Abstract:
A motorcycle comprises a chassis, a windshield attached to the chassis, and a speed sensor operative to determine instantaneous speeds of the motorcycle as the motorcycle travels. In addition, the motorcycle further comprises a position table and a windshield positioning device. The position table associates windshield positions in relation to the chassis with respective speeds of the motorcycle. The windshield positioning device is operative to move the windshield to the windshield positions associated in the position table with the instantaneous speeds of the motorcycle determined by the speed sensor.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/829,174, filed Oct. 12, 2006. 

   FIELD OF THE INVENTION 
   The present invention is directed generally to motorcycles, and, more particularly, to adjustable windshields in motorcycles. 
   BACKGROUND OF THE INVENTION 
   Many modern motorcycles comprise windshields (also called windscreens) that are positioned in front of the rider. Such windshields reduce the amount of wind impacting the rider while the motorcycle is in motion, often making the riding of the motorcycle less fatiguing for the rider. Moreover, motorcycle windshields may further act to protect the rider from other elements such as flying insects, rain, and road debris. 
   The aerodynamics of wind impinging on a windshield change significantly as a function of the speed at which the motorcycle is traveling. As a result, many modern motorcycle manufacturers have created motorcycles with windshields that may be adjusted in height and/or angle by the rider via an electric motor connected to a rider-operated switch. The 2006-model-year BMW K1200GT and Honda ST1300 ABS motorcycles, for example, comprise such electrically adjustable windshields. 
   A rider on one of these conventional types of motorcycles may desire to frequently adjust the position of the windshield as the rider&#39;s speed changes. The rider may, for example, wish to adjust the position of the windshield to have some amount of wind impinging on the rider&#39;s body during slow travel to aid in cooling the rider. However, at higher speed, this same windshield position may allow so much wind to impinge on the rider that the rider becomes uncomfortable or fatigued. As a result, the rider will desire to manipulate the position of the windshield as the rider&#39;s speed changes. Unfortunately, such an operation may need to be performed frequently as the motorcycle speed changes due to, for example, road conditions or traffic. What is more, such an operation, when performed through a rider-operated switch, may be distracting to the rider. The moving of a windshield in the conventional manner may, as a result, increase the rider&#39;s workload and reduce rider safety. 
   As a result, there is a need for a motorcycle windshield that can be adjusted for varying speed conditions without requiring that the rider frequently operate a manual switch. 
   BRIEF SUMMARY OF THE INVENTION 
   Embodiments of the present invention address the above-identified need by providing a motorcycle that comprises a windshield that can be adjusted for varying speed conditions without requiring that the rider frequently operate a manual switch. 
   In accordance with an aspect of the invention, a motorcycle comprises a chassis, a windshield attached to the chassis, and a speed sensor operative to determine instantaneous speeds of the motorcycle as the motorcycle travels. In addition, the motorcycle further comprises a position table and a windshield positioning device. The position table associates windshield positions in relation to the chassis with respective speeds of the motorcycle. The windshield positioning device is operative to move the windshield to the windshield positions associated in the position table with the instantaneous speeds of the motorcycle determined by the speed sensor. 
   In accordance with one of the above-identified embodiments of the invention, a motorcycle is operative to travel at different speeds. The motorcycle comprises a chassis, a windshield attached to the chassis, and a speed sensor operative to determine the present speed of the motorcycle. In addition, the motorcycle comprises a motor that is operative to adjust the position of the windshield (e.g., height and angle) in relation to the chassis, and a position table. The position table relates preferred windshield positions to different speeds. As the motorcycle travels, the motor changes the position of the windshield as a function of the present speed of the motorcycle in accordance with the position table. Advantageously, this allows the windshield to be automatically repositioned as the motorcycle changes speed. 
   These and other features and advantages of the present invention will become apparent from the following detailed description which is to be read in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a perspective view of a motorcycle in accordance with an illustrative embodiment of the invention. 
       FIG. 2  shows a block diagram of a windshield control apparatus in the  FIG. 1  motorcycle embodiment. 
       FIG. 3  shows a flow chart for positioning a windshield in the  FIG. 1  motorcycle embodiment. 
       FIG. 4  shows an illustrative position table in the  FIG. 1  motorcycle embodiment. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention will be described with reference to illustrative embodiments. For this reason, numerous modifications can be made to these embodiments and the results will still come within the scope of the invention. No limitations with respect to the specific embodiments described herein are intended or should be inferred. 
   The term “motorcycle” as used herein is intended to encompass any two-wheeled vehicle powered by an engine and/or motor. 
     FIG. 1  shows a motorcycle  100  in accordance with an illustrative embodiment of the invention. The motorcycle comprises a chassis  110 . Coupled to the chassis is a windshield  120 . The motorcycle also comprises a number of other elements that will be familiar to one skilled in the art but are not explicitly labeled in  FIG. 1  because they are not necessary for the understanding of the subject matter of the invention. These other elements include an engine, suspension, transmission, wheels, tires, brakes, instruments, electrical system, lights, seat and rider controls. 
