US3226960A

US3226960A - Washing machine unbalance control

Info

Publication number: US3226960A
Application number: US334455A
Authority: US
Inventors: John C Mellinger
Original assignee: Maytag Corp
Current assignee: Maytag Corp
Priority date: 1963-12-30
Filing date: 1963-12-30
Publication date: 1966-01-04
Anticipated expiration: 1983-01-04

Description

2 Sheets-Sheet 1 //vv/v TOR HELL/N652 J. C- MELLINGER WASHING MACHINE UNBALANGE CONTROL JOHN C.

Jan. 4, 1966 Filed Dec.

Jan. 4, 1966 c, MELLINGER 3,226,960

WASHING MACHINE UNBALANCE CONTROL Filed Dec. 30, 1963 2 Sheets-Sheet 2 74 w '1 //VVE/V7'0F? 79 Joy/v63 M541. was? i 90 B L J 94 MM United States Patent 3,226,960 .WASHING MACHINE UNBALANCE CONTROL John C. Mellinger, Newton, Iowa, assignor to The Maytag Company, Newton, Iowa, a corporation of Delaware Filed Dec. 30, 1963, Ser. No. 334,455 9 Claims. (CI. 6824) This application is a continuation-in-part of my copending application, Serial No. 686,450, filed September 26, 1957, entitled, Safety Control Mechanism, and now abandoned.

This invention relates to a system for controlling the speed of a fluid extractor to insure highest possible fluid extraction from all loads, including unbalanced loads, while preventing excessive vibration of said fluid extractor and subsequent walking or sliding thereof. More particularly, this invention relates to a control system for regulating the speed of a washing machine to a maximum commensurate with, and responsive to, unbalanced load conditions.

In washing machines employing centrifugal extractors, such as a combination washer-drier unit having a horizontal axis washing and fluid extraction assembly, the machine is subject to vibrations resulting from centrifugal forces developed during the extraction operation because the wet clothes are seldom distributed evenly about the spin axis. This problem is well recognized in the field and many attempts have been made to obtain even distribution and to suppress or eliminate the vibrations.

Various systems have been employed for controlling or eliminating these vibrations to prevent the walking or sliding of the machine on the supporting surface. One such system includes switch means responsive to movement of the extractor assembly for interrupting energization of the drive system to facilitate decay of the movements resulting from unbalanced forces within the extractor assembly. Such a system is responsive to movements generated at low speeds and high speeds and in cludes no time delay features and is therefore dependent upon the magnitude of movement and frequency of rotation of the extractor assembly.

'Other unbalance control systems include switch means responsive to extractor assembly movement for de-energizing the drive system for a predetermined time period of sufficiently long duration to allow the extractor to reduce its rotational speed to a substantially lower level for facilitating redistribution of material contained therein prior to a further attempt at reaccelerating to an extraction speed.

These systems provide means for controlling the vibration and thereby preventing walking and sliding of the machine relative to the supporting surface but do not insure the optimum fluid extraction from the unbalanced loads and may even prevent satisfactory extraction from being effected. These unsatisfactory results occur when the machine is de-energized prior to reaching effective extraction speeds or when the entire extraction operation is consumed in attempts at redistributing the materials contained within the extractor assembly.

It is, therefore, an object of this invention to provide a control system responsive to unbalanced load conditions for controlling the extractor velocity to insure the highest possible fluid extraction while preventing walking, sliding or excessive vibration of said fluid extractor.

It is a further object of this invention to provide a control system for centrifugal extractors responsive to centrifugal forces generated by unbalanced loads for changing the energization of the drive system for a predetermined time period of sufficiently short duration to effect a relatively small decrease in extractor velocity.

It is a still further object of the invention to provide a vibration control system including means responsive to Patented Jan. 4-, 1966 predetermined centrifugal forces measured by container movement and including a time delay means operative for effecting a relatively small decrease in container velocity.

It is a further object of the invention to provide a vibration control system having means responsive to predetermined centrifugal forces measured by container movement and having time delay means for periodically energizing said drive means at less than :full torque for predetermined periods of time to control container velocity at a maximum commensurate with unbalanced load conditions.

