Year: 1899

page_text: Date of Application, 14th June, 1899
Complete Specification Left, 12th Mar., 1900-Accepted, 14th Apr., 1900
I, THOMAS HORSFALL CALVERT, of Sunnyside, Masham, in the County of
York, Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in incubators, and, has for objects, to
insure a uniform heating of the eggs, and also to provide a simple means for
turning the eggs mechanically without removing what is technically termed the
egg-drawer.
In carrying out my invention I adopt an egg drawer of circular form, the
bottom of which is loose, and consists of a porous dished tray of perforated
metal or other suitable material, the amount of dishing being so arranged that
a uniform temperature is maintained throughout the drawer. On the dished
tray there are formed by stamping or other means, concentric grooves or channels
in which the eggs rest with their smaller ends towards the centre. The tray
may be covered with flannel or other porous material, either completely, or the
grooves or channels only may be so covered, the object being to provide a soft
porous bed for the eggs at the same time utilizing the extra frictional resistance
of the material both to ensure the eggs revolving and also to prevent them
from moving too roughly. To the underside of the tray is attached circum-
ferentially a rack, or its equivalent, which engages with a pinion attached to a
shaft working in a bearing fixed on the side of the drawer, the shaft being
extended to any suitable distance outside the apparatus. & operated by means
of a handle or other contrivance. Within the drawer and supported at the sides
is a vertical wirework frame extended to a suitable height to prevent the eggs
being carried round as the dished tray without revolving on their own axis.
A separate fixed wire or wires may be used for the same purpose, or, simply a
fixed stop in the form of a perforated metal or wood division may be employed:
or the fixed wire-work frame or division may be dispensed with entirely, and
the loose dished tray inclined from the horizontal, a small space being left
between the first and last eggs in each concentric ring, so that upon the dished
tray being revolved the eggs will roll due to gravity over the space and in this
manner be turned.
Instead of the grooves or channels being formed in the dished tray, they may
be separate therefrom, and may be made of any suitable material and attached
to the tray. The circumferential rack may be formed in the tray itself or it
may be separate therefrom and arranged vertically if so desired. The drawer
and attendant tray may be enclosed in an incubator of any suitable construction,
and provided with the necessary heating apparatus, water trough, and other
fittings.
From the foregoing description it will be seen that the eggs being arranged
in concentric rings, and the points of contact with the smaller ends of the eggs

page_text: travelling in a less circle than the points of contact with the larger ends, on
the shaft being turned, the eggs are caused to revolve with less jarring than
with apparatus at present in use.
Improvements in and relating to Incubators.
I, THOMAS HORSFALL CALVERT, of Sunnyside, Masham, 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 improvements in incubators and has for objects to
ensure a uniform heating of the eggs and also to provide a simple means for
turning the eggs mechanically without removing what is technically termed
the egg drawer.
In the accompanying drawing Figure I is a sectional elevation and Figure II
a plan of an arrangement of my invention. Figures III & IV & V showing
details of the turning mechanism. The numbers in the various figures corre-
spond. The circular egg drawer 1 is provided with a loose dished tray 2
arranged with concentric grooves or channels 2 in which the eggs 3 rest with
their smaller ends towards the centre. (In Fig. II one half of the eggs only
are shown). The tray 2 may be covered with flannel or other porous material 2b
either completely or the grooves or channels only may be so covered, the object
being to provide a soft porous bed for the eggs at the same time utilizing the
extra frictional resistance of the material both to ensure the eggs revolving
and also to prevent them moving too roughly. The dished tray 2 may consist
of a perforated metal plate, the amount of dishing being so arranged that a
uniform temperature is maintained throughout the drawer. Instead of the
grooves or channels being formed by stamping or otherwise in the tray they
may be separate therefrom and may be made of any suitable material and
attached to the tray. On the outer circumference of the tray 2 is arranged a
rack 4 which engages with the teeth of a pinion 5 actuated by means of a
shaft 6 supported on the side of the drawer by a bracket 62. The shaft 6 may
be extended to any distance and operated by means of a handle or by means
of any suitable mechanical contrivance as may be desired. To the side of
the drawer 1 are attached rings 7, 7* forming guides for the tray and between
which the tray is free to revolve in a horizontal plane by means of the rack
and pinion. In order to prevent the eggs being turned round in the dished
tray without revolving on their own axes, a vertical wire frame work is attached
to the drawer. This may consist of concentric rings 8, 8, 8b to which are
attached the radial ribs or stops 9, 92, 9b the whole being rigidly connected
to the drawer at 10. A separate fixed wire or wires may be used for the same
purpose or simply a fixed stop in the form of a perforated metal or wooden
division may be employed: or the fixed wire work frame or division may be dis-
pensed with entirely and the loose dished tray inclined from the horizontal, a
small space being left between the first and last eggs in each concentric ring
so that upon the dished tray being revolved the eggs will roll due to gravity
over the space and in this manner be turned. This arrangement is specially
applicable to cases where the apparatus is required to be used for eggs of various
sizes. The circumferential rack 4 may be formed in the tray 2 or it may be

page_text: separate therefrom and arranged vertically if so desired, or the rack may extend
for a portion of the circumference only according to the movement required,
or, the rack may be dispensed with entirely and the tray or wire frame work
may be partially revolved by means of a lever. The drawer and attendant tray
may be enclosed in an incubator of any suitable construction and provided with
the necessary heating apparatus, water trough and other fittings.
From the foregoing description it will be seen that the eggs being arranged
in concentric rings and the points of contact with the smaller ends of the eggs
travelling in a less circle than the points of contact with the larger ends, on
the tray being revolved or partially revolved by means of the shaft connected
with the pinion and rack or by means of the lever as before described the eggs
are caused to revolve and in such a manner that there is less jarring than with
apparatus at present in use.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
(1) In the circular drawers of incubators forming the circular dished tray
with concentric grooves or channels the said tray being revolved or partially
revolved by mechanical means substantially as illustrated and described.
(2) In the circular drawers of incubators arranging the dished tray in a
plane out of the horizontal so that the action of gravity is utilized for revolving
the eggs substantially as described.
(3) Circular dished trays for incubators substantially as illustrated and
described with reference to Figs. I to V inclusive.
Dated this 9th day of March 1900.