US3768114A

US3768114A - Combination rug and floor vacuum cleaner nozzle

Info

Publication number: US3768114A
Application number: US00177665A
Authority: US
Inventors: O Schwartz
Original assignee: Electrolux AB
Current assignee: Electrolux AB
Priority date: 1970-09-09
Filing date: 1971-09-03
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30
Also published as: SE345591B; CA939460A; DK137430C; DE2142882A1; GB1337819A; DE2142882C3; SU402178A3; CH538852A; ZA715621B; DK137430B; AU3303971A; FR2106388A1; JPS5131457B1; BR7105548D0; DE2142882B2; FR2106388B1; NL7111695A

Abstract

A combination rug and floor vacuum cleaner nozzle has a suction inlet which serves as one cleaning tool and is movable over a porous object like a rug to remove dirt therefrom. A brush serving as another cleaning tool is mounted on the nozzle at the vicinity of the suction inlet for movement between upper and lower positions respectively above and below the suction inlet. The suction inlet functions to remove dirt from a rug when the brush is in its upper position and the brush functions to remove dirt from a smooth object like a floor when it is in its lower position. Pneumatic mechanism operable responsive solely to operating conditions prevailing when the nozzle is moved either over a smooth object or a porous object becomes effective to automatically shift the brush above or below the suction inlet, respectively, to position the proper cleaning tool in contact with the object to be cleaned even when the vacuum producing ability of the vacuum cleaner connected to the nozzle varies within wide limits.

Description

United States Patent Schwartz Oct. 30, 1973 COMBINATION RUG AND FLOOR VACUUM CLEANER NOZZLE [75] Inventor: Osten Schwartz, Varmdo; Sweden [73] Assignee: Aktiebolaget Electrolux, Stockholm,

Sweden [22] Filed: Sept. 3, 1971 [21] Appl. No.: 177,665

[ 1 Foreign Application Priority Data Sept. 9, 1970 I Sweden ..l2260/70 15/373 [51] Int. Cl A47] 9/06 [58] Field of Search 15/319, 365, 368, 15/371, 373, 419

[56] References Cited UNITED STATES PATENTS 2,638,763 9/l954 Pfaffle et al. l5/37l 3,497,903 3/1970 Jonsson l5/3l9 3,599,271 8/1971 Ljung et al 15 319 3,659,3l2 5/1972 Mattsson...... l5/3l9 3,660,864 5/l972 Schwartz 15/319 Primary Examiner-John Petrakes Assistant ExaminerC. K. Moore Attorney-Edmund A. Fernander [57] ABSTRACT A combination rug and floor vacuum cleaner nozzle has a suction inlet which serves as one cleaning tool and is movable over a porous object like a rug to remove dirt therefrom. A brush serving as another cleaning tool is mounted on the nozzle at the vicinity of the suction inlet for movement between upper and lower positions respectively above and below the suction inlet. The suction inlet functions to remove dirt from a rug when the brush is in its upper position and the brush functions to remove dirt from a smooth ob ject like a floor when it is in its lower position. Pneumatic mechanism operable responsive solely to operating conditions prevailing when the nozzle is moved either over a smooth object or a porous object becomes effective to automatically shift the brush above or below the suction inlet, respectively, to position the proper cleaning tool in contact with the object to be cleaned even when the vacuum producing ability of the vacuum cleaner connected to the nozzle varies within wide limits.

26 Claims, 13 Drawing Figures COMBINATION RUG AND FLOOR VACUUM CLEANER NOZZLE BACKGROUND OF THE INVENTION 1. Field of the Invention One factor which influences dust absorption is the speed of the air flow through the nozzle for bodily moving and transporting dust and dirt particles from the ob ject to be cleaned to the dust bag in the suction cleaner. In a moving air stream, movement is imparted to a particle of dust or dirt by a force which is dependent upon positive atmospheric pressure at one side of the particle and a pressure at the opposite side thereof which is below atmospheric pressure. Hence, movement is imparted pneumatically to dust and dirt particles by a force which is dependent upon the difference between atmospheric pressure and the vacuum developed by the cleaner. The speed of the air flow increases with increase in the volume of air moved per unit interval of time. The capacity of brushes and nozzles working on objects is a primary and basic consideration which determines the ability of a suction cleaner to absorb dust and dirt.

When brushes are employed to suck and draw dust particles from essentially smooth objects like floors, for example, the penumatic force just referred to is not as great as it is when a porous object is being cleaned. In cleaning porous objects like carpets, for example, a brush generally is not employed and instead a nozzle is employed having an operating surface which is at the immediate vicinity of the suction inlet opening and disposed about the latter. With a nozzle of this type, dust and dirt must be sucked or drawn from the pores of an object and a higher vacuum is developed in the nozzle passageway so that movement will be imparted pneumatically to dust and dirt particles by the pneumatic force referred to above which is dependent upon the difference between atmospheric pressure and the partial vacuum developed in the nozzle passageway which, under these conditions, is higher than the partial vacuum developed when a brush is employed to clean objects which are essentially smooth and less porous.

A combination rug and floor vacuum cleaner nozzle has an opening defining a suction inlet and a brush mounted for movement on the nozzle between upper and lower positions, the brush in its upper position being above the suction inlet and in its lower position below the suction inlet. When the brush is in its upper position the suction inlet is rendered operable to remove dust and dirt from porous objectslike carpets and rugs. When the brush is in its lower position the brush is rendered operable to remove dust and dirt from smooth objects like floors.

2. Description of the Prior Art In known multi-purpose nozzles of the kind heretofore provided the brush is moved pneumatically between its upper and lower positions by mechanism which includes a rubber diaphragm to which the brush is connected, such diaphragm forming a wall of a space in communication with the path of air flow of the nozzle which is at a partial vacuum. Due to the subatmospheric pressure in the nozzle, which varies in accordance with the physical characteristics of the object over which the nozzle is moved, the diaphragm will flex to its upper or lower position and move the brush to its upper or lower position on the nozzle.

