[0001] This invention relates to a plurality of cold-storage elements for a chest freezer,
each element comprising a casing of plastics material, for example polyethylene, containing
a eutectic solution, for example, based on sodium and/or ammonium salts. These elements
are used in chest freezers in order to maintain suitably low temperatures for reasonably
lengthy periods in the event of failure of the electricity supply which feeds the
freezer compressor. In particular, the storageelements can be used in such a manner
that the eutectic solution becomes frozen by practically continuous operation of the
compressor during those (night) hours in which the mains electricity is sold at reduced
tariff. The thermal energy stored by these elements is.then utilised during those
(day) hours in which the mains electricity is sold at full tariff, so avoiding operation
of the freezer compressor during these hours.
[0002] In conventional methods (see for example U.S.A. patent 3 747 364 and GB patent 1
338 553), the storage elements constitute a structural part of the chest freezer in
the sense that they are incorporated in the structure of the chest freezer structure
in a non-removable manner. This constitutes a drawback in that it compels freezer
manufacturers to produce freezers both with and without cold storage because there
is a user requirement for both types of freezer. Moreover, it is not possible to change
the overall storage capacity of a freezer fitted with cold storage, should the user
so desire.
[0003] In order to obviate these drawbacks, the present utility model invention provides
a plurality of cold-storage elements which are each constructed to be removably mounted
in a chest freezer in contact with a refrigerated wall thereof so as to extend over
at least a portion of this wall, and are provided with means whereby they can be fitted
to one another by inosculation, and with means for remoably connecting them to the
freezer.
[0004] The invention also provides a cold-staage element for use in the plurality of such
elements, the element comprising a casing of plastics material containing a eutectic
solution, characterized in that the storage element is constructed to be removably
mounted in the freezer in contact with a refrigerated wall thereof so as to extend
over at least a portion of this wall, and is provided with means whereby it can be
fitted to another storage element by inosculation, and with means for removably connecting
it to the freezer. The invention will be more apparent from the detailed description
given hereinafter by way of example with reference to the accompanying drawing, in
which :
Figure 1 is a diagrammatic plan view of a plurality of storage elements according
to an embodiment of the invention fitted together and mounted on the vertical walls
of a chest freezer;
Figure 2 is a section on the line II-II of Figure 1 to an enlarged scale;
Figure 3 is a front view of a flat storage element;
Figure 4 is a section on the line IV-IV of Figure 3;
Figure 5 is a view of Figure 3 in the direction of the arrow V;
Figure 7 is a section on the line VI-VI of Figure 3;
Figure 7 is a front view of a storage element with curved ends;
Figure 8 is a section on the line VIII-VIII of Figure 7;
Figure 9 is a partly sectional plan view of the subject storage element of Figure
7;
Figure 10 is a section on the line X-X of Fig.9. With reference in particular to Figure
2, the reference numeral 1 indicates a chest freezer of any known construction closable
by a lid 2 and partly covered on its inner vertical walls by a plurality of cold-storage
elements 3, 4 each comprising a casing 5, 6 respectively of plastics material, for
example polyethylene, and a charge of eutectic solution, the purpose of which is to
store cold during the operation of the freezer. The storage elements 3, 4 comprise
means which enable them to be fitted together by inosculation as described in detail
hereinafter, and they are suspended from the upper edges 7 of the vertical freezer
chest 8 by means of an outwardly directed flange 9 on each element. The storage elements
on two opposite side walls of the chest 8 are kept from one another by flat grids
or braces 10, the vertical sides 11 of which are inserted into grooves 12 provided
in the flat storage elements 3. The storage elements are divided into wholly flat
elements 3 and elements 4 which have curved ends. In addition to the upper flange
9 and the groove 12, each flat element 3, as shown in Figures 3 to 6, also comprises
a vertical hollow rib 13 on one of its minor vertical sides and on the opposite minor
vertical side three parallel projections 14 one of which is offset by a distance L
from the other two which are aligned with each other. As can be seen from Figures
1, 5 and 6, the vertical hollow rib 13 of one of the flat storage elements on one
of the afore said side walls of the chest 8 inosculates with the space of dimension
I defined by the projections 14 on the adjacent flat storage element. A sealable aperture
15 is provided in the top of each storage element for changing the element with the
eutectic solution, and cup-shaped recesses 16 are provided in the front of each storage
element for stiffening purposes.
[0005] In addition to the suspension flange 9, the sealable apertures 15 for changing the
element with the eutectic solution and the cup-shaped stiffening recesses 16 each
of the curved-end storage elements 4, as shown in Figures 7 to 10, also comprises
a central vertical hollow rib 20 on one of its minor vertical sides, and on the other
minor vertical side a pair of spaced vertical hollow ribs 21 which between them define
a groove 22 to receive the hollow rib 13 of an adjacent flat element 3. The rib 20
of each curved-end storage element 4 fits between the hollow projections 14 of the
other adjacent flat element 3. The storage elements 3, 4 are mounted in the chest
8 of the freezer 1 by first hanging them one at a time on the upper edges 7 of the
walls of the chest by means of their flanges 9, then fitting them laterally into each
other by. the aforesaid inosculation means, and finally inserting the flat grids or
braces 10 into the grooves 12 in the flat storage elements 3.
[0006] It is not necessary for enough storage elements 3, 4 to be inserted in the freezer
chest to extend over the entire area of the vertical walls of the chest 8. If the
user so desires he can insert a different number of elements, even just one, in which
case it could be advantageous to secure the storage element by means of self-tapping
screws suitably located in the flange 9 of the element and screwed into the upper
edge 7 of the relevant wall of the freezer chest.
