Energy-dissipation system

[0001] The present disclosure relates to energy-absorbing apparatus, and in particular, to devices for dissipating energy associated with external impact forces. More particularly, the present disclosure relates to an energy-dissipation system included in a juvenile product such as a child-restraint system.

[0002] When exposed to an external impact force, a juvenile vehicle seat at rest on a seat in a car or truck will accelerate as it moves to a new location in the passenger compartment of a car or truck. A child seated in such a moving juvenile vehicle seat will also accelerate as the juvenile vehicle seat moves in the passenger compartment.

[0003] A g-load is a measurement of an object's acceleration measured in gs. The g is a non-SI unit equal to the nominal acceleration due to gravity on earth at sea level. A short-term acceleration experienced by a child seated in a juvenile vehicle seat (or any other juvenile seat) that moves suddenly is called a shock and is measured in gs.

[0004] An energy-dissipation system in accordance with the present disclosure is included in an apparatus that is exposed to external impact forces. In an illustrative embodiment, the energy-dissipation system is coupled to a juvenile vehicle seat to provide a child-restraint system.

[0005] In one illustrative embodiment, the energy-dissipation system includes a cup-shaped inner shell coupled to the juvenile vehicle seat, a cup-shaped outer shell arranged to cooperate with and move relative to the cup-shaped inner shell to form a variable-volume interior region therebetween, and a support frame in the variable-volume interior region. The support frame includes an endless rim made of an air-permeable material. The endless rim is arranged to lie in an air-exhaust passageway formed between the cup-shaped inner and outer shells. Air extant in the interior region is discharged to the surroundings through the air-permeable endless rim in response to telescoping movement of the cup-shaped outer shell toward the cup-shaped inner shell so as to decrease the volume of the interior region during exposure of the energy-dissipation system to an external impact force.

[0006] In another illustrative embodiment, the energy-dissipation system includes a plate-shaped inner shell coupled to the first side-wing panel, a plate-shaped outer shell separated from the plate-shaped inner shell, and a ring-shaped support frame interposed between and mated with the plate-shaped inner and outer shells and made of an air-permeable material. The plate-shaped inner and outer shells cooperate to define means for discharging air extant in an interior region formed in the ring-shaped support frame and between the plate-shaped inner and outer shells to surroundings outside the ring-shaped support frame during movement of the plate-shaped outer shell toward plate-shaped inner shell in response to exposure of the energy-dissipation system to an external impact force so that a ride-down pad comprising the plate-shaped inner and outer shells and the ring-shaped support frame absorbs external energy associated with the external impact force to minimize g-loads experienced by a child seated on the juvenile vehicle seat.

[0007] Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.

[0019] An illustrative child-restraint system 11 includes a juvenile vehicle seat 10 and an energy-dissipation system 16 coupled to juvenile vehicle seat 10 as suggested in FIG. 1. In illustrative embodiments, juvenile vehicle seat 10 includes a seat bottom 12 and a seat back 14 extending upwardly from seat bottom 12 and carrying energy-dissipation system 16.

[0020] Energy-dissipation system 16 comprises ride-down pads that are designed to minimize the g-loads experienced by a child seated on seat bottom 12 of juvenile vehicle seat 10 during exposure of seat 10 to an external impact force 20. Ride-down pads 21, 22 are shown, for example, in FIG. 1. Right-side ride-down pad 21 is shown in more detail in FIGS. 2-5. Reference is hereby made to U.S. application Ser. No. 12/327,376, filed Dec. 4, 2008, the entirety of which is hereby incorporated by reference herein, for disclosures of various ride-down pad configurations and mounting arrangements. Ride-down pads 121, 122 in accordance with another embodiment of the present disclosure are shown, for example, in FIGS. 6-10 and cooperate to form an energy-dissipation system 116.

[0021] As suggested in FIG. 1, seat back 12 of juvenile vehicle seat 10 includes a backrest 24 arranged to extend upwardly from seat bottom 12 and a headrest 26 coupled to backrest 24. Right-side ride-down pad 21 is coupled to an inner wall 27 of a first side-wing panel 31 included in headrest 26 as suggested in FIGS. 1-5. Left-side ride-down pad 22 is coupled to an inner wall 29 of a second side-wing panel 32 included in headrest 26 as shown in FIG. 1. A rear panel 30 is included in headrest 26 and arranged to interconnect first and second side-wing panels 31, 32 as suggested in FIG. 1.

