# US 11,440,640 B2 · Bi-directional no-back brake progressive modulation spring systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,640 B2 - Document ID: US11440640B2 - Status: Granted - Kind: B2 - Application number: 16/224,497 - Filed: 2018-12-18 - Published: 2020-06-18 - Granted: 2022-09-13 - Earliest claimed: 2018-12-18 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Kwan-Ho Bae; Mark J. Gardner; Jen-Shen Liu - Web page: https://patentgrep.com/patent/US11440640B2 ## CPC - B64C 13/32: using cam mechanisms - F16D 9/00: Couplings with safety member for disconnecting, e.g. breaking or melting member - B64C 13/28: mechanical - F16D 59/02: spring-loaded and adapted to be released by mechanical, fluid, or electromagnetic means - F16D 65/028: {Rollers} - F16D 2125/38: with plural cam or ball-ramp mechanisms arranged concentrically with the brake rotor axis - F16H 2035/005: {Gearings or mechanisms preventing back-driving} - B64C: AEROPLANES; HELICOPTERS - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F16H: GEARING ## Abstract Methods and systems according to one or more examples are provided for reducing chatter in a no-back brake during aiding load operations. In one example, an apparatus comprises a no-back brake, disposed within an actuator coupled to an aircraft, including a shaft, and a ball ramp plate, coupled to the shaft, to receive a force comprising an air loading force and is displaced responsive to the force. The apparatus further comprises a brake, coupled to the shaft and coupled to the ball ramp plate, and displaced by the ball ramp plate corresponding to a distance the ball ramp plate is displaced. The apparatus further comprises a modulating spring, coupled to the shaft and coupled to the brake, configured to compress in response to the brake being displaced, and the modulating spring is configured to apply a selective compressive force at the brake corresponding to a distance the brake is displaced. ## Claims ### Claim 1 An apparatus comprising: a no-back brake, disposed within an actuator coupled to an aircraft, comprising: a shaft; a ball ramp plate, coupled to the shaft, configured to receive a force comprising an air loading force and to be displaced responsive to the force; a brake, coupled to the shaft and coupled to the ball ramp plate, configured to be displaced, by the ball ramp plate, corresponding to a distance the ball ramp plate is displaced; and a modulating spring, coupled to the shaft and coupled to the brake, configured to compress in response to the brake being displaced, wherein the modulating spring is configured to apply a selective compressive force at the brake corresponding to a distance the brake is displaced, and wherein the modulating spring comprises: a first spring; a first cylindrical washer oriented adjacent to the first spring; a second spring oriented adjacent to the first cylindrical washer; and wherein the first spring and the second spring comprise a belleville spring. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the first spring and the second spring comprise a conical shape, wherein the conical shape of the first spring and the second spring are arranged in a same orientation facing the brake. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the belleville spring comprises a tapered surface, wherein the tapered surface comprises a first thickness at an inner diameter and a second thickness at an outer diameter, and wherein the first thickness is at least greater than the second thickness. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the belleville spring comprises a plurality of cutouts extending radially outward from an inner diameter to an outer diameter of the belleville spring. ### Claim 5 (depends on 1) The apparatus of claim 1, the modulating spring further comprises a second cylindrical washer oriented adjacent to the second spring, wherein the first cylindrical washer and the second cylindrical washer comprise a substantially flat cylindrical washer. ### Claim 6 (depends on 5) The apparatus of claim 5, further comprising a third spring oriented adjacent to the second cylindrical washer, wherein the third spring comprises a belleville spring, and wherein the first spring, the second spring, and the third spring are arranged in a same orientation facing the brake. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the first spring, the second spring, and the third spring comprise an alloy steel, a stainless steel, or an Inconel material. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the ball ramp plate is axially displaced by the force and configured to move the brake to compress the modulating spring. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the force comprises an aerodynamically induced air load corresponding to movement of a flap of the aircraft, and wherein the modulating spring reduces a chatter of the no-back brake associated with movement of the brake responsive to the force. ### Claim 10 A method comprising: receiving a force comprising an air load associated with a flap of an aircraft at a ball ramp plate of a no-back brake; displacing the ball ramp plate responsive to the force; displacing a brake, by the ball ramp plate, corresponding to a distance the ball ramp plate is displaced; compressing a modulating spring responsive to the brake being displaced; and applying a selective compressive force, by the modulating spring, at the brake corresponding to a distance the brake is displaced, and wherein the modulating spring comprises: a first spring; a first cylindrical washer oriented adjacent to the first spring; a second spring oriented adjacent to the first cylindrical washer; and wherein the first spring and the second spring comprise a belleville spring. ### Claim 11 (depends on 10) The method of claim 10, the method further comprising arranging a conical shape of the first spring and the second spring in a same orientation facing the brake. ### Claim 12 (depends on 10) The method of claim 10, wherein the belleville spring comprises a tapered surface, wherein the tapered surface comprises a first thickness at an inner diameter and a second thickness at an outer diameter, and wherein the first thickness is at least greater than the second thickness. ### Claim 13 (depends on 10) The method of claim 10, wherein the belleville spring comprises a plurality of cutouts extending radially outward from an inner diameter to an outer diameter of the belleville spring. ### Claim 14 (depends on 10) The method of claim 10, the modulating spring further comprises a second cylindrical washer oriented adjacent to the second spring, wherein the first cylindrical washer and the second cylindrical washer comprise a substantially flat cylindrical washer. ### Claim 15 (depends on 14) The method of claim 14, further comprising a third spring oriented adjacent to the second cylindrical washer, wherein the third spring comprises a belleville spring, the method further comprising arranging the first spring, the second spring, and the third spring in a same orientation facing the brake. ### Claim 16 (depends on 15) The method of claim 15, wherein the first spring, the second spring, and the third spring comprise an alloy steel, a stainless steel, or an Inconel material. ### Claim 17 (depends on 10) The method of claim 10, the method further comprising axially displacing the ball ramp plate by the force to move the brake to compress the modulating spring. ### Claim 18 (depends on 17) The method of claim 17, wherein the force comprises an aerodynamically induced load corresponding to movement of the flap of the aircraft, and wherein the modulating spring reduces a chatter of the no-back brake associated with movement of the brake responsive to the force.