US 3815258 A
A rotary tumbling drum for a clothes drying appliance providing a maximum drying volume for a given cabinet size. The drum is of a stepped configuration, having a large diameter portion positioned at the front of the drying appliance adjacent a loading opening in the cabinet and having a reduced diameter portion at the rear of the appliance adjacent to a drive motor within the cabinet.
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Description (OCR text may contain errors)
United States Paten [191 [111 3,815,258 1451 June 11,1974
1 DRYER HAVING DRUM WITH TWO DIFFERENT DIAMETERS  Inventor: William L. Beard, Jr., Evansville,
 Assignee: Whirlpool Corporation, Benton Harbor, Mich.
 Filed: Nov. 30, 1972  Appl. No.: 310,984
 US. Cl. 34/133, 34/139  Int. Cl F26b 11/04  Field of Search 34/133, 139, 241
 References Cited UNITED STATES PATENTS 857,161 6/1907 Cummer ..L; 34/133 3,029,525 4/1962 Pinder 3,039,285 6/1962 Smith 34/133 3,309,783 3/1967 Worst Primary Examiner-William F. OlDea Assistant Examiner-Paul Devinsky Attorney, Agent, or Fir mHill Gross, Simpson, Van Santen, Steadman, Chiara & Simpson 1 [5. i 7 ABSTRACT A rotary tumbling drur n for a clothes drying appliance providing a maximumdrying volume for a given cabinet size. The drum is of a stepped configuration, having a large diameter portion positioned at the front of the drying appliance adjacent a loading opening in the cabinet and having'a reduced diameter portion at the rear of the appliance adjacent to a drive motor within the cabinet. t
7 Claims, '3 Drawing lFigures DRUM WITH TWO DIFFERENT BACKGROUND OF THE INVENTION It is desirable in a clothes drying appliance to make the rotary tumbling drum as large as possible for a given cabinet size in order to give a clothes load the largest possible volume in which to expand during drying and to achieve an optimum tumbling action to separate and spread-out the damp clothes, thereby exposing more surface area to a drying flow of air passing through the drum. Drying drums are restricted in size in conformity with cabinet size, and by space requirements of the drive components housed within the cabinet. Dryer cabinets, in'turn, are generally limited to conform in size with mating clothes washing appliances and to size restrictions imposed by transporting and installing these appliances. In the past, the use of a single diameter drum required that the drum size reflect space requirements of the appliance drive motor.
BRIEF SUMMARY OF THE INVENTION A general object of the invention is to provide a clothes drying appliance with a drum having the largest possible drying volume for a given cabinet size.
Another object of the invention is to provide a clothes drying appliance with a stepped drum having two drum portions of substantially different diameters to promote an ideal tumbling action of clothes being dried. A feature of the invention is that the stepped drum provides an enlargement of the drumdiameter adjacent a front loading area of the appliance enclosure cabinet, at a location clear of the drive motor positioned in a rear corner of the cabinet. The step feature produces a peripheral speed variation between the two different drum portions, which is aided by a plurality of baffles to provide a greatly improved tumbling action to separate, circulate and spread-out clothing being dried. Accordingly, greater fabric surface area is exposed to the flow of drying air circulating through the drum at a given time and an improvement in drying effl'ciency is obtained compared to single diameter drum dryers of similar drum volume.
BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF THE INVENTION In the preferredembodiment of the invention, as illustrated in FIG. 1, I show a clothes drying appliance 10 comprising an enclosure cabinet 12 with a control console 14 thereon, housing a control device 16 for regulating the drying operation. A control knob 18 selectively sets the control device 16 for various drying cycles of 1 operation, as, for example, automatic or timed drying cycles. Theenclosure cabinet 12 comprises horizontal top and bottom panels 20 and 22, re spectively, a pair of vertical side panels 24, and vertical front and rear panels 26 and 28, respectively. An access opening 30 is provided inthe' front panel 26, asdefined by an axially in-turned flange 31, having aclosure door 32 cooperating therewith for loading and unloading the dryer 10.
