US3700092A

US3700092A - Catenary roll support for a conveyor belt

Info

Publication number: US3700092A
Application number: US135924A
Authority: US
Inventors: Amos J Stark; Hebert E Mcginnis
Original assignee: BF Goodrich Corp
Current assignee: Goodrich Corp
Priority date: 1971-04-21
Filing date: 1971-04-21
Publication date: 1972-10-24
Anticipated expiration: 1989-10-24
Also published as: IT953961B; AU3892072A; DE2214030A1; BR7202296D0; CA955871A; NL7204007A; GB1331036A

Abstract

A catenary type roll support for a troughed conveyor belt has cylindrical segments connected solely by tapes fastened to the surfaces of the cylindrical segments, and the first and last segments are suspended from fixed supports by anti-friction bearings.

Description

[451 Qct.24,19 72 United States Patent Stark et al.

m J m mA M MD w m U 3,068,995 12/1962 Poundstone...............l98/l92 both of Akron, Ohio [73] Assignee: The B. F. Goodrich Company,- New Primary ExaminerRichard E. Aegerter York, Attorney-William A. Shira, Jr. and Harold S. Meyer [57] ABSTRACT A catenary type roll support for a troughed conveyor 22 Filed: Apr-i121, 1971 21] Appl.No.: 135,924

belt has cylindrical segments connected solely by tapes fastened to the surfaces of the cylindrical segments, and the first and last segments are suspended from fixed supports by anti-friction bearings.

[52] US. R [51] Int. ...........B65g 15/08 [58] Field of Search......................................198/192 8 Claims, 5 Drawing Figures J Le CATENARY ROLL SUPPORT FOR A CONVEYOR BELT BACKGROUND Conveyor belts for bulk commodities are longitudinally folded into a trough shape to permit carriage of a maximum load without danger of spillage and are supported on oppositely inclined troughing rolls, usually with a horizontal roll between them. Such rolls are usually rigidly mounted, but many proposals have been made for flexible supports in which the usual three, or if desired more than three, rolls are hung from and rotate on a transverse tensioned cable or equivalent support which takes the approximate shape of a catenary.

Such catenary supporting rolls have theoretical advantages, in that their angles are to some extent selfadjusting to conform to unsymmetrical loads, and in addition swing slightly in the direction of motion of the belt so as to exert a self centering force on the belt. Nevertheless, previously proposed constructions have not met with much success because of their cost resulting from complexity of construction, or because of operating problems such as excessive friction.

SUMMARY OF THE INVENTION This invention is a catenary type roll support for troughed conveyor belts, which has a series of axially spaced cylinders joined by a plurality of flexible ties fastened to the cylindrical surfaces, and with the first and last cylinders hung from fixed supports on anti-friction bearings so as to be freely rotating.

The complete absence of a shaft of any kind in the catenary portion of the roll support is an important feature of novelty, which is largely responsible for the superiority of this over previously known catenary type rolls.

Such catenary rolls are easily manufactured at reasonable cost and provide a satisfactory support for the conveyor belts, exhibiting to the fullest extent the known advantages of this type of equipment. They contain only two bearings, one at each end, which are easily arranged with downwardly inclined openings so that they can be packed with lubricant to provide trouble free operation almost indefinitely even when exposed to the weather or to other adverse influences such as dust or grit.

THE DRAWINGS In the attached drawings,

FIG. 1 is a side view of one of the catenary type belt supports of this invention looking lengthwise of the belt.

FIG. 2 is an enlarged sectional view of one end of the belt support, showing the nature of the connection between the several cylindrical segments.

FIG. 3 is a sectional view of one of the cylindrical segments.

FIG. 4 is a modification of the construction shown in FIG. 2.

FIG. 5 is a view on a reduced scale of a modification of the ties in which they form a part of a single piece of fabric.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2, the conveyor belt support of this invention is made up of a series of segments having the shape of rolls or

cylinders

10, 11, 12, 13, and 14, which are generally axially aligned. Of course, when the series of cylinders is suspended in an approximately catenary shape, their individual axes are displaced from a straight line by a small angle. In this instance, five cylinders are shown, which is a convenient number, minimizing the angle between successive ones of the cylinders and therefore also minimizing the problems resulting from too sharp longitudinal folding of the belt which is supported by the cylinders.

