Improvements in or appertaining to Apparatus or Machinery for Polishing Plate-glass.
Year: 1891

page_text: Date of Application, 9th Jan., 1891
Complete Specification Left, 9th Oct., 1891-Accepted, 14th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Apparatus or Machinery for
Polishing Plate-glass.
We, WILLIAM SMITH of Sutton near St. Helens in the County of Lancaster
Engineer and HUDSON ATKINSON BINNEY of the London and Manchester Plate
Glass Company's Works, St. Helens, aforesaid, General Manager, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to polish plate glass without removing it from
the bed or table of what is commonly known as a disc machine upon which it
as to secure the
has already been ground and smoothed, in such a manner
greatest possible freedom from scratches or other defects generally caused by
particles of gritty matter left from the previous grinding and smoothing pro-
cesses getting between the polishing blocks and the surface of the glass to be
polished and also to secure the thorough polishing of every part of the glass
laid on the table or bed of the disc and to provide suitable and efficient
appliances therefor.
The manner in which we carry out the above is as follows. When the
grinding and smoothing operations have been completed by the disc machine in
common use, we remove in the ordinary manner the travelling bridge and runners
which have effected the grinding by means of sand and water, (and which can
only with great difficulty be freed from grit) from over the glass to be polished
to a position on one side of the disc there to remain during the whole of the
polishing operation.
We provide a polishing runner or runners each composed of a central boss
having a number of arms or spokes radiating therefrom at the outer ends of
which are held groups or clusters of polishing blocks covered with felt or other
suitable material for polishing. When the machine is at work each large
polishing runner is revolved on its axis by its contact with the glass on the
revolving disc and at the same time the clusters or groups of polishing blocks are
arranged to revolve freely on their own centres whilst travelling bodily in the
circular orbit determined by the length of the radial arms of the polishing
runner, this arrangement constantly varying the position of every block com-
posing a runner and securing the efficient distribution of the polishing material
to the whole surface of the glass.
Each cluster of blocks is not only free to revolve on its own axis but is free
also within certain limits to move vertically so that it may follow with perfect
freedom any slight undulations which may be left on the surface of the glass
when the smoothing process is finished but at the same time the centre of each
cluster is kept so far within the circumference of the disc that the polishing
blocks may be allowed to work considerably beyond the circumference of the
disc table so as to polish the corners of projecting glasses without having any
tendency to "tilt" or depart from the plane of the surface being polished.
Arrangements are made whereby the rotative movement of any particular
cluster, or the whole of them can be arrested should it be found desirable
to do so.
It is obvious that instead of using clusters of small polishing blocks, we could use
a single polishing block of large dimensions under the above conditions.
The polishing runner or runners are anchored in their proper working positions
over their revolving disc by means of radius rods one end of which fits upon the
centre pin of the polishing runner whilst the other end is attached to a pillar or.
other fixed point beyond the edge of the disc.

page_text: When the polishing operation is finished the polishing runners with the
polishing blocks attached and with their respective radius rods also connected
are raised up towards the ceiling of the workroom by suitable hoisting apparatus
and there held whilst the next set of glasses is laid, ground and smoothed ready
to be lowered into their respective positions for polishing as soon as the machinery
used for grinding and smoothing has been removed from over the glass. This method
of having one apparatus hoisted up while the other is at work obviates the
necessity of having two upper mechanisms or machines cumbering the floor of
the shop or making one machine do the double work with the requisite cleaning
and liability to cause scratches which this latter plan entails. The polishing
apparatus being hoisted up is out of the way of grit.
Dated this 9th day of January 1891.
W. P. THOMPSON & Co.,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or appertaining to Apparatus or Machinery for
Polishing Plate-glass.
We, WILLIAM SMITH of Sutton near St. Helens in the County of Lancaster,
Engineer and HUDSON ATKINSON BINNEY of the London and Manchester Plate
Glass Company's Works, St. Helens aforesaid, General Manager, 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 :-
as to
The object of this invention is to effect the polishing of plate glass, without
removing it from the bed or table of what is commonly known as a disc machine
upon which it has already been ground and smoothed, in such a manner
secure the greatest possible freedom from scratches or other defects generally
caused by particles of gritty matter, which are left from the previous grinding
and smoothing processes, getting between the polishing blocks and the surface
of the glass to be polished, also to secure the thorough polishing of every part
of the glass laid on the table or bed of such a disc machine, and, finally, to
provide suitable and efficient appliances therefor.
The manner in which the above is carried out is as follows, reference being had
to the accompanying sheets of drawings and to the figures and letters of reference
marked thereon: similar letters of reference indicate like parts in each of the
figures.
Figure 1 is an elevation of a portion of a shed having on its floor the ordinary
disc machine for grinding and smoothing, and suspended near the rafters, the
polishing apparatus forming a part of this invention.
Figure 2 is an end elevation of the shed, showing the grinding and smoothing
apparatus moved back from off the disc or table and in its place the polishing
apparatus lowered down thereon.
Figure 3 is a plan view of the apparatus on the floor of the shed as shown in
Figure 2.
Figures 4, 5 and 6 are respectively a top plan, a cross section and a bottom plan
of a cluster or group (hereinafter fully described) of polishing blocks, with connec-
tions to its arm.
The operations of grinding and smoothing the plate glass are completed by the
disc machine in_common_use; A, being the disc or table upon which the various
plates of glass B, B, B, B, are laid to be ground and smoothed and subsequently
polished.
The grinding and smoothing of the glass are effected by the ordinary grinding
and smoothing apparatus, consisting of the grinding runners C, C, which are shod
on their under surfaces with iron bars D, D. These runners are suspended by

