Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G39/00—Rollers, e.g. drive rollers, or arrangements thereof incorporated in roller-ways or other types of mechanical conveyors 
  • B65G39/02—Adaptations of individual rollers and supports therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G39/00—Rollers, e.g. drive rollers, or arrangements thereof incorporated in roller-ways or other types of mechanical conveyors 
  • B65G39/02—Adaptations of individual rollers and supports therefor
  • B65G39/04—Adaptations of individual rollers and supports therefor the rollers comprising a number of roller forming elements mounted on a single axle

Definitions

• the belt In the art of conveying bulk material with conveyor belts, the belt is normally moved in a closed loop conveying path from the material pick-up station to a material discharge station. While moving along the conveying path, the underside of the central portion of the belt receives support from spaced idler rolls on the underside of the belt.
• the upper material supporting surface of the belt is moved in a lower or belt return path whereat it is also provided with support by idler rolls.
• idler rolls on the return path contact the exterior surface of the belt which had previously been carrying the bulk material. Consequently, such return idler rolls have their exterior surfaces contacted by the materials remaining on the exterior surface of the belt whereby they may become abraded, soiled or receive other damaging effects.
• a recent advancement in improving the performance of this type of conveyor belt system is in the utilization of ceramic disks as the return idler. Such ceramic disks are superior to other disks in that they resist abrasion and soiling which would otherwise occur if another more conventional material were to be used in this area and for this function.
• Ceramic disks as return idler rolls, however, creates other problems. Specifically, ceramic disks or disks of glass or other porcelain type ceramic materials or the like are brittle and not ductile and cannot be readily machined or formed to the dimensional tolerances of steel or other materials previously utilized. Ceramic disks must be extruded or cast and then fired or otherwise baked to create their hard, brittle, abrasion resistance and cleanable properties, properties desirable for the subject purpose.
• Such ceramic disks due to their method of fabrication, inherently have variations in their inside diameter. This causes a problem in coupling them to the metallic cylindrical shaft upon which they must be secured for functioning.
• tubular sleeves are employed for coupling ceramic disks to metallic shafts.
• Such sleeves include ribs or projections on one or more surfaces of the intermediate sleeves. These ribs deflect and resile when slidingly coupling the shaft to the disk. Deformation of the ribs of the sleeve during mounting permits the proper coupling of the disks to the shaft during functioning.
• the present invention is directed to securing ceramic disks to shafts.
• This is achieved through intermediate sleeves which are cheaper, more reliable, easier to install, easier to fabricate, and generally better in all aspects to known devices for the similar purposes.
• These advantages are achieved through a particular intermediate sleeve which is made of a hard plastic with a chemical blowing agent which creates a predetermined void content.
• the exterior surface of the sleeve may be compressed and inserted into the disk for sliding the ceramic disk thereover.
• the interior surface of the sleeve may then be compressed by pressing it onto the shaft. This will thus create an extremely reliable assembly which is resistant to turning or sliding due to torque pressures received from loads during normal use as an idler roll assembly.
• Fig. 1 is a perspective view of the invention employing the plastic sleeve for securing the ceramic disks to the cylindrical shaft;
• Fig. 2 is a sectional view taken along line 2-2 of Fig. 1;
• Fig. 3 is an isometric showing of the idler roll assembly of Figs. 1 and 2 with parts broken away to show internal constructions thereof.
• a conveyor belt 10 and idler roll supporting system with the belt moveable in a path in the direction of the arrows as shown.
• the shafts 12 supporting the belt through disks 14.
• the shafts may be solid or tubular cylinders.
• the underside of the upper strand of the belt is supported by conventional steel rolls.
• the ceramic rolls of the instant invention could, however, be used there.
• Each such shaft is supported on one, but, preferably, both of its ends, by roller or other bearing assemblies 16. This permits free rotation of the shafts and disks during normal operation being driven by the driven belt.
• the ceramic disks 14 of the preferred embodiment are shown as tubular and mounted upon and concentric with the shaft for providing support directly to the belt of the conveyor assembly.
• Ceramic, glass or of other porcelain type materials are generally extruded or cast and then fired or baked rather than being machined so that close tolerances may not easily be maintained particularly at their inside diameter.
