US 2663505 A
Description (OCR text may contain errors)
Dec. 22, 1953 Filed July 17, 1951 c. E. SENNHOLTZ 2,663,505
ROTARY IMPACT HAMMER FOR PULVERIZERS 2 Sheets-Sheet 1 INVENTOR. Charles E. Sennholi} BY o/Lawn,
Dec. 22, 1953 c. E. SENNHOLTZ 2,663,505
ROTARY IMPACT HAMMER FOR PULVERIZERS Filed July 17, 1951 2 Sheets-Sheet 2 INVENTOR.
Charles E. fiennhojy (3149)., 9413 M4 vwaif Patented Dec. 22, 1953 UNITED [STAT ROTARY IMPACT HAMMER FOR PULVERIZERS Charles E. Sennholtz, Chicago, Ill. Application July 17, 1951, Serial No. 237,226
7 Claims. (Cl. 241-197) The present invention relates to rotary impact crushers or pulverizers and more particularly to improvements in the revolving hammers ordinarily associated therewith.
In general, it is an object of the present invention to provide an improved hammer having a replaceable tip which may readily and easily be installed and removed and which is not susceptible to accidental disengagement, even under the most severe operating conditions.
A further object of the invention is to provide a pulverizing hammer and a replaceable tip therefor having novel engaging surfaces which are so designed that impact and centrifugal forces acting on the tip, in the course of use of the hammer, tend to increase the holding engagement of the tip without increasing the difficulty of removing the latter.
Another object is to provide a hammer having a replaceable tip in which the tip is securely retained on the hammer in a novel manner so that the tip and the engaging surfaces are susceptible to large tolerances in size permitting economical manufacture of the tip with a minimum of machining operations.
A still further object of the invention is to provide a hammer of this character including a hammer proper and a replaceable tip, together with a wedge member by means of which the tip is securely locked in position on the hammer proper against dislodgment. A similar and related object is to provide a construction of this character in which the wedge member is maintained in a locking relationship by means of a through-bolt assembly, which latter assembly, when the hammer is in use, is 'so located and positioned with respect to the other parts of the assembly that no torsional shearing or compressional forces are transmitted to the throughbolt assembly upon impact ofthe tip with the material undergoing pulverizing.
It is another object of the invention to provide an improved pulverizing hammer which is in-' herently strong, rugged and durable so as to withstand shock and impact forces, and which has heavy duty working surfaces giving long and useful life against abrasive forces.
Finally, it is an object of the invention to provide a pulverizing hammer and a tip therefor which may be manufactured with fairly wide tolerances in the fit of the various parts without endangering the locking characteristics of the various parts when they are assembled upon the other.
other objects and advantages of the invention,
2 not at this time enumerated, will become apparent as the nature of the invention is better understood.
In the accompanying two sheets of drawings forming a part of this specification:
Fig. 3 is a perspective view of the replaceabletip.
Fig. 4 is a perspective view of a wedge member employed in connection with the present invention.
Fig. 5 is a side elevational view of the hammer proper with the tip removed.
Fig. 6 is a side elevational view of able tip, and
the replace- Fig. '7 is a side elevational view of the wedge member.
While the invention is susceptible of various modifications and alternative constructions, there is shown in the drawings and will herein be described in detail the preferred embodiment, but it is to be understod that it isnot thereby intended to limit the invention to the form dis- 1 closed, but it is intended to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended. claims.
In all of the above described views, similar characters of reference have been employed to designate similar parts throughout. Referring more particularly to the drawings, an impact hammer l0 embodying the present invention is adapted for use with various types and kinds of crushers, pulverizers, mills, or the like. The hammer construction may be readily understood without reference to the details of the pulverizer as a whole. It will suffice to say, how-. ever, that a plurality of such hammers are pivoted at the periphery of a rotating disk and are maintained in a radially extending direction due to the action of centrifugal force. The hammers are swung successively into contact with a mass of rock, coal or similar frangible material which is broken up into a loose mass by the various impacts.
