SYSTEM AND METHOD FOR GAUGING SAFE TOWING PARAMETERS

• US 20130080078A1
• Filed: 09/28/2012
• Published: 03/28/2013
• Est. Priority Date: 09/28/2011
• Status: Active Grant

• Current Assignee: Firstex Industries, Inc.
• Original Assignee: Alvin Wirthlin
• Inventors: Wirthlin, Alvin R.
• Granted Patent: US 9,464,953 B2
• Time in Patent Office: Days
• US Class Current: 702/42
• CPC Class Codes: B60D 1/248 for measuring, indicating or displaying the weight
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: G01G 19/08 for incorporation in vehicles
• CPC Class Codes: G01L 1/2243 the supports being parallelogram-shaped
• CPC Class Codes: G01L 5/136 Force sensors associated with a vehicle traction coupling vehicle connections B60D; control of vehicle brakes B60T

Abstract

A system for determining the tongue weight of a towed vehicle and other parameters includes a drawbar transducer in one embodiment and a receiver hitch transducer in another embodiment. Strain gauges are strategically located on the transducer and information regarding the towed vehicle are sent to a display. In one embodiment, a portable display unit has a radio frequency transceiver for receiving transmitted data from the transducer reflective of the towed vehicle tongue weight so that a user can view the tongue weight in practically real time. In this manner, the user can adjust the contents of the towed vehicle to achieve proper tongue weight without the necessity of going back and forth between the trailer and the transducer. A method is also disclosed for determining a safe towing condition based on the trailer tongue weight, trailer pulling force, acceleration during towing, and calculated trailer weight.

Claims

1. A drawbar transducer for determining a tongue weight of a towed vehicle, the drawbar transducer comprising:

a coupling section being adapted for connection to a hitch ball for coupling with a trailer tongue;

a mounting section being adapted for connection to a hitch of a towing vehicle; and

a transducer section located between the coupling section and the mounting section, the transducer section including;

a measurement wall having a first thickness;

at least one sensor area formed in the measurement wall having a second thickness that is less than the first thickness; and

at least one strain sensor located in the senor area for sensing a load applied to the coupling section.

2. A drawbar transducer according to claim 1, wherein the transducer section further comprises:

a top wall; and

a bottom wall;

wherein the measurement wall comprises an upright measurement wall extending between the top and bottom walls.

3. A drawbar transducer according to claim 2, wherein the upright measurement wall is located centrally between the top wall and bottom wall.

4. A drawbar transducer according to claim 3, wherein the at least one sensor area comprises first and second sensor areas formed on opposite sides of the upright measurement wall.

5. A drawbar transducer according to claim 4, wherein the at least one strain sensor comprises first and second strain sensors located in the first and second sensor areas, respectively.

6. A drawbar transducer according to claim 5, wherein the first and second sensors extend in the same direction.

7. A drawbar transducer according to claim 5, wherein the first and second sensors extend in different directions.

8. A drawbar transducer according to claim 5, wherein the top wall, bottom wall, and upright measurement wall form first and second compartments.

9. A drawbar transducer according to claim 8, and further comprising:

an electronics section located in one of the compartments, the electronics section including a PCB with a processor operably connected to the first and second strain sensors for determining a load applied to the coupling section.

10. A drawbar transducer according to claim 9, wherein the electronics section further comprises a radio frequency transmitter or transceiver for transmitting data reflective of a load applied to the coupling section.

11. A system for determining the tongue weight of a towed vehicle comprising the drawbar transducer of claim 10, and further comprising:

a portable display unit comprising;

a radio frequency receiver or transceiver for receiving the transmitted data reflective of the applied load;

a second processor for processing the transmitted data; and

a display operably connected to the second processor for displaying information related to the tongue weight of a vehicle based on the transmitted data.

12. A system according to claim 11, wherein the portable display unit comprises a smartphone.

13. A drawbar transducer according to claim 1, and further comprising:

an electronics section operably associated with the measurement wall, the electronics section including a processor operably connected to the at least one strain sensor for determining a load applied to the coupling section.

14. A drawbar transducer according to claim 13, wherein the electronics section further comprises a radio frequency transmitter or transceiver for transmitting data reflective of a load applied to the coupling section.

15. A drawbar transducer according to claim 14, wherein the electronics section further comprises:

a GPS unit operably connected to the processor for determining a location and instantaneous velocity of the towed vehicle;

an accelerometer operably connected to the processor for determining forces on the coupling section related to acceleration and deceleration;

a tilt sensor operably connected to the processor for determining an angle of the towed vehicle;

the processor being operable to process data from the GPS unit, the accelerometer, and the tilt sensor to determine an operating condition of the towed vehicle.

16. A system for determining the tongue weight of a towed vehicle comprising the drawbar transducer of claim 14, and further comprising:

a portable display unit comprising;

a radio frequency receiver or transceiver for receiving the transmitted data reflective of the applied load;

a second processor for processing the transmitted data; and

a display operably connected to the second processor for displaying information related to the tongue weight of a vehicle based on the transmitted data.

