Abstract:
A ride height gauge includes a chassis engaging member biased relative to a base member via springs. Lowering an RC car chassis onto the chassis engaging member causes the chassis engaging member to lower until the car&#39;s wheels touch a support surface on either side of the base member. The chassis engaging member&#39;s lowered position is displayed on measurement columns that measure the height of the chassis engaging member from the support surface, which can be used to determine the ride height of the vehicle. The measurement columns at opposite ends of the vehicle allow the user to simultaneously measure the ride height at either end of the vehicle without repositioning of the vehicle.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the filing date benefit of U.S. Provisional Application No. 61/408,707, filed Nov. 1, 2010, the disclosure of which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to radio controlled vehicles and, more particularly, to adjustment devices for adjusting the suspension of a wheeled vehicle. 
     BACKGROUND OF THE INVENTION 
     Radio controlled (“RC”) vehicles are a popular and sophisticated hobby. RC cars often operate under a variety of conditions, and hobbyists can adjust various aspects of their vehicle to improve speed and handling under each of those conditions. Adjusting various aspects of the vehicle&#39;s suspension in order to improve performance is a well-known and widely enjoyed feature of the hobby. 
     One aspect of the vehicle&#39;s suspension that is often adjusted to tune handling is the vehicle&#39;s ride height, defined as the distance between the bottom of the vehicle&#39;s chassis and the surface supporting the vehicle. Ride height can have a significant impact on vehicle handling and performance. A vehicle that sits low will generally experience less chassis roll and have more even weight distribution of the wheels, which can improve turning and general handling. A vehicle that sits high will generally experience more chassis roll and distribute weight selectively, which can improve traction. Right height may also affect a vehicle&#39;s ability to deal with uneven, off-road environments and track obstacles. 
     Because vehicle ride height is often tailored to track conditions, it is important to be able to quickly and conveniently measure ride height as part of tuning the vehicle. Existing ride height gauges exist in the form of stepped gauges, wherein one end of the chassis is moved across the steps until it no longer clears a step, thus determining its approximate height on that end of the chassis. The chassis can then be removed and the gauge used with the other end of the chassis to determine the height of that end. Existing ride height gauges are also sold in the form of a hand-held gauge that can be placed under a single point in the chassis to measure the distance between that point and the support surface. 
     There is a need for a ride height gauge that more conveniently measures the height of both ends of the chassis, that does so quickly and conveniently, and that can easily display the ride height for all kinds of wheeled RC vehicles without any particular calibration. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the foregoing and other shortcomings and drawbacks of adjustment devices for adjusting the suspension of a wheeled vehicle. While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. On the contrary, the invention includes all alternatives, modifications and equivalents as may be included within the spirit and scope of the present invention. 
     In one embodiment, a ride height gauge for a model vehicle includes a base member configured to engage a horizontal support surface and a chassis engaging member resiliently biased with respect to the base member and configured to move vertically relative to the base member. In one embodiment, each of the base member and the chassis engaging member comprises a respective plate. A model vehicle placed upon the chassis engaging member, with the chassis of the model vehicle engaging the chassis engaging member, will lower the chassis engaging member to a position above the horizontal support surface approximately equal to the ride height of the model vehicle. 
     In another embodiment, a ride height gauge for a model vehicle includes a base member configured to engage a horizontal support surface, spring columns and measurement columns extended vertically from the base member and a chassis engaging member having apertures for receiving the spring columns and the measurement columns therethrough. Each spring column comprises a resilient member resiliently biasing the chassis engaging member relative to the base member. A model vehicle placed upon the chassis engaging member, with the chassis of the model vehicle engaging the chassis engaging member, will lower the chassis engaging member until the wheels of the model vehicle contact with the horizontal support surface and each of the measurement columns will display a height measurement which allows the user to determine a ride height (or multiple ride heights) for the vehicle. 
