Patent Application: US-11017080-A

Abstract:
a two - speed clutch arrangement is disclosed in which an input shaft is drivingly connected to an output drum through a system of clutch shoes so as to alternatively produce direct drive of the output drum , a reduced speed drive , or a neutral condition in which drive is not transmitted to the output drum . the clutch system includes centrifugally actuated primary clutch shoes driven by the input shaft and establishing drive to an inner drum , and two different sets of friction clutches interposed between the inner drum and the output drum . the first set produces a slipping or low speed drive of the output drum , while the second direct drive set controllably establishes direct or high speed drive . shifting of the clutch arrangement is carried out by a trigger actuator , which activates clutch trigger arrangements associated with the primary clutch shoes and the direct drive clutch set . the trigger actuator is shifted between alternate positions in which either centrifugal actuation of the primary clutch shoes or the direct drive clutch set is allowed . shifting the position of the trigger actuator prior to establishment of drive to the input shaft being initiated creates a neutral condition of the clutch .

Description:
in the following detailed description , certain specific terminology will be employed for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 usc 112 , but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims . referring to the drawings , the clutch unit 10 according to the present invention is shown assembled with a drive motor 12 , with the entire assembly being adapted to be mounted within the washing machine by means of a mounting bracket 14 secured to the endface of the drive motor 12 . the drive motor output shaft 16 is adapted to drive through the clutch unit 10 to an output pulley sheave 18 , which in turn receives a belt drive connected to the washing machine transmission ( not shown ). the output shaft 16 is also coupled to a shaft extension 22 by means of a coupling 24 , and in turn the shaft extension 22 is pinned by pin 25 to a pump coupling member 26 which is adapted to receive a flexible coupling connected to the input shaft of the drain pump ( not shown ). thus , the drive motor 12 has two different drive outputs , one the output through the clutch unit 10 and the other directly driven by the output shaft 16 and shaft extension 22 , i . e ., the pump coupling member 26 . according to one of the concepts of the present invention , the clutch unit 10 is provided with a neutral condition such that the drive motor 12 can be employed to drive the shaft extension 22 and pump coupling member 26 without producing a drive input to the output pulley sheave 18 in order that the drain pump can be operated without driving the washing machine transmission . the general arrangement of the clutch unit 10 includes an outer drum 28 integral with the output pulley sheave 18 and rotatably supported by the bearing 30 on the shaft extension 22 , suitable snap retainer 32 retaining the outer drum 28 thereon . also provided is an intermediate inner drum 34 rotatably supported on a bearing 36 on the shaft extension 22 . the clutching unit 10 includes a primary clutching means interposed between the rotary input means , comprised of the output shaft 16 and shaft extension 22 , and the inner drum 34 . slip clutch means are interposed between the inner drum 34 and the outer drum 28 , as well as direct drive clutch means also interposed between the inner drum 34 and outer drum 28 . the primary clutch means comprises a centrifugal clutch which establishes a drive from the rotary input means to the inner drum 34 upon rotation above a predetermined rate or rotation . the centrifugal clutch is comprised of a pair of clutch shoes 38 and 40 which are pivoted to plate 46 secured to the output shaft 16 by a sleeve member 48 , in turn secured to the output shaft 16 to thus produce rotation of each of the clutch shoes 38 and 40 with rotation of the rotary input means . tension springs 50 and 52 are provided which bias the clutch shoes 38 and 40 inwardly and counteracting the effect of centrifugal force such that engagement of friction surface shoes 54 and 56 of clutch shoes 38 and 40 respectively is precluded until a predetermined rotation of the rate of the output shaft 16 is achieved . upon rotation of the clutch shoes 38 and 40 at said predetermined rate of rotation , clutch shoes 38 and 40 move radially outward such that the friction surface shoes 54 and 56 engage the inner surface 57 of the inner drum 34 as depicted in fig1 . whenever the clutch shoes 38 and 40 are not being rotated at or above the predetermined rate of rotation , the shoes are pivoted inwardly as depicted in fig2 to be moved out of engagement with the inner drum 34 such as to disestablish drive between the output shaft 16 and the inner drum 34 . as will hereinafter be described in detail , a triggering mechanism is employed to control this movement of the clutch shoes 38 and 40 under the influence of centrifugal force in order to provide a neutral condition . the slip clutch arrangement 58 is of the type described in aforementiond u . s . pat . no . 