Patent Publication Number: US-2015069731-A1

Title: Suspension system for child stroller

Description:
BACKGROUND 
     1. Field of Technology 
     Aspects and embodiments disclosed herein relate generally to child conveyance devices such as strollers and carriages, and more specifically, to suspension systems for same. 
     2. Discussion of Related Art 
     Young children are often conveyed by caregivers or parents in various types of baby carriages or strollers, referred to herein collectively as “strollers.” Many strollers are not provided with any form of suspension system. In such strollers, when a wheel of the stroller is pushed over an obstacle, for example, a rock, stick, or curb, an impact force may be conveyed from the wheel and through the fame of the stroller to a child in the stroller. Such an impact force may be uncomfortable and in some instances dangerous to the child. 
     SUMMARY 
     In accordance with an aspect of the present disclosure, there is provided a stroller. The stroller comprises a frame member and a suspension block coupled to the frame member. The suspension block includes a body and a suspension mechanism coupled to the body and disposed at an acute angle from a vertical axis of the body. The stroller further includes a wheel mounted on an axle, the axle supported by the suspension block. 
     In some embodiments, the suspension mechanism includes an aperture defined by sidewalls extending from sides of the suspension block, the axle passing through the aperture. 
     In some embodiments, the aperture is disposed at an angle of about 30° from the vertical axis of the body when the axle is in a home position. 
     In some embodiments, the suspension mechanism includes a spring retainer supported by the suspension mechanism. 
     In some embodiments, the axle passes through an axle aperture defined in the spring retainer. 
     In some embodiments, the spring retainer is at least partially disposed within a spring retention chamber defined in the body of the suspension block. 
     In some embodiments, the spring retainer is biased away from an upper wall of the spring retention chamber. 
     In some embodiments, the spring retainer is biased away from the upper wall of the spring retention chamber by spring having a lower end coupled to the spring retainer and an upper end disposed against the upper wall of the spring retention to chamber. 
     In some embodiments, at least a portion of the spring retainer is retained within the spring retention chamber by the axle. 
     In some embodiments, the suspension mechanism is configured and capable of absorbing an impact force applied to the wheel in a horizontal direction, an impact force applied to the wheel in a vertical direction, or an impact force applied to the wheel with components in both the horizontal direction and the vertical direction. 
     In accordance with another aspect, there is provided a suspension block for a stroller. The suspension block includes a body and a spring retention chamber defined in the body and having an axis disposed at an acute angle relative to a vertical axis of the body. 
     In some embodiments, the suspension block further comprises a suspension mechanism coupled to the body and including a biasing member configured to receive an axle of a wheel of the stroller. 
     In some embodiments, the suspension block further comprises an aperture passing through the body and disposed at a non-zero acute angle from a vertical axis of the body. 
     In some embodiments, the aperture forms an opening along an elongate axis of the spring retention chamber. 
     In some embodiments, the aperture is defined by sidewalls extending from sides of the suspension block. 
     In some embodiments, the biasing member comprises a spring retainer. 
     In some embodiments, the suspension block further comprises a spring disposed between the spring retainer and an upper wall of the spring retention chamber. 
     In some embodiments, an end of the spring fits around an upper reduced diameter portion of the spring retainer and rests against an upper shoulder portion of the spring retainer. 
     In some embodiments, the spring exerts a force on the spring retainer biasing the spring retainer out of the spring retention chamber. to In some embodiments, the spring retainer contacts a portion of an internal wall of the spring retention chamber. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings: 
         FIG. 1  is an isometric view of a wheel of a stroller coupled to a frame member of a stroller through an embodiment of a suspension block; 
         FIG. 2  is an elevational view of the wheel and suspension block of  FIG. 1 ; 
         FIG. 3  is a cross sectional view of the suspension block of  FIG. 1 ; and 
         FIG. 4  is a plan view from beneath of the wheel and suspension block of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Aspects and embodiments disclosed herein are not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. Aspects and embodiments disclosed herein are capable of being practiced or of being carried out in various ways. The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
     Some stroller designs include suspension systems which may facilitate the absorption of at least a portion of a vertical impact force which might be experienced by, for example, passing one or more wheels of a stroller over an obstacle such as a rock, stick, curb, or step. Such stroller designs, however, do not provide for absorption of horizontal impact forces, for example, impact forces which might be experienced when a stroller is inadvertently pushed against a door, wall, or other to obstacle. A child present in such strollers may be at least partially protected from vertical impact forces, but not from horizontal impact forces. 
