US3115218A

US3115218A - Band brake for a laundry machine mechanism

Info

Publication number: US3115218A
Application number: US118307A
Authority: US
Inventors: Charles R Waldrop
Original assignee: Borg Warner Corp
Current assignee: Borg Warner Corp
Priority date: 1961-06-20
Filing date: 1961-06-20
Publication date: 1963-12-24
Anticipated expiration: 1980-12-24

Description

Dec. 24, 1963 I c. R. WALDROP 3,115,218

BAND BRAKE FOR A LAUNDRY MACHINE MECHANISM Filed June 20. 1961 I arlesjf ZUaZdrqp United States Patent 3,115,218 BAND BRAKE FGR A LAUNDRY MACK-ENE MECHANHSM (Iharles R. Waldrop, Herrin, lllh, assignor to Borg-Warner Corporation, Chicago, lll., a corporation of lllinois Filed Shine 2%, i961, Ser. No. 118,307 9 Claims. (tCl. 188'77) This invention relates to a laundry machine apparatus and more particularly to a brake suitable for use in automatic laundry machines.

In the operation of certain types of automatic laundry machines, a single source of power is used for both oscillating an agitator within a laundry basket to wash the laundry, and for unitarily rotating the agitator and the laundry basket to spin the water out of the laundry by the centrifugal force effect created by the spinning. During the washing cycle, the basket has a tendency to follow the oscillations of the agitator due to the friction existing between the agitator, the laundry, and the laundry basket. As a result, the laundry basket will tend to oscillate at intervals somewhat out of phase with the agitator and thereby manifest a lagging oscillation relative thereto unless the basket is held stationary.

The tendency of the laundry basket to oscillate in a lagging manner greatly increases when the basket size and weight is increased. The known types of brakes are not adequate to stop the rotation of a laundry basket in two directions so as to prevent this type of oscillation when a large and heavy laundry basket is utilized. At best, the known types of brakes are only capable of pa.- tially or completely stopping the rotation of the basket in one direction only.

If the laundry basket were allowed to oscillate to any degree in either direction during the washing cycle, the efficiency of the agitation would be lessened and an unsightly slipping relation would exist between the agitator and the laundry basket. Further, inasmuch as the drive elements of laundry machine are subjected to repeated use under heavy load conditions, any attempt at holding or releasing the laundry basket during the appropriate cycles might cause excessive shock loads on the drive elements and contribute to extreme wear or rupture of elements of the drive train.

It is, therefore, extremely important to be able to provide a brake means for holding relatively large and heavy laundry baskets against oscillatory motion with the agitator during the washing cycle so as to prevent the unsightly and ineiiicient oscillation of the basket during the washing cycle. Also, it is important to be able to apply such a brake means without causing excessive shock loads on the elements of the drive train.

It is a primary object of this invention to provide a brake of relatively simple and economical construction for holding a laundry basket of an automatic laundry machine against oscillatory motion when the clothes agitator thereof is oscillated to effect the washing cycle.

Another object of this invention is to provide a brake which is self-energizing so as to positively hold the driven shaft against forward rotation.

A further object of this invention is to provide a brake having a brake band which is frictionally mounted on a driven shaft and free to rotate therewith so as to retard reverse rotation of the driven shaft when the brake band is held stationary.

Another object of this invention is to provide an automatically actuatable brake mechanism which can be positively applied to a driven shaft to prevent oscillation thereof and which will not cause an undue shock load on the driven shaft and associated components when ap plied thereto.

With these and other objects in View the present invention contemplates among other things, an automatically Iactu-atable brake having a braking surface in engagement with a driven shaft so as to be self-energizing in the forward direction, friction retarding in the reverse direction and which provides an actuatable positive brake for holding the driven shaft against oscillation.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects and such other objects as will appear from the following description of an embodiment of the invention illustrated with respect to the accompanying drawings wherein:

FIG. 1 is a partially sectioned view of an automatic washing machine showing the interrelation of the novel brake and the associated elements of the washing machine;

FIG. 2 is a plan view of the novel brake showing the relative positions of the elements thereof.

