CA2017512A1 - Vacuum cleaner with suction indicator - Google Patents

Abstract

VACUUM CLEANER WITH SUCTION INDICATOR

ABSTRACT OF THE DISCLOSURE

A vacuum cleaner has an adjustable-height suction nozzle. A diaphragm switch is mounted in the housing inside the nozzle and determines a differen-tial air pressure of the operating vacuum cleaner.
Voltage source terminals are self-energizing with the rotation of a rotatable brush inside the nozzle and an indicator lamp is illuminated, or extinguished, upon developing a proper suction as established by the proper adjusted height of the nozzle relative to the floor surface. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applica-tions, and is not to be construed as a limitation on the scope of the claimed subject matter.

Description

VACUUM CLEANER WITH _UCTION INDICATOR

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BACKGROUND OF THE INVENTION

Vacuum cleaners have prevlously been pro-posed wherein there was an automatlc helght adjustment of the nozzle relative to the floor, such as shown in United States Letters Patents Nos. 2,555,887;

2,583,054; 2,592,710; and 4,706,327. These were usually sufficiently complicated mechanisms that they were not commercially successful.
Vacuum cleaners have also been proposed utilizlng a diaphragm to sense the amount of vacuum either to vary a resistance, as in U.S. patent No.
~,021,879, to slow the electrlc motor, or to actuate indicator lamps, as disclosed ln U.S. patents Nos.
4,199,838 and 4,481,692.
Other vacuum cleaners have been proposed which utilize some form of sensor to indicate when the filter bag is full and requires changing, as in U.S.
patents Nos. 4,199,838 and 4,342,133. Still other patents have had some form o~ lndlcation of brush speed, either by a Hall efEect sensor, as in U.S.
patent No. 4,245,370, or by a ma~net and sensor coil, as in U.S. patents Nos. 4,692,754 and 4,728,942.

SUMMAElY O~ THE INVENTION f~ ~ ~ 7 The problem to be solved, therefore, is how to construct a vacuum cleaner with a suctlon indlcator such that the proper height of an adjustable suction nozzle relatlve to the floor may be readily deter-mlned.
This problem is solved by a vacuum cleaner havlng a suctlon nozzle inlet for cooperation-with a surface to be cleaned comprisin~, in combination, the height of the nozzle relative to a surface to be cleaned being variable, means to determine a differen-tlal alr pressure of the operatlng vacuum cleaner, an electrical swltch actuated in accordance wlth sald dlfferentlal pressure means, voltage source terminals, and lndlcator means connected electrlcally to said voltage source termi~als and said switch.
The problem may further be solved by a vacuum cleaner comprising, in combination, a nozzle connected to sald vacuum cleaner for cooperatlon with a surface to be cleaned, a rotatable brush ln said nozzle, means to adjust the height of the nozzle relative to a surface to be cleaned, a permanent magnet on said rotatable brush, a pickup coil mounted in a statlonary manner on said nozzle for cooperatlon with said rotatable permanent magnet to generate an alternating voltage, a diaphragm switch having a diaphragm and first and second electrical contacts, ..... .. . . . . .. . . i.

~ r means connecting one side of said diaphragm ~o atmos-phere, means connecting the other side of said dia-phragm to the lo~ pressure condition of said vacuum cleaner, an indicator, and means connecting said pickup coil to said diaphragm switch and said indi-cator.
The problem may still further be solved by a vacuum cleaner operating condition lndicator with the vacuum cleaner having a rotatable brush in a height-adjustable nozzle comprising, in combination, a uni-tary housing, first and second indicator lights mounted in sald housing, a diaphragm switch having a diaphragm and mounted in said housing, means mounting said housing in said height-ad~ustable nozzle wlth said indlcator lights externally vislble, means to apply the differential air pressure of the nozzle oi-.
the vacuum cleaner to opposite sides of said dia-phragm, a plckup coll mounted in sald housing and having a pole piece adapted for cooperation with a magnet rotatable with the brush of the vacuum cleaner, means connecting said pickup coil directly to sald first indicator light to be illuminated upon suffi-cient brush rotational speed, and means connectlng said pickup coil ln series with said diaphragm switch and said second indicator light to change the indi-cator condition thereof upon proper spacing of the vacuum cleaner nozzle to a surface to be cleaned to establish the difE0rential air pressure to actuate said switch.

