US 5,180,038 AGranted

Electronically controlled parking brake system

AssigneeOrscheln Co.

InventorsJames H. Arnold, Randal J. Perisho, Michael D. DeWitt, Wayne L. Soucie

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Abstract

An electronically controlled parking brake system for a vehicle including a housing connected with the vehicle chassis, a movable member adapted for connection with the parking brake cable of the vehicle, a main spring biasing the movable member toward a brake-applied position relative to the housing, an electric motor operable to displace the movable member toward a brake-released position relative to the housing, a retaining device normally retaining the movable member in the brake-released position, and a release device for releasing the retaining device, whereby the movable member is released for displacement by the main spring toward the brake-applied position. Preferably, the retaining device includes a helical clutch spring mounted concentrically on a rotatable drive screw that drives the movable member in the brake-released direction, and the release device includes a solenoid for releasing the clutch spring.

An electronically controlled parking brake system for tensioning the parking brake cable of a vehicle, comprising:

(a) a housing (2) adapted for connection with the vehicle, said housing containing a longitudinally extending chamber;
(b) a movable member (8) mounted for longitudinal movement within said chamber, said movable member being adapted for connection at one end with the parking brake cable;
(c) main spring means (30) normally biasing said movable member in one direction relative to said housing toward a brake-engaged position;
(d) drive means including an electric motor (50) for driving said movable member in the opposite direction relative to said housing toward a brake-released position, said drive means including;
(1) a drive screw (36) longitudinally arranged within the chamber of, and rotatably connected with, said housing;
(2) a drive nut (42) threadably mounted on said drive screw;
and
(3) means (42a) connecting said drive nut with said movable member;
(e) retaining means (70) normally retaining said movable member in said brake-released position, said retaining means including a helical clutch spring (70) mounted concentrically about, and having turns normally biased radially inwardly into engagement with the outer periphery of, said drive screw, said clutch spring being arranged to permit rotation of said drive screw in the brake-releasing direction, but to prevent rotation of said drive screw in the opposite direction, said clutch spring having at each end a radially outwardly extending leg portion a first one of which is connected with said housing;
and
(f) release means for (74) releasing said retaining means, said release means being operable to displace the other of said spring leg portions relative to said first leg portion in a direction to expand said clutch spring turns, thereby to release said drive screw relative to said housing and to permit said main spring means to return said movable member to its brake applied position.

8 more elements

Abstract

Claims10