US 2345387 A
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Filed May 20, 1941 2 Sheets-Sheet 1 INVENTOR H QWARD M. ELLSEY WITNES-SES:
ATTOR EY March 28, 1944. ELSEY 2,345,387
METHOD OF TESTING REFRIGERATOR CABINETS Filed May 20, 1941 2 Sheets-Sheet 2 W|TNESSESZ I INVENTOR HOWARD M. ELSEY.
Patented Mar. 28, 1944 2.345.881 usrnon or rus'rmo ass-momma oaama'rs lioward M. my, Oakmont, 1a., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh. Pa... a. corporation of Pennsyl Application May 20, 1941, ScrialxNo. 394,271
This invention relates to methods of testing refrigerator cabinet structures, for example," reirigerator doors, and more especially to a method of testing such structures for air tightness.
The outer shell of a refrigerator should be substantially air tight to prevent the relatively moist air ambient the refrigerator from circulating through the wall structure and depositing its moisture by condensation therein. This applies equally well to the door structure of the refrigerator. The outer shell of a refrigerator is not designed to withstand high air pressures so that the ordinary methods of testing for air leakage are not adapted for this work.
One object of the invention is to provide an accurate method for testing the fluid-tightness of the wall elements of refrigerator structures.
Another object of the invention is to provide a method of testing the fluid-tightness of chambers having walls not adapted to withstand high iluid pressures;
A further object is to provide a method for testing the fluid-tightness of the wall elements of refrigerator structures which method can be performed by semi-skilled labor.
Still a further object of the invention is to provide a method for testing the fluid-tightness of wall elements of refrigerator structures on a moving conveyor.
These and other objects are effected by my invention as will be apparent from the following description and claims taken in accordance with the accompanying drawings, forming a part of this application, in which:
Fig. 1 is a schematic drawing showing the apparatus for testing a refrigerator door and a section of a door being tested by said apparatus:
Fig. 2 is a plan view of the door and the testing frame positioned thereon; and,
Fig. 3 is a schematic drawing of a refrigerator door being tested on a moving conveyor.
Referring to the drawings for a detailed desciption of the invention, the reference numeral ll designates a door of a refrigerator such as described in the Patent No. 2,307,094 to Orland H. Yoxsimer and assigned to the assignee of this invention. The door I 8 comprises an outer panel ll formed of sheet steel and an inner panel I2.
gasket I] and into the marginal portion of the outer panel II to hold the door structure together.
The sealing gasket It comprises a tubular portion I! which is adapted to contact the wall of a refrigerator cabinet about its door opening to effect a substantially air-tight engagement with the wall. A refrigerator cabinet suitable for use with the door in is shown in the Patent No. 2,213- 155, granted to O. H. Yoxsimer on August 27, 1940. A hole I8 is formed in the inner panel for accommodating the latch strike of the refrigerator and a door handle l8 passes through a sealing gland 20 in the outer panel H for actuating the latch mechanism (not shown) in theinterior of the door. Loose heat-insulating material 22 islocated in the space between the outer panel II and the inner panel II.
To test the air tightness of the outer wall of the door l0 including the gasket 14 and the seal 20 in accordance with this invention, the door i0 is placed horizontally on supports 38 with the inner panel I! facing upwards and a plate 24, comprising a sheet of glass 26 surrounded by an outer frame Zl, is placed on the door with the glass 28 resting on the gasket It. The plate 24 is of'such weight that the pressure on the gasket I4 is equal to that placed on the gasket I! when the door is in actual service on the refrigerator.
A nipple 28 passes through a hole 29 in the center of the sheet 26, which nipple 28 is connected through a flexible hose 8| and other apparatus subsequently to be described with a cylinder 32 containing a gas under high pressure. A suitable gas for this purpose is oxygen because cylinders oi dry oxygen at highpressures are readily available. The other apparatus interposed between the nipple 28 and the cylinder 82 are a needle valve 85, a flow meter 84 and a pres-- sure gauge 88. The flow meter 34 is oi the type known by the trade mark Rotameter" and comprises a tapered tube 8'! and a metering rotor 38 which indicates the rate of flow 01 gas through I the flow meter.
The marginal portions of the outer panel are go bent inwardly and a flange l3 of a sealing gasket I4 is interposed between the marginal portions of the outer panel Ii and the inner panel l2. Screws vl6 pass through the marginal portions In testing a door the needle valve 35 is opened oxygen to pass through the hose 8|, the rate of flow being measured by the metering rotor 88. The plate 24 is thereupon placed on the door I0 and the rate of pressure rise in the sealed space is noted on the meter 38. It will be obvious that the oxygen escaping from the cylinder 32 passes through the nipple 28 into the space between the 0f h inner B 1 1. hrou h he flange I! of the g ass p ate 28 and the door I! and through the Since the pressure offthe gas in cylinder 32 is very high in comparison to the pressure of the gas at which the door is being tested, the rate of flow will remain practically constant regardless of the fluid-tightness of the door wall. Consequently the pressure increase indicated by the meter 36 is substantially proportional to the air-tightness of the outer wall of the door. A standard may therefore be set for each type of door which the door must meet in order to pass the test. In actual practice, it has been found expedient merely to set a minimum pressure which must be attained within a reasonable time.
