US2784584A

US2784584A - Resetting device for vibration switches of laundry machines

Info

Publication number: US2784584A
Application number: US570857A
Authority: US
Inventors: Joseph C Worst
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1956-03-12
Filing date: 1956-03-12
Publication date: 1957-03-12
Anticipated expiration: 1974-03-12
Also published as: FR1174004A

Description

March 12, 1957 J. c. WORST RESETTING DEVICE FOR VIBRATION SWITCHES OF LAUNDRY MACHINES 2 Sheets-Sheet 1 Filed March 12, 1956 FIG.

F'lG.5

FIG. 4-

I see uzucz c owrRoL INVENTOR.

JOSEPH C. WOQST BY W 5w. a,.

HIS ATTORNEY March 12, 1957 J. c. WORST RESETTING DEVICE FOR VIBRATION SWITCHES OF LAUNDRY MACHINES 2 Sheets-Sheet 2 Filed March 12, 1956 PIC-3.2

FIG. 3

A20 INVENTOR.

JOSEPH C. WORST WFW HIS ATTORNEY United States Patent RESETTING DEVICE FOR VIBRATION SWITCHES 0F LAUNDRY MACHINES Joseph C. Worst, Louisville, Ky., assignor to General Electric Company, a corporation of New York Application March 12, 1956, Serial No. 570,857

4 Claims. (Cl. 68-24) My invention relates to automatic laundry machines of the type in which the clothes basket is rotated at one speed for tumbling clothes and at a higher speed for centerifugally extracting water from the clothes; and more particularly it relates to the vibration sensing switch means included in such machines for preventing the higher speed rotation until the basket is properly balanced to eliminate excessive vibration.

When an automatic laundry machine of the rotating basket type proceeds from a washing or rinsing step into a centrifugal extraction step, vibration of the rotating basket and its enclosing tub structure increases substantially unless the clothes distribute themselves evenly around the basket. Unless the clothes are approximately evenly distributed, the basket is dynamically unbalanced and depending upon the degree of unbalance, excessive vibration may occur. To prevent excessive vibration one method of control has been to measure or sense the vibration as the basket proceeds into the higher speed operation. If the vibration is excessive, a suitable switch is automatically operated so as to change the speed control circuit and return the basket to its lower speed. This gives the clothes a chance to reorient themselves within the basket at the lower speed. After a suitable time delay the same switch is operated reversely so as to return the speed control to its other condition and attempt again the higher speed operation. Usually, the clothes will then distribute themselves properly so that the centrifugal extraction operation may proceed without delay. If, however, they do not, the basket is once more returned to the lower speed operation to allow them to reorient again. This action repeats until the clothes do distribute evenly enough to reduce vibration to an acceptable level.

The primary object of my invention is to provide a new and improved device for resetting the vibration sensing switch after the time delay period, which device uses the machine vibration itself as its actuating means and thereby does not require any separate drive motor.

Another object of my invention is to provide a switch resetting device of this type which is very inexpensive to produce and assemble on the laundry machine.

In carrying out my invention 1 provide a laundry machine having a clothes basket rotatable at a plurality of speeds and a vibration sensing or unbalance switch for returning the basket temporarily to its lower speed it excessive vibration occurs as it is shifted to its higher speed. The switch is preferably mounted on the stationary base structure of the machine, and suitable actuating means are provided on the tub structure enclosing the basket for operating the switch when excessive vibration occurs. By my invention I provide new and improved means for resetting the switch after a time delay, once it has been operated by the excessive vibration of the tub structure. This means or device is itself also operated by the vibration of the tub structure so that no separate drive means are required for it. The device includes a switch resetting member adapted to resetthe 2,784,584 Patented Mar. 12, 1957 switch and a rotatable cam member for actuating the resetting member. The cam member is driven by a wheel which is engaged by an arm mounted on the tub structure. As the tub structure vibrates, the movement of the arm actuates the wheel, and means including a one-way clutch cause the wheel to drive the cam member in one direction only. The clutch prevents reverse rotation and thereby the wheel drives the cam intermittently in the one direction until it causes resetting of the switch. Ordinarily by the time the cam has been driven far enough to reset the switch, the clothes have reoriented within the basket and the vibration of the tub structure has fallen to an acceptable level, whereby the basket may then proceed to its hi her speed rotation.

