Note: Descriptions are shown in the official language in which they were submitted.
~5~3~
Technics Field
he present invention relates to the field of mschin-
in by cutting end, more psrticulsrly 7 to rotary cutting
tools and holders or securing them in tool-c~rrier.
he present invention con be Yost successfully used
for finish machining of paper embossing calender shafts
as ~lsnts of the paper and pulp industry.
Besides, the invention can be used it metal working
for finish or semi-finish machining of petals and their
alloys, as well as for machining non-metal articles.
Background Art
Rotary cutting tool are presently used in industry
for finish and semi-finish machining of work pieces. As
compared to other types of cutting, rotary gutting which
is characterized by rotation of the Quote tool end the
workups aroulld their axes allows to prolong the service
life of the cutter, to reduce the time of machining and
to improve the finish.
Rotary cutting tools used for realization of the pro-
cuss of rotary cutting posses such common features us em-
lunate of a cutter which it cantileverly secured to the
spindle of a cutting tool outed in a bearing unit which
is instilled in the cutting tool casing. Short service
life, low rigidity sod high metal consumption are chsrac-
touristic of the conventional designs of rotary cutting
tool 8 .
Conventional holders used for securing rotary cut-.
tying tools in a tool-carrier consist of a casing with
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;
~2;~$~Z3S
holes ~ccomodating the cutting tool and fflsteners. he known holders are disadvantages it that during fasten
in of the casing of the rotary cutting tool in the hole of
the holder Sheehan the inner hole of the casing of the rota-
I cutting tool, thaw serves as a set one for the radial
supports is deformed under the action of the fastening
force, which results in a shorter service life of the no-
try cutting tool and its lower rigidity.
Know is a rotary cutting tool comprising a bowl-
-shaped cutter that is cantileverly secured to the spin-
to of the cutting tool, mounted on supports resisting
radial and axial loads and ~ccomodated in a hole of the
casino whose outer surface is a surface of a body Or no-
volition, the support resisting an axial loud being disk
posed in the hole of the cutting tool casing between the
supports resisting radial loads ("Progressive diagrams
of rotary cutting of metals" by E.G.~onovaloY, Vowed-
rink, AVOW Souse "Nikko i Tokyo" Publishing souse
Minsky 1972, p. 20~, jig. 85b).
Also known is a holder for securing a rotary cutting
tool in a tool carrier, whose casing is provided with 8
hole to ~cco~odate the cutting tool sod holes to house
fafiteners, end is mode so that it partially embraces the
cutting tool casing along an arc ("Progressive diagrams
of rotary Cutting of teals by ~.G.Konovalov, Yessed-
rink, A.V.Sous. "awoke i Tunics" Publishing souse,
Minsky 1972, p. 189, jig. 76).
ifs
or the wake of simplicity hereinafter in the spew
suffocation the terms supports resisting radial lords"
anon support resisting sun axial load will be substitu-
ted with the terms radial supports" and "an vial sup-
port', respectively.
During operation of the conventional rotary cut-
tying tool the wall of its casing resist with its limited
portion a radial load constant ion its direction.
The local loading Durham of the cutting tool C8S-
in it the point of installation of the radial support
is essentially parasols disposed symmetrically restive
to the line of action Or the resultant radial load onto
the support. Hence, the load onto the cutting tool Sheehan
is maximal in the direction of the line ox action of the
resultant radial force and monotonously decreases in the
direction opposite to the live of action of the force.
The known designs Or rotary cutting tools do not
account for the character (law) of variation of the raid at
load acting upon the cutting tool casing. The thickness
of the walls of the cutting tool casing is the sue both
in the direction of the line of action of the radial
force upon the radial supports and in the opposite direct -
lion.
Hereford, in toe known design of the rotary cutting
tool the required reedit and service life are provided
due to thickening the whole wall of the casing of the
spindle unit, which results in its greater over-all dime-
sons and metal consumption A decrease in the thickness
- 5 - -I
.
I
of the Hall of the casing of such a cutting tool results
in a lower rigidity of the cutting tool and its shorter
service fife, as well as a lower durability of the cutter.
