# US 10,865,738 B2 · Traveling finger lock for an actuator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,738 B2 - Document ID: US10865738B2 - Status: Granted - Kind: B2 - Application number: 16/286,981 - Filed: 2019-02-27 - Published: 2020-08-27 - Granted: 2020-12-15 - Earliest claimed: 2019-02-27 - Assignees: Woodward, Inc. - Applicants: Woodward, Inc. - Inventors: Joseph Thomas Kopecek - Web page: https://patentgrep.com/patent/US10865738B2 ## CPC - F02K 1/70: using thrust reverser flaps or doors mounted on the fan housing - F02K 1/763: {with actuating systems or actuating devices; Arrangement of actuators for thrust reversers} - F02K 1/766: {with blocking systems or locking devices; Arrangement of locking devices for thrust reversers} - F15B 15/26: Locking mechanisms - F15B 15/261: {using positive interengagement, e.g. balls and grooves, for locking in the end positions} - F16H 25/2454: {Brakes; Rotational locks} - 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) - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - F16H: GEARING ## Abstract The subject matter of this specification can be embodied in, among other things, a linear actuator lock apparatus, including a housing having an inner surface defining an axial cavity including a first housing portion where the axial cavity has a first lateral size, a second housing portion where the axial cavity has a second lateral size that is larger than the first lateral size, and a face from the first housing portion to the second housing portion, a piston configured for axial movement within the axial cavity, a lock finger affixed to and extending away from the piston, where a finger end is configured to contact the face when extended and fit within the first housing portion when retracted, and a sleeve configured to move between a position in which the lock finger is permitted to extend and a position configured to contact and retract the lock finger. ## Claims ### Claim 1 A linear actuator lock apparatus, comprising: a housing having an inner surface defining an axial cavity comprising: a first housing portion wherein the axial cavity has a first lateral size; a second housing portion wherein the axial cavity has a second lateral size that is larger than the first lateral size; and a face defined by the inner surface from the first housing portion to the second housing portion; a piston having a first piston end and a second piston end axially opposite the first piston end, wherein the piston is configured for axial movement within the axial cavity between a first piston position and a second piston position; a lock finger affixed to the first piston end at a first finger end and extending away from the piston to a second finger end, wherein the second finger end is configured to contact the face axially and contact the piston axially in an extended configuration and fit within the first housing portion in a retracted configuration; and a sleeve arranged within the second housing portion and configured to move axially within the second housing portion between a first sleeve position in which the lock finger is permitted to extend to the extended configuration and a second sleeve position configured to contact the lock finger and urge the lock finger to the retracted configuration. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the lock finger is configured to prevent movement of the piston toward the second piston position in the extended configuration, and permit movement of the piston toward the second piston position in the retracted configuration. ### Claim 3 (depends on 1) The apparatus of claim 1, further comprising a bias member configured to bias the lock finger away from the retracted configuration and toward the extended configuration. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the sleeve defines an axial bore, and the first piston end is configured to at least partly extend within the axial bore in the second sleeve position. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising a first seal arranged in sealing contact with the inner surface and an outer surface of the sleeve, and a second seal arranged in sealing contact with the inner surface and the outer surface of the sleeve, wherein a pressure chamber is defined by the inner surface, the face, the outer surface, the first seal, and the second seal. ### Claim 6 (depends on 1) The apparatus of claim 1, further comprising a bias member configured to urge the sleeve toward the first sleeve position. ### Claim 7 (depends on 1) The apparatus of claim 1, further comprising a pressure chamber at least partly defined by the inner surface, the piston, and a piston seal arranged in sealing contact with the piston and the inner surface. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the piston is configured to be urged from the first piston position toward the second piston position by fluid pressure provided within the pressure chamber. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the sleeve is configured to be urged from the first sleeve position toward the second sleeve position by fluid pressure provided within the pressure chamber. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the housing is configured to be affixed to an aircraft structure and the second piston end is configured to be affixed to a moveable aircraft component. ### Claim 11 A method of locking a linear actuator, the method comprising: urging axial movement of a piston within an axial cavity defined by an inner surface of a housing, away from a first piston position and toward a second piston position, wherein the piston has a first piston end and a second piston end axially opposite the first piston end; urging, by the piston, axial movement of a lock finger affixed to the first piston end at a first finger end and extending away from the piston to a second finger end in an extended configuration; contacting, by the second finger end, a face defined by the inner surface between a first housing portion wherein the axial cavity has a first lateral size to a second housing portion wherein the axial cavity has a second lateral size that is larger than the first lateral size; preventing, by the contacting, movement of the piston to the second piston position, the preventing comprising: contacting, by the second finger end, a second face defined by the piston; and transferring, by the second finger end, an axial force of the piston to the housing; urging movement of a sleeve axially from a first sleeve position to a second sleeve position within the axial cavity; contacting, by the sleeve, the lock finger; urging, by the sleeve, the lock finger from the extended configuration to a retracted configuration in which the lock finger fits within the first housing portion; and moving the piston to the second piston position. ### Claim 12 (depends on 11) The method of claim 11, further comprising applying fluid pressure to a pressure chamber that is at least partly defined by the inner surface, the piston, and a piston seal arranged in sealing contact with the piston and the inner surface. ### Claim 13 (depends on 11) The method of claim 11, further comprising urging movement of the sleeve by a spring bias. ### Claim 14 (depends on 11) The method of claim 11, further comprising: urging movement of the sleeve axially from the second sleeve position to the first sleeve position within the axial cavity; urging the piston away from the second piston position to the first piston position; passing the second finger end out of the first housing portion, past the face, into the second housing portion; and extending the lock finger away from the piston from the retracted configuration to the extended configuration. ### Claim 15 (depends on 14) The method of claim 14, further comprising extending, by a bias member, the lock finger away from the piston from the retracted configuration to the extended configuration. ### Claim 16 (depends on 14) The method of claim 14, further comprising applying fluid pressure to a pressure chamber defined by the inner surface, an outer surface of the sleeve, a first seal arranged in sealing contact with the inner surface and the outer surface of the sleeve, and a second seal arranged in sealing contact with the inner surface and the outer surface of the sleeve. ### Claim 17 (depends on 14) The method of claim 14, further comprising urging movement of the sleeve by a bias member configured to urge movement of the sleeve axially from the second sleeve position to the first sleeve position. ### Claim 18 A thrust reverser actuator system comprising: an airframe structure; a thrust reverser cowl configured to move relative to the airframe structure; a linear actuator configured to move the thrust reverser cowl relative to the airframe structure, and comprising: a housing having an inner surface defining an axial cavity comprising: a first housing portion wherein the axial cavity has a first lateral size; a second housing portion wherein the axial cavity has a second lateral size that is larger than the first lateral size; and a face defined by the inner surface from the first housing portion to the second housing portion; a piston having a first piston end and a second piston end axially opposite the first piston end, wherein the piston is configured for axial movement within the axial cavity between a first piston position and a second piston position; and a lock apparatus comprising: a lock finger affixed to the first piston end at a first finger end and extending away from the piston to a second finger end, wherein the second finger end is configured to contact the face axially and contact the piston axially in an extended configuration and fit within the first housing portion in a retracted configuration; and a sleeve arranged within the second housing portion and configured to move axially within the second housing portion between a first sleeve position in which the lock finger is permitted to extend to the extended configuration and a second sleeve position configured to contact the lock finger and urge the lock finger to the retracted configuration. ### Claim 19 (depends on 18) The system of claim 18, wherein the lock finger is configured to prevent movement of the piston toward the second piston position in the extended configuration, and permit movement of the piston toward the second piston position in the retracted configuration. ### Claim 20 (depends on 18) The system of claim 18, further comprising a pressure chamber at least partly defined by the inner surface, the piston, and a piston seal arranged in sealing contact with the piston and the inner surface, wherein the piston is configured to be urged from the first piston position toward the second piston position by fluid pressure provided within the pressure chamber.