Patent Publication Number: US-2022214710-A1

Title: Gyral-linear actuator for encoder

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/738,521, filed Jan. 9, 2020, now allowed, which claims the benefit of U.S. Provisional Patent Application Ser. No. 62/952,552, filed Dec. 23, 2019, entitled GYRAL-LINEAR ACTUATOR FOR ENCODER, the disclosures of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to actuators and in particular to actuators that are suitable for use with encoders. 
     Encoders are finding application in a variety of electronic devices, including processing devices typically used by musicians. In this regard, rotary encoders are particularly useful for digital processing devices including digital effect processors, modelers, and controllers, e.g., because the encoder is operated in a manner similar to a traditional potentiometer, which makes its use familiar to the typical musician. 
     BRIEF SUMMARY 
     According to aspects of the present disclosure, a gyral-linear actuator for an encoder comprises an actuator housing, a control member, a spring, a coupler, and an encoder connector. The actuator housing has a first end, a second end opposite the first end, and a hollow. The control member extends from the first end of the actuator housing, and the spring is positioned within the hollow of the actuator housing. The coupler has an encoder connector and an extension that couples the control member to the encoder connector. Under this configuration, the control member preferably provides a tactile interface that facilitates user interaction with the encoder. When the encoder connector is coupled to a rotary shaft of the encoder, rotation of the control member causes corresponding rotation of the encoder connector so as to turn the rotary shaft of the encoder. Likewise, depression of the control member causes corresponding depression of the rotary shaft of the encoder, thus operating a switch function of the rotary encoder. 
     According to a further aspect, the gyral-linear actuator&#39;s housing may further comprise a generally cylindrical body between the first end and the second end. Additionally, the body may comprise a male threaded portion on an outside periphery. Hence, the gyral-linear actuator may be coupled to a female threaded portion of a musical instrument easily. 
     According to a further aspect, the control member may comprise a neck axially received by the body of the actuator housing and a head positioned on a first end of the neck. 
     According to a further aspect, the control member may include an inside surface having a receiver that receives a distal end of the extension. Preferably, the receiver may comprise a socket. Further preferably, the socket may comprise a milled cross pattern. 
     According to a further aspect, the gyral-linear actuator may further comprise a cap that seats over the first spring, the cap having an aperture therethrough. Additionally, the encoder connector of the coupler may be positioned outside of the cap and the extension may pass through the aperture of the cap. 
     According to a further aspect, the actuator housing may further comprise a generally cylindrical body between the first end and the second end. The body may comprise a male threaded portion on an outside periphery and the cap may include a female threaded portion that threads onto the male threaded portion of the body of the actuator housing. 
     According to a further aspect, the extension of the coupler may comprise a primary shaft that connects to the control member. Additionally, the extension of the coupler may comprise a secondary shaft axially coupled to the primary shaft for relative axial movement therebetween. Preferably, the encoder connector is connected to the secondary shaft. 
     According to further aspects of the present disclosure, the primary shaft may have a hollow therein. The secondary shaft may be axially received in the hollow of the primary shaft. The primary shaft may have a male plug end that seats into a corresponding receptacle of the control member. Additionally, the primary shaft and the secondary shaft may have corresponding non-circular cross sections where the secondary shaft may be axially received in the hollow of the primary shaft. The encoder connector may be coupled to a rotary shaft of the encoder. Rotation of the control member may cause corresponding rotation of the encoder connector so as to turn the rotary shaft of the encoder. Additionally, depression of the control member may cause corresponding depression of the rotary shaft of the encoder operating a switch function of the rotary encoder. 
     According to a further aspect, the gyral-linear actuator may further comprise a secondary spring positioned in the hollow of the primary shaft adjacent to the secondary shaft. 
     According to a further aspect, the primary shaft may have a hollow therein. The primary shaft may have at least one key slot on an inside surface adjacent to the hollow. The secondary shaft may have at least one key that mates with a corresponding key slot of the primary shaft when the secondary shaft is axially received in the hollow of the primary shaft. 
