IMPROVEMENTS IN GREENHOUSES, AND SPECIALLY RELATING TO THE FIXINGS, PROVISIONAL SPATION
Year: 1866

page_text: LETTERS PATENT to Thomas Hungate Preston Dennis, of Chelmsford,
in the County of Essex, Horticultural Builder, for the Invention of
"IMPROVEMENTS IN GREENHOUSES, AND SPECIALLY RELATING TO THE FIXINGS,
PROVISIONAL SPECIFICATION left by the said Thomas Hungate Preston
Dennis at the Office of the Commissioners of Patents, with his Petition,
on the 17th May 1866.
I, THOMAS HUNGATE PRESTON DENNIS, of Chelmsford, in the County of
Essex, Horticultural Builder, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN GREENHOUSES, AND SPECIALLY RELATING TO THE
FIXINGS, FITTINGS, VENTILATION, AND SHADING OF THE SAME," to be as follows:--
First, as to the fixings, I attach iron or other metal eyes on plates to the
building or wall against which the greenhouse is to be placed some few inches
below the ridge line; the ridge or fixing plate is then fitted up close to the
wall, having mortices in it to allow the eyes to project through; wedges or
keys are then passed into these eyes, which force and secure the ridge or
fixing plate firmly to the building or wall; the rafters, end studs, and other
parts can then be attached to the ridge or fixing plate with screws or nails in
the usual manner. The whole can be removed by withdrawing the wedges or
keys. Or when the ridge can be brought to the top of the back wall the
following plan may be used :-A metal cramp or holdfast made of wrought

page_text: iron by preference is made to lay upon the top, and with one end turned down
over the side of the back wall, the other end to run past and overhang the
upright line of the back wall on the side against which the greenhouse is to
be fixed. In this projecting or overhanging part a long hole will be made,
and a knee or angle piece will then be fixed upon the top of the cramp or
holdfast at right angles with it, and flush with the upright line of the wall;
or this knee or angle piece may be formed out of the solid by punching the
hole on three sides only, and 'turning the piece thus punched backwards and
upwards until flush with the upright line of the wall; it is against these knees
or angles that the ridge or fixing plate (which in this case will stand partly above
the top of the wall) rests. These cramps or holdfasts will then be laid upon
the back wall at distances varying from 3 to 6 feet, and when so laid the ridge
or fixing plate (having mortices in it to allow the ends of the cramps or hold-
fasts to project through it) is then fitted up close to the wall with part of its
depth standing above the top of the wall; wedges or keys aro then passed
through the long holes of the cramps or holdfasts which force and secure the
ridge or fixing plate firmly to the back wall; the rafters and other con-
structional parts can then be attached to the ridge or fixing plate in the usual
manner, and the whole can be removed by withdrawing the wedges or keys.
The fittings will consist of metal fastenings to support and retain the sashes in
their places, and also front mullions to support the eaves plate. The ventilators
in the front and at the apex of the roof are connected by means of a hempen
rope, wire, chain, or other suitable material passing over pullies, and thence
to a long connecting rod, which being moved backwards or forwards by means
of a rack and wheel or other leverage opens or shuts the ventilators simul-
taneously.
A second plan of ventilation may be arranged at the lower part of green-
houses by building the front dwarf brick wall one foot six inches, or any other
suitable distance back from the front plate, and running out piers at intervals
of from three to four feet to support the front plate, thus forming a space
between the front plate and the wall, which being covered by a hinged or
sliding shutter forms the ventilator.
A third system of ventilation may be carried out by having a given width
of the gable end of the greenhouse directly under the end rafter, and a part or
the whole of its entire length made to open inwards, outwards, or to slide, or
in any other convenient manner, so that the aperture thus formed may direct
the current of air directly under the glass or other roof, the same arrange-
ment to be repeated at each end of the building, and it may be continued of
any suitable width from the lower part of the end rafter to the ground line, or

page_text: any part of such distance. In buildings of great lengths it
may be necessary
to have additional openings in the roof from the ridge to the eaves, which
may in some cases be extended down to the ground line. In case of divisions
being fixed in the building the same system will be carried out, but the
ventilators will be double, or so arranged that a current of air can be directed
through one compartment only, or made to traverse any number of com-
partments; these ventilators may also be made to slide or lift, or open in any
convenient manner.
As to shading, my improvements consist in the arrangement of certain
pullies and grooved or flanged travelling wheels, ratchets, and pauls, so as to
prevent the irregularity in the rolling up or down of blinds upon an inclined
surface which has hitherto been experienced from the inequality in diameter
between the blind and its roller or end at the various stages of its course up
or down a roof or from its increased or diminished bulk when wet or dry. To
accomplish this I fix one end of the blind to the roof or the ridge of the
greenhouse, and the other end to a roller which may be made of any suitable
material, and of any desired diameter; the roller will be made to run up or
down the roof upon guide bars, and will be worked by ropes or chains from
the interior of the greenhouse. At each end of the blind roller is fixed a
small pin, and a ratchet is attached to each of these pins. Two grooved
travelling wheels each of a different diameter are also fitted to and revolve
one upon each of these pins, and having pauls fitted to them, which catch
into the ratchet above described and prevents them revolving in but one
direction. In unrolling the blind the larger travelling wheel becomes fixed
to the roller by one of its pawls falling into the ratchet, and causing the roller
to travel with it. The circumference of this wheel being greater than that
of the roller, it has a tendency to get in advance of it, as it travels over more
space at each revolution than the length of blind given out by the roller; this
tendency effectually prevents the blind getting slack in unrolling. The
grooved travelling wheel at the opposite end (although it is of a smaller
diameter) from the fact of its revolving upon a pin is free to make more
revolutions than the larger, and thus is enabled to keep pace with it. In
rolling up the blind the small travelling wheel becomes fixed to the roller by
one of its pauls falling into the ratchet and causing the roller to travel with
it; the circumference of this wheel being smaller than that of the roller, it
travels over less space than the length of blind taken up by it at each revo-
lution, thus causing the blind to wind close round the roller. The grooved
travelling wheel at the opposite end (although it is of a larger diameter) from
the fact of its revolving upon a pin makes no more revolutions than enables

