US2450845A - Suction cleaner - Google Patents

Description

c. G. TROXLER ETAYL SUCTION, CLEANER Filed March 25, 1944 INVENTORS d v! m M w m my W 0 g ,fiw m s.

C. G. TROXLER ET AL SUCTION CLEANER 4 Sheets-Sheet 2 INVENTORJ' 'lzarles d-fi'oxler and I I l ATTORNEY Oct. 5, 1948.

Filed March 23, 1944 Oct. 5, 1948. c. G. TROXLER EIAL SUCTION CLEANER 4 Sheets-Shet 3 Filed March 23, 1944 S m T. m w.

S ATTORNEY 5; 1948; c. G. TROXLER ET AL 2,450,845

- SUCTION CLEANER Filed March 23, 1944 4 Sh eets-She'et 4 IN VEN T URS Charles 6. J'i'oXler and Gear 41? 1 az' er BY .9 .9

ATTORNEY Patented Oct. 5, 1948 FFICE SUCTION CLEAN EB Charles G. Troxler and George P. Daiger, Canton, Ohio, assignors to The Hoover Company, North Canton, Ohio, a corporation of Ohio Application March 23, 1944, Serial'No. 527,690

. 8 Claims.

The present invention relates to suction cleaners in general and more particularly to new and.

novel improvements in suction cleaners of the type incorporating automatically cleaned dirt separators. More particularly the invention comprises improved actuating means for the filter-cleaning nozzle in the suction cleaner of the type comprising an initial dirt separator, suction-creating means, a final dirt separator including. a filter, the collected foreign material being returned from the nozzle to the initial separator.

It is an object of the present invention to provide a new and improved suction cleaner. It is another object of the invention to provide a new and improved suction cleaner of the type incorporating initial and final dirt separators and automatic means to clean the latter and to return the collected material to the initial dirt separator. A still further object of the invention is to provide a new and novel drive for the filter-cleaning nozzle in a suction cleaner. Still another object of the invention is to provide a suction cleaner in which the filter-cleaning nozzle is actuated by the limited rotation of the stator of the driving motor of the suctioncreating means. These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawings to which they relate.

Referring now to the drawings in which a preferred embodiment of the invention is disclosed:

Figure 1 is a vertical longitudinal section through the cleaner constructed in accordance with the present invention Figure 2 is a vertical transverse section upon the line 22 of Figure 1;

' Figure 3 is a vertical transverse section upon the line 3--3 of Figure 1;

Figure 4 is a partial section upon the line 4-4 of Figure 3 and shows the escapement and its drive which function to limit the speed Of travel of the filter-cleaning nozzle;

Figure 5 is a partial section upon the line 5-5 of Figure 3 and discloses the pressure-responsive means and related parts which control the operation of the filter-cleaning nozzle;

Figure 6 is an enlargement of that part of Figure 1 showing the motor mounting and ourrent-carrying spring conductors at the forward end of the motor;

Figure 7 is a diagrammatic showing of the electrical circuit of the cleaner.

The present invention relates to suction cleaners of the type including a dirt separator provided with automatically'actuated mean which removes collected dirt. When the actuating means of the'suction-creating means are also used'to drive the filter-cleaning means it is necessary to provide for tremendous speed reduction. The driving motor for such a machine ordinarily rotates at 10,000 R. P. M., or higher, while the filter-cleaning means, which comprises a filtercleaning nozzle in a preferred form, is preferably driven at a speed in the neighborhood of 10 R; P. M., or less. reducing gears for such a reduction. In the present invention the filter-cleaning nozzle is connected to, and is driven by, the stator or field of the motor which in usual cleaner operation is fixed, the suction-creating fan being driven by the rotatable armature. The speed of stator rotation, during the operation of the filtercleaning nozzle, is governed by suitable means and the nozzle moves through approximately one revolution in one direction after which it returns to its initial position. I Thereafter the operation is repeated until the filter i cleaned sufficiently to reduce the back pressure or resistance to the flow of the air through the separator to a predetermined point.

In the drawings a preferred embodiment of the invention is illustrated. A canister type cleaner is shown comprising an elongated casing I which may be cylindrical. One end of easing I is closed by a fixed cap 2. The opposite end thereof is closed by a removable cap 3 formed with a recessed handle t and fixedly carrying a dirt receptacle or container 6 which extends into the casing I conforming to the contour of the interior thereof. Cap 3 and container 6 are removably held in place by means of manually releasable latching means I. The entire machine is slidably supported upon suitable runners secured to casing I, one of which is indicated at 8, and as is common in this type of machine a straplike handle 9 is provided on the top side thereof so that the operator may carry the machine.