Removal from the cutting tool casino Or the support
resisting the axial load presents lsbour-consuming
technological operation await requires preliminary redo-
vet of the support resisting the radial load, which is
disposed closest to the cutter. In the known design ox
the rotary cutting tool the outer diameter of the support
resisting the axial loud does not exceed the inner dime-
ton of the set hole of the cutting tool casing at the
point of installation of the radial support of the cutting
tool, which is disposed closest to the cutter, us other-
wise the assembly process would be impossible.
The known design Or the holder securing a rotary
cutting tool in 8 talker' I the ~achine-tool is
dis~d~snta~eous in that when tightening (deforming) the
holder casino with fasteners Lyon on arc, the outer sun-
face of the cutting tool casino and, consequ~ntlyl its
inner surface in which the bearing unit of the cutting
tool is mounted sure deformed. The value of the ellipseness
Or the inner surface of the hole of the cutting tool casino,
arising in this case, by 2-5 times exceeds the ellipseness
allowed or manufacture Or the seat Cole of the cutting Jo
tool casing, accommodating the radish supports This no-
suits in lower rigidity of the rotary cutting tool end
its shorter service life, and brims down the stability
- 6 -
-I
Sue
Or the cutter in the process of machining. A decrease in
the force Or tightening the holder casing with fasteners
along an arc reduces the reliability of securing ox the
cutting tool casing in the holder, which brings about
vibration in the course of machining. The glue of the
ellipseness appearing in the seat hole of the Clayton
tool casino can be decreased by increasing the thickness
of the wall of the cutting tool casing, which results in
treater metal consumption of both the cutting tool and
the holder securing it in tool carrier, as well as in
a hither cost of its manufacture. In the majority of
cases increased dimensions of the holder wake it impost
sidle to use the latter in standard metal-worXin~ equip-
Monet
Brief Description of the Invention
The yin object of the present invention it to imp-
rove a rotary cutting tool and a holder securing it in
a tool-c~rrier, which would allow for a maximum increase
in the rigidity of the rotary cutting wool.
Arthur object Or the present invention is to provide
such a cutting tool add a holder whose Swiss life would
be longer thin that of the known cutting tool and holder Jo
of the same type.
Still another object of the present invention is to
provide the above rotary cutting tool and holder for so-
curing it in a tool-carrier, which as compared to semi-
far cutting tools and holders of the some type, would be
less petal counseling.
.'. ' ' ' ' ' "
~2~5~35
The above-mentioned and other objects are acco~pli~
shed by jeans of a rotary cutting tool comprising a rota-
rye cutting tool and a holder for securing it in a tool-
-carrier of the machine-tool, which in their co~binstion
would allow to maximal increase the rigidity- and Mervin
go life of the rotary cutting tool, to rise tabulate
Or the cutter and were characterized, sty the sums tire,
by low petal consumption.
he above task is accomplished by Miss of a rotary
cutting tool comprising 8 casing with a loaned Sirius
which is essentially the surface of body Or revolution,
sod with a hole accommodating supports that resist radial lo-
ads, have another support disposed there between and resist-
in an exist load, and carry spindle with a cflntile~erly it-
Ted bowl-shaped cutter, in which, according to the inanity-
on, the hole of the cussing is srran~ed eccentrically rely-
live to its outer surface and their geometrical axes are
disposed in one end thy save plane which is the plane of
symmetry of the cutting tool, and radial threaded holes
used for securing the cutting tool casing in the holder
are made in the casino of the cutting tool in the direct
lion opposite to the direction Or displacement of the
eccentricity, at the points of installation of the sup-
ports resisting radial loans, and at the side of the
outer surface Or the casino.
Due to the f act that the hole of tyke cutting tool
casino is arranged eccentrically relative to the outer
. - 8
.
US
surface of the casing the wall of the Cowan con hove a
smaller thickness in the direction ox displacement Or the
eccentricity, the thickness of the wall griddle Monet-
nuzzle increasing according to the parabolic law, and it
reaches its maximum thickness in the direction opposite
to the direction of displacement ox the eccentricity -
This design of the cutting wool casing accounts for the
parabolic character of variations of the radial loud act
in in the course of machining upon the wall of the cutting
tool casing. whereby, in the direction of the lint of act
lion of the greatest radial force the thickness Or the
wall of the cutting tool cnsin~ is the greatest, whereas
at the points of the casing where the value of the acting
radial force is smaller than its maximum value it is the
smallest. As the character of changes in the thickness
the wall of the cutting tool casing corresponds to the
character of variations of the radial load coin there-
upon, it is possible to rise by 1.5-3 times such quell
Tut indices of the rotary cutting tool as its rigidity
and durability, preserving, it the same time, its low
petal consumption.
