US1711464A

US1711464A - Grinding machine

Info

Publication number: US1711464A
Application number: US167109A
Authority: US
Inventors: Ruprecht Louis; Alfred G Kollstede
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-02-10
Filing date: 1927-02-10
Publication date: 1929-04-30
Anticipated expiration: 1946-04-30

Description

April 3 9- L.RUPRECHTETAL 1,711,464

GRINDING MACHINE Filed Feb. 10, 1927 2 sheets-sheet 1 H 4 INVENTOR P m 3 Win. g flan/d. H J W-QM" aka-ATTORNEY April 2 L. RUPRECHT ET AL GRINDING MACHINE 2 Sheets-Sheet 2 Filed Feb 7 10,; 1927 444.4 ATTORNEY mm mm, or nom'cmm,

Patented Apr. 30, 1.929.?

UNITE]? STATES eamnme mourns.

Application fled ass 10,1927. Serial at. 167,169.:

This invention relates to a machine for performing grinding or like comminuting operations, and adapted to the requirements of" various industries, such as color grinding and numerous other purposes, particularly where uniformity in the size of the ground articles is a desider'atum.

The invention relates particularly to the type of. grinding machine in which the material'to be ground is fed by means of a feed screw or-worm to a rapidly rotated and'en 7 also results infiner and moreuniform grinding than could otherwise be obtained. A further object of the invention is to present the material uniformly. along the length of the rinder. This conduces to uniform grin mg, and also permits the use of grind-- ers of" any desired lengthr The means by which these and other objects of the invention are attained may best be understood from a detailed description of an illustrative f swing hammergrinding machine'embodying the invention which is shown in the accompanying drawing, in which Fig. 1 is'a-planview of the machine with the cover of the main casing and 'the feed hopper removed; I v y a Fig. 2 isa transversesectional view taken on the-line 2-2 of Fig. .1;

Fig. 3 is a longitudinal; sectional viiew taken on the line 33 of Fig. 1

Fig. 4 is a fragmentary transverse section on the line 4-4 of Fig. 1; and Fig. 5 is a detail view. The machine illustrated includes a main casing 10 within which is a rotary grinder 11, a eed conduit 12 extending from the main casing, feed screws 13, 13, 13 in thefeed conduit, and a' feed hop er114 opening into} the top of the feed con uit at a-substantial.

distance from the main casing. The grinder 11-is of known'form, and consists of a plurality of alternately turned hubs 15to whlch are pivoted hammers. or boaters 16. The hubs 15 are as'sembledon the middle part of a mainshaft 17 which extends across the casin 10, and is provided with bearings 18 carrie by theside walls 19 of the casing.

While the main casing may be made recend edges of the screen are en aged a tangular as showmit encloses a cylindrical; gr ndmg chamber 20 providedby a cylin-fi drically curved cover 21 enclosin the to of the grinder and a cylindrical y curv screen 22 located within the casing closing'the' lower half of the grinder. I z

23*, are fixed on'the main. sha

t 17 at opposite e5 sides of the inder ll-and close to the inner f v 1 surface of t eside walls of the casing. 'Although these disks are shown as flat, th -m be flanged orcurved or otherwise "deformed.

if desired, and for this reason the word disk I as used herein is not to be'u'nderstood to be limited to a flat disk. The disks 23, 23 contain central openings which fit tightly on the i shaft, so that no dust can pass between them and the shaft. The rapid rotation of the shaft, which is necessary for'efiective o eratlon of the grinder, causes these di 5 to throw radially outward any dust-or grit which may move along the shaft or alon the central part of the casing towards the ear-.

.ings 18. Such dust is thus prevented from a entering the bearings. Furthermore, al-

though the disks are notin actual contact; with the side walls of the casing, they are;

located so near these side walls that any dustr fili or grit which attempts to enter between them I an the casing is mmediately thrown out radiall Consequently no dust or ritcan nter t e bearings. 18. This is an a vantage 4 of great practical importance, since when previous grinding machines of the samegenera-l character have been applied to grin in'g gritty materials, it has been found' necessary to .replacethe shaft bearings at frequent m-. tervas. I I A feature of the invention consists in providing insane for facilitating the removal and replacement of the screen 22. This s impor-f tantsince the mesh of this screen should correspond to the fineness of the grindin re 100 quired.-' The side edges of this scream-w ich may be of the 'usual form of a thm screen plate mounted on a skeleton back late or of othersuitable form, are held in c annels 24 W! 2 provided in the inner surfaces of thes1de walls 19 of the main casing, as by ribs 25. cast or otherwise formed thereon. The upper or by removableshold-down bloc s .26, 27.- The ends' of theblock 2.6 have'a 'slidable'engage- 1i0 and em." no; i

lpreventing thepulverized material or I dust w ich is formed in the grinding chamber I. 20 from entering the bearings 18, disks 285-.

