GB2193725A

GB2193725A - Incubator

Info

Publication number: GB2193725A
Application number: GB08606479A
Authority: GB
Inventors: Richard Harry Mark Freeman
Original assignee: Flow Labs Ltd
Current assignee: Meda Pharmaceuticals Ltd
Priority date: 1986-03-17
Filing date: 1986-03-17
Publication date: 1988-02-17
Also published as: GB8606479D0; JPS63502797A; EP0238313A1; WO1987005623A1

Description

GB2193725A 1 SPECIFICATION door is preferably insulated for example with

glass reinforced plastics material. Holes may Incubator be provided in the heating element to allow apparatus to be attached to the surface on This invention relates to an incubator or oven 70 which the heating element is to be mounted.

for a heated environment with a substantially The temperature of the incubator or oven uniform temperature throughout. Such incuba- may be displayed on a control panel. Control tors are used, for example, for growing culture circuits may be used to maintain the housing samples where it is required to maintain the cavity at a set temperature. A common oper cultures in an environment which is stable 75 ating temperature for incubators is 37'C but with regard to, for example temperature and higher temperatures may be used in an oven or atmosphere. or for example temperatures up to about A conventional incubator comprises a hous- 130'C for sterilization of an incubator.

ing surrounded by a water jacket. Water can A fan mounted on one of the inner walls be heated to a controlled temperature by 80 may be used to circulate the air in the incuba means of heating coils and circulated through tor.

the jacket to heat the incubator. This form of A humidity reservoir may be provided in the incubator is bulky because of the water jacket. base of the incubator compartment.

The apparatus is expensive and difficult to One or more gas inlets may be provided move because of the weight of water in the 85 through the housing, for example for C02, to jacket. help maintain a stable environment. The level Incubators are also manufactured which of a given gas and temperature may be moni- have electrical heating elements but the heat tored using sensors set on the inside of the output of such elements is concentrated into a compartment. It is preferable to have a good relatively small area of the wall. This tends to 90 airtight seal on the doors especially if the cul create an uneven temperature environment tures are to be kept, for example, in a C02 within the chamber compared with either a atmosphere.

water jacketed unit or the present invention. An embodiment of the invention is de- The present invention provides an incubator scribed below with reference to the drawings.

or oven comprising an insulated housing, the 95 Figure 1 shows a front elevation of the walls of which are lined with foil track electriapparatus in accordance with the invention; cal heating elements, and a thermostat for Figure 2 is a left hand side elevation; controlling the supply of electricity to the Figure 3 is a right hand side elevation; heating elements according to the temperature Figure 4 is a cross-section on the line A-A in the incubator. 100 of Fig. 1 on an enlarged scale; Such an incubator provides a cheap and Figure 5 is a cross-section on the line B-B convenient way of creating a stable environ- of Fig. 1 on an enlarged scale; ment for culture samples. The humidity and/or Figure 6 is a plan of the foil track heating composition of the atmosphere in the housing element designed for use in the apparatus.

may be regulated as well as its temperature. 105 The apparatus comprises a rectangular hous- By dispensing with a water jacket the cost ing 1 made up of five insulated walls 2 which and weight of the incubator can be substan- form the top, bottom, back and sides of the tially reduced. housing. The sixth wall at the front of the An additional advantage of even heat distri- housing is formed by an inner door 3 and an bution is that there is less tendency for con- 110 outer insulated door 4. An instrument unit 5 is densation to occur on the chamber walls at attached to one of the side walls. A motor 6 the high humidity normally found in this type connected to two fans 7 and 8 is mounted of incubator chamber. against an outer wall of the housing within the The foil track heating elements may each be instrument unit. The fan 7 is outside the hous- in the form of a sheet consisting of metallic 115 ing and serves to cool the motor. The fan 8 foil strip with a meandering path sandwiched is inside the housing and serves to circulate between layers of electrically insulating ma- the atmosphere in the housing.

terial, for example of mylar polyester. There The housing is constructed from two shells may be several alternating layers of insulating 9 of sheet metal pop- rivetted together at their material and metallic conductive material. The 120 edges.The space between the shells is insu metallic foil strip is preferably distributed in lated with slabs of glass fibre insulating ma such a manner so as to assist in attaining a terial 10. A silicone seal 11 runs around the uniform temperature throughout the incubator opening at the front of the housing and is or oven cavity, such a distribution may require fixed to the shells 9. This silicone seal forms a variation in concentration of metallic foil 125 an airtight seal with the inner door 3 when strip across a particular sheet. The foil track the door is closed.

heating elements may be self adhesive for A base plate 12 is attached by screws 13 mounting on the inner walls and may also be to the underside of the housing. Four feet 14 mounted on the outer door. A separate ele- with screw adjustments are secured to the ment sheet may be used for each wall. The 130 plate 12.

2 GB2193725A 2 The inner door 3 is made from a 14 mm the narrow region 54 approximately four times double glazed unit in an extruded PVC frame the density in the adjacent narrow region 55 and mounted by hinges 16 to the housing. which in turn is about one and a half times The inner door is provided with a door catch the density in the remainder of the blanket.

