US3290909A

US3290909A - Laundry apparatus

Info

Publication number: US3290909A
Application number: US402193A
Authority: US
Inventors: Joseph A Schwing; Ivan J Danylenko
Original assignee: Philco Ford Corp
Current assignee: Maxar Space LLC
Priority date: 1964-10-07
Filing date: 1964-10-07
Publication date: 1966-12-13
Anticipated expiration: 1983-12-13
Also published as: GB1078476A

Description

Dec. 139 w66 J. A, scm/VIN@ ETAL 3,299,909

LAUNDRY APPARATUS Filed Oct. '7, 1964 2 Slxeets$heet l /f /Gx /3 D 13, 1966 A. scHwlNG ETAL. 3,290,909

LAUNDRY APPARATUS MAX/MUM United States Patent Oilce 3,299,999 Patented Dec. 13, 1966 3,290,909 LAUNDRY APPARATUS Joseph A. Schwing, llenndel, Pa., and Ivan ll. Danylenko,

This invention relates to laundry apparatus, and more particularly to washing machines of the type comprising a rotatable wash basket mounted within a resiliently suspended tub.

In washing machines of the foregoing type the drain opening for the tub is usually placed in a lower region of the tub and a pump is provided at a level below the tub to pump the water therefrom as the basket is rotated at a speed su'icient to centrifuge water from the clothing. Under conditions of excessive unbalance, due to uneven distribution of clothes in the basket, the resiliently mounted tub will move orbitally, and as a result water chasing occurs and exposes the drain opening to the ambient atmosphere. Such occurrence introduces air into the pump via the drain opening, causing the pum-p to become air locked. Once the pump is air locked little or no water is pumped from the tub. This condition results in reduction in centrifuging speed, due to the braking action of the water between the basket and the tub, with consequent excessive retention of water by the clothes.

It is a primary objective of this invention to provide simple and effective means for preventing air locking of -a washing machine drain pump.

The invention is featured by the provision of simple and effective means for venting air from the liquid drain pump of a washing machine without detracting substantially from the eiliciency of the pump.

In achievement of the foregoing and other objectives the invention comprises a washing machine tub adapted `to contain liquid and a drain pump for the tub disposed at a level below the minimum liquid level in the tub. The pump includes an impeller housing provided with an inlet port connected to a drain sump portion of the tub below the said minimum liquid level and an outlet port adapted for connection to a liquid disposal drain above the `maximum liquid level in the tub. Means is provided for preventing air locking of the pump, including `an air bleed port for an upper portion of said housing, and open ended conduit means extending from the air bleed port and having its open end disposed for air flow communication with the ambient atmosphere, during operation of the ptunp, at a level substantially above the level of the inlet port of the pump housing.

It is a feature of the invention that the air bleed port and conduit means associated therewith will vent air from the pump in the event air is introduced into the pump as a result of premature uncovering of the tubs drain sump portion in the final stages of clothes centriinging.

For a more complete understanding of the invention, reference may be made to the following description taken in light of the accompanying drawing, in which:

FIGURE 1 is a perspective showing of a washing machine of atype to which the invention is particularly applicable;

FIGURE 2 is an elevational showing, partly in section and with parts broken away, of a preferred embodiment of a fluid handling circuit in combination with the machine illustrated in FIGURE 1;

FIGURE 3 is a showing similar to FIGURE 2 and illustrating a modied embodiment of the invention; and

FIGURE 4 is a chart illustrative of certain performance characteristics of a machine utilizing the invention, and comparing such characteristics with a prior art machine.

With more detailed reference to the drawing, and first to FiGURES l `and 2, the illustrated washing machine 1l? comprises a cabinet 11 having a control panel 12 and an upper wall 13 provided with `an aperture 14 over which a hinged door 15 is disposed. A rotatably mounted basket 16, provided with perforations 20, is nested within the tub 17 and each has an upwardly presented opening `aligned with aperture 14 in wall 13. An agitator 21 is mounted for movements relative to basket 16 to provide for washing and rinsing fabrics in the basket. Agitator 21 is preferably of the wobble-type and is driven by known means including a shaft 22, a pulley 23, a reversible motor 2d, a motor pulley 25, and a belt 26 that drivingly interconnects the pulleys. Tub 17 and basket 1d 4are supported upon a column 1S resiliently mounted in its lower region upon a horizontal part of base portion 19 of cabinet 11.

Motor 2d is of known reversible type, and when rorated in one direction drives shaft 22 to operate agitator 21, while activating brake means (not shown) to lock spin tube 38 and prevent rotation of the basket aihxed thereto. When the motor is rotated in the other direction the brake means is deactivated to release spin tube 38 and permit rotation of the agitator and basket as a unit, to centrifuge wash liquid from clothes within the basket through the perforations 20 in the latter. Structural details of a machine of the foregoing type, are disclosed and claimed in U.S. Patent No. 3,102,408 granted to Joseph Pelensky and in the copending application of the same inventor, Serial No. 161,962, now U.S. Patent No. 2,243,021 issued March 29, 1966, filed December 26, 1962. Both are assigned to the assigneeI of the present invention.