In such known multi-purpose nozzles the diaphragm is biased to its lower position by a spring which is so adjusted that shifting of the brush on the nozzle is promoted due to changes in the physical characteristics of the object over which the nozzle is moved. With a nozzle of this type, the vacuum producing ability of the vacuum cleaner connected to the nozzle should not vary within too wide limits. If the suction ability of the vacuum cleaner should decrease to an abnormally high extent, as when the dust bag of th vacuum cleaner becomes clogged with dust and dirt, the partial vacuum or suction pressure produced in the air flow path of the nozzle can become too small to effect movement of the brush between its upper and lower positions in the nozzle. Under these conditions the brush may not be moved from its lower to its upper position and will remain in an operative position when a porous object like a carpet, for example, is being vacuumed, which is objectionable. if the vacuum producing ability of the vacuum cleaner should become excessive, the partial vacuum produced in the air flow path of the nozzle can become too great and may effect movement of the brush from its lower to its upper position when a smooth object like a floor, for example, is being vacuumed, which also is objectionable.

SUMMARY OF THE INVENTION My invention relates to a combination rug and floor vacuum cleaner nozzle of the kind referred to above in which a brush is mounted on the nozzle at the vicinity of the suction inlet for movement between upper and lower positions, the brush in its lower position being below the suction inlet and operable to remove dirt from a smooth object like a floor. The suction inlet becomes operable to remove dirt from a porous object when the brush is in its upper position above the suction inlet.

The brush is moved between its upper and lower positions by pneumatic mechanism having a control space connected by a passageway to a region of the nozzle which normally is at a partial vacuum, such region being in the path of flow of air from the suction inlet to the air outlet of the nozzle. A control valve is provided in the last-mentioned passageway.

When the valve is open and air in the control space is at a first pressure which is a partial vacuum, the pneumatic mechanism functions to move the brush to its upper position against the biasing action of resilient means. When the valve is closed and the air in the control space is at a second pressure, which is ambient air at atmospheric pressure, the mechanism functions to move the brush to its lower position with the biasing action of the resilient means.

It is an object of my invention to provide an improvement in a combination vacuum cleaner nozzle of this kind for controlling the valve. I accomplish this by providing control means operable to control the valve responsive solely to the pressure differential of air in first and second regions in its path of flow, such pressure differential varying with the physical characteristics of the surface being cleaned by the nozzle. With this construction, the pneumatic mechanism functions correctly to move the brush to its upper and lower positions with respect to the suction nozzle even when the vacuum producing ability of the vacuum cleaner connected to the nozzle varies within wide limits and when the vacuum producing ability of the vacuum cleaner should become excessive.

BRIEF DESCRIPTION OF THE DRAWING In the drawing,

FIG. 1 is a vertical sectional view of one half of a combination rug and floor vacuum cleaner nozzle embodying my invention with the brush illustrated in its lower position and operative to perform cleaning;

FIG. 2 is a sectional view taken at line 2-2 of FIG.

FIG. 3 is an enlarged fragmentary sectional view of parts shown in FIG. 2;

FIG. 4 is a view similar to FIG. 3 illustrating a modification of the invention;

FIG. 5 is a fragmentary sectional view taken at line 5-5 of FIG. 1;

FIG. 6 is a fragmentary top perspective view of interior parts of the nozzle shown in FIGS. 1 and 2;

FIG. 7 is a sectional view, taken at lines 7-7 of FIGS. 1 and 6, with the brush in its lower position and operative to perform cleaning;

FIG. 8 is a sectional view similar to FIG. 2 with the brush in its upper position and inoperative to perform cleaning;

FIG. 9 is a view similar to FIG. 3 illustrating another modification of the invention;

FIGS. 10 and 11 are fragmentary views schematically illustrating the closed and open positions of the valve shown in FIGS. 2 and 8;

FIG. 12 illustrates curves showing the difference in sub-atmospheric pressure at different regions of the nozzle passageway; and

FIG. 13 illustrates a curve showing the ratio of the sub-atmospheric pressures at different regions of the nozzle passageway as a function of the quantity of air moved through the passageway when the nozzle is being employed to clean a carpet and a smooth floor.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, the combination rug and floor vacuum cleaner nozzle 40 embodying my invention comprises an elongated hollow body 41 including top and

bottom parts

10 and 11, respectively, having a flexible diaphragm 18 therebetween to provide top and

bottom spaces

35 and 42, respectively. The top and

bottom parts

10 and 11 are detachably connected together in any suitable manner (not shown).

The peripheral edge portion of the diaphragm 18 is clamped between the abutting outer edges of the

body parts

10 and 11 and formed with an enlarged head 32 which serves as a bumper to protect objects against which the nozzle 40 may strike when being moved back and forth over an object or surface being cleaned. The diaphragm 18 desirably is formed of a suitable elastomeric material like rubber, for example.

The hollow body 41 is provided with an upwardly inclined tubular member 12. The tubular member 12 serves as an air outlet socket adapted to be connected to a source of supply of air at a partial vacuum, such as a vacuum cleaner, for example. The outlet socket 12 forms part of a passageway 16 which extends downwardly midway between the ends of the nozzle body 41 and terminates in an air inlet opening or suction inlet defined by spaced apart walls 13 which extend lengthwise of the body 41. It will now be understood that the suction inlet 15 has two branches at the bottom of the nozzle 40 which extend outwardly from a central part of the body 41, the ceilings 13a of the branches sloping downward with the higher inner ends thereof in communication with the lower end of the passageway An apertured bottom plate 14 overlies the bottom part 11 at the lower ends of the walls 13 to provide a smooth gliding surface when a porous object like a carpet or rug is being cleaned. Air sucked into the suction inlet 15 throughout its length moves toward the center part of the nozzle 40 and then flows upwardly through the passageway 16 toward the air outlet socket 12.

A four-sided brush 20 of annular form is disposed at the vicinity of the suction inlet 15. The brush 20, which comprises parallel sides 20a and connecting ends 20b, includes bristles 20c fixed to a brush back 20d of annular form. The sides 20a of brush 20 are held at 190 at the underside of a brush holder 19.

