Abstract:
A transmission shift mechanism for use in a vertical axis automatic washing machine having reversible rotary drive means has a drive gear on which is mounted an eccentric for translating rotary motion into oscillatory motion in a plane perpendicular to the washing machine axis. The oscillatory motion is transmitted to the agitator shaft of a washing machine by a rack and pinion. The pinion is rotatably mounted on the agitator shaft and has teeth on a lower surface thereof which engage teeth on an upper surface of a sleeve co-rotatable with the agitator shaft to form a jaw clutch for driving the agitator shaft from the rack and pinion. A shifter fork also connected to the eccentric operates cams to raise the pinion out of engagement with the sleeve to disengage the jaw clutch when the eccentric is rotating in a first direction, and returns the clutch teeth to engagement when the eccentric rotates in an opposite direction.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a drive mechanism and transmission for an automatic washer of the type in which clothes are washed by oscillation of a vertical agitator and subsequently have water centrifugally removed therefrom by high speed rotation of a wash basket. 
     2. Description of the Prior Art 
     Automatic laundry appliances having a pre-selected programmed cycle of operation which includes a washing period during which oscillation of an agitator imparts a movement to clothes enclosed in a wash basket and a water removal period during which the wash basket is rotated at a high speed are known in the art. It is also known in the art to operate the components of the machine during different periods of the cycle by a common drive means. When a single drive means is utilized, it is necessary to provide a transmission having a shift means which can be operated to selectively condition the drive means to supply oscillatory motion to the agitator, or to supply rotational motion to the wash basket. 
     It is known in the art to impart oscillatory motion to a vertical agitator by means of a lever connected to an eccentric and a segmental gear which engages a circular gear co-rotational with the agitator axis. 
     SUMMARY OF THE INVENTION 
     A transmission shift mechanism for a vertical axis oscillating agitator laundry appliance has a rotating drive gear on which is mounted an eccentric. The eccentric rotates in a circular aperture in one end of a rack, thereby imparting oscillatory motion to the rack in a plane perpendicular to the agitator axis. The opposite end of the rack has a loop which surrounds the agitator shaft and has teeth thereon which engage teeth carried on the circumference of a pinion which is rotatably mounted on the agitator shaft. The pinion has a second set of teeth formed on a bottom surface thereof which engage teeth carried on the upper surface of a sleeve co-rotatable with the agitator shaft to form a jaw clutch. The oscillatory motion imparted to the pinion by the rack may thereby be transferred to the sleeve to oscillate the agitator shaft. 
     A cam means for engaging and disengaging the jaw clutch comprises a pair of collars having engageable cam ramp surfaces disposed below a portion of the pinion and surrounding the sleeve which is co-rotatable with the agitator axis. The upper collar is maintained in a rotationally stationary position while the agitator shaft oscillates inside of it. 
     The lower collar carries two upwardly extending projections about its exterior, and is rotatable by abutment against the projections of two tynes carried on an end of an eccentrically controlled shifter fork. Rotation of the eccentric in one direction will cause one of the tynes on the shifter fork to abut one of the projections on the lower collar. The ramps of the cam surfaces are coordinated with the direction of rotation of the eccentric such that movement of the eccentric in a first direction will cause a first tyne to abut a projection to rotate the lower collar to move the ramps out of engagement and raise the upper collar, thereby raising the pinion and disengaging the teeth of the jaw clutch. Rotation of the eccentric in an opposite direction causes the other of the tynes on the shifter fork to abut the other projection on the lower collar, rotating the lower collar to re-engage the cam ramp surfaces, thereby allowing re-engagement of the jaw clutch pinion teeth with the teeth on the sleeve. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view, partly broken away, of a vertical axis laundry appliance. 
     FIG. 2 is a detailed sectional view of the wash basket, agitator and associated drive means of the laundry appliance of FIG. 1. 
     FIG. 3 is a cross-sectional view taken along line III--III of FIG. 2. 
     FIG. 4 is a view taken along line IV--IV of FIG. 3. 
     FIG. 5 is a view taken along line V--V of FIG. 3. 
     FIG. 6 is a detailed sectional view of the clutch mechanism shown in FIG. 3. 
