System and method for detecting an end of and/or a beginning of a stroke

• US 7,456,385 B2
• Filed: 05/03/2006
• Issued: 11/25/2008
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• Current Assignee: Phaedrus, LLC
• Original Assignee: Phaedrus, LLC
• Inventors: Engstrand, Bradley
• Primary Examiner(s): Luu; Thanh X
• Application Number:
  US11/416,685
• Publication Number:
  US 20070075227A1
• Time in Patent Office: 937 Days
• Field of Search: 250/231.1, 250/573, 73/11.9, 73/12.2, 91/1, 324/686, 123/478
• US Class Current: 250/231.1
• CPC Class Codes: G01D 5/28 with deflection of beams of light, e.g. for direct optical indication G01D5/40 takes precedence; mechanical adjustment G01D5/264
• CPC Class Codes: G01D 5/34 the beams of light being detected by photocells

Abstract

A system and a method detect that a movable element within an interior of a compartment is at an end of a stroke and/or a beginning of the stroke within the interior of the compartment. A switch and/or an electrical circuit is connected to the compartment for detecting that the movable element may be at the beginning of and/or at the end of the stroke. A microprocessor is connected to the switch or to the electrical circuit for detecting that the movable element is at the end of and/or at the beginning of the stroke within the interior of the compartment. An end cap having a light detector is connected to the compartment to measure an intensity of the light within an interior of the end cap which is attenuated by and/or is diffused by a surface of the movable element and/or of the compartment. The intensity of the light within the interior of the end cap corresponds to a position of the movable element within the interior of the compartment. The light detector determines the position of the movable element which is at the end of the stroke, at the beginning of the stroke and/or between the end of the stroke and the beginning of the stroke via the intensity of light within the interior of the end cap.

Claims

1. A system for detecting an end of a stroke or a beginning of the stroke, the system comprising:

a compartment having a body defining an interior wherein the body has an interior surface and a length defined between a first end and a second end of the compartment wherein the compartment has a movable element within the interior of the compartment wherein the movable element moves within the interior of the compartment between a first position and a second position wherein the second position is adjacent to the first end of the compartment;

a tube connected to the interior surface wherein the tube is located at the first end of the compartment and further wherein the movable element has a capacitance value and the tube has a capacitance value wherein the capacitance value of the tube is different than the capacitance value of the movable element;

an electrical circuit connected to the tube wherein the electrical circuit has a total capacitance value wherein the total capacitance value of the electrical circuit is based on the capacitance value of the tube if the movable element is not in contact with the tube and further wherein the total capacitance value of the electrical circuit is based on the capacitance value of the tube and the capacitance value of the movable element if the movable element is in contact with the tube wherein the movable element is moved to the second position within the interior of the compartment wherein contact of the movable element with the tube connects the movable element to the electrical circuit wherein contact of the movable element with the tube changes the total capacitance value of the electrical circuit;

a first detector connected to the first end of the compartment wherein the first detector determines an intensity of light emitted within the interior of the compartment wherein the intensity of the light detected within the compartment corresponds to the first position of the movable element within the compartment; and

a microprocessor connected to the electrical circuit and the first detector wherein the microprocessor detects that the movable element is located at the first position within the compartment via the intensity of the light detected within the interior of the compartment which is not attenuated by the interior surface of the compartment or the movable element wherein the microprocessor detects that the movable element is located at the second position within the interior of the compartment via the second total capacitance of the electrical circuit.

2. The system of claim 1 further comprising:

an insulator connected to the interior surface of the compartment wherein the insulator connects the tube to the interior surface of the compartment.

3. The system of claim 1 further comprising:

a surface formed on the movable element wherein the surface of the movable element or the interior surface of the compartment attenuates and diffuses the light emitted within the interior of the compartment.

4. The system of claim 1 further comprising:

a light source connected to the first end of the compartment wherein the light source emits the light into the interior of the compartment.

5. The system of claim 1 further comprising:

a second detector connected to the first end of the compartment wherein the second detector determines the intensity of the light within the interior of the compartment.

6. The system of claim 1 further comprising:

a tab connected to the movable element wherein the tab prevents the light from illuminating the interior of the compartment.

7. The system of claim 1 wherein an amount of the light emitted within the compartment is attenuated by the interior surface of the compartment wherein the amount of the light attenuated corresponds to the first position of the movable element within the compartment.

8. A system for detecting an end of a stroke or a beginning of the stroke, the system comprising:

a compartment having a body defining an interior wherein the body has an interior surface and a length defined between a first end and a second end of the compartment wherein the compartment has a movable element within the interior of the compartment wherein the movable element moves within the interior of the compartment between a first position and a second position wherein the second position is adjacent to the first end of the compartment;

an electrical circuit connected to the first end of the compartment wherein the electrical circuit has a total capacitance value wherein the movable element is moved to the second position within the interior of the compartment wherein the movable element connects to the electrical circuit at the second position wherein the movable element increases the total capacitance value of the electrical circuit;

a first detector connected to the first end of the compartment wherein the first detector determines an intensity of light emitted within the interior of the compartment wherein the intensity of the light detected within the compartment corresponds to the first position of the movable element within the compartment;

a microprocessor connected to the electrical circuit and the first detector wherein the microprocessor detects that the movable element is located at the first position within the compartment via the intensity of the light detected within the interior of the compartment which is not attenuated by the interior surface of the compartment or the movable element wherein the microprocessor detects that the movable element is located at the second position within the interior of the compartment via the second total capacitance of the electrical circuit; and

a second detector connected to the first end of the compartment wherein the second detector determines the intensity of the light within the interior of the compartment.

9. A system for detecting an end of a stroke or a beginning of the stroke, the system comprising:

a compartment having a body defining an interior wherein the body has an interior surface and a length defined between a first end and a second end of the compartment wherein the compartment has a movable element within the interior of the compartment wherein the movable element moves within the interior of the compartment between a first position and a second position wherein the second position is adjacent to the first end of the compartment;

an electrical circuit connected to the first end of the compartment wherein the electrical circuit has a total capacitance value wherein the movable element is moved to the second position within the interior of the compartment wherein the movable element connects to the electrical circuit at the second position wherein the movable element increases the total capacitance value of the electrical circuit;

a first detector connected to the first end of the compartment wherein the first detector determines an intensity of light emitted within the interior of the compartment wherein the intensity of the light detected within the compartment corresponds to the first position of the movable element within the compartment;

a microprocessor connected to the electrical circuit and the first detector wherein the microprocessor detects that the movable element is located at the first position within the compartment via the intensity of the light detected within the interior of the compartment which is not attenuated by the interior surface of the compartment or the movable element wherein the microprocessor detects that the movable element is located at the second position within the interior of the compartment via the second total capacitance of the electrical circuit; and

a tab connected to the movable element wherein the tab prevents the light from illuminating the interior of the compartment.