Dynamic headrest

Abstract

A dynamic headrest having a capabilities to move forwardly during an accident or other suitable condition so as to limit injuries to an occupant's head. The headrest optionally including an actuator configured to move the headrest forwardly in respond to rotary motion of a rotary member.

1 . A dynamic headrest for use with a vehicle seat having an occupant, the headrest comprising:
 a moveable shell configured to support a head of the occupant;   an actuator configured to move the shell forwardly, the actuator having a rotary motion resulting in linear displacement of the shell;   wherein the actuator includes a rotary member configured to rotate about a central axis in order to provide the rotary motion and a cam follower configured to move forwardly away from the central axis against a front face of the shell in order to impart the linear displacement; and   wherein the rotary member includes a cam configured to rotate about an end of the cam follower such that the rotary motion of the cam causes the cam to engage the cam follower in such as manner as to impart the linear displacement to the shell.   
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . The headrest of  claim 1  wherein the cam follower is fixed to the shell and the rotary member is fixed to a headrest support post. 
     
     
         5 . The headrest of  claim 4  wherein the cam follower is not fixed to the rotary member. 
     
     
         6 . The headrest of  claim 1  wherein the rotary member includes a spring configured to rotate about the central axis, the spring having a locked and unlocked state, the locked state corresponding with kinetic energy of the spring being stored and the unlocked state corresponding with kinetic energy of the spring being released, the cam configure to rotate with actuation of the spring from the locked to unlocked state. 
     
     
         7 . The headrest of  claim 6  wherein the rotary member is configured to reload the spring to the locked state in response to rearward movement of the shell. 
     
     
         8 . The headrest of  claim 1  further comprising a support post to support the shell, the shell moving forwardly along a portion of the support post during the linear displacement. 
     
     
         9 . The headrest of  claim 1  wherein the actuator includes a guide operable with the shell to guide movement of the shell. 
     
     
         10 . The headrest of  claim 1  further comprising a locking mechanism configured to prevent rearward movement of the headrest. 
     
     
         11 . A resettable headrest system comprising:
 a moveable shell configured to support a head of the occupant;   an actuator having a spring rotationally wound about an axis, the actuator configured to release the wound spring such that the spring rotationally unwinds about the axis in order to provide force for automatically moving the shell forwardly, the actuator being resettable with rearward movement of the shell to rewind the spring about the axis for subsequent use in providing force for automatically moving the shell forwardly; and   wherein the shell includes guides that slide along headrest support posts when the actuator moves the shell forwardly, the headrest support posts connecting the headrest to a seat back.   
     
     
         12 . The headrest of  claim 11  wherein the actuator includes a rotary member configured to rotate about a central axis in order to provide rotary motion and a cam follower configured to move forwardly away from the central axis against a front face of the shell. 
     
     
         13 . The headrest of  claim 12  wherein the rotary member includes a cam having a cam portion shaped to rotate about an end of the cam follower such that the rotary motion of the cam causes the cam portion to engage the cam follower in such as manner as to impart linear displacement to the shell. 
     
     
         14 . The headrest of  claim 13  wherein the cam follower is fixed to the shell and the rotary member is fixed to a headrest support post. 
     
     
         15 . (canceled) 
     
     
         16 . The headrest of  claim 11  further comprising a locking mechanism must be unlocked to permit rearward movement of the headrest. 
     
     
         17 . A dynamic headrest for use with a vehicle seat having a controller configured to anticipate an impending accident and to issue a signal in response thereto, the headrest comprising:
 a moveable shell configured to support a head of an occupant;   an actuator configured to move the shell forwardly upon receipt of the signal   wherein the actuator includes a number of gears configured to cooperate with a lever that engages the gears to prevent occupant impact from moving the shell rewardly   an element connected to the lever and extending beyond the headrest, the element being retractable to disengage the lever from the teeth.   
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . The headrest of  claim 17  wherein the actuator is configured to reload the spring if the lever is lifted and the shell is moved rearwardly. 
     
     
         21 . (canceled) 
     
     
         22 . The headrest of  claim 17  wherein the lever successively changes from one gear to the next as the actuator moves the shell forwardly. 
     
     
         23 . The headrest of  claim 17  wherein the actuator includes a rotary actuated spring to move the shell forwardly. 
     
     
         24 . The headrest of  claim 23  wherein the actuator is configured such that rotary motion of the spring moves the headrest linearly. 
     
     
         25 . The headrest of  claim 17  wherein the actuator includes a torsion spring to move the shell. 
     
     
         26 . The headrest of  claim 11  wherein the guides slide along a portion of the headrest support posts that is bent at an angle relative to a downwardly extending portion of the headrest support post that connects to the seat back.