The structure of the door II is not capable of withstanding high pressures, and, therefore, very low pressures and a very low flow of gas must be used. In actual practice it has been found expedient to use a rate of flow of the gas through the tube ll of three-fourths of acubic foot per hour and to limit the pressure admitted to the door to one-tenth of an inch of water in testing a door for a domestic refrigerator. when this pressure is indicated by the pressure gauge 36. the plate 24 is lifted or the valve it closed.
Fig. 3 shows the arrangement of the apparatus for testing doors on a moving conveyor. In this figure, the reference numeral 39 indicates a cohveyor which moves continuously to .the right. The conveyor 39 is provided with supports 40- which carry the doors II to be tested. The plate 24 is supported by rods 42 and a pneumatic hoist 43 which is actuated by compressed air through a hose 44. The hoist 42 in turn is supported by a monorail conveyor 4! on a rail 41 so that the plate 24 can be moved back and forth over the conveyor platform 39.
The testing operation is performed as fol-- lows: A-uniform rate of oxygen flow is established through the hose 3i as previously described. The plate 24 is then lowered by means of the hoist 43 on the door it to be tested and moves along with the conveyor 39. During this time the plate 24 drags the hoist 43 along with it. As soon as the plate 2 contacts the gasket i4 and makes a. sealing engagement therewith, the meter it rises and if the rate of rise is found to be satisfactory, or if the required pressure of one-tenth of an inch water is reached within a reasonable length of time, the hoist 4 3 is actuated to lift the plate 24.. The hoist 43 and plate 24 are thereupon moved back along the rail to the next door to be tested and the plate 24 is lowered thereon. If the rate oi. rise, or the maximum pressure attained is unsatisfactory, the sealing of the gasket i4 against the glass sheet 28 is inspected and the door It thereafter removed from the conveyor 38 and marked as to the defects discovered so that repairs can be made.
Inactual practice, the operators on the conveyor merely watch the pressure gauge 38 to see that the minimum pressure of one-tenth of an inch of water is attained within a reasonable length of time and use the travel of the conveyor I! as a timing device to determine the reasonable length of time.
Since, the testing of the doors on the conveyor requires only the lowering of the testing plat 24 thereon, the watching of a simple gauge, and the subsequent raising and moving of the plate 24 I and hoist 48, the testing can be done by semiskilled labor.
It will be obvious from the above that this invention provides an accurate test of fluid-tightness of a wall or, a refrigerator structure which structure is not adapted to withstand high fluid pressures. The invention further provides a method for testing the fluid-tightness of refrlg erator structure on a movable conveyor, which .tests can be performed by semi-skilled labor.
While I have shown my invention in but one form,it will be obvious to those skilled in the art 15 that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.
What I claim is:
l. The method of twting the fluid-tightness ofa wall element of a refrigerator, said wall being encircled by a gasket, said method comprising placing an imperforate and transparent plate in sealing engagement with said gasket, forcing a fluid at a predetermined rate into the space defined by said plate, wall, and gasket, observing the seating of said gasket against said plate by a visual inspection through said plate, and deter mining whether the pressure in said space rises above a predetermined standard.
2. The method of testing the fluid-tightnessot a wall element of a refrigerator, said well being- 85 encircled by a gasket, said method comprising placing an imperforate andtransparent plate-in. sealing engagement with said gasket, forcing a fluid at a predetermined rate into the space defined by said plate, wall, and gasket, observing thea seating of said gasket against said plate by a visual inspection through said plate, determining the rate of pressure rise in said space, and comparing said rate with a predetermined standard. 3. The method of testing the fluid-tightness of. .45. a wall of a refrigerator door, said refrigerator.
door comprising a substantially imperforate outer panel, a perforate inner panel and a gasket at the marginal edges of the inner panel, said method comprising placing the door in a position with w the gasket facing upwardly, placing a weighted Q5 inner panel into said door, and determining whether the pressure in said space rises above a predetermined standard. 4. The method of testing the fluid-tightnessof' a wall of a refrigerator door, said refrigerator door on, comprising a substantially imperforate outer panel, a perforate inner panel and a gasket at the marginal edges of the inner panel, said method comprising placing the door in a position with the gasket facing upwardly, placing a weighted 65 and transparent plate in sealing engagement'with said gasket and forcing a fluid at a uniform rate into the space between said plate, the inner panel, and said gasket, said fluid passing through said perforate inner panel into said door. inspecting '70 the sealing engagement of said gasket with said transparent plate by looking through the same.
and determining whether the pressure in said space rises above a predetermined standard.
. HOWARD M. ELBEY;