US2171248A - Vacuum cleaning apparatus - Google Patents

Description

1 Aug. 29, 1939. 'w. A. VAN BERKEL VACUUM CLEANING APPARATUS Filed Jan. 20, 1956 2 Sheets-Sheet 1 fill I Ill/1114! WW Mme A TTOR/YEY.

Aug.'29, 1939. w. A. VAN BERKEL 2,171,243

VACUUM CLEANING APPARATUS Filed Jan. 20, 1936 2 Sheets-Shed 2 mva/rrm WW 1 P M Patented Aug. 29, 1 939 UNITED STATES PATENT OFFICE VACUUM CLEANING APPARATUS Application January 20, 1936, Serial No. 59,931 In Great Britain February 21, 1935 4 Claims. (Cl. 18383) This invention relates to vacuum cleaningapparatus having provision for separating dust from the air drawn through the apparatus. 7

One object of the invention is to provide in a vacuum cleaning-apparatus a dust-separator consisting of a housing entered by a suctionconduit and adapted to have a cyclone produced within it at a zone between the ends of said conduit by the suction draught, the walls of said housing being spaced from said conduit to provide for the passage of separated dust from said zone to a dust-collector.

Another object is to prevent as far as practicable the passage of dust into the suction end, or mouth of the suction conduit by surrounding the mouth by a hollow member having provision for passage of the air drawn through the apparatus, the arrangement being such that most of the dust entrained by the air in the cyclone m'is forced towards the wall of the housing, so that only a smallproportion of such dust can be drawn into said hollow member. Such a hollow member maybe a rotary or a stationary body; or, as an alternative to a hollow member, W a stationary masking member such as a plate may be provided closely in front of the conduit mouth.

Another object is to improve the cycloneseparation effect by providing around the sucw tion-conduit a turbine to be acted upon tangentially by the stream of dust-fouled air drawn tangentially into the dust-separator housing.

Another object is to make provision for secondary cyclone-separation, the second cyclone likewise being produced by the suction draught. Another object is to provide the apparatus with a dust-separator housing which is formed with a wall that converges in thedirection from the cyclone-separation zone towards the sucm tion-condult mouth, beyond which the housing has a dust-collectorwhich may be detachably connected to it. In apparatus having provision for secondary cyclone-separation, an inner casing may be similarly formed and may likelb wise have its own dust-collector. V

Another object is to improve the dust-collection effect by providing the walls of the housing internally with dust-trapping ribs' orflanges extending transversely of the cyclone stream. 50 The construction of the air-discharging suction-generator employed would be determined according to the magnitude of suction required. For example, where a.poweriul suction action is requiredapparatus according to the invention 55 may have a suction-generator comprising a cyl inder-and-piston pump unit operated by an electricmotor. Where a less powerful suction eifect is required, an electric-motor-driven fan may be employed.

.The electric motor may have a resilient mounting consisting of rubber blocks or the like shaped -to receive the motor ends.

The suction-conduit extending into the dustseparator housing communicates with the suctiongenerator, and communication preferably takes place through one or more than one removable filter, made for example of cloth or metal gauze and preferably of such a nature that, where there are more than one filter, successive filters are of progressively lower airpassing capacity e. g. of finermesh).

Where a hollow member is provided to enclose the mouth of the suction conduit, said member may be a rotary filter drum composed mainly of perforated or open-mesh gauze material, preferably lined externally with filtering material. The action of such a rotary drum is to increase the cyclone effect and also to throw off any of the heavier particles which may contact with it. Such a drum may be motor-driven through the intermediary of a detachable slip and/or universal coupling, and a brush may be provided in the interior of the housing to sweep from the drum particles (and these would be mainly lighter particles) accumulating on its exterior. The arrangement may be such that the brush automatically adjusts itself under control of the cyclone action to sweep the drum only when the rotational speed thereof is below a predetermined limit; that is, during starting and stopping.

Difierent constructional embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

Fig. 1 is a sectional elevation of a large-capacity vacuum cleaning-apparatus.

Fig. 2 is a fragmentary sectional plan of a portion of a pump unit constituting the suctiongenerator of said apparatus.

Fig. 3 is a section on the line III-IIIv of Fig. 1.

Fig. 4 is a sectional elevation of a lower-capacity apparatus.

Fig. 5 is a sectional elevation of a modification of. the apparatus according to Fig. 4', the modification involving provision for secondary cyclone-separation.

