US 2165884 A
Description (OCR text may contain errors)
y 1939- J w. CHAMBERLIN El AL 2,165,834
CLEANING TEXTILE AND SIMILAR MATERIALS Filed March 6, 1937 11 Sheets-Sheet l ATTORNEYS.
July 11, 1939. V J. w. CHAMBERLIN ET AL CLEANING TEXTILE AND SIMILAR MATERIALS Filed March 6, 1937 ll Sheets-Sheet 2 I N V EN TORS (/MMBEEUI/ JOHN W.
W. 6 7 m m m aifi A A M E V m Y y 1939- J. w. cHAM'BERuN ET AL 2,165,884
CLEANING TEXTILE AND SIMILAR MATERIALS Filed March 6, 1937 11 Sheets-Sheet 3 .HI I l'' JNVENTOK'S. JOHN w. Ll-IHMBEEl/H 25x 42; aesizrzt/n A TTORNEY y 1939- J. w. CHAMBERLIN ET AL 2,155,384
CLEANING TEXTILE AND SIMILAR MATERIALS Filed Maqch 6, 1937 l1 Sheets-Sheet 4 I N V EN TOR$ 76 I 7 JOHN w. C/IHMBEQL/H AT RNEYS. I,
July 11, 1939.
Filed March 6, 1937 ll Sheets-Sheet 6 July 11, 1939. J. vy. CHAMBERLIN ET AL CLEANING TEXTILE AND SIMILAR HATERIAIJS Filed March 6, 1937 ll Sheets-Sheet 7 INVENTOM. C/fflMEtQUN QEX 401. 54135 1,,-
*L A ORNEYS.
y 1939- J. w. CHAMBERLIN ET AL 2,165,884
CLEANING TEXTILE AND SIMILAR MATERIALS Filed March 6, 1937 ll Sheets-Sheet 8 INVENTOR. JOHN W. CHHMBEQL/fi BY 25)! 401- BHASETKJK' /7Z m A ORNEYS.
y 1939- J. w. CHAMBERLIN ET AL 2,165,884
CLEANING 'IL'EX'TEILE AND S IMILAR MATERIALS Fil ed March 6, 19s? fig is 11 Shets-Sheet 9 July 11,1939. .1. w. CHAMBERLIN ET AL CLEANiNG TEXTILE AND SIMILAR MATERIAL S Filed March 6, 1937 ll Sheets-Sheet 10 IN V EN TORS JOHN W. CHflMBED/JH gsx mp1 anxrrr, Jr:
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J. W. CHAMBERLIN ET AL CLEANING TEXTILE AND SIMILAR MATERIALS 11 Sheets- Sheet 11 Filed March 6, 1937 i TTORNEYS.
Patented July 11,1939
PATENT oF ica CLEANING Tex-rum:
- MATERIALS John W. Chamberlin and Rex Earl Bassett, Jr.,
AND SIMILAR rare 2 ssum South Bend, Ind., assignors to Bendix Home Appliances, Inc., Detroit, Mich, a corporation of Delaware Application March s, 1931, Serial No. 129,429
This invention relates to the washing and cleaning of clothes and similar materials, and is described below in connection with a washing and rinsng and drying machine operatingautomatically according to a definite cycle,
Horizontal rotary washers have many advantages, but heretofore'they have been driven at relatively low speeds, and even then the clothes tangle to such an extent that it is necessary to reverse the direction of drive every few revolutions to permit the clothes to disentangle themselves again, This adds greatly to the time required for washing, and to the cost of building the machines.
An important feature of the present invention is based on the discovery that. while these washers must be periodically reversed when driven at low speeds, and while the efiiciency is very low at high speeds, there is a narrow range of intermediate speeds at which the washer operates at high emciency while driven continuously in the same direction. This also permits the building of 'a lighter and less expensive, as well as more eflicient machine, as the considerable weight needed in prior machines is mainly on account of the large inertia forces set up in periodically reversing a heavy drum full of wet clothes.
This critical range of speeds is such that the clothes are carried by the drum up out of the wash water, and are then thrown clear of the drum to fall across the drum back into the wash water, while at the same time currents are set' up in the wash water which also act on the clothes. bringing about a washing action of the 5 water through the fabrics in an entirely new and extremely effective manner which also has the advantage of minimizing .wear due to scrubbing action on the clothes. The manner of determining this speed, and various considerations relating to the depth of the wash water and to the clearance about the drum to permit the back currents necessary to give maximumefiectiveoess, is explained below'in detail, as well'as our own explanation of the attendingphenomena.
h gher range of speeds, at which, after the wash water is drained off, the clothes graduallyv distribute themselves uniformly about the drum ready for high-speed centrifugal -drying or e x traction. -A very important consideration, which greatly facilitates designing a cyclic automatic machine for washing and drying the clothes without removing the'm'from the drum, is that these;
two speed ranges'overlap, so that there is a ve y narrow range of speedsat which clothes will tumble in washing? as described, without tangling, so long as there is sufiicient water in the machine, and when the water is withdrawn (but at approximately the same driving speed) the clothes will distributethemselves over the periphery of the drum without tumbling", ready for high speed extraction. We are therefore able to control the action of the clothes, in "tumbling duringwashing and thereafter in distribution ready for high-speed centrifugal drying, by controlling the water in the' machine without any change in either the direction or speed of rotation of the clothes drum. This enables us to embody our invention in a very much simplified machine having a two-speed single-direction drive. Based on the above-described novel method of operation made possible by our discoveries, we have designed an improved type of washing and cleaning machine having many novel features of construction and arrangement. and. operation of, parts, which will be apparent from thefollowing description of the illustrative machine shown in the accompanying drawings, in which:
Figure 1 is a perspective view showing the top and front and one side of the machine;
Figure 2 is a perspective view of the machine from the front, with the outer casing removed; Figure 3 is a perspective view of an electric heater element;
Figure 4 is a perspective) view of the machine from the rear, with the outer casing removed;
Figure 5 is a perspective view, from the front, of the base of the machine and the shaft-supporting brackets carried thereby; v
Figure 6 is a partial verticalv section through the. soap-door; I
Figure 7 is a partial vertical section through the upper part of the clothes door;
Figure 8 is a vertical section through the ma 4 chine in a plane passing through the axis of the tub and drum;
'Figures 9 and 10 are vertical sections, at right angles to each other, through'one form of multiple control switch which may be used; We have also discovered that there is a slightly Figures 11, 12, and 13 are sectional views showing one form, and Flgures 14 and 15 are sectiona1 views, of an alternative form, of two-speed transmission, either of which may be used;
Figures 16 and 1'7 show an alternative arrange- "ment for'supplying water;
Figure 18 is a wiring diagram of the machine}; 5
Figure 19 is an operating diagram thereof;
Figure 20 is a wiring diagram of a modification o1 .the machine in which controls are provided for hot and coldwater lines, instead of supplying rather poor on heavy loads.
