US3869749A

US3869749A - Cleaning apparatus

Info

Publication number: US3869749A
Application number: US262110A
Authority: US
Inventors: Arnold B London; Jiri Nessel
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-12
Filing date: 1972-06-12
Publication date: 1975-03-11
Anticipated expiration: 1992-03-11

Abstract

An escalator cleaning apparatus comprising a carriage, a frame reciprocably mounted on the carriage and brush means mounted on the frame. Means are provided on the carriage for fixedly positioning the carriage with respect to a pair of escalator sidewalls. Vacuum means pick up dirt which is dislodged by the brush means and spray means provide spraying a liquid onto the area which is contacted by the brush means. An additional frame positioned on the carriage for reciprocation in a longitudinal direction carries a second brush means. A control means controls the forward and rearward movement of the second frame with respect to an upwardly moving escalator step surface. A control circuit operates the above apparatus in an automatic manner to vacuum, vacuum and brush, and then spray and brush.

Description

United States Patent London et al.

1 1 CLEANING APPARATUS [75] Inventors: Arnold B. London, Beverly Hills;

Jiri Nessel, Palo Alto, both of Calif.

[73] Assignee: Arnold B. London, Beverly Hills,

Calif. by said Jiri Nessel 22 Filed: June 12,1972

21 Appl. No.: 262,110

[52] [1.8. CI. l5/302, 15/21 E, 15/50 C, 15/353, 15/380 [51] Int. Cl A471 5/38 [58] Field of Search 15/49 C, 49 RB, 50 C, 81, 15/302, 308, 309, 320, 380, 381, 353, 21 E Mar. 11, 1975 3,584,329 6/1971 Cravits 15/302 Primary Examiner-Harvey C. Hornsby Assistant ExaminerC. K. Moore Attorney, Agent, or FirmGeorge F. Smyth [57] ABSTRACT An escalator cleaning apparatus comprising a carriage, a frame reciprocably mounted on the carriage and brush means mounted on the frame. Means are provided on the carriage for fixedly positioning the carriage with respect to a pair of escalator sidewalls. Vacuum means pick up dirt which is dislodged by the brush means and spray means provide spraying a liquid onto the area which is contacted by the brush means. An additional frame positioned on the carriage for reciprocation in a longitudinaldirection carries a second brush means. A control means controls the forward and rearward movement of the second frame with respect to an upwardly moving escalator step surface. A control circuit operates the above apparatus in an automatic manner to vacuum, vacuum and brush, and then spray and brush.

32 Claims, 10 Drawing Figures PATENTEB NARI I 8975 SHEET 1. 0f 6 PATENTEB HART I I975 SHEET 3 [1F 6 NRN RN CLEANING APPARATUS BACKGROUND OF THE INVENTION Escalators are in wide use in transporting large numbers of people vertically as well as horizontally. Due to their .design and mode of operation, escalators are much more efficient in moving large numbers of people than, for example, elevators.

An escalator functions in a continuous manner with people continuously getting on at one end while people get off at the other end. However, an elevator operates in a stepwise fashion in which passengers are first admitted, the elevator is then closed and moved a given vertical distance, and passengers are then discharged. Each of the steps involved in the operation of an elevator is independent of the other steps. Thus, for example, when the elevator is moving, people are neither entering or leaving. Also, when passengers are being discharged, other passengers cannot enter and vice versa. However, since the escalator functions continuously, the steps of taking on passengers, moving passengers, and discharging passengers are all carried out simultaneously and, thus, more efficiently.

During usage, the exposed escalator surfaces take on a grimy coating from debris tracked in one the users feet. The grimy coating can make the exposed surfaces more slippery and create a safety hazard. Also, the escalator surfaces can serve as a source of dirt to be tracked elsewhere throughout a place of business by its users. In any event, it is undesirable when the escalator surfaces have a grimy coating. Thus, escalators must be periodically cleaned.

There is, at the present time, no satisfactory way to quickly clean, the exposed surfaces of an escalator. Depending on the size of the escalator, cleaning may take as long as 6 to 8 hours in order to clean each step on the escalator by hand. Escalators are extensively used during ordinary business hours. Thus, the cleaning operation may have to be carried out after the close of business and involve paying the working crew at a premium hourly rate.

In view of the above difficulties, it would be very desirable if a machine could be devised to more efficiently clean the exposed surfaces of an escalator. Moreover, it would be desirable to have a machine which could clean the exposed escalator surfaces while the escalator was moving. The machine could then be placed at a fixed location and the escalator surfaces could be moved to the machine for cleaning. This would simplify the cleaning procedure and would result in a great savings in time and money.

The patent literature has reported several machines designed to clean the exposed surfaces of escalators. However, these prior machines have apparently not proven satisfactory and have not been used commercially.

SUMMARY OF THE INVENTION In accord with the present invention, a machine is provided which is capable of efficiently cleaning the exposed surfaces of an escalator while the escalator is moving. In operation, the machine is placed in a fixed position and the escalator is then operated to bring the steps to the machine for cleaning. This permits cleaning of the exposed escalator surfaces in a fraction of the time previously required and does not require shutting down the escalator for extended periods of time.

In escalators which transport people vertically; both the escalator steps and the riser portion of each step must be cleaned. Inasmuch as the riser surfaces are positioned vertically, they are particularly difficult to clean by usual methods. A desirable aspect of the machine is that it provides thorough cleaning of both the steps and the riser surfaces of an escalator.

In one embodiment of the machine, a carriage is provided with a frame reciprobably mounted on the carriage. Brush means are mounted on the frame for contact with an escalator step. Due to reciprocation of the frame, which causes a corresponding reciprocation of the brush means, the brush means are brought into contact with a larger area on the escalator step.

Desirably, the carriage may be fixedly positioned with respect to a pair of escalator sidewalls. Then, when the frame is reciprocated from side to side, the brush means is reciprocated across the width of an escalator step. This permits cleaning in the less accessible areas of the step surface which are adjacent to the escalator sidewalls. Also, it provides a machine which can clean escalator steps of various widths.

Vacuum means are desirably positioned adjacent to the brush means to pick up dirt which is dislodged by the brush means. Also, in the cleaning of an escalator step, the vacuum means may be operated idependently of the brush means to provide initial cleaning of the escalator surfaces. Then, in a subsequent operation, the steps may be contacted with the brush means to dislodge dirt which may not be initially picked up by the vacuum means, such as dirt which is lodged in grooves on the step surface.