The present invention includes unbalance sensing means responsive only to centrifugal forces resulting from unbalanced loads within the extractor assembly for controlling energization of the electric drive motor so as to limit the motor speed and extractor velocity to a. maximum commensurate with unbalanced loading thereof. Associated with the sensing means is a time delay device for maintaining the electric motor energized in a second condition of energization, at a lower torque for example, for a predetermined period of time. It is thus seen that upon actuation of the unbalance sensing means the motor is energized at less than full torque for a predetermined period of time for effecting a speed reduction. The time delay is selected to give a substantially short period of energization at less than full torque whereby a relatively small decrease in extractor speed is effected. The net result is that the extractor is allowed to decelerate from the intermediate extraction velocity at which the unbalanced condition is first sensed, to a lower extraction speed which, however, is well above the distribution speed. The velocity is then maintained between the intermediate extraction velocity and the lower extraction velocity by pulsing the motor between the two conditions of energization.

Since provision is made for effecting distribution of the materials contained within the extractor prior to proceeding into the extraction operation there are few if any advantages to be realized in returning to the tumble or redistribution velocity upon sensing an unbalanced load. The present invention therefore achieves a drive system in which the maximum possible container velocity commensurate with unbalanced conditions provides the highest possible fluid extraction without the walking, sliding or excessive vibration of the fluid extractor.

Complete details of operation oftthis invention and further objects and advantages will become evident as the description proceeds and from an examination of the accompanying drawings which illustrate a preferred embodiment of the invention and in which similar numerals refer to similar parts throughout the several views.

In the drawings:

FIGURE 1 is a view in front elevation of a combination washer-dryer, partially broken away to illustrate the container mounting and the control system included in the subject matter of this invention;

FIGURE 2 is a side elevation view, partially broken away, showing the left side of the combination washerdryer of FIGURE 1 and further showing the control system of the present invention;

FIGURE 3 is shown below FIGURE 1 and is an enlarge-d fragmentary view showing the front mounting arrangement incorporated in the present invention; and

FIGURE 4 is a diagrammatic circuit illustration incorporating the control system of thepresent invention.

Referring now to the accompanying drawings in detail, it will be seen that the combination washer-dryer unit shown in these drawings includes -a substantially flat surfaced base frame 10 mounted on legs 11. Mounted upon base frame 10 are the

channel members

13 and 14 which are welded or otherwise securely affixed in some suitable manner to the base frame to form the two major supports for the washer-dryer unit illustrated in the accompanying figures.

As is apparent from an inspection of FIGURES 1 and 2, channel members 13" and 14 are substantially triangular in elevational' configuration with the apex of thesemembers receiving

pivot pins

16 and 17. These pivot pins-16 and 17 form a two point support for tub 20' at

tub brackets

23 and 24 respectively. This allows tub or casing 20 which is fastened to

tub brackets

23 and 24, to oscillate or pivot back and forth in a primary degree of freedom on

pins

16 and 17 in an arcuate movement in response to various forces generated within tub 201 Tub 20 is maintained in an upright position on pins 16' and 17 by the two centering springs 25 connected between tub 20 and base 10 by the spring anchor brackets 26 and 23' fixed to tub 2t) and base 10 respectively. FIGURES 1 and 2 show the tub 20 as being provided with a tub damper bracket 29 which forms the support for the damper leaf spring StIcarrying the damper pad 33 in a ball and socket joint at the end of damper spring 30. Base frame 10 is provided'with an upstanding damper plate-34 which is engaged by the damper pad 33 for absorbing and dissipating the energy imparted to tub 20'by centrifugal forces generated during extraction operations involving unbalanced loads.

It'is seen that the assembly supported on

pins

16 and 17, including tub or casing2t), is mounted within a cabinet 35. The cabinet is provided. with an access door 36 for inserting-clothes into basket 38 positioned within tub 20.