.. . . . .... .................. ".. ... ... . . . ......... . . . . . . . ... ......... ...... . ... .....

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Accordingly, an ob~ect of the invention is to provlde a self-powered suction indicator which requires no electrical connection from the motor or the energization source of the motor. Accordlngly, such suction indicator may be used wlth a vacuum cleaner having a removable nozzle without need for disconnecting any electrical connections.
A feature of the inventlon'is to provide a small houslng which fits wlthin the suction nozzle of an uprlght vacuum cleaner. This nozzle also contalns a rotatable brush, and the rotation of the brush is utillzed ~o develop a voltage to energlze the suctlon indicator. In this manner, the lndicator may have two functions of indicating proper rotation of the brush, and also providing power to indicate the proper amount of suction developed when the ad~ustable nozzle is at the most advantageous spaclng from the floor or other surface to be cleaned. A dlaphragm switch is utillzed to be actuated betw'een ON and OFF conditlons, depend-ing on the amount of suckion developed in the nozzle relative to the amblent. The small housing may be completely concealed wlthln the noæzle of the vacuum cleaner and the lndicator be vislble externally of the nozz'le. The lndicator may be indicator lamps for brush rotation speed and for proper amount of suction ~or most effectlve cleaning.
Other ob~ect~ and a Euller understanding of the invention may be had by referring to the following ~ a ~

description and clalms, taken in conjunction with the accompanylng drawlng.

BRIEF DESCRIPTION OF THE DRAWING

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FIG. 1 is a perspectlve vlew of a part of a vacuum cleaner embodylng the lnvention;

FIG. 2 i5 a sectional view on line 2-2 of FIG. l;

FIG. 3 ls a front elevational view of an indicator housing;

FIG. 4 ls a sectional view on llne 4-4 of FIG. 3;
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FIG. 5 is a top plan view of the housing of FIG. 3;

FIG. 6 is a front elevatlonal vlew, simllar to FIG. 3, of an alternatlve embodlment of the lnven-tion; and FIG. 7 ls a sectlonal view on llne 7-7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT
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The flgures of the drawing illustrate a vacuum cleaner 10 which may be a canister or tank-type, but has been lllustrated as an uprigh~ household electric vacuum cleaner having a motor enclosure 11 and an adjustable-helght suctlon noæzle 12. In thls preferred embodiment, the nozzle 12 ls also removable by releasing a latch 13. Thls exposes a drive shaft 14 from the motor 15. Thls motor may be the usual electric motor energized i-rom a source of commercial power frequency (not shown) and the motor drives a fan 16, actlng in this case as a suction pump to establish a suction through a suction condult 17 of the nozzle 12 at the area of attachment to the motor enclosure 11. This suction or region of lowered air pressure is present within the nozzle 12 and draws air through the nozzle inlet opening 18. The noæzle 12 also contains a rotatable brush 20 which is driven through a belt 21 from the drive shaft 14, and should rotatlon oi- ~he brush be blocked with the motor running, the drive train for the brush ls capable of slipplng, e.g., slipping at the junction of the belt 21 and shaft 14.
The height or spacing of the nozzle relative to the floor or other surface to be cleaned is vari-able. A height-ad~ustment mechanism of a known type may be utilized, such as that disclosed in U.S. patent .. .. .... ....... j . ., .. ... ..... .. .. , ,, . . ., , .. . ....... ... .. : ~

