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FIELD OF THE INVENTION 
   The invention relates generally to an operator assembly, and particularly to an operator assembly for shifting a movable barrier. 
   BACKGROUND OF THE INVENTION 
   Operator assemblies, such as gate operators, are typically used for opening and closing of movable barriers, such as gates for selectively permitting access to a driveway or a walkway. Gate operators may use a system of linkage arms to pivot a hinged gate about its hinges and move the gate between open and closed positions. 
   Gate operators typically have a motor with an output shaft offset from the linkage or operating arms connected to the gates. However, offsetting the motor may require two different models of gate operators to be made, one for operating gates hinged on their left sides and another for operating gates hinged on their right sides. Providing two different models of gate operators, each designed for a specific hinge orientation of the gate, is disadvantageous in that it may increase the complexity and cost of producing the two different gate operators. Furthermore, having gate operators configured for solely right or left hand hinged gates limits the versatility of the operators. 
   Gates may come in a variety of different sizes, and may range from smaller gates for walkways, larger gates for single width driveways, and even larger gates for dual width driveways. Different gate sizes may require different gate operators, with each gate operator having a gearing ratio designed exclusively for the specific size or range or sizes of the gates. For example, a larger gate may require more torque than a smaller gate and thus a lower gearing ratio. A larger gate may also require slower opening by the gate operator due to the longer length thereof, in order to maintain a speed for the end of the gate opposite the hinged end comparable to a smaller gate. Producing different gate operators each having a different gearing ratio configured specifically for a particular size or range of gate sizes is disadvantageous due to the multiple different gate operators required. Furthermore, the versatility of the gate operator having a specific gear ratio for a specific gate is limited to use with that gate. 
   The linkage or arm components of a gate operator may have different formations thereon. For example, in a screw-type gate operator a thread may be provided at one end of an arm for engagement with a threaded screw. The thread may be integrally formed on the arm, or the thread may be attached separately. Attaching a separate thread to the arm can be disadvantageous because the thread may separate from the arm during repeated use. Thus, it is desirable to provide an operator assembly having components securely held together. 
   Gate operators are typically configured to be electronically activated. For example, the gate operator may be wired to a control, or may receive radio or remote control signals for activation thereof. Occassionally, however, a user may wish to open the gate manually, i.e., without the operation of the motor. Manually opening of the gate can be disadvantageous because the motor may be coupled to the arm or linkage, and movement of the arm or linkage may harm the motor. In addition, the motor may restrict the ease at which the gate can be manually shifted. Thus, it is desirable to provide an operator that is adapted to permit either manual or automated operation. 
   SUMMARY OF THE INVENTION 
   In accordance with the invention, an operator assembly for shifting a movable barrier and a method of manufacture therefor is provided that allows the operator to be configured for a wide variety of different installations and uses. 
   The operator assembly may be configured for use with different sizes of movable barriers, such as gates, thereby permitting the operator to have increased versatility. For example, the operator assembly may be provided with an adjustable output adapted for a particular barrier size or range of barrier sizes. The adjustable output may comprise a transmission having one or more components selectively interchangeable by the manufacturer, user, installer, or other person or persons to allow the gate operator to readily be tailored for the particular barrier size or range of barrier sizes. Providing a standardized operator assembly with one or more interchangeable transmission components can increase the versatility of the operator assembly and reduce manufacturing costs. 
   The operator assembly may also be configured for use with different installation configurations, thereby simplifying the set-up and use of the operator with different barrier orientations. For example, the operator assembly may be configured to be used with both barriers hinged at a right side and barriers hinged at a left side. The operator assembly may also be used with different mounting configurations, such as different pivotal mounting locations on the barrier, further increasing the versatility of the operator assembly. The operator assembly may include a substantially linear drive train or transmission, thereby eliminating the need to provide separate gate operators for left hinged barriers and right hinged barriers. Such a versatile operator assembly can simplify installation and manufacturing thereof. 
