CA1266969A - Inclined cutter for surface cleaning head - Google Patents
Inclined cutter for surface cleaning headInfo
- Publication number
- CA1266969A CA1266969A CA000471922A CA471922A CA1266969A CA 1266969 A CA1266969 A CA 1266969A CA 000471922 A CA000471922 A CA 000471922A CA 471922 A CA471922 A CA 471922A CA 1266969 A CA1266969 A CA 1266969A
- Authority
- CA
- Canada
- Prior art keywords
- cutter
- teeth
- bar
- cutters
- cage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C23/00—Auxiliary devices or arrangements for constructing, repairing, reconditioning, or taking-up road or like surfaces
- E01C23/06—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road
- E01C23/08—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for roughening or patterning; for removing the surface down to a predetermined depth high spots or material bonded to the surface, e.g. markings; for maintaining earth roads, clay courts or like surfaces by means of surface working tools, e.g. scarifiers, levelling blades
- E01C23/085—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for roughening or patterning; for removing the surface down to a predetermined depth high spots or material bonded to the surface, e.g. markings; for maintaining earth roads, clay courts or like surfaces by means of surface working tools, e.g. scarifiers, levelling blades using power-driven tools, e.g. vibratory tools
- E01C23/088—Rotary tools, e.g. milling drums
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28D—WORKING STONE OR STONE-LIKE MATERIALS
- B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
- B28D1/18—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by milling, e.g. channelling by means of milling tools
- B28D1/181—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by milling, e.g. channelling by means of milling tools using cutters loosely mounted on a turning tool support
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Crushing And Pulverization Processes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
In apparatus for removing material from the surface of a solid substrate, a rotary cutter cage has a plurality of cutters where each cutter has a plurality of projecting cutter teeth. The improvement comprises an adaptation in mounting of the cutters on the cutter rotary cage to force a lateral movement in the cutters when they impact a solid substrate being treated during rotation of the rotary cutter cage.
In apparatus for removing material from the surface of a solid substrate, a rotary cutter cage has a plurality of cutters where each cutter has a plurality of projecting cutter teeth. The improvement comprises an adaptation in mounting of the cutters on the cutter rotary cage to force a lateral movement in the cutters when they impact a solid substrate being treated during rotation of the rotary cutter cage.
Description
9~
INCI,INED CUTTER FOR SURFACE CL~ANING HEAD
Field oE the Invention This inventlc~n relates to sur~ace ~reatment equipment ~or removing a layer of the surface, and in particular, rotary cutter cages having a plurality of cutters ~or impac-ting the surface to the treated.
Background of the Invention It is often desirable to remove a layer from a solid substrate such as concrete pavement, metal decks, fibreglass decks, and -the like, so as to prepare the surface Eor a subsequent finish coating such as paintiny, sealing, or retopping. A hand operated concrete surface treatment apparatus is disclosed in United States Patent 3,156,231. The rotary cutter caye Eor the apparatus carries a plurality o~ star-shaped cutter elements. During rotation oE the cu-tter cage, the cutter elements impact the concrete surface to chip away a layer Erom the surface. A larger self-propelled surface conditioning machine is disclosed in United States Patent 3,266,8~6. The apparatus includes a rotary cutter cage having several cutter elements. The cutter cage is rotated and transported across the surface to be treated to remove a layer of material Erom the surface. United States Patent 4,275,928 disclo3es a rotary cut-ter eaye Eor ~urEace treating apparatus where the inclividual cutters are provided with carbide tippecl teeth. The incl:iviclual cutters are mounted on circu:Lar bars where each eutter element has a cylinclrical bore extending -therethrough and ln a direction perpendicular to the pLane :in which the cutter teeth :Lie. ~n United States Patent ~,040,66~ a rotary cutter caye i~ provLclecl hav:Lng cutter eLements with an ~longate bore Eormecl therein to provide Eor a proloncJe~d impact oE the eutking element on the surface being treated.
A floor roughiny machine is disclosed in United States Patent 1,964,746. The maehine ineludes a rotary eutter cage having a plurality of cutters mounted on the caye. The bore extencliny throuyh each cutter ~J>
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elemen~ is considerably larger than the bar on whieh it is mounted. This provides for a loose independent play in each cutter while being held yieldably outwardly by centri:Eugal ~orce developed during rotation oE -the cutter cage. In use, the cutter cage is rotated at speeds of approxi.mately 400 to 800 rpm. Eaeh cutter member impaets the floor slightly in advance of its point of lowest travel and therea~ter resumes its outermost position on the cage~ The bore through each o~ the cutters is cylindrical and has a central axis extending in a direetion perpendicular to the plane in which the cutter teeth lie. Should a reduced number of cutters be mounted on the eutter cage, sufEicient spaee is provided between the eutter dlsks to allow tilting oE each clisk, so that a disc may slide o~f a hard spot and eut into a softer one. Aeeordingly, a eontinued use of the eutters in this arrangement tends to round the edges of the bore of each eutter. However, the central portion oE the bore remains eylindrical with an axis perpendicular to the plane .in whieh the eutter teeth lie.
In the eleanlng and grooviny of eraeks in surEaees, Unitecl States Patent 2,66~,2~1 diseloses a eutter arrangement whieh pxovides :Eor tilting of the i.ndividua:L eutter element. The syC;tem is partieularl~
adapted ~or r~moving mate:rial :Erom grooves in eonerete.
Th~ cutter has a eentral bore substantially larger than the ba:r :i.n wh:ieh it i.q mou:nted. 'rhis permits E:reedom o~ movelllant in the eutter to move radiall.y and t:rans-raclially a.c; well as t:Lpp:ing when a le~sser number of space:r wa.shers are used. Thi.s a:Llows th~ maehLne to Eol.Low c:ra.eks .in eonere-te when goucJ.incJ them eut for reseal.incJ .
:~n p:rineiple, a:L1 of the sur:Eaee eonditioning machines, as common -to the above-diseussed prior art, rely on the eutter elements impaeting the surfaee w.ith the eutter teeth lying in a plane essentially perpendicular to the plane of the surfaee. Thus, the eutter teeth of eaeh eutter element on the eutter eage impact the surface straight on, thereby having to overcome the resistance of concrete and other surfaces to chipping caused by compressive forces.
Summar~ of the Invention In accordance with an aspect of this invention, an improvement is provided in an apparatus for removing material from -the surface of a solid substrate. The apparatus comprises a support frame, a rotary cutter cage, means for mounting ~he rotary cutter cage on the frame and means for rotating the cutter cage. The rotar~ cut-ter cage has at least one row o~ a plura~ity of cutters mounted thereon for impacting a solid substrate. The at least one row of cutters is mounted on a bar connected to the rotary cage. Each oE the cutters has a plurality of projecting cutter teeth.
The improvement comprises means for forcing a lateral movement in each of the cutters when the cutters impact a solid substrate being treated during rotation oE the cutter cage in use of said apparatus.
According to another aspect of the invention a cutter is provided for use on a rotary cutter cage of an apparatus for removing material from a surface of a solid substrate. The cutter comprises a body portion with a bore extending therethrough to receive and be moun~ed on a bar connectecl to the rotary cutter cage.
'rhe hody portion carries a plurality oE outwardly pro~ecting cutter teekh. The cutter has means for effectincJ fl lateral movemcnt Oe the cutter teeth when the cutter is in use on a rotary cutter cage.
Brie~ ~ w~n~
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PreEerred embodiments O:e the inven-tion are shown in the drawings wherein:
E'iyure 1 is a perspective view of a mobile apparatus for removiny material :Erom the surface of a solid substrate;
Figure 2 is a perspective view of a cutter element for use on a rotary cutter cage mounted within the apparatus of Figure 1;
Figure 3 is an explocled perspective view o e the rotary cutter cage of the apparatus of Figure l;
Figure 4 is a sect:ion through -the rotary cutter cage as mounted on the apparatus of Figure l;
Figure 5 is a partial side elevation of the apparatus of Figure 1 with a portion removed to show the cutter elements mounted on the cutter caye;
Figure 6 generally i],lustrates the position of the cutter elements on the cutter cage under the influence o~ centrifugal force exerted on the cutter elements;
Figure 7 shows the lateral movement of each cutter element upon impacting the surface;
F.igure 8 illustrates another embodiment for the cutter element;
Figures 9 and 10 show the respective rest and cutting action positions of the cutter element of E'i.gure 8;
Figures 11 and 12 illustrate an alternative embodiment for the bore extencling through -the cutter element to effect the lateral movement in the cutter when impacting a surface;
Fiyure 13 illustrates an alternative cu-tter tooth arranyement for the cutter elemen-ts; and Fiyures 1~ and 15 illustrate an alternative mounting of the cutter elemenl, on the rotary cutter cage.