Clothes basket 38 within tub 20 is mounted on a drive shaft 39' supported by tub 20 and rigidly connected to a largedrive pulley 40 and thereby rotated bydrive mechanism 43'. Drive mechanism 43- includes an electric motor 44 and may include variable speed means such as a three speed transmission (not shown) controllable by electrically energizable solenoids for delivering the three substantially constant speeds. include a relatively slow speed for tumbling the fabrics within container 38, an intermediate speed for distributing the materials contained within basket 33 in a substantially even loading about the inner periphery thereof, and a relatively high speed for extracting fluids from the. materials contained within basket 3%. The power train for drivingv basket 38 is thus from electric drive motor 44 through the transmission means (not shown) and drive belt 45- for rotating pulley 40 and basket 33. Other variable speed devices may, of course, be used in place of'the three speed transmission to obtain a plurality of speeds.

Whilethe rear channel member 13 actually receives and supports directly the rear pivot pin. 16, inspection ofFIGURE 3 indicates'that the same is not true as to the connection between front'channel 14 and the front pivot pin 17. The cross sectional view of FIGURE 3 shows that front pivot pin 17 is actually suspended in a floating pivot in front. channel member 14 and, in practice has a clearance of approximately 1/ of an inch from theclosest point of channel 14. The front end of tub 2t) is'supported on the front tub bracket 24, which in turn is'mounted on the front bearing sleeve 48 and on the front pivot pin 17. Pivot pin 17 is in turn supported bya lever arm 4? nested within front channel 14 and supported on the pivot pin penetrating channel member 14-as best shown in FIGURES 1 and 3.

Movement of the long lever arm 49 about pin 59 determines whether or not the front pivot pin moves relative to the front channel member 14. It will be noted that, many event, front pivot pin 17 may move only a short distance, in the structure illustrated, approximately of an inch, before pivot pin 17 will contact channel member- 14'and limit further movement of that pin, and consequently tub 20, in -a' vertical plane. While These speeds may.

this limit stop for pin 17 prevents tub 20 from separating from channel 14 when the entire machine is tipped over or upended, it is not necessary in the basic operation of the control device forming the basis for the instant invention. 7

It is thus seen that casing 29 undergoes arcuate movement in a' primary degree offreedom and that a point on the front of'thetub'may undergo small, substantially vertical movements as the tub moves in a secondary degree of freedom.

Three forces acting on lever arm 49 establish a condition of equilibrium about pin 50 in order to produce the described floating pivot of front pivot pin 17. The first of these three forces is applied upwardly through the supporting foot 53 preferably formed of iubber or some other cushioning material, located at the end of arm 4-9. The Weight of tub 2t and the parts supported by that casing provide the second-force which is applied directly to lever arm 49 through pin 1'7. The third force acting on member 4-9 is exerted by a leaf spring 54 which is inserted into opening 56 of lever arm 49 so as to form an extension of the latter member. An adjustable machine screw 55 which passes through the base of channel 14 and base frame 10, as well as the end of leaf spring extension 54, provides the means of varying the force exerted downwardly on leaf spring extension 54: In other words, as the end of leaf spring 54 is moved closer toward base frame 10 by tightening the adjustable machine screw 55, thelever arm 49 will have a greater tendency to move in a clockwise direction as viewed in FIGURE 1. It should, therefore, be apparent that the Weight of tub 20 and all parts supported by it act to move lever arm 49 in a counterclockwise direction about pin 50, whereas the flexed leaf spring extension 54 tends tomove it in a clockwise direction thereby producing a floating pivot action for front pivot pin 17 relative to the front channel member 14. It is thusseen that the mounting of the front portion of tub 20 on the floating pivot pin 17 permits a degree of movement thereof. Upon a vertical movement as in the upward direction of thefront portion of tub 20, lever arm 59 is pivoted about pivot pin Stlto move lever arm 49 in a clockwise direction. Because of the lever arm arrangement, end 58 of lever arm 49 is moved a greater distance than is pivot pin 17 and the front portion of tub 20. Thus it maybe seen that centrifugal forces generated by unbalanced loads rotating at extraction velocitieswill cause and may be measured in terms of small vertical movements of tub 20 at tub bracket 24- in a secondary degree of freedom for moving pivot pin 17 and lever arm 49 about pivot pin St A more complete and detailed description of the above combination washer-drier unit mounting system is given in the application of John C. Mellinger, Serial No. 686,450, filed September 26, 1957, of which this application is a continuation-in-part as set forth hereinabove;