   The operator assembly may include a motor having a predetermined power rating and an actuator driven by the motor for shifting the movable barrier. The motor may drive the actuator with a predetermined output force that is adjustable. According to an aspect of the invention, the predetermined power rating of the motor may comprise a predetermined maximum output torque generated by the motor independently of the predetermined output force selected for the actuator. 
   In an aspect of the invention, the adjustable transmission may include a pair of gears cooperating to define a gear ratio therebetween. To select the predetermined output force for the actuator, one or more of the gears may be replaceable with another gear to change the gear ratio. In a further aspect of the invention, both of the gears may be replaceable with another pair of gears having a different gear ratio therebetween in order to configure the output force of the actuator for use with various arrangements of movable barriers. In yet another aspect of the invention, both of the gears may be replaceable with another pair of gears having a different gear ratio therebetween in order to configure the output force of the actuator for use with various sizes of movable barriers. 
   In another aspect of the invention, the replaceable gears may provide the operator assembly with versatility as far as mounting configurations. Different gear sets may be provided to allow for the gate operator assembly to be connected relative to the movable barrier at different locations thereon. For example, connecting the operator assembly to the movable barrier at a location farther from a hinge of the barrier may provide a mechanical advantage, thereby reducing the torque required for shifting the barrier and allowing a transmission having a higher gear ratio to be used. Conversely, connecting the operator assembly to the movable barrier at a location closer to the hinge of the barrier may require an increased torque for shifting the barrier, with the increased torque provided by a transmission having a lower gear ratio. Thus, providing the gate operator with interchangeable transmission components allows the gate operator to be adapted for connection at different locations on the movable barrier. 
   In an aspect of the invention, the motor may include a housing or casing pivotably connectable relative to the movable barrier, such as to a fixed mount. The actuator may also be pivotably connectable relative to the movable barrier. 
   In an aspect of the invention, the actuator may comprise a hollow tubular member or arm having a pivot connection at an end thereof. The pivot connection may comprise a flattened region having an aperture therethrough integrally formed with the tubular member. A pin may be provided through the aperture for pivotably connecting the arm relative to the movable barrier, such as with a yoke mounted relative to the movable barrier. The flatted region may be provided by flattening or crimping the end of the hollow tubular member. The tubular member or arm may also be stamped. The aperture may then be drilled therethrough. The aperture may also be provided through the tubular member prior to flattening thereof. In an aspect of the invention, the actuator arm may have a bend or other departure from its longitudinal axis effective to offset the aperture or pivot point from the longitudinal axis of the arm, such as to provide a mechanical advantage. 
   According to an aspect of the invention, the motor may have an output shaft aligned with a drive shaft of the actuator to maximize the different barrier configurations that the operator assembly can be used with. The output shaft of the motor may be, but is not necessarily, coaxially aligned with the drive shaft of the actuator. 
   According to a further aspect of the invention, the transmission may comprise a pair of intermediate shafts provided between the drive shaft of the actuator and the motor output shaft. The intermediate shafts may be positioned normally relative to the drive and motor output shafts. Gears may be provided on the shafts for transmitting rotation from the motor output shaft to the drive shaft. As discussed above, a pair of gears may be provided having a gearing ratio therebetween for controlling the predetermined output force provided by the actuator. One of the pair of gears or both of the pair of gears may be interchangeable with another gear or another pair of gears to provide a different gear ratio and thus change the predetermined output force provided by the actuator. 
   In accordance with the invention, the operator assembly may be provided with a screw-type drive for selectively shifting the movable barrier. The actuator may comprise an arm extending between the operator assembly and the barrier. The end of the arm proximate the movable barrier may be pivotably connected relative thereto. 
   The drive shaft may comprises a threaded screw coaxially aligned with the arm, the threaded screw having a threaded region adapted for engagement with an internal thread or nut provided on the second end of the arm. The threaded screw may be arranged for rotation by the transmission, such that rotation of the motor output shaft will cause rotation of the threaded screw. Rotation of the threaded screw may then cause the nut and thus the arm to be advanced or retracted relative thereto, depending upon the direction of rotation of the motor output shaft. 
