Abstract:
This disclosure shows the supplying of fluid at a pressure greater than the pressure of the surrounding atmosphere to a cleaner in which the cleaning is done by intermittently and consecutively jetting fluid against the surface of the material being cleaned, where the total average pressure of the air or gas is maintained a few inches of water below the pressure of the surrounding atmosphere.

Description:
PRIOR RELATED APPLICATION 
     This is a continuation in part of my prior patent application Ser. No. 210,914 filed 12-22-71, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The cleaner disclosed in this invention makes use of much that was disclosed in U.S. Pat. No. 2,864,119. This patent was issued to me on Dec. 16, 1958. 
     The cleaner disclosed in the above mentioned patent depends on the difference between the pressure of the air in the surrounding atmosphere and the pressure of the air in the cleaning tool immediately above the material being cleaned to supply the pressure required to cause the rotor in the distributing valve to rotate at desired speed and to produce the required velocity of air flow through the nozzle passages. On a short pile material this cleaner does a good job of cleaning but is hard to move over the material since a high vacuum in the cleaning tool holds it tightly to the material being cleaned. On a long pile material, such as a long pile carpet, so much air flows through the material under the cleaning tool to the space inside it that no substantial vacuum can be established over the material being cleaned and the cleaner is useless. 
     SUMMARY 
     In this invention, a pressure pump is interposed between the air surrounding the cleaning tool and the air distributing valve. This pump is adapted to supply air at sufficient pressure and volume to the intake manifold, which supplies air to the air distributing valve so that the valve rotor will rotate at the desired speed and air will flow intermittently and consecutively through the nozzle passages at the desired velocity, while the pressure in the cleaning tool immediately above the material being cleaned is slightly below the pressure of the surrounding atmosphere. The exhaust pump is required to exhaust air from space, 30, with such volume as to maintain sufficient vacuum in space 30 to prevent the escape of air from this space to the air outside of the cleaning tool and at the same time to deliver the dirt laden air to a suitable dirt collector. 
     As will be explained later, by making some changes in the embodiment of the invention as shown in the drawing, the pressure pump may be eliminated and the cleaner operated by the exhaust pump operating as both an exhaust pump and as a pressure pump. 
     The object of this invention is not only to overcome the problems found in the vacuum cleaner of U.S. Pat. No. 2,864,119, but to produce a cleaner that, while requiring a relatively small amount of power and almost no maintenance, even when used in heavy commercial service, is easily capable of producing violence of agitation and velocity of air jets beyond that required or even desired for thorough cleaning of all types of material. 
     Further objects and advantages will become more apparent from the following description and explanation, reference being made to the accompaning drawing, wherein an embodiment of the invention is illustrated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view in section, the section being taken along line 1--1 of FIG. 2, except the section of valve rotor 2 is taken along line 1R--1r of FIG. 2. 
     FIG. 2 is a top plan view in section, the section being taken along line 2--2 of FIG. 1. 
     FIG. 3 is a top view of the circular entrance 20 and shaft support portion of 1. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     1 is a molded or die cast member having an open bottom circular valve rotor cavity 20. As shown in FIG. 2, nine equally spaced open bottom passages, 31 through 39, extend outward from 20 and terminate in an equally spaced straight line to the left of valve stator cavity 20. It is to be noted that these passages vary in width in substantially the same ratio as they vary in length. As passages 31, 32, 33, and 37, 38, 39 leave the valve chamber, they gradually increase in width until they reach the desired width, at a slow enough rate to prevent turbulent flow. Passages 34, 35, and 36 increase in width too rapidly and turbulent flow through them will take place. As is shown in FIG. 2, the inner ends of these passages occupy 240 ° of the circumference of circular cavity 20. The other 120 ° of the circumference of cavity 20 is an unbroken circular wall. 
     As shown in FIGS. 1 and 3, the circular entrance and shaft supporting portion of 1 has a small circular projection extending upward from the main body. From the top of this projection, circular bore 21 extends downward to circular cavity 20 and is concentric with it. The diameter of this bore is similar to the diameter of the inner race of ball bearing 4. As is shown in FIG. 3, holes 22 and 23 are tapped to fit set screws. As shown in FIG. 3, 1 has 12 holes, 40 of about the same diameter as the diameter of the lower end of the eighteen twin nozzle passages, 11 through 19. These holes are spaced in a circle and extend downward at an angle of about 35 ° from the vertical leading counter-clockwise as they extend downward. Holes, 40, as shown in the drawing, are the same diameter at both ends. They may be substantially larger at their upper ends to simplify casting or molding if desired. 
