US20100267502A1

US20100267502A1 - Sports Grip Sensor

Info

Publication number: US20100267502A1
Application number: US12/426,120
Authority: US
Inventors: Alexander Kaufman
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-04-17
Filing date: 2009-04-17
Publication date: 2010-10-21
Also published as: WO2010120976A1

Abstract

A sports training device including a pressure sensor mounted on the grip of a tennis racket or golf club is provided. The device includes a peizo-electric force sensor to monitor the grip pressure in a circular sensing area located under where palm meets the index finger. The peizo-electric sensor varies its resistance inversely with force applied is connected to an op-amp that uses a variable resistor to deliver an output voltage proportional to the force applied. This voltage triggers a vibrating motor to spin, thus alerting the user that he or she has squeezed too hard. This variable pressure sensor is connected to an alarm that will immediately notify the user when the grip is too tight. The exact amount of pressure for each player and the sports equipment used will vary widely, but can be adjusted to signal when the pressure is too great for the particular use.

Description

BACKGROUND OF THE INVENTION

The invention relates generally to a device for improving a player's sports grip, and more particularly to a device to alert a player at a correct grip tightness.
There are various tennis training devices currently on the market, including one to help give a player the correct wrist motion during a swing. However, this device does not address correct grip tightness.
Notwithstanding the availability of such a training device, there exists the need to provide a device that will signal a player to hold a sports grip with the correct amount of pressure, thereby improving his or her swing.

SUMMARY OF THE INVENTION

Generally speaking, in accordance with the invention, a sports training device including a pressure sensor mounted in the grip of a tennis racket, or golf club is provided. The device is adjustable so that the player can fine-tune the sensor to alert at the correct grip tightness. This variable pressure sensor is connected to an alarm that will immediately notify the user when the grip is too tight. The exact amount of pressure for each player and the sports equipment used will vary widely, but can be adjusted to signal when the pressure is too great for the particular use. The device is suitable for grips of a tennis racket or golf clubs.
The sports grip alerts the player when squeezed too tightly by vibrating or issuing an alarm when the sensor is tripped. A peizo-electric force sensor monitors the grip pressure in a circular sensing area located under where palm meets the index finger. This location provides reliable pressure during a swing, but more sensors may be placed around the entire handle for different sports and to improve the precision of the sensor. The peizo-electric sensor varies its resistance inversely with force applied. It is connected to an op-amp that uses a variable resistor to deliver an output voltage proportional to the force applied. This voltage triggers a vibrating motor to spin, thus alerting the user that he or she has squeezed too hard.
Accordingly, it is an object of the invention to provide a device to monitors a player's grip during swings.
It is another object of the invention to provide a device to alert a player when he or she grips too tightly during a swing.
It is a further object of the invention to provide a training device that is adjustable and suitable for a variety of players and sports.
It is yet another object of the invention to provide a training device having a pressure sensor mounted on the racket handle that is adjustable so that the player can fine-tune the racket to alert at the correct grip tightness.
It is yet further object of the invention to provide a training device to improve grip tightness that is compact and easy to use.
The invention accordingly comprises a product possessing the features, properties, and the relation of components which will be exemplified in the product hereinafter described, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing(s), in which:

FIG. 1 is a perspective view of a tennis racket including a grip sensor constructed and arranged in accordance with to the invention;

FIG. 2 is a schematic view showing the elements of the grip sensor in the tennis racket of FIG. 1;

FIG. 3 is a schematic of a simple circuit showing the electrical connections for the grip of FIG. 2;

FIG. 4 is a suitable force to voltage circuit driven by a −5V DC excitation voltage for use with the grip sensors; and;