Employment of the radial threshed holes prevents
appearance of the bending moment in the fatteners end,
conseguentl~, does not allow vibrations to appear in the
Joint of the cutting tool and the holder, which contribu-
toes to stability of the cutter in the course of machining
so the plsnea of suction of the radial force phasing
_ g _
2 S
through the radial supports end the points of fastening
the cutting tool casing (the r~stening radial threaded
holes) in the holder will in this case coincide.
In order to reduce metal consumption of the cutting
tool the amount of labor required for its manufacture,
it is guile expedient to aye the cutting tool casing ox
a stepped-c71indrical shape, whereby the step of the cut-
tin tool casino hiving the outer surface of a wrier
duster should preferably be disposed in the direct I-
Senate to the cutter US this portion ox the CUttiIlg tool
casino contains the radial support of the cutting tool,
which is closest to the cutter and determines durability
ox the latter because in the course of machining it
happens to be the most loaded one. the other portion of
the cutting tool casing haying the outer surface ox a
staller diameter contains toe radial support resisting
a radial force which is by I tires (depending on the
design features of the cutter) smaller thin the one act-
in upon the radial support disposed next to the cutter.
In view of the fact that this portion of the cutting
tool casino does not determine durability of the rotary cut-
tying tool and is least loaded in the course of machining
the outer diameter of the casing at the point Or install-
lion of the support can be substantially decreased as it
does no worsen the operating characteristics of the rota-
rye cutting tool but reduces its metal consumption.
In order to provide for the process of installation
o the support resisting the axial load into the cutting
- 10 -
issue
tool casing end it removal from the cutting tool casin~during disassembly, it is guile feasible to male a slot
opposite the support, from the side of the outer surface
of the casing end perpendicularly to the plane of Semite-
I ox the cutting tool, it which case it will become no
more necessary to preliminarily remove the support.re~isting
the radial load when extracting the support resisting the
axial load As a result, it becomes possible to place into
the cutting tool casing support resisting the axial
load of a greater voter diameter than the inner diameter
of the seat hole of the cutting tool coin at the point
of installation of the radial support closest to the cut-
tern An increased outer diameter of the support resiatin~
the axial load increases the diameter on which its solids
of revolution sure disposed, Thor raisin resistance of
the cutting tool spindle to vibration and increasing rigid
duty and durability of the rotary cutting tool. We hove
found that on increase in the diameter of the support no-
sitting the axial loud by 10~ provide the some increase
in the rigidity and durability of the rotary cutting
tool, which con be attained by increasing by 25-40% the
distance between the supports resisting radial Lindsey
However, a greater distance between the radial supports
would increase the dimensions of the cutting tool, its
metal consumption and the amount of labor required for
its manufacture.
The above and other objects are accomplished by that
,
,
5~3~i~
The above task is accomplished by that in holder
for securing a rotary cutting tool in tool-carrier,its
casing has a hole to acco~odate the casing of the cutting
tool and holes to house fasteners and is made 60 that it
partially embraces along an sac the casing Go the cutting
tool, end, in sccord~nce with the invention, it hs3 end port
Sheehan adjoining along an arc the outer surface of the cut-
tin tool cawing and a central portion disposed thereabout-
wren end with some gyp from said surface, the casing Or the
holder being made so that the ankle at which it embraces
the quote tool casing is in the range of 90 to 180 and
the holes housing fasteners being arranged coccal rein-
live to the threaded holes of the cutting tool casing.
