CA2076344A1 - Rotary tool - Google Patents

Abstract

The invention relates to a rotary tool consisting of a drive hub (N) and an interchangeable tool sleeve (H), whereby the tool sleeve (H) can be connected solidly in rotation with the drive hub (N) and has projecting engagement means on its outer circumferential surface for machining equipment. Here, the drive hub (N) consists of a drive flange (1) and a securing flange (2), whereby on the drive flange (1) axially on the outside is coaxially fitted a central motor connection (3) and at least one of the flanges (1, 2) has at least one axial projection (A) axially on the inside.
For each axial projection (A) there is an axially opposite second axial projection (A) or recess or aperture on the other flange (1 or 2) suitably arranged and at least one axial projection (A) can be arranged radially eccentrically. Here, at least one axial projection (A) forms an axial conveyor arm (4, 5). At least one axial projection (A) engages between the two flanges (1, 2) in a part of the opposite flange (1, 2) in such a way that the flange (1, 2) cannot rotate in relation to their shaped spindle. Here it is an essential part of the invention that the securing flange (2) engages closely with the driving flange (1) via at least one snap connector (9, 10) and can be released by release means.

Description

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Wo 92/06821 PCT/EP91/01992 RotarY Tool The invention relates to a rotary tool consisting of a novel dri~-e hub N and novel interchangeable tool bushings such as, more particularly, abrasive bushings and/or brush rlngs.

Conventionally, abrasive bushings and brush rings are prevailingly clamped on to rigid clamping systems that may be, for instance, radially expandable or axially tensionable, or else clamped on to rigid drive hubs in segmented or annular arrangements. ~ith known, radially expandable drive hubs, tensioning members or tensioning rubber units are contracted axially, potentially using two tensioning cones linked by way of a threaded ar-rangement, to be pressed against the inner envelope of the tool bushing. Thus, the tool bushing is entrained frictionally. Insufficient clamping, friction-reducing factors such as impurities including but not limited to oil, temperature fluctuations or higher loads possible, particularly with brushes, cause slippage because the tool bushing rotates as against the drive hub con-stituting a clamping device. Moreover, such drive hubs in the form of clamping devices are, in a direction radially to the tool axis, relatively inelastic, which makes processing of profiled or deformed workpieces less efficient and impairs the optimal use of aggres-sive means such as bristles due to a lack of elasticity and resilience characterizing bristle roots and brush belts. Owing to excessive bending moments, bristles may, moreover, be worn out or destroyed prematurely.
The brush belts that, for instance, may be used for tool bushings and frequently employed specifically for surface treatment as described, among other things, in detail below, have been known in principle for a long time and are standard articles used in and around the . , ; REPLACEMENT SHEET
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textile industry. Such known brush belts are made as yarded goods on so-called card mounting machines. Once series-production electric motors became available, this type of brush belt was made in the form of rings and used, for instance, by leather-processing firms, to clean and raise leather.

DE-GM 86 23 326 discloses a rotary tool characterized by a high degree of radial elasticity, its tool bushing being tensioned radially by an inflatable rubber hose.
Owing to the low working pressure achievable, both ab-rasion performance and working efficiency are low. The design is complicated, expensive to manufacture, and very difficult to handle. The tool bushing may easily slip inadvertently.

Driving high-performance tool bushings such as rotary ` brushes is not reasonably achievable with this clamping device used by way of drive hub.

DE-OS 37 18 932 discloses a rotary brush tool having a hub by way of clamping device and a rotary brush in the form of an annular brush belt through which U-shaped bristles protrude to project radiallv outwards. The : - ~. ., ~ ~ proper function of this type of rotary brush depends , .:
; essentially upon supporting, for processing purposes,~ the brush~belt and the U-shaped bristle~ therein con-;~ tained flexibly, i.e. subject to a certain radial -~- elasticity or movabi~ity since only this will guarantee the desired resiliantlv elastic orientation of bristles às regards their angular settings during operation en-` ~ gagement.
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Therefore, DE-OS 37 18 932 provides for operating brush belts using a rubber-elastic, radially expandable clamping device. Drive power is transmitted by positive fit. Clamping on the brush ring is a relatively complex procedure. Given insufficient tensioning or 105s of friction, for instance due to soiling of clamping sur-faces due to oil, slippage or sliding of the brush ring cannot be excluded. The bristles, supported rubber-elastically and flexibly within the brush belt sup-ported likewise develop good abrasive performance but are subject to limited elasticity and may be overtaxed, for instance with highly profiled workpieces, owing to rubber-core and brush-belt torsion. At higher speeds in excess of, say, 6000 rpm, the brush belt may be dam-aged, which would impair safety and cause hazards.

The same rotary brush in the form of an annular brush belt is disclosed by DE-OS 37 41 983 in its subclaim 8.
The drive arragement of this brush, doing without ten-sioning rubber, aims for improved characteristics. Once more, maintaining the flexibility of the brush belt and its bristles, being functionally indispensable for operating the tool, are of paramount importance. By way of solution, a clamping device is described, which device axially encompasses the brush ring at its edges in a positive fit by way of annular grooves arranged axially within the clamping device flanges so as to achieve at that point the necessary friction drive union by means of axially frictional tensioning. A
flexible brush belt being used, a "stabilizing bushing"
pushed into the interior of the brush belt is intended to prevent squashing of the brush ring otherwise en-tailed by axial tenfiioning. ~his rigid bushing, how-ever, does not only impair radial movement of the brush belt inwards and thus the fle~ibility of the brush belt .

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WO 92/06821 PCT/EP9~/01992 g itself, even the intended function seems to be jeo-pardized given this frictional drive unit. In practical use, the annular grooves are operationally insufficient to drive the brush belt by themselves; this will be achieved, if at all, by the bushing's being rigid relative to the brush ring, provided there is suf-ficient fricitional energy. The brush or the brush belt itself may easily slip under operational loads, more particularly so because the length of the axial path available for axial tensioning is limited due to the simultaneously provided axial belts radially encom-passing the brush ring on its outside. Said axial belts ensure, by terminating any sliding due to brush belt slippage, brush belt driving by positively fitting the bristles, i.e. by being in direct contact with bristle groups, where they are peripherally supported.

This will lead to a loss of flexibility of the bristles next to the axial belts so that they will permanently bend. Bristles will thus lose their effectiveness, their useful life will be terminated and they will easily break, for instance if the direction of rotation changes. Due to the axial annular grooves within the flanges and the retention belts, the elastic support and agular adjustment of tlle bristles, otherwise pos-sible, are substantially reduced and partially negated.
What is more, the axial belts in contact witll the bodies of the bristles substantially reduce the effec-tive lengtl~ available for the bristles to hend, ad-ditionally curtailing the fundamentally important and functionally indispensable fle~ibility by impairing bending elasticity of the bristles, shortening their free bending length and impairing their inclination po-tential. Simull:aneously, the fle.~ibility of the brush REPLACEMENT SHEET

20763~
WO 92/06821 PCT/EP91/0~.992 is reduced to a very high degree due to the rigid inner stabilizing bushing and the positively rigid peripheral clamping of the brush ring within the annular axial groove flanges, all detrimental to the effective action of the brush. Moreover, there is no elastic yield of the brush ring towards the brush centre line. If the rigid bushing is replaced by an elastic one, or left out altogether, efficient work becomes impossible whenever the working pressure acts radially upon the brush ring; after all, the U-shaped bristles may be pushed inwards and will have to pushed out again manu-ally in a time-consuming assembly procedure, and/or the brush ring may be pushed in radially, thus being axially shortened as well as ejected from the a~ial ring grooves of the flanges that positively retain it, - which is hazardous and might negate the function of the ~` tool.

The clamping device disclosed by DE-OS 37 41 983 is ~ characterized by clamping discs or flanges having a .~ diametre superior to the one of the tool bushings to be ni~ used. Therefore, clamping disc edges, just as the over-~ arching a~ial belts, create trouble if abrasive ::
. bushings are to be used, particularly for surface work.
If brush bushings are used with this type of clamping device, said overarching axial be].t.s inacdvertently .`. serve, as described above, for driving purposes by con-~- tacting groups of bristles during operation so that the ~ .
bristles will bend along the edges of such axial belts and brea~ if the direction c~f rotation is changed, entailing certain hazards particularly if high-speed machinery is used, such as rigllt angle grinders. Ohing to the belts overlapping at the edges, the angle of bristle movements in a periphera~ directic-ll hill be significantl~ r.educed and the lengt:h of an~ l)rri.stle REPLACEMENT SHEET

" 20763.~

bending actively substantially shortened. During brush cleaning operations relying on short bristles, such as raising or milling, the bristles will be out of func-tion just as the working face of abrasive bushings.

