Cutters – for shaping – Rotary cutting tool – Face or end mill
Reexamination Certificate
1999-10-18
2001-03-13
Wellington, A. L. (Department: 3722)
Cutters, for shaping
Rotary cutting tool
Face or end mill
C408S059000, C408S224000, C279S105100
Reexamination Certificate
active
06200073
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to machine tools and particularly to a tool attachable to a mill for performing a milling and chamfering operation simultaneously.
BACKGROUND AND INFORMATION DISCLOSURE
For the purposes of this disclosure, a milling operation in a machine shop refers to the practice of securing, a work piece in a vise that is clamped to a table that can be moved with three degrees of freedom against a rotating toolbit (cutter) that cuts away portions of the work piece in accordance with a require plan. The rotational axis of the toolbit is maintained stationary and is generally vertical. The various operations that can be performed with this arrangement include drilling holes and cutting linear slots and chamfering the edges of holes and slots. Common practice is to machine the work piece having complex surfaces using a toolbit designed for the specific operation. For example, the operation of drilling a hole requires a drill bit. moving the work piece in a linear direction so as to cut a straight groove or form a flat surface on the part requires an end mill, having a cylindrical shaft with radially extending cutting flutes.
Most jobs involve various operations in combination so that any given job usually requires several different toolbits. This necessitates performing one operation with one toolbit and then changing the toolbit to peform another operation. As a result of this situation, the present state of the art equipment has arrangements such as “quick-change” chucks, brakes, automated too changers, etc. for reducing the accumulated “down time” of the machine required for changing the tool.
A very frequent requirement for many designs is the requirement to chamfer the edge of a slot that has been cut by an end mill. Milling the slot in a first operation, changing the tool bit from an end mill to a chamfering tool and then milling the chamfer takes at least twice the time of simply milling a slot (without chamfer). A milled slot leaves a corner that has to be deburred so that, even when no cramfer is required, the careful workman will go back over the work piece and “break the edge” with a debuning tool. Another factor that adds time and expense to a milling operation involving machining an opening in a group of “boards” such as in the manufacturing of frames for a printed circuit operation is the requirement to lubricate the part with an appropriate coolant. The coolant is typically a water base lubricant and a popular method of applying the lubricant is to direct a fine spray on the surface of the part. This method is inefficient from the standpoint that the lubricant lands on a broad surface of the part far removed from the exact location where the lubricant is needed. This location is on the cutter blade about 0.050 inches from where the chip separates from the metal and where the chip rubs against the cutter surface thereby generating excessive heat.
Yet another inconvenience associated with the job of milling an opening in a group of plates is that the cutting edge of the tool bit wears and the toolbit flexes so that sources of variations are introduced which result in loss of precision in machining the workpiece.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a toolbit and method of machining using the tool bit for a machining operation that performs a milling operation and a chamfering operation simultaneously.
It is another object of this invention to provide a method of lubrication that is more effective than is provided by present practice in terms of delivering the lubricant in the right amount to the light location.
It is another object to avoid delays incurred by tool changes that characterize present methods of machining.
This invention is directed toward a combination milling bit and chamfering bit including a chamfering member being a shaft with a center bore. The shaft has on at least one end a substantially conical surface with a radially disposed cutting edge. A conventional end mill fits into the bore and where it is secured by a set screw screwed into the side of the shaft and communicates with the bore.
In one embodiment, a length of the bore distal from the chamfer cutting end of the shaft is threaded and an alien head screw is threaded into the bore. The screw serves as a positioning stop a mill having its shank (non-cutting end) inserted into the bore so that the length of the milling tool extended from the tip end of the chamfer can be firmly set and subsequently be repositioned in order to present an unused portion of the edge of the cutting flute.
In yet another embodiment, a cylindrical chamber is formed between the outer shaft surface and a cylindrical sleeve journaled onto the shaft. The sleeve, being journaled onto the shaft, is stationary and the chamber communicates with a source of lubricant through an entry port in the side of the sleeve. The lubricant is enabled to flow through an aperture in the shaft leading from the chamber to the bore of the shaft, down a groove in the side of the bore and out onto the surface of the work piece being machined at the location where cutting is actually taking place.
REFERENCES:
patent: 2429375 (1947-10-01), Smith
patent: 2470218 (1949-05-01), McNamara
patent: 2705515 (1955-04-01), Walker
patent: 2937029 (1960-05-01), Colby
patent: 2985468 (1961-05-01), Shaw et al.
patent: 3024030 (1962-03-01), Koch
patent: 5085540 (1992-02-01), Pagliaccio
patent: 5152541 (1992-10-01), Baumgartner et al.
patent: 5378091 (1995-01-01), Nakamura
patent: 5482410 (1996-01-01), Chambers
Ergenbright Erica
Smith Robert Samuel
Wellington A. L.
LandOfFree
Combination chamfering and milling tool does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Combination chamfering and milling tool, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Combination chamfering and milling tool will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2509587