As disclosed in Figs. 1 and 2, the hammer; 10 comprises a hammer arm or shank I 2 and a hammer tip l4 (see also Fig. 3) removably secured to its outer regions. The hammer arm-is pivoted in pendulous fashion at its upper end on a suitable supporting shaft (not shown) adapted to extend through an opening l6 provided at the base of the hammer arm I2. The hammer arm I2 is generally rectangular in cross section and is provided with a leading face or wall l8 and side walls 28 and 22 extending rearwardly therefrom.
Referring now to Fig. 2, the hammer arm I2 is provided with a relatively large substantially V-shaped notch 23 in the leading face 18 thereof which extends rearwardly of the hammer arm to a region approximately half-way between the leading face i8 and the trailing face or wall 24 of the hammer arm. The notch 23 is provided with a comparatively wide, flat bottom 26 having a relatively narrow, offset, inclined portion 23. The inclined portion 28 of the bottom 26 of the notch 23 merges with a side wall 36 and the flat bottom 26 merges with an opposed side wall 32, the two side walls 38 and 32 diverging forwardly and outwardly. A transverse tongue 34 projects upwardly from the forward edge of the surface or wall 36 and is of slightly less width than the widths of the hammer arm I2. The forward region of the wall or surface 32 is provided with a tapered recess cr notch 56 therein which has its wide end at the juncture between the surfaces l8 and 32 and which has its narrow end at a medial region of the surface 32. As will be described presently, the tongue 34 is designed for cooperation with a recess provided in the hammer tip l4 while the notch or recess 36 is designed for cooperation with a projection provided on a Wedge member 38 associated with the hammer assembly and by means of which the hammer tip i4 is removably secured in position on the hammer arm [2.
The hammer tip I4 is best illustrated in Fig. 3 and is generally of L-shaped design. The hammer tip is provided with a body portion 40 providing a leading impact surface 42 and a generally rounded end surface 44 which, when the tip is in position on the hammer arm l2, constitutes an extension of the generally rounded outer end 46 of the hammer arm. The hammer tip I4 is also provided with a laterally extending portion 48, the outer surface or end 59 of which is adapted to lie flush with and bear against the bottom surface 26 of the notch 23 provided on the hammer arm l2 when the two parts are in assembled position. The laterally extending portion 48 provides a surface 52 which, when the tip is assembled on the arm, opposes the surface 32 provided on the hammer arm. The surface 52 of the hammer tip !4 is provided with a tapered recess 54 which is complementary in shape to and is designed for cooperation with a second projection provided on the wedge member 38. The lateral portion 48 of the hammer tip 14 is also provided with an inner surface 56 adapted to lie flush with and bear against the inner side wall 36 of the notch 23 when the parts are assembled. An elongated recess or groove 63 is formed in the tip I4 at the juncture between the surface 56 and the inner surface 6! of the body portion 40 of the tip l4 and is adapted to re- 7 I ceive the tongue 34 therein when the parts are iassembled. The tongue 34 and groove 36 are of substantially the same proportions and are complementary in shape to each other so that ay be received within the other with hammer arm l2 with the tongue 34 fitting into the recess 66, the surface 52 of the tip and the surface or side wall 32 of the notch 23 in the hammer arm i2 provides therebetween a substantially V-shaped space in which there is adapted to be received the wedge member 33 for locking the two parts together.
