This invention relates to golf clubs generally and to putters in particular, with a novel device for indicating the slope and pitch of a putting green.
It is difficult, when on a putting green, to accurately determine the slope and pitch simply by visual examination. For that reason devices have been invented for incorporation into putters for giving some indication of the slope and pitch of the green to aid in determining with accuracy just what direction a putt must be stroked. One such device is disclosed in the U.S. Pat. No. of Darrel et al., 2,919,491, issued on Jan. 5, 1960. In the Darrel device a levelling vial is fitted into the shaft of the putter between the grip and the putter head. The levelling vial is installed by cutting a slot in the shaft and inserting the vial directly into the cut slot and then setting and gluing the vial in a level position.
While this method of installation is not entirely unsatisfactory, it suffers from some disadvantages. One of the disadvantages is getting the levelling vial properly installed and adjusted to compensate for the offset between the grip of the putter shaft and the putter head. Another problem is the lack of protection of the levelling vial from the flexing of the shaft as well as damage from being struck. Incidental to these problems is the problem of the weakening of the shaft by cutting a large enough slot into the shaft to accommodate the levelling vial. The purpose of the present invention is to eliminate all the disadvantages and to protect the vial from damage, to improve the appearance of the product and to get positive settings under a mass production condition.