Patents Assigned to Maruman Golf Co., Ltd.
  • Patent number: 4991843
    Abstract: A head of a golf club comprising a metal core member and an outer member of a plastic or a fiber reinforced plastic material fitted over the metal core member. The metal core member includes a neck portion integrally extending from a core body portion thereof for connecting to the shaft. The plastic outer member includes at least a hitting portion and a neck portion partially covering the neck portion of the core member, whereby a free end of the neck portion of the metal core member is protruded therefrom. The outer member is formed by molding while the core member is inserted therein. A cylindrical socket can be fitted on the protruding free end portion of the neck portion of the metal core member.
    Type: Grant
    Filed: March 23, 1989
    Date of Patent: February 12, 1991
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masahiro Mori
  • Patent number: 4979745
    Abstract: In an apparatus used for practicing a golf swing, a transmitter-receiver is stationarily arranged on the ground, and a relay unit is provided on the golf club in or near to head. The transmitter-receiver has an infrared light emitter and a pair of receivers. The relay unit has a receiver for receiving the light from the emitter of the transmitter-receiver and a infrared ray emitter for emitting a ray toward the pair of receivers of the transmitter-receiver. An LSI is provided for processing the light received by the pair of receivers separately, for detecting a change in intensity at time elapses for calculating the direction of the swing, and the timing of a maximum intensity for obtaining the head speed.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: December 25, 1990
    Assignee: Maruman Golf Co. Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4913435
    Abstract: An iron club and a set of iron clubs are so arranged that the causes of slicing of a ball are eliminated as much as possible. A pair of boundary lines defining a scored zone provided on a head face appear, to a player, to extend in parallel with a straight line along which the club should be swung. The iron club and the set of iron clubs are also characterized by other features which prevent slicing of the ball.
    Type: Grant
    Filed: August 24, 1987
    Date of Patent: April 3, 1990
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4890840
    Abstract: A number one wood-type golf club head comprising a body made of wood. A sole plate is secured to the bottom surface of the wooden body, and at least one cavity is provided in the wooden body and having an opening at the bottom surface, to thereby allow the golf club head to be elongated; the body having a length between a front end and a rear end thereof, from the viewpoint of the swing of the golf club, of more than 83 millimeters. This provides for a greater moment of inertia to obtain a stable drive.
    Type: Grant
    Filed: February 23, 1988
    Date of Patent: January 2, 1990
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4871174
    Abstract: In a golf club for putting, the head of the club comprises a face plate having a hitting surface extending between opposite toe and heel sides of the head and a back surface extending substantially in parallel to the hitting surface. A pair of spaced rod-like bodies are fixed to the back surface of the face plate at the toe and heel sides of the head, respectively, and extend backward and in a direction perpendicular to the hitting surface of the face plate. A shaft-mounting body, for mounting the shaft thereon, is fixedly disposed between the rod-like bodies. A hosel member is attached to the top surface of said shaft-mounting body substantially at a center of the head, the hosel member extends upwardly from the shaft-mounting body to a position near a plane containing the face plate and is connected to the shaft at that position.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: October 3, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4854583
    Abstract: A construction of portion for connecting a golf club-head (11) and a golf club shaft, comprising a vertical first elongated hole (13) extended from the upper end of and toward a point midway in the neck member (12) of the golf club-head, and a vertical second elongated hole (14) having a smaller cross section and extended downward from the base of the first elongated hole (13) in the neck member (12) of the golf club-head (11). The hollow golf shaft fitted with a reinforcing pin (16) having upper and lower fitting portions (16c, 16c) is fitted into the first and second elongated holes (13, 14). This provides an improvement in the strength of the portion connecting the golf club-head (11) and the golf club shaft (15).
