Title of Invention

"CUTTING TOOL"

Abstract A cutting tool of a cutting machine having a base element and a chisel holder, wherein the chisel holder is provided with a plug-in shoulder which is retained in a plug-in receptacle of the base element, and wherein the plug-in receptacle is spatially connected with its surroundings via one or several openings, wherein at least one of the openings is at least partially closed by means of a sealing element (30), characterized in that the chisel holder (10) rests with its stop (11) against the stop (24) of the base element (20), that the base element (20) has a shoulder (21) extending at an angle in relation to the stop (24), that a clearance (16) acting as an adjusting space is formed between the shoulder (21) of the base element (20) and the side of the chisel holder (10) facing the shoulder (21). wherein the sealing element (30) is shaped in such a way that it bridges this clearance (16).
Full Text Cutting Tool
The invention relates to a cutting tool of a cutting machine having a base element and a chisel holder, wherein the chisel holder is provided with a plug-in shoulder


which is retained in a plug-in receptacle of the base element, and wherein the plug-in receptacle is spatially connected with its surroundings via one or several openings.
Such a cutting tool is known from DE 43 22 401 C2. The cutting tool contains a chisel holder and a base element which is fastened to a cylinder-shaped cutting
body of a cutting machine. For fastening the chisel holder on the base element, the latter

has a plug-in receptacle with a Vee- guide, into svhich a plug-in shoulder of the chisel
holder can be pushed. The chisel holder is fixed in place with the aid of a pressure screw. In this connection the exact positioning of the chisel holder is given particular importance, also in case of repeated assembly/disassembly and exchange.
For absorbing the forces occurring in the course of the operation, the base element has a stop, on which the chisel holder is supported. So that the effects of the stop

are maintained arid stress on the plug-in shoulder and the plug-in receptacle is prevented to the greatest extent possible, the chisel holder is arranged offset by an adjusting space in the area around the plug-in receptacle.
It has been shown to be disadvantageous in connection with such cutting tools which are employed, for example, in road construction, that pulverized rock and
water penetrate the area of the plug-in shoulder and the plug-in receptacle. Pulverized rock
and water can cause the plug-in shoulder, as well as the pressure screw, to become caught in the plug-in receptacle. Because of this, the chisel holder can only be releaseid from the base clement with increased effort. Often the parts are damaged in the course of the forcible separation, which results in a more cost-intensive replacement. Moreover, the pulverized rock results in increased wear in this area, which leads to reduced service life
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and therefore to higher operating costs. In the course of releasing the pressure screw, din which becomes caught on Ihe pressure screw from the interior, is worked into the threaded receptacle of the base element and damages it. A repair or replacement of the base element which must take place then can only be performed with added outlay, because customarily
the base element is welded to the cutting cylinder tube- and the adjacent base elements.

Dirt on the plug-in shoulder of the chisel holtter and in the area of the plug-in receptacle of the base element is particularly disadvantageous. The particles adhering there are shattered in the course of the subsequent operation of the machine. Play is then created between the plug-in shoulder and the plug-in receptacle. The exactly fitted positioning of the chisel holder is then no longer assured. This has a negative effect, in particular in -the course of so-called fine milling. This method, which is gaining importance in actual use, is used to mill road surfaces to their final quality in one processing step. A prerequisite for this is ihat the chisel holders are exactly positioned. If one chisel holder docs not meel these criteria, it causes a wrong spot in the milling pattern, which has an effect on the total result. Thus, a chisel holder which is seated loosely in the base element can decisively worsen ihe milling quality. It cart furthermore occur that the
loosely seated chisel is completely separated from the base elemenat and sause serious damage to the tool.
It is the object of the invention to produce a cutting tool of the type mentioned at the outset, wherein the service life of the tool, in particular of the base

element is improved

This object is attained in that at least one of the openings is at least partially
closed by means of a sealing element.
The sealing element protects the transition area of the plug -in receptacle formed bctwecn the plug-in shoulder and the base element It prevents the penetration of

the plug-in receptacle by removed material and water in a simple and effective way. Once
the chisel holder has reached its worn state, it can be
the reception chamber formed by the plug-in receptacle remains clean and substantially
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free of dirt It impossible to exactly posidon anyfasten a fresh Chisel holder with little loss of time. Thus, the sealing element constitutes a simple component which permts a more

