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Dec. 7, 1948.
Filed Jan. 8, 1945
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Wank Wzgrzer,"
Patented Dec. 7, 1948
rumrso ‘ :sTArEs PATENT‘ “OFFICE
‘Frank 'Wagner, Chicago, ‘Ill., assignor to J.‘F.
v1Helrnold~&'Bro; Inc., Chicago, 111., a corpora
tion of‘ Illinois
Application. January 8, 1945, Serial No. 571,877
as claims;
(01. 76-101)
The present "invention-‘relates ‘to an improved
method I substantially reduce the time required
method of producing a die of the type used in
‘punching‘and related‘ or similar operations.
‘It is an object of the invention‘ to‘ provide a
. for the formation of a die, by entirely eliminating
the aforesaid counterboring step and by substi
tuting a simple spinning operation, I have found
that said spinning operation improves the, func
die and method of the type described whereby‘the
cost of production ‘of the die is substantially
tioning of the completed die in a manner to be
lessened by comparison with present procedures.
_ discussed.
‘A further object‘ is ‘to provide a-method for
‘Referring to Figs. 2, 3 and 4,‘the reference
producing punching dies,‘ rotary drills, and simi
numeral I 4 designates a suitable tubular blank
‘lar cutters,>which is‘capable ‘of being‘ performed 10 or body‘for‘ the'die to be produced, which may
more quickly andeasily'with a ‘well known type
of» apparatus and ‘which-‘results in'a tool having
,be-in‘ the form‘of a lengthof seamless mild steel
‘ tubing of, for example, SAE ‘1015. analysis. Alter
improved cutting e?iciency,
natively, if desired,.this .tube may be ‘fabricated
A still furtherobject is to‘ provide‘a method of
of a higher carboncontent steel or of an alloy
forming a-‘die 'or- like cutter, which, ‘except (for 15 steel of suitablecomposition, or of other suitable
‘the sharpening “of the cuttingedge thereof, in
material; depending ‘uponthe type, of cutting for
which'the ?nished dieis to‘be employed and the
volves only a-simple ‘spinning operation on a
plain tubular‘element, with resultant-high speed
limitations of ‘the further procedures to be
‘ andeconomy of production.
In the drawings,
fFigwl ‘is a‘viewrin elevation illustrating a die
or similar cutter produced in. accordance with
existing methods, which is the purpose of the
upresent. iinven‘tion'l toazsupersede;
As a ?rst step in the process, the tubular ele
ment 14‘ is set up ‘in a suitable apparatus and
subjected to a spinning operation in which the
nose thereof is spun over at [5 to frusto-conical
section, ‘as illustrated in Fig. 3, with the inner
Figs. 2, 3 and 4 are similar viewsnn vertical 25 and outer ‘diameters at said nose reduced some
transverse section, illustrating successive steps
in the production of a die or similar cutting ele
mentrsin accordance withi‘ithe provision of the
‘present invention; and
what. Of‘course, the inherent limitations of the
spinning‘procedure will impose some restriction
on the type‘ and‘ hardness of metal which can
.be employed in the cutter. , However, I have had
“ ‘Fig. 5 is a viewv illustrating a‘modi?ed method of .30 excellent results'with the SAE 1015 steel of which
performing a step in the method.
mention is made above. These matters are read
:In the production of conventional diesppunches
_ ily determinable with J the knowledge of physical
‘or like. tools, ‘such. as I have illustrated in i‘ Fig. l.
properties of‘metals by those skilled in the art.
.and designated ‘by the reference’ numeral all); it
is‘customary to operateion a ‘tubular ‘sleeve-like: 335
.blank of predetermined radial wall thickness “by
'?rst counterboring ‘said. tubular‘ elementi‘from
the rear'thereofat- II. was ‘to provide “a vsuffi
ciently great rearward clearance area of ‘cross
The factto be noted is that the spinning opera
tion provides a cutting circumference at the nose
ofthe blank which is sufliciently reduced in diam
eter, compared to the normal diameter of the
tubular die blankrearwardly thereof, to provide
adequate clearance for chips, waste, etc., and
section to enable ‘ready discharge of chips ‘of "2240 ‘that this is accomplished without counterboring
'5 board or ‘paper, cardboard, and the like, cut'by
‘the tool. Thetthus counterbored tube ‘is then
?nished'by grinding an outer cutting surface 12
or‘removal of material.