The first and

last cylinders

10 and 14 have their outward facing ends closed by plates. One such plate 15 is shown in section in FIG. 2. To it is fastened a stub axle 16, which rotates in a bearing assembly 17 which in turn is hung from a fixed support. The bearing assembly 17 is integral with an eye or trunnion such as the T-bar 18 which is hooked on a fixed support such as the known oar-lock type swivel mounted double hook 19. The book 19 and its mate on which the opposite end of the catenary is hung may be placed on a conventional frame 20.

The inward ends of the first and

last cylinders

10 and 14, and both ends of the intervening cylinders ll, 12, and 13, are formed into smooth inwardly directed curves 21. The cylinders are spaced by a distance somewhat less than their diameter and are joined by a plurality of flexible but inextensible tapes 22 distributed around the circumference and extending from the outward facing end of the first cylinder 10 to the outward facing end of the last cylinder 14.

Suitably, the cylinders are pieces of metal tubing with ends spun or swaged to form the curves 21. The

. truly cylindrical portions, but not the curves 21, are

then treated with rubber-to-metal adhesive and tapes 22 of rubberized fabric are adhered to the entire series of cylinders, evenly spaced around the circumference as shown in cross-section in FIG. 3. Preferably, the intervals between the tapes on the cylindrical surfaces are filled with rubber 23 of the same thickness as the tapes 22 to provide a cylindrical support for the belt 25 as shown in FIG. 1 and FIG. 3. To protect against abrasion an additional rubber cover 24 may be superimposed on the tapes 22 and rubber filler 23.

The several tapes are preferably constricted in the intervals between successive cylinders by wrapping with cord or by enclosing in a ring 26 to form a neck as shown in FIG. 4. The inside diameter of the ring 26 may be about one half the diameter of the

several cylinders

10, 11, 12, 13 and 14.

The rubber in which the tapes 22 are embedded, along with the added filler rubber 23 and wear cover 24, is preferably vulcanized while the tapes are constricted. As a result, the tapes become firmly bonded to the cylinders by means of the adhesive but not bonded to the curved end portions 21 where there is no adhesive. At the same time the vulcanization sets the rubber in the tapes in the inwardly bent, or necked in, constricted shape, so that each tape when not under tension tends to return to the inwardly bent position. The ring 26 can then be removed.

When the completed catenary support is hooked on properly spaced supports 19, it will sag into an approximately catenary shape, the amount of sag and therefore the inclination of the first and

last cylinders

10 and 14 depending on the exact spacing of the supports, which may be made adjustable if desired. In following the catenary curve, the successive cylinders will take positions at an angle to one another as shown in FIG. 1. When a conveyor belt 25 rests on such a support, it will be folded longitudinally to the desired trough shape as a nearly smooth curve without undesirable sharp creasing if more than the conventional three cylinders are used, and preferably five cylinders in each support.

The angular relation of each cylinder to the ones on either side will cause the one or the pair of tapes 22 nearest the bottom, that is, nearest the outside of the catenary curve, to tend to straighten out under the tension resulting from the weight of the catenary support itself as well as the weight of the belt and its load. On the other hand, all others of the tapes will be shortened and will take up a bent shape as shown at 27 in FIG. 2. The bend will tend to be inward where it will be out of the way, but if the conveyor should be operated at such a speed that centrifugal force becomes troublesome, the ring 26 can be retained in position as shown in FIG. 4 to give positive assurance of retention of the tapes out of the way of possible pinching between the belt 25 and the cylinders.

The tapes 22 can be woven or braided tapes with a selvage at each edge, or can be cut strips of woven fabric or parallel arrays of cords, as may be found most convenient. Since the portions which are adhered to the several cylinders are immobilized and only the portions between the cylinders are worked, it is even possible to utilize a continuous sheet of suitable fabric wrapped completely around the several cylinders, with the unadhered portions between the cylinders cut longitudinally'of the cylinders to form tapes, preferably with spaces circumferentially to assure flexing free from frictional engagement.

