Patent Publication Number: US-2022235855-A1

Title: Split lead screw sleeve and associated linear actuator

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from the benefit of the filing date of Chinese Patent Application no. 202110113722.8 filed on Jan. 27, 2021, the contents of which are herein incorporated by reference. 
     FIELD 
     The present disclosure relates to actuation of a vehicle closure, in particular, to a split lead screw sleeve. 
     BACKGROUND 
     A typical motor vehicle door is mounted in a door frame on the vehicle and is movable between open and closed positions. Usually the door is held in a closed position by the latching engagement between a spring-biased ratchet pivotally mounted inside the door latch and a U-shaped striker secured to the door frame. The ratchet is most often spring-biased toward the unlatched position to release the striker and is maintained in the latched position to hold the striker by a spring-biased pawl or other mechanical structure. The ratchet cannot pivot to release the striker until the pawl is moved. 
     The majority of these door latches are exclusively manually operated both to unlatch the door and to relatch the door. Typically, the manual release handles are provided on the inside and outside of the door to release the ratchet from the striker by moving the pawl so that the door can be opened. The door is closed and relatched by manually pivoting the door so that the ratchet impacts the striker with sufficient force to pivot the ratchet to the latched position against the spring force exerted by the ratchet spring. 
     An automatic opening/closing actuator of an automobile door is an important part for door opening and closing. With the development of technical conditions, more and more medium and high-grade automobiles are equipped with automatic opening/closing actuators of automobile doors, such as a sport utility vehicle (SUV) power liftgate, power side doors provided on an electric trunk of a car and a high-grade automobile, a scissor door, and a gull-wing door. The automatic opening/closing actuator of the automobile door generally converts the rotary motion of a drive motor into the reciprocating linear motion of an actuator through the thread transmission between a lead screw and a lead screw nut. Additionally, the lead screw nut is connected to a sleeve. Therefore, the sleeve to which the lead screw nut is connected is a core component of the automatic opening/closing actuator of the automobile door. At present, in general, the lead screw nut is directly plastic-coated in the sleeve. However, a mold of a large volume is needed when this structure is processed. When sleeves of different lengths are needed, it is necessary to replace the corresponding limiting mechanism or even the whole set of mold. Thus, the development cycle is long, the plastic-coated lead screw nut has poor dimension stability, and the overall production cost is high. 
     Further, current production processes for actuators involving lead screws and corresponding lead screw nuts require multiple different lengths of housing tubes and corresponding nuts, in view of differently configured vehicle closure panels and attachment locations for the actuator (e.g. actuated strut). 
     SUMMARY 
     An object of the present disclosure is to obviate or mitigate at least one of the above presented disadvantages. 
     An object of the present disclosure is to provide a split lead screw sleeve so as to help address problems that a mold of a large volume is needed when an existing sleeve connected to a lead screw nut is processed and it is necessary to replace the corresponding limiting mechanism or even the whole set of mold when sleeves of different lengths are needed. 
     An aspect is a split lead screw as provided and includes a lead screw nut, a first lead screw sleeve fixedly sleeved on the lead screw nut, and a second lead screw sleeve fixedly connected to the first lead screw sleeve. 
     An aspect provided is the lead screw nut and the first lead screw sleeve are integrally formed through injection molding. 
     An aspect provided is the lead screw nut, the first lead screw sleeve, and the second lead screw sleeve are coaxially disposed. 
     An aspect provided is a plurality of through holes are dispersedly disposed on the first lead screw sleeve. A plurality of protrusions are disposed on the outer wall of the lead screw nut. The plurality of protrusions pass through the plurality of through holes one to one. 
     A further aspect provided is a split lead screw sleeve, where the first lead screw sleeve is fixedly sleeved on the lead screw nut and the second lead screw sleeve is fixedly connected to the first lead screw sleeve. In response to different requirements of different automatic opening/closing actuators of automobile doors for the length of the lead screw sleeve, merely the length of the second lead screw sleeve needs to be adjusted and the length of the first lead screw sleeve can be fixed. A mold of a small volume is needed when the first lead screw sleeve and the lead screw nut are processed, and it is unnecessary to replace the mold. Thus, the cost is low and the development cycle is short. The lead screw nut and the first lead screw sleeve are integrally formed through injection molding so that the lead screw nut has good dimension stability. The plurality of through holes are disposed on the first lead screw sleeve. The plurality of protrusions are disposed on the outer wall of the lead screw nut. The plurality of protrusions are fitted with the plurality of through holes one to one. Thus, the lead screw nut can be limited to be prevented from moving in the first lead screw sleeve. 
