Anti Slug Device For Hammermills

Abstract

A portable feed grinder including an open topped feed receiving tub mounted on a mobile frame and having a generally horizontal stationary bottom wall and a peripheral side wall mounted for rotation on the generally vertical axis of the tub. A hammermill rotor is disposed in an opening in the tub bottom wall for feed grinding rotation on a generally horizontal axis and is partially encompassed by an underlying perforate screen member. Stationary hammer elements mounted on the bottom wall cooperate with hammers on the rotor to chop or grind material in the tub.

Description

BACKGROUND OF THE INVENTION

Portable feed grinders generally of the type commonly known as hammermills are known, these utilizing rotary hammers only and being devoid of stationary hammer elements between which the rotary hammers travel. These prior devices are adapted to receive material to be ground, such as hay, corn and other bulk feed material, from handling devices, such as conveyors, power forks and similar means. Often the feed material to be ground is dumped into the tub in rather large clumps, imposing a severe shock load on the hammermill rotor and tending to jam or overcrowd the grinding apparatus.

SUMMARY OF THE INVENTION

This invention provides a plurality of stationary hammer elements mounted on a mounting plate that is secured to the stationary bottom wall of the tub adjacent the hammermill opening therethrough. The stationary hammer elements are disposed in parallel relationship transversely of the axis of the hammermill rotor and spaced apart axially of the rotor. The stationary hammer elements project upwardly from the mounting plate and are each disposed between the path of rotary travel of a different pair of axially adjacent ones of the hammers on the hammermill rotor. The stationary hammer elements are disposed above the axis of the rotor and below the top of a circle defined by the radially outer ends of the hammers during free rotation of the rotor. The stationary hammer elements cooperate with the rotary hammers to break up the clumps in a primary zone at substantially the level of the tub bottom wall, the broken-up clumps being ground to the desired size between the hammermill rotor and the underlying portion of the perforate screen member.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view in side elevation of a tub type grinder containing the device of this invention, some parts being broken away;

FIG. 2 is an enlarged fragmentary view partly in top plan and partly in horizontal section, taken substantially on the line 2--2 of FIG. 1, some parts being broken away;

FIG. 3 is a further enlarged fragmentary section taken substantially on the line 3--3 of FIG. 2;

FIG. 4 is a fragmentary view in top plan of a portion of FIG. 2; and

FIG. 5 is an enlarged fragmentray section taken on the line 5--5 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A generally rectangular frame 1 is shown as being supported by pneumatic tire equipped wheels 2, and is adapted to be connected to a traction vehicle, such as a tractor or the like, not shown, but by means of a hitch bar 3. An open topped tub structure, indicated generally at 4, comprises a horizontally disposed stationary bottom wall 5 comprising an upper bottom wall section 6 and a lower bottom wall section 7, the bottom wall sections 6 and 7 being suitably supported on the frame 1. The tub structure 4 further includes a cross-sectionally circular peripheral wall 8 that is mounted on an annular channel member 9 supported from the frame 1 by a plurality of circumferentially spaced supporting rolls 10 journaled on brackets 11 rigidly secured to opposite sides of the frame 1. The annular channel 9 is held against lateral movement by a plurality of circumferentially spaced guide rollers 12 that are suitably journaled in a subframe member 13 shown fragmentarily in FIG. 5, the subframe member 13 supporting the stationary bottom wall 5 from the frame 1 in a suitable manner.

