US 3005224 A
Description (OCR text may contain errors)
Oct. 24, 1961 G. M. MAGARIAN 3,005,224
AIR FLOW OPERATED BRUSH DEVICES FOR VACUUM CLEANERS Filed Oct. 23, 1958 5 Sheets-Sheet l.
$5204.22 M. Macaw/914v,
Oct. 24, 1961 e. M. MAGARIAN 3,005,
AIR FLOW OPERATED BRUSH DEVICES FOR VACUUM CLEANERS Filed Oct. 25, 1958 5 Sheets-Sheet 2 522440 MFG-H2094),
IN VEN TOR.
Oct 24, 1961 G. M. MAGARIAN 3,005,224
AIR FLOW OPERATED BRUSH DEVICES FOR VACUUM CLEANERS Filed Oct. 23, 1958 5 Sheets-Sheet 3 fi e/wan M. Mqane/mg 1N VEN TOR.
ZLWMZW Oct. 24, 1961 G. M. MAGARIAN AIR FLOW OPERATED BRUSH DEVICES FOR VACUUM CLEANERS 5 Sheets-Sheet 4 Filed Oct. 23, 1958 @EQHLD M- Mnane/mg Oct. 24, 1961 G. M. MAGARIAN 3,
AIR FLOW OPERATED BRUSH mzvrcas FOR VACUUM CLEANERS Filed Oct. 23, 1958 5 Sheets-Sheet 5 IN V EN T 0R.
zdZ/ww United States Patent 3,005,224 AIR FLOW OPERATED BRUSH DEVICES FOR VACUUM CLEANERS Gerald M. Magarian, Long Beach, Calif, assignor to Preco Incorporated, Los Angeles, Calif, a corporation of California Filed Oct. 23, 1958, Ser. No. 769,257 Claims. (Cl. 15-872) The present invention relates to certain improvements in the vacuum actuated brush devices disclosed in my prior applications, Serial Number 610,285 filed September 17, 1956, now Patent No. 2,963,270 and Serial Number 670,079 filed July 5, 1957, now Patent No. 2,962,748.
In the devices there disclosed a casing has its interior divided into three chambers; a so-called turbine chamber, a rotary brush chamber, and a transmission chamber. The brush chamber has a nozzle opening through which the brush contacts the surface, typically a carpet or rug, over which the nozzle is moved. A passage leads from the brush chamber into the turbine chamber and directs air flow from the brush chamber into operating relation to the turbine; and a vacuum connection to the turbine chamber draws the air flow through the brush and turbine chambers. The turbine shaft extends into the transmission chamber and is there connected with the brush, preferably by a belt drive, to drive the brush from the turbine.
Numerous problems have been encountered in the practical development of these devices, and it is among the objectsof the present invention to satisfactorily solve those problems. The amount of power absorbed by the driving turbine or other air operated wheel--its impedance to the air flowmust be relatively small, and in that connection all frictional losses must be minimized. The transmission chamber with its belt drive is necessarily open to the brush chamber. To avoid frictional losses due to e.g. a stuffing box or similar seal where the turbine shaft passes through the wall between the turbine and brush chambers it has been found necessary to provide clearance at that passage and through which air may flow. The operating pressure in the turbine chamber is lower than that in the brush chamber, and if the transmission chamber pressure is the same as that of the brush chamber, dirt and dust laden air from the brush chamber flows through the shaft clearance and other leakages and tends to deteriorate the turbine shaft hearings in the turbine chamber.
These provisions not only prevent wear but also protect the turbine from overloading due to frictional losses.
The brush driving power derivable from a turbine or other air motor driven by the vacuum induced air flow is severely limited. Consequently, the power required to drive the brush must be limited, and its bearings are subject to dirt deterioration with consequent increased power requirement.
It is a general object of the present invention to definitely limit the power requirement for brush operation and to protect the brush bearings for long life without appreciable increase of frictional losses. Includedin this general object is the efficient protection of the turbine shaft bearings and the transmission mechanism from dust deterioration and resultant frictional losses. And also the prevention of debris accumulation or other conditions which may overload or stall the air motor.