     A further aspect provided is a split lead screw sleeve assembly, comprising: a lead screw nut; and a first lead screw sleeve having a fixedly attached connection with the lead screw nut, such that the first lead screw sleeve has a first tube end for coupling with a second tube end of an adjacent second lead screw sleeve; wherein the lead screw nut, the first lead screw sleeve, and the second lead screw sleeve are coaxially disposed when the first tube end is positioned adjacent to the second tube end. 
     A further aspect provided is a split lead screw sleeve, comprising: a lead screw nut; a first lead screw sleeve fixedly attached on the lead screw nut, wherein the lead screw nut and the first lead screw sleeve are integrally formed through injection molding; and a second lead screw sleeve fixedly connected to the first lead screw sleeve, wherein the lead screw nut, the first lead screw sleeve, and the second lead screw sleeve are coaxially disposed; and wherein a plurality of through holes are dispersedly disposed on the first lead screw sleeve, a plurality of protrusions are disposed on an outer wall of the lead screw nut, and the plurality of protrusions pass through the plurality of through holes one to one. 
     A further aspect provided is a linear actuator for a closure panel of a vehicle, the actuator comprising: a body housing for coupling to one of the closure panel and a body of the vehicle; an extension member housed in the body housing, the extension member for coupling to the other of the closure panel and the body of the vehicle, the extension member including: a split lead screw sleeve assembly having: a lead screw nut; and a first lead screw sleeve having a fixedly attached connection with the lead screw nut, such that the first lead screw sleeve has a first tube end for coupling with a second tube end of an adjacent second lead screw sleeve; wherein the lead screw nut, the first lead screw sleeve, and the second lead screw sleeve are coaxially disposed when the first tube end is positioned adjacent to the second tube end. 
     A further aspect provided is a method for assembling a split lead screw sleeve assembly, the method comprising: providing a lead screw nut; coupling the lead screw nut to a first lead screw sleeve as a fixedly attached connection with the lead screw nut; wherein that the first lead screw sleeve has a first tube end for coupling with a second tube end of an adjacent second lead screw sleeve, such that the lead screw nut, the first lead screw sleeve, and the second lead screw sleeve are coaxially disposed when the first tube end is positioned adjacent to the second tube end. 
     Preferably, the lead screw nut is made of a plastic material. Preferably, a first inserting portion is disposed at one end of the second lead screw sleeve, and the first inserting portion is inserted into and fixedly connected to the first lead screw sleeve. Preferably, a second inserting portion is disposed on the lead screw nut. The second inserting portion is inserted into the first inserting portion. The first inserting portion abuts against the lead screw nut. Preferably, the split lead screw sleeve further includes a third lead screw sleeve fixedly connected to the second lead screw sleeve, where external threads are disposed on the outer wall of the third lead screw sleeve. Preferably, an annular groove is disposed on the lead screw nut. Preferably, the outer diameter of the first lead screw sleeve is equal to the outer diameter of the second lead screw sleeve. 
     Another aspect provided is a lead screw nut assembly having a lead screw nut configured for threaded mating with a lead screw and a lead screw sleeve connected to the lead screw nut, wherein the lead screw sleeve is connectable to a second end of a first lead screw sleeve, such that the lead screw nut assembly is interchangeably connectable with a second lead screw sleeve selected from a group of second lead screw sleeves of different lengths. 
     In a related aspect, the second lead screw sleeve is connectable with a third lead screw sleeve. 
     In a related aspect, the third lead screw sleeve includes a threading for connection to a mating threading of a mount, such as for example a ball socket. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The foregoing and other aspects will be more readily appreciated having reference to the drawings, wherein: 
         FIG. 1  is perspective view of a vehicle having a closure panel; 
         FIG. 2  is further embodiment of the closure panel of  FIG. 1 ; 
         FIG. 3A  is a perspective view of an example embodiment of a linear actuator of the vehicle of  FIG. 1 ; 
         FIG. 3B  is a perspective view of an example embodiment of a linear actuator of the vehicle of  FIG. 1 ; 
         FIG. 4  is a structure view of a split lead screw sleeve of an actuator of the vehicles of  FIG. 2 ; 
         FIG. 5  is a sectional view of a split lead screw sleeve along line A-A of the actuator of  FIG. 4 ; 
         FIG. 6A  is a cross sectional view of a further embodiment of the example linear actuator of  FIG. 1 ; 
         FIG. 6B  is a cross sectional view of another further embodiment of the example linear actuator of  FIG. 1 ; and 
         FIG. 7  is an example assembly of one or more components of the linear actuator of  FIGS. 3A and 3B . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is further described below in detail in conjunction with drawings and embodiments. It is to be understood that the embodiments set forth below are intended to merely illustrate the present disclosure and not to limit the present disclosure. It is to be noted that to facilitate description, merely part, not all, of structures related to the present disclosure are illustrated in the drawings. 
