US1954175A

US1954175A - Rotary hammer

Info

Publication number: US1954175A
Application number: US553627A
Authority: US
Inventors: Sanning C Jensen
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-07-28
Filing date: 1931-07-28
Publication date: 1934-04-10
Anticipated expiration: 1951-04-10

Description

April 10, 1934. 1 s, c, JENSEN 1,954,175

ROTARY HAMMER I Original Filed July 28, 1931 2 Sheets-Sheet, l

III

gwuentoc April 10, 1934. s. c. JENSEN 1,954,175

ROTARY HAMMER Original Filed July 28, 1931 2 Sheets-Sheet 2 gwuantoc Patented Apr. 10, 1934 PATENT OFFICE ROTARY HAMMER Sanning C. Jensen, Neola, Iowa.

"Application July 28, 1931, Serial No. 553,627 Renewed September 12, 1933 6 Claims.

This invention relates to improvements in hammers for hammer mills.

In hammer mills employing the swing type hammer a series of pivotally mounted hammers are rotated at high speed over a screen through which the grain, or other matter which is ground by the revolving hammerspasses. These hammers, when new, have sharp edges which cut the grain against the screen but these edges rapidly wear away until they become rounded'and when this condition is reached the hammer has to be turned for the presentation of another one of its four cutting edges. Due to the high speed at which the machines are operated, each hammer has to be completely replaced after a few months use.

The primary object of the present invention is to provide an improved type of hammer which is so designed that a sharp cutting edge is maintained even though the edge of the hammer which is presented to the screen becomes rounded off through use and therefore the life of a hammer constructed in accordance with the present invention is much greater than one of the type at present employed.

A further object of the invention is to provide a hammer which, in addition to being so designed as to continuously present a sharp edge for the cutting of grain, is so formed as to cause the grain, or other material upon which it is working, to be forced or thrown into the path of the cutting edge. 7

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the shgwing of the drawings but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 is a perspective view of a rotary hammer constructed in accordance with the present invention.

Figure 1a is a sectional view taken in a plane parallel with the side faces of the hammer shown in Figure 1, at one end, showing the manner in which the end of the hammer wears away.

Figure lb is a fragmentary view in elevation of the inner structure of a hammer mill showing the hammers applied thereto.

the form shown in Figure 5, showing the manner in which the hammer wears.

Figure 6-is a perspective view of one end of a fifth modified form.

Figure 7 is a perspective view of one end of a sixth modified form.

Referring now more particularly to the drawings, wherein like numerals of reference indicate corresponding parts throughout the several views, the numeral 1 indicates a portion of a mill of the type in which swinging hammers of the character embodying the present invention are employed. These mills have a plurality of plates or disks 2 which are concentrically mounted in spaced relation upon a carrying shaft 3 and are connected at points about and adjacent their peripheries by bars or rods 4. Upon these bars are mounted, adjacent their ends, the hammers 5 which, when the plates are rotated, are caused to stand out through centrifugal force away from the bars upon which they are mounted. The hammers 5 illustrate one of the several modified forms of hammer embodying the present invention, one of which is shown in perspective in Figure 1. This form of hammer, which is indicated by the numeral 5, comprises an elongated relatively thick plate of highly tempered steel through which is formed, adjacent each end, an opening 6 for the passage of a rod 4. At each end of the hammer body, each corner is cut away to form the series of step-like shoulders 7, the corners 8 between which constitute the cutting edges. v

These edges wear away after the hammer has been in usefor a short period of time and become rounded, as indicated at 9 in Figure 1a. It will be readily seen from this that this rounded edge could no longer function as a cutting element and therefore the hammer would no longer be of use.

In carrying out the present invention each end of the hammer body is provided with a bore 10 which is cut therethrough from one face of one of the step-like shoulders to the opposite one and as a result it will be seen upon reference to Figure la that, although the previously sharp corner 8 wears away to the rounded condition indicated by the numeral 9, a sharp cutting edge remains at the point 11 which extends throughout substantially half the circumference of the bore. It will thus be seen that while the wearing down of the corner 8 takes away the original sharp cutting edge another cutting edge is formed where the worn surface extends across the bore 10, which continues to function as a cutter for the grain or other material against which the hammer strikes.

