Abstract:
A duct cleaning device including a flexible conduit having a first end and a second end with inlets at first end and outlets at second end to allow air to circulate within the conduit. A whipper located at first end is rotated by a drive shaft, housed within the conduit, and powered by an air-activated drive system located near to the whipper at first end of the conduit. A stationary circular brush is also located around the conduit near its first end. In operation, the air-activated drive system is activated by air passing though the conduit preferably when a vacuum is applied. The vacuum is created a pressure reducing air pump To which the second end of the conduit is attached. The device may be mounted with a dolly, and displaced within a duct using rods attached to the dolly. The loosened debris generated by the action of The whipper and brush on the internal surfaces of the duct are aspirated through the inlets and into the conduit by the vacuum.

Description:
The present invention relates to a device for cleaning ducts. More specifically, this invention pertains to a duct cleaning device with a vacuum activated rotating whipper. 
     BACKGROUND OF TH INVENTION 
     U.S. Pat. No. 5,655,256 is directed to a stationary rectangular brush for cleaning ducts that is attached to the terminal end of a vacuum hose. This brush loosens debris as die vacuum hose is moved within the duct. U.S. Pat. No. 5,802,667 discloses a duct cleaning device having a rotatable brush mounted in a helical configuration around the outer surface of a vacuum hose. The helical configuration of the brush causes rotation of the brush as it is advanced within a duct, however, there is no independent rotation of the brush if the vacuum hose is not moving within the duct, U.S. Pat. No. 5,608,941 and U.S. Pat. No. 4,792,363 describe a rotating brush positioned at the front of a vacuum hose for cleaning a duct interior. The brush rotates about a drive shaft that extends through the vacuum hose to a power source. An alternate external drive means is disclosed in U.S. Pat. No. 5,584,093 where the brush is rotated by incoming air pressure supplied by an air supply source through a hose mounted on the vacuum hose U.S. Pat. No. 5,109,567 teaches a duct cleaning device having rotating tubes disposed at the leading end of a vacuum hose. The tubes are connected to a compressed air source and the pressure caused by forcing compressed air through the tubes causes rotation of the tubes within the duct. A similar approach and device is taught in CA U.S. Pat. No. 2,221,385. 
     U.S. Pat. No. 5,107,568 relates to a duct cleaning device having a single brush extending from the leading end of a vacuum hose. The brush is attached to a flexible drive shaft that passes through the vacuum hose to a turbine located within the vacuum hose, but outside of the duct being cleaned. As air passes through the vacuum hose the turbine and drive shaft rotate. 
     These prior art devices disclose the use of a rotatable brush set in motion either manually or by a drive shaft attached to a drive means. The debris loosened by the action of the brush against the internal surfaces of ducts are then aspirated by the vacuum hose. These arrangements necessitate long drive shafts or other external sources to power the brush which rub against the interior of the vacuum hose losing poser; and reduce the effective vacuum hose cross sectional area. 
     Accordingly there is a need for an improved device for cleaning the internal surfaces of ducts. 
     It is an object of the invention to overcome disadvantages of the prior art. 
     The above object is met by the combinations of features of the main claims, the sub-claims disclose further advantageous embodiments of the invention. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a device for cleaning ducts. More specifically, this invention pertains to a duct cleaning device with a vacuum activate rotating whipper. 
     The present invention pertains to a cleaning head comprising a tubular housing having a bore, a first end and a second end, where pr second end is attached to flexible hose. The housing comprises one or more openings at or near the first end, and a shaft having a proximal and a distal end. The shaft axially located within the bore of the housing, and rotatably attached to the housing. The proximal end of the shaft extending out from the first end of tile housing. The cleaning head farther comprises a whipper coupled to the proximal end of the shaft, and a drive means coupled to the shaft and located within the housing. The cleaning head also comprises at least one radially extending brush attached to the housing and located behind the one or more openings of the housing. Preferably, the drive means comprises a screw auger. 
     The present invention also includes the cleaning head as described above further comprising a dolly. The dolly preferably comprising at least two wheel assemblies. 
     The present invention also embraces a duct cleaning device, comprising, a flexible hose operational connected with the cleaning head as described above. 
     The duct cleaning device of the present invention loosens and removes debris from the internal surface of air ducts. The duct cleaning device comprising a flexible conduit having an interior, first and second ends, said first end capable of being inserted into a duct for cleaning purposes. Inlet means at the first end and outlet means at the second end ate provided to allow air to circulate through the conduit. A drive shaft means within the conduit at the first end has a proximal end, coupled to a debris-loosening rotary circular whipper located at the first end of the conduit, and a second end coupled to an air-activated drive means located behind the rotary whipper, within the conduit. The drive shaft means is rotatable upon flow of air through the air-activated drive means. A sweeper element extends circumferentially around a portion of the conduit, and sweep debris from an internal surface of a duct. 
     In another aspect of the present invention, the second end of the conduit is attached to an air pump means, located outside the duct, for reducing the pressure within the conduit causing air to flow through the conduit for effecting the rotation of the air-activated drive means, and for removing matter loosened within the duct by the rotary whipper and sweeper element. 