     In the description of the present disclosure, unless otherwise expressly specified and limited, the term “connected to each other”, “connected”, or “fixed” is to be construed in a broad sense, for example, as fixedly connected, detachably connected, or integrated; mechanically connected or electrically connected; directly connected to each other or indirectly connected to each other via an intermediary; or internally connected or an interactional relationship between two components. For those of ordinary skill in the art, specific meanings of the preceding terms in the present disclosure may be understood based on specific situations. 
     In the present disclosure, unless otherwise expressly specified and limited, when a first feature is described as “on” or “below” a second feature, the first feature and the second feature may be in direct contact or be in contact via another feature between the two features instead of being in direct contact. Moreover, when the first feature is described as “on”, “above” or “over” the second feature, the first feature is right on, above or over the second feature, the first feature is obliquely on, above or over the second feature, or the first feature is simply at a higher level than the second feature. When the first feature is described as “under”, “below” or “underneath” the second feature, the first feature is right under, below or underneath the second feature, the first feature is obliquely under, below or underneath the second feature, or the first feature is simply at a lower level than the second feature. 
     In the description of the embodiment, the orientations or position relations indicated by terms such as “on”, “below”, “right” and the like are based on the orientations or position relations shown in the drawings. These orientations or position relations are intended merely to facilitate and simplify the description of the present disclosure, and not to indicate or imply that a device or element referred to must have such specific orientations or must be configured or operated in such specific orientations. Therefore, these orientations or position relations are not to be construed as limiting the present disclosure. In addition, the terms “first” and “second” are used merely to distinguish between descriptions and have no special meaning. 
     The present disclosure provides a split lead screw sleeve. For the split lead screw sleeve, in response to different requirements of different automatic opening/closing actuators of automobile doors for the length of the lead screw sleeve, merely the length of the second lead screw sleeve needs to be adjusted and the length of the first lead screw sleeve can be fixed. A processing mold needed by the first lead screw sleeve and the lead screw nut has a small volume, and it is unnecessary to replace the mold. Thus, the cost is low and the development cycle is short. 
       FIG. 1  is a perspective view of a vehicle  10  that includes a vehicle body  12   a  and at least one vehicle door  14  (also referred to as a closure panel  14 ). The vehicle closure panel  14  includes a latch  20  that is positioned on a frame  15  of the vehicle closure panel  14 , the latch  20  being releasably engageable with a striker  28  on the vehicle body  12  to releasably hold the vehicle closure panel  14  in a closed position. The frame  15  can also support a window  13  via a window regulator assembly mounted to the frame  15  of the vehicle closure panel  14 . An outside closure panel handle  17  can be provided for opening the latch  20  (i.e. for releasing the latch  20  from the striker  28 ) to open the vehicle closure panel  14 . Further, the vehicle closure panel  14  can have inside controls  16 ,  18  (e.g. door handle, door locking/unlocking tab, etc.) for operating the latch  20 . 
     For vehicles  10 , the closure panel  14  can be referred to as a partition or door, typically hinged, but sometimes attached by other mechanisms such as tracks, in front of an opening which is used for entering and exiting the vehicle  10  interior by people and/or cargo. In terms of vehicles  10 , the closure panel  14  may be a driver/passenger door, a lift gate (see  FIG. 2 ), or it may be some other kind of closure panel  14 , such as an upward-swinging vehicle door (i.e. what is sometimes referred to as a gull-wing door) or a conventional type of door that is hinged at a front-facing or back-facing edge of the door, and so allows the door to swing (or slide) away from (or towards) the opening in the vehicle body  12  of the vehicle  10 . Also contemplated are sliding door embodiments of the closure panel  14  and canopy door embodiments of the closure panel  14 , such that sliding doors can be a type of door that open by sliding horizontally or vertically, whereby the door is either mounted on, or suspended from a track that provides for a larger opening. Canopy doors are a type of door that sits on top of the vehicle  10  and lifts up in some way, to provide access for vehicle passengers via the opening (e.g. car canopy, aircraft canopy, etc.). Canopy doors can be connected (e.g. hinged at a defined pivot axis and/or connected for travel along a track) to the vehicle body  12  of the vehicle at the front, side or back of the door, as the application permits. It is recognized that the vehicle body  12  can be represented as a body panel of the vehicle  10 , a frame of the vehicle  10 , and/or a combination frame and body panel assembly, as desired. 