DE-OS 36 05 855 relates to a grinding tool for profiled strips of wood trimming characterized by the fact that to every base designed to support the grinding segments two clamping members fastening said segments are al-located, which members reach behind projections located on said segments. Thus, this is no driving arrangement for rotary tools such as abrasive bushings or brush rings formed out of two flanges, nor does this document provide any indication as to how - given such drive ar-rangement - warping, twisting or buckling of bristles is to be prevented, or a tool bushing to be held safely from inside.
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~, `~ DE-OS 29 30 589 relates to a stripper tool operated ro-,~ tatingly, the two flanges of which are fastened to-~; gether by riveting or welding of linking projections, which means that they are tied non-detachably to each other.

'~; DE-GM 88 C5 13~ likewise discloses a rotary brush as "
already-described, except for mentioning bristle-free belt edges entailed by manufacturing conditions, in the ~ main claim of DE-OS 37 18 932.
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,~' ' EP 03 39 933 ~. disclc)ses, among other thi.ll9S, a rotary brush formed out of individual brush ring member seg-`- ments peri,~herally arranged next to each other so as to be radiallv xur-ll>rted from outside in a closely fitting manner on the c)ut:er surface of a rigid hub, anchored 2~7~3 ~ ~

' positively within appropriate axial grooves of said hub by way of axially extending ring member rib~ having a narrow root and a wider head.

Individual brush segments, all of them initially level, formed out of bristles located in a flexible brush belt : of flat cross-section are attached, by way of their backs, on individual, likewise initially level annular member segments made of flexible polymer material of flat cross-section. On the side facing away from the brushes, said annular member segments bear said ribs that widen as distance increases. Only when being .as-sembled on said hub, brush annular member segments, .~.
initially level, will be cambered so as to be supported . snugly on the peripheral surface of said hub. This is ~ the only function served by the flexibility af said .. ~ material forming brush and annular members, which flexibility becomes operationally ineffective once said members are assembled.
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Only several segments arranged around the periphery re-sult in a c~mp].ete rotary brush around the entire hub periphery. The flan~s of the annular member ribs ex-tending radially upon assembly are in positive contact with the flanks of the radial longitudinal grooves of ~r ~ said hub so that such positive rib/groove anchori.ng causes and secures brush/annular member cambering around the hub periphery as well as, more particularl.y, radial attachment of segments on the hub acting, above all, agai.ns~ centrifugal forces. Once mounted, the seg-h ~ ments no longer have any radial ability due to the:: ; f]:exibility of their material since they fit closely ~ around the out:~r surface of the rigid hub; anyway, in : this known inst.arlce, radia]. mo~ability is neither in- tended nor dec;il~ecl.

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Wo 92/06821 PCT/EP91/01992 DE-PS 569 722 discloses a cylindrical brush intended for road cleaning machines characterized by bundles of brushes clamped into rigid annular members, which rigid annular members made of light alloy comprise radially extending inside eyes, likewise rigid, designed for the passage of anchoring screws allowing the brush rings as well as the two terminal, disc-shaped faces of the brush cylinder designed to be coupled with driving means. Thus, this is not a rotating brush having a flexible brush belt characterized by a flat cross-sec-tion, nor by U-shaped bristle members, and there is no radially flexible movability of a brush belt in opera-tion.

As compared to the state of the art, it is the obiect of the invention to develop a rotary tool improved over known rotary tools and to avoid the disadvantage en-tailed by known devices.
Moreover, said rotary tool is intended to operate at a high degree of safety, to do without any clamping device, to be operable without any complicated assembly processes and to maintain, above all, to the largest possible extent, radial tool belt flexibility in ordre ~; to achieve a maximum of operating efficiency and to ac-commodate rotationa] speeds as high as possible.
. , It is a further object of this invention to do without any screwing or clamping, to provide for safe working in both rotational directions - always subject to problems with .screwed connections - and to allow for a positive-locking tool bushing drive.

The disadvantages characterizing known rotary tools that are to be avoided according to the invention include, among other things, the fact that axiall~ ten REPLACEMS~T SHEET

-~ 2 ~ 7 ~

_ g _ sioning the two flanges by screwed connection will negatively influence and subtantially reduce the opera-tionally necessary and therefore desired elasticity of the tool bushing while requiring, moreover, much time and appropriate screwing tools whenever a bushing is to be changed. Over and above that, conventional screwed connections depend upon rotational directions and are thus inherently unsafe. Any screwed connection will moreover warp materials, increasing the loads ~ithin them, which decreases the operational chargeability as regards rotational speeds and abrasive performance, in-creases wear and tear, and leads to fluctuations in useful life. Furthermore, conventional cross-sections of driving arms are designed without providing for special shapes designed to reduce tension, which fact impedes movement and increases the plastic deformation of bristles, i.e. non-uniform abrasion and increased loading of bristles-and belt, thus entailing a decrease in useful life, increased wear, higher danger of breakage, and reduced stability under load as regards abrasiveness and rotational speeds. Conventional driv-ing arm arrangements, located radially outside the tool bushing will produce, according to the state of the art, rotational disl.ocations between drive and tool bushing, i.e. slippage and loss of power; it will produce unfavourable, single-point positively locking contact with bristles and impede their movements in un-adapted, damaging ways. Compared to tllat, the too~
bushing drive SO]UtiOIl offered by the invention pro-vides for imprvved safety, efficiency, elasticity and flexibility, and it can be used in a more universal and effective nlanner, i.e. it will be more rational~.y, simpler, more time-savin~ and more reliable.
The invention provides for a snap-action lock ]ocated, for instance, central].y in axial projections, as shown -REPLACEMENT SHEET

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on the drawing by way of an illustrative embodiment.
Said snap-action lock may likewise be provided at the ends of the driving arms or on a central shaft; pro-viding a snap-action lock similar to a bayonet catch is one example of the potential embodiments of such snap-action locks. The teaching of this invention suggests the preferential use of positive-fit snap-action locks capable of being unlatched, which locks can be pro-vided, by way of example, within centrally located pro-jections or on the outside of said central projections, and/or on driving arms; unlatching may be performed, by way of example, exclusively by certain unlatching means such as a pull-actuated mechanism.

However, the invention provides also for drivinq means designed as loops arranaed at the tool bushinq co-axiallv with res~ect to the drivinq arms of the power-ina means meshina with them, thus providing for posi-tive-lock and thus slippage-free,~ safer and more re-liable driving action.
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;~ One functionally indispensable item of central im-portance for rotary tools and, more particularly, ro-tary brushes according to the invention is flexible, .,.:
resiliantly elastic radial mo~ability of brush belt and, thus, bristle inclination during operational use since this determines to a large extent the effective-. . : ~
ness of any rotary brush. In connection with the stateof the art set forth in DE-OS 37 18 932, sllch brush belt support invariably remaining flexible even in operation was already considered important and aimed at in the form of an adjustably elastic and resilient brush belt support located on the brush be~ carrier for improved operational efficiency; however, t;llis aim was reached only partially. Therefore, this t~pe of ro~

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tary tool configured, for instance, into a rotary brush is to be developed and substantially improved according to the invention, which means that, during use, the flexibility of the brush belt and simultaneously the elastically resilient inclination adjustment of bristles in engagement is to be further improved by avoiding all measures counteracting flexibility. Thus, the invention does without radial or axial brush belt tensioning as per DE-PS 37 18 932 or DE-PS 37 41 983;
the invention avoids rigid inner radial brush belt sup-porting as had been provided, for instance, by "stabi-lizing bushing 16" of DE-PS 37 41 983; the invention avoids belt fastening in a partially positive fit by means of "annular grooves 6" as per DE-PS 37 41 983 and the invention avoids unfavourable, tangential brush contact at overarching "axial belts 7" as per DE-PS 37 41 983. According to the invention, this novel rotary tool configured, by way of example, as a brush is meant to be substantially safer for instance at high speeds; it is meant to be significantly more effective by .avoiding any slippage; and it is to be especially appropriate for being used at high speeds of rctation while simultaneously doing away with the need for com-plicated tensioning and assembly processes and dis-advantageous clamping devices.

These considerations as well as the fle.Yibility of the brush belt remaining operationally effective for a no-ticeable elasticaliy resilient radial belt brush movability and, accordi.ngly, elastica~ly resilient f]exible inclinability of comparatively not very soft but relativelv ri.gid bristles made, for instance, of steel wire constitute essential results of the design according to the invention.

