CA1054759A - Vacuum cleaner having liquid pick up control - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Several devices have been designed for picking up liquids or foams from surfaces. A typical device for domestic use is attached to a standard vacuum cleaner which provides the suction to draw up the liquids or foams. h problem has been to prevent liquids, and particularly foams, from entering and damaging the attached vacuum cleaner. Traps have been designed, but while these work well with liquids, no cheap, foolproof device for domestic use that will work with foam has been designed. A prob-lem is to design a relatively cheap device that will detect the level of foam inside a trap and has a sufficient safety factor for improper use or foam build-up within the trap. A detecting float is provided which links to a remote plug. As the float rises in response to liquids or foam level, the plug is moved into an opening thereby cutting off the suction to the trap. A
baffle is situated within the trap and positioned to control foam build-up. The float, baffle and suction tubes are so arranged that liquid or foam is unlikely to impinge on or build up on the float to impair its sensitivity. To prevent overload on the vacuum cleaner, a flap is moved automatically to open a relief path of air to the vacuum cleaner. The links between the float and the plug are connected to the float so that the mech-anical advantage easily overcomes frictional and gravitational forces.

Description

~0~4759 This invention relates to vacuum cleaning systems and more particularly to systems for picking up liquid or foam or both from a floor or similar substantially horizontal surface.
Previous systems have been designed, those of particular interest being disclosed in the following United States-patents:
1 69C ~726 Nov. 1928 Breton 3 267 51123 hug. 1966 Meyerhoefer 3 331 G9Cl& Jul. 1967 Reiber et al 3 332 lCl25 Jul. 1967 Leinfelt et al 3 562 ~4616 Feb. 1971 Creamer et al Of lesser interest are the systems described in thefollowing United States patents:

2 6G7 06719 ~ug. 1952 Minerley 2 607 G6819 Aug. 1952 Minerley 2 617 13&11 Nov. 1952 Brown~et al 2 693 GCG2 Nov. 1954 Minerley 2 &22 0614 Feb. 1958 Pettit et al It has been found necessary to manufacture machines capable of sucking up liquids that have been placed or spilled on floors. Machines designed for industrial or commercial use, such as use in factories or shops, are most suitably of the type shown by Reiber where the electric motor is integral with the fluid receptacle. Others, designed for use in the home~
are ty~lcally attached to available domestic vacuum cleaners which provlde the necessary suction to lift fluids from surfaces. The instant invention is of this latter type.
The domestic attachment is essentially a trap for liquids and ls placed between the suction head of the attachment and the vacuum cleaner. A major concern has been that liquids are apt to be extracted from the trap and delivered to the vacuum cleaner itself, causing at best, a nuisance, and at worst, structural damage to the vacuum cleaner motor.

The problem becomes compounded when the attachment is used to raise liquids from surfaces that have been cleaned wlth detergent or other foaming cleansers. The liquid, if it is not already in the form of foam, tends to foam in the trap. The foam f~lls the trap at a rate that is much higher than simple liquid would~ and, unless prevented from enterlng the vacuum cleaner by, for example, switching off the motor, would cause the nuisance or damage referred to above.
Breton, for example, solved the problem of simple liquids entering the vacuum cleaner. His float, shown best in Fig. 4 in the patent, is ineffective when foam is drawn in.
Meyerhoefer's machine suffers from the same limitations in that foam entering from above the float is likely to be drawn dlrectly into the vacuum cleaner. In Creamer and Reiber, for example, fluid enters the trap below the float. In both instances, however, the float that is raised by the fluid acts as a cut-off and it has been found that, in a great many instances, foam can bypass the float and thus get sucked into the vacuum chamber. Further, when the design by Creamer or Meyerhoefer are used in conjunction with an external vacuum source, the sharp blocking of the trap outlet creates an unusual load on the machine's motor, with possible known consequences.
The problem becomes to design an attachment for a domestic vacuum cleaner that will allow liquids or foams or both to be sucked up from a floor or carpet. A sufficient -safety factor must be introduced to prevent the suctlon of foam into the vacuum cleaner which must also be protected from overload. It being recognized that some cleaners are 3C more able to withstand overloads than others, it is preferred that the amount of ovorload be reduced to a minimum. The attachment should be light, small and easy to use, robust, cheap to manufacture as well as having functional reliability.

The problem has been overcome by providing a fluid trap with a float made of very light material and cor~ected by a linkage system to a valve in the trap outlet leadirlg to the vacuum source. Closure of the valve cuts off the vacuum souree from the trap and opens a relief valve. The relief valve permits air from the exterior to be drawn into the vacuum source, normally a domestic vacuum eleaner~ thereby avoiding an overload on the eleetric motor. The whole operates automatically and with a positive feed-back action. Preferably, the linkage is attached to the float in such a manner that considerable mechanical advantage is aehieved, minimizlng the weight and frictional load imposed by the linkage and valve hardware.
The whole is also designed in a manner that permits easier automatic shut-off of the muchine when it is in the rest position on the floor than when it is in a normal operating position. A baffle is also provided which controls the build-up of foam within the trap ln a manner that further prevents the foam belng doposited over the float and thereby bypassing the control to exit the trap and into the vacuum source.
In the drawings, which illustrate the preferred embod-iment of t~e inventlon:
Flgure 1 ls a perspective view of the floor-cleaning apparatus ln a normal operating position, with cleaning head and connected to a domestic vacuum cleaner;
Figure 2 is a vertical sectional view of the apparatus;
Figure 3 is a perspective view of the apparatus with one side wall removed.
The apparatus 1 has an inlet tube 2 and an outlet tube 3 connected respectively to 8 surface-cleaning head ~ and, via a 3G hose 5, to a standard domestic vacuum cleaner 6. The head ~
may be of any suitable type and may be connected by any standard means, such as by bayonet connection. The tube 3 may be con-nected to hose 5 by a similar standard means, or by the taper shown by Creamer. The apparatus is made of two sections, a ~ 054759 box-like rectangular lower section 7 and a taperlng, upwardly-angled upper section 8 giving an overall elongated shape.
The inlet tube 2 extends at a downwardly-projecting angle as shown and continues backwards and upwards, tube 12. A
length of tube 25 fits snugly over the upper end of tube 12 and curves in approximately a semi-circle, terminating on the lower surface 28 of section &. The tube 25 may be attached to tube 12 by friction-fit or an adhesive, or tubes 12 and 25 may be fashioned from a single piece of stock. A baffle 15 is placed within section 79 having an open space 16 between itself and the upper surface 14 of section 7. h relatively larger space exists below the baffle 15. The baffle 15 e~-tends across the section 7 and is joined to the two vertical sides of section 7, thereby providing a support for tube 12 which passes through the baffle 15. Baffle 15 ls substan-tially perpendicular to the upper surface 14 and to the sides of 7 to which it is attached~ and tube 12 passeq through ths b~ffle 15 at an angle as shown.
Tube 3 passes through the end plate 43 of section 8 and also through interior plate 42 which, with plate ~3, supports and maintains rigid the outlet tu~e 3.
Float 19 is preferably made of a light, cellular, imp-ervious material such as styrofoam. It is made from a block of the materisl and, in the preferred embodiment, has a subs-tantially seml-circular notch 18 to permit the float to rise past the position of tu~e 12 when the flost 19 is caused to swivel up to position 19a about pivot pins 24. Naturally, to prevent wear on the float 19, a sleevc ~ay be inserted into the float 19 to accomodate the pins 24. Pins 24 are located in the lower surface 2& of section 8 and support float 19 in such a manner that it projects lnto section 7, but does not interfere with baffle 15.
_~_ ~OS4759 Placed around the float 19 are two metal bands 20 -of ~lvan-i4~d or stainless steel. Located on cach band 2C~, on the upper surface of float 19 and a relatively short distance from the edge belou which plns 24 pivotably support float 19, is a loop 21. A rod 23, made preferablyi ~f stainless steel, pro-~ects upwards ~nd backwards in section 8 from each loop 21.
Each rod 23 has a lower end 22 turned outwards and substantially horizontally to link each loop 21. The upper end of each rod 23 is pivotably attached to a hollow rubber ball 32. The ends attached to the ball 32 may~ for exsmple, be turned horizon-tally inwards and lnserted in sleeves on opposlte sides of the ball 32.
Ball 32 is mounted on a metal rod 31 which is supported so that the rod 31 substantially bisects the angle made by surfaces 26 and 28 and also the angle made by the two sides of section~8. Preferably, rod 31 is approximately in the centre of the cross-sectlon of section 8. Rod 31 is slidably supp-orted by sleeves 30 and 36 inserted in supports 29 and 35 respectively. Supports 29 and 35 are mounted on the surface 28 and are arranged to be substsntially perpendicular to rod 31. Sleeves 30 and 36 may`be~of low-frictlon plastic.
Between ball 32 and support 35 is a bulkhead 33 ha~ing an opening 3~. Around the inner circum¢erence of opening 34, a gasket may be placed to form an airtight seal with ball 32 when the lstter is pressed into the opening 34 as a plug.
Perpendicular to the rod 31 and separated from the upper end by a space 41 is an armature 38, pivotably supported from the surface 26. On the lower end of 38 is a weight 39.
Armature 38 is so designed that as it swings about its pivot away from the opening bulkhead 33 into position 38a and weight 39 into position 39a, a flap 4C, rigidly attached to armature 38 and normally co~ering opening 37 in surface 26~ is pivoted away from surface 26~ thereby uncovering opening 37. In the preferred embodiment, opening 37 is offset from the centre-line of surface 26.