It will be noted in FIGURES 1 and 2 that a sensing means includinga bracketed is secured, as byscrews, to base frame 10. A lever 61 is pivotally mounted on bracket 6%. An adjustable cushioned plunger' 62 is mounted onarm 65 of -lever 61 above end 58 of lever ar-m'49. Supported on the opposite end-of lever 61 is a switch member 66. Plunger 62-is biased toward end 58- of lever'arm 49 by a coil spring, 68 connected between arm 65 of lever 61 and bracket 60.

Switch member do has a spring biased" plunger, or swit-ch'button 69 for operating'the swit'ch'con'tacts thereof. A-leaf spring'arm 70 of switch 66 is normally biased away from the resilient button 69; Button 69is normally held depressed by spring arm 70 through one leg 'of a star wheel, or cam 73, as best shown in FIGURE 2. How

ever when the lever 61 is pivoted on br-acket'etl in a counterclockwise direction, the spring 1 arm I 70- is disengaged from the legof the-star wheel 73 to release button 69. When the spring arm 7t of switchd6 is released it' springs'to a position behind a leg of star wheel 73,'so

that, when lever 61 is biased by spring 68, spring arm 70 remains disengaged from the star wheel, and button 69 of the switch 66 remains in the released position.

As shown schematically in FIGURE 4, switch member 66 includes

contacts

78, 79, and 80. Contact 78 is a common contact. Contact 79 is connected to contact 78 when switch button 69 is depressed by switch arm 70. Contact 80 is connected to contact 78 through switch 66 upon releasing of switch arm 70 to open switch button 69.

Star Wheel 73 is mounted on the output shaft of the delay timer motor 74. Delay timer motor 74 is fixed to bracket 60 and is connected electrically to contact 88 of switch 66, as shown in FIGURE 4, so that when button 69 is fully released the delay timer motor 7'4 is energized through

contacts

78 and 80. When the delay timer motor 74 is energized, it rotates the output shaft and star wheel 73 at a predetermined speed so that after a predetermined period of time, for example, five seconds, the successive leg of star wheel 73 contacts and engages spring arm 70 to depress button 69. At this time switch 66 is opened between

contacts

78 and 80, and is closed between

contacts

78 and 79 for deenergizing delay motor 74 and stopping star wheel 73 in a position as shown in FIGURE 1.

The above unbalance sensing and time delay apparatus is shown and explained more completely and in greater detail in US. Patent 3,084,799, issued to P. S. Decatur on April 9, 1963. t

A program control timer (not shown) is provided to sequentially control the combination washer-drier through a preselected series of operations. This program control timer may include

timer contacts

83, 84, and 85 to limit operation of the unbalance sensing and control means to selected portions of the cycle of operations. During the extraction operation timer contact 83 is closed to contact 84, as shown in FIGURE 4, to energize switch member 66 between power lines L and L; for controlling operation of drive motor 44 and time delay motor 74.

The circuit of FIGURE 4 includes electric drive motor 44 having run windings 86, start windings 87, and centrifugal switch 88. The circuit further includes a shunt re sistor 89 which may be selectively placed in series with electric drive motor 44. The circuit thus provides circuit means for energizing motor 44 under three different conditions. First, the motor may be energized during operations other than the extraction operation between lines L and L by a circuit which includes contacts 84 made to contact 85 and through

line

98 and 93. Secondly, the motor may be energized during extraction operations at full torque conditions by a circuit from L through contact 84 made to contact 83 and through switch member 66 with contact 78 made to contact 79, and through line 94 and line 93. And thirdly, upon encountering an unbalanced condition, operation of switch 66 closes contact 78 to contact 80 for energizing motor 44 through a circuit which includes shunt resistor 89.