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Radial pliability and inclinability as well as elastic mounting and/or supporting of the bristles bring about fundamentally important bendinc3 elasticity and elastic pliability at directions radial and at angle6 relative to the brush centre line. Thus, the full bending elas-ticity of the bristles will be maintained just as their angle of movement in a peripheral direction (i.e. the bristle inclination setting within the brush belt while in operative engagement), resulting from the support of the bristles within the elastic hrush belt due to radial bending of the brush belt directed inwards and outwards at the point where the bristle root is located within the brush belt, and due to the radial pliability with respect to the centre line of said brusll belt and of the bristles therein located. According to the in-vention, such elasticity may be adaptable than~s to the annular member capable of being firmly lin~ed with a annular member of selectable elasticity of causing re-,:
siliently elastic bristle operation, just as there may be radial bristle displacement without said inner an-nular member, thus establishing a balance between the centrifugal forces and the exterior forces of wor~ing pressure acting upon said memher. The resilience ac-cording to the in~ention, i.e. the l~]iabilit~ t-lwards the brush centre line, of bristles, bristle ~3r(-u~s7 dnd bristle belt was, accordin~ to the invent:ion, ~ )st-an-tially incr~-?ased and secured. The fle~ible hl-ll`;h helt, a~d possibly an annular member made )f fle~ib]e materia~, will be esselltial in this (~onte~t; llli~ lealls that the belts -relllaill fle~:i.bl(? ~Ni]e in ~>1)~?) ~-it i~llal el'l-gagement, i.e. that they do nc)t oll~ ~`(.)US ist ()f fle~ib]e material but are arra'l~3(e(l So a?; t ~) nl.!'i~lt ai effi-?ient: flexibi]itv Aurin~ t)rer<-~ )ns, i.~. a~ll)ll];1r meml-ers made Or fle~ le matr~ l are l)ei~ ?~ `?d REl'l.ACRMl?.N'r Sllr~T

2~7~3~il to which belts remain just as efficient and flexible while in engagement and are not rendered less flexible by tensioning means.

As provided by the invention, the attachment, support and bearing integrated into the tooling belt for in-stance in the shape of loops, as well as the drive link or coupling of the belt via the driving arms or drive couplings engaging said loops via a brush-belt drive, brush-belt holding and brush-belt supporting device makes it possible to provide, according to the inven-tion and contrary to the entire known state of the art, a secure rotary brush for operating purposes the inner periphery of said flexible brush belt or flexible an-- nular member according to the invention remaining with-out direct inner support by any object, let alone by an inner-member support that is rigid or otherwise notice-ably influences flexibility. Only via said integrated loops the brush belt, with or without annular member, is supported and radially held in position without, though, significantly impairing belt flexibility.

Thus, the brush belt ~ith or without a flexible annular member may bend, in the area of the relatively rigid bristles just irl engagement, radiallv inwards and out-wards thanks to noticeable radial movability so that, among other thillgs, the inclination of any bristles just in engagement can adjust with respect to the brush belt peripheral tangent at the bristle root, i.e. in a resilientl~ elastic and modif~able manner according to the angle of movemellt charactel-izillg said bristles in their peripheral directioll. ,Mc)reover, radial displace-ability of bristles ma~ be provided. As com~ared to PE-PS 37 18 932, the rot:arv tool according to the inven-tion E)r(-)videsl am{)llg otller things, a brl~sh ~eIt having REPI.ACRMENT SHEET

-- 20~3~

integrated 1QOPS to improve -the use and maintenance of radial brush belt flexibility during brush belt opera-tion, to enhance the security and to achieve positive-fit brush-belt support with respect to its drive means while avoiding any clamping device. By comparison, the known device operates by frictional fit, its rubber core radially warps the brush belt from inside while reducing and impairing the brush belt flexibility remaining in operation, the brush belt is no longer held if damaged, and the well-known disadvantages of complicated tensioning means exist.

To a large extent, the same is true of DE-PS 37 41 983;
after all, the brush belt will be warped and, moreover, tied positively both axially and radially to peripheral annular grooves as well as rigidly supported in a radial inwards direction so that, during operational engagement, brush belt flexibility is rendered ineffec-tive to a large extent; moreover, the bristles, being in contact with the axial belts overarching the brush b~lt from outside and thus excessively prevented from modifying their inclination in a resiliently elastic manner relatively to the brush belt as well as being supported on sharply edged members, are subject to per-manent deformation and/or bending.
~, , Another particularlY essential characteristic of the invention is tlle Positive drive of the tool bushinq bv means of drivinq arms cooperatinq in a Positivelv lock-inq fit with the tc~ol bushillq either by drive means of the tool bushinq that, Oll~V bv wav of exam~le, mav be loo~ -Sha~3ed or by 3L3einq i n contact in a peripheral di-rection e.~. with the bund]es of bristles, Particularly the sPecial cross-sectional contours of said drive arms beinq desiqned to be free from edqes in a speciallv REPLACEMENT SHEE~

2Q7~3~

adaPted manner. Thanks to the positive-fit operative engagement of the tool bushing by the drive arms, 109g of power by rotation relative to each other of drive means and tool bushing designed, by way of example, as a brush ring, is prevented.

If the tool bushing (H) is driven, for instance by driving arms located radially inside and guided axially by the inside of the tool bushing, and accomodated by the drive hub (N), the bristles of brush rings can be used in a way to be optimally movable and unimpeded in their efficiency around their radius of action. The safety flange will prevent the tool bushing from slid-ing off axi.ally, it can be slipped on simply and can be held by latching into a snap-on lock such as an axially operable bayonet catch or similar means. Moreover, this allows hazard-free work along either direction of rota-tion. Given fle~ible brush rings or abrasive bushings, possibly in addition to a particularly elastic, for in-stance rubber-elastic, filling made of elastomers or flexible rubber, powerful working pressures are ensured at the same time as a high degree of pliability and elasticity. Tllan~s to the high degree of elasticity characterizing.the brusl~ ring, there is no danger that bristles mi~ht. break. Further advantageous developments characteriæed by inventiveness as well as alternative soluti.ons along paral]el 3.ines are to be found among remaining c]aims. ~y way of example, the safety member cannot be removed except after activating some means of releaSill9 tllf.~ safety, for instarlce a safety lever, t;hus preventiJ)g a~l~ irladvertent: release. For the same rea-son, a r-refeJelltial embodiment of said release lever may be a pnl~ lever embedded within the outside tool contour.

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Said snap-on link may be provided for, and act upon, the ends of driving means or a central shaft. Of ad-vantage will be central inner projections at the periphery or within a cavity of which a snap-on mechanism may be inserted for instance as parts of a bayonet mechanism that can positively engage each other and will do so only if the driving arms match with ap-propriate recesses or projections on the flange op-posite.
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An additional increase in safety levels is achieved by special spring member design. The points of the free spring legs arranged preferentially so as to be rota-tionally symmetrical will radially spread further apart whenever subject to centrifugal forces as rotational speeds increase, which means that the forces of reten-tion and the operational security they provide will in-crease in line with rotational speeds.

Finally, a unit ready for use by employing suitable ro-tary brushes each of which constitutes further inven-tive embodiments of the rotary tool according to the invention.

Further embodiments of the invention ~ill be e~plained ~ :
with reference to the drawing, wherein:

fig. 1 shows a rotary tool according to the inven-tion as having a drive hub (N) with drive flange, rotary brush and sealed safety ~., flange in cross-section;

~ fig. 2 shows the unlocked safety flange having its - release member pulled;

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W0 92/06821 PCT/EP91~01992 fig. 3 shows the rotary tool with released safety flange;

fig. 4 shows an edgeless, specially adapted cross-sectional driving arm contour located on a knocked-down drive hub featuring a snap-on fastener the driving arms of which accept the tool bushing configured as a brush bushing, surrounding it in an over-arching positive fit from outside, while remaining untensioned and without radial inside sup-port;

fig. 5 shows, as seen from on top, a safety tool bushing according to the invention and con-- ~ figured into the shape of a safety rotary brush ring provided with several possible configurations of driving members 33, pref-erentially made into loops 34 located within brush ring 36;

M~ fig. 6 shows a safety tool bushing according to the . .
- invention and configured into the shape of a brush belt ring 31 featuring a annular mem-ber 35 radially located therein and rigidly ]inked therewith as well as driving members 33 in various configurations preferentially made into loops 34;

fig. 7 shohs a safety tool bushing according to the invention configured as a brush ring 36 made of brush belt 31 having a firmly linked re-silie~Itly soft inside filling 37 characte-ri~ed by loop-shaped recesses configured as ~ openiIlgs 3~ and designed as driving memhers;
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WO 92/06821 PCT/EP9lJ01992 fig. 8 shows a sectional view through a rotary tool having a tool bushing pursuant to fig. 7.

