US 2382304 A
Description (OCR text may contain errors)
1945- c. FOLTZ ET AL 2,382,304
KNIFE AND METHODS OF MANUFACTURE THEREOF Filed March 24, 1941 INVENTOR BYGFHE 091/46 CHEL F0471:- r
Patented Aug. 14, 1945 it 'UNlTED' STATES PATENT OFFICE KNIFE METHOD OF MANUFACTURE THEREOF,
Carl Foltzand Gaar Davis, South Bend, Ind. ApplicationMarch 24, 1941, Serial No. 384,789
6 Claims. (01. 30-343) vided with a sharp cutting edge at I! and with This invention relates to improvements in knives and methods of manufacture thereof. The present application isa companion to our application entitled Manufacture of knife blades.
It is the primary object of the present invention to provide a method of manufacture and a product assuring a rigid 'andpermanent connection between the blade and a molded, one-piece handle notwithstanding the great difference in coefficients of expansion of the steel used in the blade and the plastic used to constitute the handle.- The method and construction herein disclosed are believed to solve for the first time the problem of making a knife by the automatic injectionmoldingof the handle about the blade.
It is a further very important object of the invention to provide a knife with a hollow handle. This is important becausethe handle serves as a float to prevent the knife from sinking in dish water ,orjelsewhere. By floating the blade, the handle prevents the accidents which are so commonly experienced when a sharp knife is out of sight below the surface of the water in a .dishpan.
. It is afurther objectof th invention to pro.
vide a knife construction in which .a hollow handle and the use of a transparent plastic material in the manufacture of the handle permit printed matter to be readily and interchangeably incorporated in the handle, secure against access of water and yet readily visible to the user through the handle.
Other objects will be apparent to those skilled in the art upon study of the following disclosure of the invention.
In the drawing: Fig. 1 is a side elevation of a completed knife made in accordance with the present invention.
Fig. 2 is a plan view of the knife shown in Fig. 1. l
Fig. 3 is a view in longitudinal section of the knife shown in Fig. 1.
Figs. 4, and 6 are views taken in section on the lines 44, 5-5 and 6-6, respectively, in Fig. 1.
Fig. '7 is a view on a reduced scale showing in plan the knives and interconnecting sprues as they appear in actual practice when molded.
Like parts are identified by the same reference characters throughout the several views.
The general design of the blade and handle is preferably in accordance with the disclosure of the Patent No. 2,124,615 granted to Wallie Foltz on or about July 26, 1938. The blade 8 has a blunt point 9 and a blunt back Hi. It is proare received. That portion of the handle lying between the ridge l9 and the; back [0 of the blade is extended along the back of the blade at 24 .to bring the user's fingers into intimate proximity to the blade to facilitate the manipulation thereof.
The handle 15 is provided interiorly with a hollow at 25 adapted to receive a strip or sheet of material 26 upon which advertising or other matter may be printed or lettered to bevisible through the flat surface l6 of the handle if the handle is made of a transparent plastic material. The end of the opening 25 in the handle is sealed by a closure 1Z1 having a form complementary to that. of the handle and made with a plug portion 28 fitted to the aperture. In practice, it 'is held in place by a cement made by dissolving cellulose acetate in acetone to provide a permanent seal. The hollow handle serves as a float entirely adequate to carry the weight of the blade while, at the same time, it lightens the weight of the handle to provide a better balance therefor and to facilitate the manufacture of the handle by injection molding. The pattern or die which forms the aperture 25 carries a projection (not shown) extending into the notch 29 in the end of the blade as a means of positioning the blade during the molding operation; While the projecting lug on the pattern or die does not appear, its form is clearly indicated in Fig. 3.
The blade shank or anchorage portion I2 has holes punched therein at 30 and 3|. Between these holes at opposite sides of the anchorage portion of the blade, are the notches 32 and 33. The combined area of the holes 30 and 3| and the notches 32 and 33 is preferably approximately 50% of the total area of that portion of the blade which is embedded into the handle.
It is very important to note that when the handle material has flowed into the notches and, apertures 30, 3|, 32 and 33, it provides keys which, are partially within the metal of the blade and which partiallyengage the metal of the blade from the outside. It is because of this arrangement that the blade may baanchored firmly by;
the handle stock which are engaged in notches;
32 and 33, but it will tighten its grip upon those portions of the handle stoclewhichhave flowedi into the apertures 30 and 3|. Conversely, if the ment of the notched tang end with a core, the molding of a handle about the tang end portion of the blade and about the notched end thereof and about the core inter-engaged therewith, and the withdrawal of the core to leave a hollow in the molded handle opening at the end of the handle, and the plugging of said hollow,
4. A knife comprising the combination with a lolade,v having a, cuttingportion and, a tang porblade, the tang portion having apertures through blade expands with respect to;v the;handle, ;itywill.,
loosen its engagement upon those portions of the handle stock which have flowed into arx-Qrtures the intermediate sides at points spaced longitudin-ally-thereof-=and having notches in its opposite "margins between said apertures, the combined area oi such apertures and notches being approximately equal to the remaining area of that tan-g portion which is embedded in the handle,
30 and 3| but it will become all the more tightly 1 engaged with those portions of the handle stock are "keyed into the-notches 32 an d '3 3. Thus, regardless of temperature changes; the -rig-id-i tyand permanence ot the conne'ction be tween. the blade and the handle is maintained":
f --In actualmractice, we prefer to make the'knife assemblies inpairs by automatic injectionmoldingof-hot-plastio in the'manner showninf Fig. 7; the two handles I 5 and the two endclosures 2 being moldedsim -taneously and connected by spruesaflil 155A kn fe comprising the combination with a blade leaving a shank portion provided with a ter;min-a1 openi-r-i-g, of a handle having an interior hollowwith which saidopening communicates,
said handle being in molded unitary connection with-the shank portion of-the blade.
2; Amethod of; making a-knife which comprises the: notchi-ng of the tangend of a blade,
the positioning of the blade by interengagement of the notched tangand with" a; core, the molding of; a handle about the tang end portion of-"th e blade and about the notch-ed end thereof and about the coreinter-engagedtherewith, j and" the withdrawal oi the core to leave a hollow inithe molded handle. A
' 3-.---A method of nfa-kingakn'irfe whichcomprises the'notching of the tang e'ndofa blade,
the positioning of the blade by inter-engagev and the handle having integrally molded key portions interlockingly engaged in the apertures and notches of the tangportion embedded therein.- r
5.A knife comprising in combination a blade having. a cutting portion: and a tang portion of sheet 'metal stock, the tang: portion having longitudinally spaced aperturesintermediate its side margins and being provided with. notches inmutual ly staggered relationship in opposite sideargins ofsaid tang portions betweenthe apertures thereinand having another'notch in itsend, a handle-molded upon the tang-portion of the blade and provided with a cavity opening away from the tang portion or the blade and i'n which the notchat the end oi the blade tangis exposed, s'aidhandlehaving integral portions moldedinto keying-[relationship totheapertures" and the side marginal notches of 1 the blade tang; the-combined area of-such-apertures and side marg-inal notches being approxi m'ately equal to the remaining area of the tang portion embedded in the handle.
6. The-kniieset forth in claim l -in which the handle is provided with-- aclosure; hermetically seal-ingits cavity, the size of" the cavity being so related to the weight of the blade and handle that said cavityisadaptedyto buoyup the knife mgwater; I 1 1 CARL FOLTZ: