US3058215A

US3058215A - Roofer's knife

Info

Publication number: US3058215A
Application number: US124649A
Authority: US
Inventors: Walter C Williams
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-07-17
Filing date: 1961-07-17
Publication date: 1962-10-16
Anticipated expiration: 1979-10-16

Description

Oct. 16, 1962 W. c. WILLIAMS 3,058,215

RooFER's KNIFE Filed July 1'7, 1961 Filed .Iuly 17, 1961, Ser. No. 124,649 3 Claims. (Cl. 30-317) This invention relates to a knife and, more particularly, relates to a knife with a removable blade. While the invention is widely applicable for its purpose, it has been initially constructed to serve as a roofers knife. This initial embodiment has been selected for the present disclosure and will provide adequate guidance for those skilled in the art who may have occasion to apply the same principles to the construction of knives for other specific purposes.

Ordinarily a roofers knife is of conventional construction with the blade permanently mounted in the handle. The blade must be frequently resharpened, because it is quickly dulled, and especially so when used to cut 90 pound slate-surfaced roofing. Repeated resharpening soon makes the blade useless and a whole new knife must be purchased. The primary purpose for providing a removable blade is economy since a removable blade costs only a fraction of a whole knife. Another reason may be to make it possible to use a number of different types of blades interchangeably for different purposes.

The problem met by the invention is to provide a simple, inexpensive, but efficient construction for removably mounting a blade. The invention meets this problem by employing a two-layer shank made of folded sheet metal. The juncture between the two layers formed by the fold is at the outer end of the shank and is employed to engage one longitudinal edge of the blade. The fold is at an obtuse angle to the axis of the shank to position the blade at the desired obtuse angle. Means is provided to lengage the second longitudinal angle of the blade at at least one point to hold the blade against the diagonal fold and thus hold the blade at the desired obtuse angle relative to the shank. A feature of the presently preferred embodiment of the invention is that this means to engage the second longitudinal edge of the blade is simply a marginal tongue of one of the two layers of sheet metal, the marginal tongue being bent into the plane of the second layer.

Since the two layers of the shank form a slot to receive the inclined blade it is merely necessary to draw the two layers together to clamp the blade in a fixed manner. For this purpose one of the two shank layers of metal may be formed with an apertured boss provided with screw threads. A simple screw extending through the other layer into the boss is tightened to clamp and immobilize the blade. A feature of the selected embodiment of the invention is that this screw is also positioned to lie against the second longitudinal edge of the blade in the same manner as the marginal tongue to hold the blade snugly against the fold of the metal of the blade shank.

The features and advantages of the invention may be understood from the following detailed description and the accompanying drawing.

In the drawing, which is to be regarded as merely illustrative:

FIG. l is a side elevation of the presently preferred embodiment of the roofers knife;

FIG. 2 is a perspective view showing how a piece of sheet metal may be cut to a V-shaped configuration for folding to form the shank of the blade;

FIG` 3 is a side elevation of the sheet metal after it has been folded but before the marginal tongue is bent to its final configuration;

FIG. 4 is a transverse cross section on an enlarged scale, the cross section being taken on the angular line 4-4 of FIG. 3;

AUnited States Patent O ICC FIG. 5 is a side elevation of a folded metal shank adapted to hold a smaller removable blade; and

FIG. 6 is a fragmentary view partly in elevation and partly in section showing the shank and blade of FIG. 5 incorporated in a finished knife.

The first embodiment of the invention shown in FIG. l comprises a handle 10, a shank member 12 permanently mounted in the handle and a blade 14 removably mounted on the shank. The handle 1li may be of conventional construction. As indicated in the drawing, the handle 10 may be made of wood with a reduced end portion embraced by a ferrule 15. In a well-known manner the ferrule 15 may be formed with a slot 16 as shown in FIG. 6 and the handle may be formed with a corresponding axial slot 1S to receive the shank member.

As shown in FIG. 2. the shank member 12 may be formed from a V-shaped metal blank that is generally designated by the numeral 20. The two

arms

22 and 23 of the metal blank are folded along a line 24 at the apex of the V-shaped configuration, the line bisecting the angle that is formed by the two arms. Each of the two

arms

22 and 23 is of similar elongated configuration with parallel side edges and the two arms are reduced in width at their outer ends to form relatively narrow base portions 25. When the two

arms

22 and 23 of the V-shaped metal blank are folded together along the line 24, they form the doublelayered shank member 12.

