Centrifugal extraction machine having speed control means responsive to unbalanced weight distribution
US 3172848 A
Description (OCR text may contain errors)
March 9, 1965 J. c. WORST 3,172,848
CENTRIFUGAL EXTRACTION MACHINE HAVING SPEED CONTROL. MEANS RESPONSIVE TO UNBALANCED WEIGHT DISTRIBUTION Filed April 27, 1961 5 Sheets-Sheet 1 INVENTOR. J'OSEPH C. WORST QJWM H l S ATTORNEY March 9, 1965 J. c. WORST 7 48 CENTRIFUGAL EXTRACTIQN MACHINE HAVING SPEED CONTROL MEANS RESPONSIVE TO UNBALANCED WEIGHT DISTRIBUTION Filed April 27. 1961 5 Sheets-Sheet 2 s2 85 s4 14 e'l- 1Q 9 36 ii 4a 31 x 4;
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BYMWW HIS ATTORNEY March 9, 1965 .1. c. WORST CENTRIFUGAL EXTRACTION MACHINE HAVING SPEED CONTROL MEANS RESPONSIVE 'ro UNBALANCED WEIGHT DISTRIBUTION Filed April 2''! 1961 5 Sheets-Sheet 3 INVENTOR. JOSEPH C. WORST H\S ATTORNEY J. c. WORST CENTRIFUGAL EXTRACTION MACHINE HAVING SPEED CONTROL MEANS RESPONSIVE TO UNBALANCED WEIGHT DISTRIBUTION Filed April 2'7, 1961 5 Sheets-Sheet 4 Flag,
-IIMIIIII INVENTDR. JOSEPH C. WORST Q; P 01m! HIS ATTORNEY March 9, 1965 J. c. WORST 3,172,348
CENTRIFUGAL. EXTRACTION MACHINE HAVING SPEED CONTROL MEANS RESPONSIVE T0 UNBALANCED WEIGHT DISTRIBUTION Filed April 27. 1961 5 Sheets-Sheet 5 INVENTOR.
JOSE PH C. WORST LEEMEEE:
"MI/ 4AM z ms ATTORNEY United States Patent 3,172,848 CENTRIFUGAL EXTRACTION MACHINE HAVING SPEED CQNTRUL MEANS RESPQNSIVE T0 UN- BALANCED WEIGHT DISTRIBUTION Joseph C. Worst, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Apr. 27, 196R, Ser. No. 165,928 4 Claims. (Cl. Mil-4144) This invention relates to centrifuging machines for extracting liquid from articles by centrifugal force, and more particularly to such machines which incorporate vibration sensitive arrangements for preventing operation at speeds capable of causing vibrations harmful to the machine.
Machines which effect an extraction of liquid from articles by high speed rotation of the container in which the articles are held are subject to high centrifugal forces as a result of the high speed rotation, particularly when the load is unbalanced within the container. Typical of such machines are domestic clothes washers, wherein the clothes container is spun at the end of washing and rinsing operations to extract the wash and rinse water from them. To prevent the occurrence of unbalance-caused vibrations large enough to cause damage to the machine, centrifuging machines may be provided with unbalance mechanisms which may operate in a variety of ways to preclude harm to the machine through excessive vibration. For instance, in some cases controls are actuated by an unbalance switch to return the article receptacle to a low speed (at which the articles move about in the container) or zero speed for a brief period of time .to give the articles a chance to be redistributed, the machine thereafter again attempting high speed rotation. Another approach is to shut the machine off if an excessive unbalance is sensed by the unbalance switch. In the first of the two foregoing possible approaches, there is, of course, some degree of liquid removed from the articles, regardless of what happens. However, if the unbalance should be such that it continues to remain uncorrected through the time allotted for the centrifuging operation (such as where one or two large shag rugs are to be spun damp-dry in a washing machine) the articles will still retain a very substantial amount of liquid at the end of the centrifuging operation. If the machine is shut off completely, as in the second possibility as set forth above, then, of course, the operator has to return to the machine and start it up again.
A third approach has therefore evolved wherein the centrifuging machine is formed so that it will continue to centrifuge at the maximum speed at which the vibrational forces are within the permissible limit. This may, if so desired, be provided after a certain number of attempts at high speed spin so as not to preclude the provision of high speed spin until it appears the load is one difficult to balance.
It is an object of the present invention to provide an improved centrifugal liquid extraction machine wherein electrical means causes acceleration of the machine to full speed, by causing the electrical means to accelerate the machine toward full speed only as long as unbalancecaused vibrations are below a predetermined amplitude, and to cause deceleration of the machineif the vibrations exceed a predetermined amplitude during the period of each vibration when the predetermined amplitude is exceeded.