   According to an aspect of the invention, the internal thread or nut may comprise a molded plastic or polymer material. The nut may be molded onto the end of the actuator arm, such as by using insert molding techniques. The actuator may comprise a hollow member, such as a hollow tube or cylinder, having a wall with an inside surface and an outside surface. One or more apertures may be formed through the wall. The nut may include a portion on the outside surface and a portion on the inside surface of the wall, with material mechanically connecting the inside and outside nut portions extending through the aperture in order to secure the nut relative to the actuator arm. 
   In an aspect of the invention, the drive shaft and the actuator arm may be disposed within a housing. The housing may be fixed relative to the motor, and may comprises a hollow tubular member, such as a sleeve or tube. The coaxially aligned drive shaft and actuator arm may also be coaxially aligned with the housing. 
   A guide element may be provided on an end of the housing opposite from an end proximate the motor. The guide element may assist in maintaining the coaxial alignment with the actuator arm. In addition, the guide element may function a wiper, sliding against and/or cleaning an outer surface of the actuator arm as it moves therepast. Furthermore, the guide element may be configured to limit the outward extension of the actuator arm relative to the housing or sleeve member. The guide element may also function as a seal, preventing dirt, debris, or liquid from entering the inside of the housing or sleeve, such as to prevent contamination of lubrication between the sleeve and the actuator arm. 
   According to another aspect of the invention, the guide element may comprise a molded plastic or polymer material. The guide element may be molded onto the end of the housing or sleeve member, such as by using insert molding techniques. Similar to the actuator arm, the sleeve may comprise a hollow member, such as a hollow tube or cylinder, having a wall with an inside surface and an outside surface. One or more apertures may be formed through the wall. The guide element may include a portion on the outside surface and a portion on the inside surface of the wall, with material mechanically connecting the inside and outside guide element portions extending through the aperture in order to secure the guide element relative to the sleeve. 
   According to an aspect of the invention, the movable barrier may comprise a gate. The gate may be hinged at its left side or its right side. The motor of the operator assembly may have its output shaft generally aligned with the actuator arm thereof, thus permitting a single operator assembly to be used with both gates hinged at their left sides or gates hinged at their right sides. 
   According to another aspect of the invention, the operator assembly may be provided with a transmission having one or more interchangable gear sets positioned between the motor output shaft and the arm. A plurality of different gearing sets, each gearing set having a different gearing ratio, may be configured to be used with a single gate operator. Interchangeable gear sets allow a single gate operator to be readily adapted for use with different size gates. The gear sets may be provided to the end user, such as the installer or owner of the gate. Alternatively, the user may comprise the manufacturer, which may select a gear set for the operator assembly having the desired gear ratio and then provide the operator to the end user or installer. 
   In an embodiment of the invention, the operator assembly may include a transmission configured for selectively transmitting the motor output to the drive shaft or threaded screw. The transmission may have a configuration wherein the motor output is transmitted to the drive shaft and another configuration wherein the motor output is not transmitted to the drive shaft, thereby allowing the gate or movable barrier to be shifted without affecting the motor output. The transmission may include a cam mechanism selectively operable by a user for engaging or disengaging the transmission. When the transmission is disengaged, the user can manually shift the gate without harming the motor or without having to go against the output of the motor. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded top plan view of an operator assembly according to an embodiment of the invention; 
       FIG. 2  is a top plan view of the assembled operator assembly of  FIG. 1 ; 
       FIG. 3  is a side elevation view of the assembled operator assembly of  FIG. 1 ; 
       FIG. 4  is a front elevation view of an arm of the operator assembly of  FIG. 1  prior to formation of a threaded region and a pivot region; 
       FIG. 5  is a front elevation view of the arm of  FIG. 4  after formation of the pivot region and prior to formation of the threaded region; 
