MEASURING DEVICE FOR MEASURING A DISTANCE

• US 20100053640A1
• Filed: 02/20/2008
• Published: 03/04/2010
• Est. Priority Date: 03/13/2007
• Status: Active Grant

• Current Assignee: Haglof Sweden AB (Lifco AB)
• Original Assignee: Haglof Sweden AB (Lifco AB)
• Inventors: Jacobsen, Hans
• Granted Patent: US 7,916,312 B2
• Time in Patent Office: Days
• US Class Current: 356/635
• CPC Class Codes: G01B 11/08 for measuring diameters
• CPC Class Codes: G01B 5/0035 Measuring of dimensions of trees
• CPC Class Codes: G01B 5/08 for measuring diameters G01B5/0035 takes precedence; measuring radius of curvature G01B5/213

Abstract

A measurement arrangement has a rotation axis around a first end of an extended member having a first joint thereat, and a second joint at the opposing end. An equipment for recording measured points is connected to the second joint. The joints are connected through a cord or wire. The equipment is arranged to rotate through a pre-determined angle when the member is turned around its rotation axis. An angle sensor records the rotation of the equipment relative to the member. The cord or wire rotates the equipment through an angle corresponding to the angle that the member has rotated around its rotation axis. The equipment and the member rotate in opposite directions, and the angles of rotation are recorded when the equipment detects the limiting surface of the object on both sides of the diameter to be measured. A processor calculates the diameter based on the angles of rotation.

Claims

1. A measurement arrangement (1) for the measurement of a diameter or a width of an object, characterised in that a first joint (2) is arranged at a first end (3) of an extended member (4), around which first end (3) the measurement arrangement (1) has a rotation axis (P), in that a second joint (5) is arranged at the opposing end (6) of the extended member (4), in that an equipment (11) for recording measured points is arranged at the second joint (5) and connected to it, in that the first joint (2) and the second joint (5) are connected through a cord (8) or a wire, in that the equipment (11) for recording measured points is arranged to be rotated through a pre-determined angle when the extended member (4) is turned around its rotation axis (P), in that an angle sensor is arranged at one of the joints in order to record a rotation of the equipment (11) for recording measured points relative to the extended member (4), in that the equipment (11) for recording measured points is arranged to be rotated by means of the cord (8) or wire through an angle that corresponds to the angle that the extended member (4) has been turned around its rotation axis (P), in that the equipment (11) for recording measured points and the extended member (4) are arranged to be rotated in opposite directions, in that the angles of rotation are recorded when the equipment (11) for recording measured points detects the limiting surface of the object on both sides of the diameter that is to be measured, and in that a processor is arranged to calculate the diameter based on the said angles of rotation.

2. A measurement arrangement according to claim 1, characterised in that the directions (R) of the optical axis of the detector are mutually parallel at different angles of rotation.

3. A measurement arrangement according to claim 1, characterised in that an activation means is present in order to read the angle of rotation of the equipment (11) for recording measured points.

4. A measurement arrangement according to claim 1, characterised in that the equipment (11) for recording measured points is arranged to record the measurement points (Mh, Mv) based on the transition between reflected and non-reflected laser light.

5. A measurement arrangement according to claim 1, characterised in that the equipment (11) for recording measured points is a digital camera unit.

6. A measurement arrangement according to claim 5, characterised in that the camera unit with AGC is connected to an image processing program in order to record the transition between the object and its surroundings.

7. A measurement arrangement according to claim 1, characterised in that a contact unit (9) is arranged at the first end (3) in order to make contact with an object whose diameter (d) is to be measured.

8. A measurement arrangement according to claim 7, characterised in that the contact unit (9) is provided with at least one peg arranged to make contact with the object while a measurement is being carried out, whereby the measurement arrangement (1) is held firmly in contact with the object.

9. A measurement arrangement according to claim 1, characterised in that a vertical support is arranged at the first end (3), which support is arranged to be placed onto a supporting surface, whereby the measurement arrangement (1) is held firmly without the measurement arrangement (1) being in contact with the object that is to be measured.

10. A measurement arrangement according to claim 1, characterised in that the cord (8) or wire is attached to the part that can be rotated of the first joint (2) and the second joint (5).

11. A measurement arrangement according to claim 1, characterised in that a tensioning means (10) is located along the cord (8) or wire in a tube, whereby the cord (8) or wire is held in an extended condition.

12. A measurement arrangement according to claim 1, characterised in that the extended member (4) is arranged with a length that is sufficient to be able to measure the diameters (d) of trees, such as 10-200 cm.

13. A measurement arrangement according to claim 2, characterised in that an activation means is present in order to read the angle of rotation of the equipment (11) for recording measured points.

14. A measurement arrangement according to claim 2, characterised in that the equipment (11) for recording measured points is arranged to record the measurement points (Mh, Mv) based on the transition between reflected and non-reflected laser light.

15. A measurement arrangement according to claim 3, characterised in that the equipment (11) for recording measured points is arranged to record the measurement points (Mh, Mv) based on the transition between reflected and non-reflected laser light.

16. A measurement arrangement according to claim 2, characterised in that the equipment (11) for recording measured points is a digital camera unit.

17. A measurement arrangement according to claim 3, characterised in that the equipment (11) for recording measured points is a digital camera unit.