Improvements in Vacuum Boxes for Paper-making Machines.
Year: 1889

page_text: Date of Application, 24th Apr., 1889
Complete Specification Left, 22nd Jan., 1890-Accepted, 1st Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Vacuum Boxes for Paper-making Machines.
We, JOHN WOOD, of 82 Leith Walk, Leith, in the County of Mid Lothian, North
Britain, Engineer, and ROBERT Wood, of 531 St. George's Road, Glasgow, in the
County of Lanark, North Britain, Engineer, do hereby declare the nature of this
Invention to be as follows, that is to say :-
Our said Invention has for its object to improve the construction of vacuum boxes
for paper making machines, and to diminish the wear of the "wire" or endless wire
cloth which passes over the vacuum boxes.
In carrying out our Invention we provide two inner rollers for supporting the wire
in each vacuum box; and we provide two outer rollers one at the forward and the
other at the after side of the box, on brackets fixed to the outside of the box, the two
inner and two outer rollers being all carefully placed or adjusted so that their tops
may be in the same plane. The forward and after sides of the box are made with
their tops a little lower than the wire, and strips of rubber cloth or other suitable
flexible material are fixed along the tops in a manner to have their inner free edges
lying upon the outer upper parts of the two inner rollers nearly up to the lines
of contact of the wire. The middle parts of the inner rollers are supported and
prevented from sagging.by one or more sets of antifriction rollers carried in fixed
bearings within the box, each set consisting of a middle antifriction roller in contact
with both inner rollers and two other antifriction rollers which are in contact with
the lower outer sides of the inner rollers. The antifriction rollers are by preference
covered with rubber on their peripheries. The lower part of the vacuum box is
entirely in communication with the pipe or pipes leading to the vacuum pumps or
other suction apparatus excepting certain narrow parts extending inwards from the
ends, as far as may be required to suit the various widths of paper to be made on
the machine. At the parts referred to there are within the main box two small
narrow boxes made by preference of brass, and with flanges along the tops of their
forward and after sides in which flanges there are grooves holding strips of rubber
bearing up against the bottoms of the two inner rollers. In each small box there is
fitted to slide along it in close contact with its bottom and sides, a vertical plate or
block which also extends above the small box and has its upper part shaped to occupy
the space between the two inner rollers its front and back edges being nearly in contact
with them. Strips of rubber are placed in grooves in the front and back edges of
the plate or block to make airtight contact with the inner rollers and provision may
be made for squeezing them out into contact with the rollers. Screw spindles,
workable from the ends of the vacuum box, are provided for moving the vertical
plates or blocks inwards or outwards along the small boxes to suit the width of
paper to be made at any time. Provision is made for admitting water into the small
boxes at their outer ends so as to fill the spaces between the ends and the vertical
plates or blocks in order that if there is any leakage past the edges of the plates or
blocks water may pass rather than air. At each end of the vacuum box a sheet of
rubber cloth is fixed vertically so as to bear against the ends of the inner rollers the
internal vacuum causing the rubber cloth to cling closely to the ends of the rollers and
other parts
Dated this Twenty-third day of April 1889.
EDMUND HUNT,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Vacuum Boxes for Paper-making Machines.
We, JOHN WOOD, of 82 Leith Walk, Leith, in the County of Mid Lothian, North
Britain, Engineer, and ROBERT WOOD, of 531 St. George's Road, Glasgow, in the
County of Lanark, North Britain, 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, that is to say :-
Our said Invention has for its object to improve the construction of vacuum boxes
for paper making machines and to diminish the wear of the "wire " or endless wire
cloth which passes over the vacuum boxes.
In carrying out our Invention we provide two inner rollers for supporting the wire
in each vacuum box; and we provide two outer rollers one at the forward and one at
the after side of the box, on brackets fixed to the outside of the box, the two inner and
two outer rollers being all carefully placed or adjusted so that their tops may be in the
same plane. The space between the two inner rollers is put in communication with
the vacuum pumps or exhausting apparatus, and improved appliances are adopted to
prevent leakage of air into the said space and for adjusting its length to suit different
widths of paper.
And in order that our said Invention and the manner of performing the same may
be properly understood we hereunto append a sheet of explanatory drawings to be
hereinafter referred to and representing a vacuum box as constructed with our
improvements.
