Dual end rotary tiller blade

A rotary tiller blade for mounting along with other similar blades, on a driven tiller shaft in a rotary tiller machine, which blade is configured and arranged to provide two cutting teeth per blade which enables a faster, smoother running and more thorough ground breaking action than any other tiller blade design.

SUMMARY OF THE INVENTION 
There are two types of rotary tiller machines: front end tillers and rear 
end tillers. Each has their proponent. For example, front end tiller 
proponents correctly claim that their machines are lighter, less expensive 
and capable of operating in most soil conditions, while rear end tiller 
proponents correctly claim that their units are easier to handle and 
provide a more thorough ground breaking or pulverizing action. 
By way of this invention, however, it has been discovered that the 
operation and efficiency of both type tillers, and in particular front end 
tillers, can be greatly enhanced by the dual end rotary tiller blades 
designed in accordance with the present invention. 
Therefore, it is a general object of the present invention to provide a new 
and improved dual end rotary tiller blade design which can be used to 
improve the operating performance and efficiency of front or rear end 
tillers. 
More specifically, it is an object of the present invention to provide a 
new and improved dual end tiller blade design which provides a faster, 
smoother running and more thorough ground breaking action; and in 
addition, is more economical and simpler to manufacture than other tiller 
blade designs. 
These and other objects and advantages are attained by the provision of a 
rotary tiller blade for mounting, along with other similar blades, on a 
driven shaft in a rotary tiller machine, said blade comprising an 
elongated element with a flattened intermediate section, and oppositely 
directed cutting teeth adjacent the marginal end portions thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The front end rotary tiller 10 shown in FIG. 1 of the drawings includes a 
motor 12 mounted on the frame 14, a handle 16 with governor control 18 and 
forward control 20, a worm gear 22, operated by the forward control 20, to 
drive the tiller blade shaft 24, and a plurality of tiller blade supports 
26 for mounting the dual end rotary tiller blades 28, which are 
constructed in accordance with the teachings of the present invention. 
As shown in FIGS. 1-2 of the drawings, there are four tiller blade supports 
26, each of which have four rotary tiller blades 28 mounted thereon. Since 
each rotary tiller blade 28 is provided with two earth cutting teeth or 
sections, there will be sixteen rotary tiller blades 28 with thirty-two 
earth cutting teeth for engagement with the earth. 
At the present time, the majority of tiller manufacturers use sixteen 
rotary tiller blades which have sixteen earth cutting teeth, although 
there is at least one manufacturer which has thirty-two blades with 
thirty-two cutting teeth. However, no one is known to have sixteen rotary 
tiller blades which provide thirty-two earth cutting teeth. 
The advantages of thirty-two earth cutting teeth on sixteen rotary tiller 
blades include: faster tilling which substantially reduces tilling time, 
more thorough ground breaking or pulverization sometimes with the first 
pass of the rotary tiller, and smoother handling, particularly of front 
end tillers in various soil conditions. In addition, as will be seen from 
the ensuing discussion, the rotary tiller blades of the present invention 
do not have to be made in right and left hand configurations, but rather, 
are made in one standard blade configuration. This greatly facilitates the 
ease and economy of manufacture, as well as assembly and disassembly of 
the rotary tiller blades on the driven tiller shaft by the user. 
Accordingly, attention is now directed to the configuration are 
arrangement of the dual end rotary tiller blades 28 as shown in the 
drawings. Although two embodiments of the dual end rotary tiller blade 28 
are shown in FIGS. 3-6 and FIGS. 7-10 respectively, it will be appreciated 
that other structural configurations and arrangements, within the purview 
of the present invention, can be made. 
In the FIGS. 3-6 and FIGS. 7-10 embodiments, the same reference numerals 
will be used to designate like parts with the difference between the 
embodiments being denoted by the suffix "a" for the FIGS. 3-6 embodiment 
and the suffix "b" for the FIGS. 7-10 embodiment. 
In the FIGS. 3-6 embodiment, the dual end rotary tiller blade 28a is shown 
in FIG. 3 as being formed by a generally scrapless method from sheet steel 
material. More specifically, it will be seen that each rotary tiller blade 
28a is formed, from flattened sheet material, with a flattened 
intermediate section 30a and with opposite marginal end portions 32a, 34a 
respectively which are angularly offset relative to the flattened 
intermediate section 30a (at approximately 221/2 degrees offset from the 
intermediate section). Since each dual end rotary tiller blade 28a is 
identical, it can be seen in FIG. 3 that little scrap is lost because the 
dual end rotary tiller blades 28a can be easily cut or sheared from the 
sheet steel material one right after the other. 