The wedge member 38 is illustrated in detail in Fig. 4 and includes a tapered body portion of substantially the same width as the width of the hammer arm [2 and having one inclined face 62 adapted to fit against the face 32 and another inclined face 64 adapted to fit against the face 52 when the wedge member 38 is in position in the assembled structure. The small end or bottom surface 66 of the wedge member 33 is adapted to fit against the bottom wall 23 of the notch 23 when the parts are assembled. The face 62 of the wedge member 33 is provided with a raised tapered lug 68 complemental in shape to the tapered recess 36 provided in the wall 32 of the notch 23 and a similar raised wedge-shaped projection 70 is formed on the surface 64 of the wedge member 38, this latter projection it being substantially complemental in shape to the recess 54 provided in the surface 32 of the hammer tip I4. Thus, when the parts are in their assembled relationship with the wedge member 38 fitting into the space existing between the opposed wall surfaces 32 and 52, the projection 66 fits more or less snugly within the recess 36 and the projection 10 fits more or less snugly within the recess 54.
The small end of the tapered wedge member 38 is provided with a T-shaped slot 72 therein (Figs. 4 and 7) adapted to receive therein the head 14 of a through bolt 16. The threaded end of the bolt 16 projects into a recess 18 provided in the trailing face 24 of the hammer arm 10, and a nut 80, which may be of hexagonal design, is received on the threaded end of the bolt 16 and is wholly contained within the confines of the recess 18 to hold the Wedge member 38 firmly in position in the hammer assembly. A bore 82, which communicates with the recess 18 and bottom of the notch 23, extends through the body portion of the hammer arm 12 to accommodate the through bolt 16.
Referring now to Fig. 1, it will be seen that when the various parts including the hammer arm I2, hammer tip l4 and wedge member 38 are in assembled relationship, the combined width of the hammer arm l2 and the tip I4 in the direction of swinging movement of the hammer arm is slightly greater than the width of the shank portion of the arm and thus the leading impact surface 42 of the tip l4 projects forwardly a slight distance beyond the leading wall I8 of the hammer arm l2 to provide an impact surface somewhat in advance of the plane of the leading surface of the hammer arm 2.
The leading face 84 of the hammer arm l2 below the notch 23 is substantially flat and is inclined downwardly and rearwardly with respect to the vertical when the hammer arm is in the vertical position in which it is shown in Fig. 1. Similarly, the opposing face 6| of the hammer tip 46 is also inclined in this manner so as to lie against the face 84 when the parts are assembled. The inner surface 86 of the tongue 34 (Figs. 1 and 5) and the mating surface 88 of the groove 68 are also inclined in a plane substantially parallel to the plane of the surfaces 6| and 64.
.b n th when entrifugal forces are ti hm tip L4. ther s'a endency for the tip to be drawn inwardly toward the central plane of the hammer arm 12, thus enhancing the wedging action between these two parts. Even in the absence of the Wedge member 38 and through bolt assembly 16, the tendency would be for the two parts [2 and M of the hammer assembly to remain locked together during rotation of the pulverizer assembly.
The hammer arm l2, hammer tip l4 and wedge member 38 are respectively shown in Figs. 5, 6 and 7 and these latter figures are arranged on a single sheet of drawing so that their parts occupy substantially the same positions of orientation with respect to the vertical plane that they will occupy when the parts are assembled together. Thus, when assembling the parts, it is merely necessary to elevate the hammer tip I 4 a sufficient distance so that the surface 50 thereof clears the tongue 34, after which the parts may be moved horizontally toward each other until the tongue 34 registers vertically with the groove 60. The hammer tip [4 may then be lowered into position so that the tongue 34 enters the groove 66. The wedge member 33 may then be inserted in the tapered space which has thus been created by the positioning of the tip upon the hammer arm. As the surfaces 62 and 32 and the surfaces 64 and 30, respectively, of the wedge member 38 and hammer arm I2 move toward each other, the tapered projections 68 and 10 enter the notches or recesses 3t and 54, respectively, of the hammer arm l2 and tip I4. The through-bolt 16, which has been previously placed in position with the head 74 thereof disposed within the T-shaped slot 12, is guided through the bore 82 and thereafter the nut 80 may be applied to the threaded portion thereof and tightened to firmly clamp the parts in position. By a reversal of this process the various parts may be disassembled.
