- 1 - CUTTING TOOL ADAPTOR Technical Field
This invention relates to a cutting tool assembly of the kind that includes a shank and an exchangeable head, the head having a cutting means thereon. The cutting means may be an integral portion of the head or a cutting insert mounted on the head. The cutting tool assembly is for use in different metal cutting operations, for example, turning, grooving, threading, boring or facing wherein the cutting tool assembly may be stationary and the workpiece rotates or vice versa. Background
The applicant's previous patent application No. PCT/AU96/00234 (WO 96/33833) discloses a machine tool such as a precision boring tool that has a rotatable shank on which is mounted a head which carries a cutting insert. A unique clamping arrangement between the head and the shank, according to a preferred embodiment, includes a bearing part on the head which is wedged into a groove on the shank. In this arrangement the head is transversely adjustable relative to the shank, that is, the tool includes a mechanism for moving the bearing part along the groove. Thus the groove provides a slideway. Another patent application by the applicant No. PCT/AU97/00695 (WO
98/17426) discloses a machine tool assembly which comprises a shank and a readily exchangeable cartridge which carries a cutting means. Given the cost of a cartridge is a fraction of the cost of a whole tool, the invention of this prior application allows a business to reduce its expenses by carrying a stock of cartridges in place of a stock of cutting tools as such. Different cartridges of the stock may be for performing different cutting operations. Summary of the Invention
The present invention provides a cutting tool assembly of increased versatility to those of the previous applications. According to the invention there is provided an adaptor for a cutting tool assembly which assembly includes a shank and a head carrying a cutting means, the adaptor including a first connection means for mounting the
- 2 - adaptor on the shank and a second connection means for the head to be mounted on the adaptor, wherein one of the first and second connection means includes a groove within which a complementary part of the shank or the head is wedgingly clampable and the other of the first and second connection means includes a male bearing portion for wedgingly clamping within a complementary part of the shank or the head. Preferably the groove and the male bearing portion are mutually substantially orthogonally orientated. The invention improves the versatility of a cutting tool assembly of the kind involved in that by use of the adaptor the orientation of the head relative to the shank can be altered according to the mutual orientation of the groove and the male bearing portion, which is preferably by 90°.
Preferably the first connection means includes the male bearing portion and more preferably is a connection means as described in the above mentioned application No. PCT/AU97/00695, the disclosure of which is to be understood as incorporated herein by cross reference.
Preferably the second connection means includes the groove and more preferably is a slideway type connection means as described in the above mentioned application No. PCT/AU 96/00234, the disclosure of which is also to be understood as incorporated herein by cross reference. Having first and second connection means as disclosed in the above mentioned two patent applications further increases the versatility provided by the invention in that the head is transversely adjustable relative to the adaptor and furthermore a head and adaptor combination can be quickly released from the shank for another head to be attached to the shank. The invention also includes a cutting tool assembly including an adaptor as described above in combination with a shank and a head.
Preferably the shank of the above described cutting tool assembly includes a transverse groove in a side face thereof within which the male bearing portion of the first connection means of the adaptor is wedgingly clamped. Thus the cutting head extends laterally from the shank.
Preferred embodiments of the invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings.
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Brief Description of the Drawings
Fig. 1 is a top plan view of a cutting tool assembly that includes an adaptor according to one embodiment of the invention
Fig. 2 is an elevation view of the cutting tool assembly of Fig. 1 Fig. 3 is a top plan view of the adaptor of the Fig. 1 assembly, and
Fig. 4 is an elevation view of the adaptor of Fig. 3. Figs. 5(A) to (F) are various views of components of a cutting tool assembly including an adaptor according to another embodiment of the invention. Description of Preferred Embodiments
The cutting tool assembly shown in Figs. 1 and 2 includes a shank 10, a head 12 on which is mounted a cutting insert 14, and an adaptor 16. The shank 10 has a square cross-section and at its operative end includes a transverse groove in a side face thereof defined by side walls 18 which slope towards each other to a base surface 20. A bore 19 passes through the shank 10, from an opposite side face to that containing the transverse groove, to the base surface 20 of the transverse groove and this bore 19 includes an enlarged portion 21 for reception of the head of a draw bolt as will be described below. The groove defined by side walls 18 and base surface 20 is for receiving a male bearing portion of the adaptor 16 to be more fully described below.
As best shown in Figs. 3 and 4, the adaptor 16 includes a body formed to provide a rearwards male bearing portion 22 and having a groove in the form of female slideway 24 formed therein in a forwards surface. The male bearing portion 22 comprises side surfaces 26 which slope towards each other and an end surface 28. The included angle of surfaces 26 is preferably 60° and equals the included angle of sloping side walls 18 of the transverse groove in the shank 10. When the adaptor 16 is assembled on the shank 10, the end surface 28 of bearing portion 22 is spaced a small distance from base surface 20 of the transverse groove in shank 10 to allow the bearing portion 22 to be wedged within the transverse groove when clamped in place (as will be described below).
