Patent Application
20160257358
The present disclosure relates generally to a rubber belted track for skidsteer implements, and more particularly to a rubber belted track with metal cleats to provide traction to skidsteer implements on snow. Still more particularly, the present disclosure relates to a rubber belted skid steer track with metal cleats to grip snow-covered surfaces, especially inclines, and a smooth tread pattern to provide for flotation of the skidsteer implement.
Skidsteer is the general term for a small piece of heavy machinery with a low center of gravity. Skidsteers typically have one seat for an operator, a coupling plate on the front allowing the use of multiple attachments, and a diesel engine mounted behind the operator cab. They are zero-turn-radius vehicles, with steering being accomplished by varying the amount of power sent to each side. When full forward power is directed to a side and full reverse-power is directed to the opposite side, the machine will turn in a zero radius.
Skidsteers are produced by many companies including, but not limited to, Bobcat™, Terex™, John Deere™, and Caterpillar™. They are configured in all-wheel-drive models with four tires or track-driven models operated by a pair of belted tracks running on rollers that propel the machine.
The treads of both the wheeled and track-driven versions are typically deep to maximize the gripping force. This ensures that the vehicle remains stable under a variety of conditions while carrying loads up to the maximum rated capacity. Specialty treads are commercially available, such as tracks that fit over wheeled models and slick tracks for use in golf course maintenance designed for mar-free travel over turf.
In one or more embodiments, the skidsteer implement tracks may include cleats bolted onto the surface of a belted rubber track. Exemplary securing means for the cleats may include surface bolts, bolting from the cleat through the belt to drive lugs, or by an overmolding process. The cleats serve to enhance the traction of the implement on ice, snow, marsh, permafrost, and other terrains not typically served by presently available skidsteer configurations or aftermarket implement track applications.
This track system is designed to fit Multi Terrain Loaders (MTL's) or Compact Track Loaders (CTL's) to date manufactured by ASV, Caterpillar and Terex specifically with little or no modification to the base machine. The tracks are made up of a set of drive lugs to engage the drive system of the machine that are bolted, molded or fastened in one way or another to a reinforced rubber belt. The track, or interchangeably referred to as a belt, may be of a molded endless construction or made up of a two ended flat belt joined together into a loop by a variety of means comprising: a mechanical splice, a tapered lap joint, a vulcanized splice, a laced joint, etc. The outer surface of the belt is smooth and flat to accept the fastening of traction cleats or grousers.
These cleats may be of a multitude of materials and profiles to maximize traction and longevity on the intended primary ground conditions seen in use. The tracks's overall width may be equivalent to the general-purpose endless belt tracks provided by the Original Equipment Manufacturer (OEM) of the machine or wider than the OEM tracks. An aspect of the invention using tracks wider than the OEM offerings is constructed in an asymmetrical fashion, that is the additional width extends only past the outside edge of the endless track, and not evenly over the outside edge and the inside edge adjacent to the cab of the machine. The asymmetrical width is not as wide as the segment of the endless track that is in contact with the drive means of the skidsteer. In the art of tracked and wheeled machinery, traction cleats are also known as grousers and defined as a protrusion on the surface of a wheel or continuous track segment.
The purpose of this invention is to increase the versatility of compact track loaders by allowing them to safely and efficiently operate on terrain that was previously impassable; for example: snow, ice, tundra, and permafrost terrains. This will extend the working season of this type of machine allowing owners to access jobsites in soft terrain bases and/or low traction conditions.
The present disclosure, in some embodiments, includes a belt for use on track-driven implement machines with a molded rubber driven/grouser surface, polymer-reinforced belting, a molded rubber terrain surface, and attached metal cleats for gripping snow covered surfaces. The metal cleats may be secured to the rubber terrain surface via a mechanical fastening or an overmolding means. The rubber track density and dimensions permit the skidsteer implement to remain buoyant so as to move freely across a multitude of terrain conditions. The cleats are constructed from metal according to certain embodiments. The metal-cleated track serves to provide reliable traction to belt-driven implements on snow terrain. Unlike metal-link or over-the-tire rubber style tracks for mounting on four-wheeled skidsteers, the snow track utilizes the balanced weight, direct-drive and suspension advantages of a track-driven machine.
