A test fixture for identifying the sweet spot of a bat suspends the bat in a vertical orientation via a fixed pivot point and limits rotational movement of the bat to a single plane. A pendulum with an impact mass is caused to contact the bat at various locations along the barrel of the bat at a fixed velocity. Rotational movement of the impact mass is limited to the single plane. Peak acceleration is measured proximate to the handle of the bat. The sweet spot is identified based on measured minimum peak acceleration. For example, if there is a single measured minimum peak acceleration then the corresponding contact location at the barrel is the sweet spot. If there are multiple measured minimum peak acceleration instances then a center or average contact location of those instances in identified as the sweet spot.

An impact indicator includes a housing configured to enable movement of a mass member from a first position to a second position in response to receipt by the housing of an acceleration event. The indicator also includes switch circuitry having a compressible switch element positionable between spaced apart contacts where the switch element is configured to be in spaced apart relationship to the mass member. A passive radio-frequency identification (RFID) module is coupled to the switch circuitry and, responsive to movement of the mass member from the first position to the second position, the mass member causes a positional change of the switch element relative to the first and second contacts, and the positional change causes a state change in the switch circuitry. The RFID module outputs a value based on the state of the switch circuitry when energized.

Impact or acceleration sensor, which contains a liquid droplet and is designed such that the position and/or distribution of the liquid indicates whether an impact or any other acceleration of a predetermined minimum magnitude has occurred, includes: first and second foils, a cavity disposed between the foil faces of the foils and at least one retaining structure disposed on the foil face of the first and/or second foil and functions to maintain the liquid in a predetermined first sub-volume of the cavity. The retaining structure is a region of the first and/or second foil formed as a local elevation, depression or irregularity of the foil face, which forms a passable barrier for the wetting and/or contacting of the first and/or second foil by the liquid and defines an area piece of the foil face of the first and/or second foil corresponding to the first sub-volume.

Impact or acceleration sensor, which contains a liquid droplet and is designed such that the position and/or distribution of the liquid indicates whether an impact or any other acceleration of a predetermined minimum magnitude has occurred, includes: first and second foils, a cavity disposed between the foil faces of the foils and at least one retaining structure disposed on the foil face of the first and/or second foil and functions to maintain the liquid in a predetermined first sub-volume of the cavity. The retaining structure is a region of the first and/or second foil formed as a local elevation, depression or irregularity of the foil face, which forms a passable barrier for the wetting and/or contacting of the first and/or second foil by the liquid and defines an area piece of the foil face of the first and/or second foil corresponding to the first sub-volume.

A test fixture for identifying the sweet spot of a bat suspends the bat in a vertical orientation via a fixed pivot point and limits rotational movement of the bat to a single plane. A pendulum with an impact mass is caused to contact the bat at various locations along the barrel of the bat at a fixed velocity. Rotational movement of the impact mass is limited to the single plane. Peak acceleration is measured proximate to the handle of the bat. The sweet spot is identified based on measured minimum peak acceleration. For example, if there is a single measured minimum peak acceleration then the corresponding contact location at the barrel is the sweet spot. If there are multiple measured minimum peak acceleration instances then a center or average contact location of those instances in identified as the sweet spot.

A test fixture for identifying the sweet spot of a bat suspends the bat in a vertical orientation via a fixed pivot point and limits rotational movement of the bat to a single plane. A pendulum with an impact mass is caused to contact the bat at various locations along the barrel of the bat at a fixed velocity. Rotational movement of the impact mass is limited to the single plane. Peak acceleration is measured proximate to the handle of the bat. The sweet spot is identified based on measured minimum peak acceleration. For example, if there is a single measured minimum peak acceleration then the corresponding contact location at the barrel is the sweet spot. If there are multiple measured minimum peak acceleration instances then a center or average contact location of those instances in identified as the sweet spot.

An impact detection system for a vehicle and an impact detection method therefore are provided. The impact detection system includes an impact value calculator that determines an impact value corresponding to a magnitude of an impact applied to a vehicle, an impact location estimator that estimates a location to which the impact is applied in the vehicle and generates an impact location signal including a parameter value corresponding to the estimated location, and an effective impact determining device that compares the impact value with an impact detection reference value for each location of the vehicle, corresponding to the parameter value.

A single axis accelerometer comprising a swing arm pivotally attached to a frame is held in apposition to a stop by a threshold force until an experienced acceleration force greater than the threshold force causes a distal segment of the swing arm to release from the stop and move toward a sensor that is activated by a sensor trigger on the distal segment of the swing arm.

A single axis accelerometer comprising a swing arm pivotally attached to a frame is held in apposition to a stop by a threshold force until an experienced acceleration force greater than the threshold force causes a distal segment of the swing arm to release from the stop and move toward a sensor that is activated by a sensor trigger on the distal segment of the swing arm.

An impact sensor has a hollow container with a spring extending therethrough. A liquid is present in the cavity. The spring biases opposing valve balls to a closed position, preventing dye that is located exterior of the cavity from entering the cavity. When a force applied to the sensor exceeds a first predetermined value, the spring is compressed or displaced, allowing at least one of the valve balls to move from the closed position to an open position, thereby allowing the dye at the moving valve ball to pass into the cavity, mixing with the liquid and providing a visual indication of the exceeded force upon the sensor.