The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the coneluding portion of this specification. My invention itself, however, both as to its organization and method of operation, may be best understood by reference to the following description taken in conjunction with the accompartying drawings in which:

Fig. l is a front elevational view of a domestic laundry machine having a vibration sensing switch arrangement which includes a preferred embodiment of my switch resetting device, certain surfaces of the view being broken away in order better to illustrate details;

Fig. 2 is a side elevational view of the machine of Fig. l with the side panel removed and with certain surfaces broken away;

Fig. 3 is a fragmentary plan view of the drive means included within the machine;

Fig. 4 is a fragmentary elevational view showing the vibration sensing switch and my new and improved switch resetting device; and

Fig. 5 is a sectional view of the switch resetting device taken on the line 5-5 of Fig. 4.

Referring now to Fig. 1 I have shown therein a domestic laundry machine 1 comprising a combination washer and dryer. The machine 1 includes an outer cabinet 2 which is mounted on a supporting base structure 3. Access to the machine for loading and unloading of clothes is provided by hinged door 4 mounted in the front wall of the cabinet. A backsplasher 5 mounted at the top of the cabinet serves as a mounting means for suitable operator controls for the machine. These controls may, for example, comprise the rotatable dials 6 and 7 and the push buttons 8.

The machine 1 is of the type which includes a clothes basket rotatable about a non-vertical axis. Specifically, it includes a perforated basket 9 which is disposed for rotation about a generally horizontal axis. The basket 9 is mounted within an imperforate tub structure 10 which encloses it on all sides. The basket is rotatably supported from the tub structure by a horizontally extending shaft 11 which is mounted in an elongated bearing 12 hung from the rear wall 13 of the tub structure (see Fig. 2). The shaft 11, as well as supporting the basket, also serves as a means for turning it during the operation of the machine. The tub and the basket are provided respectively with

openings

14 and 15 in the front walls thereof which are aligned with the door opening in the front wall of the cabinet 2 so that clothes may be placed into or removed from the basket. The door 4 seals against a gasket 16 around the tub opening 14 to close off the tub completely during operation of the machine.

The tub 10 is supported from the base 3 by means of: a plurality of brackets or arms 17 which are mounted on upstanding plates 18 fixedly attached to the base 3. Four of these arms 17 are provided, two being secured to each side of the tub. The arms on the opposite side of the tub are spaced apart as shown in Fig. 2 so that the tub in effect is supported near its front and near its rear on each side thereof. Although the arms 17 can be secured directly to the wall of the tub 10, preferably and as shown, the arms 17 are attached thereto by means of suitable brackets 19. With the tub supported in the manner shown, it is able to vibrate sideways in a plane parallel to the front of the machine if the basket 9 should be unbalanced during the high speed rotation thereof. The arms 17 are relatively long compared to their width and they flex so as to allow slight sideways vibration of the tub relative to the base 3. However, the arms 17 are effective substantially to prevent vibration of the tub both from front to rear and in the vertical direction. The arms are not at all flexible in those directions so that normally front to rear and up and down vibration of the tub cannot occur. Only sideways vibration can occur. As is more fully explained hereinafter, the machine 1 includes means for sensing the amount of sidewise vibration thereby to prevent that vibration from ever becoming great enough to damage the machine or cause it to move on the floor.

I During the operation of the machine the basket 9 is driven from an electric motor 20 through a drive including a transmission assembly 21 and a pair of flexible belts 22 and 23 (see Figs. 2 and 3). The belt 22 connects the output pulley 24 of the motor to the input pulley 25 of the transmisson assembly. connects the output pulley 26 of the transmission assembly to a basket drive pulley 27 mounted on the shaft 11 of the clothes tumbling basket 9. The transmission assembly 21 is of the multiple speed type, that is, the ratio thereof can be changed so that the basket is driven at two different speeds. The transmission assembly thus provides one basket speed for clothes tumbling and another basket speed for centrifugal extraction. The ratio of the transmission assembly is changed by means of a suitable spring biased, solenoid actuated plunger 28. When the electrically operated solenoid 29 controlling the plunger 28 is de-energized, the transmission ratio is 'such that the basket is driven at a suitable speed for washing and tumbling clothes, for example, 44 revolutions per minute. However, when the solenoid 29 is energized, the plunger 28 changes the ratio of the transmission so that the basket is driven at a suitable speed for centrifugal extraction, for example, 200 revolutions per minute.