Spray means are also desirably positioned adjacent to the brush means to spray liquid onto the area which is contacted by the brush means. The use of spray means in conjunction with the brush means may, for example, be employed as the last step in the overall cleaning operation. Thus, after the loose dirt is first picked up by the vacuum means, followed by brushing to remove additional dirt, the exposed surfaces may be scrubbed by spraying the surfaces while subjecting them to a brushing action. As the spray means is operated, the water ejected by the spray means is advantageously picked up by the vacuum means to leave the escalator surfaces in a relatively dry condition.

As stated, the riser surfaces-of an escalator are difficult to clean using ordinary cleaning methods and are a problem area in the cleaning of an escalator. To provide a solution to this problem, in one embodiment of the invention a forwardly and rearwardly reciprocable brush means is supported relative to the escalator step for reciprocatory movement. Control means are provided to move the brush means fowardly at a predetermined speed over an upwardly moving escalator step surface and to retract the brush means rearwardly at a higher predetermined speed when the height of the step surface reaches a given level. As the brush means moves forwardly, it contacts not only the escalator step surface but also the escalator riser at the forward extent of its movement. Additionally, spray means may be provided in conjunction with the brush means to spray liquid onto the area to be cleaned either prior to or simultaneously with the brushing of the surface.

In a further embodiment of the invention, a reciprocable first frame and a reciprocable second frame are positioned on a carriage which may be fixedly positioned between a pair of escalator sidewalls. A first brush means carried by the first frame may be reciprocated in a transverse direction to clean the width of the escalator step surfaces while a second brush means carried by the second frame may be reciprocated in a longitudinal direction to clean not only the step surface but also the riser surfaces. Moreover, the second frame may be positioned on the first frame so that the second brush means undergoes a compound movement composed of both transverse and longitudinal reciprocation. This subjects the riser surface to a brushing action in essentially all directions to uniformly clean the surface. Both spray means and vacuum means are desirably employed with this embodiment of the invention to provide both dry and wet cleaning of the exposed escalator surfaces.

In providing an efficient escalator cleaning apparatus, it has been found desirable to utilize a liquidreceiving tank mounted on a carriage which is positioned relative to an escalator. Vacuum means are mounted on the carriage in flow communication with the liquid-receiving tank. The tank is also in flow communication with a vacuum pickup positioned on the carriage. As a result, air entering the vacuum pickup passes through the liquid in the tank before entering the vacuum means. By passing through the liquid in the tank. finely divided dust particles in the air are removed before the air is discharged.

A filter is desirably positioned in flow communication with the vacuum pickup and between the vacuum pickup and the liquid-receiving tank. Valve means may be positioned in flow communication with the vacuum pickup and positioned between the vacuum pickup and the filter with the valve means having a first position in communication with the filter and a second position in communication with the tank. Air flowing through the vacuum pickup may then be routed either to the filter or directly to the liquid-receiving tank depending upon the position of the valve means.

Spray means may be positioned on the carriage with pump means provided to convey liquid from the liquidreceiving tank to the spray means. During operation of the spray means, liquid ejected by the spray means may be reconveyed directly to the tank by the vacuum pickup when the valve means is in its second position in direct communication with the tank.

In the utilization of the apparatus, it may be desirable to cycle the apparatus automatically such that it first provides vacuuming of the exposed escalator surfaces, then vacuuming combined with a brushing action, and lastly spraying of the surfaces with a liquid combined with a brushing action. Thus, a control circuit is provided through which the machine may be operated automatically to provide the above cleaning operations in the desired sequence.

BRIEF DESCRIPTION OF THE DRAWINGS In illustrating one embodiment of the invention, reference is made to the drawings wherein:

FIG. 1 is a perspective view of a machine of the invention;

FIG. 2 is a transverse sectional view of the machine with the section taken below the liquid-receiving tank to illustrate the means for providing movement of the brushes;

FIG. 3 is a vertical section view taken along the lines 33 of FIG. 2;

FIG. 4 is a side sectional view of the machine to illustrate the internal mechanism for providing both a vacuum pickup and '-a spray means adjacent to the surfaces being cleaned;

FIG. 5 is'a front side detail view of the machine illustrating the reciprocatory movement of the riser brush in cleaning both an escalator step and its riser surface;

FIG. 6 is a detail view illustrating the means for conveying air from a vacuum pickup to a valve chamber adjacent to a liquid-receiving tank;

FIG. 7 is a circuit diagram of the control mechanism for the machine;

FIG. 8 is a partial end elevational view showing the liquid tank supported in an upwardly pivoted position to expose the mechanism positioned beneath the tank and having the machine cover in an open position;

FIG. 9 is a detail view of the supporting structure for the liquid tank as it appears when the tank is in an upwardly pivoted position, and

FIG. 10 is detail view of a supporting brace for the tank and a control rod for the brace as taken along the line 10l0 in FIG. 9.

DETAILED DESCRIPTION FIG. 1 illustrates a machine 2 having a carriage 4.supported on a pair of front wheels 6 and a rear wheel 8. A handle 10 may be utilized in moving the machine 2 with a control panel 12 conveniently positioned on the handle 10. A main brush 14 is rotatably supported adjacent the front portion of the machine 2 and a riser brush 16 is positioned forwardly of the main brush l4. Positioned between the brushes l4 and 16 are vacuum pickup nozzles 18 located at the undersides of vacuum tubes 19. A plurality of spray nozzles 20 are positioned rearwardly of the main brush l4 and a riser spray nozzle 22 is'held adjacent to the riser brush 16 by a spray tube 21.

FIG. 2, which is a top sectional view of the under structure of the machine 2, illustrates the carriage 4 supported at its forward end upon wheels 6 mounted on a main axle 28. The main axle 28 is in turn mounted in main support bearings 29 in the carriage 4. A bearing tube 30 is supported by the axle 28 through bearings 32.

A reciprocatory frame 24 is fixedly connected to the bearing tube 30 for transverse reciprocation with respect to the carriage 4. A motor 34 fixedly connected to the carriage 4 has an output shaft 36 connected to a drive disc 38 on which is mounted an adjustable eccentric 40. To adjust the eccentric 40, a radial groove may, for example, be provided in the disc 38 with the degree of eccentricity being varired by adjustably positioning the eccentric 40 within the radial groove. A turnbuckle rod 42 is connected at one end to a pivot 44 on the frame 24 while its other end is connected to the adjustable eccentric 40.