       FIG. 6  is a section view of the arm of FIG.  5  taken along line  6 — 6  showing after formation of the threaded region and the pivot region; 
       FIG. 7  is a side elevation view of a driving shaft of the operator assembly of  FIG. 1 ; 
       FIG. 8  is a section view of a sleeve of  FIG. 1  prior to formation of a guide element; 
       FIG. 9  is a side elevation view of a top portion of a sleeve prior to formation of the guide element and section view of a sleeve; 
       FIG. 10  is a section view of the sleeve of  FIG. 8  after formation of the guide element; 
       FIG. 11  is a side elevation view of the arm, sleeve and screw with the arm in a retracted position; 
       FIG. 12  is a side elevation view of the arm, sleeve and screw of  FIG. 11  with the arm in an extended position; 
       FIG. 13  is a side elevation view of a gear set for the operator assembly of  FIG. 1  according to a first embodiment of the invention; 
       FIG. 14  is a section view of a gear set for use with the gear set of  FIG. 13  according to the first embodiment of the invention; 
       FIG. 15  is a side elevation view of a gear set for the operator assembly of  FIG. 1  according to a second embodiment of the invention; 
       FIG. 16  is a section view of a gear set for use with the gear set of  FIG. 15  according to the second embodiment of the invention; 
       FIG. 17  is a section view of the threaded region of  FIG. 6 ; 
       FIG. 18  is a perspective view of the pivot region of the arm pivotably attached with a pin to a yoke mounted relative to a barrier; 
       FIG. 19  is a perspective view of the pivot connection of the operator assembly of  FIG. 1  pivotably attached to a fixed mount; 
       FIG. 20  is a perspective view of the operator assembly of  FIG. 1  showing the arm in an extended position; 
       FIG. 21  is a perspective view of the operator assembly of  FIG. 1  showing the arm in a retracted position; 
       FIG. 22  is a perspective view of the operator assembly of  FIG. 1 ; 
       FIG. 23  is a perspective view of the operator assembly of  FIG. 1  showing the arm in an extended position; 
       FIG. 24  is a perspective view of the operator assembly of  FIG. 1  showing the arm in an extended position; 
       FIG. 25  is a perspective view of the operator assembly of  FIG. 1 ; and 
       FIG. 26  is a perspective view of the operator assembly of FIG.  1 . 
   

   DETAILED DESCRIPTION 
   The invention is preferably embodied in an operator assembly  1 , and a method of manufacturing the operator assembly  1 , capable of being configured to shift movable barriers of various sizes and orientations. 
     FIGS. 1-26  illustrate an operator assembly  1  in accordance with aspects of the invention. The operator assembly  1  generally comprises a motor  10  adapted for rotating a driving shaft  30 , as illustrated in  FIG. 1 , wherein rotation of the driving shaft  30  causes the extension or retraction of an actuator arm  20  relative to the driving shaft  30  with a predetermined output force. A movable barrier, such as a gate, is pivotably connectable relative to the actuator arm  20  and is selectively movable with the predetermined output force thereof. 
   A transmission  50  is provided between an output shaft  12  of the motor  10  and the driving member  30  that allows the predetermined output force provided by the actuator arm  20  to be selectively adjustable in order to allow configuration and tailoring of the operator assembly  1  with a variety of different barrier or gate sizes. The transmission  50  includes a pair of interchangeable gears, the pair of gears  62  and  72  cooperating to provide a gearing ratio for adjusting the output force relative to the rotation of the motor output shaft  12 . 
   The interchangeable transmission components allow the operator assembly  1  to be configured according to the size of the movable barrier which it is to be used with, while still maintaining the use of the motor  10  with a predetermined power rating. For example, a larger barrier may have an increased size compared to a smaller barrier and thus require an output force having a greater torque. A larger barrier may have a greater length, and it may be desirable to configure the transmission of the operator assembly  1  to move the barrier at a slower speed as compared to the speed of moving a smaller barrier. For instance, an operator  1  not configured for use with a larger barrier may move the distal end of the barrier, opposite the hinged end thereof, at a faster rate than is desirable. For such a barrier a transmission  50  may be provided in the operator assembly  1  configured for use with such a larger barrier. The interchangeable transmission components may be installed during manufacture of the operator assembly  1 , or may be provided with the operator  1  for installation by the end user or installer. 