It will be apparent that since all the essential mating surfaces between the various parts are tapered, there are no surfaces which need to be machined to a fine tolerance in order to insure smooth, sliding engagement. As a matter of fact, the hammer tip l4 may be in the form of a simple casting and may be constructed in th form illustrated without any machining processes whatsoever. Since it is unnecessary that the tip be precisely fitted to the hammer arm to avoid looseness of play, it will be apparent that considerable dimensional variation is permissible and the tip may be turned out at a relatively low cost. This latter point is of particular advantage when it is remembered that the tip must be replaced at intervals due to the abrasion of the pulverizing material upon which it operates. If the tips are formed of cast steel it will be seen that the tapered surfaces thereof will provide proper draft for easy removal of the pattern from the mold, for example, if the parting line of the mold is drawn diagonally from the upper rear corner of the flange portion 52 to the lower leading corner of the impact face 42.
Several of the advantages of the above described construction are apparent in Figs. 1, 5 and 6. It will be seen that the lower region of the hammer arm 12 provides a relatively strong columnar support for the hammer tip I4 and that the tapered body portion 49 of the tip I 4 provides a large mass of metal for taking the brunt of the Wear on the tip. Inasmuch as the leading face 52 of the tip [4 projects beyond the leading face l8 of the hammer arm [2, a, certain amount of metal is provided for excess wear prior to the time th'at'the leading face l8 of the hammer arm is endangered. However, the wear on the leading face 42 of the tip I4 is not uniform and those portions of the tip which are furthest removed from the axial center of rotation of the hammer arm are the portions which are subject to the most wear. Thus the fact that the body portion 40 of the tip I4 is thicker adjacent the outer regions thereof than it is at regions which are inwardly removed therefrom results in an equitable distribution of the metal so that more metal is presented for wear at the region where wear is to be expected. The dotted lines in Fig. 1 indicated at w indicate the possible wear surface that may ultimately result immediately prior to the time when it is necessary to replace the tip M. It will be seen, therefore, that the leading face l8 of the hammer arm [2 is thus protected against damage by virtue of the excess metal afforded at the outer regions of the tip by the tapered body portion thereof.
I claim as my invention; 7 v
1. An impact hammer for rotary pulverizers comprising, in combination, a hammer arm presenting a leading and a trailing face, there being a notch formed in said arm adjacent the outer free end thereof extending inwardly from said leading face, a removable and generally L-shaped hammer tip of one-piece construction including a body portion presenting an impact face and a trailing'face, and a flange portion extending laterally from said body portion and presenting innor and outer faces, said-flange portion being received in said notch with its inner face in contact with one wall of the notch, the trailing face of said body portion being in contact with the leading face of said hammer arm outwardly of said notch, a wedge member disposed in said notch and bearing against the other wall of the notch and against the outer face of said flange portion to maintain the flange portion in position in the notch, and a locking bolt assembly secured at one end to the wedge member and pass ing through said hammer arm for locking said wedge member in position.
2. An impact hammer for rotary pulverizers comprising, in combination, a hammer arm presenting leading and trailing faces, there being a notch formed in said arm adjacent the outer free end thereof extending inwardly from said leading face and having inwardly tapered walls, a hammer tip of one-piece construction including a body portion presenting an impact face in advance of the leading face of said hammer arm and a trailing face in contact with the leading face of said hammer arm outwardly of said notch, said tip having a laterally projecting portion extending into said notch, a wedge member disposed in said notch and having one face thereof bearing against a wall of the notch and the other face thereof bearing against said hammer tip for retaining the latter in position on the hammer arm, and means extending through said hammer arm from the trailing face thereof and projecting into said wedge member for locking the latter in position within said notch.
