Abstract: The present drafting apparatus comprises a rail (6) removably secured along the edge of a drafting board. Normally, the rail (6) serves for guiding a T-square (2, 3) which is, for example, pulled against the rail (6) by a magnetic force. If the rail (6) is released from the brackets (8) it may be used together with the trammel heads (7) as a beam compass. For this purpose one of the trammel heads (7) is equipped with a compass needle tip (19) and the other trammel head is equipped with a compass drafting lead tip holder (16). A scale (21) attached to the rail (6) permits the precise adjustment of the radius. Further, the rail (6) when removed from the brackets (8) may also be used as a straight edge for drawing long, straight lines.

Abstract: The present drafting apparatus comprises a drafting board (1) having secured to one longitudinal edge thereof a metal rail (4). A runner (3) and a rail (2) are displaceable along the metal rail (4). The runner (3) is pulled against the metal rail (4) by magnets. A carriage (6) supporting a ruler (5) having about a square shape, is displaced along the rail (2) and held in place by magnets (43) cooperating with the rail (2) at least the edges of which are made of ferromagnetic material. In order to adjust the rail (2) through relatively small horizontal or vertical angles, the rail (2) is tiltably secured to the runner (3) for adjustment through angles of about 10.degree. to 20.degree., preferably 15.degree. in either direction from the perpendicular position relative to the runner. The tilting movement is transmitted to the rail with the aid of a rod (19) spaced from the journal stud (12) and with the aid of a slide (21) which may be arrested relative to the rail (2).

Abstract: The present base for a drawing or drafting board or the like supports the board so that the latter is adjustable in the three directions of space. After each adjustment the board may be locked in the adjusted position by a respective safety or locking device. These safety or locking devices are so arranged and constructed that a yielding is provided in response to the reaching of a load limit applied to the drawing or drafting board whereby damage to the board and its supporting structure is avoided.

Abstract: The top of a table such as a drafting table which may be adjustable in its elevation, is counterbalanced by counterbalancing elements exerting an approximately constant balancing force. The counterbalancing elements comprise at least one leaf spring forming a bow inserted between the table top and a counter abutment below the table top so that the leaf spring or springs is biassed to form said bow, whereby the load on the bow has a tendency to cause a lateral flexure of the bow. The arrangement is such, that the downwardly directed force component caused by the weight of the table top and the pressure exerted by the bent leaf spring or springs, are directed opposite to each other.