     The closure panel  14  (e.g. occupant ingress or egress controlling panels such as but not limited to vehicle doors and lift gates/hatches) can be connected to the vehicle body  12  via one or more hinges  22  (see  FIG. 2 ) and the latch assembly  20  (e.g. for retaining the closure panel  14  in a closed position once closed). It is also recognized the hinge  22  can be configured as a biased hinge  22  that can bias the closure panel  14  towards the open position and/or towards the closed position. Also connecting the closure panel  14  to the frame  15  is an extension mechanism  30  (also referred to as a spindle mechanism or counterbalance mechanism), for example used to provide a counterbalance function during closure panel  14  operation, in order to assist with opening/closing and hold position functions. 
     Referring to  FIGS. 3A and 3B , the extension mechanism  30  has a first pivot connection  32  (e.g. end fitting connection) at one end for connecting the extension mechanism  30  to the closure panel  14  and a second pivot connection  38  (e.g. end fitting connection) for pivotally connecting the extension mechanism  30  to the frame  15 . Typically, the extension mechanism  30  includes an extension member  34  (e.g. as part of an inner tube—see tubes  3 ,  240  as described below) housed in a body housing  36  (e.g. also referred to as an outer tube), such that the extension member  34  extends out of (and retracts in to) the body  36  as the closure panel  14  is opened and closed. For example, the extension mechanism  30  can be passively operated (i.e. follows movement of the closure panel  14 ) and/or actively operated (i.e. mechanically or electrically actuated and thus driving movement of the closure panel). Referring to  FIG. 3A , shown is an embodiment of the extension mechanism  30  in an extended state and in  FIG. 3B  a retracted state. 
     As shown in  FIGS. 4 and 5 , a portion of the extension mechanism  30  as shown can have a split lead screw sleeve assembly  29  including a lead screw nut  1  and a first lead screw sleeve  2 . Attached to the assembly  29  can be a second lead screw sleeve  3 . The first lead screw sleeve  2  is fixedly sleeved on the lead screw nut  1 , thereby providing a fixedly acted connection  21   c . The second lead screw sleeve  3  can be fixedly connected to the first lead screw sleeve  2  via a connection portion (e.g. tube end  31   a  of the first lead screw sleeve  2  which is affixed onto a tube end  31  of the second lead screw sleeve  3 ). These ends  31 ,  31   a  (also referred to as portions  31 ,  31   a  below) can be configured as shown (i.e. end  31  inserts within end  31   a ). Alternatively, end  31   a  can insert within end  31 . 
     The lead screw nut  1 , the first lead screw sleeve  2 , and the second lead screw sleeve  3  can be coaxially disposed. The first lead screw sleeve  2  can have a short length (e.g. shorter than a length of the second lead screw sleeve  3 ), the second lead screw sleeve  3  has a long length (e.g. longer than a length of the first lead screw sleeve  2 ), the first lead screw sleeve  2  and the second lead screw sleeve  3  can be firmly/fixedly connected to each other through processes such as welding or riveting. 
     In response to the different configurations of the different automatic opening/closing actuators of the automobile doors  14  for the length of the lead screw sleeve, merely the length of the second lead screw sleeve  3  needs to be adjusted and the length of the first lead screw sleeve  2  can be fixed. A mold of a small volume can be used when the first lead screw sleeve  2  and the lead screw nut  1  are processed, and it is unnecessary to replace the mold. Thus, the cost is low and the development cycle can be short. 