    Type: Grant
    Filed: January 13, 1989
    Date of Patent: August 8, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4838555
    Abstract: A head of a wood type golf club comprises a head body (11) formed integrally with a neck (12). The head body (11) has a club face (13) for hitting a golf ball, an upper surface (14) extending rearward in a convex curve from the upper edge of the club face (13), a sole surface (15) extending rearward on a substantially flat plane from the lower edge of the club face (13) and having a smaller area than the upper surface (14), and lateral surfaces (16) extending rearward between the upper and sole surfaces from the toe and heel edges of the club face (13). The lateral surfaces (16) are curved in substantially an S-shape from the peripheral edge of the upper surface (14) toward the peripheral edge of the sole surface (15), and the height from the sole surface (15) to the inflection point (S1) of the S-shaped profile line of the lateral surfaces (16) is increased from the toe and heel edges of the club face (13) toward the rear end of the head body (11).
    Type: Grant
    Filed: February 1, 1988
    Date of Patent: June 13, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4836550
    Abstract: A club head (10) for an iron-type golf club comprises a front wall section (11) having front side (11a) for hitting a ball (20). The front wall (11) is inclined backward from the bottom end thereof toward the top end thereof. A sole wall section (13) is connected at the front end thereof to the bottom end of the front wall section (11) and extends backward from the bottom end of the front wall section (11). A back wall section (14) is connected at the top end thereof to the back side of the front wall section (11) behind an impact point (P) at which the front wall section (11) is initially in contact with a ball (20) when the club head (11) is normally swung and at the bottom end thereof to the sole wall section (13). The back wall section (14) extends in perpendicular to the front wall section (11) between the front wall section (11) and the sole wall section ( 13).
    Type: Grant
    Filed: January 25, 1988
    Date of Patent: June 6, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4830377
    Abstract: A golf club comprises a strain gauge attached to a surface of a hollow shaft in the vicinity of a kick point for detecting a bending of the shaft and a sound indicator for generating a sound when a strain of the shaft, particularly at the kick point, exceeds a predetermined level, so that a golf player can easily confirm whether or not sufficient force is exerted on the shaft during the downswing motion.
    Type: Grant
    Filed: September 21, 1987
    Date of Patent: May 16, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4824110
    Abstract: A club head of a golf club comprises a head body having a face which is made of a material having high specific elasticity and a weight body made of another material having a specific gravity greater than that of the material of the head body and provided at and covering a substantial portion of a rear portion of the head body, the head body being provided therein with a cavity, the total weight of the weight body being heavier than that of the head body.
    Type: Grant
    Filed: February 27, 1987
    Date of Patent: April 25, 1989
    Assignee: Maruman Golf, Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4819939
    Abstract: A double-layered tubular grip (13) for a golf club shaft, comprises a tubular inner layer (14) made of a porous material secured to the outer surface of the butt end portion of the shaft (11). A tubular outer layer (15) made of a non-porous material having an elasticity greater than that of the inner layer (14) is formed separately from the inner layer (14). The outer layer (15) is pushed over the inner layer (14) and detachably fixed thereto after the inner layer (14) is secured to the outer surface of the golf club shaft (11).
    Type: Grant
    Filed: October 28, 1986
    Date of Patent: April 11, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4811950
    Abstract: A head of a golf club comprises a head body having a front surface forming a hitting surface of the head for hitting a ball and a cut-off portion other than the front surface. A fitting member for adjusting at least the weight or weight-distribution of the head is made of a material different from that of the head body and fixed to the cut-off portion of the head body so as to form a part of the outer surface of the head other than the hitting surface thereof. A cushion member made of a resilient material is disposed between the head body and the fitting member, to prevent damage to the head body and separation of the fitting member from the head body caused by an impact force produced when a golf ball is hit by the golf club head.
    Type: Grant
    Filed: July 27, 1987
    Date of Patent: March 14, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4811949
    Abstract: A construction of a club-head for a golf club comprising a club-head body (10) having a hollow inner shell (12) and an outer shell (13) which covers the inner shell. The inner shell includes two halves (14, 15) which are joined along peripheral openings thereof, in which one of the two halves is provided with at least one projecting portion (16) at the bottom thereof, and the projecting portion (16) is closely abutted against the inside bottom of the other of the two halves. This provides an improvement in the strength of the joined inner shell (12). A weight adjusting member (17) may be held within the projecting portion (16) by a closure plug (18).