As the next step, ‘the inner surface of the nose
"l5. isground. at. It and the outer surface is ap
and an inner cutting surface 13 at the front end ‘
‘propriately ground at 11 to ‘de?ne the circum
or nose thereof. Needless to say, the operation 45 ferential sharpened knife edge necessary for the
of removing metal at counterbore H preliminary
to the grinding of the cutting edge makes the
die punching operation for which the cutter is
to be employed. It may be observed at this point
production of the die or cutter a relatively time
that a cutter produced in accordance with the
consuming one, since the work is ordinarily re
above procedure appears to be somewhat com
moved from the chuck or other holder and 50 pacted or hardened at the cutting nose [5, as
reversed intermediate the two steps. In any
by re?nement of the grain structure by cold work
event the counterboring operation represents a
ing or a work hardened toughening of the metal.
distinct expenditure of time, which it is the
As to the exact scienti?c nature of the phenom
purpose of this invention to eliminate.
enon, I make no attempt to explain the same but
In addition to the fact that by the present 55 only observe that it appears to exist. The tool
the ?nished form, which may be attributable to
a work hardening phenomenon.
adjoins the cutting extremity to define a circum
ferential cutting edge adjoined rearwardly by a
further unsharpened portion of said constricted
seems to acquire improved cutting properties in
I am aware that
nose section.
this phenomenon is pronounced in certain types
of steels, for example, alloy steels of the stainless
2. The method of making a cutting tool of
hollow tubular cross section, comprising radially
variety, and desire to point out that the pres
constricting a hollow cylindrical tube at a pre
sure and kneading action attending the spinning
determined nose section substantially coincident
operation which I have described, when coupled
with the intended cutting extremity of the tool
with subsequent grinding to form knife edges l6,
l7, may well be the basis of the improved cutting 10 by spinning said tube suf?ciently to substantially
reduce the inner circumference of said nose sec
action which I have observed.
tion as compared to the normal inner circumfer
In any event and whatever the reasons under
ence of the remainder of the tube, internally
lying the improved operating characteristic of
sharpening the portion of said restricted nose sec
the tool, the method of producing the same by
simply spinning a plain tubular blank and sharp- 15 tion which immediately adjoins the cutting ex
tremity, thereby to de?ne an annular cutting
ening results in a substantial economy of time and
edge, andterminating said internal sharpening
resultant decrease in cost, while producing the
of said internally reduced nose section at a zone
necessary rear clearance for free passage and ex
rearwardly adjoining said sharpened portion and
disposed inwardly of said normal inner tube cir
pulsiOn of the chips, disks or plugs which are
punched from sheet stock in the use of the cutter.
As a ?nal operation, the sharpened cutter is
suitably treated, if the circumstances of choice of
metal for the cutter and for its intended use so
indicate, as by a cyanide bath hardening opera
tion, to provide a further hardened outer skin ad N2 in
jacent the cutting edge which will render the
same more resistant to breakage :or chipping at
3. The method of making a cutting tool of
hollow tubular cross section, comprising radially
constricting a hollow cylindrical tube at a pre
determined nose section substantially coincident
with the intended cutting extremity of the tool
by spinning said tube sufficiently to substantially
reduce the inner circumference of said nose sec
tion as compared to the normal inner circumfer
foregoing process, wherein the spinning opera~ 30 ence of the remainder of the tube, internally
sharpening the portion of said restricted nose
tion for two different dies may be performed at
section which immediately adjoins the cutting
one time. In this embodiment the blank 18 is
that point.
In Fig. 5 I have illustrated an extension of the
twice the normal length and the spinning opera
tion is performed at the middle thereof to con
strict the blank at that point. Following this the
tubular blank is out in two at the medial con
stricted portion, and the noses on each of the
resultant spun elements are sharpened and heat
treated in the manner described above.
In the above description I have referred pri
marily to the production of a die or punch. How
ever, it will be appreciated by those skilled in the
art that the manufacturing steps are equally ap
extremity, thereby to de?ne an annular cutting
edge, terminating said internal sharpening of
" said internally reduced nose section at a zone
rearwardly adjoining said sharpened portion and
disposed inwardly of said normal inner tube cir
curnference, and heat treating said tool to im
prove the cutting quality of said edge.
The following references are of record in the
plicable to the production of rotary paper drills
dif ?le of this patent:.
and the like, or in fact to any type cutter to which
the spinning operation primarily characterizing
the novel method is applicable.
I claim:
1. The method of making a cutting tool of.
Number ,
Fuller ___________ __ Nov. 14, 1893
Casey ___________ __ Oct. 10, 1905
Colthar __________ __ Apr. 2, 1907
a hollow tube to constrict the same radially at a
Ayres _________ __‘__ May 12, 1914
predetermined section intermediate the ends of
the tube, which section is substantially coincident
with the cutting extremity of the finished tool,
andthereby to reduce the inner circumference of 55
said section compared to the inner circumfer
Boyd et a1 ________ __ Dec. 16,
Dawson _________ __ Apr. 14,
Englund _________ __ May 14,
Dunlap __________ __ Oct. 15,
Findlater ________ __ June 27,
'Esser ____________ __ Apr. 30,
Tomalis __________ __ Jan. 5,
Southwick _______ __ Dec. 27,
Hothersall _______ __ June 6,
Wilkie _____________ __ Oct. 3,
Jackson _________ __ Jan. 16,
hollow tubular cross-section, comprising spinning
ence of the remainder of the tube and to harden
the material of the tube at the nose section,
transversely subdividing the tube at said section
to produce a pair of similar blanks each having a 60
nose section of internally and externally reduced
diameter, and sharpening the portion only of
said constricted nose section which immediately
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