     In one embodiment, the fixed connection  21   c  can be provided as a plurality of through holes  21  (with corresponding protrusions  21   a ) dispersedly disposed on the first lead screw sleeve  2 . A plurality of protrusions  21   a  are disposed on an outer wall  21   b  of the lead screw nut  1 . The plurality of protrusions  21   a  pass through the plurality of through holes  21  one to one, for example. The plurality of protrusions  21   a  can be fitted with the plurality of through holes  21  one to one, for example. Thus, the lead screw nut  1  can be inhibited from moving in the first lead screw sleeve  2  during operation of the extension mechanism  30 , once the lead screw nut  1  and the first lead screw sleeve  2  are connected/assembled with one another via the fixed connection  21   c . It is also recognized that the holes  21  can be formed as recesses in the body  21   b  and the protrusions  21   a  (not shown) can be formed on an inner surface  2   a  (see  FIG. 5 ) of the first lead screw sleeve  2 . 
     Alternatively, the fixed connection  21   c  can be provided, such that the lead screw nut  1  and the first lead screw sleeve  2  are integrally formed with one another through injection molding in order to provide the fixedly acted connection  21   c . In this case, the holes  21  and protrusions  21   a  can be optional (not shown). Alternatively, for example, as desired, the plurality of protrusions  21   a  on the lead screw nut  1  can be integrally formed with the body  21   b  through injection molding. As such, it is recognized that the fixed connection  21   c  can be provided by the interaction between the holes  21  and protrusions  21   a . As such, alternatively, it is recognized that the fixed connection  21   c  can be provided by the lead screw nut  1  and the first lead screw sleeve  2  being integrally formed with one another (i.e. the body  21   b  includes the tube end  31   a ) through injection molding (e.g. the holes  21  and protrusions  21   a  could be optional as part of this integrally molded embodiment). 
     Preferably, the lead screw nut  1  is made of a plastic material. The lead screw nut  1  can be plastic-coated in the first lead screw sleeve  2 . The lead screw nut  1  can have a suitable dimension stability and the overall production cost can be minimized. 
     Preferably, a first inserting portion  31  is disposed at one end of the second lead screw sleeve  3 , and the first inserting portion  31  is inserted into and fixedly connected  31   c  to the first lead screw sleeve  2  in a receiving portion  31   a  thereof. After the first inserting portion  31  is inserted into the receiving portion  31   a , the first inserting portion  31  and the first lead screw sleeve  2  can be mechanically joined such as welded or riveted (or by adhesive, crimping, press fit, etc.) to each other, thus fixedly secured to one another. The connection  31   c  between the second lead screw sleeve  3  and the first lead screw sleeve  2  can be facilitated. For example, the connection  31   c  between the second lead screw sleeve  3  and the first lead screw sleeve  2  could be by a laser welding process and thereafter polished for providing a smoother surface between the between the second lead screw sleeve  3  and the first lead screw sleeve  2 . Similarly, third lead screw sleeve  4  and the second lead screw sleeve  3  could be connected by a laser welding process and thereafter polished for providing a smoother surface there between. Split lead screw sleeve assembly  29  and/or third lead screw sleeve  4  can be manufactured separately from the first lead screw sleeve  2 . The first lead screw sleeve  2  may be provided as having different lengths while split lead screw sleeve assembly  29  and/or third lead screw sleeve  4  provide common components for connection to first lead screw sleeve  2  of various lengths. 
     Preferably, a second inserting portion  12  is disposed on the lead screw nut  1 . The second inserting portion  12  can be inserted into the first inserting portion  31 . The first inserting portion  31  abuts against the lead screw nut  1 , for example. The lead screw nut  1  can be further inhibited from being detached from the first lead screw sleeve  2 , via the fixed connection between the second inserting portion  12  and the first inserting portion  31  (e.g. via welding, press fit or other mechanical connection). 
     Preferably, the split lead screw sleeve assembly  29  further includes a third lead screw sleeve  4  fixedly connected to the second lead screw sleeve  3 . External threads  4   a  can be disposed on an outer wall  4   b  of the third lead screw sleeve  4 . The third lead screw sleeve  4  and the second lead screw sleeve  3  can be coaxially disposed. The third lead screw sleeve  4  can be used for implementing a connection to other components of the extension mechanism  30  (see  FIGS. 3A, 3B, and 6 ). For example, and with reference to  FIG. 6B , external threads  4   a  may be used to threaded engagement with mating threads  4   c  of a ball socket  119  for coupling the lead screw sleeve  3 , for example as extensible member  240 , to one of the vehicle body  14  or the closure panel  14 . 
     Preferably, an annular groove  11  can be disposed on the lead screw nut  1 . The annular groove  11  can be used for the placement of a sealing ring (not shown) so as to implement sealing when the lead screw nut  1  is fitted with other components of the extension mechanism  30 . 