In accordance with my invention, I provide a centrifugal extraction machine where the article receiving container is flexibly and rotatably secured on a frame by approporiate support means so that it vibrates relative to the frame in response to rotation of the container with an unbalanced load therein. The container may be driven at a maximum centrifuging speed, generally several hunice dred r.p.m., by electrically controlled driving means wherein a first electrical condition causes acceleration of the driving means toward the maximum speed and a second condition of the electrical means causes deceleration toward a minimum speed. The electrical arrangement includes a control circuit with a switch having an actuator connected to be moved in response to vibratory movement of the container. The switch may assume a first position in which container acceleration is provided, or a second position in which container deceleration is provided. The actuator, as moved in response to vibratory movement of the contatiner, provides the first switch position during vibratory movement below a predetermined amplitude, but moves the switch to its second position during any part of a vibration which is above the predetermined amplitude. This arrangement causes the driving means to rotate the contatiner at a speed which is generally proportional to the fraction of the total time of each vibration that the electrical means is in the first condition; since the vibrations are a result of both unbalance and speed, the less the unbalance the greater the speed at which the container is allowed to rotate by my invention.
The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. My invention itself however, both as to organization and method of operation together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings.
In the drawings,
FIGURE 1 is a front elevational view of a centrifugal extraction machine, specifically a combination clothes washer-dryer, of the type which incorporates my improved speed control arrangement;
FIGURE 2 is a rear elevational view of the combination washer-dryer of FIGURE 1, with the rear panel removed and certain surfaces broken away to illustrate details;
FIGURE 3 is a side elevational view of the combination washer-dryer of FIGURE 1, partly in section and with certain surfaces broken away to show details;
FIGURE 4 is a fragmentary view along line 44 in FIGURE 2, with the clothes basket and tub of the machine removed in order to illustrate details of the drive of the machine;
FIGURE 5 is an enlarged fragmentary plan view of the machine showing the improved vibration controlling arrangement of my invention;
FIGURE 6 is a view along line 6-6 in FIGURE 5;
FIGURE 7 is a schematic illustration depicting a circuit which incorporates my invention;
FIGURE 8 is a fragmentary enlarged plan view of a second embodiment of the improved vibration controlling arrangement of my invention;
FIGURE 9 is a view along line 99 in FIGURE 8; and
FIGURE 10 is a fragmentary enlarged, and partly schematic, plan view of a third embodiment of my invention.
Referring now to FIGURES 1, 2 and 3 of the drawings, there is shown, by way of illustration, a combination clothes washing and drying machine. It will, of course, be understood that the invention is not restricted to this particular type of laundry machine, but that to the contrary the invention has broad application in the field of centrifugal extraction machines. However, the invention finds particularly suitable application in this type of machine because the use of centrifuging machines in the home requires etficien-t opera-tion in a small amount of space.
In the machine shown, the operating elements of the machine are included within an outer cabinet structure having a central wrap-around section 1. Section 1 is as water temperature, omission of dryer function, etc.
Access to the machine is provided by a door 8 formed in section 1, mounted on concealed hinges and opened by means of a latch control 9.
As best shown in FIGURE 3, the machine is of the horizontal axis type, that is, it has a substantially cylindrical foraminous clothes basket or receptacle 1t), mounted for rotation on a generally horizontal axis, and provided with a number of inwardly extending vanes 11 which help to tumble clothes in the basket during slow rotation of the basket, and also to circulate air during drying. Basket is mounted within an imperforate tub structure 12 which encloses it on all sides. The basket is rotatably supported from the tub structure by a horizontally extending shaft 13 which is mounted in an elongated bearing 14 hung between the two sections 15 and 16 which form the rear wall of the tub structure. The shaft 13, as well as supporting the basket, also serves as a means for turning it during operation of the machine. The tub and basket are provided respectively with openings 17 and 18 in the front walls thereof, with the openings being aligned with the door in the front wall of cabinet 2, so that by opening the door clothes may be placed into or removed from the basket 10. Door 8 seals against a gasket 19 around the tub opening 17 to close off the tub completely during operation of the machine.
The assembly of tub 12 and basket It) is flexibly supported by means of a plurality of brackets or arms 20 which are mounted on an upstanding plate 21 fixedly attached to the base 2. Four of these arms are provided, two of them being secured to each side of the tub. Although the arms 20 can be secured directly to the Wall of the tub, I prefer to attach them, as shown, by means of suitable brackets 22. With tub 12 supported in the manner shown, the support of the system including the tub and the basket on the base 2 within wrap-around frame 1 is flexible in that the tub and basket may vibrate back and forth parallel to the front of the machine if the basket 10 should be unbalanced during high speed rotation thereof. However, for vibrations in the front to rear directions and in the vertical direction the arms 20 have little flexibility and prevent any substantial vibration in those directions.