     As used herein the directional term “horizontal” refers to a direction of travel of a stroller when moving normally on wheels of the stroller. The directional term “vertical” refers to a direction approximately perpendicular to the direction of travel of a stroller when moving on the wheels of stroller. 
     Aspects and embodiments disclosed herein are generally directed to a suspension system for a stroller which provides protection against both vertical and horizontal impact forces to a child present in the stroller. In some embodiments the suspension system includes a plurality of impact absorbing mechanisms, one of which may be applied to each wheel of a stroller. In some embodiments, an impact absorbing mechanism is applied to only front wheels of a stroller, while in other embodiments, impact absorbing mechanisms may be applied only to rear wheels of a stroller, and in other embodiments to all wheels of a stroller. 
     Aspects and embodiments of the disclosed suspension system may provide for an axle of a wheel of a stroller to move both horizontally and vertically relative to a frame of the stroller upon application of an impact force to the wheel of the stroller. Upon application of a horizontal and/or vertical impact force to a wheel of the stroller, the wheel and axle may be reversibly displaced in both a horizontal and vertical direction relative to the frame of the stroller. A dampening mechanism in a suspension system applied to a wheel of the stroller may absorb the vertical and/or horizontal impact force, reducing the transfer of the impact force through the frame of the stroller to a child present in the stroller. A resilient element in a suspension system applied to an axle and wheel of the stroller may bias the axle and wheel into a resting or home position from which the axle and wheel may be displaced upon application of an impact force. The resilient element may displace the axle and wheel back to the resting or home position after the impact force has been absorbed or dissipated. 
     An isometric view of an embodiment of the disclosed suspension system mounted to a wheel and frame assembly of a stroller system is illustrated in  FIG. 1 . In  FIG. 1 , only a single wheel of a stroller and a single frame member is illustrated. It to should be appreciated that similar structures as illustrated in  FIG. 1  may be applied, with or without modification, to other wheel assemblies of a stroller system. In  FIG. 1 , a frame member  110  (only a lower portion of which is illustrated) is coupled to a wheel  120  of a stroller. Coupling between the frame member  110  and the wheel  120  is made through a suspension block  130 . The suspension block  130  includes a suspension block aperture  135  which fits around a lower end  115  of the frame member  110  or which is otherwise secured to the lower end  115  of the frame member  110 . In some embodiments, both the suspension block aperture  135  and the lower end  115  of the frame member  110  are cylindrical in cross section and the suspension block  130  may rotate about a vertical axis of the lower end  115  of the frame member  110  to allow for the wheel  120  to turn relative to the frame member  110 . In some embodiments, the suspension block  130  may rotate only about the vertical axis of the lower end  115  of the frame member  110 . In some embodiments, however, the suspension block  130  is secured to the frame member  110  and does not rotate about the lower end  115  of the frame member  110 . 
     The suspension block  130  includes a diagonal aperture  140  through which an axle  150  of the wheel passes. The diagonal aperture  140  may be defined by sidewalls  145  extending from sides of the suspension block  130 . The diagonal aperture  140  may be disposed at a non-zero angle from a vertical axis of the stroller and from a horizontal axis of the stroller. The diagonal aperture  140  may be disposed at an acute angle of about 30° from a vertical axis of the stroller or about 45° from horizontal and vertical axes of the stroller when the axle  150  is in the home position, although in other embodiments, the diagonal aperture  140  may be disposed at other angles. Embodiments disclosed herein are not limited to including a diagonal aperture  140  having a shape and/or orientation as illustrated in  FIG. 1 . 