water from a single source at a predetermined desired temperature as in Figure 18;
' Figure 21 is an operating diagram to accompany Figure 20;
Figures 22, 23, and 24 are diagrammatic sections showing the action of the clothes in the drum at different speeds; and
Figure 25 is a diagram showing the washing action of the machine,
The illustrated machine comprises a casing consisting of suitable top and front and side panelslll and I2 and I4, removably mounted in any desired manner on a base l6. various combinations of these panels may be made integral with each other, as for example the top panel In. and one or more of the side panels l4.
As one convenient and rigid mounting for the tub and rotor parts described below, there may be secured to the rear of the base IS a triangular bracket l8 having its peripheral portion of channel section to provide stiffness and strength, and
provided with a central plate portion or web 20, and which carries a shaft bearing 22 at its apex. The base 15 also has secured to its forward portion one end of asecond bracket 24 yvhich has an inclined portion 26 leading to and through, and if desired rigidly secured to, the plate 20 and which then extends upwardly at 28 to support a second shaft bearing 30 spaced rearwardly from and alined with the bearing 22. A vertical third bracket 32 is shown mounted at the front of the base.
A cylindrical horizontal metal tub 34, covered with suitable heat and sound insulating material, is rigidly mounted between the brackets 18 and 32. generally cylindrical drum or clothes container 38, formed with several baflies or-inwardly-projecting ribs 40. The head of the drum 38 is radially ribbed or otherwise formed to stiffen it, and is secured to a head or spider formed or keyed or otherwise secured on one endof a shaft 42 journaled in the bearings 22 and 30. A U- section stamping 43 may be welded to the upper ends of the two shaft-supporting brackets, to tie them together and to hold the bearings 22 and 30.
The number of. baffles has considerable effect on the manner in which the machine operates. For example, the efficiency of five baflles is. high on low loads, average on medium loads, and The efficiency of three bafiles is near the average on all loads. The efficiency of four bafiles is not high on low loads, but is above average on medium loads and is high on heavy loads. For a domestic machine, four bafiles is the preferred number, because the machine is seldom operated with small loads, one pair of opposite baflies being somewhat higher than the other pair.
Between the bearings 22 and 30 the shaft 42 is provided. with a pulley 44 for a V-belt 46. passing over an idler pulley 48 adjustably mounted in-a slot 50 in the plate portion 28 of the first bracket, and over a drive pulley 52 on the driven shaft of a two-speed transmission 54 rigidly con nected to and driven by a main motor 56.
The tub 34 has pivoted thereto a clothes door 58 having a latch 63, and which swings either down to a horizontal or vertical position when open, as shown in Figure 2. If means is provided forholding the .door in a horizontalposition, it
formsa convenient support in front of the opening. The door preferably has its central portion If desired,
Within the tub 34 is a rotatable perforated made of glass, so that the washing action may readily be observed. According to one feature of our invention, adjacent and preferably above the door 58 there is mounted a soap door 62, through which soap powder or other detergent can be introduced while the machine is running and full of wash water, thereby permitting the operator to observe the formation of suds through the glazed door 58 and accurately control the amount of soap added.
The door 62 shown in the drawings is mounted on a bowed stamping 63 mounted on a pivot 65 inside the machine, so that it closes flush with the casing, and a bowed spring 6'! acts on it in tension with a toggle action to hold it shut or open, according to whether the ends of the spring are in a line on one side or the other of the hinge 65. The door closes against a frame in the form of an annular stamping ll secured to the tub 34 about the soap door opening therein. The stamping 63 is provided with wings 69, and is so shaped as to form a receptacle for soap powder when the door is horizontal, and to dump the soap powder into the machine when the door is swung shut to its vertical position. The arrangement just described is covered by our divisional application No. 231,653, filed September 26, 1938.
Water, at the desired temperature, is introduced into the tub 34 through a hose connection 64, under the control of a valve 66 operated by a solenoid or the like 68, being injected into the tub through a nozzle 69 projecting through the frame 10 of the door 58.
As hereinafter more fully explained, the water level in the tub is determined by including in the circuit of the solenoid 68 a switch '12, the
one illustrated being a double-acting switch operated to open and close two circuits, as hereinafter described, at predetermined high and low water levels, by spaced stops on a rod 14 carried by a float 16 in a float chamber 18 communieating with the interior of the tube 34.
