US2939640A - Hammer with removable tip - Google Patents

Description

T. C. WHISLER, SR

HAMMER WITH REMOVABLE TIP June 7, 1960 Filed Aug. 2, 1957 3 Sheets-Sheet 1 FIG. I .0

uvllfllllnlvllllln IMPACT DIRECTION I 2o 14? u l NVE NTOR mm C. WHISLERaSR. BY M @W ATTORNEYS June 7, 1960 T. c. WHISLER, SR 2,939,640

HAMMER WITH REMOVABLE TIP Filed Aug. 2, 1957 3 Sheets-Sheet 2 INVENTOR. THOMAS C. WHISLER,JR.

ATTORNEYS June 1960 T. c. WHISLER, SR. 2,939,640

HAMMER WITH REMOVABLE TIP Filed Aug. 2. 1957 3 Sheets-Sheet 3 F IG. 7 FIG. 8

I42 I25 I45 IIS I40 INVENTOR. THOMAS c. WH|5LER,JR.

imam/ew- ATTORNEYS States Patent Offic 2,939,640 e d Ja 60 I-IAlVIMER WITH REMOVABLE TIP Filed Aug. 2, 1957, Ser. No. 677,178

12 Claims. (Cl. 241-197) This invention relates to hammers for rotary crushers or pulverizers. This application is a contmuation-m-part of my abandoned application Ser. No. 573,666 filed March In rotary type crusher mills, a plurality of hammers are arranged circumferentially ona relatively large rotary .plate or disc driven by the main shaft of the mill, and the arrangement is such that the hammers are effective to crush and pulverize by impact the ore or other material fed into the mill. With continued operation, the leading end portions of the tips of the hammers where impact occurs gradually wear, and this is manifest in a shortening of the hammer tip which decreases the efficiency of the mill. I

Most hammer mills or rotary crushers are originally equipped with one-piece hammers, so that when the tip becomes worn it is necessary to replace the entire hammer part, dismantling the mill and removing the disc and pins on which the hammers are supported. This operation and reassemblage of the mill represent expensive ma tenance and lost operating time.

In view of the foregoing, it is advantageous to equip hammers for rotary mills with renewable tips, and the present invention pertains to hammers of this kind. The hammers in a rotary mill rotate at relatively high speed, and it is desirable to maintain as closely as possible a balance of the operating parts so as to reduce objectionable vibration, and as the hammers generally do not wear alike the tendency toward vibration is rather pronounced in some instances. One of the objects of the present invention is to removably mount the renewable tip on the shank of the hammer in such a manner asto enhance the anti-vibrational characteristics of the mill, and further to enable the retaining means for the hammer tip to have the axis thereof disposed generally parallel to or aligned in the direction of impact on the hammer.

One of the principal objectionable features encountered I especially when disposed transverse to the direction of hammer rotation, and the hammer shank becomes deformed requiring replacement of these parts. Hammers of this kind of course rotate in but one direction so that the impact forces encountered are localized, and a further object of the present invention is to enable the axis of the retainer to be disposed generally parallel to the direction of hammer rotation while at the same time so relating the renewable tip to the shank of the hammer that relatively' large bearing areas are present which effectively absorb the impact forces. Another object of the present invention is to construct the renewable tip of the hammer with a boss which fits into a complemental recess wholly within the shank, thereby safeguarding the boss against peening and increasing the effective bearing areas between the shank and the tip.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principles thereof and what I now consider to be the best mode in which I have contemplated applyingthese principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims. 1

In the drawings:

Fig. l is a front elevation of a hammer constructed in accordance with the present invention; Fig. 2 is a side elevation of the hammer of the present invention taken on the line 2-2 of Fig. 1;

a Fig. 3 is a fragmentary sectional view taken substantially'on the line 33 of Fig. 2;

Fig. 4 is a side elevation-of another form of hammer constructed in accordance with the present invention;

Fig. 5 is a side elevation of the shank for the hammer of Fig. 4;

Fig. 6 is a front elevation of the hammer shank shown in Fig. 5;

6A is a bottom view of the hammer shank 0 Fig. 6;

Fig. 7 is a rear elevation of the tip for the hammer shown in Fig. 4;

- Fig. 7A is a top plan view of the tip shown in Fig. 7; and

5 I Fig. 8 is a side elevation of the tip shown in Fig. 7A.

One form of the present invention is illustrated in Figs. 1 to 3 of the drawings as embodied in a hammer 10 of the kind adapted to be used with a rotary mill, and to this end the shank 11 of the hammer is formed at the head end 12 with a relatively large opening13 enabling the harnmer to be mounted on a corresponding supporting pin carried by a relatively large rotary plate included as basic driving structure in the mill. It will be recognized that theplate or other such supporting means which carry the hammers is adapted to mount a plurality of such hammers in equally spaced circumferential relation.

