The present disclosure relates to a track for a vehicle, and more particularly, a vehicle track including one or more cores.
Many off-road vehicles, such as earthmoving vehicles (e.g., excavators, skid steer track loaders, or multi-terrain track loaders) and agricultural vehicles, include a vehicle track coupled to a drive system, which may include, for example, one or more drive sprockets. A vehicle track may help provide traction on surfaces that traditional wheels having a circular cross-section may not be able to adequately grip. For example, a vehicle with a vehicle track may bridge a greater surface area than a vehicle with two or more circular wheels, which may help the vehicle with the vehicle track traverse surfaces that the vehicle with circular wheels would not ordinarily be able to traverse, such as uneven or loose surfaces (e.g., gravel or mud).
In some cases, a vehicle track is formed of metal, rubber, such as a molded rubber, or a combination of metal and rubber. The vehicle track may be molded as a single, integral piece or an assembly of interconnected parts that are coupled together to define a vehicle track. Some vehicle tracks include a track body with a first, interior side that is configured to engage with a drive system, and a second, exterior side that includes multiple protrusions (e.g., “traction lugs” or “tread lugs”) extending from one or more common surfaces and defining a tread pattern. In some examples, the vehicle track may include a plurality of cores embedded within the track body. The cores may define a portion of a shape of the vehicle track, engage with a drive system, or the like.
The disclosure describes systems and methods relating to a core for a vehicle track, as well as relating to a vehicle track including one or more cores. In some examples, the core (also referred to herein as a “vehicle track core”) may include a body, a first edge portion, and a second edge portion. Each of the first and second edge portions defines at least one protrusion that extends from a major surface of the respective body. The width of the at least one protrusion is less than the width of the edge portion, and a track body of the vehicle track encases the at least one protrusion. Such a vehicle track core may allow the track body to be both supported by the core and at least partially deform around the at least one protrusion. In this way, the track body may be prevented from collapsing or significantly deforming upon an application of force to a side of the track body corresponding to a respective edge portion of a core due to the support from the at least one protrusion, while still being able to at least partially deform around the at least one protrusion. The partial deformation and flexibility of the track body around the at least one protrusion may help reduce at least some stress experienced by the track body in response to a given force. Reduction of at least some stress experienced by the track body may increase the useful life of the vehicle track, such as by reducing the formation of cracks in the track body, widening of cracks in the track body, wear of the track body, prevent separation of the core and the track body, or the like.
In one example, a vehicle track includes a track body and a plurality of cores, where each core of the plurality of cores is at least partially embedded within the track body. Each core of the plurality of cores includes a body including a first end and a second end opposite the first end. The body has a body width measured along a first axis extending between the first and second ends, and a body length measured along a second axis orthogonal to the first axis. Each core of the plurality of cores also includes a first edge portion extending from the first end of the body and a second edge portion extending from the second end of the body, where each of the first and second edge portions defines at least one protrusion that extends from a major surface of the respective body. The at least one protrusion has a protrusion length that is less than the body length.
In another example, a vehicle track includes a track body and a plurality of cores, where each core of the plurality of cores is at least partially embedded within the track body. Each core of the plurality of cores includes a body including a first end and a second end opposite the first end. The body has a body width measured along a first axis extending between the first and second ends, and a body length measured along a second axis orthogonal to the first axis. Each core of the plurality of cores also includes a first edge portion extending from the first end of the body and a second edge portion extending from the second end of the body, where each of the first and second edge portions defines at least one protrusion that extends from a major surface of the respective body. The at least one protrusion has a protrusion length that is less than the body length.
In another example, a method of forming a vehicle track includes forming a plurality of cores, where each core of the plurality of cores includes a body including a first end and a second end opposite the first end. The body has a body width measured along a first axis extending between the first and second ends, and a body length measured along a second axis orthogonal to the first axis. Each core of the plurality of cores also includes a first edge portion extending from the first end of the body and a second edge portion extending from the second end of the body, where each of the first and second edge portions defines at least one protrusion that extends from a major surface of the respective body. The at least one protrusion has a protrusion length that is less than the body length. The method also includes forming a track body around at least a portion of each core of the plurality of cores such that each core of the plurality of cores is at least partially embedded within the track body.
In other examples, a method includes using any of the vehicle tracks and/or vehicle cores described herein.
The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.