page_text: it to keep pace with the smaller wheel; or the same result may be ac-
complished by having the travelling wheels of equal diameter, but the impetus
thus given to the roller when travelling down the guide bars would cause it to
perform a greater number of revolutions than required to give out the blind,
thus leaving it slack; this is counteracted by loose weights inside the roller,
these weights being left free to revolve independent of the roller will do so in
the downward motion, and thus correct the impetus imparted to the roller. I
also propose to produce the same result by having the end of the blind roller
conical in form, and with a screw thread of very sharp pitch, either sunk in or
raised upon it; these threads must be right and left hand, and require to be
fixed one upon each end of the blind roller. The ends of the cords that are
to work this roller up or down should be fixed at the top of the roof to be
shaded, and then brought round the roller end upon its smaller diameter, and
from thence back again to the starting point, and on to any suitable winding
apparatus; the cord would thus be adjusted for winding the blind upon its
rollers, and it would thus remain upon this smaller diameter of the roller end
until the blind was wound all up; upon the contrary motion being given to
the cord for the purpose of unrolling the blind they would at once shift to the
large diameter of the blind roller end; a pin or travelling wheel may be
attached to the end of the roller to work on the guide bars, or the end of the
blind rollers may be made to travel on the guide bars, but in this case single
ropes would be required.
SPECIFICATION in pursuance of the conditions of the Letters l'atent, filed
by the said Thomas Hungate Preston Dennis in the Great Seal l'atent
Office on the 16th November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HUNGATE PRESTON DENNIS, of Chelmsford, in the County of Essex, Horti-
cultural Builder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of May, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Fler
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Hungate Preston Dennis, Her special licence that I, the
said Thomas Hungate Preston Dennis, my executors, administrators, and
assigns, or such others as I, the said Thomas Hungate Preston Dennis, my
executors, administrators, and assigns, should at any time agree with, and no

page_text: others, from time to time and at all times thereafter during the term therein
expressed, should and lawfully might 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 GREENHOUSES, AND
SPECIALLY RELATING TO THE FIXINGS, FITTINGS, VENTILATION, AND SHADING OF THE
SAME," upon the condition (amongst others) that I, the said Thomas Hungate
Preston Dennis, 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 nature 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 Thomas Hungate Preston Dennis,
do hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
First, as to the fixings I attach iron or other metal eyes on plates to the
building or wall, against which the greenhouse is to be placed some few
inches below the ridge line; the ridge or fixing plate is then fitted up close to
the wall, having mortices in it to allow the eyes to project through; wedges
or keys are then passed into these eyes which force and secure the ridge or
fixing plate firmly to the building or wall; the rafters, end studs, and other
parts can then be attached to the ridge or fixing plate with screws or nails in
the usual manner. The whole can be removed by withdrawing the wedges or
keys. Or when the ridge can be brought to the top of the back wall the
following plan may be used :-A metal cramp or holdfast made of wrought iron,
by preference, is made to lay upon the top, and with one end turned down
over the side of the back wall, the other end to run past and overhang the
upright line of the back wall on the side against which the greenhouse is to
be fixed. In this projecting or overhanging part a long hole will be made; a
knee or angle piece will then be fixed upon the top of the cramp or holdfasts
at right angles with it, and flush with the upright line of the wall; or this
knce or angle may be formed out of the solid by punching the hole on three
sides only, and turning the piece thus punched backwards and upwards until flush
with the upright line of wall; it is against these knees or angles that the ridge
or fixing plate (which in this case will stand partly above the top of the wall)
rests. These cramps or holdfasts will be laid upon the back wall at distances
varying from three to six feet, and when so laid the ridge or fixing plate (having
mortices in it to allow the ends of the cramps or holdfasts to project through