Within casing I are three spaced transverse closure walls or bulkheads which are indicated by the reference characters I I, I2, and I3, the latter being a double wall with spaced sides. Wall I I is centrally apertured and carries, together with the wall I2 spaced therefrom, a cylindrical member I3 in paced relationship to the casing I and which opens through the wall II into a truncated conical member I4. 7 Cylinder I3 and cone I l form a whirl chamber I6 which opens forwardly into the dirt container It is difficult to use speed 6. A centrally apertured wall H in cylindrical member l3 separates the whirl chamber from a two stage fan chamber 18 formed in the rearward portion thereof.

An inlet conduit port 2| is adapted to receive and seat the cleaner end of a flexible dusting tool hose 22 having a suitable dirt collecting nozzle 23 at its outer end, conduit 2| enters the whirl chamber H at a tangentially extending inlet chamber 24 and through this port the dirtladen air stream makes its appearance within the machine proper. The air within whirl chamber I5 is relieved of nearly all the suspended material which it carries by centrifugal action therein. The foreign material advances through the truncated portion l4 of the chamber and into the dirt receptacle 8.

Within the fan chamber I8, which is divided into a first and second stage by a centrally located multi-vaned deflector 26, are positioned the rotating fans 21 and 28 which are rotatably car ried by the extended end of a motor shaft 29 which passes through a suitable air seal 3! in the adjacent transverse wall [2. The rotation of the fans 21 and 28 is efiective to draw substantially clean air from the whirl chamber 15, via an inlet port 32 which is provided with a strainer 33 at its entrance, and to exhaust that air through circumferentially positioned ports 34 in the second stage of the fan chamber [8 into a circular enclosing passageway formed by a cowl 36. Cowl 36 is sealed to the inner cylindrical casing l8 and to the periphery of wall I 2 and guides the air from the fan chamber through ports 3'! in wall l2 to the space between the wall I2 and the transverse wall I 3.

Between the longitudinally spaced transverse walls [2 and [3 extends a cylindrical filter element 4|, being seated upon a shouldered ring 42 adjacent the wall [2 and upon a longitudinally extending shoulder of the wall I3 itself at the other end. Filter 4| serves to divide the space within the main casing I between the walls l2 and [3 into an inner filter chamber 43 and an outer exhaust chamber 44. The latter is connected through suitable ports 46 in the wall l3 to the space between the end cap 2 and that wall so that the air exhausted through the filter may escape from the cleaner via the exhaust port 41. The latter is similar to the inlet port, being adapt ed to seat the dusting tool unit when it is desired to clean by blowing rather than by suction.

The driving unit for the suction-creating fans 21 and 28 comprises a motor the armature 5|, including the commutator 52, of which rotates with the shaft 29, being supported thereby in bearings 53 and 54 positioned in the end walls of the motor frame-casing 56 which carries the field or stator 57 of the motor. The stator 53 and the frame-casing 56 are not fixedly and non-rotatably mounted, as in the usual motor, but instead are rotatable. The end of the framecasing 56 nearest the fan chamber I8 is formed with an axially extending hub portion 58 which is rotatably mounted upon a bearing 59 carried by the wall I2 concentrically of and spaced from the motor shaft 29. The rearward end of the frame-casing 55, or that spaced farthest from the fan chamber I 8, is similarly provided with a hub portion, indicated at 6|, which is rigidly connected to a hub 62 formed on a filter-cleaning nozzle 63.

The filter-cleaning nozzle 63 is provided for the purpose of removing from the interior surface of the cylindrical final filter 4| the foreign material which collects thereon after havin escaped from the initial dirt separator comprising Whirl chamber l6. As the nozzle 53 has a relatively narrow surface-contacting mouth and as it is necessary to clean the entire filter the nozzle is mounted for rotation with the motor stator.

Nozzle 63. includes an axially extending conduit portion fi which passes through' the double wall l3 being rotatably mounted in a suitable bearing 66. Conduit 64 connects directly to a stationary air passageway 65 which connects directly to the inlet chamber 24 of the whirl chamber l9 and so makes available to the nozzle 63 the whirl chamber suction. Passageway 65 is normally closed by a butterfly valve 70. A coil spring 61 exerts a pressure between the adjacent bearing 66 and an abutment shoulder upon the conduit 64 and forces the unitary structure, com-' prising the filter-cleaning nozzle 63 and the motor frame-casing 56, toward the wall l2. A thrust bearin 68 is provided adjacent that wall which is contacted by a plate 69 rotatable with the hub 58 of the frame-casing. A sleeve ll encloses the spring 5'! to protect it from foreign material.

