Patents by Inventor Charles Dunlap
Charles Dunlap has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 12679497Abstract: Brake calipers and rotors for bicycles are described herein. An example brake caliper includes an outboard caliper portion to be disposed inboard of a frame of the bicycle. The outboard caliper portion includes an outboard caliper body and an outboard brake pad that is fixed relative to the outboard caliper body. The brake caliper also includes an inboard caliper portion coupled to the outboard caliper body. The inboard caliper portion is disposed inboard of the outboard caliper portion when the brake caliper is coupled to the bicycle. The inboard caliper portion includes an inboard caliper body and an inboard brake pad that is movable relative to the inboard caliper body.Type: GrantFiled: December 1, 2021Date of Patent: July 14, 2026Assignee: SRAM, LLCInventors: Sebastian Heyna, Henrik Braedt, Charles Dunlap
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Patent number: 12654794Abstract: Height adjustable seat posts for bicycles are described herein. An example seat post includes an upper tube and a lower tube are configured in a telescopic arrangement and moveable between at least a first position and a second position. The seat post includes an upper sealhead, a lower sealhead, a shaft coupled to the lower tube and extending through the lower sealhead and into the upper tube, and a piston in the upper tube and coupled to the shaft. The piston divides the upper tube into a first chamber between the piston and the upper sealhead and a second chamber between the piston and the lower sealhead. The seat post also includes a spacer in the second chamber between the piston and the lower sealhead to reduce a length of the height adjustable seat post in at least one of the first and second positions.Type: GrantFiled: December 12, 2023Date of Patent: June 16, 2026Assignee: SRAM, LLCInventors: Charles Dunlap, Robert Moore, Kevin Jasper, Christopher Golkiewicz, Jace Doan
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Publication number: 20260098745Abstract: A position detection device for a bicycle may include a bicycle component defining an interior and an exterior. A detectable element may be disposed in the interior of the bicycle component and movable relative to the bicycle component. At least one detecting element is disposed in the exterior of the bicycle component, the at least one detecting element operable to detect: a first position of the detectable element relative to the bicycle component, and a second position of the detectable element relative to the bicycle component, wherein the second position is different from the first position.Type: ApplicationFiled: September 29, 2025Publication date: April 9, 2026Applicant: SRAM, LLCInventors: R JOE SCHOOLCRAFT, SARAH BLAKESLEE, ALEX MCGEE, CHARLES DUNLAP
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Publication number: 20260070623Abstract: Height adjustable seat posts for bicycles are described herein. An example height adjustable seat post includes an upper tube and a lower tube configured in a telescopic arrangement. The height adjustable seat post also includes a shaft coupled to the lower tube and extending into the upper tube a piston assembly coupled to the shaft and disposed in the upper tube. The piston assembly includes a piston dividing the upper tube into a first chamber and a second chamber. The first and second chambers are filled with fluid. The piston assembly includes a valve operable between a closed state in which the fluid is blocked from flowing between the first and second chambers and an open state to enable the fluid to flow between the first and second chambers. The height adjustable seat post also includes a solenoid to control the valve.Type: ApplicationFiled: November 12, 2025Publication date: March 12, 2026Applicant: SRAM, LLCInventors: RAFER CHAMBERS, CHRISTOPHER ERIC GOLKIEWICZ, CHI HUI SU, DONALD FREDERICK COFFMAN, ALEX KYLE MCGEE, CHARLES DUNLAP
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Publication number: 20260001604Abstract: Air springs for bicycle components are described herein. An example air spring includes a tube, a first sealhead coupled to the tube, a second sealhead coupled to the tube such that a sealed pressure chamber is formed in the tube between the first and second sealheads, and a seal coupled to the second sealhead. The second sealhead and the tube are coupled along an axial interface locking length. The tube has a vent port. The seal is spaced from the vent port by a port seal gap that is less than the axial interface locking length such that as the second sealhead is being decoupled from the tube, the seal loses sealing contact with the inner surface to enable at least a portion of the sealed pressure chamber to be equalized with atmospheric air before the second sealhead is fully decoupled from the tube.Type: ApplicationFiled: June 18, 2025Publication date: January 1, 2026Applicant: SRAM, LLCInventor: CHARLES DUNLAP
