Abstract: A knife apparatus having a knife handle of a substantially C-shaped cross-section defining a groove extending in a longitudinal direction of the handle, a slider slidably received by the groove of the handle and an elongated cutting blade secured to the slider so as to be extended and retracted as the slider is slided along the length of the groove. The knife handle is provided with a series of notches formed in one of the side walls thereof. The slider has a depressable resilient tab extending therefrom in the opposite direction to the cutting blade. The depressable resilient tab is provided with a pawl adapted to be received by selected one of the notches, when the depressable resilient tab is not depressed, so as to fix the slider against the sliding movement. As the depressable resilient tab is depressed, the pawl is disengaged from the notch to allow the slider to be freely slided. The body of the slider and the depressable resilient tab are unitarily formed of a plastic.

Abstract: The ejecting member is interposed between two blade elements of a two-edge shaving blade unit in a manner to be retractably moved forwardly to eject shaved hair particles and other matters deposited in and clogging the space between the cutting edges of two blade elements. The ejecting member has an integral construction which includes an outer frame portion defining the outer profile of the ejecting member, a substantially quadrilateral aperture having at least one discontinuity and defining at its outer sides the inner edges of the outer frame portion, an inner island portion fixedly cramped between two blade elements and defined by the inner sides of the aperture, and a resilient bridge portion constituted by the discontinuity of the aperture and resiliently connecting the inner island portion to the outer frame portion.

Abstract: A cutter knife having a sheath type holder, a control knob slidably mounted in the holder and a blade attached to and retained by the control knob. The holder is provided with an elongated slot along which the control knob is moved, a longitudinal through passage through which the blade is passed, a slide bore in which a blade-retaining portion of the control knob is slidingly moved and guiding means formed in the back side thereof. The guide means is in communication with the end portion of the slide bore, and are adapted to suitably guide the blade-retaining portion of the control knob. The blade can be moved through the through passage and fixed with a desired projection length from the holder, as the control knob is moved along the elongated slot and fixed to the latter by suitable means.

Abstract: A knife comprises a knife handle or grip having a channel for receiving slidably therein a blade holder having a blade secured thereto so that the blade is withdrawn outwardly as it wears out. A series of notches are formed in the knife grip, while a V-like leaf spring is mounted on the blade holder, whereby the blade holder and hence the blade are held securely at predetermined indexed positions relative to the knife grip through engagement between the V-like leaf spring and the selected notch. A locking structure releasably locks the V-like spring member so that the latter is prevented from being accidently disengaged from the notch.