IMPROVEMENTS IN LAWN MOWING MACHINES
Year: 1880

page_text: LETTERS PATENT to William Phillips Thompson, of the Firm of W. P.
Thompson and Co., Patent Agents, of 6, Lord Street, Liverpool, in the
County of Lancaster, and of 323, High Holborn, in the County of Middlesex,
Civil Engineer, for an Invention of "IMPROVEMENTS IN LAWN MOWING
MACHINES." A communication from abroad by Phineas P. Mast, of Springfield,
Ohi
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 12th July 1880.
WILLIAM PHILLIPS THOMPSON, of the Firm of W. P. Thompson and Co., Patent
Agents, of 6, Lord Street, Liverpool, in the County of Lancaster, and of 323, High
Holborn, in the County of Middlesex, Civil Engineer. "IMPROVEMENTS IN LAWN
A communication from abroad by Phineas P. Mast, of
MOWING MACHINES."
Springfield, Ohio.
The machine consists essentially of, first, two ground wheels mounted in journals
on the sides of the main frame; second, a rotary cutting head; third, a a fixed blade
or knife at the bottom of the machine; fourth, the frame work of tho machine.
The experimental machine now made is as follows, and gives a good instance
of the carrying out of Mr. Mast's Invention into practice; a description of it will
therefore be the best mode of Provisionally Specifying the Invention:-The main
frame consists of two side or end plates, a cross brace connecting the plates at top,
a knife or knife-supporting bar connecting the plates at bottom. The two frame
plates, which are duplicates of each other, except that one is right and the other
left handed, are constructed each in a single piece. Each plate has on its inner side
a rigid journal or neck to receive an intermediate gear wheel, the first neck being
extended outward further than the other, and located upon an outwardly extended
projection or offset formed on the plate. This offset is recessed or made hollow in
the back from the inner side of the plates to form a pocket for the cutter head
pinion, and is provided with an opening in its edge which forms a communication.

page_text: between the opposite sides of the plate, so that the cutter head pinion which is
applied on the inside may engage, as hereinafter explained. The plate is also
provided on the outside with flanges to encircle and assist in concealing the driving
gear, and on the lower edge is provided with a bearing to receive the fixed knifo.
On the inner side the plate has a half box or bearing to receive tho cutter head
shaft, said box being located at the bottom of the previously mentioned opening,
which is of such size as to admit of the cutter pinion being passed through it when
the parts are being assembled. The shaft bearing or box is provided with a cap or
top plate secured in place by screws, and constructed with an upwardly extending
flange or plate, which serves to close the opening, and thus exclude dirt and other
"foreign matters.
The cutter head, which may be of any ordinary or approved construction in its
main features, has a central shaft provided on its extremo ends outside of the points
of bearing with driving pinions secured rigidly thereon. In assembling the parts
-of-tho-machine,-theso-pinions-are-first-introduced_into_the_openings_or_recessos.
beforementioned from the inner sides of the frame plates, and the cutter shaft
dropped into place in the bearings, whereupon the edges of the pinions will be
exposed on the outer sido of the plates. The cross brace and the knife are then
applied and secured in place so as to connect and hold the frame plates in a firm
and rigid manner, and the cap plates secured in place so as to fasten the cutter
shaft in position, and close the before mentioned recesses or openings. Each of tho
mainplate journals next receives from the outside a double pinion consisting of a
large pinion to gear into the cutter pinion, and a small pinion cast in one piece
with the large pinion, and designed to gear into a driving wheel or pinion. This
pinion or driving wheel is of large size, and is loosely mounted on a hollow neck or
sleeve formed centrally on the journal of the frame plate. This driving pinion has
--on-the-outer-side-a hub or neck containing next to the sleeve-excentric- or -inclined-
cavities, in which are seated loosely small balls, rollers, or pieces of metal arranged
in recesses, and serving to lock the driving pinion and ground wheel together as
the latter turns forward, but permit the ground wheel to turn backward freely and
independently.
A pawl and ratchet or other common form of catching device may be used
between the ground wheel and pinion if preferred.
During the advance of. the machine the ground wheel through the clutching
devices drives the main pinion, which in turn drives the smaller. pinion and its
larger companion, which latter drives the pinion of the cutter head, imparting to
the same a very rapid rotation: The, parts are so constructed that the axis of the
cutter head stands somewhat in advance of the axes of the ground wheels.
This arrangement, besides permitting a very compact disposition of gearing,
permits the cutter head to cut forward to a point nearly in line with the front of
the main wheels close to walls and borders, while the projection of the main or
ground wheels in advance of the cutter head serve as guards to prevent the head
from coming into and being injured by contact with stationary objects. As an
additional protection for the cutter head, the frame plates are extended forward
and provided with curved flanges on the inner side, which encircle the ends of the
cutter head blades. These flanges also serve to prevent grass from being wound
inward around the ends of the cutter head shaft. Referring to the guards, they
terminate in advance of the fixed blade, thus allowing the free escape of grass
between them.
The handle by which the machine is propelled is attached rigidly to the frame
and extended backward. Any suitable construction and mode of attachment may
be adopted. Owing to the location of the fixed knife, and the fact that the whole
machine turns together upon the journals of the main wheels, the rise and fall of
the handle and the consequent rocking of the frame within ordinary bounds is of
no moment, it being found in practice that the machine will cut steadily and at
practically uniform height on rough as well as on smooth ground.

