| 摘要 |
An assembly for drawing lines in a desired direction, the said assembly comprising a drafting board and a ruler. The ruler employed is a rolling ruler (3). The board (1) is provided with guiding stops (2), against which stops the rolling ruler is to be conducted. The stop (2) is so low, that the ruler member of the rolling ruler (3) can partly move on top of it while the roller member still stays in touch with the drafting board (1). On the other hand, the stop (2) is yet so high, that it allows for the directing of the rolling ruler (3) by pushing the ruler member against the stop (2), till it obtains the direction of the stop (3a3b3c) and the ruler (3) can be moved, maintaining its direction, to the desired spot (3d) on the drafting board (1). The amount of the stops can be two or more, so that they represent the directions most frequently needed in the drawing. They can be suspended and arranged to be pressed against the board (1) under the rolling ruler. As stops (2) can also be used two or more pins (4) located on the straight line having the desired direction. The directions determined by pins located on adjacent or opposite sides can as well be used. |
