US2825605A

US2825605A - Means for conveying powdery material in fine distribution, particularly for use in flash die casting

Info

Publication number: US2825605A
Application number: US566725A
Authority: US
Inventors: Biel Hans; Kuhfuss Runwalt; Raschke Waldemar
Original assignee: Hans Sickinger Co
Current assignee: Hans Sickinger Co
Priority date: 1955-02-22
Filing date: 1956-02-20
Publication date: 1958-03-04
Anticipated expiration: 1975-03-04

Description

BIEL ET AL March 4, 1958 MEANS FOR CONVEYING POWDERY MATERIAL IN FINE DISTRIBUTION, PARTICULARLY FOR USE IN FLASH DIE CASTING 2 Shee'ts-S'neet 1 Filed Feb. 20, 1956 March 4, 1958 v H. BIEL ET AL 2,825,605

MEANS FOR CONVEYING POWDERY MATERIAL IN FINE DISTRIBUTION, PARTICULARLYFOR USE IN FLASH DIE! CASTING Filed Feb. 20, 1956 2 Sheets-Sheet 2 of x I 1! FEE-E NVENTORS. #4713 2 e 7 iv 71 W47; flz'zzfzzsa V/JZZ 77747 iaseZZe aim 3K3 United States Patent MEANS FOR CONVEYiNG POWDERY MATERIAL IN FINE DISTRIBUTION, PARTICULARLY FOR USE IN FLAH DIE (TASTING Hans Biel, Neuifen, Runwalt Kiihfuss, Metzingen, and Waldemar Raschke, Nani-fen, Germany, assignors to Hans Sicldnger, Providence, R. I.

Application February 2t 1956, Serial No. 566,725 Claims priority, application Germany February 22, 1955 8 Claims. (Cl. 302-36) This invention relates to the conveying of powdery material in the so-called flash die casting method and similar methods of applying layers of some material. In these methods, the powdery material should be conveyed to the required apparatus in an exceedingly fine and uniform distribution. To this end, the material mixed with air in a certain ratio is educted from a container in which it is subjected to a whirling motion. In known devices, the material is whirled up either by a stream of gas or by such mechanical means as turning of the container. These means are however insufiicient. In some cases, the material when mixed with air in a certain proportion is whirled up insufficiently; in others, powder grains are screened out so that the finer particles are educted first. In most cases, a considerable remainder is left behind in the container, which is no longer educted.

It is an object of the present invention to provide a conveyor for powdery material which overcomes the disadavntages of previously known devices and is economical to fabricate, efiicient in operation and of versatile use. Other objects will be apparent from the following description and claims.

Under the present invention, a drum of generally known construction containing the material is connected with a rotary drive on a horizontal axis. Inwardly pointing blades are arranged inside the drum in such a manner that during rotation of the drum, filled to less than one half with material, the material is carried by the blades upwardly in the direction of rotation and after passing above the horizontal axial plane will drop downwardly from between the blades and fall back into the effective range of a suction point located within the drum. Through this system the above defects of previously known devices can be eliminated. The powdery material is thus whirled up in an even and vigorous manner, independent of the quantity of suction air. All grains of the material are simultaneously and uniformly seized by this whirling motion. The material contained in the container can be educted completely as even the smallest quantities will be seized and lifted by the blades.

To suit the specific nature of the material, different control arrangements may be provided. Thus, the stationary suction pipe, which projects through a sealed aperture coaxial with the drum shaft and is provided within the drum with one or more suction slits, may be rotatably adjustable independent of the drum, so that the position of the suction slits may be varied in relation to the dropping material cloud. Moreover, the rotary drive of the drum may be provided with an infinitely variable speed gear so that the drum speed may be varied. Finally, the position of the blades may be adjustable within the drum.

It is another advantageous operational feature of the apparatus of this invention that the drum, together with its drive, is incorporated in a frame preferably made of tubing, thus providing a portable structure, so that the drum may be set up either for horizontal operation or,

2,825,605 Patented Mar. 4, 1958 optionally, for vertical operation so as to be fed through a detachable cover located on the face side opposite the drive.

