Illumination – Supported by vehicle structure – Automobile
Reexamination Certificate
2000-05-02
2002-11-26
O'Shea, Sandra (Department: 2875)
Illumination
Supported by vehicle structure
Automobile
C362S276000, C362S464000, C362S469000, C315S154000, C315S159000
Reexamination Certificate
active
06485169
ABSTRACT:
BACKGROUND
This invention relates to automatic lighting systems and more specifically to automatic lighting systems for wheels and tires.
The invention disclosed here, distinguishes over the above referenced application with six novel features. First, the disclosed circuit uses a switch that is activated by deformation of the elastic tire material itself. This is not found in the above application and is not shown by any other reference. The use of the deformation-activated switch (or deformation-sensing switch) causes the lighting system to operate due to a completely different set of physical stimuli. Prior art uses sensors to detect motion through acceleration of the wheel. The lighting system disclosed here detects the tire's interaction with the ground as it rolls, and is actually insensitive to acceleration in general. For proper operation, substantial contact is needed between the elastic tire and the deformation-sensing switch. In all prior art references this is immaterial for proper operation of the lighting system. Second, the use of a delay circuit to slow activation of the illumination system is no longer needed for this new design. This is because the photo-sensing circuit and the deformation-activated switch are placed in close proximity to one another so that the photocell is near the ground and clear of any shadows caused by the skate shoe or wheel housing when the switch activates the circuit to measure ambient light. Prior art either makes no attempt at addressing this problem or uses delay circuits and averaging circuits to try and determine the actual ambient light. The disclosed invention, because of this, is effective at measuring the actual ambient light level. Third, none of the cited references show an illuminated wheel where the activation of the circuit, and subsequent measuring of the ambient light conditions, only occurs over a small portion of the wheel's rotation. This allows the designer to choose the position of the photocell when detection of light will occur, which in turn allows for optimum operation. Fourth, since the activation of the switch is intermittent, activating once each cycle for a short portion of the wheels rotation, the physical relationship between the switch and photocell is critical. All other prior art use acceleration activated motion sensors which turn on, and remain on, when a wheel is in use. Thus, prior art cannot provide timing for the positioning of the photo sensor so that it properly samples the ambient light conditions. With the disclosed invention the placement of the photocell near the activation switch is very important for proper operation, prior art does not even address such a need. Fifth, the photo sensor does not need a circuit to average the ambient light detected by the photo sensor as in application Ser. No. 09/346,918. It is not needed since the disclosed deformation switch allows sampling to take place only when the photocell is near the ground and unobstructed by the skate shoe and housing. Thus, the “actual” ambient light level can be sampled and “stored” for the remainder of the wheel's revolution. Sixth, the disclosed invention allows precisely timed intermittent illumination of the circuit. The use of a switch that activates upon the deformation of the tire as it contacts the ground allows the activation of the illumination device during a specific portion of the wheel rotation. With this control the illumination device can be made to turn “ON” only during the portion of its rotation while it is clear of the skate wheel assembly (i.e. the wheel support channel on a roller blade skate), so that light output is used more efficiently. All prior art either activates continuously, or oscillates randomly with respect to the wheel's rotation.
DESCRIPTION OF PRIOR ART
The use of lights on rotating assemblies, such as, bicycle and roller skate wheel is well known. Most systems for illuminating wheels and toys involve a battery, a manual switch, and an illumination device connected in series. The only problem with these designs is that they must be turned on by the user and also turned off. Since the most likely user of such devices are children, it is unlikely that such a system will be used properly. Either the light is not turned on at dusk or when they are turned-on, the light is not turned-off, thus draining the battery, making it unworkable to permanently seal the circuit within the elastic material.
To get around these problem a number of inventions have been designed which use the rotating motion of the wheel or toy to generate electricity to power the lights. In this way there are no external switches to turn on and off and no batteries to change. An examples of such a generator powered wheel is shown in U.S. Pat. No. 5,718,499 to Caro for a “Roller Blade Wheel Lighting System”. However, these systems are complicated, heavy, expensive to build, and are prone to failure under the harsh environment kids place them in. They also create a constant drag on the wheels which is undesirable. These systems also require specially designed skate shoes and attachments which adds to cost. The invention disclosed here does not suffer from these problems and can be used with standard roller skates wheels, standard motor vehicle tires, etc. And because the electronic circuit can be completely sealed inside a polymer or urethane tire, with no moving parts, and no external switches, its reliability is far superior to any of the generator powered designs.
Another way inventors have tried to eliminate the use of external switches is to include an acceleration sensor (i.e. motion sensor, acceleration switch, accelerometer, etc.). By including such a circuit, battery power is conserved because the device only lights when moved at sufficiently high accelerations. The use of acceleration sensors are shown in U.S. Pat. No. 5,683,164 to Chien for an “Illuminated Wheel”, U.S. Pat. No. 5,580,092 to Hsu et al. for a “Roller Skate Wheel with Light Producing Means”, U.S. Pat. No. 5,536,074 to Hsu for a “Light-Generating Wheel for an In-line Skate”, U.S. Pat. No. 5,475,572 to Tseng for a “Light Emitting Roller for Roller Skates”, U.S. Pat. No. 5,294,188 to Vancil for an “Illuminated Roller Skate Wheel”, and U.S. Pat. No. 4,363,502 to Rakerman for an “Illuminative Skate Wheel”. More advanced designs include circuit delays such as that shown in U.S. Pat. No. 5,653,523 to Roberts for a “Miniature Centrifugal Lighting Assembly”. In this last design uses a delay circuit to keep the lights on for a short time after motion has stopped. This allow the lights to continue operating even if the user pauses for a moment to rest, but shuts off after a predetermined time period. These designs are all workable systems, but still waste a great deal of battery power during the daytime when the lights are not really needed.
U.S. patent No. 5,803,574 to Szaniszlo shows a safety light for bicycle wheels which uses an acceleration switch and photo sensor to control activation only when sufficiently dark out. The acceleration switch however is unstable and produces different outputs depending on the wheel's speed of rotation. Because of this instability, a delay circuit is needed to latch the acceleration switch's contact when it occurs. However, their is no specific point in the rotation that the acceleration switch is activated, thus, the activation point can not be controlled. The disclosed invention keep very precise control over when the circuit is activated and does not depend on the rotation speed of the wheel. Thus, timing can be precisely controlled to place the photocell far away from obstructions that might cause a false reading of ambient light levels (i.e. when a wheel is partially shrouded). This is something Szaniszlo's design can not do. The disclose invention provides this control by using a deformation-activated sensor which reacts to totally different physical stimuli than an acceleration switch. An acceleration switch requires rotation or vibration of the wheel for activation, while the deforma
Hobden David V.
O'Shea Sandra
LandOfFree
Deformation-activated safety light for elastic tires does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Deformation-activated safety light for elastic tires, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Deformation-activated safety light for elastic tires will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2924783