The end portions adjoining along an arc the surface of
the cutting tool casing provide for their tight adherence
to the casing Or the cutting tool us the radius of the
arcs of the end portions corresponds to the radius ox the
outer surface of the cutting tool casing. The central port
lion disposed between the end portions and with some
gap prom the surface of the cutting tool shying provides
for uniform distribution of the load over the end Portia
owns of the holder, caused by the radial force ox cutting
so in the plane of its action (radial force) there is
no contact between the outer surface of the cutting tool
casing sod the surface of the hole of the holder casing,
To supplier mounting of the casing of the rotary cutting
tool in the holder the greatest single at which the hot-
don casino embraces the casing of the cutting tool should
'
be made us to 1~0, since other-wise, in order to con-
neat the casing of the cutting tool to the surface of
the hole of the holder cgsin~, it is necessary to Rowley-
~inaril~ ensure their strict coccal, which hampers
the assumably and increases metal consumption of the hot
don. It is not recommended to wake the angle ox embracing
staller than 90 as otherwise it will cause vibrations
of the cutting tool casino in the course of machining due
to increased specific pressures on end end portions of
the holder.
It it expedient to wake the holes housing fasteners
and made in the holder casing coaxial to the threaded ho-
lies in the casing of the cutting tool, as otherwise it is
extremely difficult to secure the cutting tool casing in
the casing of the holler. The casino of the cutting tool
is secured in the hole of the holder casing with the aid
of such widely used means as screws, pins, etc. which
are inserted into the holes housing fasteners and pro-
voided in the casing ox the holder end are screwed into
the threaded holes from the side of the outer surface
of the casino of toe cutting Tao thereby pressing the
outer surface of the cutting tool casino anisette toe
end portions of the holder.
The solder provides for revile securing of the
cussing Or the rotary cutting tool without any deformation
of its inner surface of the hole which is a seat one for
bearing support. This takes place due to the fact that
- tightening forces of the fasteners do Dot cause an
deformation in the outer surface of the casing of the cut-
- 13 -
~;~5;~35
tying tool but only contribute to its tight (strong) ache-
fence to the end percher;
- tightening forces of the fasteners do not cause any
deformation in the casing of the holder.
Brief Description of the Invention
The following detailed description of a specific em-
oddment of the present invention is given with reference
to the accompanying drawings, in which:
Fix. 1 show a general view ox a rotary cutting tool
with a hole in its casing made eccentrically relative
to its outer surface according to the invention, a long-
tudina~ section;
Fig. 2 is if view along arrow A in Fig. 1;
Fig. 3 is a section along line III-III in Fig. 2,
turned through 90;
Fix. 4 is a section along line IV-IV in Fig. 2,
turned through 90;
Fig. 5 shows a general view of a rotary cutting tool,
with the outer surface of its casino being of a stepped-
cylindrical shape, a variant of embodiment according to .
the invention, a longitudin~1 section;
. Foe 6 is a section along line VOW in it 5;
I 7 shows a general view of a holder for securing`
a rotary cutting tool in a tool-carrier, according to the
the invention, a cross-section;
Fig. 8 is a view along arrow B it . 7, turned
through 90;
Fig. 9 is a section along line IX-IX in jig. I,
- 14 -
~25~3S
turned through 90;
Fig. 10 is if section along line X-X in Yip. 8,
turned through 90.
Detailed Description of the Invention
A rightly cutting tool shown in Fig. 1 comprises if
casing 1 acco~odating a spindle 2 mounted on supports 3,4
resisting radial loads and a support 5 resisting an axial
load, the support 5 being disposed between the radish
supports 3 and 4. Cantileverly secured to the spindle Z
us a cutter 6. Axial displacement of the spindle 2 it it-
sited by a nut 7 which rests on an inner King of the ray
dial support I. Axial displsceme~t of the radial support
4 is limited by a retaining rink 8. The cutter 6 is so-
cured to the spindle 2 by means of a nut 9. A Neal 10
and a cap 11 protect from impurities a bearing unit coup-
rising the radial supports 3 rod 4 and the support no-
siesta an exist load. An outer surface 12 of the casino
1 his the shape of a body of revolution with a eater-
eel axis 13.
A hole 14 in -the casing 1 has a geometrical Axis I
and is displaced in the direction along an arrow 16 rota-
live to the outer surface 12 of the casing 1 of the cut-
tying tool over the value of an eccentricity "en.
Rsdisl threshed holes 17 phase I, 4),-18, 19 are
made in the cutting tool casing 1 in the direction oppo-
site to the direction along the sorrow 16 of displacement
of the eccentricity "e" of the hole 14 of the casing 1
- 15 -
12;~SZ3~
at the points of disposition of the radial supports 3
(jig. 2) and 4 and at the side of the outer surface 12.