As both the motor armature El and the stator 5'! are movable relative to the cleaner body, and as both are positioned within the final dirt-separator filter chamber 43, it is necessary to provide suitable means to convey electrical current thereto and therebetween, and also to protect these parts from the foreign material within the filter chamber. To accomplish this there is provided an enclosing housing 13 fixedly carried by the transverse wall l2 and extending into the final filter chamber in enclosing and spaced relationship to the frame-casing 56. The driving motor is sealed within the housing by an air seal 74 which makes sliding and sealing contact with a ring 16 carried by the hub 6|. As the driving motor is a two speed unit three conductors convey current thereto and as all motor parts are rotatable relative to the casing I it is necessary that these connections permit of this relative movement. The electrical circuit is illustrated diagrammatically in Figure 7. At :its

opposite ends the non-rotatable enclosing housing i3 is provided with insulator blocks 18 and I9. Opposite block 18 the motor stator, and more specifically the hub portion 58 of the frame-casing 55, carries two spools, indicated at 81 and 82, which are also formed of insulating material and which have a common dividing wall. Spool 8! seats a coil spring 83 which is centrally secured thereto, its outer end being fixedly secured to the insulator block 19. Spool -82 seats a similar spring 84 similarly connected. Conductors 86 and 8'! connect the inner terminalsof the coil springs or leads 83 and 84, respectively, to the two speed field winding of the stator 57.

Opposite the insulator block 79, and mounted for rotation with the hub 6| at the end of the motor spaced from the springs '83'and 84, .is a third spool 93 which seats a coil spring 92. Coil spring or lead 92 is connected between the spool and the block 79, in the manner of springs -83 and B4. A lead 93 connects spool-carried terminus of spring 92 to a brush 94 in contact with the commutator 52 of the armature. A lead 96 connects a second brush 94 to the field winding.

Electrical current is conducted to the stationary insulator blocks 18 and 19 by incoming power leads I06, I01, and H18 which extend rearwardly through the exhaust chamber 44 to the rear wall I3 and into the space between the end cap 2 and that wall. r

The conductor coil springs or leads 83, 84, and 92 are more than mere resilient electrical connectors between the stationary part of the cleaner and the movable stator of the driving motor. They provide in addition a resistance to the rotation of the stator under the driving torque of the cleaner armature 5i during normal cleaner operation. The combined strength of springs 83, 84, and 92 is such that with the motor armature rotating at low speed the combined spring strength is sufiicient to overcome the reactive torque and to move the stator in a direction to unwind the springs. With the motor armature rotating at high speed, however, the torque is sufiicient to overcome the springs and the stator rotates to wind the springs. As the motor stator is rigidly connected to the filter-cleaning nozzle 63 this stator movement is accompanied by the movement of the nozzle. The speed of movement and the degree of rotation of the nozzle must be controlled and the means which exercises this control will now be discussed.

During normal cleaner operation the driving motor operates at low speed. During this operation with dirt-laden air passing into the machine the foreign material which escapes from the initial dirt separator I8 is collected upon the interior surface of the filter 4| of the final dirt separator 43. When sufiicient materialhas collected upon the surface of filter M as to raise unduly the resistance to the fiow of air therethrough it becomes necessary to clean the filter in order that the cleaner can continue to function eificiently. In order that this filter-cleaning operation may be accomplished automatically "the inner face of the rear double wall I3 is provided with an air-responsive bellows III which carries a plunger H2 slidably mounted in a loose bearing I I3 in the rear face of wall I3. The inner face of bellows III is exposed to the pressure within the final filter chamber 43 and the outer face thereof is exposed to the pressure within the double wall I3 which is the same as the pressure between that wall and the end cap 2. The outer end of the slidable plunger H2 abuts the overturned end of a 1ever I I4 pivoted at I I3 and which is urged thereagainst by a coil spring H1. Spring H1 exerts a force which retains the bellows in its inner, or full line position as illustrated in Figures 1 and 5, except in the presence of an undesirably high pressure within the final filter chamber 43. The coil spring H1 abuts, and the pivot pin H6 is carried by, a bracket H8 secured to the double wall I3 and positioned between that wall and the end cap 2. A second pivoted lever I2! is centrally pivoted upon the pivot pin H8 and an encircling coil spring I22 about that p-in exerts a force between the bracket H8 and the lever to hold the latter against the underside of the first lever H4. This relationship is clearly illustrated in Figures 3, 5, and '7.