' Fig. 6 is a section on the line VI-VI of Fig. 5.

Fig. 7 is a sectional elevation of another construction of vacuum cleaning-apparatus.

Fig. 9 is a fragmentary sectional elevationv drawn to a larger scale, ofparts already included in Fig. 7.

Referring firstly to Figs. 1 to 3, the. apparatus therein shown has a suction-generator which is structurally separate from the dust-separator, being connected thereto by flexible tubing ID.

The suction-generator comprises a two-pistonpump unit, including opposed cylinders II in which worktwo pistons l2 which are spaced.

apart and rigidly interconnected in tandem by a rod l3. One of the pistons is coupled by a connecting rod l4 to an. electric-motor-driven crank-disc I5 which is housed in the space bounded by a casing l6 interconnecting the two cylinders, this space being permanently open to atmosphere through an opening IT. The electric motor 18 is secured to the interior of the casing i6 and drives the disc l5 through the intermediary of a pulley-drive I9 and a bevelled pinion 20 meshing with teeth on the disc. The pistons have air-inlet passages 2|, with nonreturn flap-valves 22; and suction-conduits 23 connecting the cylinder ends toa connection with the aforesaid flexible piping H) are likewise provided with non-return valves 24.

The dust-separator comprises mainly a housing 25, which is provided with an air-inlet 26 opening tangentially into the top of the housing; a

suction-conduit 21 extending axially into the interior of the housing 25; a top-casing 28, to which the piping i0 is attached; and a dustcollector 29, which is formed as a wheeled structure. The necessary cyclone effect is produced around the suction conduit and at the level of the air inlet, but said effect continues with progressively diminishing force below said level and towards that of the mouth of the suction conduit. The housing 25 is constituted by a wall which converges in the direction from the cycloneseparation zone towards the dust-collector 29, said wall being provided internally with dusttrapping ribs 30 which extend-transversely of the cyclone stream. These ribs deepen as they approach the dust-collector29 so that they exercise little or no obstruction to air and dust swirling in the cyclone separation zone but exercise maximum dust-trapping action below said zone. The dust-collector 29 is attached by catches 3| to a flange formed at the bottom of the housing 25. The suction-conduit 21 is provided on top with and opens into a circular casing consisting of a wall 32 over which thecaslng 28 fits and a bottom plate 32 which is located in place between the housing 25 and the casing 28. The parts 26, 32 and 32 constitute a filter-compartment, and these parts are de'tachably connected to the housing 25 by means of catches 33.

' With the object'of improving the cyclone-separation effect, a turbine 34 is provided in the zone of separation. The turbine consists of blades mounted on a plate which has a ballbearing or other anti-friction mounting on the suction-conduit 21, the blades being arranged in the path of air tangentially drawn into the interior of the housing, through the inlet 26 (see Fig. 3). The turbine is rotated by the air, and its blades serve to assist separation of dust by striking incoming particles and projecting them tangentially outwards.

To prevent as far as practicable the passage of dust into the mouth oi the suction-conduit .removed once the casing 28 is detached. As conventionally indicated, the further the filter material is from the suction conduit 21, the finer is its mesh; 1. e. the lower is its air-passing capacity.

The arrangement is such that in normal use of the apparatus, a stream of dust-fouled air is drawn in through the usual nozzle and pipe (not shown) attached to 'the inlet 26, acts upon the turbine and becomes whirled in a cyclone or vortex within the-housing 25. Hence, the dust is forced centrifugally towards the housing wall and strikes against the ribs 38, so that thedust falls downwards into the dust-collector 29, there being ample space for passage of the falling dust between said wall and the member 36. Air near the axis of the cyclone and therefore substantially. freed from dust enters the hollow member 36 through the opening 38 and passes down to the mouth of the suction-conduit 21. The air is drawn up through this conduit and also through the filters 39 whence it passes by way of the tubing II! to the pump-unit, which discharges the air in comparatively dust-free condition through the opening l1.

Whenever desired, the catches 3| can be disengaged and the housing 25 straightway removed from the dust-collector 29. Likewise, the catches 33 can be disengaged and the casing 28 removed, together with the filter-holding casing 32 32. and its suction-tube 21.

The apparatus described with reference to Figs. 1 to 3 is of large capacity, being suitable for, say, hotels, restaurants, hospitals, theatres, etc. The apparatus illustrated in Fig. 4 is of smaller capacity, being suitable for ordinary domestic uses. In this apparatus, the suction generator and the dust-separator are embodied in one structure.

