Cutters – for shaping – Including holder having seat for inserted tool – With separate means to fasten tool seat to holder
Reexamination Certificate
1999-04-15
2001-08-14
Tsai, Henry (Department: 3722)
Cutters, for shaping
Including holder having seat for inserted tool
With separate means to fasten tool seat to holder
C407S107000, C407S109000
Reexamination Certificate
active
06273649
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a cutting tool assembly that includes a shank and an exchangeable cartridge, the cartridge having a cutting means thereon. The cutting means may be an integral portion of the cartridge or a cutting insert mounted on the cartridge. The cutting tool assembly is for use in different metal cutting operations, for example, turning, grooving, threading, boring or facing wherein the tool assembly is mounted on a machine carriage, as in, for example, a lathe.
BACKGROUND OF THE INVENTION
A cutting tool is a relatively expensive item and this expense is compounded if a machining business has to carry a stock of different cutting tools in order to perform different cutting operations. The present invention allows for a reduction in this expense in that it provides for the exchange of a cutting cartridge on a shank rather than the exchange of a whole cutting tool. As the cost of a cartridge is a fraction of the cost of a whole tool, a business can reduce its expenses by carrying a stock of cartridges in place of a stock of tools as such, wherein different cartridges of the stock may be provided with different cutting means or carry different cutting inserts for performing different operations.
A problem with a cutting tool assembly that has an exchangeable cartridge is that the rigidity of the tool is lessened because there is no longer an integral shank supporting the cutting means or insert. The present invention addresses this problem whilst allowing for relatively ready exchange of one cutting cartridge for another.
DISCLOSURE OF THE INVENTION
According to the invention there is provided a cutting tool assembly including, a shank for mounting the cutting tool assembly on a cutting machine, a cartridge which is mountable on the shank, a cutting means on the cartridge, and releasable screw means for securing the cartridge on the shank, wherein the shank includes a seating portion for engaging the cartridge and the cartridge includes a complementary seating portion for engaging the shank, wherein each seating portion is defined by surfaces which slope towards each other such that one seating portion wedges within the other on tightening the screw means to secure the cartridge on the shank, whereby substantially all cutting forces are transmitted from the cartridge to the shank via the wedged seating portions.
Preferably the cutting means is a cutting insert that is mounted on the cartridge.
Preferably the seating portion of the shank is provided by surfaces defining a recess in the shank and the complementary seating portion of the cartridge is a bearing part for wedging within the recess.
The invention provides a stable and rigid interconnection between the cutting cartridge and the shank by virtue of the wedging of one part within the other. This wedging action is ensured by the relative shapes of a recess, which is preferably in the shank, and the complementary seating portion of the cartridge, and the screw means which is operable to clamp the complementary seating portion of the cartridge into engagement with the recess.
Preferably the recess includes facing surfaces which slope towards each other towards a base surface of the recess, and the seating portion of the cartridge which is received in the recess preferably includes opposite surfaces having a complementary slope to that of the surfaces of the recess. When the surfaces of the recess and cartridge have the same slope, a wedging of the cartridge within the recess is ensured by providing a clearance space between the base of the recess and an end face of the cartridge. Alternatively, the taper of the cartridge portion that seats in the recess may be slightly greater than that of the surfaces of the recess to ensure the wedging.
Preferably the assembly is such that a cutting force on the cutting means acts on the cartridge in the wedging direction, thereby increasing the force of contact of the cartridge portion in the shank recess. This feature assists the rigidity of the interconnection between the cutting cartridge and the shank. However the invention includes other arrangements, for example, where the cutting force acts across the wedging direction, that is along the recess rather than normal to it.
Preferably the screw means comprises a threaded hole in either the cartridge or the shank and a screw fastener which passes through a hole in the other part for engaging in the threaded hole and which is operable to clamp the cartridge into wedging engagement with the shank.
Preferably the shank and the cartridge include locating means for locating the cartridge on the shank such that the through hole and the threaded hole are aligned for reception of the screw fastener. This feature assists the quick exchange of a cartridge in that misalignment of the holes and thereby further manipulation of the position of the cartridge relative to the shank is eliminated.
Alternatively the cartridge may include a threaded hole and the shank may include a recess instead of a hole for receiving a screw fastener having a head, wherein the recess includes a shoulder against which the head of the screw fastener bears for securing the cartridge on the shank. With this alternative the cartridge is removable from the shank by loosening the screw fastener to allow it to be withdrawn from the recess whilst still engaged in the threaded hole in the cartridge, that is, the cartridge and the screw fastener are removable as a unit. This alternative provides for a quick exchange of one cartridge for another in that a mere loosening and then tightening rather than a complete removal and then re-insertion of a screw fastener is all that is required to be able to effect the exchange.
The shank and the cartridge with its cutting means may be arranged to provide a left hand or a right hand cutting tool. Also the shank may have a seating portion at both ends to allow it to carry two cartridges, for example to provide for a left hand or a right hand tool using the one shank.
The invention provides a cutting tool assembly which is simple and user friendly, involving components that are relatively easily manufactured and can be readily assembled to provide a complete tool and disassembled for the fitting of another cutting cartridge to vary that tool. The shank with its seating portion and the complementary seating portion of each of a stock of cartridges allow for a reliably accurate positioning of any one of a range of cartridges on a shank and for a cartridge to be rigidly interconnected with a shank.
Embodiments of the invention will now be described by way of non-limiting example only, with reference to the accompanying drawings.
REFERENCES:
patent: 2949662 (1960-08-01), Cook et al.
patent: 3015241 (1962-01-01), Konwal
patent: 3156031 (1964-11-01), Lundgren
patent: 3376771 (1968-04-01), Barnes
patent: 3568283 (1971-03-01), Wyss
patent: 3704958 (1972-12-01), Gulibon et al.
patent: 3811162 (1974-05-01), Bay
patent: 4080854 (1978-03-01), Peterson
patent: 4945793 (1990-08-01), Von Hass
patent: 5737984 (1998-04-01), Francia
patent: 5833403 (1998-11-01), Barazani
patent: 5961259 (1999-10-01), Ziegler
patent: WO 96/12592 (1996-05-01), None
patent: WO 96/33833 (1996-10-01), None
Tsai Henry
Wolf Greenfield & Sacks P.C.
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