The primary purpose of pivoted levers I I4 and I2I is to control a micro-switch I23 the plunger element I24 of which extends into contacting relationship with the adjacent 1ever I2I, as is clearly illustrated in Figures 5 and '7. Switch I23 selectively connects an incoming current lead I29 to the lead I01 or the lead I88 leading to the coil conductor springs 83 and 84 which in turn connect through the leads 88 and 81, respectively, to the end and midpoint of the winding of the motor field 51. With the plunger H2 in its low pressure position, in which it is normally held by the opposing spring I22, when bellows III -.is not forced outwardly by the pressure within the filter chamber 43, switch I23 is positioned as shown in Figure '7. The current then passes through the entire field winding to provide a slow motor speed. When, however, the pressure within the filter chamber 43 is sufiiciently great as to force the diaphragm I I I from the full line to the dotted line position, as shown in Figures 1 and 5, then also the plunger I I2 forces 1ever I I4 from the full to the dotted line position of Figure 5. Lever I2I' moves with lever H4, under the action of spring I22, and the switch I23 under its own bias assumes its alternative position and connects the lead I29 to the lead I01. Current then passes through the spring coil conductor 84 and the lead 81 to the midpoint of the field 51 and higher motor speed results.

At this point reference is made to Figure '7 in particular which shows the electrical circuit including the incoming current-conducting leads I26 and I21. These leads connect to the manually controlled switch I28 to which also connect the lead I29, before mentioned, and the lead I03. Lead I29 connects to the micro-switch I23while lead 188 connects to the coil conductor spring 92 and so to the motor through the lead 93 and brush 94. The circuit connections mentioned provide for manual control of the motors operation through the switch I28 and control of the motors speed by the micro-switch I23.

From the foregoing it is clear that an increase in pressure within the final filter chamber 43 resulting from a collection of foreign material upon the filter 4| results in an increase in speed of the driving motor which produces increased fan speed and increased suction. It is additionally desirable, however, to clean the filter which requires the rotation of the filter-cleaning nozzle 83 and the drawing of cleaning air therethrough. More particularly this cleaning air is drawn from the exhaust chamber 44, through the filter ll and into the nozzle 83 to pass through the passageway 65 to the whirl chamber I6, as previously indicated. The increased motor speed results in a torque on the stator which is greater than the force of springs 83, 84, and 92, and the stator tends to rotate. However, it is necessary first to unlock it, it having previously been locked by the co-action of a cam I3I and a locking pin I32. Cam I3I is fixedly mounted upon the axially extending conduit portion of the rotatable filter nozzle 63 and is positioned between the spaced sides of the double wall I3. The locking pin or latch I32 is positioned adjacent thereto and is pivotally mounted upon the forward face of wall I3. .The movable element I33 of an electrical solenoid I34 is pivotally connected to the pin I32 and, by virtue of the presence of a coil spring I36, normally urges the pin into locking engagement with the cam I3I thereby preventing rotation of the nozzle in a counterclockwise direction as viewed in Figure 2. The armature iii of the motor normally rotates in a clockwise direction, as viewed in this figure, so that the reactive torque upon the stator, which is directly transmitted to the filter-cleaning nozzle, would tend to move that element in a counterclockwise direction. The solenoid I34 is connected by conductors I38 and I39 to the incoming power conductor I86 and to the lead I81 which is energized only during high speed rotor operation. The energization of the solenoid I34 retracts'plunger I33, the looking pin I32 is moved to inoperative position, as illustrated in dotted lines'in Figure '1, thereby permitting the filter-cleaning nozzle, and of course the motor stator to rotate.

In order for the rotation of the nozzle .63 to accomplish any cleaning result air must flow through it and it is necessary that the butterfly valve 10, normally closing the air conduit 65, be moved to open position. The position of valve E6 is controlled by a second solenoid IN, the incoming power leads I42 and I43 of which are connected in parallel with the leads I38 and I 39 of the first-mentioned solenoid I34, so that the solenoids are simultaneously energized whenth'e motor rotates at high speed. The movable plunger I44 of solenoid I4I connects pivotally to valve 19 and a coil spring I45 normally holds the plunger and valve in the valve-closed position except when the solenoid is energized. It is seen then, that upon the movement of the micro-switch to the high motor speed position the filter-cleaning nozzle is released for rotation under the reaction torque and is also immediately provided with suction by the movement of the butterfly valve 13 to its open position.

To limit the rotation of the nozzle 63 to approximately or slightly more than one complete revolution means are provided which return the driving motor to its normal or slow speed of rotation upon the nozzle having moved through that arc. These means comprise a third solenoid I46 connected to the bellows-controlled second lever I2I, and an electrical switch I41 which controls the flow of current through the solenoid and which is itself controlled by a pin I43 upon the cam I3I. The plunger I24 of the micro-switch I23, as was previously described, contacts the second pivoted lever I2I which is normally held at its underlying end against the first pivoted lever I I4. When lever H4 is held by the diaphragm plunger H2, under the actuation of excessive pressure in the final filter chamber 43, so as to compress its operating spring II1 lever I2I follows the lever H4 and permits the micro-switch I23 to assume the high-speed motor position (current through lead I37). Lever IZI is movable independently of lover I i 4, however, though normally moving there with by virtue of the action of its spring I22. Electrical solenoid I46 is provided with a plunger element II which normally, with the solenoid unenergized, eXerts no influence to position the lever I2 I. With the solenoid energized, however, plunger I5I moves toward the solenoid body and draws the end of the lever I2I in the same direction thereby pivoting simultaneously the opposite end of the lever in contact with the control element I24 of the micro-switch I23. Under this action of the solenoid I46 the lever I2! is returned to the position it held before the filter cleaning operation began. In so moving it returned the micro-switch I23 to its slow motor speed position (current through lead I38).