With further reference to FIGURE 2, a wash liquid drain pump 27 is disposed atop motor 24 and below tub 17. Pump 27 includes an impeller 28, driven by the upper end of the motor'shaft to which pulley 25 is attached, and an impeller housing 29 having a pair of ports, one port being disposed in fluid flow communication with a flexible conduit or hose 31 attached to a liquid drain sump portion 32 of tub 17. The other port of housing 29 is connected to a liquid discharge conduit or hose 30 that terminates at a level above the maximum liquid level in the tub. Hose 30 is adapted to direct discharged liquid into `suitable drain means (not shown) having its inlet disposed at a level also above the maximum liquid level in the tub.

In particular accordance with the invention, and still Awith reference to FIGURE 2, an air bleed port 33 is provided in the upper, generally dome-shaped portion of impeller housing 29. An open ended conduit 34 extends upwardly from port 33 and has its open end 35 disposed for air flow communication with the ambient atmosphere at a level substantially above the level of the inlet port of the pump, in this case the opening being substantially at the level of the top of tube 17. Open end 3S comprises an air flow restrictive orifice, for example an `orifice about .O31 inch in diameter, conveniently formed in a plug fitted within conduit 34.

Rotation of motor 24 in the direction to operate agita. tor 21 during either a washing or a rinsing phase, when the tube is filled with liquid (prior to a centrifuging or spin phase for removing the liquid) causes the pump impeller 28 to be rotated in a direction in which the port connected to `drain hose 31 is the discharge port and the port connected to the discharge hose 30 is the inlet port. Under this condition the pump maintains a head sufficient to prevent outflow of liquid from tub 17 through drain sump hose 31. A relatively small amount of air is drawn in through discharge hose 311 and forced through conduit 31 into the bottom of tub 17. There is little or no pumpinduced flow of air into open end 35 of the bleed conduit 34, due to the restrictive size of the orifice and the relatively small pumping effect obtainable in the region of bleed port 33. It is desirable to keep this air flow at a minimum to prevent so-called dotation of the clothes which interferes with agitation.

Following either the wash or the rinse phase, motor 24 is reversed to rotate basket 16 at its clothes centrifuging speed, and to rotate pump 27 in a direction to drain fluid from tub 17 through conduit 31 for discharge through hose 30. As the liquid level is lowered, the baskets rotational speed increases. Assuming a condition of clothes unbalance in the rapidly spinning basket, the entire tub basket, and resiliently mounted support column 18 will nutate about its support upon base portion 19. This motion results in a large mass of water chasing the spinning basket, thereby augmenting the clothes unbalance. This body of water extends between the basket and the tub and exerts a braking force on the 'basket to reduce its speed. Also this body of water alternately covers and uncovers the drain sump, air-locking the pump at the initial uncovering. This condition renders the pump inetfective to remove the remaining wash liquid, leaving the clothes in an excessively damp condition which is particularly disadvantageous following the final spin phase when relatively low retention of water is desired.

In the apparatus of the present invention, each time the water covers the opening in the drain sump, following each uncoveringf the static head of the water will cause it to ow downwardly from sump 32 through drain hose 31 and into pump 27, while air is forced in advance of the Water and vented to the atmosphere through vent hose 34 and the orifice in open end 35. By virtue of this construction, the pump is primed for each covering of the drain sump by the wash liquid, and a pulsating fiow of liquid continues until the tub is emptied. Progressive removal of the liquid reduces the braking action, and permits increase rotational speed of the basket effective substantially to spin-dry the clothes.

With reference to FIGURE 3, a modified embodiment of the invention is illustrated in a machine of the type shown in FIGURE 2 and comprising the same essential elements, such as -agitator 121, motor 124, basket 116 provided with perforations 1211, and tub 117 supported upon column 118. A rotary impeller pump 127 is disposed atop motor 124 and includes a housing 129 and an impeller 128. An air bleed port 133 is provided in housing 129 and is in `air flow communication with a vent hose comprising an upwardly extending portion 134 and a downwardly extending portion 136. The upwardly extending portion 134 is connected to the upper region Of an enlarged vessel comprising a surge tank 137 disposed substantially at the level of the tub opening, and the `downwardly extending portion 136 is `connected to the bottom region of the surge tank. The downwardly extending portion of the vent terminates in a fluid flow connection 135 leading through the side wall of tub 117 and venting therein.