The water is preferably injected at a temperature (e. g. 110 F.) suitable for washing woolens and the like. Instead of putting in hotter water in the first place when cotton materials are to be washed, we may inject the water at the lower (110) temperature, and then heat it to raise the temperature (e. g. to around 160 F.) during the washing of the clothes. For example, an immersion heater, or an electric resistance heater, shown as a ring 19 surrounding the drain collar 8! at the bottom of the tub, may be provided. Preferably this heater is controlled by a switch 83 on the front panel 12. To inject the water at this predetermined temperature, the inlet line 64 may be connected to the outlet of a hot and cold water mixing device, which may if desired be constructed and arranged substantially as described in application No. 72,312, filed April 2, 1936, by Rex Earl Basset, Jr. This arrangement for raising the temperature of the suds during the washing operation is claimed in our division application No. 241,614 filed November 21, 1938.
The housing 18 of the float mechanism may be utilized as a breather, to maintain constant atmospheric pressure in the tub 34 even when scaled ter splashing out through the conduit. This breather arrangement is more fully described and The cleaning liquid used in the machine, for
ordinary domestic washing, may be warm or hot water with a'detergent such as a soap compound containing 72% pure soap, and 28% alkali and the like. This compound, while of greatest effectiveness with water having a hardness of 5.25 grains per U. S. gallon, is reasonably satisfactory even with absolutely soft water, where theoretically pure' soap should be used, and is cheaper than pure soap.
We find it desirable to adjust the amount of soap accurately to each load, by feeding the soap compound (as previously explained) into the ma-' chine gradually through the soap door 62 while watching the formation of the suds through the door 58. 'Since the amount of soil varies in different loads and with different types of water, the amount of soap compound must be varied to correspond.
Woolen fabrics, and certain types of colored fabrics, are best washed at approximately 110 F., while for white and fast-color cotton fabrics the optimum temperature is 160 F. However, if cotton materials are placed in water at 110 F.,
and the temperature is increased gradually to.
160 F., as explained above, the washing efficiency is some 18% higher than at a constant temperature of 160 E., and for this reason as previousy explained we prefer to supply the water at 110 F. and heat it (when cotton materials are being washed) to the 160 F. range of temperatures during the washing operation.
The drain collar 8| communicates, through :a baflle 90 which directs the-water through a screen or strainer 92, with a sump 94 drainedby a suitable drain conduit 95 controlled by a drain valve 96 operated by. a solenoid 98. A removable cover I00 permits access to the screen 92 for cleaning purposes.
While the machine has been described as rotatable about a horizontal axis, some variation is feasible, and the axis may be somewhat inclined, although the efficiency becomes very poor when the inclination is greater than The two speeds desired for the drum may be secured by means of the two-speed motor,
for example of the type described in application No. 127,191, filed February 23, 1937, by Rex Earl v Bassett, or by means of a two-speed transmission. Two such transmissions are illustrated in Figures 11-13 and inFigures 14-15.
The transmission 54 in the form of 11-13 is assembled in combination with the motor 56. This motor is illustrated as a split-phase induction motor having a stator I I8 with a winding H2, and an armature II4 provided with afan I16 and keyed on an armature shaft, Ill. The
position. The end of the armature shaft II8 has a drive pinion I24 formed thereon, and has keyed thereto a cone clutch member I26 whichis held by the bearing I22 against movement to the left. A ring gear I28 coaxial with respect to the shaft I I8 has its ends formed with cone clutch surfaces,
. one of which cooperates with the clutch member,
I26, and the other of which cooperates with a conical clutch, surface on a planet carrier I30 provided with pivot pins I32 for planet gears I34 driven by the pinion I24 and meshing with the teeth of the ring gear I28.
The planet carrier I30 is keyed to a driven shaft I36, shown as recessed to carry a pilot bearing I38 for the reduced end of the shaft H8, and which is formed with a drive pinion I40 meshing with and drivinga driven gear I42 on a shaft I44 which projects exteriorly of the casing I20, and carries the drive pulley of the previously-described belt drive for the drum.
The partsI26-I28-I30 are held clutch together to rotate as a unit, at high speed,'by the axial thrust of the shaft I36 due to pressure through a ball I46 from a plunger I48 having its conical end forming the equivalent of a knifeedge fulcrum engaged by a recess in a lever I50 having a second recess fulcrumed on a knifeedge on a part I52 bolted tothe transmission casing. The lever I50 is. operated yieldingly by means such as a spring I54 engaged by a yoke I56 pivoted to the core I58 of a solenoid I60. The solenoid is shown mounted on top of the transmission casing.
Rotation of parts I26-I 28-I30 as a unit, when clutched together by the energization of the solenoid I60, is permitted by a suitable one -way clutch, shown as includmg spring-pressed clutch rollers I62 in wedge recesses in a clutch ring I64 encircling the ringgear-I28 and non-rotatably connected to the transmission casing by means such as a bolt I66.
When the solenoid I is de-energized, the parts I24 drives the planet gears I34 on the ring gear I28, which is held against rotation backward by the one-way clutch I62I 66, to rotate the planet carrier I38 and the shaft I36 at low speed.
In the alternative transmission of Figures 14 and 15, the motor armature shaft-H8 drives a pinion I10 shown pinned to the shaft. The pinion I10, in low speed, drives a gear I12 loose on a countershaft I14. The gear I12 has in its side a mck'et receiving the laterally-bent end of a friction coil spring I16 wound on the periphery of a clutch disk I18, and in low speed the gear I12 winds the spring I15 in a direction to tighten its coils upon the clutch disk I18;
I12 to drive the shaft I14. The shaft-I14 has keyed thereon a pinion I82 driving a gear I84 on a shaft I44, corresponding to shaft I44 of the first-described transmission, and which has secured thereto the drive pulley of the belt drive for the drum.
