Washing Machine Transmission System

Abstract

A laundry machine drive mechanism for rotatively reciprocating an agitator or for centrifugally drying depending upon the direction of rotation of a drive pulley. The reciprocation of the agitator is provided by an agitator transmission that is substantially contained within the conical base portion of the agitator and has an input shaft that is positioned inside of a spin shaft in coaxial relation. The agitator transmission is compact and well balanced around the concentric spin shaft so that the complete agitator transmission may be rapidly rotated during the centrifugal drying or spin portion of a washing cycle.

Description

RELATED APPLICATIONS

J. Richard Cochran and Ronald L. Altnau, Ser. No. 323,736 filed Jan. 15, 1973 for A Conical Spring Disk Braking Mechanism.

DISCLOSURE

The present invention generally relates to a drive mechanism for laundry machines of the type which have a spin tub that is rapidly rotated for the purpose of centrifugally extracting water from clothes contained therein and an agitator which is rotatively oscillated.

Laundry machines of the type that have an agitator as well as a spin tub for centrifugal extraction of washing fluid from clothes are generally driven by a reversible electric motor and suitable input drive linkage which typically produces centrifugal drying or extraction when the motor is driven in one direction and rotative oscillation of an agitator through a suitable transmission when the motor is driven in the opposite direction. The complete drive mechanism is usually positioned below the drain tub which surrounds the spin tub of the laundry machine and, by virtue of the relative complexity of the apparatus, occupies most of the area below the drain tub. This is because the transmission for producing rotational oscillation of the agitator from a single direction rotation input as well as the necessary apparatus for enabling spinning of the spin tub for centrifugal drying must all be contained substantially below the drain tub of the laundry machine. Since the spin tube must usually be spun at a relatively rapid angular velocity to effect reasonably complete extraction of washing fluid from the clothes, it should be understood that difficulty may easily be experienced if the spin tub agitator and other components that are rotated are not reasonably well balanced.

Thus, most laundry machines are designed so that the agitator transmission portion of the drive mechanism is contained below the drain tub so that it will not be rotated during the spin or centrifugal drying portion of a washing cycle.

It is an object of the present invention to provide an improved drive mechanism for a laundry machine of the type that has a vertical oscillating agitator and a vertical spin tub, wherein the drive mechanism is more compact and occupies less space.

Another object of the present invention is to provide a drive mechanism that includes an agitator transmission for producing rotational oscillation of the agitator and wherein the transmission is substantially contained within a space surrounded by the conical base portion of the agitator itself.

Still another object of the present invention is to provide a drive mechanism that includes an agitator transmission as described above which is relatively compact and balanced, enabling it to be rapidly rotated with the spin tub during centrifugal drying or extraction.

A related object of the present invention is to provide the drive mechanism including an agitator transmission that is fabricated from a relatively small number of moving parts thereby enabling it to be compact and relatively well balanced around a center of rotation.

A more specific object of the present invention is to provide an agitator transmission having an outer housing that is adapted to provide guiding and support surfaces for the interior moving parts in addition to sealing the interior thereof from water penetration.

Yet another object of the present invention is to provide a drive mechanism having an agitator transmission that is capable of being easily serviced in that it may be completely removed from the top side of the laundry machine with a minimum of effort.

Other objects and advantages of the invention will become apparent upon reading the following detailed description while referring to the attached drawings, in which:

FIG. 1 is a partial elevation of a laundry machine showing the drain and spin tubs, the agitator and drive mechanism of the present invention, including the agitator transmission;

FIG. 2 is an enlarged partial elevation of the laundry machine shown in FIG. 1, particularly illustrating the agitator transmission of the drive mechanism embodying the present invention;

FIG. 3 is a cross section of the agitator transmission and is taken generally along the line 3--3 of FIG. 2; and

FIG. 4 is an exploded perspective view showing a portion of the agitator transmission with emphasis being placed upon the nature of relative movement between the internal components thereof.