2 , 869 , 699 and aforementioned application ser . no . 072 , 273 , filed sept . 4 , 1979 . this includes a pair of clutch shoes 62 and 64 which have arcuate friction surfaces 66 and 68 , respectively , which are urged into engagement with the outside surface 67 of the inner drum 34 by means of operator springs 65 ( fig3 ). the clutch shoes 62 and 64 ( fig1 ) also include portions 70 and 72 , respectively , which pass through slotted openings 74 and 76 in the outer drum 28 such as to be positively driven thereby . clutch shoes 62 and 64 are engaged with spring plates 63 ( fig3 ) to preclude vibration thereof . this arrangement allows a centrifugally induced outward movement of each of the clutch shoes 62 and 64 so as to reduce the frictional driving connection between the inner drum 34 and the outer drum 28 and thus produce a slipping , reduced speed drive relative to the drive motor speeds in the same manner as described in the aforementioned u . s . patent and patent application . the high speed or direct drive clutch arrangement 60 includes a pair of centrifugally actuated clutch shoes 78 and 80 ( fig2 ) which are mounted to the outer drum 28 by brackets 82 and 84 ( fig3 ) affixed to the outer drum 28 by means of integral mounting eyes 86 and 88 , 90 and 92 ( fig2 ). each of the clutch shoes 78 and 80 is mounted for rotation about pivot points 93 and 94 , and have relatively large mass trailing portions 96 and 98 such as to have a greater mass on one side of the pivot points 93 and 94 than on the other side . the leading side of each clutch shoe 78 and 80 includes a clutching arm portion 100 and 102 , provided with arcuate friction shoes 104 and 106 which are adapted to be rotated into engagement with the outside surface 67 of the inner drum 34 upon rotation thereof by the effect of the greater mass of the trailing portions 96 and 98 creating an unbalance about the respective pivot points , causing the clutch shoes 78 and 80 to rotate and move the arcuate friction shoes 104 and 106 into tight engagement therewith . this produces a direct one - to - one drive ratio between the inner drum 34 and outer drum 28 and thus establishes a direct drive from the input shaft means to the output pulley sheave 18 . the trailing portions 96 and 98 are each also provided with bumper friction material 108 and 110 , respectively , in order to cushion impacting of the shoes on the outside surface 67 in the event of slight vibrations , tending to produce an oscillation of the shoes into engagement therewith . in similar fashion to the primary clutch , the action of the direct drive clutch arrangement 60 is controlled by trigger means which operates jointly with a common solenoid actuator associated with the primary clutch means . the trigger means includes a solenoid actuator 112 mounted by means of a bracket 113 welded to the mounting bracket 14 . solenoid actuator 112 has a plunger 111 controlling the position of the actuator element 114 . when the solenoid actuator 112 is not energized , the actuator element 114 is biased by a spring 115 which remains in position as shown in fig1 positioned against the top 116 . with the solenoid actuator 112 energized , the actuator element 114 is moved to a second position against the stop 118 , a resilient lost motion connection between the plunger 111 and the actuator element 114 being provided by a spring 117 . in the first - mentioned position , the actuator element 114 lies in the path of tail portions 120 and 122 associated with trigger elements 124 and 126 , respectively , since these are located at the same radial distance outward from the clutch axis . this causes contact therebetween as the primary shoes 38 and 40 are rotated . trigger elements 124 and 126 interact with the primary clutch shoes 38 and 40 such as to either lock the clutch shoes 38 and 40 in a disengaged position or to release them to allow the centrifugal actuation thereof to occur . each of the trigger elements 124 and 126 are spring - biased by tension springs 128 to be swung about pivotal mounts 130 and 132 so as to be moved to the releasing position . in the releasing position , locking portions 134 and 136 of trigger elements 124 and 126 are clear of catch plates 138 and 140 , respectively , which are integral with the respective primary clutch shoes 38 and 40 . in the locking position , the trigger locking portions 134 and 136 are cammed into locking engagement with the respective catch plates 138 and 140 , which prevent the respective primary clutch shoes 38 and 40 from rotating outwardly in response to the terminal force and thus maintain a neutral condition of the clutch unit 10 . if the actuator element 114 is in the first position shown in fig1 when the drive motor 12 is energized , tail portions 120 and 122 are