Energization of motor 44 in a circuit which includes shunt resistor 89 in series with run windings 86 effect a reduction in the torque output of motor 44 and in turn effects a decrease in output speed. A ten ohm resistor has been found satisfactory to achieve the desired reduction in output torque and speed; however, the resistance is not necessarily a critical value since it is only necessary to provide enough torque to prevent the motor from coasting to a premature stop. This reduced output torque will continue for a predetermined period of time as controlled by the time delay motor 74 energized in a circuit between lines L and L including contact 83 made to 84 and switch contact 78 made to contact 80.

It is seen in FIGURE 2 that the combination washerdrier unit of the present embodiment includes heating means generally indicated as numeral 98. The unit further includes water supply means 99.

From the foregoing explanation, it is believed that operation of the system may be understood. Tub 20 is first loaded with the materials to be washed therein and is then filled to the desired fluid level for the Washing operations. Following a washing operation during which time clothes basket 38 is rotated at a tumbling speed of approximately 50 revolutions per minute, for example, tub 2%) is drained.

Following the washing and draining operation, the drive system is energized to provide a positive distribution speed of approximately 60 revolutions per minute for distributing the materials contained within basket 38 in an even, balanced, pattern about the inner periphery thereof. Following this distribution period the drive system is energized for rotating the basket at an extraction speed of approximately 300 revolutions per minute to separate the residual fluids from the fabrics carried within the clothes basket 38. Should a large unbalance condition remain, excessive centrifugal forces will be generated within basket 38 upon reaching the higher extraction velocities. These centrifugal forces will cause vertical movement of the front portion of tub 20 to actuate lever arm 49. Arm 61 is caused to pivot for releasing switch arm 70 and switch button 69 and thereby opening contacts 78 to 79 and making contact 78 to 80. This switch operation will energize timing motor 74 for a predetermined period of time, and will also energize electric drive motor 44 through a shunt resistor 89 for reducing the output torque thereof.

The reduced torque output of motor 44 will result in a reduction in motor speed and thus reduction in tumbler velocity and a resultant reduction of centrifugal forces. This condition of reduced torque will continue for a predetermined period of time, such as five seconds, which is a sufficiently short period of time to effect only a relatively small reduction in tumbler speed. This reduction in tumbler velocity effects a reduction in the centrifugal forces generated but is not permitted to decrease to the velocity at which the clothes are redistributed within the container. Since a distribution operation was accomplished prior to the extraction operation there are few, if any, advantages to be gained by returning to a distribution velocity upon encountering an unbalance condition. By allowing only a small decrease in tumbler speed prior to reaccelerating, the speed of the basket is maintained within a range which will effect maximum possible fluid extraction while preventing excessive vibrations and the resulting walking, or sliding, of the machine.

Upon completion of the predetermined period of time, delay switch 66 will be operated by one of the legs of star wheel 73 so that contact 78 is closed to contact 79 and motor 44 is energized through

lines

94 and 93 to provide full output torque. The motor will then reaccelerate basket 38 to a least the extraction velocity at which centrifugal forces had previously actuated lever 61. Upon encountering the predetermined unbalanced condition, lever 61 is reactuated for again energizing drive motor 44 in a reduced torque condition. This cycling operation will continue for the remainder of the extraction operation; however, the continued extraction of fluids will effect a reduction in the amount of unbalance which in turn will allow successively higher extraction speeds.

It is specifically noted that while this unbalance control system is responsive only to centrifugal forces, an additional and separate unbalance system may be provided to protect the unit from excessive arcuate .movements in the lower speed range which includes the critical speed for the unit.

It is also noted that an additional embodiment of the present invention could include the energization and deenergization of an electric motor having a flywheel arrangement for maintaining the motor in motion during the de-energization for a timed period in response to excessive unbalance instead of energization of the motor at reduced torque.

It is thus seen that the present invention provides a conrol means for a Washing machine extractor, or a horizontal axis combination washer-drier in which maximum fluid extraction is assured while preventing the undesirable results of excessive vibrations caused by unbalanced centrifugal forces. This system provides that continued extraction will take place even though an unbalanced load exists so that excessively wet clothes at the end of the cycle are avoided.

In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only, and not for purposes oflimitation. Changes in form and the proportlon of parts, as well as the substitution of equivalents are contemplated, as circumstances may suggest or render expedient, without departing from the spirit or scope of this 1nvention as further defined in the following claims.