The diaphragm 18 is formed with a cup-shaped portion which receives an open cup-shaped member 22. The member 22, which snugly rests in the cup-shaped portion of the diaphragm 18, is provided with a flange or rim 22a at its open end. The cup-shaped portion of the diaphragm 18 is clamped at 43 between the rim 22a of the member 22 and the brush holder 19.

It will now be understood that the brush holder 19, cup-shaped portion of the diaphragm 18 and cupshaped member 22 form a unitary component of the nozzle and are vertically movable as a unit when movement is imparted to the diaphragm 18. The diaphragm 18 is provided with a corrugated section 18a of annular form which is closely adjacent to the flange 22a to promote flexing movement of the diaphragm. Further, it will be understood that the structure just described and illustrated in FIG. 6, which is embodied in the side of the nozzle 40 shown in FIG. 1, is duplicated for the side of the nozzle at the other side of the outlet socket 12.

The bottom body part 11 is apertured at to receive the brush bristles 20c which move between upper and lower positions with respect to the suction inlet 15. When the brush 20 is in its upper position shown in FIG. 8 the apertured plate 14 fixed to the bottom body part 11 functions to effect cleaning of porous objects like a rug or carpet, as explained above. When the brush 20 is in its lower position below the suction inlet 15, the brush is adapted to effect cleaning of smooth objects like a floor 43, as shown in FIG. 2. A coil spring 23 is provided in the top space 35 with its upper end bearing against the top part 10 of the nozzle body 41 and its lower end bearing against the bottom of the cupshaped member 22. Hence, the spring 23 functions to urge the brush 20 to its lower position shown in FIG. 7.

When the nozzle 40 is being moved over a smooth surface like the floor 43, for example, the air in space 35 above the diaphragm 18 will be at atmospheric pressure, as will be explained presently, and the spring 23 at each side of the outlet socket 12 is rendered operable to move the diaphragm 18 and brush 20 downward, as shown in FIGS. 2 and 7. When the nozzle 40 is being moved over a porous surface 44 like a rug, for example, the air in the space 35 will be at sub-atmospheric pressure or a partial vacuum, as will be explained presently, whereby the diaphragm 18 will flex upwardly against the biasing action of each of the springs 23 to raise the brush 20 to its upper position shown in FIG. 8.

The space 35 is connected to a first region 16a in the passageway 16, in which air at a partial vacuum is flowing from the suction inlet to the air outlet 12, by structure defining a passageway 45 having first and second portions 45a and 45b, respectively. The first portion 450 includes an elongated opening or passage 46 in the wall of the top nozzle part 10 which extends from the region 16a of the passageway 16 to a chamber 47 having a larger cross-sectional area than the passage 46. The first portion 45a terminates in an opening of the chamber 47 which has a sharp edge 48, as shown in FIGS. 2 and 3.

Th passageway 45 has a break at the open end of the chamber 47, the second portion 45b thereof at such break including a chamber 49 of annular form which is disposed about the chamber 47, as seen in FIGS. 2 and 3. Referring now to FIGS. 1 and 5, it will be seen that the chamber 47 is elongated and is disposed at the center of the nozzle 41. The chamber 49, which is disposed about the chamber 47, also is of elongated form and provided with end openings 50.

As will be explained presently, a valve 51 is provided at the break in the passageway 45 which functions to close and open the break between the two portions 45a and 45b thereof. Assuming that the valve 51 is in its open position during operation of the nozzle, as shown in FIG. 8, air can flow toward the region 16a of the passageway 16 in a path of flow which includes passage 46, chamber 47, chamber 49 and end openings 50 therein to the spaces 35 in each arm of the nozzle body 41, one of which is illustrated in FIG. 1. When this operating condition prevails the diaphragm 18 will flex upward against the biasing action of the spring 23 to raise the brush to its upper position in the manner explained above and shown in FIG. 8.

If we now assume that the valve 51 is closed during operation of the nozzle, as shown in FIG. 2, air at a partial vacuum cannot flow toward the region 16a of the passageway 16 from the space 35. Under this operating condition the air in the space will be at atmospheric pressure, and the spring 20 is rendered operable to move the diaphragm 18 and brush downward, as shown in FIG. 2. Ambient air at atmospheric pressure can flow into the space 35 through an opening 52 in the nozzle body 41. The opening 52 may be referred to as a leakage opening for ambient air to flow into the space 35. Ambient air also can flow into the space 35 through cracks in the joints between the nozzle parts which may avoid the need to provide the opening 52.

As shown in FIGS. 2 and 3, the valve 51 comprises a relatively thin diaphragm having its peripheral edge portion clamped between wall structure defining the chamber 49 above the diaphragm and a chamber 53 below the diaphragm. The neutral or non-stressedposition of the diaphragm 51 is shown in FIGS. 2, 3 and 4. During operation of the nozzle the diaphragm 51 in its closed position, due to its flexibility, will assume a position more like that schematically shown in FIG. 10.

In accordance with my invention I provide control means responsive solely to the pressure differential of air in first and second regions in the path of air flow 16, such pressure differential varying with the physical characteristics of the surface being cleaned'by the nozzle and over which the nozzle body is moved. I accomplish this by making use of the portion 454 of the passageway to connect the chamber 47 above and at one side of the diaphragm valve 51 to the region 16a of the passageway 16; and by connecting the chamber 53 below and at the opposite side of the diaphragm valve 51 through an opening 54 in the nozzle wall structure to a region 16b of the passageway 16 which is removed lengthwise of the passageway from the region 16a.

During operation of the nozzle the partial vacuum at the region 1612 will be different from that at the region 16a due to the pressure drop of air flowing lengthwise of the passageway 16 between these regions. By providing a construction 55 in the passageway 16 between the

regions

16a and 16b, the pressure differential between these regions can be increased. The chamber 47 will acquire the partial vacuum or negative pressure prevailing in the passageway 16 at the region 16a which is at the right of the constriction 55. The chamber 53 will acquire the partial vacuum or negative pressure prevailing in the passageway 16 at the region 16b which is at the left of the constriction 55, the negative pressure at the region 16b having a lower absolute value than the negative pressure at the region 16a.

