Load cell that is symmetrical about a central vertical axis

• US 9,709,436 B2
• Filed: 03/15/2013
• Issued: 07/18/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Johnson, Thomas H.
• Primary Examiner(s): Gibson, Randy
• Application Number:
  US13/839,664
• Publication Number:
  US 20140262557A1
• Time in Patent Office: 1,586 Days
• Field of Search: 177211, 177229, 177238-244, 177DIG 9
• CPC Class Codes: G01G 21/08 Bearing mountings or adjusting means therefor
• CPC Class Codes: G01G 23/002 Means for correcting for obliquity of mounting for pendulum-weight apparatus G01G1/16
• CPC Class Codes: G01G 23/005 Means for preventing overload
• CPC Class Codes: G01G 3/14 measuring variations of electrical resistance G01G3/13 takes precedence
• CPC Class Codes: G01G 3/1412 the supports being parallelogram shaped

Abstract

The invention relates to a load cell symmetrical about a central vertical axis and comprising first and second mounting surfaces, each on the same horizontal plane and configured for attachment to a support structure and to a loading fixture respectively.

Claims

1. A load cell assembly comprising only one load cell symmetrical about a central vertical axis and comprising first and second mounting surfaces each on the same horizontal plane;

and

a plurality of load cell attachment brackets coupled to the load cell at the first and second mounting surfaces, wherein the load cell attachment brackets are configured for attachment to a support structure and to a loading fixture, wherein at least one of;

the plurality of load cell attachment brackets are arrayed one above the other, and the plurality of load cell attachment brackets are arranged above the only one load cell;

or

the plurality of load cell attachment brackets have a longitudinal axis extending in a same direction as the only one load cell.

20. A load cell assembly according to claim 1 wherein the load cell comprises mounting fixtures.

21. A load cell assembly according to claim 20 wherein the load cell comprises at least one mounting fixture in each of the first and the second mounting surfaces.

22. A load cell assembly according to claim 20 wherein the mounting fixtures are symmetrical about the central vertical axis of the load cell.

23. A load cell assembly according to claim 20 wherein a pair of mounting fixtures is located in each of the first and the second mounting surfaces.

24. A weigh scale comprising a load cell assembly according to claim 1, wherein each of the load cell attachment brackets are identical.

25. A weigh scale comprising a load cell assembly according to claim 1, wherein each of the load cell attachment brackets extend, with respect to a longitudinal axis of the load cell and with respect to a direction normal to the longitudinal direction of the load cell, beyond the outer periphery of the load cell.

26. A weigh scale comprising a load cell assembly according to claim 1, wherein respective load limiting elements are located in respective alignment apertures extending from a first of the load cell attachment brackets to a second of the load cell attachment brackets.

28. A load cell assembly according to claim 1 wherein the plurality of load cell attachment brackets have a longitudinal axis extending in the same direction as the only one load cell.

29. A load cell assembly according to claim 1 wherein the plurality of load cell attachment brackets have a foot print that extends beyond all sides of the only one load cell when viewed from a direction where the load cell attachment brackets are interposed between the load cell.

2. A weigh scale comprising a load cell symmetrical about a central vertical axis and comprising first and second mounting surfaces, each on the same horizontal plane and configured for attachment to a support structure and to a loading fixture respectively, the load cell coupled to a load cell attachment bracket assembly comprising a pair of load cell attachment brackets each having mounting elements, wherein each of the load cell attachment brackets extend, with respect to a longitudinal axis of the load cell, from the first mounting surface to beyond the second mounting surface.

27. A weigh scale according to claim 2, wherein each of the load cell attachment brackets of the pair are identical.

3. A load cell assembly comprising a load cell symmetrical about a central vertical axis and comprising first and second mounting surfaces each on the same horizontal plane;

and

a plurality of load cell attachment brackets coupled to the load cell at the first and second mounting surfaces, wherein the load cell attachment brackets are configured for attachment to a support structure and to a loading fixture, wherein

the plurality of load cell attachment brackets are arrayed one above the other, and the plurality of load cell attachment brackets are arranged above the load cell.

4. A load cell assembly according to claim 3 wherein the mounting surfaces are located at opposing ends of the load cell and are equidistant the central vertical axis.

5. A load cell assembly according to claim 3 wherein the mounting surfaces are located at opposing ends of the load cell and are equidistant the central vertical axis and are symmetrical thereabout.

6. A load cell assembly according to claim 3 wherein the load cell is formed of a block of material.

7. A load cell assembly according to claim 3 wherein the load cell comprises one or more apertures therein.

8. A load cell assembly according to claim 3 wherein the load cell comprises a first loading member and a second loading member coupled together and capable of relative vertical deflection with respect to one another.

9. A load cell assembly according to claim 8 wherein the first and second mounting surfaces are located in the same horizontal plane on the first and second loading members respectively.

10. A load cell assembly according to claim 8 wherein a first flexure element and a second flexure element are each coupled to the first and the second loading member and are arranged to deform in response to the relative deflection between the first and the second loading members.

11. A load cell assembly according to claim 10 wherein the first flexure element and the second flexure element are capable of symmetric deformation as a result of shear forces perpendicular to the mounting surfaces of the load cell in response to the relative vertical deflection between the first and the second loading members.

12. A load cell assembly according to claim 3 wherein the load cell comprises one or more force responsive elements.

13. A load cell assembly according to claim 12 wherein the force responsive element is engagable with a suitable measuring device operable to detect and measure the effect of shear force perpendicular to the mounting surfaces of the load cell resulting from the shear forces and/or differential bending moments attributable to a load applied to the load cell.

14. A load cell assembly according to claim 3 wherein the load cell comprises one or more strain responsive elements.

15. A load cell assembly according to claim 14 wherein the strain responsive element is engagable with a suitable measuring device operable to detect and measure the effect of shear force perpendicular to the mounting surfaces of the load cell resulting from the shear forces and/or differential bending moments attributable to a load applied to the load cell.

16. A load cell assembly according to claim 15 wherein the strain responsive element is a structural member for mounting a displacement transducer.

17. A load cell assembly according to claim 14 wherein the strain responsive elements are strain gauges that are affixed to the load cell.

18. A load cell assembly according to claim 10 wherein strain gauges are affixed to the inner surface of the first and the second flexure element respectively.

19. A load cell assembly according to claim 14 wherein the strain responsive elements are strain gauge(s) located such that, in use, the load cell is operable to detect a load caused by shear forces or differential bending moments applied to the load cell by detecting the shear force perpendicular to the mounting surfaces.

30. A load cell assembly according to claim 3 wherein the plurality of load cell attachment brackets have a longitudinal axis extending in a same direction as the load cell.

31. A weigh scale including a load cell assembly according to claim 3, wherein the weigh scale is a bench scale.

32. The load cell assembly of claim 3, wherein the load cell includes a first through passage extending from a first side of the load cell to a second side of the load cell, the second side of the load cell opposite the first side of the load cell, and a second through passage extending from a third side of the load cell to a fourth side of the load cell, the fourth side opposite the second side, wherein the first and second through passages extend in a direction normal to the length direction, and wherein the first and second passages meet each other such that a through passage extends from the first side to the fourth side and a through passage extends from the second side to the third side.