Fig. 1 shows a sectional view through an illustrative embodiment of a rotary tool the drive flange 1 of which forms the tool bushing carrier properly speaking. In this embodiment, motor connection 3 is firmly linked with driving flange 1, simultaneously constituting the central axial projection 6. The inside of projection 6 is bored so as to accept the parts of the snap-onloc~
link mechanism located within safety flange 2. To per-mit latching of loc~ing members 10, projection 6 is provided with a rectangularly recessed annular groove 9 the radius of which groove decreases in the direction towards motor connection 3. Safety flange 2 is slipped on, projection 7 is pushed over projection 6 so as to be secured against being rotated, and the locking mem-bers 10 located within the inside space of projection 7 are submerged in projection 6 and latched into annular groove 9. One possible embodiment for the driving arms 4 are tubes guided through loop-shaped driving members 14 formed, for instance, radially on the inside of tool bushing ~, in the process accommodating in a positive lock projections 5 on safety flange 2.

Fig. 2 shows safety flange 2, it.s release lever 11 pulled. Hollow cyli.nder 13 constricts the locking mem-bers 10 of spring bushing 8 far enough to ma~e their inner diametre smaller than the inner diametre of pro-jection 6. Thl~s, safet;y member ~1 cannot remain in the pOSitiOll i].lustrated. The spring forces of locki.ng mem-bers 10, acting radi.a].ly, force reiease member ll hac~
into its initial and/or safety position characteri7.ed by spring brlshing ~ being spread and locking members 10 .~
~- prvjecting outwards radi.ally.
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-Fig. 3 shows safety flange 2 detached from drive flange 1, the spring legs of spring bushing 8 and its locking members 10 being back in their spread rest positions, while release member 11 and its pull knob 12 are pro-tected in their inner axial position within the axial outer contour of safety flange 2. The drive member is presented with safety flange 2 detached.

Pursuant to fiq. 4, drivinq arms 4 sup~ort bushinq H
radiallv fro~ outside, which means that the drivinq arms 4 are located radiallv outside the bushinq dia-metre. In the process, axial belts and/or axial projec-tions and/or driving arms 4 are in positive contact with bristle groups of brush tools. Belts overarching outside might constrict, given inadapted cross-sec-tional contours of the driving arms 4, the moving angles of bristles in a peripheral direction as well as towards the rotary plane; thus, bristle lengths avail-able for bending actively could be shortened substan-tially. Compared to known embodiments, the invariably positive drive of tool bushing H by means of the axial driving arms 4 will prevent any loss of power due to any rotation of tool bushing H and drive hub N with respect to each other. Owing to the fact that the cross-sectional contours of the driving arms 4 are adapted to the contour of brush belt and bristles de-formed during too] operation, bristles and brush belt may, while in engagement, adapt to flexibly elastic operational deformal:ions and positions, which will op-timize their use. Safetv flan~e 2 prevents any a~ial sliding away of tool bushing H froM drive hub N if flanges 1, 2 are attaclled to eacll other, for instance by means of a snap-o-l connection S, a multiplicity of other embodiments being possible.

REPLACEMENT SIIF,ET

20~3~ii WO 92/06~21 PCT/EP91/01992 In order to render the embodiment of the rotary tool according to the invention, i.e. consisting of drive hub N and tool bushing H, suitable for radially ex-terior retention of tool bushing H by drive hub N, the radially exterior driving arms 4 are configured, on their radially interior sides and on the two lateral areas contiguous thereto, for centering purposes as well as for driving the rotation of tool bushing H, wi.thout edges and with a special cross-sectional con-tour in their peripheral directions. For this purpose, the cross-sections of driving arms 4 may be substan-tially free from edges and have, at least in the effec-tive directions acting upon tool bushing H, a substan-tially convex periphery, i..e. have i.n all effective areas a substantially oval. or elliptical or bean-shaped outline, the side located radially outside having a radius of curvature inferior to the radius characteris-tic of tool bushing H, or of drive hub N, or of safety flange 2. Moreover, the convex, radial outsi.de may pro-ject at least partially beyond the periphery of drive hub N and of safety flange 2. During operations,- the cross-sectionally conve~, radially inner inside of the driving arms ~ is used for radial supporting of tool bushing H constituting, for instance, a brush belt ring, its collve~ sllape perlnitting said hrush belt to have regionally radial movabi].ity and pliability due to bristle loadin~, hhich ~oul.d he pre~ented ~y a concave or straight inner contour of.the radial.ly inner driving cross-sectional lines. The edgeless progress \~ia the transitiona]. curvat-llres of radiall~ inner d~ radial.l~
outer drivinc3 arm crc)ss-sectic)llal coiltours is located in radia] areas eq~lal t(~, or fr~)ln t~o to fi~? t.imes the multiple of, t.l-)e diametre of t.lle ~rushes t(- l-e used.
More particularl~, this t.rallsit:iona]. cur~at.ure may preferentiall~ h~ a ~U~ orresporldill~3~ in a l!ar-ticularly ad~-dl-lta(~e(,us en~ d-i~ nt, ~In~ t)~`lldill9 ~ille R~PI,A~EMENT SllEET

2~70~
.

function of a bendi.ng beam clamped at one end and sub-ject, at its other ends, to a transverse force or forces, said clamping corresponding to the radially inner bristle holding within the brush belt, and the transverse loading being located radially farther outside to correspond, for instance, to the peripheral forces actin~ upon the free ends of bristle tips during operations. Other types of transitional curvatures, such as spiral or involute contours, may be considered advantageous. An illustrative embodiment of the inven-tion having this type of special edgeless driving arm cross-sectional contour according to the invention is shown in the drawing as per fig. 4.

Said embodiment comprises a driving flange 1 having no less than three driving arms 4 spread uniformly over the periphery and extending parallel to each other and to the axis of rotation, located so as to e~tend axially away from the radially outer areas of the front side of driving flange 1 in an orientation axially in-side and facing safety flange 2. In the central area, there may preferably be located a for instance bored central projection 6 On whi.cll snap-on connection S may be arranged. Displaced axially in the direction of ro-tary axis Z, there is a safety flange para].lel to drive flange 1 and provided with manipulati.ng means 12, preferably configured intc) a pul] ~nob.

For the driving arms 9I the safety f].ange comprises in its radia]]~ oul-.er (1l-e~1s ho].ding memhers ]5 in lhe shape of recessec: lr~ adapted to form a positive lc~ck with the conl:ollr~; of drivir~g arlns 4 t:o allc~w for axially and radia]l.y immovab]e b~;t detachable positiorl-ing of said drivi.rlg arms g. `lallipu].atillg means 1~, preferably c~ fig~ 3 illt.~ d pllll krlOh, Illay c7C~Ilal.t' thP

REPL,~CEME:NT SHEET

-- 207~

- 22 ~

snap-on connection S between driving flange 1 and safe-ty flange 2 for unlocking purposes, e.g. within projec-tion 6, within which snap-on connection snapping means locked detachably may be released and unlocked by pulling said manipulating means 12 towards rotary axis z of the rotary tool. According to the invention, the cross-sections of said driving arms 4 are designed to be edgeless and convex, for instance oval, on all sides so that they have a convex radial outer side 17 and, surprisingly as compared to the state of the art, a likewise convex radially inner side 16 characterized by a radius of curvature that, compared to outer side 17 is for instance preferably larger. Outer side 17 is characterized by a radius of curvature inferior to the radius of safety flange 2 and/or of driving flange 1 and/or of tool bushing H and may for instance project partially beyond the periphery of safety flange 2.
Than~s to this design according to the invention, tool bushings H that can be held, such as brush rings devoid of bristles in a peripheral direction in the area of driving arms 4, radially outside in the area where the periphery of tool bushing H may support itself radially on the convex are-a 16 located radially inside. The bristles projecting radial.ly outside wil] partially be in lateral, positive contact. with the side areas 18 of the driving arm cross-sections that are devoid of edges, rounded and have an adapted curvature contour, ,; ~
which causes the tool bushing to be driven.
~, ~;~ Than~s to the special rounding of the radially inner ;.~ area and of the lateral areas ~8 of the driving arms 4, hi.ch areas face the bristles, the fle~ible brush belt ~:` and the bri.st].es in contact with it wil.l not buckle but ~ be supported in the area of terminal deformation in a .~ mallrler adapled to their free, lrldd-dependelll: deforma-~. ~
'~ ' REPLACEMENT S~EET

:

207~ }
-WO 92~06821 ~ PCT/EP91/01992 tion. Surprisingly, this makes it possible not to have buckle, as would happen under conventional conditions, either the brush belt or the bristles so that, accord-ing to the invention, they may transmit rotary drive forces without damage or premature wear and tear at high levels of power for optimum operation and abra-sion. The bristles may, both on the convex lateral faces 18 of the driving arms 4 characterized by adapted curvatures that face the bristles and on the convex radial outer sides 17, be in edgeless contact while in operation so that there is no danger that the bristles might break or be otherwise damaged. The same is true of the movable, flexible brush belt of the brush ring.
In a surprising manner, it thus becomes possible not to buckle either the brush belt nor the bristles, as would happen under conventional conditions, so that, accord-ing to the invention, they may transmit rotary drive forces without damage or premature wear and tear at high power for optimum operation and abrasion.

