CA1085151A - Rotary cutting tool for machining the surfaces of various workpieces and materials - Google Patents

Abstract

Abstract of the Disclosure The present invention relates to rotary cutting tools and can find most utility when applied for abrading the cylindrical surfaces of small-sized blanks. The tool comprises a number of the gangs of elastic cutting elements made as equal-length wire segments held together with one of their ends in a close proximity to which said cutting elements are forced against one another with their side surface, while the other (vacant) ends of the cutting elements establish the tool cutting surface featuring a factor of its filling with the butt ends of the cutting elements lying within 0.1 and 0.99. Each of the gangs of cutting elements (as viewed in a longitudinal section there-of) is essentially two opposite trapezia spaced equidistantly from the tool axis of rotation and facing said axis with their greater bases, a feature that adds much to the cutting capacity of the tool proposed herein.

Description

~L~8~
ROTARY CUTTING TOO~ FOR MAC~INING ~HE SURFACES
OF VARIOUS WORKPIEC~S AND MA'rBRIA~S

The presen-t invention relates generally to cutting tools and more ~peci~ically to rotary cutting -tools for ma-chining the surfaces o~ cylindrical worl~:pieces.
The invention can find most utility when used ~or ab-rading the cylindrical sur~aces of small-diame-ter blanks, such as wire rods subject to ~urther treatment in wire draw-ing machines.
It is known to e~tensively use at present diverse method~ o:~ and tools ~or cleaning the cyl:indrical ~ur~aces O:e varlou~ metal and nonm~tal workp:ieces, said method~ b~-ln~ as ~ollow~s (1) dip-scouring;

(2) treatme~t with abrasive wheels and belts;

(3) treatment in special snagging machines3

(4) treatment with rotary metal brushes3

(5) needle-milling.
ost commonly applicable in the present-day cleaning co~
practice is the tinuous dipping method and stationary-bath dipping o~ cylindrical surfaces o~ various workpieces and materials.
However, the disadvantages inherent in chemical dipp-_I ~

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' ' ' ' ~ 2-i~g process is a matter of common knowledge, i.e.~ it causes environmental contamination, produces harrnful ef~ect upon attending personnel and involves much capital investments and operating costs.
Cylindrical surfaces of various workpieces and mate-rials are also known to be cleaned with abrasives in ~pe-cial stationary machine~.
However, abra~ive wheels and belts feature but low en durance, while if used for -treating tough or ductile mate-rials, they are liable to get smeared and eorm burnt spots on the surface bein~ machined.
Furthermore, abra~ive cleanin~ Oe c~lirldriQal gurface~
i~ a laboutiou~ and co~tly ~rooe~s which badly a~lect~
uutomation owint~ to low ~nduranc~ ol' the abraslve tools used.
Abrasive cleaning i9 incapable oY efficiently machin-ing tough nonferrous materials, such as aluminium, copper, etc.
In addition, abrasive tools lade the surrounding atmo-sphere with abrasive dust in the course of machining.
Cleanin~ of cylindrical sur~aces of workpiece~ and ma-terials can also be carried out in special ~na~ginK ~rinders.
EIowever, such machine~ are capable O:e removing only surface flaws for a minimum depth Oe 0.5 mm, thus being not ~, :' -- 101~5~

suitable for cleaning off thin ~cale.
One o~ the cardinal disadva~tage~ of said method re-sides in h~avy loases of metal and great consumption o~ ~na~-ging tools.
Used in the present-day practice is the clea~ing of cylindrical surfaces O:e metal surfaces with the use of ro-tary brushes having inside cutting surfclce (cf., e.K~,, US
Patent No. 3,820, 184 ~1. 15/104.04).
Said brushes contain each a number of gangs of radial-ly arranged "bristles" held together with their one end and ~orming the tool working aurface, with their other end, said "bristlea" beinK held together in a ~anK aLong the outside perimeter thereo~ to form a rinB in a cro~s ae¢tLon o~' the tool.
However, the known brushes fail to cut off scale from the blank surfaces or fo~m cross notches on the surface be-inK machined for retaining grease during further machining in drawing benches, bei~g suitable only for par-tial removal of outside loo~ened layer o~ rust and dirt.
There is findin~ ever e~tending applica-tion at preaent one more method of cleanin~j cylindrical ~urface~ with the u~e of a cu-tting tool, i.e., needle-type millin~ cutter.This is accounted for by the ~act that such tools possess high cutting capacity and are convenient and simple in operatio~.