effective tool change, and at the same lime substantially increases the service lifc of the base element. The sealing element can also be constituted. by a grease layer
Depending on the shape and arangement of the sealing element a reproducible and exactly fitting position of the chisel holder is made possible.
In accordance with a preferred embodiement variation of the invention it can be provided that the sealing element is arranged around the plug-in receptacle at least in
some areas between the chisel holder and the base element. By means. of this/an area is protected through which often massive amounts of dirt can enter.
Particularly effective sealing is achieved in that the scaling element is embodied as a molded element having the contour of fee circumference/Of tha plug-in shoulder of the chisel holder. The design is furthermore particularly installation friendly,
because the sealing element can be placed on the plug^a shoulder of the chisel holder for mountiog and can lhen.be installed in the base element together with the chisel holder.
Because the base element has a circumferential bezel around the plug-in receptacle, which is used as a seat for the sealing element, it is achieved that the scaling element is immovably seated during operations. Moreover, the bezel provides the space
into which the sealing element is definitely pressed in the course of mounting without a
possibility of being destroyed itself. An optimal sealing effect is achieved by this.
Permanent sealing of the area to be protected is achieved in that the sealing element is made of a permanently clastic material, preferable of silicon, or of a thermoplastic elastomer.

-A'preferred embodiment provides that tha chisel holder rests with its stop against.the stop of the base element, that the base element has a shoulder extending at an angle in relation to the stop, thai u clearance acting as an adjusting" space is formed between the shoulder of the base element and the side of the chisel holder facing the shoulder, wherein the sealing element is shaped in such a way that it bridges this clearance.
By means of this it is achieved that pulverized rock, and watercannot penetrate the plug-in receptacle through the adjustment space.
A particularly easy assembly and assured scalingefjfecls are-acBieved in that
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the sealing elment is angled in a manner corresponding to the angle between the shoulder and the stop of the base element.
Good sealing of the different gap widths in the area of the stop and the adjustment space can be achieved in that the sealing element has a section of an O-shaped cross section, which rests at least in pan against the stop of the base element and has a section which is angled off in relation 10 the latter, which rests against the shoulder of the base element and has a thickened cross section which bridges the clearance st least partially


An advantageous embodiment of the invention prdvides that the angled-off section has a wedge-shaped sealing lip, which us matched to the shape fo the adjustment space, Uneverness and production tolerenaces of the chisel holder and the base element compensated by this.
A cost-effective manufacture even in large numbers, as well as narrow tolerance and a design matched to the production process are made possible in that the
sealing element is embodied as an injection-moided element, and the sprue nose is arranged in an area of the cross section which hasbeen thickened corresponding to the clearance, By means of this it is achieved that the sprue nose does not hamper the sealing effect of the-sealing element.
A simple and exactly fitting mounting of the chisel holder on the base element is achieved in that the sealing element is drawn as a separate plastic component on the plug- in shoulder, or that the sealing element is injection-molded On the plug-in shoulder as a plastic component.
A preferred embodiment of the invention provides that the chisel holder of the cutting tool is provided with a plug-in shoulder formed on a base body and the plug-in
i ' '
shoulder has a sealing element extending around the plug-in shoulder in at least partial areas of its outer circumference. By means of this it is achieved that it is possible to preform the chisel holder with the plug-in shoulder and the sealing element as a structural unit, to Stock it as a unit and to install it quickly and cost- effectively as a replacement part. The invention will be explained in greater detail in what follows by means

of exemplary embodiments represented in the drawings Shown are in:
Fig. 1, in a lateral view and in section a. cutting tool with-an exchangeable chisel holder in the partially assembled state,
Fig. 2, in a lateral view and in section the cutting tool in accordance with Fig, 1 with the chisel holder inserted,
Fig. 3a, a sealing element in a view from above,
Fig. 3b, the sealing element in accordance with Fig. 3a in a lateral view.
The cutting tool (1) in Fig. 1 consists of a base element ,(20), Into which an exchangeable chisel holder (10) can be inserted. The cutting tool (1) the further more has a
sealing element (30) and a pressure screw (40), which is used for fixing the chisel holder (10) in place in the base element (20).
The chisel holder (10) consists of a base body (17) and on its lower end has 8 plug-in shoulder (15), which can be inserted into a corresponding plug-in receptacle(22) at the base element (20). The insertion movement of the chisel holder (10). into; the base element (20) is limited in its rear area by a stop (11) at the chisd holder (10) and by stop (24) on'the base element (20) located opposite it. On Us front edge, the plug-in shoulder (15) has at least one guide face (15.1), which is .guided ini thecourse of the insertion of the chisel holder (10) by means of a corresponding Vee guide (22.1) in the plug-in receptacle (22).
Furthermore, the chisel holder (10) has a chisel receptacle (12)t into which a

turning chisel, which is also easy to exchange, can be inserted, thc longitudinal axis of the
chisel receptacle (12) forms an acute angle in respect to the axis of the; plug-in shoulder (15),
A sealing clement (30) has been drawn on the plug-in shoulder (15), whose