    Type: Grant
    Filed: September 21, 1987
    Date of Patent: March 14, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4798384
    Abstract: A club-head (11) for an iron golf club in which the outer shell (13) and core body (14) of the club-head are formed of metals having a different specific weight from each other. The weight of the embedded core body is concentrated at the center of the hitting portion of the club head. This allows an improvement in the weight distribution and disposition of the center of gravity of the club-head (11), and since the outer shell (13) is made of a metal, prevents scratching and cracking of the surface of the outer shell (13).
    Type: Grant
    Filed: May 27, 1987
    Date of Patent: January 17, 1989
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4787638
    Abstract: A golf ball comprises a body having a spherical outer surface and a plurality of first dimples arranged substantially uniformly in the spherical outer surface thereof. The body also has a plurality of indentations which are smaller than the first dimples and arranged substantially uniformly in the spherical outer surface and the inside surface of the first dimples. The indentations may be formed by grit blasting.
    Type: Grant
    Filed: January 30, 1987
    Date of Patent: November 29, 1988
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4754971
    Abstract: A set of golf clubs, each having a striking surface with a different angle of loft and a coefficiency of friction. The coefficient of friction gradually increases in accordance with a gradual decrease of the angle of loft and a gradual increase of the club length. Therefore, the longer the club is, the smaller the angle of loft of the club and the larger the coefficient of friction becomes. It is easy to provide a back spin on a ball even with a longer club.
    Type: Grant
    Filed: July 21, 1986
    Date of Patent: July 5, 1988
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4754969
    Abstract: A set of golf clubs wherein each club head includes a closed hollow behind the striking face. The thickness of each striking face is gradually decreased as the length of each shaft is gradually increased.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: July 5, 1988
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4754970
    Abstract: A golf club set comprising a series of golf clubs, each having a hitting surface for hitting a two-piece type golf ball. The hitting surface of each club of the set having a loft angle increasing in angle relative to the loft angle of the immediately preceding club in the set. The hitting surface of the lowest loft angle club in the set having a loft angle larger than 40.degree.. The hitting surface of each of the golf clubs in the set having different coefficients of friction and the coefficient of friction increases with the increase in loft angle.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: July 5, 1988
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4754974
    Abstract: A head of a golf club comprises a head body having a face portion, for hitting a golf ball, and a back portion. A surface structure for producing a turbulent boundary layer in the air on the outer surface of the head body is provided on the outer surface substantially throughout a region from the periphery of the face portion of the head body to the back portion of the head body. The surface structure may include a plurality of fine grooves or a plurality of fine fibers erected on the outer surface of the head body.
    Type: Grant
    Filed: January 30, 1987
    Date of Patent: July 5, 1988
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi
  • Patent number: 4732389
    Abstract: A golf club head for a wood type club comprises a head body (11) having a face for hitting a golf ball, the face being inclined upward and backward. A face plate (12) is provided in the face of the head body (11), and a sole plate (13) is provided in the backside of the head body (11). A bar-shaped weight (18) is provided in the head body (11) and extends substantially perpendicular to the face from the backside of the face plate toward the backside of the head body (11) so that the longitudinal axis of the bar-shaped weight (18) passes through the central portion of the face of the head body (11). A back weight (19) is provided in the backside of the head body (11) so that the line connecting the center of gravity of the golf club head (11) and the sweet spot thereof coincides with the longitudinal axis of the bar-shaped weight (18).
    Type: Grant
    Filed: November 25, 1986
    Date of Patent: March 22, 1988
    Assignee: Maruman Golf Co., Ltd.
    Inventor: Masashi Kobayashi