     The above and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
         FIG. 1  is perspective view of a ride height gauge in accordance with one embodiment of the present invention; 
         FIG. 2  is a side plan view of the gauge shown in  FIG. 1 ; 
         FIG. 3  is an end plan view of the gauge shown in  FIGS. 1 and 2 ; 
         FIG. 4  is side plan view of a ride height gauge in accordance with another embodiment of the present invention; and 
         FIG. 5  is a side plan view of the ride height gauge of  FIG. 4  shown expanded. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIG. 1 , a full-body ride height gauge  10  in accordance with one embodiment includes a base member  20 , a chassis engaging member  30 , spring columns  40  and measurement columns  50  operatively coupled together to form the ride height gauge  10 . In one embodiment, each of the base member  20  and the chassis engaging member  30  comprises a respective plate as shown in the figures. It will be appreciated, however, that other structures or configurations of the base member  20  and chassis engaging member  30  are possible as well without departing from the spirit and scope of the present invention. 
     Each of the spring columns  40  and the measurement columns  50  may be fixedly attached to the base member  20 . The columns  40 ,  50  may be permanently affixed to the base member  20 , or they may be removably affixed for convenient storage of the ride height gauge  10  when not in use. 
     The measurement columns  50  include indicia  52  convenient for measuring distance. The indicia may measure fractions of an inch, millimeters, or any other length unit appropriate for measuring a height from a surface  70  supporting the ride height gauge  10 . In one embodiment, the indicia  52  may be positioned to take into account the total height from the support surface  70 , including the height of the base member  20 . The indicia  52  may instead show the height from the top of the base member  20 , or may mark intervals of distance without marking an absolute distance from any set point. Where the measurement columns  50  readily detach from the base member  20 , different measurement columns with different indicia may be provided in accordance with the preferences of the user. The measurement columns  50  may even allow for custom marks to be made by a user to denote one or more preferred height values. 
     In the exemplary embodiment, the chassis engaging member  30  includes apertures  32  positioned to receive the spring columns  40  and measurement columns  50  therethrough. While the position of the columns  40 ,  50  may act to keep the chassis engaging member  30  mainly parallel to the base member  20 , the apertures  32  may be sized to be significantly greater in diameter than the columns  40 ,  50  so that the chassis engaging member  30  can deviate significantly from level when appropriate. In one embodiment, one or more levels (not shown) may be included upon the chassis engaging member  30  to provide additional indication as to whether or not the chassis engaging member  30  is level. Each column  40  may include threads  41  and a limiting member, such as a nut  43 , which prevents the chassis engaging member  30  from traveling off of the columns  40 ,  50 . 
     Sometimes an uneven ride height is desirable. For example, in some vehicles, the front and rear suspensions are tuned to have the front and rear ends of the chassis at different heights to improve handling. Since the chassis engaging member  30  can deviate significantly from level, the front and rear measurement columns  50  allow the user to measure different front and rear ride heights when the vehicle is placed upon the gauge without having to reposition the vehicle to make additional measurements. 
     In the exemplary embodiment, each spring column  40  may include a spring  42  attached to two spring cradles  44 ,  46 . The upper spring cradle  44  moves freely in the vertical direction along the column  40 , while the lower spring cradle  46  includes a means to securely fasten it to a set location along the height of the column  40 . As shown, the means may be a wing fastener  48  that engages the column  40  when tightened. A wing fastener  48  or other suitable means may allow for adjustment of the location that the lower cradle  46  fastens to the column  40 . Alternatively, the lower cradle  46  may be permanently affixed to a set position on the spring column  40 , such as through a weld or adhesive attachment, or the use of a screw or other fastener in a single drilled hole or other positioned feature in the column (not shown). 
     Although shown as compression coil springs, any resilient member may be used to resiliently bias the chassis engaging member  30  relative to the base member  20 . In the illustrated embodiment, each spring  42  is a coil compression spring with a weak spring constant, such that the force that it exerts is sufficient to bias the chassis engaging member  30  away from the base member  20  to elevate the chassis engaging member  30  to a height above the expected maximum ride height of a vehicle to be measured, but not sufficient to impede an accurate ride height measurement near the minimum expected ride height of the vehicle when the vehicle rests upon the chassis engaging member  30  as described in detail below. The adjustable lower spring cradle  46  may aid in placing the spring  42  within the correct height range for a given vehicle. A lower force constant for the spring  42  reflects a longer operable range. 
