US3820214A - Method of fabricating a cooling chamber for a water cooler - Google Patents

Abstract

A RELATIVELY LOW COST COOLING CHAMBER FORMED OF INNER AND OUTER CONCENTRICALLY DISPOSED CYLINDERS AND OPPOSITE END CAPS FOR THE OUTER CYLINDER, THE ENDS OF THE OUTER CYLINDER BEING FORMED TO PROVIDE SEATS WHICH MECHANICALLY HOLD THE END CAPS SO THAT A LOW TEMPERATURE BONDING MATERIAL MAY BE USED TO PROVIDE THE SEAL BETWEEN THE END CAPS AND THE OUTER CYLINDER AND WITHOUT THE HEATING OPERATION FOR EFFECTING THE BONDING AT THE ENDS DISTURBING THE BONDING OF OTHER LOW TEMPERATURE BONDING MATERIAL USED PREVIOUSLY TO BOND OTHER PARTS OF THE CHAMBER.

Description

United States Patent [191 SllOltES 1451 June 28, 1974 [54] METHOD OF FABRICATING A COOLING 2,401,231 5/1946 Crawford 29 458 x CHAMBER FOR A WATER COOLER 2,444,833 7/1948 Lampert 29/458 2,718,583 9/1955 Noland et a1. 156/69 X [75] Inventor: Carl E- S o es, um Ohio 2,726,184 12/1955 Cox et a1. 156/69 3,197,975 8/1965 B l' 29/157.3 R [73] Assgnw ga ggggg fi corporat'on 3,648,477 3/1972 ssal ll e 62/394 x [22] Filed: Apr. 30, 1973 Primary E.\'aminer-Charles W. Lanham Assistant Examiner-D. C. Reiley, Ill [2]] App! 356673 Attorney, Agent, or Firm-E. C. Arenz Related US. Application Data [63] Clfntijnuatiion of Ser. No. 116,793, Feb. 19, 1971, 57 .ABSTRACT a "e I A relatively low cost cooling chamber formed of inner [52 11.8. C1 29/1s7.3 R, 29/458, 29/1510. 1, and cutcr concentrically disposed cylindcrs and PP 165/66, 156/69 site end caps for the outer cylinder, the ends of the 511 1111.0 B2ld 53/00 cutcr cylindcr bcing fcrmcd to P Scam which [58] Field of Search 62/66 394, 395; 156/69, mechanically hold the end caps so that a low tempera- 156/182 165/66 29/157 3 R, 458 ture bonding material may be used to provide the seal DIG 1 between the end caps and the outer cylinder and without the heating operation for effecting the bonding at [56] References Qited the ends disturbing'the bonding of other low tempera- UNITED STATES PATENTS ture bonding material used previously to bond other parts of the chamber. 1,906,450 5/1933 Demers 165/142 l/194l. Schabacker 29/458 6 Claims, 3 Drawing Figures This is a continuation of application Ser. No. 1 16,793 filed Feb. 19, I971, now abandoned. t

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains to the art of water Cooling chambers for pressurized water coolers.

2. Description of the Prior Art Water cooling chambers for pressurized water coolers have been made in various forms to meet design requirements, to comply with various health codes, and to reasonably efficiently cool water, and have a reasonable cost. Of the various forms with which I am familiar, those shown in US. Pat. Nos. 3,475,922 and 3,200,848 are exemplary of chambers having some resemblance to the chamber of the present invention.

The main aim of my invention is to provide a cooling chamber which satisfactorily meets the design and efficiency requirements, and is less costly to build than those chambers with which I am familiar.

SUMMARY OF THE INVENTION In accordance with my invention, the water cooler chamber construction includes an outer substantially uniform diameter cylinder and an inner substantially uniform diameter cylinder of shorter length than the outer cylinder, heat transfer promoting means in the annular space defined between the inner and outer cylinders, an end cap at both the upper and lower ends of the outer cylinder, with the end caps including a circumferential flange telescopically received at the end of the outer cylinder with cooperating means being provided at the end of the outer cylinder and by the end cap to provide a mechanical Capturing of the end cap by the outer cylinder. The advantage of this arrangement is that stock copper tubes, such as are used for waste and vent lines in plumbing, may be used to provide the inner and outer cylinders, with substantially all of the bonding between the parts forming the major part of the Chamber being accomplished with low temperature bonding material such as pure tin before the end caps are applied. Then, the end caps, which are also pre-tinned with low temperature bonding material such as puretin, are mechanically captured and heat applied to the ends of the cylinder to provide the sealing bond between the outer cylinder and the end caps.