Referring now particularly to FIGURE 4, and also to FIGURES 2 and 3, during the operation of the machine the basket 10 is driven from an electric motor 23. The drive from the motor to the basket includes a pulley 24 which is secured to the motor shaft so as to rotate therewith, and over which passes a belt 25 which drives an adjustable sheave assembly 26. The adjustable sheave assembly includes a shaft 27 to which are rigidly secured two sheave plates 28 and 29. An intermediate sheave plate 30 is keyed on shaft 27 so as to be movable along the shaft 27 to varying distances from sheaves 28 and 2-9. It will be observed (FIGURE 3) that sheave plate 28 has a sloping surface 31 which, in cooperation with a sloping surface 32 on movable sheave plate 30, forms a groove 33 of adjustable width. Similarly, on its other side, movable sheave plate 30 is provided with a sloping surface 34 which cooperates with sloping surface 35 of rigidly secured sheave plate 29 to form a second groove 36 of adjustable width. Since belt 25 has a predetermined width, it can be seen that movement of sheave plate 30 relative to sheave plate 28 will cause the belt 25 to seat in groove 33 at a distance from the center of shaft 27 which is determined by the distance of sheave plate 30 from sheave plate 28.
The linear speed of belt 25 is constant, assuming the speed of motor 23 to be substantially constant, and therefore the rotational speed of the adjustable sheave assembly 26 is dependent upon the sheave diameter provided by the cooperation of sheave plates 28 and 30. When the sheave plates 28 and 39 are in the position shown in the figures, sheave assembly 26 is rotating at a relatively low speed. As sheave plate 3% is moved to the left, as viewed in FIGURE 3, away from sheave plate 28, then belt 25 will move in radially toward shaft 27 as groove 33 widens, and will cause a greater rotational speed of the sheave assembly 26 for a given rotational speed of pulley 24 by motor 23.
A second belt 37 is driven in groove 36- by the sheave formed by the cooperation of the sheave plates 30 and 29. When adjustable sheave plate 30 is in the position shown so that groove 36 is quite wide, belt 37 has to move in radially toward shaft 27 a substantial amount before it seats on the surfaces 34 and 35 of sheave plates 30 and 29 respectively. This means that for a given rotational speed of the adjustable sheave assembly (as imparted to it by belt 25), belt 37 will be travelling at a relatively low rate of linear speed. As sheave plate 30 is moved to the left so that belt 37 is forced outwardly in groove 36, then for a given rotational speed of the sheave assembly a relatively high linear speed of belt 37 is provided. Thus, by controlling the position of sheave plate 30, an infinite variety of speeds between the two limits of position of the sheave plate may be provided, with the arrangement shown in FIGURE 3 providing the lowest output speed to belt 37 since belt 25 is causing the lowest rate of rotation of sheave assembly 26, and rotation of the she-ave assembly 26 is causing the lowest linear speed of belt 37. The highest rate of speed will be provided when sheave plate 30 is moved as far as possible to the right (FIGURE 2), in which case belt 25 moves inwardly as far as possible to provide the highest rotational speed of the assembly 26 for a given linear speed of belt 25, and the output linear speed of belt 37 is the highest possible for a given rotational speed of assembly 25.
Belt 37 passes over a sheave 38 which forms a unitary assembly with a sheave 39 which drives the belt 40. Referring now primarily to FIGURES 2 and 3, it will be seen that belt 40 drives a sheave ll which is rigidly secured to the end of shaft 13 so as to rotate basket 10'.
Returning now to the adjustable sheave assembly 26, and with particular reference to FIGURE 2, it will be observed that the assembly is mounted on an arm 42 which is pivotably secured on a pin 43, the pin being held in a bracket 44 secured to the base 2 of the machine. A spring 45 has one end 46 secured to the machine base and has its other end 47 secured to an arm 48 which is also secured on pin 43 and to shaft 27 so as to bias assembly 26 to the left. At the outer end 49 of arm 48 there is secured a chain member 59. At its other end (FIGURE 4) chain member St) is secured to a pulley 51 operated through a small electric motor and gear train assembly 52.
It will be seen that when pulley 51 is caused to rotate by assembly 52 it will wind up chain and, through arm 43, will move the entire adjustable sheave assembly to the right causing arm 42 to pivot to the right as viewed in FIGURE 2. Since belt 25 cannot stretch, it will be apparent that when this occurs belt 25 will move inwardly within groove 33 forcing sheave 30 to the left, as viewed in FIGURE 3, to efliect an increase in the speed transmitted to sheave 41 and basket 10. When motor and gear train assembly 52 is shut off, the spring 45 overcomes the motor and pulls the adjustable sheave assembly 26 back to the position shown in the figures to reduce the speed.
The assembly of sheaves 38 and 39 is also movably mounted, on a linkage arrangement 53 pivotably secured on a pin 54 mounted within a bracket 55 secured to the base. The linkage arrangement includes two arms 56 and 57 which are pivotably secured together through a pin 58. A spring 59, secured at one end 60 to member 21 adjacent base 2 of the machine, is secured at its other end 61 to the assembly of sheaves 38 and 39 so as to bias them downwardly and to the right, as viewed in FIGURE 2, in order to elfect a belt tensioning function for belts 37 and 40.
