Patent Publication Number: US-11382810-B2

Title: Fold, recline, and tilt mechanisms for a personal mobility vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/817,763, filed Mar. 13, 2019, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates in general to foldable and adjustable personal mobility vehicles. In particular, this invention relates to personal mobility vehicles, such as strollers and wheelchairs, that have an adjustable backrest and wheel support frame that can be easily manipulated into a compact package, suitable for transport. 
     Personal mobility vehicles, such a wheelchairs and strollers, have adjustable backrests that provide the ability to recline or tilt to provide a comfortable position for a seated user. Some of these vehicles are also foldable into a compact package so that they can be transported more easily. In a reclining adjustment, the backrest frame is angled relative to the seat frame. In a tilting adjustment, the backrest frame and seat frame are angled, as a unit, relative to the base frame or the support surface. In order to fold a stroller, for example, into the compact travel package the frame is unlatched and pivoted from a use position to a folded position. These adjustment mechanisms are typically separate elements that require separate manipulations. 
     For example, the backrest may be reclined or folded relative to the seat frame by removing a pin or other support member and moving the backrest to the desired position. To place the personal mobility vehicle in a folded position, the base frame may be unlatched by a separate locking device and articulated such that the wheels are drawn toward the frame and/or each other so that less space is consumed by the structure. The separate manipulations of these elements is cumbersome. Thus, it would be desirable to provide a personal mobility vehicle that permits backrest adjustment and also permits folding of the vehicle with a single actuation point, for at least each side frame structure. It would further be desirable to provide a tilt capability in conjunction with the single point recline and fold capability. 
     SUMMARY OF THE INVENTION 
     This invention relates to foldable and adjustable personal mobility vehicles. In particular, this invention relates to personal mobility vehicles, such as strollers and wheelchairs, that have an adjustable backrest and support frame that can be easily manipulated into a compact package, suitable for transport from a single actuation point. 
     A side frame assembly of a personal mobility vehicle includes a base frame assembly, a seat frame, a backrest cane, and a backrest link. The seat frame has a rail housing that supports a folding actuation rail and a recline adjustment rail for relative linear movement and concurrent linear movement. The folding actuation rail can be selectively fixed relative to the rail housing between a first position of the base frame assembly and a second position of the base frame assembly that is more compact than the first position. The backrest cane is pivotally attached to the seat frame. The backrest link pivotally attached to the backrest cane and pivotally attached to the recline adjustment rail such that pivoting movement of the backrest cane moves the folding actuation rail between the first and second positions. 
     The first position of the side frame assembly defines a use position and the second position defines a folded position of the backrest cane and the base frame assembly. 
     The recline adjustment rail defines a plurality of recline adjustment positions of the backrest cane relative to the seat frame. One of the seat frame or the rail housing supports a latch pin for relative movement between a recline enabling position and a folding enabling position. The latch pin engages the folding actuation rail and the recline adjustment rail such that when the latch pin is moved to the recline enabling position the backrest cane is enabled to move the recline actuation rail into the plurality of recline positions. When the latch pin is moved to the folding enabling position, the recline adjustment rail moves the folding actuation rail between the first and second positions. The backrest cane supports a handle that moves the latch pin between the recline enabling position and the folding enabling position. 
     The folding actuation rail includes a recline trigger and the recline actuation rail has a fold return detent, the recline trigger engages the fold return detent to enable the recline actuation rail to move the folding actuation rail from the second position to the first position. The rail housing includes a trip pin that releases the recline trigger from the fold return detent when the folding actuation rail is moved to the first position. 
     The base frame assembly has a front support link pivotally connected to one of the seat frame or the rail housing and a rear link is pivotally connected to the one of the seat frame or the rail housing. The front support link and the rear support link are pivotally coupled together to concurrently move between the first position and the second position in response to the movement of the folding actuation rail. A tilt link is pivotally connected between the folding actuation rail and the rear support link. The tilt link includes a plurality of tilt positioning apertures that define a plurality of tilt positions of the seat frame and backrest cane relative to a support surface. The plurality of tilt positioning apertures engage at least one aperture on the rear support link to define the plurality of tilt positions. 