As illustrated, rotary movement produced by the motor 34 is readily converted to transverse reciprocatory movement through the eccentric 40 and turnbuckle rod 42 to impart transverse reciprocatory movement to the frame 24. By adjusting the position of the eccentric 40 or the length of the turnbuckle rod 42, the extent of the transverse movement imparted to the frame 24 may be varied. This provides additional flexibility when the machine 2 is used to clean escalators of varying widths. The transverse movement imparted to the frame 24 may, for example, be increased for escalators of greater width or decreased for escalators having a narrower width.

The main brush 14 is rotatably supported by a bearing tube 46 which is fixedly connected to the frame 24. Radial bearings 48 are positioned between the bearing tube 46 and a rotatable shaft 50 while radial spacers 52 interconnect the shaft 50 with a brush tube 54. The bristles of the brush 14 project from the brush tube 54 which may be an integral part of the brush structure. Thus, when a main brush 14 is replaced, the brush tube 54 may be removed from the shaft 50 and replaced with a new brush and a new brush tube.

An L-shaped lifter plate 58 is fixedly connected to the frame 24 adjacent its rearward end. A lower surface of the plate 58 is engaged by a lifter roller 60. The roller 60 is eccentrically mounted on a plate 62 positioned on a shaft 64. The shaft 64 is connected at its other end to a lever 66 such that movement of the lever 66 causes rotation of the shaft 64. The raised position of the roller 60 is determined by a stop member 67 which engages the lever 66.

A riser brush frame 26 is slidably received within the frame 24 for forward and rearward reciprocatory movement. As shown in FIG. 3, the riser brush frame 26 is slidably supported at its forward end by support wheels 120 and at its rearward end by a riser slide bracket 90 which is fixedly connected to the riser frame 26. The bracket 90 has an upper plate which bears against the upper surface of the frame 24. Connecting bolts 91 connect the upper plate of the bracket 90 to the riser frame 26 and are received within a riser slot 92. The length of the slot 92 permits forward and rearward reciprocation of the riser frame 26 with respect to the supporting frame 24. A rack 122 secured to the riser frame 26 is engaged by a pinion gear 118. The pin-.

ion gear 118 is driven by a reversible rack motor 116 fixedly connected to the frame 24 to provide rotation of the gear 118 in moving the riser frame 26 both forwardly and rearwardly.

A stub frame 124 is connected to the riser frame 26 adjacent its forward end and affixed to the stub frame is a riser bearing tube 68. A riser brush shaft 56 is supported by bearing tube 68 through bearings 70 while radial spacers 74 interconnect the shaft 56 with a riser tube 72. The riser tube 72 may be an integral part of the riser brush 16 to be replaced along with the riser brush.

The main brushes 14 are driven by a brush motor 76 which is secured to the frame 24 by bolts 78. A brush motor sprocket 80 driven by the motor 76 engages a chain drive 128. The chain drive 128 engages a brush sprocket 82 secured to the shaft 50 to impart rotational movement of the shaft 50 and the brushes 14. A bevel gear 84 positioned on the main brush shaft 50 drives a bevel gear 86 positioned on the riser brush shaft 56 through a flexible drive 88. The flexible drive 88 includes bevel gears 130 and 126 with bevel gear 130 engaging drive gear 84 while bevel gear 126 engages the driver gear 86. As described, rotational movement is imparted to both the main brushes l4 and riser brushes 16 from the brush motor 76. The motor 76 directly drives the main brushes 14 through chain drive 128 while the riser brushes 16 are driven from the main brush shaft 50 through the flexible drive 88.

In operation of the machine, as illustrated in FIGS. 2 and 3, the main brushes 14 are reciprocated in a transverse direction by the transverse reciprocation of the frame 24. The riser brushes 16 are reciprocated in a forward and rearward direction by reciprocation of the riser frame 26 acting through the stub frame 124. As the brushes reciprocate, the carriage 4 is preferably maintained in a stationary position between a pair of escalator sidewalls 115. The carriage 4 is flxed with respect to the escalator sidewalls 115 by rotation of a lock lever 94. The lock lever 94 is carried on a shaft 96 rotatably positioned within bearings 98 secured to the carriage 4. A pair of cams 100 and 102 are positioned on the shaft 96 opposite a pair of stabilizer receptacle openings 104 and 106.

As illustrated in FIG. 2, a stabilizer tube positioned within receptacle opening 104 carries a stablizer flange 108. A padding layer 112 is affixed to the outer side of the flange 108 and a bumper layer 114 is positioned about the exterior of the tube 110 outwardly of the flange 108. As the shaft 96 is rotated by movement of the lock lever 94, the cam surface 100 engages the end of tube 110 to force it outwardly away from the side of the carriage 4. When this occurs, the flange 108 and padding layer 112 are brought into firm engagement with the interior surface of the escalator sidewall while the padding 114 engages the end surface 113 of the sidewall 115. A second stabilizer tube 109 positioned on the opposite side of the carriage 4 from the stabilizer tube 110 includes a flange 111 having a padding layer 117 on its outer surface. The stabilizer tube 109, as illustrated, may be fixed in position with respect to the carriage 4 while the stabilizer tube 110 is movable in a transverse direction with respect to the carriage through rotation of the lock lever 94 and shaft 96. With the tube 110 extended through contact with the cam 100, the carraige 4 is fixedly positioned between the sidewalls 115 to provide a fixed support for the reciprocating brushes 14 and 16. When the carriage 4 is fixedly positioned between the sidewalls 115, the padding layer 117 on the flange 111 is in contact with one of the sidewalls 115 while the padding layer 112 on the flange 108 is in contact with the other of the sidewalls to fixedly position the carriage between the sidewalls.

The shape of escalator sidewalls may vary somewhat depending upon the escalator manufacturer. Thus, depending upon the shape of the escalator sidewall, the stabilizer tube 110 can be inserted into the receptacle opening 106 which is positioned inwardly from the opening 104. When positioned within opening 106, the outward movement of the tube 110 results from contact of the cammed surface 102 with the end surface of the tube 110. As thus held between the escalator sidewalls 115, the carriage 4 is supported on a horizontal surface 134, such as a floor, by the front wheels 6 and the rear wheel 8.

Turning to FIG. 4, a liquid-receiving tank 136 is supported on the reciprocable frame 24 on a plurality of transversely positioned brace assemblies 132 which will subsequently be described in more detail. The liquid level within the tank 136 may be visually observed by the operator through a sight glass 135 and additional liquid may be added through a flexible tube 155 on removal of a fill cap 154. The position of a float 144 within the tank 136 is determined by its liquid level and, as liquid is added through flexible tube 155, the float 144 rises and actuates a switch 145 to close a shutoff valve 146 in tube 155.