Adjacent the gear I84 the shaft I44 has sleeved thereon the extended hub of the drive pinion I10,
which hub is formed with a screw thread I86 onwhich is mounted a disk I88 about the periphery of which is wound a coil friction spring I89 having its end turned outwardly to engage and be held by a plunger I81; attached to the core I56 of a solenoid I60 which is energized when high speed is desired.
The-spring I89, when so held against rotation,
tends to unwind, but still has sufficient frictional drag on the disk I88 to cause the latter to I26I28I30 are de-clutched, whereupon pinion shift axially on the thread I86, to force toward the-left a gear I90 loosely mounted on the hub of the pinion I10. The gear I90 has its opposite side recessed to receive a small multiple-disk clutch I92, alternate plates of which are keyed to the gear I90 and to the hub of the pinion I-10. This clutches the gear I90 to the pinion I10.
The gear I90 drives (at higher speed) a gear I94 keyed on the shaft I 14, and causes that shaft to rotate faster. This causes the thread I80 to I turn in the disk I18 in a direction to back that disk off from gear I12. Since this tends to unwind the spring I16, it merely turns with a light frictional drag on the disk I18, since the disk I18 and the gear I12 are now unclutched and the disk is turning (with the shaft I14) faster than the gear.
The above-described transmission of Figures 14 and 15 is claimed per se in application No. 120,700, filed January 15, 1937, by Thomas B. Martin, since, while we may use it in the novel combinations embodied in our machine, the structure per se of this transmission is not of our invention.
For controlling the-cycle of operations, we may use the multiple cyclic switch described, and claimed per se, in application No. 78,635, filed May 8, 1936, by Rex Earl Bassett. Another cyclic switch which may be used is shown in Figures 9 and 10 of the attached drawings, and is substantially the same as that claimed in application No. 240,163, filed November 12, 1938, by Rex Earl Bassett, Jr. This switch includes a separable two-part housing 200, 202 carried by a bracket 204 provided with a spring catch or retainer 206 and which is mounted on the front panel I2. A cable 208 is made up of the various electric connections from the valve solenoids, the motor, etc., and each of these connections is secured to one of a plurality of sockets 2I0 carried by an insulator plate 2I2 forming the rear face of the housing part 200.
The housing part 202 has mounted therein an electric motor 2I4 connected in parallel with the motor 56 (see Figures 18 and 20 and which is a self-starting motor of some kind, preferably a synchronous motor or the like. This motor 2I4 drives a suitable reduction gearing 2I6 (not shown in detail) which in turn drives a shaft 2I8 at a speed, for example, of one revolution per minute. If preferred, the shaft 2I8 may be connected, for example by a flexible shaft, directly to the main motor 56.
The shaft 2I 8 is shown as provided with a earn 220 (note Figure 10) which once each revolution gradually lifts and then suddenly drops a pivoted lever 222 having a cam roller 224 riding on I the periphery of the cam 220. Each downward movement of the lever 222 causes a pawl 226 pivoted thereto to advance by one tooth a ratchet 228, a holding pawl 230 preventing retrograde movement of the ratchet. A spring 232 tensioned between the pawls 226 and 230 holds both pawls against the ratchet 228, and also serves to urge the lever 222 downwardly toward the cam 220.
An'insulator plate 234 forming the front end of the casing section 202 is connected to a partition 236 by insulated tie rods 238 which extend rearwardly to support the drive unit consisting of the motor 2I4 and the reduction gear 2 I6. The partition 236 carries a bushing 240 which serves as a bearing for the shaft 2), and also for the reduced rear end of a main timer camshaft 242 on which the ratchet 228 is mounted.
The shaft 242 is also journaled in the front plate 234, and extends forwardly through the casing section 200 andthrough the front panel 12, and has detachably mounted thereon a suitable indicator handle 244 moving over a scale may be used for the clothes door 58.
'tral position with the parts in line.
246 (Figure 1) which is graduated to indicate the cycle of the machine. handle 244, the casing section 202 with the mechanism inclosed therein, and including the shaft 242, can be removed bodily for adjustment or repair, without disturbing the connections 208'.
The shaft 242- has fixed .thereon a series .of Bakelite cams'250, shown mounted in a unit on a sleeve 252 which is pressed onto the shaft, to'
raise and lower the outer contacts of a series I, 2, 3, 4, (or Ia, 2a, 3a, 4a, 5a in Figure 20) "of spring contacts mounted on the face plate 234, and forming a series of control switches. The contactsare connected .to plugs 256 adaptedto be detachably inserted in the sockets 2I0, for the double purpose of connecting the casing sections 200 and 202 and electrically connecting the leads 208 with the switches I, 2, 3, 4, etc.
'It will benoted from the wiring diagrams in Figures 18 and 20 that switch I controls both motors 56 and 2I4, switch 2 the high-speed clutch solenoid I60, switch 3 the drain valvesolenoid 98 and switch 4 the inlet valve 68, or 68a in' the alternative arrangement of Figure 20.
By turning the indicator handle 244 forward (which is permitted by the ratchet 228, which can turn forward but not backward) the switch I is closed, and this switch remains closed, to cause the two motors to operate, until the end of the cycle. Also, the indicator handle 244 may when desired be turned forward over part of the Wash" period, to shorten it by that much when the full period will not be required. From there on, the control switch causes the machine to operate automatically for the remainder of the cycle.
Figures 16 and 1'1 illustrate an alternative arrangement, in which no heater is used, and hot and cold water are mixed in the machine, and which may be used with the wiring of Figure 20 and the cycle of Figure 21. In this arrangement nected to two hose elements 264 inclosed in a heat-insulating cover 266 to form a heat-transfer means by which the cold water is partially heated before reaching the machine. The hot water hose connects to the inlet hose 64 directly through a valve 66a operated by a solenoid 68a operatively controlled by the switch 4a. The cold water is controlled by a second valve operated by a solenoid 68b. This solenoid 68b is connected in series with a thermostatic switch 19a and with switches 5a (cyclic) and 83 (manual) arranged in parallel. series with the switch 4a. When switch 83 is closed, the thermostatic switch 19a controls the cold water supply regardless of the switch So, whenever the switch 411 is closed.
