US2270318A - Vacuum cleaner pneumatic annunciator - Google Patents

Description

- Jan. 1942- w. LEATHERS VACUUM :CLEANER PNEUMATIC ANNUNCIATOR Filed July 11, 1938 its resistance to air-flow therethrough, as ex Patented Jan. 20,1942

VACUUM CLEANER PNEUMATIC ANNUNcmTon Ward Leases, ne er-111,! N. J .,-assignor -'flto Quadrex Corporation, New

notation of Delaware Application July 1'1, 193s, Serial N o. 18,647? '(Cl. 116-67) 'lClalm.

My invention applies particularly to canister type .vacuum-cleaners, i. e., those having the filter enclosed in a casing along with a motor j driven air-impelling unit.

' This type of vacuum-cleaner has its air how easily impeded by the accumulation of dirt, such as carpet nap, on the walls of the filter, and where v the filter is designed of such type that it may be shaken, it is highly desirable to know when such shaking should be done, particularly when the air flow is obstructed to the point where the cleaning iunction at the nozzle is materially impaired, although the cleaner has not accumu- V lated sumcient dirt to require emptying. k

' The object my invention is to produce an automatic' device that will inform the operator York, bl. Y., a cor- U pressed in terms ofdifferential"pressuresjand, as

disclosed in this specification, gives an' iannunciation relative tolthefamplitudefof aid difife'rential and hence of said resistance:

My inventionfis'appiicable 2' ster type vacuum-cleaners of the horizontal-axis type or the vertical -axis. type, f buti I I havepreferred to set 'it forth as applied toia yertica'l-axis type machine. (Amorecomplete description oi? the, type shown; herein may beefifound ,g'inj'my copending application for Letters Patent, Serial No.

In order to set forth my'invention so that all those familiar with these arts may understand it, I have prepared the following specification,

. to which I have appended the drawing'gof which:

:audibly or the true working condition of the umachine. It is the object to give a mildnotiilcation of thefact that thenozzle is not cleaning at its full capacity, to give a more strident noti fication if the cleaning function becomes still more seriously impaired, and to give an insistent and vociferous indication if a careless operator permits the dirt toaccumulate in the filter, or the dirt-receptacle, or both, to a point where the machine is practically useless for cleaning purposes.

Machines of the type described usually have within the case areas or chambers of several diflerent pressures when the machine is in operation This invention functions by'means of there is a pressure in the area of the machine after expulsion of air .irom the compressor and before it has passed to the open air, which is normally higher than atmosphere.

. My invention is concerned with determining the resistance to air flow through the filter which alters the normal diilerence between the first and second named pressures; and it utilizes the third pressure (or atmosphere could be substituted) tor annunciating purposes when actuated by means controllable by the differential pressure between the first two pressures Such a device gives information concerning the accumulation of. dirt on the surface of the filter, and

anism.

corporatlng this Figure 1 is a vertical, partial cross-section of a vertical-axis typecanistervacuum cleaner ininvention. f j i Figure 2 is a vertical cross-section of" the annunciator.. i 11 Figure 3- is a verticalcross section of'a modified sound producer for same. 1

"Figure 4 is a vertical. cross section ofa pressure-juncture for the filter.

Figures 5 and 6 show the filtersh'aking mech- A vertical-axis."canistertype vacuum-cleaner with an upper IDOltiOIl' 1,: Fig. :1, comprising a filterl, a motor-drivenair-impelling unit 3, an exhaust pressure chamber l, sound muffler (or supplementary filter) 5. and handle 6, is separable from a lower portion 1 comprising a dirtreceptacle pan 8 and a hose attachment 9 along a horizontal line, indicated at II). A filter 2 comprises two truncated cones joined together at a ring II. The ring is movable in all directions for shaking purposes by a handle l2 on the outside of the machine. This handle mechanism is hingeable and raisable, passes into the machine through rubber washers i3 (see Fig. 5) so that it has a substantially universal movement. The filter ring II is held up by springs (shown in Fig. 6). A stop I on the handle enables the .ring to bedepressed for shaking purposes by means of a .bow l5 operably related with the handle and joined by means or trunnions to the sides of the ring H. The filter 2 requires no fastening at its center l6 where it is drawn by the springs mentioned, over a supporting nose I! (more fully shown in Fig. 4

