Knife

Abstract: A utility knife includes a blade holder (14) slidably received in two casings (10, 40) which have a front portion hooked together. A knob (34) is pivotally coupled to one casing (10) and has one end (36) biased to engage with the other casing (40). A spring (28) may bias the casings (10, 40) away from each other when the knob (34) is disengaged from the other casing (40) and for allowing the casings (10, 40) to be easily separated from each other by the user. The casings (10, 40) have a notch (30, 44) for safely receiving the knob (34).

Description: The invention relates to a utility knife according to the preamble of claim 1. Typical utility knives comprise a housing having two casings secured together by latches. However, once the latches are released, the casings may not be easily separated from each other by the users. The invention, which is defined by claim 1, is to provide a utility knife having two casings that may be separated from each other by a spring member when the latches are actuated. FIG. 1 is an exploded view of a utility knife; FIG. 2 is a plane view of the knife; FIGS. 3 and 4 are cross sectional views illustrating the operation of the knife. Referring to FIGS. 1-3, a utility knife comprises a housing 1 including two casings 10, 40 having a channel 12 formed in the front portion for slidably receiving a holder 14 of a blade 22. The casing 10 has one or more recesses 16 formed in the front portion and defined by one or more bulges 18. The blade holder 14 includes a resilient arm 15 extended rearward and having a button 17 extended upward for allowing the user to move the blade 22 inward and outward of the housing 1. The arm 15 includes a catch 20 for engaging with the recesses 16 of the casing 10 and for securing the holder 14 to the casing 10. The holder 14 may be moved relative to the housing 1 when the catch 20 is disengaged from the recesses 16 of the casing 10 by the button 17 until the catch 20 is engaged with the other recesses 16 of the casing 10. The outward movement of the blade 22 relative to the housing 1 may thus be determined by the engagement between the catch 20 and the recesses 16 of the casing 10. The holder 14 includes an extension 23 for engaging into an aperture 19 of the casing 10 and for stably securing the holder 14 to the casing 10 when the holder 14 is moved inward of the housing 1. The casing 40 includes a hook or a depression 42 formed in the front portion, and the other casing 10 includes a corresponding depression or a hook 24 for engaging with the depression 42 of the casing 40 and for allowing the rear portions of the casings 10, 40 to be moved away from each other for a small distance (FIG. 4). The casings 10, 40 each includes a notch 30, 44 formed in the rear portion and each includes a hole 26 formed in the rear portion for receiving a spring 28 which may bias the casings 10, 40 away from each other. The casing 40 includes a jut 46 extended inward of the notch 44 thereof. The casing 10 includes a bar 31 extended inward of the notch 30 thereof and includes a hole 32 for receiving one end of a spring 33. A knob 34 includes a middle portion pivotally secured to the bar 31 at a pivot shaft 35 and includes one end 36 that may be biased to engage with the jut 46 of the casing 40 by the spring 33 (FIG. 3) and to lock the casings 10, 40 together. The other end 38 of the knob 34 may engage with a stop 37 that extends inward of the notch 30, for limiting the rotational movement of the knob 34. As shown in FIG. 3, the spring 33 may bias the end 36 of the knob 34 to engage with the jut 46 of the casing 40 and to lock the casings 10, 40 together. The spring 28 may relatively force the jut 46 to engage with the end 36 of the knob 34, such that the casings 10, 40 may be solidly locked together. When the other end 38 of the knob 34 is depressed against the spring 33 to disengage the end 36 of the knob 34 from the jut 46 of the casing 40 (FIG. 4), the spring 28 may bias the rear portions of the casings 10, 40 away from each other such that the user may easily separate the casings 10, 40 away from each other. The jut 46 may include a curved surface 48 (FIGS.. 3, 4) for allowing the jut 46 to easily move over to engage with the end 36 of the knob 34 when the rear portion of the casing 40 is forced toward the rear end of the casing 10. The end 36 of the knob 34 may thus move to engage with the jut 46 to lock the casings 10, 40 together without depressing the knob 34. As shown in FIG. 2, the knob 34 is received in the notches 30, 44 of the casings 10, 40 and thus will not be depressed inadvertently. Without the bar 31, the knob 34 may also be directly and pivotally coupled to the casing 10.

Claims: A knife comprising a first casing (10) and a second casing (40) each including a rear portion and a front portion, a blade holder (14) received in the front portions of the casings (10, 40), means (24, 42) for hooking the front portions of the casings (10, 40) together, characterized in that : a knob (34) is pivotally coupled to the rear portion of the first casing (10) and includes a first end (36), means (33) for biasing the first end (36) of the knob (34) to engage with the rear portion of the second casing (40), and means (28) for biasing the rear portions of the casings (10, 40) away from each other. The knife as claimed in claim 1, wherein the casings (10, 40) each includes a notch (30, 44) for receiving the knob (34). The knife as claimed in claim 1, wherein the first casing (10) includes a bar (31), the knob (34) is pivotally coupled to the bar (31). The knife as claimed in claim 1, wherein the second casing (40) includes a jut (46) formed on the rear portion for engaging with the first end (36) of the knob (34). The knife as claimed in claim 1, wherein the first casing (10) includes a stop (37), the knob (34) has a second end (38) for engaging with the stop (37). The knife as claimed in claim 1, wherein the front portions of the casings (10, 40) include a channel (12) for slidably receiving the holder (14). The knife as claimed in claim 1, wherein the first casing (10) includes at least one recess (16), the holder (14) includes an arm (15) having a button (17) extended outward of the casings (10, 40) and includes a catch (20) for engaging with the recess (16) of the first casing (10). The knife as claimed in claim 1, wherein the first casing (10) includes an aperture (19), the holder (14) includes an extension (23) for engaging into the aperture (19) of the first casing (10).

Inventors: HUANG YIN HAN, HUANG, YIN HAN
Applicants: HUANG YIN HAN, HUANG, YIN HAN
Application year: 1999
Main classification: B26B5
IPC codes: B26B5