In order to facilitate the draining of the tub 34, a water pump 210 may be mounted on the end of the motor 56, and driven by that motor, between the tub 34 and the drain valve 96. The pump is not necessary if there is a gravity drain, but is essential when the water has to be lifted agai st gravity into a set-tub or the like.
Figure '7 illustrates one form of latch which In this arrangement the latch handle 60 is pivoted at the top of the door, coaxially with a separate latch member 212 connected to the handle by a lostmotion pin-and-slot connection 214. The latch member 212 forms a toggle with a compression spring 216 which holds the latch member 212 either closed or open until manipulation of the handle 60 moves the toggle to and past its cen The latch By removing the The switch 83 is in.
40 the hot and cold water pipes 260 and 262 are con-- member 212 is preferably formed with a U-shaped recess for the stationary hook-shaped retainer 218, so that when the door is slammed shut the impact of the latch member 212 itself will cause shifting of the toggle past center to a position where spring 216 holds the door tightly shut.
. A clothes receptacle or drum 38 having a volume of approximately 3600 cubic inches is required for efficiently washing a quantity of textiles weighing nine pounds when dry, with a proper quantity of water; however,-the machine will operate reasonably satisfactorily if the load does not exceed six pounds per cubic foot of cylinder capacity. One axial end of the receptacle or drum is preferably left open, as previously described, for the insertion and removal of the textiles, the shaft upon which the receptacle rotates being located at the other end., The preferred dimensions for a cylinder of this capacity are a diameter of twenty inches and a length of twelve inches. These dimensions give a volume of approximately 3769.92 cubic inches, and the theoretical optimum load is 9.5 pounds dry weight oftextiles, as hereinafter more fully explained.
Bailles may be provided if desired, on the vertical back and front walls of the drum or onother surfaces contacted by the textiles, as well as the bailies 40 projecting inwardly from the periphery. At any rate some irregularity of the periphery of the cylinder is highly essential. No very great difierence exists between baffies having cross-sectional angles from to 60, in the particular machine herein illustrated. When the angle is increased beyond 60, however, efficiency drops rapidly until almost zero eillciency is reached at In present commercial practice the height of the bailles averages 22.2% of the diameter of the cylinder.- In domestic practice baflies having a height that is 20% of the diameter of the cylinder are usually used. Such high baflles are necessary to lift the clothesin a low-speed cylinder, as the clothes gather in front of the baffles.
Low baflles have'a desirable scrubbing action on the clothes, but cannot be used with these low-. speed machines. We have determined that in our machine the highest efficiency is reached with bailles having a height that is 1.5% of the diameter of the cylinder. It isbelieved that in this optimum construction a balance is struck between the liftingaction of high-baffles and the scrubbing action of low baffles,
In one cylinder twenty inches in diameter which we have used very'successfully, the baifles were onexlnch and a half high, with a cross-sectional angle of.45. The table below summarizes the comparative efficiencies ofbaiiles of various I heights, at high of rotation, expressed as the quantity of dirt removed in a certain stand- 00 ardwashing-operatlon.
. 7 Hcightin ,Dirtre- Proportbnofcylinderdlametm aches moved 3 illustrated machine approximately from 2 to 'In the operation of the machine described 9 /2 pounds. When the cyclic control switch is started, warm wash water is injected into the tub 34 until it reaches-a depth whichis preferably approximately 25% of the drum cylinder diameter, i. e. five inches for a twenty-inch drum. There should be a clearance between the drum and the tub sufficient for the back currents of the water; this clearance should be at least 20% and preferably 25% of the water depth.
This load is about double that which can be handled in the usual low-speed machine; for example, one of these prior machines with a 20- inch cylinder 12 inches deep would be restricted to a load of about 5 pounds instead of anoptimum load of Q pounds and a maximum of about 12 pounds in our machine.
Based on the best observations we have been able to make, our explanation of the theoretical background of the invention is as follows. At low rotational speeds, the centrifugal force acting on the clothes is not sufllcient to hold them against the drum to any considerable height, so they soon tangle up into a ball as shown inFigure 22, and merely roll around with very little washing action. This is why prior low-speed machines must periodically be reversed to untangle the clothes.
When the speed is increased to the point where the centrifugal force at the drum periphery is 50% or more of the gravitational force acting on the, clothes, the clothes stop rolling into a ball and the tangling is'less. When the centrifugal force at the drum periphery reaches 70% of the gravitational force, the clothes are carried nearly to the top of the drum and then fall back across the'drum, traversing a path which is roughly an ellipse. At this speed, which is expressed generally, in revolutions per minute, by the formula 2500 drum radius in feet avery efiective optimum washing action takes place, and there is very little tangling.
At speeds exceeding this, up to that a little below that at which the clothes are held against the drumall the way around, tangling disappears entirely and the washing action, while slightly slightly more) of the gravitational force, as the clothes are lifted with the water by the rotating cylinder, as illustrated in Figure 25, parts of the clothes and part of the water are beyond a crit ical circle K (Figure 25) where, except for water action, the clothes .would be held against the cylinderall the way around, the centrifugal action over-balancing gravity. As the drum turns, the water outside of this critical circle is thrown centrifugally out through the drum perforations and drains back down to the bottom of the tub.
- Part of the water, and parts of the clothes, being inside the critical circle X, as the drum ap proaohes the zenith position, tend to fall back across the drum, the clothes tending to drag with them also that part of the load which is beyond the critical circle. Due to their inertia, they fall across-the drum as shown in Figures 23 and 25, to a point on the opposite lower side of the drum.
