US3145912A

US3145912A - Portable centrifugal pump

Info

Publication number: US3145912A
Application number: US210757A
Authority: US
Inventors: Weis Arthur
Original assignee: ARTAG PLASTICS CORP
Current assignee: ARTAG PLASTICS CORP
Priority date: 1962-07-18
Filing date: 1962-07-18
Publication date: 1964-08-25
Anticipated expiration: 1981-08-25

Description

Aug. 25, 1964 A was 3,145,912

PORTABLE CENTRIFUGAL PUMP Filed July 18, 1962 4 Sheets-Sheet 1 I I INVENTOR.

% /W Zl/r A TTORNE YS Aug. 25, 1964 wE s PORTABLE CENTRIFUGAL PUMP 4 Sheets-Sheet 2 Filed July 18, 1962 I NVEN TOR. 74/2771 We/s A TTORNE YS Aug. 25, 1964 A. WEIS 3,145,912

PORTABLE CENTRIFUGAL PUMP Filed July 18, 1962 4 Sheets-Sheet s INVEN TOR. Jrzhur Wel's A TTORNE YS Aug. 25, 1964 A. WEIS PORTABLE CENTRIFUGAL PUMP 4 Sheets-Sheet 4 Filed July 18, 1962 INVENTOR, Arthur We/s A TTORNE YS United States Patent 3,145,912 PORTABLE CENTRIFUGAL PUMP Arthur Weis, Chicago, Ill., assignor to Artag Plastics Corporation, Chicago, lll., a corporation of Illhrois Filed July 18, 1962, Ser. No. 210,757 3 Claims. ((11.230-127) This invention relates to improvements in pumps or blowers and more particularly relates to an improved form of centrifugal blower or pump which may be used to pump fluid such as air or water.

A principal object of the present invention is to provide a portable non-corrosive light-weight hand operated pump particularly adapted for supplying fresh air to fall-out shelters and the like, and arranged with a view towards utmost simplicity and efliciency in construction and operation.

A further object of the invention is to provide a compact lightweight centrifugal pump for fall-out shelters and the like in which the impeller of the pump is operated by a hand crank through step-up drive gearing, and in which the casing and impeller of the pump are made from a plastic material, making the pump suitable for use in fall-out shelters and for storing in the shelter without corroding.

Another object of the invention is to provide a simple form of centrifugal pump for fall-out shelters and the like in which the casing of the pump is so constructed and arranged as to enable the pump to readily be converted from a negative pressure air pump toa positive pressure air pump.

A still further object of the invention is to improve upon the centrifugal pumps heretofore in use by so arranging the casing and impeller of the pump that they may be made from a plastic, without impairing the strength or efficiency of the pump.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings where- FIGURE 1 is a front end view of a centrifugal pump constructed in accordance with the principles of the present invention;

FIGURE 2 is a transverse sectional view of the pump, taken substantially along line IIII of FIGURE 1;

' FIGURE 3 is a transverse sectional view of a rear housing part of the pump for converting the pump from a negative pressure pump to a positive pressure pump;

FIGURE 4 is a side elevational view of the pump with one end cover removed in order to show certain parts of the impeller and scroll;

FIGURE 5 is a sectional view taken substantially along line VV of FIGURE 1, illustrating certain of the drive gearing to the pump;

FIGURE 6 is a transverse sectional view taken substantially along line VIVI 0f FIGURE 1 and showing certain other drive gearing not shown in FIGURE 5; and FIGURE 7 is a sectional view taken substantially along line VIIVII of FIGURE 4 and showing a portion of a pump vane in transverse section.

In the embodiment of the invention illustrated in the drawings, I have shown in FIGURES 1 and 2, a centrifugal pump or blower including a housing 10 comprising a front housing part 11 mounted on and extending upwardly from

spaced legs

12, 13 and 14, forming a base for the pump. The casing 10 also has a rear housing part 15 conforming to the housing part 11 and suitably secured thereto in air tight relation with respect thereto. The

housing parts

11 and 15 also have mating parts of a hand grip 17 formed integrally therewith and fastened together in an abutting relation with respect to each other by machine screws 18 which may extend through one part and be threaded in the other part.

The

housing parts

11 and 15 are preferably made from a non-corrosive material and may be made from a plastic such as, polypropylene. It should be understood that the housing parts may also be made from various other plastic materials and may be made from lightweight non-corrosive metals if desired.