During operation, the bristles can be in edgeless con-tact both on the convex lateral surfaces of the driving arms ~ characterized by adapted curvatures that face ~^- the bristles and on the convex radial outer side 7 so ~-. that there is no danger of breaking or otherwise dan~-aging the bristles. The same is true for the movable, flexibIe brush belt of the brush ring.
:
One object of the invention is, among other things, to develop a higll-secllrity rotarv tool such as ~ ro~:ary safety brush that avoids the dangers and safety draw-~-~ backs mentioned when evaluating the state of tlle art above, instead working in a highly safe manner at high rates of efficiency, power ancl rotational s~eecl, d~-ing without any clampiny device, dispenc.ing witll com REPLAC~MEN'r SHEET

207~3~L

cated assembly procedures for handling purposes and, above all, maintaining radial bristle belt flexibility for maximum operational efficiency and speeds of rota-tion as high as possible.

According to the solution provided by the invention, said task may be fulfilled by a positively fitting drive design located between drive hub N and tool bushing H as disclosed by the illustrative embodiments shown in fig. 5 and fig. 6.

The tool, configured for instance as a rotary safety ~brush to be used, say, for surface treatment, will be characterized by the following features: a one or multi-part flexible tooling belt 36 such as brush belt 31 having a flat cross-section will be provided; it may be configured into a closed loop such as a brush ring.
In this case, bristle members 32 will be attached to :
brush belt 31 by way of brush ring, bristle members 32 being U-shaped, their free legs protruding at least :
7: partially outside through brush belt 31 for their free ~ ends to project predominantly in a radial direction ;s; outside beyond brush belt 31. Said brush belt 31 will ~ remain untensioned and retain, even while in opera-. .~
tional engagement, a noticeable degree of radial flexi-bility allowing for movability of brush belt 31 radially directed both inwards and outwards while operations are in progress. Along brush belt 31, driv-ing members 33 - configured for instance as loops 3~ -may be arranyed for positively loc~ing engagement by coupling means designed to drive brush belt 31. By ~o-cating said driving means 33 within such brush ring, substantial advantages are provided. This type of posi-tively loc~ing drive connection re]iably prevents REPLACEMENT SHEE~

. . . ^ .

2Q7~3~;~

slippa~e, i.e. any twisting away of the brush ring from said coupling means, thus making any clamping device as well as any clamping procedure superfluous.

Since, as compared to the brush pursuant to DE-OS 37 gl 983, there is no need for disadvantageous axial supporting belts, brush flexibility due to the bending elasticity of bristles, decisive for proper function, will be fully maintained as well as the angle of brush movement in peripheral directions, essential for proper function and resulting from bristle reten-tion within the elastically flexible and movable brush belt, which means that thanks to the belt flexibility remaining to a large degree unimpaired even in opera-tion since even the driven brush belt will invariably retain a certain degree of noticeable local inward and outward mo~ability of individual brush belt areas, i.e.
elastic brush belt flexibility, due to the positively locking brush ring support within said loops.

Owing to the fact that it is possible for the roots of said U-shaped bristles to be exposed at the inner peri-phery of brush belt 31 of such brush ring, said bristles or groups of bristles may, during operations, be pushed slightly inwards through the brush belt with-out any substantial hindrance once the centrifugal forces acting upon said bristles are overcome by the operating forces acting UpOIl the bristles if no inside support is provided, a fact which may be desirable for certain applications, for instc3nce i.f hiahly profiled surfaces are to be processed, in order to favour bristle immersj.on. Configuri.llg into loops 34 of driving members 33 i.s characterized by t:he speci.al advantage .~
that, in the event of any malfun~tion, the rotary brush remains positi.vely cou~led with the cc-u~ling means of .. the drive.
;~
REPLACEMENT S~.EET

207S3~ l~

Pursuant to a further embodiment of the invention shown in fig. 5, fig. 6 discloses an additional annular mem-ber 35 arranged within brush ring 36, which annular member may form, moreover, loops 34. Said annular mem-ber 35 will prevent the bristles from being pushed out of the brush ring inwards towards the brush centre line. Flexibility of the brush, i.e. its pliability to-wards the central axis as well as the elasticity of bristles and groups of bristles in their positions at an angle with respect to peripheral tangents may be ad-justed by influencing the thickness of, and the material used for, brush ring 35 and said annular mem-ber. If several brush segments are joined into a ring, several bristle types may be linked within a rotary brush. Said annular member 35 firmly linked (by vul-canizing, cementing, stitching) with the brush belt and adjustable as regards its elasticity and/or flexibi-lity, will cause resiliently elastic bristle operation without allowing them to be pushed irreversibly out of brush belt 31 in a radial direction towards the interior of the brush ring.

In a further inventive embodiment disclosed as per fig.
7, the resilient properties (pliability of brush belt 31 in a radial direction, i.e. towards and away from the brush centre line) of bristles 32 and groups of bristles may be enhanced by a flexible elastomer member 37 anchored firmly within brush ring 36, for instance a piece of sponge rubber introduced i nto the hollow brush ring 36. For pc-sitively ]ocking engagement of c~upling means for driving purposes intc) the brush hub, loops or appropriate lool~ e recesses 3~ coaxial to the axes of said driving arms may be pro~ided. As fi~. 5 showed the top view of a r-)~ary s;t-ety h]^ush ~ccording to the invention and pro~.~ided wi~:h ~ie\~ral pc)lelll:ial driving .

~EPLACRMENT Sl~EET

2~7~3~

means within the inside of a brush ring 36 otherwise free and unfilled, fig. 6 disclosed a rotary safety brush having a firmly attached annular member 35 as well as 1OQPS 34 attached in various manners, ~hi~e fig. 7 shows a rotary safety brush according to the in-vention with or without a firmly attached annular mem-ber but having a resiliently soft inner filling 37 within brush ring 36, within which filling only re-cesses 38 allowing for drive coupliny are provided.

Fig. 8 shows a sectional view of the rotary brush pur-suant to the comments as per fig. 5 and/or fig. 6 and/
or fig. 6. In this context, fig. 5 discloses various embodiments of a rotary safety brush according to the invention characterized by U-shaped bristles 32 placed through brush belt 31. Brush belt 31 is locked into a ring so that the free bristle ends project radially outwards. Loop-formed driving members 33 are arranged to be integrated on to brush ring 36, which driving members are simultaneously capable of linking several brush belt segments into a annular member. Driving mem-bers ,such as driving arms ~ of' a drive coupling are pushed into driving members 33, thus forming the brush belt support and fastening while maintaining a notice-able degree of radially elastic, flexible brush belt movability while simultaneousl~ constituting the p~si-tive-loc~ brush belt drive. netail A in fig. 5 shows a loop-shaped driving member 33 attached within brush belt 31; detai] ~ in fig. 5, the root of a loop-shaped driving member 33 simultanec)lls~y linkiy hrllsh belt seg-ments; detail C in fig. 5, such a driving member 33 having a ~oop-shaped head piece, loop 39, detail D in fig. 5, a dri~ing loop 3~ formed by cementing, vul-canizing, ~titching or .st,apliny cut of brush belt 31 itself. In fi~. 6, the irlside of the rotary safety ~ .

REPLACRMENT SHRET

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brush is provided with an elastically flexible, ri.gid~y attached annular member 35, the driving member 33 for details A, ~, C and D being of a design similar to the one of driving members 33 in details A, B, C and D on fig. 5. Detail E of fig. 6 shows a driving loop 34 formed out of annular member 35. Fig. 7 shows a rotary safety brush according to the invention having a firmly attached annular member 36 and a flexibly elastic, yielding inner filling 37. Inner filling 37 may consist of sponge rub~er or some other similar material; in-side, it is firmly attached to brusll belt 31 or annular member 35.

Filling 37 displays loop-like recesses appropriate for engaging the drive coupling.
, .
Fig. 8 shows a sectional view through a rotary safety brush of the type described above. Its U-shaped bristles are pushed through brush belt 31 until their bottom touches the belt, where they are supported on the flexible annular member 35 firmly attached to brush belt 31. A drive coupling provided with drive flange 1 designed for motors is pushed through driving loops 34 or driving recesses 38 and interlocked by means of a covering or safety flan~e 2, for instance by way of a snap-on connection. Since the flexible brush belt ring with or without flexible annular member 35 is not rigidly supported on its inner peripheral surface, the brush belt maintains, in a manner decisive for its function, above all radially elastic flexibility for a noti.ceable degree of radial and elastic pliability and brush inclination adjustment. According to the inven-tion, driving members 14, configured into driving loops 34 in this illustrative embodiment, may have other shapes for a posit.ively locki.ng connection wit.h driving arms 4 and/or axi.al projectiolls A.