Refer-ring to the drawings, there is illustrated an automatically operated laundry or clothes washing machine, generally designated by the numeral 9, having an automatically actuatable brake 10* which is particularly suitable for use in the automatic type of laundry machine 9. The laundry machine 9 is of the type fully described in U.S. Patent No. 2,807,951. The above-mentioned patent may be referred to for a full understanding of the complete workings of this type of laundry machine, including the drive mechanism therefor. For the purpose of this application, the only elements of the laundry machine and the drive mechanism therefor which will be referred to are those elements which are pertinent to the understanding of this invention.

A preferred embodiment of the novel brake 10' is illustrated in FIGS. 1 and 2. The drive mechanism of the washing machine includes, among other things, a motor 11 mounted on a steel support member 12 by bolts 13 The motor 11 is provided with a drive shaft 14 which has a pulley 15 secured thereto by a screw 16. The pulley 15 is drivingly connected to a pulley 17 by a belt 18 and the pulley 17 is secured to a shaft 19 by a screw 26". The shaft 19 is rotatably mounted on bearings 21 in the support member 12 and is drivingly attached to a clutch hub 22 by virtue of a flexible coupling generally designated by the numeral 23. The clutch hub 22 is drivingly secured to a shaft 24 by a screw 25 and is provided with a clutch drum surface 26.

A sleeve shaft 30 is coaxially mounted on the shaft 24 and is provided, at the lower end thereof, with a clutch drum surface 31 adjacent the clutch drum surface 26, and with a brake drum surface 32. immediately thereabove. A self-energizing spring clutch 33 is provided on the

adjacent drum surfaces

26 and 31 for providing a resilient drive connection between the clutch drum surface 26 of the clutch hub 22 and the clutch drum surface 31 of the sleeve shaft 36. This driving connection is provided in the forward direction and is self-releasing to disconnect the drive when the clutch hub 22 is driven in the reverse direction. The sleeve shaft 3t) is rotatably mounted in a stationary sleeve 34 which is rigidly secured to the supporting member 12 of the laundry machine 9.

The upper end of the sleeve shaft 30 is rigidly connected to a casing id of a transmission, generally designated by the numeral 41, which forms the bottom of a laundry basket 42. The transmission 41 is adapted to be driven by the shaft 24 and thereby impart an oscillatory motion to an agitator 43 which is rotatably mounted on an extension 44 of the transmission casing 40. The abovementioned US. patent may be referred to for a more complete and detailed description of the transmission. For purposes of this application, it is only important to note that the transmission casing 40 forms a part of the 3 laundry basket 42 and that the drive train within the transmission 41 imparts an oscillatory motion to the agitator 43 which is rotatably mounted on the transmission extension 44 within the clothes basket 4-2.

The improved brake ltl (FIGS. 1 and 2) includes, among other things, a brake band 45 positioned around the brake drum surface 32 of the sleeve shaft 3h. The brake band 45 is provided with a conventional brake band material 45a which is secured to the band 4-5 and is in frictional engagement with the brake drum surface 32 of the shaft 3ft. A pair of positioning rings 46 are secured in the brake drum 32 of the sleeve shaft 36 and are adapted to support the brake band 45 and otherwise retain the brake band 45 against longitudinal movement on the brake drum surface 32. The brake band 4-5 is provided with a lip 47 which may be engaged for holding the band 45 stationary.

Brake band 45 is adapted to be self-energizing so that, when held stationary, the band 45 will tend to wrap around the brake drum 32 and thereby positively grip the brake drum 32 and hold the sleeve shaft 3% against rotation in the forward or counterclockwise direction (FIG. 2). It should be noted that the brake band 4-5 is adapted to be in frictional engagement with the brake drum 32 at all times so that, when held stationary, the band 45 will exert a braking force on the brake drum surface 32 of the sleeve shaft 30 and thereby tend to hold the sleeve shaft against rotation in the reverse or clockwise direction (PEG. 2). The sleeve shaft brake drum surface 32 is provided with a notch 48 (FIG. 2) having one surface thereof defining a chordal surface 49 of the sleeve shaft 3t) and another surface thereof defining a radial surface 50 of the sleeve shaft 30.