Figures, 1, 2, and 3, of the drawings are, respectively, a plan, a longitudinal
vertical section, and a transverse vertical section. In these drawings the same reference
numerals are used to mark the same or like parts wherever they are repeated.
The vacuum box, as delineated, is made with a wooden bottom, 4, wooden sides, 5,
and brass ends, 6; and in bearings in the ends, 6, are carried the two inner rollers, 7,
which may be driven in any convenient way so as to have the same surface speed as
the wire. Two outer rollers, 8, are carried on brackets, 9, fixed to the sides, 5, of the
box. The sides, 5, of the box, are made with their tops a little lower than the wire,
and strips, 10, of rubber cloth, or other suitable flexible impermeable material are
fixed along the tops in a manner to have their inner free edges lying upon the outer upper
parts of the two inner rollers, 7, nearly up to the lines of contact of the wire. The
middle parts of the inner rollers, 7, are supported and prevented from sagging by one
or more sets of antifriction rollers, 11, 12, carried in fixed bearings, 13, within the
box, each set consisting of a middle antifriction roller, 11, in contact with both inner
rollers, 7, and two other antifriction rollers, 12, in contact with the lower outer sides
of the inner rollers. The antifriction rollers, 11, 12, are by preference covered with
rubber on their peripheries. The lower part of the vacuum box is entirely in com-
munication with the pipe; 14, (or pipes) leading to the vacuum pumps or other suction
apparatus, excepting certain narrow parts extending inwards from the ends, as far
as may be required to suit the various widths of paper to be made on the machine.
At the parts referred to, there are within the main box two small narrow boxes, 15,
made by preference of brass, and with flanges, 16, along the tops of their forward
and after sides; upon which flanges, 16, strips, 17, of rubber or other suitable flexible
material are fixed so as to bear up against the bottoms of the two inner rollers, 7. In
each small box, 15, there is fitted to slide along it, in close contact with its bottom
and sides, a vertical plate or block, 18, which also extends above the small box and
has its upper part, 19, shaped to occupy the space between the two inner rollers, 7,
its front and back edges being nearly in contact with them. Strips of rubber may
be placed in grooves in the front and back edges of the upper part, 19, of the plate
or block, to make airtight contact with the inner rollers, 7; and provision may be
made for squeezing the rubber strips out into contact with the rollers. Instead of
rubber, sponge, 20, may be packed in between a fixed side of the upper part, 19, of
the plate or block, and a plate which can be adjusted by screws to squeeze out the

page_text: sponge into contact with the inner rollers, 7.
A strip of wood is fixed on the top of
the upper part, 19, of the plate or block to be in contact with the under side of the
wire. Screw spindles, 21, workable from the ends of the vacuum box, are provided
for moving the vertical plates or blocks, 18, 19, inwards or outwards along the small
boxes, 15, to suit the width of paper to be made at any time. Provision is made by
means of a hole, 22, for admitting water into each small box, 15, at its end, so as to
fill the space between the end and the vertical plate or block, 18, 19, in order that
if there is any leakage past the edges of the plate or block water may pass rather than
air. At each end of the vacuum box a sheet, 23, of rubber cloth is held vertically by
means of a plate, 24, so as to bear against the ends of the inner rollers, 7, the internal
vacuum causing the rubber cloth to cling closely to the ends of the rollers, 7, and
other parts, and more particularly to prevent leakage at the ends between the rollers
and the forward and after sides, 5, of the vacuum box. Also along the spaces, between
the rollers, 7, and the box sides, 5, we find it advantageous to place sponge, 25, on
shelves, 26, so as to be in contact with the rollers and to keep their surfaces uniformly
wet with water.
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. Combining, constructing, and arranging the parts of vacuum boxes for paper
making machines in the improved manner substantially as hereinbefore described and
as shown in the accompanying drawings.
2. In a vacuum box applying the suction to the wire between two rollers supporting
the wire and having their middle parts supported by antifriction rollers, combined
with appliances for preventing leakage of air down past the outer sides of the rollers,
and past vertical plates or blocks which are adjustable for different widths of paper,
substantially as herein before described.
3. The improved construction and arrangement of the narrow inner boxes with
their adjustable vertical plates or blocks substantially as and for the purposes herein-
before described.
Dated this Twenty-first day of January 1890.
EDMUND HUNT,
Applicants' Agent.