The geometrical axes 13 and 15 sure disposed in plane
20 which is the plane of Sumter of toe cutting tool.
At the point of installation of the radish support 3
(Fig. 3) the cutting tool casing 1 has a thickness
vying along its perimeter. In the direction of display
cement ox the eccentricity "e", indicated by the arrow
16, the thickness of the wall ox tune cutting tool casing
1 decreases monotonously to reach its smallest value Spin
which is disposed in the plane 20 Or symmetry of the cut-
twig tool. In the direction opposite to the direction
indicated by the arrow 16 the thickness of the wall Or
the casing 1 ~nr.otonously increases and reaches its
greatest valve Smocks which is also disposed in the plane
20 of symmetry of the cutting tool.
At the point of installation of the radial support
4 (Fix. 4) the casing 1 of the quoter tool also has
thickness varying along its perimeter. the values of the
greatest Sax sod smallest Spin thicknesses of the wall
of the casino 1 sure disposed diametrically in the plane
20 of symmetry of the cutting tool
The number of fasteners disposed in the casing 1 Or
the cutting tool con be increased and, for instance, at
the point of disposition of the radial support 4 it con
be recommended that during mschi~ing of intermittent
surfaces two radial threaded holes disposed at both sides
of the plane 20 of symmetry of the cutting tool be jade.
- 16 -
.
. ' . '. ' . ' ' .
US Z 3 5
A rotary cutting tool shown in jig. 5 comprisescasin6 21 having a spindle I mounted on radial support
23t 24 and a support 25 resisting an axial load and en-
range between the radial supports 23 and 24. A cutter
26 is cantileverly secured by nut 27 on the spindle 22
- whose axial displacement is limited by 8 nut 28 resting
upon an inner ring of the radial support 24, Axing disk
placement of the radial support 24 is limited by a retain-
in rink 29. A seal 30 and a cap 31 protect the bearing
unit from impurities. The outer surface of the casino 21
of the cutting tool is jade of a stepped-cylindrical she-
pew whereby a step 32 of the cozily 21 having the outer
surface 34 Or a greater diameter is disposed in the dip
feat vicinity to the cutter 26. A step 33 of the ceding
21 having the outer surface 35 ox a smaller diameter is
the remotest from the cutter 26. A hole 36 of the cutting
tool chosen 21 with a geometrical axis 37 is displaced
relative to the outer surfaces 34 an I of the casing 21
in the direction indicated by an arrow 38. Because of the
different diameters of the steps 32 and 33 of the casing
21 the values of displacement of the eccentricity are
different too. The geometrical axis 37 Or the hole 36 is
displaced relative to the geometrical axis 39 Or the
outer surface 34 of the casing 21 of the cutting tool
over a value en. Tlle~eolaetrical axis 37 Or the hole 36
is displaced relative to the geometrical axis 40 of the
surface 35 Or the casing 21 over a value en, en > en in
any case. The geometrical sues 37, 39 end 40 are disposed
- 17 -
~ZZ~3S
in one plane 41 (Fig. 6) which is the plane of symmetry
of the cutting tool, otherwise the labor consumption of
manufacture and production C05t of the writer cutting
tool increase as the casing 21 becomes difficult to pa-
nectar. There is possible a case when the value of
displacement Or the eccentricity en I- i. 8. the geomet-
rival axis 37 of the hole 36 of the cawing 21 coincides
with the geometrical axis 39 of the outer surfs 35,
when the metal consumption of the rotary cutting tool
decreases.
The stew 32 of the cutting tool casino 21 accomoda-
yes the radial support 23 which is the closest to the
cutter and which determines the rigidity and durability of
the rotary cutting tool as in the course of machining it
resists the rusticity loan which by several tires exceeds the
loud acting upon the Ludlow support 24. Therefore to Roy
reedit of the support 23, it is necessary to increase
the thickness of the ~11 Or the coin at the point Or
il~stallntion of the radial support I for which purpose
the step 32 Or the chosen 21 having the outer Sirius 34
of a greeter diameter should be disposed in the direct
vicinity to the cutter 26. The radial support 24 which
is the remotest from the cutter 26 does not determine
rigidity and durability of the rotary cutting tool us in
the course of machining it is loaded with an insignificant
radial force, for which reason, in order to decrease metal
consumption of the rotary cutting tool, this support 24
should be disposed in the step 33 of the cutting tool
- 18
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.