FIG. 5 are a Resistance Curve and a Conductance Curve for the circuit of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of a tennis racket 11 having a handle 12 with a grip 13 and racket head 14. Handle 12 includes a grip sensor 16. The details of grip 16 are shown in FIG. 2. Grip sensor 16 includes a pattern of piezo electric force sensors 17, 18, 19 and 21 placed within in grip 1B with and electrical circuit 22. Handle 12 also includes a sensitivity adjustment knob 23 operatively connected to electrical circuit 22.
Grip sensor 16 alerts a player when grip 13 is squeezed too tightly by vibrating when one of the sensors is tripped. Each sensor is a peizo-electric force sensor that monitors the pressure on grip 13. This small circular sensing area is located under where palm generally meets the index finger. This location provides reliable pressure during a tennis or golf swing, but more sensors around the entire handle could be added to improve the precision of the sensor.
Typical sensors are ultra-thin and flexible printed circuits. These paper-thin force sensors can measure force between almost any two surfaces and are durable enough to stand up to sports environments due to their construction, flexibility and force measurement ability. Such sensors are available to measure forces in the range of from zero to 100 pounds.
The sensors are constructed of two layers of substrate of a polymer film, such as a polyester film. A conductive material, such as silver is deposited in the form of a circle or other suitable pattern, followed by a layer of a pressure sensitive ink. A suitable adhesive is then used to laminate the two layers of substrate and electrode together to form an individual sensor. The silver circle or pattern on top of the pressure-sensitive ink defines the active sensing area of the sensor. Silver or other conductive material extends from the sensing area to the connectors at one end of the sensor, thereby forming the conductive leads.

EXAMPLE 1

Each peizo-electric sensor varies its resistance inversely with force applied and is connected to an op-amp that uses a variable resistor to deliver an output voltage proportional to the force applied. This voltage triggers a vibrating motor 24 to spin, thus alerting the user that he or she has squeezed too hard. The system is powered by battery. In an exemplary embodiment, 5 n-type batteries 26 provide a voltage into sensor 17 of −3 V and a voltage of 4.5 V into an inverting operational amplifier 27 to produce an analog output based on the sensor resistance with additional sensors 18, 19, and 21 connected to op- amps 28, 29 and 31 for controlling vibrator 24 as shown in the schematic illustration of FIG. 3 how sensors 17, 18, 19 and 21 are connected to power source 26 and vibrator 24.
One such commercially available sensor is a FlexiForce brand sensor from TekScan, Inc. of South Boston, Mass. The Tekscan sensors operate in the circuit of FIG. 4 and have the Resistance vs. Force curve and Conductance vs. Force curve shown in FIG. 5. In FIG. 4, the following applies: V_OUT=−V*(R_F/R_S).
Grip sensor 17 has a 1 mega-ohm variable resistor 32 coupled to adjustment knob 23 used to control the sensitivity of the sensors. A 20 mA relay is connected to the output voltage of the op amp to power the vibrator. Details of the sensor circuit are set forth in U.S. Pat. No. 6,222,936, the contents of which is encompassed here as by reference.
This disclosure provides a product that monitors a player's grip during swings and alerts the player when he or she grips too tightly. Correct grip pressure is essential to a good swing and it is not easy to diagnose a grip that is too tight.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above product without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawing(s) shall be interpreted as illustrative and not in a limiting sense.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes of the invention.

Claims

1. (canceled)

2. (canceled)

3. The sports grip of claim 8, wherein the handle is a tennis racquet handle.

4. The sports grip of claim 8, wherein the handle is a golf club shaft.

5. (canceled)

6. (canceled)

7. (canceled)

8. A sports grip, comprising:

a grip handle with a grip covering;

at least one piezo-electric sensor and sensor circuit including an operational amplifier having a variable resistor with the resistance of the resistor varying inversely with force applied to the grip to deliver an output voltage proportional to the force applied to the sensor mounted to the handle below the grip covering;

a vibrator located in the grip handle and operatively connected to the output of the sensor circuit;

an adjustment control on the handle to control the force necessary to allow the circuit to operate the vibrator; and

the piezo-electric sensor for varying the force necessary to operate the vibrator thereby increasing the vibration to alert a user when he or she has squeezed too hard by applying too much force to the grip.

9. The sports grip of claim 8, wherein the sensor includes two layers of a substrate of a polymer film and a conductive material deposited in the form of a suitable pattern on the polymer film with a layer of a pressure sensitive ink on the pattern and the two layers laminated with an adhesive to form the individual sensor, whereby the pattern on top of the pressure-sensitive ink defines the active sensing area of the sensor.

10. The sports grip of claim 9, wherein the polymer film is a polyester film.

11. The sports grip of claim 9, wherein the conductive material is silver.