Detailed ~escription oe the Pre:eerred Embod:iments The apparatu.s 10 of F.i.yu:re 1 has a support Erame generall,y cle.si.gnatccl 12 w:ith housing 1~ Eor a rotary cutter cage 16 mounted w:Lthin and on the :Erame. A
moto:~ ln dr.iv~-3r-3-the rotary cutter cage throuyh a belt dr.ive housed with.in helt housing 20. ~ harldle 22 with control ~3w:itch 2~ .is mo~lnted to the rear of support Frame 12. A helght adjustment knob 26 is provided conven:iently at the uppex portion of the handle 22 to allow the operator to adjust the height O:e the rotary cutter cage relative'to the surface to be treated. Not shown in Flgure 1 are h.inged wheels at the rear o:E the .support frame which operate in conjunction with the i9~i~
front wheels 30 mounted to the housing 14. Thi~ system allows the operator, by adjusting knob 26, to vary the height of the rotary cutt2r cage relative to the ~urface to be treated, and thereby vary the depth of the layer to be removed from the ~olid substrate.
Various embodiment~ are provided for the cuttsr elements mounted on the rotary cutter cage 16 to cau~e a lateral movement in the cutter~ of the rotary cutter cage when the cutter~ impact the surfac2. With re~erence to Figure 3, the housing 14 has bearing blocks 32 and 34 mounted at each end of housing 14. A sha~t 36 extends through block 34 to which a drive pulley 38 is keyed and driven by drive belt 40 housed within b~lt housing 20. Mounted to the other end o~ shaft 36 i8 a drive hub 42 having four outwardly extending drive pin8 44 equally spaced about the hub 42. Centrally of the hub 42 i8 a threaded bore 46 which recelve3 the threaded end 48 o~ a connecting rod 50 of the rotary cutter cage.
The rotary cutter cage 16 ha~ a central axle 52, which is hollow and open-ended at each end 54 and 56.
Centrally of the axle 52 i3 mounted a pair o~
semi-circular segment3 58 and 60. At each end of the cutter aage 16 are and plates 62 and 64. In end plate 62 are blind end hole~ 68 and in plate 64 are apertures 66. Correspondingly in segments 58 and 60 are apertur~
70~ The a~ertures 66, 68 and 70 are aligned with one ano~h~r to receive the ~our carrier bar~ 72 which extend through thn aliyned aperture~ to be ~upported by the end plate~ 62, 64 and the central ae~ment~ 58 and 60. A~
the bar~ 72 are pa~sed ~hrough the aperture~, cutter elements 74 and spacer wa~her~ 7~ are a~embled on the bar 72. With the hars in place and all cutter elements a~aembled thereon to provide a complete cutter cage 16, the bars 72 are secured in place by way o~ an end plat~
78 which is ~ecured to the outside o~ plate 6~ by Allen sarew Pastaner~ 80.
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5 a The outer side of end plates 62 includes four apertures to receive the drive pin~ 44. Thu~; the . . .
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a~sembled rotary cutter cage is positioned on the drive pin~ 44 and connector bar 50 is passed through bearing 32 and threaded into aperture 46 o~ drive hub 42~ This compl~tes the assembly of the rotaxy cutter cage onto the drive system. At the same time, this method of asse~bly for the cutter cage provides ~or quick removal o~ the cutter cage, should replacement o~ the cutter elements be required, or the installation of anotAer cutter cage having different type~ of elements is lo desired. Thi~ provides for a variety o~ uses ~or the sur~ace treating apparatus while only requiring dif~erent sets o~ cutter elements.
In accordance with an embodiment of Figure 2, a cutter element 74 is in the shape o~ a ~tar having a body portion 82 with outwardly pro~ectlng teeth 84 having hardened cutter tips 86. A cylindrical bore 88 extends through the body portion 82 where the cutter tlp~ 86 are symmetrlcal about the central axis 90. The bore 88 i~ larger than the rotary cutter cage carrier bar 72. Accordlng to this embodlment, the bar 72 1 circular and ha~ a diameter le~8 than the diameter o~
the bore 88. ~he spacer ring 76 whlch may be a metal 0-ring has an ~nternal dlameter ~llghtly greater than the diameter o~ the bar 72 where the outer dlameter o~ the ring 76 ~oe~ no~ exceed the radial axtenk o~ the base portlon 92 o~ the cutter teeth. Thi~ arrang~menk allow~
l~teral movemqnt Q~ the cutter teeth 86 whan the cutter element 74 impact~ the ~urPace to be treated. The width o~ the metal 0-ring ln ~pacing apark ad~acent cutters ~0 preclude~ one o~ the cutter~ inter~ering with a tilting movement o~ an ad~acant cutter when the cutter teeth move latarally.
With re~erence to Figure 5, the di~erenca in dlamaters between the bore 88 o~ each cutter element 74 and the diameter o~ the carrier bar 72 is shown. The rotary cutter cage rotates in the direction o~ arrow 94 6 a due to the centrifugal ~orce of the cutter Plement 74.
The spacs 96 developed between the bore of each element and the bar circum~erence is located outwardly o~ th~
corresponding bar. cutter el~ment 74a is shown a~
impacting the surface 98 of the solid substrate 100.
The cutt~r 74a is demonstrated as being raised slightly from its outermost position on tha carrier bar 72. The //// ' ~ . _ .. _ .
.
', !1.~-~ ~ ~7~ ~9 dep-th -to which the cutter 74a will cut into the surlace 78 of the substrate is determined by the positioning of the Eront wheel 30 and the rear wheel 102. The adjustment knob 26 can vary the height of the wheel 102 by swivelling carrier arm 104 relative to the frame structure 14. As the rear wheel 102 is swung upwardly relative to the frame 14 to lower the frame towards the surface 98, the respective carrier bar 72 is lowered so as to press the cutter element 74a into the surface after it has impacted it by an interaction of the carrier bar against the lower portion of the bore 88.
Referring to Figure 4, the assembled rotary cutter cage 16 is illustrated in detail. The connector rod 50, as explained, is threaded into the bore 46 of the drive hub 42. The inner face 108 o~ the enlarged head portion 110 of the connector rod 50 clamps the end plates 62 and 64 between the drive hub 42 and the spacer washer 106. The thread direction o~ threaded bore 46 is such to ensure -tightening o rod end 48 in the bore 46 during operative rotation of -the cutter cage. A recess 112 is provided in head 110 to permit use of an Allen wrench to init.ially tlghten the rod S0.
The segments 58 and 60 are provicled centrally of -the ~5 rotary cutter cage 16 -to lend support to the carrier rods 72 to avoid stress crack:ing in the rods dur.ing the abuse to whi.ch they are subjected :in chipp.ing ~t ha:rd material.s such as conc.rete. The rotar~ cutter cage inC LU~Ieg :EOUL- car:r:ic.r rod~ 72 and thus provicles Eour 30 rows Oe cutters ac.r.oss the width of the ent.ire cutter cag~.. The support segments 58 and 6~ are of:E~et to ensure tha-k the cutters Oe one :row overlap the space between the next .row Oe cu tters in the central .rcyion.
~s ~eneral.l.y shown in F:igure ~, the upper row o:E
autters 74 all slant itt a fi.rst direction, whereas the bot-tom row oE cutters impacking the surface slant in an opposite direct.ion.
With reference to E'igures 6 and 7, the action is demonstrated in more detail. As shown ln Figure 6, the ~ 9~J~
upper edge of the bore 88a is contacting the carrier bar 7~. Assuming centrifugal ~oree is acting on the individual cutters 7~, the cutters will tend to slope ln the direction shown in Figure 6, because -the cutter -teeth 86 lie in a plane offset laterally of the bore contac-t point 88a. Due to the mass of the concave shaped plate for the star-shaped cutter, the cutter tends to pivot about contact point 88a so that the individual cutters tilt generally in the direction shown in Figure 6. The O-ring spacers 76 may be loose fitting on the bar. This loose fit for the spacers may permit a slight tilting in accommodaking the overall tilting of the adjaeent cutters.