~;225~3S
casing 21 having the outer surface 35 of a smaller dip-
Peter. A slot 42 it 5, 6) necessary for assembly end
disassembly of the support 25 18 maze in the cutting tool
casing 1 opposite the support 25 resisting en axial load
and perpendicularly to iota plane 41 of ~ymmetr~. Provision
of the slot 42 in the cutting tool casing 21 makes it pox-
sidle to mount the support 25 resisting on axial load
of a wrester outer diameter than the outer diameter of
the radial support 23 which is the closest to the cutter
260 the increased outer diameter Or the upper 25 inquiry-
sues the diameter of the traveling path ox the solids of
revolution, the rigidity Or mQUntin~ of the spindle 22
in the support 25 and, consequently, the reedit And
durability of the rotary cutting tool as A whole. The slot
42 used for preventing dust from getting into the bearing
unit is covered with a casing (not show in the drawings).
It is recommended to make the height h (Fig. 5) and the
width C (Fig. 6) of the slot 42 by I mm greater than
the height and the outer diameter of thy support 25 nests-
tin an exist load.
It is recommended to use thy rotary cutting tool whose
casing is provided with s slot for machining intermittent
surfaces and in other cases in which impact loads are in-
hornet. It is expedient to wake the slot at the side of the
staller thickness of the wall of the cutting tool casino
as this decreases the amount of labor required for its
manufacture.
19
'I
3LZZS~35
it. 7 shows a holder for securing A rotary Quoted
tool in tool-carrier, comprising a casing 43 go 8)
which has a hole to accommodate a casino 45 (Fig. 9)
of the cutting tori lid holes 46 I 8), 47, 48 for
housing Issteners 49 (Fix. 9), 50, 51 (Fix. 10). The
casino I of the holder is made so that it partially umbra-
cues the casino 45 of the rotary cutting tool along arcs
52, 53. the casing 43 ox the holder has end`portio~s 54
(Fits. 7, 8) and 55 which adjoin the outer surface of the
casino 45 of the cutting tool along arcs I end 53, Disco-
sod between the end portions 54 and 55 is a central port
lion 56 having central angle Jo an arranged with a zap
from the outer surface 57 of the casino 45 Or the rotary
cutting tool. the casing 43 ox the holder is made so that
the angle at which it embraces the casing 45 of the
cutting tool is in the range to 90 to 180. the holes 46,
47, 48 housing the fasteners 49,50,51 of the casing 43 of
the holder are made coaxial to threaded holes 58, 59, 60
of the casino 45 of the cutting tool. The holder has a
shank 61 ho which it is mounted and secured in the tool-
-carrier of the m~chine-tool.
he hole 44 of the casing 43 of the holder cores-
ponds to the outer surface 57 Or the casing 45 Or the
cutting tool, thereby providing tight adherence of the
end portions I and 55 Or the Collogue 43 of the holder
to the outer surface 57 of the casino 45 of the rotary
cutting tool along the arcs 52 and 53. Provision Or the
end pro lion 54 and I disposed at the both sides of the
- 20 -
,
Sue
central portion 56 ensures uniform force of fasteniIl~ of
the cussing 45 of the cutting tool to the end portions 54,
55 and in the course of aching mazes it possible to
distribute symmetricfllly the load caused by the cutting
force over the casing 43 of the holder, which contributes :.
to its rigidly Since the threaded holes I 59, 60 of .
the casino 45 of the retrieve cutting tool ore jade coaxial
to the holes 46, 47, 48 housing the fasteners 49, I, 51,
it is not difficult to secure the casing 45 of the rotary
cutting tool in the hole 44 of the casing 43 of the holder
by way of squire fasteners, for example, the squire 49,
50, 51 into the threaded holes 58, 59, 60 of the casing 45
ox the cutting tool.
