APPARATUS FOR PREVENTING WHIPLASH

Abstract: A vehicle-installed supporting seat for a passenger (28) is provided, which includes a seat back (12) provided with an integral head-neck restraint (14) comprising a cranium support portion (16) and a cervical spine support portion (18). Each portion includes a layer of resilient material (20) supported on an underlying inflexible support shell (22), which together act to effectively define a contour (24) that interfits with the posterior contour (26) of the passenger's cranium and cervical spine. A controllably deformable energy absorbing crush zone (40) is disposed to the rear of the shell as to be compressed by the rearward displacement of the shell. The cervical and cranium support portions act to substantially simultaneously decelerate the cranium and cervical spine of the passenger during a vehicle rear end impact while the controlled deformation of the crush zone absorbs energy, to prevent whiplash-related injuries to the passenger.

Description: APPARATUS FOR PREVENTING WHIPLASH FIELD OF THE INVENTION This invention relates generally to apparatus for supporting a person's cranium, cervical, thoracic, and lumbar spine, including passenger safety apparatus for vehicles, and more specifically, relates to apparatus for preventing whiplash related and similar injuries. BACKGROUND OF INVENTION Whiplash related injuries are caused by the rapid acceleration of a person's cranium and cervical spine, which occurs, for example, in a rear end automobile collision. The rapid acceleration causes the extension and flexion ofthe cervical spine which, in turn, can cause severe injury. Types of whiplash related injuries include fractured and/or dislocated vertebrae, torn ligaments (both anterior and posterior ofthe spinal column), and avulsion of parts ofthe vertebrae, ligaments and intervertebrae discs. Similar injuries can occur to the thoracic and lumbar spinal areas. It has thus been found, for example, that the C4, C5 and C6 cervical vertebrae, and the paravertebrae ligaments are most often damaged with whiplash related injuries, although the entire cervical as well as the thoracic and lumbar spine may well be involved. Rapid hyperextension ofthe cervical spine can thus stretch the anterior longitudinal ligament, thus placing it in traction and causing either bone or ligamentous damage. Such hyperextension typically damages the Cl through C7 cervical vertebrae. The vertebral artery, which extends through an opening in the vertebrae, and the sympathetic nerve fibers that surround the artery are also often damaged. These types of injuries cause severe disabilities and, in some instances, death. Seatbacks and/or headrests in automobiles, trucks, and other types of vehicles are provided to prevent whiplash related injuries to passengers during collisions, but typically fail. During a rear-end vehicle collision, the forces ofthe collision typically cause a passenger's cranium and cervical spine to rapidly accelerate toward the rear of the vehicle. Once the cranium strikes the seatback or headrest, it then rapidly accelerates in the opposite direction toward the front ofthe vehicle. The rearward acceleration ofthe cranium, and resulting collision with the seatback or headrest, causes hyperextension ofthe cervical spine and, thus typically injures the anterior structure ofthe passenger's neck. The forward acceleration ofthe cranium, on the other hand, causes hyperflexion ofthe cervical spine and typically injures the posterior structure ofthe neck. One problem with known seatbacks and/or headrests is that the surface intended to stop the movement of a person's head and neck is typically flat, or does not correspond to the posterior contour thereof. As a result, during a rear-end collision, typically the back, or posterior portion ofthe cranium is the first portion ofthe passenger's body to strike the seatback or headrest. However, the cervical spine, which is located inferiorly with respect to the posterior portion ofthe cranium, continues to move toward the headrest. As a result, the cervical spine is forced to move relative to the cranium which, in turn, causes severe vertebral damage. Also, the top surfaces of many known headrests are located at about the same height, or below the height of a passenger's ears, which is normally about the center of gravity ofthe head. When a passenger's cranium is forced against such a headrest during a collision, it often slides upwardly over the top edge ofthe headrest. As a result, the cranium is stretched upwardly relative to the cervical spine, typically causing further vertebral damage. In my issued U.S. Patents Nos. 5,181,763 and 5,290,091, the entire disclosures of which are hereby incorporated by reference, apparatus is disclosed for preventing whiplash-related injuries to a passenger in a vehicle. In one embodiment ofthese inventions, the apparatus comprises a frame supported on a seat ofthe vehicle and located behind the cranium and cervical spine of a passenger on the seat. A layer of resilient material is supported on the frame, the layer of resilient material defining a supporting means located behind the cranium and cervical spine ofthe passenger and defining one or more contours that interfit with the posterior contour ofthe passenger's cranium and cervical spine. The supporting means includes a first surface located behind the passenger's cranium and projecting upwardly