An isometric view of a skidsteer 100 fitted with smooth-surface endless tracks 102 is depicted in
A rearview of a skidsteer implement 200 is shown in
The underside of the endless track segment 400 shown in
An aspect of the invention using an endless track belt 503 in a one-piece configuration with an external traction cleat 500 is depicted in the front, segment view of
A traction cleat 600 with a u-shaped terrain contacting edge 604 is shown in
An isometric view of a skidsteer 700 is shown as
According to certain aspects of the invention, traction cleats 802 may be less than the width of the endless track belt 801 and installed in a horizontally staggered fashion, as depicted in the segment view included in
According to certain embodiments, the two rubber surfaces of the belt are constructed in a single molding process typical of track belt construction. The metal cleats are attached to the belt with a mechanical fastening means that is a bolt according to some embodiments. The snow-tread-skidsteer-track mounts and travels in the same fashion as a belt sold with the skidsteer by the OEM.
The track of the present disclosure is comprised of a series of modular drive lugs, one or more endless belts, and traction cleats. Modular drive lugs are defined as aftermarket drive lugs designed for replacing or retrofitting existing OEM skidsteer tracks. Modular drive lugs are not a feature of an endless track added during a molding process. Instead, the modular drive lugs may replace molded drive lugs that are damaged as a result of belt wear. According to the present disclosure, modular drive lugs are used as a means to add-on traction cleats that were not originally a constituent of an OEM endless track. The traction cleats are secured to the modular drive lugs, through the cross-section of the endless belts with a mechanical fastening means.
According to certain aspects of the invention, the drive lugs are molded to the inner surface of the belt as an alternative to using modular drive lugs. The traction cleats may be secured to the molded drive lugs, but this is not required. Alternatively, the cleats may be secured to the endless track belt via a mechanical fastening means penetrating the cross-section of the belt. According to certain aspects of the invention, the traction cleats are secured to the terrain-contacting surface of the belt via an overmolding process.
The drive lugs are a modular design; modular meaning they may exist as a separate component to be implemented as a stand-alone addition to existing tracks. According to some aspects of the present invention, the cleats are provided as a component for constructing a new track. The materials of construction of the drive lugs consists of fiber reinforced polymers, ultra-high molecular weight plastic (UHMW), polymer coated metal, machined rubber, molded rubber, and metal, or any combination of materials sufficient to provide positive engagement of the track and the drive sprocket and idlers wheels. An example of a fiber-reinforced polymer is a polymer matrix reinforced with fibers. The polymer is commonly epoxy, vinyl, or polyester, and the fibers are commonly glass, carbon fiber, or aramid fibers.
The drive lugs have a flat surface to mate with the track belt and a profile similar to that of an OEM molded rubber drive lug so that they interlock with the machines drive system in a satisfactory way and provide acceptable wear properties and longevity equivalent to or greater than OEM rubber tracks in applicable service conditions. The mechanical fastening means provides the security and force via a clamping mechanism to mate the flat surface of the drive lug to the track belt. The lug provides mounting holes, studs, rivets etc. oriented perpendicular to the mating surface and passing through the same plane in order to intersect the track belting and mechanically engage the outer cleats. The lug may have threaded holes to receive mechanically threaded fasteners or also have holes machined in particular shapes to secure a specific fastener, such as a hex nut threaded to a machine bolt.
The track belting is constructed from internally reinforced vulcanized rubber. The reinforcement materials may include, but are not limited, to: polyester, aramid fibers, Kevlar, metallic wire, nylon, cloth etc. and may be molded in a continuous loop, also known as an endless belt, or having two ends joined together to form a loop. Exemplary methods for splicing two ends together may include mechanical hinging, lacing, a glued scarf, a vulcanized joint, and a lap joint.
The belting of the present invention has integral holes through its cross-section to receive mechanical fasteners for the attachment of drive lugs and traction cleats. One embodiment of the track belting includes metal bushings as reinforcement within the rubber material. These bushings are in a direction parallel to the mechanical fastener length, perpendicular from the horizon for a flat track, and serve to strengthen and define the mechanical fastener holes.