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~ here pertains to such -tools a rotary cutting tool~
comprising a number o~ elastic cutting elements arranged ra-dially on an arbor and made as equal-length wire segment3 held together with their one ends in a clo5e proximity to which said cutting elemen-ts are forced against one another ~ææ
Wittl ~heir side surface, whereas the opposite ~e=~$ ends thereof establish the tool cu-tting ~urface shaped as a sur-~ace o~ revolution, the ratio between tt:le sum o~ the face Ç r ~ Q
areas of the YRe~ ends of the wire segments on the tool CuttinK surface and the total area of the tool cu-tting sur-face being within 0.10 to 0.99 (cf. e.K,, US Patent No. ~, 928,900). Said tool .eeatllres its cutting c'lements ap;gregat-ed into ganKM lnterlaid by spaoer r:Lng~ witnin thc æone o~
their ends held to~cther, so that the cllrvature o~ the cutt-ing surface in the tool cross section follow~ sub~tantially the curvature o~ the surface being machined.
However, said known tool is applicable largely for cleaning the surface o~ rolled stock and peeling cast work-pieces, has a restricted use in cleaning small-diameter cy-llndrical surfaces and i9 ~uite inapplicable ~or treating wire rods. 'rhis i~ e~plained by the ~act that such a trea-tment produce~ longitudinal grooves or notchos on tha sur~ace -there-of rat~er than -transverse ones, the ~ormer being incapable o~ retainin~ grease on the wire rod sur~ace which is indis-': ~

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pensable for fu.rl:her treatrnent of wire ro-ls in wire drawing machines.
It is an object of the present invention to provide a rotary cu-tting tool, wherein its cut~ing capacity would be much increased due to an irnproved cons-truction of a gang of cutting elements thereof.
It is an important object of the presen-t invention to provide a rotary cutting tool featuring higher efficiency.
Accordingly, the present invention provldes a rotary cutting tool for machining the surfaces of various workpieces and materials, comprising: an arbor; a plurality of gangs of elastic cutting elements shaped as equal-length wire segments arranged rad.ially on said arbor; sa:id e.l.ast:ic cuttlng el.ements he.ing held toclether at one oE the.i:r ends a].ony the outsi.de per.imctcr the:reo.E -to .Eo:rm a r:ing :i.n the tool cross sect:i.on, and ~orced against one another at their side surfaces adjacen-t said held-together ends; free ends of said elastic cuttiny elements opposite to those held -together, forming a tool cutting sur:Eace being arranged such that ratio of -the sum of the areas of said free ends to the area of said tool cutting surfaces lies within the range 0.1 to 0.99; said ratio being known as -the arrangement density of said free ends; each oE said ganys of said elas-tic cutting elements, as viewed in longitud:irlal sect:ion, being essentially two opposite trapezia spaced equidistan-tly from the tool axis of rotation and facing said axis with the greater bases thereof; the ratio between the greater trapezium base and the lesser base thereo~ being determined from the following relation;

B = ~y (1 ~~ D

whexe B denotes the width of the tool cutting surface; Bl stands for the wi.dth of the surface established by the ends of the tool 'Y
cutting elements held together; `YO = 1 is the ratio between the `Y
,~' ~5~51 arrangement density of the ends of cutting elements on the surface at which their ends held together, and the arrangement density of the tool cuttiny surface A; Q indicates the length of cutting elements; and D represents the diameter of the tool cutting surface A.