page_text: the shafts E, E, from the regulating levers F, F, which are controlled by the
hand wheels and screws G, G, at each end of the travelling bridge H, H.
The travelling bridge H H can be propelled in either a forward or backward
direction by means of the hand wheels I, I, along the rails J, J.
After the grinding and smoothing operation is accomplished in the ordinary
manner, the travelling bridge H, H, and runners C, C, which have effected the
grinding and smoothing by means of sand and water (and which can only
with great difficulty be freed from grit) are removed from over the glass to be
polished to a position, as shown in Figures 2 and 3, on one side of the disc or
table A, there to remain during the whole of the polishing operation, which is
then carried on as follows:-
A polishing runner or runners is or are provided, (two are shown on the
drawings, as will be seen from Figure 3) each composed of a centre pin or
central stud having a number of arms or spokes radiating therefrom, at the outer
ends of which arms or spokes are held groups or clusters of polishing blocks,
covered with felt or other suitable material for polishing.
As will be seen from the drawings (Figure 3) the polishing runners (each
composed of the centre pin, or central stud U with lifting ring at top and with
radiating arms or spokes forming a frame or spider K, K) control the travel of
the clusters, groups or planet discs L L of polishing blocks, over the face of the
glass B, B, being polished.
The groups, series or clusters L, L, of polishing blocks are shown, in Figure 6 of
the drawings, as plates on which the polishing blocks M, M, are cast, but the
polishing blocks M, M, may be separate and independent of each other, and be
afterwards rigidly connected to form the cluster or group L.
The polishing blocks M, M, are shown, five in number, and circular in shape, but
this is not of importance, the groups or clusters L, L, may be formed of more or
less than five polishing blocks, and the latter may be of any shape.
At or near the centre of each group or cluster is a projecting pin or stud N, N,
which fits loosely in the bushes fixed in the outer ends of the radial arms or
spokes K K of the polishing runner, so that the group or cluster may be free to
revolve on its axis.
A nut or collar O is screwed on the upper end of the stud N, Figure 5, and the
length of the stud, from the point V, where it leaves the casting of the cluster or
group to the collar O, is about half an inch longer than the bush through which it
passes, so that each cluster or group L, L, of polishing blocks may rest freely on
the glass immediately below it when in work. When the machine is at work, each
large polishing runner is revolved on its axis by contact with the glass on the
revolving disc, and at the same time the clusters or groups L, L, of polishing blocks
can revolve freely on their own centres whilst travelling bodily in the circular
orbit determined by the length of the radial arms or spokes K K of the polishing
runner.
By this arrangement, the position of every block M, composing a runner, is con-
stantly varied, and an efficient distribution of the polishing material to the whole
surface of the glass is secured.
Each one of the clusters or groups L, L, of polishing blocks, is not only free to
revolve around its own axis, but is free also, within certain limits, to move
vertically, so that it may follow with perfect freedom any slight undulations which
may be left in the surface of the glass when the grinding and smoothing process is
finished, but, at the same time, the centre of each one of such clusters or groups
kept so far within the circumference of the disc or table A that the polishing
blocks M M may be allowed to work considerably beyond the circumference of the
disc or table, so as to polish the corners of projecting glasses without having any
tendency to "tilt" or depart from the plane of the surface being polished, as will
be clearly seen from Figure 3.
If the covering of felt or other polishing material of the clusters or groups L, L,
become torn or injured, or if, from any other cause, it be desired to arrest. the