Rotary movement is imparted to the peripheral wall 8 of the tub structure 4 by a pneumatic tire equipped drive wheel 14 that is suitably journaled in the frame 1 for rotation on a vertical axis parallel to the axis of the tub structure 4, the drive wheel 14 tangentially engaging the outer circumferential surface of the annular channel 9 to impart rotation thereto. The drive wheel 14 is driven from a conventional fluid pressure operated motor 15 by means of a pulley 16 mounted fast on an output or drive shaft 17 on the motor 15, a second pulley 18 mounted fast on the shaft 19 of the wheel 14, and an endless drive belt 20 entrained over the pulleys 16 and 18. The motor 15 is driven from a pump 21 that is operatively coupled to gearing, not shown, within a gear box 22 having an input shaft 23 and an output shaft 24. A pulley 25 is mounted on the output shaft 24 and is coupled to a second pulley 26 mounted on a shaft 27 which drives the pump 21, an endless belt 28 being entrained over the pulleys 25 and 26. The input shaft 23 is connected to an elongated drive shaft 29 by means of a universal coupling 30, the shaft 29 being adapted to be connected to the power take-off mechanism of the tractor, not shown. The drive arrangement is such that the peripheral wall 8 of the tub structure 4 rotates in a clockwise direction with respect to FIG. 2, for a purpose which will hereinafter become apparent.

The lower floor section 7 defines a generally rectangular opening 31 therethrough, the opening being generally rectangular and extending radially from substantially the axis of the tub structure 4 to the peripheral wall 8 thereof. As shown in FIG. 3, one side of the opening 31 is defined by a downturned flange portion 32 of the lower bottom wall section 7, the opposite side of the opening 31 being defined by a channel member 33 having a ramp portion 34 that slopes downwardly from the bottom wall 7 toward the opening 31. At its inner edge portion, the member 33 is formed to provide a downturned flange 35. A hammermill rotor, indicated generally at 36, includes an axial shaft 37, a plurality of circular plate members 38 mounted on the shaft 37 and held in predetermined spaced-apart relationship by spacer plates or the like 39, a plurality of circumferentially spaced mounting rods 40 extending through aligned openings in the plate members 38 in radially outwardly spaced parallel relationship to the axis of the shaft 37, and a plurality of hammers 41 having transverse openings 42 adjacent their opposite ends for mounting the hammers 41 at either of their opposite ends on the mounting rods 40, for swinging movements of the hammers 41 about the axes of their respective mounting rods 40. The rotor shaft 37 is disposed generally centrally between the opposite sides of the opening 31 in the lower bottom wall section 7 and below the level of the bottom wall section 7 so that, when the rotor 36 is rotated and the hammers 41 are disposed to project radially outwardly with respect to the shaft 37, the radially outer ends of the hammers 41 will project above the level of the lower bottom wall section 7, as shown in FIG. 3. The opposite ends of the rotor shaft 37 are suitably journaled in bearings, not shown, in the well-known manner. As shown by full and dotted lines in FIG. 2, the rotor shaft 37 is operatively connected to the output shaft 24 of gear box 22 by means of a connecting shaft 43 and a pair of universal couplings 44. The hammermill further includes a cross-sectionally generally U-shaped screen 45 having opposite side edges disposed adjacent the flange portion 32 and flange 35, the screen 45 underlying and partially encompassing the rotor 36, and being secured in place by the usual well-known means, not shown. In the embodiment of the grinding rotor shown, the hammers 41 are disposed in axially spaced groups of axially and circumferentially spaced hammers. The groups are diagrammatically shown in FIG. 2 and shown in greater detail in FIG. 4.

When material to be ground, such as hay, corn or other feed material, is delivered to the tub structure 4, the feed material falls on both bottom wall sections 6 and 7. The material which falls upon the bottom wall section 6 is carried around by rotation of the peripheral wall 8 to the opening 31 where it is ground by the hammers 41, the ground feed being discharged through the apertures of the screen 45 to a hopper like portion 46 underlying the screen 45. The ground material falls on a belt conveyor 47 underlying the hopper 46, the conveyor 47 delivering the material to a delivery belt conveyor shown more or less diagrammatically in FIG. 1 and indicated at 48. The conveyor 48 is supported by a pair of legs 49, extending upwardly from frame 1, one of the legs being shown in FIG. 1, and a pair of ties or links 50, one of which is shown in FIG. 1.

