US2733000A

US2733000A - sparklin

Info

Publication number: US2733000A
Authority: US
Publication date: 1956-01-31
Anticipated expiration: 1973-01-31

Description

Jan. 31, 1956 c. H. SPARKLIN 2,733,000

CUTTER MECHANISM FOR A VACUUM CLEANER Filed Nov. 16, 1951 3 sheets sheet l 31. 195 c. H. SPARKLIN CUTTER MECHANISM FOR A VACUUM CLEANER 3 Sheets-Sheet 2 Filed Nov. 16 1951 Jan. 31, 1956 c. H. SPARKLIN CUTTER MECHANISM FOR A VACUUM CLEANER 3 Sheets-Sheet 5 Filed NOV. 16, 1951 United States Patent 2,733,000 CUTTER MECHANISM non A VACUUM CLEANER Charles H. Sparklin, Chicago, Ill., assignor to Birtman Electric Company, a corporation of Iliinois Application November 16, 1951, Serial No. 256,701 2 Claims. Cl. 230-132 This invention relates to a vacuum cleaner having a motor operated fan therein and relates particularly to a cutter device for severing solid foreign material deposited inan exhaust portion of the cleaner.

Q Electrically operated vacuum cleaners ordinarily employ a centrifugal fan for drawing dirt-laden air through the nozzle of the cleaner and exhausting it intoa porous bag in which the dirt is separated from the air. In many cleaners of this type it has been found that paper, String and other foreign materials tend to gather on any memberthat is located adjacent the periphery of'the fan and in the exhaust passage and against which the foreign matter is blown by the fan. This foreign matter, particularly paper, often assumes such a large bulk that it seriously interferes with the operation of the cleaner. In order to overcome the above described problems, I have' invented a vacuum cleaner cutter mechanism by means of which paper and. other foreign material is severed into smaller pieces and blown out with the exhaust air into the bag with the remainder of the dirt. The new vacuum cleaner is provided with a centrifugal fan having a rotatable impeller and an exhaust passage way of helical shape from'the impeller. This passageway has its entrance or shallowest part adjacent to the impeller and its exit spaced from the impeller and rearwardly of the entrance. I provide a fixed cutter .blade at this entrance on which bulky foreign material such as paper is deposited and a second cutter blade on the impeller for rotation therewith for cooperation With'the V fixed blade to sever foreign material deposited at the entrance. With this structure one portionof the severed material passes directly rearwardly out the exit and another portion passes around the passageway to be again cut if it again becomes caught at the entrance. In the preferred construction the fixed blade extends across the full width of the exhaust passageway in the region adjacent to the impeller and the blades are cuived and sloped to provide a scissors action.

The invention will be described as shown in the accompanying drawings. Of the drawings: Fig. 1 is a fragmentaryjlongitudinal vertical section through a vacuum cleaner embodying the invention; Fig. 2 is a front elevation of the rotatable impeller and associated structure; Fig. 3 is a fragmentary enlarged section taken substantially along line'33 of Fig. 2; Fig. 4 is a fragmentary enlarged elevational view showing the rotatable cutter blade approaching the fixed cutter blade; Fig. 5 is a section taken substantially alongline 5-5 of Fig. 1; and Fig.6 is a rear elevational view of themotor casing and associated structure of the cleaner. ;In the embodiment shown in the accompanying draw.-' ings the vacuum cleaner is supportedon spaced wheels 11 and is adapted to be propelled by means of a'h'andle 12. The cleaner includes a casing 13.within an outer housing 14. The casing 13 is provided with a removable front portion 13a having roughly the shape of atruncated 2,733,000 Patented Jan. 31, 1956 cally. The front portion 13a has an enlarged circular opening 13b at the front or apex thereof.

Spaced inwardly from the front portion 13a and substantially parallel thereto over a portion of its surface is a second casing portion 15. Between the casing portions 13a and 15 there is located a centrifugal fan 16 of generally conical shape having a plurality of blades 17 thereon. The blades are curved in the customary manner, as shown in Fig. 2, and extend slightly less than the full distance between the front casing portion 13a and the second casing portion 15. The outer edge of each blade 17 is substantially horizontal, as shown in'Fig. l, and the base of the conical fan 16 is curved rearwardly so that these horizontal edges are substantially tangential to this curved portion. I

The casing 13 rearwardly of the removable casing portion 13a is provided with an exhaust passage 18 of generally helical shape. As is shown in Fig. 5, this exhaust passage which is of expanding cross section communicates through almost 360 with the exhaust from the centrifugal impeller or fan 16. The entrance to the v munication with a dust bag in the usual manner.