. The front and rear sides 14F and 14R of the shank of the hammer are tapered inwardly in the direction proceeding away from the head 12 of the shank, and at the end of the shank opposite the head 12 a renewable tip 15 is provided and is removably mounted thereon in a way now ,to be described.

prolong the life of the tip 15 the front side 18 is tapered in an opposite direction in comparison to the front side 14F of the shank 11, which is to say that inasmuchas the impacting force indicated by legend in Fig. 2 is applied to the front side 18 ofthe tip 15 the front of the tip is provided with surplusage metal forwardly of the front side 14F of the shank 11. This is but exemplary, however, since any desired shape may be imparted to the front side of the tip depending upon operating conditions and the material or alloy of which the tip '15 is cast.

The front side 14F of the hammer shank is undercut to afford a'shoulder 20 extending inwardly in the direction of the longitudinal axis of the hammer, and a tapered bearing face 21' that is substantially normal to the direction of impact extendsfrom the shoulder 20 toward fiat end .22 of the shank 11 which serves as a second bearing face.

The tip 15 includes a front head or flange 23 which is complementary to the front recess in the shank 11 defined by the shoulder and the bearing face 21, so that the tip 15 has a bearing face 25 opposite the bearing face of the shank 11 and a shoulder 26 opposite the shoulder 20 of the shank 11. The tip 15 is also formed with a bearing face 27 complemental to the bearing face 22 of the hammer shank.

As shown in Fig. 3, the shank 11 proceeding inwardly from the bearing face 21 is provided with a generally T-shape'cl, elongated recess 29 having an enlargement 30 serving as a socket for a complemental part on the .tip 1'5 'as will be mentioned below. The recess 29 inwardly of the shank 11 terminates at an internal wall 31 of the shank, and on the side 14R of the shank 11 opposite the bearing face 21 another inwardly extending recess 33 is formed which terminates at an internal end wall 36 of the shank 11 spaced from the aforementioned end wall 31. It will be recognized particularly in Fig. 2 that the longitudinal axes of the recesses 29 and 33 are aligned, and that the axis common to these two recesses is generally parallel to the direction of applied impact force indicated by legend in Fig. 2. i

It will he observed in Fig. 3 that the recess 29 includes a neck 38 of reduced dimension, and this neck portion opens at the bearing face 22 of the shank'11 and extends forwardly to the bearing face '21 sothat a corresponding slot is provided at the bottom of the shank 11.

Formed on the bearing face 27 of the "tip 15 inwardly of the rear end 17 of the tip 15 is an elongated T-s'haped boss 40 Which extends radially inwardly in relation of the shank 11. This boss includes an inclined neck 41 that is comple-mental to the slot 38, and the boss 40 additionally includes an enlarged head 42 as shown in Fig; 3 which is complemental to the enlarged portion 30 of the T-sha'ped recess in the shank 11. The forward end of the head 42 of the boss 40 is spaced from the bearing face 25 of the'ti p 1'5, and the neck or Web portion 41 of the boss 40 extends to the bearing face 25 as shown in Fig. 2. In mounting the tip 15 to the shank 1 1 it is merely necessary to align the boss 40 with the T-shaped recess in the shank and then to insert the boss 40 into the recess 29. Thus, the boss 40 includes parallel shoulders 43 between the head 42 and neck 41 engagea-ble with corresponding parallel shoulders '44 afiorded by the recess 29, and the head 42 of the boss 40 and the shoulders 43 are inclined parallel to the longitudinal axis of the recess 29 and the shoulders 44. The engageable shoulders 43 and 44 represent the primary support for the head on the shank of the hammer, but initially there may be space therebetwe'en as 'shown'in Fig. 3.

The boss 40 at the end away fromthe neck 41 is provided with a Ue'ha'ped opening 45, Fig. 3, and when the tip 15 is mounted on the shank -11 as mentioned above the recess 45 in the boss 40 is aligned with anaperture #6 *that extends between the two end walls 31 and 36. Prior to arranging the tip 15 complement'ally on the shank 11, a retainer bolt 47 is set in the recess 45 in the boss 40 so that the head 47 thereof is disposed against the end of the head of the boss 40 opposite the bearing face 25 of thetip 15 so as to pass through the opening 46, and in this way the head of the bolt is 'shieldably disposed inwardly of the tip 15. After the tip 15 has been corhplementally related to the shank 11, the threaded end of the bolt opposite the head 47 thereof is shieldably disposed within the recess 33 and a nut 50 and a lock washer 51 are then mounted on the threaded end of the bolt and the nut 50 is tightened to securely associate the tip '15 with the shank 11 of the hammer.

