Cutting by use of rotating axially moving tool – Tool or tool with support – Having stepped cutting edges
Reexamination Certificate
1999-01-15
2001-07-31
Howell, Daniel W. (Department: 3722)
Cutting by use of rotating axially moving tool
Tool or tool with support
Having stepped cutting edges
C408S230000
Reexamination Certificate
active
06267542
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a chiseless drill bit tip. More particularly, the invention relates to a drill bit tip in which all touching points between the drill and the drilled bore are cutting points.
BACKGROUND OF THE INVENTION
Drill bits having tips of varying shapes and serving different purposes are well known in the art. In most instances, the drill bit tips form a chisel structure that effectively pushes the drilled material to the side while the drill is rotating. Unfortunately, however, these drill bit tips create friction and produce undesired heat.
FIG. 1
is illustrative of this type of conventional solid type drill bit. The prior art drill bit
10
comprises a shank
12
with cutting edges
14
and
16
. Each cutting edge
14
and
16
is defined by the intersection of one of the relief surfaces
18
and
20
and its respective rake surface
22
and
24
. Further, the two relief surfaces
18
and
20
form a cusp or chisel edge
26
at the tip of the drill bit
10
.
The prior art does disclose various different drill bit tips, but each fails to suggest a structure which would provide a relief angle. Specifically, U.S. Pat. No. 4,671,710 eliminates the chisel by forming recessed surfaces in the neighborhood of the axis of rotation of the drill. However, due to the inner cone of the “v” shape and the width of cone “&dgr;”, this structure makes the non-cutting zone smaller and provides no relief angle to the inner cutting edges.
FIGS. 2A and 2B
are also illustrative of standard carbide drill tips having the cutting edges
38
,
40
connected via a chisel
42
. The cutting edges
38
,
40
are parallel to each other, and to the diameter line of the drill bit. However, the cutting edges
38
,
40
fail to pass through the center
44
of the drill bit tip.
Drill bit tips addressing the issue of heat generated by the friction of the rotating drill bit are disclosed in the prior art. This combination of friction and heat distort the shape of the drill by distorting the chisel, detracting from the efficiency of the drill to create more heat. The prior art devices inadequately solve the heat problem. As a result, a need exists for a drill bit with a tip structure that efficiently and effectively eliminates heat caused by friction while drilling a bore in an object. The present invention provides such a drill bit tip structure.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a drill bit having a tip structure that provides a drilling impact point that reduces heat generated by friction.
It is further an object of the present invention to provide a drill bit wherein all the touching points between the drill and the drilled bore are cutting points, thereby creating cutting edges.
It is also an object of the present invention to provide a drill bit wherein the tip structure cutting edges are aligned along the diameter line passing through the center point and axis of rotation of the drill bit.
It is another object of the present invention to provide a drill bit wherein the tip structure cutting edges are aligned along the whole diameter line of the drill bit.
It is further an object of the present invention to provide a drill bit wherein the tip structure cutting edges are passed along the inner portion of the drill bit using only the inner part of the diameter line, allowing for the outer part of the cutting edges not to be aligned on the diameter line of the drill bit.
It is also an object of the present invention to provide a drill bit wherein the tip structure is such as to provide a relief angle to the inner cutting edges.
It is also an object of the present invention to provide a drill bit tip wherein the tip structure is such that it provides an easy and inexpensive way to be resharpened without distracting from the main objects of the present invention.
Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention.
REFERENCES:
patent: Re. 247699 (1960-01-01), Willingham
patent: 305625 (1884-09-01), Newey, Jr.
patent: 1069930 (1913-08-01), Down
patent: 1418485 (1922-06-01), Smith
patent: 1467491 (1923-09-01), Oliver
patent: 2334089 (1943-11-01), Hallden
patent: 2401307 (1946-06-01), Manewich
patent: 2898786 (1959-08-01), Willingham
patent: 3028773 (1962-04-01), Borneman
patent: 3452625 (1969-07-01), Russo
patent: 3564947 (1971-02-01), Maier
patent: 3824026 (1974-07-01), Gaskins
patent: 4143723 (1979-03-01), Schmotzer
patent: 4373839 (1983-02-01), Negishi et al.
patent: 4556347 (1985-12-01), Barish
patent: 4565471 (1986-01-01), Negishi et al.
patent: 4645389 (1987-02-01), Maier
patent: 4671710 (1987-06-01), Araki
patent: 4687388 (1987-08-01), Yokota et al.
patent: 4770571 (1988-09-01), Potemkin
patent: 5092718 (1992-03-01), Shallenberger
patent: 5184689 (1993-02-01), Sheirer et al.
patent: 5304020 (1994-04-01), Reccius
patent: 244711 (1966-01-01), None
patent: 537476 (1993-04-01), None
patent: 832238 (1960-04-01), None
patent: 1514510 (1989-10-01), None
Howell Daniel W.
Welsh & Flaxman LLC
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