IMPROVE- MENTS IN TURNIP THINNERS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by the said John Garrood at the Office
of the Commissioners of Patents on the 24th June 1878.
"
JOHN GARROOD, of Fakenham, in the County of Norfolk, Engineer. IMPROVE-
MENTS IN TURNIP THINNERS."
The object of this Invention is to simplify the construction of turnip thinners,
and to minimise the power required in working the hoes by causing the hoes to
strike into the ground to the required depth, then to move in a horizontal line
across their respective rows of turnips to be thinned, and to rise out of the ground
at an angle that will allow the hoes to clear the ground without lifting or throwing
up the soil.
Suppose it be desired to construct a turnip thinnor to act upon one row of
turnips only, I connect the bar which carries the hoe at one end of the crank pin of
a disc or crank arm, and support the other end by a bowle working in a cam or
segment groove, which may be formed either on the end of the bar or on a fixed or
moving part of the framing. When the hoe bar carries the cam groove, the bowle
or guide pin will be fitted to the framing, and vice versa.
The rotation of the crank shaft will impart an irregular oscillating endway
motion to the hoe bar and thus enable the hoe to take up a good position for
penetrating the ground, follow a horizontal course or nearly so while in the ground,
and on rising out of the ground to tip forward, and so clear itself of the soil.
By mounting the cam groove guide or the guiding bowle on an adjustable portion
of the framing, the dip of the hoe into the ground, to suit the work in hand, may
be regulated with facility.
When, as is usual, two lines of turnips are required to be thinned at one traverse.
of the implement, I operate a second hoe bar from the same crank pin, supporting

page_text: its outer end as above explained. The two hoes will then act simultaneously on
their respective lines of turnips, or, if desired, they may be caused to act alternately,
thus expending the power obtained from the draught of the implement in the inost
advantageous manner.
In some cases I propose to make the outer ends of the hoe bars follow the irregu-
larities of the ground by supporting parts of the framing which carry the guides or
the guide pins, as the case may be, on wheels which run on the ground and will
rise and fall with the irregularities presented to them.
The crank shaft which lies longitudinally of the implement will receive its rotary
motion through suitable gearing from one or both of the running wheels.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Garrood in the Great Seal Patent Office on the 24th December
1878.
JOHN GARROOD, of Fakenham, in the County of Norfolk, Engineer. "IMPROVE-
MENTS IN TURNIP THINNERS."
The object of this Invention is to simplify the construction of turnip thinners,
and to minimise the power required in working the hoes by causing the hoes to
strike into the ground to the required depth, then to move in a horizontal or nearly
horizontal line across their respective rows of turnips to be thinned, and to rise out
of the ground at an angle that will allow the hoes to clear the ground without
lifting or throwing up the soil.
Suppose it to be desired to construct a turnip thinner to act upon one row of
turnips only, I connect the bar which carries the hoe at one end to the crank pin of
a disc or crank arm and support the other end in a manner which will allow of its
having a free motion end wisc.
The rotation of the crank shaft will impart an irregular oscillating endway
motion to the hoe bar, and thus enable the hoe to take up a good position for
penetrating the ground, follow a horizontal course or nearly so while in the ground,
and, on rising out of the ground, to tip forward, and so clear itself of the soil.
In the accompanying Drawing,-
Fig. 1 shows in side elevation, Fig. 2 in plan view, and Fig. 3 in transverso
section, a turnip thinner constructed according to my Invention, and capable of
acting upon two rows of turnips simultaneously.
In theso Figures A is the main framing fitted with a pair of draft shafts B, and
mounted upon a pair of broad travelling wheels C. These wheels are fitted to a
transverse shaft D and locked thereto by means of an ordinary pawle and ratchet
arrangement, which will allow of the implement being readily turned in the field.
Mounted loosely on this shaft is a socketed sleeve bearing E, which forms a support
for a spindle F that has a bearing also in a pendant bracket piece A¹ of the
framing. Keyed to this spindle F is a plate G which carries a crank pin g, which
crank pin serves as a fulcrum for the inner ends of the hoe bars H, H. The outer

page_text: ends of these bars are supported by link rods H' which depend from vertical
sliding racks H2, H2. These racks slide in guides formed in bracket castings A²,
which are bolted to and form part of the main framing. By means of pressure
springs h, the rack bars are retained in any position to which they may be adjusted,
and their adjustment is effected by means of sector racks which form terminations
to the hand levers I. These levers have their fulcrum at i in the guides A².
Hare the hoes fitted to the horizontal bars H and capable of adjustment thereon
to or from the centre of the instrument, in order to suit various widths apart of
the turnips.
The motion for working the hoes is derived from the crank ping of the crank
plate G, which plate receives a rotary motion through a bevil pinion f(which is
keyed on the spindle F) gearing into a bevil wheel & keyed on the shaft D.
When the hoes and their bars are properly set and the implement is drawn over
the field in a direction parallel to the rows of turnips to be thinned, the throw of
the crank pin will give the desired motion to the hoes, causing them to enter the
ground, make a transverse cut across the rows of turnips, and rise clear of the
ground as above explained.
Figures 4 and 5 shew a slight modification of the means for supporting the outer
onds of the hoe bars.
In this instance, the rack bar H is extended downwards below the level of the
hoe bars, and they carry at their lower ends pivot pins, on which rock short
links H that connect the hoc bars H with the pendant rack bars.
This arrangement will slightly modify the action of the hoes by reason of their
fixed point of support being below instead of above the mean height of the hoe
bars.
A further modification is shown at Fig. 6, which represents the outer end of the
hoe bar as slotted longitudinally to receive the coupling pin of the pendant end of
the rack bar H.
Having now set forth the nature of my Invention of "Improvements in Turnip
Thinners," and explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent I claim, the
arrangement of mechanism for actuating the hoes of turnip thinners and adjusting
their dip as above described.
In witness whereof, I, the said John Garrood, have hereunto set my hand
and scal, this Twenty-third day of December, in the year of our Lord One
thousand sight hundred and soventy-eight