     As shown in FIGS. 1 and 2, valve rotor 2 is a molded or die cast cup-shaped member having two circular walls. The outside diameter of the outer wall is about 1/64 of an inch less than the inside diameter of the valve rotor cavity 20. The overall height of 2 is about 1/32 of an inch less than the depth of cavity 20. The height of the outer wall of 2 is about 1.32 of an inch more than the height of its inner wall. 
     The inside diameter of cavity 24 is such that the outer race of ball bearing 4 can slide easily but snugly into it. This inside diameter has two shallow grooves cut into it, so located that retaining rings 5 and 6 can fasten the outer race of 4 in about the center of the inner wall of 2. 
     As shown in FIG. 2, the space between the wall surrounding space 24 and the outer wall of rotor 2 is divided into three similar sections- 47, 48 and 49, by three radial walls- 53, 54 and 55. As shown in FIG. 1, these three radial walls are about 2/3 as high as the outer circular wall of 2. As shown in FIG. 2, the outer circular wall of 2 is interrupted by three equally spaced vertical openings- 50, 51 and 52. 
     As described on Page 4, Lines 12-18, the 12 holes in 1 lead in a counter clockwise direction as they extend downward with air under pressure flowing from a pressure pump into intake manifold 41, and as shown in FIG. 1 flowing downward in a counter clockwise direction into the space between the inner and outer walls of rotor 2. This rotating air flow impinges against radial walls 53, 54 and 55 of rotor 2 and exerts force to cause rotor 2 to rotate in a counter clockwise direction. The volume of air flowing through rotor 2 is almost constant, as is the speed at which the rotor rotates. 
     As shown in FIG. 1, shaft 3 has an outside diameter that fits easily but snugly into bore 21 of 1 and into the inner race of ball bearing 4. Shaft 3 has a hole 27 through its center. The diameter of this hole, except for its top end, is about 1/2 the diameter of shaft 3. The upper end of hole 27 is smaller and is tapped at 26 to fit a set screw. Two shallow grooves are cut in the outer surface of shaft 3 to accommodate retaining rings and are so placed that rings 7 and 8 can fasten ball bearing 4 in a position about 3/32 of an inch above the end of shaft 3. Four holes, 25, are drilled through shaft 3 into hole 27 and are so placed as to be located between ball bearing 4 and the top of cavity 20. Shaft 3 should be positioned in hole 21 so that the circular wall surrounding space 24 just fully clears the top of cavity 20. 
     As shown in FIG. 1, fluid flow means, 9 has a flat top and is adapted to support 1 and to fit with it in a substantially air-tight manner. The top ends of the 18 round nozzle passages, 11 through 19 in 9, are spaced and positioned to register with passages 31 through 39 in 1. As shown in FIG. 1, passages 11 through 19 are substantially larger at their top end and slant downward to the right at an angle of about 15 °. By making small changes in 1 and 9, holes 11-19 could be vertical permitting less complicated and expensive tools for casting or molding 9. 28 is an elongated cavity extending the full width of 9 and passage 29 is formed by a gap in the center of the right wall surrounding 28. 
     10 is an elongated member having an elongated generally rectangular opening, 30, through it, and makes contact with the material being cleaned and is adapted to be connected to 9 in an easily replaceable manner. 
     As shown in FIG. 1, intake manifold 41 is formed of sheet metal, is adapted to be connected to the intake portion of 1 in a substantially air-tight manner and to accept the discharge or pressure side of pump 42. Pump 42 may be considered a vacuum-pressure pump. Exhaust manifold 44 is formed of sheet metal, is adapted to be connected to 9 and 10 in a substantially air-tight manner and to connect to the vacuum side of the vacuum-pressure pump 42 through passage 29 and space 28 to space 30 in elongated rectangular member 10 immediately above the material being cleaned. 
