US2467865A - Hammer for impact pulverizer - Google Patents

Description

-April 19, 1949. F. E, SM TH 2,467,865

HAMMER FOR IMPACT PULVERIZERS Filed May 3, 1944 2 Sheets-Sheet 1 3 April 19, 1949.

F. E. SMITH HAMMER FOR IMPACT PULVERIZERS Filed May}, 1944 2 Sheets-Sheet 2 Patented Apr. 19, 1949 Application May 3, 1944, Serial No. 533,351 -1 Claim. (01. 241 19v)' l The present invention relates generally to improvements in rotary impact crushers or pulverizers, and has particular reference to improvements in the revolving hammers adapted for use therein.

Pulverizing hammers of the type disclosed in my prior Patent No. 2,152,332 are provided with a replaceable wear tip which is reversibly and re movably connected to the outer end of the hammer arm, and which has oppositely disposed impact faces formed with marginal corners or edges that extend transversely of the path of movement for impact with the incoming material to be pulverized. These impact corners or edges are adapted to be disposed individually in a1ead ing or working position at the extreme outer end of the hammer upon securing the tip thereto in different selective positions of assembly. When the arm and the tip are symmetrically arranged relative to the longitudinal center line of the hammer, as has been the practice heretofore, the two outermost impact edges are equidistant from the axis of revolution and are located respectively in leading and trailing positions. Consequently, as wear occurs in use, the leading edge will recede and after a certain amount of such recession, the trailing edge will also come into contactwith the material being pulverized and hence into the line of wear. It is, therefore, desirable, in order to obtain full and uniform wear on all impact edges of the replaceable tip, that the tip be reversed frequently and at proper times back and forth into its different selective positions on the hammer arm. Such reversal of necessity requires.

frequent attention, and involves inconvenience and loss of production'time.

The primary object of the present invention is to provide a novel pulverizing hammer, having a plurality of selectively available impact corners or edges which willbe eflicient and comparatively long-lived in use, and which in particular will permit each of the impact edges to be worn out completely.

Another object is to provide anew and improved pulverizing ham-mer having areversible. tip which is removably connected to the hammer arm in such a manner that when any one of a plurality of impact corners or edges is located for use in working position, it alone will be subject to Wear until completely worn out, while the other edge or edges will be spaced inwardly away from the line of wear.

A further object is to provide a novel pulver izing hammer having an arm and a replaceable tip in which the tip is so mounted that the center of gravity is located in advance of the center line of the arm, whereby to project one impact edge out-, wardly radially beyond the other edge or edges.

A general object is to provide a new and improved pulverizer hammer which is simple and inexpensive to manufacture, which permits of a maximum amount of Wear with a minimum loss of scrap metal when the tip is replaced, and which requires little attention in use and adjustment of the tip only after each edge is completely worn out. I

Other objects and advantages will become apparent as the description proceeds.

In the accompanying drawings,

Figure 1 is a. side elevational view of an impact hammer with a four-corner tip embodying the features of my invention.

A Fig. 2 is anenlarged perspective view illustrat ing the arm and tip of the hammer in disassembled relation.

Fig. 3 is a side elevational view of a modified form of hammer with a two-corner tip.

Fig. 4 is a. front face view of the hammer shown in Fig. 3.

Fig. 5 is a sectional view taken along the line 5-5 of Fig. 3.

Fig. 6 is a transverse vertical sectional view of a pulverizer provided with impact hammers embodying the features of my invention.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, .but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claim.

Referring"more panticularly to the drawings,

impact hammers embodying the present invention are adapted for use in various types and kinds of crushers vor pulverizers, and for purposes of illustration one form of hammer is shown in connection with a rotary pulverizer of con for the material, such as stone, to be crushedor pulverized. Suitably mounted in the casing l0 is a drive shaft 13 adapted to be connected toxa source of power (not shown).. Hammer. suspension means is mounted on the shaft I 3,-

and in the present instance comprises a plurality otaxially spaced disks l4 (one shown) se 3 cured in fixed relation to the shaft. A plurality of hammers l5, four in the present instance, are suitably secured in uniformly peripherally spaced relation to the disks l4 and project radially there from. The casing II] is provided in the top por-,

"tion with a liner plate Hi and in the bottom with a grate structure U, conforming generally to the circle of revolution of the hammers l5.

It will be understood. that inusethe, hammers are revolved at very; high speeds; Hence, they are subjected to heavy centrifugal force and also to severe impact in reducing the material to be. pulverized. Wear occurs at the outer leading edges of the hammer tips, and necessitates fre 'quent replacement of the hammers.