The proportioning of the various parts of the drive assembly above-described is such as to provide an appropriate range of speeds. For instance, when the parts are in their position as shown, a tumbling speed of approximately 46 r.p.m. may be provided to the basket 10 while in the other extreme position a centrifuging speed of approximately 400 rpm. is provided to the basket.
In order to admit water to the machine for washing operations, connections 62 and 63 are provided through which hot and could water may be supplied to the machine for the washing operation. A valve controlled by a solenoid 64 admits hot water to the machine and a valve controlled by an opposed solenoid 65 admits cold water to the machine. The hot and cold water valves controlled by solenoids 64 and 65 discharge through a common outlet 66, through a suitable air gap, and into a funnel 67 which leads to a pump 68 formed at the bottom of tub 12. The connection may be made through a suitable conduit 69, part of which is shown leading from the funnel 67 and part of which is shown extending from the sump 68. The air gap provided by the funnel 67 makes it impossible, as is well known, for water to be siphoned from the machine and thereby contaminate the incoming water supply line. A pressure actuated sensing device or water level control 70 may be provided to control both solenoids 64 and 65 so as to provide the proper water level in the machine during the washing operation. Sensing device 70 may be connected to the interior of tub 12 by a suita ble conduit 71 which connects with the tub adjacent the bottom thereof at 72 as shown.
The illustrated machine is of the type which uses cold water during the drying cycle for condensing the moisture extracted from the clothes. The condenser water is admitted to the machine through an additional solenoid actuated valve controlled by a solenoid 73 which is energized during the drying operation so that the valve passes water at a suitable rate sufficient to condense from the air the moisture vaporized from the clothes. As shown, the condenser Water valve discharges into a conduit 74 which leads through an appropriate air gap to a funnel 75 connected by a downwardly extending conduit 76 to an opening 77 in the side of the tub 12. The condenser water than flows from opening 77 in a thin sheet down the lower left wall 78 of the tub so as to cool a substantial portion of the side wall and provide a large cool surface for condensing the moisture extracted from the clothes.
The wash and rinse water used during the washing portion of the operation, and the condenser water and the moisture extracted from the clothes during a heat drying operation, are discharged from the machine through the sump 68 formed at the bottom of the tub. A suitable discharge hose 79 leads from the sump to a pump 80 (FIGURE 4) continuously driven by motor 23, and from pump 80 an outlet 81 (FIGURE 2) extends upwardly to a valve 82 which is suitably controlled by a solenoid (shown only schematically at 83 in FIG- URE 7). Valve 82 is suitably formed in a conventional manner so that when the solenoid is energized the valve 82 is closed and when the solenoid is not energized the valve 82 is opened. In other words, for water to be retained in the tub 12 the solenoid must be energized to close the valve 82 so that the continuous operation of the pump'will not be effective to drain the tub.
It will be understood that from valve 82 connection is made to a suitable drain (not shown).
To heat the clothes during the heat drying portion of the cycle, there is provided in the machine a suitable heater assembly which, as shown in FIGURE 2, may include a pair of heaters 84 and 85. When the heat ers are energized during the drying cycle they operate to heat the basket 10 which, through its rotation, then contacts the clothes to transfer its heat to the clothes. In addition, since the outer cylindrical wall of the basket is forarninous, i.e., perforated by a great many small spaced openings 86, the heating elements also heat the clothes directly by radiation and convection. The heat thus transferred to the clothes causes vapor migration out of the clothes so as to effect drying thereof.
Referring now to the schematic circuit diagram of FIGURE 7, there is shown a simplified control arrangement for the machine of FIGURES 1, 2, 3 and 4 in which the electrical system of the machine is energized across a suitable source of power through conductors 87, 88 and 89. Generally, in commercial practice, 220 volts are impressed across conductors 88 and 89, with 110 volts appearing between each of them and the neu tral conductor 87.
Directly connected to neutral line 87 is a timer motor 90 of any conventional well known type. The timer motor forms a part of a conventional sequence control assembly wherein a number of cams A, B, C, D, E, F, G, and H control a number of switches such as those indi cated by the numerals 91 through 98. The timer motor, the cams and the switches generally form a unitary assembly which may be positioned within the backsplasher 4 of the machine behind one of the dials 6 so that the one dial may be used for manual control of the position of cams A through H. When the timer motor 90 is energized, cams A through H are rotated slowly to cause the switches 91 through 98 to open and close in a suitable sequence so as to effect the desired operation in the machine. This occurs when the dial 6 is used to advance the cams from an Off position, which they normally attain at the end of a cycle, to a Start position when another cycle of operation is desired. Positioning the cams in their Start position causes the switch 98 to be closed by cam H so as to complete an energizing circuit for the timer motor 90 across conductors 87 and 88. Thus, when the one dial 6 is relased after having been put in the Start position, the operation of the timer motor will cause the switches which it controls to open and close in a suitable sequence.
