IMPROVEMENTS IN APPARATUS FOR GRINDING LAWN MOWER CUTTERS."
Year: 1882

page_text: LETTERS PATENT to Thomas Henry Gillott, of Royston, in the County of Herts
for an Invention of "IMPROVEMENTS IN APPARATUS FOR GRINDING LAWN
MOWER CUTTERS."
PROVISIONAL SPECIFICATION left by the said Thomas Henry Gillott at the
Office of the Commissioners of Patents on the 13th November 1882.
THOMAS HENRY GILLOTT, of Royston, in the County of Herts
IN APPARATUS FOR GRINDING LAWN MOWER CUTTERS
"
"IMPROVEMENTS
This invention relates to improvements in apparatus for grinding lawn mower
cutters whereby the construction of the apparatus is simplified, its length
diminished and its action rendered more easy.
In carrying out my invention I employ a trough or receiver provided with
bearings in which works a longitudinally slotted hollow shaft or sleeve provided
with a handle for rotating the same. Within the hollow shaft is placed a screw
threaded spindle, the said threaded spindle being fixed so as not to rotate with the
hollow shaft; on the threaded spindle works a nut having a projection which
extends through the slot in the hollow shaft and is fixed to a grindstone which is
placed on the hollow shaft so that it can slide thereon at the same time that it
revolves therewith. Adjustable or removeable bearings are provided to receive
the ends of the lawn mower cutter to be ground, motion being communicated to
the cutter either direct from the hollow shaft by a chain and chain wheels, or from
a carrier on the axle of the cutter operated by an adjustable spindle driven from
the hollow shaft by cog gearing, or a chain and chain wheels or equivalent means.
The operation of the apparatus is as follows:-
The ends of the axle of the cutter to be ground are placed in the bearings which
are then adjusted so as to bring the cutter up to the grindstone-The handle of"
the apparatus is then turned and the grindstone will revolve with and move along
the herein-before described hollow shaft against the cutter which also revolves
with the hollow shaft as herein before described; the grindstone can thus be moved
backwards and forwards against the cutter, the direction of the motion of the
grindstone being reversed by reversing the direction of rotation of the hollow
shaft

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Henry Gillott in the Great Seal Patent Office on the
12th May 1883.
THOMAS HENRY GILLOTT of Royston in the County of Herts, "IMPROVEMENTS
IN APPARATUS FOR GRINDING LAWN MOWER CUTTERS
"
This invention relates to improvements in apparatus for grinding lawn mower
cutters whereby the construction of the apparatus is simplified its length diminished
and its action rendered more easy.
In carrying out my invention I employ a trough or receiver provided with
bearings in which works a longitudinally slotted hollow shaft or sleeve provided
with a handle for rotating the same. Within the hollow shaft is placed a screw
threaded spindle the said threaded spindle being fixed so as not to rotate with
the hollow shaft; on the threaded spindle works a nut having a projection which
extends through the slot in the hollow shaft and is fixed to a grindstone which is
placed on the hollow shaft so that it can slide thereon at the same time that it
revolves therewith. Adjustable or removeable bearings are provided to receive
-the-ends.of.the lawn mower cutter to be ground motion being cominunicated to the
cutter either direct from the hollow shaft by a chain-and-chain-wheels,.or_from_a
carrier on the axle of the cutter operated by an adjustable spindle drivon from.
the hollow shaft by cog gearing or a chain aud chain wheels, or equivalent means..
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawing in which figure 1, is a plan;
figure 2,-is-n-front-elevation_and_figure 3, an end view of an apparatus for grinding
lawn mower cutters constructed according to my invention the apparatus-being-
operated by hand power and gearing; figure 4, is- a. longitudinal section on lino
A, B, of figure 1; figure 5, is a transverse section on line C, D of figuro 1; figure 6,
is an end view shewing the apparatus driven by power and a chain and chain
wheels. Similar letters in all the figures represent similar or corresponding parts.
In figures 1, to 5, a, is the trough or receiver provided with the bearings b; c, the
longitudinally slotted hollow shaft or sleeve working in the said bearings and
driven by the handle d; e, is the fixed screw threaded spindle within the sleeve c;
f, is the nut on the threaded spindle e; g, the projection of the said nut extending
through the slot h, in the sleeve or hollow shaft c, the said projection g, being
suitably fixed such as by means of a screw bolt i, to the grindstone j, which
grindstone j, can slide on the hollow shaft at the same time that it revolves
therewith;k, k, are the adjustable and removeable bearings fixed on the projecting
flange, of the trough a, the said bearings serving to receive the ends m, of the
lawn mower cutter ; o, is the carrier fixed on one of the ends m, of the cutter
spindle the cranked end of the carrier passing into the slot p, of the projection q,
on the spindler, working in the slotted brackets, by means of which slot t, and
the bolt u, the bracket 8, may be adjusted to compensate for wear; the spindler,
and consequently the cutter is driven by gearing v, vl, va, from the hollow shaft or
sleeve c, the intermediate wheel v', being adjustable in the slot w, or the cutter
may be driven from the hollow shaft c, by a chain and chain wheels.
The operation of the apparatus is as follows:-
The ends m, of the axle of the cutter n, to be ground are placed in the
bearings h, k, which are then adjusted by their hand screws k¹, k, so as to bring
the cutter n, up to the grindstone j. The handle d, of the apparatus is then turned
and the nut f, by means of the projection g, will cause the grindstone ; to revolve
with and move along the hollow shaft c, against the cutter n, which also revolves
with the hollow shaft c as herein before described; the grindstone j, can thus be

page_text: moved backwards and forwards against the cutter n, the direction or the motion of
the grindstone j, being reversed by reversing the direction of rotation of the hollow
shaft c.
When the grindstone j, has worn to such an extent that the slot p, is not long
enough to allow of the rotation of the carrier o, the bearing 8, of the spindle r, is
moved inwards and the intermediate wheel vl, properly adjusted; or instead of the
wheel, being adjustable a smaller wheel may be adapted as required for the
spindle r.
The arrangement shown in figure 6, is substantially the same as that herein-
before described except that in place of the gearing v, v², v³, chain wheels x, x', a³,
and a chain y, are employed which arrangement 'I prefer when the apparatus
is driven by power.
Having thus described my said invention and the best means I am acquainted
with for carrying the same into effect I would have it understood that what I
claim is:-
Firstly. The improved apparatus for grinding lawn mower cutters arranged and
operating substantially in the manner herein before described and represented in
the several figures of the accompanying drawing.
Secondly. In an apparatus for grinding lawn mower cutters the combination of
the slotted hollow shaft or sleeve, threaded spindle and nut, the said nut being
connected to the grindstone through the slot in the sleeve as and for the purposes
hereinbefore described and represented in the accompanying drawing,
Thirdly, In an apparatus for grinding lawn mower cutters the combination
with adjustable cutter bearings of a carrier such as that described operated from an
adjustable spindle substantially as and for the purposes set forth.
In Witness whereof I the said Thomas Henry Gillott have hereto set my
hand and seal this tenth day of May in the year of our Lord one thousand
eight hundred and eighty three