The traction cleats of the present invention may be constructed from several materials including steel, aluminum, plastic, and rubber, and combinations of materials therein. Examples of combinations according to some embodiments are an aluminum frame coated with rubber, or an aluminum frame with a hardened steel insert to provide support specific to terrain conditions.
The cleats of the present invention consist of a flat segment, straight holes in the plane of the flat surface, of a depth dimension equal to its cross-section, and a cleat segment, perpendicular to and displaced horizontally from, the flat segment. The flat segment has a mating surface to contact an outside surface of the track belt. The holes of the flat segment accept fasteners from the drive lugs through the track belt to construct a clamping mechanism for securing the cleat to the track belt. The perpendicular orientation of the cleat segment to the flat segment serves to transfer the drive torque of the machine to the underlying terrain.
The cleats are superimposed on the belt and serve to enhance the traction of the present invention on surfaces requiring enhanced traction, such as snow-covered incline slopes. According to one embodiment, the cleats are of equal width arranged perpendicular to the direction of the belt's travel over the implements drive system. The cleats may span the width of a track belt. Alternatively, the width of the cleats may be a fraction of the width of the drive belt and installed in a horizontally staggered configuration a direction that is transverse to the driven direction of the belt. In the horizontally staggered configuration of certain embodiments, no single cleat spans the entire width of the belt, but instead the width of the belt is spanned by a serious of cleats each having a width less than the width of the belt.
The cleats are offset from the outside edge of the belt towards the inside, or machine edge of the belt, by the width of each successive cleat. The proportional width of a cleat determines the number required to span the width of the belt. For example, the width of the cleat may be one-third the width of the belt. A first cleat is placed at the outside edge of the belt, a second cleat placed in the center third, but offset by a longitudinal distance, and a third cleat placed the same longitudinal distance forward, but spanning a one-third width of the belt to reach the inside, or machine edge of the belt. The width of offset cleats is determined by the traction needs of the application, the material of construction of the cleats, and the permitted impact of specialized terrain such as muskeg, snow-covered inclines, and ice-covered surfaces.
The offset pattern of cleats may also be used to span open spaces on drive systems utilizing multiple belts. Also according to some embodiments, cleats that span the entire width of the belt, and are not installed in an offset pattern, may also be used to span open spaces of multi-belt systems. Cleats may integrate the securing portion of the mechanical fastener originating from the drive lug, i.e. a tapped hole or a provision for a secondary fastener including but not limited to; nut and washer, hardened plate with tapped holes, captive nut strip etc. According to some embodiments, the modular cleats include modifications functioning as secondary traction aides such as serrated edges, ice spikes, and end caps.
According to an aspect of the invention, the overall width of the track is equal to the Original Equipment Manufacturer's (OEM) width dimension. The cleat design of these embodiments provides a capability for a machine to function in loose, soft or slippery conditions with a sharper terrain-contacting edge, thus having increased traction in comparison to an OEM track. Additionally, the cleats of this invention will have a greater pitch than the molded cleats of OEM rubber tracks. Pitch is defined as the distance between cleats on the tread side of a track, and the distance between drive lugs on the underside of the track. The cleats are taller than the molded rubber cleats of the OEM belt, not so tall (the distance between the top edge of the cleat to the belt surface), to result in a brittle cleat or a durability loss that will limit the machines ability to traverse hard ground. According to some aspects, the cleat may be square, u-shaped, or a combination thereof.
Another aspect of the invention is suited for applications primarily concerned with operation in snowy conditions. The tracks of these embodiments are arranged in a width dimension greater than OEM tracks. This results in a track belt and cleats that extend beyond the width of the machine's drive undercarriage that contacts the drive lugs of the belt. The purpose of this arrangement is to lower the ground pressure of the machine increasing flotation properties while keeping the undercarriage closer to the centerline of the machine so as to decrease bearing loads and contact with hydraulic plumbing and control system hardware.
In the present disclosure, the main purpose for asymmetrical tracks is to reduce ground pressure, increase flotation and tractive effort within the original track contact length and to require no modification of the undercarriage of the machine. Cleats for this embodiment will have a taller and sharper profile to penetrate snow and ice terrains. Other aspects of the invention include cleat shapes consisting of ice spikes and/or end caps spaced out in a pattern that optimizes traction, yet minimizes weight and turning force required for acceptable machine handling characteristics.