     According to further aspects of the present disclosure, a gyral-linear actuator for an encoder comprises an actuator housing, a control member, a spring, a cap, and a coupler. The actuator housing has a first end, a second end opposite the first end, and a hollow. The control member extends from the first end of the actuator housing. Moreover, the spring is positioned within the hollow of the actuator housing, and the cap seats over the spring (e.g., the cap couples to the second end of the actuator housing). The coupler has an encoder connector and an extension. The encoder connector can be positioned “outside” the cap opposite the actuator housing. In this configuration, the extension couples between the control member and the encoder connector. For instance, the extension can pass through an aperture of the cap and extend into the hollow of the actuator housing, where the extension couples to the control member. In this regard, when the encoder connector is coupled to a rotary shaft of the encoder, rotation of the control member causes corresponding rotation of the encoder connector so as to turn the rotary shaft of the encoder. Moreover, depression of the control member causes corresponding depression of the rotary shaft of the encoder operating a switch function of the rotary encoder. In some embodiments, the control member is a button that is suitable for foot actuation of the switch function. Moreover, a user can grab and rotate the button, which correspondingly turns the rotary shaft of the encoder. 
     According to a further aspect of the present disclosure, the actuator housing may further comprise a generally cylindrical body between the first end and the second end. Additionally, the body may comprise a male threaded portion on an outside periphery. 
     According to a further aspect, the control member may comprise a neck axially received by the body of the actuator housing. Additionally, the control member may comprise a head positioned on a first end of the neck. 
     According to a further aspect, the control member may include an inside surface having a receiver that may receive a distal end of the extension. Additionally, the receiver may comprise a receptacle. 
     According to yet further aspects of the present disclosure, a gyral-linear actuator for an encoder comprises an actuator housing, a control member, a first spring, a primary shaft, a cap, and a shaft coupler. The actuator housing has a first end, a second end opposite the first end, a body between the first end and the second end, and a hollow that extends into the body from the second end thereof. The control member extends from the first end of the actuator housing. In this regard, the control member is rotatable within the actuator housing and is capable of axial movement within the body. The first spring is positioned within the hollow of the actuator housing, and the primary shaft is positioned within the first spring and within the hollow. Moreover, the primary shaft couples to the control member. The cap seats over the first spring. For instance, the cap can couple to the second end of the actuator housing, thus containing the first spring in the actuator housing between the control member and the cap. The shaft coupler has a secondary shaft that passes through an aperture of the cap and engages the primary shaft. The shaft coupler also includes an encoder connector at a distal end of the secondary shaft. When the gyral-linear actuator is connected to an encoder, the encoder connector couples to a rotary shaft of the encoder. Thus, in operation, rotation of the control member causes corresponding rotation of the primary shaft, which causes corresponding rotation of the secondary shaft, which causes corresponding rotation of the encoder connector so as to turn the rotary shaft of the encoder. Likewise, depression of the control member causes corresponding depression of the rotary shaft of the encoder via the primary shaft and the secondary shaft, thus operating a switch function of the rotary encoder. In some embodiments, a secondary spring is positioned in cooperation between the primary shaft and the secondary shaft. 
     According to further aspects, the body may comprise a male threaded portion on an outside periphery thereof. Further, the cap may comprise a cylindrical, knurled cap. Further, the aperture in the cap may be axially aligned with the body of the actuator housing. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is an example embodiment of a gyral-linear actuator according to aspects of the present disclosure; 
         FIG. 2  is a side view of a gyral-linear actuator shown connected to an exemplary rotary encoder according to aspects of the present disclosure; 
         FIG. 3  is a perspective view of the gyral-linear actuator of  FIG. 2 ; 
         FIG. 4  is another perspective view of the gyral-linear actuator of  FIG. 2 ; 
         FIG. 5  is another example embodiment of a gyral-linear actuator according to aspects of the present disclosure; 
         FIG. 6  is yet another example embodiment of a gyral-linear actuator according to aspects of the present disclosure; 
         FIG. 7  is a partial exploded view of parts comprising a gyral-linear actuator according to aspects of the present disclosure; and 
         FIG. 8  is an inside view of a control member according to aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     A rotary encoder is a useful feature for electronic devices, including digital effect processors, modelers, and controllers. Such encoders provide even further usability and convenience when combined with a switch function. In this regard, a typical encoder includes an encoder shaft that can be rotated to generate encoder data. Moreover, the shaft can be pressed, e.g., in a direction orthogonal to a plane in which the encoder shaft is rotated, in order to operate a switch function. Unfortunately, encoders are currently provided as delicate electrical components that are not ruggedized. As such, a typical encoder is not suitable for harsh operating conditions such as using foot pressure to activate the switch of the encoder. 