above the approximate center of mass ofthe passenger's cranium and having a substantially flat portion including a cranium contact zone for contacting and supporting the approximate central posterior area ofthe passenger's cranium; and a second surface located below the first surface and defining a substantially convex smooth curve, the maximum protrusion point of which projects anteriorly relative to the flat portion of the first surface. The second surface thereby contacts and supports the posterior portion ofthe passenger's cervical spine substantially simultaneously with the contact ofthe passenger's cranium with the first surface, thereby substantially simultaneously decelerating the cranium and cervical spine during a vehicle collision to prevent whiplash-related injuries to the passenger. In such prior invention, the second surface is smoothly joined to the first surfaces by a transition surface which extends anteriorly at an obtuse angle from the first surface and is located to support the passenger's posterior area approximately where the cranium meets the cervical spine. A support member is coupled to the frame and supported on the seat, the support member being vertically moveable relative to the seat to adjust the position ofthe apparatus relative to the passenger and. thus, adjust the position ofthe supporting means to correspond to the posterior contour ofthe passenger's cranium and cervical spine. The frame can define a hollow enclosure and the layer of resilient material may consist essentially of a urethane foam which is molded thereon. The frame is journaled to the support member and normally biased toward the front of the seat, whereupon during a vehicle collision, when the passenger's head is forced toward the apparatus, the posterior portion ofthe passenger's cranium initially contacts the first surface ofthe supporting means and rotates the frame relative to the support member toward the back ofthe seat and, in turn, rotates the second supporting surface into contact with the posterior portion ofthe passenger's lower cranium and cervical spine. In a further embodiment of our prior apparatus, the first and second surfaces are defined at mutually spaced first and second support bodies, and the apparatus further includes means for vertically and horizontally displacing the first and second surfaces to adjust the position of same to accurately interfit with the posterior contour of different passengers. The first and second support bodies can be coupled to the frame and rendered movable by rack and pinion or equivalent means to enable desired vertical and/or horizontal displacements of same. It may be noted in the foregoing discussions, that the construction of most prior art seatbacks and head rests incorporate materials that in an effort to provide maximum comfort, are highly resilient. Such materials while they may absorb some ofthe impact energy which is generated as the passenger is thrown rearwardly against the seat during a rear end impact, promptly transfer the absorbed energy back to the passenger, causing a rebound effect, which only adds to the detrimental conditions which foster injury. In accordance with the foregoing, it may be regarded as an object ofthe present invention, to overcome the problems and disadvantages of known apparatus for preventing whiplash, such as vehicle headrests and seatbacks. It is a further object ofthe present invention, to provide apparatus ofthe foregoing type, which includes means for efficiently and safely absorbing impact energy, thereby further diminishing the likelihood of passenger injury. SUMMARY OF THE INVENTION Now in accordance with the present invention, important modifications and improvements have been made in the aforementioned prior art apparatus to thereby provide improved apparatus for preventing whiplash-related injuries to a passenger in a vehicle. In accordance with the invention, a vehicle-installed supporting seat for the passenger is provided, which includes a seat back provided with an integral head- neck restraint comprising a cranium support portion and a cervical spine support portion. Each said portion includes a layer of resilient material supported on an underlying inflexible support shell, which together act to effectively define a contour that interfits with the posterior contour ofthe passenger's cranium and cervical spine. This contour thus presents a first surface located behind the passenger's cranium for contacting the approximate center of mass ofthe cranium and supporting the approximate central posterior area ofthe passenger's cranium, and a second surface located below the first surface and defining a substantially convex smooth curve, the maximum protrusion point of which projects anteriorly relative to where the first surface contacts the center of mass ofthe passenger's cranium, the said second surface thereby contacting and supporting the posterior portion ofthe passenger's cervical spine substantially simultaneously with the said contact ofthe passenger's cranium with said first surface. The support shell is rearwardly displaceable upon being subjected to impressed forces generated from the passenger pressing against the restraint as a result of a rear end impact at said vehicle. A controllably deformable energy absorbing crush zone is disposed to the rear of the shell as to be compressed by the rearward displacement ofthe shell. The interfitting contour