Title of Invention

A SINGLE DOOR FROST-FREE REFRIGERATOR

Abstract

A single door frost-free refrigerator comprising 8, thermally insulated r.:abinet (1), with a dorJr (2) forlling one side of the c~abinet. a compressrJr (13). evaporatrJr (8~). a fan (9) with a Klotor for forced convection of cool air. tellperature controller (15) /~haracterised by a freezer compartment (3) seperated from a fresh food compartment (4) by lIeans of insulated partitirJns (5, 10) and an air tight closure (6) for the freezer compartment (3), the said evaporator (8) and said fan (9) being located behind the insulated partition (10) disprJsed vertically. the said insulated partitions (5, 10) having air ducts (7) for air flow. 8 tiller controlled defrosting heater (16) housed in a buffle (18) for defrosting and collecting means (11) for collecting the water drained by defrosting in a drain tray (12).

Full Text

The invention relates to a single door frost-free refrigerator. Refrigerators can be broadly classified into direct cool refrigerators and frost-free refrigerators. Both these types normally consist of a freezer compartment and a fresh-food compartment, Depending upon the construction, direct cool refrigerators are either a single door type or double door type. In a single door, direct cool refrigerator, the evaporator is bent into a box to form the freezer compartment. An internal insulated plastic door closes this freezer compartment. Both the freezer compartment and fresh-food compartment are enclosed in a cabinet with a single external door. The existing double door direct cool refrigerators consist of separate freezer compartment and fresh-food compartment with two separate external doors. In ail the direct cool refrigerators, the air circulation from the evaporator to the interiors of ttie compartment is by natural convection. In these refrigerators frost forms inside the freezer compartment during their normal operation. The frost formed inside the freezer reduces the efficiency of the system, the usable storage volume and gives rise to a messy freezer interiors. These refrigerators have to be defrosted periodically to melt the frost formed inside the freezer compartment. The defrosting is either manually initiated and manually terminated or manually initiated and automatically terminated. Based on the refrigerator size and its intended use, direct cool refrigerator can be designed for a small or a large freezer compartment. The existing frost-free refrigerator consist of multiple compartments with multiple external doors. At least two external doors are provided in the existing frost-free refrigerators, one each for freezer compartment and fresh-food compartment, In frost-free refrigerators the air circulation Is forced convection type. An electric fan takes the warm and humid air inside the cabinet and blows it over an evaporator, which is located behind a partition. The warm and humid air from the compartments is cooled and dehumidified. This cold and dehumidified air is then supplied to the freezer compartment and fresh-food compartment by the fan. As a result of this, all the moisture inside the cabinet is trapped and stored in the form of frost on the evaporator located behind the partition. Since only dry and cold air enters into the freezer compartment, the freezer compartment interior is clean and free from frost. A timer-controlled heater periodically and automatically defrosts the frost formed on the evaporator. The principle used in working, the frost-free refrigerators necessitate larger freezer compartment compared to that of a direct cool refrigerator of same volume. As already mentioned frost-free refrigerators invariably have multiple external doors, The provision of multiple doors generally increase the cost of the refrigerator due to the larger number of components required and the increase in labour. The object of this invention is to propose a frost-free refrigerator with a single external door comprising a frost-free freezer compartment and a fresh food compartment. Unlike the existing frost-free refrigerators known in the art, the single door frost-free refrigerator according to the invention consists of a single external door and a relatively smaller freezer compartment. It combines the advantages of direct cooling refrigerator and frost-free refrigerators, without any further disadvantages. Thus the invention provides a single door frost-free refrigerator comprising a thermally insulated cabinet, with a door forming one side of the cabinet, a compressor, evaporator, a fan with a motor for forced convection of cool air, temperature controller characterised in that a freezer compartment seperated from a fresh food compartment by means of insulated partitions and an air tight closure for the freezer compartment, the said evaporator and said fan being located behind the insulated partition disposed vertically, the said insulated partitions having air ducts for air flow, a timer controlled defrosting heater housed in a buffle for defrosting and collecting means for collecting the water drained by defrosting in a drain tray. The invention will now be described in detail with reference to the acompanying drawings shown as a prefered embodiment. Fig 1 : shows a single door frost-free refr igerator according to the invention. Fig 2 : shows enlarged portion containing freezer compartment of the refrigerator shown in Fig, 1. The single door frost-free refrigerator consists of a main insulated cabinet and a fan (9) with motor are located behind the insulated partition disposed vertically allowing air from the fan to flow partly to the freezer compartment (3) and partly to fresh-food compartment (4 ) through air ducts A defrosting heater (16) housed in a buffle (18) is provided with a drain tube (11), The drain tube (11) leads the drained water to a drain tray (12) located outside the cabinet (1) and preferably above the compressor (13). The door (2) is preferably provided with shelves. A temperature controller light and other control switches are housed in a housing (15) and preferably located above the closure (6) of the freezer compartment The required temperatures inside the freezer compartment and fresh food compartment are achieved and maintained by the cooling system and temperature controls. The required temperature difference between fresh food compartment and freezer compartment is maintained by the insulated partition, insulated door and air circulation system that circulates air in required quantities. The forced air circulation along with timer controlled defrosting mechanism maintains the freezer compartment frost-free. Various embodiments of the single door frost-free refrigerator according to the invention can be aaade within the FK^npe of this invention, For example , the construction of freezer closure, insulated partition, air circulation system, location of the controls, volume of the freezer compartment depending upon the total volume of the refrigerator etc, can be varied and yet the same inventive features can be incorporated. WE CLAIM: 1 A single door frost-free refrigerator comprising a thermally insulated cabinet (1), with a door forming one side of the cab inet, a compressor (13), evaporator (8 ), a fan (9) with a motor for forced convection of cool air, temperature controller characterised by a freezer compartment (3) seperated from a fresh food compartment (4) by means of insulated partitions (5, 10) and an air tight closure (6) for the freezer compartment and said fan disposed vertically, the said insulated partitions (5, 10) having air ducts (7) for air flow, a timer controlled defrosting heater (IB) housed in a buffle (18> for defrosting and collecting means (11> for collecting the water drained by defrosting in a drain tray (12). 2. The single door frost-free refrigerator as claimed in claim 1, wherein the temperature controller (15) is a thermostat control. 3. The single door frost-free refrigerator as claimed in claims 1 or 2, wherein the collecting means for collecting the water drained by defrosting comprises a buffle (18) connected to a drain tray (12) located outside the cabinet (1) through a drain tube (11). 4 A single door frost-free refrigerator, substantially as hereinabove described and Illustrated with reference to the accompanying drawings -

Documents:

829-mas-1999- claims.pdf

829-mas-1999- correspondence others.pdf

829-mas-1999- correspondence po.pdf

829-mas-1999- description complete.pdf

829-mas-1999- drawings.pdf

829-mas-1999- form 1.pdf

829-mas-1999- form 19.pdf

829-mas-1999- form 26.pdf

829-mas-1999- form 3.pdf

829-mas-99 claims granted.pdf

829-mas-99 decription (complete) granted.pdf

829-mas-99 drawings granted.pdf