The present inventionaccomplishes these, and other objectives to appear, by, as one feature, mounting the rotary brush to float under a fixed pressureits own weight-and thus bear on e.g. a carpet with a fixed and limited pressure. Another feature maybe described generally as provision for controlled air flow through the several chambers. Included in that feature is provision for inward air flow over the brush hearings to protect them from dust deterioration, and provision for air admission to the transmission chamber to set up air flow through that chamber to the brush chamber. The air flows through the device, and the pressures in the several chambers, are so controlled that deleterious flow of dust laden air is eliminated or minimized-with reference not only to the turbine shaft bearings but also the transmission mechanism and the brush bearings. Overloading or stalling of the air motor is also prevented by provisions to protect and clear all the moving parts of the device from possible clogging by solid objects and accumulation of debris; and, generally, provisions are made to prevent overloading or stalling of the air motor under any normal conditions of operation.
These and other objects and accomplishments will appear from the following description and accompanying drawings of an illustrative embodiment of the invention.
In the drawings:
FIG. 1 is a perspective showing the external appearance of the improved device;
FIG. 2 is a side elevation of the same;
FIG. 3 is a plan showing the device at full scale as it appears with the cover 50 of FIGS. 1 and 2 removed;
FIGS. 4, 5 and 6 are sections taken, respectively, on lines 44, 5-5 and 6-6 of FIG. 3;
FIG. 6a is a section on line 6a-6a of FIG. 6;
FIG. 7 is a section taken on lines 7-7 of FIGS. 1, 3 and 8;
FIG. 8 is a section on lines 8-8 of FIG. 7 and FIG. 3;
FIG. 9 is an enlarged detail section on lines 99 of FIGS. 3 and 4;
FIG. 10 is a detail fragmentary elevational view taken as indicated by line 10-10 on FIG. 7;
FIG. 11 is a detailed fragmentary bottom plan view taken as indicated by line 11--11 on FIG. 7;
FIGS. 12 and 13 are detail sections on line 12-12 of FIG. 7 and lines 1313 of FIGS. 7 and 17, respectively;
FIG. 14 is a perspective showing certain parts of the device dis-assembled;
FIG. 15 is a perspective showing the part hereinafter termed the scroll;
FIG. 16 is a perspective showing the scroll and its mounting dis-assembled; and
FIG. 17 is a fragmentary section on line 17---17 of FIG. 8.
The external casing of the improved device is made up essentially of a lower body member 52 and the cover 50, the former preferably of metal, the latter preferably of plastic. The somewhat flexible cover fits over the upper edges of the body to make a fluid-tight but removable joint such as shown at 54 in FIGS. 7, 8, and 4 to 6, and 9.
The interior of the casing is divided into three chambers. An elongate brush chamber 56, with a lower elongate nozzle opening 58, houses a rotary brush 60 composed of a core 62 and radial brushes 64. At each end of the brush chamber, beyond the ends of nozzle opening 58, body 52 is formed with runners 66 which project below the level of the lips 68 that define the sides of the elongate nozzle opening. These runners ride the surface of e.g. a rug or carpet to prevent the narrow, transversely extending, lips from engaging a carpet or rug too heavily. (See FIGS. 5, 7 and 9.) The brush is mounted at each end in a supporting and bearing structure that will be later described.
The-interior of part 50a of the casing is divided by a wall structure 70 (FIGS. 3, 7 and 8) into two chambers, a turbine chamber 72 and a belt chamber 74. Wall structure 70 (with the parts it carries) is a unit separate from the casing, and its wall engages the casing walls of the body and cover in fluid-tight engagement. It is held in place by the screws shown at 71 in FIGS. 7 and 13. A turbine wheel 76 is mounted in the turbine chamber on a shaft 78 that is journaled in a bearing structure 80 carried by wall structure 70. Shaft 78 projects through wall structure 70 into belt chamber 74, and its end 781 carries a cogged belt wheel 82 .(see FIGS. 3, 6 and 8).
