# US 2021/0276722 A1 · Hydraulic thrust vector yaw control for rocket catapult motor assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276722 A1 - Document ID: US20210276722A1 - Status: Published application - Kind: A1 - Application number: 16/892,972 - Filed: 2020-06-04 - Published: 2021-09-09 - Earliest claimed: 2019-07-12 - Assignees: AMI Industries, Inc. - Applicants: AMI Industries, Inc. - Inventors: Bradley Mastrolia - Web page: https://patentgrep.com/patent/US20210276722A1 ## CPC - B64D 25/10: Ejector seats - F02K 9/84: using movable nozzles - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) ## Abstract A motor cap assembly for an ejection seat may comprise a servo valve assembly, a reservoir a cylinder, a motor cap manifold housing comprising a monolithic body having an internal manifold structure integral to the body configured to communicate a gas between a pressure source and a gas block, and configured to communicate a hydraulic fluid between, the reservoir, the servo valve assembly, and the cylinder, a rack piston disposed within the cylinder and configured to translate axially therein between a base end and a head end of the cylinder, and a motor cap outer housing coupled circumferentially about the motor cap manifold housing, wherein the motor cap outer housing is configured to rotate circumferentially about the motor cap manifold housing in response to an axial translation of the rack piston. ## Claims ### Claim 1 A motor cap assembly, comprising: a servo valve assembly; a reservoir; a gas block; a motor cap manifold housing comprising a monolithic body having an internal manifold structure integral to the monolithic body configured to communicate a gas between a pressure source and the gas block; a rack piston disposed within a cylinder defined by the motor cap manifold housing, the rack piston being configured to translate axially between a base end and a head end of the cylinder, wherein the internal manifold structure of the motor cap manifold housing is configured to communicate a hydraulic fluid between, the reservoir, the servo valve assembly, and the cylinder; and a motor cap outer housing coupled circumferentially about the motor cap manifold housing, wherein the motor cap outer housing is configured to rotate circumferentially about the motor cap manifold housing in response to an axial translation of the rack piston. ### Claim 2 (depends on 1) The motor cap assembly of claim 1, wherein the gas block includes a gas nipple piston configured to translate within the gas block in response to a rotation of the motor cap outer housing. ### Claim 3 (depends on 2) The motor cap assembly of claim 2, wherein the motor cap outer housing comprises a gas tap selectively in fluid communication with the gas block via the gas nipple piston. ### Claim 4 (depends on 3) The motor cap assembly of claim 3, wherein the cylinder is integral to the motor cap manifold housing. ### Claim 5 (depends on 4) The motor cap assembly of claim 4, wherein the cylinder comprises a pinion window. ### Claim 6 (depends on 5) The motor cap assembly of claim 5, wherein the rack piston comprises a toothed rack coupled to a pinion gear via the pinion window. ### Claim 7 (depends on 6) The motor cap assembly of claim 6, wherein the pinion gear is operatively coupled to a drive ring gear. ### Claim 8 (depends on 7) The motor cap assembly of claim 7, wherein the drive ring gear is operatively coupled to a drive ring integral to the motor cap outer housing. ### Claim 9 (depends on 1) The motor cap assembly of claim 1, further comprising a tangible, non-transitory memory configured to communicate with a controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: determining, by the controller, a current yaw angle; determining, by the controller, a desired yaw angle; and controlling, by the controller, the motor cap manifold housing to a yaw command angle based on the desired yaw angle. ### Claim 10 An ejection seat, comprising: a seat pan; a seat back coupled to the seat pan; and a rocket catapult assembly coupled to the seat back, the rocket catapult assembly including: a motor assembly configured to generate a high pressure gas, a nozzle assembly coupled to the motor assembly and configured to receive the high pressure gas, and a motor cap assembly coupled to the motor assembly distal of the nozzle assembly and configured to receive the high pressure gas, the motor cap assembly comprising: a servo valve assembly, a reservoir; a gas block; a motor cap manifold housing comprising a monolithic body having an internal manifold structure integral to the monolithic body configured to communicate the high pressure gas between the motor assembly and the gas block; a rack piston disposed within a cylinder defined by the motor cap manifold housing, the rack piston being configured to translate axially within the cylinder, wherein the internal manifold structure of the motor cap manifold housing is configured to communicate a hydraulic fluid between, the reservoir, the servo valve assembly, and the cylinder; and a motor cap outer housing coupled circumferentially about the motor cap manifold housing, wherein the motor cap outer housing is configured to rotate circumferentially about the motor cap manifold housing in response to an axial translation of the rack piston. ### Claim 11 (depends on 10) The ejection seat of claim 10, wherein the gas block includes a gas nipple piston configured to translate within the gas block in response to a rotation of the motor cap outer housing. ### Claim 12 (depends on 11) The ejection seat of claim 11, wherein the motor cap outer housing comprises a gas tap selectively in fluid communication with the gas block via the gas nipple piston. ### Claim 13 (depends on 12) The ejection seat of claim 12, wherein the cylinder is integral to the motor cap manifold housing. ### Claim 14 (depends on 13) The ejection seat of claim 13, wherein the cylinder comprises a pinion window. ### Claim 15 (depends on 14) The ejection seat of claim 14, wherein the rack piston comprises a toothed rack coupled to a pinion gear via the pinion window. ### Claim 16 (depends on 15) The ejection seat of claim 15, wherein the pinion gear is operatively coupled to a drive ring gear. ### Claim 17 (depends on 16) The ejection seat of claim 16, wherein the drive ring gear is operatively coupled to a drive ring integral to the motor cap outer housing. ### Claim 18 (depends on 10) The ejection seat of claim 10, further comprising a tangible, non-transitory memory configured to communicate with a controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: determining, by the controller, a current yaw angle; determining, by the controller, a desired yaw angle; and controlling, by the controller, the motor cap manifold housing to a yaw command angle based on the desired yaw angle. ### Claim 19 An article of manufacture including a tangible, non-transitory computer-readable storage medium having instructions stored thereon that, in response to execution by a processor, cause the processor to perform operations comprising: transitioning, by the processor, a rocket catapult assembly from an inactive to an active state; retracting, by the processor, a gas nipple piston and breaking a fluid communication between a gas cylinder and a gas port; determining, by the processor, a current yaw angle based on a yaw rate signal; determining, by the processor, a desired yaw angle based on a first pressure signal; and controlling, by the processor, a motor cap assembly to a yaw command angle based on the desired yaw angle. ### Claim 20 (depends on 19) The article of manufacture of claim 19, wherein the operations further comprise: determining, by the processor, a thrust based on a second pressure signal; calculating, by the processor, a yaw moment based on a first gain function of the current yaw angle, the desired yaw angle, and a second gain function, wherein the second gain function is based on the yaw rate signal; and calculating, by the processor, the yaw command angle based on the thrust and the yaw moment.