In the currently preferred construction the outer cylinder is provided with indent means about the circumference of both ends of the outer cylinder to form seats for the edges of the end flanges of the caps, and then the outer cylinder, at the extreme end edges, is rolled over or peened to mechanically capture the end caps.

Additional features forming a part of the preferred construction of the invention will be detailed hereinafl ter.

DRAWING DESCRIPTION FIG. I is a partly schematic, isometric view of a drinking water cooler, with a portion of the cabinet broken away to expose some of the main interior parts;

FIG. 2 is a partly broken, vertical sectional view of the cooling chamber according to the invention;

FIG. 3 is a partly broken top view of the cooling chamber of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drinking water cooler illustrated in FIG. 1 generally includes: a cabinet 10; a cooling chamber 12 supplied with water near its top end through water tube 14 and having a top-connected bubbler valve 16; a basin top 18 having a drain outlet (not shown) connected to the pre-cooling and insulated drain pipe 20; and a refrigeration system including a compressor 22, condenser 24, and evaporator coils 26 wrapped about the exterior of the cooling chamber 12. The chamber and coils are covered with thennal insulation (not shown) for cold retention.

The main parts of the cooling chamber 12 include an outer shell cylinder 28 of substantially uniform diameter from end to end, an inner core cylinder 30 also of substantially uniform diameter and of less length than the shell cylinder and which is concentrically disposed within the outer shell cylinder so as to form an annular space 32 between the walls of the cylinders, heat transfer promoting means in the form of corrugated fins also designated 32 and which are best seen in FIG. 3, refrigerant tube assembly formed of the tubes 26 wound helically and in partly flattened form about the outside of the outer shell cylinder 28, an interior wall 34 and water directing tube 36 assembly secured at the upper end of the inner core cylinder 30, and top cap assembly 38, and bottom cap assembly 40, at the top and bottom, respectively, of the cooling chamber.

In assembling the chamber, the refrigerant tubes 26 are wrapped about the outer shell cylinder, the fin means 32 in the form of the circular sleeve formed of the corrugated fins is inserted within the outer shell cylinder, and the inner core cylinder 30 is then inserted inside the sleeve formed of the fins and expanded by means of a plug to push the fins 32 into a tightly confined condition between the walls of the chambers so that a high degree of thermal contact between the fins and the chamber walls is mechanically obtained. The wall 34 and water directing tube 36 at the top of the Core cylinder are then installed in assembled form as shown, and the entire assembly is tin dipped to bond the parts together with the high quality thermal contact. In accordance with the preferred construction substantially pure tin (which is a relatively low temperature bonding material) is used in this operation to maintain a high degree of cleanliness and also to obtain the benefit of the excellent properties of pure tin as the thermal bonding material.

A feature of the construction according to the invention is the way in which the end caps 38 and 40 are connected to the remainder of the water cooling chamber. Near the upper end of the outer shell cylinder 28 an indented bead 42 is provided about the circumference of the cylinder. The end cap 38 includes a circumferential flange 44 dimensioned so that the rim of the flange will seat upon the bead when the end cap is assembled to the outer cylinder shell. Then the extreme end edge 46 of the outer shell cylinder is rolled over or peened to mechanically capture the cap 38 in its illustrated position in FIG. 2.

The upper end cap assembly also includes a brass fitting 48 which is provided with dual passages therein, one of which serves as the inlet to the water cooling chamber, and the other of which serves as the outlet leading to the bubbler 16. The inlet passage 50 connects to the water directing tube 36 through a stub tube 52 which is telescopically received within the upper flared end of the water directing tube. The outlet water passage 54 (FIG. 3) is open at its bottom to the interior space of the water chamber at the top end thereof, and is open at its top to the base of a stainless steel nipple 56 which is screwed into the upper end of the brass fitting 48 after the cap has been assembled to the remainder of the chamber. The water tube 14 referred to in connection with FIG. 1 connects to the side of the inlet passage 50 as shown in FIG. 2.

Before the upper cap 38 and its associated parts are assembled to the outer shell cylinder 28, the assembly is electro-tin-plated. Then after the cap has been assembled to the outer cylinder and mechanically secured as noted, the cap assembly is heated along with the upper part of the chamber so that the various tinned surfaces will bond to each other.

The lower cap 40 carries a drain plug fitting 56 and a hollow control well tube 58 which is arranged to extend vertically in the annular space 32 between one pair of adjacent corrugated fins. The lower cap 40 is also electro-tin-plated, then assembled to the chamber and mechanically captured by the rolled over flange 60 holding the end cap flange 62 with its rim against the bead64 adjacent the lower end of the outer shell cylinder.

