IMPROVEMENTS IN POTATOE DIGGERS
Year: 1880

page_text: LETTERS PATENT to John Wallace, of the Firm of John Wallace and Sons, of
Glasgow, in the County of Lanark, North Britain, Agricultural Implement
Makers, for an Invention of "IMPROVEMENTS IN POTATOE DIGGERS."
PROVISIONAL SPECIFICATION left by the said John Wallace at the Office
of the Commissioners of Patents on the 26th October 1880.
JOHN WALLACE, of the Firm of John Wallace and Sons, of Glasgow, in the
County of Lanark, North Britain, Agricultural Implement Makers. "IMPROVE
MENTS IN POTATOE DIGGERS."
This Invention has for its object to improve the construction and action of
potato diggers, and in carrying it out the rotating digging instrument, which is
of the well known Hanson kind, is carried on a frame mounted on three wheels,
two being at the sides on the same axle, and the third being in front and on a
lever jointed to the frame. On the axle of the two wheels there is placed a bevil
wheel which can be put into gear by means of a lever and clutch, and which
gears with a bevil pinion on a short longitudinal shaft. This longitudinal shaft
extends forwards from the axle in a position near one of the side wheels, and the
digging instrument, which is a radiating set of forks, is fixed on the front end of
it. The digging instrument is thus at or near the front at one side instead of
being at the middle of the back, as in previous diggers, and several practical
advantages are thereby obtained, the weight and strain being better supported by
the three wheels, whilst the wheel following the digging instrument passes over
the cleared ground instead of over the shaws. The sock is fixed to the front of the
frame, and may be of the usual angular form with the angle projecting forward at its
middle, or it may consist of a plate with a single front inclined edge. By means
of the lever to which the front wheel is fitted, the front of the frame may be raised
or lowered so as to hold the digging instrument and sock entirely clear of the
ground, or so as to adjust them at any desired working depth.
In a second modification the longitudinal shaft with the digging instrument on
it is placed outside of the side wheel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Wallace in the Great Seal Patent Office on the 25th April
1881.
$
JOHN WALLACE, of the Firm of John Wallace and Sons, of Glasgow, in the
County of Lanark, North Britain, Agricultural Implement Makers. IMPROVE-
MENTS IN POTATO DIGGERS."
My said Invention has for its object to improve the construction and action of
potato diggers, and in carrying it out the rotating digging instrument, which is of
the well known Hanson kind, is carried on a frame mounted on three wheels, two
being at the sides on the same axle, and the third being in front and on a lever
jointed to the frame. The digging instrument, which is a radiating set of forks, is
near the front of the machine at one side instead of being at the middle of the
back, as in previous diggers; and several practical advantages are thereby obtained,
the weight and strain being better supported by the three wheels, whilst the
wheel following the digging instrument passes over the cleared ground instead of
over the shaws. Motion is imparted to the digging instrument from the axle of
the two wheels through an engaging clutch and bevil wheels, and the shaft
carrying the digging instrument may be placed either outside of the side wheel or
partly inside of the side wheel, being in the latter case, by preference, inclined in
plan so as to hold the instrument more to the side of the machine.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append a Sheet of explanatory Drawings,
to be hereinafter referred to, and representing two modifications of my improved
potato diggers.
Figure 1 on the accompanying Sheet of Drawings is a plan of one modification
of the machine, and Figures 2 and 3 are a plan and a side elevation of the second
modification. In these Drawings the same reference numerals are used to mark
the same or like parts wherever they are repeated.
In both modifications of my improved digger, there is in each case a frame 4
mounted on a pair of side wheels 5 which are on one axle 6, and there is a third
wheel 7 which is in front of the two side wheels, and is held in a swivelling fork 8
attached to a lever bar 9. This lever bar 9 is jointed at its back end to the body
frame 4, and at about its middle it has centered on it a hand lever 10, the front
end of which is connected by a link 11 to a forward projecting part 12 of the body
frame; this hand lever 10 serving for raising or lowering the front part 12 of the
body frame, and being held in any of its positions by a pin passed through it and
through one of several holes in a holding plate 13. On the axle 6 of the two side
wheels there is placed a bevil wheel 14 which can be put into gear by means of a
clutch 15 and lever 16, and which gears with a bevil pinion 17 on a short
horizontal shaft 18 extending towards the forward part of the machine, being
carried in two bearings formed or fixed in suitable positions on the framing. The
digging instrument 19 is fixed on the front end of the shaft 18, and rotates in a
plane at right angles to the line of travel of the machine in the modification
shown in Figure 1, but in a plane inclined to the line of travel in the modification
shown in Figures 2 and 3. The sock 20 usually employed with the Hanson
digging instrument is by its shank or arm fixed to the front projecting part 12 of
the body frame, and, as shown in Figure 1, is of the usual angular form with the
angle projecting forward at its middle. In the modification shown in Figures 2
and 3, the sock 20 has its form adapted to the inclined or oblique position of the
digging instrument 19, and its front edge is made with a single incline.
Having thus particularly described my said Invention and the manner of
performing the same, 1 have to state that I do not restrict myself to the precise

page_text: details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by and in terms of the
herein before in part recited Letters Patent is,-
1. The arranging or combining together of the parts of potato diggers, sub-
stantially in the improved manner hereinbefore described.
2. The placing of the digging instrument at the forward lateral part of the
machine, as hereinbefore described.
In witness whereof, I, the said John Wallace, have hereunto set my hand
and seal, this Twenty-third day of April, in the year of our Lord One
thousand eight hundred and eighty-one.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JOHN WALLACE. (L.S.)