For illustrative purposes, the switches have been shown as controlling various components of the machine. Thus, switch 91 controls the drain valve solenoid 83, switch 92 controls the condenser valve solenoid 73, switches 94 and 95 respectively control the hot and cold water solenoids 64 and 65, switch 96 controls energization of gear motor assembly 52, and switch 97 controls the drive motor 23. The other timer switch 93 controls energization of a relay 99, and relay 99 in turn controls a pair of switches 180 and 101 both in series with the heaters 84 and 85 so that when relay 99 is energized the switches 100 and 101 are closed to provide energization of the heaters 84 and 85 across the 220 volt source through conductors 88 and 89.
It will be recognized that, in the conventional manner, the switches control the components so as to provide a suitable sequence of stops in the machine to effect a laundering operation. For purposes of brevity, a particular sequence in which the switches are opened and closed will not be fully described, such sequences being relatively conventional features and susceptible of many modifications. In general, water is initially introduced into the machine with the drain valve closed for a washing step; then the water is drained out at the end of the washing step, and several rinses are provided with warm, hot or cold water, each rinse being followed by draining; all washing and rinsing operations are provided with the basket 10 being rotated at tumbling speed, that is, with the gear motor assembly 52 de-e'nergized so that the movable sheave assembly 26 is pulled into the position shown in FIGURE 2 by the spring 45. After the last rinse (and after wash and intermediate rinses also, if so desired), a high speed spin is provided in the machine so as to remove as much liquid as possible from the clothes by centrifuging prior to the heat extraction of the remainder of the liquid in the clothes. The high speed spin operation is effected by closure of switch 96 by cam F so as to'energize the gear motor assembly 52 which then overcomes the spring and starts winding up the chain 'on pulley 51 to pull assembly 26 to the right (FIGURE 2 it being understood that the gear motor assembly 52 is of the type which may remain stalled without adverse effect once it has Wound the chain up.
Completing the description of a laundering operation, at the end of the high speed spin the timer motormay close the switch 93 to cause energization of the heaters 84 and 85, as described above. This drying operation, conducted at tumbling speed, is continued for a suitable period at the end of which the clothes have been fully laundered including washing, rinsing, spin extraction of liquid, and heat drying; the timer motor 90 then opens all its associated switchesto de-ener'gize the machine and terminate the operation.
As mentioned above, during the spin operationthe gear motor assembly 52 is energized and this energizationcauses the chain 50" to be wound up on pulley 51. It will be understood that, in the structure shown, the gear motor assembly 52 takes-a period of several seconds to move the sheave assembly 26 over to its far right hand position (FIGURE 2), that is, to accelerate the basket from tumble speed to its maximum spin speed. It will further be understood, as has been stated above, that unbalanced distribution of clothes in the basket 10 may occur, and that as a result vibrations of the machine may be induced which, if the machine is permitted to accelerate to itsmaximum speed of 400 r.p.m., might be injurious to the machine.
To prevent this occurrence, I provide the switch assembly shown in FIGURE 1 by the numeral 102 and which appears enlarged and in full detail in FIGURES 5 and 6 to which reference is now made. It will be observed from FIGURES 5 and 6 that the assembly 102 includes a bracket member 103 having an upstanding portion 104' and a horizontal portion 105. Portion 105 is secured to base 2 of the machine so that the assembly 102 is for the main part rigidly secured to the stationary parts, or frame,- of the machine. A sheet of insulating material 106 is secured to the front of part 104 and may, as shown in FIGURE 5, extend substantially across the full width of the part- 104; At the center of sheet 106-, there is provided an insert 107' of conductive material such as metal; this insert forms the stationary contact which is shown in series with switch 95 in FIGURE 7, being connected thereto by a suitable conductor 109 insulated from the frame by the conventional covering 1101 A pin member 1 11'- is secured near the top of member 104 and acts as a support pivot for a member 112. Member 112, in turn, is rigidly but adjustably secured to a member 113 by suitablethrez'ad ed members such as screws 114 which fit through a slot 115 in member 113 so that it can he slipped up and down relative to member 112;.
across the face ofmember 106 and its insert 107. At the top end of member 112there is formed a clip 11) within which a generally spherical end portion of a member 1121 is secured. The member 121 in turn is fastened to the bottom of sump 68' which is, as previously stated, formed on the bottom of tub 1'2 and is positioned so as to vibrate with basket 10 on legs 20 when such vibrations occur as a result of an unbalanced load within the basket during high speed rotation.- The vibrations occur primarily in a-horizontal plane parallel to the front of the machine so' that' the member 121 moves substantially horizontally as shown in FIGURE 5.