661 (FIGS. 3, 6 and 6a) extends across the nozzle open- I ing 58 under the belt and wheel 84. The present preferred ratio of belt drive is about three to one.
Wall structure 70 embodies, preferably as an integral unit, a partition wall 100 (see FIGS. 3, 7 and 8), and a partition wall 102 (FIGS. 3, 7 and 17) that divides the t a turbine chamber 72 from the brush chamber 56. The lower edges of walls 100 and 102 fit the walls of body 52 closely; and cover 50 has fluid-tight engagement with their upper edges, as indicated at 541 in FIGS. 7 and 17. Partition wall 100, with the parts it carries, divides the turbine chamber from the belt chamber.
Referring now more particularly to FIG. 8, bearing structure 80, carried on wall 100, includes an outer bearing housing 106 integral with 100. Housing 106 carries the bearing bushings 108 and 110, in which shaft 78 is journaled, and an oil soaked wicking 112 to insure lubrication. A bearing cap 114, pressed over the end of housing 106, overhangs the end of the bearing and has a central opening closely surrounding either the shaft 78 or,
as shown here, the hub 116 of a disk 118 set on shaft 78 to rotate with it. Disk 118 has a rim 119 overhanging the capped bearing end. The clearance at the center of cap 114, around the shaft or around hub 116 is a positive clearance, to avoid-energy absorbing friction at that point, but is as small as practicable.
Wall 100 carries, preferably integrally, a circular rimwall 120 that projects into the belt chamber, spacedly around bearing housing 80, to enclose a rather large subchamber 122. Sub-chamber 122 is widely open to turbine chamber 72 via several large openings 124 in wall 100, and is closed at its belt-chamber end by a diaphragm 126 pressed into wall 120 and centrally, closely but spacedly, surrounding shaft 78 or hub 116 outside disk 118. The positive clearance at the center of 126 is also as small as practicable.
Outside of diaphragm 126, a large disk 130 is set on shaft end 781 to rotate with the shaft. Hub 116 and belt wheel 82, with disk 130 between them, may all be set on the shaft to rotate with it by forcing them onto the fluted or knurled shaft end 781.
As will be understood from later parts of the description, the air pressure in turbine chamber 72 is always lower than that in brush chamber 56 and belt chamber 74. In a vacuum cleaning device of the character herein described, where the brush is driven by a vacuum actuated air motor, it is of primary importance to minimize power losses such as would be intrinsically caused by friction in a packing gland around shaft 78 where it projects into the belt chamber. The described arrangement completely eliminates frictional losses and at the same time protects the shaft bearings from wear due to dust entering the space adjacent the bearing from the belt chamber.
Certain provisions to be later described provide for the air pressure in belt chamber 74 being always greater, or at least not less, than that in brush chamber 56. There being no air flow from the brush chamber into the belt chamber, no substantial amount of dust enters the belt chamber. And whatever 'dust does so enter is prevented fromv contaminating the shaft bearings by the arrangements shown.
Dust is first thrown out centrifugally by the large rotating disk 130 outside the diaphragm 126 and thereby prevented from reaching the small clearance passage at the center of that diaphragm. Due to the fact that subchamber 122 is widely open, via openings 124, to turbine chamber 72, 122 may be regarded as effectively a part of the turbine chamber and the diaphragm 126 as part of the effective partition wall between the belt and turbine chambers. Pressure in 122 surrounding the bearing being the same as in 72, there is necessarily .a small air flow through the small clearance at the center of 126. Whatever very small amount of dust may be carried on that air flow immediately impinges on rotating disk 118 that overhangs the bearing end, to be thrown outward centrifugally by that disk away from the bearing structure into the relatively large sub-chamber 122 and thence drawn by slow air flow into the turbine chamber proper 72. Once in the turbine chamber all dust is drawn out through the suction outlet that communicates with the turbine chamber.