As shown in FIGS. 2 and 3, the sharp edge 48 at the open end of the chamber 47 defines a seat for the diaphragm 51 when the latter is in its closed position. The ratio between the cross-sectional area defined by the sharp edge or seat 48 and the total area of the diaphragm valve 51 is such that the conditions of movement of the diaphragm valve at both sides of the edge of the seat 48 will be the same. In other words, the zones of the diaphragm valve 51 at both sides of the edge of the seat 48 and immediately adjacent thereto will flex and move in substantially the same manner as schematically illustrated in FIG. 10. This means that the diaphragm valve 51, which is very resilient, can bulge to the same extent and degree at both sides of the edge of the seat 48.

In the nozzle shown in FIGS. 1 to 3 and 5 to 8 and described above, the operating features inherent in its operation can be expressed as follows:

I. The force for operating the shifting diaphragm 18 of nozzle 40 having the valve 51 is greater than in nozzles which do not have such a valve.

2. Shifting of the working member, that is, the brush 20 occurs only when the throttling resistance between the nozzle 40 and the surface to be cleaned changes and independently of changes in the suction ability of the vacuum cleaner. The suction ability of the vacuum cleaner can vary with clogging of a dust bag and variations in voltage of the electrical supply to the vacuum cleaner motor, for example.

Referring to FIGS. 10 and 11, which schematically illustrate the closed and open positions of the diaphragm valve 51 in FIGS. 2 and 8, respectively, the pressure designations refer to the sub-atmospheric or negative pressures and are represented as forces of tension. With this definition the pressure of ambient air outside the nozzle is represented by the equation 17 5 In FIGS. 10 and 11 g and q designate the relative permeability in the openings with the areas a, and a With local throttling zones:

so that q, +q =1.

When the diaphragm valve 51 is open and space 35 is connected to the ambient and, via the valve, exposed to the pressure p the resulting pressure will be:

In the following:

F the sealing force in the valve F the force acting on the diaphragm when the valve is open a and b are dimensions of diaphragm 53 as shown in FIG. 10.

The equations of equilibrium will be:

on a floor on a carpet be within the respective range of work. The conditions therefor are a/(a b) lp max. and

qz lam/p2".

Conditions of stability When F equals zero when passing over from floor to carpet and hence:

a/(a b) p /p o,

1",, has to assume a positive value Should F,, become negative, the diaphragm will return to sealing position and will then open again, this action of the diaphragm being repeated. The diaphragm will thus oscillate.

Accordingly, the condition of stability will be a/(a b) q The same condition is applicable when changing over from carpet to floor.

Shifting of the brush is independent of the suction ability of the vacuum cleaner The pressure fall through the nozzle to the two openings of

channels

54 and 46 can be expressed as a quadratic function of the quantity of air (Q m /min.):

PI I'Q Pz 2'Q wherein K and K are coefficients only depending on the flow conditions into the nozzle to the positions where p, and p, are to be determined. With the nozzle in unchanged position on the same working surface K and K will be constant and will also be constant, independent of Q. Shifting as set for a certain value of p lp p /p between the limit values (p /p max. and (p /p min. by appropriate dimensioning of a/(a b) and q will then always occur in the same point relative to the limit values mentioned.

The force operating the brush shifting mechanism Sub-atmospheric or negative pressure (1 p; acting on the shifting diaphragm 18 is used for shifting of the brush 20. From FIG. 13 it appears that at an appropriately set shifting point q (approximately equals) 0.6 and p 440 mm wc (water column) giving a q p 240 mm we. The shifting point will be situated so that a good margin to the limit values for floor and carpet, respectively, is obtained. Moreover, a/(a b) q which will give stability in the shifting operation. Should only the difference in p between floor and carpet be used for shifting at the same vacuum curve (shown in FIG. 12) the sub-atmospheric or negative pressure acting on the brush shifting diaphragm 18 should only be mm wc even if shifting occurred at the limit values.

The function of the diaphragm valve 51 is determined by the negative pressures prevailing on opposite sides of the diaphragm at the zone closest to the edge of the seat defined by the sharp edge 48. The ratio of the area defined by the seat 48 to the total area of the diaphragm is of secondary importance. As pointed out above, the only requirement that must be satisfied is that the distance between the edge of the seat 48 and the region of the diaphragm 51 at its peripheral edge portion, at which it is fixed, is sufficient to enable the resilient diaphragm to move to the same extent and degree at the zone at both sides and close to the edge of the seat 48 as schematically illustrated in FIG. 10.

When the nozzle 40 is employed to clean a smooth surface like the floor 43 as shown in FIGS. 2 and 7, the absolute value of the negative pressure in the passageway 16, and also in the chamber 53, will be comparatively low while the quantity of air being moved through the passageway will be relatively high. By providing the constriction 55 the absolute value of the negative pressure at the open end of the passage 46 adjacent to region 16a of the passageway 16, which is to the right of the constriction 55, and also the absolute value of the negative pressure in the chamber 47, will be considerably higher than the absolute value of the negative pressure in the passageway 16 to the left of the constriction 55 due to the relatively high pressure drop across the latter. Since air can leak through the opening 52 into the space 35 and also into the space 49 through its end openings 50, the chamber 49 will approximately be at atmospheric pressure. The passageway 16 at the constriction 55 is so dimensioned that, under the operating conditions that have been assumed, the diaphragm valve 51 will be in its closed position against the seat 48. Consequently, the diaphragm 18 will be biased downward by the spring 23 and move the brush 20 to its lower position below the suction inlet 15, as shown in FIGS. 2 and 7.

When the nozzle 40 is employed to clean a porous object like a rug, the absolute value of the negative pressure in the passageway 16 will be comparatively high while the quantity of air being moved through the passageway will be small. The difference between the negative pressures on opposite sides of the constriction 55 will be small due to the relatively low pressure drop across the latter and hence the negative pressures prevailing in the

chambers

47 and 53 will be approximately equal. Under these operating conditions the diaphragm valve 51 will move to its open position.