This horizontal movement of member 121 causes the end portion 120 thereof to pivot the member 112 about pin 111 in a clockwise direction. Until the vibrations reach a predetermined amplitude, the movement of contact 117 is not great enough to prevent it from having continuous engagement with contact 107. However, when the amplitude of the vibrations reaches the predetermined level, the contact11'7 no longer engages insert 107 of member 106' at the end of its vibrational movement, but instead is in engagement} only with the insulating material forming the remainder of sheet member 106'. In other words, the members 112 and 11-3 together form an actuator which is secured to be moved by the vibrations of the flexibly supported parts of the machine, the amplitude of movement of the actuator assembly being proportional to the amplitude of the vibrations, and the amplitude of the vibrations in turn being proportional to the combination of unbalance and speed.
It can be seen that during vibrations within the predetermined amplitude the contact 117 always engages contact 107. When the vibrations increase above this predetermined amplitude as a result of an increase in speed, then the contact 117, above the predetermined amplitude, passes out of engagement with contact 107 so that the switch represented by assembly 102 is opened. In effect, when switch 96' is closed to cause a spin operation to be provided, the switch assembly 102 then becomes the controlling factor in the energization" of gear motor assembly 52. As long as the vibrations are within the predetermined amplitude, switch 102 is continuously closed and the gear motor 52 is energized to cause acceleration toward the maximum spin speed of the basket.
If the load is properly balanced, this state of affairs will continue to the maximum spin speed and the centrifuging will take place at that speed. However, in the event that the load of clothes should be unbalanced, the suspended system will vibrate, the amplitude of the vibration increasing as the speed of rotation of the container increases because of the increase in the centrifugal force of the unbalance. In this connection; it will be recognized that the greater the unbalance the greater the amplitude of the vibrations will be for any givenspin' speed. When the vibrations reach the point at which an additional increase in basket speed would cause undesirable vibrations, the amplitude of movement of the actuator assembly is such that contact 117 moves out of engagement with contact 107 at each end of each vibration. During this period of separation of contact 117 and 107, the gear motor assembly 52 is de-energized and spring 45 consequently pulls the sheave assembly 26 slightly to the left as viewed in FIGURE 2. This arrangement has the result that the unbalanced the load the lower the speed at which the accelerating effect of the energized gear motor and the decelerating effect of the spring 45 during deenergization of the gear motor set each other off so that the speed is at a substantially constant level. To put it differently, the greater the unbalance, the lower the speed which is reached by the rotating basket at the time the unbalances cause the set-off between the gear motor and the spring to occur. Thus, the desired result is achieved of providing the maximum speed which is permissible without vibrations of dangerous proportions occurring.
For highly unbalanced loads, a low spin speed will be provided since it will be at that low speed that the predetermined amplitude of vibration at which contacts 107 and 117 are separated occur, while for slightly unbalanced loads a relatively high speed will be reached before the separation of the contacts occurs and for generally balanced loads no separation will occur, the contacts 107 and 117 remaining in engagement to complete the circuit energizing the gear motor 52 throughout the spin operation.
Referring now to FIGURES 8 and 9, there is shown a second embodiment of my invention wherein a modified switch assembly 122 is used to control the speed of rotation of basket 10, it being understood that like parts are referred to by the same numerals already used. In switch assembly 122, there is a member 123 having a horizontally extending portion 124 rigidly secured to base 2 of the machine and a vertically extending portion 125. Rigidly secured to portion 125 is a substantially coextensive member 126 which has an opening 127 therein within which is secured portion 128 of a contact member 130 having an insulating covering 129 around it where it joins member 126. Contact 130 also has a portion 131 adapted to be engaged on opposite sides by a pair of contacts 132 and 133 respectively secured at the ends of flexible contact arms 134 and 135. The contact arms are secured at their upper ends by any suitable means, such as rivets 136 and 137 having insulating coverings 138 and 139 around them, to extensions 140 and 140a of member 123 extending from part 125 at the top end thereof.
A rivet 141 provides a'pivot support for an actuator member 142 having a lower end portion 143 to which is secured an insulating member 144. Member 144, upon pivoting of member 142 about rivet 141, is arranged, as can be seen from a comparison of FIGURES 8 and 9, to engage arm 134 upon pivoting clockwise and arm 135 when pivoting counterclockwise. At the top end of member 142 there is provided a notch 145 into which extends the downwardly formed end 146 of a spring arm 147 rigidly secured by a bracket 148 to the sump 68; thus, in effect, the spring arm 147 form a part of the flexibly supported system of the machine. The spring arm when positioned as shown is relatively rigid in a horizontal direction, but has enough spring so that its end 146 remains within notch 145 and thus remains in engagement with the actuator member 142.
