An Improved Plan of Temporary PARTES or other Materials on Tables.
Year: 1887

page_text: Date of Application, 18th June, 1887
Complete Left, 19th Mar., 1888
Complete Accepted, 4th May, 1888
An Improved Plan of Temporary PARTES
or other Materials on Tables.
1 ROBERT THOMPSON of King Street Wigan in the County of Lancaster Engineer
AN IMPROVED PLAN OF
do hereby declare the nature of my invention for
TEMPORARILY FIXING SHEETS OR SLABS OF GLASS OR OTHER MATERIAL ON TABLES
to be as follows :-
Instead of using Cement or Plaster of Paris for the purpose of temporarily fixing
Sheets or Slabs of Glass or other Material to Stone or tables for the purpose of
Grinding or Polishing them, I fix them by means of a vacuum formed in suitable
spaces or vessels in or on the table and so creating a pressure nearly equal to that of
the atmosphere on the sheet or Slab to be fixed over Spaces or Vessels so placed. I
make the bed or table for receiving the sheet or slab to be operated on by preference
of cast iron in one or more parts. This bed or table consists of a plate or plates with
openings through it for receiving the vessels afterwards described and having flanges
round each plate so that if required they can be bolted together and if necessary with
ribs or flanges for strengthening them where required. On this bed or plate at the
openings above referred to I fix short circular guides by preference of cast iron by
means of flanges round each guide or I sometimes cast flanges round each opening
and into each of these guides or openings I fit a circular vessel. I make these
vessels open on the top with flanges at that part and I fix a ring of Rubber or other
soft or elastic substance in a groove turned on the upper flange. I bore out the circular
guide or openings and turn up the vessels on their outsides so that the latter will fit
into the former and be free to rise and fall in them. Between the underside of the
flanges on the vessels and the upper faces of the guides or openings I sometimes
insert a spiral or other spring so that the vessel will be kept up to the sheet or slab
to be placed on it before the vacuum is applied so as to cause it to adapt itself to any
irregularity in the sheet or slab to be fixed. 1 connect these vessels with each other
and with a vacuum pump or vessel through holes in their lower sides by means of

page_text: Rubber tubes and other pipes. L.provide for an accidental breakage of the sheet or
slab over any of the vessels by an elastic diaphragm a piston or a self acting valve
inside each vessel.
By this means I prevent such fracture or any sudden inrush of air from destroying
the vacuum in any but the particular vessel or opening in which it may have
occurred.
By opening the communication between the vacuum pump or vessel and the vessels
or openings in the table and creating a vacuum in them after the sheet or slab
has been placed on the table I fix the sheet or slab to the vessels or openings so long
as the vacuum is maintained in them by means of the atmospheric pressure, and by
means of the vessels so attached to the sheet or slab and the guides attached to the
table or bed the sheet or slab is able to resist the friction on its surface caused by the
grinding or polishing operations.
By admitting the air to the vessels on the table I liberate the sheet or
slab so that it can be removed or turned as required. If necessary I fill up the
spaces on the bed or table between the vessels with cement or other material to about
the level of the upper sides of the vessels when at rest so as to support those parts
of the sheet or slab not resting on the vessels. Instead of separate vessels and guides
as described I sometimes make the upper part of the bed or table of stone or cement
with a space between it and the solid bottom of the table and I make suitable
openings through the stone or cement which communicate with the space below the
same I cover the upper part of the table so arranged with sheet Rubber or other
elastic material upon which I place the sheet or slab to be fixed and by exhausting the
air out of the lower space and the openings I draw down the elastic sheet and so fix
the sheet or slab by atmospheric pressure over the openings.
Dated this Seventeenth day of June 1887.

page_text: or other Materials on Tables.
I ROBERT THOMPSON late of King Street Wigan and now of 18 Chapel Street
Liverpool both 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 :-
Instead of using Cement or Plaster of Paris for the purpose of temporarily fixing
Sheets or Slabs of Glass or other materials to stone or tables for the purpose of
Grinding or polishing them, I fix them by means of a vacuum formed in suitable
spaces or vessels in or on the table and so creating a pressure nearly equal to that
of the atmosphere on the sheet or slab to be fixed over the spaces or vessels so placed.
I make the bed or table for receiving the sheet or slab to be operated upon by
preference of cast iron in one or more parts. This bed or table consists of a plate or
plates with openings through it or them for receiving the vessels afterwards described
and having flanges round each plate so that if required they can be bolted together
and if necessary I cast ribs or flanges on the plates for strengthening them where
required.
On this bed or table at the openings above referred to I fix short circular guides by
preference of cast iron, by means of flanges round each guide or I sometimes cast
flanges round each opening. I bore out these vessels and form the upper parts of
them so as to secure spiral springs round them and having a raised part to receive
the vacuum vessels when loaded with the sheets or slabs. I fit an open topped circular
vessel into each of these guides and turn it up so that it can freely rise or fall in
them. I cast a flange round these vessels at their upper part and I make a recess in
the top of each of these flanges into which I place a circular ring of india rubber or
other soft or elastic material. I make this elastic ring thick enough to stand clear of
the vacuum vessels.
Between the underside of the flanges on the vacuum vessels and the lower part of the
recess turned in the flanges of the guides 1 fit a spiral or other spring of sufficient
elasticity to raise the vacuum vessels slightly froin their seats on the flanges of the
guides.
By this means the vacuum vessels stand above the rest of the table when not loaded
with the sheets or slabs and they will adapt themselves to any slight irregularity in
the sheet or slab to which they have to be fixed. I connect these vacuum vessels with
each other and with an air pump or vacuum reservoir by means of elbows through
their lower sides, elastic tubes and pipes.