Under these last-mentioned operating conditions the space 35, and also the chamber 49, will assume a negative pressure which will be sufficient to overcome the downward biasing action of the spring 23. When this occurs the brush 20 will be retracted into the space 42 above the apertured plate 14.

It will now be understood that the valve 51 is movable between open and closed positions and in a second passageway 45 intermediate the ends thereof and acted upon by the pressure differential of air at a partial vacuum in a first region 16a of a first passageway 16 and of air at a partial vacuum in a second region 16b of the first passageway 16. The valve 51 moves to its closed position, as seen in FIGS. 2, 3 and 10, when the pressure differential is above a definite value and the rate at which air flows through the first passageway 16 is in a first range. This is the condition that prevails when cleaning the floor 43, as shown in FIG. 2. The valve 51 moves to its open position, as seen in FIGS. 8 and 11, when the pressure differential is below the definite value and the rate at which air flows through the first passageway 16 is in a second lower range. This is the condition that prevails when cleaning the rug 44, as shown in FIG. 8. Further, the movable mounting means for the brush 20, which includes the diaphragm 18 and can be referred to as the second operating surface, is rendered operable to move the brush 20 to its upper position when the valve 51 is in its open position.

More particularly, the spring means 23 acts on the diaphragm to move the second operating surface or brush 20 in a first direction to its lower position, the nozzle body 41 having a space 35 defined by wall means formed by the top body part and the diaphragm 18. The section 45b of the second passageway 45, which is connected to the mounting means or diaphragm 18 in the manner explained above, is in communication with the space 35, as shown in FIGS. 1, 2 and 5.

The mounting means for diaphragm 18 is acted upon by air at a partial vacuum when the valve 51 moves to its open position and the second passageway 45 is open. Such air at a partial vacuum and in the space 35 is operable to overcome the spring means 23 and move the second operating surface or brush 20 in a second opposite direction to its upper position. As explained above, the wall means formed by the top body part 10 and, with the diaphragm l8, defining the space 35, has an opening 52, as seen in FIG. 1, for ambient air at atmospheric pressure to flow into the space 35.

The nozzle 40 is supported by rollers or wheels 56 which function to hold the nozzle at one level with respect to a smooth surface in the manner shown in FIG. 2. The rollers 56 are of such thickness that they will sink into a carpet or rug and maintain the apertured plate 14 at the suction inlet in operative position to perform cleaning, as shown in FIG. 8.

In FIG. 4 I have shown a modification in which an additional throttling zone 57 is introduced between the passage 46 and the chamber 47, whereby the negative pressure in the chamber 49 will attain an optimal value. However, throttling in the passage 46 must not be excessive because, in such case, the nozzle 40 will be slow-acting and there will be risk, when the nozzle is moved from a floor to a carpet, for example, that the brush will not immediately leave its working position. Since air continuously leaks into the space 35 and the chamber 49 through the aperture 52, the diaphragm valve 51 will open at regular intervals and move to its closed position when the nozzle 40 is employed on a porous object like a carpet. However, by suitably dimensioning the spring 23 and the throttling means disposed on one hand in the passage 46 and on the other hand at the aperture 52, the negative pressure in the chamber 49 will not fall to such an extent when the diaphragm valve 51 is closed that the diaphragm 118 will be acted upon in a downward direction before the diaphragm valve 51 opens again. Therefore, the brush 20 will be retracted continuously in the nozzle body 41 during vacuum cleaning of a carpet or rug.

FIG. 9 illustrates another modification in which a piston-like part 58 is connected to the diaphragm valve 511 in such manner that the piston-like part moves rectilinearly to and from the seat 48. In FIG. 9 the elongated passage 46 in the wall of the top nozzle part extends downward to a chamber 47 having a larger cross-sectional area than the passage 46. Further, the chamber 53 in the first-described embodiment of FIGS. 2 and 3 is eliminated in the modification of FIG. 9 in which the diaphragm valve 51' defines a wall part of the nozzle passageway 16 at the region 16b thereof.

When the valve 51' in FIG. 9 is open an operating condition is established which is similar to that illustrated in FIG. 8 for the first described embodiment. In such case air at a partial vacuum can flow from the region 16a of the passageway 16 through passage 46 and chamber 47 directly into the spaces 35 in each arm of the nozzle body, one of which is shown in FIG. 9 with its leakage opening 52' which corresponds to the leakage opening 52 seen in FIG. I.

In the modification of FIG. 9 the ratio between the area defined by the seat 48 and the total diaphragm area is of great importance while the negative pressure at zones closely adjacent to the edge of the seat 48' is not important. Then the cross-sectional area of the portion of the diaphragm valve 51' facing the region 1612 of the nozzle passageway should be approximately twice the cross-sectional area defined by the seat 48'.

I claim:

l. A vacuum cleaner nozzle which includes a. first and second operating surfaces for performing different types of cleaning,

b. said nozzle comprising a body including means defining a first passageway having a suction inlet at the vicinity of said operating surfaces and an outlet adapted to be connected to a source of supply of air at a partial vacuum, said first passageway providing a path of flow for air between the inlet and outlet,

c. means for mounting said second operating surface on said body for movement between upper and lower positions with respect to said first operating surface, said first operating surface functioning to clean an object with which it is in contact when said second operating surface is in its upper position and said second operating surface functioning to clean an object with which it is in contact when it is in its lower position,

(I. means providing a second passageway having one end thereof in communication with a first region of said first passageway and the opposite end thereof in communication with said movable mounting means,

e. a valve which is movable between open and closed positions and in said second passageway intermediate the ends thereof and acted upon by the pressure differential of air at a partial vacuum in said first region of said first passageway and of air at a partial vacuum in a second region of said first passageway,

f. said valve moving to its closed position when said pressure differential is above a definite value and the rate at which air flows through said first passageway is in a first range and moving to its open position when saidvpressure differential is below the definite value and the rate at which air flows through said first passageway is in a second lower range, and

. said movable mounting means being rendered operable to move said second operating surface to its upper position when said valve is in its open position.