   The windshield  120  is operative to be configured into various different positions. Each windshield position comprises some combination of height and angle relative to the chassis  110 .  FIG. 2  shows a block diagram of elements within the motorcycle  100  associated with the positioning of the windshield. The motorcycle includes a speed sensor  210 , a rider-operated switch  220 , a motor controller  230 , a position table  240 , and a windshield positioning motor  250 . 
   The speed sensor  210  provides an indication to the motor controller  230  of the present speed (i.e., the instantaneous speed) of the motorcycle. The speed sensor may be, for example, a conventional analog or digital speedometer or, alternatively, a global positioning system operative to determine the motorcycle&#39;s speed. The motor controller, in turn, is preferably an electronic component that controls the windshield positioning motor  250  in accordance with the rider-operated switch  220  or the position table  240 , described in greater detail below. Finally, the windshield positioning motor is preferably an electric motor coupled to the windshield  120  and operative to move the windshield in both height and angle in relation to the chassis  110 . 
   One skilled in the art will recognize how an electric motor may be implemented in the motorcycle  100  to move the windshield  120 . As stated before, such electric motors are conventionally used in several modern, commercially-available motorcycles. The windshield positioning motor  250  may, for example, comprise a digitally controlled stepper motor. The motor controller  230 , in turn, will preferably comprise conventional digital circuitry operative to send electrical signals to the electromagnets in the stepper motor and allow the stepper motor to move in a precise, reproducible manner. The motor controller may, for example, comprise a digital microcontroller. 
     FIG. 3  shows an illustrative process flow that allows the elements in  FIG. 2  to position the windshield  120  in accordance with aspects of this invention. Step  310  comprises programming the position table  240 . In such a step, the rider preferably rides the motorcycle  100  at different speeds and adjusts the windshield to the rider&#39;s preferred positions at the different speeds using the rider-operated switch  220 . The rider operated-switch, in turn, is connected to the motor controller  230  which commands the windshield positioning motor  250  to move the windshield in accordance with the rider&#39;s inputs. 
   As the rider is positioning the windshield  120  at various speeds via the rider-operated switch  220 , a preferred windshield position is associated by the motor controller  230  with the various speeds returned by the speed sensor  210 . These preferred windshield positions and associated speeds are stored in the position table  240 .  FIG. 4  shows an example of various entries in the position table (where a given windshield position is represented by a letter). The table, may for example, record the preferred position of the windshield at every 2 mile-per-hour increment, although this is entirely arbitrary and other increments would still come within the scope of the invention. The position table, itself, may be integrated in the motor controller or may be a discrete device. The position table, may, for example, be implemented in a conventional Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory or random-access memory (RAM), all of which will be familiar to one skilled in the art. 
   Once programmed in this way, the motorcycle  100  enters a mode in which the windshield  120  is automatically adjusted to the rider&#39;s preferred positions as the motorcycle changes speed without the rider having to move the windshield via the rider-operated switch  220 . This automated positioning sequence is represented in  FIG. 3  by steps  320 - 340 . In step  320 , the speed sensor  210  measures the speed at which the motorcycle is presently traveling and outputs that speed to the motor controller  230 . In step  330 , the motor controller addresses the position table  240  with the present speed. The position table, in turn, returns the preferred windshield position associated with the speed entry nearest the present speed. Finally, in step  340 , the motor controller commands the windshield positioning motor  250  to adjust the windshield to the position returned by the position table. 
   Accordingly, once in the automated positioning sequence, the rider is no longer required to operate the rider-operated switch  220  in order to maintain the windshield  120  at the rider&#39;s preferred positions as the rider changes speed. The rider is, therefore, left to concentrate on other aspects of riding the motorcycle while enjoying the benefits of an adjustable windshield. 
   The sequence of steps  320 - 340  is preferably repeated as long as the motorcycle  100  is in operation. If, however, during this automated sequence, the rider decides that a windshield position different from that programmed into the position table  240  is desired, the rider may preferably reenter the programming step  310  by, for example, merely pushing the rider-operated switch  220 . Once back in step  310 , the rider may change some or all of the entries in the position table before reentering the automated positioning sequence (i.e., steps  320 - 340 ). 
   Optionally, the position table  240  may have separate entries for more than one rider. Advantageously, this would allow two or more riders to ride the same motorcycle and have preferred windshield entries that are customized to each rider&#39;s preferences. 
   It is to be understood that, although illustrative embodiments of the present invention have been described herein with reference to the accompanying figures, the invention is not limited to those precise embodiments. One skilled in the art will recognize various other changes and modifications that may be made without departing from the scope of the appended claims.