CA2264565A1 - Utility knife - Google Patents

Abstract

An improved utility knife (10) comprises a handle (12) having hinged sections secured together in the closed position by a releasable latch (20). A
retractable blade (14) and blade carrier (44) are positively secured and retained within the handle (12). A fixed blade embodiment (80) is also disclosed.

Description

CA 02264565 1999-02-26WO 99/00224 PCT/US98/13770UTILITY KNIFETechnical FieldThe present invention relates generally to knives andknife handles. More particularly, this invention pertainsto a new and unique utility knife of improved constructionfor more durability as well as more convenient use andoperation.Background ArtUtility knives are useful in a wide variety ofapplications, and many variations of such knives have beenavailable heretofore. Such knives generally comprise ahandle releasably secured about either a fixed orretractable blade, which can be replaced as necessary.Various blades for such knives have also been available.Such utility knives are typically constructed for easeof replacement of the blades. However, two hands andcareful attention and handling are typically requiredbecause the parts are usually secured together only when theknife is closed. It is not uncommon for at least some ofthe knife to come apart and require reassembly in theprocess of opening/closing" it Ct) change blades. This isinconvenient and unnecessarily time consuming andCA 02264565 1999-02-26W0 99/00224 PCT/US98/13770frustrating. Some parts of utility knives are relativelysmall and can easily fall out and become lost. Moreover,this can. be difficult and even unsafe when. working in aprecarious position, such as up on a roof, ladder orscaffold.Another common problem with such utility knives relatesto the manner in which the blades are supported and securedwithin the handle. In some knives of the prior art theblades can be twisted and become loose, and in some cases,even come out between the sections of the handle whileworking.Some attempts have been made to address these problems.For example, one utility knife of the prior art has handlesections that are connected by a transverse central pivot.This avoids the problem of the handle coming apart, but doesnot address the problem of internal parts falling out whenthe handle is open.A need has thus arisen for a new and unique utilityknife of improved construction of greater durability as wellas more convenient use and operation.CA 02264565 1999-02-26W0 99/00224 PCT/US98/13770Summary of InventionThe present invention comprises a utility knife thatovercomes the foregoing and other difficulties associatedwith the prior art. In accordance with the invention thereis provided an improved utility knife having a handle withsections that are hinged together and secured in the closedposition by a releasable thumb-actuated latch for actuationwith one hand. The utility knife herein also incorporatesvarious internal improvements for positively retaining theblade as well as the blade carrier therein. Provision isalso made for positively retaining spare blades within thehandle. Both retractable and fixed blade embodiments aredisclosed.Brief Description of DrawingA better understanding of the invention can be had byreference to the following Detailed Description inconjunction with the accompanying Drawing, wherein:Fig. 1 is a side view of a utility knife incorporatinga first embodiment of the invention, shown closed;Fig. 2 is an inside view of one side, shown open withthe hinge pin exploded away and the blade shown in phantomlines;CA 02264565 1999-02-26W0 99/00224 PCT/US98/13770Fig. 3 is an inside view of the other side, shown open;Fig. 4 is an rear end View of the utility knife, shownclosed;Fig. 5 is an enlarged cross sectional View taken alonglines 5-5 of Fig. 1 in the direction of the arrows;Figs. 6 and 7 are partial sectional details showing thefastener in latched and unlatched positions, respectively;Fig. 8 is an enlarged side view of the blade carrierwith the blade shown in phantom lines;Fig. 9 is a top View of the blade carrier;Fig. 10 is a front end view of the blade carrier;Fig. 11 is a side view of a utility knife incorporatinga second embodiment of the invention, shown closed;Fig. 12 is an inside view of one side of the handle,shown open with the hinge pin exploded away and the bladeshown in phantom lines; andFig. 13 is an inside View of the other side of thehandle, shown open. CA 02264565 1999-02-26W0 99/00224 PCT/US98/13770Detailed DescriptionReferring now to the Drawing, wherein like referencenumerals designate like or corresponding elements throughoutthe views, and particularly referring to Fig. 1, there isshown a utility knife 10 incorporating a first embodiment ofthe present invention. As will be explained. more fullyhereinafter, the knife 10 incorporates various improvementssubstantially enhancing operation and use.The knife 10 includes a handle 12 with a retractableblade 14 which is nmvable between extended and retractedpositions through a slot 15 in the front end by means of athumb-actuated button 16. The blade 14 is of conventionalconstruction. Various types of such blades are availableand any suitable blade can be used. Blade 14 has beenillustrated as a trapezoidal blade with a stright bottomcutting edge, however, it will be understood that theparticular type of blade used is not critical to practice ofthe invention.In the preferred embodiment, the rear end of handle 14is bent downwardly at about 15 to 25 degrees, and preferably19 degrees, from the front end as shown in U.S. Pat.4,038,719, the entire disclosure of which is incorporatedCA 02264565 1999-02-26W0 99/00224 PCT/US98/13770herein by reference, for ergonomic reasons. However, thehandle could be straight or even bent at a different angle,if desired.The handle 12 is preferably formed of die cast zinc fordurability, although any suitable material could be used.Referring now to Figs. 1-4, the handle 12 is of splitconstruction comprising two mating half sections 12a and 12bconnected together by a hinge 16. This comprises animportant feature of the present invention because itpermits the knife 10 to be opened. without the handle 12falling apart, which can easily occur with some of theutility knives of the prior art. This facilitates alignmentduring closing, and also helps avoid misplacement andpossible loss of part of the handle 12, which in turn allowsthe blade 14 to be changed more quickly and conveniently.In the preferred embodiment the hinge 16 is located atthe rear end of handle 12, although it could. be locatedelsewhere such as along the bottom side, if desired. Also,while any suitable construction can be utilized, the hinge16 preferably consists of a roll pin 18 inserted from thebottom through aligned holes in overlapping portions of thehandle sections 12a and 12b as shown. See Fig. 4. ACA 02264565 1999-02-26W0 99/00224 PCT/US98/13770longitudinal fingernail notch 19 is preferably provided inthe underside of handle 12 to facilitate opening.The handle 12 is selectively secured together by areleasable latch or fastener 20 for ease of opening. Anysuitable fastener can be used. For example, a screwextending through a hole in one handle section for threadedreceipt in an internally threaded boss in the other handlesection, could be used. A captured screw could also be usedfor fastener 20 so that it remains with one of the handlesections when knife 10 is open.In the preferred embodiment, the fastener 20 comprisesa spring—loaded latch assembly like that shown in U.S. Pat.5,022,156 which is assigned