A latch 54 is pivotally mounted on a pin 55 secured in a bracket 56 which in turn is secured to the support member 12 of the laundry machine. The latch is substantially arcuate in shape and is provided with the hole 57. A tension spring 58 is secured at one end thereof to the bracket 56 and at the other end thereof to the latch 54 through the hole 57 so that the latch 54 is urged to pivot clockwise (FIG. 2) about the pin 55 toward the sleeve shaft 30. The latch 54 is provided with a projection 59 having a surface 6d adapted to engage the radial surface i? of the notch 48 in the sleeve shaft 36 to prevent rotation of the sleeve shaft in the reverse direction. The latch 54 is also provided with a surface 61 adapted to engage the chordal surface 2% of the sleeve shaft 3t when the sleeve shaft is rotated in the forward direction. It should be noted that, when the sleeve shaft 36 is rotated in a counterclockwise direction, the chordal surface 45 will cam against the projection surface 61 and urge the latch 54 out of the notch 48 against the action of the tension spring 58.

The latch 54 is provided with a slot 62 which is separated from the brake surface 6t) of the projection 5? by a surface or platform 65. The slot 62 is adapted to receive the lip 47 of the brake band 45 when the projection 59 is allowed to enter the notch 48 of the sleeve shaft 3h. The self-energizing brake band is thereby held against counterclockwise rotation (FIG. 2) which in turn will cause the brake band 4-5 to hold the sleeve shaft 39 against counterclockwise or forward rotation.

A solenoid 64 is secured to the bracket 56 at @363 and is provided with a movable core as connected to a link 68a which is pivotally secured to the latch 54 by a pin 69. The solenoid 64 is actuatable to retract the core 68 to the right (FIG. 2) so as to pivot the latch 54 counterclockwise about the pin 55 to remove the latch projection 59 from the notch 48 in the sleeve shaft 36 The brake action of the latch 54 against the sleeve shaft 3%) in the reverse direction is thus released.

General Operation In operation of the Washing machine drive mechanism, the motor ll is first actuated so as to rotate shaft l4 in the forward or counterclockwise direction (FIG. 2) to provide power for the washing cycle. The motor 11 is subsequently actuated so as to rotate shaft 14 in the reverse or clockwise direction (FIG. 2) to provide power for the Water-removing spin cycle. In particular, the washing cycle is provided when the motor 11 is rotated in the forward direction so that the pulley 15 will drive the pulley 17 in the forward direction by virtue of the interconnecting belt 18. As a consequence, the shaft 19 will also be driven in the forward direction, and by virtue of the flexible coupling 23 and the clutch hub 22, the shaft 24 will be driven in the forward direction by the shaft 19. It should be noted that the spring clutch 33 is adapted to release when the clutch hub 22 is rotated in the forward direction so that shaft 19 will not transmit forward motion to the sleeve shaft 3% during the wash cycle.

When the shaft 24 is rotated in the forward direction, the transmission 41 will impart an oscillatory motion to the agitator 43. The laundry basket 42 is held against similar oscillatory motion by virtue of the novel brake 19, the operation of which will be subsequently described in detail. The brake ll) engages the brake drum surface 32 to hold the sleeve shaft 3%) against rotation. As a consequence, the transmission 41 and connected laundry basket 42, which are rigidly connected to the sleeve shaft 3d, are likewise held against oscillatory motion during the washing cycle.

The spin cycle is provided by reversing the direction of the motor if and by releasing the brake it). The reversal of the motor ll causes the clutch drum 3i and the shaft 24 to rotate in a reverse direction. As a result, the spring clutch 33 will be caused to engage the clutch drum surfaces 26 and 31 of the clutch hub 22 and the sleeve shaft 31? respectively. The sleeve shaft 30 and the shaft 24 will be locked together and will rotate as a unit inasmuch as the brake ll) is released. The transmission 41 and the basket 42 connected to the sleeve shaft 3t) and the drive shaft 24 will rotate with the agitator 4,3 in the reverse direction ata relatively high speed determined by the size of the pulleys 15 and 17. This high speed reverse rotation results in a water-removing spin cycle which is timed to continue until the water is removed from the clothes contained in the clothes basket 42.