     FIG. 7 is a view taken along line VII--VII of FIG. 6. 
     FIG. 8 is a schematic view of the shifter mechanism of FIG. 3 showing the shifter fork in various positions during the cycle of operation. 
     FIG. 9 is an exploded view of the clutch mechanism of FIG. 3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An automatic laundry appliance is generally illustrated in FIG. 1 at 10 as comprising a tub 19 which has a perforate clothes container or spin basket 21 contained therein and an agitator 22 vertically disposed within the spin basket 21, mounted for oscillatory movement with respect thereto. The basket 21 is mounted for spinning movement during centrifugal extraction of water from the clothes within the basket 21. The tub 19, the spin basket 21, the agitator 22 and a drive mechanism 23 therefor are contained in a cabinet 11. 
     The cabinet 11 has a top 12 having a hinged lid 13 which is opened to afford access to a clothes-receiving opening 24 which is defined by a tub ring 20 extending about the tub and over a corresponding opening in the spin basket 21. The cabinet 11 also includes a program controller including a timer dial 16 connected to a timer 15 which is mounted on a control panel portion 14 of the cabinet 11. Suitable wiring connects the timer 15 to the drive mechanism 23 and to other electrical components of the appliance to control operation of a wash cycle as is well known in the art. The program controller provides the washing appliance with a sequence of events including agitating the clothes load in a washing portion, spinning the clothes load in the basket 21 to centrifuge the washing liquid therefrom, agitating the clothes load in a rinsing portion, and spinning the clothes load in the basket 21 to centrifuge the rinsing liquid therefrom. The timer dial 16 and the timer 15 may be mounted in any desired location and are shown in the present location for illustrative purposes only. 
     All components inside the cabinet 11 are supported by struts 17, having a suspension system 18 connected thereto to minimize vibration. Referring to FIG. 2, the drive mechanism 23 also operates a pump 43. The drive mechanism 23, and other components such as a transmission housing 32 and a motor housing 42, are suspended from a mounting plate 25 by mounting means such as a bolt and sleeve arrangement 36. Portions of hoses 43a associated with the pump are also illustrated in FIG. 2. The tub 19 is also mounted to the mounting plate 25 by means of bolts such as 26. A grommet 41 maintains a water-tight relationship between the tub 19 and an agitator encasement column 40. A brake means 35 is also provided to operate in association with a spin tube 107 and an agitator shaft 30, and has a dish shaped member mounted to the mounting plate 25. 
     The agitator 22 is attached to the agitator shaft 30 by threaded means 31 and the spin basket 21 is attached to the spin tube 107 by threaded drive block means 34. 
     The shifting mechanism is shown in detail sectional views in FIGS. 3, 6 and 7, and in an exploded view in FIG. 9. The agitator shaft 30 extends into a receptacle 33 in the housing 32 and rests on a bearing plate 37 and a bearing 35 allowing rotation of the shaft 30 about its central vertical axis with a minimum of friction. 
     Oscillatory movement is imparted to the agitator shaft 30 as follows. As shown in FIGS. 3 and 4, a worm gear 85 is attached to a drive shaft 105 journaled in transmission housing 32 and driven by a motor contained in the housing 42 (FIG. 2). The worm 85 engages teeth 84 on a main drive gear 83, thereby imparting rotational movement to the drive gear 83 about a jack shaft 80. A washer 86 reduces friction between the housing 32 and the drive gear 83. An eccentric 95 is integrally formed on an upper portion of the main drive gear 83. The jack shaft 80 and the agitator 30 are parallel to each other, and a rack shown generally at 92 is disposed in a plane normal to the shafts. 