In examples described herein, a vehicle track includes a track body and one or more cores, which may be embedded in the track body or otherwise fully or partially surrounded by the track body. The track body is configured to engage with a drive system of a vehicle and engage with a ground surface in order to move a vehicle mounted to the vehicle track. The cores are configured to stabilize a track body, maintain a shape of a track body, strengthen a track body, define one or more structures of a track body, and/or reduce stress experienced by a track body.
In some examples described herein, a core may include a body, and first and second edge portions that each define at least one protrusion that extends from a major surface of the respective body. The length of the at least one protrusion is less than the length of the body of the core, and a track body of the vehicle track encases the at least one protrusion. A vehicle track core configured in this manner may allow the track body to be supported by the core while also enabling the track body to at least partially deform around the at least one protrusion when stress is applied to a respective side of the track body. The combination of partial deformation and support may reduce at least some stress experienced by the track body in response to a given applied force, prevent collapse of the track body, or the like. Reduction of at least some stress experienced by the track body may increase the useful life of the vehicle track. For example, the formation of cracks in the track body, widening of cracks in the track body, wear of the track body, prevent separation of the core and the track body, or the like may be reduced or slowed.
In examples in which a vehicle track core does not include the at least one protrusion that enables a track body to partially deform relative to the at least one protrusion, a track body encasing the vehicle track core may become detached from the vehicle track core, may not be able to deform or flex around a protrusion, and/or may not be supported by the vehicle track core upon an application of force on the track body. As a result, application of force on the track body may increase stress on the track body, which may result in the formation of cracks in the track body, widening of cracks that may have previously formed in the track body, separation of the core and the track body, or other wear of the track body. Such wear, unattachment of the track body to the vehicle track core, lack of support of the track body, forced rigidity of the track body, or combinations thereof may reduce the useful life of the vehicle track.
In
First side 14A defines an inner circumference of track body 14 and is configured to mount vehicle track 10 to a drive system of a vehicle. In the example shown in
First side 14A of track body 14 also defines a plurality of ribs 22 that are configured to engage with drive sprocket teeth 12A of drive sprocket wheel 12 when vehicle track 10 is mounted on drive sprocket wheel 12. As drive sprocket wheel 12 rotates, drive sprocket teeth 12A engage with apertures defined between ribs 22, which rotates vehicle track 10. As a result of the rotation of vehicle track 10, vehicle track 10 (and any vehicle on which vehicle track 10 is mounted) moves in a first direction (e.g., forward). If drive sprocket wheel 12 is rotated in an opposite direction, vehicle track 10 moves in a second direction opposite to the first direction (e.g., backward).
While drive sprocket wheel 12 is shown in the example of
Second side 14B of track body 14 defines an outer circumference of track body 14 (or perimeter in the case of a non-circular track body 14) and at least a part of second side 14B is configured to engage with an exterior surface (e.g., the ground) when vehicle track 10 is mounted on a vehicle, and thus, second side 14B may be referred to as an “exterior” side of track body 14. In order to help track body 14 engage with the exterior surface, second side 14B comprises a tread pattern 24, which is defined by multiple traction lugs extending from a common surface. In some examples, tread pattern 24 is design based on an application of vehicle track 10, performance characteristics desired of vehicle track 10, type of vehicle that vehicle track 10 is mounted on, or the like. Tread pattern 24 may be any suitable tread pattern to fit particular needs.
Track body 14 of vehicle track 10 may be defined by a single molded piece of material or may be an assembly of interconnected parts that are coupled or bonded together to define a vehicle track. In some examples, track body 14 of vehicle track 10 includes (e.g., is formed from or otherwise includes) an elastomer. For example, track body 14 may include a natural rubber, a synthetic rubber, or another elastomeric material. Examples of suitable synthetic rubbers include styrene butadiene rubber and polybutadiene rubber. In some examples, track body 14 may also include other agents and activators to help achieve desired material properties, such as reinforcing agents, vulcanization accelerators, antiozonants, antioxidants, vulcanizing agents, retarders, rubber softeners, tackifiers, or the like. The exact composition of track body 14 may depend upon various factors, including the particular application vehicle track 10 is intended to be used with.