The vacuum pickup nozzles 18 are positioned between the main brushes l4 and the riser brushes 16 by vacuum tubes 19. To draw a vacuum through vaccum pickups 18, a vacuum generator 138 is actuated by a motor (not shown) to draw a vacuum through a duct 137. Air which is drawn through duct 137 by the vacuum generator 138 is exhausted through an air outlet 164 in a hood 212. Integrally associated with the vacuum generator 138 is a centrifugal water-air separator 140 which is powered by the vacuum generator motor. As air is drawn through the separator 140 from the tank 136, there is a reduction in presssure within the tank 136. The tank 136 communicates with a plenum chamber 141 through an opening 143 to cause a corresponding reduction in the pressure within plenum chamber 141. The reduction in pressure opens a spring-biased check valve 142 positioned between the plenum chamber 141 and a dry filter bag enclosure 150 which contains a dry filter bag 148. The pressure within enclosure 150 is indicated with a transducer 151. The filter bag 148 is connected through a removable hood 152 with a flexible tube 156. The tube 156 leads to a valvechamber 158 which contains a valve flap 160 positioned as shown in solid line drawing in FIG. 4. The valve flap 160 is actuatable by a solenoid 162 between its solid line position shown as 160 and its position shown in phantom in FIG. 4 as 160a.

The valve chamber 158 communicates directly with vacuum tubes 19 to draw a vacuum through the vacuum pickups 18. As described, the air entering vacuum tubes .19 through vacuum pickups 18 passes through the valve chamber 158 and then through flexible tube 156 to the filer bag 148. Particulate materials are removed from the air by the filter bag 148 and the air then passes through check valve 142 into the tank 136. The contact of the air with the liquid within tank 136 removes fine dust particles and the air is then discharged through vacuum generator 138 after having water removed from the air by the centrifugal separator 140.

A plurality of the spray nozzles 20 are positioned along a nozzle bar 200 positioned transversely of the carriage 4 and rearwardly of the main brushes 14. As shown, the spray nozzles 20 are directed toward the brushes 14 such that liquid discharged by the nozzles 20 is sprayed onto the area contacted by brushes 14. Liquid supplied to the spray nozzles 20 is drawn from the tank 136 through an inlet tube 166. The liquid passes upwardly through the tube 166 into a hood 168 in communication with a wet filter bag 172. The bag 172 is supported within a wet bag container chamber 170 whose bottom is closed by a micro-porous filter 174 positioned on support flanges 176. The pressure within chamber 170 is indicated by a transducer 153.

After the liquid passes through the wet filter bag 172 and micro-porous filter 174, it is conveyed to a plenum chamber 178 leading to an inlet pipe 180 to a pump 182. The pump 182 is driven by a motor 184 positioned on support housing 185. A pump outlet pipe 186 leads to a proportioning valve 188 interconnecting a bypass tube 192 and an outlet tube 190. Depending on the position of the valve 188, all or part of the liquid may be fed to the outlet tube 190 to increase the amount ofliquid being discharged through nozzles 20. If it is desired to decrease the quantity of liquid being discharged, a portion of the liquid may be recycled directly to the tank 136 through the bypass tube 192.

The outlet tube 190 passes through a port 194 in the tank 136 to a solenoid operated valve 196. By actuation of the valve 196, part or all of the liquid may be conducted through the spray tube 21 to spray nozzle 22 positioned adjacent the riser brushes 16. A fender 218 partially covers the brushes l6 and is supported by mounting bolts 224 and a support brace 222, both of which are connected to the stub frame 124. A clamp 220 surrounding the spray tube 21 supports the tube with respect to the fender 218. A valve 198 is positioned in the tube 190 downwstream from the valve 196 and through adjustment of valve 198, the amount of liquid discharged through nozzles 20 can be further controlled.

When liquid is discharged through the spray nozzles 20, the solenoid 162 is actuated to move the valve flap within valve chamber 158 to its position as shown in phantom at a. When so positioned, the valve flap 160 closes the outlet from valve chamber 158 to the flexible tube 156. Thus, as liquid is discharged through nozzles 20, it is picked up by vacuum pickups 18 and conveyed to the valve chamber 158. The mixture of liquid and air is then conveyed to tank 136 through a wet discharge tube 204 whose lower end is supported by a float 206 connected to the tube 204 through a perforated collar 208. As the float 206 moves up or down with the level of iquid within the tank l36,the lower end of the discharge tube 204 is likewise moved up or down and is maintained in close proximity to the level of liquid within the tank 136. When the lower end of the discharge tube 204 is positioned either below or too far above the liquid level in the tank 136, a large amount of turbulence and foaming results when air passes into the tank 136 through tube 204. However, by maintaining the lower end of the tube 204 at a predetermined distance from the liquid by the float 206, excessive turbulence is prevented. The perforations in the collar 208 permit air and liquid to pass upwardly through the perforations to relieve pressure buildup beneath the collar 208. A spring 216 depending from the forward end of the hood 212 is connected to the vacuum tubes 19 to provide additional support for the tubes.

The movement of the riser brush 16 from a rearward to a forward position is illustrated in FIG. 5 in which the brush is shown in solid line drawing in its rearward position and in phantom at 16a in its forward position. An escalator step 226 is illustrated during its movement from a lowered position 226a to an intermediate posi tion 226b and to a raised position 226. A switch lever 230 having a roller actuator 232 at its outer end is pivotally connected to the stub frame 124. Movement of the switch lever 230 causes movement of a switch arm 234 about a pivot point 236.

When the escalator step is in its lowered position 226a, the roller actuator is in its lowered position 232a. During this condition, the switch arm 234 occupies the position shown in FIG. 5. With the switch arm 234 in this position, a solenoid is actuated to open a valve 196 (FIG. 4) to discharge liquid through the spray nozzle 22. The discharged liquid impinges on step surface 226 and on a vertical riser 228. As the escalator step" moves to an intermediate position 226b, the roller actuator is moved to an intermediate position 232b to bring the rearward end of the switch arm 234 into contact with a switch 238. When this occurs, the valve 196 is closed to stop the discharge of liquid through spray nozzle 22 while the rack motor 116 (FIG. 2) is started to move the riser brush 16 forwardly at a controlled rate of speed. As brush 16 moves forwardly, it rotates in the direction of the arrow A to traverse across the step 226 and into contact with the riser 228.