     The specification drawing does not show a motor to drive pump 42. The dust collector or tank, screen or filter 43 is connected between the manifold 44 and the input to pump 42. A by-pass valve 45 is connected to conduit 46 for regulating the air flow and pressure into manifold 41 and the vacuum in space 30. This device also includes hose or hoses, supporting wheels, handle, or other well known parts. The parts not shown are not a part of the invention and have been omitted to simplify the disclosure. 
     EXPLANATORY COMMENTS 
     In the embodiment of the invention shown in the drawing, the discharge exits of the eighteen nozzle passages, 11 through 19, are 9/32 inches in diameter and are spaced on 11/16 inch centers. Pressure pump 42 should have capacity to supply about 55 cubic feet of air per minute at a pressure of about 50 inches of water vacuum in space 30 of 5 to 10 inches of water while exhausting about 60 cubic feet of air per minute. 
     With holes 40 as shown in FIG. 3, having a diameter of about member having an elongated generally rectangular opening, 30, through it, and of an inch, valve rotor 2 should rotate at about 3,000 rpm and air should discharge from each of the 18 nozzle passages, 11 through 19, intermittently and consecutively about 9,000 times per minute and strike the material being cleaned at peak speeds of 150 miles per hour. This amounts to a total of 162,000 jets of air at 150 miles per hour striking the material covered by the cleaning tool each minute. 
     In this method of cleaning, rapidly repeated jets of high speed air are effective in producing the agitation required to loosen surface litter and to strike with the force needed to break it loose. The high speed jets easily penetrate material having the longest pile and are effective in removing the deepest embedded dirt. The violence of agitation and speed of air jets can easily be reduced by providing an adjustable restriction 45, between the atmosphere and pressure pump 42 or between and intake manifold 41. 
     As shown in FIG. 1, valve rotor 2 is supported on shaft 3 by a single ball bearing. This bearing is a 12 millimeter double shielded light duty deep groove bearing and is produced by most major manufacturers. This bearing is easy to apply, is very lightly loaded and should have a life of hundreds of thousands of hours. After considerable use, by removing the screw from 26, a few drops of oil can be applied through hollow shaft 3 to the bottom of space 24 to prevent the grease in bearing 4 from drying out. 
     If used many hours daily in commercial use, 10 should be made of a long-wearing material. For domestic use, it could be of a single piece with 9. 
     As shown in FIG. 2, 32 and 31 are progressively wider than 33. At 3,000 revolutions per minute, the time available for the air jets to reach maximum speed is about 0.0015 seconds. The main resistance to this build up in speed is the inertia of the air between spaces 47, 48 and 49, and the outlets of nozzle passages 11 through 19. The inertia of the air in ducts 31 through 39 is the only variable in the rate in which are velocity will build in nozzle passages 11 through 19. I have discovered that if the cross sectional area of ducts are made to have similar ratios to their length, they will offer similar resistances to change of volume of flow through them. Applying this principle to passages 31 through 33 and 37 through 39, passages 11 through 13 and 17 through 19 will have about the same peak speeds of air through them. Passages 14 through 16 will have higher peak speeds but not by an objectionable amount. 
     As previously indicated, the embodiment of the invention as described in the specification may be adapted to operate without using an exhaust pump by making the following changes and adjustments: change the elongated rectangular member having a solid cross section, which surrounds 10, to a member having an inverted U-shaped cross section, the open end of the U adapted to contact the material being cleaned. Connect the closed end of the U-shaped section to intake manifold 41 by passages adjustable as to resistance to air flow. Remove exhaust pump 45 and connect exhaust manifold 44 directly to the litter collecting container. Place the cleaning tool on the material to be cleaned and start pressure pump 42. Adjust the resistance to air flow of the passages connecting the closed end of the U-shaped section of 10 to the intake manifold 41 until the pressure in the inverted U of 10 is substantially above the pressure in space 30. 
     The cleaner is now ready to use, the higher pressure in the inverted U-shaped space in 10 preventing any leaking of litter-laden air from escaping to the atmosphere. This adaptation of the invention, while requiring no vacuum, is limited to use on material having a narrow range of porosity without adjustment. On porous material, like long pull carpet, or where the litter-laden air is to be delivered at some distance, an exhaust pump would be desirable. 
     While the embodiment of the invention shown is a preferred form, it is to be understood that other forms, including that described immediately above, may be adapted falling within the scope of the claims that follow