I claim:

1. In a washing machine operable through a series of operations including an extraction operation, the combination comprising: a casing; container means rotatably mounted within said casing on a non-"ertical axis and adapted to receive materials to be washed therein; a base member; means for pivotally supporting said casing on said base member for movement in one primary degree of freedom relative thereto; drive means including electric motor means for rotating said container means at a plurality of velocities including a tumble velocity and a relatively high extraction velocity; means for energizing said drive means to effect acceleration of said container means toward said extraction velocity; and vibration control means responsive at intermediate velocities to predetermined unbalanced centrifugal forces within said container means for interrupting said acceleration to effect deceleration of said container means toward a lower extraction velocity and including timing means for maintaining said deceleration for a predetermined time period, said vibration control means being operative after termination of said predetermined time period for effecting reacceleration of said container means toward said high extraction velocity, said predetermined period of time being of sufiiciently short duration to limit deceleration of said container means to an extraction velocity substantially above said tumble velocity.

- 2. In a washing machine operable through a series of operations including an extraction operation, the combination comprising: a casing; container means rotatably mounted within said casing on a non-vertical axis and adapted to receive materials to be washed therein; a base member; means for pivotally supporting said casing on said base member for movement in one primary degree offreedomrelative thereto; drive means including electric motor means for rotating said container means at a plurality of velocities including a tumble velocity and a relatively highextraction velocity; means for energizing said drive means in a first full torque condition foreffecting acceleration of said container means toward said extraction velocity; and vibration control means responsive to a predetermined unbalanced centrifugal force generated within said container means measured by movement of said casing in a secondary degree of freedom for effecting a change in the energization of said motor means from said first fulltorque condition to a second reduced torque condition and including timing means for maintaining energization in said second condition. for a predetermined period of time, said predetermined period of time being of sufficiently short duration to effect a decrease in velocity of said container means to .a lower extractionvvelocity substantially above said tumble velocity, said vibration, control means and. said energizing means being cooperable during said extraction operation for cycling energization of said motor means between said first fulltorque condition and said second reduced torque condition responsive to sensing of said centrifugal force and termination of said predetermined time period, respectively, whereby said extraction velocity is maintained between said lower extraction velocity and said relatively high extraction velocity.

3. in a washing machine operable through a series of operations including an extraction operation, the combination comprising: a casing; container means rotatably mounted within said casing on a non-vertical axis and adapted to receive materials to be washed therein; a base member; means for pivotally supporting said casing on :said base member for movement in one primary degree of freedom relative thereto; drive means including electric motor means for rotating said container means at :a plurality of velocities including a tumble velocity and a relatively high extraction velocity; means for energizing said drive means in a first full torque condition to effect .acceleration of said container means toward said extraction velocity; regulation means operative during said extraction operation and responsive only to a predetermined amount of unbalanced centrifugal force generated within said container means measured by movement of said casing in a secondary degree of freedom for effecting a change in the energization of said drive means from said first full torque condition to asecond reduced torque condition; and timing means for maintaining said drive means energized in said second reduced torque condition for a predetermined period of time to effect a decrease in container velocity to a lower extraction velocity, said energizing means being responsive to termination of said predetermined period of time for re-energizing said drive means in said first full torque condition to effect reacceleration of said container means toward said high extraction velocity.

4. In a washing machine operable through a series of operations including a centrifugal fluid extraction operation, the combination comprising: a casing; container means rotatably mounted within said casing on a nonvcrtical axis and adapted to receive materials to be washed therein; a base member; means for pivotally supporting said casing on said base member for movement in one primary degree of freedom relative thereto; drive means including electric motor means for rotating said container means at a plurality of velocities including a distribution velocity and a relatively high extraction velocity; means for energizing said drive means to effect acceleration of said container means toward said high extraction velocity; and vibration control means responsive at velocities below said high extraction velocity to a predetermined unbalanced centrifugal force measured by movement of said casing in a secondary degree of freedom to interrupt said acceleration and to effect deceleration of said container means and including timing means for maintaining said deceleration over a predetermined time period, said predetermined time period being of sufficiently short duration to limit deceleration to a lower extraction velocity above said distribution velocity, said vibration control means being further operative after said predetermined time period for effectingv reacceleration of said container means toward said high extraction velocity.