It has been found in actual tests that the entrance 19 to the exhaust passage operates as a barrier against which pieces of paper and other foreign material tend to gather. If not removed, this paper and the like accumulates to such a large amount that it interferes With the efficient wire withthe base portion arranged substantiallyvertioperation of the cleaner. In order to remove this foreign material there is provided a fixed cutter blade 22 attached as by screws 23 to the entrance 19 of the exhaust passage so that the cutting edge 22a extends beyond the casing at this entrance in position to have paper and other foreign material deposited thereon. This fixed blade has the cutting edge 22a concave with the point of deepest curvature being adjacent to the impeller 16.

Cooperating with the fixed cutter blade 22 is a second cutter blade 24fastened to the impeller 16 for rotation therewith. In order to balance the impeller it is provided with a thickened portion substantially diametrically opposite the blade 24, as shown in Fig. 1, and this portion serves as a counterbalance. The second cutter blade is 'provided with an inclined cutting edge adapted to cooperate with the cutting edge 22a of the fixed cutter blade 22 and sever paper and the like deposited thereon. As can be seen from Fig. 4, the concave cutter edge 22a and the sloped cutting edge 24a cooperate to have a slicing action or a scissors effect.

In providing the exhaust passage 18 with a cross sectional area increasingflin size from the entrance 199i the exhaust passage to the exit 21 thereof, the rear wall 13c forming the exhaust passage is helically curved. Added cross sectional areas are also provided by posi tioning the inner casing wall 13d inwardly with respect to the outer edge 17a of the blades 17. This gives the elfect of immediately enlarging the exhaust passage from the impeller 16 and speeds the volume flow of air.

In order to rotate the fan or impeller 16, this impeller is mounted on a-wshaft 25 which serves as'an extension ofthe. motor shaft 26. This-shaft ZS-extends through theopening 13b and is provided with a spindle 27 for driving a belt 28; This belt passes around the spindle 27 and then around the hub of a brush 29 for rotating this, brush. t

In the ordinary cleaner of the general type shown in the drawings it has been found that hair, stringand the like work their way in behind the impeller 16 and become wrapped around the rotating shaft 25 or around the inner surface of the hub of the impeller 16 through which the shaft .25 extends. In order to prevent this action there is provided a shield 30 attached to the casing that forms a part of the exhaust passage with this shield extending over the peripheral rim of the impeller 16 to prevent foreign material entering behind the impeller. This shield is adjacent to the periphery of the impeller and overlaps the peripheral area of the impeller, as shown most clearly in Fig. 3. The shield is spaced from the peripheralrim a distance sufiicient to permit normal play in the shaft 25 and thus the impeller 16. In the embodiment shown in the drawings the shield includes an annular planar portion 30a extending outwardly from the inner Wall 13d of the exhaust passage 18 and a cylindrical portion 30b overlapping the peripheral area or rim of the impeller 16. In the embodiment shown the casing portion 15 that is behind the impeller 16 is attached to the remainder of the casing in which the exhaust passage 18 is located by means of spaced bolts 31. The planar portion 3th: of the shield is clamped between the casing portion 15 and the casing portion in which the exhaust passage 18 is formed. 7

In order to provide efficient ventilation of the motor 32, there is provided a centrifugal ventilating fan 33 mounted on the motor shaft 26 immediately behind the front shaft bearing '34. Air is directed into the center of this fan 33 by means of a baffle 35 located inwardly of the fan 33 and the wall 13d defining the exhaust air passage 18 from the nozzle of the cleaner. This baliie 35 has a substantially cylindrical portion 35a positioned inwardly of the wall 13d and a substantially annular planar portion 35b located at the inner end of the portion 35a. This planar portion 35b extends to the wall 13a to make an effective sealing contact therewith. On the front edge of the cylindrical portion 35a there is provided another planar portion 35c extending inwardly and located just rearwardly of the rear edges of the blades 33a of the fan 33. This planar portion 350 is provided with an air inlet opening 35d concentric with the fan 33. This circular opening 35d is located just outwardly of the innermost edges 33b of the fan blades 33a. With this construction, rotation of the fan 33 causes air to be drawn across the motor 32 and through the opening 35a in the other planar portion 350 and then forced outwardly by the rotating blades 33a into the passage 36 defined by the inner surface of'the wall 13d, the cylindrical portion 35a and the first planar portion 35b.