2. A vacuum cleaner nozzle as set forth in claim 1 in which said second region in said first passageway is removed lengthwise therein from said first region, and means between said first and second regions for throttling air flowing in said first passageway between said regions.

3. A vacuum cleaner nozzle as set forth in claim 2 in which said second passageway has a break at which the adjacent ends of two sections thereof terminate, one of said sections in communication with said first region of said first passageway terminating in an opening at said break which defines a seat against which one face of said valve is adapted to move in sealing relation therewith, a first segment of said one face of said valve moving against said seat defining a first part of the area of said valve, and the other of said sections of said second passageway in communication with said movable mounting means also terminating at an opening at said break, a second segment of said one face of said valve co-acting with the last-mentioned opening of the other of aid sections defining a second remaining part of said valve area, and the opposite face of said valve being in communication with said second region of said first passageway.

4. A vacuum cleaner nozzle as set forth in claim 3 in which said valve comprises a flexible diaphragm, and means for securing the peripheral edge portion of said diaphragm in said body adjacent to said break in said second passageway, the ratio of the area of the first part of said diaphragm to the entire cross-sectional area thereof being such that flexing of said first and second segments of said diaphragm at opposing sides of said seat in substantially the same manner is promoted when said diaphragm moves to its closed position.

5. A vacuum cleaner nozzle as set forth in claim 3 in which said valve comprises a resilient diaphragm, means for securing the peripheral edge portion of said diaphragm in said body adjacent to said break in said second passageway, said seat being defined by a sharp edge formed at said break by the opening in said first section of said second passageway, and said diaphragm having a larger cross-sectional area than the crosssectional area of said seat with the radial distance of said diaphragm from said seat to the peripheral edge portion thereof being such that zones of said diaphragm at both sides of the edge of said seat and immediately adjacent thereto flex and move in substantially the same manner.

6. A vacuum cleaner nozzle as set forth in claim 1 in which said means for movably mounting said second operating surface on said body comprises a diaphragm, spring means acting on said diaphragm for moving said second operating surface in a first direction to its lower position, and said movable mounting means being acted upon by air at a partial vacuum when said valve moves to its open position and said second passageway is open, such air at a partial vacuum being operable to overcome said spring means and mov said second operating surface in a second opposite direction to its upper position.

7. A vacuum cleaner nozzle as set forth in claim 3 in which said first section of said second passageway includes two portions, a first portion of which is nearer to said first region of said first passageway and a second portion of which is nearer to said valve and has the opening defining said seat, and the cross-sectional area of said second portion at said seat being greater than the cross-sectional area of said first portion.

8. A vacuum cleaner nozzle as set forth in claim 7 in which the junction between the first and second portions has a restriction which throttles air flowing therethrough when said valve is in its open position.

9. A vacuum cleaner nozzle as set forth in claim 3 in which said means for movably mounting said second operating surface on said body comprises a diaphragm, spring means acting on said diaphragm for moving said second operating surface in a first direction to its lower position, said body having a space defined by wall means and said diaphragm, the other of said sections of said second passageway in communication with said mounting means being connected to said space, said mounting means being acted upon by air at a partial vacuum when said valve moves to its open position and said second passageway is open, such air at a partial vacuum and in said space being operable to overcome said spring means and more said second operating surface in a second opposite direction to its upper position, and said wall means defining said space having an opening for ambient air at atmospheric pressure to flow into said space.

10. A vacuum cleaner nozzle which includes a. first and second operating surfaces for performing different types of cleaning,

. means for mounting said second operating surface on said body for movement between upper and lower positions with respect to said first operating surface, (1 said first operating surface being operable to clean a soft porous surface with which it is in contact when said second operating surface is in its upper position and (2) said second operating surface being operable to clean a smooth surface with which it is in contact when it is in its lower position,

. structure defining a space,

. said mounting means being operable (l) to move said second operating surface relative to said first operating surface from its lower position to its upper position responsive to air in said space at a first pressure which is at a partial vacuum and operable (2) to move said second operating surface relative to said first operating surface to its lower position responsive to air in said space at a second higher pressure,

f. means providing a second passageway for air between said first passageway and said space,

g. valve means in said second passageway which is movable between closed and open positions,

h. means operable to control said valve means responsivc solely to the pressure differential of air in first and second regions in said first passageway which varies with the physical characteristics of the surface being cleaned by the nozzle and over which said body is moved, said valve means moving to its closed position when said pressure differential is above a definite value and the rate at which air flows through said first passageway is relatively high and in a first range and moving to its open position when said pressure differential is below the definite value and the rate at which air flows through said first passageway is relatively low and in a second lower range, andi. said structure defining said space being so constructed and formed that, during normal operation of said nozzle when said outlet is connected to a source of supply of air at a partial vacuum, the air in said space will be at the first pressure when said valve means is open and at the second higher pressure when said valve means is closed.

11. A vacuum cleaner nozzleas set forth in claim in which said means for mounting said second operating surface on said body for movement between its upper and lower positions comprises a flexible diaphragm.

12. A vacuum cleaner nozzle as set forth in claim 11 i in which said structure defining said space includes said flexible diaphragm.

113.A vacuum cleaner nozzle as set forth in claim 12 which includes resilient means biasing said flexible diaphragm to render the latter operable to move said second operating surface in one direction to its lower position when said valve means is closed and the air in said space is at the second higher pressure, the air in said space at the first pressure, which is at a partial vacuum when said valve means is open, overcoming the biasing action of said flexible diaphragm means by said resilient means to move said second operating surface in the opposite direction to its upper position.

14. A vacuum cleaner nozzle as set forth in claim 10 in which said structure defining said space is so constructed and formed that, during normal operation of said nozzle when said outlet is connected to a source of supply of air at a partial vacuum, ambient air can flow into said space and the air therein will be at the second higher pressure which is at or approaches atmospheric pressure when said valve means is closed and at the first pressure which is at a partial vacuum when said valve means is open.