to Better Tools, Inc. theassignee hereof, and the entire disclosure of which isincorporated herein by reference.The fastener 20 includes a shaft 22 that extendsthrough a hole 24 in the handle section 12b. A cap 26 isprovided on the outside end of the shaft 22, while a crossmember 28 is provided on the inside end of the shaft. Asnap ring 30 is provided in a circumferential groove betweenthe ends of shaft 22 on the inside of the handle section12b, while a spring 32 is provided between the other side ofCA 02264565 1999-02-26WO 99/00224 PCT/US98/13770the handle section and cap 26. The shaft 22 is thusretained on the handle section 12b, but is normally biasedoutwardly by spring 32. A slotted hole 34 is provided inthe opposite handle section 12a, as best seen in Fig. 2, inalignment with hole 24 for receiving the T—shaped inner endof shaft 22.The shaft 22 can thus be pushed inwardly by cap 32 sothat the cross member 28 passes through hole 34, after whichthe shaft can be turned to seat the cross member 28 in acounterbore 36 on the outside of handle section 12a in orderto latch handle 12 in a closed position. Turning the shaft22 the other direction releases the cross member 28 so thatit can be pulled back through the slotted hole 34 by spring32 in order to urge the shaft outwardly to unlatch thehandle 12 for blade replacement, etc.Fig. 6 shows the fastener 20 in a latched position,while Fig. 7 shows it in an unlatched position, both withhandle 12 closed.Figs. 6 and 7 also show some refinements to fastener 20over the latch assembly shown in U.S. Pat. 5,022,156. Theoutside end of hole 24 is preferably counterbored as shownso that cap 26 is recessed and substantially flush in theCA 02264565 1999-02-26WO 99/00224 PCT/US98/13770latched position. A transverse ridge 38 is preferablyprovided on the top of cap 26. One end of the ridge 38 iscurved and smooth while the other end extends beyond theperiphery of cap 26 for cooperation with a fixed bump 40 onthe outside of handle section 12b. This facilitates thumbmanipulation so that knife 10 can be unlatched with onehand, while minimizing snagging and possible inadvertentunlatching.The outside end of slotted hole 34 is also preferablycounterbored, with a pair of ridges 42 being providedtherein to act as stops for the ends of cross member 28 inthe latched position. Adjoining surfaces of the crossmember 28 and slotted hole 34 are preferably V—shaped, asbest seen in Fig. 7, for positive retention of the shaft 22in the latched position. Also, the underside of the end ofthe ridge 38 is preferably angled as shown for cooperationwith the bump 40, resulting in a camming effect when shaft22 is turned to the latched position, as best seen in Fig.6 .Referring to Figs. 2, 3 and 5, further internalconstructional details of handle 12 can be seen. The blade14 is mounted on a blade carrier 44 that is guided andsupported on a pair of ribs 46 on the inside of section 12aCA 02264565 1999-02-26W0 99/00224 PCT/US98/13770for movment between extended and retracted positions. Inaccordance with the preferred construction the blade carrier44 is also retained by a rivet 47 extending through alongitudinal slot 48 therein. This comprises an importantfeature of the present invention because it prevents theblade carrier 44 from falling out when knife 10 is opened.The blade carrier 44 includes an integral longitudinalspring arm 50 with a lateral tab 52 at the end. The thumbbutton 16 is connected to arm 50 and extends through. alongitudinal slot 54 in the top of handle 12 foraccomodating movement thereof. Actuation of the the thumbbutton 16 flexes the spring arm 50 so that tab 52 can beselectively positioned into one of the detents or notches 56in handle section 12a to extend or retract the blade 14 andsecure it in position as desired.In reference to Figs. 5 and 8-10, the blade carrier 44is of generally channel—like configuration with opposing topand bottom flanges 58 and 60 and a rear locating tab 62 tofacilitate proper receipt and positioning of the blade 14 onthe carrier. The middle portion of carrier 44 containingslot 48 is recessed as shown to ride between ribs 46.10CA 02264565 1999-02-26WO 99/00224 PCT/US98/13770In the preferred embodiment the blade carrier 44further includes a T—shaped lug 64 within a gap in the topflange 58 for cooperation with a notch in the top edge ofblade 14, which must be inserted before the bottom edge forproper seating. Further support is provided by ribs 65 onthe inside of handle section 12b. This comprises animportant feature of the present invention because itresists twisting and facilitates positive retention of blade14 on the carrier 44.A pair of longitudinal raised extensions 66 and 68, asbest seen in Fig. 2, are preferably provided in the handlesection 12a for further guiding and supporting the bladecarrier 44 toward and away from the from opening 15. Theextensions 66 and 68 are adapted for receipt in opposingnotches 70 and 72, respectively, in the handle section 12b,as best seen in Fig. 3, to act as stops. This alsocomprises an important feature of the present inventionbecause the blade 14 and/or blade carrier 44 cannot passbetween the handle sections 12a and 12b.A rear compartment 74 is provided within handle 12 forstoring extra replacement blades 14, which are positivelyretained therein by a magnet 76 so that they do notinadvertently fall out when the handle is opened. AllCA 02264565 1999-02-26W0 99/00224 PCT/US98/13770longitudinal extension 78 is also preferably provided sothat the blades 14 cannot come out between the handlesections 12a and 12b or interfere with closing of the handle12.Referring now to Figs. 11-13, there is shown a utilityknife 80 incorporating a second embodiment of the invention.The knife 80 includes numerous component parts that aresubstantially identical in construction and function tothose of knife 10 of the first embodiment. The samereference numerals have been used to identify such componentparts in knife 80, but with prime (’) notations fordifferentiation.The primary distinction between the embodimentscomprises the fact that knife 80 is of the fixed blade type.The handle 12' is similar except that the blade 14' restsdirectly on ribs 46' located by a fixed lug 82. The blade14' is preferably positively retained by a magnet 84 againstinadvertently falling out when handle 12' is opened. Threeribs 65' are provided on handle section 12b‘. Otherwiseknife 80 is similar to knife 10.From the foregoing, it will thus be understood that thepresent invention comprises a new and unique utility knife12CA 02264565 1999-02-26WO 99/00224 PCT/US98/ 13770having several advantages over the prior art. Onesignificant advantage is that the handle sections are hingedtogether so that they cannot come apart. Anothersignificant advantage is that various internal componentsare positively" retained and secured against inadvertentlyfalling out when the knife is opened. The knife herein canbe unlatched and opened with one hand. Attention has beenpaid to making the blade resistant to dislocation undertwisting. Other advantages will be evident to those skilledin the art.13CA 02264565 1999-02-26WO 99/00224 PCT/U598/13770Although particular embodiments of the invention havebeen illustrated in the accompanying Drawing and describedin the foregoing Detailed Description, it will be understoodthat the invention is not limited only to the embodimentsdisclosed, but is intended to embrace any equivalents,modifications and/or rearrangements of elements fallingwithin the scope of the invention as defined by thefollowing Claims.14