When the water drains away, the clothes tend force.
Experiments on wet clothes without preliminary washing show that the best speed for distributing the clothes in the drum is that at which the circle X is quite close to the drum, i. e. at which the centrifugal force at the drum periphery is approximately 100% of the gravitational force, or even slightly more. This is, in revolutions per minute, approximately determined by the formula 3000 drum radius in feet We believe that one important feature of our invention is in the great simplification of the machine made possible by our discovery that at a speed approximating, or slightly below, the one determined by this formula, clothes will have a satisfactory washing action with a single direction drive when there is water in the machine, and will also distribute properly when the water is drained out.
The above action, especially the washing action, depends to some extent also on the load in the machine, on the water level, and on the clearance between the drum and the tub. The minimum load that will tumble in the novel described manner during washing is about 1 pounds of dry clothes per cubic foot of drum volume, and the maximum that will distribute effectively is about 4 pounds per cubic foot of cylinder (drum) volume, although effective washing takes place up to six pounds per cubic foot of drum volume. Thus in the illustrated machine, with a 20-inch drum, to wash and distribute effectively, the load should be between 2 /2 to 9% pounds (dry weight).
The water level is also important. Below about 20% of the drum diameter, the water does not operate efiectively to cause thedescribed tumbling of the clothes. At about 25% of the drum diameter (i. e. 5 inches with a 20 inch drum) an optimum condition is reached where there is a maximum tumbling. Above 30%, as the increasing water level causes more flotation and less tumbling'of the clothes, and as the onev action interferes with the other the 'eifectiveness drops considerably.
Above about 40% to 50%, up to a point where the cylinder is nearly full, an efiective washing action is secured by the agitation of the clothes floated in the water. This last is an effective type of washing, although less so than with the tumbling described as a 25% water level, but
it requires a great deal of water and soap. Where this is not a serious. drawback, an efficient washing machine can be used utilizing a water level of from 45% to of the drum diameter, and most of the mechanical features of our invention are highly advantageous in such a machine.
The optimum water level, however, is around 25%, and at least between 22% and 30% of the drum diameter, with the scrubbing action due to the described tumbling, together with economy of water and soap.
It is also important, as above explained, especially with the optimum water level and with the clothes tumbling as described, to have a clearance between the tub and the drum which is at least 20% and preferably 25% of the water level (i. e. at least 1%; inches with a 20 inch drum). Greater clearance does .not seem to afi'ect the eificiency much either way, but increases the amount of water used. The clearance is not of very critical importance in floating the clothes with the water above 45% of the drum diameter, as the return currents described below are only as described when the clothes are tum- Y most of the water is forced out radially into the tub as indicated by the arrows. The water level in thetub changes slightly from the static level A-A to an inclined level B-B. Inside the drum the water level drops to the curve C. The water forced out into the tub in the area Y drains back down clockwise into the bottom of the tub.
The clothes, with most of the rest of the water, fall away from the top of the drum in a curved path which is the resultant of the centrifugal and gravitational components, and-are thrown across the drum above its axis, back into the wash water at the bottom. A little water is carried all the way around by the drum, as indicated by the arrows D.
Water flows back into the drum mainly as indicated by arrows E, in an area just above the bottom of the drum on the side from which the drum is turning. This is because the water by the time it has reached the bottom of the drum has again picked up enough centrifugal force, added to the head inside the drum indicated by the line C, to balance'the head (B--B) outside the drum. Water reaches the area E inainly along three paths: (1) the back-flowing water from area Y, indicated by arrows F, (2) a small eddy G due to the fact that the area E is slightly below the level 13-3, and (3) a horizontal flow of water in the tub around the front and back walls of the drum (arrows H). A little water is also carried around by the drum (arrows D).
The inflow of water at E lifts the materials being washed away from the drum, as indicated at K. This inflow takes place'continuously, and insures that no articles of: clothing will stick to the drum. I
The critical water level (i. e. about 25% of the drum diameter) is that level at which the head of water outside the drum-is sufliciently greater than the head within the drum plus the centrifugal force on the water within the drum, to cause the above-described inrush of water at E.
With the described water level and drum clearance, and with a load within the described limits, the speed of rotation should be between (in revolutions per minute) 2500 drum radius in feet at which speed there is the maximum washing action, and about drum radius in feet at which speed there is a satisfactory washing action with a maximum distributing action after draining out the water. We prefer to use a speed substantially at the upper limit of this range, as perfect distribution is more important than a few minutes greater washing time. While, therefore, the upper limit of this range may vary a few revolutions per minute above or below that derived from the formula, on account of variawashing speed has been at the top of the critical range, the clothes will rotate almost in contact with the drum. Withdrawing the water at the end of the washing period may also decrease the load on the motor so that the speed steps up slightly, whereupon the ellipse expands until it almost fills the drum. The garments however can still move freely relatively to each other, and
if desired, be reduced by turning the multiple control switch ahead as previously explained. At
the end of this period, the drain valve opens, and the dirty wash water runs out. This closes the float switch again, and (since the inlet valve is open) injects'clean water to flush out the clothes. Before the clothes can begin to distribute themselves as described below,-the drain valve may if desired be closed again, to give a rinsing period during which the clothes are tumbled-in clean water. Or if preferred the druni may be operated at high speed for a short time, after the draining, and then the tub refilled with clean rinse water and the clothes again tumbled. The drain valve finally opens to give a final short flushing period. If desired, there may bemore than one of these rinsing periods.
