Improvements in Lawn Mowers.
Year: 1897

page_text: Date of Application, 17th Sept., 1897-Accepted, 4th Dec.,
1897
Improvements in Lawn Mowers.
I, STEPHEN OLIN JOHNSON of 810 Second Avenue, Detroit, Michigan, United States
of America, manufacturer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained, in
and by the following statement.
The object of this invention is to construct a lawn mower, that it is easily
convertible from one form in which it is essentially adapted for mowing a lawn into
another form in which it is essentially adapted for trimming it.
An indespensible requirement of a perfect lawn mower is that the revolving cutter
head should be supported upon wheels placed at the ends of the shaft of the cutter
head so that the knives in revolving will always maintain the same distance from
the ground and thereby, cut the lawn evenly therewith.
These projecting wheels (which in the majority of the constructions of lawn mowers
also impart motion to the cutter head through suitable intermediate gearing)
however prevent the operator from approaching close enough to the trees, walls,
fences, side walks or other boundary marks, to cut clear to the outside edge and
requiring therefore some extra labor, or what is called trimming the lawn, which is
usually performed by hand or other special trimming tools.
With my improved lawn mower this work of trimming may be equally well
accomplished all as more fully hereinafter described and shown in the accompanying
drawings.
Fig. 1 is a plan view of my lawn mower (partly in section).
Fig. 2 is a perspective view thereof showing it as converted into a trimmer.
Fig. 3 is a detached perspective view of one of the detachable supporting wheels.
Fig. 4 is a vertical cross section on line xx Fig. 1.
Fig. 5 is a vertical cross-section on, line y y Fig. 1.
The frame of the lawn mower is formed with two parallel side plates A between
which is journaled the rotary knife head B. These side plates are secured to rear-
wardly and inwardly extending brackets C which thus form a sufficient contraction
of the frame to afford room on the outside of the brackets for two drive wheels D
of
within the space cut by the knives. These drive wheels by means
intermediate gears impart motion to a transverse shaft inclosed within the hollow
frame bar E and from the center of this shaft motion is transmitted through
intermediate gear enclosed in the enlargement F of the frame to a shaft G running
forward in the center of the frame and revolving the shaft H of the knife head
through intermediate gear inclosed in the housing I.
The knife head has two sets of knives J J¹ which are staggered in relation to each
other and the shaft G has a crook K whereby the knives (which overlap in the center)
and the crook which revolves with the shaft G dodge each other, the crook passing
around the end of each knife just at the moment of passing each other.
The front end of the frame is supported upon ground wheels L placed in line with
the revolving cutter head. Each wheel is secured by a bolt a to a plate b in such
manner that the bolt forms a stub axle upon which the wheel is free to revolve.
The plate bis preferably of sheet metal formed with a vertical recess c upon the

page_text: inside adapted to receive the nut d of the bolt and with a vertical slot e for the screw
threaded end of the bolt to pass through and seat with a shoulder f against the
plate, whereby the bolt is secured in position on the plate b vertically adjustably.
The plate b at its forward end has a tongue g adapted to engage into a slot h in
the plate A and at its rearward end it has a stud i which is adapted to be engaged
into the orifice k in the plate A. On the inside the plate A is provided with lugs jj
through which the clamping screw k is screw threaded. The lower end of this
clamping screw is conically reduced and a corresponding seat for it is formed on
the stud i.
With a lawn mower thus constructed it will be seen that it takes but a few seconds
to take the wheels L off or put them on again.
With the wheels taken off as shown in Fig. 2, it is a perfect trimmer as the
knives virtually cut to the full width of the frame and the operator can cut the grass
close to the fence, wall or other boundary of the lawn, he can also cut as high or low
as he wants by merely raising or lowering the handle which raises or lowers the
knives without stopping their movement and thus if the grass on a border is
especially long he can cut the top off first and then cut it again closer down and
when the trimming can be all done on one side it is not even necessary to take more
than one wheel off.
As arranged in Fig. 1 in which the wheels L are in position it is a perfect lawn
mower as the wheels L properly guide the cutter head over the ground so that it
follows all the irregularities thereof, whereas in the absence of the front wheels the
rear wheels would have to guide it as as these are some distance in rear of the cutter
head they would improperly guide it upon uneven ground.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
A lawn mower convertible into a lawn trimmer by having it provided with
attachable and detachable wheels to its frame in line with the cutter head, in
addition to rear drive wheels which form independent supports of the lawn mower
and have a central drive connection with the cutter head and are located together
with the frame and drive connection within the path of the cutter head.
Dated this 17th day of September 1897.
HASELTINE LAKE & Co.,
45 Southampton Buildings, London, W.C. Agents for the Applicant.