As the riser brush 16 moves to its forward position 16a, the escalator step continues to rise to reach the position shown in solid line drawing as 226. As this occurs, the actuator roller is moved to its solid line position shown as 232. This causes movement of the switch lever 230 to bring switch arm 234 into contact with a switch 240 while maintaining contact with switch 238. When the switch arm 234 contacts switch 240, the brush 16 is retracted rapidly to its position shown in solid line drawing at 16. This causes the actuator roller to drop to the position shown at 232a which breaks the contact of arm 234 with

switches

238 and 240. With the actuator roller in position 232a, the solenoid operated valve 196 is again opened to discharge liquid through the spray nozzle 22 and the entire operation is repeated for the next escalator step which is rising into contact with roller actuator 232, etc.

Due to the rotation of brush 16 in the direction of the arrow A, both the dirt and liquid on step 226 and riser 228 are swept rearwardly beneath the vacuum pickups l8 and are conveyed to the tank 136 in the manner described previously. As the escalator steps move from a lowered position at the level of floor surface 134 to the position shown at 2260, the steps pass beneath the main brushes 14 which are reciprocated from side to side to pass across the width of the step surfaces. The brushes 14 are rotated in the direction of the arrow B. Thus, dirt dislodged by the brushes 14 as well as the liquid sprayed beneath the brushes 14 by nozzles (FIG. 4) are conveyed forwardly to the vacuum pickups 18.

FIG. 6 illustrates the integral structure of the vacuum tubes 19, vacuum pickups l8, float 206, perforated collar 208, and wet discharge tube 204. A riser piper 205 is connected to the flexible tube 156 as illustrated in FIG. 4. The overall structure, as illustrated, provides an open space 244 which passes around the duct 137 (FIG. 4) and a vertical open space 242 between tubes 19 to provide for reciprocal movement of the riser frame 26 (FIG. 2). As illustrated, the unit is supported at its rearward end by the float 206 whose level is determined by the liquid level (indicated by the arrow C) within the tank 136.

FIG. 7 illustrates the electrical control circuitry for the apparatus of the invention. An input line 286 providing the power for operation leads to a main switch 252. When the main switch 252 is in a closed position, the wet transducer 153 and dry transducer 151 are each energized to indicate respectively the pressure within the wet filter container 170 and the pressure within the dry filter container 150 (FIG. 4). These pressures indicate the condition of the wet filter bag 172 and dry filter bag 172. As the bags become clogged with dirt, the pressures within the

containers

170 and 150 will increase with the pressure in wet container 170 indicated on gauge 278 and the pressure in container 150 indicated on gauge 280.

With the switch 252 in a closed position, power is fed to the switch 145 which is actuated by the float 144. As described previously, when float 144 rises to a particular level, the switch 145 is closed to close the valve 146 in liquid inlet 155. With switch 145 closed, electrical energy is also fed to a light 284 which indicates visually that the tank 136 is full.

A switch 254 which actuates the brush motor 76 is connected in series with the main switch 252. When switch 254 is closed, the brush motor 76 is operated to cause rotational movement of the brushes as described previously. A normally closed thermal switch 270 is in series with motor 76 and when motor 76 becomes over heated, the switch 270 is opened.

A switch 256 connected in series with main switch 252 actuates the crank motor 34. When main switch 252 and switch 256 are closed, the crank motor 34 is operated to cause transverse reciprocation of the frame 24 as described previously.

A switch 258 connected in series with main switch 252 controls the rack motor 116. When the

switches

252 and 258 are closed, power is fed to the motor 116 through

switches

238 and 240. As described previously, with reference to FIG. 5, the

switches

238 and 240 are controlled by movement of a switch lever 230 and an actuating roller 232. When switch arm 234 contacts switch 238, the throw of the switch is moved to the position shown in FIG. 7. When contact is broken, the throw of the switch 238 moves to position B. When the switch arm 234 contacts switch 240, the double pole throw of the switch is at position A and when contact is broken, the throw of switch 240 is moved to position B.

As illustrated in FIG. 7, the throw of switch 238 is at position A to feed power through the switch 238 to motor 116. With the throw of switch 240 at position B, a portion of the current passes through a variable resistor 274 which is adjustable to regulate the power input to secondary winding 272 of motor 116. This causes the motor 116 to move brush 16 in a forward direction at a rate controllable by the position of the variable resistor 274.

When the escalator step surface reaches the position shown in solid line drawing at 226 in FIG. 5, the switch arm 234 contacts switch 240 which causes the throw of switch 240 to move to position A while the throw of switch 238 remains at position A. This reverses the po' larity of the electrical input to secondary winding 272, bypassing the resistor 274. This causes a reversal in the polarity of the secondary winding current and also an increase in the current to the secondary winding to reverse the direction of the motor I16 and to increase its speed in proportion to the increased current in secondary winding 272. This results in retraction of the brush 16 as illustrated in FIG. 5.

With the brush 16 in a retracted position as shown in solid line drawing in FIG. 5, the actuator roller drops to its lowered position at 2320 and breaks the contact between switch arm 234 and the

switches

238 and 240. When this occurs, the throw of switch 238 moves to position B while the throw of switch 240 returns to position B. Current is then fed to the solenoid valve 196 to cause the ejection of liquid through the spray nozzle 22. The circuitry for the solenoid valve 196 illustrated in FIG. 7 includes a box labeled riser spray solenoid. This box does not indicate a switch, as such, but merely identifies the function of the solenoid circuit.

A switch 260 connected in series with main switch 252 controls the power input to a vacuum motor 139 which operates the vacuum generator 138. When both switches 252 and 260 are closed, power is fed to the vacuum generator motor 139. A switch 262 connected in series with main switch 252 operates the pump motor I84. When both switches 252 and 264 are closed, the motor 184 is operated to pump liquid from the tank 136 to the spray nozzles 20. A thermal switch 276 is connected in series with motor 184 and the switch 276 is opened when motor 184 becomes overheated.

A flap solenoid switch 264 connected in series with main switch 252 actuates the flap solenoid 162. When both switches 252 and 264 are closed, the solenoid 162 is actuated to move the valve flap to its position shown in phantom in FIG. 4 as 160a. When switch 264 is open, the valve flap is located in its solid line position shown at 160 in FIG. 4.

