US1789874A - Yieldable propeller - Google Patents

Description

Jam 20, 1931. s, LILLY 1,789,874

' YIELDABLE PROPELLER Filed 001;. 15,, 1928 Snow doc Scott HLMIH.

In 19. %rdinarily the blades will be maintained in mm; Jan. 20, 1931 PATENT OFFICE scorer 1:. unit, or romno, omaassronoa, 3r unsma assrenmnnrs, r0 sr. nears rum com-m, or new roux, N. 2., acoaromrron or new YORK YIELDABLE PROPELLEB Application filed October 15, 1828. Serial No. 812,496.

This invention relates to a yieldable propeller and has for its object to provide a problades which automatically adjust themse s glroximately even pressure u on the material vertical section,

scharged, regardless of t e rate of discharge. g

The invention will be described as aBphed to a device similar to that disclosed in atent No. 1,658,734, issued to Lewis D. Nelson February 7, 1928, for feeding material into valve bags, and is particularly adapted for feeding granular or pulverulent material.

In the accompanying drawings forming a part of this specification, Figure 1 shows a on the line 11 of Figure 2, throu h a propeller embodying the invention, wit a portion of a casing suflicient to indicate the relation of the propeller to the casing; Fi re 2 is a plan view of the'parts shown in i 1; Fig. 3 is a fra mentary section on the lme 3--3 of Fig. 1; ig. 4 is a detail view showing a portion of a propeller blade.

In the construction shown, there is a casing 10 which may be .of substantially cylindrical formation, having a bottom 11 and a discharge spout 12 at one side thereof adjacent the bottom. Immediately above the bottom there is a disk 13 having a conical boss 14 around its center and mounted upon a vertical shaft 15, which may be driven in any desired manner. Attached to the u per' surface of disk 13 there is a series of lades 16. The blades are shown mounted in ooves 17 formed in the upper portion of dis 13.

In the construction shown, the bottom 18 of the groove is formed so that there is a substantia 1y portion of boss 14 to the outer end of oove 17. The upper side of the groove 17 1s narrowed towards the outer edge of the disk so as to leave overhanging In S 19. A flange 20 is attached to the lower e go of each blade 16 and is adapted to fit into. a groove 17 the "flange being notched at 21 to receive lugs 19, and the shoulder 22 at the end of the notch 21 being adapted to rest against the inner end of the radii of the disk which would I through said top, and, therefore,

continuous curve from the upper.

position by centrifugal force and the friction of the material thereon, which both operate to crowd the blades outward to the limit allowed by shoulders 22 and lugs 19; but, if desired, the flange 20 may be provided with a hole 23 registering, when the blade is in position, with a hole 24 in the bottom of groove 17, and the blade may be secured in position by a screw 25 passing through the holes. As will be seen most clearly from Fig. 3, the blade is normally curved so that the top 26 is advanced in the direction towards which the propeller revolves, as indicated by arrow 27. The blades aremade ofspring metal so that the will yield under pressure.

Ili will be readily understood that the mate- -rial in casing 10 falls down by gravity into the path of the revolving blades. In the construction shown, the bottom of the blade is arranged radially of disk 13. The top 26 of the blade is parallel with the bottom of the blade, but since it is normally positioned in advance of the bottom, as indicated in Figs. 2 and 3, the top of the blade is at an angle to pass has a tendency to crowd material outward away from the center of the disk. At the same time, the curvature of the blade acts to crowd material downward and prevent its return upward into the casing. The result is that material caught in front of a blade is forced downward and outward until it escapes in the direction of arrow 28 through outlet 12, as long as the blade maintains its normal position.

When the flow of material from the outlet is obstructed'by the closure of gate 29, or for any other reason, the resistance encountered the blades is increased so that the top of e blade is pressed backward nearer to the radial plane passing throu hthe bottom of the blade. It will be readi y seen that when the top of the blade far that the bladeis vertical, the material is no longerpressed downward by the curved.

is pressed backwards so material, as discussed above,

twisting action of the free end of upper the gate is closed, there may be a continued pressure which will bend the top of the blade even slightly back to the bottom thereof. In

this case, the reverse condition from that first described results,

press material inward and upward sufiicientto counterbalance the excess centrifugal orce.

It will be readily seen from the above that yieldable blades mounted in the described manner result in a continuous pressure on the material during the revolution of the propeller, which pressure is automatically maintained within a comparatively narrow range by the straightening of the blades when resistance is encountered, and their return to normal position when, resistance is lessened. In this way the feeding force exerted upon the material remains within comparatively narrow limits regardless of the speed of discharge of material.

The number of blades may be varied as desired. In the construction shown, disk 13 is grooved for six blades, with-the blades such distance apart that at least one of them will.

be constantly forcing material towards the outlet passage.

For various reasons it is desirable to have the discharge of a tpackage-filling device as nearly constant an uniform as practicable. The construction of the blades is such that they tend to exert a uniform pressure on the and the ample ment of a considerable number of blades ten to make the discharge more uniform during each revolution of the propeller.

In the construction shown, the blades are illustrated as bein of substantially as large size as can be fitte on the disk outside of t e central cone. As will be seen from Fig. 1, the inner end of the upper edge 26 of the blade projects to the rear of the cone, as viewed in that figure, butwhen the blade is straightened up the upward edge is raised sufiiciently to escape being obstructed in its movement by the central cone.