     The rack 92 has a circular aperture 108 at one end thereof which receives eccentric 95. An opposite end of the rack 92 has a loop 93 which surrounds the agitator shaft 30. A row of teeth 94 are carried on one side of the loop 93 and engage teeth 53 which are carried on a portion of the exterior of a pinion 52 which rotates freely about the agitator shaft 30. The side of the loop 93 opposite the teeth 94 has a smooth bearing surface 106 which moves against a portion of the exterior of the pinion 52 which has no teeth thereon, thereby insuring complete engagement of the teeth 53 on the pinion 52 and the teeth 94 on the rack 92. As the eccentric 95 is rotated by the main gear 83, a reciprocal motion in a plane normal to the agitator shaft 30 is imparted to the rack 92. This reciprocatory motion is transferred to the pinion 52 by means of engagement of the teeth 94 and 53. Oscillatory motion is thus transferred to the pinion 52. This motion is then transferred to the agitator shaft 30 through a jaw clutch means described below. 
     The pinion 52 has a second set of teeth 54 integrally formed on a lower portion and disposed downwardly to form the driving member of the jaw clutch. (See FIG. 9). The circumference of the lower toothed portion of pinion 52 is slightly less than the circumference of the main portion of the pinion, thereby forming an annular ledge 57 which is normal to the agitator shaft 30. The teeth 54 on the pinion 52 are arranged to engage similar teeth 55 carried on an upper surface of a sleeve or driven member 56 of the jaw clutch. The sleeve 56 has holes 60 (FIG. 9) disposed in the side walls thereof, which receive a pin 62. The pin 62 also passes through a bore 61 disposed in the agitator shaft 30. Insertion of the pin 62 in the holes 60 and the bore 61 maintains the sleeve 56 in co-rotatable relation to the agitator shaft 30. Although the pinion 52 is free to rotate about the agitator shaft 30, when the teeth 54 and 55 are engaged, the oscillatory motion of the pinion 52 is transferred to the sleeve 56 so that the motion is in turn transferred to the agitator shaft 30. 
     As shown in FIG. 6, the teeth 54 and 55 are maintained in engagement by means of a biasing spring 51 which abuts an upper surface of the pinion 52. An upper portion of the spring 51 bears against a snap ring 50 which is maintained in position by being placed in a circumferential groove (not shown) in the agitator shaft 30. 
     It is desired to maintain the jaw clutch teeth 54 and 55 in engagement only during the agitate portion of the laundry appliance cycle to oscillate the agitator 22, and to disengage the teeth 54 and 55 during a spin portion of the cycle so that the agitator is free to rotate with the spin basket 21. When this sequence of events is repeated, it is then desirable to re-engage the teeth 54 and 55 to allow the oscillatory motion of the agitator to again result. Referring to FIGS. 6, 7 and 9, engagement and disengagement of the teeth 54 and 55 is accomplished by cam means including a pair of collars 63 and 71, disposed between the pinion 52 and a base washer 75 and also surrounding the agitator shaft 30 and sleeve 56. The upper collar 63 has a plurality of downwardly extending cam ramp surfaces 70, and the lower collar 71 has the same number, for example three, upwardly extending mating cam ramp surfaces 72. Both collars 63 and 71 are free to rotate about the agitator shaft 30. The upper collar 63 is maintained in a rotationally stationary position relative to the agitator shaft 30 by means of a radially protruding anchor 64 which has a hole 65 vertically disposed therein. A stud 66 inserted into a hole 65 and extending into a receptacle 67 in the housing 32 allows limited vertical motion of the upper cam member 63 in relation to the agitator shaft 30, but prevents rotational movement relative thereto. A vertical pin 76 extending from the base washer 75 also extends into the hole 65 in the anchor 64 so that rotation of the base washer 75 is also prevented. 
     The lower collar 71 has an exterior portion 73, with two upwardly extending lugs 74A and 74B mounted thereon approximately 140° apart. A thin wall web member 109 extends between the lugs 74A and 74B to prevent interference between a shifter fork 96 and upper collar 63. An appropriate force imparted to the lugs 74A and 74B will thus rotate the lower collar 71 in an appropriate direction to effect engagement or disengagement of the cam ramp surfaces 70 and 72. When the cam ramp surfaces 70 and 72 are disengaged, the upper cam member 63 is raised the height of the cam ramp surface 72 and pushes against the surface 57 on the pinion 52 through a washer 58, thereby raising the pinion by an identical distance to disengage the jaw clutch teeth 54 and 55. The spring 51 is compressed slightly to allow such movement. 