An elastomeric track body 14 may help provide better maneuverability of a vehicle, better ride quality, and/or increased traction as compared to steel vehicle tracks. In one example, the rubber including first side 14A (including guide lugs 18 and ribs 22) has a hardness in a range of about 63 durometer to about 83 durometer, while the rubber including second side 14B has a hardness in a range of about 53 durometer to about 73 durometer. As one example, a rubber having a hardness of about 73 durometer may be used to form first side 14A, while a rubber having a hardness of about 63 durometer may be used to form second side 14B. In other examples, however, track body 14 may be formed from elastomeric or other materials having other durometers. The durometers for the rubber may be measured using the Shore A scale.
In order to increase the strength of vehicle track 10, vehicle track 10 may include may include multiple reinforcing members 26 coupled to track body 14. Reinforcing members 26 extend in a substantially longitudinal direction of track body 14. The longitudinal direction of track body 14 may correspond to a direction that defines a circumference or perimeter of track body 14. Reinforcing members 26 may be embedded in track body 14, such as by placing reinforcing members 26 between layers in track body 14 or embedding reinforcing member 26 in track body 14 during a molding process. Vehicle track 10 may include any suitable number of reinforcing members 26 in any suitable arrangement. For example, in some examples, track body 14 may include about 30 to about 80 reinforcing members 26. The number of reinforcing members 26 may be selected based on a width of track body 14 and/or the desired application of vehicle track 10.
Reinforcing members 26 may be a flexible steel cord (or cable) having a minimum tensile strength of about 400 kilograms. The ends of each reinforcing member 26 may be coupled together in some examples. For example, the ends of each reinforcing member 26 may be adjacent to each other, which may be referred to as a jointless connection, or the ends may overlap in at least one direction, which may be referred to as a jointed connection.
In addition to reinforcing members 26, vehicle track 10 also includes a plurality of cores 16 embedded in track body 14. In some examples, cores 16 embedded in track body 14 or a portion of cores 16 embedded in track body 14 may also be encased (e.g., substantially encompassed by track body 14). The plurality of cores 16 may include any suitable number of cores 16. In some cases, cores 16 may also be referred to as “links” of vehicle track 10. Cores 16 may be embedded (e.g., partially or fully embedded) in track body 14 such that at least a portion of each core 16 is within or surrounded by track body 14. In some examples, cores 16 may be fully embedded in track body 14, and cores 16 may not be exposed as a part of vehicle track 10. In other examples, cores 16 may be partially embedded in track body 14, and a portion of cores 16 may be exposed as a part of vehicle track 10 (e.g., the portion of cores 16 not embedded in track body 14 may be visible).
In some examples, such as in examples in which track body 14 includes multiple layers of material, cores 16 may be positioned (e.g., embedded) between layers of material. Alternatively, in examples in which track body 14 is molded, cores 16 may be introduced into the molding material prior to curing the material to form track body 14, such that the molding material partially or fully surrounds each of the cores 16. In either case, cores 16 may be partially or fully embedded in track body 14.
Cores 16 may be made of any suitable material. In some examples, cores 16 include a metal, such as steel, iron, or another metal. In some such examples, cores 16 may include a single, continuous piece of metal. For example, cores 16 may be manufactured by hot forging, using metal rods, or cast from metal. In other examples, cores 16 may be composed of two or more sections and attached together to form core 16. As one example, a first section of core 16 may be configured to align with the drive sprocket teeth 12A in order to help move vehicle track 10, and a second section may be the remainder of core 16. In some examples, the two sections may be attached or otherwise integrated into a single core 16.
Cores 16 are configured to support track body 14, while also allowing track body 14 to at least partially deform and/or flex, upon the application of a force on a respective side of track body 14. Cores 16 include a first and a second edge portions that each define at least one protrusion with a length (e.g., as measured in the longitudinal direction of track body 14) that is less than a length (e.g., as measured in the longitudinal direction of track body 14) of the respective edge portion. Cores 16 may be embedded in track body 14, and track body 14 may encase the at least one protrusion such that track body 14 both is supported by and can deform around the at least one protrusion upon the application of force on track body 14. For example, track body 14 may encase the at least one protrusion by substantially encompassing the at least one protrusion.