The primary feature of the present, invention resides in the provision of animpact hammerhaving a replaceable tip with a plurality of im- I pact corners or edges which can be easily and quickly reversed to permit successive use orall the impact edges before, requiring replacement; and which in difierentpositions; of,adjustment, willf subject only the active edge to.wearthrough contact with the material being pulverized.

Referring first to the form of Figs. 1 and 2, the hammerconstituting one exemplary embodiment of the invention com-prisesa pivotal-suspension member which maybe of any suitab-le'type', and which is shownas. a flat-sided hammer arm. l8 adapted to be pivotally connected at one end to the disks M for swinging movement. Intl'le present instance, the inner end of the arm I 8. is formed with an opening 19 adapted't'o receive a supporting shaft 20 anchored'ilto the disks. l4 and extending through the intervening space, in. parallel relation .to the shaft [3. In operation, centrifugal force will causethe arm [,8 normally to occupy a generally radialipositionjwith refer-. ence to the axis of revolution.

A. replaceable wear tip. 2| is reversibly secured to the other or outer end of the arm I28; and. is removably; connected thereto. by a strong joint. The tip 2| is provided with a plurality of spaced. impact edges. which extend transversely of the path of revolution, and which are, adapted; to, be located. singly in active position, by selective reversal of the tip onthearm l8; In the par? ticular form shown, the tip 21 is generally rec-.- tangular in cross section and is formed with front and rear impact faces 22 and23. The four. transverse corners A, B, C and D, which extenclalOng. and define the margins of the impact faces. 22 and 23, constitute the impactedges. These edges. are comparatively sharp at the start, but as they wear in use will recede and become. rounded'valon the line of wear 24. Pref'era'bly,.the.impactfaces. 22 and. 23' are slightly hollow V-shaped'.,

The tip 2| is supported'on the arml.8',in.such. a manner that only one of theimpactedgesata time wil be located in active or working position.- to; strike the materialbeing pulverized. Asa re.- sult, the inactive edges. will be maintained. out; of" contact withthe-material, and. wear. wlllbe. con.- fined to the active edge.

Selective location of theimpactedges singly. in. active position, is accomplished by mountingthe; tip 2! on the front-or leading side of. the arm. l8,. whereby the center. ofgravityH of thehammer islocated ona radial line, h-h throughthe axes of.

the shafts l3 and 20 eccentrically. to. and in ade 70 the tip can be reverse-d for exam'file Side for vance of; the longitudinal center line a -a and center-of'gravity A of the arm 18, and trailing the center of gravity T of the tip 2| on the radialline' t--t through the axis of the shaft; More-par ticularly; one orthe other-of the impact-faces 2'2 7'5 active position, and finally upon reversal side for and 23 is seated against a complemental mounting surface 25 on the front of a cross head 26 integral with the outer end of the arm 18. With the tip 2! so mounted, two of the impact edges, for example the edges A and B, are located in a leading position, and the other two edges, for example the edges C and D, are located in a trailing position. The outermost leading edge, for example the edge A, is disposed inz-active position to. strike the material being pulverized, and in use is subject to wear down to the line of wear 24. By reason of the eccentricity of the center of gravity, the four-corner tip Zl will occupy a forward-1y and outwardly inclined position so that the outermost trailing edge, for example the edge D, is caused to move through a reduced circle of revolution well within the line 24 and, therefore, out-0f striking contact with the material. Obviously, the innermost impact edges 13 and C are spaced radially inwardly from. the outermost edges A and C. and, therefore, are also out. of: striking contact with thematerial.

The joint for positively locating and: connect? ing the tip 2| in different selective positions to: the arm l8 comprises twospaced keysor lugs 21 projecting forwardly from-opposite side areas-of; the mounting surface 25, and adapted to be re. ceived in complemental recesses; 0r grooves; formed in opposite sides of the tip. The grooves; 28. open to both impact faces 22- and2r3: so that: the lugs 2'! will engage in oneend or the: other; thereby permitting reversal of the tip front. for; rear to locateeither the edges A and, B orrther edges'C and Din the foremost or'leading position.. The grooves also are locatedsymmetricallyacross: the sides of the tip 2i so that the latter canbm reversed side for side to locate either'the edges; A and D or B and C in the outermost position... Preferably, the lugs 2'! are tapered, and the.op.--

posite ends of thegrooves 28 are correspondingly:

flared to obtain close wedge engagement:

As. an. additional locating and interlocking: means, the head. 26 is provided with'an intermet diate square lug'or projection 29 between the lugs 21 and adapted tobe received in either of two: complemental openings Bilwhich are formed cen-- trally in the respective impact faces 22 and 23 and separated by an intermediate wall or web 3-1. To secure the tip in position of assembly, a bolt: 32 is adapted to be inserted through a hole 33in the web 3i and an alined bore 34 opening through the. square 1'ug29 and the head 26, and tobe' tightened by a nut threadedthereon against the rear face of the arm l8.

