US2886979A - Balancing mechanism for washing machines - Google Patents

Description

May 19, 1959 G. c. BAXTER 2,386,979

' BALANCING MECHANISM FOR WASHING MACHINES Filed ma 21, 1956 5 Sheets-Sheet 1 A INVENTOR. Gee/'9: C fiaxfer G. C. BAXTER BALANCING MECHANISM FOR WASHING MACHINES May 19,1959

3 Sheets-Sheet 2 Filed May 21. 1956 J N! y m m m r d m f w n 6 w 1 y 19, 1959 G. c. BIAXTEVR' 2,886,979

BALANCING MECHANISM FOR WASHING MACHINES.

- Filed May 21, 1956 v 5 Sheets-Sheet 5 IN VEN TOR.

2,886,979 Patented May 19, 1959 BALANCING MECHANiSM FOR WASHING MACHINES George C. Baxter, Marion, Kans., assignor to Flex-Prop Corporation, Marion, Kans.

Application May 21, 1956, Serial No. 586,137

3 Claims. (Cl. 74-573) This invention relates to new and useful improvements in washing machines, and has particular reference to the dynamic balancing of the rotary washing cylinder.

In washing machines particularly of the larger com mercial types wherein the clothing or other material to be laundered is supported in a horizontal perforated drum, said drum being rotated at a relatively slow speed to provide a tumbling action on the material within the drum, it

has been found difficult and impractical, if not actually impossible, to spin dry the contents of the drum; that is, torotate the drum at a high speed so that the Water in the material within the drum is driven outwardly by cen trifugal force through the perforations of the drum. The difficulty arises from the fact that the material being laundered can and usually does arrange itself principally at one side of the drum, with the result that if the drum is rotated at a. speed. great enough to effect the spin dry operation, the condition of unbalance of the drum causes severe vibration and eccentric loading of the drum bearings, with the resultant strain, wear, and failure of said bearings, and also a pronounced tendency of the entire washing machine to be jerked or shaken loose from its moorings.

The principal object of the present invention is, therefore, the provision in a washing machine of the class described of means whereby the cylinder thereof is auto rnatically counterbalanced to offset any condition of un balance caused by eccentric placement of the material being laundered therein.

This object is accomplished generally by mounting the cylinder so that it may gyrate slightly about its normal axis as a result of any unbalanced distribution of the load therein, mounting on said cylinder an annular tank concentrically therewith, said tank being divided into se,,- mental compartments, and providingeach of said compartments with valving means actuated by lateral displacement of the cylinder during its gyration to selectively deliver water to or eject water from said compartments in such a manner as to compensate for the unbalanced load in the cylinder.

Other objects are simplicity and economy of construction, efficiency, sensitivity, dependability and speed of operation, and adaptability for use in a wide variety of applications.

With these objects in View, as well as other objects which will appear in the course of the specification, ref erence will be had to the drawing, wherein:

Fig. l is a fragmentary vertical sectional view of a washing machine, being taken on line I--I of Fig. 2, showing a balancing mechanism embodying the present in vention applied thereto, with parts left in elevation,

Figs. 2 and 3 are sectional views taken respectively on lines IIII and IIIIII of Fig. 1, and

Fig. 4 is an enlarged, fragmentary sectional view taken on line IV-IV of Fig. 3.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to a cylindrical case or housing having its axis disposed horizontally, and having its rear end wall 4 *afiixed as by rivets 6 to a vertical standard 8 forming a portion of a rigid frame, and its forward end wall 10 being provided with a central door opening 12 fitted with adoor closure 14. Said housing is provided at its bottom with a drain opening 1-6 which it will be understood is controlled by a suitable valve, not shown.

Disposed within housing 2 is a washing cylinder 18 having a perforated cylindrical Wall 20, a planarforward end wall 22 adjacent front housing wall 10 and havingia central aperture 24 formed therein registering with door opening 12, and a planar rearward end wall 26. Said cylinder is provided internally with a plurality of vanes 28 spaced angularly about the periphery thereof and ex tending radially inwardly from cylinder wall 20. Said cylinder is supported coaxially with housing 2 by means of a hollow shaft 30. Said shaft is provided at its forward end with a flange 32 which is secured to the end wall 26 of the cylinder by means of rivets 34. Said shaft extends rearwardly through a hole 36 provided therefor in housing wall 4 and standard 8, and is rotatably mounted in a pair of ball bearings 38 mounted in a bear ing housing lli rigidly affixed to said standard. The bearing 38 closest to cylinder 18 is mounted in a rubber seat 42 whereby to permit a slight movement of said bearing laterally of the shaft for a purpose more fully described below.

A pulley 44 is fixed on a rearwardly extended portion of shaft 30, and is operably connected by means of belt 46 with an electric motor or other power unit, not shown, by means of which shaft 3'1) and cylinder 18 may be rotated at various speeds. The extreme rearward end of shaft 30 is carried rotatably in a bore 48 of a block 50 attached to standard it by bracket 52, and is sealed in said here by packing 54- and packing gland 56. A host:

5% or other conduit is connected to block 58 so as to furnish water under pressure to bore 48 and to hollow shaft 30.