   The selectively adjustable transmission  50  of the operator apparatus of the invention allows the same type of motor  10  to be used for different gate sizes. For example, a four pole motor may be used for both small and large gate sizes, when coupled with a transmission  50  having an appropriate gear ratio. A six pole or other type of motor may also be used with the operator apparatus of the invention. 
   As illustrated in  FIG. 1 , the transmission comprises two separate gear assemblies  60  and  70 , each comprising a freely rotatable shaft  64  or  74  arranged substantially normal relative to the output shaft  12  of the motor  10 . The shafts  64  and  74  may have ends rotatable within bushings or other friction and/or wear reducing elements  66  and  76 . Each shaft  64  or  74  has two gears  62  and  68  or  72  and  78  mounted thereon. 
   The first shaft  64  has gear  68  adapted to be driven by a gear  14  provided on the motor output shaft  12 . Rotation of the gear  68  causes rotation of the first shaft  64 , which in turn causes rotation of the gear  62 . The gear  62  is positioned for driving engagement with gear  72 , mounted on the second shaft  74 . Rotation of the gear  72  by the gear  62  causes rotation of the second shaft  74  and thus rotation of the gear  78  mounted thereto. The gear  78  is positioned for driving engagement with a gear  32  connected relative to an end of the driving shaft  30 . Thus, the transmission  50  provides for the rotation of the driving shaft via rotation of the motor output shaft  12 . 
   The predetermined output force of the actuator arm  20  is determined by the transmission  50 . In particular, the output force is determined by the gear ratio of the transmission  50  which is determined, in part, by the ratio between the gear  62  and gear  72 . The gear  62  and the gear  72  are adapted to be readily interchangeable with different gears having a different gear ratio therebetween, thereby allowing the selective adjustment of the predetermined output force of the actuator arm  20 . For example, a first set of gears  62 ( a ) and  72 ( a ), as illustrated in  FIGS. 13 and 14 , may have a 1:1 gear ratio therebetween. Such a 1:1 gear ratio may be suitable for use in a gate operator  1  configured for use with a small sized movable barrier. A second set of gears  62 ( b ) and  72 ( b ), as illustrated in  FIGS. 15 and 16 , may have a 3:2 gear ratio therebetween for stepping down the rotational output of the motor  10 . A 3:2 gear ratio may be useful for larger sized movable barriers, where an increased torque and slower barrier shifting is desired. The gears  62  and  72  may comprise idler gears, and the gears  14 ,  32 ,  68 , and  78  may comprise worm-type gears, or other such gears adapted for transmitting rotational forces in perpendicular arrangments. 
   The transmission  50  of the gate operator  1  is configured to be selective engaged and disengaged from the motor output shaft  12 , allowing for the shifting of the movable barrier without operation of the motor output shaft  12 . For example, the transmission  50  may be disengaged to permit the manual shifting of the movable barrier without causing the rotation of the motor output shaft, thereby reducing potential harm to the motor  10 . 
   As illustrated in  FIGS. 14 and 16 , the first shaft  64  comprises two independently rotatable shafts  82  and  84 . The shaft  82  has the gear  62  mounted thereon, and the shaft  84  has the gear  68  mounted thereon. A spring  86  is provided between the shafts  82  and  84  and biases the shafts  82  and  84  apart. When the shafts  82  and  84  are biased apart, they are allowed to rotate independently of each other. Thus, when biased apart, the rotation of the gear  68 , such as by manually shifting of the movable barrier, will not cause the rotation of the gear  62  and resulting rotation of the gear  14  on the motor output shaft  12 . 
   Operation of a camming mechanism  90 , illustrated in  FIG. 1 , can provide a force overcoming the biasing force of the spring  86  to bias the shafts  82  and  84  together so that the two shafts  82  and  84  rotate dependently upon each other, i.e., rotation of gear  68  will cause rotation of gear  62 , and vice versa. The camming mechanism  90  comprises a pin  92  extending through a bore  88  formed in shaft  84 . The pin  92  is selective slidable within the bore  88  relative to the shaft  84  upon operation of a camming lever mechanism  94 . Movement of the pin  92  against the biasing force of the spring  86  pushes coupling element  96  against the shaft  82  for coupling the shafts  82  and  84  together for dependent rotation. Conversely, release of the pin  92  with the camming lever mechanism  94  allow for the spring  86  to bias the coupling element  96  away from the shaft  82 , thereby decoupling the shafts  82  and  84  to allow independent rotation thereof. 