A preferred embodiment of the invention is described in detail with the aid of attached drawings, in which:

Figure 1 represents a side view partly in cross section of the apparatus in its operational position;

Fig. 2 is a cross-sectional view taken along the line 2-2 of Fig. l and showing the arrangement of blades within the drum;

Fig. 3 is a front view of the apparatus taken in the direction of arrow 3 of Fig. 1 and showing suction tube adjusting means;

Fig. 4- is a detail view of a portion of the belt drive taken along the line 4-4 or Fig. 1;

Fig. 5 is a side view of the apparatus in its operational position, showing the side opposite that of Fig. 1;

Fig. 6 is a fragmentary view of the device in the feeding position with detached cover and suction pipe holder; and

Figure 7 is a fragmentary side elevational view showing a modified form of invention which incorporates angularly adjustable blades.

The receptacle for the powdery material is a cylindrical drum it which may be closed at its open end with a cover 2. Cover 2 can be locked in its closed position with the aid of quick-action toggle levers 3 of known design which are located at the drum edge. A flanged shaft 3 is fixed to the bottom of drum 1 opposite cover 2 to serve as a rotatable support.

Drum I, together with its drive, is carried by a frame 5 consisting of welded tubes. The drum drive is accommodated in and supported by a housing 6 that extends across nearly half of frame 5 and which is formed by sheet metal Walls fastened between the tubes of frame 5 (one wall being removed in Figure 1 for illustrative purposes). For the drive of drum 1 an electric motor 7 is provided which, in the present embodiment of the invention, is positioned at the outer face wall of housing 6. Drum shaft 4 is mounted in a bearing 8 forming part of a gear case 9 located at the front end of housing 6 opposite motor 7. The free end of drum shaft 4 projecting from hearing 8 within housing 6 carries a worm wheel It) which meshes with a worm on shaft 11 mounted in gear case 9. Worm shaft 11 is connected to a shaft 14, which is also mounted in gear case 9, by means of a pair of spur gears l2, 13 within gear case 9. Between shaft I4 and motor 7 a back gear shaft 15 is provided which is driven by V-belt drive 16 from the motor and which drives shaft 14 by another V-belt. Gear 13 may be dis placed on shaft 14 by means of a shiftable lever 18 in such a manner as to be brought out of mesh with gear 12 of worm shaft 11, thus interrupting the driving connection between motor 7 and drum 1. Thus the drum may be clutched with the drive, in the present embodiment, with the aid of control lever 18 projecting through a slot in the outer front wall of housing 6. Similarly, the clutch could be incorporated in a variable speed gear operable by lever 18.

Back gear shaft 15 is mounted between motor 7 and gear case 9 on a rocking lever 19 which may be adjusted by means of a rod 20 and crank 21 operated by a control knob 22 located on a side wall of housing 6. The two V-belts 16 and 17 are passed between V-belt pulleys 23, 24 and 25 mounted on shaft 15, the central pulley 24 being provided with inclined faces on either side and sli-dably mounted on back gear shaft 15. As a result, an infinitely variable transmission is obtained between the motor shaft and the coupling shaft. If lever 19 is moved by means of control knob 22, for instance in the direction of arrow 26 in Figure 1, the distance between back gear shaft 15 and the motor shaft increases while that between the back gear shaft and coupling shaft 14 decreases. Therefore central V-belt pulley 24 is displaced axially in such a manner that the motor belt 16 is pulled down deeper between V-belt pulleys 23 and 24 so as to run on a smaller diameter, while the second belt 1'7 between V-belt pulleys 24 and 25 is moved outward onto a larger diameter. As a result, the transmission ratio between motor 7 and drum 1, is changed so that the drum speed is increased. To start and stop motor 7, a switch 27 is provided on the same side of housing 6 on which knob 22 for the speed control is located. On the same side of housing 6 a current supply line 28 is introduced.

The inside wall of drum 1 is provided with a plurality of blades 29 which, in the present embodiment, are arranged in a radial system (Figure 2). These blades 29 are preferably attached to a hollow cylinder 30 fitted into the drum, and extend the entire length between drum bottom and cover 2. if required, the blades may be linked with the shell of the drum or cylinder 30 and rendered angularly adjustable with respect to the drum shell by means of a ring movably mounted at either face side.

Figure 7 shows a modified form of the invention which incorporates angularly adjustable blades. In this figure, a drum 44 is shown having a cover 45 at one end, a hollow cylinder 46 being disposed within the drum. Fixed to the interior of cylinder 46 are a plurality of pairs of trunnions 47, said trunnions being located at opposite ends of the cylinder. Between each pair of trunnions, a blade 48 is pivoted for rocking movement by means of pins 49 extending from the ends of the blades. A longer pin 51 is attached to one end of each blade and extends into a slot 52 in a ring 53, this ring being disposed at one end of cylinder 46 and being held in position by an annular spacing member 54. Ring 53 is provided with a plurality of slots 52, a pin being disposed within each slot. it will be apparent from an examination of Figure 7 that, by rotatably adjusting ring 53, the angular positions of blades 48 may be simultaneously altered.