Each core 29 of the plurality of cores includes a body 30 and edge portions 38A, 38B. Body 30 may have any suitable shape, and includes a first end 36A and a second end 36B opposite first end 36A. Body 30 may define a body width extending between first end 36A and second end 36B. As illustrated in
Body 30 may also define a body length, such as body length LB measured along a second axis B that is orthogonal to first axis A. In some examples, second axis B is in the direction of the longitudinal (or circumferential) direction of track body 37. In some cases, the body width WB of body 30 may be longer than the body length LB of body 30.
An edge portion extends from each end 36A, 36B of body 30. For example, first edge portion 38A extends from first end 36A, and second edge portion 38B extends from second end 36B. Each of first edge portion 38A and second edge portion 38B may define at least one protrusion 40A and 40B, respectively, that extends from a major surface 31 of body 30. Major surface 31 of body 30 may include one or more surfaces of core 29 that does not include edge portions 38A, 38B and/or any structures (e.g., a lug protrusion 32A, 32B or a lug channel 34 defined by body 30). In some examples, major surface 31 corresponds or aligns with a first side of track body 37 configured to engage with a drive system of a vehicle (e.g., similar to first side 14A of
The at least one protrusion 40A, 40B may be any suitable shape. For example, the at least one protrusion 40A, 40B of each edge portion 38A, 38B may have a square-like profile, a rounded profile, a triangular profile, or any other profile. In some examples, the at least one protrusion 40A, 40B of each edge portion 38A, 38B is the same shape and/or size for both edge portions 38A, 38B. In other examples, the shape and/or size of each protrusion 40A, 40B of each edge portion 38A, 38B may be different.
Each core 29 is embedded within track body 37 such that track body 37 encases the at least one protrusion 40A, 40B of each edge portion 38A, 38B. For example, track body 37 may substantially encompass or surround the at least one protrusion 40A, 40B, e.g., in direct contact with the at least one protrusion 40A, 40B. In some examples, core 29 encased by track body 37 may be more tightly held within track body 37 (and may move less relative to track body 37) in comparison to a core that is not encased by track body 37. In other examples, cores 29 may be embedded in track body 37 but not encased by track body 37. For example, core 29 may be embedded in a pocket defined by track body 37, but the pocket may not closely match a shape of or entirely surround one or more portions of core 29. In some of these examples, all portions of core 29 may not contact track body 37 at the same time. In examples in which track body 37 encases core 29, a pocket of track body 37 may closely correspond to a shape of core 29, such that the pocket corresponds relatively precisely to surround the shape and size of the at least one protrusion 40A, 40B. In some examples, core 29 encased by track body 37 may be less likely to separate from, or significantly move within, track body 37.
Each protrusion 40A, 40B has a protrusion width WP that is less than the body width WB of the respective body 30, the width being measured in a direction orthogonal to the respective lengths LP, LB. As a result, each edge portion 38A, 38B may define a channel (
Plurality of cores 29 may define one or more structures of vehicle track 28 by being embedded in track body 37. For example, body 30 of core 29 may define one or more lug protrusions 32A, 32B that define guide lugs 33A, 33B. As illustrated in
Lug protrusions 32A, 32B and lug channel 34 may be any suitable size or shape to fit particular needs and an intended use of vehicle track 28. For examples, lug protrusions 32A, 32B and lug channel 34 may be any suitable size or shape such that guide lugs 33A, 33B and guide channel 35 defined by lug protrusions 32A, 32B and lug channel 34 align with the drive sprocket wheel (e.g., drive sprocket wheel 12 of
Core 50 includes a first edge portion 52A and a second edge portion 52B. Each of first edge portion 52A and second edge portion 52B defines at least one protrusion that extends from major surface 31 of body 30. In the example of
In some examples, support of track body 14 may include helping track body 14 maintain its shape, preventing track body 14 from collapsing or substantially deforming, maintaining engagement of track body 14 with a ground surface, or the like. The support of track body 14 by protrusions 54A-54D may result in increased stability of a vehicle mounted to vehicle track 10 and/or an increase in the useful life of vehicle track 10. Upon an application of force (e.g., in the direction of arrows A1 and/or A2) on track body 14, track body 14 may be moved in the direction of arrows A1 and/or A2, resulting in a portion of track body 14 being pushed against protrusions 54A and/or 54B. During this application of force in the direction of arrows A1 and/or A2, track body 14 may be supported by protrusions 54A and 54B, which may help maintain the shape of track body 14 and prevent collapse or complete deformation of track body 14.