While the present invention will be described in connection with a preferred embodiment, it should be understood that the intention is not to be limited to the particular embodiment shown but, on the contrary, it is the intention to cover the various alternative and equivalent arrangements that are included with the spirit and scope of the appended claims.

Turning to the drawings, and particularly FIG. 1, a laundry machine is illustrated which has a vertical tub and agitator together with a drive mechanism embodying the present invention. Broadly stated, the laundry machine has a cylindrical open top drain tub 10 which is supported on a suitable framework 12. Within the drain tub 10 is an open top cylindrical spin tub 14 which is rotatable about a vertical axis. The particular spin tub 14 illustrated is an imperforate container which is filled with water for washing and rinsing clothes. During rapid rotation or spinning, the tub 14 acts a a centrifuge to discharge water over the upper edges and into the drain tub 10 and thereby remove excess water from the clothes. Washing is accomplished by a centrally positioned agitator 16 which rotatively oscillates about a vertical axis concentric with the spin axis of the spin tub 14. As shown, the lower portion of the agitator 16 is generally conical shaped and the agitator may have one or more generally radially outwardly extending vanes or flanges 18 for agitating the water during oscillation of the agitator.

In a normal cycle of operation, clothes are placed in the spin tub 14 and wash water and detergent are added. The agitator 16 is then rotatively oscillated for a predetermined time to wash the clothes. Thereafter, the spin tub 14 is rotated at high speed to centrifugally extract the wash water from the clothes and spin tub. Upon completion of the spinning, rinse water is added and, if desired, the agitator 16 is restarted. After again stopping the agitator, the tub 14 is again spun to extract the rinse water from the clothes and upon completion of this task, typically completes the cycle of operation and enables the clothes to be removed from the machine.

The present invention is directed to the drive mechanism for providing oscillation of agitator 16 as well as for rapidly rotating the spin tub and agitator for centrifugally drying the clothes being washed and, more particularly, to the agitator transmission of the drive mechanism, indicated generally at 20, which is effective to provide rotational oscillation of its output shaft and the agitator 16 responsive to single direction rotation at its input. The spin tub 14 is held or restrained from rotating when the agitator is being oscillated by the application of braking force on the spin tub 14 by a braking mechanism, indicated generally at 22, which will not be described in extensive detail herein, the braking mechanism being the subject of a separate application by Cochran and Altnau, which is cross referenced herein and assigned to the same assignee as the present invention.

In keeping with the present invention, the spin tub 14, agitator 16 and agitator transmission 20 are supported by an upright tubular pedestal 24 that contains upper and lower bearings 26 and 28 in which a spin shaft 30 is journaled. The upper bearings 26 are not in direct contact with the spin shaft 30, however, as the spin shaft 30 is fitted interiorally of a downwardly extending annular collar 32 of a housing cover 34 of an agitator transmission housing 36. The tubular pedestal 24 also includes an annular bushing 38 that contacts the cover 34 and thereby supports the agitator transmission, agitator and spin tub 14. It should be realized that rotation of the spin shaft 30 will enable the complete spin tub 14, agitator 16 and agitator transmission 20 to rotate in bearings 26 and 28.

To drive the spin tub and agitator, a reversible electric motor 40 is provided, its output having a pulley 42 driving a belt 44 that is also carried by a second pulley 46 attached to a shaft 48 of a pump 50 as well as a fluid drive 52. The fluid drive has an output pulley 54 carrying a belt 56 which is also carried by a drive pulley 58 that is adapted to drive the spin shaft 30 or agitator transmission 20, depending upon the direction in which it is rotating.