When the flexibly supported system vibrates as a result of unbalances within the basket 10 during high speed rotation thereof, pivoting of member 142 about rivet 141 is caused in substantially the same manner that, in connection with the structure of FIGURES and 6, pivoting of member 112 on pin 111 is caused. This pivoting action is without effect as long as the vibrations remain small enough so that the member 142 does not move sufiiciently for insulated portion 144 to engage either of the contact arms 134 or 135. However, when the vibrations exceed a predetermined amplitude, the actuator member 142 will be oscillated back and forth by spring arm 147 with an amplitude sufficient to engage contact arms 134 and 135 and, thus, move contacts 132 and 133 alternately out of engagement with contact section 131.
It will be understood at this point that the energizing circuit for the gear motor assembly 52 may be made to pass through the contact arm 134 and contact 132, then through the stationary contact section 131, and then through contact 133 and contact arm 135. With this arrangement, separation of either of contacts 132 or 133 from contact section 131 de-energizes the gear motor assembly 52 with the result previously described in connection with FIGURES 5 and 6. It can thus be seen that the desired results of my invention may be achieved by a different structure from that shown in FIGURES 5 and 6, the main difference between the two structures being that in the first embodiment a sliding type of contact was provided in response to vibrations whereas in the struc-- id ture of FIGURES 8 and 9 the sliding contact is obviated by the structure shown.
Referring now to FIGURE 10, there is shown a third embodiment of my invention, it being understood that this structure also is used in a machine having the drive system of FIGURE 4 together with the structural feature shown in FIGURES 2 and 3. The gear motor assembly 52 in this case includes a conventional reversible shaded pole motor having a main winding 149 and a pair of wound shading coils 156 and 151, it being understood that the laminated core of the motor is indicated schematically at 152. Shading coil 150 may be provided in a complete electrically conductive loop which includes a stationary contact 153 and a movable contact 154 of a switch generally indicated at 155, and a conductor 156 connected to movable contact 154. The shading coil 151 may be similarly connected in a closed loop through a stationary contact 157 which is engageable by movable contact 154 when button 158 is depressed. Normally, a spring 159 biases the movable contact 154 into engagement with stationary contact 153 so as to complete the loop for shading coil 150.
In the conventional manner of shaded pole motors, the motor will start to operate when the main winding 149 is energized across a source of power and a loop is completed for one or theother of the shading coils. In this connection, it will be understood that winding 149 is connected in series with the timer switch 96 previously described in connection with FIGURE 7. Shading coil 150 is arranged sothat, when its loop is completed by engagement of contacts 153 and 154, the timer motor assembly 52 rotates in a first direction so as to wind up the pulley 51 (FIGURE 4). However, when the button 158 is depressed against the action of spring 159 to move contact 154 into engagement with contact 157, the loop for coil 151) is opened and the loop for coil 151 is closed. Coil 151 causes the gear motor assembly 52 to rotate in the opposite direction thereby providing an unwinding operation insofar as the chain 50 and pulley 51 of FIGURE 4 are concerned.
Rigidly secured to the base of sump 68, in the same manner as previously described, is a member which, in the present case, may be formed as an L-shaped bracket 160. The bracket 160, upon horizontal vibrations of the movable system of the machine as previously described, operates button 158, when the vibrations reach a predetermined amplitude, through an intermediate actuator assembly generally indicated by the numeral 161. Assembly 161 is fully described and illustrated in Patent 2,832,- 208, Stone, issued on April 29, 1958, and assigned to the General Electric Company, owner of the present invention. In general terms, the actuator assembly may include an adjustable scissors arrangement in which a pair of movable members 162 and 163 are formed as arms pivotably mounted on a pin 164 mounted on the base 2. The one arm 162 of the scissors engages bracket so as to be moved thereby, and the other arm 163 is moved by arm 162 through a spring 165 so as to depress button 158 upon a suflicient movement of the tub as fully described in the aforementioned Stone patent.
It will be observed that, as long as the vibrations do not reach the predetermined amplitude discussed hereabove in detail, the gear motor assembly 52 will be energized in the direction to cause acceleration of the basket 10 of the machine. However, when the predetermined amplitude of vibrations is reached because of high speed rotation with an unbalanced weight distribution, the actuator assembly 161 depresses button 158- to move contact 154 from the position to which it is biased so as to complete the loop for coil 150 to a second position in which it instead completes a loop for coil 151. This particular arrangement permits the gear motor assembly to assist the spring 45 in decelerating the basket during the part of each vibration when the vibrational movement is in the excessive amplitude area. This structure may be desirable in cases where the amount of inertia to be overcome is so substantial that the brief period of each vibration during which it exceeds the predetermined amplitude may not be sufiicient to permit spring 45 to provide a large enough deceleration for the purposes of the invention. 7
While in accordance with the patent statutes I have described what at present are considered to be the preferred embodiments 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. As an example of such a modification, but without limitation as to other modifications, the drive arrangement may be formed so that deceleration is toward a stopped condition as a; minimum speed rather than the tumbling speed of the illustrated machine; this would be a likely arrangement where centrifuging was the only function of the machine, i.e., it did not Wash or heatdry. As a further example, while a constant speed motor driving a variable speed transmission has been illustrated as the most likely structure to be used, it is readily conceivable that motors which have their speed variable by different means may also be used. In such a case, the electrical controlling means will naturally assume a different form from the precise type illustrated herein; thus, a resistance might be provided as a controlling means for the driving means, the resistance being included in series with the motor when vibrations became larger than they should and being excluded at other times. I therefore aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.