   According to another aspect of the gate operator  1  of the invention, the driving shaft  30  and the motor output shaft  12  are substantially coaxial. The driving shaft  30  is also substantially coaxially aligned with the actuator arm  20 . The coaxial arrangements allow for the gate operator  1  to be used with a variety of different configurations of movable barriers, and allow for versatility in the installation of the operator assembly  1 . For instance, the coaxial arrangements provide a gate operator  1  that can be used with both left hinged gates and right hinged gates. 
   As discussed hereinabove, rotation of the driving shaft  30  causes the extension or retraction of the actuator arm  20  relative to the driving shaft  30  with a predetermined output force. When the operator assembly  1  is pivotably connected at one end to a mount fixed independently relative to the movable barrier and at another end pivotably connected relative to the movable barrier, the extension or retraction of the actuator arm  20  causes the shifting of the movable barrier. 
   In an aspect of the invention, a pivot connection  2  is provided at an end of the operator assembly. A pivot connection  22  is also provided at an end of the actuator arm  20  opposite the other pivot connection  2 , as illustrated in  FIGS. 1-3 . The pivot connection  2  is fixable relative to a mount independent of the movable barrier while the other pivot connection  22  is fixable relative to the movable barrier. These pivot positions may also be reversed. The pivot connection  22  may be offset from the longitudinal axis of the arm  20 , such as by forming a bend or elbow in the arm  20 , to provide a mechanical advantage or to provide for a variety of different installation configurations for the operator assembly  1 . 
   The driving shaft  30  comprises a shaft  32  having external threads  34  thereon, as illustrated in  FIG. 7. A  threaded member or nut  100  is provided on the opposite end of the actuator arm  20  from the pivot connection  22 . The external threads  34  of the driving shaft  30  cooperate with internal threads  102  formed on the nut  100  to extend or retract the actuator arm  20  relative to the driving shaft  30 . Both the driving shaft  30  and the actuator arm  20  are housed within a hollow housing or sleeve  40 , as illustrated in  FIGS. 1 ,  11 , and  12 . In its retracted state the actuator arm  20  is substantially received within the housing  40 , and the nut  100  is in threaded engagement with the shaft  30  and located proximate the motor  10 , as illustrated in FIG.  11 . As the driving shaft  30  rotates, the external threads  34  thereon, in combination with the pivot connection  22  being fixed relative to the driving shaft  30 , cause the outward extension of the arm  20  relative to the housing  40  to an extended position, as illustrated in FIG.  12 . An aperture  36  in the drive shaft  30  allows for the coupling of a shaft  22  thereto. The gear  32 , discussed hereinabove, is mounted to the shaft  120  for rotating the driving shaft  30 , as illustrated in FIG.  12 . 
   As illustrated in  FIGS. 11 and 12 , a guide element  110  is provided at an end of the housing  40  opposite the motor  10 . The guide element  110  functions to maintain the arm  20  and the housing  40  in coaxial alignment. The guide element or member  110  also functions as a seal, restricting the entry of dirt or other debris between the housing  40  and the arm  20 . In addition, the guide element  110  functions to limit the outward extension of the arm  20  relative to the housing  40  by engagement with the nut  100  on the end of the arm  20 , as illustrated in FIG.  12 . The guide element  110  also functions as a slide or wiper, sliding against and/or cleaning the arm  20  as it moves therepast. 