The rear housing part 15 has an inlet opening 19 leading thereinto coaxial with the center of an impeller 20 mounted on a drive shaft 21, journalled in the housing part 11 on a bearing 22. The inlet opening 19 may have a flexible tube (not shown) connected thereto and leading outside of the shelter to a source of fresh air, to accommodate fresh air to be drawn into the impeller chamber 23 within the housing 10 to be expelled through an outlet 24 (FIGURE 4), leading from a scroll 25 within said housing. The outlet 24 leads tangentially of a helical wall 26 of the scroll 25.

The front housing part 11 of the casing 10 has an outwardly opening recessed portion 29, closed by a detachable cover 30 and with said cover forming a gear casing, encasing step-up gearing driven by a hand crank 31 on the outside of the cover 30 and driving the impeller 20 at a substantially increased speed of rotation from the speed of rotation of the hand crank 31. The hand crank 31 is mounted on the outer end of a crank shaft 32 journalled in the cover 30 and in a boss 33 within the gear casing 29, formed integrally with the rear housing part 11, on spaced bearings 35 (FIGURE 6).

The drive connection from the hand crank 31 to the impeller shaft 21 is a step-up drive connection and includes a spur gear 36 pressed on a knurled portion of the crank shaft 32 and meshing with an idler pinion 37 on an idler shaft 39. A spur gear 40 is shown as being formed integrally with the hub of the idler pinion 37 and as meshing with and driving a pinion 41 freely mounted on the crank shaft 32. A spur gear 42 is shown as being formed integrally with the spur pinion 41 and as meshing with and driving a spur pinion 43 secured to the impeller shaft 41 for driving said shaft. The gears just mentioned may be made from a nylon material while the shafts may be made from stainless steel.

It may here be seen that a compact arrangementof step-up gearing is provided for driving the impeller shaft 21 and impeller 20 from the hand crank 31 at asubstantially increased speed of rotation from the speed of rotation of the hand crank 31. A suitable step-up gear ratio is a ratio of 1 to 46, although the ratio may be greater or less than this ratio, in accordance with the requirements for ease in driving the impeller by hand to produce the required air flow to provide sufficient air to safely ventilate the fall out shelter. I

The impeller chamber 23 is formed by a frusto conical face 44 of a disk 45 of the impeller and a generally frusto conical wall 46 of the rear housing part 15 (FIGURE 2).

3 The conical face 44 of the disk 45, with the frusto conical wall 46 form a converging annular passageway spaced inwardly of and leading generally radially of the impeller to the scroll 25. The disk 45 has a central boss 47 formed integrally therewith and shown as being pressed onto a knurled end 48 of the shaft 21.

The disk 45 has a plurality of equally spaced blades or vanes 50 projecting from the face thereof generally perpendicular thereto, as shown in FIGURE 7. The vanes 50 are spaced radially from the center of the disk 45 and the inner end portions thereof are generally in alignment with the extended inner margins of the inlet 19. The vanes 50 have outer edges 51 spaced closely adjacent and conforming to the frusto conical wall 46 of the impeller chamber 23 and terminating at their inner ends at a cylindrical wall 52 of larger diameter than the inlet 19, and converging at its outer end to the inlet in a uniform curve and forming a plenum chamber at the inlet end portion of the impeller chamber.

The impeller blades or vanes 50 extend outwardly along the frusto conical face 24 at retreating angles with respect to radial lines extending to the center of the impeller, and have forwardly curved end portions forming said vanes into a plurality of impelling pockets or buckets 53, opening in the direction of rotation ofthe impeller. The inner end portions of the vanes 50 terminate adjacent the inner end of the frusto conical wall 46 of the impeller chamber 23, and are inclined to open towards the inlet 19. The impeller 20 may be made from a plastic material such as polypropylene, or other suitable polymers.

The scroll formed by the

mating housing parts

11 and 12 has a peripheral central generally helical wall portion 26, starting from a cut-off lip 56 at the outlet 24 and generating a helix diverging from the impeller 20 as said wall portion merges into the outlet 24. The scroll also has opposite semi-circular side wall portions 59 and 60 formed in the

respective housing parts

11 and 15 and facing each other and leading from the wall portion 26 and terminating at the outer edge of the impeller chamber 23, to form a widened scroll or fluid passageway chamber, increasing in cross-sectional area from the cut-off lip 56 to the outlet 24.

The pump just described is known as a negative pressure pump or blower, that is, a negative static pressure is produced at the pump inlet by the sucking action of the pump as air is drawn through the inlet into the impeller chamber. Static pressure, as herein referred to, is the pressure measured in a gas in such a manner that the velocity of the gas has no afiect on the measurement. The static pressure at the blower outlet is the positive pressure the blower must operate against.