A hollow annular tank 60 is disposed concentrically about washing cylinder 18 in outwardly spaced relation therefrom, being afiixed rigidly thereto by means of fasteners 62 (see Fig. 2). Said tank is divided by radial partitions 64 into four equal segmental compartments 66, 68, 7d and 72, each of which may be designated in itself as a tank. Each of said compartments or tanks has a valve 7 attached to the forwardwall thereof, said valve being supplied with water through a pipe 76 communieating with hollow shaft 36 intermediate rear walls 26 and 4- of cylinder 13 and housing 2. Said pipes extend radially outwardly along rear wall 26 of the cylinder, being secured thereto by suitable clips 78, then forwardly between tank 60 and cylinder wall 20, being secured to the latter by suitable clips 80.

Each of valves 74, best shown in Fig. 4, comprises a body 82 secured to tank 66 by fasteners 84 (see Fig. 3), and having a bore 86 formed therein so as to be radial to cylinder 18, pipe 76 communicating with the inner end of said bore. Adjacent the inner end of the bore, body 82 is provided with a lateral port 88 interconnecting said bore with the interior of the associated tank compart ment 66, 68, 76) or 72, and adjacent the outer end of the bore a port 90 interconnects the bore with the tank compartment. Intermediate bores 88 and 90, body 82 is provided with an air vent port 92 interconnecting bore 86 with the tank compartment. A tube 94 secured in port 92 extends adjacent the inner wall of annular tank 60. Disposed for longitudinal movement in bore 86 is a valve slide 96 which is of such length that when in its central position as shown in Fig. 4 it covers and closes all of ports 88, 90 and 92. Said slide is provided intermediate its ends with a pair of peripheral grooves 98 which are normally disposed respectively at opposite sides of vent port 92. Said slide has a yoke 100 secured therein and extending forwardly therefrom through a slot 102 formed in valve body 82 longitudinally of bore 86. Said yoke carries a pair of rollers 104 and 106. Said rollers are disposed on axes parallel to the axis of cylinder 18, and have rolling contact respectively with the outer and inner surfaces of a cylindrical flange or track 108 which is rigidly secured to the inner surface of front wall of housing 2, in concentric relation with shaft 30.

In the washing and rinsing portions of the operating cycle, the cylinder 18 is turned at a relatively slow speed, the material therein being elevated and dropped by vanes 28 in a tumbling action in the washing or rinsing solutions contained in housing 2 and entering cylinder 18 through the perforations thereof. The means for introducing the various washing and rinsing solutions into the housing, and for controlling drain 16 to retain or eject said solutions are not here shown. They are not involved in the present nvention, except that it will be noted that annular tank 60 is spaced sufiiciently far away from cylinder 18 so as not to interfere with the circulation of solutions through the perforations of the cylinder.

When it is desired to spin dry the material being washed, drain 16 is opened and the rotational speed of cylinder 18 is greatly increased. Then, if a greater portion of the material being laundered is disposed at one side or the other of the cylinder, and is held against the cylinder by centrifugal force, the cylinder will be unbalanced thereby and there will be a strong tendency for the cylinder to gyrate about its normal axis, the direction of the ofiset of the geometric axis of the cylinder from its normal rotational axis being at all times toward the heavy side of the cylinder, and the degree of offset being proportional to the mass of the unbalancing weight of the material Within the cylinder. This gyration would occur to some extent by flexing of shaft 30, even if bearings 38 were fixed. However, to permit said gyration to occur without objectionable overloading of said bearings, and to increase the sensitivity of the device, one of said bearings is rendered transversely yieldable by its retention in resilient rubber seat 42, as previously described.

Assuming that the unbalancing load in cylinder 18 is centered at the side thereof subtending tank compartment 66, the cylinder gyration will force compartment 66 away from the axis of shaft 30, and the opposite compartment 70 toward said axis. Considering first the valve 74 serving tank compartment 66, it will be seen that slide 96 thereof will be held radially stationary by the engagement of its rollers 104 and 106 with track 108, and valve body 82 will be forced outwardly over said slide. This opens port 90, and water in tank compartment 66 flows outwardly by centrifugal force through port 90 and bore 86 into housing 2. At the same time, valve 74 serving the opposite tank compartment 70 is affected in a reverse manner, body 82 being forced inwardly over slide 96. This opens port 88, and water under pressure from the associated pipe 76 flows through valve bore 86 and port 88 into compartment 70. These operations continue, water being drained from compartment 66 and added to compartment 70, until the overall mass carried by shaft 30 is balanced dynamically around said shaft, and the gyration about the shaft axis ceases. As the gyration gradually subsides, valves 74 gradually return to their neutral positions, closing ports 88 and 90 thereof. The cylinder may then be safely rotated at a speed suificient to drive water from the contents thereby by centrifugal force until said contents are in the usual damp dry condition.