RF.PT.ACF.MT3NT SllEET

, 2~7~
WO 92/06821 PCTtEP91/01992 More particularly, another essentia] part of the rotary tool according to the invention consists, partic~larly if lower rotational speeds are used, in the possible arrangement of an elastically expandable mass ring act-ing if subject to centrifugal forces within tool bushing H in order to provide inner support to said bushing more particularly at lower rotational speeds so as to permit a particularly high degree of working power and wor~ing pres~ure forces to be achieved even in radial directions. Said type of mass ring is sug-gested by broken lines in fig. 5, however only as a sectional segment. In this conte,Yt, the mass ring 50 properly spea~ing may consist of mass ring members 5n subject to centrifugal forces that may be guided mov-ably for instance by means of radial guiding shanks 52 within a closed holding ring 51 and prestressed radi-ally, for instance by means of springs 54 that may be supported on holding ring 51 and on the mass ring mem-bers 50 and/or via stops 55 at the guiding shanks 52, while mass ring members 50 would support, at rotational working speeds, the brush belt 31 at a preselectable rate of rotation and, at the same time, in an elas-tically fle~i~)le radial manner.

Thi:s illustrative en~bodiment for mass ring design Might consist in slotted mass ring bushings made of a re-siliently elastic material, which bushings, while at rest and radially not e~panded might, for instance, be in slight contact wit]l the inner periphery of brush belt 3i, or in anotller illustrative embodiment consist of a mass rin~ 1ayer in the form of annular segMents made, for instance of a metal or an elastomer etc, which, while at rest would be in contact e.g. not at all or e.g. ~nl~ s]ig)~tly witll the inner diametre of REPLACEMENT ~HEET

207~3~ll brush belt 31 and be supported radially in a firmly linked manner by the outer peripheral surface of a re-siliently elastic flexible rubber filling located within the brush belt.

Besides, numerous further embodiments are possible and therefore an integral part of the invention in respect of the configuration of such mass ring, the outer dia-metre of said mass ring according to the invention tending to increase in a resiliently elastic manner under the influence of rotational speeds; therefore, it will, subject to rotational speeds, act radially from inside outwards upon the brush ring and/or the bristle roots, the mass ring at rest, being of a resiliently elastic design, having a smaller diametre and being supported, while in operation, in supportive conctact on brush belt 31, at le~st for part of the periphery.

For the elastically expandable mass ring R provided by the invention and to be located, if provided, within tool bushing H freely and more particularly radially within said tool bushing H as well as coaxially in respect thereof, some resiliently elastic elastomer and!or metal may be used. This mass ring, to be used preferably at lower rotational speeds and high operat-ing power can be expanded radially by the centrifugal forces acting within it, for instance under the in-fluence of rotational speeds, and will be connected with the radially inner peripheral surface of tool bushing H so that mass ring R mav support itself out-wardly at the inner peripheral surface of tool bushing H, for instance at the brush be]t inner diametre and its bristle roots.

-REPLACEMENT SHEET

; 2~7~3~"~

Further providing special means of self-ventilation of the rotary too]., particularly at high speeds and high power levels, is likewise an integral part of thi.s in-vention.
;

For this purpose, the rotary tool according to the in-vention and consisting of drive hub N and inter-changeable tool bushing H is provided, among other things, with additional flow guiding vanes located on drive hub N and/or on tool bushing H. During operation of the rotary tool, these additional flow guiding vanes will act to cool the rotary tool by causing additional turbulence at said rotary tool within the medium, such as air, surrounding it; said flow guiding vanes may have the shape of a turbine or a compressor and/or a blade wheel or an impeller. The additional flow of the surrounding medium so achievable will thus be effected in a predominantly axial direction through the radially inner section of tool bushing H and/or the outer sur-face of the rotary tool: the flow guiding vanes con-figured, for instance, into shapes similar to turbines or blade wheels wil]. be arranged in a predominantly axial manner on one or both of f].anges 1 and 2 of drive hub N, or on the front side facing away from said other flange 2 or 1, or else predominantly radially within tool bushing H on drive hub N.

Such cooling, for inst-.allce from inside, is suggested in a schematic and i].ll.lstrati.ve manner by means of open-ill9S 4] loca~ed lad-;ally fllrtllel^ inwards witllill olle of the flange wal].s Wll:iC]'! may siml~ltallec)usly bear blade r-.il~s 43 oti il~ M.sid~a, which ~ladf? r:ibs creale a dy-namic pressilrie ~f l:h~ ambient air direct-ed into opening 41, thus guidi"~J ~ Oh 01 air as indicated by t:he arrOWS inl:o ~ inSir~ t~le t'('~t'~r`y t~ , Whil.? on tlle Rr,Fl..AC33MF.N'I' Slll~l,l`

2~'7~3~

other flan~e wall there may be openings 42 located for instance further outwards and allowing the flow af air to leave the inside of the rotary tool towards the am-bient air, said openillys 42 being provided, for in-stance, with addi.tional blade ribs creating a low pres-sure area around said openings 42 as the rotary tool turns so that a powerful flow of air will here leave the tool as indicated by the arrows. ~umerous openings 41 and 42 are possi.ble, just as other designs and em-bodiments of the f].ow surfaces within and outside the rotary tool, such as heli.coidal guide vanes similar to threads, etc.

Said flow guiding vanes of the rotary tool according to the invention.may be operated li~e a compressor or like a turbine, and/or like a blade wheel or an impeller, or they may preferably exploit instead of, or together therewith, for instance the mass forces inherent in the flow medium by using for instance centrifugal forces and/or the force of i.nertia acting upon the fluid whenever the tool is rotating. ~y way of example, ap-propriately arranged openinrJ.s along differing radii away from the a~is of rotati.on might be indicated, linked e.g. with blade-shapr?~ surface contours located, for instance, on flanges ~ arld/ol- 2.

. .~
Self-ventilation of the rotar\; to~l according to the invention as well as the rnacis ring support inside the tool bushing dependent upon rotatiollal sE)eeds according to the invenl.i.i~n are ;nrl;~at(-~d ;~nl~ schematical]~r on figures 5 and 13 ar,d ant~ . ahown separately in a spe~ific fjgur*. Hl)~ ?l, n!) le:i~ ricl.ion tc~ the i.l-lustrative er~borlirne~ s ;~. fo3^th is intended.

Rl'l'l,A~r~ l'N'I' ~H~.I'I`

2~'7~3~

- With this rotary tool according to the invention the various embodiments contributing to higher efficiency, power, safety etc. over the state of the art are, in and of themselves, already suitable to effect improve-ments over the art and to avoid its specific disad-vantages; however, they may be used and combined in any proportion among and/or with each other so as to achieve tool optimization for the practical require-ments entailed by any concrete application, in the pro-cess operatin~, in any event, at a level superior to the comparable state of the art and avoiding its various disadvantages at least partially but, if at all possible, completely; in this context, the invention is not meant to be limited to the illustrative embodiments shown but wi.ll include among its components all alter-narive and equivalent means.

REprJAcEMENlll S~ T

Claims (38)

P a t e n t C l a i m s

1. Rotary tool consisting of drive hub (N) and inter-changeable tool bushing (H), characterized in that - the tool bushing (H) may be linked with drive hub (N) so as to be rotationally rigid, and that means of engagement for processing measures protrude from its outer peripheral surface, - the drive hub (N) consists of a drive flange (1) and a safety flange (2), - on said drive flange (1) a central motor connection (3) is provided coaxially on the axial outside of said drive flange, - at least one of the flanges (1, 2) comprises on its axial inside at least one axial projection (A), - axially opposite to each axial projection (A) the other flange (1 or 2) comprises a second axial pro-jection (A) or a recess or opening correspondingly allocated, - at least one axial projection (A) may be arranged radially off centre, - at least one axial projection (A) forms an axial driving arm (4, 5), - at least one axial projection (A) engages part of the opposite flange (1, 2) between the two flanges (1, 2) so that the flanges (1, 2) cannot be rotated with respect to each other referred to their common axis, - the safety flange (2) latches into the driving flange (1) by means of at least one positively locking snap-on connection (9, 10), - at least one member of at least one snap-on connec-tion (9, 10) is located at least on one projection (A), - the snap-on connection (9, 10) links the flanges (1, 2) in an axially lockable arrangement, - the snap-on connection (9, 10) is configured as a fastener similar to a bayonet catch, and - the snap-on connection (9, 10) can be released by unlocking means, for instance exclusively by the actuation thereof, and that said unlocking means if constituted by a release device (11).