The pump, however, may readily be converted from a negative pressure pump to a positive pressure pump by interchanging a rear housing part 61, shown in FIGURE 3, for the rear housing part 15. The rear housing part 61 mates with the front housing part 11, to form the impeller chamber 23 and scroll 25, and has an inner frusto conical wall 63 like the frusto conical wall 23 and diverging from the scroll and terminating at an inlet 65, pro tected by a screen or grating 66.

In a positive pressure pump, the resistance to the flow of air into the impeller chamber and scroll has been reduced to such an extent that the pressure at the inlet is a positive static pressure rather than a negative static pressure. A positive pressure pump may advantageously be used to provide a circulation of air in a fall-out shelter and to exhaust stale or contaminated air from the shelter.

The pump just described either in the form of a positive pressure pump or a negative pressure pump provides a compact non-corrosive lightweight portable pump of ample capacity to provide the fresh air requirements for a small family type of fall-out shelter, which may contain from 6 to 20 occupants, to prevent carbon dioxide concentration of the air in the shelter, and also to remove objectionable body odors from the shelter.

The minimum amount of fresh air required per person for cubic feet of volume to prevent carbon dioxide concentration from rising above a safe level is 4 c.f.m. and a shelter large enough for six persons, assuming 100 cubic feet of shelter volume per person, requires as a minimum, 24 c.f.m. The fresh air required to remove objectionable body odors from a sedentary adult is approximately 24 c.f.m. at 100 cubic feet per person. The maximum ventilation requirement, therefore, for a six person shelter is approximately 144 c.f.m.

For a 20 person fall-out shelter, assuming the internal volume of the shelter to be 2000 cubic feet, the minimum and maximum ventilation requirements would be 80 and 480 c.f.m. respectively. In order to satisfy the maximum requirements for a 20 person fall-out shelter, more than one pump may be used, the pump of the present invention producing over c.f.m. at minus 0.75 static pressure at the pump inlet, when operated by hand without the exercise of an undue amount of exertion by the operation.

It should here be understood that while the pump herein disclosed is described as a centrifugal blower for use in impelling air that it may advantageously be used in impelling water or other fluids.

While I have herein shown and described one form in which my invention may be attained, it may readily be understood that various variations and modifications in the invention may be attained without departing from the spirit and scope of the novel concepts thereof as defined by the claims appended hereto.

I claim as my invention:

1. A centrifugal ventilating pump comprising an upright two piece housing made from a light weight noncorrosive material having a front part having an outwardly opening gear casing therein and a rear part mating with said front part, an impeller chamber within said housing parts and having a front planar interior wall portion, an impeller journalled in said impeller chamber and having a rear face abutting said front planar interior wall portion, said impeller chamber also having a rear frustoconical interior wall portion facing said impeller and spaced axially therefrom and generally sloping outwardly from the outer periphery of said impeller toward the extended axis of rotation of said impeller, a plenum chamber leading into the small diameter end of said frustoconical interior wall, an inlet leading into said plenum chamber coaxial of the axis of rotation of said impeller, an outlet leading from the bottom portion of said housing generally tangential of said impeller and with said housing defining a cut-off lip extending between said wall portions transversely of said impeller and adjacent the outer margin of said impeller, a scroll extending about said impeller chamber having an inner peripheral wall increasing in radial spacing from the center of said impeller from said cut-off lip to said outlet in the general form of a helix and progressively increasing in cross-section from said cut-off lip to said outlet, a crank journalled in said front part and having a shaft extending within said gear casing, step-up drive gearing in said gear casing and connecting said crank shaft with said impeller, said impeller including a frusto-conical disk generally conforming to the frusto-conical form of said rear interior wall portion and having a plurality of spaced vanes extending axially of and along the frusto-conical face thereof from positions spaced radially outwardly from the center of said disk at the intersection of the projected margin of said inlet with said disk and extending along said disk toward the periphery thereof at retreating angles with respect to the direction of rotation of said disk and having curved outer end portions curved forwardly in the direction of rotation of said impeller and forming impeller buckets impelling fluid from said inlet through said outlet, said vanes having inner edges sloping outwardly from the intersection of the extended margin of said inlet with said impeller to positions adjacent the margin of said plenum chamber and having outer faces conforming to and having 5 close clearance with said frusto-conical face of said rear interior wall partion.

2. A centrifugal ventilating pump in accordance with claim 1 wherein said housing parts and impeller are made from a plastic material.