Immediately upon the repositioning of the micro-switch I23 to the low motor speed position, that illustrated in Figure 7, the combined strength of the coiled spring conductors 83, 84, and 92 overcomes the torque acting upon the motor stator 51 and the filter-cleaning nozzle, under the force of these springs, returns in a clockwise direction to its original position in which it will again be locked by the action of the lever I32 with the cam I3I, the holding solenoid I34 of the lever having become de-energized upon the opening of the high speed motor circuit as is clearly evidenced in Figure 7.

To insure that the solenoid I46 controlling the second lever I2I will be actuated when the filtercleaning nozzle has made substantially one complete revolution, and also to provide for its deenergization when the filter-cleaning nozzle has returned to its original position, the solenoid is connected electrically by conductors I53 and I 54 to the incoming conductor I29 and to the switch I41, respectively, the other side of the switch I41 being connected by the lead I56 to the second incoming lead I36. Switch I41 is of the overcenter snap action type with its moving element or lever positioned in the path of the pin I48 carried by the rotatable cam I3I which rotates with the filter-cleaning nozzle 63. In both directions of rotation of the cam I3I the pin I48 contacts the switch lever near the end of the nozzle rotation and moves the lever to its opposite position. As shown in Figure '1 the cleaner is performing its normal cleaning operation with the motor rotating at low speed. Should the filter-cleaning operation begin the latch I 32 wouldmove to its dotted line inoperative position upon the energization of solenoid I34 and the cam I3I would rotate counterclockwise, under the actuation of the high speed motor torque. The cam rotation moves the pin I48 into contact with the opposite side of the snap lever from that shown in full line 5 in Figure '1 and causes that element to pivot from the full line to the dotted line position. This immediately energizes the solenoid I46 and its plunger I5I causes the second lever I2I to return the micro-switch I23 to its original position, that shown in full lines in Figure 7, and slow speed motor operation ensues. Thereupon the filtercleaning nozzle under the action of the coil springs 83, 84, and 92 as described, returns to its original position. The cam I3I, fixed to the nozzle, rotates in a clockwise direction and the pin I48 again contacts the switch lever and returns it to the full line position of Figure 7. The springs having unwound themselves and the latch I32 would assume its locking position under the urging of the solenoid spring I 36, it being assumed that the cleaning operation has sufiiciently re duced the pressure within the final dirt separator 43 as to permit the diaphragm III to return to its original position.

In addition to the foregoing it is desirable that the filter-cleaning nozzle travel at a relatively slow speed during the cleaning operation, and that it be returned to its original position at a much greater speed as .it performs no cleaning in the return travel. To provide this result an escapement ISI is mounted between the double wall I3. Escapement I6I includes a body containing a gas or a liquid and within which is positioned a traveling piston I62 having an apertured valve I63 pivoted adjacent an escape port 64. A rod I 66 connects to the piston and the relationship is such that with fluid or gas in the casing the piston is free to move with relatively great speed in one direction, the flow of the gas or fluid through the port I64 opening the valve I63. This would be the downward direction as viewed in Figure 3. The piston moves with a reduced speed in the opposite direction for the valve closes the port I 64 and it is necessary for the fluid to pass through the smaller aperture of the valve I63.

The escapement is directly connected to the rotating hollow conduit 64 of the filter-cleaning nozzle 63 by means of a chain of gears I1I, I12, and I13, the latter meshing with a toothed quadrant I14 carried by shaft I16, the opposite end of which is provided with a lever 111 which pivotally engages the piston rod I66. The gear ratio i such that the lever I11 moves through about eighty degrees upon' one complete rotation of the filter-clean ng nozzle. The escapement I6I is pivotally mounted upon the adjacent wall I3, as indicated at I8I. in order to accommodate necessary angular movement.

