US 2540266 A
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Description (OCR text may contain errors)
L. E. JOHNSON, JR
SLATTED BELT CONVEYER FileiizMgqh 2 Feb. 6, 1951 L IIIIIIIIII/I JaZz Patented Feb. 6, 1951 UNITED S TA T E'S PATEN T F Fl CE 2,540,266 7 SLATTED BELT .coNvEY-En Lawrence. E, Johnson, J g, Hinsdale, Ill. Application March 2, 1949, 'Serial'No. 79,222
4 Claims v This invention relates to an improvement in flexible belting for conveyors of the type in which the'belting is provided with spacedtransverse slats which assist in moving material on a conveyor.
Flexible conveyor belts may be iomnedof-iabric, rubber, or rubberized fabric. Many .such belts are made of a heavy rade of canvas, and are used in the conveyors of harvesters or threshing machines. For such use, the belt is commonly provided with .a plurality of spaced transverse slats which, when the belt is in place, are rupon its outer surface and serve to push the grain, straw, .or the like along thelconveyorand prevent the'produce from sliding rearwardly where the conveyor is steeply pitched.
The principal object of the invention is to provide canvas belting having an improved slat which costs little to attach to the Iabric and which is very strongly secured thereto. Y A number of .expedients have been adapted for securing the slats to the .canvasesused in ecnveyors. Thus, it has been common practice to rivet orstaple the slat to the Surface of the canvas; or in some cases, a combination of rivets and staples have been used. Thishas'been a generally unsatisfactory way of fastening the slats to the canvas, because grain or straw is readily pushed between the canvas and the slat, and eventually tears the slat loose from the canvas. Furthermore, very expensive machinery is required for the heavy stapling or riveting. g
Another method has been to use rubber slats, vulcanized to a rubber or rubberized frabric ,belt. This avoids the tendency of the slats to pull cit,
but is quite expensive both ast material cost and cost of processing. 1
It has also been known toplacea protective canvas fiap over the slat to prevent the entry of straw or other material between the slat and the canvas belt. This requires several extra stitching operations in the vicinity of each slat and furthermore, the canvas protective strip does not lie close against the upright side ofthe slat, and accordingly much of the effectiveness of the slat as a propelling bar is lost.
A somewhat more satlsfactory arrangement has been developed in which a slat is placed beneath the canvas which is then held snugly on the slat by a U-shaped metal overlay having outwardly flared lower edges. The bar, canvas and overlay are riveted together with rivets extending through the superposed elements from top to bottom. Even with this arrangemenhthereis sometendency for material to work ts "gif -between the canvas and the overlay Pursuant to the object heretofore sta ed, and
in an eifort to remedy the defects in the prior art devices, I have found that the pr lem can be completely solvedby using .a rod or bar which is laid against the lower suriace of the canvas and about which the-canvasis passed toii orm aiocn A longitudinally splittube may then :beslid 1W8! the loop of canvas and the bar, and pressed on-tothe canvas and "the bar to clamp the t l together. The "bar thus serves as alocking memher which holds the canvas in the :split tube, and the bar and tube together forma slat. This way of forming the slat and securing it-to-the canvas permits the use of very inexpensive assemblin machinery-asiinple press is practically the only quipment n e ary nd secures "the slat and the canvas --t0gther in such .a way that material cann t, W rk in be ween them so as. to :pull the slat from the canvas.
The invention is illustrated in .a preferred em qdiment in the accompanying drawings in which:
Fig. 1 is a plan view ofa section of flexible -belt ing embodying the invention; Fig. 2 is asldeelevation thereof: Fig. '3 is an enlarged sectional view of the improved slat construction; Fig. 4 is aperspective view of the "split tube: Fig. :5 is a perspective View of the'loeking bar; Fig. .6 is an enlarged sectional view of an improved slat :using a modified form of locking bar; .and Fig. '7 is a perspective View of the modified form of lockin bar. 1
While there is shown in the drawings and herein described in detail a preferred form of the invention in flexible belting for conveyors, it is not intended to limit the invention to the particular belting or arrangement'shown. The scope of the invention will be pointed out in the appended claims.