15. A vacuum cleaner nozzle as set forth in claim 14 in which said structure defining said space includes a wall member having an opening for ambient air to flow into said space.

16. A vacuum cleaner nozzle which includes a. first and second operating surfaces for performing different types of cleaning,

. means for mounting said second operating surface on said body for movement between upper and lower positions with respect to said first operating surface, (I said first operating surface being operable to clean a soft porous surface with which it is in contact when said second operating surface is in its upper position and (2) said second operating surface being operable to clean a smooth surface with which it is in contact when it is in its lower position,

d. structure defining a space,

e. said mounting means being operable (l) to move said second operating surface relative to said first operating surface from its lower position to its upper position responsive to air in said space at a first pressure which is at a partial vacuum and operable (2) to move said second operating surface relative to said first operating surface to its lower position responsive to air in said space at a second higher pressure,

f. means providing a second passageway for air between a first region in said first passageway and said space,

h. means providing a third passageway for air which extends from a second region in said first passageway to said valve means, said third passageway being out of communication with said second passageway,

i. said valve means and second and third passageways being so constructed and arranged that said valve means moves to its closed position when the pressure differential of air in said first and second regions of said first passageway is above a definite value and the rate at which air flows through said first passageway is in a first range and moves to its open position when the pressure differential of air in said first and second regions of said first passageway is below the definite value and the rate at which air flows through said first passageway is in a second lower range, and

j. said structure defining said space being so constructed and formed that, during normal operation of said nozzle when said outlet is connected to a source of supply air at a partial vacuum, the air in said space will be at the first pressure when said valve means is open and at the second higher pressure when said valve means is closed.

17. A vacuum cleaner nozzle as set forth in claim 16 in which said first and second regions in said first passageway are spaced apart lengthwise thereof.

18. A vacuum cleaner nozzle as set forth in claim 17 in which said means defining said first passageway is of reduced crosssectional area at a zone between said first and second regions.

19. A vacuum cleaner nozzle as set forth in claim 16 in which said valve means comprises a diaphragm, said third passageway being out of communication with said second passageway by said diaphragm.

20. A vacuum cleaner nozzle as set forth in claim 19 in which said third passageway extending from said second region in said first passageway terminates at said diaphragm.

21. A vacuum cleaner nozzle as set forth in claim 20 in which said second passageway includes first and second sections, said first section at one end being in communication which said first region in said first passageway and at the other end terminating at an opening defining a seat against which said diaphragm bears when said valve means is closed, said second section at one end being in communication with said space and at the other end terminating at an opening of annular form which is adjacent to said diaphragm and disposed about said seat.

22. A vacuum cleaner nozzle as set forth in claim 21 in which the area of said diaphragm includes one portion substantially equal to the cross-sectional area of said seat and another portion substantially equal to the cross-sectional area of the opening of annular form at the other end of said second section of said second passageway.

23. A vacuum cleaner nozzle as set forth in claim 21 in which said diaphragm has a larger cross-sectional area than the cross-sectional area of said seat with the radial distance of said diaphragm from said seat to its periphery being such that zones of said diaphragm at both ides of the edge of said seat and immediately adjacent thereto flex and move in substantially the same manner.

24. A vacuum cleaner nozzle as set forth in cliam 23 in which said seat has a sharp edge.

25. A vacuum cleaner nozzle as set forth in claim 21 in which said first section of said second passageway, at a zone adjacent to said seat, is of larger crosssectional area than the portion thereof nearer to said first passageway.

26. A vacuum cleaner nozzle as set forth in cliam 25 in which the air outlet end of said zone is of reduced cross-sectional area and throttles air in its path of flow from said diaphragm to said first passageway in said first section of said second passageway.

Claims

1. A vacuum cleaner nozzle which includes a. first and second operating surfaces for performing different types of cleaning, b. said nozzle comprising a body including means defining a first passageway having a suction inlet at the vicinity of said operating surfaces and an outlet adapted to be connected to a source of supply of air at a partial vacuum, said first passageway providing a path of flow for air between the inlet and outlet, c. means for mounting said second operating surface on said body for movement between upper and lower positions with respect to said first operating surface, said first operating surface functioning to clean an object with which it is in contact when said second operating surface is in its upper position and said second operating surface functioning to clean an object with which it is in contact when it is in its lower position, d. means providing a second passageway having one end thereof in communication with a first region of said first passageway and the opposite end thereof in communication with said movable mounting means, e. a valve which is movable between open and closed positions and in said second passageway intermediate the ends thereof and acted upon by the pressure differential of air at a partial vacuum in said first region of said first passageway and of air At a partial vacuum in a second region of said first passageway, f. said valve moving to its closed position when said pressure differential is above a definite value and the rate at which air flows through said first passageway is in a first range and moving to its open position when said pressure differential is below the definite value and the rate at which air flows through said first passageway is in a second lower range, and g. said movable mounting means being rendered operable to move said second operating surface to its upper position when said valve is in its open position.

3. A vacuum cleaner nozzle as set forth in claim 2 in which said second passageway has a break at which the adjacent ends of two sections thereof terminate, one of said sections in communication with said first region of said first passageway terminating in an opening at said break which defines a seat against which one face of said valve is adapted to move in sealing relation therewith, a first segment of said one face of said valve moving against said seat defining a first part of the area of said valve, and the other of said sections of said second passageway in communication with said movable mounting means also terminating at an opening at said break, a second segment of said one face of said valve co-acting with the last-mentioned opening of the other of said sections defining a second remaining part of said valve area, and the opposite face of said valve being in communication with said second region of said first passageway.

5. A vacuum cleaner nozzle as set forth in claim 3 in which said valve comprises a resilient diaphragm, means for securing the peripheral edge portion of said diaphragm in said body adjacent to said break in said second passageway, said seat being defined by a sharp edge formed at said break by the opening in said first section of said second passageway, and said diaphragm having a larger cross-sectional area than the cross-sectional area of said seat with the radial distance of said diaphragm from said seat to the peripheral edge portion thereof being such that zones of said diaphragm at both sides of the edge of said seat and immediately adjacent thereto flex and move in substantially the same manner.

