Improvements in or appertaining to Apparatus or Machinery for Grinding and Smoothing Plate Glass and other Hard Surfaces.
Year: 1890

page_text: Date of Application, 19th May, 1890
Complete Specification Left, 18th Feb., 1891-Accepted, 21st Mar, 1891
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Apparatus or Machinery for
Grinding and Smoothing Plate Glass and other Hard Surfaces.
I, WILLIAM SMITH, of Sutton, near St. Helens, in the County of Lancaster,
Engineer, do hereby declare the nature of this invention to be as follows :-
The runners which have hitherto been employed for grinding glass are strong
frames of wood or metal, covered on the underside with wooden planks, to which
are attached bars of iron with intervening spaces, the grinding of the glass being
effected by the iron bars through the medium of sand and water.
This runner,
whilst fully answering its purpose for grinding, is not suitable for the finer operation
of smoothing, because of the difficulty of washing it so free from sand when the
grinding is finished, as to prevent scratches being made in the surface of the glass
during the smoothing operation.
The object of my invention is to construct a runner which shall be an efficient
grinder, and at the same time capable of being so easily washed free from sand when
the grinding is finished that the smoothing operation may immediately follow without
removing the glass or changing the runner.
For this purpose, I construct a strong rigid runner frame to which I attach metal
grinding plates direct, without the intervention of any other foundation than the
rigid runner frame. These plates are so formed that, whilst sand and water pass
freely through for the purpose of grinding, small pebbles in the sand or pieces of
cullet which may get in the runner by accident will be readily thrown out without
risk to the glass. The grinding plates may be in one or more pieces, but they are
so arranged as to present, in all positions of the runner, a true plane to the surface
of the glass, so that grooves or ridges shall not be left on the glass in any part of
the operations.
One plan of doing this is as follows:-
The grinding plate or plates have slots or vacant spaces so arranged that the
plate of glass throughout its area shall, as near as possible, have in every part an
equal amount of rubbing, and the slots are so proportioned, shaped and arranged as
to have a tendency, while the plate is in motion, to plough any larger grains, small
pebbles or pieces of cullet to the outside and throw them off the edge of the plate.
The grinding plate may be made in one piece, thus dispensing with the rigid
frame for connecting and keeping the plates in position when made up of 2 or more
pieces.
Provision is made for adding weight to the runner as the plates wear thinner so
as to keep up its grinding power.
The improved runners are applicable to every form of grinding machine, whether
known as overhead, fly frame with double or treble runners, revolving discs or any
other description.
Dated this 17th day of Max 1890
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in or appertaining to Apparatus or Machinery for
Grinding and Smoothing Plate Glass and other Hard Surfaces.
I, WILLIAM SMITH, of Sutton, near St. Helens, in the County of Lancaster,
Engineer, 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 runners which have hitherto been employed for grinding glass are strong
frames of wood or metal, covered on the underside with wooden planks, to which
are attached bars of iron with intervening spaces, the grinding of the glass being
effected by the iron bars through the medium of sand and water. This runner,
whilst fully answering its purpose for grinding, is not suitable for the finer operation
of smoothing, because of the difficulty of washing it so free from sand when the
grinding is finished, as to prevent scratches being made in the surface of the glass
during the smoothing operation.
The object of my invention is to construct a runner which shall be an efficient
grinder, and, at the same time, capable of being so easily washed free from sand
when the grinding is finished that the smoothing operation may immediately follow
without removing the glass or changing the runner.
For this purpose, I construct a strong rigid runner frame to which I attach metal
grinding plates direct, without the intervention of any other foundation than the
rigid runner frame. These plates are so formed that, whilst sand and water pass
freely through for the purpose of grinding, small pebbles in the sand or pieces of
cullet, which may get in the unner by accident, will be readily thrown out without
risk to the glass. The grinding plates may be in one or more pieces, but they are
so arranged as to present, in all positions of the runner, a true plane to the surface
of the glass, so that grooves or ridges shall not be left on the glass in any part of
the operations.
The improved runners are applicable to every form of grinding machine, whether
known as overhead, fly frame with double or treble runners, revolving disc, or any
other description.
The drawings show the invention as applied to two different kinds of machine for
grinding plate glass.
Figure 1 is a front elevation of one form of an "overhead" machine, in which
A is the runner, driven in a circular orbit by the crank B, and also revolving on
its own centre by reason of its friction on the glass C, while travelling round the
crank circle.
Figure 2 is a plan of the runner and the glass being ground.
Figures 3 and 4 are respectively section and plan of underside of one of the
grinding plates.
The runner, in this case, is shown as composed of a strong and rigid frame of
wood a, to which is secured, by means of T headed bolts, (or other suitable mode
of fastening) the 4 metal plates a¹'a' a'a', which perform the grinding and smoothing
operations. These plates are made with long slots a² a² running from near the
centre of the runner towards the ends thereof, so that any foreign substance, such
as pebbles, cullet, etcetera, which may be thrown accidentally into the runner along
with the sand used for grinding, will be thrown centrifugally to the outer end of
the slot and so be dropped over the edge of the glass C, the outer ends of the
slots a² being arranged to reach beyond the edge of the glass C.
Cross passages or spaces a³ a³ from one slot to another are also provided, so that,
during the grinding and smoothing operations, every part of the runner may be fed
with sand for grinding or emery for the finer process of smoothing.
DD are pockets for holding weights which can be used to compensate for the
loss of weight sustained by the runner, owing to the wear of the grinding plates.

page_text: and
Figure 5 shows a front elevation, partly in section, of a revolving disc machine,
Figure 6 is a plan showing the table E, upon which the glass C (Figure 5) is
laid and also the runners A A' by means of which the grinding and smoothing of
the glass are to be effected. The runners A¹ A¹ are shown in this case with
strong rigid frames of metal A2 A2, secured to the vertical shafts F F. The
metal grinding plates a¹ a', for grinding and smoothing, may be fastened to the
rigid frame by means of T headed bolts or other approved mode of fastening, so as
to admit of being easily and quickly changed when worn out.
The plates aa¹ are constructed in a manner substantially the same as those
shown in Figures 1 to 4, being provided with slots a² a² for the discharge of pebbles,
etcetera, over the edge of the glass C, and with cross passages or spaces a³ a³ for
the purpose described.
If desired, the grinding plate may be made in one piece, thus dispensing with
the rigid frame for connecting and keeping the plates in position when made up of
2 or more pieces.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. A runner or runners having the grinding or smoothing plates attached to the
runner frame direct without the intervention of any other foundation, substantially
as described.
2. Grinding or smoothing plates constructed with slots and cross passages formed
in the plates themselves, substantially as and for the purposes described.
Dated this 17th day of February 1891
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.