     However, according to aspects of the present disclosure, a ruggedized actuator is provided as an encoder add-on, thus forming a ruggedized control. More particularly, the actuator herein extends the functionality of a typical rotary encoder, and in particular, a rotary encoder with a switch function, to a form that is usable in harsh environments that require ruggedized controls. A non-limiting example of a ruggedized application is to adapt an otherwise delicate encoder with a ruggedized actuator for use in a foot operable processing device. Such a device is used for instance, by musicians that require the ability to change settings of a processing device using foot switching while simultaneously playing an instrument, e.g., a keyboard, horn, percussion instrument, stringed musical instrument such as a guitar or bass, etc. A ruggedized actuator as described herein can also find application in industrial settings, e.g., on industrial controls, robots, industrial controllers, etc. Yet further, a ruggedized actuator as described herein can find application in industrial vehicles, consumer vehicles, various processing devices, etc., that require the use of an encoder. 
     Referring now to the drawings, and in particular to  FIG. 1 , an example embodiment of a gyral-linear actuator  10  is illustrated in an exploded view. The gyral-linear actuator  10  provides a ruggedized actuator that is suitable for attachment to an encoder, thus forming a ruggedized control. In this regard, the gyral-linear actuator  10  includes an actuator housing  12  having a first end  14 , a second end  16  opposite the first end, and a hollow  18 . As illustrated, the actuator housing  12  can further comprise a generally cylindrical body  20  between the first end  14  and the second end  16 . The body  20  is illustrated as having a male threaded portion  22  on an outside periphery thereof. The male threaded portion  22  provides a convenient means to attach the gyral-linear actuator  10  to an equipment housing, e.g., using one or more nuts (not shown). Attachment of the actuator housing  12  rigidly and directly to an equipment housing provides a first force absorbing means that can transfer/distribute some force applied to the gyral-linear actuator  10  to the equipment housing thus isolating at least a portion of the applied force from a corresponding encoder. 
     In this regard, depending upon mounting requirements of the gyral-linear actuator  10 , not all the body  20  need include a threaded portion  22 . Moreover, in some embodiments, there may be no male threaded portion  22 . 
     The gyral-linear actuator  10  also comprises a control member  24  extending from the first end  14  of the actuator housing  12 . The control member  24  defines the portion of the gyral-linear actuator  10  for user interaction. For example, as will be described in greater detail herein. The control member  24  can be rotated relative to the body  20  (e.g., for rotational control of a corresponding encoder). The control member  24  may also be depressed relative to the body  20  (e.g., to control a switch function, where provided, on a corresponding encoder). As such, the control member  24  is also capable of axial movement relative to the body  20 . As such, the control member  24  may be configured in a manner that facilitates rotation and/or axial movement relative to the actuator housing  12 . 
     By way of example, the illustrated control member  24  includes a neck  26  axially received by the body  20  of the actuator housing  12 . The control member  24  is also illustrated as having a head  28  positioned on a first (distal) end of the neck  26 . In this regard, a user can actuate a switch by depressing the head  28  of the control member  24 , which axially moves the neck  26  into the body  20 . In some embodiments, the gyral-linear actuator  10  is ruggedized in a manner making the device suitable for operation by a foot of a user. In this example implementation, the head  28  is dimensioned so as to be comfortable to fit underneath a typical user&#39;s foot. The neck  26  provides a convenient way to position the head  28 , and optionally control a throw (i.e., maximum length of axial travel) of the control member  24  relative to the actuator housing  12 . 
     In some embodiments, the control member  24  can optionally include a shoulder, flange, washer, nut, or other suitable structure (not shown) that is positioned in the hollow  18  that forms an interference preventing the control member  24  from pushing through the first end  14  of the actuator housing  12 . Alternatively, the actuator housing  12  can “neck in” or include other feature that prevents the control member  24  from pushing through the first end  14  of the actuator housing  12 . 