4,078,275. The exact type of height-adjusting nozzle mechanism is not critical, and the mechanism shown in the aforementioned patent is merely illustrative of one of many height-adjusting mechanisms. This mechanism incorporates generally a pedal 24 which, when depressed to the phantom position, lowers a skid or wheel 25 which supports the vacuum cleaner 10 relative to the floor. By so depressiny the pedal 24 around the pivot shaft 26~ the wheel is lowered and the vacuum cleaner suction nozzle 12 is raised to its maximum extent. In this position, the air readily is admitted to the suction nozzle inlet 18 so that the vacuum or lowered air pressure within the nozzle 12 is of a low value. An escapement pedal 27 may be repeatedly depressed against the urging of a spring 28 to release an escapement pawl 29 relative to a ratchet 30. Each depression of the escapement pawl 29 lowers the suction nozzle inlet incrementally until the suction inlet 18 is resting on the floor. With the suction inlet completely closed off, a considerable vacuum may be developed inside the nozzle 12 by the fan 16. For example, this might be in the order of 12 to 15 inches of water as a differential air prsssure relative to the ambient. It has been found that if the nozzle 12 is closely spaced off the rug or other surface to be cleaned, a desirable high rate of air flow is created between the nozzle inlet and A~

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through the pile of the carpeting ior a maximum clean-ing effect, and this could result in a pressure dlf-ferential equal only to two or three inches of water instead of the full nozzle down pressure of 12 $o 15 inches o~ water. Such nozzle height will vary in accordance with the type of surface, whether it be a plush, medlum, low, loop, sculptured, or undulating pile type carpet, a hard surface bare floor, and the like, but two to three inches of water as a differen-tial air pressure has beer. found to be the best suc-tion cleanlng conditLon for most dirty,alr-type up-riyht cleaners for general home cleaning, and may be higher ~or clean alr uprlghts, canisters, and central vacuum units.
An lndicator houslng 38 is mounted a~ainst the rear wall of the nozzle 12 by a single screw 39, the screw being normally hldden beneath a rubber bumper 40. FIGS. 3, 4, and 5 better show the con-struction o~ the indlcator housing 38 and FIG. 2 shows generally its positlon withln the nozzle 12. The housing 38 has flrst and second indicators 41 and 42, shown as lamps, to indicate proper brush rotation and the best suctlon condltion, respectively. The housing 38 is a unitary housing o~ some in~ulation material, such as plastlcs. A pole piece 45 ls fixed in the housing 38, with a pickup coll 46 surroundlng thls pole piece. With the housing 38 mounted within the nozzle 12, the pole piece ls positioned close to the .. . . . .... . ..

f,j .~, rotating brush 20, on which 2 permanent magnet ~7 is located to sweep past the pole plece ~5 and develop a voltage at voltage source terminals 48 and 49 upon rotation of the brush 20. These voltage source termi-nals 48 and 49 are connected by conductors 50 and 51 to the flrst indicator lamp 41 to illumlnate this lamp upon sufficient rotatlonal speed of the brush. This lamp is vlsible behind a transparent or translucent lens 53, as shown ln FIG. 1, and indlcates the suffl-cient rotational speed of the brush. Should the adjustable nozzle 12 be positioned too closely to the surface to be cleaned, the rotatable brush may strike the carpet or other material, slowing, or even stop ping, such brush due to the sllppable drive traln, with slipping primarily between the belt 21 and the motor shaft 14. In such case, a voltage ceases to be produced at the voltage source terminals 48 and 49, and the lndicator lamp 41 will be extinguished.
A diaphragm switch 54 ls mounted within the housing 38, and is an electrlcal switch responslve to the operatlng condltlon of the vacuum cleaner 10. In this em~odiment, it ls responslve to a suction condi-tion, namely, the lower air pressure within the nozzle 12 relative to the ambient. The hou~ing 38 has a circular shoulder 55 against which a first face 62 of a circular, flexible diaphragm 56 is located. An in~er~ 57 o~ solid insulating material is loca~ed in the housiny 38 and in engagement with a second face 63 ~ ~ 7~ L~

