Patent Application
20060000266
The present invention generally relates to measuring instruments, and particularly to a measuring instrument suited to measuring at least two parameters indicative of the condition of a vehicle tire.
Inflated rubber (synthetic as well as natural) tires are commonly used as the interface between vehicles and road surfaces. Inflated rubber tires absorb some of the bumps encountered on the road, while additionally improving the traction between the vehicle and the road. Tires are often provided with a tread that functions to redirect water and other road debris to improve the traction between the tire and the road. To improve tire performance, tires should be properly inflated and should include sufficient tread to provide the desired traction.
Tire inflation and tread condition are especially important for motorcycles where only two tires contact the road. The recommended tire pressure for a motorcycle may vary greatly as a function of the load on the tires (e.g., one rider or two riders) or the riding conditions (e.g., dry pavement vs. wet pavement). As such, it is important to frequently check the tire pressure.
Furthermore, excessive tread wear may reduce the traction achieved when riding a motorcycle, especially during adverse weather conditions (e.g., rain, snow, sleet, and the like). Therefore, it is important that the rider also monitor the tread condition on tires.
The present invention generally provides a gauge that is capable of measuring two parameters that are indicative of tire condition. Generally, these parameters include the tire pressure and the tread depth. By combining a pressure gauge and a tread depth gauge into a single device, the space occupied by the measuring devices is reduced when compared to two separate gauges. In addition, the combination makes it more likely that a rider will measure both parameters simultaneously rather than just one of the two. This will give the rider a more complete picture of the condition of the tires. The tread depth gauge also indicates the relative condition of the tire using a color-coded tread depth scale. The color-coded scale makes interpretation of the results easy for the rider.
The detailed description particularly refers to the accompanying figures in which:
Before any embodiments of the invention are explained, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof is meant to encompass the items listed thereafter and equivalence thereof as well as additional items. The terms “connected,” “coupled,” and “mounted” and variations thereof are used broadly and encompass direct and indirect connections, couplings, and mountings.
As shown in
The pressure-responsive member 110 includes a hollow C-shaped tube 120 (often referred to as a Bourdon tube) having a first end in fluid communication with the flexible hose 105 and a second end that is sealed and is coupled to a linkage 125. The linkage 125 includes an arm member 130 that is pivotable about both of its ends and a gear member 135. A first end of the arm member 130 connects to the sealed end of the tube 120 and a second end of the arm member 130 connects to an extension that projects from the gear member 135. The gear member 135 engages a second gear 140 that is fixedly attached to the first needle 80 such that rotation of the second gear 140 produces a corresponding rotation of the first needle 80. A biasing member in the form of a torsional spring 145 biases the needle 80 toward its low-pressure position (illustrated in
While a dial-type pressure gauge and mechanism has been described, one of ordinary skill will realize that other types of pressure gauges (e.g., load cells, capacitive sensors, optical sensors, and the like) could be employed. In addition, other mechanisms or linkages could be employed to measure pressure. As such, the invention should not be limited to only the dial-type gauge and mechanism described.
The depth gauge 70, illustrated in
Referring to
Many different parameters can be measured to indicate the condition of the tire 40. These parameters include, but are not limited to, internal pressure, tread depth, tire thickness, tire resilience, side wall wear, and the like. As such, while the foregoing discussion describes the two gauges 65, 70 as a pressure gauge and a tread depth gauge respectively, other gauges that measure other parameters could be employed.
Turning to
The depth scale 95 interacts with the second needle 90 to indicate the depth of the tire tread being measured. The depth scale 95, as illustrated in
Many different tires 40 can be used on vehicles and motorcycles 10. For example, long life tires can be used on motorcycles 10 that are used for touring. Low-profile tires may be used on motorcycles 10 that are used less frequently. These two types of tires include very different treads. The long life tire, when new, includes a relatively thick or deep tread when compared to a new low-profile tire. As such, a tread depth measurement that indicates one-half of the tread on the long life tire has been worn, may be the same measurement result achieved when measuring the tread of a new low-profile tire. Thus, the actual quantity of tread wear is not indicative of tire life. Rather, the actual tread depth is indicative. No matter the tire employed, a tread depth of about 2/32 of an inch ( 1/16 ) or less indicates a worn tire. Of course some tire manufacturers may indicate that a tire is not worn until the tread depth is less than 2/32 of an inch, or that a tire is worn even when more than 2/32 of an inch of tread remains.
Because a tire with a tread depth of 2/32 of an inch or less is generally considered worn out, the second scale 95 includes a color coding scheme that further indicates the status of the tire's tread. The depths from 2/32 ( 1/16 ) of an inch to zero are located within a first zone 180. The first zone 180 is colored red to indicate to the rider that the tire tread is worn and that the tire 40 should be replaced. A second zone 185 extends from 2/32 of an inch to a predetermined value, such as 5/32 of an inch as illustrated in
To use the instrument 55 or 200, the user connects the fill valve fitting 50 to the fill valve 45 of the tire 40 being evaluated. A small quantity of the air within the tire 40 flows into the flexible tube 105 (rigid tube 205 in the construction of
The user then extends the probe 150 by pressing down on the pin 172. The probe 150 is then positioned within a tire tread and the housing 60 is moved into contact with the tire 40. The rack 155 moves in response to the probe's contact with the bottom of the tire tread until the housing 60 contacts the outermost surface of the tire 40. Thus, the probe 150 extends beyond the housing 60 an amount that is substantially equal to the depth of the tire tread. The movement of the rack 155 rotates the associated gears 160, 165 to rotate the second needle 90. The user can simply look at which color zone 180, 185, 190 the needle 90 is in to evaluate the tire's tread depth or can look at the actual measurement. Using the instrument 55, 205 as just described provides the user with accurate and useful data regarding the condition of the vehicle's tires 40.
Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.
