ROTARY TILLER

ROTOCULTEUR

English Abstract

ABSTRACT OF THE DISCLOSURE
A rotary tiller includes a pair of circular plates which
are rotated by a single drive connected to a shaft on each plate
by pulleys and belts; a plurality of radial rows of teeth, which
are slidably mounted in the plates; and a cam arrangement for
reciprocating each tooth once during each revolution of the
plates, so that debris is removed from the teeth.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A rotary tiller comprising
(a) circular rotor plate means;
(b) a plurality of radially extending rows of teeth
means carried by said plate means extending downwardly therefrom
in use, each said row including a plurality of said teeth means;
and
(c) drive means for rotating said rotor plate means,
whereby said teeth means can be caused to cultivate the soil in
circular paths when the rotor plate means is rotated in a fixed
position.
2. A rotary tiller according to claim 1, including cam
means for causing said teeth means to reciprocate vertically
during rotation with said rotor plate means.
3. A rotary tiller according to claim 1, including a
plurality of rotor plates for rotation by said drive means.
4. A rotary tiller according to claim 3, wherein said
drive means includes shaft means on each of said rotor plates;
pulley means on said shaft means; and belt means for connecting
said pulley means to a drive motor.
5. A rotary tiller according to claim 2, wherein said
cam means includes a radially extending lift bar carrying said
teeth means in each said row, and a pair of cams for engagement
by the ends of said lift bar during rotation of said rotor plate
means for raising and lowering said lift bar and teeth means.
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Description

This invention relates to a tiller, and in particular
to a rotary tiller.
The conven-tional tiller includes a frame, usually rect-
angular, or a bar to which is connected a plurality of cutter
teeth. With a view to efficiently preparing -the earth for planting,
rotary tillers have been proposed. Usually~ tillers of this
type include a plurality of shafts with an arm rotatably mounted
thereon, and a tooth at each end of the arm for cutting through
the soll. However, to the inventor's knowledge a rotary tiller
including a plurality of teeth driven by a single drive has never
been proposedO
The object of the present invention is to provide a rela-
tively simple tiller in which a plurality of teeth are driven in
a circle by a single drive.
It is preferable to reciprocate the teeth vertically
during rotation, so that earth and debris on the teeth is removed.
Thus, the tiller is less likely to become clogged during use.
Accordingly, the present invention relates to a rotary
tiller comprising:
~0 (a) a rotor plate means;
(b) a plurality of teeth means carried by said plate
means and extending downwardly therefrom in use; and
(c) drive means for rotating said rotor plate means,
whereby said teeth can be caused to cultivate the soil in a
circular path when the rotor plate means is rotated in a fixed
position.
The invention will now be described in greater detail wi-th
reference to the accompanying drawings, which illustrate a
preferred embodiment of the invention, and wherein:
-- 1 --

Figure 1 is a schematic plan view of a rotary tiller in
accordance with the present invention;
Figure ~ is a schematic perspective view from above of
a portion of the tiller of Fig. l;
Figure 3 is a perspective view from above of a tooth
return mechanism;
Figure 4 is a cross section taken generally along line
IV-IV of Fig. 4;
Figure 5 is a perspective view of one end of a cam
follower and cam used in the tiller of Figs. 1 to 4; and
Figure 6 is a perspective view oE the other end of the
cam follower of Fig. 5.
With reference to the Figs. 1 and 2 of the drawings, the
rotary tiller of the present invention includes a pair of circular
rotor plates 1 and 2. The plates 1 and 2 would normally be mounted
in a frame (not shown) for rotation around their longitudinal
axes. A shaft 3 (Fig. 2) extends upwardly from each plate 1 and 2
through a bushing 4. A pulley 5 on the top end of the shaft 3
i5 connected to one of a palr of pulleys 6 on the top end of a
~0 shaft 7 by a belt 8. The shaft 7 extends downwardly through a
bushing 9. A pulley 10 on the lower end of the shaft 7 is
connected to a drive pulley 11 by a belt 12. The pulley 11 is a
driven pulley and is connected to or part of a drive assembly
(not shown), i.e. the pulley 11 is on the end of a motor drive
shaft, or is connected to the drive shaft by a transmission. In
any event, the pulley 11 is used to rotate the pulley 10, the
shaft 7, the pulleys 6, the pulleys 5, the shafts 3 and consequently
the plates 1 and 2.
The bushings 4 and 9 are interconnected by a crossbar 14.

It should be readily apparent that the drive elements, including
the bushings 4 and 9 are fixedly mounted on a towing frame (not
shown) or the like, and that the plates 1 and 2 are rotatable.
With reference to Figs. 3 and 4, a plurality of teeth 16
are slidably mounted in each plate 1 and 2 for vertical recipro-
cation therein. Each tooth 16 includes a shank 17 which extends
through a bushing 18 in the plate 1 or 2, so that the tooth can
slide vertically in the plate. As shown in Fig. 1, there are a
plurality of rows of teeth 16 extendlng radially of each plate
1 and 2.
In order to reciprocate the teeth 16 in the plates 1 and
2, each tooth 16 extends through and is connected to a radially
extending lif-t bar 19. A helical spring 20 is provided on the
shank 17 of each of the innermost and outermost teeth 16 in each
row of teeth. The springs 20 are sandwiched between the lift
bar 19 and an inverted U-shaped bracket 21. The bracket 21 is
connected to the plate 1 or 2. The shank 17 of the tooth 16
extends upwardly thxough a bushing 22 in the bracket 21. Thus,
when the tooth 16 and the liEt bar 19 move upwardly, the spring
20 is compressed to bias the teeth and the lift bar downwardly
into the earth.
The lift bar 19 is reciprocated by a pair of cams 23 and
24 (Figs. 5 and 6). Each of the cams 23 and 24 is defined by a
ramp for receiving a roller 25 on the end of the lift bar 19. The
cam 23 is integral with the bushing 4 and extends radially outwardly
into the circular path of travel of the inner end o~ the rod 19.
The cam 24 is on the bottom end of an arm 27 (Figs. 1 and 6), which
extends downwardly from the crossbar 14. The cam 24 extends
inwardly into the circular path of travel of the ou-ter end of

the rod 19. Thus, as the plate 1 or 2 rotakes, the rollers 25
ride up and down the cams 23 and 24 to cause the lift bars 19
and -the teeth 16 attached thereto to reciprocate vertically.
In operation, the rotor plates 1 and 2 are towed wi-th
the teeth 16 penetrating the soil. The plates 1 and 2 are
rotated by the pulley 11, belt 12, pulley 10, shaft 7, pulleys 6,
belts 8, pulleys 5 and shafts 3. During each revolution of each
plate 1 and 2, the rods 19 are moved upwardly to withdraw the
teeth 16 at least partially from the soil. As a result, debris
adhering to the teeth i5 periodically dislodged to prevent clog-
ging of the tiller.
The tiller of the pre~ent invention i5 useful for culti-
vating close to plants without damaging the plants.