Air entering at the hose juncture 9 passes upward into chamber l8 within the filter. It then passes through the filter to a chamber 20 from 6 which it is drawn by the Ian 2| through an inlet and the suction chamber 20 varies in use.

to the fan 22. The filter'is spaced from the inlet 22 by means of any desirable spacer 25, such as a wire cage. The air from the Ian 2! is delivered to chamber 4 from whence it finds exhaust to atmosphere through muiiier or auxiliary filter 5. During this operation the pressures within the three chambers mentioned differ widely. That within the chamber 20 is the lowest, being considerably below atmosphere. That within the chamber I8 is not so low as that in chamber 20 but also below atmosphere. That within the chamber 4 is above atmosphere. The differential pressure between the inside filter-chamber l8,

dirt accumulates on the filter the machine becomes less efiicient. It is desirable under these circumstances to notify the user who may then shake the filter and renew the full efilciency of the machine. If, however, the filter and dirtreceptacle accumulate such quantity of dirt as to continuously impair the cleaning function, it is desirable that the operator be notified of that fact so that the machine must then be emptied.

I have accomplished this purpose by means of i a sound device illustrated in Fig. 2. An annular 1 diaphragm I is enclosed on both sides forming a lower pressure chamber 3| which communicates by means of a hollow wire 32 with the chamber 18 within the filter. This means of communication may be established in any desired manner, but for the type of machine set forth herewith the method is described under Fig. 4. An upper pressure chamber 33 communicates by means of a tube or hose 34 with the middle chamber 20. In the upper diaphragm enclosure 1 have provided a valve 35, the stem of which is joined to the diaphragm 30. When the valve is raised by pressure beneath the diaphragm the valve uncovers ports which permits air from the high pressure chamber 4 to pass into the chamber 33 and on into the chamber 20 by means of the tube 34., This movement of air is utilized for making sound in any desired manner. By enclosing the inlet, as at 40, and properly disposing a. reed 4|, such as is used in saxophones or other wind instruments, sound is produced -when the valve is opened. The diaphragm is shown as an annular, corrugated, bronze sheet having its own spring resistance to displacement.

It may, of course, be provided with a spring (Fig. 3), if desired, to resist its upward movement. A bracket 43 is used for holding this diaphragm-pressure-unit to the top of the machine. As the differential between the pressures in chambers l8 and 20 increases, the valve 35 tends to open more and more. As the opening increases the sound produced by the reed 4| increases in volume. By predetermining the spring resistance, the reed may be made to give a modest note when the cleaning at the end of the nozzle becomes somewhat impaired. It may be made to produce an ever louder note or sound with the increased impairment of the cleaning function.

It should be noted for the purpose of operating this sound device that air from the chamber having the highest pressure in the machine is permitted to pass to the chamber having the lowest pressure in the machine.

Any other sound device operated by pressureair may be used. As an illustration, a diagrammatic whistle is shown in Fig. 3. Air passing through the openings 45 and 46 produce sound in volume roughly proportionate to the air-fiow.

The separator cage 25, see Fig. 4, is provided with inner and outer ferrules 48 between which the wires are joined. An inverted moulded rubber mushroom 50 is held within the inner ferrule. The hollow wire 32 is joined to the top of the rubber mushroom and communicates by means of a hole through the rubber with an open chamber 5! at the bottom. Air pressure within the filter communicates through the filter to the chamber 5|, hence to the inside of the hollow wire registering the pressure of the chamber II on the lower side of the diaphragm.

Having set forth my invention in understandable terms, I wish to make note of the fact that many types of sound devices operated by air may be used and controlled by the diiferential pressures as set forth in this specification without departing from the spirit of my invention.

What I claim is:

In an audible indicator for use on a vacuumcleaner, a sound-producing device operated by air supplied by the differential in pressure between the inlet and outlet sides of the air impeller of said cleaner and having means responsive to a second pressure differential, that on opposite sides of the filter of said cleaner for controlling the fiow of air through the said sound-producing device.

WARD LEATHERS.

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