US2576717A

US2576717A - Suction cleaner filter

Info

Publication number: US2576717A
Application number: US771967A
Authority: US
Inventors: Dale C Gerber
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1947-09-03
Filing date: 1947-09-03
Publication date: 1951-11-27
Anticipated expiration: 1968-11-27

Description

NOV. 27, D, c, GERBER SUCTION CLEANER FILTER Filed Sept. 3, 1947 Fly. 1

INVENTOR. De la C. Gerber f a ATTORNEY.

Patented Nov. 27, 1951 SUCTION CLEANER FILTER Dale G. Gerber,.North Canton, Ohio, assignor to The Hoover Company, NorthCanton, Ohio, a

corporation of Ohio Application September 3, 1947, Serial No. 771,967

The present invention relates to filters and more particularly to filters composed of fibrous material having exterior fibers removed.

In the usual filter for suction cleaners the material has a matted napped surface to which the dirt adheres and prevents removal of the dirt when the filter is cleaned,- and as a result when the filter is re-used the back pressure becomes excessive and reduces the cleaning -efficiencyofthe suction cleaner. The present invention provides a filter fabric wherein the matted napped. surface'is' removed to form a smooth surface upon which the dirt initially contacts, and the smooth surface functions ,to cause the easy removal of the dirt deposited thereon when the filter is cleaned. Removal of the matted napped surface does not injure the fibers in the body portion of the filter material and thus the filtering efficiency of the material. is not reduced;

. An object of the invention is toprovide a filter forinedf from fibrous material. Another object is to provide a fibrous filter having projecting fibers shortened while retaining the necessary filtering. characteristics. A further object is to provide a fibrous filter adapted for use with a suction cleaner and having the fibers in the dirt contacting surface shortened to form a smooth dirt collecting surface which can be easily cleaned. Another object is to provide a method of shortening fibers projecting from the body of a fibrous filter material. Still another object is to provide a method of treating fibrous filtering material by subjecting the material to an electrical charge to raise fibers from the body of the material and thereafter shortening the fibers by v singeing the latter to substantially the body of the material. Other objects and advantages of the invention will be apparent from the following specification and drawing, wherein:

Figure 1 illustrates the filter in a suction cleaner;

Figure 2 is a view of the apparatus for creating an electrical charge in the filter material to raise the fibers and to singe the projecting fibers;

Figure 3 is a section of the filter material prior to shortening the fibers; and

Figure 4 is a section of the filter material after the fibers have been shortened on the dirt contacting surface of the filter.

The invention herein disclosed is for purposes of illustration applied to a suction cleaner comprising a casing l supported on runners II and having a suction end cap I2 and an exhaust end cap IS. The end cap I! is provided with an inlet 3' Claims. (01. 183-5 1) 2 r M for connection to an unshown hose andcleaning tool which engages a surface to be cleaned,

and the rear end cap l3 has an outlet l5 which.

canalso-beprovided-with a cleaning toolina manner Well known in the art. Adirt filtering bag is is supported in the casing lfl to remove the dirt-from the dirt-laden airpassing through the inlet l4 into the bag, and a-motor-fan unit I] provides the suction for moving the air stream and exhausting it through the outlet l5. The

filter materialmay be paper; cloth or other suit,-

able material and as shown in Figure 3 prior ,to v being. processed is a single ply cloth 21L having yarnsil vsecured together by warp face yarns 22,

23, and 24. The exposed surfaces 30, and-3l of the material prior to being processed-is a mass of intermingled matted fibers or nap 32, and it is these fibers which retain the dirt in the usual suc-.

tion cleaner bag and prevent .removing all of the dirt when the bag is being cleaned.

The process for removing the matted fibers or nap 32 from the surface 30 is shown in Figure 2 sides of the material, and the electrodes are connected to a suitable source of high frequency current. Disposed above the electrode 40 and beneath the material 20 is a gas manifold 42 having two rows of burners 43--43 in the electrostatic field and adjacent the outer fibers of the material.

