a. Field of Invention
This application pertains to an automatic apparatus and method for measuring various dimensions such as the distance between two points. More specifically, the distance is obtained from a remote location by measuring the distances from the remote location to each of the points, measuring other parameters to determine the distance therebetween, wherein preferably a single laser device is used to make all the measurements. Other dimensions characteristic of objects such areas, volumes and/or relative positions of different objects are obtained by using three or more points.
b. Description of the Prior Art
It is frequently important to measure the distance between two points. For example, surveyors have a large number of tools and devices and disposal to measure the distances between landmarks, as well as their elevation and relative bearing.
Contractors and other professionals in the building industry often need to measure distances between various critical points as well. Traditionally this was accomplished by extending or laying down a measuring tape between the two points and reading the distance from the tape. If the tape was too short, or if there are obstacles between the points, then intermediate measurements are made along the path between the two points. Of course, this process is tedious and time-consuming. Moreover, in some instances, one or both points of interest are inaccessible and therefore the distance between them can be determined using indirect means or approximations.
Recently, the task of measuring devices has been eased somewhat by the availability of electronic measurement devices. These devices are now readily available and work by sending out an ultrasound, laser or other types of beams and determining the transit time required for the beam to reach the selected point, and return. One such device, called the Laser Dimension Master is made by Calculated Industries of Carson City, Nev. The device has a head rotatable between two perpendicular positions and generates an ultrasound beam for making measurements and a visible laser beam for aiming the device. While these devices are easy to use, most of them can still only measure the distance from the measuring device and a remote point and cannot be used from a remote location to measure the distance between two arbitrary points. One exception presently known are the laser measuring device made by Lasermeters of Edmond, Okla. (See Lasermeters.com). This company makes a line of devices under the name of Disto. A Disto device can be used to measure the distance between two points using three measurements. First, the device is directed at the first point and a measurement is taken. Next, the device is directed at an intermediate point disposed along a perpendicular line to the line between the two points and a second measurement is taken Finally, the device is directed at the second point and a third measurement is taken. The distances between the first point, the intermediate point, and the second point are determined using the Pythagorean theorem, and then added. This approach has many problems which render it impractical for most applications. First, the user must determine by eye the location of the intermediate point. Obviously this process introduces a degree of uncertainty and inaccuracy. Second, in most instances, except in very special instances, the intermediate point does not even fall between the two points, in which case, the distances must be subtracted, not added. Devices are also known that measure electronically the orientation of an object with respect to the North Pole. These devices or electronic compasses are used in various transportation means for navigation, in surveying devices, and so on. Moreover, historically, devices were well known, such as water bubbles and plumb lines that could be used to determine whether a flat member or surface was truly vertical or horizontal or to indicate the angle between a surface and a vertical or horizontal axis. More recently, devices have become available that measure such angles electronically and provide a digital signal indicative of the angle of a selected surface or line and either the vertical or horizontal axis. One such device is the Macklanburg-Duncan Electronic Digital Protractor available from Sears, Inc. of Chicago-part NO. #00940195000.