It will be readily understood that a greater or less degree of curvature than that disclosed in the drawin as well as a variation in the number of bla es utilized, may be made without departing from the principles of the invention. Furthermore, if desired, the" shape of the blade may be otherwise varied.

At the right of Figures shown a blade 30 which has a top portion 31 extendin approximately as farradially of the prope er as blades 16 but being comparatively narrow vertically and connected to the bottom flange b a shank 32. In this case the blade is curv zontal plane as well as in the vertical plane so that when it meets with resistance the tion 31 will tend to straighten shan 2 vertically and horizontally.

so that the blade tends to it will be understood that -a lateral discharge openin land 2 there is normally in the horirthsaid outer end At the lower left portion of Fi re 2 there is shown a blade 33 similar to bla e 16 exce t that the upper portion is no longer than t e bottom thereof.

It will be readily understood that various other modifications may be made in the shape of the blades, as well as in their number,

within the scope of the appended claims.

What I claim is: 1. In apparatus of the character described,

an approximately cylindrical casing havin rotatably, substantially concentric with the and are moved towards a vertical position by resistance of material.

2. In apparatus of the character described,

an a proximately cylindrical casin having a disc arge outlet t rough the si e thereof adjacent one end and a propeller mounted rotatably, substantially concentric with the casing, and in register withsaid opening, the propeller being provided with spring blades normall curved in a direction to force the materia towards the end of the casing and outward therefrom but so that pressure thereon will tend to straighten the blades towards a radial position.

described,

3. In apparatus of the character tin-approximately cylindrical casin having a rough-the si e thereof and a propeller mounted rotatably, substantially concentric with the discharge outlet t adjacent one end casing, and in register with said opening, the

pro ller being provided with spring blades,

'sai blades bein mounted on their edges towards the end 0 the casing and having said ed es extend substantially radial of the proler and the blades normally curving away om said edges and in the direction of rotation of the propeller.

4. In apparatus of a casing having a substantially .cylmdrica portion with a substantially vertical axis and bottom thereof, and a prope er in the bottom of the casing substantially concentric therewith and comp'risin a disk in the bottom of the casing and bla I upon the upper side of the disk, said blades being substantially in registerwith'said d1 scharge opening, having one edge held rigid radially of the disk and being curved forward to normaly tend to press and be moved towards from said edge so as material downward I a vertical position b resistance of material.

5. In a paratus o the character described, a rotatab e propeller provided with a blade mounted ad acentits radially outer end and having a resilient portion extending from towards the axis of the prothe character described I es of resilient material 7 adjacent the l 'peller,but normally in advance of said outer end in the direction of the rotation of the a lateral discharge opening adjacent the botv ward and there portion of said grooves and bla tom thereof, and a propeller in the bottom of the casing, substantially concentric therewith, and comprising a disk in thebottom of the casing and resilient blades upon the upper side of the disk, said blades being substantially' in register with said discharge opening and having their bottoms extend substantially radial of the propeller, the curvature of the blades being such that the major portion of each blade is normally ahead of the bottoms thereof in the direction of rotation of the propeller.

1 7. In apparatus of the character described, a casing having a substantially cylindrical portion with a substantially vertical axis 'and a lateral discharge opening adjacent the bottom thereof, and a propeller in the bottom of the casing, substantially concentrictherewith, and comprising a disk in the bottom of the casing, the disk havin g a hub portion rising from its upper side, the outer side of the hub portion being curved-downward" and outward and there being grooves inthe upper surface of the disk, the bottoms of said grooves being substantially of a continuation of the curve of the outer surface of said hub and there being stop lugs in the upper outer portion of said grooves, and blades having flanges on their lower edges adapted to enter said ooves and abut against said lugs to position the blades.

' 8. In apparatus of the character .described a casing having a substantially cylindrical portion with a substantially vertical axis and a lateral discharge opening adjacent the bottom thereof, and a propeller in the bottom of the casing, substantially concentric therei with, and comprising a disk in the bottom of -the casing, the disk havin a hub portion rising) from its upper side, t e outer side of the hu portion bemglcurved downward and outeing grooves in the upper surface of a the disks, the bottoms" of said grooves being substantially a continuation of the curve of the outer surface of said hub. and there being stop lugs in the u per outer dies having mounted along a line substantiall radial of the propeller and being norma ly curved away from said line of support forwardly in .forward position with respect to the rotation of the propeller, but movable towards its rearward position by pressure of material being fed.

11. In apparatus of the character described, a substantially cylindrical casing having a radial discharge opening, and a propeller rotatable about an axis extending longitudinally of the casing, said propeller being in the radial plane of said 0 ening and comprising a blade extending su stantially radially but with its inner portion normally in advance of its" outer portion, said blade being resiliently held in position and the inner portion being constructed to yield under pressure of propelled material a greater distance angularly of the propeller than the outer portion yields under like resistance.

In testimony whereof I have hereunto signed my name to this s cification.

' S6 TT H. LILLY.

flanges on their lower edges adapted to enter said grooves and abut against said lugs to position the blades, said blades being made of spring material and the upper sides thereof bemg normally in advance of the side connected to said flanges. A

9. In apparatus of the character described, a casing, and a propeller in the casing having a blade of spring material, said blade being

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