     In some embodiments the axle may extend across the stroller to a second wheel and form a common axle for both the wheel  120  and the second wheel. In such embodiments a single suspension block  130  may provide impact protection for both the wheel  120  and the second wheel. In other embodiments, each wheel of the stroller is mounted on a separate axle  150  and each wheel may be provided with an associated suspension block  130 . 
     As shown in  FIG. 2  and  FIG. 3 , the axle  150  is supported by a suspension mechanism disposed within the suspension block  130 . The axle  150  passes through an axle aperture  165  defined in a spring retainer  160  disposed within the body of the suspension block  130 . A spring  170  biases the spring retainer  160  out of the body of the suspension bock  130  and biases the axle  150  toward a lower forward end  140 ′ of the diagonal aperture  140 . When disposed against the side wall  145  of the diagonal aperture  140  at the lower forward end  140 ′ of the diagonal aperture  140 , the axle  150  is considered to be in the resting or home position. A forward horizontal direction of travel of the wheel  120  is indicated by the arrow F in  FIG. 2 . 
     In  FIG. 3 , which is a cross sectional view of a portion of the suspension block  130 , it can be seen that a lower end of the spring  170  engages with and couples to the spring retainer  160 . The lower end of the spring  170  may couple to the spring retainer  160  by fitting around an upper reduced diameter portion  175  of the spring retainer  160 . The lower end of the spring  170  may rest against an upper shoulder portion  180  of the spring retainer  160 . Other methods of coupling the spring  170  to the spring retainer  160  will be recognized by one of ordinary skill in the art and embodiments disclosed herein are not limited to including the illustrated mechanism for coupling the spring  170  to the spring retainer  160  unless explicitly set forth in the claims. 
     The spring retainer  160  and spring  170  are disposed within a spring retention chamber  190  defined in the body of the suspension block  130 . The spring retention chamber  190  may include an elongate chamber having an axis A along its elongate dimension which is disposed at a non-zero angle relative to a vertical axis A′ of the suspension block aperture  135  and to an axis normal to the vertical axis A′ of the suspension block aperture  135 , for example, at an acute angle of about 30° or about 45° relative to the vertical axis A′ of the suspension block aperture  135 . An upper end of the spring  170  opposite from the lower end of the spring  170  which engages and couples to the spring retainer  160  is disposed against an upper internal wall  195  of the spring retention chamber  190 . 
     The vertical axis of the body of the suspension block and the vertical axis of the lower end  115  of the frame member  110  may be considered parallel to the vertical axis A′ of the suspension block aperture  135 . 
     An outer surface  200  of the spring retainer  160  and at least a portion of an inner wall  205  of the spring retention chamber may have substantially similar cross sections, for example, as illustrated in  FIG. 4 , substantially circular cross sections. A small clearance is provided between the outer surface  200  of the spring retainer  160  and the portion of the inner wall  205  of the spring retention chamber  190  so that the spring retainer  160  may reciprocate up and down through the spring retention chamber  190 , i.e., towards and away from the upper internal wall  195  of the spring retention chamber  190 . 
     In some embodiments, the outer surface  200  of the spring retainer  160  and the inner wall  205  of the spring retention chamber  190  may have different cross sections than illustrated. For example, the outer surface  200  of the spring retainer  160  and the inner wall  205  of the spring retention chamber  190  may have cross sections which are rectangular, oval, or having the shape of any other regular or irregular polygon. In some embodiments, the outer surface  200  of the spring retainer  160  may contact the inner wall  205  of the spring retention chamber  190  about a substantial amount or an entirety of its periphery. In other embodiments, such as illustrated in  FIG. 4 , the inner wall  205  of the spring retention chamber  190  may have portions which contact the outer surface  200  of the spring retainer  160  and other portions which do not. 