5. In a washing machine operable through a series of operations including an extraction operation, the combination comprising: a casing; container means rotatably mounted within said casing on a non-vertical axis and adapted to receive materials to be washed therein; a base member; means for pivotally supporting said casing on said base member for movement in one primary degree of freedom relative thereto; drive means including electric motor means for rotating said container'means at a plurality of velocities including a tumble velocity and a relatively high extraction velocity; means for energizing said motor means in a first full torque condition for effecting acceleration of said container means toward said extraction velocity; sensing means responsive to a predetermined movement of said casing in a secondary degree of freedom caused only by unbalanced centrifugal forces within said container means; circuit means including switch means and resistance means responsive to said sensing means for effecting a change in the energization of said motor means from said first full torque condition to a second lower torque condition to interrupt said acceleration and to initiate deceleration of said container means; timing means controlled by said circuit means for maintaining said motor means energized in said second condition for a predetermined period of time, said predetermined period of time being of sufficiently short duration to effect a decrease in container velocity to a lower extraction velocity substantially above said tumble velocity, said energizing means being further operative after said predetermined period of time for elfecting reacceleration of said container means from said lower extraction velocity towards said high extraction velocity.

6. In a washing machine operable through a series of operations including a centrifugal fluid extraction operation, the combination comprising: a casing; container means rotatably mounted with said casing on a non-vertical axis and adapted to receive materials to be washed therein; a base member; means for pivotally supporting said casing on said base member for movement in one primary degree of freedom relative thereto; drive means including electric motor means for rotating said container means at a plurality of velocities including a tumble velocity, a distribution velocity, and a relatively high extraction velocity; means including switching means operative in a first position for energizing said drive means in a first condition to effect acceleration of said container means toward said extraction velocity; sensing means responsive to a predetermined unbalanced centrifugal force measured by movement of said casing in a secondary degree of freedom at intermediate extraction velocities for effecting operation of said switching means from said first position to a second position, said switch means being operative in said second position for energizing said drive means in a second condition to initiate deceleration of said container means; timing means for maintaining said drive means energized in said second condition for a predetermined time period, said predetermined time period being of sufficiently short duration to limit deceleration of said container means to an extraction velocity substantially above said distribution velocity, said switching means being responsive to said timing means for returning from said second position to said first position after termination of said predetermined period of time for effecting re-energization of said drive means in said first condition and reacceleration of said container means toward said high extraction velocity whereby said container means is controlled to successively higher intermediate extraction velocities between the intermediate velocity at which the predetermined centrifugal force was first sensed and said high extraction velocity.

7. In a washing machine operable through a series of operations including a centrifugal fluid extraction operation, the combination comprising: a casing; container means rotatably mounted within said casing on a nonvertical axis and adapted to receive materials to be washed therein; a base member; means for supporting said casing on said base member for movement in one primary degree of freedom relative thereto; drive means including electric motor means for rotating said container means at a plurality of velocities including a tumble velocity, a distribution velocity, and a relatively high extraction velocity; means for energizing said drive means for operating said container means at said distribution velocity for a period of time to obtain substantially even distribution of materials in said container; means for energizing said drive means to effect acceleration of said container means toward said extraction velocity; and vibration control means operative during said extraction operation and responsive to predetermined unbalanced centrifugal forces measured by movement of said casing in a secondary degree of freedom for interrupting said acceleration and effecting deceleration of said container means toward a lower extraction velocity, said vibration control means further including timing means for effecting a predetermined time delay of sufliciently short duration to prevent deceleration to said tumble velocity and being operative after said time delay for effecting re-acceleration of said container means toward said high extraction velocity.

