IMPROVEMENTS IN THE CONSTRUCTION OF POTATO DIGGERS
Year: 1878

page_text: LETTERS PATENT to Lewis Augustus Aspinwall, of Albaný, in the State of
New York, United States of America, but at present of 33, Chancery Lane,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
CONSTRUCTION OF POTATO DIGGERS."
aled the 2nd May 1879, and dated the 5th November 1878.
PROVISIONAL SPECIFICATION left by the said Lewis Augustus Aspinwall
at the Office of the Commissioners of Patents on the 5th November 1878.
LEWIS AUGUSTUS ASPINWALL, of Albany, in the State of New York, United
States of America, but at present of 33, Chancery Lane, in the County of
Middlesex. "IMPROVEMENTS IN THE CONSTRUCTION OF POTATO DIGGERS."
In the Specification of a previous Patent, dated 30th November, 1877, No. 4517,
I have described a separator provided with two flat, twisted, or screw shaped blades
starting from the same part of the separator and crossing each other at or near their
outer ends.
Now, according to this present Invention I construct a separator consisting
mainly of two bars or two pairs of bars by preference flat of a peculiar construction.
Each of these bars is of a step by step construction, and arranged so as to form a
kind of screw that is not of a continuous line as an ordinary screw but of sections or
steps. I prefer to taper and split the outer ends and to terminate them in curves
instead of steps. The steps may be angular or rounded. These screw bars are
fastened to a head disc or ring on a barrel or boss revolving on a fixed stud or on a
spindle supported in the side frame of the machine. The rotary motion may be
imparted in a similar way as described in the aforesaid previous patent
Specification.

page_text: and clogging with earth.
The number of bars. may be varied according to size and requirements of the
machine.
I prefer not to use any cross bars or connections between the aforesaid step screw
bars.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Lewis Augustus Aspinwall in the Great Seal Patent Office on the
5th May 1879.
LEWIS AUGUSTUS ASPINWALL, of Albany, in the State of New York, United
States of America, but at present of 33, Chancery Lane, in the County of
Middlesex. "IMPROVEMENTS IN THE CONSTRUCTION OF POTATO DIGGERS."
In the Specification of a previous Patent, dated 30th November, 1877, No. 4517, I
have described a separator provided with two flat, twisted, or screw shaped blades
starting from the same part of the separator and crossing each other at or near
their outer ends.
Now, according to this present Invention I construct a separator consisting
mainly of two bars or two pairs of bars by preference flat of a peculiar construction.
Each of these bars is of a step by step construction, and arranged so as to form a
kind of screw that is not of a continuous line as an ordinary screw but of sections
or steps. I prefer to taper and split the outer ends and to terminate them in
curves instead of steps. The steps may be angular or rounded. These screw bars
are fastened to a head disc or ring on a barrel or boss revolving on a fixed stud
or spindle supported-in the-side-frame-of the machine. The rotary motion may
be imparted in a similar way as described in the aforesaid previous patent
Specification.
I prefer to make the bars of such a size or section as to vibrate slightly by the
movement and working of the implement in order to prevent the accumulation of
and clogging with earth.
The number of bars may be varied according to size and requirements of the
machine.
I prefer not to use any cross bars or connections between the aforesaid step screw
bars.
My present improvements will be fully understood by reference to the accom-
panying Drawings, of which Figure 1 is a side elevation of the machine or
implement; Figure 2, a vertical longitudinal section through same; and Figure 3,
a plan; Figures 4 to 10 are details.
The platform A¹ is carried and connected with the barrel of the top frame A by
the two straps A2, in which is the wheel axle B which carries the two loose carriage.
wheels C and C¹. A is the top frame of the machine'; it has several bolt holes a;