It is recommended to choose the angle it which the
casino 43 of the holder embraces the casing 45 of the rotary
cutting tool depending on the condition of machining. For
example, for finish machining when the radial cutting force
does not exceed 10-15 kg, the Nile 90-120, for
symphonies machining, when the radial cutting force does
Slot exceed 35-40 I 120 - 150, in all other cases
150 ' 180 I:
he Nile which determines the position of the
central portion 56 ~eparfltin6 the end portion end 55
of the casino 43 of the holder is recommended to be select
ted depending on the Nile of embracing or example,
with - 90 -120, 30 35 with = 90-150,
= 35-40 and with 150 180, 40-90.
If the angle is chosen treater thin thy recommended
- 21 -
assess
one, this will decrease the length of' the arc of contact
Or the end portions 54 and 55 with the outer surface 57
of the casino 45 of the rotary cutting tool and, kinesic-
entoil ill decrease the strength of the joint ox the coin
45 of the rotary cutting tool with the casing I of the
holder. If the angle is chosen staller than the recomb
wended one, the plane in which the resultant of the cut-
tying force acts will pass through one of the end portions
54 or 55 of the casino 43 of the holler, which will result
in vibrations during Canaan.
In the case when the outer surface ox the cutting
-tool casing is of a stepped-cylindrical ape, the surface
of the hole of toe holder chosen should be also jade of
a step~ed-cylindricsl shape corresponding to the outer sun-
face of the casing ox the rotary cutting tool.
During assembly of the casing 45 of the cutting tool
with the chosen 43 Or the holder the fasteners 49, 50, 51
tightly press the outer surface 57 Or the cutting tool
Reincite the end portions 54 and 55 of the casino I ox the
holder The tightening force Our the rssteners 49, 50, I
does not deform the casing 45 of the rotary cutting tool;
as the tightening force of the fasteners 49, 50, 51 in
creases the tightness (strength) of adherence of the cay .
sing 45 of the cutting tool to the end portions 54 and So
along the arcs 52 and 53 increases too, the shape of slid
end portions 54 and 55 corresponding along the whole area
of contact to the shape of the outer surface 57 of the
casing 45 of the cutting tool The tightening force of
.
.
~L2;~:5~3S
the fasneters 49, 50, 51 does jot deform the casing 43 of
the holder either, which ensures reliable end durable
operation of the rotary cutting tool, and increases its
rigidity, preserYillg, at the same time, its small metal
consumption.
Principle of Operation
A rotary cutting tool shown in issue. 6 and holder
for securing it it a tool-c~rrier, shown in its 7-10,
jade according to the invention, operate so follows. Prior
to machining, a rotary cutting tool is secured in the hole
44 of the assign 43 of the holder, for which purpose the
casino 45 of the rotary cutting tool is placed into the
hole 44 of the casirlg 43 of the holder in such a wanner
tout the geometIicDl axes of the threaded holes 58, 59,60
mode in the easing 45 of the rotary cutting tool coincide
with the geometrical axes of the holes 46 I 48 housing
the fasteners of the casing 43 of the holder. ThereupoIl,
the fasteners 49, 50, 51 are screwed into the threaded
holes 58, 59, 60 of the casing of the cutting tool end are
tightened to press the casino 45 of the rotary cutting
tool against the end portions 54 end 55 of the casing 43
of the holder. As the arcs 52 end 53 forming the end port
lions 54 end 55 by their shape correspond to the shape of
the outer surface 57 of the casing 45 of the rotary cutting
tool. the tightening force provides for tight erroneous
of the surface 57 of the casing 45 of the cutting tool to
the end portions 54 and 55. As the force of tightening
-23-
~2i2523~;i
the fasteners 49, 50, 51 increases, the adherence of the
outer surface 57 of the casing I of the rotary cutting tools
to the arcs 52 and 53 of the end portions 54 and 55 becomes
tighter; whereby the force Of tightening the f~sterlers 49,
50~ 51 does not deform the casino; *3 of the holder, wish,
in its turn prevents deformation ox the outer surface 57
of the casing 45 of the rotary Quoted; tool and, kinesic-
entoil defor~atioII of its hole in which the radial supports
are mounted. Besides, this provides for the optimal coy
lions of the bearing; unit of the rotary cutting tool during
operation.
T.'lith the rotary cutting tool secured in the casino 43
of the holder, the latter in inserted with its shank 61
into the taol-carrier of the machine tool and it secured
therein.