     The gyral-linear actuator  10  also comprises a spring  30  within the hollow  18  of the actuator housing  12 . The spring  30  is illustrated as a conventional coil spring. However, other spring configurations and materials can be used. For instance, the spring  30  can be a resilient material, etc. The spring  30  provides the primary resistance to depression of the head  28  of the control member  24 , e.g., to activate a switch of a corresponding encoder. The spring  30  also provides a return force that biases the head  28  of the control member  24  away from the actuator housing  12  in a ready position to be actuated. For instance, an end of the spring  30  can engage the neck  26  (or other suitable abutment surface) of the control member  24  to bias the control member  24  relative to the actuator housing  12 . Stepping on the head  28  or otherwise axially moving the head  28  towards the actuator housing  12  compresses the spring  30 . When pressure is relieved from the head  28  of the control member  24 , the biasing force of the spring  30  returns the control member  24  to a ready state where the head  28  is axially returned to a position distal from the actuator housing  12 . In this regard, the specific parameters of the spring  30  are selected to account for a desired switch resistance, which is likely to be application dependent. In some embodiments, the spring  30  further ruggedizes the gyral-linear actuator  10  by setting a bias force to correspond to a force anticipated by foot pressure. 
     The gyral-linear actuator  10  still further includes a coupler  32 . The coupler  32  includes an extension  34  and an encoder connector  36 . The extension  34  is a generally elongate member that couples the control member  24  to the encoder connector  36 . The encoder connector  36  provides a connection to a corresponding rotary encoder. As such, the shape and configuration of the encoder connector  36  can vary, e.g., depending upon the geometry of the shaft of a select encoder that the gyral-linear actuator  10  attaches. For instance, the encoder connector  36  illustrated in  FIG. 1  includes a bell that forms a friction fit with an encoder shaft. In this regard, the encoder connector  36  can be integral with the extension  34 , or the encoder connector  36  can be attached, connected, or otherwise fixed to the extension  34 . 
     Referring to  FIG. 2 ,  FIG. 3 , and  FIG. 4  generally, an example implementation of the gyral-linear actuator  10  is shown attached to an encoder to form a ruggedized control. Notably, the gyral-linear actuator  10  illustrated in  FIG. 2 - FIG. 4  is presented for illustrative purposes, and can include any combination of features and/or structures described in the various embodiments of gyral-linear actuators described herein. As such, like structure is illustrated with like reference numbers except as otherwise noted. 
     For sake of illustration of operation,  FIG. 2 - FIG. 4  collectively show a gyral-linear actuator  10  having an actuator housing  12 . The actuator housing  12  can include features analogous to that described with regard to  FIG. 1 . Moreover, the actuator housing  12  in this illustrated embodiment includes a keyway  38  along an outside periphery thereof (e.g., in an axial direction). The keyway  38  is not required, but provides a convenient way to lock the gyral-linear actuator  10  to a corresponding enclosure (e.g., using a corresponding key) so that the actuator housing  12  does not rotate or twist relative to the enclosure. 
     Analogous to that shown in  FIG. 1 , extending axially from a first end  14  of the actuator housing  12  is a control member  24  having a neck  26  and head  28 . 
       FIG. 2 - FIG. 4  also show an embodiment where the gyral-linear actuator  10  includes a cap  40 . The cap  40  is optional, e.g., the functionality of the cap  40  can be implemented in another means, such as the design of the actuator housing  12  itself. In general, the cap  40  threads onto the actuator housing  12  and provides an abutment surface for the spring (not shown—but analogous to the spring  30  of  FIG. 1 ). For instance, where the actuator housing  12  includes a male threaded portion  22 , the cap  40  can include a female threaded portion that threads onto the male threaded portion  22  of the body  20  of the actuator housing  12 . The cap  40  can also be implemented as a cylindrical, knurled cap  40 . 
     Thus, in an example embodiment, an inside surface of the cap  40  that covers over the second end  16  of the actuator housing  12  can be used to define an abutment surface so that the spring  30  ( FIG. 1 ) is seated between the abutment surface of the cap  40  and the control member  24 . The cap  40  can also provide an external shoulder  41  for mounting the gyral-linear actuator  10  to a corresponding enclosure (not shown), e.g., when used in combination with a nut (not shown) that threads onto the actuator housing  12 . 