page_text: it) is then fitted up close to the wall with part of its depth standing above-the
top of the wall; wedges or keys are then passed through the long holes of the
cramps or holdfasts, which force and secure the ridge or fixing plate firmly to
the back wall. The rafters and other constructional parts can then be
attached to the ridge or fixing plate in the usual manner, and the whole can
be removed by withdrawing the wedges or keys. The fittings will consist of
metal fastenings to support and retain the sashes in their places, and also
front mullions to support the eaves plate. The ventilators in the front and at
the apex of the roof are connected by means of a hempen rope, wire, chain,
or other suitable material passing over pullies and thence to a long connecting
rod, which being moved backwards or forwards by means of a rack and
wheel or other leverage, opens or shuts the ventilators simultaneously.
A second plan of ventilation may be arranged at the lower part of green-
houses by building the front dwarf brick wall one foot six inches, or any other
suitable distance back from the front plate, and running out piers at intervals
of from three to four feet to support the front plate, thus forming a space
between the front plate and the wall, which being covered by a hinged or
sliding shutter forms the ventilator.
A third system of ventilation may be carried out by having a given width
of the gable end of a greenhouse directly under the end rafter, and a part or
the whole of its entire length made to open inwards, outwards, or to slide, or
in any other convenient manner, so that the aperture thus formed may direct
the current of air directly under the glass or other roof, the same arrangement
to be repeated at each end of the building, and it may be continued of any
suitable width from the lower part of the end rafter to the ground line, or any
part of such distance. In buildings of great length it may be necessary to
have additional openings in the roof from the ridge to the eaves, which may
in some cases be extended down to the ground line. In case of divisions being
fixed in the building the same system will be carried out, but the ventilators
will be double or so arranged that a current of air can be directed.through
one compartment only or made to traverse any number of compartments;
these ventilators may also be made to slide or lift or open in any convenient
manner.
•
As to shading, my improvements consist in the arrangement of certain
pulley and grooved or flanged travelling wheels, ratchets, and pauls, so as to
prevent the irregularity in the rolling up or down of blinds upon an inclined
surface, which has hitherto been experienced from the inequality in diameter
between the blind and its roller or end at the various stages of its course up
or, down a roof, or from its increased or diminished bulk when wet or dry.

page_text: To accomplish this I fix one end of the blind to the roof or the ridge of the
greenhouse, and the other end to a roller, which may be made of any suitable
material and of any desired diameter; the roller will be made to run up or
down the roof upon guide bars, and will be worked by ropes or chains from
the interior of the greenhouse. At each end of the blind roller is fixed a
small pin, and a ratchet is attached to each of these pins. Two grooved
travelling wheels, each of a different diameter, are also fitted to and revolve
one upon each of these pins, and having pauls fitted to them which catch into
the ratchet above described, and prevent them revolving in but one direction.
In unrolling the blind the larger travelling wheel becomes fixed to the roller
by one of its pauls falling into the ratchet, and causing the roller to travel
with it. The circumference of this wheel being greater than that of the roller
it has a tendency to get in advance of it as it travels over more space at each
revolution than the length of blind given out by the roller, this tendency
effectually provents the blind getting slack in unrolling. The grooved
travelling wheel at the opposite end (although it is of a smaller diameter)
from the fact of its revolving upon a pin is free to make more revolutions than
the larger, and thus is enabled to keep pace with it. In rolling up the blind
the small travelling wheel becomes fixed to the roller by one of its pauls
falling into the ratchett and causing the roller to travel with it. The circum-
ference of this wheel being smaller than that of the roller it travels over less
space than the length of blind taken up by it at each revolution, thus causing
the blind to wind close round the roller. The grooved travelling wheel at the
opposite end (although it is of a larger diameter) from the fact of its revolving
upon a pin makes no more revolutions than enables it to keep pace with the
smaller wheel; or the same results may be accomplished by having the
travelling wheels of equal diameter, but the impetus thus given to the roller
when travelling down the guide bars would cause it to perform a greater
number of revolutions than required to give out the blind, thus leaving it
slack. This counteracted by loose weights inside the roller, these weights being
left free to revolve independently of the roller will do so in the downward
motion, and thus correct the impetus imparted to the roller.
I also propose to produce the same result by having the ends of the blind
roller conical in form, and with a screw thread of very sharp pitch, either
sunk in or raised upon it; these threads must be right and left hand, and
require to be fixed one upon each end of blind roller; the ends of the cords
that are to work this roller up or down should be fixed at the top or bottom
of the roof to be shaded, and then brought round the roller end upon its
smaller diameter, and from thence back again to the starting points, and on

page_text: to any suitable winding apparatus, the cord would thus be adjusted for
winding the blind upon its rollers, and it would remain upon this smaller
diameter of the roller end until the blind is all wound up. Upon the contrary
motion being given to the cord for the purpose of unrolling the blind, they
would at once shift to the larger diameter of the blind roller end; a pin or
travelling wheel may be attached to the end of the roller to work on the
guide bars. Or the ends of the blind rollers may be made to travel on the
guide bars, but in this case single ropes would be required.
In witness whereof, I, the said Thomas Hungate Preston Dennis, have
hereunto set my band and seal, this Thirteenth day of November, in
the year of our Lord One thousand eight hundred and sixty-six.