A support 27, shown as a triangular fin attached to and projecting perpendicularly downwards from surface 2~, is arranged so that~ when placed in a rest position~ the apparatus rests with line 10 being substantially the floor level. In a working position the apparatus is typically in a position that has line 9 parallel with the floor.
~hè operation of the apparatus will now be described.
When the apparatus is in the rest position on the floor and without liquld inside~ ball 32 and float 19 will be in their lower-most positions~ limited either by float 19 resting on the bottom of section 7, or by ball 32 cGming to rest aguinst support 29. Due to weight 39, flap 40 remains cover-ing opening 37.
When the apparatus is raised to the operating position~
line 9 becomes substantially horizontal and the force exerted by weight 39 is increased and serves to close opening 37 more ~irmly. When suction is applied to outlet 3, air is drawn in through inlet 2~ along tubes 12 and 25, through opening 3 and out through outlet tube 3.
As liquid or liquid and air is suckcd up tube 2, the liquid is driven round the curve of tube 25 and introduced at a very small angle to surface 28. Since no abrupt changes of direction take place, the liquid is unlikely to be atomized or to foam. As the level of liquid rises, the surface being approximately in parallel with line 9, and comes into contact with float 19, float 19 starts to float upwards about its pivot 24 unti~ it approaches position 19a. At the same time ball 32 is moved up towards opening 34. The movement ic transmitted from the float 19 via linking rods 23 to ball 32, causlng rod 31 to slide in its sleeves 30 and 36 and to approach arma-ture 3&.
As position 19a is approached by float 19, ball 32 ~ (~54759 approaches position 32a and opening 34 becomes restricted and the pressure above bulkhead 33 tends to fall signif~cantly ~elow the pressure in section ô below bulkhead 33. The pressure has a posltlve feedback effect to draw ball 32 into opening 34, thereby cutting off suc~ion in sections 7 and ~ below bulkhead 33. Simultaneously, rod 31 moves up with ball 32 to displace armature 38 into posltion 38a, uncovering opening 37, thereby relieving the vacuum created in the zone above bulkhead 33 snd remOving the posslbility of overload on the vacuum cleaner 10 motOr.
When foam, or a foaming liquid, is drawn into the appar-atus~ it is ejected from tube 25 along the surface 28 and under the float 19. Any build-up of foam takes place under the float and on the side o~ the baffle 15 farther from the float 19 and only a small amount of foam accumulates on the upper surface of float 19. The float 19, being made of very light material, is lifted as foam accumulates and shuts off t~e source Or suction by blocklng opening 34 and uncovering opening 37 as described sbovo. Because of the very light material of ~loat 19 and because of the considerable mechanical advantage des-igned into the system, it has been found that this arrangement is an~efficient solution to the problem described above.
Although the apparatus has been designed to operate in the position descri~ed and will not function if, for example placed on its side, the light material of float 19 and the mechanical advantage allow 9 sufficient safety margin for the apparatus to function when partly tipped over, with support 27 at, say, 45 to thc vertical plane. It is also obvious that operation at such an angle reduces the effect of ~eight 39, permitting the opening 37 to be more easily opened.
Also~ if the angle of the apparatus is changed so that it is operated at a low angle, i.e. in a position close to the rest position~ the liquid level tends to rise along surface 28, increasing the danger o~ ~7qu~ or foam boing sucked up into outlet 3. ~owever, at such a low angle, thc weight of the hardware 23,31, and 32 is applied at a lower angle~ thereby off-erlng less resistance to its operation. Weight 39, too, is suspended from a more nearly vertical position, making the moving of weight 39 to position 39a and thc uncovering of open-ing 37 easier. All of this reduces the danger of a malfunction of the apparatus when used in other than the preferred position.
In surface 14, a removable plug 17 blocks a hole placed near the intersection of surfaces 14 and 26. h similar plug 11, blocks a hole near the lower edge of front 13 in section 7.
When the apparatus is not in use, plug 11 may be removed to drain liquid in the apparatus, and plug 17 may be removed to introduce water or other suitable liquid to flush out the interior.
It ls observed that while the apparatus described is th~
preferred embodiment, simple changes may be maae to improve appearance or to take advantage Or different manuracturing methods. For example, ~hile sections 7 and 8 are shown as being rectangular in cross-section, some other flat-bottomed cross-section, such as a trapezium or arch, may advantageously be used. Similarly the manner of slidably mounting ball 32 may vary and the ball itself may find some other conventional shape for blocking entrance 34. Weight 39 may be made adjustable to accomodate cleaners having different powers, or if a less efficient system is acceptable, weight 39 may be replaced by some other stored-energy device such as a spring.
The rods 23 may find some other way of being attached to the float 19 and to the ball 32 and may, by simple desigh changes, be reduced in number to one.