Movement of the material between the electrodes 40 and 4| causes the material to pass through the electrostatic field and the fibers receive an electrical charge and are aligned with the electric field, and as a result of such charge the nap or fibers are pulled away from and are perpendicular to the body of the material so that the fibers are no longer matted into the body of the material. While the fibers are raised from the body of the material, the burners 43-43 singe the ends of the fibers to shorten the latter andthus prevent the fibers from forming a matted surface, and the resulting surface shown at 45 in Figure 4 provides a relatively smooth dirt contacting surface from which the dirt may easily be removed when the filter is being cleaned.

The speed of movement of the material between the electrodes 40 and 4| depends upon the size of the electrodes, thestrength of the electrostatic field and the heat of the singeing fiame.

I have found that the voltage applied to the electrodes can be varied over a wide range and have employed voltages from 1500 to 4000 per square inch. If desired the burners 43 can be arranged to one side of the electrodes 40 and 4|.

The processed filter material shown in Figure 4 is formed into, the dirt filtering bag IS with the smooth surface 45'forming the, interior-and the napped surface 3| the exterior of the bag; The dirt-laden air passes through the inlet l4. into the bag l6 and first contacts the smooth inner surface 45, and the remaining portion of' the filter body removes the dirt from the dirt-laden air stream as the latter passes through the material, and the cleaned air is then discharged through the outlet l5.

In cleaning the bag Hi, the end cap l4 and the bag I 6 are removed and the dirt is easily dislodged from the bag because of the relatively smooth inner surface 45.

While I have shown and'described' buta single modification of myinvention, it is to be understood that this modification is to be taken as illustrative only and not in alimiting sense. I

do not wish to be limited to'the particular'structure and process shown and described, but to include all equivalent variations thereof except as limited by the scope of the claims. *Iclaim:

In a suction cleaner. a dirt filtering bag having anopening-ior'emptying collected dirt, suction; creating means for moving an air stream from the interior'of said bag and through the walLthereof ;to remove the dirt in said air stream, said filter b'a'g being of fibrous material includ ing in its structure relatively long fibers projecting from the bodyof the material to form the exterior surface ofrsaid bag, said material in-. cluding relatively short fibers projecting from the body of said, material to formthe inside surface of l the bag, said short fibers initially con tacting .saidair streanrto remove dirttherefromL said short fibers providing a. relatively smooth.

surface interiorlyiof the bag for easily. dislodging' the collected dirt through said bag opening.

2. A dirt filter adapted for use in a suction cleaner having suction creating means for mov-.

ing an air stream'through a filter and comprising: ,a-fibrous material including inits structure; relatively long fibers and relatively short fibers.

projecting from opposite sides of the body of said material, said short fibers on one side of said body being charred to present a relatively smooth surface of short fibers so disposed in the cleaner to initially contact the dirt to be removed from the air stream and collecting some of the removed dirt thereon, said relatively long fibers on the opposite side of saidbody beinguncharred to remove any dirt remaining in the air stream, the

charred short fibers forming said smooth surface initially contacting the dirt permitting easy removal of dirt collected thereon to clean said filter in comparison to any dirt which may have collected on said relatively long uncharred fibers on said opposite side of said material.

' 3,.In a. suction cleaner, a dirt filtering bag having an opening for emptying collected dirt, suction;creatingrmeans for moving an air stream from the interior of said bag and through the wall "thereof to remove the dirt in said air stream, said filter bag being of fibrous material including in its structure'fibers shortened to'substantiallythe bodyof the material to form the interior surfaceof said bag to initially contact' thedirt, said shortened fibers so projecting from said'body of='the material to form an unmatted fibrous surface to provide a relatively smooth interior surface on said bag for easily dislodging" the collected dirt therefrom through said bag opening; I I

y l DALE C. GERBER;

' REFERENCES CITED 'The iollowing'references are of recordinthe file of this patent: i

' UNITED STATES PATENTS