Abstract: A fire damper tool is provided for assisting a user opening the shutters of an HVAC fire damper after the shutters have closed. The device comprises a scissor tool that is hand-driven for separating the closed shutters without requiring the user to exert force on the doors while opening. The tool comprises a first and second set of scissor arms connected to a common pin. A threaded rod connects the proximal ends of the scissor arms along one side of the pin, while the distal ends of the scissor arms are positioned between the closed fire damper doors. A hand driven nut draws the proximal ends of the scissor arms together, causing the proximal ends thereof to spread, and in turn spread the fire damper doors. The tool is useful for confined areas where mechanical advantage is necessary for separating items, and is particularly suited for commercial HVAC applications.

Abstract: The invention concerns a drafting head for a drafting machine, with a gring member (4) having several actuating elements (6, 8, 10) arranged on the gripping member (4) and capable of being actuated by a hand of the user that is resting on the gripping member (4) for the purpose of executing various switching statuses, as for example, disengaging, free- (unrestricted) switching, secured braking (locking) of the normal side, respectively for releasing the locking of the normal side of the drafting head (1). Provided here is at least one actuating element (6, 8) for disengaging and/or free-switching of the normal side of the drafting head (1), and one actuating element (10) for locking the normal side of the drafting head (1). Actuating element (10) for locking is arranged on the gripping member (4) such that it rests against the inner surface of the ball of the thumb of the user hand resting on the gripping member (4).

Abstract: An attachment for a drafting machine having a protractor head has a scale which is securable to the head. By operation of the head, the scale is movable on the drawing board between a first position and a second position disposed at a predetermined acute angle to the first position. On the ruling edge of the scale, there is an index point which is usable when the scale is in the first position to mark the location for the placement of a required symbol. A template is mounted below the scale for rotation about an axis perpendicular to the drawing board and this template is provided with a plurality of outlines which serve as stencils for applying symbols to a drawing. An indicator on the structure supporting the template enables a particular symbol outline to be selected and placed in a position which will coincide with the marked location when the scale is moved to the second position.