     This summary of the invention does not necessarily describe all necessary features of the invention but that the invention may also reside in a sub-combination of The described features. 
     Advantageously, the air-activated drive means of the present invention is positioned within the leading portion of the vacuum hose, immediately adjacent with the rotatory whipper assembly. The air-activated drive means is powered by the air flow through the vacuum hose when a vacuum is applied through the vacuum hose. With such an arrangement, there is no need for lengthy drive shafts, which rub against the interior of the vacuum hose losing poser and reduce power and reducing the effective vacuum hose cross sectional area, or other external sources to power the rotating whipper, for example high pressure hoses. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein: 
     FIGS.  1 (A) and (B) show a side view of an aspect of an embodiment of the present invention comprising a cleaning head with bristle brush and rotating whipper. 
     FIG.  1 (A) shows a cleaning head with a screw auger drive means. 
     FIG.  1 (B) shows a cleaning head with a fan drive means and a dolly. 
     FIG. 2 shows an end view, from the back of an aspect of an embodiment of the present invention of a cleaning head. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     The present invention relates to a device for cleaning ducts. More specifically, this invention pertains to a duct cleaning device with a vacuum activated rotating whipper. 
     The following description is of a preferred embodiment by way of example only and without limitation to the combination of features necessary for carrying the invention into effect. 
     With reference to FIGS.  1 (A) and (B) and  2 , the duct cleanina device comprises a cleaning head ( 10 ) which may be releaseably attached to, or integrated with, a flexible conduit or vacuum hose ( 20 ). The cleaning head comprises a tubular housing ( 25 ) to which one or more radial brushes  30  are attached The tubular housing may be of any appropriate length required to traverse a duct an 4  house the drive means and whipper as described below. At, or adjacent the front end of the housing is positioned one or more openings  35 , that freely permit the passage of air from outside the cleaning head through opening ( 35 ) and bore of the cleaning head to The vacuum hose  20 . The openings may be positioned along the side of the housing as indicated in FIG.  1 (A), at the front end of the housing, or a combination thereof. 
     Whipper ( 40 ) is comprised of a plurality of bristles ( 45 ), each bristle or cluster of bristles are attached to a coupler ( 50 ). Coupler  50  is affixed to shaft  60  via any suitable means, for example but not limited to, a key or screw. Shaft  60  is rotatably mounted to the front end of housing  25  via any suitable means for example, but not limited to, a bearing. Shaft  60  extends though the bore of cleaning head  10 , and is rotatabty attached to a stabilizer bar ( 80 ) via a second bearing ( 55 ) or any other suitable means as known in the art, for example bat not limited to a lubricated or polymeric sleeve. Stabilizer bar  80  is positioned within the housing, for example, at the rear of the cleaning head. 
     If opening  35  is positioned at the front end of housing  25 , a second stabilizer bar may be used to rotatably mount shaft  60  at the front end of the housing. If openings ( 35 ) are positioned along the sides of the housing, then the front end of the housing may be sealed and a bearing or other suitable means that permits rotational attachment of shaft  60  to the front of the housing positioned centrally therein. 
     An air activated drive means,  70 , is attached to shaft  60 , so that when the cleaning head is attached to vacuum hose  20 , and a vacuum is applied though the vacuum hose, air enters openings  35  and passes though the bore and by drive means  70  thereby imparting rotation to shaft  60  through drive means  70 . Any suitable drive means that is activated by air passing though the bore may be used to impart rotation to shaft  60  and attached whipper  40 . For example, which is not to be considered limiting in any manner, drive means ( 70 ) may comprise one or more fans, each fan comprising a plurality of blades that extend radially from a sleeve that is attached to the shaft. The blades may be of any length, for example up to about the circumference of housing  25 . However, it is to be understood that the length of each blade is sized and spaced in such a manner so that particulate matter may readily pass through the bore and not clog the drive means, while at the same time, the blades of a sufficient length to ensure chat the drive means is activated when a vacuum is applied through hose  20 . 
     Drive means  70  may also comprise a screw auger, attached to a sleeve that is attached to the shaft, or the screw auger may be directly attached to shaft  60 . The screw auger extends from about the front end of the shaft, adjacent to opening  35  (see FIG.  1 (A)), and along the shaft towards stabilizer bar ( 80 ). The screw auger may be of any suitable length and extend part, or all of the length of shaft  60 . Preferably, the screw auger completes at least one revolution around shaft  60 . The screw auger may be continuous of discontinuous along the length of shaft  60 . The screw auger may also comprise one or more blades that extend perpendicularly from the shaft and which are of a height suitable to impart rotation to the drive means when a vacuum is applied through the vacuum hose. Preferably, drive means  70  is a screw auger. 
     By using a drive means as described above, located at the front of the vacuum hose and activated by the air flow arising from a vacuum within the vacuum hose, no lengthy drive shafts or pressure hoses are required with the cleaning head of the present invention. Furthermore, no movement of the vacuum hose within the duct is required to activate the whipper. 