The provision o~ a concave or dished shape for each of the cutter elements 74 causes a lateral movement of the cut-ter teeth 86 during impaeting of the cutter elements with the surEaee 98 of the solid substrate. It has been found that the bes-t cireumferential speeds for operatin~ -the eutter cage are in the range of l,800 to 3,000 feet/minute. At these speeds it is di-Eficult to properly ascertain what is happening wikh the cutter teeth 86 when -they impact a sur~ace. ~1owever, based on the results oE wear patterns on the cutter teeth, i.t i9 reali~ed tha-t the teeth are moving cJenerally in the diree-tion of arrow llg cluriny impaet or at :Least on initial impaet with the solicl substra-te. rrhe bottom port:lon 72a o~ the earrier rod i9 contact~ncJ the bottorn oE the hore portion a-t 88b a:Eter the eutter 7~a :impaets a sureace in the manr1er shown :in F~icJure 5. Due to the cutter teeth a6 :1.y.ing ln a p:lane :Lateral.ly o.e.~set o:E the bore eontaet area 88b, a moment arm is exerted about 88b to tilt the cutte:r element 7~1a in -the clirection opposite to khat of Figure 6 and thus ef:Eec-t a lateral movement in a cutter tooth 86 in the dl.reetion o:~ arrow ll~. As a result, -the ~orces imparted by the cutter teeth 86 onto the surface 98 have both a downward and horizontal eomponent.
~2~9Ç;.9 It is ~elieved to be this lateral sideways mcvement ol the cutter teeth which substantially improves the efficiency o~ this -type o~ cutter element compared to those of the prior art. In tes-ts conducted on concret~, the e~fectiveness of the star-shaped cutter teeth having a dish shaped of Figure 6, have at least a five-fold and in some instances eight-fold increase in ef~ectiveness in removing a concrete surface layer compared to the standard star-shaped cutter elements of the prior art patents such as United States 4,275,928 and United States 3,156,231. At these high speeds it is difficult to ascertain how the lateral movement in the cutter teeth accomplishes th:is significant improvement. It is theorized, however, that the lateral movement o:E -the cutter teeth improve the chipping action due to the fact that concrete has resistance to breakage in the compressive direction approximately ten -times greater than .its resistance to breakage in the tensile direction. I-t is believed that the lateral movement of the cutter teeth 86 in produciny a horizontal component of force take advantage of the weaker tensile strength of the concrete compared to its compressive strength. The cutter elements in accordance w:ith this invention in having a concave or dished shape provide the means for e:Efectiny latera.l. movement o~ the cutter teeth on i.mpacti.ng the surface. It ir) appreciated that the degree of concavity .;.n each cut-ter element has to be within a certain angular range in orcler to e:E:Eect this kiclc~over act:Lon Oe the cutters. ~'he angle bctween cutter tooth .Eaces 86-l and 86b ma~ range f:rom 90 to lS0. The p:re:ee:r:red anyle i.~-; approximatel~ 120. Once the cutle:r elemen-t .1.eave.r-.) the r~ur:Eace beiny treated, centri:Euy.ll ~orce :in e~sence resets the cutter to the opposite angle~ as r.~hown in Figure 6, to optimize on the extent Oe cutter tooth movement 86 :in the d.irection of arrow 114 o:E Figure 7.
W.i.th the remaining cu-tter elements illustrated in Figures 8 through 15, various arrangements are provided on the cutters to effect this lateral movement in the cutter teeth when impactincJ the surface being treated.
With -the cutter elements o~ Figures 8, 9 and 10, the cu-t~e.r element 116 consists of a body portion 118 having embedded therein carbide tips 120 symmetrically spaced abou-t the central a~is 122 of the cutter element. The body portion 118 is scalloped at areas 12~ between adjacent carbide tips to provide for wear on the carbide tips. A bore 126 extends through the body portion 118 of the cutter element 116 as shown in Figure 9. The bore 126 consists of a countersunk tapered portion 128 opening to one side 130 of the cutter element. The countersunk portion 128 extends across the major portion of the bore leaving a minor portion 132 openin~ to the other side 13~ oE the cutter element. The carbide tipped teeth 120 all lie generally in the same plane indi.cated by dotted li.ne 136. The plane of the cutter teeth is laterally offset of the minor c~lindrical portion 132. The body portion of the cutter element 116 is considerably heavier than the thinner plate portion of the cutter element 7~.
Due to -the lateral offset of the plane 136 of the cutter teeth relative to the contact area oE the cutter bore 132 against the bar 72, centr:i:Eugal forces acting on the cutter elements cause them to t:ilt gcnera].ly in the d:Lrect:ion indicated in :Fiyure 10. As previously e~plainecl, at high speed rotation~ of the~e cutter elementc~, :it i~ dif:icult to ascertain exactl.y wha-t action occur~ .in the cutter -teeth~ Mowever, it is theor:ixecl tha-t on :impact the cut-te.r e:Lement~ are tilted further :in the di:rectlon Oe ar.row 138 on the carrier bar 72 between the contact po.int 72a of the carrier bar ancl 132a o:E the cutter bore. ~rhis til-ting ac-tion is evidencecl b~ wear pat-terns on the cutter teeth where the so:Et~r metal in the area 1~0 is worn of:E to expose the edge oE the carbide tips 120. Therefore, in -the manner di~cussed in shaping the cutter bore, means is provided Eor effecting a lateral movement in the direction of arrow 138 for -the cutter teeth to take :. .
i r~
advantage of the weaker tensile strength o~ the concrete for purposes o~ removing a layer of concrete Erom the surface o~ the solid substrateO
In Figures 11 and 12, another embodiment for the bore configuration o~ the cutter elements for effecting lateral movement o~ the cutter teeth on impact with the surface ls illustrr~ted. The cutter element 142 has a plurality of cutter teeth 144 about its periphery and all lying in the sarne plane generally indicated by dotted line 146. The cutter teeth 1~ are carried on spikes about the perimeter of the cutter element 142.
The body portion 1~8 for the cutter element includes a bore generally designated 150 for mounting on the carrier bar 72. The bore 150, formed in the body portion ]~8 o~ the cutter element, has an axis 152 which is tilted relative to the plane 1~4 within which the cutter teeth 14~ lie. The bore 150 is oblong as shown in Figure 12 and has upper and lower bore surfaces 154 and 156. In use, the edge port~on 158 of the bore face 15~ is initially in contact wi-th the carrier bar 72 due to the centrifugal forces. The cutter element is encouraged to tilt in the direction shown in Figure 11 and on impact tilt further to the position shown in E'igure 11. Once the cutter is in contact with the surface, rotation is induced in the cutter 1~2 about the bar 72. Due -to the tilted orientatlon Oe the bore 150, the cutter -tends -to wobble as it rotates about th~ bar. r~hls wobble action enhances thc c~hipping efEect oE the teeth on the surEace as the teel:h move laterally. ~n add:ltion, as the cukter rotate~, pressure Oe the teeth on the surEace ls cycl:Lca:Lly increased clue to the oblong shape of the bore 150. rrhis action Eurther enhances the cut-ter eEficiency.
F'igure 13 il:Lustrates an alternative arrangement for the cut-ter teeth on a cutter element 162. rrhe cutter teeth 16~ lie in a plane adjacent a face 166 o~
the cutter element which is o~fset Erom the minor cy]indrical portion 168 oE the bore 170. The bore 170 9~;.9 also includes a tapered countersunk portion 172 which provides an arrangement similar to the bore 126 o~
cutter element 116 shown in Fi~ure 8. As with the action of the cutter element demonstrated in ~igure 10, similarly the bore 170 effects a lateral movement o~
the cutter teeth 164 in the direction of arrow 17~.
The cutter teeth 164 are at the end o~ spike portions similar to those of Figures 11 and 1~. Therefore, with the embodiments of Figure 8, 11 and 13, by way of shaping the bore for the cutter elements, the lateral movement in the cutter teeth of each cutter element during impact with the surface being treated signiEicantly improves the material removal by the chipping action of the teeth.
A third arranyement for effecting lateral movement in the cutter teeth is shown in Figures 1~ and 15. The cutter element 176 comprises a cylindrical collar 178 having a cylindrical bore 180. Mounted to the collar are a plurality of outwardly projecting spikes 182 having hardened cutter teeth portions 18~. The circular bore 1~0 is o~ a diameter to Eit over the carrier bar 72 in the manner shown in Figure lS. The cutter teeth 1~ lie generally in the plane 186 which is tilted relative to the central a~.is 188 oE the carrier bar 72 and of the cylindrical bore 180 of the collar 178~ Thus the plane, o.E cutter teeth 186 is tilted re~lat:Lve to the central a~i.s 18~. On impact, the cutter element 176 rotates Oll carr.ier bar 72. The til.ted plane o:~ the cutte.r teeth on the col:Lar e.E~ects a latera:l rnovement O:e the -teeth across the concrete sur~ace, b~ wa~ of a wo~b:l.e-t~pe movement along the surEclce, to ~emove acJyre~.~Jively rnaterial from the sur.~ace o.~ the so.Licl ~ubstrate.