     The appropriate force to rotate the lower collar 71 is applied to the lugs 74A and 74B by the shifter fork 96. The shifter fork 96 is operated by the eccentric 95 and is located between the rack 92 and the main drive gear 82 (see FIGS. 3 and 4). A recess 100 is provided at one end of the shifter fork 96, so that the shifter fork 96 may partially surround the upper collar 63. A pair of tynes 101A and 101B extend downwardly from the shifter 96 and are arranged to abut lugs 74A and 74B respectively. 
     Operation of the shifter fork is demonstrated in FIGS. 5 and 8. The position of the tynes 101A and 101B with respect to the lower collar 71 is determined by the direction of rotation of the eccentric 95. The shifter fork 96 is acted upon by the frictional drag forces created between the shifter fork 96, the rack 92, the upper surface of the drive gear 83 and the outer peripheral surface of the eccentric 95. 
     The positioning of the shifter fork 96 during the agitate portion of a wash cycle is shown in FIG. 5. The drive gear 83 is being driven in a clockwise direction by the worm 85. The shifter fork 96 will thus be moved between positions shown by solid line 96 and dashed line 96C, so that the tyne 101B abuts against the lug 74B. The lower cam member 71 will thus be rotated in a clockwise direction so that the cam ramp surfaces 70 and 72 will be driven into mating engagement, and there will be no space between the lower collar 71 and the upper collar 63. Thus, the teeth 54 on the pinion 52 and the teeth 55 on the sleeve 56 will be driven into engagement under the influence of biasing spring 51. The oscillatory motion of the pinion 52 will therefore be transferred to the agitator shaft 30, so that the agitator 22 will oscillate in the tub 20. 
     When the main gear 83 is rotated in a counter-clockwise direction for the spin portion of the cycle, as shown in FIG. 8, the shifter fork 96 will be changed from the position shown in FIG. 5 to the position shown by the dashed line 96B, and the solid line 96A. The tyne 101A will abut the lug 74A imparting a limited counter-clockwise rotation to the lower cam member 71 as the eccentric 95 rotates, thereby disengaging the cam ramp surfaces 70 and 72 as shown in FIG. 7. The upper cam member 63 will thus be raised a height equal to the height of the ramp surface 72. The upper collar 63 abuts the washer 58 and thus the surface 57 on the pinion 52 so that the pinion 52 is also raised as identical height so that the teeth 54 and 55 are disengaged. The spring 51 is compressed slightly to allow this change in position. 
     During both clockwise and counter-clockwise rotation of the main drive gear 83, the tynes 101A and 101B extend a sufficient distance toward agitate shaft 30 to prevent complete disengagement of the shifter fork 96 away from the shaft. 
     During the spin portion of the cycle, spin basket 21 will be driven by a spin gear 81 having teeth 82 about the circumference which engage teeth 87 carried on a spin collar 107. Rotation of the spin collar 107 causes operation of the spin clutch and basket brake mechanism to effect rotation of the clothes basket 21. A delay means, shown generally at 91 in FIG. 3 is disposed in an annular groove 90 in the lower portion of the spin gear 81 to insure that the spin gear 81 will not be engaged to begin rotation of the basket 21 until a complete revolution of the main gear 83 in the counter-clockwise direction has occurred. One revolution is sufficient to insure that the shifter fork 96 will have changed from the position in FIG. 5 to the position in FIG. 8 and that the lower collar 71 will have rotated in the appropriate direction to disengage the teeth 54 and 55. The program control means through timer 15 provides the signal necessary to reverse the direction of the motor between the spin and agitate portions of the wash cycle. It will be understood that the scope of the cam ramp surfaces 70 and 72 is determined by the direction of the rotation of the main gear 83 during various portions of the wash cycle. The direction of the slope shown in the various figures is coordinated with a clockwise main gear rotation during the agitate portion of the cycle, and a counter-clockwise rotation of the main gear 83 during a spin portion of the cycle. If the directions were reversed, the slopes of the ramps 70 and 72 need only be reversed to accomplish engagement and disengagement. 
     Although various modifications and changes may be apparent to those skilled in the art, applicant intends to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of applicant&#39;s contribution to the art.