In Figure 2 there is shown a modified form of the hammer illustrated in Figure 1, wherein each end of the body 12 is provided with a straight terminal portion 13 across each side face of which so i is formed a V-shaped groove 14 and this portion of the body has formed therethrough from one edge face tothe other, between the grooves 14, a passage 15.

In Figure 3 the straight terminal portion of the hammer body 16 has its transverse corners beveled off to form an end which is in the form of an inverted V, as indicated by the numeral 17, and from one edge face to the opposite edge face between the beveled sides of this inverted V- shaped end there is formed through the body the passage 18.

In Figure 4 the body 19 has each end edge formed with a pair of longitudinally extending V-shaped ribs 20-, and extending through each end, from one side edge to the other, are the two passages or bores 21 each of which is parallel with and disposed between the angled faces of a rib in the manner illustrated.

In Figure 5 the hammer body 22, which is shown, has two straight terminal end portions 23 the same as in the other forms and the end edge of each of these portions is left flat, as in the form shown in Figure 1, but instead of a single bore extending through each of these end portions from one side edge to the other there are formed two bores, each of which is indicated by the numeral 24, which are disposed in side by side relation.

The form of hammer shown in Figure 6 is substantially the same as that shown in Figure 5, except that each straight end portion 25 of the body 26 has in place of a pair of circular bores of the character indicated by the numeral 24, one or more passages 2'7 of triangular crosssection, one side of the angle being in relatively close proximity to and parallel with the face of the adjacent end edge.

Figure 7 illustrates still another form of hammer wherein the body 28 has the straight end portions 29 of the same character as the

portions

23 and 25, but in place of the passages of the character shown in connection with the forms illustrated in Figures 5 and 6, one or more square passages 30 is formed from one side edge to the other of each end portion, it being preferred that three small passages of this character be em,- ployed and disposed in side by side relation in the manner shown, each having a side parallel with the adjacent end edge face.

Figure 5a illustrates the manner in which a pair of curved cutting edges would be formed through the wearing away of a corner of the straight portion of a hammer of the character illustrated in Figure 5. It will be seen that through the wearing away of the corner of the straight end portion 23 of this hammer two curved cutting edges 31 are formed by the bores being cut obliquely through the wearing away of the body. It will thus be seen that whereas a hammer of this character would become useless after being worn in the manner illustrated. if these bores were not provided, by the provision of these bores two extra cutting edges are formed which makes it possible to continue the use of the hammer over a long period of time.

In addition to forming each end of the hammer in one of the several modified forms illustrated for the purpose of providing an additional cutting edge in the manner described, the mill in which the hammer is used is made more efficient by forming each hammer of a much greater width between its side edges and substantially midway between its ends so as to provide each side edge' with the two inclined shoulders 32 which taper inwardly in the manner illustrated.

The hammer bodies thus gradually decrease in width from their transverse centers toward the straight end portions thereof and in this manner the grain, or other material, is driven toward the free ends of the hammers as they rotate in the mill.

From the foregoing description it be readily seen that by the use of hammers of the character herein described the operation of the mill will be made much more economical, due to the fact that the hammers will not have to be replaced as is necessary at the present time.

Having thus described the invention, what is claimed is:

1. A rotary hammer, comprising an elongated flat plate-like body having an aperture through one end and having the end and side edges remote from the apertured end formed to provide cutting corners, and the said last mentioned and having a passage formed therethrough from one side edge to the other and parallel with the side faces of the body.

2. A rotary hammer, comprising an elongated flat plate-like body having an aperture transversely through one end and having the end remote from said aperture cut square across to form cutting corners, said last mentioned end of the body having a passage formed therethrough parallel to the side faces of the body and from one side edge to the other and in relatively close proximity to the square cut end edge.

3. A rotary hammer, comprising an elongated flat body tapering at its side edges from the transverse center thereof toward each end and terminating at each end in a straight portion faces and end edge faces at right angles thereto,-

said straight portions having grooves formed transversely of the side faces thereof and further having a passage formed therethrough parallel with the end edge faces and opening through the side edge faces thereof, the body further having an aperture opening through the side faces at each end.

5. A rotary hammer, comprising an elongated fiat body having straight end portions, each end portion having the side comers beveled off to form a central edge extending from one side edge to the other, and each end portion further havside edge faces, the end portions being formed to provide a ridge having an edge extending from one side edge face to the other, and the end portions further having a. passage formed therethrough from one side edge face to the other and paralleling the side faces thereof SANNING C. JENSEN.