New or Improved Means for Automatically Controlling the Ventilators of Greenhouses, Vineries, or the like Buildings, or for analogous purposes.
Year: 1892

page_text: Date of Application. 17th Feb., 1892
Complete Specification Left, 17th Nov., 1892-Accepted, 11th Feb.. 1893
PROVISIONAL SPECIFICATION.
New or Improved Means for Automatically Controlling the
Ventilators of Greenhouses, Vineries, or the like Buildings, or
for analogous purposes.
1, JOHN ANDERSON, of No. 5 West Terrace, North Ormesby, Middlesbro', in
the County of York, Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention relates to means for automatically controlling the ventilators of
greenhouses, vineries, or the like buildings, in which the temperature is regulated
by the admission or exclusion of outside air according to the time of day, the power
of the sun, or the internal temperature of the building.
According to the present practice, outside air is admitted into greenhouses and
other buildings by an attendant opening certain windows or ventilators more or less
from time to time according to judgement or rule, and in the case of greenhouses
and vineries it is well known that to avoid undue variation of temperature
constant attention to the ventilators is often necessary.
The object of my invention is to furnish such ventilators with a contrivance
which will automatically control the ventilators by means of mechanism attached
to and operated by an expansion bar which expands and contracts with the heat of
the sun or any variation of temperature accessible to it.
In carrying my invention into effect I provide a bar of metal which is especially
sensitive to variations of temperature such as zinc, one end which is secured in
position whilst the other end is free. To the free end is attached a lever working
on a fulcrum so as to vibrate or respond to any change of length in the expansion
bar. This lever is made sufficiently sensitive for the purposes of my invention by
having the arm between its connection with the expansion bar and the fulcrum
short relatively to the other arm. This lever is held in position and works on a pin
fixed on a suitably placed bracket. A rod or wire secured to the end of the long
arm of this lever extends to the lever of the ventilator to which it is secured.
It will thus be seen that any movement imparted to what I will term the expansion
bar lever is transmitted through the wire rod to the ventilator lever, and in this
way the ventilator automatically opens and shuts with the expansion and contraction
of the expansion bar. As the wire rod will preferably be too light for the purpose
of applying the compressive strain requisite to force the ventilator lever up in
opening the ventilator, a spiral spring may be attached to and suitably fixed at the
other side thereof to effect this purpose, and the wire rod will pull the lever back
as a fall in temperature contracts the expansion bar. The expansion bar should
he of considerable normal length to expand and contract to the requisite extent
required to actuate the lever attached to it, and is preferably of a V or groove
shape in section to expose its surface more advantageously to the varying position
of the sun.
Dated this 16th day of hahmo 1000

page_text: COMPLETE SPECIFICATION.
the
New or Improved Means for Automatically Controlling
Ventilators of Greenhouses, Vineries, or the like Buildings, or
for analogous purposes.
1. JOHN ANDERSON, of 5, West Terrace, North Ormesby, in the County of
York, 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 :-
My invention relates, to means for automatically controlling the ventilators of
greenhouses, vineries, or the like buildings in which the temperature is regulated
by the admission or exclusion of outside air according to the time of day, the power
of the sun, or the internal temperature of the building.
According to the present practice outside air is admitted into greenhouses and the
like buildings by an attendant opening certain windows or ventilators more or less
from time to time according to judgement or rule, and in the case of greenhouses and
vineries it is well known that to avoid undue variation of temperature constant
attention to the ventilators is often necessary.
The object of my invention is to furnish such ventilators with a contrivance
which will automatically control the said ventilators by means of mechanism
attached to and operated by a bar which expands or contracts with every variation
of temperature accessible to it.
In carrying my invention into effect provide a bar of some metal which is
especially sensitive to variations of temperature, such as zinc one end of which
is secured in position whilst the other is free, so that any variation in the length of
the bar due to expansion or contraction is represented by a to and fro movement
of the free end. It will thus be seen that by providing such a bar of sufficient
length to impart a suitable movement to the free end thereof with each variation of
temperature acting upon it (8 feet being found a suitable length for ordinary
purposes with a bar of zinc), an automatic motive power is set up, the action of
which as transmitted through suitable mechanism and utilized as hereinafter
described constitutes the essential feature of my invention.
But in order that my invention may be fully understood and readily carried into
effect, will proceed to describe the same with reference to the accompanying
drawings in which are illustrated certain modifications intended to show it as
applied to the window sash of a greenhouse and from the description of which its
application for analogous purposes can be readily understood.
In the drawings,
Figure 1 is a sectional view of a greenhouse window to the ventilator of which
my automatic controlling device is shown connected in the working position with
the ventilator sash closed.
Figure 2 is a part plan view corresponding thereto, and
Figure 3 is a similar view to Figure 1 with the ventilator sash set open, the
combination of parts in this figure being in all respects the same as in Figures 1
and 2, except in respect of the substitution of a spiral spring for a weighted lever.
Figure 4 is a sectional view taken on line ea of Figure 1, and drawn to a larger
scale.
The same letters of reference indicate like parts in all the figures.
The section a of the window is shown as a fixture, and section 6 is the ventilator
sash working upon hinges . c is a bar of tee iron, or the like section in which
lightness is combined with rigidity, the various moving parts and their strains
being supported from it. The bar e extends the full length of the window frame
and is fixed to opposite bars thereof. d is an attachment to the bar C, such as au
angle piece rivetted on, to afford a ready means of bolting the expansion bar e

