Patent Application
20070278347
The present invention will be better understood from a reading of the following detailed description, taken in conjunction with the accompanying drawing figures in which like references designate like elements and, in which:
The drawing figures are intended to illustrate the general manner of construction and are not necessarily to scale. In the detailed description and in the drawing figures, specific illustrative examples are shown and herein described in detail. It should be understood, however, that the drawing the figures and detailed description are not intended to limit the invention to the particular form disclosed, but are merely illustrative and intended to teach one of ordinary skill how to make and/or use the invention claimed herein and for setting forth the best mode for carrying out the invention.
With reference to
With additional reference to
Torque from shaft 34 enters gearbox 36 via a flexible coupling 38 which allows for some misalignment between gearbox 36 and shaft 34. Gearbox 36 contains a number of gears that provide a moderate gear reduction between shaft 34 and lead screw 40. In the illustrative embodiment, the pitch of lead screw 40 is the same as the pitch of lead screws 22 and 24. Accordingly, gearbox 36 provides a gear reduction between 0.9 to 1 and 0.5 to 1 preferably about 0.7 to 1. Gearbox 36 also reverses the direction of rotation between shaft 34 and lead screw 40 for reasons that will be explained more fully hereinafter.
With further reference to
Ejection seat 10 further comprises a crewmember harness strap 48. Crewmember harness strap 48 attaches to the crewmember's flight harness at the shoulder level to restrain the crewmember during maneuvering and to pull the crewmember tightly into the seat back during an ejection. Crewmember harness strap 48 is paid in and out of a power operated reel 50. Because of the limited space available inside frame 12, power operated reel 50 cannot be mounted to the headrest bracket 44. Accordingly, to accommodate the movement of headrest bracket 44, crewmember harness strap 48 is fed from power operated reel over a rolling capstan 52 through a conventional harness pulley 54 across a stationary capstan 56 (or simply through a slot in headrest bracket 44) and terminating at a rigid connection 58 to headrest bracket 44 in a manner well known in the art.
As can be seen from the foregoing, in operation, as frame 12 is moved from its lowest position as shown in
Although certain illustrative embodiments and methods have been disclosed herein, it will be apparent from the foregoing disclosure to those skilled in the art that variations and modifications of such embodiments and methods may be made without departing from the spirit and scope of the invention. For example, although in the illustrative embodiment lead screw 40 has the same pitch as lead screws 22 and 24 but turns at 50% to 90% of the speed of lead screws 22 and 24 any combination of pitches and gear reductions that cause the headrest to move in an opposite direction from the seat frame at from 50% to 90% of the linear rate of the seat frame are considered within the scope of the invention. Accordingly, it is intended that the invention shall be limited only to the extent required by the appended claims and the rules and principals of applicable law.
