Circular saw blade

A rotary saw blade having a substantially circular disc with opposed parallel faces and a centrally located opening through the disc to receive a drive member to rotate the disc. The outer edge of the disc has a plurality of equally spaced depth gauge protuberances located around its periphery and a pair of spaced holes extend through the disc adjacent to the outer edge at each protuberance. A saw tooth is attached to the disc on one face at alternate pairs of holes and a saw tooth is attached to the disc on the opposite face at the remaining pairs of holes. Each saw tooth has a cutting edge and a depth gauge and the depth gauge on each saw tooth has a shape and a size which are complementary with a depth gauge protuberance on the outer edge of the disc, and a face of the depth gauge on each saw tooth is in contact with a face of a protuberance on the outer edge of the disc. Each saw tooth is attached to the disc by rivets.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates generally to a circular saw blade and more 
particularly to a circular saw blade utilizing conventional use links 
normally used on the chain of a chain saw attached to a generally circular 
disc for use in brush cutting. Each cutter link is attached to the 
circular disc by a rivet which may have an enlarged center portion located 
within the disc. 
In clearing land of brush and small trees, lightweight machines are used 
which are carried by the workmen and include a small gasoline driven 
engine which rotates a drive shaft having a cutting blade attached 
thereto. These machines are used in areas which are remote from service 
facilities, and hence it is important that the equipment be simple, 
efficient and easy to repair on site. The blades which are currently 
utilized generally have teeth formed integrally with the disc, and if a 
blade is to bbe sharpened, the whole blade must be removed and a new blade 
inserted on the drive shaft so that the removed blade can be taken to a 
service facility for sharpening. Such requires a substantialy inventory of 
blades at the job site and requires the transportion of blades to and from 
the service facility which is expensive and time consuming. Additionally, 
it is important that the blade design minimize the kick reaction which 
occurs when the blade contacts an object. 
2. Description of the Prior Art 
U.S. Pat. No. 4,627,322 discloses a circular saw blade assembly having a 
central portion formed from two discs which define a chain track around 
the circumference thereof and a regular chain saw chain is located in the 
track. In the aforementioned patent, the cutting links and depth gauges 
are all a part of a continuous chain fitted into the slot, and hence if 
the chain breaks at any point, the circular saw blade assembly is rendered 
inoperable. Additionally, the cutting chain has a tendency to slip in the 
track during cutting which decreases the cutting efficiency of the blade. 
U.S. Pat. Nos. 2,958,348; 3,425,467 and 4,563,929 and Swedish Pat. No. 
80,528 disclose rotary cutting blades, but none of these patents disclose 
depth gauges formed directly on the periphery of the disc portion of the 
blade, and for this reason the blades disclosed in these patents have a 
greater tendency to the kick reaction than the blade disclosed herein. 
None of the known prior art discloses a circular saw blade assembly wherein 
standard chain cutter links are attached to a cylindrical disc which has 
depth gauge portions formed directly thereon to reinforce the depth gauge 
on the standard saw chain cutter link and to reduce the kick reaction 
while increasing productivity. 
SUMMARY OF THE PRESENT INVENTION 
The invention is directed to a saw blade which utilizes a substantially 
cylindrical disc having raised portions or protuberances spaced around its 
periphery corresponding to the spacing of the depth gauges of the saw 
teeth which are cutter links normally utilized on a regular saw chain. The 
saw teeth or cutter links are attached around the periphery of the disc in 
combination with either a plain elongated tie strap or an elongated tie 
strap which includes a depth gauge portion. Each tie strap is located on 
the face of the disc opposite the face upon which the corresponding cutter 
link is mounted. The first arrangement described above is termed a dual 
raker blade, and the second arrangement is termed a triple raker blade. 
In both arrangements, the cutter links and tie straps are attached to the 
disc by means of two parallel rivets which extend through holes in the 
disc and through correspondingly spaced holes in the base of each cutter 
link and in each tie strap either with or without a depth gauge portion. 
The rivets may have an enlarged center portion for contact with the 
periphery of a hole through the periphery of the disc. 
The rivets are peened over the hold the cutter links and tie straps onto 
the disc, and therefore a cutter link may be easily removed and replaced 
in the field with normal tools within a relatively short period of time as 
distinguished from taking a blade to a repair facility. Refurbishing the 
saw blade in the field with factory sharpened cutter links contributes 
greatly to the efficiency of the user and decreases the cost of 
transporting the blade to a repair facility and maintaining an inventory 
of blades in the field. 
