Patent Application
20060052032
1. Field of the Invention
The present invention relates to electric-powered model vehicles, such as model trains, and more particularly, to an adaptive drive mechanism for a model train or other model vehicle.
2. Description of Related Art
Various model trains and vehicles are known in the art, which model an actual or imaginary train or vehicle at a reduced scale. In a typical model layout, a model train having an engine is provided. The model train engine includes an electrical motor that receives power from a voltage that is applied to model railway tracks. A transformer is used to apply the power to the tracks, while contacts (e.g., a roller) on the bottom of the train, or metallic wheels of the train, pick up the applied power for the train motor. In some model train layouts, the transformer controls the amplitude, and in a DC system, the polarity, of the voltage, thereby controlling the speed and direction of the train. In HO systems, the voltage is a DC voltage. In O-gauge systems, the track voltage is an AC voltage transformed by the transformer from a household line voltage provided by a standard wall socket, such 120 or 240 V, to a reduced AC voltage, such as 0-18 volts AC.
Model electric trains therefore include a drive train linking one or more pairs of powered drive wheels to an electric motor housed in a model locomotive. Many model locomotives make use of a direct gear drive, such as a spur gear set or other gear drive. Direct gear drives provide a direct mechanical link between the motor and the drive wheels, and are generally recognized as providing excellent responsiveness and low backlash for speed control and motion reversal. Properly designed gear drives are also reliable, have low maintenance requirements, and long service lives. These characteristics make gear drives prevalent in many model vehicles.
Notwithstanding their advantages, gear drive mechanisms may be subject to certain disadvantages. Conventional gear drives are used with a relatively rigid or stiff mechanical connection between the drive wheels and the motor. Consequently, displacement of the drive wheels from bumps or unevenness of a model track is transmitted to the model locomotive, which may visibly bounce up and down or sway side-to-side in a way that does not resemble a full-scale locomotive. Modern full-scale locomotives employ sophisticated drive trains and suspension systems, as well as being much more massive than reduced-scale model locomotives. Full-scale model locomotives therefore may exhibit a much smoother, stable response to vibration received from travel over the track bed, as compared to many prior-art model vehicles. Achieving a more realistic dynamic response in model vehicles is desirable, but only within certain economic constraints. For example, merely scaling down all the primary mechanical characteristics of actual locomotives, such as mass, moment of inertia, suspension and drive systems, is not economically feasible for model vehicles intended for consumer toy or hobbyist applications.
Accordingly, a need exists for a model train with a drive mechanism that overcomes these and other limitations of the prior art.
The invention provides a reduced-scale model vehicle with an adaptive drive mechanism for driving drive wheels of a model locomotive of the like. The drive mechanism transmits motive power through a direct gear drive, without sacrificing the ability to absorb bumps and other irregularities in a model track layout. A model locomotive equipped with the drive mechanism therefore reacts to the track bed in a way that more closely resembles, at a reduced scale, the performance of a full-scale locomotive. At the same time, the benefits of a gear drive, such as responsiveness, low backlash, reliability, and low maintenance, are preserved for the enjoyment of the model hobbyist.
In an embodiment of the invention, a gear drive mechanism provides a direct mechanical linkage to a model locomotive engine, while at the same time providing the drive wheels of the locomotive with a floating mechanism. The gear mechanism may be configured for translating speed and torque from the output shaft of the motor to the drive wheels of a model locomotive, in any suitable manner as known in the art. The floating mechanism permits the drive wheels to “float,” in the sense that the drive wheels are provided with freedom of movement relative to the drive mechanism, while still remaining in gear. Thus, when the drive wheels encounter a bump or other unevenness in the track, they are free to move independently of the gear train and of the locomotive. Forces from motion over the track are thereby at least partly isolated from the locomotive, which enjoys a more stable, vibration-free ride. This provides a more realistic effect and enjoyment to the model hobbyist.
In an embodiment of the invention, the gear drive and floating mechanism are provided in a “truck” assembly. The truck comprises a plurality of wheels, which in a full-scale locomotive are needed to bear the massive weight of the locomotive. A reduced-scale truck may be configured to resemble various types of full-scale locomotive trucks. For the convenience of the hobbyist, the model truck may comprise a modular unit that can readily be removed for maintenance, repair or for use with a compatible locomotive.
A more complete understanding of the model vehicle with an adaptive drive mechanism will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings which will first be described briefly.