     Additionally, the cap  40  has an aperture  42  that extends therethrough. The aperture  42  is coaxially aligned with the coupler  32 , and provides a means for the extension  34  to pass from within the actuator housing  12  (where the extension  34  couples to the control member  24 ), to a position outside the actuator housing  12  (where the extension  34  couples to the encoder connector  36 ). 
       FIG. 2 - FIG. 4  further show the gyral-linear actuator  10  coupled to an encoder  50 . When the encoder connector  36  of the gyral-linear actuator  10  is coupled to a rotary encoder shaft  52  of the encoder  50 , rotation of the control member  24  causes corresponding rotation of the encoder connector  36  so as to turn the rotary encoder shaft  52  of the encoder  50 . Likewise, depression of the control member  24  causes corresponding depression of the rotary encoder shaft  52  of the encoder  50  (e.g., via the coupler  32  including the extension  34  and the encoder connector  36 ), thus operating a switch function of the rotary encoder  50 . Here, the “throw” of the switching function can be controlled in part, by the length of the neck  26  of the control member  24 , as the head  28  causes interference with the actuator housing  12 , thus limiting the axial travel of the control member. The spring  30  ( FIG. 1 ) within the actuator housing  12  can also potentially limit the axial travel distance due to compression. 
     The spring  30  (not shown) provides a biasing force to default the control member  24  to an extended state distally displaced axially from the actuator housing  12 , thus corresponding to a retracted position of the coupler  32 . The spring  30  also sets the “stiffness” or resistance to the gyral-linear actuator  10 . As the head  28  of the control member  24  is depressed (axially moved towards the actuator housing  12 ), the coupler  32  correspondingly moves axially downward. This axial movement operates the switch function of the encoder  50 . In this embodiment, the coupler  32  is fixedly connected to the control member  24 . As such, rotation of the head  28  and/or neck  26  cause corresponding rotation of the coupler  32 . As the coupler  32  rotates responsive to rotation of the control member  24 , the encoder connector  36  rotates the rotary encoder shaft  52 , thus operating the encoder  50 . Here, the encoder connector  36  may form a frictional connection to the rotary encoder shaft  52 , e.g., making the connection temporary/non-permanent. Moreover, the frictional mating of the encoder connector  36  to the rotary encoder shaft  52  ensures reliable operation as a switch and rotational encoder. 
     Referring to  FIG. 5 , another embodiment of a gyral-linear actuator  10 ′ is illustrated according to various aspects of the present disclosure. In this regard, the gyral linear actuator of  FIG. 5  includes components analogous to the gyral-linear actuator  10  of  FIG. 1 - FIG. 4 . As such, like structure is illustrated with like reference numbers, and operation is analogous unless otherwise discussed herein. 
     Analogous to that illustrated in  FIG. 1 , the gyral-linear actuator  10 ′ includes an actuator housing  12  having a first end  14 , a second end  16  opposite the first end, and a hollow  18 . As illustrated, the actuator housing  12  further comprises a generally cylindrical body  20  between the first end  14  and the second end  16 . Moreover, the body  20  is illustrated as having a male threaded portion  22  on an outside periphery thereof. 
     The gyral-linear actuator  10  also comprises a control member  24  extending from the first end  14  of the actuator housing  12 . By way of example, the illustrated control member  24  includes a neck  26  axially received by the body  20  of the actuator housing  12 , and a head  28  at the distal end of the neck  26 . The control member  24  is configured for rotational movement relative to the actuator housing  12 , and for axial movement within the hollow  18  of the actuator housing  12 . 
     The gyral-linear actuator  10 ′ also comprises a spring  30  within the hollow  18  of the actuator housing  12 . An optional cap  40  can be used to contain the spring  30  within the hollow  18  of the actuator housing  12 . 
     The above components of the gyral-linear actuator  10 ′ are analogous to those like parts of  FIG. 1 , and will thus not be discussed further. 
