1. Field of the Invention
The present invention relates to a connecting structure for a striking plate of a golf club head. In particular, the present invention relates to a connecting structure for connecting a striking plate to a body of a golf club head for simplifying assembling and positioning for a subsequent welding procedure.
2. Description of Related Art
Taiwan Patent Publication No. 327606 discloses a method for connecting a golf club head body and a striking plate, both made of metal. The golf club head body includes a recess for engaging with the striking plate. The recess includes a shoulder on which a welding material is placed. The striking plate is inserted into the recess and presses against the shoulder to cause deformation of a protruded portion on an inner edge of the shoulder, thereby filling the welding material into a gap defined between the striking plate, the shoulder, and the protruded portion. The welding material is in the form of metal powder and has a melting point lower than that of the golf club head body and that of the striking plate. The combination of the golf club head body and the striking plate is placed into a vacuum furnace or an inert gas atmosphere in a high temperature furnace and then heated at a temperature higher than the melting point of the welding material and lower than the melting point of the golf club head body and lower than the melting point of the striking plate. The molten welding material fills the tiny gaps between the golf club head and the striking plate by capillary action. A solid golf club head without welding marks on appearance is obtained after cooling.
Nevertheless, the gap between the striking plate, the shoulder, and the protruded portion can receive a limited amount of welding material, with a portion of the welding material filling the tiny gaps between an inner perimeter delimiting the recess and an outer perimeter of the striking plate. Thus, the remaining welding material is insufficient to fill the gap between the striking plate, the shoulder, and the protruded portion. Cavities are formed accordingly. As a result, when the striking plate is subjected to a striking stress and thus elastically deforms, cracks are apt to be generated in the welding areas. Further, the gap between the outer perimeter of the striking plate and the inner perimeter delimiting the recess must be precisely controlled to assure the welding material for braze welding to fill the tiny gaps by capillary action. Hence, additional equipment is required for milling the golf club head body and the striking plate so as to precisely control the tolerance of the gap regardless of the process for manufacturing the golf club head body and the striking plate (such as precision casting). The overall time for manufacturing the golf club head and the manufacturing cost are both increased, which is detrimental to mass production.
Taiwan Patent Publication No. 469144, a patent of addition of Taiwan Publication No. 327606, proposes an ordinary welding (such as argon welding) along a seam between the striking plate and the golf club head body after braze welding. Finally, the outer surface of the golf club head is subjected to grinding and surface finishing to guarantee the bonding strength by external welding. Nevertheless, the tolerance between the golf club head body and the striking plate requires precise control. Further, the overall time for manufacturing the golf club head and the manufacturing cost are both increased, which is detrimental to mass production.