page_text: rotary movement of any one of the clusters or groups L, L, of the polishing
blocks M M, and it be desired to keep any one or more of such polishing blocks on
the smooth plane of the glass, the pin 1', Figure 5, is dropped through the hole Q,
in the arm of the polishing runner, into one of the corresponding holes in the back
of such group or cluster.
It is obvious that, instead of using groups or clusters of small polishing blocks, a
single polishing block of large dimensions could be used under the above conditions.
The polishing runner or runners are anchored, in their proper working positions
over the revolving disc or table A, by means of radius rods or arms R R, one end
of which fits upon the centre pin or central stud U of the polishing runner, whilst
the other end is attached to a pillar or other fixed point S S, beyond the edge of
the disc or table.
The radius rods or arms stand at an angle of 90° more or less with each other as
shown in Figure 3, but, when the polishing operation is completed, they are
released from the pillars S, S, and are hoisted with the polishing runners until clear
of the pillars, when they are then set directly opposite each other and there secured
in any suitable or convenient manner, such as by catches on the ends of the radial
arms or spokes K K, of the polishing runners.
The object of supporting the radius rods or arms R, R, and holding them firmly
in such a position across the polishing runner is that each polishing runner, with its
clusters or groups L, L, and radius rods or arms R, R, may be evenly balanced,
ready for hoisting to the ceiling of the workroom, as shown in Figure 2, after the
polishing operation has been completed.
When the polishing operation is finished, the polishing runners, with the groups
or clusters of polishing blocks L, L, attached, and with their respective radius rods
or arms R R also connected, are raised towards the ceiling of the workroom by
suitable hoisting apparatus and there held whilst the next set of glasses is laid,
ground and smoothed, when they-the polishing runners-will be ready to be
Lowered into their respective positions for polishing as soon as the machinery used
for grinding and smoothing has been removed from over the glass.
The hoisting apparatus, as shown in Figure 2 of the drawings, is composed of a
hydraulic cylinder T, with the usual pulleys, chain and counterpoise weight and
valve arrangements for hoisting and lowering the polishing runners as required.
To make the hoisting operation, as much as possible, automatic, any ordinary
trigger or catch arrangement may be provided for automatically catching the
crosshead of the hydraulic apparatus immediately the polishing runners are hoisted
to the position shown by dotted lines in Figure 2, and for holding same until the
polishing runners require to be lowered.
This method of having one apparatus hoisted up whilst the other is at work
obviates having two travelling carriages or upper mechanisms, and, if a single
carriage be used for the three processes, the cleaning and liability to scratches in
such an arrangement. The polishing apparatus being hoisted up is out of the way
of grit
Further, by constructing the polishing runners with the clusters or groups L Lat
an equal distance from the centre pin or central stud U, the total weight of the
polishing runner and a large proportion of the weight of the radius rods or arms R R
are distributed by means of the arms or spokes K K over the clusters or groups LL,
and, by having the blocks M M of each cluster or group equally distant from the
pin or stud N, it follows that the combined weight of the polishing runner (with a
large proportion of the weight of the radius rods or arms) and of the clusters or
groups L L are again equally distributed over each of the blocks M M of such
clusters or groups.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The combination of an ordinary grinding and smoothing disc having a travelling

page_text: carriage with an independent polishing apparatus capable of being raised toward
the ceiling or roof of the workshop and of being kept there during the grinding
and smoothing process and of being lowered into position and securely anchored on
the surface of the glass when the latter is ready to be polished.
2. In a glass polishing machine one or more rotatable frames K carrying groups
of blocks L also free to rotate on their axes substantially as described.
3. Making these subsidiary groups with further subsidiary blocks M.
4. So arranging the apparatus that parts of the groups of blocks or their
subsidiary blocks M when at their furthest points from the centre of the disc A
carrying the glass shall project beyond the edge of the said disc far enough to
polish the projecting corners of glass without having any tendency to tilt the centre
of gravity of each group of blocks being at all times inside the circumference of the
disc A which carries the glass.
5. The application of a locking device in combination with the groups L by
which when desired they can be prevented from rotating on their axes so that any
portion of the felt or other material used for polishing which may be torn can be
prevented from going beyond the circumference of the disc carrying the glass.
Dated this 8th day of October 1891.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London,
Agents for the Applicants.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London,
Agents for the Applicants.