     Different from the embodiment of  FIG. 1 , the gyral-linear actuator  10 ′ includes a coupler  32 ′. The coupler  32 ′ is analogous to the coupler  32  of  FIG. 1 , in that the coupler  32 ′ includes an extension  34  and an encoder connector  36 . However, as illustrated in the embodiment of  FIG. 5 , the extension  34  of the coupler  32 ′ comprises a primary shaft  62  that connects to the control member  24 . The extension  34  also comprises a secondary shaft  64  axially coupled to the primary shaft  62  for relative axial (but not rotational) movement therebetween. In this regard, the encoder connector  36  is connected to the secondary shaft  64 . Here the encoder connector  36  can be integral with the secondary shaft  64 , or the encoder connector  36  can connect as a separate component. 
       FIG. 5  is an exploded view for illustrative purposes. In this regard, the cap  40  is schematically shown to the right of the secondary shaft  64 . In practice, the secondary shaft  64  may pass through the aperture  42  in the cap  40  such that a bell defining the encoder connector  36  is on one side of the cap  40  opposite the length of the secondary shaft  64  as described more fully herein. 
     In an example embodiment, the primary shaft  62  is a generally elongate shaft structure having a hollow  66  therein. The secondary shaft  64  is axially received in the hollow  66  of the primary shaft  62 . However, the generally elongate shaft need not be cylindrical. For instance, the primary shaft  62  can have any desired geometric cross-section (e.g., square, rectangular, circular, hexagonal, etc.). Analogously, the secondary shaft  64  is also a generally elongate shaft structure. However, the generally elongate shaft need not be cylindrical. For instance, the secondary shaft  64  can have any desired geometric cross-section (e.g., square, rectangular, circular, hexagonal, etc.). Moreover, the primary shaft  62  and the secondary shaft  64  need not have the same shape. For instance, as shown in  FIG. 5  (solely for illustrative, non-limiting purposes), the primary shaft  62  has a generally hexagonal cross-section, whereas the secondary shaft  64  has a generally “star pattern” cross-section due to the key arrangement. 
     As noted above, the primary shaft  62  axially moves relative to the secondary shaft  64 . In this regard, certain embodiments can include a feature such as a key  68  (or set of keys  68 ) on the outside surface of the secondary shaft  64  that mate with corresponding key slot(s)  70  on an inside surface of the primary shaft  62  adjacent to the hollow  66  when the secondary shaft  64  is axially received in the hollow  66  of the primary shaft  62 . This arrangement allows axial movement of the primary shaft  62  relative to the secondary shaft  64 , while restricting rotational relative movement of the primary shaft  62  relative to the secondary shaft  64 . Thus, in some embodiments, the secondary shaft  64  has at least one key  68 , and correspondingly, the primary shaft  62  has at least one key slot. Each key of the secondary shaft  64  mates with a corresponding key slot of the primary shaft  62  when the secondary shaft  64  is axially received in the hollow  66  of the primary shaft  62 . 
     Also, in some embodiments (not shown), the second shaft  64  may axially receive the primary shaft  62 . Under such embodiments, a feature such as a key or set of keys can be provided on the outside surface of the primary shaft  62  that mate with corresponding key slots (not shown) on an inside surface of the second shaft  64 , e.g., analogous to that described above. 
     Thus, in some embodiments, the primary shaft  62  and the secondary shaft  64  have corresponding non-circular cross sections where the secondary shaft  64  is axially received in the hollow  66  of the primary shaft  62 . In other example implementations, the primary shaft  62  and/or the secondary shaft  64  can have a circular cross-section, e.g., so long as when the encoder connector is coupled to a rotary shaft of the encoder, rotation of the control member causes corresponding rotation of the encoder connector so as to turn the rotary shaft of the encoder, and depression of the control member causes corresponding depression of the rotary shaft of the encoder operating a switch function of the rotary encoder. 
     Moreover, in some embodiments, a secondary spring  74  is positioned between the primary shaft  62  and the secondary shaft  64 . For instance, the secondary spring  74  can be placed in the hollow  66  of the primary shaft  62  adjacent to the secondary shaft  64  (e.g., adjacent to a first end thereof). In this regard, the secondary shaft  64  may include a feature  76  such as a tip, nub, dome, etc., that provides a seat that receives an end of the secondary spring  74 . This configuration assists to prevent switch failure due to excess force, serving as a secondary dampener to the spring  30 . Moreover, the secondary spring  74  extends the linear action (axial) range making the gyral-linear actuator  10  compatible with different encoders by allowing for compensation in the variability of switch travel distance. As such, the gyral-linear actuator  10 ′ includes adjustable features (including features that auto-adjust) for different applications. 