contacted thereby to be pivoted about the pivotal mounts 130 and 132 to the releasing position with the clutch thus allowed to move outwardly and establish drive between the inner drum 34 and the input shaft 16 . in the second position , the actuator element 114 is positioned in the path of the tail portions 142 and 144 associated with respective direct drive clutch triggers 146 and 148 as the outer drum 28 rotates , which are pivotally mounted on respective mounting pins 154 and 156 mounted to bores formed in flanges 150 and 152 and also to sections of the brackets 82 and 84 . each of the direct drive clutch triggers 146 and 148 includes a locking portion 158 and 160 which coacts when rotated with the respective trailing portions 96 and 98 of the direct drive clutch shoes 78 and 80 , moving into with the respective outer surfaces 162 and 164 thereof . the direct drive clutch triggers are urged into the locking position by means of tension springs 166 and 168 , respectively . tension spring 166 is connected at one end to a tab portion 178 integral with tail portion 170 of trigger 146 and at the other end to tab portion 174 formed on plate 82 . similarly , tension spring 168 is connected at one end to tab portion 172 of trigger 148 and at its other end to tab 176 formed on bracket 84 . thus , the locking portions 158 and 160 tend to wedge into the intervening space between the outer surfaces 162 and 164 of the trailing portions 96 and 98 , respectively , and the interior of the outer drum 28 to preclude centrifugal actuation of the respective direct drive clutch shoes 78 and 80 into engagement with the inner drum 34 . upon the actuator element 114 moving into the path of the tail portions 142 and 144 , respectively , however , the locking portions 158 and 160 are rotated over center out of engagement therewith and enable the centrifugal force exerted by the trailing portions 96 and 98 to hold the locking portions 158 and 160 in this position . in this mode , the drive is established by the engagement of the direct drive clutch shoes 78 and 80 . it can be understood from the above that three different modes of operation are enabled by the two conditions of the solenoid actuator 112 as described above when the solenoid is energized , the actuator element moving from the first position to the second position . whenever the solenoid actuator 112 is deenergized , the spring bias causes the actuator element 114 to again move to the first position shown in fig1 . if the solenoid actuator 112 is deenergized at the time of the start up of the drive motor 12 , the actuator element 114 , being in the first position , contacts the tail portions 120 and 122 of the respective trigger elements 124 and 126 causing release of the primary clutch shoes 38 and 40 with centrifugal actuation thereof enabled such as to establish drive between the output shaft 16 and the inner drum 34 . if the solenoid 112 continues in a deenergized state , the direct drive clutch triggers 146 and 148 remain in locking engagement with the trailing portions 96 and 98 of the direct drive clutch shoes 78 and 80 and accordingly drive from the inner drum 34 to the outer drum 28 is via the clutch shoes 62 and 64 . this thereby establishes low speed drive from the output shaft 16 to the outer drum 28 and output pulley sheave 18 . if the solenoid 112 is energized at this point , the actuator element 114 moves from the first position to the second position and into the path of the tail portions 142 and 144 causing the direct clutch triggers 146 and 148 corresponding thereto be rotated out of the locking position . this enables the direct drive clutch shoes 78 and 80 to be engaged with the inner drum 34 and establish direct or high speed drive through the unit . in order to establish neutral , the solenoid actuator 112 is energized prior to the start up of the drive motor 12 and the actuator element 114 is caused to move from the first position to the second position . this allows the trigger elements 124 and 126 to remain in the locking position after the drive motor 12 is energized , precluding the establishment of drive through the primary clutch means from the output shaft to the inner drum 34 and accordingly a neutral condition of the clutch unit is produced . therefore , a simple two - position solenoid actuation enables neutral , high and low speed drive modes . it will be appreciated that the trigger and actuator arrangements are simple and rugged in construction , such as to be enabled to be manufactured at relatively low cost while operating in a highly reliable manner suitable for such applications as washing machine drive units . it will also be seen that the provision of the high speed direct drive clutch shoes mounted to the drum eliminates the need for a separate carrier plate as required in the design described in u . s . pat . no . 2 , 869 , 699 , thereby simplifying the drive unit and reducing the number of clutch sets to a minimum 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