spacer  530 . The armature plate  522  may include a ferromagnetic material to be acted upon by a magnetic force. The friction pad  518  may include a material designed to prevent slipping when the armature plate  522  and the friction pad  518  are pressed together. In some embodiments, the friction pad  518  may include a compound resin having a copper wire facing. In some embodiments, the friction pad  518  may include a ceramic material. Finally, the brake assembly  500  includes a coil assembly  532  including coiled wires therein (not shown) with contacts  534  connected to the coiled wires and fasteners  536  for coupling the coil assembly  532  to the mounting plate  502  through standoffs  506 . 
     When brake assembly  500  is assembled, a motor shaft may be disposed through the opening  514  of collar  512 , the opening  520  of friction pad  518 , through an opening in armature plate  522 , and into, but not through, an opening in spring  528 . The opening  514  may have a non-circular inner profile (shown here as having a flat surface) and the motor shaft may have a non-circular outer profile (having a flat surface in this implementation) that interfaces with the non-circular inner profile (e.g., flat surface) of the opening  514 . This interface couples the motor the rotation of the shaft to the collar  512  so that the collar  512  rotates when the motor shaft rotates. The base  516  of collar  512  may fit over the first spacer  504  one side, allowing the collar  512  to freely rotate, and may be seated inside the opening  520  of friction pad  518 . In the depicted embodiment, both the base  516  and the opening  520  have a non-circular shapes, shown in this example as hexagonal shapes. Other shapes are contemplated, such as square, triangular, octagonal, etc. In this way, the rotation of collar  512  is coupled to the friction pad  518  with the collar  512  rotating the friction pad  518  as the motor shaft rotates. 
     The opening in the armature plate  522  fits over the collar  512  so that the armature plate  522  is disposed adjacent to friction pad  518  in the brake assembly  500 . In this configuration, the armature plate  522  may physically contact the friction pad  518 , but is not coupled to friction pad  518 . When fully assembled, the standoffs  506  of the mounting plate  502  may be disposed adjacent to and through the cutouts  526  of the armature plate  522 . In this way, the standoffs  506  may prevent the armature plate from rotating when cutouts  526  physically contact standoffs  506 . The spring  528  is disposed adjacent to and physically contacting the armature plate  522 . The collar  512  may extend through the opening in the armature plate  522  and into the opening in the spring  528 , but not through the spring  528 . In this way, the collar  512  may prevent the lateral displacement of the spring  528 . In some embodiments, a different mechanism may be used for preventing the lateral displacement of the spring  528 . The second spacer  530  may include a lip which permits a portion of the second spacer  530  to be seated within the spring  528  while the lip of the second spacer  530  rests on an outer surface of the spring  528 . Assembly of the brake assembly  500  is completed when the coil assembly  532  is fastened to mounting plate  502  using fasteners  536 . 
     During normal operation, an electric current may be used to engage and disengage the brake assembly to either permit or arrest rotation of the motor shaft. The electric current may be provided to coil assembly through contacts  534 . 
     When no electric current is applied to contacts  534 , the brake assembly  500  is engaged, arresting rotation of the motor shaft thereby stopping movement of the garage door. Generally, when the motor is not running, the brake assembly  500  is engaged, inhibiting movement. In this state, spring  528  presses against an inside surface of the coil assembly  532  on one end and into the armature plate  522  on the other end. This force from the spring  528  presses the armature plate  522  against, and physically contacting, the friction pad  518 . In this configuration, the friction between friction pad  518  and armature plate  522  permits little, to no, slipping of the friction pad  518  with respect to the armature plate  522 . The cutouts  526  of the armature plate  522  physically contacting the standoffs  506  prevent the armature plate  522  from rotating. In this way, the friction pad  518  is prevented from rotating, which prevents the collar  512  from rotating, and ultimately the motor shaft is prevented from rotating, thereby preventing movement the garage door. This maintains the operator at the current position and prevents the garage door from opening or closing without the use of significant external force. 