Turbine 76, set rigidly on the shaft end 782 that projects into the turbine chamber, is of the bucketed type shown in FIGS. 7 and 8. As shown best in FIGS. 14, 16 and 17, there is a relatively large suction opening through the wall 102 that separates brush chamber 56 from turbine chamber 72. Projecting into the turbine chamber around that opening is a wall formation, generallydesignated 152, having edge formations such as shown best at 154 in FIG. 16. A tapering scroll 158 of the general form shown in FIGS. 15 and 16, and channelshaped in cross-section as shown, for example, in FIGS. 8 and 12, has its end edges 156 at its larger end in close abutment to the wall edges 154. The channel formation of the scroll has an outer web 160 (see FIGS. 8, l2 and 17) and side flanges 162 and 164. The scroll as a whole is arcuate in shape and the inner edges of its side flanges closely surround a portion of the periphery of turbine 76 at one axial side of its buckets 761 (FIGS. 8 and 17). Its web 160 tapers in arcuately toward the outlet end 166 of the scroll as best shown in FIG. 17. The cross-sectional size of the scroll consequently tapers from approximately that shown in FIG. 8, to substantially zero at the outlet end 166.
,The scroll, which is composed of a flexible rubber-like plastic is held in place by mountings at its larger end. Formed integrally with its flange .162 (the flange that is adjacent wall 100 as shown in FIG. 8) is a pocket formation 168 (see FIGS. 8 and 16) having an outer flange 170. A sector-shaped flat metal clamping member 172 fits in the pocket, and a screw 174 (FIG. 8) extending through wall 100 threads into 172 to hold and press pocket flange against that wall. As indicated in FIGS. 7 and 17, clamping member 172 extends for some distance along the curved length of the scroll from its larger intake end; but, as shown in FIG. 8, it holds that part of the scroll only by clamping the pocket flange 170 and consequently mounts that larger end part of the inner flange 162 of the scroll, and that end of the scroll itself, more or less flexibly. Extending through about the same partial scroll length is a thin spring-metal strip 176 lying against the scroll web 160 and riveted medially at 178 to the web. This metal strip is outwardly and then reversely turned at its end at 180 around the base end of the scroll web (see FIGS. 7 and 17) to prevent dirt from catching under its leading end, and to prevent plug 188 (later described) from displacing the strip when inserted.
The opposite or outer scroll flange 164 is held against one of the edges 154 of wall formation 15-2 by a clamping plate 180 secured to the wall formation 152 by screw 182 (see FIG. 12). The clamping plate 180 extends only along the length of the wall edge designated 154a in FIG. 16 and consequently holds rigidly only the base end part of the scroll. The scroll mounting, considered as a whole, mounts and holds-only the base or intake end substantially rigidly with relation tothe wall structure 152 at the suction opening v150, mounts the inner scroll flange 162 and the web 160 somewhat flexibly,but allows full flexibility of the outer flange 164 throughout its length and full flexibility of the whole terminal end part of the scroll beyond the ends of clamping plate 172 and spring reinforcement 176. The over-all result is that, although the flexible scroll is held closely in its proper relation to turbine 76, its outer flange 164 may resiliently flex outwardly (to the left in FIG. 8) throughout its whole length; the whole length of the scroll may flex radially outwardly due to the flexibility of the mounting at the pocket flange 170 and the flexibility of reinforcement 176; the whole length of the inner flange 162 may flex laterally toward wall 100; and the terminal length of the scroll beyond 172 and 176 may freely flex radially outwardly, and its flanges laterally, with full freedom within the resilient flexibility of the scroll material. The walls of the scroll are quite thin; and, composed of a plastic such as polyethylene, the scroll is quite flexible. The result is that any object of large size, like e.g. a button, may escape from thescroll by lifting the scroll from the turbine and/or by spreading its flanges. Or, if such an object is caught in the turbine buckets, it will be thrown out centrifugally into the turbine chamber during rotation of the buckets through the approximate 180 not surrounded by the scroll.
Suction outlet 140, as shown in FIG. 7, adapted for connection to a tubular suction wand (141 in FIG. 1), connects directly to turbine chamber 72. The portion 180a of clamping plate 180 (FIGS. 7 and 8) extends across the corner of the turbine chamber to prevent accumulation of dust and other debris in that corner.