In order to provide ~or even wear on the cu-tters, the~ are allowed to rota-te on the carrier bar to avoicl the ~ame teeth alwa~s impacting the ~ur:Eace and wearing the cutte:r down in one area more than the other. It has been found that in treating concrete surEaces, this lateral motion in the cutter teeth provides a smoother finish ~or the treated surface than the normal planar -types of cutter elements which ~ertically impact the surface being treated. Furthermore, it has been found that the cutter elements las-t considerably longer although they achieve superior results concernlng the amount of material removed during a comparable timeframe ~or both the prior art types of cutters and the cutters according to this invention. It is theori.zed that by using the cutters according to this invent:lon which tend to attack the surface being treated at an angle, takes advantage oE the weaker tensile strength of the material being treated, such as concrete, to provide a superior rate of material removal.
The cutter elements may include carbide bits embedded therein or may be formed of metal which has hardened tips. For example, the star-shaped cutters of Figure 2 may be formed from plate steel with the star-shaped cut out and subsequently dished to ~orm the concaved cross section. The selected steel may be a high carbon steel such as C-1075 and hardened to a Rockwell hardness of up to C60. The concavity in the plate may be formed by a proc~ressive die working on -the 2S blank p:Late portion. The shaped cutter .is then hardened to tile desired hardness. The carbide tip cutters may have their hody portion .Eormecl by s-tampincJ
them from metal o:r fo.rmed b~ lnvestment casting with carbi.de tips :in placc :i.n the mold. In :EormincJ the wall po:rt.ion :i.n the carbicle tip cutters such as in Pigure 8, :it :L~ preEerable to leav(3 the smal]. cylindrical shoulcler 132 which has bctter wear characteristics than the arrangement of the conica:L porti.on 12~ extending all the way ou-t to the other side 1~4 of cutter body portion. The cutter body portion may be formed from a "Super Impacto" (trademark) metal sold by Atlas Steels o~ Toronto, Canada. In forming the bore, the desired angle of the conical portion of the bore or the plane of tilt o~ the cutter teeth relative to the central ~',,, ,. ' '' ;
axis of -the carrier bar or collar may range from 5 to 75. Although improved working characteristics are achieved when the angle varies from 10 to 60, and preEerably from 15 to 45.
The O-ring spacers used with the cutter element 74 of Figure 2 may be formed of spring wire which have an o-verall external diameter less than the height of the body port.ion of the cutter element to enable the cutters to oscillate during use of the cutter elements.
While preferred embodiments have been described and illustrated herein, a person skilled in the art will appreciate that changes and modifications may be made thereto without departin~ from the spirit and scope of -this inven-tion as defined in the appended claims.
INCI,INED CUTTER FOR SURFACE CL~ANING HEAD
Field oE the Invention This inventlc~n relates to sur~ace ~reatment equipment ~or removing a layer of the surface, and in particular, rotary cutter cages having a plurality of cutters ~or impac-ting the surface to the treated.
Background of the Invention It is often desirable to remove a layer from a solid substrate such as concrete pavement, metal decks, fibreglass decks, and -the like, so as to prepare the surface Eor a subsequent finish coating such as paintiny, sealing, or retopping. A hand operated concrete surface treatment apparatus is disclosed in United States Patent 3,156,231. The rotary cutter caye Eor the apparatus carries a plurality o~ star-shaped cutter elements. During rotation oE the cu-tter cage, the cutter elements impact the concrete surface to chip away a layer Erom the surface. A larger self-propelled surface conditioning machine is disclosed in United States Patent 3,266,8~6. The apparatus includes a rotary cutter cage having several cutter elements. The cutter cage is rotated and transported across the surface to be treated to remove a layer of material Erom the surface. United States Patent 4,275,928 disclo3es a rotary cut-ter eaye Eor ~urEace treating apparatus where the inclividual cutters are provided with carbide tippecl teeth. The incl:iviclual cutters are mounted on circu:Lar bars where each eutter element has a cylinclrical bore extending -therethrough and ln a direction perpendicular to the pLane :in which the cutter teeth :Lie. ~n United States Patent ~,040,66~ a rotary cutter caye i~ provLclecl hav:Lng cutter eLements with an ~longate bore Eormecl therein to provide Eor a proloncJe~d impact oE the eutking element on the surface being treated.
A floor roughiny machine is disclosed in United States Patent 1,964,746. The maehine ineludes a rotary eutter cage having a plurality of cutters mounted on the caye. The bore extencliny throuyh each cutter ~J>
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elemen~ is considerably larger than the bar on whieh it is mounted. This provides for a loose independent play in each cutter while being held yieldably outwardly by centri:Eugal ~orce developed during rotation oE -the cutter cage. In use, the cutter cage is rotated at speeds of approxi.mately 400 to 800 rpm. Eaeh cutter member impaets the floor slightly in advance of its point of lowest travel and therea~ter resumes its outermost position on the cage~ The bore through each o~ the cutters is cylindrical and has a central axis extending in a direetion perpendicular to the plane in which the cutter teeth lie. Should a reduced number of cutters be mounted on the eutter cage, sufEicient spaee is provided between the eutter dlsks to allow tilting oE each clisk, so that a disc may slide o~f a hard spot and eut into a softer one. Aeeordingly, a eontinued use of the eutters in this arrangement tends to round the edges of the bore of each eutter. However, the central portion oE the bore remains eylindrical with an axis perpendicular to the plane .in whieh the eutter teeth lie.
In the eleanlng and grooviny of eraeks in surEaees, Unitecl States Patent 2,66~,2~1 diseloses a eutter arrangement whieh pxovides :Eor tilting of the i.ndividua:L eutter element. The syC;tem is partieularl~
adapted ~or r~moving mate:rial :Erom grooves in eonerete.
Th~ cutter has a eentral bore substantially larger than the ba:r :i.n wh:ieh it i.q mou:nted. 'rhis permits E:reedom o~ movelllant in the eutter to move radiall.y and t:rans-raclially a.c; well as t:Lpp:ing when a le~sser number of space:r wa.shers are used. Thi.s a:Llows th~ maehLne to Eol.Low c:ra.eks .in eonere-te when goucJ.incJ them eut for reseal.incJ .
:~n p:rineiple, a:L1 of the sur:Eaee eonditioning machines, as common -to the above-diseussed prior art, rely on the eutter elements impaeting the surfaee w.ith the eutter teeth lying in a plane essentially perpendicular to the plane of the surfaee. Thus, the eutter teeth of eaeh eutter element on the eutter eage impact the surface straight on, thereby having to overcome the resistance of concrete and other surfaces to chipping caused by compressive forces.
Summar~ of the Invention In accordance with an aspect of this invention, an improvement is provided in an apparatus for removing material from -the surface of a solid substrate. The apparatus comprises a support frame, a rotary cutter cage, means for mounting ~he rotary cutter cage on the frame and means for rotating the cutter cage. The rotar~ cut-ter cage has at least one row o~ a plura~ity of cutters mounted thereon for impacting a solid substrate. The at least one row of cutters is mounted on a bar connected to the rotary cage. Each oE the cutters has a plurality of projecting cutter teeth.
The improvement comprises means for forcing a lateral movement in each of the cutters when the cutters impact a solid substrate being treated during rotation oE the cutter cage in use of said apparatus.
According to another aspect of the invention a cutter is provided for use on a rotary cutter cage of an apparatus for removing material from a surface of a solid substrate. The cutter comprises a body portion with a bore extending therethrough to receive and be moun~ed on a bar connectecl to the rotary cutter cage.
'rhe hody portion carries a plurality oE outwardly pro~ecting cutter teekh. The cutter has means for effectincJ fl lateral movemcnt Oe the cutter teeth when the cutter is in use on a rotary cutter cage.
Brie~ ~ w~n~
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PreEerred embodiments O:e the inven-tion are shown in the drawings wherein:
E'iyure 1 is a perspective view of a mobile apparatus for removiny material :Erom the surface of a solid substrate;
Figure 2 is a perspective view of a cutter element for use on a rotary cutter cage mounted within the apparatus of Figure 1;
Figure 3 is an explocled perspective view o e the rotary cutter cage of the apparatus of Figure l;
Figure 4 is a sect:ion through -the rotary cutter cage as mounted on the apparatus of Figure l;
Figure 5 is a partial side elevation of the apparatus of Figure 1 with a portion removed to show the cutter elements mounted on the cutter caye;
Figure 6 generally i],lustrates the position of the cutter elements on the cutter cage under the influence o~ centrifugal force exerted on the cutter elements;
Figure 7 shows the lateral movement of each cutter element upon impacting the surface;
F.igure 8 illustrates another embodiment for the cutter element;
Figures 9 and 10 show the respective rest and cutting action positions of the cutter element of E'i.gure 8;
Figures 11 and 12 illustrate an alternative embodiment for the bore extencling through -the cutter element to effect the lateral movement in the cutter when impacting a surface;
Fiyure 13 illustrates an alternative cu-tter tooth arranyement for the cutter elemen-ts; and Fiyures 1~ and 15 illustrate an alternative mounting of the cutter elemenl, on the rotary cutter cage.