Brake Operation The brake id is operated through a cycle which spans both the wash and the spin cycle of the laundry machine. The operation of the brake It? will now be described beginning with that part of the brake cycle corresponding to the washing cycle of the laundry machine. During the washing cycle, the brake it is actuated so as to hold the rigidly interconnected sleeve shaft 3%, transmission 41 and clothes basket 4-2 against any rotational or oscillatory motion. More particularly, the tension spring 5-3 will hold the latch 54 in the leftmost position (FIG. 2) with the surface 60 of the latch 54 in engagement with the radial surface Stl of the notch 48 so as to hold the sleeve shaft 30 against reverse or clockwise rotation (PEG. 2).

Likewise, during the washing cycle, the lip 47 of the brake band 45 is positioned in the slot 62 for holding the brake band 45 against forward or counterclockwise rotation (FIG. 2). The brake band 4'5 will in turn grip the brake drum surface 32 of the sleeve shaft 34 by virtue of the self-energizing characteristic of the brake band 45, to hold the sleeve shaft 349 against forward or counterclockwise rotation. Thus, during the washing cycle, the latch 54 is urged toward the sleeve shaft 30 (FIG. 2) by the spring 53 so as to positively hold the sleeve shaft 3t) against oscillatory movement.

When the washing cycle is completed, the motor ll will be actuated from the forward to the reverse condition to provide the water-removing spin cycle of the laundry machine as previously described. Inasmuch as the solenoid 64 is in the reverse circuit for the motor 11, the solenoid 64 will be actuated when the motor 11 is in the reverse condition. Thus, when the spin cycle of the laundry machine is initiated, the solenoid 6% will be actuated. so as to move the solenoid plunger 63 to the right (FIG. 2) which in turn will cause the latch 54 to pivot counterclockwise about the pin 55.

The latch 54 is thus removed from engagement with the radial surface 59 of the sleeve shaft notch 48 and the lip 47 of the brake band ie. The brake band 45 is thereupon free to rotate with the sleeve shaft 3% in its supported position between the positioning collars In this condition, the sleeve shaft Sill is free from the reaction of the brake and is caused to rotate in the forward or clockwise direction (FIG. 2) by the movement of the clutch hub 22 which is connected to the sleeve shaft 34 by the spring clutch 33.

It should be noted that, when the motor lll is actuated from the forward to the reverse condition, the driven shaft 19 and the sleeve shaft 3% will thus be rotated in a reverse direction. There is frictional drag between the sleeve shaft 3%) and the brake band 45 which may cause the lip 47 of the brake band 4-5 to force itself against the upper surface tit) of the latch 5 and thereby resist the forward or counterclockwise rotation of the latch 54. Under these circumstances it should be noted that the chordal surface 49 of the sleeve shaft 3t) will have a camming effect on the surface 61 of the projection so as to aid the solenoid 64 to force the latch 54 out of engagement with the radial surface 553 of the notch 48 in the sleeve shaft 3i) and thereby aid in the removal of the latch 54 from the lip 47 of the brake band 45. The solenoid 64 is thereupon free to completely remove the latch 54 from any engagement with the sleeve shaft 3% or the lip 47 of the brake band 45 so that the sleeve shaft 359 and the brake band 45 are free to rotate in the reverse or clockwise direction for the spin cycle.

When the spin cycle has been completed, the motor 11 is deenergized and, as a consequence, the solenoid 64, which is in the reverse circuit with the motor 11, will likewise be deenergized. Upon deenergization of the solenoid 64, the latch 54 will be urged clockwise about the pin 55 in response to the force exerted thereon by the spring 53. The sleeve shaft 39 will continue to rotate in a reverse direction due to the inertia of the laundry basket and its contents. inasmuch as there is a frictional drag between the brake band 45 and sleeve shaft 3%, the brake band 45 will continue to rotate in the reverse direction with the sleeve shaft 39.

