US2273157A

US2273157A - Heat transferring device

Info

Publication number: US2273157A
Application number: US200357A
Authority: US
Inventors: Tenney Dwight
Original assignee: EDWIN F TILLEY
Current assignee: EDWIN F TILLEY
Priority date: 1938-04-06
Filing date: 1938-04-06
Publication date: 1942-02-17
Anticipated expiration: 1959-02-17

Description

Feb. 17, 1942. D. TENNEY HEAT TRANSFERRING DEVICE Filed April 6, 1938 INVENTOR;

Orv/7hr Tenney a) Mv- W ATTORNEYS tips of all of the radiating fingers.

Patented Feb. 17, 1942 UNITED STATE HEAT TRANSFERRING DEVICE Dwight Tenney, Verona, N. J., assignor to Edwin F. Tilley, Dunellen, N. J.

Application April 6, 1938, Serial No. 200,357

1 Claim.

This invention relates to heat exchange devices. It is in the nature of an improvement upon heat exchange devices of the type which consists of a tube or conduit for carrying a heating or cooling medium and provided with a heat transferring element which consists of a strip of metal wound spirally about the tube and provided with integral, radially extending fingers.

Such a device is subject to the objection that the radially extending fingers have no substantial strength or rigidity so that they are apt to be disarranged and deformed during shipment or other handling of the device. It is necessary, therefore, that the device be packed and handled with the utmost care to avoid detrimental deformation. The device is also subject to the objection that the finger edges are raw, sharp edges which are apt to cut or scratch the hands of workmen who are required to handle or install the device.

It is an object of the present invention to overcome these difliculties of the prior structure and at the same time to increase the heat transferring efiiciency. To these ends, the device is, in general, constructed as before, but there is added a binding strip of sheet metal which is spiral in form and which is folded over to embrace the The binding strip, though itself light, combines with the radiating fingers to produce a rigid and substantial wound spirally. around the tube I, this strip being formed with a multiplicity of radiating fingers 3 which are integral with the strip, and which project substantially at right angles to the strip body and substantially radially of the tube l. A sheet metal binding strip 4 is folded about and pressed upon the outer extremities of all of the fingers 3, the strip 4 taking a helical form as illustrated in conformity with the disposition of the outer extremities of the fingers.

The strip 4, though of light gauge metal, is itself a fairly rigid member because of the fact that it is folded upon itself. The strip, moreover, serves to combine and unite the outer extremities of all of the fingers so that the fingers support the strip and afford mutual support to structure which is not at all fragile or delicate and which can be handled and shipped, therefore, without liability of being damaged. The strip moreover forms a smooth guard edge for the edges of fingers which protect the workmans hands against liability of cuts. The strip further provides an additional metallic body for promoting the transference of heat, and thereby increases the heat transferring eiliciency of the structure.

Other objects and advantages of the invention will hereinafter appear.

In the drawing forming part of this specification and illustrating a practical and advantageous embodiment of the invention;

Fig. 1 is a sectional. plan view partly broken away of a device embodying the invention;

Fig. 2 is a fragmentary view in side elevation partly broken away of the device of Fig. 1; and

Fig. 3 is a sectional, detail view illustrating a A strip of metal 2 is one another through the strip. The result is that the fragility and delicacy of the radiating fingers is completely eliminated and a sturdy and substantial structure is produced which is not at all likely to be damaged when handled without special or extraordinary care.

The binding strip 4, moreover, serves to cover and guard the raw edges of the outer extremities of the fingers 3, thereby substantially eliminating all likelihood of a workman cutting or scratching his hands in handling or installing the device. This latter point is of importance in protecting the mechanics who make the device, the persons who pack and unpack the device before and after transportation, and the workmen who install the device for use.

The binding strip 4 has the still further advantage that it provides an added heat absorbing body of metal, in heat transferring relation with the fingers 3, which serves to increase the heat transferring capacity of the device.

The device may be made in any suitable manner and of any suitable material having high heat conductivity, such as copper or aluminum.

-A method of making the device which is very economical and advantageous involves mounting the tube I for rotation and feeding a strip of sheet metal from a reel toward the rotating tube. On its way to the tube the strip 2 has slits formed in it to divide a portion of its width into fingers 3, and the fingers are then bent at right angles to the unsevered body of the strip. The strip is wound continuously on to the tube in the form illustrated in Figs. 1 and 2. A strip of metal to form the binding strip 4 is also fed from a reel toward the revolving tube l into meeting relation with the outer extremities of the fingers 3. While traveling toward such meeting relation, the

strip is first bent to the acute angular form illustrated in dot and dash lines in Fig. 3. In this form' it meets the outer end of each finger I in the same radial plane in which the inner end of the finger meets the tube I. At that point the strip 4 i folded inward to the final or full line condition illustrated in Fig. 3. The tube holder may be mounted upon a carriage'which is driven in the direction of the axis of the tube I, in barmany with the pitch of the spiral or, if preferred, the tube holder may be axially immovable and the feeding and forming mechanisms for the

strips

2 and 4 may be mounted upon a carriage which is driven in the direction of the axis of the tube I in harmony with the pitch of the spiral.

The parts having been assembled in the manner described, the entire device is desirably immersed in acid to clean the surface and is dried by heat. It is then held over a solder pot while molten solder is poured over the entire exterior surface, and is subjected to a blast of air to blow away excess solder. The solder coated device is then quenched. This treatment causes the solder to fill in crevices which may remain between the strip 2 and the tube I, between adjacent turns of the strip 2, and between the fingers and the strip 4. The thermal conductivity of the device is substantially improved by thus improving the metal to metal contact. and at the same time the structure is made more rigid by fixing the parts more securely and firmly in relation to one another.

I have described what I believe to be the best embodiments of my invention. I do not wish. however, to be confined to the embodiments shown, but what I desire to cover by letters Patent is set forth in the appended claim.

I claim:

A heat transferring device, comprising in combination, a substantially cylindrical. body. a strip of thin sheet metal wound helically thereon and having a multiplicity of integral radiating fingers with the outer ends of the same spaced and separated but disposed in a substantial helical series and a strip of thin sheet metal extended continuously over the separated ends of said radiating fingers and folded flat down over the opposite faces of. said fingers in clamping engagement therewith and forming a continuous helical guard enclosing and entirely covering the ends of said fingers and binding the separated fingers together in their spaced relation.

DWIGHT TENNEY.