Detailed ~escription oe the Pre:eerred Embod:iments The apparatu.s 10 of F.i.yu:re 1 has a support Erame generall,y cle.si.gnatccl 12 w:ith housing 1~ Eor a rotary cutter cage 16 mounted w:Lthin and on the :Erame. A
moto:~ ln dr.iv~-3r-3-the rotary cutter cage throuyh a belt dr.ive housed with.in helt housing 20. ~ harldle 22 with control ~3w:itch 2~ .is mo~lnted to the rear of support Frame 12. A helght adjustment knob 26 is provided conven:iently at the uppex portion of the handle 22 to allow the operator to adjust the height O:e the rotary cutter cage relative'to the surface to be treated. Not shown in Flgure 1 are h.inged wheels at the rear o:E the .support frame which operate in conjunction with the i9~i~
front wheels 30 mounted to the housing 14. Thi~ system allows the operator, by adjusting knob 26, to vary the height of the rotary cutt2r cage relative to the ~urface to be treated, and thereby vary the depth of the layer to be removed from the ~olid substrate.
Various embodiment~ are provided for the cuttsr elements mounted on the rotary cutter cage 16 to cau~e a lateral movement in the cutter~ of the rotary cutter cage when the cutter~ impact the surfac2. With re~erence to Figure 3, the housing 14 has bearing blocks 32 and 34 mounted at each end of housing 14. A sha~t 36 extends through block 34 to which a drive pulley 38 is keyed and driven by drive belt 40 housed within b~lt housing 20. Mounted to the other end o~ shaft 36 i8 a drive hub 42 having four outwardly extending drive pin8 44 equally spaced about the hub 42. Centrally of the hub 42 i8 a threaded bore 46 which recelve3 the threaded end 48 o~ a connecting rod 50 of the rotary cutter cage.
The rotary cutter cage 16 ha~ a central axle 52, which is hollow and open-ended at each end 54 and 56.
Centrally of the axle 52 i3 mounted a pair o~
semi-circular segment3 58 and 60. At each end of the cutter aage 16 are and plates 62 and 64. In end plate 62 are blind end hole~ 68 and in plate 64 are apertures 66. Correspondingly in segments 58 and 60 are apertur~
70~ The a~ertures 66, 68 and 70 are aligned with one ano~h~r to receive the ~our carrier bar~ 72 which extend through thn aliyned aperture~ to be ~upported by the end plate~ 62, 64 and the central ae~ment~ 58 and 60. A~
the bar~ 72 are pa~sed ~hrough the aperture~, cutter elements 74 and spacer wa~her~ 7~ are a~embled on the bar 72. With the hars in place and all cutter elements a~aembled thereon to provide a complete cutter cage 16, the bars 72 are secured in place by way o~ an end plat~
78 which is ~ecured to the outside o~ plate 6~ by Allen sarew Pastaner~ 80.
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5 a The outer side of end plates 62 includes four apertures to receive the drive pin~ 44. Thu~; the . . .
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a~sembled rotary cutter cage is positioned on the drive pin~ 44 and connector bar 50 is passed through bearing 32 and threaded into aperture 46 o~ drive hub 42~ This compl~tes the assembly of the rotaxy cutter cage onto the drive system. At the same time, this method of asse~bly for the cutter cage provides ~or quick removal o~ the cutter cage, should replacement o~ the cutter elements be required, or the installation of anotAer cutter cage having different type~ of elements is lo desired. Thi~ provides for a variety o~ uses ~or the sur~ace treating apparatus while only requiring dif~erent sets o~ cutter elements.
In accordance with an embodiment of Figure 2, a cutter element 74 is in the shape o~ a ~tar having a body portion 82 with outwardly pro~ectlng teeth 84 having hardened cutter tips 86. A cylindrical bore 88 extends through the body portion 82 where the cutter tlp~ 86 are symmetrlcal about the central axis 90. The bore 88 i~ larger than the rotary cutter cage carrier bar 72. Accordlng to this embodlment, the bar 72 1 circular and ha~ a diameter le~8 than the diameter o~
the bore 88. ~he spacer ring 76 whlch may be a metal 0-ring has an ~nternal dlameter ~llghtly greater than the diameter o~ the bar 72 where the outer dlameter o~ the ring 76 ~oe~ no~ exceed the radial axtenk o~ the base portlon 92 o~ the cutter teeth. Thi~ arrang~menk allow~
l~teral movemqnt Q~ the cutter teeth 86 whan the cutter element 74 impact~ the ~urPace to be treated. The width o~ the metal 0-ring ln ~pacing apark ad~acent cutters ~0 preclude~ one o~ the cutter~ inter~ering with a tilting movement o~ an ad~acant cutter when the cutter teeth move latarally.
With re~erence to Figure 5, the di~erenca in dlamaters between the bore 88 o~ each cutter element 74 and the diameter o~ the carrier bar 72 is shown. The rotary cutter cage rotates in the direction o~ arrow 94 6 a due to the centrifugal ~orce of the cutter Plement 74.
The spacs 96 developed between the bore of each element and the bar circum~erence is located outwardly o~ th~
corresponding bar. cutter el~ment 74a is shown a~
impacting the surface 98 of the solid substrate 100.
The cutt~r 74a is demonstrated as being raised slightly from its outermost position on tha carrier bar 72. The //// ' ~ . _ .. _ .
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', !1.~-~ ~ ~7~ ~9 dep-th -to which the cutter 74a will cut into the surlace 78 of the substrate is determined by the positioning of the Eront wheel 30 and the rear wheel 102. The adjustment knob 26 can vary the height of the wheel 102 by swivelling carrier arm 104 relative to the frame structure 14. As the rear wheel 102 is swung upwardly relative to the frame 14 to lower the frame towards the surface 98, the respective carrier bar 72 is lowered so as to press the cutter element 74a into the surface after it has impacted it by an interaction of the carrier bar against the lower portion of the bore 88.
Referring to Figure 4, the assembled rotary cutter cage 16 is illustrated in detail. The connector rod 50, as explained, is threaded into the bore 46 of the drive hub 42. The inner face 108 o~ the enlarged head portion 110 of the connector rod 50 clamps the end plates 62 and 64 between the drive hub 42 and the spacer washer 106. The thread direction o~ threaded bore 46 is such to ensure -tightening o rod end 48 in the bore 46 during operative rotation of -the cutter cage. A recess 112 is provided in head 110 to permit use of an Allen wrench to init.ially tlghten the rod S0.
The segments 58 and 60 are provicled centrally of -the ~5 rotary cutter cage 16 -to lend support to the carrier rods 72 to avoid stress crack:ing in the rods dur.ing the abuse to whi.ch they are subjected :in chipp.ing ~t ha:rd material.s such as conc.rete. The rotar~ cutter cage inC LU~Ieg :EOUL- car:r:ic.r rod~ 72 and thus provicles Eour 30 rows Oe cutters ac.r.oss the width of the ent.ire cutter cag~.. The support segments 58 and 6~ are of:E~et to ensure tha-k the cutters Oe one :row overlap the space between the next .row Oe cu tters in the central .rcyion.
~s ~eneral.l.y shown in F:igure ~, the upper row o:E
autters 74 all slant itt a fi.rst direction, whereas the bot-tom row oE cutters impacking the surface slant in an opposite direct.ion.
With reference to E'igures 6 and 7, the action is demonstrated in more detail. As shown ln Figure 6, the ~ 9~J~
upper edge of the bore 88a is contacting the carrier bar 7~. Assuming centrifugal ~oree is acting on the individual cutters 7~, the cutters will tend to slope ln the direction shown in Figure 6, because -the cutter -teeth 86 lie in a plane offset laterally of the bore contac-t point 88a. Due to the mass of the concave shaped plate for the star-shaped cutter, the cutter tends to pivot about contact point 88a so that the individual cutters tilt generally in the direction shown in Figure 6. The O-ring spacers 76 may be loose fitting on the bar. This loose fit for the spacers may permit a slight tilting in accommodaking the overall tilting of the adjaeent cutters.