Briefly stated, when the motor 40 is operating in a clockwise direction as viewed from beneath it, the pulleys 46, 54 and 58 will also be driven in a clockwise direction which results in rotation of the spin tub 14. However, when the motor is driven in the opposite direction, causing the pulleys 46, 54 and 58 to be driven in a counterclockwise direction, the agitator 16 will be oscillated. When the pulley 58 is driven in the counterclockwise direction to produce the oscillation of the agitator 16, the spin shaft 30 and spin tub is held or restrained by the brake mechanism 22. Rotating the pulley 58 in a clockwise direction is effective to release the braking mechanism 22 and permit the spin shaft 30 to be rotated which drives the spin tub until the spin portion of the washing cycle is terminated. As is described in the copending application cross referenced herein, as soon as the pulley 58 is turned in a counterclockwise direction relative to the clockwise rotating spin shaft or tube 30, the braking mechanism 32 will be applied to quickly stop rotation of the spin shaft and spin tub 14.

In keeping with the present invention, the pulley 58 is attached to an input shaft 60 that drives the agitator transmission 20 when the pulley is driven in the counterclockwise direction as viewed from the bottom of the laundry machine. This is achieved by virtue of the pulley 58 being axially slidable on the input shaft 60 and having a pair of downwardly extending helical surfaces at the hub portion that cooperatively engage inclined helical surfaces of a fixed washer 62 that is attached to the shaft 60 by a washer 64 and bolt 66 threadly inserted in a suitable aperture at the end of the shaft 60. As is more fully described in the above cross referenced application of Cochran and Altnau, rotation of the pulley 58 in the counterclockwise direction has the effect of rotating the shaft 60 in the same direction with no relative movement between the pulley and shaft. The operation of the braking mechanism 22 is also uneffected and is thereby maintained in a braked condition which prevents the spin shaft 30 and spin tub 14 from rotating. However, when the pulley 58 is rotated in the clockwise direction, the cooperating helical surfaces of the washer 62 permit the pulley 58 to climb or ride up the washer 62 causing the pulley 58 to move upwardly toward the spin shaft until it makes contact therewith while simultaneously operating to release the braking mechanism 22 and, responsive to further rotation of the pulley 58 in the same direction, causing a spin shaft 30 to rotate which occurs during the spin portion of a washing cycle.

In keeping with the present invention, the agitator transmission 20 is substantially contained beneath the conical shaped base portion of the agitator 16. As best shown in FIGS. 2-4, the agitator transmission 20 has a conical shaped housing 36 and cooperating housing cover 34 generally contained between the conical base of the agitator 16 and the bottom elevation of the spin tub 14.

As can be seen from the drawings, the agitator transmission 20 has an output shaft 72 extending upwardly from the housing 36, the output shaft 72 being rotatable within an elongated cylindrical member 74 that engages a cooperating opening within the upper portion of the housing 36 in sealed relation. The cylindrical member has upper and lower bushings 77, 79 for reducing friction and wear. The top of the output agitator shaft 72 has a tapered hexagon block 81 for fittingly engaging the agitator 16. Thus, when the agitator transmission shaft 60 is rotated in a counterclockwise direction when viewed from below it, the output shaft 72 will oscillate the agitator.

To provide the oscillating motion of the agitator responsive to single direction rotation of the agitator transmission input shaft 60, the operation can best be described while referring to the simplified and exploded perspective view of FIG. 4. The input shaft 60 is shown to have a pinion gear 76 attached to its upper end. A speed reducer gear 78 having upper and lower gear teeth 80 and 82 is rotatable about a fixed stud 84 and is at an elevation so that the lower teeth 82 mesh with the pinion 76. A large internal gear 90 is provided and has internal teeth 92 which mesh with the upper teeth 80 of the reducer 78. Thus, when the reducer 78 is rotated about its fixed stud 84, it rotates the internal gear 90 around its center. Within the top surface of the internal gear 90 is an aperture 94 adapted to receive a stud 96 over which fits a slide 98 having a generally rectangular outer configuration which engages a slideway 100 of a rack carriage 102. The rack carriage 102 may be reciprocated along a generally horizontal path as shown by the adjacently placed arrows, it having an elongated bore adapted to receive a cylindrical guide rod 104 that is fixed to the housing 36 at both ends. The rack carriage has a straight generally vertical toothed bar 106 that meshes with a pinion gear 108 fixed to the output shaft 72. In operation, rotation of the internal gear 90 will move the stud 96 around a circular path generally corresponding to the arrows as shown. The slider will accordingly be moved back and forth in the slideway 100 of the rack carriage while simultaneously traveling in an orbital path to reciprocate the rack carriage along the guide rod 104. The toothed bar 106 will accordingly rotate the pinion 108 attached to the output shaft 72 in opposite directions as the toothed bar is reciprocated.