During the operation of the machine the various electrical components thereof are under the control of the timer operated sequence control indicated schematically at 30 in Fig. 4. A suitable sequence control and a complete circuit for the machine 1 are shown in the eopending application of Walter E. Gray, J12, S. N. 512,612, filed June 2, 1955 and assigned to the same assignee as the present invention. In Fig. 4 I have shown the sequence control 30 schematically and have illustrated therewith only those electrical components which are necessary to the understanding of my invention. The components shown include the main drive motor 20 and the actuating coil 31 of the transmission assembly solenoid 29.

Besides the elements illustrated it will be understood that the sequence control 30 also controls suitable means whereby water is admitted to and discharged from the machine, and suitable heating means within the machine. A water inlet tube 32 and a sheathed type resistance heater 33 are both shown in Fig. 2. Any suitable electrically actuated means, such as a drain pump (not shown), can be used to control the discharge of water from the machine.

The sequence control 30 is energized by means of a pair of

supply conductors

34 and 35. During the operation of the machine a suitable switch or switches within the control are closed so that the motor 20 is continuously energized to rotate the basket 9. The switch means within the sequence control connect one side of the motor to the line 34 and the other side of the motor is con- The belt 23 nected directly to the supply line 35. As mentioned above, the clothes basket 9 is rotated at a relatively low speed for tumbling the clothes, which tumbling action is employed during the washing, the rinsing and the fluff drying steps of the machine. However, in order to extract water from the clothes in the basket by centrifugal extraction the basket is rotated at a higher speed for certain periods during the operation of the machine. To cause rotation of the machine at this higher speed the sequence control closes switch means therein so as to energize the coil 31 of the transmission assembly solenoid and shift the transmission assembly to its higher speed ratio. The circuit through which the sequence control energizes the solenoid coil 31 will be explained hereinafter.

As soon as the transmission is shifted, the basket 9 begins to rotate at its higher speed, for example, 200 R. P. M. If the clothes within the basket distribute approximately evenly, the higher speed rotation does not cause any objectionable vibration of the basket and its supporting structure. However, if the clothes distribute unevenly as the higher speed rotation begins, the resulting dynamic unbalance causes a noticeable vibration of the basket and the tub. In fact, if the distribution of the clothes around the basket is sufficiently uneven, the vibration may be excessive, sufficient to damage the machine or cause it to move on the floor if continued.

In order to prevent excessive vibration from occurring when the basket is shifted to its higher speed, a switch is provided for temporarily de-energizing the solenoid coil 31 if the vibration exceeds a pre-selected, permissible limit, for example thirty thousandths of an inch in amplitude. This vibration sensing or unbalance switch 36 is shown in Figs. 1 and 4. The switch 36 is operated by means of a relative movement occurring between the tub 10 and the base 3. In my preferred embodiment the switch is mounted on the base 3, and is actuated by means of a depending bracket 37 on the tub. Between the bracket and the switch there is interposed a switch operating device 38 which is operative to transmit the motion of the bracket to the switch. The device 38 may be simply and easily adjusted to correct both for production variations in the spacing between the bracket and the switch and for changes in the spacing caused by shipment thereby to insure that the unbalance switch is operated exactly at the limit of permissible vibration of the tub. This device 38 is described in detail and claimed in the eopending application of Aidan M. Stone, S. N. 526,104, filed August 3, 1955, and assigned to the same assignee as the present invention.