Claims (10)

Claims What is claimed is:

1. A utility knife, which comprises:
a handle having opposite front and rear ends, said handle being of longitudinally split construction having opposite mating portions;
a hinge interconnecting the portions of said handle for movement between open and closed postions;
means for mounting a blade within said handle extending out of a slot in the front end of said handle; and latch means for releasably securing the portions of said handle together in the closed position.

2. The utility knife of claim 1, wherein said handle is formed of metal.

3. The utility knife according to claim 2, wherein said handle is formed of die cast zinc.

4. The utility knife of claim 1, wherein the rear end of said handle is bent downwardly at a predtermined angle from the front end.

5. The utility knife of claim 1, wherein said hinge comprises overlapping adjacent portions of said handle interconnected by a roll pin extending through aligned openings therein.

6. The utility knife according to claim 5, wherein said hinge is located at the rear end of said handle.

7. The utility knife of claim 1, wherein said blade mounting means comprises:
a plurality of longitudinal ribs extending rearwardly from the slot in the front end of said handle on opposite inside surfaces of said handle portions;
a blade carrier;
means for mounting said blade carrier on one of said handle portions for longitudinal sliding movement toward and away from the slot; and means for selectively securing said blade carrier in a plurality of longitudinal positions.

8. The utility knife according to claim 7, wherein said means for mounting said blade carrier includes a fastener extending through a longitudinal slot.

9. The utility knife according to claim 7, wherein the slot is located in a longitudinal recess in said blade carrier.

10. The utility knife according to claim 7, wherein said blade carrier is of generally channel-like configuration including:
a pair of spaced apart, longitudinal top and bottom flanges adapted for receiving the top and bottom edges of a blade therebetween;
a rear locating tab; and a T-shaped lug in a gap in the upper flange adapted for cooperating with a notch in the blade for purposes of retention.