and thereby the inflexible shell, upon being displaced by said forces toward the underlying crush zone, retain the shape ofthe contour, whereby the cervical and cranium support portions act to substantially simultaneously decelerate the cranium and cervical spine ofthe passenger during a vehicle rear end impact, while the controlled deformation ofthe crush zone absorbs energy, to prevent whiplash-related injuries to the passenger. The second surface of said contour is smoothly joined to said first surface by a transition surface of said contour, which extends anteriorly at an obtuse angle from said first surface, and which is located to support the passenger's posterior area approximately where the cranium meets the cervical spine. The maximum protrusion point of said second surface projects anteriorly relative to said flat portion of said first surface a distance of 1 to 6 inches, and the maximum protrusion point is from 3 to 9 inches below the cranium contact zone. The apparatus ofthe invention preferably further includes a thoracic and lumbar spine support portion which are defined by downward extension ofthe support shell, resilient material and contour; whereby the thoracic and lumbar spine portion ofthe passenger are decelerated with the cranium and cervical spine during a rear end impact. The crush zone may comprise one or more air bladders, and valve means responsive to rear end vehicular impact to enable the one or more bladders to at least partially deflate. The inflexible shell can, for example, be linked to one or more mechanical actuators which open the valves upon a predetermined displacement ofthe shell; or one or more sensors can upon detecting a rear end impact, actuate the valves to enable controlled deflation ofthe air bladders. Similarly, one or more rear impact sensors can enable control signals upon an impact of sufficient magnitude, which signal disables a restraint means, e.g. by releasing a mechanical stop which otherwise prevents displacement ofthe inflexible shell (or of a plate linked to the shell) against or into the crush zone. In another aspect ofthe invention, the cmsh zone can comprise an impact collapsible cellular stmcture, such as a frangible foam. In still a further aspect, the cmsh zone may comprise an elastically deformable material which absorbs energy at a substantially more rapid rate than it releases same. The cmsh zone may be sandwiched between the inflexible shell and a spaced fixed, rigid plate; or the crash zone can be spaced from the rear ofthe shell and contacted and compressed by an intermediate plate which is linked for displacement with the shell. Rearward displacement ofthe shell may be resisted by restraining means adapted to collapse at a preset strain. BRIEF DESCRIPTION OF THE DRAWINGS The invention is diagrammatically illustrated, by way of example, in the drawings appended hereto in which: Figure 1 is a simplified, schematic cross-section illustrating apparatus in accordance with the present invention; Figure 2 is a schematic block diagram illustrating use of an impact sensor to enable controlled collapse ofa series of air bladders where the latter comprise the cmsh zone; Figure 3 depicts an enlarged cross-section of a portion ofthe Figure 1 apparatus, and illustrates an arrangement enabling rearward displacement ofthe inflexible shell to occur at a pre-set force level; and Figure 4 is a partial cross sectional view, similar to Figure 1 , but showing an arrangement wherein the crash zone is formed toward the rear ofthe seat back. DESCRIPTION OF PREFERRED EMBODIMENTS In Figure 1, a cross-sectional view, schematic in nature, appears through apparatus 10 in accordance with the present invention. The vehicle-installed supporting seat for the passenger includes a conventional seating area, which is not shown in the drawing. Extending in a vertically upward direction from the seating area is a seat back 12 provided with an integral head-neck restraint 14 comprising a cramum support portion 16 and a cervical spine support portion 18. Each said portion includes a layer of resilient material 20 supported on an underlying inflexible support shell 22. The material 20 and the shell 22 together act to effectively define a contour 24 that interfits with the posterior contour 26 ofthe passenger 28's cranium and cervical spine. This contour 26 thus presents a first surface 29 located behind the passenger's cranium for contacting the approximate center of mass ofthe cranium and supporting the approximate central posterior area ofthe passenger's cranium, and a second surface 30 located below the first surface and defining a substantially convex smooth curve, the maximum protrusion point 32 of which projects anteriorly relative to where the first surface 29 contacts the center of mass ofthe passenger's cranium, the said second surface 30 thereby contacting and supporting the posterior portion ofthe passenger's cervical spine substantially simultaneously with the said contact ofthe passenger's cranium with said first surface. The support shell 22 may comprise a hard relatively inflexible plastic, or similarly may comprise metal or the like. Shell 22 is rearwardly displaceable upon being subjected to impressed forces generated from the passenger 28 pressing against the restraint as a result of a rear end impact at the vehicle. In the embodiment shown in Figure 1 this is enabled by having the shell 22 formed as a front