held

ment with vertical grooves 28 formed in the side walls of the casing. This block is normally held down against one end edge of the screen by the cover 21, but may be lifted out vertically to permit removal-of the screen when this cover is removed. The block 27 contains a central opening which forms the inner end of the feed conduit 12 in which the screws 13, 13", 13 are located, so that, this block cannot be raised vertically like the block 26. The grooves 28 in the side walls 19 in which the ends of this block are held are, therefore, made wider than the block, so that the block ma be moved horizontally inward to uncover the upper" end of the screen 22,

and thus to permit the application of a pressing instrument to this edge of the screen to force the screen out'at the opposite end of the casing. If rigidly supported hammers are used, this will, of course, be done when the grinder is so turned that none of the hammers are directly opposite the block 27. To retain the block 27 in its normal operative position and out of the path of: the heaters during the operation of the machine, filler pieces 29 are inserted in the grooves 28. These pieces are held in position by the cover 21. It is apparent that the arrangement described. provides for ready removal and replacement of the screen, and at the same time holds the screen rigidly in its proper position during the operation of the machine. In order to prevent any possible protrusion of any part of the end edges of the screen into the path of the ends of. the hammers, or direct wearing contact of the rapidly moving material in the chamber with the end edges of the screen, the

blocks

26 and 27 are provided at their lower inner edges with downwardly projecting flanges 26" and 27*, most desirably tapered as shown, which when the parts are positioned extend in front of the screen edges.

Important features of the invention are embodied in the means for feeding the material to be ground into the grinding chamber 20.-

The feed opening 30 into this chamber from the conduit 12 is provided by the opening in the hold-down block 27 It is narrow but of sufiicient length to extend a substantial distance along the axial length of the grinder 11. When the feed conduit is arranged to feed the material in a horizontal direct-ion as shown, the feed opening 30 is located substantially on the level with the axis of the grinder, although it is desirable to place the middle of the opening slightly above this axis so that the lower edge of the opening is on the level with the axis. 7

'The feed ponduit 12 extends to the feed opening 30 and is most desirably of the same width andheight as the feed opening. In order that the,feed screws'13, 13 and 13 may deliver the material to the grinder in a compacted mass, the feed conduit extendsin such wardfinclination. For most materials, itlnost desirably extends horizontally, as shown.

The inner portion of the conduit is closed,

while'the top of the outer portion of the conduit is in communication through a supply opening 31 with the feed hopper 11in The floor of the conduit 12 is formed to provide a plurality of semi-circular grooves 32, 32, 32 extending lengthwise of the conduit. A plurality of feed screws 13 13", 1o, corresponding in number tothatof these grooves, are located in the feed conduit coaxially with the grooves, and in such manner that their threads just clear the grooves. The upper wall 33 of the enclosed inner portion of the conduit is formed to provide corresponding semi-cylindrical grooves 34*, 34, 34 which closely enclose the upper portions of the threads of the screws.

The feed. screws are supported entirely from their rear ends. Each screw extends from a shaft 35 which is provided with spaced bearings 36 located beyond the outer end of the feed conduit. Each screw is most desirably'made integral with its supporting shaft. This mounting of'the feed screws not only avoids the use of a bearing in the feed conduit, which would tend to obstruct the movement of the material. but also has the advantage of making it possible to extend the feed screws to apoint very close to the periphcry of the grinder. This results in finer and more efficient grinding than would otherwise be obtainable.

In order to supply the material uniformly across the length of the grinder, all the feed screws are most desirably rotated at the same speed by a common driving means which, in

the form shown, consists of a worm 38 engaging' gears 39 of uniform size fixed on the shafts of the screws In order to provide for a constant ratio between the speed of the grinder and that of the feed screws during an operation of the machine, the worm 38 is connected with the main shaft 17, for example. by means of a belt 40 and appropriate belt pulleys, as shown.