Thereafter, the drain valve remaining open, the inlet valve finally closes, the drum still being driven at its lower speed. It will be noted that the distribution period that follows the last opening of the drain valve includes a tirfie (usually about one minute) when the clothes are first substantially in the washing and rinsing part of the cycle, and then as rinse water is injected while the drain remains open, to give the final flushing action, the-clothes gradually lose their load of water,,and begin to distribute themselves gradually uniformly about the periphery of the drum. If the motor is not so powerful but that, as the load on the motor decreases as the water drains out, the motor speed steps up a few revolutions per minute, this will bring the speed to a still more effective speed for distribution; however, this is not necessary although it is usually desirable to use such a motor because of considerations of cost, since its use is not detrimental.
The second part of this period, after the closing of the inlet valve, and which is usually about another minute, sees the clothes lose enough water (partly by merely draining off and partly by the low-speed centrifugal action of the driun) to become dry enough to give approximately uniform distribution about the cylinder, tumbling gradually ceasing and the. ellipse of moving clothes gradually expanding until it almost fills the drum. With very heavy loads there may remain a little tumbling of a garment or two clear at the center, but not enough even then to produce substantial unbalance of the drum when it is speeded up.
Thus, by selecting a speed which will cause tumbling when there is water in the tub, and
which is also within the range which will cause distribution when thewater is drained out, it
becomes possible to drive the drum constantly at a single speed and in one direction only, until ready for the high speed extraction step. The
the water, rather than by complicated speed varying controls such as have always heretofore been considered necessary.
Finally, as already explained, the transmission is shifted into high speed for a period of time long enough to extract most of the water, leaving the clothes substantially ready for ironing, and then the cycle automatically comes to a close. Almost immediately upon the increase in speed, the clothes which are undergoing distribution in a shape which is roughly elliptical, expand out against the drum and cease all tumbling.
The details of theabove-described cycle of operations will be apparent by comparing Figures 18 and-19. Figure 14 shows the wiring of the two motors 56 and 2, the multiple switches I, 2, 3, and l, the solenoids I60, 98, and 68, the heater 19, the double-acting float switch 72, and the manual switch 83 in series with the heater 1!), and their connections to the usual H0 volt line wires. Figure 15 shows a cycle of the machine (45 minutes long) with concentric zones indicating the switches I, 2, 3, and 4 and the float switch '12. It will be noted that this switch in one position (tub filled to" the desired level with water) closes the circuit through the heater 19 if the switch 83 is closed, so-that the heater cannot be turned on unless the tub contains water. In its other extreme position the switch is in the circuit for the clutch solenoid I60, so that the transmission cannot be shifted into high speed unless the tub is emptied of water.
In this cycle the multiple switch, after a segment in which all switches areofi, and beyond which the multiple switch is turned manually to start the machine, causes the machine to operate in the following sequence: (1) adjustable washing period, with the float switch closing as soon as the tub is filled to the desired level, (2) drain valve opens and, as soon as the water level drops enough to open the inlet "valve, rinse water is sprayed in to give a flushing period, (3) a distribution period which in practice is merged in the latter part of the flushing period asthe water drains away, (4) a short high-speed extraction period, (5) rinsing by tumbling the clothes in clean water, (6) drain and flush, (7) distribute, and (8) extract at 'high speed, a total of about 45 minutes.
By leading hot and cold water conduits 264 into the machine as described in connection with Figure 16, and providing hot and cold water valves controlled bythe solenoids 68a and 68b, the heater I9 may be eliminated, and the wiring of the diagram of Figure 20 and the cycle illustrated in ever that valve is open, while the cold water valve has its solenoid 68b in series with the thermostat switch 19a and connected to the line through switches 5a and 83 in parallel.
Thus if switch 83 is closed, the cold water goes on whenever the switch 4a operates the solenoid 68a, provided the water is hot enough to operate the switch 19a, so that mixed water is used all through the i cycle. If, 'however, switch 83 is open, inspection of Figure l'l-will show that during the washing period the cold water is turned off regardless of the thermostat 19a, and high temperature water is used; however, during the second (or both) of the two rinse periods valve 5a isclosed and mixed water is used.
In the cycle of Figure 21, there is first, (after advancing the multiple switch to start the machine) a soaking period during which the machine is filled with mixed warm water and then drained, leaving the clothes thoroughly soaked, whereupon the machine stops. The operator then comes back as soon as convenient, and again starts the machine by advancing the multiple switch, at thesame time adding soap powder until he sees that suds of the desired soapiness have formed.
There then follow the steps (after washing is completed) of (1) drain and flush, (2) distribute, (3) extract, (4) fill and rinse, (5) drain and flush, (6) distribute, (7) extract; (8) fill and rinse- (9) drain and flush, (10) distribute, and (11) extract. The total running time is about one hour. The steps indicated as (7), (8) (9) and (10) may if desired be omitted.
While one particular machine and its operation have been described in detail, it is not our intention to limit the scope of the invention by that description, orotherwise than by the terms of the appended claims. The above-described brackets for supporting the tub are claimed inapplication No. 135,955, filed April 9, 1937, by Alfred H. Haberstump, and application No. 135,954, filed April 9, 1937, by Andrew 0. McCollum and Lovett-.
1. That method of cleaning fabric materials such as clothes, by the manipulation of a rotatable generally cylindrical and generally horizontal drum, which comprises rotating the loaded drum continuously in one direction with its lower portion dipping into a cleaning liquid and at such a speed that the wet materials are held centrifugally against the rotating drum until near the uppermost position thereof and then drop by gravity into the cleaning liquid, said speed being in the range (in revolutions per minute) between 2500 w drum radius in feet as a minimum and about 3000 drum radius infeet centrifugally after they are so distributed by driving the drum in said direction at a much higher speed. 7
2. That method of cleaning fabric materials such as clothes, by the manipulation of a rotatable generally cylindrical and generally horizontal drum, which comprises rotating the loaded drum continuously in one direction and dipping into cleaning liquid maintained at a level be-. tween 20% and 30% of the drum diameter and with a clearance around the drum adequate to permit back flowing currents and not less than 20 of the liquid level and at a speed in the range (in revolutions per minute) between 2500 drum radius in feet as a minimum and about drum radius in feet as a maximum, whereby the materials are carried by the drum on each revolution to a point near the top of the drum and then fall clear of and across the drum into the cleaning liquid at the bottom ofthe drum.