Thus, the projection 59 of the latch 54 will engage the brake band 45 at some point on the outer surface thereof. The brake band and the sleeve shaft 36 will continue to rotate together in the reverse or clockwise direction until the lip 47 of the brake band engages the surface as of the notch 4% projection. When the reverse speed of the sleeve shaft 3ft is still high, the sleeve shaft will urge the brake band 45 in a reverse or clockwise rotation and thereby urge the lip 47 of the brake band 45 into engagement with the surface as of the latch 54. The force of the spring 58 is such that the frictional force exerted by the lip 47 on the radial surface 6! of the latch 54 is sufficient to prevent pivotal movement of the latch 54 when the reverse speed of the sleeve shaft is still high.

The brake band 45 is held by the latch projection 59 against continued reverse rotation and will thereby cause the brake band 45 to exert a frictional drag on the reverse or clockwise rotation of the sleeve shaft 3%. This frictional drag will reduce the reverse speed of the sleeve shaft 30 which in turn will lessen the force exerted by the lip 47 on the radial surface 6% of the latch projection 59. As a result, the latch 54 will be gradually released from the frictional force exerted by the lip 47 so that the spring 58 will eventually be able to pivot the latch 54 clockwise until the lip 47 engages the surface 63 of the latch 5d.

At this point, the projection 59 has not entered the notch 48 of the sleeve shaft Sll but the spring 58 will continue to urge the latch 54 clockwise against the lip 47 of the brake band 45 and thereby cause the brake band 45 to press against the sleeve shaft 3% to further retard the reverse or clockwise rotation of the sleeve shaft 3i). When the reverse rotation of the sleeve shaft 3% is sufficiently retarded, the brake 16 is in condition to be actuated for the positive braking portion of braking cycle which is necessary for the washing cycle of the laundry machine.

Energization of the motor 11 in the forward or counterclockwise direction for the washing cycle, after being deenergized from the reverse spin drive, is timed so that the sleeve shaft 3t has had sufficient time to have been stopped or substantially stopped by the brake ill. Upon energization of the motor 11 in the forward or counterclockwise direction for the washing cycle, the spring clutch 33 will be released and the transmission 41 will impart a reciprocating motion to the interconnected laundry basket 42, transmission 41 and sleeve shaft 3%, whereupon the frictional contact between the brake band 45' and the sleeve shaft 3% will urge the brake band 45 to oscillate.

However, inasmuch as the brake band 45 is self-energizing in the forward or counterclockwise direction only, the sleeve shaft 3t) will meet less resistance from the brake band 45 when moving in the reverse direction than when moving in the forward direction. As a result, the lip 47 of the brake band 45 will be moved by the sleeve shaft brake drum 32 to a point adjacent the slot 62 in the latch 54 during the forward rotation of the sleeve shaft 36. The spring 58 will then be able to pivot the latch 54- clockwise urging the lip 47 of the brake band 45 into the slot 62 and simultaneously urging the projection into engagement with the sleeve shaft brake drum 32.

The oscillating Washing action will continue to cause the sleeve shaft 3th to oscillate but the sleeve shaft 30 is held against forward or counterclockwise rotation by the self-energizing brake band 45. The sleeve shaft 3i will thereby be held more positively against forward or counterclockwise rotation than against reverse or clockwise rotation. As a result, the sleeve shaft fill will be moved intermittently in the reverse or clockwise direction until the notch 43 is moved adjacent the latch projection 59. The force exerted on the latch 54 by the spring 53 will then be free to move the latch projection 59 into the notch 48 by pivoting the latch 54 clockwise about the pin 5'5. The radial surface 66) of the projection 59 will thereafter likewise engage the radial surface 59 of the sleeve shaft notch 48 and provide a positive brake for preventing reverse rotation of the sleeve shaft It should be noted that the latch 54 will positively hold the sleeve shaft 349 against both reverse and forward rotation by virtue of the latch projection 5h positioned in the notch 43 and by virtue of the brake band lip 47 being retained in the latch slot 62 respectively. Upon termination of the washing cycle, the brake ill? will be actuated as previously indicated thus completing the cycle of operation of the brake it).

I wish it to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

1. A brake for a laundry machine drive mechanism wherein a shaft is alternately urged for forward and reverse oscillating movement and for rotational reverse movement which comprises a brake drum on the shaft, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith in said for ward and reverse movements of said shaft and operable to resist said movements of said shaft when held against rotational movement, a latch actuatable for engaging said brake band and said shaft to hold said brake hand against said movements and to hold said shaft against reverse rotational movement, and means for actuating said latch.

