US 3796416 A
A humidifier drum construction having two spaced rigid circular end pieces and at least one unitary circumferentially disposed connecting piece therebetween, each connecting piece having an elongated flexible rail element and a plurality of rigid spaced rung elements thereon, whereby during drum fabrication the rail element can be flexed from the flat to a curvature smaller than the circular end pieces and the rung elements can be fitted transversely to and secured between the end pieces.
Description (OCR text may contain errors)
United States Patent [191 Knudsen Mar. 12, 1974 1 HUMIDIFIER DRUM CONSTRUCTION  Inventor: Robert F. Knudsen, Concord, Mich.
 Assignee: McGraw-Edison Company, Elgin,
 Filed: Sept. 7, 1972  Appl. No.: 287,056
52 us. Cl 261/92, 55/400, 55/498, 1 55/500, 55/D1G. 31 51 rm. (:1 B01! 3/04  Field of Search 261/92; 55/400, 404, 497-499,
 References Cited UNITED STATES PATENTS 2,782,015 2/1957 Perrine 261/92 X 2,941,620
V 6/1960 Thornburgh 55/498 3,596,886 8/1971 Trautman 261/92 3,598,370 8/1971 Hoag 3,599,942 8/1971 Herr 261/92 Primary Examiner-Tim R. Miles Assistant Examiner-Richard L. Chiesa  ABSTRACT A humidifier drum construction having two spaced rigid circular end pieces and at least one unitary circumferentially disposed connecting piece therebetween, each connecting piece having an elongated flexible rail element and a plurality of rigid spaced rung elements thereon, whereby during drum fabrication the rail element can be flexed from the flat to a curvature smaller than thecirculalr end pieces and the rung elements can be fitted transversely to and secured between the end pieces.
8 Claims, 6 Drawing Figures HUMIDIFIER DRUM CONSTRUCTION In certain humidifying devices, it is common to support a porus matting on a cylinder drum, to rotate the drum through water to wet the matting, and to provide forced air flow through the wetted matting for adding moisture to the air. The drum is formed of plastic to be I lightweight and corrosive resistant, and must be shaped true to allow proper support in and rotation through the water.
An object of this invention is to provide a drum construction having separate prefabricated components that can be easily and accurately assembled to form the finished drum. This allows the components to be fabricated, if required by a plastic specialist and shipped to the humidifier manufacturer, who then can assemble and secure the components together as required, using perhaps at most only simple fixtures or assembly aids.
Specifically, the invention discloses a humidifier drum having rigid end pieces either or each being provided with the-appropriate required close tolerance drum support edges, and further having at least one unitary piece connected between the end pieces. Each unitary connecting piece is in the form of a ladder having at least one flexible elongated rail element and a plurality of spaced rigid rung elements thereon. The end and connecting pieces can be shipped flat or nested with like pieces, can be assembled such as in a fixture by flexing the rail element to the curvature of the end pieces and fitting the rung elements between the end pieces, and can be secured together as by mechanical or chemical bonding.
The invention will be more fully understood and appreciated after referring to the following specification, the accompanying drawing forming a part thereof, wherein:
FIG. I is a perspective view of a drum formed according to the invention disclosed herein, and showing in phantom its typical relationship in a humidifier;
FIG. 2 is a longitudinal cross section of the assembled humidifier drum shown in FIG. 1;
FIG. 3 is a top plan view of a preferred embodiment of a connecting piece used in the fabrication of the drum shown in FIGS. 1 and 2;
FIG. 4 is an elevational view of the connecting piece sembly; and
FIG. 6 is a sectional view similar to FIG. 2, except showing the end and connecting pieces preassembled.
The humidifier drum assembly 10 shown is typically rotated about a horizontal axis where the lower part of the drum lies beneath and passes through water confined in an open top tank within a humidifier case. The drum assembly consists of a structural drum fonn 12 which has an open periphery and a porous matting 14 supported on the periphery which becomes wetted as the drum is rotated through the water. A fan 18 (phantom only) draws ambient air through an opening 20 (phantom only) in the case for forced air flow thereafter through the wetted matting and discharge outside the humidifier.
The disclosed humidifier drum 12 has a pair of spaced end pieces 30 and 32 and at least one unitary piece 34 connected between the end pieces. The end piece 30 is actually a hoop configuration and has a circular inner edge 36 which can ride on spaced powered rolls 37 (FIG/1 phantom only) journaled from the humidifier case showing one typical drive support of the drum. The end piece 32 is shown as a closed disc having conical wall 38 effective to diffuse the air coming toward it from the fan 18 to the circumferential drum periphery and matting 14 thereon. The wall 38 is well drafted even to its outer edge to allow compact nesting of line end pieces 32 within one another. The end pieces 30 and 32 have circular radially extended rims 40 and 42 respectively, typically of equal size where the drum is to be a right angle cylinder, and mutually facing cylindrical bosses 44 and 46 likewise of the same size.
