Device for measuring the relative position of a material measure and a reading head

• US 20100050455A1
• Filed: 08/13/2009
• Published: 03/04/2010
• Est. Priority Date: 08/27/2008
• Status: Active Grant

• Current Assignee: Sick Stegmann GmbH (Sick Management GmbH)
• Original Assignee: Sick Stegmann GmbH (Sick Management GmbH)
• Inventors: Siraky, Josef
• Granted Patent: US 7,908,762 B2
• Time in Patent Office: Days
• US Class Current: 33/708
• CPC Class Codes: G01D 5/2457 Incremental encoders having reference marks

Abstract

A device for measuring the relative position of a material measure (10) and a reading head (12) is described, in which the material measure (10) has an incremental scale (14); in which the incremental scale (14) is non-magnetically scanned at a high resolution by a scanner (16) belonging to the reading head (12); in which the material measure (10) has permanent magnets (18), which are positioned at equidistant intervals in the direction of measurement and which establish continuous and adjoining segments (20) within the incremental scale (14); in which the magnetic field created by the permanent magnets (18) following each other in succession is recorded by at least one magnetic sensor (24) belonging to the reading head (12); in which the magnitude of the recorded magnetic field (22) is used to assign the position of the reading head (12) to a step of the incremental scale (14) within the segment (20) defined by these permanent magnets (18); and in which a Wiegand wire device (26, 28) belonging to the reading head (10) produces segment-counting pulses upon traversing the permanent magnets (18) and these pulses are counted and permanently stored in the storage component.

Claims

1. Device for measuring the relative position of a material measure (10) and a reading head (12), in which the material measure (10) has an incremental scale (14);

in which the incremental scale (14) is non-magnetically scanned at a high resolution by a scanner (16) belonging to the reading head (12);

in which the material measure (10) has permanent magnets (18), which are positioned at equidistant intervals in the direction of measurement and which establish continuous and adjoining segments (20) within the incremental scale (14);

in which the magnetic field created by the permanent magnets (18) following each other in succession is recorded by at least one magnetic sensor (24) belonging to the reading head (12);

in which the magnitude of the recorded magnetic field (22) is used to assign the position of the reading head (12) to a step of the incremental scale (14) within the segment (20) defined by these permanent magnets (18); and

in which a Wiegand wire device (26, 28) belonging to the reading head (10) produces segment-counting pulses upon traversing the permanent magnets (18) and these pulses are counted and permanently stored in the storage component.

2. Device according to claim 1, in which the incremental scale (14) is scanned in an optical, capacitive, or inductive manner.

3. Device according to claim 1, in which the magnetic sensors (24) are magneto-resistive sensors.

4. Device according to claim 1, in which the storage component counts the segment-counting pulses upwards or downward depending on the direction of relative motion.

5. Device according to claim 1, in which the counting circuit and the storage component are independent of external energy sources.

6. Device according to claim 5, in which the counting circuit and the storage component are fed by a battery.

7. Device according to claim 5, in which the counting circuit and the storage component are fed by the energy of the segment-counting pulses.

8. Device according to claim 1, in which the permanent magnets (18) succeed each other with an alternating polarity.

9. Device according to claim 1, in which the distance in the measuring direction between the permanent magnets (18) is at least equal to the length in the measuring direction of the reading head (12).