   The guide element  110  is attached in-situ to the end of the housing  40 , as illustrated in detail in FIG.  10 . The guide element  110  comprises a molded plastic or polymer material. An outer portion  112  of the guide element  110  surrounds an exterior surface  46  of a wall  48  of the tubular housing  40  and an inner portion  114  of the guide element  110  surrounds an interior surface  44  of the housing  40 . A pair of apertures  42  are provided in the wall  48  of the housing  40 , allowing portions  116  of the guide element  110  to mechanically connect the inner and outer portions  114  and  112  thereof, thereby securing the guide element  110  relative to the housing  40 . In a method according to an aspect of the invention, the guide element  110  may be molded, such as by insert molding techniques, to the end of the housing  40 . During the molding, the joining portions  116  of the guide element  110  are formed between the inner and outer portions  112  and  114  thereof. 
   Similar to the construction of the guide element  110  and the joining thereof to the housing  40 , the nut  100 , discussed above, includes an inner portion  104  and an outer portion  106  joined via portions  108  extending through a pair of apertures  28  in the arm  20 , as illustrated in FIG.  17 . The inner portion  104  of the nut  100 , which includes the internal threaded region  102 , surrounds an interior surface  136  of a wall  132  of the tubular arm  20 . The exterior portion  106  of the nut  100  surrounds an exterior surface  134  of the wall  132  of the arm  20 . As with the guide element  110 , the nut  100  is molded, such by using insert molding techniques, in-situ to the end of the arm  20 . The portions  108  of the nut  100  provide a secure mechanical connection of the nut  100  relative to the arm  20 . 
   Different lengths of arms  20  and housings  40  may be used to vary the amount of extension of the arm  20 . For example, a shorter housing  40 , such as illustrated in  FIG. 8 , may be used. A longer housing  40 , such as illustrated in  FIG. 9 , may also be used. 
   As illustrated in  FIG. 6 , the actuator arm  22  comprises a cylindrical tube with an end, opposite an end proximate the motor  10 , having a pivot connection  22  comprising a flattened region  24  with an aperture therethrough  26 . A bushing or other friction reducing surface, such as a bronze or plastic bushing, may be provided for insertion through the aperture and around a pin  142 . The aperture  26  is adapted to receive the pin  142  or other suitable member for pivotably connecting the arm  22  to the movable barrier, such as with a yoke  140  mounted relative to the barrier, as illustrated in FIG.  18 . Forming the pivot connection  22  with a flattened region  24  minimizes the number of parts required for the actuator arm  22 , such as if a separate pivot connection were attached to the end of the arm  22 . Furthermore, the pivot connection  22  provides for simplified manufacture of the actuator arm  20 . For example, the pivot connection  22  may be formed by flattening, crimping, or stamping a cylindrical tube, such as illustrated in  FIG. 4 , to create the flattened region  24 , as illustrated in FIG.  5 . The aperture  26  may be provided in the flattened region  24  after the flattening thereof. The aperture  26  may also be provided in the cylindrical tube prior to flattening thereof. 
   As illustrated in  FIG. 2 , the motor  10  and the transmission  50  are provided within a casing  150 . The casing  150  may be formed of a plastic or polymer material, and can be shaped to add visual appeal to the operator apparatus  1 , to protect the components from dirt, debris, or liquid, and/or to provide mounting surfaces for the various components thereof. As illustrated in  FIG. 1 , the casing  150  comprises at least two separate shells  152  and  154  that may be joined together to form the casing  150 , such as by adhesive or friction joining. 
   The term barrier, as used herein, includes gates and other movable barriers. The barrier may include a single hinged gate, or dual hinged gates, each having an operator assembly  1  for shifting thereof. Other types of gate configurations and barriers are also contemplated by the invention, and the operator assembly or gate operator  1  of the invention may be used therewith. 
   From the foregoing, it will be appreciated that the invention provides an operator assembly and method for manufacturing an operator assembly. While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.

Summary:
An operator assembly for shifting a movable barrier between open and closed positions thereof, wherein the operator assembly can be configured to function with a variety of different barrier sizes and orientations. The operator assembly may include one or more interchangeable transmission components for adapting the operator for use with different gate sizes and installations. The operator assembly may also comprise a substantially linear drive train for permitting use with different barrier orientations.