The operation of the invention constructed as above described is as follows: In normal cleanin operation the electrical circuit of the machine is as illustrated in Figure '1 in full lines, and the driving motor rotates at low speed. Cleaning air is drawn into the machine through the main nozzle 23 and passes throu h the dusting tool 22 into the inlet port 2|, through the inlet chamber 24 and into the whirl chamber I6 under the action of the suction-creating fans 21 and 28. Centrifugal force acting on the whirling air in the, whirl chamber I 6 causes suspended foreign material to become separated from the carrying air stream and to move from the front end of the whirl chamber into the dirt receptacle 6. The 'air, less practically all of the foreign material, enters the fan chamber I by way of the inlet 32. After passing through the two stages of the fan chamber I8 the air is ex austed through the exhaust port 34 and enters'the final dirt separator 43. Under the pressure of the suction-creating fans the air is forced through the final filter 4| into the discharge chamber 44, all foreign material collecting upon the surface of the filter. The a r escapes from the discharge chamber 44 through the ports 46 and makes its way from the machine at the exhaust port 41. 1

In this normal cleaning operation of the cleane the motor stator or frame-casing 56, together with the filter-cleaning nozzle 63 attached rigidly thereto, are fixed relative to the casing I and have no movement. The cleaning operation may continue as described until such time as the foreign material collected in the final filter chamber 43 upon the final filter 4| has increased the resistance to'the passage of a r through that element to'an extent such that it becomes desirable to remove it in order to increase the flow of airthrough the machine. and improve its operating efiiciency. This undesirable situation is evidenced by an increase in the back pressure within chamber 43 which increase in pressure has the'effect of moving the bellows diaphragm I I I from the full line to the dotted line positions illustrated in Figures 1, 5, and 7. This movement of the bel ows immediately effects the pivotal movement of the levers H4 and I2I and the micro-switch I 23 is moved by the latter from the low speed motor position, illustrated in full lines in Figures '7 to the high speed motor position in which current flows through the lead I 01. This movement of the micro-switch,'and this increase in the speed of motor operation, pro" duces several efiects immediately. Immediately the solenoid MI is energized and the butterfly valve opens, thereby connecting the"filter cleaning nozzle with the suction within the whirl chamber and air is drawn through the filter ti, through the filter-cleaning nozzle, and into the whirl chamber. Because the dirt has become agglomerated by collecting upon the final filter 4I it i this time removed from the air in the whirl chamber. Additionally the solenoid I34 i energized and the cam-locking latch I32 moves from the full line position in Figure '1 to the dotted line.

The locking cam I 3| is thereupon, released for rotation and, under the torque exerted upon the stator in the high speed rotation of the armature the nozzle rotates in a counterclockwise direction as indicated by the arrow in Figure '7. The spring conductors '83, 84, and 92 are wound byvthis movement. At the beginning of the filter-cleaning operation the switch I41 is related and the switch-actuating pin I48 is positioned a illustrated in full lines in Figure '1.

The speed of travel of the filter-cleaning nozzle 63 is controlled, as described, by the escapement I6l. At the beginning of the nozzle travel the piston I62 is positioned as illustrated in full lines in Figure 3 and its travel toward the upper or dotted line position is synchronous with the rotation of the nozzle 63. Because of the relationship of the small aperture in valve I63 to the port I 64 in the piston I62 the latter travels at relatively slow speed and, the escapement being geared directly to the nozzle as previously described, the nozzle also is held to a slow speed.

The travel of the filter-cleaning nozzle 63 in 7 its cleaning operation continues inaa counterclockwise direction, as viewed in Figures 2 and 7, for substantially one complete revolution at which time the cam-carried pin I48 upon the cam I3I has contacted the operating lever of the switch I41 upon the opposite side from that shown in Figures 2 and 7 and, with a snap action, has moved the contact to the dotted line position shown in Figure 7. Solenoid I46 is immediately energized by this closing of the switch I41 and thereupon its plunger I5I pivots the second pivoted lever I2I into contact with the actuating plunger I24 of micro-switch I23 where-- upon the latter moves from the high speed position, in which current passes through lead I01 to the reduced field winding, to the low motor speed position, that illustrated in full lines in Figure 7 and in which current passes through the lead I08. i n

Upon the motor speed being reduced the reactive force acting upon the stator 51 is reduced and is less than the combined torque exerted by the coil spring conductors B3, 84, and 92. Thereupon these springs reverse the direction of travel of the stator and the nozzle and cause them to travel in a clockwise direction as viewed in Figures 2 and 7; This clockwise travel of the filter cleaning nozzle will continue until the cam-car'- ried pin I48 has again actuated the switchI41 to open it, that is, move it to the full line posi- I tion of Figure 1, whereupon the solenoid I46- is de-energized releasing the pivoted lever I2I which then moves from theplunger I24 of the microswitch I23. The latter under its own normal, bias moves again to the high speed position in which current passes throughthe lead I01 to the divided field winding. Thereupon the torque acting upon the stator is again suiiiciently great to overcome the combined forces of the springs as described and a cleaning travel of the filter-cleaning nozzle again results in the exact manner aforedescribed.