A section of flexible material is hemmed along its longitudinal edges at I!) and II to form a, belt l2 of suitable width. Preferably, the flexible material is canvas, although it may be a rubberized fabric. At regular intervals along its length the belt is provided with transverse slats, indicated generally at 13, and it is the manner in which the slats l3 are constructed and joined to the belt l2 which forms the subject matter of this invention.
As best seen in Fig. =3, a locking rod or bar I4 is placed against the underside of the belt 12, and the materialis passed about the locking bar l'4 to form a loop l5. i-Th'e" locking bar I4 is prefer ably substantially incompressible so as to hold the loop of material in shape, even against considerable pressure. Accordingly, it is suitably a metal or plastic rod, bar or tube, or may be a rope, or cable.
A tubular member I6 is longitudinally slit alon one of its sides at IT, and its outer surface serves as the surface of the slat. Preferably the tubular member I5 is rectangular in cross-section so as to provide upright side walls which furnish a substantially perpendicular interruption to the upper surface of the belt in order to be as effective as possible in carrying produce along on it. As is well known to the workers in the art, the height of the slat should not exceed approximately of an inch, because of the rather small clearances adjacent the driving and idler rollers of most of the machinery upon which such belt conveyors are used.
The split tube It may be slid endwise over the fabric loop I5 and locking bar I I, and may then be pressed together by squeezing its upright side walls I8 and I9 so that the canvas will be clamped tightly between said side walls and the surface of the locking bar I4. Preferably the slit I1 is wide enough that the edges of the tube do not grip the fabric I even when the tube has been pressed in place, the gripping action being between the side walls I8 and I9 of the tube and the surface of the locking bar I4. If the gripping action were by the margins of the slit II, it would cause excessive wear of the fabric along those lines. Likewise, if the tube It is of thin material the edges thereof forming the margins of the slit I! may be rolled, as at 20 and ZI, to prevent cutting of the fabric.
In the alternative embodiment shown in Fig. 6, the elements are similar to those in the preferred embodiment except for the locking bar. Iii-this form, fabric II I] is passed about a locking bar H4, which has a shape generally like a railroad rail; to form a loop H and is held in place by the clamping action of a split tube H6. The rail-shaped locking bar has a longitudinal rib or stem I22 which extends below the loop I I5 in the material and has oppositely directed flanges I23 and I24 forming a foot at its lower end. The foot made by flanges I23 and I24 form a protectivestrip beneath the loop I I5, so as to eliminate wear at'the sharply turned portion of the canvas forming the lower extremity of the loop as the canvas passes over the driving and idler rollers of a conveyor mechanism.
1. Flexible belting for conveyors comprising: a length of flexible material; a transverse locking-bar against the underside of said flexible materlal, about which the material is passed to form a loop, said locking bar having a longitudinal rib extending below the loop in the material with oppositely directed flanges at its lower end to form a protecting strip beneath the loop; and fastening means gripping the generally upright portions of said loop of material against the locking bar to secure the material thereto and form a transverse ridge projecting above the plane of the upper surface of the belting.
2. Flexible belting for conveyors comprising: a length of flexible material; a transverse looking bar against the underside of said flexible material, about which the material is passed to form a loop, said locking bar having a longitudinal rib extending below the loop in the material with oppositely directed flanges at its lower end to form a protecting strip beneath the loop; and rigid clamp means embracing said loop in the material and clamping it securely to the looking bar to form a transverse ridge projecting above'the plane of the upper surface of the belting.
3. Belting according to claim 2 wherein the clamp means comprises a longitudinally split tube pressed about the material and the locking bar.
4. Flexible belting for conveyors comprising: a length of heavy canvas of suitable width to form a conveyor belt; a transverse rail-shaped locking bar extending across the underside of said canvas, about which the canvas is passed to form a loop, the stem of the rail-shaped looking; bar projecting below the loop in the canvas so that the foot of the rail may serve as a protective strip for the lower margin of the loop; and a rectangular longitudinally split tube .embracing the loop in the material and pressed thereon tovsecure said loop to the locking bar, the
proportions of said tube and of the locking bar being such that the canvas is gripped by the upright side walls of the tube and is not gripped by the margins of the split in the tube.
LAWRENCE E. JOHNSON, JR.
REFERENCES CITED The following references are of record in the meet this patent:
UNITED STATES PATENTS Anderson et al. Jan 26, 1943