Load cell apparatus having a gap measuring device

• US 6,680,443 B2
• Filed: 06/19/2002
• Issued: 01/20/2004
• Est. Priority Date: 06/22/2001
• Status: Expired due to Fees

• Current Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Original Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Inventors: Dixon, Steven A.
• Primary Examiner(s): GIBSON, RANDY W
• Application Number:
  US10/174,913
• Publication Number:
  US 20030000746A1
• Time in Patent Office: 580 Days
• Field of Search: 177/144, 177/210.R, 177/210.C, 177/211, 177/210.EM, 177/229, 177/DIG.9
• US Class Current: 177/144
• CPC Class Codes: A61G 7/0527 Weighing devices
• CPC Class Codes: G01G 19/445 in a horizontal position
• CPC Class Codes: G01G 9/00 Methods of, or apparatus for, the determination of weight, not provided for in groups G01G1/00 - G01G7/00

Abstract

A load cell apparatus for use with a structure comprises a cell block that flexes in response to an applied load and a transducer that is adapted to measure a distance across a gap. In some embodiments, the gap is defined between the transducer and the structure, and in other embodiments, the gap is defined between the transducer and the cell block.

Claims

1. A load cell apparatus for use with a structure, the load cell apparatus comprising

a cell block that flexes in a first direction relative to the structure in response to an applied load, and

a transducer coupled to only one of the cell block and the structure, the transducer being adapted to measure a distance across an open gap defined between the transducer and the other of the cell block and the structure, the transducer emitting a beam of electromagnetic energy in a direction substantially parallel to the first direction.

2. The load cell apparatus of claim 1, wherein the cell block is adapted to couple to the structure.

3. The load cell apparatus of claim 2, wherein the structure provides a target surface and the transducer emits electromagnetic energy toward the target surface.

4. The load cell apparatus of claim 1, wherein the transducer includes an end face that faces the structure.

5. The load cell apparatus of claim 1, wherein the cell block includes a planar surface and the transducer includes an end face that is substantially coplanar with the planar surface.

6. The load cell apparatus of claim 5, further comprising a stud extending from the cell block along an axis that is parallel with the planar surface.

7. The load cell apparatus of claim 6, wherein the cell block includes an end surface, the stud extends from the end surface, and the end surface is substantially perpendicular to the planar surface.

8. The load cell apparatus of claim 1, further comprising an electric circuit, the transducer generating an output signal that corresponds to the distance across the gap, and the output signal being processed by the electric circuit.

9. The load cell apparatus of claim 8, wherein the electric circuit is coupled to the cell block.

10. The load cell apparatus of claim 8, wherein the electric circuit generates a processed signal that corresponds to the load being applied to the movable portion of the cell block.

11. The load cell apparatus of claim 1, wherein the transducer produces a shaped electromagnetic field.

12. The load cell apparatus of claim 1, wherein the transducer emits electromagnetic energy into the gap.

13. A load cell apparatus for use with a structure, the load cell apparatus comprising a cell block that flexes in response to an applied load, and a transducer being adapted to measure a distance across a gap defined between the transducer and the structure, the cell block being formed to include a threaded bore and the transducer includes a threaded portion received in the threaded bore.

14. The load cell apparatus of claim 13, wherein the transducer includes a sensing head, the threaded portion includes a passage therethrough, and the transducer includes a wire extending from the sensing head and through the passage.

15. The load cell apparatus of claim 14, wherein the threaded portion has a first diameter, the sensing head has a second diameter, and the second diameter is larger than the first diameter.

16. A load cell apparatus for use with a structure, the load cell apparatus comprising

a cell block having a first portion that is adapted to couple to the structure and a second portion that is spaced apart from the structure, an open gap being defined between the second portion and the structure, the second portion being movable toward the structure to decrease the gap in response to a load applied in a first direction, and

a transducer configured to sense a distance across the gap, the transducer being coupled to only one of the cell block and the structure, the transducer emitting a beam of electromagnetic energy in a direction substantially parallel to the first direction.

17. The load cell apparatus of claim 16, wherein the first portion of the cell block is adapted to abut the structure.

18. The load cell apparatus of claim 16, wherein the transducer includes a planar end face and the second portion of the cell block includes a planar surface that is substantially parallel with the planar end face.

19. The load cell apparatus of claim 16, further comprising an electric circuit, the transducer generating an output signal that corresponds to the distance across the gap, and the output signal being processed by the electric circuit.

20. The load cell apparatus of claim 19, wherein the electric circuit generates a processed signal that corresponds to the load being applied to the movable portion of the cell block.

21. The load cell apparatus of claim 16, wherein the transducer produces a shaped electromagnetic field.

22. The load cell apparatus of claim 16, wherein the transducer emits electromagnetic energy into the gap.

23. A load cell apparatus for use with a structure, the load cell apparatus comprising a cell block having a first portion that is adapted to couple to the structure and a second portion that is spaced apart from the structure, a gap being defined between the second portion and the structure, and a transducer configured to sense a distance across the gap, the transducer including a threaded portion that is adapted for receipt in a threaded hole formed in the structure.

24. The load cell apparatus of claim 23, wherein the transducer includes a sensing head, the threaded portion includes a passage therethrough, and the transducer includes a wire extending from the sensing head and through the passage.

25. The load cell apparatus of claim 24, wherein the threaded portion has a first diameter, the sensing head has a second diameter, and the second diameter is larger than the first diameter.

26. A load cell apparatus for use with a structure, the load cell apparatus comprising

a cell block supported with respect to the structure, the cell block deflecting under application of a load in a first direction, an open gap being defined between the cell block and the structure, and

means for measuring a distance across the gap, the measuring means being coupled to only one of the cell block and the structure, the measuring means emitting a beam of electromagnetic energy in a direction substantially parallel to the first direction.

27. The load cell apparatus of claim 26, wherein the measuring means is coupled to the cell block.

28. The load cell apparatus of claim 26, wherein the measuring means is coupled to the structure.

29. A load cell apparatus comprising two elements defining an open gap therebetween, at least one of the elements being deflectable under a load applied in a first direction to vary the gap, and a transducer for measuring the gap that changes in response to the load, the transducer being coupled to only one of the two elements, the transducer emitting a beam of electromagnetic energy in a direction substantially parallel to the first direction.

30. The load cell apparatus of claim 29, wherein the transducer includes an end face that faces the gap.

31. The load cell apparatus of claim 29, wherein the transducer measures the gap using shaped electromagnetic field technology.

32. A load cell apparatus comprises two elements defining an open gap therebetween, at least one of the elements being deflectable under a load applied in a first direction to change the size of the gap, and a transducer is positioned and configured to measure the size of the gap change in response to the load, the transducer is coupled to only one of the two elements, the transducer emits a beam of electromagnetic energy in a direction substantially parallel to the first direction.