The disclosed invention is directed toward bale forming belts on round hay balers. More specifically, the invention is a bale forming belt with an improved transverse stiffness and excellent fastener retention.
This invention addresses the need to make the bale forming belts on round hay balers stiffer in the transverse direction. The increase in transverse stiffness counteracts the tendency of the belts to roll over on itself causing damage to the belt and shortening the service life of the belt. Also transversely stiff belts maintain their position on the machine when slack, i.e. very low tension, conditions occur during baler operations. Increased transverse stiffness has long been recognized as a desirable feature in belts used on round hay balers. Manufacturers of these balers have historically advised belt producers of their desire for improved transverse stiffness to enhance the operation of round balers.
Increased transverse stiffness must be achieved without a loss of fastener retention. The belts must have excellent fastener holding properties, both as measured by static pull tests and by dynamic tests. The fastened ends of the belt represent the critical point for maintaining service life of the belt.
The increased transverse stiffness ideally should also be achieved in combination with optimized longitudinal flexibility. The hay baling belts should have sufficient flexibility to enable the belts to run around the relatively small pulleys of the hay baling machines.
The most effective method of increasing transverse stiffness is to use extruded monofilament cords of polyester, nylon, glass, or other material in the outside plies of these multiply belts. The monofilament cords are oriented in the transverse direction.
Current technology, as seen in U.S. Pat. No. 4,518,647, uses outside plies that contain 100% monofilament fill cords. While this approach achieves dramatic transverse stiffness in the belt, there are shortcomings in the physical properties and cost of the belt.
Monofilament cords have lower tensile strength than comparable sized twisted multifilament cords. While a belt with 100% monofilament fill cords has dramatically high transverse stiffness, the tensile strength of the belt is reduced. In addition, due to the extremely smooth outer surface of the monofilament, the cord has a limited adhesive dip pick up.
The disclosed belt construction has optimized properties of transverse stiffness and tensile strength. The fastener holding capabilities, as well as other physical properties, are maintained at a desired level. The inventive construction also keeps the cost increase, due to the use of monofilament cords, proportionate to the benefit gained in increased transverse stiffness, producing a more cost efficient product.
In accordance with the present invention, a belting material is disclosed which has optimized transverse stiffness and improved fastener holding capabilities.
In accordance with the disclosed invention, a multi-ply belting material is disclosed wherein at least one woven ply has at most a fifty percent fill rate in the weft, or fill, direction of monofilament cords.
In a further aspect of the disclosed invention, the belting material is disclosed with a minimum of five percent monofilament cords in the fill direction of the woven belting ply material.
In another aspect of the disclosed invention, the belting material is disclosed wherein at least one woven ply has between five to fifty percent extruded monofilament cords in the fill direction.
In accordance with another embodiment of the present invention, a three ply belting material is disclosed wherein the outermost woven plies have, in the fill direction, at most fifty percent monofilament cords.
In accordance with another aspect of the present invention, belting material is disclosed which has optimized transverse stiffness, improved fastener holding capabilities, and improved longitudinal flexibility.
In accordance with another embodiment of the present invention, a two-ply belting is disclosed wherein both woven plies have at most, in the fill direction, fifty percent monofilament cords.
In accordance with a further aspect of the invention, the two ply belting has a monofilament fill frequency of fifty to five percent.
xe2x80x9cFabricxe2x80x9d denotes a network of essentially unidirectionally extending cord/yarns, which may be twisted, and which may in turn be composed of a pluabty of a multiplicity of filaments (which may also be twisted). The fabric is woven and flexible.
xe2x80x9cFillxe2x80x9d refers to the cord/yarn woven at right angles to the warp cord/yarn or warp direction of the fabric.
xe2x80x9cWarpxe2x80x9d refers to a network of essentially unidirectionally extending cords/yarns, which extend in the longitudinal direction of the belt.
xe2x80x9cWeftxe2x80x9d (filling) refers to the cord/yarn placed at right angles to the warp cord/yarns.
xe2x80x9cYamxe2x80x9d: a generic term for a continuous strand of textile fibers or filaments. Yarn occurs in the following forms:
1) a number of fibers twisted together;
2) a number of filaments laid together without twist;
3) a number of filaments laid together with a degree of twist;
4) a single filament with or without twist (monofilament).