The provision o~ a concave or dished shape for each of the cutter elements 74 causes a lateral movement of the cut-ter teeth 86 during impaeting of the cutter elements with the surEaee 98 of the solid substrate. It has been found that the bes-t cireumferential speeds for operatin~ -the eutter cage are in the range of l,800 to 3,000 feet/minute. At these speeds it is di-Eficult to properly ascertain what is happening wikh the cutter teeth 86 when -they impact a sur~ace. ~1owever, based on the results oE wear patterns on the cutter teeth, i.t i9 reali~ed tha-t the teeth are moving cJenerally in the diree-tion of arrow llg cluriny impaet or at :Least on initial impaet with the solicl substra-te. rrhe bottom port:lon 72a o~ the earrier rod i9 contact~ncJ the bottorn oE the hore portion a-t 88b a:Eter the eutter 7~a :impaets a sureace in the manr1er shown :in F~icJure 5. Due to the cutter teeth a6 :1.y.ing ln a p:lane :Lateral.ly o.e.~set o:E the bore eontaet area 88b, a moment arm is exerted about 88b to tilt the cutte:r element 7~1a in -the clirection opposite to khat of Figure 6 and thus ef:Eec-t a lateral movement in a cutter tooth 86 in the dl.reetion o:~ arrow ll~. As a result, -the ~orces imparted by the cutter teeth 86 onto the surface 98 have both a downward and horizontal eomponent.
~2~9Ç;.9 It is ~elieved to be this lateral sideways mcvement ol the cutter teeth which substantially improves the efficiency o~ this -type o~ cutter element compared to those of the prior art. In tes-ts conducted on concret~, the e~fectiveness of the star-shaped cutter teeth having a dish shaped of Figure 6, have at least a five-fold and in some instances eight-fold increase in ef~ectiveness in removing a concrete surface layer compared to the standard star-shaped cutter elements of the prior art patents such as United States 4,275,928 and United States 3,156,231. At these high speeds it is difficult to ascertain how the lateral movement in the cutter teeth accomplishes th:is significant improvement. It is theorized, however, that the lateral movement o:E -the cutter teeth improve the chipping action due to the fact that concrete has resistance to breakage in the compressive direction approximately ten -times greater than .its resistance to breakage in the tensile direction. I-t is believed that the lateral movement of the cutter teeth 86 in produciny a horizontal component of force take advantage of the weaker tensile strength of the concrete compared to its compressive strength. The cutter elements in accordance w:ith this invention in having a concave or dished shape provide the means for e:Efectiny latera.l. movement o~ the cutter teeth on i.mpacti.ng the surface. It ir) appreciated that the degree of concavity .;.n each cut-ter element has to be within a certain angular range in orcler to e:E:Eect this kiclc~over act:Lon Oe the cutters. ~'he angle bctween cutter tooth .Eaces 86-l and 86b ma~ range f:rom 90 to lS0. The p:re:ee:r:red anyle i.~-; approximatel~ 120. Once the cutle:r elemen-t .1.eave.r-.) the r~ur:Eace beiny treated, centri:Euy.ll ~orce :in e~sence resets the cutter to the opposite angle~ as r.~hown in Figure 6, to optimize on the extent Oe cutter tooth movement 86 :in the d.irection of arrow 114 o:E Figure 7.
W.i.th the remaining cu-tter elements illustrated in Figures 8 through 15, various arrangements are provided on the cutters to effect this lateral movement in the cutter teeth when impactincJ the surface being treated.
With -the cutter elements o~ Figures 8, 9 and 10, the cu-t~e.r element 116 consists of a body portion 118 having embedded therein carbide tips 120 symmetrically spaced abou-t the central a~is 122 of the cutter element. The body portion 118 is scalloped at areas 12~ between adjacent carbide tips to provide for wear on the carbide tips. A bore 126 extends through the body portion 118 of the cutter element 116 as shown in Figure 9. The bore 126 consists of a countersunk tapered portion 128 opening to one side 130 of the cutter element. The countersunk portion 128 extends across the major portion of the bore leaving a minor portion 132 openin~ to the other side 13~ oE the cutter element. The carbide tipped teeth 120 all lie generally in the same plane indi.cated by dotted li.ne 136. The plane of the cutter teeth is laterally offset of the minor c~lindrical portion 132. The body portion of the cutter element 116 is considerably heavier than the thinner plate portion of the cutter element 7~.
Due to -the lateral offset of the plane 136 of the cutter teeth relative to the contact area oE the cutter bore 132 against the bar 72, centr:i:Eugal forces acting on the cutter elements cause them to t:ilt gcnera].ly in the d:Lrect:ion indicated in :Fiyure 10. As previously e~plainecl, at high speed rotation~ of the~e cutter elementc~, :it i~ dif:icult to ascertain exactl.y wha-t action occur~ .in the cutter -teeth~ Mowever, it is theor:ixecl tha-t on :impact the cut-te.r e:Lement~ are tilted further :in the di:rectlon Oe ar.row 138 on the carrier bar 72 between the contact po.int 72a of the carrier bar ancl 132a o:E the cutter bore. ~rhis til-ting ac-tion is evidencecl b~ wear pat-terns on the cutter teeth where the so:Et~r metal in the area 1~0 is worn of:E to expose the edge oE the carbide tips 120. Therefore, in -the manner di~cussed in shaping the cutter bore, means is provided Eor effecting a lateral movement in the direction of arrow 138 for -the cutter teeth to take :. .
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advantage of the weaker tensile strength o~ the concrete for purposes o~ removing a layer of concrete Erom the surface o~ the solid substrateO
In Figures 11 and 12, another embodiment for the bore configuration o~ the cutter elements for effecting lateral movement o~ the cutter teeth on impact with the surface ls illustrr~ted. The cutter element 142 has a plurality of cutter teeth 144 about its periphery and all lying in the sarne plane generally indicated by dotted line 146. The cutter teeth 1~ are carried on spikes about the perimeter of the cutter element 142.
The body portion 1~8 for the cutter element includes a bore generally designated 150 for mounting on the carrier bar 72. The bore 150, formed in the body portion ]~8 o~ the cutter element, has an axis 152 which is tilted relative to the plane 1~4 within which the cutter teeth 14~ lie. The bore 150 is oblong as shown in Figure 12 and has upper and lower bore surfaces 154 and 156. In use, the edge port~on 158 of the bore face 15~ is initially in contact wi-th the carrier bar 72 due to the centrifugal forces. The cutter element is encouraged to tilt in the direction shown in Figure 11 and on impact tilt further to the position shown in E'igure 11. Once the cutter is in contact with the surface, rotation is induced in the cutter 1~2 about the bar 72. Due -to the tilted orientatlon Oe the bore 150, the cutter -tends -to wobble as it rotates about th~ bar. r~hls wobble action enhances thc c~hipping efEect oE the teeth on the surEace as the teel:h move laterally. ~n add:ltion, as the cukter rotate~, pressure Oe the teeth on the surEace ls cycl:Lca:Lly increased clue to the oblong shape of the bore 150. rrhis action Eurther enhances the cut-ter eEficiency.
F'igure 13 il:Lustrates an alternative arrangement for the cut-ter teeth on a cutter element 162. rrhe cutter teeth 16~ lie in a plane adjacent a face 166 o~
the cutter element which is o~fset Erom the minor cy]indrical portion 168 oE the bore 170. The bore 170 9~;.9 also includes a tapered countersunk portion 172 which provides an arrangement similar to the bore 126 o~
cutter element 116 shown in Fi~ure 8. As with the action of the cutter element demonstrated in ~igure 10, similarly the bore 170 effects a lateral movement o~
the cutter teeth 164 in the direction of arrow 17~.
The cutter teeth 164 are at the end o~ spike portions similar to those of Figures 11 and 1~. Therefore, with the embodiments of Figure 8, 11 and 13, by way of shaping the bore for the cutter elements, the lateral movement in the cutter teeth of each cutter element during impact with the surface being treated signiEicantly improves the material removal by the chipping action of the teeth.
A third arranyement for effecting lateral movement in the cutter teeth is shown in Figures 1~ and 15. The cutter element 176 comprises a cylindrical collar 178 having a cylindrical bore 180. Mounted to the collar are a plurality of outwardly projecting spikes 182 having hardened cutter teeth portions 18~. The circular bore 1~0 is o~ a diameter to Eit over the carrier bar 72 in the manner shown in Figure lS. The cutter teeth 1~ lie generally in the plane 186 which is tilted relative to the central a~.is 188 oE the carrier bar 72 and of the cylindrical bore 180 of the collar 178~ Thus the plane, o.E cutter teeth 186 is tilted re~lat:Lve to the central a~i.s 18~. On impact, the cutter element 176 rotates Oll carr.ier bar 72. The til.ted plane o:~ the cutte.r teeth on the col:Lar e.E~ects a latera:l rnovement O:e the -teeth across the concrete sur~ace, b~ wa~ of a wo~b:l.e-t~pe movement along the surEclce, to ~emove acJyre~.~Jively rnaterial from the sur.~ace o.~ the so.Licl ~ubstrate.