[0022] During a collision or other incident, application of an external impact force 20 to first side-wing panel 31 of headrest 26 causes energy to be transferred from an impacting object (not shown) to right-side ride-down pad 21 as suggested in FIGS. 1 and 5. Ride-down pad 21 discharges air 23 contained therein to the surroundings and absorbs that transferred energy as suggested in FIG. 5. Transferred energy is absorbed to minimize the magnitude of a resulting force applied to a child 100 seated in juvenile vehicle seat 10 by a force transmitter 200 comprising outer cover 80, right-side ride-down pad 21, and first side-wing panel 31 (all included in juvenile vehicle seat 10) during the collision.

[0023] Ride-down pad 21 functions to minimize the g-loads (acceleration) experienced by child 100 seated on seat bottom 12 of juvenile vehicle seat 10 during exposure of seat 10 to external impact force 20 as suggested in FIG. 5. Ride-down pad 21 also functions to maximize the time interval (i.e., ride-down time) between the moment the impacting object strikes juvenile vehicle seat to apply the external impact force 20 to ride-down pad 21 and the moment that resulting force reaches zero. Ride-down pad 22 functions in a manner similar to ride-down pad 21.

[0024] As suggested in FIGS. 2 and 4, right-side ride-down pad 21 is configured to retain air 23 in an interior region formed therein. This air 23 is discharged as suggested in FIG. 5 when ride-down pad 21 to exposed to an external impact force 20 to absorb energy associated with external impact force 20.

[0025] As suggested in FIGS. 2-4, ride-down pad 21 includes an inner shell 34 coupled to first side-wing panel 31 of headrest 26, an outer shell 38 separated from inner shell 34, and a support frame 36 interposed between inner and outer shells 34, 38. Inner and outer shells 34, 38 cooperate to form an interior region 40 therebetween and to form an air-exhaust passageway 46 therebetween. In an illustrative embodiment, a portion of support frame 36 is positioned to lie in air-exhaust passageway 46 as suggested in FIGS. 2 and 4.

[0026] As suggested in FIGS. 2-4, outer shell 38 is mounted for movement relative to inner shell 34 to vary the volume of interior region 40. Interior region 40 provides an air chamber in ride-down pad 21. In a pre-collision position shown, for example, in FIGS. 2 and 4, outer shell 38 is positioned relative to inner shell 34 to provide interior region 40 with a maximum volume. During a collision in which first side-wing panel 27 of juvenile vehicle seat 10 is exposed to an external impact force 20, outer shell 38 moves relative to inner shell 34 and toward first side-wing panel 27 to reduce the volume of interior region 40 and cause air 23 extant in interior region 40 to flow out of the air chamber provided in ride-down pad 21 to the surroundings through air-exhaust passageway 46 as shown, for example, in FIG. 5.

[0027] Inner shell 34 is cup-shaped in an illustrative embodiment and includes a plate 341 and an endless rim 342 as suggested in FIGS. 2 and 3. Plate 341 is round and flat and endless rim 342 is annular and coupled to a perimeter edge of plate 341 in the illustrated embodiment. Rim 342 is characterized by an external diameter D1 as suggested in FIG. 4. A fastener 35 such as an adhesive or a hook-and-loop system is used to hold plate 341 (and thus inner shell 34) in a stationary position on inner wall 27 of first side-wing panel 31 as suggested in FIGS. 4 and 5.

[0028] Outer shell 38 is cup-shaped in an illustrative embodiment and includes a plate 381 and an endless rim 382 as suggested in FIGS. 2 and 3. Plate 381 is round and flat and endless rim 382 is annular an coupled to a perimeter edge of plate 381 in the illustrated embodiment. Rim 382 is characterized by an internal diameter D2 as suggested in FIG. 4. Internal diameter D2 of rim 382 is greater than external diameter D1 of rim 342 to allow outer shell 38 to mate in telescoping relation to inner shell 34 as suggested in FIGS. 4 and 5 wherein rim 342 of inner shell 34 is movable inside and relative to rim 382 of outer shell 38.