With respect to more specific construction features of the agitator transmission 20 and referring to FIGS. 1-3, the input shaft 60 is coaxially positioned interiorly of the spin shaft 30 and is free to rotate relative to the spin shaft 30 within the upper and lower annular bushings 112, 114. The pinion gear 76, attached to the upper end of the input shaft 60 by means of a washer 116 and bolt 118, is prohibited from rotating relative to the shaft by means of cooperating grooves and splines (See FIG. 4). The stud 84 is retained by the housing cover 34 and has a smooth outer surface so that the speed reducer 78 may freely rotate around it.

In accordance with an important aspect of the present invention, the internal gear 90 has its outer peripheral surface smoothly machined to enable it to be rotated around its center line without substantial resistance. To this end, the outer periphery of the internal gear is guided by the mating internal cylindrical wall of the housing 36 and thereby limits the movement of the internal gear to rotation around its center, even though there is no center shaft associated with it. Similarly, the internal gear 90 is vertically supported by the upper surface 120 of the housing cover 34 and it should be understood that the internal gear may be readily removed from the transmission in the event a number of bolts 122 holding the cover 34 to the upper housing 36 are removed and the cover is removed therefrom.

In accordance with another aspect of the present invention the upper surface of the internal gear 90 is also machined to a smooth surface, because the rack carriage is in slidable contact with it during operation, as is the slider 98.

In keeping with the invention, the housing 36 has a pair of protrusions 126 to permit the rack carriage to reciprocate a greater distance within the housing, the protrusions 126 also having apertures 128 for receiving the guide rod 104 which limits the rack carriage to only reciprocating movement as shown in solid and phantom lines in FIG. 3. It should be readily understood, that the bore in the rack carriage which slidingly receives the guide rod 104 is parallel to the straight toothed bar 106, so that during reciprocating movement of the rack carriage 102, the toothed bar will mesh with and rotatively oscillate the pinion 108 and thereby oscillate the output shaft 72 and agitator 16.

It should be understood from the above detailed description that an improved drive mechanism for a laundry machine has been shown and described, and has many advantages in terms of its compactness and simplicity of operation. The balanced design of the agitator transmission enables it to be placed above the drain tub so that it may be rapidly rotated during the spin portion of the washing cycle, and its compactness permits it to be substantially located inside of the base of the agitator. It is believed that the drive mechanism of the present invention satisfies all of the objects and advantages that have been previously described.

Claims

I claim as my invention:

1. A drive mechanism for a laundry machine having a vertical spin tub and an agitator therein, said agitator having a generally conical shaped base, said mechanism comprising:

a reversible motor operatively connected to a pulley that is adapted to be driven in either direction,

means for rotatively driving said spin tub upon rotation of said pulley in one direction,

means for braking said spin tub against rotation during rotation of said pulley in a second direction,

agitator transmission means being substantially contained within the area defined by said conical shaped base and comprising,

a rotatable input shaft, means for rotating said input shaft in response to rotation of said pulley in the second direction,

an output shaft connected to said agitator,

a generally conical shaped, substantially fluid tight housing, said housing being attached to the lower center portion of said spin tub;

said rotatable input shaft having a pinion gear at its upper end,

a reducer having a pair of concentric gears, one of which is larger and adapted to mesh with said pinion gear;

a rotatable internal gear, the outer circular periphery of which is substantially smooth to slidingly contact the cooperating inner surface of said housing, the internal teeth of which engage the other gear of said reducer, the upper surface of said internal gear supporting an eccentrically positioned pin,