Thus it will be appreciated that both the top and end caps are secured and bonded to the chamber in essentially the same fashion. When the end caps and ends of the chamber are heated to effect the bonding, an additional seal of 95 percent tin solder is applied to insure 1 that all the space between the facing surfaces to be bonded is filled and to form fillets at the chamber rim and end caps. However, since substantially pure tin is used in the interior parts of the chamber and in pretinning the top cap and bottom cap, a full bond between the contacting surfaces is assured and the assembly is free of contaminating oxides. Such oxides have typically resulted from methods where brazing or heliarcing with resultant high temperatures is used in prior art arrangements for sealing an end of a water cooling chamber.

In an effort to aid in a full appreciation of the advantages of the invention, the following is noted. By using substantially uniform diameter cylinders in which both ends are to be ultimately capped, it is possible to use standard stock copper tubing such as 2 and 3 inch diameter copper tubing of the character used for waste and vent lines in ordinary plumbing practice. While it would be expected that the prior art problems typically experienced in sealing ends of water cooling chambers would be doubled by an arrangement in which both ends must be capped, by using the construction according to the invention in which substantially pure tin is used and all of the parts are pre-tinned, with the end caps being mechanically captured so that requirements of high strength bonding materials is avoided, a relatively low cost cooling chamber is obtained in which the quality of the seal in bonding and the strength of the chamber is fully adequate for its intended purpose.

By placing the control well 58 in the annular space 32, so that in this position the thermal element within the well is influenced by the temperature of both water and refrigerant, ambient temperature changes do not unduly influence the control element. Accordingly, adequately uniform water temperature is obtained despite changes in ambient temperature. Further, in connection with the control location, another advantage of having the control in the annular space as distinguished from either being adjacent the refrigeration tubes on the outside, or in the center space of the water cooling chamber, is that a relatively less expensive control element may be used to give adequately constant water temperature control. The difference in expense is typically due to the difference in differential temperature at which the element causes the switch means to be actuated between on and off positions. It is noted that it is not new to provide a control element in such an annular space, but it is pointed out that with the-noted construction of the water chamber the provision of the control element in the annular space is easily accommodated and is compatible with the construction as a whole.

It will be seen that the water directing tube 36 is provided with a curved end which directs inlet water into the chamber toward the wall of the inner core cylinder. This is considered to be advantageous in that it creates some turbulence in the inner cylinder as distinguished from an axially directed flow of the inlet water through the inner space.

It will be also appreciated from FIG. 2 that the inlet water must first pass the length of the inner core, and then reverse direction to flow up through the annular space 32 in reaching the space at the top of the chamber in communication with the outlet passage 54. Thus, not only is a relatively long water circuit provided, but the water is also subjected to the coldest part of the chamber in passing through the annular space and also influences the control element in the well 58.

I claim:

1. The method of making a water cooler chamber comprising:

assembling an outer, substantially-uniform-diameter,

cylinder having upper and lower open ends with an inner, coaxially-disposed, substantially-uniform diameter cylinder of shorter length than saidouter cylinder and locating heat transfer promoting means in the annular space formed between said inner and outer cylinders;

applying a coating of relatively low bonding temperature material to the assembly of said inner and outer cylinders and said heat transfer promoting means to bond'the parts of the assembly together;

forming a pair of end caps for closing both the upper and the lower end of said outer cylinder, and applying a coating of relatively low bonding temperature material to both of said end caps;

fitting said end caps to the ends of said outer cylinder in telescopic relation thereto and mechanically capturing each end cap relative to said outer cylinder; and

then heating said end caps and the ends of said outer cylinder to bond the facing surfaces thereof to each other.

2. The method of claim 1 wherein:

said end caps are telescopically received within the ends of said outer cylinder; and

said mechanically capturing step includes displacing the extreme end edges of said outer cylinder inwardly.

3. The method of claim 1 wherein:

said coating of relatively low bonding temperature material is applied the assembly by dipping said assembly in a relatively pure tin solder, and to said end caps by electro-tin-plating said caps.

4. The method of claim 2 including:

forming an indented bead near each end of said outer cylinder to serve as stops for said end caps.

5. The method of claim 1 including:

wrapping refrigerant tube means of partly flattened cross-section in a helical array about said outer cylinder before applying said coating to said assembly.

6. The method of claim 1 including:

locating a barrier wall with an open ended tube projecting therethrough in the upper end of said inner cylinder in said assembly before applying said coating to said assembly; and

assembling a tube to said upper end cap, with one end extending downwardly for subsequent connection to said tube carried by said barrier wall, before applying said coating to said upper end cap.

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