Abstract: A hair cutter comprising a cover plate displaceably disposed relative to and opposite a blade carrier plate, the cover plate having a row of teeth covering a blade cutting edge. Downwardly pointing teeth-like arresting projections are mounted on a flanged downwardly facing part of the blade carrier plate and positively engage upwardly pointing arresting teeth on lateral shoulders of a push button actuating element, the latter disposed perpendicular to the plane of the blade. The arresting projections are biased into an arresting position and are releasable by a push button actuating element which slidably projects through a complementary opening formed in the cover plate, whereby the arresting teeth of the shoulders being released from the downwardly pointing and complementary arresting teeth upon pushing the push button actuating element downwardly.

Abstract: A retractable cutting implement, such as a utility knife, comprises a sleeve-like handle member having a cavity portion with the handle member being open at the base and at one end through a first longitudinal slot. A carrier member is pivotally mounted to the handle for pivotal movement into and out of the cavity with the carrier member being resiliently held within the cavity when it is pivotally moved into the cavity for substantially closing the cavity. The carrier member comprises a substantially enclosed longitudinally extending chamber with a passage therein in communication with the one end of the first slot in the handle member and a blade carriage member is slidably mountable in this chamber for slidable movement toward and away from the passage.

Abstract: Rotary motion is converted to linear motion by multiple thread sets which cooperate to provide precise control of the amount of rotary motion thus converted. As applied to a precision positioning device for a tool, blade or other object, the thread sets are preferably arranged in a serial and/or telescoped configuration. A relatively simple precision hand tool positioning device is realized by having one thread set arranged in a common direction but reduced pitch relative to the other set. The finiteness of the object positioning is further enhanced by moving it with respect to an inclined plane. A retaining device for gripping the element to be moved is directly associated with a shank having the smaller pitched thread set thereon. The shank is prevented from rotating but allowed to move linearly relative to a housing and the threads thereof engage a spindle which has another set of threads for engaging the housing. A calibrated indicator of the shank position in easily readable format is provided.

Abstract: A hair cutting and trimming device for use by an individual includes a body portion constitution a carrier for a comb, the length of which is adjustable in relation to the body portion to control the length of cut of the hair, and a blade mounted on the body portion and in close proximity to the tines of the comb. The tines include notches or grooves to lift and guide the hair, enabling the blade effectively to shear off the hair at a predetermined length determined by the adjustment of the comb in relation to the body portion of the device.