22, a catch retaining element 23 is mounted 70 Thus, in a particular example, the foil ele- on one of the side walls of the housing. ment is distributed within the blanket in the The outer door 4 is constructed from outer following manner:

and inner shells pop-rivetted together with in- 30% of the element is distributed evenly sulation of glass reinforced plastics material over an area 54 of 40mm x 544mm 25 in the space between the two shells. The 75 60% of the element is distributed evenly outer door is mounted on pivots 26 on brack- over an area 55 of 454mmx544mrn ets 27 attached to one of the side walls of 10% of the element is distributed over an the housing compartment. A magnetic catch area 56 of 5Ommx544mm and decreasing in 28 is provided on the outer shell of the corn- density from the junction with the high density partment with a corresponding retaining ele- 80 area 54 towards the lower element density ment 29 in the outer door. Silicone seals are area 55.

held at the junction of the outer and inner The variations in foil density compensate for shells of the door; these form an airtight seal variations in heat loss from different parts of with the outer shell of the walls when both the incubator. The heat loss tends to be doors are closed. The outer door is recessed 85 greater towards the glass inner door. The ele to accommodate the catch and catch retaining ment shown in Fig. 6 is designed for the four element for the inner door. walls adjacent the glass door. The element on A proximity switch 31 is provided to the the rear wall is designed with a high density inner door 3 which turns off the motor for the area closest to the fan storage where the ex fan when the inner door is opened. 90 tra heat is conducted away.

The inner walls of both the housing and the On the inner shell walls of the housing are outer door are each covered with foil track mounted brackets for nylon shelf spacers 33 heating elements 32. One sheet or blanket of by which runners 34 are held. Shelves 35 are foil track element is used for each wall. supported by the runners. The shelves are An example of a heating blanket is shown 95 stainless steel baffle plates with a rectangular in Fig. 6. array of circular holes.

The heating blanket 50 is made of two On the inner surface of the roof of the layers of myiar polyester 60 interleaved with a housing are mounted a gas sensor (C02) 36 distributed foil element. The elements are con- and a temperature sensor 37. These sensors nected in series to a 220/240 volt supply and 100 are connected by wires to control circuits 38 consumes about 100 watts. on the instrument unit. A humidity reservoir One side of the blanket has a self adhesive 41 is provided in the base of the housing.

coating. The self adhesive coating is for The instrument unit 5 mounted beside the mounting the blanket on the wall or door of housing, contains a control panel 39 for set the incubator. The adhesive used is stable up 105 ting the temperature and C02 level. The con to at least 13WC. trol panel then displays the actual temperature Holes 51 are provided in the blanket at and C02 levels by means of the sensors in the places which correspond to protruding sup- housing and the control circuit switches on ports, instruments etc. on the wall of the and off the current to the heating blankets or main cavity. The foil element extends as close 110 the gas flow to achieve and maintain a stable as possible to the edges of the holes while environment.

maintaining a safe margin for electrical insula- The instrument unit also contains a gas feed tion. 40 from an external source. This allows pure An element-free margin 52 is also left - C02 to be fed into the housing.

around the edge of the blanket for electrical 115

Claims

safety. CLAIMS

The element is provided with terminals 53 1. An incubator or oven comprising an in- for connection to the power supply and con- sulated housing, the wall of which are lined trols housed in the instrument unit. with foil track electrical heating elements, and In Fig. 6 part of the top layer 60 of myiar 120 a temperature sensor for controlling the supply polyester has been removed to show part of of electricity to the heating elements according the foil element 61. The foil element consists to the temperature in the incubator.

of a strip of metallic foil of uniform width
2. An incubator or oven according to claim which follows a meandering path across the 1 in which the walls of the housing comprise blanket. Both ends of the strip terminate at 125 outer and inner shells with insulating material the terminals 53. The spacing between adja- contained between them.

cent sections of the strip is different in differ- 3. An incubator or oven according to claim ent parts of the blanket so that the heat out- 1 or 2 in which the housing has a door and put varies across the blanket. In the embodi- foil track heating element is mounted on the ment the density of the foil track strip is in 130 inside of the door.
3 GB2193725A 3
4. An incubator or oven according to any preceding claim in which the housing has a door comprising inner and outer shells with insulating material contained between the shells.
5. An incubator or oven according to claims 3 or 4 which is provided with an inner door of transparent material adjacent to the inside of the door of the housing.
6. An incubator or oven according to any of the preceding claims in which the housing is rectangular and has a door forming at least part of one wall of the housing, the other five walls of the housing all being lined with foil track heat elements.
7. An incubator substantially as hereinbe- fore described with reference to the accom panying Figs. 1 to 5.
8. An incubator substantially as hereinbe- fore described with reference to the drawings, at least one of the walls being lined with the heating element of Fig. 6.

Published 1988 atThe Patent Office, State House, 66/71 High Holborn, London WC1 R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD.

Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.