• the shaft could be fixedly supported at its end or ends with fixed support assemblies.
• Rotatable bearing assemblies could be located upon and secured to the fixed shaft with the exterior surface of each such bearing assembly being adapted to receive the sleeve 18 and ceramic disk 14.
• the sleeve 18 Located between the shaft 12 and disk 14, in the disclosed preferred embodiment, is the sleeve 18 of tubular shape for coupling the shaft and disk in such fashion so as to preclude rotation therebetween when met with a turning force as might occur in applications for idler rolls in conveyor assemblies.
• the shaft, sleeve and disk jointly constitute the roller assembly 20.
• the sleeve is preferably injection molded, extruded or otherwise constructed of acrylonitrile- butadiene-styrene copolymer, ABS, or other rigid plastic such as rigid polyvinyl chloride, PVC, high density, ultra high molecular weight polyethylene (molecular weight is usually in the range of 2-6 million) or polypropylene.
• Such rigid plastic is then provided with a chemical blowing agent such as carbon dioxide or nitrogen to create a rigid foam having as for example a 40% to 45% void content.
• a chemical blowing agent such as carbon dioxide or nitrogen
• Any chemical blowing agent that is both organic and inorganic, may be used.
• useful blowing agents are sodium bicarbonate or ammonium carbonate, either alone or in combination with organic acids such as stearic acid; maleic or phthalic anhydride with calcium carbonate or barium peroxide; organic acids with aluminum or magnesium powder; hydrazine derivatives of organic sulfo acids, benzilmonohydrazone. and the like.
• the voids are normally created by adding the blowing agent either before or during extrusion.
• the void content is intended to provide a sleeve whose compression range exceeds at least 10% of the maximum tolerance of the inside diameter of the disk and the outside diameter of the shaft.
• the void content could be reduced to about 25%. If reduced to beneath 25%, problems could arise since the sleeve could become relatively hard to unacceptably overly reduce its compressibility for use over the wide range of tolerances which might be generall encountered.
• the void content could also be increased up to 50%. But if increased to over 50%, sleeve problems could also arise since the sleeve could begin to get too weak in its gripping properties between the disk and shaft which it is intended to couple.
• a greater than 50% void content would generally render such sleeve unacceptable over a sufficiently wide range of applications.
• the amount of chemical blowing agent provided in the rigid plastic compound prior to or during extrusion or molding will determine in large part the characteristics of the resultant sleeve. Laboratory tests have shown that there is a definite relationship between the torque and residual void content of the sleeve after being pressed on a shaft.
• the resulting sleeve when constructed in accordance with the above-described materials will exhibit from 10% compression at the high side of the tolerance level to up to 25% compression at the low side of the tolerance level when the blowing agent approaches the 50% void content.
• a 45% void content created through the blowing agent into the ABS sleeve prior to its extrusion will create the optimum blend of compressibility, hardness and resistance to slip for most applications as idler rolls and conveyor assemblies
• the sleeve should never be compressed beyond the theoretical zero void volume dimension, i.e., that dimension where compression is beyond that normally permitted by the supplied void content since such compression would cause harmful effects on the otherwise noncompressible plastic.
• the sleeve should not be overly compressed since it would set up undesirable stresses in the ceramic sleeve normally in moderate tension from the sleeve.
• the resulting assembly might, for example, include a ceramic disk having a 2-37/64 inch inside diameter while being 1-1/2 inches long.
• the commercial tolerance of such a ceramic disk might be plus or minus .038 inch.
• An appropriate sleeve to accommodate the disks would be nominally made with 2.190 inches inside diameter and a 2.594 inch outside diameter.
• the sleeve in such an assembly made from ABS was found to be a noncombustive, nonrusting, having a long life, be abrasion resistant, impact absorbent, impervious to acid, grease, oil, water and electrolysis and resilient from 0° to 150°F.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Rollers For Roller Conveyors For Transfer (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=22194341

Family Applications (1)

Country Status (4)

Citations (3)

Family Cites Families (3)

• 1980
  • 1980-09-22 WO PCT/US1980/001260 patent/WO1981001132A1/en not_active Application Discontinuation
  • 1980-09-22 JP JP50262180A patent/JPS56501360A/ja active Pending
  • 1980-10-01 ZA ZA00806060A patent/ZA806060B/xx unknown
• 1981
  • 1981-05-04 EP EP19800902201 patent/EP0038838A4/de not_active Withdrawn

Patent Citations (3)

Non-Patent Citations (1)

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