In operation of the apparatus shown in FIGURE 3, rotation of motor 124 in the direction to rotate shaft 122 and operate agitator 121 will also rotate impeller 128 in a direction balancing the head of liquid in the tub 117 and drain hose 131 to prevent outliow of wash liquid, as was the case in the FIGURE 2 embodiment of the invention. Also during this operation, for which the wash liquid is at or near the maximum level as indicated, liquid will fill the tub drain conduit 131, pump housing 129, and a portion of the vertically extending portion 134 (see broken line) of the air bleed conduit. Also, liquid will rise only part way into the downwardly extending portion 136 (see broken line) of the air bleed conduit, there being air trapped in the surge tank 137. The presence of air in the upper portion of this inverted U-tube arrangement prei vents liquid in the tub from being recirculated to interferc with agitator induced liquid flow, and the connections to the tank 137 are such as to ensure provision of an air lock in this arrangement despite any sudden pressure surges that may occur. For example, While the tub is filling with liquid, the motor and pump are inoperative. When the tub has filled to the maximum level, or such other operating level as may have been selected, the rnotor is started to operate the agitator. Starting of the motor also starts the pump, which action is accompanied by a relatviely short-term, low-pressure surge at the eye of the pump, in the region of bleed port 133. However, due to the relatively large volume of tank 137, any short term liquid flow upwardly through conduit portion 136, due to the low pressure surge at the pump, is dissipated in the surge tank.

Upon initiation of the spin phase, by reversing the motor 124 to rotate both shaft 122 and spin tube 138 following either a wash or a rinse phase, liquid is forced through port and upwardly through conduit portion 136, due to centrifugal force created by the rapidly rotating basket 116. The entrapped air in the inverted U- tube means is driven by the Water through tank 137 and conduit portion 134, into pump housing 129 by way of air bleed port 133. This liquid joins the liquid withdrawn through drain hose 131, and the joined streams of liquid are pumped out through the discharge hose 130. This dual intake enhances the discharge flow rate in its initial stages, thereby to ensure removal of wash liquid in the time allotted to the spin phase. This is important when the liquid level of the tub is sufficiently lowered, connection 135 of conduit portion 136 breaks to air, and the pumping rate of pump 127 is somewhat reduced. Upon breaking of the liquid seal to port 135, the surge tank 137 and its associated conduits provide an air vent path for any air introduced into pump housing 129 due to water chasing, as was described in connection With the previous embodiment illustrated in FIGURE l.

Advantages deriving from the present invention are demonstrated graphically in FIGURE 4. In tests conducted by applicants assignee, a prior art machine (A- non-vented) was operated under a controlled unbalance condition in its linal spin phase. Residual liquid in the tub, which had not been removed due to air locking of the pump, amounted to l5 pounds. In contrast, similar tests on the FIGURE 2 embodiment (C) resulted in an average of 2% lbs. of residual liquid, and tests on the FIGURE 3 embodiment (B) resulted in an average of 2l/2 lbs. of residual liquid.

In summary, the invention provides simple and effective means for preventing air locking of a washing machine drain pump, without detracting substantially from the efficiency of the pump.

We claim:

1. In a Washing machine including a tub adapted to contain liquid, and a drain pump for said tub disposed at a level below the minimum liquid level in said tub, said pump including an impeller and a housing for the latter provided with an inlet port connected to a portion of said tub disposed below said minimum level and an outlet port adapted for connection to a drain disposed above the maximum liquid level in said tub, means for preventing air locking of said pump, comprising: an air bleed port for an upper portion of said housing; and open ended conduit means extending from said air bleed port and having its open end disposed for air flow communication with the ambient atmosphere, during operation of said pump, at a level substantially above the level of said inlet port of said pump housing, said conduit means including one portion that extends upwardly to a region adjacent the upper portion of said tub, and another portion that extends downwardly and has its open end communicating with said tub through a lateral wall portion thereof.

2. A machine according to claim 1 and further characterized in that said conduit means includes an enlarged section between the recited upwardly and downwardly extending portions, the downwardly 'extending portion communicating with the lower region of said enlarged section and the upwardly extending portion communicating with the upper region of said enlarged section.

3. A washing machine including a tub adapted to contain liquid, a basket for clothes rotatably mounted within said tub to centrifuge wash liquid from clothes contained therein into said tub, a drain sump in the lower portion of said tub, for draining liquid from said tub, said liquid beng susceptible of chasing whereby said drain pump is uncovered and exposed to the atmosphere, a drain pump for said tub disposed at a level below said sump, said pump including an impeller and a housing for the latter provided with an inlet port connected to said tub sump and an outlet port adapted for connection to a drain at a level above the maximum liquid level in said tub, and means for preventing air locking of said pump upon exposure of said sump to atmosphere comprising an air bleed port for an upper portion of said housing and open ended conduit means extending from said air bleed port and having its open end disposed for air flow communication with the atmosphere, during operation of said pump, at a level substantially above the level of said inlet port of said pump housing, said conduit means including one portion that extends upwardly to a region adjacent the upper portion of said tub, and another portion that extends downwardly and has its open end communicating with said tub through a lateral wall portion thereof.