1~547S9 DET~ILS OF PREFERRED EMkODIMENT

The following dimensions have been successfully used in prototype models:
The width at the widest part of the device, i.e. width of surface 14 is approximately 6"; the height at the same location, i.e. the height of the side surfaces is approximstely 5~l Gap 16 above the baffle ls ~", while the gap below is 1~"~
giving a baffle of about 3" in height. The length Or surfaces 26 and 28 are 12~" and 15" respectively. When at its rest lC position, surface 14 (which is about ~" long) subtends an o o angle of some 10 to 15 to the floor. In the operating pos-itlon, its angle is downwards at roughly 50 . The ball-like plug 32 is 2~" diameter ~nd blocks an opening of 1~" diameter.
Space 41 is small~ and ~' has been used. A typic~l g~p between the float ~nd surface 28 is ~". The float itself is made of 1"
thick material and has dimensions of ~pproximately 4" by 5".
Inlet and outlet tubes are 1~" diameter.
The distance from the pivot point on the float ~ point of connection Or rods 23 is relatively small, giving a considerab~
2C mechanical advantage, having an effective length of less than 1".
Effective lengths of less than about ~" allow only liDited travel o~ the plug.
Opening 37 is shown as round~ a ~" diameter hole having been found suitable. A cruciform opening has also been used to be covered by flap or plug ~0.
The following materials are preferred:
The two lower surfaces and the remaining shell itself may be made from galvanized steel or polycarbonate. The same material may be used for the b~ffle, internal supports and the armature and weight. B~nds 20 may be made of stainless or galvsnized steel and have longitudinal strips cut from the width and bent over to accommodat~ in an obvious manner~ the stainless steel rods 23. Tubes 12~ 25 and 3 may be made of chromed or stainless steel or polycarbonate. Various sleeves used may be of chromed steel or nylon.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

(1) A vacuum cleaning device comprising a substantially elongated reservoir having an upper cavity and a lower cavity;
first fluid valve means connecting said cavities;
fluid inlet means in said lower cavity;
air outlet means in said upper cavity;
said inlet means being attached to a cleaning head arranged to pick up fluid from a surface when said outlet means is connected to a vacuum source and said first valve means is in a normal open position;
means located within said first cavity for detecting the level of liquid or foam or both within said first cavity;
means responsive to said means for detecting for control-ling said first valve means and for controlling a second valve means;
said second valve means being in a normally closed position and connecting said upper cavity to the atmosphere;
whereby when said liquid or foam or both in said first cavity reaches a predetermined level, said means for detecting causes said responsive means to move said first valve means to a closed position, thereby shutting off all fluid flow from said inlet means to said vacuum source, and to move said second valve means to an open position, thereby opening a relief path from the vacuum source to the atmosphere via said upper cavity.