[0029] Support frame 36 is cup-shaped in an illustrative embodiment and includes a rim 362 as suggested in FIGS. 2 and 3. Rim 362 of support frame 36 is annular and arranged to mate with an exterior surface of rim 342 of inner shell 34. Any suitable means can be used to retain support-frame rim 362 in a stationary position on inner-shell rim 342 in the illustrated embodiment as shown, for example, in FIGS. 4 and 5.

[0030] Support frame 36 also includes in an illustrative embodiment, a plate 361 coupled to an outer edge of support-frame rim 362 as shown, for example, in FIGS. 2-5. Plate 361 is round and flat in an illustrative embodiment. Plate 361 is made of an air-permeable material as suggested in FIG. 5 to allow flow of air 23 extant in a first air chamber 401 provided between support-frame plate 361 and inner-shell plate 341 through plate 361 to reach air-exhaust passageway 46 defined between inner-shell rim 342 and outer-shell rim 382.

[0031] Support-frame rim 362 is arranged to extend through annular air-exhaust passageway 46 as suggested in FIGS. 2 and 4. Annular air-exhaust passageway 46 is characterized by a width dimension WD as suggested in FIG. 4. Air 23 can flow through support-frame rim 362 as it flows through air-exhaust passageway 46 as suggested in FIG. 5 owing to the permeability of the material used to make support-frame rim 362.

[0032] Outer-shell plate 381 and support-frame plate 361 cooperate to form a second air chamber 402 therebetween as suggested in FIGS. 2 and 4. Second air chamber 402 can vary in volume in response to movement of all or part of outer shell 38 relative to support frame 36 as suggested in FIGS. 4 and 5. As noted herein, support-frame plate and rim 361, 362 is made of an air-permeable material so as to allow flow of air 23 extant in second air chamber 402 through plate 361 and rim 362 to reach and flow the rough air-exhaust passageway 46 defined between inner-shell rim 342 and outer-shell rim 382.

[0033] During assembly, inner and outer shells 34, 38 and support frame 36 are joined together in the order suggested in FIG. 3 to produce ride-down pad 21 as suggested in FIGS. 2 and 4. Outer-shell rim 382 is configured to provide means for yieldably gripping support-frame rim 362 while a portion of support-frame rim 362 is trapped therebetween to cause outer shell 38 to remain normally in an initial position shown in FIGS. 2 and 4 relative to inner shell 34 and support frame 36 until ride-down pad 21 is exposed to a sufficient external impact force 20 to cause relative movement of inner and outer shells 34, 38 as suggested in FIG. 5. As noted herein, such relative movement decreases the volume of interior region 40 and causes air 23 in interior region 40 to flow through air-exhaust passageway 46 and a permeable portion of support-frame rim 362 located in air-exhaust passageway 46 to the surroundings outside of ride-down pad 21.

[0034] It is also within the scope of this disclosure to manufacture inner and outer shells 34, 38 and support frame 36 using deformable materials that will yield as suggested in FIG. 5 under loads such as a sufficient external impact force 20. Such deformation can lead to a decrease in the volume of interior region 40, which decrease causes air 23 to be discharged to the surroundings as suggested in FIG. 5. During a collision, the volume of interior region 40 decreased (in contrast to the pre-collision volume of interior region 40 shown in FIG. 4) due to shell deformation and relative shell movement to cause air 23 to be discharged from interior region 40 to the surroundings through air-exhaust passageway 46.

[0035] In an illustrative embodiment, an outer cover 80 is coupled to headrest 26 and arranged to cover each of right-side and left-side ride-down pads 21, 22. Outer cover 80 functions to dissipate energy associated with external impact forces 20 and to protect ride-down pads 21, 22 from damage. In an illustrative embodiment, outer cover 80 includes an outer skin 82 and a cushion 84 under outer skin 82 as shown, for example, in FIGS. 3-5. Outer cover 80 is arranged to cover outer shell 38 and locate ride-down pad 21 in a space formed between outer cover 38 and first side-wing panel 31 as suggested in FIG. 4. Outer cover 80 mates with an exterior surface of outer shell 38 while an opposite interior surface of outer shell 38 mates with support frame 36 as also shown in FIG. 4.

[0036] Child restraint 11 comprises a juvenile vehicle seat 10 and an energy-dissipation 16 system coupled to juvenile vehicle seat 10 as suggested in FIGS. 1-5. Energy-dissipation system 16 comprises a ride-down pad 21 including an inner shell 34 coupled to juvenile vehicle seat 10 and an outer shell 38 arranged for movement relative to inner shell 34 and to cooperate with inner shell 34 to define an interior region 40 therebetween sized to vary in volume in response to movement of outer shell 38 toward inner shell 34 as suggested in FIGS. 4 and 5. Ride-down pad 21 also includes a support frame 36 interposed between and mated with inner and outer shells 34, 38 and made of an air-permeable material as suggested in FIGS. 2, 4, and 5. Inner and outer shells 34, 38 cooperate to define means for causing air 23 extant in an air chamber 401, 402 included in interior region 40 to pass through a portion 361, 362 of support frame 36 as air 23 is discharged from interior region 40 to the surrounding region during movement of outer shell 38 toward inner shell 34 in response to an external impact force 20 so that ride-down pad 21 absorbs external energy associated with external impact force 20 to minimize g-loads experienced by a child seated on juvenile vehicle seat 10 as suggested in FIG. 5.

[0037] Inner and outer shells 34, 38 are arranged to lie in spaced-apart relation to one another as suggested in FIGS. 2, 4, and 5 to form therebetween an air-exhaust passageway 46 opening into interior region 40. A portion 362 of support frame 36 lies in air-exhaust passageway 46 as suggested in FIG. 4. Inner shell 34 includes an endless rim 342. Outer shell 38 includes an endless rim 382 arranged to lie in spaced-apart relation to endless rim 342 of inner shell 34 to define air-exhaust passageway 46 therebetween as suggested in FIG. 4.

[0038] Portion 362 of support frame 36 is an endless rim arranged to lie in air-exhaust passageway 46 and surround and mate with endless rim 342 of inner shell 34 as suggested in FIGS. 2-4. Endless rim 382 of outer shell 38 is arranged to surround and mate with endless rim 362 of support frame 36 as suggested in FIGS. 2-4.

[0039] Inner shell 34 further includes a plate 341 coupled to first side-wing panel 31 and to endless rim 342 of inner shell 34 as suggested in FIG. 3. Outer shell 38 further includes a plate 381 coupled to endless rim 382 of outer shell 38 and arranged to lie in spaced-apart relation to plate 341 of inner shell 34 to define interior region 40 therebetween as suggested in FIG. 4.

[0040] Support frame 36 further includes a plate 361 coupled to endless rim 362 of support frame 36 and arranged to lie in interior region 40 in spaced-apart relation to each of plates 341, 381 of inner and outer shells 34, 38 as suggested in FIG. 4. Plates 341 of inner shell 34 and support frame 36 cooperate to define a first air chamber 401 therebetween as shown in FIG. 4. Plates 361, 381 of support frame 36 and outer shell 38 cooperate to define a second air chamber 402 therebetween as shown in FIG. 4. Air 23 in interior region 40 is free to pass through air-permeable portions of plate 361 and endless rim 362 of support frame 36 to flow between first and second air chambers 401, 402 and air-exhaust passageway 46 during movement of outer shell 38 toward inner shell 34 as suggested in FIG. 5.

[0041] Air-exhaust passageway 46 is ring-shaped and portion 362 of support frame 36 is ring-shaped and sized to fill air-exhaust passageway 46 as suggested in FIGS. 2 and 4. Outer shell 38 is clamped to inner shell 34 to trap portion 362 of support frame 36 therebetween in an initial position of outer shell 38 relative to inner shell 34 as suggested in FIGS. 2 and 4 to establish a predetermined initial volume of interior region 40 and yet to slip relative to portion 362 of support frame 36 during movement of outer shell 38 toward inner shell 34 to compress air 23 extant in interior region 40 to cause such air 23 to flow out of interior region 40 to the surroundings through air-exhaust passageway 46 as suggested in FIG. 5.

