IMPROVEMENTS. IN THE MANUFACTURE AND CONSTRUCTION OF HOODS FOR VENTILATORS
Year: 1864

page_text: LETTERS PATENT to Robert Holt, of Little Lever, near Bolton, in the
County of Lancaster, Terra Cotta Manufacturer, for the Invention of
"IMPROVEMENTS. IN THE MANUFACTURE AND CONSTRUCTION OF HOODS FOR
VENTILATORS."
Sealed the 17th February 1865, and dated the 16th September 1864.
PROVISIONAL SPECIFICATION left by the said Robert Holt at the
Office of the Commissioners of Patents, with his Petition, on the
16th September 1864.
I, ROBERT HOLT, of Little Lever, near Bolton, in the County of Lan-
caster, Terra Cotta Manufacturer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE AND CONSTRUCTION
OF HOODS FOR VENTILATORS," to be as follows:-
My Invention consists in manufacturing the revolving hoods of ventilators
of terra cotta or other earthenware instead of sheet metal, as heretofore
customary..
. My improvement in the construction of the revolving hoods of ventilators
consists in making a small opening through the back of the hood opposite the
main orifice for assisting the draught. The chimney top is also made of
terra cotta or other earthenware, as in chimney tops without hoods' of the
present construction; the pivot for the hood is also made as usual. By thus
manufacturing the revolving hoods of ventilating chimney tops they are
rendered much more durable and less expensive.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Holt in the Great Seal Patent Office on the
11th March 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
HOLT, of Little Lever, near Bolton, in the County of Lancaster, Terra Cotta
Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of September, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Robert Holt, Her special license that I, the said Robert
Holt, my executors, administrators, and assigns, or such others as I, the
said Robert Holt, my executors, administrators, and assigns; should at any-
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully miglit make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel-Islands, and Isle of Man, an Invention for." IMPROVEMENTS IN
THE MANUFACTURE AND CONSTRUCTION OF HOODS FOR VENTILATORS," upon the
condition (amongst others) that I, the said Robert Holt, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the naturė
of the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Robert Holt, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
. My Invention consists in manufacturing the revolving hoods of ventilators of
terra cotta or other earthenware instead of sheet metal, as heretofore customary.
My improvement in the construction of the revolving hoods of ventilators
consists in making a small opening through the back of the hood opposite the
main orifice for assisting the draught. The chimney top is also made of
terra cotta or other earthenware as in chimney tops without hoods of the
present construction; the pivot for the hood is also made as usual. By thus
manufacturing the revolving hoods of ventilating chimney tops they are
rendered much more durable and less expensive.

page_text: And in order that my Invention may be fully understood and readily carried
into operation, I will proceed to describe the accompanying Sheet of Draw-
ings, reference being had to the figures and letters marked thereon.
Figure 1 is a sectional elevation, and Figure 2 a front view of a.chimney
top to which my improved ventilating hood is applied; Figure 3 is a plan of
the said hood.
a is the chimney top, which is made as usual of terra cotta or any other
suitable material; b is the improved ventilating hood, which, instead of being
made of sheet metal as now customary, is made of terra cotta or other
earthenware.
In manufacturing my improved hoods a mould is made of the form and
size required, which is filled with terra cotta in a plastic state; the hood is
then dried and baked in an oven or stove as in manufacturing other articles
of terra cotta. The vane c is also made of terra cotta detached from the
hood, but secured to it by a bolt, the head of which serves as socket for the
top of the pivot or spindle d, the lower end of which is supported in a foot-
step in the cross rail e, fixed in the chimney top; the cross railf for guiding
the spindle d is also fixed in the chimney top, and the cross rail g is fixed to
the hood. By this arrangement the hood is firmly connected to the chimney
top and free to swivel with the least wind. The main advantage of my
Invention is to increase the durability of ventilating hoods and to reduce
their cost. The dotted lines h in Figure 1 represent a small opening through
the back of ventilating hoods to assist the draught, and in order to prevent the
admission of strong currents of air I place a guard or screen in front of the
opening.
Having thus stated the nature of my Invention, and described the manner
of performing the same, I declare that I claim,-
First, manufacturing the hoods of chimney tops of terra cotta or other
earthenware.
And, secondly, the application of an opening h in ventilating hoods as
described.
In witness whereof, I, the said Robert Holt, have hereto set my hand
and seal, the Ninth day of March, One thousand eight hundred and
sixty-five.
ROBERT HOLT. (L.S.)