In the return travel of the filter-cleaning nozzle the speed of travel is greatly increased for the escapement IiiI does not exercise the retardingaction, the pivoted controlling valve I63 moving to open position and permitting of a much greater and more rapid flow of the fluid through the piston port I64. Also, in the return travel of the nozzle 63 no air flows therethrough, the solenoid I4I being ole-energized upon the movement of the micro-switch I23 to its high speed position and the butterfly valve 10 automatically closingunder the actuation of its. spring I46.

'Th'is'sequence of cleaning travel and return travel; of the filter-cleaning nozzle will continue indefinitely until the pressure within the final filter chamber 43 is reduced to a desirable point. This is socbecause so long as the pressure remains above this desirable point the bellows II! remains expanded as shown in dotted lines in Figures 1 and 7 and the lever H4 is held in a position to position the second lever I 2! to permit the micro-switch I23 to move to the high speed position. The movement of the second lever IZI by the solenoid I46 to eifect the return of the nozzle to its starting position effects, it is to be noted, no change in the bellows-controlled lever lldwhich controls the position of second lever I21 when the solenoid I46 is not energized. Upon sufficient cleaning of the filter having taken place to reduce the resistance to the flow of air'through thefilter II to a desirable point the pressure within the final filter chamber 43 permits the diaphragm III to return to the full line position of Figures 1 and 7. Immediately this occurs the levers H4 and I2I are moved by the sprin II I to their full line positions of Figure 7 and the plunger I 24 returns the micro-switch I23 to the low motor speed position, illustrated in full lines in Figure '7. Thereupon, as previously described, the coil conductor springs 83, 84, and 85 return the-nozzle to its initial position.

Each time the motor returns to its low speed operation current is cut off from the solenoids I34 and MI and immediately the latch lever I 32, actuated' by the former solenoid, returns to its looking position while the butterfly valve controlled by the latter solenoid returns to its closing relationship. The immediate return of the latch lever I32 to locking position does not interfere with the travel of the filter-cleaning nozzle under the impetus of the coil springs until a final locking position has been reached as is clearly evident in Figures 2 and 7, the direction of travel under the springs being in a clockwise direction.

(Dnce the pressure-actuated diaphragm I reassumes its original position the machine immediately-reassumesits original cleaning relationship and the relationship of the parts is as illusinitial dirt separator, a suction-creating fan unit todraw air into and through said initial separator,-anda final dirt separator to receive air exhausted from said fan unit, a motor todrive said fan unit including a rotor and a stator; said rotor being-connected to said fan unit in driving relationship, meansmounting said stator for rotation, acoiled' conductor spring connecting said stator toa source of current, a cleaning element movable with respect tosaz'd final separator and connectedito said stator and. driven in one direction thereby, and means to limit the rotation of said stator .Whenactuating said cleaning element.

2.111 a suction cleaner of the type having an initial. dirt separator, a suction-creating fan unit toodraw air into and through said initial separator, and a final. dirt separator to receive air. exhausted. from saidfanunit; a motor to drive said fan unit including a rotor and a stator, said rotor being connected to said fan unit in driving relationship, means mounting said stator-for rotation, acoiled conductor spring connecting said stator t'oa sourceofcurrent, locking meansnormallyr preventing rotatf on of saidstator, a cleaning element for saidfinal separator connected to said stator and-movable therewith relative to said final-separator; pressure-operated means controlled by the pressure in said final separator to release said locking means, and means to control the speed of travel of said cleaning element under the actuation of said stator;

3. In a suction cleaner of the type having an initial dirt separator, asuction-creating fan unit to draw air into. and through said initial separator, and a final dirt separator to receive air exhausted from said fan unit and including an air permeable-filter element; a two speed motor to drive said fan unit including a rotor and a stator; said rotor being connected to said fan unit in driving relationship, means mounting said stator for rotation, locking means normally retaining said stator against rotation, coiled spring conductors connecting said stator to a source of current and positioned as to belwound by the rotationofsaid stator in a direction opposite to the direction of rotor rotation, said springs exerting a'torque on said stator which is greater thanthe torque exerted. thereby in the slow speed-rotation of said rotor but which is less than the-torque exerted thereby in the high speed rotation: of' said rotor, a filter-cleaning nozzle connected to said stator and movable thereby relative .to said filter to remove foreign material therefrom; and means including means controlled by the pressure in said final dirt separator to control the: speed'of rotation of said rotor and to release said lockingmeans.