Following the initial forming step as shown in FIG. 3, the marginal end 
portions 32a, 34a of each rotary tiller blade 28a are bent in opposite 
directions from the intermediate flattened section 30a to provide 
oppositely directed cutting sections or teeth. As best seen in FIGS. 3-4, 
the marginal end portion 32a is bent at 36a in the area of the juncture 
between the marginal end portion 32a and intermediate section, while the 
marginal end portion 34a is bent in an opposite direction to the marginal 
end portion 32a in an area which is spaced from the juncture between the 
marginal end portion 34a and intermediate section 30a and is at an angle 
thereto (approximately 30 degrees offset from the intermediate section). 
In the FIG. 4 position, the marginal end portion 32a is shown as being 
bent upwardly while the marginal end portion 34a is shown as being bent 
downwardly. 
When thus formed and bent, the dual end rotary tiller blades 28a provide 
oppositely directed cutting edges or teeth 40a on marginal end portion 32a 
and 42a on marginal end portion 34a. This is best seen in FIGS. 5-6 of the 
drawings. As a result, each blade 28a has a pair of oppositely directed 
cutting edges or teeth 40a, 42a for engaging the earth. Preferably, the 
cutting teeth 40a, 42a are sharpened or formed in such a way to slice into 
the earth. 
It will be seen in FIGS. 1-2 that when four dual end rotary tiller blades 
28a are mounted on the tiller blade supports 26, adjacent blades 28a are 
mounted at 90 degrees relative to one another as shown to provide 
engagement with the earth at 45 degree increments, by alternating adjacent 
cutting edges or teeth 40a, 42a of adjacent blades 28a. Further, it will 
be seen that there are four tiller blade supports 26, which secure the 
blades 28a thereto by suitable fasteners, each of which carry four blades 
28i a or a total of 16 rotary tiller blades 28a with thirty-two cutting 
edges or teeth 40a, 42. 
In the FIGS. 7-10 embodiment, the dual end rotary tiller blades 28b are 
shown in the initial scrapless method forming step of FIG. 7 as being 
generally similar in shape to the rotary tiller blades 28a as illustrated 
in FIG. 3, except that the rotary tiller blades 28b are somewhat longer in 
order that the blades 28b can overlap adjacent tiller blade support 26. 
This blade overlapping feature of the FIGS. 7-10 embodiment is best seen 
in FIG. 2 of the drawings. 
Each of the dual end rotary tiller blades 28b, as shown in FIG. 7, include 
a flattened intermediate section 30b with opposite marginal end portions 
32b, 34b that are angularly offset relative to the flattened intermediate 
section 30b, at approximately 221/2 degrees relative thereto. 
After the initial forming step shown in FIG. 7, the marginal end portions 
32b, 34b of each dual end rotary tiller blade 28b are bent in opposite 
directions from the intermediate flattened section 30b to provide 
oppositely directed cutting teeth. As best seen in FIGS. 7-8, the marginal 
end portions 32b, 34b are both bent in an area spaced from the juncture 
between the marginal end portions 32b, 34b and the intermediate section 
30b. More specifically, it will be seen that the marginal end portion is 
bent at 36b, at an angle of approximately 50 degrees from the marginal end 
portion 32b, while the marginal end portion 34b is bent at 38b, at an 
angle of approximately 621/2 degrees from the marginal end portion 34b. 
FIGS. 8-10 best illustrate the desired form of the dual end rotary tiller 
blade 28b. As best seen in FIG. 8, the marginal end portion 32b is bent 
upwardly at 36b while the marginal end portion 34b is bent downwardly at 
38b. When formed and bent in this manner, the dual end rotary tiller 
blades 28b provide oppositely directed cutting edges to teeth 40b, 42b on 
the marginal end portions 32b, 34b respectively. The oppositely directed 
cutting edges or teeth 40b, 42b are best shown in FIGS. 9-10. 
As compared with the FIGS. 3-6 embodiment, the marginal end portions 32b, 
34b, and therefore, the cutting edges or teeth 40b, 42b of the FIGS. 7-10 
embodiment, are designed to overlap adjacent marginal end portions 32b, 
34b of dual end rotary tiller blades 28b which are mounted on adjacent 
rotary tiller supports 26 of the driven tiller shaft 24, as is shown in 
FIG. 2. This overlapping feature assures complete tilling to the depth 
desired across the full width of earth engagement by the rotary tiller 
blades. 
From the foregoing, it will be appreciated that the dual end rotary tiller 
blades of the present invention provide improved tiller performance by 
unique blade design that assures faster tilling, smoother tiller operation 
and more complete pulverization or ground breaking, and at the same time, 
will allow simple and economical manufacture of standard type blades.