3. An impact hammer for rotary pulverizers comprising, in combination, a hammer arm presenting a leading and a trailing face, there being a notch formed in said arm adjacent the outer free end thereof extending inwardly from said leading face, said notch having opposed inwardly tapering walls, a removable, generally L-shaped hammer tip of one-piece construction including a body portion presenting an impact face and a trailing face, and a flange portion extending :laterally from said body :portion and presenting innor and outer ,fa'ces, .sa-id :flange portion being received in said notch w-ith its inner face in contact with'one wall-of the latter, the trailing face of said body portion being in contact with the leading face of the hammer arm outwardly of said notch, there being a @groove formed in the outer face of said flange portion, there being a groove formed inone wall of said notch,a tapered wedge received within-saidznotch and having projections formed thereon fitting into said grooves.
said wedge member serving to retain said hammer tip in position on said -hammer arm, and means extending through said hammer arm and engaging said wedge .member for locking the latter in position within said .notc-h.
'4. In combination, a hammer arm for rotary pulverizers having a notch formed in the outer regions thereof extending inwardly from its leading face, a removable tip tor said arm including a body portion overlying the leading face of said arm outlardly of the notch and in contact therewith, said tip having a laterally extending portion'thereof projecting into said notch and bearing against one wall thereof, interlocking upright abutments on said wall of said notch and on said laterally extending portion for preventing forward movement of the latter outwardly of the notch, a rearwardly tapered wedge member disposed in said notch and bearing against the other wall of the notch and against said laterally extending portion for locking said laterally extending portion inposition within said notch, and
v fastening means for holding said wedge against dislodgment from said notch.
5. In combination, a hammer arm for rotary pulverizers having a leading face and a trailing face, a forwardly extending jaw adjacent the outer end of said arm terminating rearwardly of said leading face, said arm and jaw being of the same uniform width, an inwardly extending tongue formed on the forward end of said jaw, a removable hammer tip including a body portion abutting against the forward end of said jaw, there being a groove in said tip into which said tongue extends, a Wedge member fitting between a face of said body portion and a face of said hammer tip for maintaining said hammer tip in position on the hammer arm, and a bolt extending through said hammer arm and secured in said wedge member for locking the latter in position against the hammer tip and hammer arm.
8i 6. In combination, a hammer arm for rotary pulverizers having a notch formed in the outer regions thereof extending inwardly from its leading face, a removable tip for said arm including a body portion overlying the leading face of said arm outwardly of said notch, said tip having a rearwardly extending portion projecting into said notch and in contact with one wall thereof, a rearwardly tapered wedge member disposed in said notch, a first tongue and groove connection between said Wedge and the other wall of said notch, a second tongue and groove connection between said wedge and said rearwardly extending portion of said tip, said first and second tongue groove connections preventing relative sidewise displacement of said wedge, and fastening means for holding said wedge against displacement forwardly out of said notch.
7-. In combination, a hammer arm for rotary pulverizers having a leading face and a trailing face, a notch formed in the outer regions of said arm extending rearwardly from said leading face, a removable hammer tip including a body portion abutting the leading face of said arm outwardly of said notch and a rearwardly ex tending flange portion projecting into said notch and engaging one wall thereof, said wall and said flange having a transversely extending tongue and groove connection thereb'etvve'en, a rearward-.
1y tapered wedge positioned in said notch between said flange portion and the other wall of said notch, a first forwardly and rearwardly extending tongue and groove connection between said wedge and the other wall of said notch, a second forwardly and rearwardly extending tongue and groove connection between said wedge and said flange, said first and second connections preventing relative sidewi'se movement of said wedge, and fastening means extending through said hammer arm for restraining said wedge against displacement forwardly out of said notch.
CHARLES E. SENNHOLTZ.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,186,071 Bledsoe June 6, 1916 1,491,416 Plaisted Apr. 22, 1924 1,491,417 Plaisted l Apr. 22, 1924 1,630,021 Lucas May 24, 1927 2,531,597 Anderson Nov. 28, 1950. 2,534,301 Sennholtz 1 Dec. 19, 1950 ars". o