2. Rotary tool according to at least one of the other claims, characterized in that the engagement means for processing purposes are bristles.

3. Rotary tool according to at least one of the other claims, characterized in that on every flange (1, 2) an axial projection (6, 7) is arranged coaxially in a cen-tral position, which projection is opposite to the other one allocated to it so as to form a positive lock.

4. Rotary tool according to at least one of the other claims, characterized in that the snap-on connection (9, 10) is to a large extent arranged on at least one projection (A), for instance within it, and by way of example on projections (6, 7) arranged coaxially, or by way of example at projections (A) arranged in a radi-ally decentral position, and said projections may form axial driving arms (4, 5).

5. Rotary tool according to at least one of the other claims, characterized in that at least one largely hol-low projection (A, 6) comprises inside at least one an-nular groove (9) concentric, for instance, with respect to projection (A, 6) and designed for latching at least one locking member (10), which annular groove preferably decreases in its radial depth in a direction towards the drive flange (3).

6. Rotary tool according to at least one of the other claims, characterized in that - at least one first projection (A, 6) may be im-mersed into at least one opposite second projection (A, 7) in a corresponding positively locking way whenever drive flange (1) and safety flange (2) are brought together, - at least one first projection (A, 6) may have an outer, for instance out of round, non-circular outer profile and at least one second projection (A, 7) a corresponding, for instance out of round, non-circular inner profile, and - the corresponding profiles may be arranged on axial recesses or projections (5) located eccentrically that they invariably correspond, for instance, with driving arms (4) in a positive lock.

7. Rotary tool according to at least one of the other claims, characterized in that closing members (10) are formed out of elastically resilient members, for in-stance a partially slit spring bushing (8), the spring members being fastened, for instance, as a spring bushing (8) within said at least second projection (A, 7).

8. Rotary tool according to at least one of the other claims, characterized in that projections (A) in the form of driving arms (4) and, corresponding thereto, axial recesses or projections (5) are distributed ec-centrically but symmetrically over the periphery of the flanges (1, 2).

9. Rotary tool according to at least one of the other claims, characterized in that at least one part of the release device (11) is guided centrally through the safety flange (2).

10. Rotary tool according to at least one of the other claims, characterized in that said release device (11) acts releasingly upon the actuation by pulling a pulling knob (12).

11. Rotary tool in accordance with claim 10, characterized in that safety flange (2) is designed so that pulling knob (12) can be retracted into it.

12. Rotary tool according to at least one of the other claims, characterized in that motor connection (3) was developed to use the same axle that is simultaneously to be used as a projection (A or 6).

13. Rotary tool according to at least one of the other claims, characterized in that - locking members (10) are subject to radial pre-tensioning and may be tensioned radially for de-locking purposes in view of the fact that the points of locking members (10) e.g. conically formed at the outer periphery may be surrounded, by way of example, by a hollow cylinder (13), - said hollow cylinder (13) may be linked with a pulling knob (12), and - said hollow cylinder constricts, if pulling knob (12) is actuated by pulling it, the diametre of the locking members (10) e.g. by means of a wedge-like surface in the manner of an axial movement along an incline or a conical surface, - the pulling knob (12) is pulled in its rest posi-tion against its axial (rest) stop without being actuated.

14. Rotary tool according to at least one of the other claims, characterized in that a rotary brush ring (31) having U-shaped bristles is provided by way of inter-changeable tool bushing (H).

15. Rotary tool according to at least one of the other claims, characterized in that - the tool bushing (H), for instance configured into a rotary brush ring (31) is provided with integrat-ed driving members (14) that may have the shape of loops and that may be formed by the tool bushing (H) or the rotary brush ring (31) themselves, - driving arms (4) are guided through the driving members (14), and - axial movements of the tool bushing (H) or the ro-tary brush ring (31) are prevented, to a large ex-tent, by the flanges (1, 2).

16. Rotary tool consisting of drive hub (N) and inter-changeable tool bushing (H), characterized in that - the tool bushing (H) may be linked with the drive hub (N) so as to be rotationally rigid, and that means of engagement for processing measures protrude from its outer peripheral surface, - the drive hub (N) consists of a drive flange (1) and a safety flange (2), - in an axially outer position, a centralized motor connection (3) is provided coaxially on the drive flange (1), - at least one of the flanges has at least one axial projection (A) in its axially inside area, - axially opposite every axial projection (A) a second axial projection (A) or a recess or an open-ing is provided at the other flange (1 or 2) in an appropriately allocated area, - at least one axial projection (A) may be arranged in a radially eccentrical position, - at least one axial projection (A) forms an axial driving arm (4, 5), - at least one axial projection (A) between the flanges (1, 2) meshes with part of the opposite flange (1, 2) so that the flanges (1, 2) cannot be rotated with respect to each other with reference to their common axis, - the tool bushing (H) is configured into a rotary brush ring (31), - the safety flange (2) is detachably fixed on the drive flange (1) so that both flanges have the same axis and maintain a certain distance with respect to each other, - at least two driving arms (4, 5) are provided on the drive flange (1) at the same radial distance from the axis (Z) of rotation in a position rota-tionally symmetrical and at the same rotary pitch with respect to each other, - the driving arms (4, 5) support and drive the tool bushing (H) in a positively locking manner and are configured, for this purpose, so as to have a cross-section free from edges and substantially convex in all active directions, more particularly so as to have at least in their active areas a sub-stantially either circular or oval or elliptical or bean-shaped cross-section.

17. Rotary tool according to at least one of the other claims, characterized in that the driving arms (4, 5) support the tool bushing (H) radially from outside in a positively locking manner.

18. Rotary tool in accordance with claim 17, characterized in that the radius of curvature of the radially inner side of the cross-section of said driving arms (4, 5) is equal or superior to the radius of curvature of the radially outer side.

19. Rotary tool in accordance with claim 17 or 18, charac-terized in that the radial cross-section of the driving arms (4, 5) is convex in all directions.

20. Rotary tool according to one of the claims from 17 through 19, characterized in that the curvature linking the radially inner side of the cross-section of said driving arms (4, 5) with the radially outer side of said cross-section approximates the bending line func-tion of a beam clamped at one end and loaded trans-versely on its other end.

21. Rotary tool according to one of the claims from 17 through 20, characterized in that the curvature linking the radially inner side of the cross-section of said driving arms (4, 5) with the radially outer side of such cross-section has a minimum radius corresponding to once, or a multiple of for instance two to five times, the bristle diametre of the brush rings to be used.

22. Rotary tool according to one of the claims from 17 through 21, characterized in that the convex radial outer side of the driving arms (4, 5) projects at least partially beyond the periphery of the flanges (1, 2).

23. Rotary tool according to at least one of the other claims, characterized in that - the safety flange (2) is detachably fixed in an axial direction on the drive flange (1) by means of a snap-on connection configured, for instance, into a fastener similar to a bayonet catch, and - the safety flange (2) can be unlocked from the drive flange (1) exclusively by means of release means such as an unlocking device.

24. Rotary tool according to at least one of the other claims, characterized in that the driving arms (4, 5) engage the tool bushing (H) radially inside it in order to support and drive it.

25. Rotary tool according to claim 24, characterized in that - the tool bushing (H) is provided with integrated driving members (14) which may have the shape of loops and which may be formed out of the tool bushing itself, - the driving arms (4, 5) lock positively into the driving members (14), being for instance guided through them, and - the substantial axial movements of the tool bushing (H) between the flanges (1, 2) are prevented.

26. Rotary tool according to at least one of the other claims, characterized in that - the tool bushing (H) consists of a single or multi-part belt, for instance a brush belt (31), having a flat cross-section and being configured into a closed safety rotary ring, and in that on belt (31) of tool bushing (H) bristle members (32) are at-tached which may be U-shaped and the free legs of which protrude at least partially through the belt (31) in a radially outwards direction to protrude, with their free ends, in a predominantly radially direction outside away from belt (31) of tool bushing (H), and the tool bushing (H) formed for instance out of brush belt (31) remains untensioned and maintains, even during operations, a noticeable radial flexibility allowing, in operation, a noticeable movability of the tool bushing (H) formed out of brush belt (31) directed radially in-wards or outwards, - driving members (14) configured for instance into loops (34) are provided, integrated into the tool.
bushing ring to allow for positively locking en-gagement of a drive coupling for instance in the form of drive arms (4, 5) supporting and driving the tool bushing (H), and that said driving members (14) may be formed out of the tool bushing (H) or its belt (31) themselves, and - said tool bushing (H) is suitable for accommodation of, and fastening to, a suitable drive hub (N).