18. A drawbar transducer according to claim 16, wherein the display is a remote display adapted for wireless connection to the transducer body for receiving data from the transducer body indicative of the applied load.

20. A drawbar transducer according to claim 18, wherein the upright measurement wall is located centrally between the top wall and bottom wall.

17. A system for determining the tongue weight of a towed vehicle, the system comprising:

A) a transducer body having;

i) a coupling section adapted for connection to a hitch ball for coupling with a trailer tongue;

ii) a mounting section being adapted for receipt into a receiver hitch of a towing vehicle; and

iii) a transducer section located between the coupling section and the mounting section, the transducer section including;

a) first and second compartments formed in opposite sides of the transducer body to form a measurement wall with a first thickness;

b) first and second sensor areas formed in opposite sides of the measurement wall in the first and second compartments, respectively, the measurement wall having a second thickness at the sensor areas that is less than the first thickness; and

c) at least one strain sensor located in at least one of the first and second senor areas for sensing a load applied to the coupling section; and

B) a display for displaying information related to the tongue weight of a towed vehicle based on the transmitted data.

19. A drawbar transducer according to claim 17, wherein the transducer section further comprises:

a top wall; and

a bottom wall;

wherein the measurement wall comprises an upright measurement wall extending between the top and bottom walls.

21. A receiver hitch system comprising:

a crossbar;

a mounting bracket connected at opposite ends of the crossbar for connecting the receiver hitch to a tow vehicle;

a receiver tube extending rearwardly from the crossbar, the receiver tube being adapted for connection to a drawbar to thereby couple a trailer to the tow vehicle;

a first strain sensor operably associated with the receiver hitch for measuring at least one of a trailer tongue weight and trailer pull force; and

a processor operably connected to the first strain sensor for calculating the at least one trailer tongue weight and trailer pull force.

22. A receiver hitch system according to claim 21, and further comprising a second strain sensor operably associated with the receiver hitch for measuring the other of the trailer tongue weight and trailer pull force, the second strain sensor being operably connected to the processor for calculating the other of the trailer tongue weight and trailer pull force, the second strain sensor.

23. A receiver hitch system according to claim 22, wherein the first sensor is connected to the receiver tube for measuring the trailer tongue weight and the second sensor is connected to the drawbar for measuring the trailer pull force.

24. A receiver hitch system according to claim 23, and further comprising an accelerometer operably associated with the processor for determining an acceleration of the tow vehicle.

25. A receiver hitch system according to claim 24, wherein the processor is programmed to calculate a weight of the trailer based on the determined acceleration and trailer pull force.

26. A receiver hitch system according to claim 25, wherein the processor is programmed to calculate a ratio of the trailer tongue weight to trailer weight and determine a safe towing condition when the calculated ratio falls within a predetermined ratio range.

32. A method according to claim 24, and further comprising determining a safe towing condition when a ratio of the tongue weight to the trailer weight is within a predetermined range.

27. A modular strain sensor assembly comprising:

a sensor mounting plate have a first face and a second face located on an opposite side of the sensor mounting plate;

a first recessed sensor area formed in the first face;

a second recessed sensor area formed in the second face opposite the first recessed sensor area to thereby create a center web therebetween;

a first strain gauge fixedly secured to the center web in the first recessed sensor area;

a second strain gauge fixedly secured to the center web in the second recessed sensor area;

wherein a first thickness between the first and second faces is greater than a second thickness of the center web such that shear stresses on the center web is greater than shear stresses on the first and second faces when a load is applied to the modular strain sensor assembly.

28. A receiver hitch system having at least at least one modular strain sensor assembly according to claim 27, and further comprising:

a crossbar;

a mounting bracket connected at opposite ends of the crossbar for connecting the receiver hitch to a tow vehicle;

a receiver tube extending rearwardly from the crossbar, the receiver tube being adapted for connection to a drawbar to thereby couple a trailer to the tow vehicle;

wherein the at least one modular strain sensor assembly is located on one of the receiver tube and crossbar for measuring one of a trailer pull force and a trailer tongue weight.

29. A receiver hitch system according to claim 28, and further comprising a second modular strain sensor assembly located on the other of the receiver tube and crossbar for measuring the other of the trailer pull force and trailer tongue weight.

30. A receiver hitch system according to claim 29, and further comprising a processor operably connected to the first and second modular strain sensor assemblies for calculating the trailer tongue weight and trailer pull force.

31. A method for determining a safe towing condition of a trailer with respect to a predetermined tow rating of a tow vehicle, the method comprising:

determining a tongue weight of the trailer;

pulling the trailer with the tow vehicle;

measuring acceleration and pull forces of the trailer during pulling;

determining the weight of the trailer by dividing the pull force by the acceleration multiplying the quotient by a gravitational acceleration.

33. A method according to claim 31, and further comprising:

monitoring the pull forces during trailer towing;

calculating an average drag coefficient based on the pull forces at constant velocity; and

signaling when a new drag coefficient is greater than a predetermined change in the average drag coefficient.