Each protrusion 54A-54D has a protrusion length that is less than the length of body 30 of core 50. For example, protrusion 54A has a protrusion length LP1 that is less body length LB1, protrusion 54B has a protrusion length LP2 that is less body length LB1, protrusion 54C has a protrusion length LP3 that is less body length LB1, and protrusion 54D has a protrusion length LP4 that is less body length LB. In the example of
Channels 56A and 56B may be any suitable shape and/or size to fit particular needs and an intended use of vehicle track 10. In some examples, a larger channel may enable track body 14 to deform and/or flex more than a smaller channel upon the application of a given force on a respective side of track body 14. On the other hand, in some examples, a larger channel may result in the two protrusions of the respective edge portion being smaller than those of an edge portion defining a smaller channel. The smaller protrusions may provide less support to track body 14 upon the application of force on a respective side of track body 14 in comparison to larger protrusions. In some examples, the length LP1, LP2, LP3, LP4 of each respective protrusion 54A-54D may be greater than or equal to the length LC1, LC2 of the respective channel 56A, 56B of the respective edge portion 52A, 52B. In other examples, the length LP1, LP2, LP3, LP4 of each respective protrusion 54A-54D may be less than the length LC1, LC2 of the respective channel 56A, 56B of the respective edge portion 52A, 52B.
In the example of
Each of channels 56A and 56B may enable track body 14 to at least partially deform around protrusions 54A-54D upon an application of force on track body 14. For example, channel 56A of first edge portion 52A may allow track body 14 to at least partially deform around protrusions 54A and 54B upon an application of force on a side of track body 14 corresponding to first edge portion 52A. Channel 56A may allow track body 14 to at least partially deform around protrusions 54A and 54B, such as deform toward channel 56A in the direction of arrow B, upon such an application of force in the direction of arrow B. In this way, track body 14 may be supported by protrusions 54A and 54B, while at least partially deforming around protrusions 54A and 54B (e.g., toward channel 56A). Similar to first edge portion 52A, protrusions 54C, 54D of second edge portion 52B may support track body 14 upon an application of force on a side of track body 14 corresponding to second edge portion 52B, and channel 56B of second edge portion 52B may enable track body 14 to deform around protrusions 54C, 54D upon the application of force in a direction toward channel 56B.
The combination of the support of track body 14 by protrusions 54A-54D and the at least partial deformation of track body 14 around protrusions 54A-54D toward channel 56A, 56B may increase the useful life of a vehicle track, such as vehicle track 10 of
Core 60 includes a first edge portion 62A and a second edge portion 62B on an opposite side of core 60 from first edge portion 62A. Each of first edge portion 62A and second edge portion 62B defines at least one protrusion that extends from major surface 74 of the respective body 72. In the example of
Each protrusion 64A, 64B has a protrusion length that is less than the length LB2 of body 72 of core 60. For example, protrusion 64A has a protrusion length LP5 that is less body length LB2, and protrusion 64B has a protrusion length LP6 that is less body length LB2. The body length LB2 of core 60 may extend between a first side surface 66A and a second side surface 66B of body 72, and the protrusion length LP5, LP6 of each protrusion 64A, 64B may extend between a third side surface 68A and a fourth side surface 68B of the respective protrusion 64A, 64B. In some examples, third side surface 68A of protrusion 64A is offset from first side surface 66A of body 72. In this way, first edge portion 62A may define a first side region 70A proximate third side surface 68A (e.g., next to protrusion 64A). Additionally, or alternatively, fourth side surface 68B of protrusion 64A may be offset from second side surface 66B of body 72. In some such examples, first edge portion 62A may additionally, or alternatively, define a second side region 70B proximate fourth side surface 68B (e.g., next to protrusion 64A, but on the opposite side of first side region 70A). Edge portion 62B may define third side region 70C and fourth side region 70D similar to first and second side regions 70A, 70B. When track body 14 encases each protrusion 64A, 64B track body 14 also extends within each side region 70A-70D to surround and substantially encompass each protrusion 64A, 64B.