of the diaphragm 56~ A first termlnal 5~ is fixed on the insert 57, and ls secured to a metal contact dlsc or blade 60 on the second face 63 of the diaphragm to be deflectable therewith. A second terminal 59 ls mounted on the insert 57 and, as shown, may be adjust-able by having an adjustment screw 61 passiny through the insert to be selectlvely engageable by the contac-t disc 60.
The shoulder 55 of the housing 38 cooperat-ing with the first face 62 of the diaphragm 56 creates a first pressure chamber 64. In this embodimen~, thls first pressure chamber is open to the ambient by means of a port 65, which extends through an aperture 66 ln the wall of the nozzle 12. An optional O-rlng 67 may be used to prevent air leakage at thls aperture 66.
The insert 57 has an annular flange 69 which ls sealed to the second face 63 of the diaphragm 56 to establish a second pressure chamber 70. Thls second pressure chamber is exposed to a lower pres~ure operatlng condltlon of the operatlng vacuum cleaner 10 by means of a condult 71 whlch ls exposed to the lower air pressure lnside the nozzle 12. A fllter 72 is pro-vlded inslde the conduit 71 to help keep dust and other contamlnants from lnslde the pressure chamber 70. Thls fllter 72 is preferably removable for clean~
lng, and the conduit 71 ls aligned wlth the contact dlsc 60. Thls provides physlcal protection to the flexlble diaphragm 56 so that should someone poke a '7a ~ ~

pin or other object into the conduit 71 for cleaning, it will not puncture the diaphragm 56.
The terminals 58 and 59 of the dlaphragm switch 54 are connected in circuit with the voltage source terminals 48 and ~9. The voltage source terminal 4~ is connec~ed to the terminal 58 by the conductor 50. The circult proceeds through the dia-phragm switch i-rom terminal 58 to 59, and then, by a conductor 74, to the second lndlcator lamp 42. The other lead of this lamp is connec~ted by a conductor 75 and conductor 51 to the voltage source terminal 49.
By this connection, when the diaphragm switch 54 is closed, the voltage source terminals 48 and 49 will illuminate the second indicator lamp 42.
When the vacuum cleaner 10 ls first turned on for use, the operator may depres~ the pedal 24 to raise the nozzle 12 to its maximum height relative to the floor. With the motor 15 energized and running, the rotatable brush 20 will be rotating at approxi-mately its maximum speed because the brush will not be in contact with the carpet, and also the nozzle inlet openlng 18 will be considerabl~ spaced irom the ~loor sur~ace to o~er little obstruction to intake of air.
The rotating pèrmanent magnet 47 will then generate a voltage at the voltage source terminals 48 and 49, and the first indicator lamp ~1 will be illuminated, for example, with a green light, to indicate propèr rota-tion of the rotatable brush 20. Should this light not .. . .. .. ; .. ., .... ~: -r be illuminated, it might indicate a jammed brush or broken belt 21. Thus, the operator of the vacuum cleaner is alerted to any defective conditions. Next, the escapement pedal 27 should be proyressively de-pressed to gradually incrementally lower the nozzle 12 toward the floor surface. Thls will increasingly choke off intake of air as the nozzle inlet opening 18 moves downwardly toward the correct operating position of the adjustable height nozzle. At the proper oper-ating height, the rotatable brush 20 will be brushing the carpet, and the inlet open.l.ng 18 will be suffi-ciently restricted to develop a low pressure area inside the nozzle 12 of approximately two to three inches of water. The helght o the nozzle relative to the floor surface i-or thls proper operating condltion will vary in accordance with the type of floor sur-face, but with this two to three inches of water as a differential air pressure, the flexible diaphragm 56 will be deflected sufficiently that the contact disc 60 engages the adjustable screw 61. This closing of the switch will illuminate the second indicaEor lamp ~2, whlch may be a red lndicator lamp, for example, vislble behind a lens as shown ln FIG. 1. Thls will be a readlly vlsible indication to the operator oE the vacuum cleaner that the adjustable height nozzle is set for maximum cleaning efficiency for the particular type of floor surface.

