FAQs: Inertia Report
The following excerpt comes from a report entitled "SHAKER™ Inertial Over Sweep Analysis", created by WST Inc. For a complete copy of the report please contact "info@wipershaker.com".
Test Descriptions
It's well known in automotive sectors that wiper arm/blade assemblies have been designed as so to deal with relatively large volumes of snow, and further, heavy metal winter (“booted”) blades have been in use on vehicles for over 50 years. Yet, other than spoilers mounted to wiper arms/blades, no other objects have ever really been attached to wiper arm/blade assemblies – until now with the innovative SHAKER™ Wiper De-icer Plus.
The purpose of the test performed was to determine, if mounting SHAKER™ units to both the driver's & passenger side wiper arms, would cause any detrimental effect on the wiper arm/blade/drive assembly in the form of what the industry calls “Over Sweep”. This Over Sweep would be viewed as the wiper arm/blade assembly travelling beyond its normal wear patterns of the windshield and thus possibly crossing over the “A-pillar” of the vehicle.
The test was performed as so to determine “worst case” conditions as can be seen in the test data section. To further extend the worst case scenario, the 10 year old test vehicle used, has already had various configurations of SHAKER™ units mounted and in use for more than 6 years, without any sign of failure or cause for concern, e.g., no measurable “backlash” in drive system or increased “over sweep” patterns.
Set-up
For the test, new wiper blades (offering the highest coefficient of friction) were utilised. The driver's side wiper arm was 22” long while its blade was 21” long. On the passenger side, the arm was 22” long while its blade was 20” long. The ambient temperature was 25 Celsius, with nil wind conditions.
The “No Friction” aspect was accomplished by elevating the wiper arm/blade assemblies via a free moving string system. This allowed the wiper blades to travel approximately 1” above the surface of the windshield and thus not permitting any drag coefficient of the blade against the windshield. SHAKER™ units were mounted to the driver's and passenger side wiper arms to create the largest possible inertia effect.
Figure 3.
Recorded Data
The recorded data for all the tests was operationally and visually measured. From a pass/fail perspective, the product must not cause the wiper blade assembly to extend over the a-pillar section of the vehicle at any time during the test. Specifically, to determine what extra travel (over sweep) occurs, if any, when SHAKER™ units are mounted to the driver & passenger side wiper arms.
Test Summary
|
Tests |
Conditions |
Recorded Data |
Results |
Completed |
Report Ref.# |
|
" A "
Continual Low Speed Wiper
|
Full Blade Contact With Dry Windshield, NO
SHAKERT INSTALLED.
|
The driver's blade maximum sweep was recorded as point " A " on the A-pillar side of the windshield. |
See "A" in Figure 3. |
April
2004 |
Rel.A003 |
|
"B"
Continual Low Speed Wiper
|
Full Blade Contact With Dry Windshield, WITH BOTH SHAKERT's INSTALLED,
but not operating. |
The drivers blade maximum sweep was recorded as point " B " on the A-pillar side of the windshield |
See "B" in Figure 3.
NOTE : B=A |
April
2004 |
Rel. A003 |
|
" C "
Continual Low Speed Wiper
|
Both Blades Elevated
(i.e, no friction)
WITH NO
SHAKERT INSTALLED. |
The drivers blade vertical sweep position was recorded as point " C " on the A-pillar side of the windshield |
See "C" in Figure 3. |
April
2004
|
Rel. A003 |
|
" D "
Continual Low Speed Wiper
|
Full Blade Contact With Dry Windshield,
WITH BOTH
SHAKERT's INSTALLED,
and operating.
|
Both units were activated while the blades were travelling across the windshield, which allowed the blades to "skip". The maximum sweep of the driver blade was recorded as point " D ". |
See "D" in Figure 3.
NOTE : D=C |
April
2004 |
Rel. A003 |
|
" E "
Continual Low Speed Wiper
|
Both Blades Elevated
(i.e., no friction)
WITH BOTH
SHAKERT's INSTALLED,
but not operating |
The drivers blade vertical sweep position was recorded as point " E " on the A-pillar side of the windshield |
See "E" in Figure 3.
NOTE : E=C |
April
2004
|
Rel. A003 |
|
" F "
Continual High Speed Wiper
|
Full Blade Contact With Dry Windshield
WITH NO
SHAKERT
INSTALLED
|
The driver's blade maximum sweep was recorded as point " F " on the A-pillar side of the windshield. |
See "F" in Figure 3. |
April
2004
|
Rel. A003 |
|
" G "
Continual High Speed Wiper
|
Full Blade Contact With Dry Windshield,
WITH BOTH SHAKERT's INSTALLED, but not operating |
The drivers blade maximum sweep was recorded as point " G " on the A-pillar side of the windshield |
See "G" in Figure 3.
NOTE : G=F |
April
2004
|
Rel. A003 |
|
" H"
Continual High Speed Wiper
|
Both Blades Elevated (i.e., no friction )
WITH BOTH
SHAKERT's INSTALLED,
but not operating |
The drivers blade vertical sweep position was recorded as point " H " on the A-pillar side of the windshield |
See "H" in Figure 3.
NOTE : H=C |
April
2004
|
Rel. A003 |
Conclusion
As can be seen in the Figure 3, The SHAKER™ caused no measurable difference related to any extra over sweep of the wiper arm/blade/drive assembly, as compared to when there were no SHAKER™ units mounted to the wiper arm/blade/drive assembly, i.e., “ H ”=” C ”. This is very important to understand, as one can easily assume that the system was designed for the worst case scenario of no friction situations, i.e., wiper arm/blades moving in the full vertical position and, the close to no friction scenario of severe wind lift and heavy rains. When the SHAKER™ units were installed in the no friction situation (“H”), the wiper arm/blade/drive assembly did not travel any further than the designed range (“C”). It should also be noted that there was no measurable backlash in the test vehicles' wiper drive system. This same vehicle has had SHAKER™ units in use for over 6 years.
These results are further reinforced by the Torque Analysis completed by CA Elliott Inc Design & Manufacturing Services, (“Effective Analysis of a SHAKER™ on a Wiper Arm/Blade/Linkage/Transmission Assembly”).
Based on the various data collected, Wiper Shaker Technology Inc. believes strongly that this product will operate well within a typical wiper assembly's operational parameters. Also, this high quality made product will improve safety by helping maintain good wiper blade capabilities during winter driving.
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