8. In a washing machine operable through a series of operations including a centrifugal fluid extraction operation, the combination comprising: container means rotatably mounted and adapted to receive materials to be washed therein; a base member; means for supporting said container means on said base member for movement relative thereto; drive means including electric motor means for rotating said container means at a relatively high extraction velocity; means for energizing said drive means to effect acceleration of said container means toward said extraction velocity; and vibration control means responsive to a predetermined unbalanced centrifugal force generated in said container means during said extraction operation and including switch means for interrupting said acceleration and effecting deceleration of said container means toward a lower extraction velocity and above a distribution speed and further including means operative following initiation of said deceleration for effecting a time delay of sufiiciently short duration to effect said lower extraction velocity, said vibration control means being operative after termination of said time delay for effecting reacceleration of said container means toward said high extraction velocity.

9. In a washing machine operable through a series of operations including a centrifugal extraction operation, the combination comprising: a casing; container means rotatably mounted within said casing on a non-vertical axis and adapted to receive materials to be washed therein; a base member; means for supporting said casing on said base member for movement relative thereto; drive means including electric motor means for rotating said container means at a plurality of velocities including a tumble velocity and a relatively high extraction velocity; means for energizing said drive means to effect acceleration of said container means toward said extraction velocity; and vibration control means operative during at least a portion of said extraction operation and responsive to predetermined unbalanced centrifugal forces measured by movement of said casing for interrupting said acceleration and effecting deceleration of said container means toward a lower extraction velocity and including means operative following initiation of said deceleration for effecting a substantially constant time delay of sufficiently short duration to prevent deceleration to said tumble velocity, said vibration control means being operative after termination of said time delay means for effecting reacceleration of said container means toward said high extraction velocity.

References Cited by the Examiner UNITED STATES PATENTS 2,981,089 4/1961 Neyhouse et al 6824 3,084,799 4/1963 Decatur 6824 X 3,172,848 3/1965 Worst 68-24 X FOREIGN PATENTS 829,292 3/1960 Great Britain.

WALTER A. SCHEEL, Primary Examiner.

WILLIAM 1. PRICE, Examiner.

Claims

1. IN A WASHING MACHINE OPERABLE THROUGH A SERIES OF OPERATIONS INCLUDING AN EXTRACTION OPERATION, THE COMBINATION COMPRISING: A CASING; CONTAINER MEANS ROTATABLY MOUNTED WITHIN SAID CASING ON A NON-VERTICAL AXIS AND ADAPTED TO RECEIVE MATERIALS TO BE WASHED THEREIN; A BASE MEMBER; MEANS FOR PIVOTALLY SUPPORTING SAID CASING ON SAID BASE MEMBER FOR MOVEMENT IN ONE PRIMARY DEGREE OF FREEDOM RELATIVE THERETO; DRIVE MEANS INCLUDING ELECTRIC MOTOR MEANS FOR ROTATING SAID CONTAINER MEANS AT A PLURALITY OF VELOCITIES INCLUDING A TUMBLE VELOCITY AND A RELATIVELY HIGH EXTRACTION VELOCITY; MEANS FOR ENERGIZING SAID DRIVE MEANS TO EFFECT ACCELERATION OF SAID CONTAINER MEANS TOWARD SAID EXTRACTION VELOCITY; AND VIBRATION CONTROL MEANS RESPONSIVE AT INTERMEDIATE VELOCITIES TO PREDETERMINED UNBALANCED CENTRIFUGAL FORCES WITHIN SAID CONTAINER MEANS FOR INTERRUPTING SAID ACCELERATION TO EFFECT DECELERATION OF SAID CONTAINER MEANS TOWARD A LOWER EXTRACTION VELOCITY AND INCLUDING TIMING MEANS FOR MAINTAINING SAID DECELERATION FOR A PREDETERMINED TIME PERIOD, SAID VIBRATION CONTROL MEANS BEING OPERATIVE AFTER TERMINATION OF SAID PREDETERMINED TIME PERIOD FOR EFFECTING REACCELERATION OF SAID CONTAINER MEANS TOWARD SAID HIGH EXTRACTION VELOCITY, SAID PREDETERMNED PERIOD OF TIME BEING OF SUFFICIENTLY SHORT DURATION TO LIMIT DECELERATION OF SAID CONTAINER MEANS O AN EXTRACTION VELOCITY SUBSTANTIALLY ABOVE SAID TUMBLE VELOCITY.