contour is matched to the prism-shaped cross-section of the plug-in receptacle (15) wjih its guide faces (15.1). The sealing element (30) can be designed to be angled, corresponding to the angle between ihe shoulder (21) and the,stop (24) of the base element (20). Here, the sealing (30) has an 0-shaped cross seetion (31) in the a^ca of the stop (24)
and a cross section, which is thickened in comparison with it, in the area of the shoulder (21). In this case this area is preferably embodied as a wedge-shaped sealing lip (34).
In the area of the plug-in receptacle (22), the base element is provided with a bezel (23) extending around the plug-in receptacle (22), which is used as a seating for the sealing clement (30).
Fig. 2 shows the same cutting tool as the one in Fig. 1 in section after the chisel bolder (10) has been completely inserted into the base element (20). Here, the pressure screw (40). which has preferably b«n embodied as a stud serew and has » jcrew

thread (41) and a flattened shaft (42), acts with its shaft (42) on a pressure face (14) constituted by a V-shaped recess (13) on the side of the plug-in shoulder (15) located opposite the guide face (15.1).
When the pressure screw (40) is tightened, forces result which push the chisel holder (10) against the base element (20),' In the course o.f this the stop (1 1) of the chisel holder (10) is supported on the stop (24) of the base clement. In,the course .of.this, the sealing element (30) is seated with its area (31) of O-shaped cross section in the bezel (23) of the base element (20) designed as the sealing seat. The originally O-shaped cross section is pressed during this in such a way that an optimum sealing effect Is geaerated.
•A'clearance (16), acring as an adjustment space,, is formed between the
i
shoulder (21) in the front part of the base element (20) and the face of the; chisel holder (10) located opposite the shoulder (21). Because of its cross section, which is thickened in this area, and Ihe simultaneous embodiment as a wedge-shaped sealing lip 04), the sealing element (30) bridges the clearance (16), so that an optimal sealing effect. is also achieved by this.; By means of this it is achieved that no waste material particles can peneirate into
the area of the plug-in receptacle. This makes the exchange of the chisel holders (10) easier. At the same time it is achieved by means of this arrangement that not water with waste material particles can penetrate ihtf area of the shaft (42).,and the pressure face (14)

qf the plug-in shoulder (15).
Figs. 3a and 3b represent an embodiment of the sealing element (30) in a view from above and in a lateral view.
The sealing element (30) is embodied as a molded part, having the contour of the circumference of the plug-in shoulder (15) of the phisel holder (10), The sealing element (30) is angled corresponding to the angle between the shoulder (21) and the stop (24) of the base element (20), wherein the sealing element (30) has at least one section of
an Q-shaped cross section, which rests against the stop. (24) of the base element(20) The


angled section (32) resting against the shoulder (21) of the base element (20) has a cross section which is thickened corresponding to the clearance (16). An angljed section (32) embodied as a wedge-shaped sealing lip (34) here increases the sealing Effect.
. . In this case the sealing element (30) is made of a permanemtly elastic material and is preferably designed as an injection-molded element. Silicons are used as the materials, pxamples of this are so-called liquid silicon rubbers (LSR)for example SILOPREN(R) made by GE BAYER Silicones, which can be produced by means of the so called liquid injector molding (LIM) process, furthermore suitable are thermoplastic
elastomers, for example SANTOPRENEtR), made by ADVANCED ELASTOMER SYSTEMS, which can be worked by the normal injection-molding process. The sprue,
which is customary in connection with injection-molding processes, has been, displaced here into the thickened area of the clearance (16), so that the sprue nose (33) docs'not hamper the sealing effect of the scaling dement (30).
It can furthermore be provided that the sealing element (30) is directly formed on the formed-on plug-in shoulder (15) of the chisel holder (10), and in this case encloses .the exterior circumference of the plug-in shoulder (15) at least partially. In the same way it can be provided that the sealing element (30).is directly formed on the base element (20) in the area around the plug-in receptacle (22)^ and encloses the exterior circumference of the plug-in receptacle (22) at least partially.
It should be mentioned here that the'/invention is not limited to the cross-sectional shape of a plug-in shoulder (15) represented above. Instead, any arbitrary

different cross-sectional variants are conceivable, such as round cross sections or plug-in shoulders of a conical shape, for example.
As it becomes clear from the drawings, the plug-in receptacle (22) in the base element (20) facing away from the chisel holder (10) is embodied to be open. This opening is closet, together with the connected cutting cylinder tube, not represented in the drawings, by means of a weld seam connection.