It will be seen that this action is automatic and continuous, and that the degree of gyration of the cylinder need only be very slight at the most, the correction taking place almost as rapidly as the gyration can develop. The speed of response of the device is of course determined by the speed with which water can be added to or drained from the tank compartments, and is determined by the capacity of valves 74. This response speed should be sufiiciently great to correct any condition of balance during the time the cylinder is gradually accelerated to full speed. It will be seen also that the speed of response of the device is enhanced by the double action thereof, that is, the simultaneous addition of water to one compartment and removal of water from the opposite compartment. This substantially cuts in half the amount of water which otherwise would have to pass through any one of the valves if the device functioned solely either by the addition or by the subtraction of water. This double action also renders it unnecessary to have any particular amount of water in the tank compartments at the start of operation. Normally the tanks will be partially filled, and the double action will occur as described. However, if the compartments should happen to be full, then the device can function solely by draining water from the tank compartment at the heavy side of the cylinder, and if the compartments should be empty, the device can function solely by adding water to the compartment at the light side of the cylinder.

Sensitivity of the device is provided by placing the rollers 194106 which control valves 74 at the extreme forward end of cylinder 18, in which position they are subjected to the greatest degree of offset of the cylinder due to gyration thereof. The sensitivity as well as speed of response could also be increased by using more than the four tank compartments shown. Three or any larger number of compartments could be used.

It will be seen in Fig. 4 that whenever valve slide 96 is moved to open either of ports 88 or 90, one of grooves 98 will register with vent port 92, so that the associated tank will be vented to housing 2 through said groove and slot 102. This venting is of course necessary to permit easy and rapid ingress and egress of water to and from the tank. Tube 94 extends to the radially inward portion of the tank since the water in the tank is forced to the outer portion of the tank by centrifugal force during operation. It would be possible to use permanently open vents, for example in the inner cylindrical walls of the tanks. However, in that case, or with any open vents, certain of the tanks would drain while others would not when the machine comes to rest, and therefore the machine would necessarily start under a condition of extreme unbalance when next operated. It is therefore desirable that the vents close automatically as shown except when water is being added to or removed from the tanks.

While I have shown and described a specific embodiment of my invention, it will be apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire :to protect by Letters Patent is:

1. In a washing machine, a housing, a cylinder carried rotatably in said housing and adapted to carry the material to be washed, and to gyrate slightly about its normal axis during rotation if said material is distributed in an unbalanced relation about the axis thereof, a plurality of tanks aflixed to said cylinder in spaced relation from the axis thereof and in angularly spaced relation around said axis, means connecting each of said tanks to a source of liquid under pressure, a supply valve associated with and mounted on each of said tanks and controlling the passage of liquid through said connecting means, each of said valves having an operating member, and a circular track member aflixed in said housing in concentric relation with the normal axis of said cylinder, said valve operating member engaging said track member at all times and being operable by movement of said cylinder transversely to its axis whereby when said cylinder moves transversely to its normal aXiS. uring unbalanced gyration, one or more of said valves will be opened to deliver liquid to the tank or tanks at the light side of said cylinder.

2. The structure as recited in claim 1 wherein each of said tanks is provided also with a drain port and a valve controlling said drain port, said supply and drain valves comprising a single compound valve operable by said valve operating member, said operating member functioning to close both of said valves when said cylinder rotates on its normal axis, to open said drain valve when that portion of the cylinder adjacent which said compound valve is mounted moves away from the normal axis of the cylinder during gyration thereof, and to open said supply valve when that portion of the cylinder adjacent which said compound valve is mounted moves toward the normal axis of the cylinder during 15 gyration thereof.

3. The structure as recited in claim 2 wherein said compound valve comprises a body member mounted on the tank associated therewith and having a bore formed therein radially to said cylinder, liquid under pressure being supplied to the inner end of said bore and the inner and outer ends of said bore and interconnecting said bore with the associated tank, and a slide carried for longitudinal movement in said bore and having a length sufficient to close both of said ports, said valve operating member being fixed to said slide and engaging said track whereby said slide is held radially stationary during balanced rotation of said cylinder, and whereby during unbalanced gyration of said cylinder, said valve body will be moved radially inwardly or outwardly along said slide to open one or the other of said ports selectively.

References Cited in the file of this patent UNITED STATES PATENTS 305,026 Stillman Sept. 9, 1884 1,604,748 Grauer Oct. 26, 1926 2,224,241 Verdier et a1. ]Dec. 10, 1940 2,584,942 Thearle Feb. 5, 1952 20 2,687,215 Armstrong Aug. 24, 1954 outer end of said bore being open, said body having a pair of ports formed therein respectively adjacent the FOREIGN PATENTS 136,390 Germany July 8, 1952

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