6. A vacuum cleaner nozzle as set forth in claim 1 in which said means for movably mounting said second operating surface on said body comprises a diaphragm, spring means acting on said diaphragm for moving said second operating surface in a first direction to its lower position, and said movable mounting means being acted upon by air at a partial vacuum when said valve moves to its open position and said second passageway is open, such air at a partial vacuum being operable to overcome said spring means and move said second operating surface in a second opposite direction to its upper position.

10. A vacuum cleaner nozzle which includes a. first and second operating surfaces for performing different types of cleaning, b. said nozzle comprising a body including means defining a first passageway having a suction inlet at the vicinity of said operating surfaces and an outlet adapted to be connected to a source of supply of air at a partial vacuum, said first passageway providing a path of flow for air between the inlet and outlet, c. means for mounting said second operating surface on said body for movement between upper and lower positions with respect to said first operating surface, (1) said first operating surface being operable to clean a soft porous surface with which it is in contact when said second operating surface is in its upper position and (2) said second operating surface being operable to clean a smooth surface with which it is in contact when it is in its lower position, d. structure defining a space, e. said mounting means being operable (1) to move said second operating surface relative to said first operating surface from its lower position to its upper position responsive to air in said space at a first pressure which is at a partial vacuum and operable (2) to move said second operating surface relative to said first operating surface to its lower position responsive to air in said space at a second higher pressure, f. means providing a second passageway for air between said first passageway and said space, g. valve means in said second passageway which is movable between closed and open positions, h. means operable to control said valve means responsive solely to the pressure differential of air in first and second regions in said first passageway which varies with the physical characteristics of the surface being cleaned by the nozzle and over which said body is moved, said valve means moving to its closed position when said pressure differential is above a definite value and the rate at which air flows through said first passageway is relatively high and in a first range and moving to its open position when said pressure differential is below the definite value and the rate at which air flows through said first passageway is relatively low and in a second lower range, and i. said structure defining said space being so constructed and formed that, during normal operation of said nozzle when said outlet is connected to a source of supply of air at a partial vacuum, the air in said space will be at the first pressure when said valve means is open and at the second higher pressure when said valve means is closed.

11. A vacuum cleaner nozzle as set forth in claim 10 in which said means for mounting said second operating surface on said body for movement between its upper and lowEr positions comprises a flexible diaphragm.

12. A vacuum cleaner nozzle as set forth in claim 11 in which said structure defining said space includes said flexible diaphragm.

13. A vacuum cleaner nozzle as set forth in claim 12 which includes resilient means biasing said flexible diaphragm to render the latter operable to move said second operating surface in one direction to its lower position when said valve means is closed and the air in said space is at the second higher pressure, the air in said space at the first pressure, which is at a partial vacuum when said valve means is open, overcoming the biasing action of said flexible diaphragm means by said resilient means to move said second operating surface in the opposite direction to its upper position.

16. A vacuum cleaner nozzle which includes a. first and second operating surfaces for performing different types of cleaning, b. said nozzle comprising a body including means defining a first passageway having a suction inlet at the vicinity of said operating surfaces and an outlet adapted to be connected to a source of supply of air at a partial vacuum, said first passageway providing a path of flow for air between the inlet and outlet, c. means for mounting said second operating surface on said body for movement between upper and lower positions with respect to said first operating surface, (1) said first operating surface being operable to clean a soft porous surface with which it is in contact when said second operating surface is in its upper position and (2) said second operating surface being operable to clean a smooth surface with which it is in contact when it is in its lower position, d. structure defining a space, e. said mounting means being operable (1) to move said second operating surface relative to said first operating surface from its lower position to its upper position responsive to air in said space at a first pressure which is at a partial vacuum and operable (2) to move said second operating surface relative to said first operating surface to its lower position responsive to air in said space at a second higher pressure, f. means providing a second passageway for air between a first region in said first passageway and said space, g. valve means in said second passageway which is movable between closed and open positions, h. means providing a third passageway for air which extends from a second region in said first passageway to said valve means, said third passageway being out of communication with said second passageway, i. said valve means and second and third passageways being so constructed and arranged that said valve means moves to its closed position when the pressure differential of air in said first and second regions of said first passageway is above a definite value and the rate at which air flows through said first passageway is in a first range and moves to its open position when the pressure differential of air in said first and second regions of said first passageway is below the definite value and the rate at which air flows through said first passageway is in a second lower range, and j. said structure defining said space being so constructed and formed that, during normal operation of said nozzle when said outlet is connected to a source of supply air at a partial vacuum, the air in said space will be at the first pressure when said valve means is open and at the second higher pressure when said valve means is closed.

18. A vacuum cleaner nozzle as set forth in claim 17 in which said means defining said first passageway is of reduced cross-sectional area at a zone between said first and second regions.

21. A vacuum cleaner nozzle as set forth in claim 20 in which said second passageway includes first and second sections, said first section at one end being in communication with said first region in said first passageway and at the other end terminating at an opening defining a seat against which said diaphragm bears when said valve means is closed, said second section at one end being in communication with said space and at the other end terminating at an opening of annular form which is adjacent to said diaphragm and disposed about said seat.

23. A vacuum cleaner nozzle as set forth in claim 21 in which said diaphragm has a larger cross-sectional area than the cross-sectional area of said seat with the radial distance of said diaphragm from said seat to its periphery being such that zones of said diaphragm at both sides of the edge of said seat and immediately adjacent thereto flex and move in substantially the same manner.

24. A vacuum cleaner nozzle as set forth in claim 23 in which said seat has a sharp edge.

25. A vacuum cleaner nozzle as set forth in claim 21 in which said first section of said second passageway, at a zone adjacent to said seat, is of larger cross-sectional area than the portion thereof nearer to said first passageway.

26. A vacuum cleaner nozzle as set forth in claim 25 in which the air outlet end of said zone is of reduced cross-sectional area and throttles air in its path of flow from said diaphragm to said first passageway in said first section of said second passageway.