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Publication number: 20260002570Abstract: A brake caliper includes a caliper housing having a first cavity. A sleeve is disposed in the first cavity. The sleeve is reciprocally slidable relative to the caliper housing along an axial direction. The sleeve includes a second cavity. A piston is disposed in the second cavity. The piston is reciprocally slidable relative to the sleeve along the axial direction. A first seal is disposed between the sleeve and the caliper housing. A second seal is disposed between the piston and the sleeve.Type: ApplicationFiled: June 27, 2024Publication date: January 1, 2026Applicant: SRAM, LLCInventors: CHARLES DUNLAP, BRIAN JORDAN, KEVIN WESLING
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Publication number: 20250368291Abstract: A steerer device for a two-wheeled vehicle is provided. The steerer device may generally include a steerer adaptable for handlebar control and rotatable about a steering axis, at least one fork leg assembly, the at least one fork leg assembly including a wheel mounting interface, and a crown connecting the steerer and the at least one fork leg assembly. At least one rotational stop may be fixed on the crown, the at least one rotational stop sized and shaped to limit rotation of the crown about the steering axis.Type: ApplicationFiled: May 27, 2025Publication date: December 4, 2025Applicant: SRAM, LLCInventors: MICHAEL MAXWELL, BRENT PACKER, CHARLES DUNLAP
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Publication number: 20250313299Abstract: Front forks for bicycles are described herein. An example front fork includes a leg including an upper tube and a lower tube. The upper tube and the lower tube are configured in a telescopic arrangement. The upper tube and the lower tube define an interior region that is sealed and contains a volume of air in the lower tube. The front fork also includes a valve coupled to the upper tube at or near a top end of the upper tube. A flow path is formed between the volume of air in the lower tube and the valve such that when the valve is opened, pressure in the lower tube is equalized with atmospheric pressure.Type: ApplicationFiled: March 27, 2025Publication date: October 9, 2025Applicant: SRAM, LLCInventors: CHARLES DUNLAP, TIMOTHY LYNCH, MICHAEL MAXWELL, ALEXANDER ROSENBERRY, JONATHAN WATT
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Publication number: 20250196955Abstract: A seat post assembly includes a first tube moveable along an axis between a first position and a second position and a second tube telescopically moveable along the axis relative to the first tube between a retracted position and an extended position. A positioning assembly configured to adjustably position the second tube relative to the first tube. An electric actuator is adapted to be automatically electrically connected to a power source when the first tube is moved from the first position to the second position, and automatically electrically disconnected from the power source when the first tube is moved from the second position to the first position. The electric actuator is movable to actuate the positioning assembly in response to an electrical current adapted to be transmitted from the power source when the first tube is in the first position to adjustably position the second tube relative to the first tube.Type: ApplicationFiled: March 6, 2025Publication date: June 19, 2025Applicant: SRAM, LLCInventors: BRIAN JORDAN, CHARLES DUNLAP, SAGE HAHN
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Publication number: 20250187687Abstract: Height adjustable seat posts for bicycles are described herein. An example seat post includes an upper tube and a lower tube are configured in a telescopic arrangement and moveable between at least a first position and a second position. The seat post includes an upper sealhead, a lower sealhead, a shaft coupled to the lower tube and extending through the lower sealhead and into the upper tube, and a piston in the upper tube and coupled to the shaft. The piston divides the upper tube into a first chamber between the piston and the upper sealhead and a second chamber between the piston and the lower sealhead. The seat post also includes a spacer in the second chamber between the piston and the lower sealhead to reduce a length of the height adjustable seat post in at least one of the first and second positions.Type: ApplicationFiled: December 12, 2023Publication date: June 12, 2025Applicant: SRAM, LLCInventors: CHARLES DUNLAP, ROBERT MOORE, KEVIN JASPER, CHRISTOPHER GOLKIEWICZ, JACE DOAN