Coaxially with drum 1, a tube 31 projects through a bore in drum cover 2, being sealed to the drum cover so that rotation is permitted but axial movement is prevented. The portion of tube 31 located within drum 1 is closed at its free end While its shell is provided with one or more slots 32. The end of tube 31 located outside cover 2 is adapted to be connected with a preferably fiexible suction conduit 33. Between the conduit end and cover 2, a swinging arm 34 is arranged on tube 31, in which a set screw 35 is mounted parallel to the drum shaft. By means of this set screw 35, tube 31 can be fastened to a holding device connected with frame 5. The holding device is equipped with a ring 36 surrounding tube 31 which ring is provided with teeth to receive the point of set screw 35. For locking on frame 5, ring 36 is provided with radial arms 37 having bores at their ends to fit over studs 38 projecting from the tubes of the front structure of frame 5. By tightening set screw 35, tube 31 is thus locked with frame 5. Tube 31 can be adjusted by turning arm 34 and displacing set screw 35 on holder ring 36 to any desired position with respect to cover 2 or drum ll, thus enabling the position of the slots 32 in tube 31 to be changed within the drum. To introduce tube 3?: into holder ring 36, the latter has been provided with a slotted aperture 39 (Figure 3) on its circumference.

Tubular frame is constructed as a supporting structure of portable type. To this end, it is provided with handles 40 located on the face side near drum cover 2. On its opposite side a kind of handle is provided (41) by the shape of housing 6. The longitudinal sides of tubular frame 5 are designed as undercarriage skids.

To feed the powdery material, the apparatus is set up in the vertical position shown in Figure 6 so that the open front side of drum 1 that may be closed with cover 2 is pointing upward. After

holder

36, 37 and cover 2 have been removed, the drum may be fed from above. The powder quantity to be fed into the drum should not exceed one half of the drum space with loose density, so that the bulk remains below the drum shaft (Figure 2) while the drum is in its horizontal position. After the drum has thus been charged and cover 2 and

holder

36, 37 have been replaced, the apparatus is brought, for instance, into the position illustrated in Figure 5 so that the drum assumes a horizontal position. Now motor '7 is started by means of switch 27. The clutch 12, 13 is engaged by means of hand lever 13 so that the drum revolves. By turning knob 22, the speed of the drum may be adjusted. Suction tube 31 is brought into its proper position in which it will be locked by means of set screw 35 located on

holder

36, 37 and finally is connected with the suction system.

As the drum revolves, a part of the powdery material is always carried upard in the sense of rotation, and will then slide down, while in the drum section above the horizontal axial plane, by its own weight, from between blades 29 and drop back into the lower drum section. The dropping material will form a fine cloud of material, part of which will be educted through slots 32 in suction tube 31. As blades 29 will seize the material even when the container is almost empty, complete conveyance of the material is produced under constantly uniform conditions. Through adjustment of the drum speed, positioning of suction slots 32 on suction tube 31, and, in case of need, adjustment of inclination of blades 29, the specific requirements of the individual material can be fully met with. in the present embodiment, blades 29 are arranged parallel to the drum shaft. They could however be arranged at an angle to the dum shaft, i. e., in a helical or spiral manner.

As the material is conveyed through the air, provision must be made for admission of air into the drum. For this purpose, the drum is provided in a suitable place with a bore (not shown). This bore is preferably made on the face side of the drum opposite cover 2. In order to ensure that air penetrates the drum and to prevent leakage of material through this bore, the latter is suitably covered with a fine screen.

The pressure within the drum may be adjusted by the provision of one or more apertures in suction tube 31 outside the drum, each of which should be capable of being completely or partially closed by a screw 43 as shown in Figure 6. As these apertures may be closed gradually, the rate of admission of outside air into the suction tube is adjustable and will depend on such factors as the material graining, intensity of pressure in the drum and the specific gravity of the powdery material.