piece 22a and a rear piece 22b, the two pieces being interconnected by one or more flexible accordion pleats, the uppermost of which appears at 34. In another embodiment ofthe invention the pleats 34 can instead of being entirely flexible, be formed of rigid interconnected units as shown in the enlarged partial view of Figure 3. In this arrangement, the elements 34a and 34b are disposed to shear from one another at point 36 upon a preset force level being attained, whereby rearward displacement of shell 22 only can occur when impact forces are sufficient to cause the said shearing. A controllably deformable energy absorbing crash zone 40 is disposed to the rear of the shell 22 as to be compressed by the rearward displacement ofthe shell. The interfitting contour 24 and thereby the inflexible shell 22, upon being displaced by said forces toward the underlying crush zone 40, retain the shape ofthe contour 24, whereby the cervical and cranium support portions act to substantially simultaneously decelerate the cranium and cervical spine ofthe passenger during a vehicle rear end impact, while the controlled deformation ofthe crash zone absorbs energy, to prevent whiplash-related injuries to the passenger. The second surface 30 of contour 24 is smoothly joined to the first surface 29 by a transition surface 42 of said contour, which extends anteriorly at an obtuse angle from said first surface, and which is located to support the passenger's posterior area approximately where the cranium meets the cervical spine. The maximum protmsion point 32 of said second surface 30 projects anteriorly relative to said flat portion of said first surface 29 a distance of 1 to 6 inches, and the maximum protmsion point 32 is from 3 to 9 inches below the cranium contact zone. The apparatus 10 ofthe invention preferably further includes thoracic and lumbar spine support portions 46 and 48, which are defined by downward extension ofthe support shell 22, resilient material 20 and contour 24; whereby the thoracic and lumbar spine portions ofthe passenger 28 are decelerated with the cranium and cervical spine during a rear end impact. The crush zone 40 may comprise one or more air bladders, and valve means responsive to rear end vehicular impact to enable the one or more bladders to at least partially deflate. One such arrangement enabling this is shown schematically in Figure 2. Illustratively three air bladders 50, 52 and 54 are shown, which may be disposed in side by side relation as crash zone 40. Each ofthe air bladders may be vented to atmosphere by respective normally closed valves 56, 58, and 60, which can be solonoid actuated. An impact sensor 62 is mounted to the vehicle and the signal output from same is provided to logic and valve actuator means 64. In the event that the output signal from sensor 62 exceeds a predetermined threshold level, control signals are provided to valves 56, 58, and 60, causing same to open and permit rapid but controlled deflation ofthe air bladders. Thus the crush zone is responsive to a rear end impact exceeding a predetermined level, and under such conditions acts to absorb energy as the shell 22 is displaced toward the crash zone. In another embodiment of the invention, the inflexible shell can be linked to one or more mechanical actuators which open the valves upon a predetermined displacement ofthe shell. In another aspect ofthe invention, the crash zone can comprise an impact collapsible cellular structure, such as a frangible foam. The cellular structure can similarly comprise the well known bubble packing, which is commonly used to protect fragile objects during shipping. Other controllably collapsible or deformable materials can be used for crush zone 40, for example frangible ceramic or organic foams, or the like. The important consideration is that any such materials shall collapse or deform under suitable imposed forces in a controllable fashion so that they not only enable controlled rearward displacement of piece 22a, but also absorb energy in doing so. Thus by way of example, it will be clear that the bubble type packing material referred to absorbs energy during collapse as each ofthe cells is raptured due to pressure forces. In still a further aspect, the crash zone may comprise an elastically deformable material which absorbs energy at a substantially more rapid rate than it releases same. The crush zone 40 may as shown in Figure 1 be sandwiched between the inflexible shell 22 (via piece 22a) and a spaced fixed, rigid plate 49, which is maintained in its position by support members 23 which extend between plate 49 and back piece 22b. Compression springs 51 may be provided between shell 22 and plate 49 to aid in restoring the original spacing following the controlled collapse ofthe crash zone. In the variation shown in the partial cross section of Figure 4, the crash zone 40 is placed to the rear of seat back 12. Here the rearward displacement of piece 22a moves plate 49a which is rigidly linked to piece 22a by members 23a. While the present invention has been particularly described in terms of specific embodiments thereof, it will be understood that numerous variations upon the invention are now enabled to those skilled in the art, which variations yet reside within the scope ofthe present teaching. Accordingly, the invention is to be broadly constraed and limited only by the scope and spirit ofthe claims now appended hereto.