     The front support link includes a front wheel and the rear support link includes a rear wheel. The front support link and the rear support link are pivotally coupled through a connecting link. At least one cross member mount is supported on one of a tilt link pivot or the connecting link such that a cross member is attached to the cross member mount and connected to a second side frame assembly to define the personal mobility vehicle. 
     Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevation view of an embodiment of a personal mobility vehicle having a tilt and folding mechanism in accordance with the invention. 
         FIG. 2  is a perspective view of an outwardly positioned surface of a side frame assembly of a personal mobility vehicle similar to  FIG. 1 . 
         FIG. 3  is a perspective view of an inwardly positioned surface of the side frame assembly of  FIG. 2 . 
         FIG. 4  is an elevation view of the side frame assembly of  FIG. 2  in a use position. 
         FIG. 5  is an elevation view of the side frame assembly of  FIG. 4  in partially folded position. 
         FIG. 6  is an elevation view of the side frame assembly of  FIG. 4  in a fully folded position. 
         FIG. 7  is an enlarged view of  FIG. 3 . 
         FIG. 8  is a cross-sectional, perspective view of the recline and fold mechanism in accordance with the invention. 
         FIG. 9  is a cross-sectional, elevation view of the recline and fold mechanism of  FIG. 8  with the backrest assembly in a use position. 
         FIG. 10  is a cross sectional, elevation view of the recline and fold mechanism of  FIG. 8  with the backrest assembly in a fully folded position. 
         FIG. 11A  is an elevation view of the side frame assembly showing the backrest at a first recline angle. 
         FIG. 11B  is an enlarged, elevation view, in cross-section, showing the recline and fold mechanism in the first recline angle. 
         FIG. 12A  is an elevation view of the side frame assembly showing the backrest at a second recline angle. 
         FIG. 12B  is an enlarged, elevation view, in cross-section, showing the recline and fold mechanism in the second recline angle. 
         FIG. 13A  is an enlarged, elevation view of a backrest and seat frame assembly in a first tilt position. 
         FIG. 13B  is an enlarged, elevation view of a backrest and seat frame assembly in a second tilt position. 
         FIG. 13C  is an enlarged, elevation view of a backrest and seat frame assembly in a third tilt position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, there is illustrated in  FIG. 1  a personal mobility vehicle  10  having a recline and fold mechanism and a tilt mechanism in accordance with the invention. Though shown and described in the context of a stroller, the mechanisms described herein may be used on any type of personal mobility vehicle or seating device, such as for example a wheelchair or a folding chair. The stroller  10  is further shown and described in the context of a single side frame, though it should be understood that the stroller comprises two side frames that form a complete stroller unit. The stroller  10  is illustrated without seat and backrest cushions or other user interfaces, such as arm rests and head rests in order to clearly show the operation of the invention. 
     The stroller  10  includes a backrest assembly  12  and a seat assembly  14 . The backrest assembly  12  includes a backrest frame having spaced apart backrest canes  16 , representing right and left sides of the stroller, and an attendant handle  18 . The backrest canes are each pivotally attached to the seat assembly  14  at a backrest pivot  12   a . In one embodiment, the handle  18  connects both canes  16 , though each cane may have a separate handle. In one embodiment, the handle  18  is pivotally mounted to the canes  16  in order to actuate a recline and fold mechanism which will be described in detail below. Alternatively, the recline and fold mechanism may be actuated in any suitable manner including by a powered actuator or another mechanical linkage, cable, or mechanism. The seat assembly  14  includes a seat frame, shown generally at  20 , that may have an adjustment frame  22   a  defining a plurality of adjustment points and a rail housing  22   b  supporting the recline and fold mechanism. The adjustment frame  22   a  and the rail housing  22   b  may be formed in a single seat frame structure as shown in  FIGS. 2-13C  or may be separate elements as shown in  FIG. 1 . The rail housing  22   b  supports two slide rails, as shown in  FIGS. 8-10 , that slide longitudinally relative to the rail housing  22   b  and relative to each other to transfer movement of the backrest assembly to either a reclining movement or a folding movement, as will be described below in detail. A legrest or foot board assembly  22   c  may be supported by the adjustment frame  22   a  or the rail housing  22   b.    