27. Rotary tool according to at least one of the other claims, characterized in that an elastically expandable mass ring (R) consisting for instance predominantly of resiliently elastic elastomer and/or metal is provided radially within the tool bushing (H) and coaxially therewith, which mass ring may expand under the in-fluence of centrifugal forces acting within itself and linked with the radially inner peripheral surface of tool bushing (H) so that the mass ring (R) supports itself, depending upon rotational speeds, outwards on the inner peripheral surface of tool bushing (H), for instance at the inner diametre of the brush belt hold-ing the bristle roots.

28. Rotary tool consisting of drive hub (N) and inter-changeable tool bushing (H), characterized in that - the tool bushing (H) may be linked in a rota-tionally rigid manner with drive hub (N), means of engagement for processing purposes project from its outer peripheral surface, and the tool bushing (H) is configured into a rotary safety tool for surface treatment, for instance as a rotary brush, - the tool bushing (H) consists of a one or multi-part belt, for instance a brush belt (31), having a flat cross-section and being formed into a closed rotary safety ring, and that e.g. bristle members (32) are attached to belt (31) of tool bushing (H), which bristle members may be U-shaped, their free legs protruding at least partially outwards through belt (31) in a radial direction to project their free ends in a predominantly radial direction out-wards out of belt (31) of tool bushing (H), and that tool bushing (H) configured for instance into a brush belt (31), remaining untensioned and main-taing, even when in operation, a noticeable degree of radial flexibility that allows, during opera-tional use, for a noticeable degree of elastic flexibility oriented radially inwards or outwards for the tool bushing (H) configured, for instance, into a brush belt (31), - driving members (14) configured for instance into loops (34) are provided, integrated into the tool bushing ring to allow for positively locking en-gagement of a drive coupling for instance in the form of drive arms (4, 5) supporting and driving the tool bushing (H), and that said driving members (14) may be formed out of the tool bushing (H) or its belt (31) themselves, and - said tool bushing (H) is suitable for the accommo-dation of, and for fastening to, a suitable drive hub (N) having the following characteristics:
- the drive hub (N) consists of a drive flange (1) and a safety flange (2), a centralized motor connection (3) is provided outside co-axially on the drive flange (1), at least one of the flanges has at least one axial projec-tion (A) in its axially inside area, axially opposite every axial projection (A) a second axial projection (A) or a recess or an opening is provided at the other flange (1 or 2) in an appropriately allocated area, at least one axial projection (A) may be arranged in a radially eccentrical position, at least one axial projection (A) forms an axial driving arm (4, 5), at least one axial projection (A) be-tween the flanges (1, 2) meshes with part of the opposite flange (1, 2) so that the flanges (1, 2) cannot be rotated with respect to each other with reference to their common axis, the tool bushing (H) is configured into a rotary brush ring (31), the safety flange (2) is de-tachably fixed on the drive flange (1) so that both flanges have the same axis and maintain a certain distance with respect to each other, at least two driving arms (4, 5) are provided for instance on drive flange (1) at the same radial distance from the axis (Z) of rotation in a po-sition rotationally symmetrical and at the same rotary pitch with respect to each other, the driving arms (4, 5) may be guided by driving members (14), and any substantial movement in an axial direction of the tool bushing (H) be-tween the flanges (1, 2) is prevented.

29. Rotary tool according to at least one of the other claims, characterized in that - the tool bushing (H) comprises radially within the outer belt (31) configured into a ring, for in-stance a blush ring, another annular member (35) made of flexible belt having a flat cross-section, - the radially outer belt (31) by its inside back (36), for instance a brush back, and the annular member (35) with its outer envelope are linked to-gether non-rotatably and in a permanently rigid manner so that said annular member (35) covers for instance the backs of the bristle assemblies (2).

30. Rotary tool according to at least one of the other claims, characterized in that the driving members (14) are formed, for instance as loops (34) by belt (31), for instance the brush belt, or by a radially inner an-nular member (35) provided by way of example, or by belt (31) and an annular member (35) possibly located therein in a radial arrangement.

31. Rotary tool according to at least one of the other claims, characterized in that the cylindrical hollow space within the tool bushing (H) comprises an elas-tically yielding filling (37), for instance radially within a brush belt (31) or radially within an annular member (35), which filling forms a firm connection with the tool bushing (H), for instance with annular member (35).

32. Rotary tool according to claim 31, characterized in that said filling (37) comprises at least one recess (38) arranged coaxially with respect to the loop-shaped driving members (14), within which recess, by way of example, driving members (14) or drive coupling members formed by annular member (35), for instance in the shape of loops (34), may engage.

33. Rotary tool according to at least one of the other claims, characterized in that drive hub (N) and/or tool bushing (H) are formed to have additional flow guiding vanes designed to generate, as the rotary tool is operated, cooling action upon said rotary tool by creating additional flows of the medium, for instance air, surrounding the rotary tool, on or along said tool.

34. Rotary tool according to claim 33, characterized in that the flow guiding vanes are designed so as to cause the additional flow so generated of the surrounding me-dium to be led in a predominantly axial direction through the radial inside of the tool bushing (H), or predominantly across the outer surface of the rotary tool.

35. Rotary tool consisting of drive hub (N) and inter-changeable tool bushing (H), characterized in that - the tool bushing (H) can be connected in a rota-tionally rigid manner with drive hub (N) and en-gagement means for processing purposes, for in-stance bristles or grains of abrasive, project from its outer peripheral surface, - the drive hub (N) consists of a drive flange (1) and a safety flange (2), - on said drive flange (1) a central motor connection (3) is provided coaxially on the axial outside of said drive flange, - at least one of the flanges (1, 2) comprises on its axial inside at least one axial projection (A), - axially opposite to each axial projection (A) the other flange (1 or 2) comprises a second axial pro-jection (A) or a recess or opening correspondingly allocated, - at least one axial projection (A) may be arranged radially off centre, - at least one axial projection (A) forms an axial driving arm (4, 5), - at least one axial projection (A) engages part of the opposite flange (1, 2) between the two flanges (1, 2) so that the flanges (1, 2) cannot be rotated with respect to each other referred to their common axis, - the drive hub N and/or the tool bushing (H) is configured to feature additional flow guiding vanes located on drive in a manner to have said vanes act to cool the rotary tool by causing ad-ditional turbulence at said rotary tool within the medium, such as air, surrounding it, - said flow guiding vanes may be configured to have the shape of a turbine or a compressor and/
or a blade wheel or an impeller so that the ad-ditional flow of the surrounding medium so achievable will be effected in a predominantly axial direction through the radially inner sec-tion of tool bushing (H) and/or the outer sur-face of the rotary tool, said flow guiding vanes - configured, for instance, into shapes similar to turbines or blade wheels - being arranged in a predominantly axial manner on one or both of flanges (1 or 2) of drive hub (N), or on the front side facing away from said other flange (2 or 1), or else predominantly radially within tool bushing (H) on drive hub (N).

36. Rotary tool according to claim 34 or 35, characterized in that the flow guiding vanes operate in the manner of a compressor or a turbine and/or a blade wheel or an impeller, and/or use mass forces inherent in the flow medium, such as centrifugal forces and/or inertia.

37. Rotary tool according to at least one of the other claims, characterized in that the driving are (4, 5) serve to support and drive the tool bushing (H) by being in positive contact therewith and, for this pur-poses, are designed to have an edgeless and substan-tially convex cross-section in all active directions, which cross-section shall be, at least as regards more particularly its effective area, of substantially cir-cular or oval or elliptical or bean-shaped form.

38. Rotary tool consisting of drive hub (N) and inter-changeable tool bushing (H), characterized in that - the tool bushing (H) may be linked with drive hub (N) so as to be rotationally rigid, and means of engagement for processing measures, such as bristles or grains of abrasive, protrude from its outer peripheral surface, - the drive hub (N) consists of a drive flange (1) and a safety flange (2), - on said drive flange (1) a central motor connection (3) is provided coaxially on the axial outside of said drive flange, - at least one of the flanges (1, 2) comprises on its axial inside at least one axial projection (A), - axially opposite to each axial projection (A) the other flange (1 or 2) comprises a second axial pro-jection (A) or a recess or opening correspondingly allocated, - at least one axial projection (A) may be arranged radially off centre, - at least one axial projection (A) forms an axial driving arm (4, 5), - at least one axial projection (A) engages part of the opposite flange (1, 2) between the two flanges (1, 2) so that the flanges (1, 2) cannot be rotated with respect to each other referred to their common axis, - an elastically expandable mass ring (R), made for instance predominantly out of a resiliently elastic plastic and/or metal, is provided within tool bushing (H) coaxially in respect thereof, said mass ring being expandable radially by the centrifugal forces acting within and being connected with the radially inner peripheral surface of tool bushing (H) so that, depending upon rotational speeds, mass ring (R) may sup-port itself outwardly at the inner peripheral surface of tool bushing (H), for instance at the brush belt inner diametre and its bristle roots.