FIG. shows how-the ties or tapes 22 can form parts of a single sheet of rubberized fabric as just described. This is a smallscale showing of the shape of the fabric before it is adhered to the cylinders. The two

ends

28 and 29 correspond to the outwardly facing ends of the first and last cylinders and 14. The adjacent uncut portion 30 next to edge 28 will cover the first cylinder 10 and the other uncut portions 31, 32, 33, and 34 respectively will cover the

other cylinders

11, 12, 13 and 14 in that order. The fabric between the uncut portions is cut longitudinally, leaving ties or tapes 35 connecting the ends of the fabric. The minimum width of the ties 35 should have the same relation to the maximum width of the cutouts 36 as the diameter of the ring 26 to the difference between its diameter and the diameter of the several cylinders 10 to 14, so that the ties will be wide enough to sustain the entire tension load to which they will be subjected without crowding against one another when inwardly bent as at 27.

his found that the flexing of the tapes, as the cylinders rotate, consumes so little energy that this new form of catenary support operates almost without friction. Moreover, the simplicity of fabrication, and the use of only a single pair ,of anti-friction bearings, which can be permanently lubricated and sealed, assures a reasonable first cost and little or no maintenance expense. Conse uentl this new construction appears to make the full ene its of catenary supports practically available to conveyor belt users for the first time.

Although fabric tapes arranged parallel to the axes of the cylinders are preferred, other kinds of ties can be substituted, such as stout cords, arranged either parallel or in a criss-cross or other pattern.

Embedment of the tapes in rubber is also preferred, as it protects the fabric from deterioration and furnishes a convenient and simple means of attachment to the cylinders. In case of operation without rings 26, the rubber also provides a pronounced tendency for the tapes to fold inward during rotation. The same effect can be obtained with other elastomers with the obvious changes in manufacturing procedure, or if desired for some reason, embedment of the ties can be omitted altogether and other means for fastening the ties to the cylinders can be used.

We claim:

1. A catenary type roll support for a conveyor belt, comprising a plurality of generally axially aligned spaced cylinders, a series of longitudinal flexible ties distributed around the circumference of the cylinders and. extending across the space between the cylindrical surfaces of adjacent cylinders, the ties being fastened to the several cylinders to connect each cylinder to the next adjacent one, and means for suspending the end cylinders for free rotation from fixed supports.

2. A catenary type roll support for a conveyor belt as in claim 1, in which the flexible ties are inextensible tapes.

3. A catenary type roll support for a conveyor belt as in claim 2, in which the flexible ties are fabric tapes embedded in elastomer, extend along all of the cylinders, and are adhered to the cylinders.

4. A catenary type roll support for a conveyor belt as in claim 3, in which the ends of the cylinders facing another cylinder are curved inward toward the axis of the cylinder.

5. A catenary type roll support for a conveyor belt as in claim 1, in which the ends of the cylinders facing another cylinder are curved inward toward the axis of the cylinder; the flexible ties are fabric tapes embedded in rubber, extend along all of the cylinders, and are adhered to the cylindrical portions of the cylinders; and

v the cylindrical portions of the cylinders are covered with rubber to form a generally cylindrical surface.

6. A catenary type roll support for a conveyor belt as in claim 5, in which the tapes between cylinders are constricted by a ring smaller than the cylinders.

7. A catenary type roll support for a conveyor belt as in claim 5, in which the rubber embedding the tapes is set in an inwardly directed fold to which it tends to return when not under tension.

8. A catenary type roll support for a conveyor belt as in claim 5, in which the number of cylinders in each support is not less than four.

Claims

1. A catenary type roll support for a conveyor belt, comprising a plurality of generally axially aligned spaced cylinders, a series of longitudinal flexible ties distributed around the circumference of the cylinders and extending across the space between the cylindrical surfaces of adjacent cylinders, the ties being fastened to the several cylinders to connect each cylinder to the next adjacent one, and means for suspending the end cylinders for free rotation from fixed supports.

5. A catenary type roll support for a conveyor belt as in claim 1, in which the ends of the cylinders facing another cylinder are curved inward toward the axis of the cylinder; the flexible ties are fabric tapes embedded in rubber, extend along all of the cylinders, and are adhered to the cylindrical portions of the cylinders; and the cylindrical portions of the cylinders are covered with rubber to form a generally cylindrical surface.