IMPROVEMENTS IN LAWN MOWING MACHINES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by James Bryce Brown at the Office
of the Commissioners of Patents, with his Petition, on the 17th
February 1865.
I, JAMES BRYCE BROWN, of Eighteen, Cannon Street, City of London, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN LAWN MOWING MACHINES," to be as follows:-
This Invention has for its object improvements in machinery for cutting or
mowing the edges of grass or turf.
In constructing lawn mowing machines. I make the spiral cutters of the
usual form, and consisting of from six to twelve blades ranged spirally round
an axis or shaft. The ends of this shaft are placed in square journals set in
a vertical groove in such a manner that they are capable of sliding with the
shaft upwards or downwards, their motion being adjusted by two set screws
to each journal, one being placed above and the other below the journal, and
by this means the cutters may be set accurately to the cutting edge of the
sole plate. These journals are placed inside the side plates of the machine,
so as to be out of the way of dresses, flowers, and shrubs. The front rollers
of the machine I make of wood or iron, revolving upon a shaft, the ends of
which are placed loosely in cast or wrought iron bearings, so as to be also
capable of motion, and these bearings are either cast or forged upon the
lower ends of screws passing through corresponding vertical holes in the side
plates, upon which screws are placed two nuts, each one being above the

page_text: hole and the other below, and by means of these nuts the bearings of these
rollers can be accurately adjusted.
The two large rollers or drums of the machine I make of cast iron, and
place them loosely upon a wrought-iron shaft, the rollers being separate and
independent, and the ends of the shaft being placed in bearings fixed to the
side plates of the machine. By means of a self-acting double-clutch placed
between the bosses of the drums, I am enabled to make the shaft, and conse-
quently the cutters, revolve only when one or both of the drums are revolving
forwards.
4
The motion of the drums when revolving forwards is carried to the
cutters by spur wheels and pinions, one spur wheel being placed upon the
drum shaft, and gearing into a pinion placed upon one end of an intermediate
shaft running in bearings in the side plates, and upon the other end of this
shaft is placed a second wheel similar to the one on the drum shaft, which
second wheel gears into a second pinion upon the cutter shaft. In order to
avoid the noise occasioned by the revolution of these wheels, I make the two
largest wheels double, one being fixed and the other being capable of revolving
through a distance equal to about one half of the pitch of the teeth of the
wheels, its teeth being sprung in advance of the teeth of the fixed wheel by
means of straight, curved, spiral, or india-rubber springs placed either upon
the shaft or upon the boss or arms of the wheels in any convenient manner.
By this means the teeth when working between each other will adjust them-
selves so as to avoid all the "back-lash" or rattle of plain spur wheels as usually
made.
The pinion upon the cutter shaft I place in a guard of wrought or cast iron
which also extends upwards so as partially to cover the wheel which drives
this pinion, thereby preventing the teeth from getting choked with grass or
dirt when the machine is in operation. The side plates or frames, wheels,
and pinions, drum scraper, shafts, tie rods, and side frames of the grass box of
the machine I make of maleable cast iron, by which means I avoid the
breakage of these parts, which continually occurs when constructed of
cast iron only, and by keeping all the working parts, including journals,
ends of shafts, and bolts and nuts inside the side plates or frames, I am
enabled considerably to improve the general appearance and practical utility
of lawn mowing machines.