US2506455A - Swing hammer mill - Google Patents

Description

y 1950 D. w. JACKSON 2,506,455

SWING HAMMER MILL Filed June 2, 1947 2 Sheets-Sheet 1 Fig. I

/Nl/ENTOE," Ei 3 DPYSEIC WALTON JACKSON y 1950 D. w. JACKSON 2,506,455

SWING HAMMER MILL Filed June 2, 1947 2 Sheets-Sheet 2 0 q\ q. N 99 \IT a L 0 l0 m m V N c d N LO ml m //-/\/E/ /To/e; Dsrexc WALTON JACKSON,

' proved grinding mill wherein the housing of Patented M ay z, 1950 SWING HAMMER MILL Dcrlo Walton Jackson, Wakefield, England, as-

lignor to The Jeffrey Manufacturing Company, a corporation of Ohio Application June 2, 1347, Serial No. 751,743

Great Britain December 3, 1945 Section 1, Public Law 690, August 3, 1946 Patent expires December 3, 1965 7 This invention relates to swing hammer mills for pulverizing materials.

An object of my invention is to provide an E- e mill houses a grinding rotor and both the drivin motor for the rotor and the housing of the mill are covered and are cooled by air circulated through the enclosure formed by the cover over the motor and grinder housing and over heat exchanging fins on the grinding mill housing by a fan contained within the cover.

Other objects of the invention will appear hereinafter, the novel features and combinations bein set forth in the appended claim.

In the accompanying drawings:

Figure l is a half sectional side elevation;

Figure 2 is a section on the line II-II of Figure 1; and

Figure 3 is a perspective view showing a suitable conflguration of housing for the mill.

Referring to the drawings, the body part or housing of the mill or grinder is constituted by (a) an upper portion embodying as an integral casting a substantially quarter-cylindrical wall I partly bounding the crushing chamber 33, a. top inlet or feed opening 2 extendingalong such wall parallel with its axis and midway between the ends of the arc, a tangential feed tube 3 extending from such wall and formed in its integral closed end 3a with a concentric bore 4 lined with a bush 4a cooperating with a bush 5a in the upper integral part is of a segmental wall part 5 of the housing of the grinder to receive the end journals of a feed screw 6, and (b) by an open ended tubular base portion 1 adapted to accommodate a substantially semi-cylindrical screen 8, the upper and base body portions being bolted and sealed together at the upper open end of the base portion I through opposed flanges Ia and la respectively.

The axis of said tangential feed tube 3 is horizontal and perpendicular to the radius passing through the said inlet or feed opening 2 of the semi-cylindrical wall I, the cylindrical wall of the interior of this tube being interrupted at the inner end by the said inlet or feed opening 2 which it seals.

The end of the feed screw journaled in the bush 4a carries at its extremity a sprocket wheel 9 driven via a chain ID from a sprocket wheel II on the shaft l2 of a geared electric motor l3 the base ll of which is secured by depending inverted T-shaped webs or ribs (not shown) to a bed plate l5 forming an integral semi-lateral and diagonal wall or shell part of the upper part I, such bed plate I! being channeled to receive the T-shaped bars or ribs. The end of the tangential feed tube 3 remote from the inlet or feed opening 2 has a relatively short or shallow upstanding flared and flanged inlet hopper is sealed thereto which, by its upper flange 20, is sealingly but removably fixed about the edges of a rectangular opening 2| in the top of a part II of a cover that cooperates with a removable end cover part Hi to form a substantially open bottomed removable separable cover that encloses the mill. The lower marginal parts of these cover elements are sealed and secured by screws 40 to the base plate 4! of the'mill which cooperates with the open bottomed cover to form a complete enclosure for the mill.

The lower open end of the tubular body part I of the mill rests upon and is sealed about a discharge opening in the base plate 4| and is pro-- 2| longed bi-laterally relatively to the upper part to carry housings 22 accommodating self-aligning ball bearings 23' for the rotor shaft 24, one end of which passes through and beyond the appropriate housing to receive a multiple-V 5 rope pulley 25 to enable the shaft to be driven from an electric motor 42 or other suitable power unit, secured to the base plate 4|. This rotor shaft 24 passes axially across the crushing or reducing chamber 33 which is constituted by a removable nearly semi-cylindrical screen plate 8 supported by ledges 26 on the lower body part of the mill, and two symmetrical segmental, i. e. nearly quarter-cylindrical, liners 28 seated against the semi-cylindrical wall inner surface vof the upper body part of the mill housing and having opposed parallel edges 28a spaced apart at the inlet opening of said wall so as not to obscure such opening.

The said screen plate 8 preferably embodies a single perforated plate having reinforcing side flanges, its ends being flanged as at 26a for rigidity, its longitudinal flanges having breaker bars 30 interposed between them and the lower edges of the two segmental liners 28'. These 1 breaker bars are square section bars having the same thickness as the said liners and establishing continuity of the screen and the segmental liners.