2. A brake for a laundry machine drive mechanism wherein a shaft is alternately urged for oscillating movement between forward and reverse and for rotational movement in reverse which comprises a brake drum on the shaft, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse movements of said shaft for preventing said forward movement of said brake drum and for retarding reverse rotational movements of said shaft when held against rotational movement, a latch actu-atable for engaging said brake band and said shaft to hold said brake band and said driven shaft against rotational movements, and means for actuating said latch.

3. A brake for a laundry machine drive mechanism wherein a shaft is alternately urged for oscillating movement between forward and reverse and for rotational movement in reverse which comprises a brake drum on the shaft, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse movements of said shaft for preventing said forward movement of said brake drum and for retarding reverse rotational movement of said shaft when held against rotational movement, a latch actuatable for engaging said brake band and said shaft to hold said brake band against rotational movements and to hold said shaft against reverse rotational movement, and means for actuating said latch.

4. A brake for a laundry machine drive mechanism having a shaft alternately urged for oscillating movement between forward and reverse and for rotational movement in reverse which comprises a brake drum on the shaft, a selfenergizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse movements of said shaft for preventing said forward movement of said brake drum and for retarding reverse rotation of said shaft when held against reverse rotation and forward rotational movement respectively, a latch pivotable toward said brake band to a first position for engaging said brake band to hold said brake hand against reverse rotational movement, said latch being pivotable to a second position beyond said first position for positively engaging said shaft and said brake band to hold said shaft against reverse rotational movement and to hold said brake hand against forward rotational movement when said shaft is urged to oscillate, and means for urging said latch to pivot.

5. A brake for a laundry machine drive mechanism having a shaft alternately urged for oscillatory movement between forward and reverse and for rotational movement in reverse which comprises a brake drum on a shaft, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse movement of said shaft preventing said forward movement of said brake drum and for retarding reverse rotational movement of said driven shaft when held against reverse and forward rotational movements respectively, a latch pivotable toward said brake band to a first position for engaging said brake band to hold said brake hand against reverse rotational movement, means on said latch for engaging said brake band to prevent further pivotal movement of said latch toward said brake hand during reverse rotational movement of said shaft, said latch being pivotable to a second position beyond said first position for positively engaging said shaft and said brake band to positively hold said shaft against reverse rotational movement and to hold said brake hand against forward and reverse rotational movement when said shaft is urged to oscillate, and means for urging said latch to pivot.

6. A brake for a laundry machine drive mechanism having a shaft alternately urged for oscillatory movement between forward and reverse and for rotational movement in reverse which comprises a brake drum on the shaft, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse movement of said shaft for preventing said forward movement of said brake drum and for retarding reverse rotational movement of said driven shaft when held against reverse and forward rotational movements respectively, a lip formed on said brake band and extending radially therefrom, a latch pivotable toward said brake band to a first position for engaging said lip to hold said brake hand against reverse rotational movement, means on said latch for engaging the end of said lip to prevent further pivotal movement of said latch during reverse rotational movement of said shaft, said latch being pivotable to a second position beyond said first position for positively engaging said shaft and said lip to hold said shaft against reverse rotational movement and to hold said brake band against forward and reverse rotational movements when said shaft is urged to oscillate, and means for urging said latch to pivot.

7. A brake for a laundry machine drive mechanism having a shaft alternately urged for oscillatory movement between forward and reverse and for rotational movement in reverse which comprises a brake drum formed on the driven shaft, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse movement of said shaft for preventing said forward movement of said brake drum and for retarding reverse rotational movement of said shaft when held against reverse and forward rotational movements respectively, a lip formed on said brake band and extending radially therefrom, :a latch pivotable toward said brake band to a first position for engaging said lip to hold said brake band against reverse rotational movement, means on said latch for engaging said lip to prevent further pivotal movement of said latch during reverse rotational movement of said shaft, said latch having a slot therein adapted for receiving said lip to prevent oscillatory movements of said brake band, said lip being pivotable to a second position beyond said first position for positively engaging said shaft and for forcing said lip into the slot of said latch to hold said shaft against reverse rotational movement and to hold said brake band against forward and reverse rotational movement respectively when said shaft is urged to oscillate, and means for urging said latch to pivot.