     When an electric current is applied to contacts  534 , the brake assembly  500  is disengaged, thereby permitting rotation of the motor shaft and allowing movement of the garage door. Generally, when the motor powered and running (e.g. the motor shafts are rotating) a current is applied to contacts  534  to disengage the brake assembly  500 . When the current is applied to contacts  534  an electromagnetic field is generated by the coils inside the coil assembly  532 . The electromagnetic field draws the armature plate  522  towards the coil assembly  532 , compressing the spring  528  in the process. In this state, the armature plate  522  is no longer in contact with the friction pad  518 . The friction pad  518 , collar  512 , and the motor shaft may rotate freely to move the garage door. 
     With reference to  FIG.  6   , there is illustrated a brake release mechanism for a jackshaft operator according to embodiments of the present disclosure. As can be seen in the illustration, the jackshaft brake release mechanism  600  is not require a mid-gear train disconnect and does not have as many parts as the conventional jackshaft mid-gear train disconnect.  FIG.  6    illustrates a brake assembly  500  including brake release lever  508  and tabs  524  as discussed above with respect to  FIG.  5   . As depicted, brake release lever  508  is coupled to mounting plate  502  at points B, around which the brake release lever can pivot. Brake assembly  500  is coupled to the chassis  401  of a jackshaft operator, such as operator  400  described above with respect to  FIG.  4   . Specifically, brake assembly  500  is mounted on a side panel  402  of the jackshaft operator and over a motor shaft  602 . A release bracket  604  is coupled to the side panel  402  of the chassis  401 , adjacent to, and disposed over, a top portion of brake release lever  508 . Release bracket  604  includes an opening  606 . A release cord  608  may be passed through the opening  606  and attached to an upper portion of the brake release lever  508 . In the depicted embodiment, the release cord  608  may be secured to the side panel  402  by brackets  610  which guide the release cord  608  around the brake assembly  500  and toward the ground for use. In some embodiments, brackets  610  may be removed and the release cord  608  may extend through the release bracket  604 , over the brake assembly  500 , and down toward the ground for use. 
     As depicted in  FIG.  6   , the jackshaft brake release mechanism  600  is not engaged, or is not active. In this configuration, the brake assembly  500  is engaged and operates as described above with respect to  FIG.  5   . The garage door may not be manually operated without requiring significant force to overcome the braking provided by the brake assembly  500 . 
     To activate, or engage, the jackshaft brake release mechanism  600  the release cord  608  is pulled, creating tension in the release cord  608 , and may be held or tied off to maintain the tension in the release cord  608 . Pulling the release cord  608  pivots the brake release lever  508  about point B. This moves the upper portion of the brake release lever  508  away from the side panel  402  and toward the release bracket  604 . This movement is sufficient for the notch features  510  of the of the brake release lever  508  to engage the tabs  524  of the armature plate  522 . The brake release lever  508  pushes, and moves, the armature plate  522 , separating the armature plate  522  from the friction pad  518  and compressing the spring  528 . This mechanism disengages the brake assembly  500  similar to the process described above except that a mechanical force is used instead of an electromagnetic force. At this point, the motor shaft may rotate freely, allowing the garage door to be operated manually. 
     To deactivate the jackshaft brake release mechanism  600 , the tension in the release cord  608  may be released by untying and releasing the release cord  608 . With the tension in the release cord  608  released, the spring  518  inside the brake assembly  500  pushes the armature plate  522  moving it back to its original position pressed against the friction pad  518 . The tabs  524  of the armature plate  522  move the brake release lever  508  back to its original position. In this state, the brake is fully re-engaged, and the brake release is disengaged. 
     Persons of ordinary skill in the art will recognize the simplicity and efficiency of this design. The new jackshaft brake release mechanism  600  uses fewer parts than conventional designs by implementing the release in a new and innovate manner. The jackshaft brake release mechanism  600  contains fewer parts to wear out and fewer parts that produce noise. Additionally, there is a cost savings in this design because fewer parts are used. 