Cleats may be of equal length, spanning the entire width of the track or of a staggered pattern having a full-length cleat then a shorter cleat that only spans the inner belt or width of the OEM track and under carriage. The cleats may be shaped metal or may be smaller components of fabricated metal such as pipe end caps. The end caps are from shaped tubing and may be round, square, or rectangular in shape. They are mounted in an orientation where the open face of the end cap is joined to a flat piece of metal for securing to the belt or drive lugs. The closed face of the end cap is used to contact, penetrate, and grip the terrain. Alternatively, a mechanical fastener may be recessed, countersunk, or joined to the closed face of the end cap at one of its ends, and its opposite end extends through the track and secures the end cap to the drive side of the endless belt or a modular drive lug. Mechanical fastening alternatives refer to mechanical fastening means of all aspects and embodiments of the present disclosure.
Another aspect of the invention is a track belt with modular lugs and a cleat designed for use on hard bottomed terrain with a soft covering, such as a paved roadway or parking lot covered by fresh snow. According to this aspect, the tracks would consist of cleats arranged in a fashion to maximize ground pressure while enhancing forward traction with the installation of a cleat acting as a cutting surface. This arrangement is especially applicable to terrain surfaces with a soft covering for penetration of the traction cleat, but containing a hard terrain surface underneath the soft covering where minimal contact is desired. This is accomplished by a cleat height and profile with a minimum edge thickness acceptable to provide smooth travel and machine operation over said terrain examples.
This embodiment would utilize a cleat made up of a combination of materials chosen for their grip on slippery terrain and would be beneficial in the snow and ice removal industry. Examples of material combinations for the cleat component include aluminum cleats overmolded with vulcanized rubber, hard rubber cleats, angle or L-shaped polymer material, angle or L-shaped fiber-reinforced polymers, and combinations therein.
An aspect of the current invention is an endless, flexible, track for use on track-driven implements comprising an inner surface, modular drive lugs to engage a driving mechanism of the implement, and interchangeable traction cleats spanning the width of the track. Integral is defined as: the through holes are within the body of the belt and are not visible once the modular drive lugs have been bolted to the traction cleats. The modular drive lugs have integral through-holes to receive a fastening means and are mounted to the inner surface of the belt. The outer surface of the belt contacts the terrain and is comprised of a slick rubber surface. The width of the belt is between 11 inches and 22 inches, according to some aspects of the invention. Implement traction and drive efficiency may be optimized for some terrain applications if the pitch of the traction cleats is equal to the pitch of the drive cleats. According to another aspect of the invention for use on other terrain applications susceptible to damage from traction cleats, the pitch of the traction cleats is between ½ and ¼ the pitch of the drive lugs. Another aspect of the invention comprises a configuration wherein the width of individual traction cleats are one-third to one-half the width of the track, and the traction cleats are installed in a horizontally staggered position. The staggering of the traction cleats is dictated by a pitch of the staggered cleats equal to the pitch of the drive lugs multiplied by the fraction of the belt width that is the width of the traction cleats. This serves to create an optimal match of cleat pitch to a specific terrain.
According to other aspects of the invention, the shape of the traction cleat is an L-shaped angle material. A horizontal segment of the L-shape contacts the outer surface of the track and a vertical segment, connected to the horizontal segment of the L-shape, serves as a traction-enhancing means. The L-shaped bracket is dimensioned with the length of the horizontal segment of the L-shape is between 1.25 inches and 3 inches, and the length of the vertical segment of the L-shape is between 0.5 inches and 2.0 inches.
Another aspect of the invention is a multi-piece belt with a gap to reduce ground pressure, improve flotation, and adapt the invention to additional track-driven implements. This consists of an endless, flexible, track for use on track-driven implements comprising an inner belt and an outer belt with a gap between the two belts, and drive lugs mounted to the drive side of the inner and outer belts to engage a driving mechanism of the implement, the drive lugs having through-holes to receive a fastening means and mounted to the inner surface of the track. The drive lugs may be modular. The outer surface of the endless belt contacts terrain, the outer surface being comprised of a slick rubber surface, and interchangeable traction cleats bridge a gap between the inner and outer belts, spanning the width of the track. To provide balance to the two-track with gap aspect, the width of the gap between the inner and outer belts is equal to the width of the inner belt, and the gap has a dimension between 2 inches and 6 inches.