The present invention provides a model locomotive with a force-isolating drive train, that overcomes the limitations of the prior art. In the detailed description that follows, like element numerals are used to indicate like elements appearing in one or more of the figures.
Power source 14 may comprise a conventional AC or DC transformer, depending on the requirements of railroad layout 10, and in particular, model vehicle 16. Additionally, power source 14 may provide a fixed output, a variable output, or both. In an exemplary embodiment, railroad layout 10 comprises an O-gauge layout and power source 14 comprises an AC transformer which transforms typical AC line voltage (e.g., 120 VAC) to a reduced level (e.g., 0-18 VAC for a conventional O-gauge variable output model train transformer) and supplies the same to track 12.
With reference to
With continued reference to
Gear set 30, also called a gear train, may be mounted to frame 24, disposed between and engaged with first and second drive axles 26, 28. Gear set 30 may comprise one or more gears, such as, for example, five gears 301, 302, 303, 304, 305, each of which is in mesh with each adjacent gear of gear set 30, and each of which has its own respective gear axle 441, 442, 443, 444, 445, coupled to frame 24. Two gears of gear set 30, gears 301 and 305, for example, are also in mesh with output gears 401, 402, respectively, and accordingly, gear set 30 is operative to assist in the driving of output gears 401, 402, and therefore, model vehicle 16. As shown in
When model vehicle 16 is commanded to move, motor 52 turns output shaft 50. Worm gear 48 is attached to shaft 50 and rotates in either a clockwise or counterclockwise direction. This rotation is transferred to gear 46, which then causes axle 444 and corresponding gear 304 to rotate, which then, through the arrangement of gears in gear set 30, causes output gears 401, 402, and therefore, drive axles 26, 28 and wheels 361, 362, 381, 382 to rotate, thereby causing model vehicle 16 to move. It should be noted, however, that this arrangement and configuration are provided for exemplary purposes only and is not meant to be limiting in nature. In alternate embodiments, gear 46 may be associated with any of gear axles 441, 442, 443, 444, 445, or one of the gears of gear set 30 may be driven directly by output shaft 50. Similarly, one of output gears 401, 402 may be driven by output shaft 50 with the gears of gear set 30 transferring the rotation of the driven output gear to the other output gear.
An interior space 32 may be provided in or adjacent to frame 24, in which one of the output gears 401 may be disposed. Referring to
First drive axle 26 is disposed at least partly within space 32, while second drive axle 28 may be disposed at least partly within space 34. In this arrangement, and with particular reference to
In the illustrated embodiment, drive axle 26 is pivotally coupled to fixed gear axle 441 of gear 301, while drive axle 28 is pivotally coupled to fixed gear axle 445 of gear 305. It should be noted, however, that illustrated mounting of drive axles 26, 28 to adjacent gear axles, while believed to be advantageous, is provided for exemplary purposes only. Drive axles 26, 28 may be movable coupled to any portion of track frame 24 that is similarly situated to gear axles 44, and that will allow for the functionality described herein. More complex suspensions may be used, but are likely to entail considerably greater cost. For example, a spring-loaded wishbone suspension with universal joints, such as used for automobiles, may be used to permit vertical motion while transmitting torque to the drive wheels. Such an arrangement would likely be much more complex and expensive to implement. On the other hand, various simplified suspensions may be devised that may permit vertical movement of the drive wheels at an acceptable cost, and the invention is not limited to a pivoting coupling as shown in the exemplary embodiment.
In accordance with the illustrated embodiment, when model vehicle 16 traverses an uneven portion of track, axles 26, 28 pivot about adjacent gear axles 44, thereby isolating the locomotive from vertical forces and absorbing energy from the vertical force input. While providing a partly independent suspension, truck 24 and gear train 30 also function as a transmission for transmitting torque to the drive wheels. A cost-effective force-isolating drive mechanism for stabilizing a model vehicle is thus provided, which retains all of the advantages of conventional gear drives.
Having thus described a preferred embodiment of a model vehicle with an force-isolating drive mechanism, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, a particular drive mechanism has been illustrated, but it should be apparent that the inventive concepts described above would be equally applicable to other mechanisms, for example belt drives or chain drives, arranged according to the spirit and scope of the invention. The invention is defined by the following claims.
This application claims priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Application No. 60/575,591, filed May 28, 2004, which application is specifically incorporated herein, in its entirety, by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60575591 | May 2004 | US |