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Patent number: 12291297Abstract: Height adjustable seat posts for bicycles are described herein. An example height adjustable seat post includes an upper tube and a lower tube configured in a telescopic arrangement. The height adjustable seat post also includes a shaft coupled to the lower tube and extending into the upper tube a piston assembly coupled to the shaft and disposed in the upper tube. The piston assembly includes a piston dividing the upper tube into a first chamber and a second chamber. The first and second chambers are filled with fluid. The piston assembly includes a valve operable between a closed state in which the fluid is blocked from flowing between the first and second chambers and an open state to enable the fluid to flow between the first and second chambers. The height adjustable seat post also includes a solenoid to control the valve.Type: GrantFiled: February 15, 2023Date of Patent: May 6, 2025Assignee: SRAM, LLCInventors: Rafer Chambers, Christopher Eric Golkiewicz, Chi Hui Su, Donald Frederick Coffman, Alex Kyle McGee, Charles Dunlap
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Patent number: 12286180Abstract: A seat post assembly for a bicycle includes a first tube having a first distal end and a second tube having a second distal end. A distance between the first distal end of the first tube and the second distal end of the second tube is at a maximum when the first tube is in a first position relative to the second tube. The seat post assembly also includes a first chamber and a second chamber that are fluidly coupleable. The first chamber is a positive fluid chamber, and the second chamber is a negative fluid chamber. The seat post assembly includes a fluid volume disposed in the first chamber and the second chamber. The fluid volume includes a compressible fluid. The first chamber is configured to act as a spring configured to bias the first tube towards the first position relative to the second tube.Type: GrantFiled: February 15, 2023Date of Patent: April 29, 2025Assignee: SRAM, LLCInventors: Rafer Chambers, Charles Dunlap
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Publication number: 20250128783Abstract: A control line router for a headset of a bicycle includes a barrier disposed between a component of the bicycle and a segment of a control line within a headtube of the bicycle.Type: ApplicationFiled: October 15, 2024Publication date: April 24, 2025Applicant: SRAM, LLCInventors: CHARLES DUNLAP, KEVIN WESLING
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Publication number: 20250115323Abstract: Height adjustable seat posts for bicycles are described herein. An example height adjustable seat post includes an upper tube and a lower tube configured in a telescopic arrangement. The height adjustable seat post also includes a shaft coupled to the lower tube and extending into the upper tube a piston assembly coupled to the shaft and disposed in the upper tube. The piston assembly includes a piston dividing the upper tube into a first chamber and a second chamber. The first and second chambers are filled with fluid. The piston assembly includes a valve operable between a closed state in which the fluid is blocked from flowing between the first and second chambers and an open state to enable the fluid to flow between the first and second chambers. The height adjustable seat post also includes a solenoid to control the valve.Type: ApplicationFiled: December 17, 2024Publication date: April 10, 2025Applicant: SRAM, LLCInventors: RAFER CHAMBERS, CHRISTOPHER ERIC GOLKIEWICZ, CHI HUI SU, DONALD FREDERICK COFFMAN, ALEX KYLE MCGEE, CHARLES DUNLAP
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Patent number: 12269547Abstract: A seat post assembly includes a first tube moveable along an axis between a first position and a second position and a second tube telescopically moveable along the axis relative to the first tube between a retracted position and an extended position. A positioning assembly configured to adjustably position the second tube relative to the first tube. An electric actuator is adapted to be automatically electrically connected to a power source when the first tube is moved from the first position to the second position, and automatically electrically disconnected from the power source when the first tube is moved from the second position to the first position. The electric actuator is movable to actuate the positioning assembly in response to an electrical current adapted to be transmitted from the power source when the first tube is in the first position to adjustably position the second tube relative to the first tube.Type: GrantFiled: November 21, 2022Date of Patent: April 8, 2025Assignee: SRAM, LLCInventors: Brian Jordan, Charles Dunlap, Sage Hahn