page_text: I fit a tap or taps to the main pipe at or near the outside of the table so that I can
connect the vacuum vessels with the air pump or with the atmosphere or isolate them
as desired. I provide for an accidental breakage of the sheet or slab over any of
the vacuum vessels by an elastic diaphragm or by preference by a self acting valvo
insido each vacuum vessel and I support and keep this self acting valve open in its
normal state by a spiral or other spring. By this means I prevent the effect of an
accidental breakage of the sheet or slab over any vacuum vessel from extending
beyond that vessel. By opening the communication between the air pump or vacuum
reservoir and the vacuum vessels in the table after the sheet or slab has been placed
on them I create a vacuum in each vessel and so fix them to the sheet or slab so long
as a vacuum is maintained in them and by means of the guides fixed or cast
to the table the vacuum vessels and with them the sheet or slab is prevented from
being moved end ways or sideways whilst being ground or polished on its upper side.
By closing the communication between the vacuum vessels and the air pump or
vacuum reservoir and by opening the communication between the vacuum vessels and
the atmosphere I liberate the sheet or slab so that it can be removed from the table or
turned over as required.
I fill up the spaces round the vacuum vessels and guides and the flanges round the
table to the level of the upper side of these vessels and flanges with cement or other
material make this intermediate part smooth and level and I fix strips of soft
material such as india rubber, thick cloth or felt on this bed so as to form a soft.
support for the sheet or slab not supported by the vacuum vessels and I arrange so
that the sheet or slab shall be evenly supported by this soft bed and by the
india rubber rings on the vacuum vessels when the vessels are resting on their solid
seats.
It will thus be seen that when one or more sheets or slabs have to be fixed on the
table they are laid on the india rubber rings on the vacuum vessels which are raised
slightly above the general body of the table by the springs. As soon as the weight
of the sheet or slab rests on the vacuum vessels they are pressed down on their seats
and at the same time the rest of the sheet or slab rests on the soft bed between the
vacuum vessels. As soon as the communication is opened between the vacuum vessels
and the air pump the vacuum vessels fix themselves to the underside of the sheet or slab
but being held in position by the guides the sheet or slab is secured from any lateral or
end movement when being ground or polished. In the accompanying drawings which
I have numbered III III and IV respectively Drawing No. I is a plan of the table for
an ordinary plate glass polishing machine. Drawing No. II is a longitudinal section
through the same showing the vacuum vessels by crosses in the plan and in
outline in the section. Drawings Nos. III & IV are enlarged sections of vacuum
vessels showing the guides cast with the table in No. IV and showing them fitted to
the table in No. III and the self acting valves in them and also showing a part of
the table with the soft bed and the sheet of glass before the vacuum vessels are
pressed down by it. In Drawings Nos. I & II x is the moveable table of an ordinary
polishing machine for plate glass A, A, A are the cast iron tables shown in three
parts fitted into it B, B, B are the vacuum vessels shown by crosses in the plan and
in outline only in the section. The pipes connecting the vacuum vessels and towards
the air pump are indicated by dotted lines in the plan and are marked a, b. In
Drawings Nos. III & IV A, A, are parts of the cast iron tables A', A' are the guides
for the vacuum vessels B is one of the suction vessels C is the india rubber or other
elastic ring on it D is the self acting valve E is the elbow pipe passing through the
lower part of the suction vessel and secured to it by the nut F G is an india rubber
or other elastic pipe leading to the main pipes below the body of the table by means
of which the vacuum vessels can rise or fall in the guides without interfering with
the vacuum in them H is the cement packing and K the soft top on it for supporting
the sheet or slab between the vacuum vessels I is the spiral spring for raising the
vacuum vessels when not loaded J is the spiral spring for supporting and keeping
the self acting valve open in its normal state. L is the sheet or slab of glass or other
material to be temporarily fixed on the table.

page_text: 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 I do not
claim the use of atmospheric pressure for fixing sheets or slabs on tables but I do
claim
1. The method of temporarily fixing sheets or slabs on tables by means of
independent vessels attached to them by suction and which vessels when so fixed are
free to rise and fall vertically but are prevented from moving laterally or endways by
the guides fixed to the table.
2. The method of raising the vacuum vessels above the ordinary level of the
table by means of springs between the flanges on them and the guides.
3. The method of supporting the sheet or slab by the flanges of the vacuum vessels
resting on the guides and by the bed of the table.
4. The arrangement of the india rubber rings on the vacuum vessels which form
air-tight joints with the sheet or slab and the soft bed of the table for supporting the
sheets or slabs.
5. The self acting air valve raised off its seat by the spiral springs but free to fall
and close by any sudden inrush of air in any of the vacuum vessels.
Dated this Seventeenth day of Mauch 1000
ROBT. THOMPSON.