Abstract: A chain saw bar having an elongated shape, a saw chain guideway around substantially the length of the perimeter thereof, with a matching saw chain sprocket in the nose thereof, and calculated points of variation in strength in the interior of the bar at points removed from the sprocket, the points of variation in strength acting so that if the bar is subjected to an excessive bending force, the bar will tend to become bent initially at one point of variation in strength and with increased bending force at a subsequent point of variation in strength. In this way, extreme bending of the bar at one location and pinching of the sprocket are minimized.

Abstract: An actuating device for automatically controlling the position of a movably mounted vehicle mirror comprises a motor controlled by switches for selectively actuating the motor in response to angular displacement of a trailer with respect to the vehicle. The switches are actuated in response to movement of the trailer and responsively close a circuit connecting a power source to the motor. Preferably, the switching means can include means for disconnecting the power source after a predetermined rotation of the motor in order to avoid excess energy use. Preferably, the disconnecting means comprises a plurality of switches arranged to contact lobes of a rotating cam at predetermined rotational positions of the cam. The cam can be concentrically secured to the rotor shaft or can be connected to the rotor shaft by a lever mechanism in order to form a crank which translates the rotor movement to linear displacement on a mirror positioning member.

Abstract: An improved drive assembly for a powered chain saw or the like, which drive assembly includes a drive sprocket having a hub portion centrally and presenting a hub extension at one end for coaxially registering within the centered opening of the end wall of a clutch drum, and an axially extending apertured reinforcing washer disposed between the teeth of the sprocket wheel and surrounding the tips thereof in the region of abutment of the drive sprocket and clutch drum so as to register within the recesses of the sprocket teeth and present an extended joining area therebetween for securing same against separation.

Abstract: In a segmented bar having a longitudinal axis, a first bar section slidably interengageable with a second bar section under longitudinal axially displacement to move into and out of end to end abutting interlocking mating relation, each of said bar sections presenting corresponding longitudinally extending mating surface formations on opposite sides and corresponding longitudinally extending mating edge formations along opposite edges, each bar section terminating in an abutting end edge formation to be presented to the abutting end edge formation of the other of said bar sections when disposed in interlocking mating relation, the opposed surface formations of one of said sections each including a locating recess therein and offset in relation to each other and each bounded by a portion of the extent of its adjacent abutting end edge formation, the opposed surface formations of the other of said sections each including a mating projection for each of said locating recesses and likewise offset in relation to e