     Preferably housing  25  is made from a rigid material such as a thermoplastic plastic or metal, and provides rigid support to withstand a vacuum applied through hose  20 , rotation of shaft  60  and whipper  40  attached thereto, as well as the resistance felt by brush  30  as the cleaning head is passed through a duct. Cleaning head  10  may be permanently affixed to vacuum hose  20  by any suitable means including rivets, welding and the Like, or the cleaning head may be integrated with, and manufactured as one piece with, the vacuum hose. It is also conceived that cleaning head  10  may be releaseable attached to the vacuum hose and removed as required to substitute heads with varying diameter brushes ( 30 ) and whippers ( 40 ). Means for releaseable attachment include either internal or external screw threads ( 15 ) on housing  25 , That mate with corresponding screw threads either on the external or internal surface of vacuum hose  20 , respectively, or the housing may slide within or over the vacuum hose and be releaseably attached using screws, blots, C-clip, pins or other releaseable attachment means. Preferably, cleaning head  10  fits tightly with vacuum hose  20  to minimize loss of vacuum at this junction. 
     One or more circular bristle brushes  30  may be attached to housing  25 . The bristle brushes are made from any suitable bristle as known in the art and are typically attached to a sleeve that may be releaseably mounted over housing  25 . Such releaseable mounting may include screw threads on the inside of the sleeve that mate with screw threads positioned on the outer surface of housing  25 . The brush-sleeve assembly may also be attached using screws, bolts, C-clips and the like. Preferably, the brush is removable from housing  25 , however, brush  30  may also be permanently attached to the housing. The bristles of brush  30  extend radially from the sleeve or housing and are of a length to fit within a duct of similar diameter thereby removing debris from the inside of the duct wall, while also positioning cleaning head ( 10 ) centrally within the duct. The bristles are of a sufficient rigidity to permit cleaning of the inside of the duct, while not limiting movement of the cleaning head within the duct. Brush  30  typically comprises a plurality of rows of bristles, and if desired, one or more brushes may be positioned along housing  25 . These brushes, or bristles within one brush may be of the same or different stiffness. However, it is to be understood that the cleaning head of the present invention may also comprise other means for centering the cleaning head within a duct, for example but not limited to wheel assemblies (described below), or extending tubular members (see U.S. Pat. No. 5,109,567, which is incorporated here in by reference). If there is no circular bristle brush positioned on the cleaning head, then dirt and debris within he duct are dislodged by the whipper. 
     Whipper  40  comprises bristles ( 45 ) that radially extend from coupler  50  and are of a length and stiffness that ensures that when the inside surface of a duct is struck by the rotating bristles, debris is loosened and dislodged from the duct. The bristles of whipper  40  may be grouped in clusters of bristles ( 45 ), each cluster positioned around the circumference of coupler  50 . Whipper  40  comprises at least one such cluster of bristles. A bristle or cluster of bristles may be releaseably attached to coupler  50 , typically passing though openings within coupler  50  and attached thereto via a screw, for example, but not limited to a set screw, thereby permitting replacement of the bristles ( 45 ) as required. Whipper  40 , comprising bristles ( 45 ) and coupler  50 , may .also be replaced as a unit as needed to ensure a whipper of sufficient diameter for the duct to be cleaned, or to replace the bristle clusters. One or more rows of bristles may be placed along coupler  50 . The bristles may be made from, but are not limited to, a stiff polymeric material, for example a plastic, or flexible spring wire, or a combination thereof. 
     The cleaning head of the present invention, when attached to a flexible conduit, or vacuum hose, is introduced within a duct to be cleaned. The vacuum hose is operationally connected to a motor means capable of producing a vacuum within the vacuum hose. The motor means may be that as found in any standard vacuum device including hand pushed portable vacuum cleaners, or truck mounted vacuum cleaners. The vacuum applied by the motor means draws air from the duct being cleaned into the cleaning head thereby activating the drive means as described above. 
     To assist in the passage of the cleaning head-vacuum hose assembly through the duct, a dolly ( 65 ) may be attached to the cleaning head, or vacuum hose immediately behind the cleaning head so help position the cleaning head centrally within the duct. The dolly may comprise two or more wheel assemblies ( 75 ) that ride along the interior of the duct These wheel assemblies may be attached to radially extendable arms which are affixed at one end to the cleaning head or vacuum hose (see U.S. Pat. No. 5,584,093, which is incorporated herein by reference). If two wheel assemblies are used. These assemblies are positioned on opposite sides of the cleaning head, or vacuum hose, to ensure a central position of the cleaning head within the duct. However, more than two assemblies may be used, preferably placed equidistantly around the circumference of the cleaning head or vacuum hose. Rods may be used to push the dolly and assist in passage of the cleaning head through the duct. These rods may be pivotally attached to, or removably positioned against a registration means to, guide the cleaning head-vacuum hose assembly with a duct. 
     The above description is not intended to limit the claimed invention in any manner, furthermore, the discussed combination of features might not be absolutely necessary for the inventive solution. 
     All citations are herein incorporated by reference. 
     The present invention has been described with regard to preferred embodiments, however, it will be obvious to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described herein.