[0042] Support frame 36 further includes a plate 361 coupled to the portion 362 of support frame 36 that is ring-shaped. Plate 361 of support frame 36 is arranged to lie in and partition interior region 40 to form a first air chamber 401 between inner shell 34 and plate 361 of support frame 36 and to form a second air chamber 402 between outer shell 38 and plate 381 of support frame 36 as suggested in FIG. 4. Air 23 in interior region 40 is free to pass through air-permeable portions of plate 361 of support frame 361 and portion 362 of support frame 36 that is ring-shaped to flow between first and second air chambers 401, 402 and air-exhaust passageway 46 during movement of outer shell 38 toward inner shell 34 as suggested in FIG. 5.

[0043] In a second embodiment of the present disclosure, a child restraint 111 includes right-side and left-side ride-down pads 121, 122 mounted on juvenile vehicle seat 10 as shown in FIG. 6. As suggested in FIGS. 9 and 10, right-side ride-down pad 121 is configured to absorb energy associated with external impact force 20 during a collision involving child restraint 111.

[0044] As suggested in FIGS. 7-9, ride-down pad 121 includes an inner shell 134 coupled to first side-wing panel 31 of headrest 26, an outer shell 138 separated from inner shell 134, and a support frame 136 interposed between inner and outer shells 134, 138. Inner and outer shells 134, 138 cooperate to form an interior region 140 therebetween and to form an air-exhaust passageway 146 therebetween.

[0045] Inner shell 134 is plate-shaped in an illustrative embodiment shown in FIGS. 7-10. Inner shell 134 is round and flat in the illustrated embodiment. A fastener 135 such as an adhesive or a hook-and-loop system is used to hold inner shell 134 in a stationary position on inner wall 27 of first side-wing panel 31 as suggested in FIGS. 9 and 10.

[0046] Outer shell 138 is plate-shaped in an illustrative embodiment shown in FIGS. 7-10. Outer shell 138 is round and flat in the illustrated embodiment. Inner and outer shell 134, 138 each has the same diameter D as suggested in FIG. 9.

[0047] Support frame 136 is ring-shaped in an illustrative embodiment as suggested in FIGS. 8 and 9. Support frame 136 includes an annular inner face 141 mating with inner shell 134, an annular outer face 142 mating with outer shell 138, a cylindrical exterior side wall 143 having diameter D and extending between inner and outer shells 134, 138, and a cylindrical interior side wall 144 having a diameter d and forming an interior cavity 145 surrounded by ring-shaped support frame 136 and arranged to lie between inner and outer shells 134, 138 as suggested in FIGS. 8 and 9.

[0048] Support frame 136 includes an inner face 141 mating with inner shell 134, an outer face 142 mating with outer shell 138, and an exterior side wall 143 extending between inner and outer faces 141, 142 and inner and outer shells 134, 138 as suggested in FIGS. 7 and 8. Support frame 136 further includes an endless interior wall 144 forming an interior cavity 145 between inner and outer shells 134, 136 as suggested. Inner face 141 has an annular shape, outer face 142 has an annular shape, and exterior side wall 143 has an annular shape as suggested in FIG. 8.

[0049] Support frame 136 is made of a deformable and air-permeable material. Support frame 136 is configured to provide means for supporting inner and outer shells 134, 136 in an initial position separated from one another to establish an initial volume of interior region 140 until relative movement of inner and outer shells 134, 138 happens when ride-down pad 121 is exposed to an external impact force 20 so that deformable support frame 136 deforms at a rate that allows ride-down pad 121 to absorb external energy associated with external impact force 20.

[0050] As suggested in FIG. 10, during an illustrative collision, external impact force 20 strikes first side-wing panel 31 of headrest 26 to deform support frame 136 in right-side ride-down pad 121. During such deformation, some of the air 23 extant in interior region 140 is discharged to the surroundings through air-exhaust passageway 146. Some of the energy associated with external impact force 20 has been dissipated owing, in part to deformation of deformable support frame 136 and discharge of air 23 from interior region 140 as suggested in FIG. 10. This minimizes a resulting force 200 applied to child 100 seated in juvenile seat 10 of child restraint 111. This energy absorption feature minimizes the g-loads (acceleration) experienced by child 100 and also maximizes the ride-down time between the first strike of an impacting object on first side-wing panel 31 of headrest 26 of juvenile vehicle seat 10 and the moment the resulting force reaches zero.