3. A centrifugal ventilating pump in accordance with claim 1 wherein said housing parts are made from polypropylene.

References Cited in the file of this patent UNITED STATES PATENTS I 941,980 Deslot Nov. 30, 1909 6 Still Apr. 21, 1914 Fullemann J an. 2, 1945 Chubbuck Feb. 26, 1957 Bleier Aug. 12, 1958 Dalton June 21, 1960 Pabst Jan. 3, 1961 Prasse et a1 June 19, 1962 FOREIGN PATENTS France Aug. 2, 1902 France Apr. 3, 1928 France Nov. 29, 1929 France Mar. 17, 1931

Claims

1. A CENTRIFUGAL VENTILATING PUMP COMPRISING AN UPRIGHT TWO PIECE HOUSING MADE FROM A LIGHT WEIGHT NONCORROSIVE MATERIAL HAVING A FRONT PART HAVING AN OUTWARDLY OPENING GEAR CASING THEREIN AND A REAR PART MATING WITH SAID FRONT PART, AN IMPELLER CHAMBER WITHIN SAID HOUSING PARTS AND HAVING A FRONT PLANAR INTERIOR WALL PORTION, AN IMPELLER JOURNALLED IN SAID IMPELLER CHAMBER AND HAVING A REAR FACE ABUTTING SAID FRONT PLANAR INTERIOR WALL PORTION, SAID IMPELLER CHAMBER ALSO HAVING A REAR FRUSTOCONICAL INTERIOR WALL PORTION FACING SAID IMPELLER AND SPACED AXIALLY THEREFROM AND GENERALLY SLOPING OUTWARDLY FROM THE OUTER PERIPHERY OF SAID IMPELLER TOWARD THE EXTENDED AXIS OF ROTATION OF SAID IMPELLER, A PLENUM CHAMBER LEADING INTO THE SMALL DIAMETER END OF SAID FRUSTOCONICAL INTERIOR WALL, AN INLET LEADING INTO SAID PLENUM CHAMBER COAXIAL OF THE AXIS OF ROTATION OF SAID IMPELLER, AN OUTLET LEADING FROM THE BOTTOM PORTION OF SAID HOUSING GENERALLY TANGENTIAL OF SAID IMPELLER AND WITH SAID HOUSING DEFINING A CUT-OFF LIP EXTENDING BETWEEN SAID WALL PORTIONS TRANSVERSELY OF SAID IMPELLER AND ADJACENT TO OUTER MARGIN OF SAID IMPELLER, A SCROLL EXTENDING ABOUT SAID IMPELLER CHAMBER HAVING AN INNER PERIPHERAL WALL INCREASING IN RADIAL SPACING FROM THE CENTER OF SAID IMPELLER FROM SAID CUT-OFF LIP TO SAID OUTLET IN THE GENERAL FORM OF A HELIX AND PROGRESSIVELY INCERASING IN CROSS-SECTION FROM SAID CUT-OFF LIP TO SAID OUTLET, A CRANK JOURNALLED IN SAID FRONT PART AND HAVING A SHAFT EXTENDING WITHIN SAID GEAR CASING, A STP-UP DRIVE GEARING IN SAID GEAR CASING AND CONNECTING SAID CRANK SHAFT WITH SAID IMPELLER, SAID IMPELLER INCLUDING A FRUSTO-CONICAL FACE THEREOF FROM POSITIONS SPACED RADIALLY OUTWARDLY FROM THE CENTER OF SAID DISK AT THE INTERSECTION OF THE PROJECTED MARGIN OF SAID INLET WITH SAID DISK AND EXTENDING ALONG SAID DISK TOWARD THE PRERIPHERY THEREOF AT RETREATING ANGLES WITH RESPECT TO THE DIRECTION OF ROTATION OF SAID DISK AND HAVING CURVED OUTER END PORTIONS CURVED FORWARDLY IN THE DIRECTION OF ROTATION OF SAID IMPELLER AND FORMING IMPELLER BUCKETS IMPELLING FLUID FROM SAID INLET THROUGH SAID OUTLET, SAID VANES HAVING INNER EDGES SLOPING OUTWARDLY FROM THE INTERSECTION OF THE EXTENDED MARGIN OF SAID INLET WITH SAID IMPELLER TO POSITIONS ADJACENT THE MARGIN OF SAID PLENUM CHAMBER AND HAVING OUTER FACES CONFORMING TO AND HAVING CLOSE CLEARANCE WITH SAID FRUSTO-CONICAL FACE OF SAID REAR INTERIOR WALL PORTION.