page_text: The spokes of the ground wheel are located at the outer side, and the wheel is
dished or made concave on the inner side in such manner as to permit the sleeve
and driving pinion thereon to set back within the wheel, thus reducing the width
of the machine, and making the same more compact. This wheel is applicable to
all machines of this class. By mounting the pinion on a sleeve on the main wheel,
a long bearing is secured without widening the machine, and this fact it is,
combined with the dishing of the wheels, that admits of the pinion being
successfully located thereon."
On each side of the machine a covering plate is applied over the gearing against
the flanges of the main frame. These plates in connection with the flanges entirely
conceal the gearing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Phillips Thompson in the Great Seal Patent Office on the
12th January 1881.
WILLIAM PHILLIPS THOMPSON, of the Firm of W. P. Thompson and Co., Patent
Agents, of 6, Lord Street, Liverpool, in the County of Lancaster, and of 323, High 5
Holborn, in the County of Middlesex, Civil Engineer. "IMPROVEMENTS IN LAWN-
MOWING MACHINES." A communication from abroad by Phineas P. Mast, of
Springfield-Ohio:
This Invention relates to that class of machines in which a rotary head operates
in connection with a fixed blade in the bottom of the frame, and particularly to
that class in which the fixed blade is hung between two ground wheels which carry
the entire machine, the objects being to secure a uniform height of cut on uneven
ground, to reduce the width of the machine, and to render the same simple in
construction. With these ends in view the Invention consists in the manner of
hanging the cutter head in the machine, in the construction and arrangement of
the driving gear, and in the construction of the main frame, as hereinafter
explained.
Fig. 1 represents a top plan view of the machine; Fig. 2, an end clevation of the
same with the ground wheel partly broken away at the centre in order to expose
the clutch to view; Fig. 3, a transverse central section of the gearing on one-side.
of the machine taken on the line x, x, of Fig. 2; Fig. 4, a longitudinal vertical
section of the machine on the line y, y, Fig. 1; Figs. 5 and 6, perspective views of
one of the frame plates looking from opposite sides of the same; Figs. 7, 8, 9,
and 10, views of details. A, A, represent the two ground wheels mounted on
journals on the sides of the main frame; B, the rotary cutting head, and C, the
fixed blado or knife at the bottom of the machine.
The main frame consists of two side or end plates D, a cross brace E connecting
the plates at the top, and the knife or knife-supporting bar C connecting the plates
at the bottom.
The two frame plates D, which are duplicates of each other, except that one is
right and the other left-handed, are constructed each in a single piece, as shown in
Figs. 5 and 6. Each plate has on the inner side a rigid journal or neck a to
receive the ground wheel, and a similar neck b to receive an intermediate gear
wheel, the first neck being extended outward further than the other, and located
upon an outwardly extended projection or offset c formed on the plato, as shown in
Figs. 3, 5, and 6. This offset is recessed or made hollow in the back from the inner
side of the plates, as shown at d, to form a pocket for the cutter-head pinion, and
is provided with an opening e in its edge, which forms a communication between
the opposite sides of the plate, so that the cutter-head pinion which is applied on
the inside may engage with the driving pinion applied on the outside, as hereinafter
explained. The plate is also provided on the outside with flanges f to encircle and
assist in concealing the driving gear, and on the lower edge is provided with a
bearing to receive the fixed knife. On the inner side the plate has a half box or
bearing to receive the cutter head shaft, said box being located at the bottom of
the previously mentioned opening d, which is of such size as to admit of the cutter-
pinion being passed through it when the parts are being assembled. The shaft
bearing or box is provided with a cap or top plate m secured in place by screws,
and constructed, as shown in Fig. 7, with an upwardly-extending flange or plate m¹,
which serves to close the opening d, as represented in Fig. 3, and thus exclude dirt
and other foreign matters.
The cutter-head C, which may be of any ordinary or approved construction in its
main features, has a central shaft provided on its extreme ends outside of the points