     The stroller  10  includes a base frame  24  that supports front and back wheels  26   a  and  26   b , respectively. The front wheels  26   a  are illustrated as caster wheels though they may be fixed wheels, mounted separately or coupled together by an axle (not shown). The base frame  24  includes a front support link  28  that supports the front wheel  26   a  and a rear support linkage, shown generally at  30 . The rear support linkage  30  includes a tilt link  32  and a rear frame link  34 , that supports the rear wheel  26   b . A connecting link  36  is pivotally coupled to the front support link  28  and the rear frame link  34 . The backrest canes  16  are each connected to one of the slide rails within the rail housing, as shown in  FIGS. 8-10 , by a backrest link  38 . The tilt link  32  is pivotally connected to the other slide rail at a first end and to the rear frame link  34  at a second end. The operation of the recline and fold mechanism will be described in the context of  FIGS. 2-12B , though the embodiment of  FIG. 1  operates in a similar manner. 
     Referring now to  FIGS. 2 and 3 , there is illustrated a second embodiment of a stroller having a side frame assembly, shown generally at  100 . The side frame  100  comprises a backrest frame assembly, shown generally at  102 , and a seat frame assembly, shown generally at  104 . The side frame  100  is illustrated as a right side frame which is configured to be connected to a mirror image left side frame to form the stroller. The backrest frame assembly  102  includes a backrest cane or backrest tube  106  illustrated as a hollow tube though such is not required. The backrest cane  106  pivotally connects to a rail housing  108  of the seat frame assembly  104  by way of a backrest clevis yoke  110 . In the illustrated embodiment, a rail clevis yoke  112  is fixed to the rail housing  108  of the seat frame assembly  104  and pivotally connected to the backrest clevis yoke  110 . Alternatively, the backrest clevis yoke  110  may connect directly to a portion of the rail housing  108 . 
     The seat frame assembly  104  includes an adjustment section  114  having a dovetail or other guiding element  114   a  and plurality of adjustment points or apertures  114   b  to permit a cross tube support  116  to be positioned to support different length seating structures. The cross tube support  116  has a cross member mount  116   a  configured to permit attachment of a cross member (not shown) between the right to left side frame assemblies. A seat mount  118  locates and supports different seating structures. The cross tube support  116  may also include a seat support  116   b  to support a portion of the seating structure that extends along the seat frame assembly  104 . The rail housing  108  includes a trip pin  120  that extends into the housing, as will be described below. A rear frame link pivot support  122  attaches to the seat frame  104  and may be integrally formed with the rail clevis yoke  112  or may be a separately mounted structure. 
     A base frame, shown generally at  124 , includes a front caster wheel assembly  126   a  connected to a front support link  128 . The front support link  128  includes an upper arm  128   a  that is pivotally connected to the seat frame  104  by a front arm pivot  130 . A legrest support  128   b  may extend from the upper arm  128   a  to support a legrest or foot board structure, similar to that shown in  FIG. 1 . The front support link  128  may include a lower arm  128   c  extending rearward. The lower arm  128   c  is pivotally connected to a connecting link  132  by an interconnecting pivot  134  that links a front portion of the base frame  124  to a rear portion. The connecting link  132  is pivotally connected to a rear link  136  at a suspension pivot point, shown generally at  138 . In the illustrated embodiment, the suspension pivot point  138  of the connecting link  132  includes a plurality of pivot points to permit adjustment of how the user&#39;s weight is applied to the base frame  124 . The connecting link  132  may also include a cross member mount similar to cross member mount  116   a.    