4. A machine according to claim 3 and further characterized in that said conduit means includes an enlarged section between the recited upwardly and downwardly extending portions, the downwardly extending portion communicating with the lower region of said enlarged section and the upwardly extending portion communicating with the upper region of said enlarged section.

5. A washing machine including a tub adapted to con tain liquid, a basket for clothes rotatably mounted within said tub to centrifuge wash liquid from clothes contained therein into said tub, clothes and wash liquid agitator means within said basket operable while said basket is held substantially stationary, reversible drive means rotatable in one direction to rotate said basket and said agitator means as a unit, said drive means being rotatable in the other direction to drive said agitator means while said basket is held stationary, a drain sump in the lower portion of said tub for draining liquid from said tub, said liquid being susceptible of chasing as said basket is rotated at centrifuging speeds, whereby said drain sump is uncovered and exposed to the atmosphere, a drain pump driven by said reversible drive means for said tub disposed at a level below said sump, said pump including an impeller and a housing for the latter provided with an inlet port connected to said tub sump and an outlet port adapted for connection to a drain at a level above the maximum liquid level in said tub, and means for preventing air locking of said pump upon exposure of said sump to atmosphere when the drive means is driven in a direction to rotate said basket at centrifuging speed, comprising: an air bleed port for an upper portion of said housing; open ended conduit means extending from said air bleed port and having its open end disposed for air flow communication with the atmosphere, during operation of said pump, at a level substantially above the level of said inlet port of said pump housing; and means for impeding the ow of air through said conduit means into said pump as it is driven with the drive means while the latter rotates in the direction for driving the agitator means, said means for impeding air flow being associated with said conduit means in a region above the level of liquid in said tub, and permitting outflow of air from said pump as it tends to become air locked when said basket is rotated at centrifuging speed.

6. A washing machine according to claim 5, and characterized in that said means for impeding air ow comprises an air Flow restrictive orifice disposed in series air iiow relation with the recited open end ot said open ended conduit means.

7. A washing machine according to claim 5 and characterized in that said conduit means includes one portion that extends upwardly to a region adjacent the upper portion of said tub, and another portion that extends downwardly and has its open end communicating with said tub through a lateral wall portion thereof, and said means for impeding the ow of air comprises an en larged section between the upwardly and downwardly extending portions of said conduit means, the downwardly extending portion communicating with the lower region of said enlarged section and the upwardly extending portion communicating with the upper region of said enlarged section.

References Cited by the Examiner UNITED STATES PATENTS 2,901,294 8/1959 Smith 68--23 X 3,018,650 l/l962 Schmidt 68-208 X FOREIGN PATENTS 1,290,705 3/1962 France.

WILLIAM I. PRICE, Primary Examinez'.

Claims

1. IN A WASHING MACHINE INCLUDING A TUB ADAPTED TO CONTAIN LIQUID, AND A DRAIN PUMP FOR SAID TUB DISPOSED AT A LEVEL BELOW THE MINIMUM LIQUID LEVEL IN SAID TUB, SAID PUMP INCLUDING AN IMPELLER AND A HOUSING FOR THE LATTER PROVIDED WITH AN INLET PORT CONNECTED TO A PORTION OF SAID TUB DISPOSED BELOW SAID MINIMUM LEVEL AND AN OUTLET PORT ADAPTED FOR CONNECTION TO A DRAIN DISPOSED ABOVE THE MAXIMUM LIQUID LEVEL IN SAID TUB, MEANS FOR PREVENTING AIR LOCKING OF SAID PUMP, COMPRISING: AN AIR BLEED PORT FOR AN UPPER PORTION OF SAID HOUSING; AND OPEN ENDED CONDUIT MEANS EXTENDING FROM SAID AIR BLEED PORT AND HAVING ITS OPEN END DISPOSED FOR AIR FLOW COMMUNICATION WITH THE AMBIENT ATMOSPHERE, DURING OPERATION OF SAID PUMP, AT A LEVEL SUBSTANTIALLY ABOVE THE LEVEL OF SAID INLET PORT OF SAID PUMP HOUSING, SAID CONDUIT MEANS INCLUDING ONE PORTION THAT EXTENDS UPWARDLY TO A REGION ADJACENT THE UPPER PORTION OF SAID TUB, AND ANOTHER PORTION THAT EXTENS DOWNWARDLY AND HAS ITS OPEN END COMMUNICATING WITH SAID TUB THROUGH A LATERAL WALL PORTION THEREOF.