Saw blade tooth form and method therefor

Details Saw blade tooth form and method therefor Saw blade tooth form and method therefor

1997-09-26

2002-08-06

Rada, Rinaldi I. (Department: 3724)

Cutting

Tool or tool with support

Toothed blade or tooth therefor

C083S838000, C083S852000, C083S853000, C030S166300, C076S112000

Reexamination Certificate

active

06427573

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to saw blades. More particularly, the present invention relates to a unique design of saw tooth profile for saw blades and a method of manufacturing saw blades having this unique design of saw tooth profile.
BACKGROUND OF THE INVENTION
A typical saw blade has a blade edge made up of a sequence of sharp points which are referred to as teeth. These teeth cut a trench or kerf that allows the free entry of the saw blade to cut an article. The cutting action of the saw blade involves urging the article to be cut transversely into the rotating or longitudinally moving saw blade or transversely urging the moving saw blade into the article. As the saw blade and article are urged together, the teeth of the saw blade dig in and remove particles from the article in a rapidly repetitive action. By this repetitive action, the kerf is increased in depth until the article is cut. This cutting action which remove a portion of the article is substantially different than “slicing” where the fibers of the article are simply moved apart.
FIG. 1
illustrates a portion of a conventional saw blade
10
showing the profile of a conventional tooth
12
. Tooth
12
includes a positive hook angle
14
, a tooth angle
16
and a clearance angle
18
. Other nomenclature used in the description of saw teeth include the tooth pitch or spacing
20
, the tooth gullet
22
and the depth of the gullet
24
. The direction of cut for saw blade
10
is shown by arrow
26
. During the cutting of an article by a saw blade, there must be sufficient clearance between the saw blade and the sawn surfaces or sidewalls of the kerf being created in order to eliminate binding or friction between the saw blade and the cut article. This clearance can be achieved by either taper grinding or offsetting the saw tooth. Taper grinding, shown in
FIG. 2A
, is a process that removes the material on the sides of the saw blade to make the cutting tip the widest part on the blade. Offsetting, shown in
FIG. 2B
, is a process that bends or places a “set” in the saw tooth to make the cutting tip the widest part on the blade. Either method, taper grinding or offsetting, provides the necessary clearance between the saw blade and the sidewalls of the kerf being made in the article to eliminate any binding of the saw blade in the kerf.
Various improvements to the conventional tooth profile shown in
FIG. 1
have been proffered.
FIGS. 3A and 3B
illustrate a saw blade
30
cutting into an article
31
. Saw blade
30
has a plurality of teeth
32
having a positive hook angle
33
which incorporate “fleam grinding” or alternate beveling of each gullet
34
between the plurality of teeth
32
. In particular, the plurality of teeth
32
have their front faces
36
and their rear faces
38
oppositely beveled. This is accomplished by having the bevel on the front gullet of each tooth
32
facing in the opposite direction to the bevel on the rear gullet of each tooth
32
in alternate order throughout the saw blade. This beveled tooth profile generates a tooth point of substantially triangular prismatic shape which better enables the teeth to effect the removal of portions of the article. The triangular prismatic tooth profile is manufactured by grinding each tooth gullet
34
in a direction which is opposite to that of an adjacent tooth gullet
34
. Grinding each gullet
34
simultaneously grinds a front face
36
of one tooth and a rear face
38
of the tooth adjacent to it. This grinding or beveling of each gullet
34
is normally done at a compound angle, which causes the bottom of each gullet
34
between the teeth
32
to slope in an upwards and a backwards direction due to the beveled front face of each tooth meeting the beveled rear face of the tooth in front of it in an oblique line. This beveling of the gullets is designed to aid in the removal of cut material from the gullets. However, the conventional fleam ground blade still packs the gullets with chips and dust. The compound beveling of the gullets creates a dead space or neutral area in the bottom of the gullet due to one face of the gullet directing chips to one side of the blade with the opposite face of the gullet directing chips to the opposite side of the blade. This dead space or neutral area causes the undesirable accumulation of chips within the base of the gullet. This problem is especially acute when the thickness of the material being cut is large or exceeds the stroke of the blade, which is typically between one-half of an inch and one inch. This conventional compound beveling creates a tooth cutting edge
39
having a conventional negative rake angle
40
(FIG.
3
B). A negative rake angle provides an aggressive cutting tooth and causes the highest (relative to the base of the gullet), leading tip of the cutting face on the conventional fleam-ground tooth-form to always contact the workpiece first during the forward stroke of the cutting blade, with the remainder of the cutting face being angled downwardly and rearwardly away from the surface being cut. This can be seen in
FIGS. 3A and 3B
where the higher, leading tip
42
contacts the workpiece first and the lower, trailing tip
44
will contact the workpiece last during the cutting stroke. A negative rake angle is present when, measured from the lowest to the highest point of the cutting edge, the cutting edge is toward the cut with respect to horizontal as seen in FIG.
3
B.
Various other tooth profiles for saw blades have been proposed. However, most of these earlier known designs have not experienced widespread commercial use as they typically do not lend themselves to automated manufacturing processes and therefore are too costly to produce. Consequently, there is a need to continue with the development of saw tooth profiles and there is also a need for improving the known manufacturing processes to mass-produce improved saw tooth profiles in a cost-effective manner.
SUMMARY OF THE INVENTION
The present invention provides the art with a saw blade exhibiting improved strength by having a body with a plurality of saw teeth having a unique tooth profile disposed along one edge of the blade. The leading and trailing faces of each saw tooth are formed by a radiused beveled gullet. The gullet of the trailing face is beveled in an opposite direction to the gullet of the leading face. This opposite beveling of the gullets is in alternate order throughout the saw blade. A cutting edge is formed on the point of each tooth by the intersection of the leading face of each tooth and a planar surface generally parallel to the beveled gullet of the trailing face of each tooth. The unique profile of the saw tooth of the present invention provides a saw tooth having a positive rake angle which yields a larger amount of blade material under the cutting face. This larger amount of material significantly increases the strength of the blade, greatly enhances the blade's stability and increases the blade's life and sharpness retention.
In addition to the unique profile of the saw teeth, the present invention provides the art with a unique manufacturing process for manufacturing the tooth profile according to the present invention.
Other advantages and objects of the present invention will become apparent to those skilled in the art from the subsequent detailed description, appended claims and drawings.


REFERENCES:
patent: 29982 (1860-09-01), Mason
patent: 71473 (1867-11-01), Emerson
patent: 133828 (1872-12-01), Brown
patent: 229772 (1880-07-01), Suisse
patent: 352624 (1886-11-01), Loughlin
patent: 391843 (1888-10-01), Gray
patent: 503522 (1893-08-01), Bowles
patent: 790072 (1905-05-01), McLean
patent: 858652 (1907-07-01), Harrison
patent: 1336209 (1920-04-01), Driver
patent: 1649864 (1927-11-01), Sherman
patent: 2224867 (1940-12-01), Hechler
patent: 2535439 (1950-12-01), McEwan
patent: 2633880 (1953-04-01), Mattson
patent: 2635327 (1953-04-01), Enlow
patent: 2637355 (1953-05-01), Chapin
patent: 2648360 (1953-08-01), Pall
patent: 2750669 (1956-06-01), Hohmann
patent: 275

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