The dryer 10 further includes a' stepped drying container for tumbling clothes, in the form of a revolving drum 34 housed within the cabinet 12 and extending axially from the front panel 26 to a bulkhead 36 spaced forwardly of rear panel 28. The drum 34 includes an open imperforated cylindrical rear portion 38 and an imperforated generally cylindrical front portion 39. Front portion 39 is of a greater diameter than said rear portion 38 and is connected thereto by means of an offset flange 40. Front portion 39 includes a radially inwardextending front closure wall 41 having an access opening 42 therein formed by means of an axially outturned flange 43. The flange 43 provides a forwardly extending bearing annulus which overlies and'is suitably journaled on complemental flange 31 of the cabi net l2. It will be apparent from the foregoing that opening 42 into drum 34 "and opening30 formed in front panel 26 are concentric, providing access into the rotatable drum 34 from outside the cabinet l2.-Drum 34 is supported at the rear by a pair of support rollers 48 (one being illustrated) mounted on bulkhead 36. A raceway on circumferential groove 50, indented in the peripheral wall of rear portion 38 serves as a track for the rollers 48.
A motor 52, mounted to bottom panel 22 in a rear corner of cabinet 12, rotatably drives the drum 34 by means of a drive belt 54 extending around the periphery of and in frictional engagement with rear portion 38 and around a motor pulley 56 mounted at one end of motor shaft 58. The other end of motor shaft 58 drives a blower60, arranged to circulate air through the drum 34. Blower 60 is included in a warm air system 62 posi tioned between rear panel 28 and bulkhead 36.
Bulkhead 36 serves to enclose the-open-ended rear portion 38of drum 34 and provides a fixed rear wall in which to locate a pair of spaced openings, comprising an air inlet 64 and an air outlet 66. The blower 60 draws moisture-laden air from the interior of drum 34 through outlet 66, through a removable lint screen 68, air duct to the blower 60 and out of the cabinet 12 through exhaust duct 72. Air exhausted from the drum 34 is replaced by ambient airentering the warm air system 62 by way of an intake opening in the rearpanel 28 (not shown), drawn through a fresh air duct 74., passing over heater means 76 and into the drum 34 through inlet 64. The wann air system 62 thus circulates a stream of warm air through the drum 34, subjecting clothing placed therein to a drying environment to remove moisture from the fabrics while the clothing is tumbed as the drum rotates.
In some instances it is desirable to freshen dry clothing or air dry delicate fabrics without subjecting them to heated air. Herein, the warm air system 62 will operate in the mariner just described, however, the
heater means 76 will be rendered inoperative by an appropriate setting of the control device 16.
To encourage tumbling action in the clothing being dried, a plurality of circumferentially spaced baffles 78 are mounted on the inner surfaces of the drum 34. As shown in FIG. 3, baffles 78 extend axially along the front and rear portions 39, 38 of the drum 34, each 7 being secured at one end by screws 80 directly to the inner cylindrical side wall 82 of a rear portion 38 while the other end is secured by screws 80 to mounting surface 88 of longitudinal rib members 84. Rib members 84 are formed as indentations in the cylindrical side wall 86 of front portion 39, extending radially inward whereby the mounting surfaces 88 are aligned with the cylindrical side wall 82 of the smaller diameter rear portion 38. Rib members 84 also serve as outward radial extensions of baffles 78. In an alternate form, rib members 84 may be eliminated and baffles 78 may be shaped so as to include the rib members 84- whereby the baffles can be directly secured to cylindrical side walls 82, 86 and extend along the longitudinal contour of the drums interior. Conversely, the inner edge of baffles 78 may be stepped or tapered.
It may be seen from FIG. 2 that the diameter of rear portion 38 of drum 34 is restricted due to the space requirements of motor 52 positioned in the rear corner of enclosure cabinet 12, while front portion 39, being located forward and clear of motor 52 has been enlarged to a maximum diameter consistent with the interior of enclosure cabinet 12. The larger diameter portion 39, positioned forwardly, effectively utilizes the available cabinet space and enhances the loading qualities of the dryer 10. The larger and smaller diameter drum portions 38, 39 both contribute significantly to the drums total volume and provide a differential between peripheral speeds of the two portions. These two different peripheral drum speeds, inherent in the stepped drum 34, are effective to vary the tumbling action, encouraging the circulation of clothing back and forth between the two drum portions 38 and 39, as well as tending to open-out and separate the clothing being dried to accelerate the drying process by providing a more intimate exposure of the clothing to the flow of drying air entering the drum at the rear.
