Waste bin scale, load cell and method of measuring a waste bin load

• US 9,562,801 B2
• Filed: 03/14/2014
• Issued: 02/07/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Larry D. Santi
• Original Assignee: Larry D. Santi
• Inventors: Santi, Larry D.
• Primary Examiner(s): Huls, Natalie
• Application Number:
  US14/213,758
• Publication Number:
  US 20140262552A1
• Time in Patent Office: 1,061 Days
• US Class Current: 1/1
• CPC Class Codes: G01G 19/083 lift truck scale
• CPC Class Codes: G01G 3/14 measuring variations of electrical resistance G01G3/13 takes precedence
• CPC Class Codes: G01L 1/22 using resistance strain gauges

Abstract

A waste bin scale to measure a cantilevered load carried by lift members of a lift system. The waste bin scale includes a base coupleable to the lift system, a lift member support system; and a plurality of load cells. Each load cell is coupled between the base and the lift member support system, and includes a structural member configured to deform during application of a load applied by the waste bin, where the deformation is indicative of the applied load. Other related waste bin scales, load cells therefor and methods of measuring waste bin scale loads are also provided.

Claims

1. A scale to measure a cantilevered load carried by lift members of a lift system, the scale comprising:

a base coupleable to the lift system;

a lift member support system; and

a plurality of load cells coupled between the base and the lift member support system, each load cell comprising;

an elongated, vertically oriented structural member having an elongated, vertically oriented aperture extending through an entirety of a width thereof which defines at least one pair of offset strain gauge mounting surfaces that are parallel to a horizontal reference plane; and

an arrangement of strain gauges to sense deformations at least at one or more locations on the at least one pair of offset strain gauge mounting surfaces,

wherein the elongated, vertically oriented structural member of each load cell further comprises a transverse base flange, the load cell being coupled to the base via the transverse base flange, and

wherein the elongated, vertically oriented structural member of each load cell further comprises a vertically extending dove tail structure, the load cell being coupled to the lift member support system via the vertically extending dove tail structure.

2. The scale of claim 1 wherein the lift system is a portion of a waste bin collection vehicle, and wherein the cantilevered load is a waste bin.

3. The scale of claim 1 wherein, for each load cell, the elongated, vertically oriented aperture defines an upper strain gauge mounting surface and a lower strain gauge mounting surface that are each parallel to the horizontal reference plane.

4. The scale of claim 1 wherein the elongated, vertically oriented aperture is U-shaped or I-shaped.

5. The scale of claim 1 wherein, for each load cell, the elongated, vertically oriented aperture defines at least one thin-walled structural portion adjacent to the elongated, vertically oriented aperture.

6. The scale of claim 1 wherein the structural member of each load cell includes at least one thin-walled structural portion with opposing surfaces that are generally parallel to the horizontal reference plane.

7. The scale of claim 1 wherein the structural member of each load cell includes a plurality of distinct apertures extending through a width therewith in series to define at least one thin-walled structural portion between the apertures.

8. The scale of claim 1 wherein the lift member support system includes a plurality of load cell cavities for insertably receiving the vertically extending dove tail structure of a respective one of the plurality of load cells.

9. The scale of claim 1 wherein the lift member support system bears on an upper surface of each load cell during operation.

10. The scale of claim 1 wherein the lift member support system is configured to support at least two lift members for lifting waste bins in a cantilevered manner.

11. The scale of claim 1, further comprising:

a protective skirt to assist in preventing debris from contacting the load cells during use.

12. The scale of claim 1, further comprising, for each load cell:

a first bridge arrangement of strain gauges including one pair of strain gauges mounted on one of the parallel offset mounting surfaces located at one of opposing ends of the load cell and including one pair of strain gauges mounted on one of the parallel offset mounting surfaces located at the other one of the opposing ends of the load cell; and

a second bridge arrangement of strain gauges including one pair of strain gauges mounted on one of the parallel offset mounting surfaces located at one of the opposing ends of the load cell and one pair of strain gauges mounted on one of the parallel offset mounting surfaces located at the other one of the opposing ends of the load cell.

13. The scale of claim 12 wherein the first bridge arrangement of strain gauges includes a first set of strain gauges located on one of parallel offset mounting surfaces at an upper end of the structural member and a second set of strain gauges located on one of parallel offset mounting surfaces at a lower end of the structural member, and wherein the second bridge arrangement of strain gauges includes a first set of strain gauges located on one of parallel offset mounting surfaces at the upper end of the structural member and a second set of strain gauges located on one of parallel offset mounting surfaces at the lower end of the structural member.

14. The scale of claim 13 wherein at least some of the strain gauges of the first bridge arrangement are positioned generally opposite of corresponding strain gauges of the second bridge arrangement.

15. The scale of claim 13 wherein the first set of strain gauges of the first bridge arrangement is located further away from the horizontal reference plane of the load cell than the first set of strain gauges of the second bridge arrangement, and wherein a spread of the first set of strain gauges of the first bridge arrangement is greater than a spread of the first set of strain gauges of the second bridge arrangement.

16. The scale of claim 15 wherein each of the first set of strain gauges of each of the first and the second bridge arrangements includes one strain gauge arranged to be placed in tension during use and one strain gauge arranged to be placed in compression during use.

17. The scale of claim 12 wherein the aperture defines an upper strain gauge mounting surface and a lower strain gauge mounting surface that each include a surface generally directed toward each other.

18. The scale of claim 12 wherein the structural member of each load cell includes a plurality of distinct apertures extending through a width therewith in series to define at least one thin-walled structural portion between the apertures.

19. The scale of claim 12 wherein the first bridge arrangement of strain gauges exhibits a signal increase when the load is positioned on forks with increasing distance from the load cell and the second bridge arrangement of strain gauges exhibits a signal decrease when the load is positioned on the forks with increasing distance from the load cell.

20. The scale of claim 19 wherein the arrangement of strain gauges is configured such that a magnitude of the signal increase exhibited by the first bridge arrangement when the load is positioned on the forks with increasing distance from the load cell is about equal to a magnitude of the corresponding signal decrease exhibited by the second bridge arrangement such that a summation of the magnitudes of the signals of the first and second bridge arrangements remains generally constant with changing position of the load along the forks.