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It i9 due to such a cons1ructiona:L arrangement of the propo~ed tool tha-t the con-tact o~' the tool cutting sur~ace i~Jith the s~face being treated occur~ over an area which makes it possible to considerably i~crea~e tool Gutting ca-pacity and diminish the number of tools required for the entire blank perimeter to covar.
In addition, the above-suggested ratio between the width o~ the -tool cutting sur~ace and the sur~ace of the wire ends held toKether makes provision for an angular po-~ition o~ the vacant peripheral ends of cutting elements with the surface be:ing machined which i~ instrumental in providlng a po~itive cutting angle ~ with respect to the di~ectlon o~ axlal travel oL' the workpiece be:in~; treated and obtaining an e~actly preset ~actor oI' it~ lling with the butts o~ the vacant ends of cutting elements lying with-in 0.1 to 0.99, thereby addint~ to the tool cutting capacity~
To promote understarlding, a detailed description o~
an exemplary embodiment o~ the pre~ent invention is se-t ~orth hereinbelow with re~erence to -the accompanying draw-ing~, wherein~
~ ig. 1 i~ a ~che~atic view of tha proposed cutting tool composed o~ a number o~' the garlg~ o:L cutting elements~
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Fig. 2 shows the cutting tool of Fig. 1, wherein a number of the gar)gs of cutting el.ements are aggregated into groups.
The herein-proposed rotary cutting tool for machining predominantly cylindrical workpieces (Fig. 1) comprises a number of gangs 1 of elastic cutting elements 2 made as, say, equal-length wire segments held together at one of their ends 3. In a close proximity to said ends 3 held together the cutt-ing elements 2 are forced against one another with their side surfaces, while their opposite free ends 4 define the tool cutting surface A. The ratio of the sum of -the areas of the cutting element ends to the area A of the cutting surface formed by the ends is known as the arrangement densit~ or .illiny factor, and must l.ie w.ith.in the range 0.1 to 0.99.
Provided betwccn the~ s:idc sur:Eaces o~ the gangs 1 on the side of the he:Ld-togethe:r ends 3 of the cu-t-ting elements 2 are spacer rings 5 having annular recesses 6. The gangs 1 of the elastic cutting elements 2 along with the spacer rings .
5 are enclosed in an eccentric bush 7. The cutting elements 2 may be made of round, square or rectangular-section wire, as well as be shaped as plates reinforced with cemented carbide or abrasive material. Each of the gangs 1 of the cutting elements 2 .is shaped as a ring whose longitud.inal section is essentially two trapezia 8 spaced equidistantly from the tool axis of rotation and facing said axis .
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5~,.51 9_ with their greater bases 9. In addition, -the ratio between the ~rea-ter base 9 of -the trapezium 8 an.d a lesser base lO
thereof is determined ~rom the ~ollowin~; relation:

Bl 1 (1 ~
where B denotes the wldth o~ the cutti.ng sur~ace A;
Bl stands ~or the width of the surface established by the ~leld-together ends 3 o~ the cutting elements 2;
= ~' is the ratio between -the density o~ arrang0ment o~ th~ butb ends o~ th0 outting elem0nt~ 2 on the ~ur~aoc l'ormed by their ends 3 held together, and -th0 d0n~1ty o~ arl~arl~em0nt o~ the butb end~ o~ the cutting elements 2 on the tool cutting surface A;
indicates the le~th o~ cutting elements;
D means -the diameter o~ the -tool cutting surface A.
'~he proposed tool (~ig. 2) may be composed o~ a number of the gangs 1 o~ the cutting elements 2 assembled into gro-ups II, 90 that the adjacent groups II o~ the ganK~ L are o~set with re9pect to 0ach oth0r by a quant:ity C which is determined ~rom the ~ollowing relation:
C = D - Do ~ 2~ (II) where D stands ~or the diame-ter o~ the tool cutting surface .,. ~ , , : ' ' lS~L

A;
Do denotes the diame-ter of the surface being treated;
~ means the amount of the radial deflection of the tool caused by the surface being treated which is determined experimentally.
Such a construction of the tool enables one to simplify the gear trains of the machine as the blank is machined by vir-tue of the stock travelling towards the arrow E and of the tool rotation substantially round its own axis, whereas tool rotation round the blank is negligible, mostly for changing the place of contact of the cutting surface A with the surface being machined.
The proposed constructional arrangement o~ the cutting tool and the ratio between the wid-th o~ the tool cutting surface and the width o~ its surace at -the held-tocJether ends rnake lt possible to effect the contact between the cut-ting surface and the surface being treated substantially over an area, and to obtain :~
an exactly preset arrangement density of the free ends of cutting .
elements which as a whole adds much to the tool cutting capacity and enables one to reduce the number of tools required for the entire blank perimeter to cover.
Disclosed hereinbelow are some examples of practical embodiment of the tool discussed hereinbefore.