Another hammer embodying the features of the present invention is illustrated at 110 in Fig. 4, the hammer 110 including 'a' shank 111 formed at its head 112 with an enlarged o ening 11 3 for the purpose described above.

"the shank.

4 The sides 114F and 114R of the shank respectively, represent the front and rear sides of the shank of the hammer, assuming the hammer to be rotated in the direction indicated by arrow in Fig. 4. The shank 111 is provided with a renewable tip 115 on the front side thereof and at the end opposite the head 112.

The tip 115 includes a bottom wear shoe 116 having a substantially flat bottom side 116A, and the tip further includes a substantially flat front side 118 which takes the impact encountered in mill operation. Thus, the front side 113 of the 'tip 115 represents the leading side or face, and in order to compensate for impact in the manner described in connection with the foregoing embodiment of the invention, it will be seen that a substantial amount of surplusage metal is provided at what constitutes the apex of the tip 115.

As best shown in Fig. 6, the hammer shank 111 is formed with outwardly directed left :and right hand shoulders 1111. and 111R. These shoulders have sloped upper surfaces 1118, Fig. 5, and the outer or free side surfaces of the shoulders 1111. and 111R lie in substantially true flat vertical "planes 111V, Fig. 6.

It will be readily recognized from Fig. 6 that the shank :1-11 is somewhat in the nature of an inverted T- member affording a forward bearing face 121 of generous area which is interrupted by a relatively large generally T-shape'd re'ces's which will be described in more detail hereinbelow. Referring to Fig. 5, it will'be observed that the shank 111 has a second or end bearing face 122 extended somewhat normal to the forward bearing face 121. Thus, the bearing face 122 is in effect a hearing face at the end of the shank 111 opposite the head 112, and the bearing face 122 is afforded by terminating the shoulders 111L and 111R short of the lower extreme end 111E, Figs. 5 and 6, of the shank 111. Such construction provides what can be viewed as a thrust surface 1 111 at the lower end of the hammer shank relative to which the rear end 115R, Fig. 4, of the tip 115 will normally be spaced. The spacing between the surfaces 111T and 115R can be viewed as a take-up space. It will also be observed in Fig. 4 that surfaces and projections to be described hereinafter are also suitably configured for such relative movement between the tip and It will moreover be appreciated that such dimensioning of the parts facilitates casting. Referring to Fig. '8, the tip 115 includes bearing faces 125 and 127 that are complernent'al to the bearing faces 121 and 122 of the hammer shank. Engageability of the bearing faces 'will be described in more detail below.

The 'T-sha'pe'd recess formed in the forward bearing face 121 of the shank is indicated at 129 in Fig. 6. The recess 129 includes a transverse portion 130, Fig. 5, defined by a downwardly facing surface 130]) that extends inwardly from the forward bearing face 121 of the ham- 'rn'e'r shank, end surfaces 139E, Fig. 6, and spaced apart lower surfaces 130L and 130R which afford left and righthand shoulders for a purpose to be described. The transverse portion 136} of the recess 129 communicates with a vertical neck portion 138, Fig. 6, the neck portion 138 extending all the Way to and opening at the lower bearing surface 122 of the hammer shank. As will be observed in Fig. 6A, the ends of the recess 130 become progressively shallow proceeding outwardly from the neck portion 138.

The recess 129 terminates at an internal wall 1:31, Figs. 5 and 6, and on the side 114R of the shank 111 opposite the bearing face 121 another inwardly extend- 'ing recess 133, Fig. 5, is provided which terminates at'an internal end 'wall 136 of the hammer shank spaced from the end wall 131 by a solid web portion 137. It will be recognized particularly in Figs. 4 and 5 that the recesses 131? and 133 are aligned and that the axes thereof are common and inclined relative to the vertical center line of the shank 111. This disposes the shoulders '130L and 130R to point generally in the direction of concentrated impact on the hammer tip as described above. r The hammer 115, as mentioned, includes bearing faces 125 and 127 respectively complemental to the bearing faces 121 and 122 of the hammer shank so as to flatly engage therewith as indicated in Fig. 4. It was also men-- tioned that'the bearing faces of theshank are interrupted by a recess 129, and likewisethe bearing faces of the tip 115 are interrupted by a .T-shaped boss 140, Figs. 7 and 8, which is adapted to fit complementally in the T-shaped recess 129 of the shank "111. Thus, the boss 140 includes a neck 141 which projects vertically from and is "centered medially on the bearing face 127 of the tip 115.

