VEHICLE WEIGHING MEANS

• US 3,854,540 A
• Filed: 08/03/1973
• Issued: 12/17/1974
• Est. Priority Date: 08/03/1973
• Status: Expired due to Term

• Current Assignee: Godfrey A. Holmstrom Jr
• Original Assignee: Godfrey A. Holmstrom Jr
• Inventors: Holmstrom, Godfrey A. Jr.
• Primary Examiner(s): Wilkinson, Richard B.
• Assistant Examiner(s): Miska, Vit W.
• Application Number:
  US05/385,288
• Time in Patent Office: 501 Days
• Field of Search: 177/136-139,210-211,208 73/141A
• US Class Current: 177/136
• CPC Class Codes: G01G 19/10 having fluid weight-sensitive devices
• CPC Class Codes: G01G 19/12 having electrical weight-sensitive devices
• CPC Class Codes: G01G 3/1404 combined with means to connect the strain gauges on electrical bridges
• CPC Class Codes: G01G 5/04 with means for measuring the pressure imposed by the load on a liquid pressure gauges per se G01L

Abstract

Means including strain gauges and transducers for accurately reflecting the weight carried by a fifth wheel mounted upon a tractor or the weight carried upon the axles of a vehicle using air bag suspension. The pressure generated in air bags is transmitted by transducer to an amplifier and then to a digital readout, normally located in the cab of the vehicle. To determine the weight upon the axle of the tractor, a load cell is mounted beneath the fifth wheel. Load is reflected by a deflection in the load cell, which is amplified and transmitted to the cab portion of the vehicle.

Claims

1. A fifth wheel weighing system for sensing the weight of a trailer transmitted to the fifth wheel of a tractor which comprises two load cels spaced apart and secured to the tractor, each load cell comprising transducer means including an elongated bending beam secured at its ends and adapted to deflect upon application of a downward load at the beam midsection, strain sensing means applied to said bending beam to provide electrical signals proportional to vertical loads applied to said beam midsection, and fifth wheel support means secured to and extending above said beam midsection;

a fifth wheel in load bearing contact with said fifth wheel support means;

connecting means securing said fifth wheel to the fifth wheel support means of each load cell such that said fifth wheel is able to shift position and remain in continuous load bearing contact with both fifth wheel support means such that vertical loads applied to said fifth wheel are transferred to the beam midsections through respective fifth wheel support means.

2. The system of claim 1 wherein each fifth wheel support means comprises a member secured to the respective beam midsection and provided with an arcuate exterior surface which rests in load bearing contact in a corresponding arcuate surface provided on said fifth wheel;

and wherein a pivot pin secures said fifth wheel to said member in a manner such that said pin is substantially free of vertical load forces applied to said fifth wheel.

3. The system of claim 1 wherein the trailer is carried on rear wheels by at least two air bag suspension means;

two pressure transducers secured to the trailer, one responsive to pressure changes in one air bag suspension means and the other responsive to pressure changes in the other air bag suspension means, each pressure transducer including a pressure-sensitive diaphragm, strain sensing means applied to said diaphragm to provide electrical signals proportional to pressures applied to said diaphragm;

amplifier means secured to the trailer combining the electrical signals from the two strain sensing means and providing a combined output;

weight readout means electrically coupled to said amplifier means and to the fifth wheel strain sensing means providing a visual indication of trailer weight applied to the air bag suspension means and to the fifth wheel.

4. A fifth wheel load cell for use in pairs for supporting a tractor fifth wheel to sense trailer weights transmitted to the tractor fifth wheel which comprises an elongated bending beam adapted to deflect upon application of a transverse load at the beam midsection, tractor mounting means to which the ends of said bending beam are secured, strain sensing means applied to said bending beam to provide electrical signals proportional to loads applied to said beam midsection, fifth wheel support means secured to and extending outward from said beam midsection and providing an exterior bearing surface for load bearing contact with the underside of a fifth wheel such that vertical loads applied to a fifth wheel are transferred directly to said beam midsection through said fifth wheel support means.

5. The load cell of claim 4 wherein said fifth wheel support means comprises a boss secured to the beam midsection and provided with an arcuate outer surface for load bearing contact with the underside of a fifth wheel.