When hay or other feed material is dumped into the tub structure 4 to be ground, it is often in the form of large clumps of material which, when such clumps move into engagement with the rotating hammers 41, often impose a severe shock load on the rotor 36, and tend to become jammed or at least overcrowded into the space between the plate members 38 and the underlying screen 45, interfering with efficient operation of the grinder. For the purpose of preventing such shock loads and jamming of material into the hammermill, I provide a plurality of rigid plate-like stationary hammer elements 51 having outer ends welded or otherwise rigidly secured to an elongated mounting plate 52. The mounting plate 52 extends longitudinally of the opening 31 in the lower bottom wall section 7, and rests upon the ramp portion 34 of the channel member 33. The ramp portion 34 and mounting plate 52 are provided with a plurality of cooperating longitudinally spaced slots for reception of nut-equipped clamping screws or the like 54. Further, the mounting plate 52 is formed to provide a downturned longitudinally extending flange 55 between which and the flange 35 the adjacent longitudinally edge of the screen 45 is disposed. The stationary hammer elements 51 project vertically upwardly from the mounting plate 52 and extend longitudinally in a direction transversely of the axis of the hammermill rotor 36, each stationary hammer element 51 being disposed between the paths of travel of adjacent pairs of the groups of said hammers 41, see FIGS. 2 and 4. With reference to FIG. 3, it will be seen that the stationary hammer elements 51 are disposed above the level of the axis of the hammermill rotor 36 and below the top of a circle described by the radially outer ends of hammers 41 when the hammers 41 extend radially outwardly with respect to the rotor shaft 37. With this arrangement of stationary hammer elements 51 relative to the groups of hammers 41, large clumps of hay, corn or other feed material dumped into the tub structure 4 are initially broken up into smaller clumps in the zone or region of the stationary hammer elements 51, and are more efficiently and fully ground to smaller particle size by the hammers 41 against the bottom portion of the screen 45. Further, with the above-described arrangement shock loads against the hammermill rotor 36 are reduced to a minimum with a resultant smoother end more efficient grinding operation.

The above-described invention has been fully tested and found to be completely satisfactory for the accomplishment of the objective set forth; and, while I have shown and described a preferred embodiment of my improvement in portable feed grinder construction, it will be appreciated that the same is capable of modification without departure from the spirit and scope of the invention, as defined in the claims.

Claims

I claim:

1. In a portable feed grinder including; a mobile frame, an open topped tub structure having a stationary bottom wall and circular peripheral wall mounted for rotation on the generally vertical axis of the tub structure, said bottom wall having an opening therethrough, said opening extending generally radially from adjacent the axis of the tub structure toward said peripheral wall, a grinder rotor disposed in said opening and journaled for rotation on a generally horizontal axis extending longitudinally of the opening, said rotor including a rotor shaft and a plurality of axially and circumferentially spaced relatively movable hammers operatively carried by said shaft for common rotation therewith, a grinder screen underlying and partially encompassing said rotor, and means for imparting rotation to said tub and grinding rotation to said rotor; the combination of mounting plate means disposed adjacent one side of said opening in the bottom wall, a plurality of rigid plate-like relatively stationary hammer elements projecting in generally vertical planes from said mounting plate means and disposed in spaced-apart parallel relationship transversely of the axis of said rotor, each of said relatively stationary hammer elements extending generally toward the opposite side of said opening laterally from said mounting plate means and between paths of travel of different spaced ones of said relatively movable hammer, said relatively stationary hammer elements being disposed above the axis of rotation of said rotor and below the top of a circle defined by the radially outer ends of said relatively movable hammers during rotation of the rotor.

2. The portable grinder defined in claim 1 in which said mounting plate means has a top surface sloping downwardly toward said opening, said relatively stationary hammer elements projecting upwardly from said top surface.

3. The portable grinder defined in claim 2 in which said bottom wall includes a ramp portion sloping downwardly toward said opening and terminating in a downturned flange defining one side of said opening, said mounting plate means having a downturned lip in laterally inwardly spaced parallel relation to said flange for reception therebetween of a portion of said grinder screen, and means anchoring said mounting plate means on said ramp portion.

4. The portable grinder defined in claim 1 in which said relatively movable hammers are disposed in axially spaced groups, each group including a plurality of said axially and circumferentially spaced hammers, each of said relatively stationary hammer elements being disposed between a different pair of adjacent groups of said relatively movable hammers.