A cycle speed adjuster 248 connected to the main switch 252 through a switch 282 controls the power input to a cam motor 250. The cam motor is an AC-DC motor and the cycle speed adjuster 248 may be a variable resistor in the secondary winding circuit of cam motor 250. To operate the machine automatically, a control knob 266 is turned in a clockwise direction. A shaft 267 connected to the knob 266 carries a plurality of cams 268. The individual cams operate the individual switches positioned opposite the cams. On clockwise rotation of the knob 266 with switch 282 closed, a main switch cam closes the main switch 252 which then feeds power to the cam motor 250. The cam motor 250 rotates the shaft 267 at a controlled speed to bring the various cams into contact with the individual switches at preselected times to cause automatic cycling of the machine.

With main switch 252 closed, the first cycle in the machine is dry vacuuming. During dry vacuuming, main switch 252 is closed, crank motor switch 256 is closed, vacuum motor switch 260 is closed, and flap solenoid switch 264 is open. At the end of dry vacuuming, as determined by the speed of rotation of the shaft 267 and the configuration of the various cammed surfaces, the machine is cycled to a dry brushing operation. During dry brushing, main switch 252 is closed, brush motor switch 254 is closed, crank motor switch 256 is closed, vacuum motor switch 260 is closed, and the flap solenoid switch 264 remains open. This causes reciprocation of the main brushes 14 with dirt being picked up through vacuum pickups 18.

At the end of the dry brushing operation, the machine is cycled through a wet brushing operation. During this operation, switches 252, 254, 256, 258, 260, 262, and 264, are all closed. This causes transverse reciprocation of main brushes 14, forward and rearward reciprocation of riser brushes 16, ejection of water through both spray nozzles 20 and riser spray nozzle 22, and pick up of water and dirt through the vacuum pickups 18. During this operation, the valve flap 160 occupies the position shown at 160a in FIG. 4 so that the dirt and water are transferred directly to the tank 136. At the end of the wet brushing operation, the main switch cam moves out of contact with main switch 252 to switch off the power to cam motor 250.

In addition to being operated automatically, the machine may be operated manually. During manual operation, the switch 282 is open to switch off the power to cam motor 250. Then, the control knob 266 is rotated to the desired position to vacuum, brush and vacuum, or wet brush. A slip clutch 288 positioned between shaft 267 and cam motor 250 permits manual rotation of shaft 267 when the motor 250 is switched off. lndicia (not shown) may be positioned on the front face of control knob 266 to indicate the required position of knob 266 for vacuuming, vacuuming and brushing, or spraying and brushing.

FIG. 8 illustrates the position of the liquid receiving tank 136 when the brace assembly 132 is unfolded to its open position. Each of the brace assemblies 132 is supported transversely on the frame 24. A brace assembly 132 includes a lower brace 290 to which is pivotally connected an upper brace 292. With brace 292 pivoted upwardly as shown in FIG. 8, the brace 292 is supported in its upward position by a support bracc 294. The upper end of support brace 294 is connected at pivot 300 to upper brace 292 while its lower end engages the lower brace 290 to act as a prop for brace 292. A control rod 298 is connected to brace 294 to provide rotational movement of brace 294 about pivot 300.

As shown in FIG. 8, the liquid tank 136 is canted upwardly from its normal position indicated in phantom as 136'. A support housing 302, supported on the tank 136 is likewise canted upwardly from its normal position 302'. The hood 212 is shown in its open position by pivoting about a hinge 210 between the hood 212 and support housing 302. The hood, indicated in its normal upright position at 212, may be maintained in a closed position through engagement with a hood latch 214. With the hood 212 in its open position and the tank 136 canted upwardly as in FIG. 7, the machine has an accordion-like appearance with the mechanism of the machine exposed for easy access.

The brace assembly 132, as shown in FIG. 9, has a triangular appearance in its open position. The lower brace 290 forms the bottom leg with brace 294 forming the upright leg and brace 292 forming the diagonal leg of the triangle. A rod 304 supports the brace 292 for pivotal movement with respect to brace 290. Since brace 292 is fixedly connected to the tank 136 while brace 290 is fixedly connected to the frame 24, the tank 136 is canted upwardly with the brace assembly 132 in its opened position. The brace 290 is an upwardly directed channel; brace 292 is a downwardly directed channel having a width less than that of brace 290, and brace 294 has a width less than that of brace 292. Rotation of the control rod 298 in the direction of the arrow in FIG. 9 causes the indicated pivotal movement of brace 294 into contact with the brace 292. This permits closing of the brace assembly 232 to a position where brace 294 fits within brace 292 which, in turn, fits within brace 290 in a nested arrangement. The tank 136 may be removed from frame 24 by removing rod 304 and sliding the tank 136 and brace 292 with respect to brace 290.

The control rod 298, as shown in FIG. 10, is fixedly connected to the brace 294 by any suitable means. One

way of accomplishing this, for example, is by welds 306 between the control rod 298 and the brace 294.

In order to level the machine of the present invention, the height of the rear wheel 8 may be made adjustable. Thus, for example, the wheel 8 may be supported relative to the carriage on a threaded rod which engages a threaded opening in the carriage. By rotating the rod with respect to the threaded opening, the rod may be moved up or down to vary the height of the wheel 8 which is pivotally supported with respect to the rod such that the plane of the wheel 8 may be varied with respect to the axis of the rod.

As described in the foregoing description, the liquid tank 136 is supported on the reciprocable frame 24.

Depending on the size of the tank 136 and the liquid level within the tank, it may be desirable in many instances to support the tank 136 directly on the carriage 4 rather than on the frame 24. With the tank 136 mounted on frame 24, some sloshing of liquid will occur when the tank 136 is reciprocated. This can be eliminated by mounting the tank 136 on the carriage 4 which remains stationary.

With the machine 2 positioned with respect to an escalator, the front wheels 6 may extend over a portion of the escalator surface which moves horizontally, eg., the moving step surfaces which initially may undergo horizontal movement before undergoing vertical movement. With the machine 2 so positioned, the front wheels 6 are free to rotate as an escalator surface moves beneath the wheels 6.

The machine of the invention provides efficient cleaning of the exposed surfaces of an escalator in a fraction of the time previously required. The machine is quite vesatile in that it provides cleaning, not only of the escalator step surfaces, but also the riser surfaces. The cleaning is quite thorough since, in a complete cycle, the escalator steps are vacuumed, dry brushed, and then wetbrushed. The dirt removed fromm the escalator steps is not discharged directly to the atmosphere but is filtered and also contacted with liquid prior to discharge.