And (FIGS. 11, 12 and 17) a clean-out opening 186 is provided at the base end of the scroll under the wall formation 152, closed by a removable soft plastic plug 188 with a finger tab 189. The inner surface 190 of this plug is shaped to an easy flow contour from the lower edge of suction opening 150, flush with the body wall 521 at that point, to a point flush with the base end of scroll web 160 (see FIG. 17).
The shield unit 89, surrounding belt 86 and wheel 84, is best shown in FIGS. 3, 6 and 6a. Two flanges 891 rise from the body wall at opposite sides of runner 661 to spacedly encircle the lower half of brush core 62 at opposite sides of belt wheel 84. A shield member 892, of flexible plastic, has two side flanges 893 spacedly encircling the upper half of brush core 62 with their lower edges resting on flanges 891 as seen in FIGS. 6 and 6a. An integral wall 894 joins these flanges at their outer edges (left hand edges in FIG. 6) and the flanges 893 and wall 894 have curved upper edges 895 that engage with yielding pressure on the under face of casing cover 50. Wall 102 that separates brush chamber 56 from turbine chamber 72 (see FIG. 3) has a terminal edge at 102a that engages the vertical edge of shield flange 893 (the right hand one in FIG. 6a). The belt-passing opening 88 between belt chamber 74 and brush chamber 56 thus extends between wall edge 102a, or that shield flange 893, and the opposite shield flange 893 (the left hand one in FIG. 6a).
The brush supporting and journaling structure (identical at both ends of the brush) is shown in FIGS. 3, 4
A cap piece 200 is fitted on the end of brush core 62 and rigidly carries the central pivot pin 281 the projecting end of which is journaled in bearing block 202. The bearing block, of rectangular shape as seen in FIG. 4, rides against a flange 203 struck out from a member 204 secured by screws 285 in position against end wall 206 of the brush member. In FIG. 4 it will be noted. that member 204 is mounted through the medium of two mounting jmembers 204a of equal lengths, mutually parallel and parallel to the extent of guide flange 20 3. These mounting or supporting members join plate memher- 204 at'their upper ends only and are held by the securing screws 205 at their lower ends. Bearing block "202 has acentralv projection 207 that rides end-wise against a rib 208 raised on the inner face of end wall 206; these projections at each end of the brush and the end (left hand in FIG. 9) of pin 201 taking the end thrust and locating the brush axially. As will be seen by comparison of FIGS. 4 and 6, the guide flange 203 extends in a plane substantially normal to the plane of the axes of the brush and of drive shaft781. Thus, as the bearing block rides up and down on the guide flange, belt 86 remains at the same tension. That tension may be, and preferably is, very small, but large enough to hold block 202, against the guide flange. The guide flange has stop lugs 210 at its upper and lower ends to limit the blocks vertical movement.
Due to the orientation of guide flange 203 relative to the plane of the brush and drive shaft axes, the brush floats, under only its own weight, up and down guided by the guide flange, against which it is held lightly by the slight belt tension. The floating brush consequently bears on a rug or carpet with a fixed and limited pressure due solely to its own weight. Normally the brush, with new unworn bristles, is supported on a carpet in about the relative position shown in FIG. 7. As the bristles wear shorter, the brush. simply drops down further on its guides, still maintaining the same limited pressure. The amount of bristle wear that is thus automatically accom modated in the present design is about a quarter inch reduction in brush diameter before performance starts to diminish. Within such a limit no manual adjustment of the brush position is necessary. Even if a thin carpet is drawn up into the nozzle by the suction, the brush floats up to still maintain the same limited pressure. Ihis limitation of the constant pressure is a feature of the present invention that Prevents the driving turbine from being overloaded and stalled.
In all normal operating positions of the brush, the hearing blocks 202 ride between the limiting lugs 210. Upper lug 210 limits upward brush movement to keep the brush from rubbing on the cover. The lower lugs 210 merely prevent a worn out brush from falling so low as to allow brush pulley or the belt to rub on and wear through runner 661. If a brush is not worn out, its lowest position in operation is determined solely by contact with the rug. If not in contact with a rug or other surface, the bristles rest on the inner curved face of rear lip 68 (the one to the right in FIGS; 5 and 7).