     With reference to  FIGS.  7 A,  7 B, and  7 C , depict perspective illustrations of an exemplary hoist brake release mechanism according to an example embodiment.  FIG.  7 A  depicts components of the hoist brake release mechanism without the chain wheel to better display certain aspects of the brake release mechanism.  FIG.  7 B  depicts the hoist brake release mechanism in a disengaged, or not activate, state.  FIG.  7 C  depicts the hoist brake release mechanism in an engaged, or active, state. The hoist operator depicted may be the hoist operator  400  described above with respect to  FIG.  4    with the addition of a chain wheel and additional parts, as described below, for the release mechanism. 
     Depicted in  FIGS.  7 A- 7 C  is a chassis  401 , in these illustrations chassis  401  includes side panels  402 . An electric box  404  is coupled to the chassis  401 . A brake assembly  500  is mounted to a side panel  402  of the chassis  401 . A motor  702  is mounted between side panels  402  with a motor shaft  704  extending through a side panel  402  and into the brake assembly  500 . In the depicted embodiment, another motor shaft  704  extends through the other side panel  402  and is operable to drive transfer shaft  410  and output shaft  412 . The brake assembly  500  includes brake release lever  508  which includes a release lever extension  706 . 
     The hoist brake release mechanism  700  includes a cam base  708 , a release cam lever  710 , and a chain wheel  712 . The cam base  708  having sloped edges is coupled to a side panel  402  of the chassis  401 , physically contacting the side panel  402 . Transfer shaft  410  passes through side panel  402 , cam base  708 , release cam lever  710 , and chain wheel  712 . A spring  714  is disposed over the exposed transfer shaft  410 , adjacent the chain wheel  712 . A cross pin  716  is disposed through the transfer shaft transverse to the axial direction of the transfer shaft  410 . Cross pin  716  may be operable to hold spring  714  over the transfer shaft, between the cross pin  716  and the chain wheel  712 . Pins  718  are coupled to chain wheel  712  and are operable to engage cross pin  716  when spring  714  is compressed. 
     As depicted in  FIGS.  7 A- 7 C , the release cam lever  710  is longer in a first direction than in a second direction allowing for a release cord  726  to apply a torque to the release cam lever  710 . The release cord  726  may be attached to point  720  on the release cam lever  710 . The release cam lever  710  may include a hollow body  722 , operable for moving chain wheel  712 , attached to one face of the release cam lever  710 . The release cam lever  710  may include a hollow protrusion  724  having sloped edges, attached to an opposing second face, through which transfer shaft  410  may pass. The sloped edges of the hollow protrusion  724  may interface with sloped edges of the cam base  708  allowing the release cam lever  710  to slide over the cam base  708  along the sloped edges. This configuration is operable to translate rotary motion around the axis of the transfer shaft  410  to a linear motion along the axis of the transfer shaft  410 . As illustrated, when the release cam lever  710  is rotated clock-wise the sloped edges of the hollow protrusion  724  slide up and along the sloped edges of the cam base  708  thereby pushing the release cam lever  710  away from the side panel  402  and toward the chain wheel  712 . In some embodiments, a release cord attached to point  720  is pulled, producing a torque on the release cam lever  710  that causes the clock-wise rotation of the release cam lever  710 . 
     The brake release is activated, or engaged, by the linear motion of the release cam lever  710  along the axis of the transfer shaft  410  in two ways. First, the release cam lever  710  moves chain wheel  712  along the axis of the transfer shaft  410 , compressing spring  714 , so that the pins  718  physically contact the cross pin  716 . This couples the chain wheel  712  to the transfer shaft  410  so that any rotation imparted on the chain wheel  712 , such as by pulling a chain, is imparted on the transfer shaft  410 . In this way, a chain may be used for manual operation of the garage door. Second, the release cam lever  710  physically contacts the release lever extension  706  and moves the brake release lever  508  away from the side panel  402 . As the brake release lever  508  moves it engages the tabs  524  of the armature plate  522 , moving the armature plate  522  away from the friction pad  518 , thereby disengaging the brake assembly  500 . In this configuration, as depicted in  FIG.  7 B , the motor shaft  704  may rotate freely as the chain wheel  712  is rotated. 