page_text: thereto, thus rigidly fixing one end, and leaving all variation of length due to
expansion and contraction to be accomodated by the movement of the other end
which is left free for the purpose. This movement is communicated to a lever
working on a fulcrum f in the bar e, which lever is made sufficiently sensitive for
the purposes of my invention by having accurately fitting joints and one arm
which is jointed to the expansion bar e by a pin or the like, very short relatively
to the other arm. A rod, wire, or hollow tube secured to the end of the long
arm f' of the said lever extends to the lever of the ventilator b to which it is
secured. It will thus be seen that any movement imparted to what I will term the
expansion bar lever is transmitted through the wire rod g to the ventilator
lever h, and in this way the ventilator automatically opens and shuts with the
expansion and contraction of the expansion bar e. As the wire rod will pre-
ferably be too light for the purpose of applying the compressive strain requisite to
force the ventilator lever up in opening the ventilator. I prefer to apply to this
wire a tensile strain only, and to use it in combination with the weight w on the
arm of the ventilator as shown in Figure 1, or with a spiral spring s as shown in
substitution thereof in Figure 3, the said tensile strain in the wire rod affording
a controlling check to the effort of the weight w or springs to lift the arm h of the
ventilator lever and so open the window sash b. When the expansion bar e is cool
or below a certain grade of temperature the wire rod g is drawn into and held in
the position shown in Figure by the arm of the expansion bar lever, and the
ventilator is kept closed; but as the heat expands the bar e, the corresponding
movement of the arm " allows the wire rod to be drawn by the weight w or
springs and the arm of the ventilator lever lifts up the sash as shown in Figure 3.
With the cooling of the expansion bar e, the reverse operation takes place, the sash
closing in to its original position when the temperature accessible to the expansion
bar has fallen below a certain grade.
The above described mode of operating the parts which control the ventilator are
applicable when the weight w or the springs is calculated to over balance the
sash b, in which case the tensile strain in the rod pulls against them in all
positions of the ventilator sash. But if desirable it is obvious that this mode of
operating the same parts can be reversed by constructing the sash to over balance
the weight w or spring s, in which case by substituting a tube for a wire rod ga
compressive strain is transmitted to the sash lever exerting a thrust against it in
all positions of the ventilator sash, except when closed, that is when the rod or
tube g is retained in its normal position by the cooling of the expansion bar e. The
sash is preferably secured to the lever h to retain its position against wind
pressure.
Referring to Figure 4 which is intended to show more particularly the section of
the expansion bar, I would observe that the section of this bar should be designed
principally with regard to presenting the most favourable exposure to the effect of
the temperature which it is intended should act upon it, and in the case of green-
houses the V or grooved shape in section as shown is thought to be especially
favourable for exposing its surface advantageously to the varying position of
the sun.
In cases where several ventilators are placed in line or are otherwise conveniently
arranged, the controlling mechanism can be so designed that the expansion and
contraction of one expansion bar is transmitted to two or more ventilators in the
same way as to only one, care being taken that all the moving parts are sufficiently
well balanced and put together to take their relative movements in the manner
required.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be and can be performed, I here declare
that I do not limit myself to the precise details of my invention as hereinbefore
specified and as illustrated on the accompanying drawings because equivalent
modifications or variations can be made in such details and quite consistent with

page_text: the principles or characteristic features of my invention, and in conclusion I declare
that what claim is :-
In the means for automatically controlling the ventilators of greenhouses, vineries,
or the like buildings in which the temperature is regulated by the admission or
exclusion of outside air, the use of a bar which is especially sensitive to variations
of temperature, the expansion and contraction of which is transmitted through
levers and their accessory parts to one or more ventilator sashes, all arranged, com-
bined and operating together, substantially in the manner as hereinbefore described
and illustrated by way of example in the accompanying drawings.
Dated this 16th day of November 1892.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.