We claim:

1. An escalator cleaning apparatus comprising a carriage;

means to fixedly position said carriage between a pair of escalator sidewalls;

wheels mounted on the underside of said carriage;

a reciprocable first frame positioned on said carriage for reciprocation in a transverse direction;

first brush means carried by said reciprocable first frame;

a reciprocable second frame positioned with respect to said carriage for reciprocation in a longitudinal direction;

second brush means carried by said second frame;

and

said second frame extending forwardly of said first frame,

whereby said first brush means is reciprocated in a transverse direction to an escalator step surface and said second brush means is reciprocated in a longitudinal direction to an escalator step surface.

2. The apparatus of claim 1 including vacuum means positioned between said first and second brush means;

said first and second brush means each including a rotatable brush whose direction of rotation is toward said vacuum means.

3. An escalator cleaning apparatus including a forwardly and rearwardly reciprocable brush means;

means to support said brush means for reciprocatory movement, and

control means to move said brush means forwardly at a predetermined speed over an upwardly moving escalator step surface and to retract said brush means rearwardly at a higher predeterminedspeed when the height of the step surface reaches a predetermined level.

4. The apparatus of claim 3 including means to reciprocate said brush means from side to side as said brush means is reciprocated forwardly and rearwardly.

5. The apparatus of claim 3 including spray means positioned adjacent said brush means to spray a liquid onto the escalator step surface.

6. The apparatus of claim 3 wherein said brush means includes a rotatable brush; and including means to rotate said brush during movement of said brush over an escalator step surface.

7. The apparatus of claim 6 wherein said brush is positioned to contact an upwardly moving escalator step surface and a riser surface positioned forwardly thereof during reciprocatory movement of said brush.

8. The apparatus of claim 7 wherein said predetermined forward speed brings said brush into firm contact with the riser surface prior the retraction of said brush.

9. The apparatus of claim 3 including second brush means positioned rearwardly of said brush means, and

said second brush means being reciprocable from side to side in a transverse direction.

10. A cleaning apparatus comprising a carriage having a pair of forward wheels mounted on either side of said carriage;

an axle interconnecting said forward wheels;

a frame slidably supported at its forward end for transverse movement on said axle;

vertically adjustable support means supporting the rearward end of said frame;

brush means carried on said frame; and

means to reciprocate said frame in a direction transverse to said carriage.

11. The apparatus of claim 10 wherein said brush means is positioned on said frame forwardly of said axle,

whereby upward movement of said support means pivots said frame forwardly about said axle to move said brush means downwardly and downward movement of said support means pivots said frame rearwardly about said axle to move said brush means upwardly.

12. The cleaning apparatus of claim 10 including a second frame reciprocably mounted on said first mentioned frame for forward and rearward reciprocation, and

second brush means carried by saidsecond frame.

13. An escalator cleaning apparatus comprising a carriage;

a frame reciprocably mounted on said carriage;

brush means mounted on said framefor contact with an escalator surface; and

means to reciprocate said frame from side to side when said carriageis fixed with respect to a pair of escalator sidewalls,

whereby said brush means is reciprocated across the width of an escalator step to clean in the areas on the step surface which are adjacent to the escalator sidewalls.

14. The apparatus of claim 13 including vacuum means positioned adjacent said brush means to pick up dirt dislodged by said brush means.

15. The apparatus of claim 14 including spray means positioned adjacent to said brush means for spraying a liquid onto the area contacted by said brush means, and

said vacuum means positioned to pick up liquid from said brush means.

16. The apparatus of claim 14 including filter means positioned in flow communication with said vacuum means to remove dirt in the air passing through said vacuum means.

17. The apparatus of claim 13 including spray means positioned adjacent to said brush means for spraying a liquid onto the area contacted by said brush means.

18. The apparatus of claim 1 including spray means positioned adjacent to said first brush means, and

spray means positioned adjacent to said second brush means,

whereby liquid is sprayed onto an escalator step surface contacted by said first brush means and onto a riser surface contacted by said second brush means.

19. The apparatus of claim 18 including vacuum means positioned adjacent to said first and second brush means to receive dirt dislodged by said first and second brush meansand liquid discharged by said spray means.

20. The apparatus of claim 13 including extensible means on said carriage which are movable in a transverse direction with respect to said carriage into contact with a pair of fixed escalator sidewalls to fixedly position the carriage between said sidewalls.

21. The apparatus of claim 20 including a second brush means, and

means on said apparatus to position said second brush means for contact with a riser surface of an escalator step.

22. The apparatus of claim 21 including means associated with the second brush means to provide movement of the second brush means in cleaning the riser surfaces of moving escalator steps.

23. An escalator cleaning apparatus comprising:

a carriage;

a brush reciprocably mounted with respect to said carriage;

extensible means on said carriage for fixing the position of said carriage between a pair of fixed escalator sidewalls;

said extensible means being extendible in a transverse direction with respect to said carriage to contact an escalator sidewall in fixing the position of the carriage between said sidewalls;

said extensible means being retractable in a transverse direction to move out of contact with said sidewall in releasing said carriage with respect to said sidewalls, and

means to reciprocate said brush from side to side when said carriage is fixed with respect to the escalator sidewalls,

24. The apparatus of claim 23 wherein said brush means includes a rotatable brush positioned transversely with respect to said carriage.

v25. The apparatus of claim 13 wherein said brush means includes a rotatable brush positioned transversely to said frame.

26. The apparatus of claim 25 including spray means positioned on one side of said rotatable brush for spraying liquid onto the area contacted by said brush;

vacuum means positioned on the other side of said rotatable brush to pick up liquid from said brush and said brush rotated in a direction from said spray means toward said vacuum means to carry liquid from said spray means to said vacuum means.

27. A cleaning apparatus comprising:

a wheeled carriage;

a frame reciprocably mounted on said carriage;

brush means mounted on said frame to contact a surface being cleaned;

a liquid tank mounted on said carriage;

vacuum means mounted on said carriage;

' a vacuum pick-up positioned on said carriage adjacent the area being cleaned to pick up dirt dislodged by said brush means;

a filter positioned in flow communication with said vacuum pick-up between said vacuum pick-up and said tank;

said vacuum means in flow communication with said tank to draw a vacuum within said tank and said tank in flow communication with said vacuum pick-up such that the vacuum drawn in said tank is communicated to said pick-up and the air received by said pick-up passes through liquid in said tank before entering said vacuum means.

28. The apparatus of claim 27 including spray means positioned on said carriage adjacent to said brush means, and

pump means to convey liquid from said tank to said spray means.