The neck 141 of the T-boss-140 is provided at the upper end thereof with an enlarged transverse head 142 complemental to the transverse portion 130 of the recess 129 in the hammer shank.

It will be seen that the renewable hammer tip 115 is r fully complemental to substantially all forward area portions of the hammer shank between what has been termed the thrust face or surface 111T and the forward upper sections of the shoulders 111L and 111R of the hammer shank. Accordingly, the hammer tip and shank are.

adapted tobe complementally engaged and fitted together fin the manner illustrated in Fig. '4 with the neck of the T-boss disposed in the. neck portion 138 of the hammer shank recess 129, and with the crosshead 142 of the T-boss disposed inthe portion 130 of the hammer shank recess 129. When. the parts have. been properly fitted together in this manner, the bearing face 125 of the hammer tip engages the front bearing face. 121 of the hammer shank, and the bearing face 127 of the hammer tip enlarly the shoulders 143,.arefiwholly confined by and within the hammer shank, which is to say that the side sections of the hammer shank, which in this instance are represented by the side wallsof the shoulders 111L and 111R, completely. cap and shroud the attaching boss 140.

As in the instance of the hammer 10, the shoulders of I the T-boss on the wtipare juxtaposedabove the comple- 'mental internal shoulders or. surfaces of the shank, 130L and 130R in this instance; and this constitutes the primary mode of mounting the tip to the hammer shank.

Openings are "formed in the hammer shank and'the T-boss, and when the parts are complementally fitted together in the manner illustrated in Fig. 4, these openingsi register and areadapted to take a retainer means for removably securing'the hammer tip to the shank. Thus, an aperture 146, Fig. 5; is extended through the {web portion 137 of the hammer shank which separates 5 the recesses 129 and 133, the opening 146 being centered relative to therecess 129 as sho'wn'in Fig. 6. A U-slot 145, Fig. 7, is formed in the medial portion of the T-boss 140, 'and' the U-slot 145 registers with the opening 146 'in' the hammer shank when the parts are assembled as shown in Fig. 4. Referring to Fig. 7A, it is to-be noted that the U-slot 145 communicates with an enlargement 145A, the enlargement 145A having both a greater width and a greater depth tha'ntheU-slot 145 as will be seen "inFig.-7. V V

The retainer means is similar to the retainer means described in the embodimentof Figs. 1 to 3, and thus is' conveniently in the form of a nutand bolt assembly incl uding'-a"bol-t 147, Fig. 4, havingo'a head,148 and a threaded end 147E, a nut 150, and a lock washer 7151.

Prior to assembly, the shank of the bolt 147 is reposed in the U'-slot V145 ofthe hammer tip boss with thehead 148 of the bolt reposed in the enlargement 145A. Asa

consequence;the.threaded end of the bolt is dispos d the hammer. 1 many event, it will be appreciated that =outwardlyof the T-boss 140. The tip 115 having the bolt thus mounted therein is then associated, with the hammer shank so that the threaded end of the bolt passes through the opening l46vtherefor in the web .137 of the end of the bolt withinthe recess 133, whereupon the nut 150 is then tightened to firmly draw the hammer tip 115 up on the hammer shank to bringthe respective bearing faces of the tip and hammer shank into tight engagement. Preferably the openings 145 and 146 are so oriented that the axes thereof point, together with the complemental internal shoulders of the tip and shank, in the direction of concentrated impact on the hammer tip during use of the retainermeans has the axes thereof disposed to travel generally parallel to the direction of hammer rotation rather than transverse thereto.

It will be seen from the foregoing that under the present invention the opposed bearing faces of the tip and the shank ofthe hammer are'of relatively large areaand that these are provided'at areas where the impacting forces are concentrated so as to increase substantially the ability of the hammer to absorb. and dissipate the impact forces.- The retaining bolt that is used to hold the tip to the shank is arranged so that its axis travels generally parallel to the direction of hammer rotation, and preferably so that'its axis points generally in the direction of the major appliedfimpa'ct force.' In this way, vibration of the hammer; isIeduced' to a minimum. The

relation between the longitudinal axis of the shank and usual four quadrants result as indicated at I, 'H, III and IV numbering clockwise in the standard geometrical fashion from the upper right-hand quadrant. Due to the ,inclination of the axis RA of'the retainer means,.the angleAC enclosedby the intersecting axes in the third quadrant III isan acute angle, and the same relationship holdstrue for the hammer as illustrated in Fig. 4. As will be observedparticularly in Figs.'3 and 4-, the boss on the hammer tip is wholly confined by the hammer shank.