3. That method of cleaning fabric materials such as clothes, by the manipulation of a rotatable generally cylindrical and generally horizontal drum, which comprises rotating the loaded drum continuously in one direction and with its lower portion dipping into cleaning liquid and with a clearance around the drum adequate to permit back-flowing currents and at a speed in the range (in revolutions per minute) between 2500 drum radius infect as a minimum and about drum radius in feet as a maximum, whereby the materials are car ried by the drum on each revolution to a point near the top of the drum and then fall clear of and across the drum into the cleaning liquid at the bottom of the drum.
4. That method of cleaning fabric materials such as clothes, by the manipulation of a rotatable generally cylindrical and generally horizon-. tal drum, which comprises rotating the loaded drum continuously in one direction and dipping into cleaning liquid maintained at a level between 20% and 30% of the drum diameter and with a clearance around the drum adequate to permit back-flowing currents and not less than 20% of the liquid level and at a speed approximating (in revolutions per minute) 2500 drum radius in feet 5. That method of cleaning fabric materials drum, which comprises rotating the loaded drum continuously in one direction and dipping into cleaning liquid maintained at a level between 20% and 30% of the drum diameter, and with a clearance around the drum adequate to permit back-flowing currents and not less than 20% of the liquid level, and at a speed in the range (in revolutions per minute) between 2500 'drum radius in feet as a minimum and about 3000 drum radius in feet Fun . by the drum on as a maximum, whereby the materials are carried by the drum on each revolution to a point near the top of the drum and then fall clear of and across the drum into the cleaning liquid at the bottom of the drum, and thereafter draining the liquid away while continuing to rotate the drum at the same speed and in the same direction for a considerable period 01 time to cause said materials to distribute themselves gradually about the periphery of the drum and partially to extract the cleaning liquid therefrom, ready for high-speed final extraction.
6. That method of cleaning such as clothes, by the manipulation of a rotatable generally cylindrical and generally horizontal drum, which comprises rotating the loaded drum continuously in one direction and with its lower portion dipping into cleaning liquid and with a clearance around the drum adequate to permit back-flowlngcurrents and at a speed in the range (in revolutions per minute) between drum radius in feet as a minimum and about as a maximum, whereby the materials are carried each revolution to a point near the top of the drum and then fall clear of and across the drum into thecleaning liquid at the bottom of the drum, and thereafter draining the liquid away while continuing to rotate the drum at the same speed and in the same direction for a considerable period of time to cause said materials to distribute themselves gradually about the more cleaning periphery of the drum and partially to extract the cleaning liquid therefrom, final extraction.
'7. That method of cleaning fabric materials such as clothes, by the manipulation of a rotatable generally cylindrical and generally horizontal drum, which comprises rotating the loaded drum continuously in one direction and dipping into cleaning liquid maintained at a level between and of the drum diameter, and with a clear ance around the drum adequate to permit backflowing currents and not less than 20% of the liquid level, and at a speed in the range (in revolutions per minute) between 2500 drum radius in feet as a minimum and about 3000 ,7 drum radius in feet as a markimum, whereby the materials arecarried by the drum on each revolution to a point near the top of the drum and ing the liquid away while continuing to rotate the drum at the same speed and in the same direction for a considerable period 01 time to cause said materials to distribute themselves gradually about the periphery of the drum and partially to extract the cleaning liquid therefrom, ready for high-speed final extraction, and injecting liquid to pass through the clothes and bedra'inedaway during the first part of the distributing step to flush dirty cleaning liquid from the clothes and to cause the distribution to start gradually.
fabric materials ready for high speed as a maximum,
'uld and while speed approximating (in revolutions per then fall clear of the cleaning liquid at a. That method of cleaning fabric materials such as clothes, by the manipulation of a rotatable generally cylindrical and generally horizontal drum, which comprises rotating the loaded drum continuously in one direction and with its lower portion dipping into cleaning liquid and with a clearance around the drum adequate to permit back-flowing currents and at a speed in the range (in revolutions per minute) between 2500 drum radius in feel:
as a minimum and about .a 22 drum radius in feet as a maximum, whereby the materials are carried by the druin on each revolution to a point near the top of the drum and then fall clear of and across the drum into the cleaning liquid at the rotating said drum continuously in one direction for a considerable period of time ata speed in the range (in revolutions per minute) between 2500 drum radius in feet as a minimum and about 3000 drum radius in feet until said materials are distri uted uniformly about the periphery of the drum, and then extracting the liquid from said materials by'rotating the drum at a much hi her 10. That method of drying fabrics such as clothes after washing them in a rotatable generally cylindrical and generally'horizontal drum, which comprises draining away the washing liqthe washing away rotating said drum continuously in one direction for a considerable period of time at a minute) 3000 h drum radius in l'eet until said about the periphery tracting the liquid from said or the drum, and then exproximately 2500 V drum radius in feet,
whereby the textiles are kept moving freely relatively to one another while the receptacle is rotating.
materials are distributed uniformly liquid is drainin materials by rotating the drum at a much higher spee v 1 1. A method of washing textiles in a tumbling receptacle that comprises placing in the recepta-' cle not more than six pounds dry weight of texreceptacle ona axis at'a speed of ap-"