ADJUSTABLE CUTTING TOOL HOLDER FOR A PEELING OPERATION

Abstract: The invention provides a tool for bar peeling comprising a rotatable cutter head (11) with circumferentially spaced toolholders (15) each of which is provided with a U-shaped recess (17) along one of its side surfaces in which a wedge shaped element (19) is longitudinally displaceable so that an insert (13) carried by said toolholder is subjected to radial adjustment upon a longitudinal displacement of said wedge shaped element (19).

Description: ADJUSTABLECUTTINGTOOLHOLDER FORA PEELINGOPERATION The present invention relates to a cutting tool holder for a bar peeling operation, including a rotary cutter head that carries a plurality of tool holders each equipped with one or several inserts of cemented carbide or similar wear resistant material. Bar peeling is a method by which an elongated bar is feeded through a rotary cutter head equipped with a plurality of cutting tools distantly provided around the periphery of said cutter head for the purpose of removing from the bar a thin layer of millscale, surface cracks etc. that results from the hot rolling of such bars or tubes . In order to achieve the best results regarding tolerances and surface finish, two different types of inserts are usually combined in the same holder. It is desirable being able to make a fine adjustment of the exact radial position of such insert (normally 4) . Normally we are talking about an adjustment range of 0,01 mm. This adjustment is usually accomplished by grinding the supporting bevel face of the insert after the insert has been put into its location in the holder. The disadvantage of this method is that by grinding the insert also means taking away the surface layer that normally has been deposited on the surface of the insert, normally by CVD-technique, for the purpose of increasing the lifetime of the insert. Hence, before starting to use the insert the increased performance ability of the insert achieved by said layer deposition is taken away by grinding. Further, it is almost impossible to make exactly the same amount of grinding on all the four inserts of such rotary cutter head of a bar peeling machine which additionally impairs the precision of the tools. In view thereof, it is a purpose of this invention to provide a tool holder in which the inserts can be maintained in their positions whilst being adjustable with other means. It is another purpose of this invention to provide a toolholder that is equipped with means that will enable radial adjustment with simple means without having to provide separate fixtures for said inserts and holders during the adjustment. It is a purpose to provide such adjustment means that accurate fine adjustments can be made without removing the tool holder from its location in the bar peeling machine. The invention provides a mechanism for fine adjustment of the radial position of the cutting edge with a very good precision. It is important to be able to make such radial adjustment without affecting the pre-adjusted axial position of same insert. These and other objects of the invention are achieved by a cutting tool for bar peeling which comprises a rotatable cutter head equipped with a plurality of toolholders around its periphery, each of which is carrying at least one cutting insert of wear resistant material. The objects and advantages of the invention will become more apparent from the following detailed description of a preferred embodiment thereof in connection with the accompanying drawings in which: Fig 1 is a perspective view of a conventional cutting tool for bar peeling, Fig 2 is a perspective view of a toolholder for bar peeling provided with a cutting insert, Fig 3 is a side view of a wedge element aimed for use together with the toolholder in Fig 2, Fig 4 is an end view of a wedge element as shown in Fig 3, Fig 5 is a plan view of the wedge element in Fig 3, Fig 6 is a plan view of a toolholder as shown in Fig 2, and Fig 7 is an end view of a toolholder as shown in Fig 2. In Fig 1 there is a cylindrical bar 10 which is intended to be subject of a bar peeling operation by a rotary cutting head 11 equipped with a plurality of radially extending holder shafts 12, each of which is carrying one or several cutting inserts 13 of cemented carbide or similar hard and wear resistant material. The head 11 is intended to rotate about an axis which coincides with the longitudinal axis of the cylindrical bar 10. As appears from Fig 2 each insert 13 is located in a site or pocket 14 of a toolholder 15 that is arranged to be releasably attached to the holder shaft 12. The rear wall of said toolholder 15 is along a portion of its length provided with a T-slot connection 16 intended to engage with a correspondingly designed clamping device provided in the rotary head 11. Further, said toolholder is along one of its edge surfaces provided with a U-shaped recess 17 that extends along the entire length of said toolholder 15. The recess 17 has a depth that continously increases from one end surface 18 towards the opposite end. A wedge shaped element 19 is releasably arranged in said recess 17 by means of a screw 20 such that said wedge element becomes longitudinally displaceable in relation to the toolholder 15. As appears from Fig 3-5 the wedge element 19 is provided with a laterally extending protrusion 21 that extends substantially perpendicularly from the longitudinal direction of the wedge, said protrusion being located centrally at one end of the wedge and having a smaller width than said wedge. The protrusion 21 is provided with a central threaded hole 22 for threaded engagement with a screw 23 having right hand and left hand threaded portions intended for threaded engagement with a corresponding threaded bore in the holder 15. Further, said wedge 19 is provided with an elongated slot 24 for the receipt of the screw 20, whereby the head of said screw 20 has a larger diameter than the width of said slot 24. Hence, the underneath surface 25 of the wedge 19 is intended to slidingly abut against the bottom surface of the recess 17. This adjustability in the longitudinal direction of the wedge is facilitated due to the fact that the protrusion 21 is exposed and accessible from one end of the toolholder as best appears from Fig 6-7. As best appears from Fig 6-7, the wedge element 19 is received in the toolholder 15 along its entire length. The protrusion 21 is received in a corresponding recess 26 in the toolholder 15 whereas the remainder of the wedge 19 is received in recess 17. The left hand threaded portion 27 of the screw 23 is threadingly engaged with the protrusion 21 whereas the right hand threaded portion 28 of said screw is threadably engaged with a hole 29 in the toolholder 15 at the same inclination as the wedge surface 25. As a consequence, upon threading the screw 23 into the toolholder 15, the wedge 19 is with one surface going to be in fixed abutment with an abutment surface in the holder shaft 12 whereas the opposite surface 25 of the wedge is going to provide a movement radially inwards of the toolholder 15 and the insert 13 provided thereon.