In order to provide entrance and exhaust of the motor cooling air, the frame 37 containing the inotor 32 is provided on its rear surface with air entrance openings 37a, 37b, 37c, 37d, and 37e. When the fan 33 is in operation, air is drawn through these openings 37a to 37c,

inclusive, where it flows across the motor 32 and through the shield opening 35d into the center of the centrifugal fan 33. From this fan, the air flows outwardly between guide means formed by the second casing portion 15 and bafiie planar portion 350 and then through the passage 36. The air then passes out an opening 38 (Fig. 5) to the atmosphere. This opening is formed by cutting away a portion of the casing 13d just to the rear and upwardly of the exhaust passage entrance 19. This cutout part forming the opening 38 extends arcuately around the fan 33 about 90 (Fig. 5) and is located to the right of the casing forming the exhaust air passage when the cleaner is viewed from the front of Fig. l.

The bafiie 35 and associated structure have a multiple function. In one respect, by locating the cylindrical 'por tion 35a adjacent themotor 32 the shield serves to direct air across the motor for maximum cooling. Similarly, the inwardly directed planar portion 35c also aids in directing air across the motor. The combination of the portion 35a and the planar portions 35b and'35c also provide one side of the outlet passage 36 for exhausting the air from the centrifugal fan 33'. By locating the guide means including the planar portion 35c adjacent to the blades 33a the fan 33 operates at maximum efiiciency to draw a strong air current across the motor in substantially streamline flow. By locating the inlet opening 35d in the bafiie adjacent the inner edges of the blades 33a, all of the air is directed to the inner edges of the blades 33a so that maximum suction and thus maximum air flow is obtained.

By locating the fixed cutter blade 22 at the entrance 19 to the exhaust passageway 18 with the exit 21 of the passageway spaced from the impeller 16 and rearwardly of the entrance 19 and by providing a second cutter blade rotatable with the impeller and cooperating with the fixed blade to sever foreign material deposited at this entrance and thus on the fixed blade, one portion of the severed material will pass directly rearwardly and through the exit 21 into the dust bag of the cleaner. The other portion which will be forwardly of the fixed blade 22 as seen in Fig. 1 will pass around the exit passageway 18 so that it can again be cut if necessary and if it again catches on the fixed blade 22. This arrangement and operation not only prevents jamming of the impeller but also insures that all large particles are immediately cut into small pieces and exhausted into the bag. This has the dual effect of providing that all foreign matter be exhausted into the bag without delay and also results in a smooth air fiow and less back pressure as any particles flowing around the exhaust passageway with the air are necessarily small comminuted particles except possibly the foreign material which pass directly rearwardly from the fixed blade 22 out the exhaust 21. This latter material is in the exhaust air stream such a very small time it has little eifect on raising the back pressure.

The ventilating apparatus including the fan 33, baflle 35-and associated structure is described and claimed in Addison Ballard Bradley, Jr. application Serial No. 256,726, filed November 16, 1951. The thread shield including the member 30 and associated structure is described and claimed in Frank S. Howard application Serial No. 256,874, filed November 17, 1951.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description unless otherwise specified but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

Iclaim:

1. In a centrifugal fan structure including a rotatable fluid impeller and means constituting an exhaust passage extending around the impeller periphery and rearwardly thereof in'an axial direction, the exhaust passage increasing in depth helically substantially parallel to said axial direction from an area of substantial width adjacent to the periphery to an exhaust port, a fixed cutter blade located at said area and extending laterally across the exhaust passage to catch foreign material that may be lodged at said area, and a second cutter blade on the impeller for cooperation with the fixed blade to sever material lodged thereon, both said cutter blades being located beyond the periphery of the impeller to prevent substantial interference with the operation of the impeller.

2. The fan structure of claim 1 wherein the fixed cutter blade is provided with a concave cutting edge of relatively great depth and the second cutter blade is provided with a cutting edge sloped with respect to said concave cutting edge and cooperating with said concave cutting edge to produce a scissors action therebetween.

References Cited in the file of this patent UNITED STATES PATENTS