What I claim as new and desire to secure by Letters Patent of the United States is:
1. A centrifugal extraction machine comprising: a frame; an article-receiving container positioned on said frame; support means flexibly and rotatably securing said container to said frame for vibratory movement relative to said frame in response to rotation of said container with an unbalanced weight distribution; driving means for rotating said container at a predetermined maximum centrifuging speed; electrical means controlling said driving means, said electrical means having a first condition wherein said driving means accelerates said container toward the maximum speed and having a second condition wherein said driving means decelerates said container toward a minimum speed; and a control circuit for said electrical means including a switch assembly, said switch assembly comprising a first member secured to said frame, an actuator movably secured on said support member, and means movable in vibration with said container engaging said actuator for moving said actuator in response to vibrations, said first member including a stationary contact, said actuator including a movable contact slidable across said stationary contact during vibrations and engaged with said stationary contact when there are no vibrations, said actuator sliding said movable contact past the edge of said stationary contact during the part of each vibration above a predetermined amplitude when said vibrations exceeds said predetermined amplitude, said switch assembly being arranged in said circuit to provide said first electrical means condition when said contacts are in electric engagement with each other, and to provide said second electrical means condition only when said contacts are outof engagement with each other, whereby said electrical means causes said driving means to rotate said container at aspeed generally proportional to the fraction of the total time of each vibration. that said electrical means is insaid first condition.
2. The apparatus defined in claim 1 wherein said actuator is pivotably secured intermediate its ends to said first member, said actuator having said movable contact secured to it adjacent one end thereof and being connected to said container for vibratory movement thereby adjacent its other end.
3. A centrifugal extraction machine comprising: a frame; an article-receiving container positioned on said frame; support means flexibly and rotatably securing said container to said frame for vibratory movement relative to said frame in response to rotation of said container with an unbalanced Weight distribution; driving means for rotating said container at a predetermined maximum centrifuging speed; electrical means controlling said driving means, said electrical means having a first condition wherein said driving means accelerates said container toward said maximum speed and having a second condition wherein said driving means decelerates said container toward a minimum speed; and a control circuit for said electrical means including a switch assembly having a first member with a stationary contact secured thereon, second and third movable contacts engaging said first contact on opposite sides thereof, flexible contact arms respectively secured at one end to said first member and respectively carrying said movable contacts adjacent their other ends, and an actuator movably secured on said first member and having a portion positioned between said contact arms, said actuator being connected to said container to be movable in response to vibrations of said container, said actuator portion between said contact arms engaging said contact arms at each end of its range of movement when vibrations exceed a predetermined amplitude whereby said actuator separates said movable contacts alternately from said stationary contact during a part of each vibration above said predetermined amplitude when said vibrations exceed said predetermined amplitude; said switch assembly being arranged in said circuit to provide said first electrical means condition when both movable contacts engage said stationary contact, and to provide said second electrical means condition only when either movable contact is out of engagement with said stationary contact, whereby said electrical means causes said driving means to rotate said container at a speed generally proportional to the fraction of the total time of each vibration that said electrical means is in said first condition.
4. The apparatus defined in claim 3 wherein said actuator is pivotably secured intermediate its ends on said first member, said actuator portion extending between the said contact arm adjacent one end of said actuator, said actuator being connected to said container for vibratory movement thereby adjacent its other end.
References Cited by the Examiner UNITED STATES PATENTS 1,946,725 2/34 Andrews et al. 2,613,756 10/52 Smith ZOO-61.45 2,784,584 3/57 Worst 210-144 X 2,832,208 4/58 Stone 210-144 X 2,967,621 1/61 Metzger 210-144 X 3,003,090 11/61 Neyhouse et al. 68-24 X 3,014,590 12/61 Metzger 210-144 3,014,591 12/61 Stone et a1. 210-144 3,049,021 8/62 Neyhouse et al. 68-24 X 3,055,203 9/62 Toma 68-24 X FOREIGN PATENTS 829,292 3/60 Great Britain. 550,746 11/56 Italy.
REUBEN FRIEDMAN, Primary Examiner.
CHARLES SUKALO, RQBERT F. BURNETT,