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An alternative mode of operation could also be employed, as follows. With the suction inlet completely closed against the surface to be cleaned, a considerable vacuum inside the nozzle will be devel-oped by the motor-fan sys~em. For example, it could be as high as 15 inches of water lift as a pressure differential. Although there will be a small amount of air flow through the carpet pile, it would no~ be suf~icient to do a good cleaning jobO The second indicator light 42, possibly red in color, will be ligh-ted due to the diaphragm pressure swi~ch closing, thus indicating poor cleaning. Raising the no2zle incrementally would cause the light 42 to extinguish, at which point the dlfferential of pressure will have dropped off and air flow permitted to increase, pro-viding maximum cleaning condition.
A third embodiment is illustrated in FIGS. 6 and 7 as an indicator housing 80, with reference numerals the same as in FIGS. 3 and ~ for the same parts. A third indicator 81 is added, which may be yellow or orange. This indicator is energized by conductor 75 and a new conductor 82 leading to voltage source terminal 49. ~ second contact 83 is normally closed against a diaphragm contact blade 84 on the atmospheric side Oe the diaphragm 56. Contact 83 is connected to a terminal 85, which is connected by a conductor 86 to the indicator 87.

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In operation, the indicator 41 would be the rotation indicator, as before. The indicator 42 would again be a red lamp. With the cleaner turned "on" and brush roll runnlng and nozzle height fully up, the brush roll turn indicator 41 would be lighted as beEore, but so ~ould the orange/yellow light 81.
Lowering the nozzle incrementally to the desired height would turn the red light ~42 on and orange/yellow light 81 off. This is functionally the same as the concept in the first embodiment, except that the third light 81 indicates to the operator that the nozzle is too high to clean properly.
It will be noted that the voltage source terminals ~8 and 49 are capable of developing a volt-age even though the nozzle 12 is removable from the motor enclosure 11, and there are no electrical con-nections between the motor enclosure 11 and nozzle 12.
Thus, the nozzle 12 may be removed so that the motor shaft 14 and/or suction fan 16 may be used for other applications. The lndicator means 41, 42 and 81 and the voltage source terminals ~8 and 49 are mounted in the removable nozzle 12, with an absence of all elec-trical connections from the motor enclosure to the nozzle. The rotating permanent magnet 47 is a means to develop a voltage ih cooperation with the plckup coil 46 in accordance with rotation of the brush 20.
The indicator houslng 38 or 80 is small and easily mounted inside the nozzle 12 by the single screw 39.

The port 65 passing through the aperture 66 helps orient the housing 38 for proper positioning. The houslng i5 therefore hidden inside the nozzle 12, but the indicator lamps 41, 42, and 81 are visible exter-nally of the nozzle 12 to the vacuum cleaner operator through apertures such as apertures 77 in the top of the nozzle 12. A curable plastics material 78 ~ay be filled inside the housing 38 to cover the insert 57 and help seal the insert to the diaphragm 56 and also to provide protection to the relatively small gauge conductors 50, 51, 74, and 75. This makes a rugged housing whlch is sealed except for the port 65 and conduit 71 for easy handling during production and assembly.
The present disclosure includes that con-tained in the appended claims, as well as that of the foregoing descrlption. Although this invention has been described in its preferred form with a certaln degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and of the circuit and the comblnation and arrangement o~ parts and clrcult elements may be resorted to without departing from the spirit and the scope oE the invention as hereinafter claimed.

Claims (21)

1. A vacuum cleaner having a suction nozzle inlet for cooperation with a surface to be cleaned, comprising, in combination:
the height of the nozzle relative to a surface to be cleaned being variable;
means to determine a differential air pressure of the operating vacuum cleaner;
an electrical switch actuated in accor-dance with said differential pressure means;
voltage source terminals; and indicator means connected electrically to said voltage source terminals and said switch.

2. The vacuum cleaner as set forth in claim 1, including a rotatable brush driven by a motor through a slippable drive; and means to develop a voltage at said voltage source terminals in accordance with rotation of the brush and with no electrical connection to the motor or to the energization source of the motor.

3. The vacuum cleaner as set forth in claim 1, including an electric motor energizable from a commercial frequency power source, the motor driving a fan to create a suction, said motor being in an enclo-sure with said nozzle being removable therefrom, there being an absence of all electrical connections from said motor enclosure to said nozzle; and said indicator means and voltage source terminals being mounted in said removable nozzle.