By utilizing removable cutter links on a disc-shaped base for brush 
cutting, blades may be readily sharpened or replaced with new cutter links 
in the field by the machine operator. Also, the depth gauges on the cutter 
links and the depth gauge protuberances on the disc act as a solid unit 
which prevent breaking due to contact between the cutting edges of the 
cutter links and objects such as rocks which will damage the cutting 
edges. The design of the disc with depth gauge protuberances provides firm 
resistance to the blade binding in a cut which substantially reduces the 
kick reaction of the blade and consequently provides for enhanced control 
by the operator. The circular saw blade of the invention is of relatively 
low cost as it utilizes cutter links and tie straps which are standard for 
chain saw chains and need not be specially made for inclusion in the 
circular saw blade.

In the following description of the preferred embodiments of the invention, 
like reference numerals refer to like parts throughout. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The rotary saw blade shown in FIG. 1 of the drawings is a dual raker blade 
as it has only two depth gauges in connection with each cutter link or saw 
tooth. The blade consists of a centerl disc portion 1 formed at its 
periphery with a plurality of substantially equally spaced depth gauge 
protuberances 2 which are complementary with the depth gauges of the 
cutter links 3. Thus, each cutter link or saw tooth 3 has a top plate 5 
with a leading cutting edge 6, a base portion 7, a gullet 8 and a depth 
gauge 9. The base portion of each cutter link is formed with a pair of 
spaced holes (not shown). 
As will be seen in FIG. 1 of the drawings, the center portion of the disc 1 
has a central hole 11 formed therein to accommodate a drive shaft for 
rotating the blade and a plurality of spaced pairs of holes 12 around its 
peripheral portion adjacent to the outer edge and in relationship to the 
depth gauge protuberances 2 on disc 1 for proper alignment with the depth 
gauge on each cutter link. Each tie strap 15 has a pair of spaced holes 
which correspond with the spacing of the holes in the cutter links and 
each pair of holes 12 in the disc. The rivets 17 have their ends peened 
over to hold the cutter links and tie straps tightly against the opposed 
faces of the disc 1. As will also be seen in FIG. 1 of the drawings, 
alternate cutting links are on opposite faces of the disc, i.e., right 
hand cutter links are on one side of the disc and left hand cutter links 
on the opposite side of the disc. 
As shown in FIG. 2 of the drawings, the depth gauge 9 formed on the cutter 
link 3 has the same shape and height as the depth gauge protuberance 2 
formed on the periphery of disc 1 so that, in effect, a double depth gauge 
is provided giving added strength to the depth gauge and protection of the 
cutting edge 6 is increased. 
The embodiment shown in FIGS. 3 and 4 of the drawings is the same as that 
shown in FIGS. 1 and 2 except that the tie strap 20 is formed with a depth 
gauge 21 which is complementary in shape and height to the depth gauge 9 
on the cutter link in the depth gauge protuberance 2 on the periphery of 
the disc 1. It is for this reason that the blade shown in FIGS. 3 and 4 of 
the drawings is termed a triple raker blade. The triple raker blade 
provides additional strength and additional protection for the cutting 
edge, and therefore the blade may be utilized to cut heavier brush when 
the terrain is more rocky than normal. Additionally, the triple raker 
blade has a greater positive effect on the reduction of kick reaction 
during cutting and, therefore, provides enhanced control and greater 
productivity. The reduction in kickback is achieved as a result of the 
increased facial area of the three depth gauges. 
FIG. 5 of the drawings shows a cutter link which is the same as the cutter 
link described heretofore except that it is provided with a preset rivet 
17' which is installed at the factory. The cutter link with a preset rivet 
may be installed more easily than a cutter link which merely has rivet 
receiving holes. The tie straps of both the dual raker designa and the 
triple raker design are shown, respectively, with a preset rivet 17' in 
FIGS. 6 and 7 of the drawings. Each of the preset rivets 17' has an 
enlarged diameter center portion which is substantially the same length as 
the width of said disc and fits within a hole 12 in disc 1 and contacts 
the periphery of the hole. In this arrangement, the holes 12 in the disc 
have a larger diameter than the holes in the cutter links and the tie 
straps. The utilization of rivets with an enlarged center portion provides 
greater rigidity to the connection between the cutter links and the disc, 
and a stronger rotary blade saw results. The regular rivets 17 may also be 
provided with an enlarged diameter center portion to increase the rigidity 
of the connection between the cutter links and the disc. 
Although a central hole 11 is shown and described herein for receiving a 
drive means to rotate the saw blade, it will be understood by those 
skilled in the art that other arrangements may be utilized to rotate the 
saw blade. 
While preferred embodiments of the invention have been described herein, it 
is to be understood that the invention may be embodied within the scope of 
the appended claims.