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The female slideway 24 is orthogonally orientated relative to the bearing portion 22 and comprises side walls 30 which slope inwardly to a base 32. The included angle of side walls 30 is preferably 60°.
The adaptor also includes means in the form of a locating plate 34 (see Figs. 1 and 2 - not shown in Figs. 3 and 4) which is attached to an end face 36 of the bearing portion 22 (see Fig. 4) by set screws 38 engaging in tapped holes 39. A bore 40 extends through adaptor 16 from end surface 28 of bearing portion 22 to base 32 of female slideway 24. The locating plate 34 ensures bores 19 and 40 are aligned when the adaptor 16 is assembled with shank 10. Any suitable means may be provided on the adaptor 16 for locating it relative to a shank 10 for aligning the bores 19 and 40. The male bearing portion 22 of the adaptor 16 provides a first connection means for mounting the adaptor on the shank 10 and the female slideway 24 provides a second connection means for a head to be mounted on the adaptor as will now be described.
Head 12 is the same as described in Application No. PCT/AU96/00234 and reference should be made to this prior application for a full description of the head. For the present disclosure it is sufficient to identify that it includes a bearing portion 42 which can be wedged within the female slideway 24 when clamped in place. Thus, as best seen in Fig. 2, the bearing portion 42 of head 12 includes sloping surfaces which match walls 30 of slideway 24 and an end surface which is spaced a small distance from the base 32 of the slideway 24.
A draw bolt 44 is passed through bore 19 in shank 10 and bore 40 in adaptor 16 and screwed into engagement with an adjusting mechanism of the head 12 (as fully described in PCT/AU96/00234) to clamp the head 12 to the adaptor 16 and the adaptor 16 to the shank 10. Tightening bolt 44 brings its head into engagement with the shoulder in bore 19 at the junction with bore 21 and this causes the bearing portion 42 of head 12 to be drawn into and wedged within female slideway 24 of adaptor 16 and concomitantly for bearing portion 22 of adaptor 16 to wedge within the groove 18-20 in shank 10. This wedging interconnection of the three parts of the cutting tool assembly ensures a very rigid and stable structure which gives excellent cutting results.
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The shank 10 may be configured to provide for quick assembly and quick disassembly of a head 12, adaptor 16 and bolt 44 combination. This may be provided by converting bore 19-21 in the shank 10 into a groove which is open at the top surface (with reference to Fig. 1) of the shank 10. Thus, quick disassembly is achievable by simply loosening draw bolt 44 and then relatively lifting the head 12/adaptor 16/bolt 44 combination off the shank 10. A shank which provides this facility is more fully described in Application No. PCT/AU97/00695 and reference should be made to this application for further details. As illustrated by Fig. 1 , the described combination provides for a cutting insert 14 to be located in a plane parallel to that of the shank 10. By use of the adjusting mechanism of the head 12, the cutting insert 14 is adjustable in a direction parallel to the longitudinal axis of the shank. The head 12 may also be mounted directly on the shank 10 (by engagement of its bearing portion 42 in the transverse groove defined by walls 18-20) which will locate the cutting insert 14 in an orthogonal plane to that of the shank 10. Thus the provision of the adaptor 16 increases the versatility of a cutting tool assembly as it provides a wider range of set up and adjustment options.
In Figs. 5(A) to (F), the same reference numerals as in Figs. 1 to 4 are used to indicate corresponding elements. Fig. 5(A) shows a head 12 having a cutting insert 14 which is generally similar to the head of figures 1-4 and is a head as described in PCT/AU96/00234. Figs 5(C) and (D) show two forms for a shank 10 which include a quick assembly and disassembly groove as described above, which is indicated by reference 46. The shanks 10 are for mounting in the tool post of a cutting machine. The shank of Fig. 5(C) provides for mounting of an adaptor 16 (see Figs 5(B), (E) and (F) at an angle to the axis of the shank rather than orthogonally as in the Fig. 5(D) shank.
The adaptor 16 (shown in top plan view in Fig. 5(B), side elevation in Fig. 5(E) and end elevation in Fig. 5(F) is generally similar to that of Figures 1- 4 except that it has a circular cross section body 48 (see Fig. 5(F)). Body 48 can be extended longitudinally to give a larger separation between male bearing portion 22 and female slideway 24. Similarly, the adaptor of figures 1-
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4 may also have a longer extent. It is also within the scope of the invention for the orthogonally directed female slideway 24 to be angled relative to the longitudinal axis of the adaptor, for example in the plan view of Fig. 5(B), the slideway 24 may be orientated such that head 12 is angled at 45° to the longitudinal axis of adaptor 16.
Although the invention has been exemplified by particular embodiments, it is to be understood that various modifications and alterations are possible. For example, other types of heads may be used, the shank may have a cross- section which is other than square or the first connection means may have a female instead of a male form and correspondingly the second connection means may have a male instead of a female form. Other variations, modifications and/or additions may also be made and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the scope of the following claims.