WE CLAIM:
1. A cutting tool of a cutting machine having a base element and a chisel holder,
wherein the chisel holder is provided with a plug-in shoulder which is retained in a plug-in
receptacle of the base element, and wherein the plug-in receptacle is spatially connected
with its surroundings via one or several openings, wherein at least one of the openings is at
least partially closed by means of a sealing element (30),
characterized in that
the chisel holder (10) rests with its stop (11) against the stop (24) of the base element (20).
that the base element (20) has a shoulder (21) extending at an angle in relation to the stop (24),
that a clearance (16) acting as an adjusting space is formed between the shoulder (21) of the base element (20) and the side of the chisel holder (10) facing the shoulder (21). wherein the sealing element (30) is shaped in such a way that it bridges this clearance (16).
2. The cutting tool as claimed in claim 1, wherein the sealing (30) is arranged, at least in some area between the chisel holder (10) and the base element (20), around the plug-in receptacle (22).
3. The cutting tool as claimed in claim 1 or 2. wherein the sealing element (30) is embodied as a molded element having the contour of the circumference of the plug-in shoulder (15) of the chisel holder (10).
4. The cutting tool as claimed in one of claims 1 to 3, wherein the base element (20) as a circumferential bezel (23) extending at least partially around the plug-in-receptacle (22). which is used as a seat for the sealing element (30).
5. The cutting tool as claimed in one of claims 1 to 4, wherein the sealing element
(30) is made of a permanently elastic material, preferable of silicon, or of a thermoplastic
elastomer.
6. The cutting tool as claimed in one of claims 1 to 5, wherein the sealing element
(30) is angled in a manner corresponding to the angle between the shoulder (21) and the
stop (24) of the base element (20).
7. The cutting tool as claimed in one of claims 1 to 6, wherein the sealing element
(30) has a section of an O-shaped cross section (31), which rests at least in part against an
area of the base element (20) assigned to the stop (24), and has a section (32) which is
angled off in relation to the latter, which rests against the shoulder (21) of the base element
(20) and has a thickened cross section which bridges the clearance (16) at least partially.
8. The cutting tool as claimed in claim 7, wherein the angled-off section (32) has a wedge-shaped sealing lip (34).
9. The cutting tool as claimed in one of claims 7 or 8, wherein the sealing element (30) is embodied as an injection molded element, and the sprue nose (33) is arranged in an area of the cross section which has been thickened corresponding to the clearance (16).
10. The cutting tool as claimed in one of claims 1 to 9, wherein the sealing element (30) is drawn as a separate plastic component on the plug-in shoulder (15), or that the sealing element (30) is injection-molded on the plug-in shoulder (15) as a plastic component.

Documents:

2828-DELNP-2005-Abstract-(06-10-2010).pdf

2828-delnp-2005-abstract.pdf

2828-DELNP-2005-Claims-(06-10-2010).pdf

2828-delnp-2005-claims.pdf

2828-DELNP-2005-Correspondence-Others-(06-10-2010).pdf

2828-DELNP-2005-Correspondence-Others-(24-07-2009).pdf

2828-delnp-2005-correspondence-others.pdf

2828-delnp-2005-description (complete).pdf

2828-DELNP-2005-Drawings-(06-10-2010).pdf

2828-delnp-2005-drawings.pdf

2828-DELNP-2005-Form-1-(06-10-2010).pdf

2828-delnp-2005-form-1.pdf

2828-delnp-2005-form-13.pdf

2828-delnp-2005-form-18.pdf

2828-DELNP-2005-Form-2-(06-10-2010).pdf

2828-delnp-2005-form-2.pdf

2828-DELNP-2005-Form-26-(24-07-2009).pdf

2828-DELNP-2005-Form-3-(06-10-2010).pdf

2828-delnp-2005-form-3.pdf

2828-DELNP-2005-Form-5-(06-10-2010).pdf

2828-delnp-2005-form-5.pdf

2828-delnp-2005-pct-210.pdf

2828-DELNP-2005-Petition-137-(06-10-2010).pdf

2828-DELNP-2005-Petition-138-(06-10-2010).pdf

abstract.jpg


Patent Number 248498
Indian Patent Application Number 2828/DELNP/2005
PG Journal Number 29/2011
Publication Date 22-Jul-2011
Grant Date 20-Jul-2011
Date of Filing 24-Jun-2005
Name of Patentee WIRTGEN GmbH
Applicant Address HOHNERSTR 2, 53578 WINDHAGEN GERMANY.
Inventors:
# Inventor's Name Inventor's Address
1 TEWES GUNTER HEIDEWEG 16, 53578 WIDHAGEN GERMANY.
2 HOLL BERND HERRENGARTEN 49, 53577 NEUSTADT GERMANY.
PCT International Classification Number E21C 35/193
PCT International Application Number PCT/EP2003/011288
PCT International Filing date 2003-10-11
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 DE10261646.9 2002-12-27 Germany