Each of side region 70A-70D may enable track body 14 to at least partially deform around protrusions 64A, 64B upon an application of force on track body 14. For example, side regions 70A and 70B of first edge portion 62A may allow track body 14 to at least partially deform around protrusions 64A upon an application of force on a side of track body 14 corresponding to first edge portion 62A. Side regions 70A, 70B may allow track body 14 to at least partially deform around protrusion 64A such that track body 14 deforms toward side region 70A, 70B in the direction of arrows B1 and B2, upon such an application of force. In this way, track body 14 may be supported by protrusion 64A, while at least partially deforming around protrusion 64A (e.g., toward side regions 70A, 70B).
In the example of
The combination of the support of track body 14 by protrusions 64A, 64B and the at least partial deformation of track body 14 around protrusions 64A, 64B toward side regions 70A-70D may increase the useful life of a vehicle track, such as vehicle track 10 of
In the example of
Although examples of cores with edge portions each including one or two protrusions, one channel, and/or two side regions were specifically described herein, each edge portion may define any number of protrusions having a protrusion length less than a body length, any number of channels, and/or any number of side regions. For example, one or both edge portions of a vehicle track core may define three protrusions and two channels. Moreover, the first edge portion and the second edge portion of a core may not be the same in some examples. As one example, a core may include a first edge portion similar to first edge portion 52A of
Obstruction 82A, 82B may result in one or more increased forces applied on vehicle track 28, a change in a distribution of forces applied on vehicle track 28, or both. For example, as seen in
The application of increased forces F1, F2, F3, and/or F4 on vehicle track 28 may put additional stress on vehicle track 28, which, in some examples, may increase or accelerate the wear of vehicle track 28. For example, the formation of cracks in the track body 37, widening of cracks in the track body 37, separation of core 29 from track body 37, or the like may be increased or accelerated due to the additional stress. In some examples, the use of core 29 including first and second edge portions 38A, 38B (or the other cores described herein) may help mitigate the effects of the additional stress on vehicle track 28, such as added stress due to obstruction 82A, 82B. For example, edge portion 38A, 38B (e.g., at least one protrusion 40A, 40B of each edge portion 38A, 38B) may support track body 37 upon the application of increased forces F1, F2, F3, and/or F4 on track body 37. Edge portion 38A, 38B (e.g., a channel or a side region of each edge portion 38A, 38B) may also allow track body 37 to at least partially deform (e.g., around the at least one protrusion 40A, 40B of each edge portion 38A, 38B). The partial deformation of track body 37 relative to the at least one protrusion 40A, 40B may help distribute the stress due to the increased forces F1, F2, F3, and/or F4 to other portions of track body 37, which may minimize a stress point of track body 37 due to the increased forces F1, F2, F3, and/or F4. For example, rather than the stress from forces F1, F2, F3, and/or F4 and from track body 37 pushing against the at least one protrusion 40A, 40B being relatively confined to edge portion 38A, 38B, the flexibility of track body 37 relative to the at least one protrusion 40A, 40B may help distribute the stress across track body 37. In this way, track body 37 is prevented from fully deforming or collapsing, and is also able to have some flexibility under the application of increased forces F1, F2, F3, and/or F4, reducing the stress on track body 37 (or on at least a portion of track body 37).
The technique of
In some examples, the plurality of cores 29 include a metal. In some such examples, each core 29 of the plurality of cores 29 may include a single, continuous piece of metal. In other examples, each core 29 may be composed of two or more sections and attached together to form body 30 and/or edge portions 38A, 38B of core 29.
The plurality of cores 29 may be formed using any suitable technique. For example, the plurality of cores 29 may be formed using a hot forging technique, a metal rod technique, a casting technique, or another technique. In some examples, the shape of core 29 may be easier to control using a casting technique, and the consistency of the quality of cores 29 may be easier to control using a hot forging technique.
In some examples, the technique of
The technique of
Track body 37 may include an elastomer, such as a natural rubber, a synthetic rubber, or another elastomeric material. In examples in which track body 37 includes a natural or a synthetic rubber, forming track body 37 around at least a portion of each core 29 of the plurality of cores 29 may include a vulcanization technique. In some examples, forming track body 37 around at least a portion of each core 29 of the plurality of cores 29 may include a molding technique.
Various examples have been described. These and other examples are within the scope of the following claims.
This application claims the benefit of U.S. Provisional Application Ser. No. 62/624,437, filed Jan. 31, 2018, and entitled, “VEHICLE TRACK CORE,” the entire content of which is incorporated herein by reference.
Number | Date | Country | |
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62624437 | Jan 2018 | US |