IMPROVEMENTS IN HYDRAULIC PRESSES
Year: 1880

page_text: LETTERS PATENT to James Watson, of Gloucester Crescent, Hyde Park, in
the County of Middlesex, Engineer, for an Invention of "IMPROVEMENTS IN
HYDRAULIC PRESSES."
PROVISIONAL SPECIFICATION left by the said James Watson at the Office
of the Commissioners of Patents on the 30th November 1880.
JAMES WATSON, of Gloucester Crescent, Hyde Park, in the County of Middlesex,
Engineer. "IMPROVEMENTS IN HYDRAULIC PRESSES."
My Invention has reference more particularly to the hydraulic press described in
the Specification of former Letters Patent granted to me, and dated the 28th
October 1869, No. 3123.
It has been found that when very great power is applied to this press the jute
or other material which is being compressed into a bale is sometimes forced down
between the bars or teeth of the "grid iron" or grid described in the said
Specification, and it cannot be freed therefrom without much difficulty and without
damage. The clearance or space between the bars or teeth of the grid has hitherto
been about 13ths of an inch, and this width has been necessary because the teeth of
the bottom follower, between which the grid teeth have to pass have been about
11th of an inch wide, this being the least width consistent with the requisite
strength.
Now my present Invention consists in so shaping the teeth of the grid and of
the bottom follower that the clearance between the former is sufficiently reduced
to prevent the jute or other material being forced to an inconvenient extent
between them, while the teeth of the follower still retain the necessary strength.
In carrying out my Invention I make the teeth of the grid wider at and near
their upper surface than at their other parts, and I make the upper part of the
teeth of the bottom follower correspondingly narrower at and near the points, so as
to allow of the widened portion of the grid teeth passing between them. The
teeth of the follower may, for example, be conical in section, and the grid teeth be
shaped like an inverted cone; but I prefer that the increased width of the grid teeth
shall extend for about, say, 2 inches from their upper surface, and then diminish
by a gradual taper until the old or narrower width of teeth is attained; the bottom

page_text: follower teeth being of corresponding shape are sufficiently wide at their lower
part to give them the requisite strength.
Without limiting myself to any particular width of clearance, I may say that the
reduction to one inch of the clearance between the grid teeth at their upper part
will generally be sufficient to prevent the material being forced to an inconvenient
extent between them.
Another advantage resulting from my Invention is that the upper part of the
bottom follower teeth being narrower than hitherto in proportion to the clearance
between the grid teeth at their lower parts, the liability of the points of the
bottom follower teeth striking against the grid teeth when not quite in position is
impossible, from the fact that the clearance of grid frame sideways in the press is
only ths of an inch either way from the middle position, while the points of the
bottom follower teeth have the clearance on each side when in the middle
position.
TO

page_text: SPECIFICATION in pursuance of the conditions of the Letters ratent nied by
the said James Watson in the Great Seal Patent Office on the 26th May
1881.
JAMES WATSON, of Gloucester Crescent, Hyde Park, in the County of Middlesex,
Engineer. "IMPROVEMENTS IN HYDRAULIC PRESSES."
My Invention has reference to hydraulic presses which have a grid iron or grid,
as described in the Specification of former Letters Patent granted to me, and dated
28th October 1869, No. 3123.
It has been found that when very great power is applied to this press the jute
or other material which is being compressed into a bale is sometimes forced down
between the bars or teeth of the grid, and it cannot be freed therefrom without
much difficulty and without damage. The clearance or space between the bars or
teeth of the grid has hitherto been about 13ths of an inch, and this width has been
necessary because the teeth of the bottom follower, between which the grid teeth
have to pass, have been about 11th of an inch wide, this being the least width
consistent with the requisite strength.
Now my present Invention consists in so shaping the teeth of the grid and of
the bottom follower that the clearance between the former is sufficiently reduced
to prevent the jute or other material being forced to an inconvenient extent
between them, while the teeth of the follower still retain the necessary strength.
In carrying out my Invention I make the teeth of the grid wider at and near
their upper surface than at their other parts, and I make the upper part of the
teeth of the bottom follower correspondingly narrower at and near the points, so
as to allow of the widened portion of the grid teeth passing between them. The
teeth of the follower may, for example, be conical in section, and the grid teeth be
shaped like an inverted cone; but I prefer that the increased width of the grid
teeth shall extend for about, say, 1 inch from their upper surface, and then
diminish by a gradual taper until the old or narrower width of teeth is attained;
the bottom follower teeth being of corresponding shape are sufficiently wide at
their lower part to give them the requisite strength.
The accompanying Drawing represents the grid and the bottom follower of a
press, with their teeth constructed as just described. a, a, are the grid teeth, and
b, b, the teeth of the bottom follower fixed into the follower c in any ordinary
manner. It will be seen that the grid teeth a, a, are of increased width at top,
this increased width extending down to the point 1, and it then diminishes by a
gradual taper to the point 2 until the old or narrower width of the teeth is
attained. The teeth b, b, are of sufficient width at their lower part to give them
the requisite strength, while they are narrowed at their upper part, as shown, to
correspond with the grid teeth a, a.
Without limiting myself to any particular width of clearance, I may say that
the reduction to one inch of the clearance between the grid teeth at the upper part
will generally be sufficient to prevent the material being forced to an inconvenient
extent between them.
Another advantage resulting from my Invention is that the upper part of the
bottom follower teeth being narrower than hitherto in proportion to the clearance
between the grid teeth at their lower parts, the liability of the points of the
bottom follower teeth striking against the grid teeth, when not quite in position is
impossible, from the fact that the clearance of the grid frame sideways in the press

page_text: is only
ths of an inch either way from the middle position, while the points of
the bottom follower teeth have 16 ths clearance on each side when in the middle
position.
In witness whereof, I, the said James Watson, have hereunto set my hand and
seal, this Eleventh day of May, One thousand eight hundred and eighty
one.
JAMES WATSON. (L.S.)