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Publication number: 20250083762Abstract: A seat post assembly for a bicycle includes a first tube having a first distal end, and a second tube having a second distal end. The first tube is movable relative to the second tube to establish a distance between the first distal end and the second distal end. The distance is at a maximum distance when the first tube is in a first position relative to the second tube. The seat post assembly includes a seal disposed within the second tube and connected to the first tube or the second tube. The seat post assembly includes a piston coupled to the seal when the first tube is in the first position. A position of the seal relative to the second distal end is adjustable, such that the first position of the first tube relative to the second tube is adjustable via the coupling between the piston and the seal.Type: ApplicationFiled: November 21, 2024Publication date: March 13, 2025Applicant: SRAM, LLCInventors: CHARLES DUNLAP, RAFER CHAMBERS
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Publication number: 20250074539Abstract: Brake mounts for bicycles are described herein. The brake mounts are for coupling a brake caliper to a bicycle. An example brake mount includes a bracket having a first side and a second side opposite the first side. The bracket has bores to receive fasteners to couple the brake caliper to the bracket. The brake mount includes a sleeve extending from the first side of the bracket. An opening extends through the sleeve and the bracket. The opening is to receive an axle of a hub assembly of the bicycle. The sleeve is to extend into an axle opening in a frame of the bicycle. A distal end of the sleeve is threaded. The brake mount also includes a nut to be threadably coupled to the distal end of the sleeve when the sleeve is inserted into the axle opening in the frame e.Type: ApplicationFiled: November 18, 2024Publication date: March 6, 2025Applicant: SRAM, LLCInventors: SEBASTIAN HEYNA, HENRIK BRAEDT, CHARLES DUNLAP
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Publication number: 20250042490Abstract: Height adjustable seat posts for bicycles are described herein. An example height adjustable seat post includes an upper tube and a lower tube configured in a telescopic arrangement. The height adjustable seat post includes a piston in the upper tube that divides the upper tube into a first chamber and a second chamber. The piston defines a fluid passageway between the first chamber and the second chamber. The height adjustable seat post also includes a plug in the fluid passageway. The plug is moveable in a linear direction between an open position to enable fluid flow through the fluid passageway and a closed position to block fluid flow through the fluid passageway. The height adjustable seat post further includes a motor and a cam assembly to convert rotational motion of the motor to linear movement of the plug.Type: ApplicationFiled: July 25, 2024Publication date: February 6, 2025Applicant: SRAM, LLCInventors: CHARLES DUNLAP, KOSTYANTYN KOZIY
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Patent number: 12187377Abstract: Brake mounts for bicycles are described herein. The brake mounts are for coupling a brake caliper to a bicycle. An example brake mount includes a bracket having a first side and a second side opposite the first side. The bracket has bores to receive fasteners to couple the brake caliper to the bracket. The brake mount includes a sleeve extending from the first side of the bracket. An opening extends through the sleeve and the bracket. The opening is to receive an axle of a hub assembly of the bicycle. The sleeve is to extend into an axle opening in a frame of the bicycle. A distal end of the sleeve is threaded. The brake mount also includes a nut to be threadably coupled to the distal end of the sleeve when the sleeve is inserted into the axle opening in the frame e.Type: GrantFiled: December 1, 2021Date of Patent: January 7, 2025Assignee: SRAM, LLCInventors: Sebastian Heyna, Henrik Braedt, Charles Dunlap
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Patent number: 12179870Abstract: A seat post assembly for a bicycle includes a first tube having a first distal end, and a second tube having a second distal end. The first tube is movable relative to the second tube to establish a distance between the first distal end and the second distal end. The distance is at a maximum distance when the first tube is in a first position relative to the second tube. The seat post assembly includes a seal disposed within the second tube and connected to the first tube or the second tube. The seat post assembly includes a piston coupled to the seal when the first tube is in the first position. A position of the seal relative to the second distal end is adjustable, such that the first position of the first tube relative to the second tube is adjustable via the coupling between the piston and the seal.Type: GrantFiled: February 14, 2023Date of Patent: December 31, 2024Assignee: SRAM, LLCInventors: Charles Dunlap, Rafer Chambers