According to another aspect of the invention, the traction cleat is an L-shaped angle material; a horizontal segment of the L-shape contacts the outer surface of the track, a vertical segment, connected to the horizontal segment of the L-shape serves as a traction-enhancing means, and the angle material spans the gap between the inner and outer belts. The shape of the traction cleat according to some aspects is an L-shape, but other shapes pertain to additional aspects of the invention, depending on the desired tread pattern and traction requirements dictated by the terrain type and machine size.
According to some aspects of the invention, the traction cleat is a shaped metal extrusion with a horizontal segment to contact the outer surface of the track, and a polygon-shaped vertical segment to serve as a terrain penetrating means, and specifically, the polygon-shaped vertical segment is chosen from the group consisting of: triangle, rectangle, square, semi-circle, trapezoid, rhombus, parallelogram, triangle-on-square, triangle-on-rectangle, pentagon, hexagon, octagon, six-point star, five-point star, crescent moon.
One aspect of the present disclosure is the modular nature of the track. This permits a tailoring of the invention to specialized terrain types currently underserved by commercially available machines. The method of making an aspect of the present invention, an endless track suited for use on low-friction applications is comprised of assembling an endless track constructed of a flexible elastomeric rubber, wherein the endless track has an inner surface to engage a drive system of a track-driven implement and an outer, terrain-contacting surface. Modular drive lugs are subsequently fastened through holes travelling through a cross-section of the endless track. While the modular drive lug is mounted to the underside, or inner surface, of the endless track in order to contact the implement's drive mechanism, the outer surface of the endless track, or alternatively described as the topside or terrain-contacting surface of the track, is the location to mechanically fasten a traction cleat. The mechanical fastening means extends through a cross-section of the endless track and attaches the traction cleats to the modular drive lugs. Alternatively, the drive lugs may be molded.
According to certain aspects of the invention, the cross-section of the endless track contains a metal bushing to reinforce the hole of the cross-section of the endless track. Additionally, the fastening means to secure the modular drive lug to the traction cleat is one of the group consisting of: threaded bolt to a threaded nut secured in the drive lug through a machined opening mated to the threaded nut, rivets, hollow rods attached to the traction cleat to mate to drilled holes of the modular drive lug, studs integral to the traction cleat, studs integral to the modular drive lug, and combinations therein.
According to certain aspects of the invention, the endless, flexible track has the drive lugs mounted to the drive surface of the belt, are modular and, are constructed with through-holes to receive a fastening means and mounted to the drive surface of the belt. In addition, according to other aspects and embodiments of the present invention, the drive lugs are configured to install the flexible track over four rubber drive wheels of wheel-driven skidsteer implements. According to certain aspects of the invention, the method to manufacture the endless track will include steps to secure metal bushings through the cross-section of the endless track. According to certain aspects, the method to secure metal bushings to accommodate a fastening means within the endless track is an overmolding process. The drive lugs may also be molded.
The metal bushings serve to reinforce the holes used by mechanical fastening means for securing the traction cleats. The traction cleats may also be fastened to the endless track through its cross-section without being fastened to the drive lugs. The fastening means to secure the modular drive lug to the traction cleat is one of the group consisting of: threaded bolt to a threaded nut secured in the drive lug through a machined opening mated to the threaded nut, rivets, hollow rods attached to the traction cleat to mate to drilled holes of the modular drive lug, studs integral to the traction cleat, studs integral to the modular drive lug, and combinations therein. According to certain aspects of the invention, the drive lugs are fastened to the inner surface of the endless track via a molding process used to form the endless track.
This application claims the benefit of U.S. Provisional Application No. 62/129935, filed Mar. 8, 2015.
| Number | Date | Country | |
|---|---|---|---|
| 62129935 | Mar 2015 | US |