The V-shaped metal blank may be stamped out of sheet metal by a single punch press operation and at the same time the blank may be apertured in the manner shown in FIG. 2. The apertures include small apertures 26 in the ends of the two base portions 25 respectively which apertures register with each other when the blank is folded. The blank is further formed with an aperture 28 in the arm 22 and an aperture 30 in the arm 23 which apertures register with each other when the sheet metal is folded. The aperture 30 is formed into a boss 32 as shown in FIG. 4 and the boss is internally screw-threaded. After the two

arms

22 and 23 are folded together as shown in FIG. 3, a suitable screw 34 is inserted through the aperture 28 and is threaded into the aperture 34 to serve as means for drawing the two layers of metal together for the purpose of rigidly clamping the removable blade 14 in position.

As shown in FIGS. 2 and 3 the arm 22 of the V- shaped metal blank 2li is formed with a marginal tongue 35. After the two

arms

22 and 23 are folded together, the marginal tongue 35 is bent to the position shown in dotted lines in FIG. 4 to cause the tongue to extend into the plane of the second arm or layer 23. As may -be seen in FIG. l, the bent marginal tongue 35 is positioned adjacent the leading side edge 36 of the removable blade 14 to hold the trailing side edge 38 of the blade snugly against the juncture or fold 40 at the outer end of the shank member 12. In this particular embodiment of the invention the screw 34 also lies against the leading side edge 36 of the removable blade to serve as further means for holding the blade 14 against the juncture 4t) to maintain the blade at the desired obtuse angle relative to the shank member 12.

The leading side edge 36 of the blade 14 may be termed a first longitudinal edge of the blade and the trailing side edge 38 may be termed a second longitudinal edge of the blade. As may lbe seen in FIG. l a portion of the first longitudinal edge is sharpened and this portion extends away from the shank laterally thereof. The remaining portion of the first longitudinal edge 36 is unsharpened and the second longitudinal edge 40 is also unsharpened. The blade is confined in the slot of the shank by means engaging the two unsharpened edges of the blade.

The narrow base portions 25 of the two arms lie 3 snugly together face to face and extend through the slot 16 of the ferrule 15 into the axial slot 18 of the handle 10. A suitable cross pin 42 lmay secure the base portions 25 in the manner vshown in FIG. 6. The cross pin extends through the two apertures 26 of the base portions of the shank member and is peened to form heads 44 on its opposite ends.

It is a simple matter to insert a removable blade 14 into the slot formed vby the folded shank member to po- A sition the blade as shown in FIG. 1. The screw 34 is then tightened to clamp the blade in a iixed manner. The blade may be replaced whenever desired, it being a simple matter to loosen the clamping screw 34 temporarily for this purpose.

The removable blade may be of the conguration of the blade 14 in FIG. l. This con-figuration is suitable for cutting plain pound felt. This blade 14 is somewhat wider than a conventional hacksaw blade. The shank member 12a shown in FIG. 5 is of the same construction as the shank member 12 in FIGS. 1 and 3 but is dimensioned to hold a narrower blade 14a. The narrower blade 14a comprises a piece of hacksaw blade that is ground as shown to form a concavely curved cutting edge 45.

My description in specific detail of the selected embodiments of the invention will suggest various changes, substitutions and other departures from my disclosure within the spirit and scope of the appended claims.

I claim:

1. In a knife, the combination of:

a handle;

a shank member mounted on said handle and comprising a V-shaped piece of sheet material having two arms at an obtuse angle relative to each other, said sheet material being folded at the apex of the V- shaped configuration along a line that bisects said angle, the folded material providing two layers forming a Slot, the fold of said layers being at an acute angle relative to the length of the shank member; Y

tudinal edge on one side of the blade and a second longitudinal edge on the other side of the blade, a portion of said first edge of the blade toward one end thereof being sharpened and extending away from the shank member laterally thereof, the remaining portion of said rst longitudinal edge of the blade and the second longitudinal edge of the blade being unsharpened, said second unsharpened longitudinal edge of the blade abutting said fold, one of said layers of the shank member being formed with a tongue on one of its edges, said tongue 'being bent across said Slot in abutment with the unsharpened portion of the rst longitudinal edge of the blade; and

screw means extending into the two layers of the shank member across said slot in abutment with said unsharpened portion of the rst longitudinal edge of the blade, said screw means releasably drawing said two layers of the shank member towards each other to clamp the blade, said tongue and screw means being spaced apart to cooperate for holding the blade against said fold, said fold extending over the lfull width of the shank member for stabilizing the blade.

2. A knife as set forth in claim 1 in which the two ends of said two layers of the shank member are flat and are reduced in width to less width than the handle and are telescoped into the handle.

3. A knife as set vforth in claim 1 in which the two layers of the shank mem-ber have aligned apertures to receive said screw means, one of said apertures being formed to the configuration of an outwardly extending lboss and being threaded for engagement by the screw means.

References Cited in the le of this patent UNITED STATES PATENTS 98,286 May Dec. 28, 1869 164,675 Cushman June 22, 1875 1,044,303 Unsinger Nov. 12, 1912 2,272,805 Jaasund et al. Feb. 10, 1942