The connecting piece 34 is fabricated as by molding from plastic as a unitary component having a pair of elongated side rails 48 and 50 and a plurality of spaced cross or rung elements 52 connected between the rails. The rails are of rectangular cross section narrow in the direction transverse to the rungs to allow the flexure from the flat (FIG. 4) to the circular (FIG. 5) and wide in a direction parallel to the rungs to give lateral stability to the piece. Each rung is circular or eliptical in cross section to provide smooth exterior surfaces and give lateral rigidity.
In the configuration shown, open recesses 54 and 56 are provided in the end piece bosses to receive rail elements 48 and 50 respectively, of the connecting element 34. To assemble the components, side rail 50 is fitted into its receiving recess 56 and the opposite end piece 30 is fitted with its recess 54 over the opposite side rail 48. The components are then fused in place by adhesive or by chemical bonding, or by ultrasonic welding or by staking. To provide for a foolproof as sembly, the eliptical cross section of the end rungs is extended across the rail and the end piece recesses are enlarged in only the corresponding specific areas to receive these rungs. When assembled, the outer circumferential land areas 60 and 62 of the end piece bosses and the central part of each rung generally line up with one another so that the matting 14 can be uniformly supported thereon between the rims 40 and 42.
While end piece 30 is shown with an interior edge that rides on the drive rollers, it would be entirely possible for the humidifier case to have support rolls (not shown) upon which the end piece exterior edges 40 and/or 42 would ride for powered support of the drum. Likewise, the diffuser end piece 32 is shown completely closed in the center, but this could be modifiedby having an opening covered by matting if greater matting surface area were desired. Likewise the connecting element 34 has been illustrated as having two side rails, although a third rail might be added for rigidity, or the elongated rail might actually be located spaced from the rung ends which thus would be directly secured to the end pieces. Only a single connecting element 34 has been illustrated which curves almost throughout the 360 of the circle with the end rungs 52 spaced apart only some 5 to 15 consistent with manufacturing toler ances without causing binding of same. It would be possible for extremely large drums where the length of a single connecting element might be too cumbersome to handle to use more than one such connecting element. In such a case, each of perhaps two similar elements would extend less than 180 again allowing an appropriate amount of clearance between the adjacent ends.
What is claimed is:
l. A humidifier drum, comprising in combination a pair of end pieces and innerconnecting means between and fixedly locating said end pieces, each end piece being rigid and having similarly sized circular exterior edges, one of the end pieces being in the form of a hoop and thereby also having an interior edge, the innerconnecting means consisting of at least one unitary piece having at least one elongated rail element and a plurality of spaced cross rung elements thereon, the rail element being flexible in the direction transverse to the rung elements to allow the shaping of same from the flat to a curve smaller than the exterior edges of the end pieces and the rung elements each being rigid and terminating at their ends along spaced parallel planes, and means between the end pieces'and each unitary piece for rigidly joining the pieces together with each rail element extending parallel of and the rung elements extending transversely of the end piece exterior edges.
2. A humidifier drum according to claim 1, wherein each unitary piece has a pair of elongated rail elements and the spaced cross rung elements are extended transversely of and between the rail elements.
3. A humidifier drum according to claim 1, wherein each end piece has an annular boss disposed to project toward the other in assembled position and being of similar size and shape, and wherein each unitary piece cooperates with the end piece bosses effective for joining the pieces together.
4. A humidifier drum according to claim 3, wherein each boss is provided with a recess suitable for receiving and cooperating with the unitary piece effective for rigidly joining the pieces together.
5. A humidifier drum according to claim 3, wherein each unitary piece has two elongated rail elements and the cross rung elements are extended transversely of and between and terminate at the rail elements and wherein the end piece bosses have annular recesses provided in adjacent faces thereof suited to receive the rail elements effective for joining the pieces together.
6. A humidifier drum according to claim 5, wherein each rung element has a generally circular or eliptical cross section to provide a smooth exterior surface devoid of corners.
7. A humidifier drum according to claim 5, wherein each end piece has a circumferential land area and a radial rim outwardly adjacent the land area, and wherein the exterior edge of each rung element lines up with the adjacent end piece land areas.
8. A humidifier drum, comprising in combination a pair of end pieces and innerconnecting means between and fixedly locating said end pieces, each end piece being rigid and having exterior edges sized to define the exterior of the drum, the innerconnecting means consisting of at least one unitary piece having a pair of elongated rail elements and a plurality of spaced cross rung elements extended therebetween, the rail elements being flexible in the direction transverse to the rung elements to allow the shaping of same from the flat to a curve smaller than the exterior edges of the end pieces and the rung elements each being rigid, and means between the end pieces and rail elements of each unitary piece for rigidly joining the pieces together with each rail element extending parallel to and the rung elements extending transversely of the end piece exterior edges.