a rack carriage having a straight toothed bar and a horizontal slideway positioned generally perpendicular to said toothed bar, said rack having a slider adapted to overlie said pin supported by said internal gear, said slider being slidable within said slideway,

means for guiding said rack carriage to limit movement thereof to only reciprocating along a path parallel to said toothed bar and

said output shaft including a pinion gear meshing with said toothed bar,

so that rotation of said drive shaft rotates said reducer and internal gear, said internal gear moving said slider in an orbital path to thereby reciprocate the rack carriage along said path, the reciprocating toothed bar of said rack carriage causing rotational oscillation of said shaft pinion gear and agitator.

2. A drive mechanism as defined in claim 1 wherein said guide means includes an elongated cylindrical guide rod secured to said housing, said rack carriage having an elongated cylindrical bore parallel to said toothed bar and adapted to receive said guide rod in sliding engagement to thereby limit movement of said rack carriage to reciprocating movement along said path.

3. A drive mechanism as defined in claim 1 wherein said reducer is rotatable around a stud retained by said housing.

4. A drive mechanism as defined in claim 1 including a spin drive shaft surrounding said agitator input shaft, said spin drive shaft being rotatable responsive to rotation of said pulley in said first direction, and release of said brake means responsive to rotation of said pulley in said first direction.

5. A drive mechanism as defined in claim 4 wherein said pulley has at least one helical surface adapted to engage a cooperating helical surface of a washer fixed to the input shaft of said agitator transmission means, said pulley being adapted to rotate said agitator input shaft when driven in said second direction, the helical surface of said pulley being effective to climb the helical surface of said fixed washer when said pulley is rotated in said one direction, said climbing being effective to release said braking means and enable said outer spin shaft, spin tub, agitator and agitator transmission means to rotate in said one direction for the purpose of centrifugal drying.

6. A drive mechanism as defined in claim 5 wherein said pulley and said washer each have a pair of helical surfaces so that rotation of said pulley in said first direction causes said pulley to climb said washer and release said brake means substantially within one half revolution thereof in said first direction.

7. A drive mechanism as defined in claim 4 wherein said agitator transmission input shaft in positioned inside of said spin shaft, said braking means being adapted to prevent rotation of said spin shaft, said agitator transmission input shaft being free to rotate when said braking means prevents rotation of said spin shaft.

8. A drive mechanism for a laundry machine of the type that has a vertical spin tub for centrifugal drying and an oscillator agitator therein, said agitator having a generally conical shaped base, the mechanism comprising:

a reversible motor operatively connected to a drive pulley that is adapted to rotate in either first or second directions, the first rotational direction being operative to rotate the spin tub and agitator for the purpose of providing centrifugal drying, the second rotational direction being operative to provide oscillating movement of said agitator;

coaxial spin and agitator drive shafts, the agitator drive shaft being concentric with and inside of said spin drive shaft and adapted to rotate relative to said spin drive shaft when said pulley is rotated in said second direction;

braking means for preventing rotation of said spin drive shaft when said pulley is rotated in said second direction, said braking means being adapted to release said spin shaft for rotational movement responsive to rotation of said drive pulley in said first direction;

a lower housing supporting said agitator and spin drive shafts to prevent translational movement thereof, but permitting rotation of said spin shaft, spin tub and agitator relative to said lower housing when said drive pulley is rotated in said first direction;

agitator transmission means within a transmission housing being substantially contained within the area of said agitator conical base, said agitator transmission means being effective to provide oscillating agitator rotational movement responsive to rotation of said agitator drive shaft in said second direction, said agitator transmission means including an internal gear the outer circular periphery of which is substantially smooth, said transmission housing having a mating internal cylindrical wall for receiving the internal gear to prevent translational movement while permitting rotation thereof;

the compact placement of said agitator transmission substantially within the conical volume beneath said agitator base being effective to provide a relatively balanced weight that is conducive to minimizing unbalance and vibration conditions during relatively fast rotation in said first direction which occurs during centrifugal drying.