Abstract: Filing gauge for sharpening of a saw chain with cutter (13) and depth gauge (14), comprising a housing (21) which can be located on the saw chain in two angular positions, two parallel shafts (26,27) fixed to the housing, two rollers (28,29) with guiding grooves for a round file slidingly journalled on the shafts, a roller follower (30) slidingly journalled on the shafts without angular mobility and permitting only parallel and simultaneous motion of the rollers, and a guide plate (40) for filing the depth gauge swingably affixed to the housing.

Abstract: A device for locating a desired information track on an information carrier, after an information transducer has been passed over the information tracks on the carrier in the transverse direction in response to a starting pulse, which utilizes a control signal that is derived from the alternating voltage thus obtained, to keep the relative velocity of the transducer relative to the information tracks constant.

Abstract: A device at an unfoldable escape-ladder, which is assembled of rungs (1), the ends (3) of which are attached between flexible lateral members (5), preferably steel wires, which rungs (1) are longish and made of plate-shaped material and can be stacked, the upper portion of the escape-ladder intended to be attached to a wall (6), a stay or the like, which escape ladder in folded state has the rungs (1) lying stacked and forming with each of the steel wires (5) a ring for each rung (1), which escape-ladder is provided with a means for releasing the ladder. According to the invention, two steel wires (4) or rods are provided which are located in parallel and rigidly mounted along the direction, which the ladder in unfolded state is desired to assume, which steel wires (4) or rods extend through the rings formed by the first-mentioned steel wires (5).

Abstract: A device at an unfoldable escape-ladder assembled of rungs (1), the ends of which are attached between flexible lateral members (2), preferably steel wires, said rungs (1) being longish and of plate-shaped material and capable to be stacked, the upper portion of the escape-ladder intended to be attached to a wall (4), a stay or the like, which escape-ladder in folded state having its rungs (1) lying stacked and each of the steel wires (2) forming a ring for each rung (1), which escape ladder is provided with a means for releasing the ladder. According to the invention, each rung (1 ) has substantially S-shaped cross-section, where the free ends of the S-shaped portion (7) are extended so as to form two parallel legs (8,9), and that the steel wires (2) are attached on the rungs (1) with their substantial longitudinal direction perpendicular to said legs.