     Preferably, the outer diameter of the first lead screw sleeve  2  can be equal to the outer diameter of the second lead screw sleeve  3  so that the connection is facilitated and the appearance is as desired. 
     Referring to  FIGS. 3A, 3B, 4, and 5 , a linear actuator  30  for a closure panel  14  of the vehicle  10  can comprise: a body housing  36  for coupling to one of the closure panel  14  and a body  15  of the vehicle  10 ; an extension member  34  housed in the body housing  36 , the extension member  34  for coupling to the other of the closure panel  14  and the body  15  of the vehicle  10 , the extension member  34  including: a split lead screw sleeve assembly  29  having: a lead screw nut  1 ; and a first lead screw sleeve  2  having a fixedly attached connection  21   c  with the lead screw nut  1 , such that the first lead screw sleeve  2  has a first tube end  31   a  for coupling with a second tube end  31  of an adjacent second lead screw sleeve  3 ; wherein the lead screw nut  1 , the first lead screw sleeve  2 , and the second lead screw sleeve  3  are coaxially disposed when the first tube end  31   a  is positioned adjacent to the second tube end  31 . 
       FIG. 6  shows an example configuration for the extension mechanism  30  (e.g. linear actuator of  FIGS. 1-5 , for example a spring loaded strut. A housing  235  (e.g. body housing  36 ) also contains an extension member  240  (e.g. split lead screw sleeve assembly  29  as part of the extension member  34 —see  FIGS. 3A, 3B, 4, and 5 ) used to extend from, or retract within, the housing  235  to effect the resulting location of the closure panel  14  with respect to the door frame  15 . For example, an extended extension member  240  (e.g. including sleeves  2 , 3 ) results in positioning the closure panel  14  in the extended state (see  FIG. 3A ), while a retracted extension member  240  results in positioning the closure panel  14  in a retracted state (see  FIG. 3B ) with respect to the door frame  15 . It is recognized that the linear actuator  30  can be implemented as a strut (see  FIG. 2  as an example type of strut). The linear actuator  30  can be of a biasing type (e.g. spring and/or gas charge supplying the bias). In one example, see  FIG. 6A , the extension member  240  is actively driven by via a lead screw  140 . The extension member  240  is either extended from, or retracted into, the housing  235 . It is recognized that the linear actuator  30  can have the lead screw  140  operated actively (i.e. driven) by a motor  25  (e.g. electrical). 
     The linear actuator  30  with the body  235  (e.g. housing) has a first end  238  for connecting to pivot point  32  and a second end  36  for connecting to the closure panel  14  at mount  118 . In this configuration, the linear actuator  30 , by example only, has the extension member  240  (e.g. a stator member slideably engageable with a rotary output member such as via mated threads) positioned in an interior of the housing  235 . The extension member  240  is coupled to the lead screw  140  via a travel member  245  (for example as an integral part of or separate to the extension member  240 , as an example of the lead screw nut  1 —see  FIG. 4 ), such that rotation of the lead screw  140  causes travel of the travel member  245  along the lead screw  140 , to result in extension or retraction of the extension member  240  with respect to the housing  235 . As discussed in relation to  FIG. 6A , the travel member  245  and the lead screw  140  are coupled to one another via mated threads  1   a —see  FIG. 5 . As shown, the linear actuator  30  can be a strut having a resilient element of the power spring (not shown) for providing the counterbalance torque (T) during operation of the closure panel  14  in moving between the extended and retracted positions. 
     Referring again to  FIG. 6A , the travel member  245  is positioned at one end of the extension member  240 . As such, as the extension member  240  is displaced along the longitudinal axis  41 , as the attached travel member  245  is displaced along the lead screw  140 . As such, as the closure panel  14  is moved between the extended and retracted positions (see  FIGS. 3A and 3B ), the position of the travel member  245  along the lead screw  140  varies, thereby providing for reciprocation of the travel member  245  along the longitudinal axis  41  of the lead screw  140 . 