Claims: WHAT IS CLAIMED IS: 1. Apparatus for preventing whiplash-related injuries to a passenger in a vehicle, comprising: a vehicle-installed supporting seat for said passenger, which includes a seat back provided with an integral head-neck restraint comprising a cranium support portion and a cervical spine support portion; each said portion including a layer of resilient material supported on an underlying inflexible support shell, and together acting to effectively define a contour that interfϊts with the posterior contour ofthe passenger's cranium and cervical spine; said contour presenting a first surface located behind the passenger's cranium for contacting the approximate center of mass ofthe cranium and supporting the approximate central posterior area ofthe passenger's cranium, and a second surface located below the first surface and defining a substantially convex smooth curve, the maximum protrusion point of which projects anteriorly relative to where the first surface contacts the center of mass ofthe passenger's cranium, said second surface thereby contacting and supporting the posterior portion ofthe passenger's cervical spine substantially simultaneously with the said contact ofthe passenger's cranium with said first surface; said support shell being rearwardly displaceable upon being subjected to impressed forces generated from the said passenger pressing against the restraint as a result of a rear end impact at said vehicle; and a controllably deformable energy absorbing crash zone being disposed to the rear of said shell as to be compressed by said rearward displacement ofthe shell; said interfitting contour and thereby said inflexible shell upon being displaced by said forces toward the underlying crash zone, retaining the shape ofthe contour, whereby said cervical and cranium support portions act to substantially simultaneously decelerate the cranium and cervical spine ofthe passenger during a vehicle rear end impact, while the controlled deformation of said crash zone absorbs energy, to prevent whiplash-related injuries to the passenger. 2. Apparatus in accordance with claim 1, wherein said second surface of said contour is smoothly joined to said first surface by a transition surface of said contour, which extends anteriorly at an obtuse angle from said first surface, and which is located to support the passenger's posterior area approximately where the cranium meets the cervical spine. 3. Apparatus in accordance with claim 1, wherein the said maximum protrusion point of said second surface projects anteriorly relative to said flat portion of said first surface a distance of 1 to 6 inches. 4. Apparatus in accordance with claim 3, wherein said maximum protrasion point is from 3 to 9 inches below said cranium contact zone. 5. Apparatus in accordance with claim 1 , further including a thoracic and lumbar spine support portion which are defined by downward extension of said support shell, resilient material and contour; whereby the thoracic and lumbar spine portion ofthe passenger are decelerated with the cranium and cervical spine during a said rear end impact. 6. Apparatus in accordance with claims 1 or 5, wherein the said crash zone comprises one or more air bladders, and valve means responsive to said impact to enable said one or more bladders to at least partially deflate upon vehicular impact. 7. Apparatus in accordance with claims 1 or 5, wherein said crash zone comprises an impact collapsible cellular structure. 8. Apparatus in accordance with claims 1 or 5, wherein said crush zone comprises an elastically deformable material which absorbs energy at a substantially more rapid rate than it releases same. 9. Apparatus in accordance with claims 1 or 5, wherein said crash zone is sandwiched between said shell and a spaced fixed, rigid plate. 10. Apparatus in accordance with claims 1 or 5, wherein said crash zone is spaced from the rear of said shell and contacted and compressed by an intermediate plate which is linked for displacement with said shell. 11. Apparatus in accordance with claims 1 or 5, wherein rearward displacement of said shell is resisted by restraining means adapted to collapse at a preset strain. 12. Apparatus in accordance with claims 1 or 5, further including sensor means for enabling a control signal upon a rear end impact of sufficient magnitude, and wherein rearward displacement of said shell or of a plate rigidly linked to said shell against said crash zone, is resisted by restraining means which are disabled by said control signal. 13. Apparatus in accordance with claim 6, wherein said shell is linked to one or more mechanical valve actuators, which open said valves upon a predetermined displacement of said shell.

Inventors: DELLANNO RONALD P, DELLANNO, RONALD, P.
Applicants: DELLANNO RONALD P, DELLANNO, RONALD, P.
Application year: 1996
Main classification: B60N2
IPC codes: B60N2