Just inside the cap 200 and beyond the end of nozzle opening 58, there is a dust baffle, composed of a lower flange 220 (FIGS. 5 and 9) that spacedly surrounds the lower half of brush core 62, and an upper member 222 seated on flange 220 and engaging the cover 50 and the walls of the brush chamber, and spacedly surrounding the upper half of the brush core. The clearance is suflicient to allow the mentioned vertical movements of the brush; but the baffle, together with certain air flow provisions described below, effectively keeps dust and debris away from the bearing at each brush end.
At each end of the brush chamber outside the baflle, there is a small air opening 224 (FIGS. 3, 4 and 9). These openings are very small compared to the size of nozzle opening 58. Another air opening 226 (FIGS. 3 and 7) leads through the outer wall of belt chamber 74. Suction applied to suction connection lowers the pressure in turbine chamber 72 to a vacuum of say, sixteen inches of water below atmosphere. In average operation about three quarters of that vacuum is spent in driving the turbine and brush, leaving a vacuum of about four inches of water to be maintained via the scroll and opening in the brush chamber and nozzle. The actual amount of vacuum maintained in the brush chamber depends then mainly on the freedom or obstruction of nozzle opening 5-8. The total air admission. areas of openings 224 and opening 226 is greatly less than the nozzle area; as shown here, about 5 percent of the nozzle area. Although the average vacuum applied to the nozzle is reduced below that applied to the turbine chamber, subclearances, to the brush chamber.
the turbine chamber.
'7 stantially the full air stream flows through the nozzle. And it is air flow, not vacuum as such, that moves the dirt. In average operation, the air stream through the nozzle and a rug is only reduced by about twenty to twenty-five percent by the brush-drive.
The small air vents 2.24 admit small air flows into the brush bearing chambers which lie outside the dust bafiles 220, 222. Because all dirt laden air is being drawn toward the center of the brush chamber, only a moderate air velocity inwardly through the clearances 015220, .222 around the brush core, is necessary to keep dust out of the brush bearing chambers. Consequently vents 224- may be several times smaller than those clearances, which are large enough to allow the floating brush movements spoken of. Admission of air through vents 224- slightly raises the pressure in the brush chamber and'in the interconnected transmission chamber.
The whole dirt carrying air stream from the right hand part of the brush chamber (the part above belt guard 89 in FIG. 3) must be drawn over and through the belt guard to reach the outlet at 150 to the turbine chamber. The belt guard also has clearance around the brush core to allow the stated brush movements. Consequently, although the belt guard does not stop off the complete internal cross-section ofthe brush chamber (see FIG. 6), a certain part of the dust laden stream tends to pass through the guard clearances and over the belt and the brush pulley. To overcome this tendency, somewhat greater air velocity is required from the transmission chamber into the brush chamber than is required to protect the brush bearing chambers. This alone would require vent 2.26 to be larger than vents 224, but there is also a certain amount of air leakage from the transmission chamber to the turbine chamber through the small clemance around the shaft that must be made up by vent 226 and a much greater amount leaks over the top of wall 70 from the transmission chamber. For these reasons, vent .226 is considerably larger than vents 224, as it must be to be effective.
From the foregoing, it can be seen that regardless of the size of vent 226, and its efiect on brush chamber pressure, brush bearing chamber pressure will always be very slightly above that in the brush chamber. And as long as vent 226 is large enough to make up for leaks and still deliver air to the brush chamber, its pressure will also be slightly above brush chamber pressure. And,
:due to that difference in pressure between the transmission chamber and the brush chamber, the major air flow through and from the transmission chamber will be through the open communication via the open belt guard That flow has the result of keeping dirt out of the transmission chamber and oil the belt; and minimizes the amount of dirt carried by the small air leaks from the transmission chamber to Thus, by the air flows into the ends of the brush chamber and into the belt chamber, the brush bearings, the belt and belt wheels, and the turbine shaft bearings are protected against undue wear.