8. A brake for a laundry machine drive mechanism having a shaft alternately urged for oscillatory movement between forward and reverse and for rotational movement in reverse which comprises a brake drum on the shaft, said brake drum having a radial notch formed therein, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse movement of said shaft for preventing said forward movement of said brake drum and for retarding reverse rotational movement of said driven shaft when held against reverse rotation and forward rotational movements respectively, a lip formed on said brake band and extending radially therefrom, a latch pivotable toward said brake band to a first position for engaging said lip to hold said brake band against reverse rotational movement, a platform on said latch for engaging the end of said lip to prevent further pivotal movement of said latch during reverse rotational movement of said shaft, said latch having a slot therein adapted for receiving said lip to prevent oscillatory movements of said brake band, said latch being pivotable to a second position beyond said first position for engaging said shaft and for forcing said lip into the slot of said latch to hold said shaft against reverse rotational movement and to positively hold said brake band against forward and reverse rotational movement respectively when said shaft is urged to oscillate, and means for urging said latch to pivot.

9. A brake band for a laundry machine driving mechanism having a 'drive shaft alternately urged for rotary movement in reverse and for oscillatory movement be- 9 tween forward and reverse which comprises a brake drum on the shaft, said brake drum having a radially extending notch formed therein, a self-energizing brake band frictionally engaged with said brake drum and normally rotatable therewith during said forward and reverse move ment of said shaft for preventing forward rotational movement of said brake drum and for retarding reverse rotational movement of said driven shaft when held against reverse and forward rotational movement respectively, a lip on said brake band extending radially therefrom, a latch pivotally secured to the support member, a projection on said latch and adapted to engage said lip and the notch formed in said shaft, a platform on said latch adjacent said projection adapted to engage the end of said lip, said latch having a slot formed therein adjacent said platform and adapted to receive said lip, spring means urging said latch toward said brake band for causing said projection to engage the brake band lip to stop reverse rotational movement of said brake band, said spring means urging said platform against said lip to prevent further pivotal movement of said latch toward said shaft during reverse rotational movement of said brake band, said latch having a slot formed therein adjacent said platform receiving said lip during oscillatory movement of said brake band for holding said brake hand against reverse and forward rotational movement and for allowing said projection to be moved by said spring means into the notch in said shaft to hold said shaft against reverse rotational movement, and means for pivoting said latch means away from said brake band and said driven shaft to remove said projection from the notch and said lip from the slot to allow free rotational movement of said driven shaft and said brake band.

References Cited in the file of this patent UNITED STATES PATENTS 2,728,428 Cohen Dec. 27, 1955 2,946,409 Jennings July 26, 1960 FOREIGN PATENTS 141,953 Austria June 11, 1935

Claims

1. A BRAKE FOR A LAUNDRY MACHINE DRIVE MECHANISM WHEREIN A SHAFT IS ALTERNATELY URGED FOR FORWARD AND REVERSE OSCILLATING MOVEMENT AND FOR ROTATIONAL REVERSE MOVEMENT WHICH COMPRISES A BRAKE DRUM ON THE SHAFT, A SELF-ENERGIZING BRAKE BAND FRICTIONALLY ENGAGED WITH SAID BRAKE DRUM AND NORMALLY ROTATABLE THEREWITH IN SAID FORWARD AND REVERSE MOVEMENTS OF SAID SHAFT AND OPERABLE TO RESIST SAID MOVEMENTS OF SAID SHAFT WHEN HELD AGAINST ROTATIONAL MOVEMENT, A LATCH ACTUATABLE FOR ENGAGING SAID BRAKE BAND AND SAID SHAFT TO HOLD SAID BRAKE BAND AGAINST SAID MOVEMENTS AND TO HOLD SAID SHAFT AGAINST REVERSE ROTATIONAL MOVEMENT, AND MEANS FOR ACTUATING SAID LATCH.