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~ample 1 rotaryVtUtool ~ or peeling wire rod stock ~u~Pd~F
inside diameter D O:e the tool cutting ~ur~ace A
b4~ equal to 30 mm, Proceeding ~rom the tool cutting e~
ciency the width B o~ its cutting surface A equals 30 mm.
~he factor ~ of density o~ arrangement of the butt ends of cutting elements on the cutting ~urface A is equal to 0.8.
Proceeding ~rom a preset tool endurance equal -to 500 operat-;
ing hours let us assume the length 1 o~ the cutting elements~
equal to 25 mm. Inasmuch as a maximum possible factor ~ o~
density of arran~jem~nt o~ the butt ends o~ cutting elements on the ~ur~ace establi~tled by thelr ends held to~eth~r, in ca~e thc cutting elements are made as round-wire ~egments, is equal to 0.906, and a practically attainable clensity (a~ter applying a pressing ~orce not below 20 kgf/cm2) i~
equal to 0.88 or 0.9, we assume ~, to be equal to 0.9.
~hen ~ind that ~ 0.89. (III) 'L`hen, taking into account that, according to the in~ention B1 (1 ~ 2P ) (I) we ~ind that B (IV) B =(1 ~ -D ) o . .

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" ~85153 Having substi-tuted all the a~ore-s-tated magnitudes of the respective ~uan~ities -to Equatiorl IV~ we shall obtain:
3 = 12.7 mm Bl ~9 (1 ~ 2325 ~) Inasmuch -the sur~ace o~ a gang o~ cu-tting elements, as viewed ~rom the helt~-together ends thereo~, a9sumes somewhat convexity after having been exposed to presslng, the numeric-al value of Bl lies within 11.5 and 12 mm.
Example 2 'The rotary cutting tool made according to Example 1, is used in f~roups o~ the f~ang~ o~ cuttlnf;, elem~n~s ~or treat-ing wir~ rod ~tock reaturinf/; Do - 10 mm. In thi~ ca~e th~
amount by which one o~ the f~'rOUpS O~ the f~ang~ of cuttinK
elements is o~fset with respect to the other groups is equal to: ;
C = D - Do ~ 2 Q (V) or C = 30 - 10 ~ 2 0.5 - 21 mm. ~:

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A rotary cutting tool for machining the surfaces of various workpieces and materials, comprising: an arbor; a plurality of gangs of elastic cutting elements shaped as equal-length wire segments arranged radially on said arbor; said elastic cutting elements being held together at one of their ends along the outside perimeter thereof to form a ring in the tool cross section, and forced against one another at their side surfaces adjacent said held together ends; free ends of said elastic cutting elements opposite to those held together, forming a tool cutting surface being arranged such that ratio of the sum of the areas of said free ends to the area of said tool cutting surfaces lies within the range of 0.1 to 0.99;
said ratio being known as the arrangement density of said free ends; each of said gangs of said elastic cutting elements, as viewed in longitudinal section, being essentially two opposite trapezia spaced equidistantly from the tool axis of rotation and facing said axis with the greater bases thereof; the ratio between the greater trapezium base and the lesser base thereof being determined from the following relation:

where B denotes the width of the tool cutting surface; B1 stands for the width of the surface established by the ends of the tool cutting elements held together; ?o = ? is the ratio between the arrangement density of the ends of cutting elements on the surface at which their ends held together, and the arrangement density of the tool cutting surface A; ? indicates the length of cutting elements; and D represents the diameter of the tool cutting surface A.

2. A tool as claimed in Claim 1, wherein the adjacent groups of the gangs of cutting elements are offset with respect to each other by a distance found from the following equation:
C = D - Do + 2 .DELTA.
where D stands for the diameter of the tool cutting surface;
Do denotes the diameter of the surface being treated; .DELTA. represents the amount of the radial deflection of the tool caused by the surface being treated.