     The rear link  136  is illustrated having a “boomerang” or angled shape and the connecting link  132  pivotally attaches at the elbow or mid-point pivot  136   a . The mid-point pivot  136   a  may include a plurality of pivot apertures to provide additional adjustments to the base frame  124 . Alternatively, the rear link  136  may have a different geometric shape including straight. The rear link  136  is pivotally mounted to the rear frame link pivot support  122  at an upper link pivot  136   b  and supports a rear wheel  126   b  at a lower end  136   c . The boomerang shape of the rear link  136  and rearward extending configuration of the lower end  136   c  creates an “over center” locking condition that assists in stabilizing the stroller and recline and fold mechanism. 
     A tilt link  140  is pivotally mounted at a lower end  140   a  to the rear link  136 . In the illustrated embodiment, the tilt link lower end  140   a  pivotally attaches to the mid-point pivot  136   a  and further includes a plurality of tilt adjustment apertures  142  to adjust the tilt angle of the seat and backrest assembly, as shown in  FIGS. 7 and 13A-13C . Matching the different apertures of the lower end  140   a  to different apertures of the mid-point pivot  136   a  of the rear link  136  provides a range of tilt adjustment to the seat and backrest assembly. As shown in  FIGS. 13A-13C , “tilt” is an adjustment of the seat and backrest together as a unit relative to the support surface. “Recline” is an adjustment where the backrest angle is adjusted relative to the seating surface, as shown in  FIGS. 11A and 12A . 
     The upper end  140   b  of the tilt link  140  is pivotally connected to a folding actuation rail, shown generally at  144  in  FIG. 8 . The upper end  140   b  may also include a cross member mount similar to cross member mount  116   a . The folding actuation rail  144  is supported for linear movement relative to the rail housing  108  and may include linear bearing elements if so desired. A tilt link mounting arm  146  extends from the forward end of the folding actuation rail  144  to below the rail housing  108  where the tilt link upper end  140   b  is pivotally attached. A recline adjustment rail  148  is also supported for linear movement relative to the rail housing  108  and also relative to the folding actuation rail  144 . A recline mounting arm  150  extends from the forward end of the recline adjustment rail  148  and pivotally connects to a backrest link  152  at a first end. The backrest link  152  is pivotally connected to the backrest frame at a pivot point  154 . The pivot point  154  is illustrated as connected to the backrest cane  106  though other locations on the backrest frame may be utilized. The recline adjustment rail  148  and the folding actuation rail  144  form a recline and folding mechanism  156  and are illustrated as positioned above and below each other. Alternatively the rails  144  and  148  may be positioned in a side-by-side relationship. 
     The folding actuation rail  144  includes a fold position locking aperture  158  that permits a latch pin  160  to pass through. The folding actuation rail  144  also includes a recline trigger  162  that is resiliently biased toward a fold return detent  164  formed in the recline adjustment rail  148 . The recline trigger  162  engages the fold return detent  164  as the rails  144  and  148  are moved together to fold the backrest frame assembly  102  toward the seat frame assembly  104 . The recline trigger  162  causes the folding actuation rail  144  to be drawn rearward with the recline adjustment rail during an unfolding maneuver where the backrest assembly is returned to a use position (backrest assembly positioned to accept a seated user). As the backrest frame assembly  102  is brought to the upright position, the  152  backrest link draws the recline adjustment rail  148  and the folding actuation rail  144  rearward in the rail housing  108 . In the use position, the recline trigger  162  is disengaged from the return detent  164  by the trip pin  120  contacting the inclined surface  162   a  of the recline trigger  162 , shown in  FIG. 7 . 
     The recline adjustment rail  148  includes a plurality of recline angle adjustment apertures  166  that define angular position of the backrest frame assembly  102  relative to the seat frame assembly  104 . Each aperture  166  is configured to receive the latch pin  160  to fix the backrest frame assembly in a desired recline position. Any number of recline angle adjustment apertures  166  may be provided to create the desired recline adjustment increments. The latch pin  160  is resiliently biased into engagement with the folding actuation rail  144  and the recline adjustment rail  148  as shown in  FIG. 9 . 