The operating device 38 includes a pair of

arms

39 and 40 which are pivoted that their lower end on a bracket 41 attached to the base of the machine. The arm 39 engages the depending bracket 37 attached to the tub structure and the right hand arm 40 engages an operating button 43 of the switch 36. Between the two arms there is disposed a coil spring 44 which is effective to transmit the motion of the arm 39 to the arm 45. Thus whenever excessive vibration of the tub structure occurs, the arm 40 is actuated by the vibration through the bracket 37, the arm 39 and the spring 44 so as to operate the switch; After the switch has been operated the spring 44 compresses so as to allow further movement of the bracket 37 and the arm 39 without damage to the switch.

The scissors device 33 is adjusted so that the switch button 43 is operated at the desired maximum allowable vibration of the tub by means of a third pivoted arm 45. The arm 45 includes a tab 46 which extends through a slot in the arm 40 and it mounts a screw 47 which extends through a slot in the arm 39. A spring 48 pulls the arm 45 against an inclined surface of an adjusting slide 49 which may be adjusted by means of a suitable adjusting screw. The manner in which the device is pre-set through adjustment of the slide 49 and a 5 loosening and re-tightening of the screw 47 is fully described in the aforesaid Stone application Serial No. 526,104. It will not bede cribed herein since it forms no part of the present invention.

The switch 36 which is operated by the scissors device 38 is provided with two

terminals

50 and 51, and besides the operating button 43 it further includes a second operating button 52 on the opposite side of the switch. Within its outer casing the switch is provided with a contactor which is movable between two positions. In one of the positions of this contactor the

terminals

50 and 51 are connected together and in the second position thereof the

terminals

50 and 51 are disconnected. When the button 43 is pressed, the contactor is moved so as to disconnect the

terminals

50 and 51, whereas when the button 52 is pressed the contactor is moved so as to connect together the

terminals

50 and 51.

The switch 36 is connected serially in the circuit for the coil 31 of the transmisison solenoid. Commencing with the supply conductor 34, the circuit for the coil extends through the sequence control and a line 53 to the switch terminal 51. The circuit is completed from the switch terminal 58 through a conductor 54, the solenoid coil 31 and a connection 55 to the supply line 35. With the coil 31 and the switch 36 connected in this manner it will be seen that when the switch terminals 50 and '1 are connected together, the solenoid coil 31 can be energized by the sequence control. Conversely, when these terminals are disconnected, the solenoid coil cannot be energized.

To initiate centrifugal extraction the sequence control closes suitable switch means therein so as to energize the coil 31 through switch 36. If excessive vibration occurs as the basket shifts to its higher speed, the switch button 43 is actuated by bracket 42 and scissors device 38 so as to open the switch 36. This de-energizes the solenoid coil 31 and allows the basket to return to its lower speed operation. The clothes then have an opportunity to reorient themselves in the basket at the lower speed, whereby they may not unbalance the basket when is returned to its higher speed rotation.

My invention is directed to a new and improved device for resetting the switch 36 in order to attempt again the higher speed rotation of the basket after the lower speed rotation. This switch resetting device is best shown in Figs. 4 and 5; and it is so constructed and arranged that it is driven by the vibration of the tub structure itself whereby no separate drive motor is required. For operating the switch the device includes a leaf spring 56 which is fixedly mounted at its lower end on the same bracket 57 which mounts the switch itself. Adjacent its center portion the leaf spring or resilient member 56 is adapted to engage the actuating button 52 of the switch and at its upper end it is engaged by a rotatable cam 53. As the cam 58 moves in the counterclockwise direction as shown by the arrow, it bends the upper end of the leaf spring 56 to the right (as viewed in Fig. 4). This bending of the spring continues until such time as the maximum diameter portion or rise of the cam passes over the top of the leaf spring. At that time the spring slips past the cam and snaps quickly back toward the switch 36. As it snaps, the spring strikes the button 52 and thereby moves the ccntactor within the switch so as to close the

terminals

50 and 51. This, of course, closes the circuit to the solenoid 31-and again shifts the basket to its higher speed.