In operation, and assuming that the tip 2! isinitially secured in position of assembly with one of the impact edges, for example the edge A, disposed in the outermost leading position for strik ingengagement with the material being pulverized, centrifugal force will" cause the tip to as sume a position inclinedto the radius of revolution, with the active edge A describing a maxi mum circle of revolution. The other" impact edges B, C, and D will describe lesser circles of revolution, and hence remain out of striking contact-with the material. Upon continued use; the edge A will be worn away down to the line 2'4, and; when the edge has been completely worn down,.

side, to dispose the other impact edgeB' of the.

face 22 inactive position. When the secondedge B has been completely worn down, the tip can be reversed front for rear to'dispose the edgeC' in.

side the edge D can be disposed in active position.

Figs. 3, 4 and 5 illustrate a modified form of the invention having a two-corner replaceable tip 20*. The construction is generally similar to that of the hammer with the four-comer tip, and corresponding parts thereof are identified by the same reference numerals as in the first form, plus the letter a. In this form, the tip 2| has a rear surface 23 adapted to seat against the front surface 25- of the head 26, and has only one impact face 22* with transverse marginal corners or impact edges E and F. The surfaces 23 and 25 are fiat and located substantially in an axial plane through the shaft 20. The tip Zi is not reversible front for rear and, hence, the recesses 28 do not extend to the face 22 The lugs 2'! of the joint are tapered on such an angle that the outermost inclined sides thereof are substantially parallel to the line of wear 24*, thereby making availabl a maximum amount of stock to be worn away at each corner. In this form, as in the form of Figs. 1 and 6, the tip 21a has a center of gravity T on a radial line tt' through the axis of the hole l9a, and the arm l8a has a center of gravity A on a radial line a'a also through the axis of the hole l9a, and the hammer including the arm Mia and eccentrically mounted tip 2la has a center of gravity H intermediate the centers of gravity T' and A on at radial line h-h' extending through the axes of the opening I 9a and the shaft 13 when the hammer is subjected to centrifugal force.

It will be evident that I have provided a new and improved impact hammer which has a plurality of impact corners or edges adapted to be used one after another until completely worn out, and in which none of the corners excepting the one located in active position is subject to wear. As a result, all corners of the hammer can be fully worn down in performing useful work and to leave a minimum of stock to be discarded when the tip is replaced. Frequent reversal of the tip is unnecessary so that undue loss of production time is avoided.

I claim as my invention:

An impact hammer for rotary pulverizers comprising, in combination, a hammer arm adapted to be supported at one end and having, a cross head on the other end with a mounting surface on the leading side, two forwardly projecting wedge lugs extending in spaced relation from oposite ends of said surface, and an intermediate lug extending forwardly from said surface between said wedge lugs, a four-sided hammer tip having front and rear faces adapted to be seated directly against said surface and having four transverse corners defining impact edges at the inner and outer margins of said faces, said tip being formed in opposite ends with transverse grooves flared outwardly in each direction from an intermediate point and adapted to interfit selectively with said wedge lugs and being formed in said faces with openings separated by an intermediate web and adapted to interfit and receive said intermediate lug, said tip being reversible on said surface side for side and front for rear to present any one of said four corners in an outermost forward working position, and being located in advance of and spaced from the center line of said arm, whereby to cause the trailing outermost corner to have a lesser circle of revolution than the forward outermost corner, and a clamping bolt adapted to be extended through said web and said intermediate lug for removably securing said tip to said head in selected position of adjustment.

FORREST E. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,085,692 Liggett Feb. 3, 19 14 1,424,225 Williams Aug. 1, 1922 1,434,540 Hiller Nov. 7, 1922 1,476,177 Plaisted Dec. 4, 1923 1,562,048 Plaisted Nov, 17, 1925 1,630,021 Lucas May 24, 1927 1,655,238 Plaisted Jan. 3, 1928 1,693,058 Shelton Nov. 27, 1928 2,152,332 Smith Mar. 28, 1939 2,331,597 Coles Oct. 12, 1943 FOREIGN PATENTS Number Country Date 660,974 France Feb. 26, 1929 r 475,430 Great Britain Nov. 19, 1937

Images