While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

l. A device for conveying powdery material in fine distribution, comprising a drum, means supporting said drum for rotation on a horizontal axis, drive means for rotating said drum, a plurality of inwardly projecting blades extending along the inner surface of said drum, said blades being so arranged as to carry material upwardly in the direction of rotation of said drum which material may drop from between the blades to form a cloud, a suction tube connected to the interior of said drum to draw off the cloud of powdery material, said suction tube having a cylindrical outer surface and extending a substantial distance into said drum coaxially thereof, and a plurality of openings in said cylindrical surface along the portion of said tube within said drum.

2. A device for conveying powdery material in fine distribution, comprising a drum, means supporting said drum for rotation on a horizontal axis, drive means for rotating said drum, a plurality of inwardly projecting blades extending along the inner surface of said drum, said blades being so arranged as to carry material upwardly in the direction of rotation of said drum which material may drop from between the blades to form a cloud, a tube of cylindrical shape extending coaxially through one end of said drum into the interior thereof, a seal between said tube and said drum end, means for connecting the outer end of said tube to a source of suction, and an opening in the cylindrical surface on the inner portion of said tube, whereby the cloud of powdery material may be educted through said tube.

3. The combination according to claim 2, said tube opening comprising a slot in the wall of said tube, and means mounting said tube for rotatable adjustment independently of the position of said drum, whereby said slot may be angularly adjusted with respect to the cloud of powdery material.

4. A device for conveying powdery material in fine distribution, comprising a drum, means supporting said drum for rotation on a horizontal axis, drive means for rotating said drum, an infinitely variable transmission gearing included in said drive means, a plurality of inwardly projecting blades extending along the inner surface of said drum, said blades being so arranged as to carry material upwardly in the direction of rotation of said drum which material may drop from between the blades to form a cloud, a suction tube connected to the interior of said drum to draw off the cloud of powdery material, said suction tube having a cylindrical outer surface and extending a substantial distance into said drum coaxially thereof, and a plurality of openings in said cylindrical surface along the portion of said tube within said drum.

5. A device for conveying powdery material in fine distribution, comprising a drum, means supporting said drum for rotation on a horizontal axis, drive means for rotating said drum, a plurality of inwardly projecting blades extending along the inner surface of said drum, said blades being so arranged as to carry material upwardly in the direction of rotation of said drum which material may drop from between the blades to form a cloud, means for adjusting the inclination of said blades with respect to the drum surface, and a suction tube connected to the interior of said drum to draw off the cloud of powdery material.

6. A device for conveying powdery material in fine distribution, comprising a rectangular frame, a fiat supporting portion at one end of said frame, a second fiat supporting portion on one side of said frame, whereby the frame is capable of standing upright or resting on its side, a drum mounted within one portion of said frame, means supporting said drum for rotation on an axis parallel to the length of said frame, a removable cover on said drum adjacent the end of said frame opposite said first flat supporting portion, drive means mounted within another portion of said frame for continuously rotating said drum, a plurality of inwardly projecting blades extending along the inner surface of said drum, said blades being so shaped as to carry powdery material upwardly within said drum in the direction of rotation of the drum and permitting said material to drop back so as to form a cloud, and a suction tube connected with said drum interior for educting said material cloud therefrom, the arrangement of said parts being such that said drum may be charged when said frame is standing in its upright position and said material may be educted when said frame is resting on its side.

7. The combination according to claim 6, said suction tube extending coaxially through said cover, and means for adjustably securing said tube in selected angular positions, comprising a holder secured to said frame and concentric with said tube axis, a radial arm on said tube, and means for adjustably securing said arm to said holder.

8. A device for conveying powdery material in fine distribution, comprising a drum, means supporting said drum for rotation on a horizontal axis, drive means for rotating said drum, a plurality of inwardly projecting blades extending along inner surface of said drum, said blades being so arranged as to carry material upwardly in the direction of rotation of said drum which material may drop from between the blades to form a cloud, a tube having a cylindrical outer surface extending coaxially through one end of said drum into the interior thereof, a seal between said tube and said drum end, means for connecting the outer end of said tube to a source of suction, an opening in said cylindrical surface on the inner portion of said tube, whereby the cloud of powdery material may be educted through said tube, a pressure-regulating aperture in said tube connected to the atmosphere outside said drum, and an adjustable restriction for said aperture, whereby the degree of suction may be varied.

References Cited in the file of this patent UNITED STATES PATENTS 995,422 Clarke June 13, 1911 1,686,256 Royle Oct. 2, 1928 2,471,314 Curtis May 24, 1949 2,503,170 Plos Apr. 4, 1950