     Persons of ordinary skill in the art will appreciate that the implementations encompassed by the present disclosure are not limited to the particular exemplary implementations described above. In that regard, although illustrative implementations have been shown and described, a wide range of modification, change, combination, and substitution is contemplated in the foregoing disclosure. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the present disclosure. 
     The present disclosure is directed to a movable barrier operator release mechanism which includes a first side panel that has a first side and an opposing second side. The movable barrier operator release mechanism further includes a motor, including a first shaft, disposed at the first side of the first panel. A brake assembly is disposed at the second side of the first panel. The first shaft extends through the first side panel and into the brake assembly. The brake assembly may stop the rotation of the first shaft when engaged. A first lever, operable to disengage the brake assembly, is disposed between the brake assembly and the first side panel. The brake assembly may include a mounting plate. A first end of the first lever may be coupled to the mounting plate and an opposing second end of the first lever may be able to move in a linear direction. A bracket may be coupled to the second side of the first side panel and be disposed above the brake assembly and over a portion of the first lever. The bracket may include a hole through which a cable may pass and be attached to the first lever. 
     The movable barrier operator release mechanism may further include a second shaft disposed above the first shaft extending through the first side panel. A chain wheel may be disposed around the second shaft and be operable to rotate the second shaft. A second lever may be disposed around the second shaft. The second lever may translate rotational movement into linear movement. The second lever may have a first length in a first direction and a second length in a second direction where the first direction is perpendicular to the second direction. The first length may be greater than the second length. 
     The present disclosure is further directed to a movable barrier operator release mechanism including a chassis that has a first panel and an opposing second panel. The first panel has a first face and an opposing second face. The movable barrier operator release mechanism further includes a motor mounted between the first face of the first panel and the second panel. The motor includes first shaft that extends through the first panel. A brake assembly is mounted to the second face. The first shaft extends into the brake assembly. A first lever, with a first end and an opposing second end, is coupled to the brake assembly. The first lever pivots about the first end to disengage the brake assembly. The movable barrier operator release mechanism may include a cable attached to second end of the first lever to move the first lever. A bracket may be coupled to the second face of the first panel and disposed over the second end of the first lever. The bracket may include a hole through which the cable may extend, providing leverage for moving the first lever. 
     The movable barrier operator release mechanism may further include a second lever disposed above the first lever. The second lever may move the first lever when the rotated. A second shaft extending through the first panel may be disposed above the first shaft. The second shaft may extend through an opening in the second lever. The second lever may move away from the first panel when it is rotated. The second lever may disengage the brake assembly when it moves away from the first panel. A chain wheel may be disposed around the second shaft. The second lever may couple the rotation of the chain wheel to the rotation of the second shaft when it moves away from the first panel. A spring may be disposed around the second shaft and between the chain wheel and the second lever to disengage the rotation of the chain wheel from the second shaft. 
     The present disclosure is further directed to a movable barrier operator release mechanism that includes a chassis having a first panel and a first shaft extending away from the first panel. The movable barrier operator release mechanism further includes a second shaft disposed over the first shaft and extending in the first direction away from the first panel. A brake assembly is coupled to the first panel with the first shaft extending into the brake assembly. The brake assembly includes a first lever pivotally operable to disengage the brake assembly when moved in the first direction. A second lever is disposed around the second shaft. The second lever translates rotational movement into linear movement and moves the first lever in the first direction. The movable barrier operator release mechanism may further include a chain wheel having a first and second side that is disposed adjacent to the second lever with the second lever disposed between the first side of the chain wheel and the first side panel. A spring may be disposed between the second lever and the chain wheel. A first pin may be disposed transversely through the shaft perpendicular to the axial direction and adjacent the second side of the chain wheel. The second shaft may extend through the chain wheel and the spring. The chain wheel may include a second pin disposed on the second side of the chain wheel that engages the first pin to couple the rotation of the chain wheel to the second shaft. There may be a structure having sloped side walls coupled to the first panel. The second lever may have a first length in a second direction and a second length in a third direction where the second direction is perpendicular to the third direction and the second direction is perpendicular to the first direction. The first length may be greater than the second length.