Claims: Claims 1. A tool for bar peeling comprising a rotatable cutter head (11) equipped with a plurality of holder shafts (12) each of which is carrying a toolholder (15) equipped with one or several inserts (13) of wear resistant material, each said toolholder being secured to said holder shaft by releasable locking means (16) c h a r a c t e r i z e d in that a wedge shaped element (19) is releasably arranged and longitudinally displaceable with one wedge surface (25) in slidable engagement with a corresponding surface of the toolholder (15) and with an opposite surface slidingly engaged with a support surface in the holder shaft (12) said wedge element (19) having at one end a protrusion (21) that extends substantially perpendicularly from said wedge, in which a right and left hand threaded screw (23) is received in order to actuate the wedge element so that, upon longitudinally displacing the wedge element, the toolholder (15) and the insert (13) are subjected to a radial adjustment. 2. A tool as defined in claim 1, c h a r a c t e r i z e d in that one edge surface of the toolholder (15) is provided with a U-shaped recess (17) , the depth of which increases from one end surface (18) towards the opposite end, said wedge element (19) being received in said recess. 3. A tool as defined in claim 1, c h a r a c t e r i z e d in that the protrusion (21) has a smaller width than the wedge element while being received in a corresponding recess (26) in the toolholder (15) . 4. A tool as defined in claim 2, c h a r a c t e r i z e d in that the U-shaped recess (17) along the entire length of the toolholder (15) . 5. A tool as defined in any of the claims 1-4, c h a r a c t e r i z e d in that wedge-actuating screw (23) extends essentially parallel with the underneath surface (25) of the wedge (19) and that said screw is threadingly engaged in the toolholder in a position between the insert (13) and the underneath surface (25) of the wedge element (19) . 6. A tool as defined in any of the claims 1-5, c h a r a c t e r i z e d in that the screw (23) is threadably received in a threaded bore (29) in the toolholder (15) whilst threadably received in a threaded bore (22) in the protrusion that extends linearly with said threaded bore (29) in the toolholder said threaded bores (22, 29) extending in a direction parallel with the underneath side (25) of the wedge element (19) .

Inventors: DAHLLOEF YNGVE, DAHLLOEF, YNGVE
Applicants: SANDVIK AB
Application year: 1993
Main classification: B23B5
IPC codes: B23B5, B23B29