1. A snow plow having an adjustable vehicle mounting assembly, the snow plow comprising a main plow body comprising a moldboard having a plowing face and a pushing face opposed to the plowing face, the adjustable vehicle mounting assembly comprising:
two support frames carried by the pushing face of the moldboard, the support frames being longitudinally spaced from one another;
at least one guide shaft carried by each support frame;
the at least one guide shaft being substantially fixed relative to the support frames and the pushing face of the moldboard; and
two vehicle receivers securable to a plowing vehicle, each vehicle receiver being slidably received on a corresponding at least one guide shaft and adapted for non-rotating, parallel linear movement along the respective guide shafts toward and away from a surface-engaging edge of the snow plow within a limited range of motion.
2. The snow plow of claim 1, wherein each support frame carries a single guide shaft of polygonal cross-section and the vehicle receiver includes a corresponding sleeve in which the guide shaft is received.
3. The snow plow of claim 1, wherein each support frame carries at least two spaced-apart guide shafts and the vehicle receiver includes at least one guide bar having corresponding spaced-apart guide apertures in which the guide shafts are received.
4. The snow plow of claim 2, wherein:
each support frame comprises a pair of opposed, spaced-apart mounting plates;
each guide shaft is disposed between a respective pair of mounting plates;
each guide shaft is secured by mounting rods extending through opposed mounting apertures defined at opposite ends of the respective mounting plates and through correspondingly positioned shaft apertures defined through the guide shaft at opposite ends of the guide shaft.
5. The snow plow of claim 4, wherein the mounting rods are removable and replaceable to permit removal of the guide shafts to enable the vehicle receivers to be replaced with different vehicle receivers.
6. The snow plow of claim 3, wherein:
each support frame comprises a pair of opposed, spaced-apart mounting plates;
each pair of spaced-apart mounting plates being secured to one another by a pair of parallel, spaced-apart crossbars extending between the mounting plates;
the crossbars having mounting apertures defined therein, with the mounting apertures in each crossbar being in registration with the mounting apertures in the other crossbar in the pair of crossbars;
the guide shafts being mounted in the mounting apertures in the crossbars;
the guide shafts being secured in position by locking pins that are friction fit into rod apertures at one end of each guide shaft and by locating rings secured to apertures at the opposite end of each guide shaft.
7. The snow plow of claim 6, wherein the locking pins are removable and replaceable to permit removal of the guide shafts to enable the vehicle receivers to be replaced with different vehicle receivers.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of analyzing variations in an indicator of the behavior of a mechanism, the method being characterized in that it comprises the following operations:
extracting noise and any discontinuities from the indicator in order to obtain a trend;
comparing variations in the trend with one or more reference values;
indicating a fault of the mechanism as a function of the result of the comparison;
wherein, in order to extract any discontinuities, the following operations are also performed:
searching for and subtracting out any outlier data in the indicator data; and
extracting any edge data from the data obtained from said searching operation.
2. A method according to claim 1, in which, in order to find the times of the outlier data:
a moving median value of the indicator data is subtracted from the indicator data in order to obtain noisy data; and
the time is identified for which the ratio of the amplitude of the noisy data to the indicator data level is greater than a threshold.
3. A method according to claim 1, in which, in order to identify the presence of an edge in the data, variations in the scale coefficients corresponding to a wavelet transform of variations in the data are analyzed.
4. A method according to claim 3, in which a potential edge is identified in the data when the ratio bp of a mean of the sale coefficients to the standard deviation of the variations of these coefficients, exceeds a first determined value tp, and when the ratio bm of said mean of the scale coefficients to the level of the data exceeds a second determined value tm.
5. A method according to claim 1, in which, the following operations are also performed:
calculating the level of the noise;
comparing variations in the level of the noise with one or more reference values; and
indicating a fault of the mechanism as a function of the results of the comparison performed in operation.
6. A method according to claim 5, in which, in order to compare variations in the noise level with reference values, the following operations are performed:
calculating scale variation data of a wavelet transform of the noise level variations; and
comparing the scale variation data of the wavelet transform of the noise level with the reference values.
7. A method according to claim 3, in which use is made of the Haar wavelet and of the scale function associated with the Haar wavelet.
8. A method according to claim 1, in which, when an edge is detected, the time of the edge is compared with historical data concerning maintenance of the mechanism.
9. A method according to claim 1, in which the amplitude of the data is compared with at least one third reference value.
10. A method according to claim 4, in which a fault of the mechanism is diagnosed as a function of the results of the comparisons.
11. A method according to claim 1, further including the following successive prior operations:
normalizing variations of the indicator with reference to simultaneous variations of an operating parameter of the mechanism; and
then, in a training stage, determining reference values or thresholds for the rate of variation of at least one component of the indicator from the variations of the indicator during a period of operation without any fault of the mechanism.
12. A method according to claim 11, in which the normalization operation includes parametric modeling of the indicator or of measurements from the indicator is extracted.
13. A method according to claim 11, in which the normalization operation comprises filtering indication variation data.
14. A method according to claim 1, in which the mechanism is a rotorcraft transmission mechanism, the indicator is derived from vibration measurements performed on the rotorcraft in flight, and the operating parameter is the air speed of the rotorcraft.
15. A method according to claim 1, in which, in order to compare the trend variations with reference values, the following operations are performed:
calculating scale variation data of a wavelet transform of the trend data; and
comparing the scale variation data of the wavelet transform of the trend data with reference values.
16. Apparatus for diagnosing a mechanism as a function of data generated from vibration measurements performed on the mechanism, the apparatus being characterized in that it is programmed to perform the operations of a method comprising the following operations:
extracting noise and any discontinuities from the indicator in order to obtain a trend;
comparing variations in the trend with one or more reference values;
indicating a fault of the mechanism as a function of the result of the comparison;
wherein, in order to extract any discontinuities, the following operations are also performed:
searching for and subtracting out any outlier data in the indicator data; and
extracting any edge data from the data obtained from said searching operation.