The invention relates to rigging for actuator-controlled doors or linkages, and more particularly to a method of aligning rigging for actuator-controlled doors or linkages.
In some applications that have an actuator-controlled door, such as an inlet door for an inlet duct on aeronautical vehicles, adjustment of the inlet door is by way of a clevis and adjustment nut coupled to a door actuator to fair the door. The current adjustment procedure for such a door comprises sequentially adjusting the clevis and adjustment nut in the door open position and measuring the resulting fair in the closed position, repeating this sequence as necessary to achieve a desired fair of the door.
In the closed position, there are two factors that most affect the desired fair of the door. These two factors are door seal preload, which creates stress in the system, wherein generally lower stress is better; and door seal compression, which maintains a fire barrier, wherein generally more compression is better. These two factors result in opposing design points that create a narrow window of required door adjustment tolerance. The current adjustment procedure does not ensure the combination of required door seal preload and door seal compression due to dimension tolerance of the door components that combine to cause variation between the adjustment of the door in the open position and measurement of the fair in the closed position.
The invention generally comprises a method of adjusting a hinged linkage that has at least one linear actuator coupled to it, wherein one end of the actuator couples to the linkage and another end fastens to a stationary mounting by way of a rod with a threaded end that mates with a threaded aperture in a ferrule nut that has a threaded section passing through an aperture in the stationary mounting, comprising the steps of: extending the actuator to open the linkage; placing at least one elastic element with a desired force constant over the threaded section of the ferrule nut; threading an adjustment nut onto the threaded section of the ferrule nut with a desired gap between the adjustment nut and the stationary mounting; retracting the actuator to close the linkage; and rotating the adjustment nut and the ferrule nut together to compress the elastic element against the stationary mounting; extending the actuator to open the linkage; and rotating the adjustment nut to compress the elastic element against the stationary mounting.
At least one elastic element 30 fits over the threaded section ferrule nut threaded section 24. Each elastic element 30 may comprise a spring washer, such as a spring washer of the cupped “Belleville” or wave type, a helical compression spring, or even an elastomeric washer. A combination of different types of the elastic elements 30 is also feasible. Elastic elements 30 of the Belleville type are particularly convenient in that they may stack in a combination of alternate, same or mixed direction to get a decreased or increased resultant force constant. In any case, the force constant of the selected elastic element 30 or combination of elastic elements 30 should result in a force amounting to a desired level of force that corresponds to the desired preload for the linkage 4.
A flat washer 32 may optionally fit over the ferrule nut threaded section 24; followed by a ferrule nut adjustment nut 34 and a ferrule nut jam nut 36, both of which thread onto the ferrule nut threaded section 24 to securely hold the elastic elements 30 in place with a desired level of preload for the linkage 4. A rod jam nut 38 may thread onto the rod threaded end 20 to prevent rotation of the ferrule nut 18 on the rod 16.
The next step is to loosen the adjustment nut 34 and then “hand tighten” it against the flat washer 32, as shown in
The next step is to thread the ferrule nut jam nut 36 onto the ferrule nut threaded section 24 and tighten it against the adjustment nut 34, as shown in
The next step is to loosen and remove the ferrule nut jam nut 36, taking care to not rotate the ferrule nut 18, as shown in
Of course, if the elastic element 30 or elastic element 30 combination provides the desired degree of preload for the linkage 4 and no range of adjustment is necessary, it is possible to proceed directly from threading the ferrule nut adjustment nut 34 onto the ferrule nut threaded section 24 and tighten it against the flat washer 32 as shown in
The described embodiments of the invention are only some illustrative implementations of the invention wherein changes and substitutions of the various parts and arrangement thereof are within the scope of the invention as set forth in the attached claims.
Number | Name | Date | Kind |
---|---|---|---|
678680 | Nash | Jul 1901 | A |
4009765 | Leskovec et al. | Mar 1977 | A |
4735018 | Duncan et al. | Apr 1988 | A |
4925364 | Das | May 1990 | A |
4934203 | Bailey et al. | Jun 1990 | A |
20020112318 | Shin | Aug 2002 | A1 |
20050178224 | Czarnek | Aug 2005 | A1 |
Number | Date | Country | |
---|---|---|---|
20100205864 A1 | Aug 2010 | US |