       FIGS. 4-6  illustrate the motion of the backrest and seat frame assemblies  102  and  104 , and the base frame  124  during a folding operation. In order to fold the backrest frame assembly  102  toward the seat frame assembly  104 , as shown in  FIG. 10 , the latch pin  160  is pulled out of engagement with one of the plurality of angle adjustment apertures  166  and the fold position locking aperture  158 . The latch pin  160  is actuated by cable or rod  168  that is operated by a handle, such as handle  18 . Alternatively, the latch pin  160  may be actuated by a solenoid or other mechanism. The recline adjustment rail  148  is moved forward by the backrest link  152  acting on the recline mounting arm  150 . A stop  170  contacts the end of the folding actuation rail  144  causing both rails to move together toward the front of the rail housing  108 . 
     The tilt link mounting arm  146  moves the tilt link  140  forward and upward toward the rail housing  108  in a clockwise motion when viewing the outside of the right side frame assembly  100 . The tilt link  140  pulls on the mid-point pivot  136   a  causing the rear link  136  to pivot counterclockwise about the upper link pivot  136   b . The rear link  136  can be drawn into contact with the seat frame assembly  102  to create a compact package for easy transport. To return the backrest frame assembly  102  to the upright position, the backrest is rotated counterclockwise until the latch pin  160  is moved upward by the inclined rear surfaces of the recline adjustment rail  148  and the folding actuation rail  144  and brought into alignment with the fold position locking aperture  158  and at least the first aperture of the plurality of recline angle adjustment apertures  166 . When the backrest, seat and base frames are in a use position, the weight of the stroller and the user cause the rear wheel  126   b  to be biased in a rearward direction (clockwise as shown in  FIGS. 2 and 4 ) which is resisted by the tilt link  140  and the folding actuation rail  144 . The tilt link  140  draws the folding actuation rail  144  into a stop defining a rearward end of travel of the rail support channels of the rail housing  108 . This prevents the latch pin  160  from binding in the apertures  158  and  166  so that the pin is easily withdrawn. 
     Referring now to  FIGS. 11A-12B , a backrest reclining operation sequence is depicted. In the reclining operation, the latch pin  160  is withdrawn from the engaged one of the plurality of recline angle adjustment apertures  166  but remains engaged in the fold position locking aperture  158 . The recline adjustment rail  148  is free to move relative to the folding actuation rail  144  and the rail housing  108 . The folding actuation rail  148  is maintained in position by the user and stroller weight acting on the base frame linkages and by the latch pin  160  as a failsafe. The recline trigger  162  is withdrawn from the detent  164  by the trip pin  120  also permitting movement of the recline adjustment rail  148 . As the backrest frame assembly  102  is pivoted relative to the seat frame assembly  104 , the backrest link  152  slides the recline adjustment rail  148  to align to latch pin  160  with the desired aperture  166 . Since the latch pin is biased into engagement with the apertures  158  and  166  by the resilient member, the backrest can be moved to each of the apertures  166  in an indexed manner by permitting the latch pin to contact the surface of the rail  148  between the apertures. Thus, the backrest may be moved from a first recline position of angle α 1  to a second recline position α 2  in a stepwise sequence. Holding the latch pin out of engagement permits free movement of the backrest through the range of recline angles. During the reclining operation, the base frame stays in the same position. 
     Referring now to  FIGS. 13A-13C , a tilt adjustment is illustrated with the stroller embodiment of  FIG. 1 . However, it should be appreciated that the same adjustments may be made to the embodiment of a stroller having side frames  100 . Tilt adjustment is realized by aligning apertures of the tilt link  32 , such as apertures  32   a ,  32   b , or  32   c  with apertures of the rear frame link  34 , such as apertures  34   a ,  34   b , or  34   c . A tilt pin  50  is inserted into the aligned apertures to provide the desired tilt angle. 
     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.