As shown in FIG. 3, the offset flange 40 is preferably disposed at a substantial angle so as to minimize any barrier between the two drum portions 38 and 39 which might impede the migration of clothing to the rear of the drum.
Numerous modifications of the invention may be apparent to those skilled in the art without departing from the spirit and scope of the invention, and it is to be un derstood I wish to claim all such modifications as may be reasonably and properly included within the scope of the appended claims.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A clothes drying appliance having in combination:
a cabinet; a drum rotatably mounted in said cabinet; an access opening in said cabinet providing access to said drum; means to circulate the air through said drum; drive means positioned within said cabinet, remote from said access opening and drivably coupled to said drum and said air circulating means; heating means to heat air being circulated through the drum, said drum having a front wall formed with an access opening therein and through which a batch of materials to be tumbled may be selectively inserted and removed, and an outer peripheral circumferential continuous wall means for said drum comprising a first portion forming a first cylindrical wall extending axially rearwardly away from said front wall and being spaced radially concentrically outwardly from the rotational axis of the drum at a first spacing dimension,
thereby to form radially inwardly thereof a first tumbling zone of a first given cross-sectional area, and comprising a second portion forming a second cylindrical wall extending axially forwardly away from a rear portion of the drum and being spaced raidally concentrically outwardly of the rotational axis of the drum at a second spacing dimension different from said first spacing dimension, thereby to form inwardly thereof a second tumbling zone of a cross-sectional area correspondingly different from said first cross-sectional area,
and an intermediate offset flange forming a radial wall integrally joining said first and second cylindrical walls and providing a junction between the first and second tumbling zones.
2. For use in a clothes drying appliance, a container for tumbling clothes comprising:
a drum rotatable on a generally horizontal axis,
said drum having a rear portion adapted to be disposed closely adjacent a bulkhead of an enclosure cabinet and through which temperature conditioned air is circulated through the drum, said drum having a front wall formed with an access opening therein and through which a batch of materials to be tumbled may be selectively inserted and removed, and an outer peripheral circumferential continuous wall means for said drum comprising a first portion forming a first cylindrical wall extending axially rearwardly away from said front wall and being spaced radially concentrically outwardly from the rotational axis of the drum at a first spacing dimension, thereby to form radially inwardly thereof a first tumbling zone of a first given cross-sectional area, and comprising a second portion forming a second cylindrical wall extending axially forwardly away from said rear portion and being spaced radially concentrically outwardly of the rotational axis of the drum at a second spacing dimension different from said first spacing dimension,
thereby to form radially inwardly thereof a second tumbling zone of a cross-sectional area correspondingly different from said first cross-sectional area,
and an intermediate offset flange forming a radial integrally joining said first and second cylindrical walls and providing a junction between the first and second tumbling zones.
3. The clothes drying appliance according to claim 2, wherein the first and second generally cylindrical wall portions are generally equal in length.
4. The clothes drying appliance according to claim 2, further characterized by said offset flange comprising an angled connection between said first and second generally cylindrical wall portions whereby materials being dried may freely move from one portion into the other portion during drum rotation.
5. The invention as defined in claim 2 and further characterized by 6 baffle means in said drum to encourage tumbling in 7. The invention of claim 2 and further characterized said first and second zones and comprising rib by the clothes drying appliance constituting a clothes means projecting radially inwardly into the tumdryer having a cabinet providing said bulkhead and in bling zones and extending axially beween the front which said drum is rotatably driven, and rear of the drum. 5 said second cylindrical wall being of lesser diame- 6. The clothes drying appliance according to claim 5, ter than said first cylindrical wall, wherein said first generally cylindrical portion has at and a drive motor in said cabinet adjacent said secleast one longitudinal indented rib member for supportend wall portion and being drivingly connected to ing a baffle, said rib member extending radially insaid drum by a belt means engaging said second cywardly to align with said smaller diameter of said sec- 10 lindrical wall. 0nd generally cylindrical portion.