     While in the exemplary embodiment the springs  42  are shown and described as being located between the base member  20  and the chassis engaging member  30  to bias the chassis engaging member  30  away from the base member  20 , it is contemplated in an alternative embodiment that the springs  42  may comprise extension springs located above the chassis engaging member  30  to likewise bias the chassis engaging member  30  away from the base member  20 . 
     The width of the chassis engaging member  30  is less than the width of an RC vehicle chassis, such that the underside of an RC vehicle  60  to be measured can rest on the chassis engaging member  30  with its wheels protruding from either side. The base member  20 , which may be the same width as the chassis engaging member  30 , is also narrow enough to allow the wheels of the vehicle  60  to pass unhindered to the surface upon which the gauge  10  rests. The vehicle  60  depresses the chassis engaging member  30  until its wheels touch the surface. The distance between the underside of the vehicle chassis and the support surface is shown by the chassis engaging member  30  intersecting the indicia  52  on the measurement columns  50 , thereby allowing simultaneous measurement of the front and rear ride heights of the model vehicle. 
     As shown in  FIG. 2  (and again in  FIG. 4 ), the chassis engaging member  30  may be flexible to accommodate a vehicle chassis underside that is slightly lower in the middle than on either end. The chassis engaging member  30  is shown bending slightly below plane P in the center to demonstrate this flexibility in the chassis engaging member  30  if necessary to accommodate the vehicle chassis. 
     RC cars are made in a variety of sizes, which accommodate both a range of sizes in the source vehicles they simulate as well as a variety of scales, including ⅛, 1/10 and 1/12 scale models. In order to accommodate a range of vehicle lengths, a gauge  10 ′ according to another embodiment is shown in  FIGS. 4 and 5  having expandable chassis engaging and base members  30 ′ and  20 ′, respectively. As shown in  FIGS. 4 and 5 , the expandable gauge  10 ′ may contain any of the features and variations described above. The same reference numbers denote the same components throughout the various figures. 
     In the illustrated embodiment, the expandable gauge  10 ′ includes an expandable dual telescoping chassis engaging member  30 ′ constructed of two primary chassis engaging members  30   a ,  30   b  and an extension member  30   c . Each of the primary chassis engaging members  30   a ,  30   b  includes a wing fastener  38 , which tightens to fix the chassis engaging members  30   a ,  30   b  into place. When in a collapsed position, the primary chassis engaging members  30   a ,  30   b  may be in contact and the extension member  30   c  not visible, as shown in  FIG. 4 . When expanded to accommodate a larger vehicle  60 ′, as shown in  FIG. 5 , the extension member  30   c  accommodates the center of the vehicle chassis as each of the primary chassis engaging members  30   a ,  30   b  move outward to increase the total length of the chassis engaging member. Similarly, the expandable telescoping base member  20 ′ may also include two primary base members  20   a ,  20   b , an extension member  20   c , and wing fasteners  28  to allow for the same expansion of the base member. The extension may be variable, or the wing fasteners or other fasteners may mate with one or more apertures in the expansion members  20   c ,  30   c  that provide pre-set internal lengths for the gauge  10 ′. 
     In one embodiment, the base member  20  and the chassis engaging member  30  are single elongated members that extend the length of the gauge. It is contemplated that the base member or the chassis engaging member may instead represent smaller segments that occupy only select sections of the gauge. In an alternative embodiment, separate base members support the columns at either end of the gauge. In yet another alternative embodiment, separate chassis engaging members support the ends of the vehicle chassis at either end of the gauge. The separate base members and chassis engaging members may be connected by support members or may stand freely. 
     Other the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of applicant to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants&#39; invention.