Mechanical protractor

DETAILED DESCRIPTION An object of the present invention is to provide a new and improved device for measuring the angle between two lines.
Another object of the present invention is to provide a new and improved device for measuring the angle between two lines on a drawing or between two elongated objects such as walls or the like.
A further object of the present invention is to provide a new and improved device for measuring the angle between two lines on a drawing or the like without extending the lines to their point of intersection.
An additional object of the present invention is to provide a device for accurately measuring the angle between two lines independently of the path taken by the device to obtain the measurement.
Briefly, the present invention is directed to a new and improved device for measuring the angle between two lines on a drawing, or between two physical objects.
A preferred embodiment of the device or mechanical protractor according to the invention includes a housing having one open side that may be covered by a transparent window or the like.
A pair of wheels each preferably having substantially the same configuration and size is rotatably mounted within the housing.
Extending between the wheels is a shaft having its first end secured to the first wheel and its second end passing through the second wheel and into the open side of the housing.
The shaft maintains the wheels separated by a distance predeterminedly related to the radii of the two wheels, preferably by a distance approximately equal to the radius of each wheel.
A scale calibrated in degrees is affixed to the second wheel, and a pointer is secured to the second end of the shaft and adjacent the scale.
The outer peripheral surfaces of the first and second wheels extend through the bottom of the housing so that the housing may be moved on the surface of the drawing (or floor) from one line (or wall) to another causing independent rotation of the first and second wheels.
The rotation imparted to the first wheel by movement of the housing causes the pointer to rotate