page_text: of bearing, with driving pinions & secured rigidly thereon. In assembling the parts
of the machine, these pinions are first introduced into the openings or recesses d
from the inner sides of the frame plates, and the cutter-shaft dropped into place in
the bearings h, whereupon the edges of pinions will be exposed on the outer sides
of the plates through the openings c. The cross brace E and the knifo are then
applied, and secured in place so as to connect and hold the frame plates in a firm
and rigid manner, and the cap plates m secured in place so as to fasten the cutter
shaft in position, and close the recesses or openings d. Each of the main plate
journals & next receives from the outside a double pinion n, o, consisting of tho
large pinion n to gear into the cutter pinion k, and the small pinion o cast in one
piece with the large pinion, and designed to gear into a driving wheel or pinion p.
The pinion ? is of large size, and is mounted loosely-on-a-hollow-neck-or-sleeve-
formed centrally on the inner side of the ground-wheel A, which latter is in turn
mounted loosely on the journal a of the frame plate. The pinion p has on the
outside a hub or neck containing next to the sleeve ? eccentric or inclined cavities 8,
in which are seated loosely small balls, rollers, or pieces of metal t, arranged either
as shown in Fig. 9 or Fig. 10, as preferred, and which serve to lock the pinion p
and ground-wheel together as the latter turns forward, but permit the ground-
wheel to turn backward freely and independently. A pawl and ratchet or other
common form of clutching devices may be used between the ground wheel and
pinion if preferred. During the advance of the machine, the ground-wheel through
the clutching devices drives the pinion 2, which in turn drives the small pinion o
and its larger companion n, which latter drives the pinion k of the cutter-head,
imparting to the same a very rapid rotation. The parts are so constructed that
the axis of the cutter head stands somewhat in advance of the axis of the ground-
wheels.
This arrangement, besides permitting a very compact disposition of the gearing,
permits the cutter head to cut forward to a point nearly in line with the front of
the, main wheels, close to walls and borders, while the projection of the main or
ground-wheels in advance of the cutter-head serve as guards to prevent the head
from coming into, and being injured by, contact with stationary objects. As an
additional protection for the cutter-head, the frame-plates are extended forward
and provided with curved flanges won the inner side, which encircle the ends of
the cutter-head blades, as represented in Figs. 3 and 4. These flanges also serve to
prevent grass from being wound inward around the ends of the cutter-head shaft.
Referring to Fig. 4, it will be seen that the guards w terminate in advance of tho
fixed blade C, thus allowing the free escape of grass between them.
The handle K by which the machine is propelled will be attached rigidly to the
fraine and extended backward, as shown in the Drawings. Any suitable con-
struction and mode of attachment may be adopted. Owing to the location of the
fixed knife, and the fact that the whole machine turns together upon the journals
of the main wheels, the rise and fall of the handle and the consequent rocking of
the frame within ordinary bounds is of no moment, it being found in practice that
the machine will cut steadily, and at practicably uniform height on rough as well
as on smooth ground.
Referring to Figs. 1 and 3, it will be noticed that the spokes of tho ground-wheel
are located at the outer side, and that the wheel is dished or made concave on the
inner side in such manner as to permit the sleever and the pinion p thereon to set
back within the wheel, thus reducing the width of the machine, and making the
same more compact. This wheel is applicable to all machines of this class. By
mounting the pinion on a sleeve on the main wheel a long bearing is secured for
each, without widening the machine, and this fact it is, combined with the dishing
of the wheels, that admits of the pinion being successfully located therein.
On each side of the machine a covering plate a', such as shown in Fig. 8, is
applied over the gearing against the flanges fof the main frame. These plates in
connection with the flanges entirely conceal the gearing.
Having now described the Invention, exactly as communicated to me by my

page_text: foreign correspondent, I wish it to be understood that what I believe to be new
and desire to protect under the herein before in part recited Letters Patent is,-
First. The combination of the main frame, the two ground-wheels supporting the
same, and the cutter-head mounted in the frame with its axis in advance of the
axis of the wheels, and its front side in rear of the front of the wheels, substantially
as and for the purpose described.
Second. A frame plate for a lawn mower recessed to permit two pinions to be
applied from opposite sides, and geared together, substantially as shown and
described.
Third. The frame-plate recessed at d and provided with the opening e forming a
communication between the opposite sides of the plate, substantially as shown and
described.
Fourth. The frame-plate for a lawn mower having the recess d, opening e, and
bearing h, substantially as described and shown.
Fifth. The frame-plate provided with the opening d, and bearing h, substantially
as shown.
Sixth. In combination with the frame plate having the opening or recess d and
bearing h, the cap piece m, provided with the flange m'.
Seventh. The combination of the frame plate having recess 'd, the cutter
provided with pinion k, the double pinion n, o, the pinion p, and the ground-wheel
clutched to pinion p, substantially as described.
Eighth. In a lawn mower, the combination of a frame-plate, and two spur pinions
located on opposite sides of said plate, and gearing together in one and the same
plane through an opening in the plate, substantially as described and shown.
In witness whereof, I, the said William Phillips Thompson, have hereunto set
my hand and seal, this Tenth day of January, in the year of our Lord One
thousand eight hundred and eighty one.
117M D THOMPSON