In order to provide ~or even wear on the cu-tters, the~ are allowed to rota-te on the carrier bar to avoicl the ~ame teeth alwa~s impacting the ~ur:Eace and wearing the cutte:r down in one area more than the other. It has been found that in treating concrete surEaces, this lateral motion in the cutter teeth provides a smoother finish ~or the treated surface than the normal planar -types of cutter elements which ~ertically impact the surface being treated. Furthermore, it has been found that the cutter elements las-t considerably longer although they achieve superior results concernlng the amount of material removed during a comparable timeframe ~or both the prior art types of cutters and the cutters according to this invention. It is theori.zed that by using the cutters according to this invent:lon which tend to attack the surface being treated at an angle, takes advantage oE the weaker tensile strength of the material being treated, such as concrete, to provide a superior rate of material removal.
The cutter elements may include carbide bits embedded therein or may be formed of metal which has hardened tips. For example, the star-shaped cutters of Figure 2 may be formed from plate steel with the star-shaped cut out and subsequently dished to ~orm the concaved cross section. The selected steel may be a high carbon steel such as C-1075 and hardened to a Rockwell hardness of up to C60. The concavity in the plate may be formed by a proc~ressive die working on -the 2S blank p:Late portion. The shaped cutter .is then hardened to tile desired hardness. The carbide tip cutters may have their hody portion .Eormecl by s-tampincJ
them from metal o:r fo.rmed b~ lnvestment casting with carbi.de tips :in placc :i.n the mold. In :EormincJ the wall po:rt.ion :i.n the carbicle tip cutters such as in Pigure 8, :it :L~ preEerable to leav(3 the smal]. cylindrical shoulcler 132 which has bctter wear characteristics than the arrangement of the conica:L porti.on 12~ extending all the way ou-t to the other side 1~4 of cutter body portion. The cutter body portion may be formed from a "Super Impacto" (trademark) metal sold by Atlas Steels o~ Toronto, Canada. In forming the bore, the desired angle of the conical portion of the bore or the plane of tilt o~ the cutter teeth relative to the central ~',,, ,. ' '' ;
axis of -the carrier bar or collar may range from 5 to 75. Although improved working characteristics are achieved when the angle varies from 10 to 60, and preEerably from 15 to 45.
The O-ring spacers used with the cutter element 74 of Figure 2 may be formed of spring wire which have an o-verall external diameter less than the height of the body port.ion of the cutter element to enable the cutters to oscillate during use of the cutter elements.
While preferred embodiments have been described and illustrated herein, a person skilled in the art will appreciate that changes and modifications may be made thereto without departin~ from the spirit and scope of -this inven-tion as defined in the appended claims.
Claims (42)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:
1. In an apparatus for removing material from the surface of a solid substrate comprising a support frame, a rotary cutter cage, means for mounting said rotary cutter cage on said support frame, means for rotating said rotary cutter cage about a central axis, said rotary cutter cage having at least one row of a plurality of cutters mounted thereon for impacting a solid substrate, said at least one row of cutters being mounted on a bar connected to said rotary cage, said bar being spaced from and parallel to said central axis, each of said cutters having a plurality of projecting cutter teeth, and said cutters being mounted loosely on said bar, the improvement comprising means on each said cutter for forcing a lateral movement in said cutter teeth in a direction generally along said bar when said cutters impact a solid substrata being treated during rotation of said rotary cutter cage in use of said apparatus.
2. In an apparatus of claim 1, said means for forcing said lateral movement comprising a bore formed centrally of each said cutter with said cutter being concave in shape, each said cutter bore being larger than said bar to mount loosely said cutter on said bar, the concave shape of said cutter effecting lateral movement of said cutter teeth when impacting a solid substrate being treated.
3. In an apparatus of claim 1, said means for forcing said lateral movement comprising a bore formed centrally of each said cutter, said bore being larger than said bar to mount loosely said cutter on said bar, said bore 15 a having a tapered countersunk portion extending along a majority of and opening outwardly of said bore, said countersunk portion effecting lateral movement of said cutter teeth when impacting a solid substrate being treated.
4. In an apparatus of claim 1, said means for forcing said lateral movement comprising a bore formed centrally of each said cutter, said bore being larger than said bar to mount loosely said cutter on said bar, said bore extending along an axis which is tilted relative to a central axis of said cutter, said cutter teeth all lying generally in the same plane, said cutter central axis being perpendicular to said plane defined by said cutter teeth, said tilted cutter bore effecting lateral movement of said cutter teeth when impacting a solid substrate being treated.
5. In an apparatus of claim 1, said means for forcing said lateral movement comprising a cylindrical collar having a cylindrical bore of a diameter greater than said bar to permit relative rotation between said collar and said bar, said plurality of cutter teeth lying generally in a plane, said plane being tilted relative to a central axis of said cylindrical bore, said tilted mounting of said cutter teeth on said collar effecting lateral movement of said cutter teeth when impacting a solid substrate being treated.
6. In an apparatus of claim 2, said cutter being a generally circular plate which in diametrical cross-section is concave, said cutter teeth being formed in said plate and extending outwardly to define a concave star-shaped cutter.
7. In an apparatus of claim 6, said cutter teeth being of hardened steel.
8. In an apparatus of claim 6, said rotary cutter cage having circular end plates to which at least one pair of diametrically opposing bars are mounted, each bar being circular in cross-section and carrying a plurality of said star-shaped cutters, a spacer ring being provided between adjacent cutters on said bar, the number of cutters on said bar being such to permit said lateral movement of said cutter teeth.
9. In an apparatus of claim 8, said spacer ring being a metal O-ring of ring thickness and internal diameter which precludes interference with a tilting movement of each said cutter during said lateral movement of said cutter teeth.
10. In an apparatus of claim 3, a plurality of said cutters being placed on said bar to provide a set of cutters, said countersunk portions of said set of cutters all opening out in the same direction, said bore having a minor cylindrical wall portion adjacent said major countersunk portion, a central plane extending through said cutter and in which said cutter teeth lie, each said cutter pivoting on said minor cylindrical wall portion which is laterally offset of said central plane whereby impacting said cutter on a solid substrate during rotation o e said cutter cage forces said cutter teeth to move laterally due to interaction of said bore countersunk portion and said bar.
11. In an apparatus of claim 10, wherein said cutter teeth are of hardened steel, said cutter having a body portion into which said cutter teeth are embedded, said cutter teeth being symmetrically arranged about said cutter bore, said body portion being formed of a material which is softer than said hardened steel teeth.
12. In an apparatus of claim 11, wherein said body portion is essentially cylindrical and having a peripheral face, said cutter teeth being embedded in said peripheral face of said body portion, said teeth being equally spaced about the peripheral face, said cylindrical body portion being scalloped between adjacent teeth.
13. In an apparatus of claim 10, said rotary cutter cage having circular end plates to which at least one pair of diametrically opposing bars are mounted, each bar being circular in cross-section and carrying a plurality of said cutters, the number of cutters on said bar being such to permit said lateral movement of said cutter teeth.
14. In an apparatus of claim 10, wherein said cutter has a hub and a plurality of spikes extending radially outwardly thereof, said spikes having hardened tips to form said cutter teeth.
15. In an apparatus of claim 4, said cutter teeth lying generally in the same plane, said plane extending centrally through said cutter.
16. In an apparatus of claim 15, said rotary cutter cage having circular end plates to which at least one pair of diametrically opposing bars are mounted, each bar being circular in cross-section and carrying a plurality of said cutters, the number of cutters on said bar being such to permit said lateral movement of said cutter teeth.
17. In an apparatus of claim 5, said cutter having a plurality of spikes extending radially outwardly of said collar, said cutter teeth being provided at end portions of said spikes.
18. In an apparatus of claim 17, said spike ends being of hardened steel to provide said cutter teeth.
19. In an apparatus of claim 17, said rotary cutter cage having circular end plates to which at least one pair of diametrically opposing bars are mounted, each bar being circular in cross-section and carrying a plurality of said cutters, the number of cutters on said bar being such to permit said lateral movement of said cutter teeth.
20. A cutter for use on a rotary cutter cage of an apparatus for removing material from a surface of a solid substrate, said cutter comprising a body portion with a bore extending therethrough to receive and be mounted loosely on a bar secured to the rotary cutter cage, said body portion carrying a plurality of outwardly projecting cutter teeth, said cutter having means for effecting a lateral movement of said cutter teeth when said cutter is in use on a rotary cutter cage.
21. A cutter of claim 20 wherein said cutter body portion is a plate, said means for effecting said lateral movement comprising a concave cross-sectional shape for said plate whereby said cutter teeth are located in a plane laterally offset from said bore in said body portion.