The rotary cutting tool shoYJn in Fix. 1 functions as
follows. As a result of rotation of the workups and the
longitudinal feed of the cutting tool the cutter 6 rotates
together with the swindle 2 of t-he awaken tool in the boa-
rink unit around the geometrical axis 15. By means of the
outer ring of the radial support the radial load PRY
(Fig. 1) is resisted by a limited portion of the seat sun-
face of the hole 14 of the Quietly tool casino; 1 in the
direction of the live of action of the radial force. The
local load dozier of the casino, 1 of the rotary cutting
tool at the point of installation of the ray i at Cypriot 3
nigh is most loaded tooth a radial load is essentially a
-- 24 _
~zs~s
parabola which is disposed symmetrically relative to the
line of action of the radial loan. Since the shape of the
outer surface I of the casing 1 of the rotary cutting
tool relative to the hole I ox the casing 1 is also a
parabolic curve disposed symmetrically relative to the
plane of symmetry 20 of the cutting tool, the greatest Sax
(Fig. 3) value of the thesis ox the wall of the rotary
cutting tool casino 1 corresponds to the greatest value of
the radial load acting in the plane of symmetry 20 of the
cutting tool. A smaller value of the thesis of the wall
of the cutting tool casing corresponds to a smaller value
of the radial load, and at the points of the casino 1
where there is no radial load the thic'L~ess of the wall
of the casing 1 is the smallest Spin (I ), thy S no-
suiting in higher rigidity and durability of the rotary
cutting tool, preserving, at the same time, its Dow metal
consumption. It is expedient to use the rotary cutting
wool shown in jig. 1 in the cases when the radial load
acting on the radial support 4 which is the remotest from
the cutter 6 is by 3-5 times smaller thaw the radial load
acting upon the radial support I. .
In the cases ennui it is necessary to decrease the me-
tat consumption of the rotary cutting too it is expedient
to use the design of the cutting tool, in accordance with
which its casing is made of a stepped-cylindrical shape,
the portion of the cutting tool Casey Hun the outer
surface of a greater diameter being disposed in the dip
feat vicinity of the cutter.
- 25 - :
.
Sue
In the cases when the process of machining is kirk-
terraced by impact loads it is most expedient to Use the
design of the rotary cutting tool, in accordance with
which a slot is made in its casino perpendicularly to-the
plane of symmetry of the cutting tool whereby the outer
diameter of the support resisting in axial load should be
maximal increased, which will result in Herr rigidity and
durability of the cutting tool.
The radial force acting upon the casino 45 of the no-
try cutting tool secured in the casing I of the holder
uniformly presses the casino 45 of the cutting tool at the
point ox installation of the radial support which is the
closest to the cutter against the arcs 52 and 53 of the
end portions 54 and 55 with forces pi = pi (Fix. 4) which
are approximately equal to each other.
The fasteners 49, 50 create forces P of tightening
the casino *5 of the cutting tool and the surface of the
hole 44 of the casino 43 of the holder, which act in the
directions coinciding with the forces pi and PI. This in-
creases the strength of contact of the outer surface 57 of
the casing 45 of the cutting tool and the surfaces 52 and
53 of the end portions I and 55.
In the course of machining, the radial support winch
is the remotest from the cutter and the portion of the
cutting tool casino 45, in which it is disposed, are load-
Ed with a radial force Pi whose value is by 3-5 times
smaller than the value of the radial force acting on the
radial support which is the closest to the cutter. where
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.
I I I S
fore, the direction of the line of action of the riddled caused-by the force Pi exerts practically no ln~lu-
once on the strength ox connection of the casing 45 of the
cutting tool with the casing 43 of the holder because
the force P (Figs. 9, 10) ox tightening with the fastener
51 is by on order greater thaw the radial load caused by
the force Pi
he rotary cutting tool and the holder securing it
in a tool carrier, according to the present invention, are
easy to manufacture and are characterized by low metal
consumption; the service life of the holder is unlimited
and, as compared to the known designs of rotary Cutting
toots, durability of the rotary cutting tool according to
the invention is by 3-4 times greater owing to its treater
rigidity. the rotary cutting tool is resistant to vlbra-
Sheehan and stability ox the cutter of this cuttirlg tool
it by ~.2-1.4 times higher thaw that of the rotary cutting
tool of the known designs.
.
.. 27
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