Thetwo liners 28 have internal serrated surfaces 31 to cooperate with the hammers 32 in breaking up the material fed by the feed screw into the crushing chamber 33 through the inlet opening 2. The hammers 32 are each in the form of a substantially wedge section bar parallel with the axis of the crushing chamber and having near body its ends a pair of relatively short parallel lateral 3 arms 34 with, apertured bosses 84a at their ends remote from the bar to pivot upon the appropriate one of a plurality of parallel equi-distantly screw to be removed readily when the segment 5 has been removed, its appropriate end is fixed to a co-axial extension 4a by a peg 6b and keeper spaced rods secured across rotor discs fixed to the rotor shaft, such discs preferably comprising two end annular plates 36 and an intermediate annular plate 31 and constituting with the hammers, the rotor. A pair of concentrically bossed locating or end plates 38 are fitted to the shaft 24 to secure the said rods against axial displacement.

The purpose of positioning the hopper and feed opening ill at the free end of the said feed tube 3 is to ofiset such opening relatively to the top feed opening 2 in the crushing chamber so that the material being fed in the tube feed 3 and the inlet opening or hopper l9 seals the entrance to the crushing chamber thereby controlling the ingress of air thereto. To enable a regulated supply of air or an inert gas to be admitted to the crushing chamber without producing a high blast or blower action by the high speed of travelling hammers, one or more, preferably two, inlet ports 39 are provided in the mill body and communicating with the crushing chamber via a vertical compartment I40 extending across opposed portions of the upper and lower body parts and open at its lower end to one side of the screen 8, so that air, or aninert gas, can pass through the screen into the crushing chamber. Screw plugs 44 normally close these ports.

Instead of the screen comprising a slotted or perforated plate, it may comprise a plurality of integral or individually removable bars. -By using a detachable screen, variations in screen openings can be effected readily.

The cover is formed with a finned ventilating inlet opening 45 covered by a perforated screen, and one end of the base carries an electric motor 46 driving a fan 41 rotating in an outlet opening 48 in the base, such opening being covered by a reticulated screen 49. The action of this ventilating fan is to circulate and change the cooling air inside the cover to maintain an even running temperature of the mill and its motors 41, I: and 46.

By sealing off the air from the inlet of the mfll, the machine absorbs very little power to run light as compared to when the machine runs in'open atmosphere.

As seen in Figs. 1 and 2, all of the members which form the body or housing of the mill or grinder are provided with outwardly extending heat exchange flanges or fins adapted to transfer. heat to the ambient air within the enclosure formed by the cover parts l1 and I 8 and the base 4|. The heat exchanging fins of the open ended tubular portion or member 1 of the mill or grinder areseen at 5|, the fins of the member 5 are seen at 52and a fin of the feed tube 3 is seen at 53.

Space, as at 50, is afforded to enable a workman to pass his hand easily under the screen when screens are being changed. Also 'by splitting the upper part of the mill body to afford the removable segment 5 the hammers and screens can be changed without completely dismantling the machine. Still further, to enable the feed pin 60.

From the foregoing description it will be apparent that I have provided an improved grinding mill assembly wherein the housing or body of the grinder or mill is enclosed by a cover or enclosure means having inlet and outlet or exhaust openings in which there is a fan for circulating cooling air over the motors of the apparatus within the enclosure and over the grinder housing in contact with its heat exchange flanges or fins for cooling the motors and grinder.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claim hereto appended and applicant wishes therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of the invention, what it is desired to secure by Letters Patent of the United States is:

A grinder assembly including a base frame, a grinder housing on said base frame having external heating exchange fins adapted to transfer heat to air flowing therearound, means associated with said grinder housing forming a material inlet thereto, a rotor in said grinder housing, a motor for driving said rotor also on said base frame, a separatable removable two-piece substantially open bottomed cover for said grinder housing and motor adapted to be carried and substantially closed at its bottom by said base frame and including an opening adapted to coowrate with said material inlet, a ventilating inlet in said cover at one side of said motor, a ventilating outlet in said base frame at the opposite side of said motor, a fan, and means mounting said fan on said base frame within said cover and adjacent said ventilating outlet for moving air through said ventilating inlet around said motor and grinder housing and out of said cover through said ventilating outlet.

DERIC WALTON JACKSON.

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

UNITED STATES PATENTS Number Name Date 1,214,558 Liggett Feb. 6, 1917 1,381,266 Andrews June 14, 1921 1,560,766 Crites Nov. 10, 1925 1,641,409 Bell Sept. 6, 1927 1,660,269 Knox Feb. 21, 1928 1,771,163 Crites July 22, 1930 1,829,985 Flaherty Nov. 3, 1931 2,154,963 Swager Apr. 18, 1939 2,211,518 Scherbaum Aug. 13, 1940 2,279,961 Whittaker Apr. 14, 1942 2,359,911 Grindle Oct. 10, 1944 2,402,170 Lund June 18, 1946 2,440,051 Lind et al Apr. 20, 1948

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