     The portions of the inner wall  205  of the spring retention chamber  190  which contact the outer surface  200  of the spring retainer  160  may function as linear bearings which position the spring retainer  160  within the retention chamber  190  and guide movement of the spring retainer  160  within the retention chamber  190 . The portions of the inner wall  205  of the spring retention chamber  190  which contact the outer surface  200  of the spring retainer  160  may frictionally engage the outer surface  200  of the spring retainer  160 , thus providing a damping mechanism slowing the movement of the spring retainer  160  through the retention chamber  190  due to the application of a impact force to the wheel  120  and/or a force applied from the spring  170 . 
     The spring retainer  160  is biased away from the upper internal wall  195  of the spring retention chamber  190  by the spring  170 . The spring retainer  160  is retained within the spring retention chamber  190  because as the spring retainer  160  is pushed out from the spring retention chamber  190  it comes to a point where the axle  150  which passes through the axle aperture  165  defined in the spring retainer  160  comes into contact with the sidewall  145  of the diagonal aperture  140  at the lower forward end  140 ′ of the diagonal aperture  140 , preventing further movement of the spring retainer  160  from within the spring retention chamber  190 . 
     In other embodiments, a biasing and/or shock absorbing element other than or in addition to the spring  170  may be provided between the spring retainer  160  and upper internal wall  195  of the spring retention chamber  190 . The biasing element may be any element which provides a force biasing the spring retainer  160  away from the upper internal wall  195  of the spring retention chamber  190 . The biasing element may include, for example, one or more of a pneumatic piston, a balloon or bladder, a fluid or gas filled shock absorber, a pair of magnets having like poles facing one another with one of the magnets disposed on an upper portion of the spring retainer  160  and the other on the upper internal wall  195  of the spring retention chamber  190 , an electromagnetic coil or solenoid, a resilient rubber or foam material, or any other form of biasing and/or shock absorbing element or system known in the art. 
     In use, if an impact force is applied to the wheel  120  in a rearward direction (a direction opposite that of arrow F) and/or an upwards vertical direction, the axle  150  pushes on the spring retainer  160 , displacing the spring retainer  160  against the biasing force of the spring  170  upwards through the spring retention chamber  190 . The axle  150  may travel in a rearward and upward direction through a portion of the diagonal aperture  140 . Upon application of a sufficiently high impact force to the wheel  120 , the axle  150  may travel in a rearward and upward direction through the diagonal aperture  140  until the axle comes into contact with the rearward upper portion  140 ″ of the sidewall  145 . The spring  170  absorbs the energy of the impact force dampening the force so that a sharp impact is not transferred into the frame member  110  of the stroller and to a child who may be present in the stroller. 
     In an alternate embodiment of a suspension block, a first spring  170  or other biasing and/or shock absorbing element may be disposed against an upper side of the spring retainer  160  as illustrated in  FIGS. 2 and 3 , and a second spring  170  or other biasing and/or shock absorbing element may be disposed against a lower side of the to spring retainer  160 . The spring retainer  160  may be disposed within the spring retention chamber  190 , which may be modified from the spring retention chamber  190  illustrated in  FIGS. 2 and 3  to include a closed lower end defining a lower internal wall. The second spring  170  or other biasing and/or shock absorbing element may be disposed between the lower side of the spring retainer  160  and the lower internal wall of the spring retention chamber. Such a suspension block could absorb and/or dampen impact forces applied to a wheel having an axis supported by the spring retainer  160  in both a forward and a rearward direction and in both an upward and a downward direction. 
     The suspension system may be disassembled and reassembled by a user or by a service technician to, for example, replace one or more components if desired. The axle  150  may be slid through the axle aperture  165  until it disengages from the spring retainer  160 . The spring retainer  160  and/or spring  170  may then be removed from the spring retention chamber  190 . The spring retainer  160  and/or spring  170  may be replaced and/or inserted back into the spring retention chamber  190 . Insertion of the axle  150  through the diagonal aperture  140  and through the axle aperture  165  will secure the spring retainer  160  and spring  170  within the spring retention chamber  190 . 
     Having thus described several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the disclosure. Accordingly, the foregoing description and drawings are by way of example only.