page_text: ?"
the platform A' and the top frame A are united by a bolt a' which may be placed
in any one of the holes a, whereby the position of the pole P which is united to
the platform A' can be adjusted laterally. To the top frame A is fastened a
bracket which is securely stayed by means of the stay or strap 7, and in com-
bination with the lever G serves to raise the plough D from off the ground when
the implement is to be turned or conveyed along without working. For as the
lever G is pulled back the roller rides on the platform A' and the lever ³ is
brought into a vertical position, thereby raising the bracket and with it the top
frame A to which it is connected and to which the plough D is also connected by
the arm D'..
The screw F passing through the nut f on the frame A and abutting against the
lead wheel frame N which at its upper or back extensions N' and N is jointed to
the frame A serves to regulate the depth to which the plough D enters the ground,
the front or lead wheel O¹ running in the furrow and carrying the coulter N³.
The separator constructed according to my aforesaid former patent Specification
was provided with two flat, twisted, or screw shaped blades starting from the same
part of the separator and crossing each other at or near their outer ends.
The separator constructed according to my present Invention is shown in one
form at Figures 4 and 5, the former being a side view and the latter an end view
of same. It is fixed on a spindle d which works in a long boss on the bracket or
plate g, which by means of three bolts is secured to the side frame A³ of the
machine; c and c¹ are two pairs of bars, by preference flat (or they may be of an
oval or other section); the outer bars c, c, start from opposite sides of a boss, ring,
or disc e, and proceed step by step in a mainly circular or curved direction and so
as to form a kind of screw, but not of a continuous line as an ordinary screw, but
of sections or steps.
The bars c, c', are by preference tapered off toward the outer ends, as shewn.
The outer bars care by preference split at the ends, as shown. It will be noticed
that the step by step form in this case only extends part of their length, and I
prefer to terminate their outer or free ends in easy curves, as here shown.
The spindle supported in and free to revolve in the boss g as described is on
the outer end fitted with a pinion M which receives rotary motion from the tooth
wheel L fixed on the axle B when the road wheel C, which is loose on the same
axle, is clutched in with it and when the machine is travelled along over the
ground.
The road wheel C is clutched in with the tooth wheel L by throwing the pawl J
into the ratchet wheel K which is fast on the axle B; the pawl J is jointed to the
plate J which is bolted to the nave of the travelling wheel C; j is a bent spring
for holding the pawl in gear, or for holding it quite out of gear when raised into
the position shown in dotted lines.
The separator might be made to revolve on a fixed stud, instead of being fixed
on a spindle as here shown.
Figure 6 is a view of a separator with two of the bars c, c¹, removed so as to
shew more clearly how the bars c, c¹, are arranged.
Figure 7 is a side view, and Figure 8 an end view of a separator with two step
screw bars c only.
The ends of the bars c, c¹, serve to separate the potatoes from their "halms." The
number of bars may be varied according to size and requirements of the machine.
I prefer not to use any cross bars or connections between the aforesaid step screw
bars. The step parts of the bars may be made with slightly rounded corners, but
I prefer to make them sharp, as shown.
I prefer to make the bars of such a size, or section, or form as to vibrate slightly
by the movement and working of the implement in order to prevent the accumula-
tion of and clogging up with earth.
The plough share D may be formed as shown and described in my aforesaid
Specification, or it may advantageously be formed as here shown and more clearly at

page_text: I also prefer to use the form and mode of fixing of plough shown here.
And having thus described and ascertained the nature of this Invention, I declare
that I claim,
-
Firstly. Constructing the separator in potato digging machines with two or more
bars of a step by step or sectional form starting from a head, or disc, or ring, and
proceeding in a helical or mainly or approximately helical direction, all substantially
as set forth.
-Secondly. The application of a separator, constructed-as claimed, to a potato-
digging machine of the general form and construction herein before shown and
described.
In witness whereof, I, the said Lewis Augustus Aspinwall, have hereunto set
my hand and seal, this Third day of May, in the year of our Lord One
thousand eight hundred and seventy-nine.
L. AUGS. ASPINWALL. (L.S.)