US 2014/0190290 A1 · METHOD AND SYSTEM FOR TENSIONING PARK BRAKE CABLES

Abstract

A method of tensioning a park brake system of a vehicle includes providing an adjustment mechanism having a nut in threaded engagement with a rod that defines a signal to noise ratio therebetween. The nut is advanced on the rod to remove slack until torque applied to the nut indicates that the park cables include a tension equal to an offset tension level. The nut is then retracted on the rod to introduce slack into the park cables and reduce the tension in the park cables to a target slack tension level. A signal to noise ratio between the nut and the rod is improved so that the cable tension may be predicted by the torque required to turn the nut on the rod, thereby allowing a torque indicating tool to measure the tension in the park cables my measuring the torque required to turn the nut on the rod.

Claims20

Dependent claims

A method of tensioning a park brake system of a vehicle, the method comprising:

providing an adjustment mechanism having a threaded nut in threaded engagement with a threaded rod, wherein the threaded nut and the threaded rod define a signal to noise ratio therebetween that allows tension measurement of a plurality of park cables based upon a torque applied to the threaded nut;
measuring torque applied to the threaded nut, while advancing the threaded nut on the threaded rod to remove slack and tighten the plurality of park cables, with a torque indicating tool until the measured torque indicates that the plurality of park cables include a tension equal to an offset tension level;
and
retracting the threaded nut on the threaded rod to introduce slack into the park cables and reduce the tension in the park cables to a target tension level.

1 more element

A park cable system for a vehicle, the park cable system comprising:

an actuation lever;
a first cable having a first end and a second end;
and
an adjustment mechanism interconnecting the actuation lever and the first cable, wherein the adjustment mechanism includes:
an adjustment nut coupled to the actuation lever;
and
a rod coupled to the first end of the first cable and disposed in threaded engagement with the adjustment nut;
wherein advancing the adjustment nut on the rod decreases a length between the actuation lever and the second end of the first cable to increase a tension of the first cable, and wherein retracting the adjustment nut on the rod increases the length between the actuation lever and the second end of the first cable to decrease the tension of the first cable;
wherein the adjustment nut and the rod include a course thread form as defined under the Unified Thread Standard, such that advancing the adjustment nut along the rod defines a signal to noise ratio therebetween, as calculated by the Nominal-The-Best Type 1 method, that is equal to or greater than 25 dB with a standard deviation equal to or less than 75 Newtons, and allows tension measurement of the first cable based upon a torque applied to the adjustment nut, the signal to noise ratio being defined by the equation:
S
/
N
≅
10


Log

(
y
_
2
σ
n
-
1
2
)
wherein S/N is the signal to noise ratio, y is the mean of a plurality of cable tension values for a given torque input;
and σn-1 is the standard deviation of the plurality of cable tension values for the given torque input.

27 more elements

Dependencies are inferred from the claim text.

Method and system for tensioning park brake cables

Life of this patent

Method and system for tensioning park brake cables

Life of this patent

Abstract

Claims20