By my invention the cam 58 is driven by means of the vibration of the tub itself rather than by means of a. separate timer motor. To effect that result an arm 59 is provided on the bracket 37 of the tub, which extends outwardly toward the switch resetting device. The arm 59 at its outer end is provided with a pad 68 of wear resistant friction material, such as brake lining, on its lower surface, and this pad 69 engages a disc or wheel 61 for driving the cam 58. In my preferred embodiment the wheel 61 and the cam 58 are both mounted on and suitably attache'dtoa rotatable shaft 62 which is journaled in an elongated bearing 63 (see Fig. 5). The bearing 63 preferably comprises a powdered metal, oil impregnated member, and it is supported by means of a stationary sleeve 64 which is brazed, staked or otherwise attached to the switch mounting bracket 57.

When the tub vibrates, the arm 59 moves the friction pad 60 back and forth across the top of the wheel 61 to rotate the wheel, the shaft 62 and the cam 58. In order, however, to cause the cam to be driven in one direction only rather than being oscillated back and forth, one way clutch means are provided which permit rotation of the wheel 61 in only one direction. The one way clutch means comprise a clutch spring 65 which is wound around both a protruding hub 66 provided on the wheel and the inner portion 67 of the stationary sleeve 64. The region surrounding the spring is preferably packed with grease and enclosed by a suitable grease retainer such as the rubber sleeve 68.

When the wheel is driven in one direction, the counterclockwise direction as seen in Fig. 4, the spring 65 tends to loosen or unwind. Thereby it does not couple the wheel hub 66 to the stationary sleeve 64, and the wheel drives the cam freely. However, when the arm 59 starts to drive the wheel in the other direction, the spring winds tightly down upon the hub 66 and the stationary sleeve 64. This locks the hub to the sleeve and prevents movement of the wheel and the cam in that direction. As a result of this action of the clutch spring, the wheel and the cam are intermittently driven in one direction only as the tub vibrates. As the tub vibrates back and forth, the arm 59 turns the wheel 61 and the cam 58 as the tub moves in one direction, but as the tub moves in the other direction the wheel and the cam are held stationary by the spring and the friction pad 60 slides across the wheel.

When the switch 36 is opened upon excessive vibration of the tub, the vibration does not, of course, stop immediately when the switch is opened. Rather, as the basket slows down and the clothes re-orient themselves this vibration continues. As result of this continuing vibration the wheel 61 drives the cam 58 intermittently through one complete revolution thereof. The basket may slow down completely to tumble speed before the revolution of the cam is completed. However, as the basket then rotates at tumble speed there is enough vibration of the tub to move the wheel 61 and complete the revolution of the cam. Thus as the basket slows down, the cam 53 progressively causes a bending of the spring 56, and after a time delay following the opening of switch 36 the cam moves far enough that the spring snaps back so as to operate the switch button 52. The operation of the button 52 as mentioned above closes the circuit for the solenoid coil 31 and returns the machine to its high speed operation.

It will be understood that in certain machines it may be desirable to reset the switch before the vibration of the tub as the basket slows down drives the cam 58 through one complete revolution. In such a case the cam may be provided with two or more rises in order to actuate the spring 56 and reset the switch 36 after a shorter cam rotation.

If the clothes have re-oriented so that they distribute evenly around the basket when the switch 36 is reclosed, the high speed rotation will continue until such time as the sequence control 30 opens the circuit to the solenoid coil 31. If, however, the clothes still do not distribute evenly, the same steps will occur again. In other words the unbalance switch will be operated by the vibration of the basket and the tub structure so as to return the tub temporarily to its lower speed operation. After a suitable time delay the switch will then be reset by my novel device so as to return the basket to its high speed rotation. Ordinarily a single return of the basket to its lower speed is sutficient to redistribute the clothes properly, but infrequently several tries may be required before the basket will rotate at the higher speed without excessive vibration.

From the above it will be seen that I have provided an improved device for resetting a vibration sensing switch, which does not require a separate control or timer motor. Rather in my improved resetting device the vibration of the tub itself is used to produce the resetting action. Through the operation of the device the vibratory motion of the tub causes a one way rotation of the spring operating cam, whereby the switch is reset after a suitable time delay.