(2) A device as claimed in claim 1 wherein said means for det-ecting is a float of lightweight, closed-cell, impervious mater-ial and has a first end and a second end remote from said first end;
said float being pivoted at a point near said first end.

(3) A device as claimed in claim 2 wherein said inlet means is a tube projecting upwardly within said lower cavity and curving to terminate at a downwardly-projecting angle, substantially tangentially to surface within said lower cavity, said tube terminating in an outlet above said float but displaced therefrom so that effluence from said tube does not directly impinge on said float.

(4) A device as claimed in claim 3 including baffle means substantially across the width of said lower cavity, such that said float interposes said outlet and said baffle means, and having an open space between an upper edge of said baffle means, and the surface of said lower cavity and a further open space between a lower edge of said baffle means and an opposite surface of said cavity, whereby effluence from said tube is ejected into said lower cavity, bypassing said float, and flows between the lower edge of said baffle means and said opposite surface and whereby any build-up of foam tends to occur on the side of the said baffle means that is further from said float and said outlet.

(5) A device as claimed in claims 2, 3, or 4 wherein said means responsive to said float is a rigid, linking rod connecting said first valve, said rod being connected to said float between the point of pivot and the centre of mass of said float, whereby as said float pivotably floats upwards as a result Or rising liquid or foam or both within said first cavity, said first valve means is controlled with a mechanical advantage greater than unity;
a further rigid, linking rod connecting said first valve means to said second valve means, whereby motion of said first valve means imparts motion to said second valve means.

(6) A vacuum cleaning device comprising a first substantially flat surface and a second substantially flat surface, said first and said second surfaces being joined at an obtuse angle about a first straight edge in said first surface and a second straight edge in said second surface;
a shell attached to said first and second surfaces about the remaining edges of said first and second surfaces to form a substantially enclosed elongated receptical or reservoir;
a bulkhead joined to said second surface and to said shell whereby said enclosed receptical is separated into a first cavity defined by said first and second surfaces. said bulkhead and said shell and a second cavity defined by said bulkhead said second surface and said shell;
an inlet tube extending through said shell and into said first cavity, said tube extending within said first cavity at an acute angle to said first surface and substantially perpend-icular to said first and second straight edges;
a curved section of tube within said first cavity extend-ing from the end of said inlet tube within said first cavity and curving along a path substantially describing a section of the circumference of a circle and terminating in an open end adjacent, and at a low angle, to said second surface;
a float supported on a pivot near the termination of said curved section of tube and arranged so that the axis of said pivot is substantially parallel to said first and second straight edges and substantially perpendicular to said inlet tube and curved section of tube, said float being supported by said pivot so that a space exists between said float and said second surface, said float being arranged so that most of the mass of said float extends from said pivot and away from said open end;
an opening in said bulkhead whereby there may be fluid flow between said first and second cavities;
a plug situated in said first cavity between said float and said opening and adapted to move into a closing position to prevent fluid flow between said cavities;
a linking mechanism connecting said float and said plug whereby as said float is caused to pivot so that its mass moves away from said first and second surfaces, said plug moves to-wards, and finally into said closing position;
a first opening in that portion of said shell defining a boundary of said second cavity whereby fluid flow may take place between said second cavity and the exterior; a flap normally covering said first opening;
a linking rod connected to said plug and extending through said opening in said bulkhead and terminating adjacent an arm-ature, said armature being rigidly connected to said flap, stored -energy means connected to said armature for maintaining said flap in its normally-covering position whereby movement of said plug towards said closing position, causes movement of said linking rod and said armature and thereby causes said flap to uncover said first opening;
an outlet tube extending through said shell from said second cavity;

a cleaning head attached to said inlet tube;
a vacuum source attached to said outlet tube;
whereby fluid consisting of liquid or air or foam or any combination thereof may be drawn into said first cavity via said gleaning head, said inlet tube and said curved section of tube and air only may be drawn via said opening in said bulkhead into said second cavity and therefrom to said vacuum source via said outlet tube;
and whereby the accumulation of liquid or foam or both within said first cavity causes said float to pivot upwards, causing said plug to be moved into a closing position by said linking mechanism and said flap to be moved from its normally -covering position, thereby shutting off said vacuum source from said inlet tube, and opening a relief path from said vacuum source to the exterior via said opening in said shell.