Referring to Fig. 4, the dust-separator housing 25 is again surmounted by a compartment containing filter frames 39 and filtering materials 39 to 39 but in this construction the casing 28 is surmounted by an additional casing 40 containing an electric motor 4|, which has a resilient mounting consisting of annular rubber blocks 42 fitted within the casing 40 and shaped to receive the motor ends. The suction-generator consists of a fan mounted abovethe filters and within the casing 28, the fan consisting of a plate 43 secured to the motor-shaft, a plurality of small blades 44 secured to said plate, and another plate 45 secured to the blades and provided with an open centre through which air can pass between the plates 43, 45 and be discharged by the blades 44 through a tangentially arranged.

outlet 46 on the wall of the casing 28. The cyclone is obtained simply by arranging the air inlet 26'tangentially at the top of the housing' 25. The suction-conduit 21 extends from its flanged plate 32 immediately below the lowermost filter 39 to the vicinity of amasking plate 41, which as shown is fixed to the housing 25.

The arrangement is such that dust-fouled air drawn into the apparatus by way of the inlet 26 whirls in a cyclone so that, as in the previous construction, the dust is forced centrifugally drawn into the mouth of the suction-conduit 21, andthe masking member 41 acts to prevent dust from being entrained with the air. Such .dust as may be entrained by the air passing up the conduit 21 is filtered out by the series of filters 39 to 39 so that the air finally discharged through the outlet 46 by the fan is in a comparatively dust-free. condition.

Fig. 5 shows a modification of the apparatus illustrated in Fig. 4, the modification consisting in the provision of means whereby secondary cyclone-separation is obtained. As shown, thesuction-conduit 21 has secured to it a casing 50 (surrounding the mouth of the conduit) and adapted, like the outer housing 25, to have a cyclone produced within it. For this purpose, the inner casing 50 is provided with an air inlet 5| which is tangentially arranged near the top of the casing 50 at a level just below the primary cyclone separation zone within the outer housing 25. ,The inlets 26 and ill are arranged distinctly out of alignment with one another so that air entering by the inlet 26 cannot pass direct/t the air inlet but must first of all take part in the primary cyclone. The inner casing 50 has a neat sliding connection with an auxiliary dustcollector i2 The bottom of the suction-conduit 21 is masked by a plate 41 which, as shown, forms part of the conduit itself. 1

The arrangement is such that air still fouled with dust is drawn from the primary cyclone through the tangential inlet 5|, so that a second cyclone is setup within the inner casing 50. Accordingly, further cyclonic separation takes place and the separated dust falls into the auxiliary collector 52.

With reference now to the apparatus illus' trated in Figs. 7 to 9, in this construction the dust-separator housing is of cylindrical form, the housing being provided with a tangentially arranged inlet Bi near its top and with vertical dusttrapping ribs 62. The suction-conduit 63 consists of a wide tube depending from a supporting plate 64. The housing 60 is surmounted by a casing 65 which houses a filter and a suction-generating fan. In the construction shown, there is only one sheet of filtering material 86, but if desired provision could be made for additional filters, and the filtering material is readily removable, like the material 39 39 39 according to Figs. 1 and 4. The fan consists of a pair of plates 61, 69 with a plurality of small blades 88 mounted between them, the lower plate 69 having an open centre. The casing 65 within which the fan works is provided with a tangentially arranged air outlet 10. The driving motor H is supported by annular rubber blocks 12 within a casing 13 which surmounts the compartment 85. Catches l4 serve to attach the interconnected casings 65 and 13, and also the suction-conduit-supportingplate 64 to the housing I, the arrangement being such that withdrawal of the catches permits immediate separation of the parts mentioned from one another.

There is no separate dust-collector, the dust collecting in the bottom of the housing 60, the dimensions of which are such that anannular passage for falling dust is provided from the cyclone-separator zone at or near the top of the provided in the main dust-collector housing to the dust-collection zone at the bottom thereof. l