22. A cutter of claim 21 wherein said cutter teeth are of hardened steel.
23. A cutter of claim 20 wherein said cutter teeth are generally located in a plane, said means for effecting said lateral movement comprises a tapered countersunk portion extending along a majority of said bore past said plane of said cutter and opening outwardly to a side of said cutter, a minor portion of said bore being cylindrical, said plane being laterally offset from said minor cylindrical portion.
24. A cutter of claim 23 wherein said plane extends centrally through said cutter.
25. A cutter of claim 23 wherein said plane is laterally offset of a central plane extending through said cutter.
26. A cutter of claim 20 wherein said cutter teeth lie generally in a plane, said means for effecting said lateral movement comprises a cylindrical bore having a central axis which is tilted relative to said plane.
27. A cutter of claim 26 wherein said cutter has a cylindrical collar within which said bore is defined, said bore having a central axis extending along its length, said cutter teeth extending radially outwardly of said collar, said plane being tilted relative to said collar central bore.
28. In an apparatus for removing material from the surface of a solid substrate comprising a support frame, a rotary cutter cage, means for mounting said rotary cutter cage on said support frame, means for rotating said rotary cutter cage about a central axis, said rotary cutter cage having at least one row of a plurality of cutters mounted thereon for impacting a solid substrate, said at least one row of cutters being mounted on a bar connected to said rotary cage, each cutter having a body portion with a bore extending therethrough to receive and be mounted on said bar, said bar being spaced apart from and parallel to said central axis, each of said cutters having a plurality of projecting cutter teeth, the improvement comprising means on each said cutter for forcing a lateral movement in said cutter teeth in a direction generally along said bar when said cutters impact a solid substrate being treated during rotation of said rotary cutter cage in use of said apparatus, said means for forcing said lateral movement comprising a contact point in said bore of each said cutter which contacts said bar and about which said cutter pivots as said cutter teeth move laterally and said cutter teeth of each said cutter lie in a plane offset laterally of said contact point in said bore.
29. In an apparatus for removing material from the surface of a solid substrate comprising a support frame, a rotary cutter cage, means for mounting said rotary cutter cage on said support frame, means for rotating said rotary cutter cage about a central axis, said rotary cutter cage having at least one row of a plurality of cutters mounted thereon for impacting a solid substrate, said at least one row of cutters being mounted on a bar connected to said rotary cage, said bar being spaced from and parallel to said central axis, each of said cutters having a plurality of projecting cutter teeth, and said cutters being mounted loosely on said bar the improvement comprising means on each said cutter for forcing a lateral movement in said cutter teeth in a direction generally along said bar when said cutters impact a solid substrate being treated during rotation of said rotary cutter cage in use of said apparatus, said means for forcing said lateral movement comprising a bore formed centrally of each said cutter with said cutter being concave in shape, each said cutter bore being larger than said bar to mount loosely said cutter on said bar, the concave shape of said cutter effecting lateral movement of said cutter teeth when impacting a solid substrate being treated.
30. In an apparatus of claim 29, said cutter being a generally circular plate which in diametrical cross-section is concave, said cutter teeth being formed in said plate and extending outwardly to define a concave star-shaped cutter.
31. In an apparatus of claim 30, said cutter teeth being of hardened steel.
32. In an apparatus of claim 30, said rotary cutter cage having circular end plates to which at least one pair of diametrically opposing bars are mounted, each bar being circular in cross-section and carrying a plurality of said star-shaped cutters, a spacer ring being provided between adjacent cutters such to permit said lateral movement of said cutter teeth.
33. In an apparatus of claim 32, said spacer ring being a metal O-ring of a width and internal diameter which precludes one of said cutters interfering with a tilting movement of an adjacent said cutter during said lateral movement of said cutter teeth.
34. In an apparatus for removing material from the surface of a solid substrate comprising a support frame, a rotary cutter cage, means for mounting said rotary cutter cage on said support frame, means for rotating said rotary cutter cage about a central axis, said rotary cutter cage having at least one row of a plurality of cutters mounted thereon for impacting a solid substrate, said at least one row of cutters being mounted on a bar connected to said rotary cage, said bar being spaced from and parallel to said central axis, each of said cutters having a plurality of projecting cutter teeth, and said cutters being mounted loosely on said bar the improvement comprising means on each said cutter for forcing a lateral movement in said cutter teeth in a direction generally along said bar when said cutters impact a solid substrate being treated during rotation of said rotary cutter cage in use of said apparatus, said means for forcing said lateral movement comprising a bore formed centrally of each said cutter, said bore being larger than said bar to mount loosely said cutter on said bar, said bore having a tapered countersunk portion extending along a majority of and opening outwardly of said bore, said countersunk portion effecting lateral movement of said cutter teeth when impacting a solid substrate being treated.
35. In an apparatus of claim 34, a plurality of said cutters being placed on said bar to provide a set of cutters, said countersunk portions of said set of cutters all opening out in the same direction, said bore having a minor cylindrical wall portion adjacent said countersunk portion, a central plane extending through said cutter and in which said cutter teeth lie, each said cutter pivoting on said minor cylindrical wall portion which is laterally offset of said central plane whereby impacting said cutter on a solid substrate during rotation of said cutter cage forces said cutter teeth to move laterally duo to interaction of said bore countersunk portion and said bar.
36. In an apparatus of claim 35, wherein said cutter teeth are of hardened steel, said cutter having a body portion into which said cutter teeth are embedded, said cutter teeth being symmetrically arranged about said cutter bore, said body portion being formed of a material which is softer than said hardened steel teeth.
37. In an apparatus of claim 36, wherein said body portion is essentially cylindrical and having a peripheral face, said cutter teeth being embedded in said peripheral face of said body portion, said teeth being equally spaced about the peripheral face, said cylindrical body portion being scalloped between adjacent teeth.
38. In an apparatus of claim 35, said rotary cutter cage having circular end plates -to which at least one pair of diametrically opposing bars are mounted, each bar being circular in cross-section and carrying a plurality of said cutters, the number of cutters on said bar being such to permit said lateral movement of said cutter teeth.
39. In an apparatus of claim 35, wherein said cutter has a hub and a plurality of spikes extending radially outwardly thereof, said spikes having hardened tips to form said cutter teeth.
40. In an apparatus for removing material from the surface of a solid substrate comprising a support frame, a rotary cutter cage, means for mounting said rotary cutter cage on said support frame, means for rotating said rotary cutter cage about a central axis, said rotary cutter cage having at least one row of a plurality of cutters mounted thereon for impacting a solid substrate, said at least one row of cutters being mounted on a bar connected to said rotary cage, said bar being spaced from and parallel to said central axis, each of said cutters having a plurality of projecting cutter teeth, and said cutters being mounted loosely on said bar the improvement comprising means on each said cutter for forcing a lateral movement in said cutter teeth in a direction generally along said bar when said cutters impact a solid substrate being treated during rotating of said rotary cutter cage in use of said apparatus, said cutter teeth of each said cutter all lying generally in the same plane where said cutter teeth define a circle having a centre, said cutter having a central axis which extends through said centre and which extends perpendicularly to said plane defined by said teeth, said means for forcing said lateral movement comprising a bore formed centrally of each said cutter, said bore being larger than said bar to mount loosely said cutter on said bar, said bore extending along an axis which is titled relative to said central axis of said cutter, said tilted cutter bore effecting lateral movement of said cutter teeth when impacting a solid substrate being treated.
41. In an apparatus of claim 40, said plane extending centrally through said cutter.
42. In an apparatus of claim 41, said rotary cutter cage having circular end plates to which at least one pair of diametrically opposing bars are mounted, each bar being circular in cross-section and carrying a plurality of said cutters, the number of cutters on said bar being such to permit said lateral movement of said cutter teeth.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000471922A CA1266969A (en) | 1985-01-11 | 1985-01-11 | Inclined cutter for surface cleaning head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000471922A CA1266969A (en) | 1985-01-11 | 1985-01-11 | Inclined cutter for surface cleaning head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1266969A true CA1266969A (en) | 1990-03-27 |
Family
ID=4129556
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000471922A Expired CA1266969A (en) | 1985-01-11 | 1985-01-11 | Inclined cutter for surface cleaning head |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1266969A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1300226A1 (en) * | 2001-10-03 | 2003-04-09 | Air-tec AG | Milling cutter wheel for floor milling machines |
-
1985
- 1985-01-11 CA CA000471922A patent/CA1266969A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1300226A1 (en) * | 2001-10-03 | 2003-04-09 | Air-tec AG | Milling cutter wheel for floor milling machines |
| CH696975A5 (en) * | 2001-10-03 | 2008-02-29 | Airtec Ag | Milling wheels to a bottom milling. |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |