Swing training device for golf club

1. A swing training device, which is mounted on a golf club with a shaft connected to a neck of a head, comprising

an axial hole and a gap communicated with the axial hole, such that the swing training device has a substantially C-shaped aspect in a cross section,

wherein an orientation of the axial hole is tilted relative to that of the gap,

wherein a diameter of the axial hole is greater than or equal to a diameter of the neck of the head of the golf club,

a width of the gap is greater than a diameter of the shaft of the club at a portion adjacent to the head, and

the diameter of the neck is greater than the width of the gap.

2. The swing training device as defined in claim 1 , wherein the device is made of metal.

3. The swing training device as defined in claim 1 , further comprising an elastic member provided on a sidewall of the axial hole.

4. The swing training device as defined in claim 3 , wherein the device is provided with a slot on the sidewall, and the elastic member is fixed in the slot with a distal end thereof extruded out of the slot.

5. The swing training device as defined in claim 1 , wherein the device has a housing made of a flexible material with the axial hole and the gap, in which at least a weight member is received.

6. The swing training device as defined in claim 5 , wherein the weight member is a metallic block embedded in the housing.

7. The swing training device as defined in claim 1 , wherein the weight member is metallic grains or pellets filled in the housing.

8. The swing training device as defined in claim 1 , further comprising a light emitting member projecting light to who hold the golf club.

9. The swing training device as defined in claim 8 , wherein the light emitting device has a light emitting diode and at least a battery.

10. The swing training device as defined in claim 9 , wherein the light emitting device further has a switch to turn on or turn off the light emitting diode.