In the operation of the machine which has been described, the material to be ground is placed in the hopper 14 in such manner that it feed opening, successively strike the end of the compacted mass of material from below as it is-forced into the grinding chamber, and act to comminute it. As the material becomes sufliciently connninuted, it passes through the screen 22, and may be collected in a bag ell or other suitable receptacle at the bottom of the main casing 10. As will be understood by those skilled in the art, the fineness ot'the grinding may be regulated by changing the screen and hychanging the speed of the grinder and the feed screws, and to some extent by changing the ratio between these speeds. The higher the speed of the grinder and the finer the screen, the finer the grinding. While the speeds at which the high speed grinder and the relatively low speed feed screws should be driven depend on the nature of the material being ground and the fineness of grinding required. it may be noted by wayof illustration that the speed of the grinder v has been varied from 500 to 5500 R. P. M., and that of the feed screws from to 200 R. P. M., depending, as stated, on the fineness of grinding-required, the kind of material being ground, and also on the size of the grinder and the size and pitch of the feed screws. v

What is claimed is:

1. A machine of the class described, comprising a main casing, a feed conduit extending to an opening in the periphery of the main casing at an angle such that gravity does not urge the materialin the conduit toward the main casing and provided with a supply opening at a substantial distance from its inner end, a feed screw in said conduit adapted to move material along the conduit and to force it into the-main casing in a compacted mass, a plurality of heaters in the main casing, and means for moving said heaters so thatthey successively strike from below the compacted massforced' into the casing by the feed screw. A machme of the class descrlbed, com-. prising a horlzontal cvlindrlcal main casing,

a feed conduit extending horizontally to an opening in the periphery of the main casing opening into themain casing, a grinder in the main casing, beaterson said grinder, and

of, the teed screw.

' means for rotating the grinder so that'theheaters move upwardly across the inner end ,3. A' machine of the class described, comprising a rotary'grinder, a main casing enclosing a cylindrical chamber having a peripheraladmission slot extending parallel to said opening 'extendingto said opening and I provided with a supply opening in its top 10- conduit, spaced bearings for said shaft 10-.

cated a substantial distance from its inner end, and means in the feed condult for compacting the material to be ground and forcing y it through said slot at a uniform rate along the length of the slot. v

4. A machine of the class described, comprising a main casing enclosing a cylindrical.

chamherhaving .an oblong peripheral opening extending parallel to its axis and substantially from one of its ends to the other, a rotary grinder in the casing, a feed conduit whose cross-section cor-responds to said opening extending to said opening and provided with a supply opening inits top located a substantial distance from its inner end, a plurality of feed screws located side by side in the feed conduit, and means for rotating all of said feed screws at the same rate.

5. A machine of the class described, comprising a main casing, a, rotary grinder there- 1n, afeed conduit extending to an opening 1n the periphery of the casing and having a supply opening at a substantial distance from its inner end, a shaft at the outer end ofsaid cated beyondsaid opening, and a feed screw located in the conduit with its inner end close to the periphery of the grinder and wholly supported by said shaft.

.6. In a machine of the class described, the combination of a wide, shallow, horizontal feed conduit having a plurality of longitudinal, semi-cylindrical grooves in its-bottom, a plurality of feed screws in said conduit each of which is coaxial with one of said semicylindrical grooves, and driving'rneans for said feed screws positively connected to. each of them. b

7 In a machine of the class described, the combination with a main casing, a rotary grinder therein, a feed conduit opening to' the main casing, and a feed screw in'the con-' of the grinder andsubstantially onthe level with its axis, of a screen support below the grinder, a cylindrically curved screen supported thereby, a removable block engaging the upper edge of the screen at the side of thegrinder opposite to the feed screw, and a re- 1' movable block which engages the other upper edge of the screen, contains an opening for the passage of the feed screw, and is'monnted' so as to slide longitudinally of the feed screw to expose said upper edge of the screen.

8. A 'pulverizing machine, comprising means for horlzontally compacting material to be pulverized, and moving it horizontally,

and heaters successively striking the forward In testimony whereof, we have hereunto set our hands.

LOUIS RUPRECI-IT.

portion of the compacted mass from below. the axis of the grander and substantially from Y ALFRED G. KoLLs'rnnEI