One other feature influences the vacuum pressure in the brush chamber. A pressure relief valve, shown in FIGS. 3, 7 and 10, comprises a valve flap 230 hung in the brush chamber would make the device diificult to 7 push. The relief valve is set to open at about seven inches of water vacuum in the brush chamber, thus limiting the vacuum in that chamber to approximately that amount. Operation of the device on most of the common types of rugs and carpets does not normally raise the vacuum 'in that chamber to=the relief :point. Relief of the vacuum as abovestated also prevents stoppage of the .air flow and stalling of the air motor, regardless of the type of surface being cleaned.
One other feature of the present improvement prevents stalling of the air motor, otherwise likely to occur. There is comparatively little air flow through the space between the wall and the adjacent end of the air motor 76 (see FIG. 8). Without some provision for removal, debris such as fibrous dirt tends to accumulate in the space and packs there until its drag slows the turbine down or stalls it. To remove that dirt and prevent its accumulation, projecting radial ribs 250 are formed on that end of the turbine, and a spiral ridge 252 projects from Wall 1% in a position closely cleared by the rotating ribs. The ribs rotate the debris into contact with the spiral ridge which then forces the debris out beyond the turbine periphery.
In brief summary; the brush pressure is fixedly limited by the fact that it floats under a fixed pressure, preferably the pressure due to its own weight; the protection :of its bearings against wear during a long life minimizes frictional loss there; the fact that the belt is under very little tension (it may be quite loose, as shown in FIG. 6) and that the tension is not varied by the floating movements of the brush, leads to very little energy loss in the belt transmission; the protection of the belt transmission, by air flow from the belt or transmission chamber'through the belt guard to the brush chamber, minimizes energy loss in that transmission through a long life; and elimination of dust, etc., from the transmission chamber by that air flow protects the air motor shaft bearing from wear. The total result is a practical brush and vacuum cleaning mechanism in which the brush is driven by the vacuum induced air stream with a comparatively small reduction in the volume of that stream; and a mechanism of long operative life.
1. In a vacuum cleaning device of the character described, the combination of a casing divided into an' elongate brush chamber with an elongate lower nozzle opening, an air motor chamber and a transmission chamber separated by a partition wall structure, the trans mission chamber having an opening to the brush chamber, an air motor in the air motor chamber, a suction outlet connected to the air motor chamber, an air flow passage leading from the brush chamber into the air motor chamber to the air motor, a journaled shaft driven by the air motor and extending through the partition wall structure into the transmission chamber, a brush in the brush chamber in proximity to the nozzle opening and rotatable on an axis substantially parallel to the plane of and longitudinally of the nozzle opening, bearing members located in the end portions of the brush chamber journalling the brush for rotation on said axis, a slightly tensioned driving belt extending fromthe air motor shaft in the transmission chamber to the brush in the brush chamber, and bearing guide structures in the end portions of the brush chamber, each said structure embodying a plate extending across the chamber end, a substantially rectilinear bearing guide member carried by the plate at that side only of the associated bearing member which faces toward the air motor shaft, said guide member extending in a guiding plane which extends toward and away from the nozzle opening and which is substantially parallel to the brush axis and substantially normal to the plane determined by the brush axis and the extent of the driving belt, the bearing memher having a substantially rectilinear face that is held against the guide member substantially solely by the slight tension of the driving belt, and two elongate supporting members for the plate each joined to the plate at one end and mounted on the casing at their other ends, said supporting members being of substantially equal lengths and with their lengths substantially parallel to each other and to the extent of the guide member, allso that the brush is free to float in directions parallel to said guiding plane under substantially only its own weight.