While in accordance with the patent statutes 1 have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a laundry machine, a base structure, a rotatable clothes basket, a tub structure enclosing and rotatably supporting said basket, means supporting said tub structure from said base structure, drive means for driving said basket at a plurality of different speeds, electrically actuated means for shifting said basket from a lower speed to a higher speed, a switch mounted on one of said structures for controlling said electrically actuated means upon the occurrence of excessive vibration of said tub structure when said basket is shifted to said higher speed, switch actuating means mounted on the other of said structures for operating said switch when said excessive vibrations occurs thereby to return said basket to said lower speed, and means actuated by the vibration of said tub structure after said switch is operated for re-setting said switch after a time delay thereby to shift said basket back to said higher speed, said means comprising a switch resetting member mounted on said one structure, a rotatable member for actuating said switch resetting member, a wheel mounted on said one structure for driving said rotatable member, an arm mounted on said other structure and engaging said wheel for actuating said wheel as said tub structure vibrates, and means including oneway clutch means for causing said wheel to drive said rotatable member in one direction only for actuating said switch resetting member.

2. In a laundry machine, a rotatable clothes basket, a tub structure enclosing and rotatably supporting said hasket, means supporting said tub structure from the base of said machine, drive means for driving said basket at a plurality of different speeds, electricallyactuated means for shifting said basket from a lower speed to a higher speed, a switch mounted on said base for controlling said electrically actuated means upon the occurrence of excessive vibration of said tub when said basket is shifted to said higher speed, switch actuating means mounted on said tub structure for operating said switch when said excessive vibration occurs thereby to return said basket to said lower speed, and means actuated by the vibration resetting said switch after a time delay thereby to shift said basket again to said higher speed, said means comprising a resilient switch resetting member, a cam for flexing said resilient member to cause said resilient member to spring back and re-set said switch, a wheel for driving said cam, an arm mounted on said tub structure and engaging said wheel for actuating said wheel as said tub structure vibrates, and means including one-way clutch means for causing said wheel to drive said cam in one direction only for flexing aid resilient member to reset said switch.

3. In a laundry machine, a base structure, a rotatable clothes basket, a tub structure enclosing and rotatably supporting said basket, means supporting said tub structure from said base structure, drive means for driving said basket at a plurality of different speeds, electrically actuated means for shifting said basket from a lower speed to a higher speed, a switch mounted on said base structure for controlling said electrically actuated means upon the occurrence of excessive vibration of said tub structure when said basket is shifted to said higher speed, switch actuating means mounted on said tub structure Ior operating said switch upon the occurrence of said excessive vibration thereby to return said basket to said lower speed, and means actuated by the vibration of said tub structure after said switch is operated for resetting said switch after a time delay, thereby to shift said basket again to said higher speed, said means comprising a leaf-spring for engaging and resetting said switch, a cam for bending said spring to cause said spring to snap against and reset said switch, a wheel for driving said cam, an arm mounted on said tub structure and engaging said wheel for moving said wheel as said tub vibrates, and means including one-way clutch means for causing said wheel to drive said cam in one direction only for bending said spring to reset said switch.

4. In a laundry machine, a base structure, a rotatable clothes basket, a tub structure enclosing and rotatably supporting said basket, means supporting said tub structure from said base structure, drive means for driving said basket at a plurality of different speeds, electrically actuated means for shifting said basket from a lower speed to a higher speed, a switch mounted on said base structure for controlling said electrically actuated means upon the occurrence of excessive vibration of said tub structure when said basket is shifted to said higher speed, switch actuating means mounted on said tub structure for operating said switch when said excessive vibration occurs thereby to shift said basket back to said lower speed, and means actuated by the vibration of said basket after said switch is operated for resetting said switch after a time delay thereby to shift said basket back to said higher speed, said means comprising a leaf-spring for engaging and resetting said switch, a cam for bending said spring to cause said spring to snap against and reset said switch, a wheel for driving said cam, a single shaft mounting said cam and said Wheel, an arm mounted on said tub structure and engaging said wheel for moving said wheel as said tub structure vibrates, a stationary member, and a one-way clutch spring connecting said wheel and said stationary member to permit said wheel to be .driven in one direction only for rotating said cam to reset said switch.

No references cited.