# US 2009/0260929 A1 · Electric Actuator Unit for a Vehicle Brake Assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0260929 A1 - Document ID: US20090260929A1 - Status: Published application - Kind: A1 - Application number: 12/084,277 - Filed: 2006-10-26 - Published: 2009-10-22 - Earliest claimed: 2005-10-31 - Assignees: Kelsey-Hayes Company - Inventors: Brian Boyle; David Kwierant; Ralf Leiter - Web page: https://patentgrep.com/patent/US20090260929A1 ## CPC - B60T 13/746: {and mechanical transmission of the braking action} - F16D 65/22: adapted for pressing members apart {, e.g. for drum brakes} - F16D 2121/24: using motors - F16D 2125/40: Screw-and-nut - F16D 2125/48: with parallel stationary axes, e.g. spur gears - F16D 2125/582: {Flexible element, e.g. spring, other than the main force generating element} - F16D 2125/68: Lever-link mechanisms, e.g. toggles with change of force ratio - F16D 2125/70: Rods - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract An improved structure for an electric actuator unit for use in a brake assembly. According to an embodiment, a drum brake assembly comprises a mounting flange having an abutment; a backing plate secured to the mounting flange, the backing plate having a pair of brake shoes supported thereon; and an electric actuator unit for actuating the drum brake assembly to selectively move the brake shoes between a braking and a non-braking position, the electric actuator unit including a motor, a gear-set operatively coupled to be driven by the motor, a spindle nut operatively coupled to be rotationally driven by the gear-set, a pull rod operatively coupled to be translatorily driven by the spindle nut, and a brake shoe actuation link assembly operatively coupled to be actuated by the pull rod to thereby move the brake shoes between the braking and non-braking positions, the pull rod being operatively coupled to the brake shoe actuation link assembly by a link, the link having a first end pivotally connected to the pull rod and a second end pivotally connected to a second member of the brake shoe actuation link assembly. ## Claims ### Claim 1 A drum brake assembly comprising: a mounting flange having an abutment; a backing plate secured to said mounting flange, said backing plate having a pair of brake shoes supported thereon; and an electric actuator unit for actuating the drum brake assembly to selectively move said brake shoes between a braking and a non-braking position, said electric actuator unit including a motor, a gear-set operatively coupled to be driven by said motor, a spindle nut operatively coupled to be rotationally driven by said gear-set, a pull rod operatively coupled to be translatorily driven by said spindle nut, and a brake shoe actuation link assembly operatively coupled to be actuated by said pull rod to thereby move said brake shoes between said braking and non-braking positions, said pull rod being operatively coupled to said brake shoe actuation link assembly by a link, said link having a first end pivotally connected to said pull rod and a second end pivotally connected to a second member of said brake shoe actuation link assembly. ### Claim 2 (depends on 1) The drum brake assembly of claim 1 wherein said drum brake assembly is a drum-in-hat disc brake assembly and said electric actuator unit is for actuating a parking and emergency brake of said drum-in-hat disc brake assembly. ### Claim 3 (depends on 1) The drum brake assembly of claim 1 further including a spring member operatively coupled to said pull rod for applying a follow up force to said pull rod when said brake shoes are in said braking position. ### Claim 4 (depends on 3) The drum brake assembly of claim 3 further including a cartridge housing, said cartridge housing adapted to carry said spring member, said spindle nut and said pull rod. ### Claim 5 (depends on 1) The drum brake assembly of claim 1 wherein said motor defines a first axis and said spindle nut and said pull rod defines a second axis which is parallel to said first axis. ### Claim 6 (depends on 1) The drum brake assembly of claim 1 wherein said motor defines a first axis, said spindle nut defines a second axis, and said pull rod defines a third axis, said first, second and third axes being parallel to one another. ### Claim 7 (depends on 1) The drum brake assembly of claim 1 wherein said second member of said brake shoe actuation link assembly is pivotally connected to a first member of said brake shoe actuation link assembly. ### Claim 8 (depends on 1) The drum brake assembly of claim 1 wherein one of said link and said second member includes a raised tab, the other one of said link and said second member includes a countersunk opening, and wherein said link is operatively coupled to said second member by deforming a portion of said raised tab into said countersunk opening. ### Claim 9 (depends on 1) The drum brake assembly of claim 1 wherein said pull rod includes an externally threaded portion and said spindle nut includes an internally threaded portion which meshes with said externally threaded portion of said pull rod whereby rotation of said spindle nut causes translatory movement of said pull rod. ### Claim 10 (depends on 1) The drum brake assembly of claim 1 wherein said pull rod includes an enlarged head, said spindle nut includes a shoulder, and wherein when said electric actuator unit is in said non-braking position said enlarged head of said pull rod engages said shoulder of said spindle nut. ### Claim 11 An electric actuator unit for a drum brake assembly comprising: an electric actuator unit for actuating the drum brake assembly to selectively move a pair of brake shoes of the drum brake assembly between a braking and a non-braking position, said electric actuator unit including a motor, a gear-set operatively coupled to be driven by said motor, a spindle nut operatively coupled to be rotationally driven by said gear-set, a pull rod operatively coupled to be translatorily driven by said spindle nut, and a brake shoe actuation link assembly operatively coupled to be actuated by said pull rod to thereby move the brake shoes between the braking and non-braking positions, said pull rod being operatively coupled to said brake shoe actuation link assembly by a link, said link having a first end pivotally connected to said pull rod and a second end pivotally connected to a second member of said brake shoe actuation link assembly. ### Claim 12 (depends on 11) The electric actuator unit of claim 11 wherein said drum brake assembly is a drum-in-hat disc brake assembly and said electric actuator unit is for actuating a parking and emergency brake of said drum-in-hat disc brake assembly. ### Claim 13 (depends on 11) The electric actuator unit of claim 11 further including a spring member operatively coupled to said pull rod for applying a follow up force to said pull rod when the brake shoes are in the braking position. ### Claim 14 (depends on 13) The electric actuator unit of claim 13 further including a cartridge housing, said cartridge housing adapted to carry said spring member, said spindle nut and said pull rod. ### Claim 15 (depends on 11) The electric actuator unit of claim 11 wherein said motor defines a first axis and said spindle nut and said pull rod defines a second axis which is parallel to said first axis. ### Claim 16 (depends on 11) The electric actuator unit of claim 11 wherein said motor defines a first axis, said spindle nut defines a second axis, and said pull rod defines a third axis, said first, second and third axes being parallel to one another. ### Claim 17 (depends on 11) The electric actuator unit of claim 11 wherein said second member of said brake shoe actuation link assembly is pivotally connected to a first member of said brake shoe actuation link assembly. ### Claim 18 (depends on 11) The electric actuator unit of claim 11 wherein one of said link and said second member includes a raised tab, the other one of said link and said second member includes a countersunk opening, and wherein said link is operatively coupled to said second member by deforming a portion of said raised tab into said countersunk opening. ### Claim 19 (depends on 11) The electric actuator unit of claim 11 wherein said pull rod includes an externally threaded portion and said spindle nut includes an internally threaded portion which meshes with said externally threaded portion of said pull rod whereby rotation of said spindle nut causes translatory movement of said pull rod. ### Claim 20 (depends on 11) The electric actuator unit of claim 11 wherein said pull rod includes an enlarged head, said spindle nut includes a shoulder, and wherein when said electric actuator unit is in said non-braking position said enlarged head of said pull rod engages said shoulder of said spindle nut.