2. In a vacuum cleaning device of the character described, the combination of a casing divided into an elongate brush chamber with an elongate lower nozzle opening, an air motor chamber and a transmission chamber separated by a partition wall structure, the transmission chamber having an opening to the brush chamber, an air motor in the air motor chamber, a suction outlet connected to the air motor chamber, an air flow passage leading from the brush chamber into the air motor chamber to the air motor, a journaled shaft driven by the air motor and extending through the partition wall structure into the transmission chamber, a brush in the brush chamber in proximity to the nozzle opening and rotatable on an axis substantially parallel to the plane of and longitudinally of the nozzle opening, bearing members located in the end portions of the brush chamber journalling the brush for rotation on said axis, a slightly tensioned driving belt extending from the air motor shaft in the transmission chamber to the brush in the brush chamber, and bearing guiding members slidably guiding said bearing members for free movement in a guiding plane which extends toward and away from the nozzle opening and which is substantially parallel to the brush axis and substantially normal to the plane determined by the brush axis and the extent of the driving belt, all so that the brush is free to float in directions parallel to said guiding plane under substantially only its own weight; the brush chamber and its nozzle opening being elongate in the direction of the brush axis, the brush chamber having end walls and the nozzle opening having ends spaced from the end walls, said bearing members and their guiding members being located in the spaces between the end walls and the ends of the nozzle opening, and baffles extending across the brush chamber outside the ends of the nozzle opening and between that opening and the bearing members nad having clearance around the brush, and openings of limited size admitting air to the spaces between the end walls and the baflies.
3. The combination defined in claim 2, and in which said bearing guiding members comprise guide pieces extending in said guiding plane at the sides of the bearing members toward the air motor shaft, the bearing members being held against said guide pieces substantially solely by the slight tension of the driving belt.
4. In a vacuum cleaning device of the character described, the combination of a casing divided into an elongate brush chamber with an elongate lower nozzle opening, an air motor chamber and a transmission chamber separated by a partition wall structure, the transmission chamber having an opening to the brush chamber, an air motor in the air motor chamber, a suction outlet connected to the air motor chamber, an air flow passage leading from the brush chamber into the air motor chamber to the air motor, a journaled shaft driven by the air motor and extending through the partition wall structure into the transmission chamber, a brush in the brush chamber in proximity to the nozzle opening and rotatable on an axis substantially parallel to the plane of and longitudinally of the nozzle opening, bearing members located in the end portions of the brush chamber journalling the brush for rotation on said axis, a slightly tensioned driving belt extending from the air motor shaft in the transmission chamber to the brush in the brush chamber, and bearing guiding members slidably guiding said bearing members for free movement in a guiding plane which extends toward and away from the nozzle opening and which is substantially parallel to the brush axis and substantially normal to the plane determined by the brush axis and the extent of the driving belt, all so that the brush is free to float in directions parallel to said guiding plane under substantially only its own weight, the brush chamber and its nozzle opening being elongate in the direction of the brush axis, the brush chamber having end walls and the nozzle opening having ends spaced from the end walls, said bearing members and their guiding members being located in the spaces between the end walls and the ends of the nozzle opening, and openings of limited size in the end walls admitting air to the spaces between the end walls and the ends of the nozzle opening.
5. In a vacuum cleaning device, the combination of a casing forming an elongate brush chamber with an elongate lower nozzle opening, an elongate brush in the brush chamber in proximity to the nozzle opening and rotatable on an axis substantially parallel to the plane of the nozzle opening, means for rotating the brush and for applying suction to the brush chamber, the brush chamber having end walls, and the nozzle opening having ends spaced from the end walls, the brush com prising a central substantially cylindric core with the brush elements set along its length between planes spaced inwardly of the core ends, the core ends projecting into the end spaces between the nozzle ends: and the end walls, bailies extending across the brush chamber outside the ends of the nozzle opening and spacedly surrounding the projecting end portions of the brush core to partially close off said end spaces from the remaining interior of the brush chamber, circular caps of larger diameters than the core mounted on the core ends between the bailies and the end walls, pivot pins on said rotation axis carried by said caps and projecting outwardly from the core ends, bearing members journalling said pivot pins, said bearing members being located in the spaces between the core caps and the end walls, and openings of limited size admitting air through upper parts only of the end walls into said end spaces.
References Cited in the file of this patent