29. The apparatus of claim 27 wherein said brush means is reciprocable in a direction transverse to said carriage.

30. The apparatus of claim 27 including valve means positioned in flow communication with said vacuum pickup between said vacuum pickup and said filter;

said valve means having a first position which communicates said pickup with said filter and a second position which communicates said pickup directly with said tank and bypasses said filter,

whereby air flowing through said vacuum pickup flows to said filter when said valve means is in its first position and flows directly to said tank when said valve means is in its second position.

31. The apparatus of claim 30 including spray means positioned on said carriage adjacent to said brush means;

pump means to convey liquid from said tank to said spray means; and

said valve means being in its second position during operation of said spray means to return liquid passing through said vacuum pickup directly to said tank.

32. The apparatus of claim 27 including said brush means being reciprocable in a longitudinal direction with respect to said carriage, and

control means actuatable by the height of an upwardly moving escalator step surface to control the forward and rearward movement of said brush means with respect to the upwardly moving step surface.

Claims

1. An escalator cleaning apparatus comprising a carriage; means to fixedly position said carriage between a pair of escalator sidewalls; wheels mounted on the underside of said carriage; a reciprocable first frame positioned on said carriage for reciprocation in a transverse direction; first brush means carried by said reciprocable first frame; a reciprocable second frame positioned with respect to said carriage for reciprocation in a longitudinal direction; second brush means carried by said second frame; and said second frame extending forwardly of said first frame, whereby said first brush means is reciprocated in a transverse direction to an escalator step surface and said second brush means is reciprocated in a longitudinal direction to an escalator step surface.

2. The apparatus of claim 1 including vacuum means positioned between said first and second brush means; said first and second brush means each including a rotatable brush whose direction of rotation is toward said vacuum means.

3. An escalator cleaning apparatus including a forwardly and rearwardly reciprocable brush means; means to support said brush means for reciprocatory movement, and control means to move said brush means forwardly at a predetermined speed over an upwardly moving escalator step surface and to retract said brush means rearwardly at a higher predetermined speed when the height of the step surface reaches a predetermined level.

9. The apparatus of claim 3 including second brush means positioned rearwardly of said brush means, and said second brush means being reciprocable from side to side in a transverse direction.

10. A cleaning apparatus comprising a carriage having a pair of forward wheels mounted on either side of said carriage; an axle interconnecting said forward wheels; a frame slidably supported at its forward end for transverse movement on said axle; vertically adjustable support means supporting the rearward end of said frame; brush means carried on said frame; and means to reciprocate said frame in a direction transverse to said carriage.

11. The apparatus of claim 10 wherein said brush means is positioned on said frame forwardly of said axle, whereby upward movement of said support means pivots said frame forwardly about said axle to move said brush means downwardly and downward movement of said support means pivots said frame rearwardly about said axle to move said brush means upwardly.

12. The cleaning apparatus of claim 10 including a second frame reciprocably mounted on said first mentioned frame for forward and rearward reciprocation, and second brush means carried by said second frame.

13. An escalaTor cleaning apparatus comprising a carriage; a frame reciprocably mounted on said carriage; brush means mounted on said frame for contact with an escalator surface; and means to reciprocate said frame from side to side when said carriage is fixed with respect to a pair of escalator sidewalls, whereby said brush means is reciprocated across the width of an escalator step to clean in the areas on the step surface which are adjacent to the escalator sidewalls.

15. The apparatus of claim 14 including spray means positioned adjacent to said brush means for spraying a liquid onto the area contacted by said brush means, and said vacuum means positioned to pick up liquid from said brush means.

18. The apparatus of claim 1 including spray means positioned adjacent to said first brush means, and spray means positioned adjacent to said second brush means, whereby liquid is sprayed onto an escalator step surface contacted by said first brush means and onto a riser surface contacted by said second brush means.

19. The apparatus of claim 18 including vacuum means positioned adjacent to said first and second brush means to receive dirt dislodged by said first and second brush means and liquid discharged by said spray means.

21. The apparatus of claim 20 including a second brush means, and means on said apparatus to position said second brush means for contact with a riser surface of an escalator step.

23. An escalator cleaning apparatus comprising: a carriage; a brush reciprocably mounted with respect to said carriage; extensible means on said carriage for fixing the position of said carriage between a pair of fixed escalator sidewalls; said extensible means being extendible in a transverse direction with respect to said carriage to contact an escalator sidewall in fixing the position of the carriage between said sidewalls; said extensible means being retractable in a transverse direction to move out of contact with said sidewall in releasing said carriage with respect to said sidewalls, and means to reciprocate said brush from side to side when said carriage is fixed with respect to the escalator sidewalls, whereby said brush means is reciprocated across the width of an escalator step to clean in the areas on the step surface which are adjacent to the escalator sidewalls.

25. The apparatus of claim 13 wherein said brush means includes a rotatable brush positioned transversely to said frame.

26. The apparatus of claim 25 including spray means positioned on one side of said rotatable brush for spraying liquid onto the area contacted by said brush; vacuum means positioned on the other side of said rotatable brush to pick up liquid from said brush and said brush rotated in a direction from said spray means toward said vacuum means to carry liquid from saId spray means to said vacuum means.

27. A cleaning apparatus comprising: a wheeled carriage; a frame reciprocably mounted on said carriage; brush means mounted on said frame to contact a surface being cleaned; a liquid tank mounted on said carriage; vacuum means mounted on said carriage; a vacuum pick-up positioned on said carriage adjacent the area being cleaned to pick up dirt dislodged by said brush means; a filter positioned in flow communication with said vacuum pick-up between said vacuum pick-up and said tank; said vacuum means in flow communication with said tank to draw a vacuum within said tank and said tank in flow communication with said vacuum pick-up such that the vacuum drawn in said tank is communicated to said pick-up and the air received by said pick-up passes through liquid in said tank before entering said vacuum means.

28. The apparatus of claim 27 including spray means positioned on said carriage adjacent to said brush means, and pump means to convey liquid from said tank to said spray means.

30. The apparatus of claim 27 including valve means positioned in flow communication with said vacuum pickup between said vacuum pickup and said filter; said valve means having a first position which communicates said pickup with said filter and a second position which communicates said pickup directly with said tank and bypasses said filter, whereby air flowing through said vacuum pickup flows to said filter when said valve means is in its first position and flows directly to said tank when said valve means is in its second position.

31. The apparatus of claim 30 including spray means positioned on said carriage adjacent to said brush means; pump means to convey liquid from said tank to said spray means; and said valve means being in its second position during operation of said spray means to return liquid passing through said vacuum pickup directly to said tank.