The mouth of the suction-conduit s3 is enclosed in a hollow member, but in this construction the hollow member consists of a rotary drum 15 composed'mainly of perforated or open-mesh gauze material, a bag 18 of filtering fabric being drawn over the drum. The drum is supported by spiders 11 which secure it'to the lower portion of a .shaft 18, this shaft being rotatably mounted in spider-supported bearings 19 in the interior of the suction-conduit 63. The top of the drum 16 consists of an annular closure plate 80 neatly surrounding the suction-conduit 63. The shaft '18 constitutes an extension of the motor-shaft 8|, the two shafts being coupled together by a detachable universal slip coupling,

consisting of the following parts: a flange 82 secured to the motorshaft; a facing of rubber or the like on'a plate 84; one or more torsionand-compression springs 85 securing the plate 84 to a flange 86 at the top of the extension shaft 18. The arrangementis such that, when the detachable parts of the apparatus occupy their operative relationship, the facing 83 is pressed into frictional engagement with the flange 82 and accordingly driving power is transmitted from the shaft 8| to the drum 15. The upper bearing 79 would preferably be provided with a thrust-bearing 19 to take the weight of the drum and withstand the pressure of the springs 85.

The aforesaid filtering material 66 is supported by aperforated reinforcement plate 81 which also supports a sealing ring 88 serving to close the space between the filtering material and the flange 82. Accordingly, air drawn up the conduit 63 can only pass to the fan through ,the filtering material 66.

In the operation of the apparatus, the cyclone is set up, as in the previous constructions, mainly at or near the top of the dust-separator housing. Air is drawn through the perforated wall of the rotary drum I5, and most of the dust remaining after cyclone-separation is filtered out by the material T6. The air drawn up the suctionconduit 63 is again filtered by the material 66 before being discharged by the fan through the outlet 10, so that the discharged air is practically dust-free.

The apparatus includes a brush 89 forsweeping from the filtering fabric 16 any particles which accumulate thereon. The brush is supported by a member 90 which is journalled at its ends in'bearings 9| fixed to the housing 60. A torsion spring 92 lightly urges the merger -90 to rotate and carry the brush 89 against the drum filter I6. During operation of the apparaing, a multi-blade dust deflector so mounted that it rotates in a plane with said inlet conduit and around said outlet conduit, the deflector throwing the heavier and lagging dust partigles tothe outer portion of the'housing, a conical wall contially parallel to said conical wall to form therewith an annular separation zone of approximately constant radial width, said masking element/being arranged to masksaid outlet conduit, and said conical wall and masking element limiting the separation zone beneath the deflector, vanes spaced around the inner periphery pf the conical dust can slide down the gradually increasing channels formed by the vanes.

2. In a vacuum-cleaning-apparatus' of the type which is portable and adapted for domestic purposes, a dust separator comprising a housing, an

inlet conduit tangentially arranged in said housing, an outlet conduit arranged inside said housing, a conical wall constituting a lower part of said housing, an inner masking element arranged to mask said outlet conduit, and said conical wall and masking element limiting the lower portion of the separation zone, vanes spaced around the inner periphery of the conical wall, the radial dimensions of said vanes increasing with the depth so that the cyclone separation action started in the upper portion of the housing by the tangential inlet conduit is, as it continues into the lower separation zone, gradually diminished by the increasing depth of the vanes and decrease in the space wherein the air is free to rotate, and a removable collector into which the dust can slide down the gradually increasing channels formed by' the vanes.

3. In a vacuum-cleaning-apparatus of the type which is portable and adapted for domestic purposes, a dust separator comprising a housing, an

periphery of the conical wall, the radial dimen-' sions of said vanes increasing with the depth so that the cyclone separation action started in the upper portion of the housing by the tangential inlet conduit is, as it continues into the lower separation zone, gradually diminished by the increasing depth of the vanes and corresponding decrease in the space wherein the air is free to rotate, and a removable collector into which the dust canslide down the gradually increasing channels formed by the vanes.

4. In a vacuum-cleaning-apparatus of the type which is portable and adapted for domestic p111 poses, a dust separator comprising a housing constituted by a wall, an inlet conduit tangentially arranged in said housing, an outlet conduit anranged inside said'housing, an inner masking element the side of which is substantially parallel to said wall to form therewith an annular separa- 1 tion zone of approximately constant radial width, said maskingelement being arranged to mask said outlet conduit, and said wall and masking element limiting the lower portion of the separation zone, and varies spaced around the inner periphery of the wall, the radial dimensions of said vanes increasing with the depth so that the cyclone separation action started in the upper portion of the housing by the tangential inlet conduit is, as it continues into the lower separation zone, gradually diminished by the increasing depth of the vanes and corresponding decrease in the space wherein the air is free to rotate.

WILHELMUS ADRIANUS VAN BERKEL-

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