4. In a suction cleaner of the type having an initial dirt separator, a suction-creating fan unit todraw air into and through 'said initial separator, and a final dirt separator to receive air exhausted f'romrsaidfan unit and including an air-permeable, filter element; a two speed motor to drive said fan unit including a rotor and a stator, said rotor being connected to said fan unit in driving relationship, means, mounting said statorqior rotation; locking means normally retaining said stator against rotation, coiled spring conductors connecting said. stator tora source of. ourrentLan-d positioned as tobe wound bytherotation oi saidxstator in adirection opposite to. the direction. otrotor rotation, said springs exertingza; torque on said stator which is greater than the torque exerted thereby in the sloW speedrotation-oi said rotor but which is less than the torque exerted thereby in the high speed rotation of said rotor, a filter-cleaning nozzle connected to said stator and movable thereby relative to said filter to remove foreign material therefrom, first means to increase the speed of said rotor, second means to release said locking means: to permit said stator and nozzle to rotate, third means to connect said nozzle to said initial dirt separator, and pressure-operated means controlled by the pressure in said final dirt separator to actuate said first, second and third means in-the. presence of a predetermined pressure in said final dirt separator.

5. In a suction cleaner of the type having an initial dirt separatona suction-creating fan unit to draw air into and through said initial separator, and a finaldirt separator to receive air exhausted from. said .fan unit and including an air permeable filter element; a two speed motor to drive said fanunit including a rotor and a stator, said rotor being connected to said fan unit in. driving relationship, means mounting said stator: for rotation, .locking.means normally retaining said stator against rotation, coiled spring conductors connecting said stator to a source of current and positioned as to be wound by the rotation of said stator in a direction opposite to the direction of rotor rotation, said springs exerting a torque on said stator which'is greater than the torque exerted thereby in the slow speed rotation of said rotor but which is less than the torque exerted thereby in the high speed rotation of said rotor, a filter-cleaning nozzle connected to said stator and movable thereby relative to said filter to remove foreign material therefrom, first means to increase the speed of said rotor, second means to release said locking means to permit said stator and nozzle to rotate, third means to connect said nozzle to said initial dirt separator, fourth means to reduce the speed of said rotor upon said stator traveling through a predetermined arc of rotation whereby said coiled spring conductors are enabled to rotate said stator in the opposite direction toward its original starting position, and pressure-operated means controlled by the pressure in said final dirt separator to actuate said first, second and third means in the presence of a predetermined pressure in said final dirt separator.

6. In a suction cleaner of the type having an initial dirt separator, a suction-creating fan unit to draw air into and through saidinitial separator, and a final dirt separator including a filter connected to receive air exhausted from said fan unit; a driving motor including a rotatably mounted rotor and stator, said rotor being connected to said fan unit, coiled conductor springs connecting said stator to a source of electrical current, permitting limited rotation of and arranged to exert a turning torque upon said stator to return it to its starting position, a filter-cleaning nozzle mounted for movement over said filter and connected to said stator for movement thereby, locking means to restrain said stator, and pressure-responsive means responsive to pressure in said final dirt separator to effect the release of said locking means to permit said stator to rotate.

'7. In a suction cleaner of thetype having an initial dirt separator, a suction-creating fan unit to draw air into and through said initial separator, and a final dirt separator including a filter connected to receive air exhausted from said fan unit; a driving motor includin a rotatably mounted rotor and stator, said'rotor being connected to said fan unit, a coiled conductor spring connecting said stator to a source of electrical current, permitting limited rotation of and arranged to exert a turning torque upon said stator to return it to its starting position, a filter-cleaning nozzle mounted for movement over said' filter and connected to said stator for movement thereby, valve means controlling the flow of cleaning air through said filter-cleaning nozzle, locking means to restrain the rotation of said stator, means to move said valve means and said locking means to open positions, and pressureresponsive means responsive to pressure in said final dirt separator to actuate said last-mentioned means upon the existence of a predetermined pressure in said final dirt separator.

8. In a suction cleaner of the type having an intial dirt separator, a suction-creating fan unit to draw air into and through said initial separator, and a final dirt separator including a filter, connected. to receive air exhausted from said fan unit; a driving motor for said fan unit, a filter-cleaning nozzle connected to said driving motor for limited travel in one direction over said filter, air-conducting means connectin said nozzle to said initial dirt, separator, locking means normally retaining said nozzle in fixed position, means including pressure-responsive means controlled by the pressure of said final dirt separator to release said locking means, pring means to return said nozzle to its starting position, and speed-controlling means restricting the speed of travel of said nozzle under the actuation of said motor and allowing a higher speed of return travel under the actuation of said spring means. CHARLES G. TROXLER.

GEORGE P. DAIGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 361,711 Nagel et a1 Apr. 26, 1887 540,720 Clark June 11, 1895 2,026,834 Holly Jan. '7, 1936 2,149,135 Eriksson-Jons Feb. 28, 1939 2,247,472 Bible July 1, 1941 2,276,805 Tolman Mar. 17, 1942 2,369,649 Abrams Feb. 20, 1945 FOREIGN PATENTS Number 1 Country Date 114,262 Australia Nov. 19, 1940 353,837 Great Britain Jan. 21, 1930

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