Abstract: A device for measuring stiffness of the string bed of a racket, includes a main body adapted to sit on the string bed; a force measuring device mounted to the main body; a biasing arrangement connected to the force measuring device and adapted to be connected to the string bed for deflecting the string bed in relation to the force measuring device, and causing the force measuring device to output a signal corresponding to the deflection of the string bed; a stop connected to the main body in a manner such that the stop is not acted upon by the deflection of the string bed when deflected by the biasing arrangement and which limits the string bed to a predetermined amount of deflection by the biasing arrangement; a switch to provide an output when the string bed is deflected to at least a predetermined position; a display for displaying the stiffness of the string bed in accordance with the signal output from the force measuring device in response to a change in the output from the switch as the string bed move

Abstract: A system to analyze vibration data includes circuitry that receives the vibration data, which is generated by a sensor that senses vibration of an object. The circuitry also analyzes the vibration data based on stored predetermined vibration data, and determines a characteristic of the object based on the analysis.

Abstract: In some embodiments, devices for measuring strings of a racket include a housing and a button. The devices also include a setting device that determines the frame size of the racket in response to the button being depressed and a spring system that adjusts pre-tension of the strings in response to the button being depressed. The devices further include a calibrated leaf spring having strain gages and an adjustment screw which is affixed to the button and which makes the starting measuring pressure onto the calibrated leaf spring adjustable. The devices still further include a fixing part which becomes fixed to the housing when force is applied to the button that causes the spring system to reach a specified level of compression and a display that reflects pressure on the strings in response to pressure applied to the strain gages.

Abstract: An apparatus for measuring tension in guy wire systems wherein the lower end of the guy wire has a thimble adjoined by a connection pin to a yoke or clevis of a turnbuckle shackle bolt connected to an earth anchor. A block assembly is removably received beneath the clevis and a thimble-engaging jaw assembly is removably received on the guy wire above the clevis. The block assembly and jaw assembly are connected at one end by a threaded rod assembly that includes a strain sensor connected with an indicator device, and by a threaded rod at their opposed end. The jaw assembly is drawn downward by adjusting nuts on the threaded rods beneath the block assembly to engage the thimble and move it downward transferring the tension to the threaded rod and threaded rod assembly which is sensed by the strain sensor and indicated by the indicator device.