Abstract: An instrument for performing various drawing and measurement functions is disclosed. The instrument includes an elongated plate having a straight edge and a measurement region. A protractor plate is connected to the elongated plate and cooperates with a rotatable center dial for the drawing and measuring of angles. The instrument also preferably includes holes through the elongated plate. The holes are configured to receive a marking instrument so the device can be used as a compass. Additionally, an attachment region allows the instrument to be held in a conventional ring binder.

Abstract: The present invention relates to tools such as scissors, shears, pruners, and the like, which are resiliently biased to an open position, and which have a locking mechanism to keep these tools in a closed configuration. More particularly, this invention is concerned with tools having a pair of cooperatively engaging members provided with a resilient lock slidable within slots formed in these members. The lock includes a button having a yieldable head merging into a shank extending through the slots, the shank being joined to a cap. The head and cap have concavely shaped faces so that they are effectively in contact with the tool in respective annular regions of the tool, the area of these regions being proportional to the degree of compressive force applied to the lock.

Abstract: A rotary cutter having a handle, a cylindrical head formed on one end of the handle and having a planar surface on each side of the head, an actuating member pivotally mounted in the head, a circular blade mounted on the actuating member and having a pinking or wave shaped cutting edge offset from the blade to form a hub, the blade being secured to one side of the actuating member with the hub located in a parallel relation to one of the planar surfaces, and a finger guard formed as an integral part of the handle and head.

Abstract: A sheath which permits the user to adjust the degree of retentional engagement of the knife within the sheath. The sheath is provided with a simple, adjustable, latch mechanism engaging the knife to prevent their accidental disengagement. The latch mechanism is substantially received within the sheath.