4. The vacuum cleaner as set forth in claim 3, including a rotatable brush in said nozzle; and means to develop a voltage at said voltage source terminals in accordance with rotation of said brush.

5. The vacuum cleaner as set forth in claim 1, wherein said differential air pressure means is mounted to be responsive to the difference in air pressure between said nozzle and the ambient.

6. The vacuum cleaner as set forth in claim 1, wherein said differential pressure means includes a deflectable diaphragm; and said electrical switch being movable by said diaphragm.

7. A vacuum cleaner comprising, in combina-tion:
a nozzle connected to said vacuum clean-er for cooperation with a surface to be cleaned;
a rotatable brush in said nozzle;
means to adjust the height of the nozzle relative to a surface to be cleaned;
a permanent magnet on said rotatable brush;
a pickup coil mounted in a stationary manner on said nozzle for cooperation with said rotat-able permanent magnet to generate an alternating voltage;
a diaphragm switch having a diaphragm and first and second electrical contacts;
means connecting one side of said dia-phragm to atmosphere;
means connecting the other side of said diaphragm to the low pressure condition of said vacuum cleaner;
an indicator; and means connecting said pickup coil to said diaphragm switch and said indicator.

8. A vacuum cleaner as set forth in claim 7, wherein said indicator is a lamp.

9. A vacuum cleaner as set forth in claim 7, including a housing for said pickup coil, diaphragm switch, and indicator.

10. A vacuum cleaner as set forth in claim 9, including means to secure said housing to said nozzle.

11. A vacuum cleaner as set forth in claim 9, including means to secure said housing within said nozzle, with said indicator being visible externally of said nozzle.

12. A vacuum cleaner as set forth in claim 7, wherein said indicator is energized upon the nozzle being height-adjusted toward the surface to he cleaned.

13. A vacuum cleaner as set forth in claim 7, wherein said indicator is de-energized upon the nozzle being height-adjusted away from the surface to be cleaned.

14. A vacuum cleaner operating condition indicator with the vacuum cleaner having a rotatable brush in a height-adjustable nozzle, comprising, in combination:
a unitary housing;
first and second indicator lights mounted in said housing;
a diaphragm switch having a diaphragm and mounted in said housing;
means mounting said housing in said height-adjustable nozzle with said indicator lights externally visible;
means to apply the differential air pressure of the nozzle of the vacuum cleaner to oppo-site sides of said diaphragm;
a pickup coil mounted in said housing and having a pole piece adapted for cooperation with a magnet rotatable with the brush of the vacuum cleaner;
means connecting said pickup coil directly to said first indicator light to be illumi-nated upon sufficient brush rotational speed; and means connecting said pickup coil in series with said diaphragm switch and said second indicator light to change the indicator condition thereof upon proper spacing of the vacuum cleaner nozzle to a surface to be cleaned to establish the differential air pressure to actuate said switch.

15. A vacuum cleaner operating condition indicator as set forth in claim 14, including said diaphragm being flexible;
means sealing a first face of said diaphragm to said housing; and an insert secured to said housing and having an annular shoulder sealed to said second face of said diaphragm to form a low pressure chamber.

16. A vacuum cleaner operating condition indicator as set forth in claim 15, including a mov-able contact mounted to be actuated by said diaphragm and electrically connected to a first switch terminal;
and a second switch terminal mounted on said insert.

17. A vacuum cleaner operating condition indicator as set forth in claim 14, including:
means to apply ambient air pressure to one side of said diaphragm; and conduit means to apply the lower air pressure within the nozzle to the other side of said diaphragm.

18. A vacuum cleaner operating condition indicator as set forth in claim 17, including a filter in said conduit means.

19. A vacuum cleaner operating condition indicator as set forth in claim 17, including a metal contact on the low pressure side of said diaphragm as part of said switch.

20. A vacuum cleaner operating condition indicator as set forth in claim 19, wherein said conduit means is aligned with said contact for physi-cal protection for said diaphragm.

21. A vacuum cleaner operating condition indicator as set forth in claim 12, including:
a third indicator light in said hous-ing; and a third electrical contact on the other side of said diaphragm connected to said third indi-cator light.