     Referring again to  FIG. 6A , the embodiment of the linear actuator  30  is shown including the housing  235  having a lower housing  112  and an upper housing  114  for containing the extension member  240  (e.g. extensible shaft/rod). The fixed mount  118  is attached to an end wall  126  of lower housing  112  proximal to the door frame  15 . Upper housing  114  provides a (e.g. cylindrical) sidewall  141  defining a chamber  134  that is open at both ends. A distal end wall  128  of lower housing  112  includes an aperture  130 . The lead screw  140  (or referred to as a lead screw  140  or rotary output member powered by rotary motion of the motor  25 ) which can be used to transport or otherwise guide the travel member  245  (connected to the extension member  240 ) along the longitudinal axis  41 . For example, the travel member  245  contains an internally facing series of threads  1   a  in bore  161  that are mated to an externally facing series of threads on the lead screw  140 , as desired. Extensible member  240  provides a cylindrical sidewall  154  defining a chamber  156  and can be concentrically mounted between upper housing  114  and lead screw  140 . As described earlier, pivot mount  238  (i.e. pivot point  32 ) is attached to the distal end of extensible member  240 . The nut  245  (also referred to as the travel member  245  or screw nut  1 ) is mounted around the proximal end of extensible member  240  relative to lower housing  112  and is coupled with lead screw  140  in order to convert the rotational movement of lead screw  140  into the linear motion of the extensible member  240  along the longitudinal axis  41  of lead screw  140 . The nut  245  can include splines that extend into opposing coaxial slots provided on the inside of upper housing  114  to inhibit nut  245  from rotating as the nut  245  travels along the longitudinal axis  41 . Alternatively, the nut  245  may be configured without the splines and thus be free to rotate as the nut  245  travels along the longitudinal axis  41 , without departing from the scope of the description. An integrally-formed outer lip  164  in upper housing  114  can provide an environmental seal between chamber  134  and the outside. 
     A spring housing  138  can be provided in lower housing  112  and defined by cylindrical sidewall  122 , end wall  128 , and a flange  166 . Within spring housing  138 , a power spring (not shown in  FIG. 6A ) similar to the power spring can be optionally coiled around lead screw  140 , providing a mechanical counterbalance to the weight of the closure panel  14 . One end of the optional power spring can be positioned or otherwise attached to the travel member  245  and the other is secured to a portion of cylindrical sidewall  122 . 
     As such, given the above, the screw nut  1  can be referred to as the travel member  245  (e.g. a plastic nut for threaded connection to the lead screw  140 ). Further, first lead screw sleeve  2  can be referred to as portion of the housing  240  to which the nut  1  is molded with as described. Further, screw nut  1  and lead screw sleeve  2  can form the assembly  29  (see  FIG. 4 ) which can be connected to the lead screw sleeve  3  (e.g. extension member  240  or also referred to as the lead screw sleeve  3 ) to form the extension member  240  connected to the travel member  245 . Further, the optional third lead screw sleeve  4  can be used to connect the assembly  29  to other components of the linear actuator  30 , such as but not limited to further portions of the extension member  240 . 
     An advantage of the assembly  29  is all you have to do is make components  1  and  2  as this unit assembly  29  and then connect to whatever length tube  3  (e.g. lead screw sleeve  3 ) you need, in order to provide the extension member  240  appropriate to the dimensions of the closure panel  14  and associated extension mechanism  30  (based on the distance between the pivot points  28 ,  38  (see  FIG. 1 ). So, therefore, one can mass product the assembly  29 , and then have small batches of longer lead screw sleeve  3  as needed. This is compared to having to make small batches of a tube have a different lengths and nuts. 
     Referring to  FIG. 7 , shown is a method  200  of assembling the split lead screw sleeve assembly  29  including the steps of: providing  202  a lead screw nut  1 ; and coupling  204  the lead screw nut  1  to a first lead screw sleeve  2  as a fixedly attached connection with the lead screw nut  1 . Further, in subsequently assembling the assembly  29  with other components of the linear actuator  30 , the first lead screw sleeve  2  has a first tube end  31   a  for coupling  206  with a second tube end  31  of an adjacent second lead screw sleeve  3 , such that the lead screw nut  1 , the first lead screw sleeve  2 , and the second lead screw sleeve  3  are coaxially disposed when the first tube end  31   a  is positioned adjacent to the second tube end  31 . 
     The preceding example embodiments of the present disclosure are merely used for clearly illustrating the present disclosure and are not intended to limit implementations of the present disclosure. Those of ordinary skill in the art can make various apparent modifications, adaptations, and substitutions without departing from the scope of the present disclosure. The implementations of the present disclosure cannot be and do not need to be all exhausted herein. Any modifications, equivalent substitutions, improvements, and the like made within the spirit and principle of the present disclosure are within the scope of the claims of the present disclosure.