. This protects the boss and its neck against peening and further assures thatthe bearing faces of the tip and hammer shank are of maximum effective area.

Hence while I have illustrated and described pre- .:ferred embodiments of my invention, it is to be understood that these arecapable of variation and modification, and 'I therefore. do" not wish to be limited to the precise details set forth,-.but. desire to avail myself of such changes. and alterations as fall within the purview of the following claims I claim:

1. A hammer for a rotary mill comprising, a shank having a head adapted 'tO 'be carried by a rotary'part of; the mill, said shank having afrecess in one side of the I shank affording a shoulder extending inwardly firom said side'and 'afiording a'for'ward facing bearing face in a plane generally normal to the direction of impact and extending from theinner end of the-shoulder to the end ofxthe shank opposite the head, said end 'of theshank. V

opposite the head serving asa-second bearing face on the shank, a" renewable tip .on the end of-the shank opposite the head and having bearing faces 'complemental to said bearing faces of the shank, said shankhaving an elongated 'T-shaped recess formed-therein which proceedstinwardly from the first-named bearing face along an inclined axis pointing generallyin the direction of impact, said renewable tip on the bearing face thereof that is .cnmrlsmsnta to the sa as-sawe beari s; sss.

having a longitudinal axis, a forward facing bearing face on one side of the shank extending toward one end of the shank, said shank having a second end bearing face disposed substantially normal to the first-named bearing face, a renewable tip for the shank and having bearing faces complemental to said bearing faces of the shank, said shank having a recess formed therein proceeding inwardly from one side of the shank, said recess aifordin'g shoulders which are inclined so as to point generally in the direction of impact and disposed wholly internally of said shank, said renewable tip having a boss projecting therefrom formed with shoulders complemental to the shoulders afforded by said recess in the shank so as to point generally in the direction of impact, and retainer means passed through aligned openings in said boss and shank to removably hold the tip to the shank of the hammer, the longitudinal axis of said retainer means being disposed on a line which intersects said axis of said shank and which is so inclined relative to said axis of said shank as to define an acute angle in the third quadrant produced by said intersecting axes, and said shoulders all extending parallel to said axis of said retainer means.

9. A hammer for a rotary mill comprising, a shank, a forward facing bearing face on one side of the shank extending toward one end of the shank, said end of the shank serving at least in part as a second bearing face, a renewable tip on said end of the shank and having bearing faces complemental to said bearing faces of the shank, said shank having a recess formed therein proceeding inwardly from the first-named bearing face, said recess affording shoulders which are disposed wholly internally of said shank and inclined so as to point generally in the direction of'impact, said renewable tip on the bearing face complemental to the second-named bearing face of the shank having aboss projecting therefrom formed with shoulders complemental to the shoulders afforded by said recess in the shank and disposed wholly within the recess in the shank, and retainer means removably holding the tip to the shank of the hammer.

10. A hammer for a rotary mill comprising, a shank, a

renewable tip, for the shank, said shank having-an internal recess formed therein in the shape of the letter T and proceeding inwardly from an outer surface of the shank,

said recess affording at least four internal surfaces disposed wholly internally of the sides of the shank, said renewable tip having a boss projecting therefrom formed with external surface complemental to the internal surfaces afforded by said recess in the shank, said boss on the tip being seated in the recess of the shank with said internal surfaces and said external surfaces in juxtaposition thereby mounting the tip on the shank of the hammer, and retainer means removably holding the tip to the shank of the hammer.

11. A hammer for a rotary mill comprising, a shank having a longitudinal axis, a forward facing bearing face on one side of the shank extending to one end of the shank, said end of the shank serving as a second bearing face, a renewable tip on said end of the shank and having bearing faces complemental to said bearing faces of the shank, said shank having a recess formed therein proceeding inwardly from one side thereof, said recess affording spaced shoulders disposed wholly internally of said shank, and the axis of said recess being inclined so as to point generally in the direction of impact, said renewable tip having a boss projecting therefrom that is complemental to and fitted in the recess in the shank so as to be inclined to point generally in the direction of impact, and retainer means passed through aligned openings in said boss and shank to removably hold the tip to the shank of the hammer, said retainer means being aligned on an axis which intersects said axis of the shank and which is so inclined relative to said shank as to define an acute angle in the third quadrant produced by said intersecting axes.

12. A hammer for a rotary mill including a shank' References Cited in the file of this patent UNITED STATES PATENTS 1,717,759 Briggs .Tune 18, 1929 2,467,865 Smith Apr. 19, 1949 2,534,302 Sennholtz Dec. 19, 1950 2,566,758 Anderson Sept. 4, 1951

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