Automatic laser plumb line

• US 5,992,029 A
• Filed: 08/14/1997
• Issued: 11/30/1999
• Est. Priority Date: 08/14/1997
• Status: Expired due to Fees

• Current Assignee: Dong, Dawei
• Original Assignee: Dong, Dawei
• Inventors: Dong, Dawei
• Primary Examiner(s): Fulton, Christopher W.
• Application Number:
  US08/911,129
• Time in Patent Office: 838 Days
• Field of Search: 33/227, 33/281, 33/282, 33/283, 33/285, 33/286, 33/391, 33/392, 33/402, 33/DIG. 21, 33/366.11, 33/366.24, 33/366.27
• US Class Current: 33/227
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01C 15/004 Reference lines, planes or sectors
• CPC Class Codes: G01C 15/105 Optical plumbing
• CPC Class Codes: Y10S 33/21 with laser

Abstract

A laser line device suitable for construction. The laser line instrument automatically aligns a vertical laser beam so that the beam is perpendicular to the earth'"'"'s core. The laser module is connected to a pendulum which serves to automatically level the device. The pendulum is damped by permanent magnets. The bearing on which the pendulum is mounted serves as a portion of the electrical circuit of the device.

Claims

1. An automatic laser plumb line generating device comprising:

a laser line generator module mounted on a pendulum, said pendulum is suspended in a housing means,

a pendulum swing damping mechanism, and

an electrical power supply;

wherein

a rigid suspending means affixed to said housing means supports said pendulum, said suspending means provides positive and negative contacts for a power supply circuit of said laser line generator module, thereby eliminating any need for wires to extend from said laser line generator module, which reduces variation in a swing path of said pendulum.

2. The automatic laser plumb line generating device claimed in claim 1 wherein:

said pendulum swing damping mechanism is a magnetic field applied around an at-rest position of a pendulum body, said pendulum body being formed from a material subject to magnetic force.

3. The automatic laser plumb line generating device claimed in claim 2 wherein:

said pendulum includes an adjustment means to adjust said at-rest position of said pendulum body, thereby ensuring that a true plumb line is produced.

4. The automatic laser plumb line generating device claimed in claim 1 wherein:

said pendulum includes an adjustment means to adjust an at-rest position of said pendulum, thereby ensuring that a true plumb line is produced.