     Also shown in  FIG. 5  is an embodiment where the primary shaft  62  has a male plug end  80  that seats into a corresponding receptacle of the control member  24 . The male plug end  80  can also be implemented on the embodiment of  FIG. 1 . Also, the plug/socket relationship can be reversed, where the control member  24  includes a male plug end that connects to a mating socket in the end of the coupler  32 . 
     As an example of assembly, the control member  24  is installed in actuator housing  12 . The control member  24  includes (e.g., via the neck  26  or some other suitable component), a feature that prevents the control member from pushing through the first end  14  of the actuator housing  12 . The spring  30  is dropped into the hollow  18  of the actuator housing  12  through the second end  16 . Then, the primary shaft  62  is dropped into the hollow  18  of the actuator housing  12  within the spring  30  such that the end  80  mates with a corresponding receptacle of the control member  24 . The cap  40  is then screwed onto the threaded portion  22  of the body  20  (or is otherwise attached to the body  20 ) of the actuator housing  12  thus containing the spring  30  within the actuator housing  12 . 
     The secondary spring  74  is dropped through the aperture  42  of the cap  40  and into the hollow  66  of the primary shaft  62 . Then the secondary shaft  64  is passed through the aperture  42  of the cap  40  and is axially received into the hollow  66  of the primary shaft  62  seating the secondary spring  74 . Here, the shaft portion of the secondary shaft  64  extends through the aperture  42  in the cap  40  and the “bell” of secondary shaft  64  defining the encoder connector  36  extends axially past the cap  40 . 
     Referring to  FIG. 6 , a gyral-linear actuator  10 ″ is illustrated according to further embodiments of the present invention. In this regard, the gyral linear actuator  10 ″ of  FIG. 6  includes components analogous to the gyral-linear actuator  10 ′ of  FIG. 5 . As such, like structure is illustrated with like reference numbers, and operation is analogous unless otherwise discussed herein. 
     Here, in order to seat the coupler  32  into the actuator housing  12 , an insert  82  is installed into the hollow  18  at the second end  16  of the actuator housing  12 . The insert  82  engages the control member  24  and provides a socket for receiving the plug end  80  of the extension  34  (e.g., primary shaft  62  as shown). Here, the spring  30  is removed for clarity of illustrating the insert  82 . However, where desired, the spring  30  can be included. 
     Referring to  FIG. 7 , an example embodiment illustrates the primary shaft  62  axially receiving the secondary shaft  64  with the spring  74  engaged thereby. Here, compressing the secondary spring  74  moves the encoder connector  36  relatively closer to the plug end  80  of the primary shaft  62 , and the bias of the secondary spring  74  in a non-compressed state moves the encoder connector  36  relatively farther from the plug end  80 . This allows for adjustments to be made automatically to account for specific encoder requirements. Also, the keys  68  cooperate with corresponding slots  70  to prevent relative rotation of the primary shaft  62  relative to the secondary shaft  64 . Other mechanisms can be used to prevent relative rotation therebetween. 
     Also shown in  FIG. 7  is an example configuration of the plug end  80  at the tip of the primary shaft  62 . As illustrated, the plug end  80  takes the form of a cross pattern. 
     Referring to  FIG. 8 , the control member  24  (or optional insert  82 ) includes a receiver, implemented as a socket  84 . The socket  84  has a shape complimentary to the shape of the plug end  80 . For instance, the socket  84  can comprise a milled cross pattern. In this regard, a bottom surface of the control member  24  opposite the head  28  (e.g., bottom surface of the neck  26 ) can include a receptacle forming the socket  84 . The socket  84  can be milled into the control member  24 , or otherwise formed. Alternatively, the insert  82 , where used, can include a molded or milled socket as described above. 
     Referring to  FIG. 7  and  FIG. 8 , when receiver receives a distal end of the extension  34  (e.g., the plug end  80  is received into the mating socket  84 ), rotation of the head  28  of the control member  24 , causes corresponding rotation of the neck  26 . Because of the cross pattern of the plug and socket, the rotation of the neck  26  causes corresponding rotation of the coupler  32 . 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. Aspects of the disclosure were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.