Abstract:
A golf putter in which both the tactile response and ball launching characteristics may be independently varied over relatively wide respective ranges includes a head in the face of which is formed a stepped cross-section cutout portion which receives a stepped cross-section insert. The putter head includes an outer insert lamination which fits into a complementarity-shaped front recessed portion of the cutout, the outer lamination having an outer generally flat face flush with the front face of the head. Inwards of the recessed portion of the cutout in the front face of the putter head is a pocket adapted to receive and enclose from exterior exposure an inner insert lamination. The outer insert lamination has an outer surface which affords a desired tactile response to a golfer upon impacting a golf ball, while the inner insert lamination has a weight, weight distribution, and resilience which may be varied independently from the properties of the front lamination to achieve desired ball impacting characteristics.

Description:
BACKGROUND OF THE INVENTION 
     A. Field of the Invention 
     The present invention relates to golf clubs. More particularly, the invention relates to an improved golf putter having a laminated face insert in which only a single lamination thereof is exposed. 
     B. Description of Background Art 
     In recognition of problems encountered with controlling the direction and speed of golf balls putted toward the hole on a golf course green, the present inventor disclosed a novel golf putter design for improving putting skills in U.S. Pat. No. 5,458,332, Golf Putter Head With A Cushioning Face, issued Oct. 17, 1995. That patent disclosed golf putters in which the heads of the putters were provided with a face insert comprising a polymer pad having a rebound factor directly related to the distance to an intended target, i.e., the hole. For short putts and/or fast greens, a low rebound factor of say 12.5% was disclosed as being desirable for putts of about 10 feet, 25% for 15-20 foot putts, 33.5% for putts of about 30 feet, and 50% for putts of 40 feet or greater. According to the invention, the precise value of selected rebound factor would of course be a matter of personal choice, as long as putters having higher rebound factors are selected for longer putts and/or slow greens. 
     In U.S. Pat. No. 5,674,132, issued Oct. 7, 1997, the present inventor disclosed further improvements in golf clubs, in which the rebound factor and hardness of woods and irons as well as putters could be independently varied over a wider range to achieve selected ball propulsion distances and feel. 
     In co-pending U.S. patent application Ser. No. 08/944,080, filed Oct. 4, 1997, the present inventor disclosed a Golf Putter Head With Interchangeable Rebound Control Insert. In that patent application, putters were disclosed in which the heads were provided with interchangeable rebound control inserts, each consisting of a front rebound control pad made of a resilient material, and a rear fastener plate. A recess having a uniform height and extending inward from the front face of the putter receives the insert. The insert is secured to the body of the head by screws which are inserted through holes which extend through the body and the bottom wall of the recess, the screws threadably engaging blind threaded holes in the rear surface of the insert. 
     The present invention was conceived of to provide an improved golf putter provided with a laminated face insert in which only an outer, ball-contacting lamination thereof is exposed, thereby allowing an inner portion of the insert to have a thickness, shape, and material properties which may all differ from those of the outer lamination. 
     OBJECTS OF THE INVENTION 
     The object of the present invention is to provide a golf putter having a head which includes a face insert, in which only the face, upper and lower sides of an outer portion of the insert are exposed. 
     Another object of the invention is to provide a golf putter head which includes an insert having an outer portion which is exposed and an inner portion which is enclosed within a pocket in the head. 
     Another object of the invention is to provide a golf putter head which includes a laminated face insert in which only the outer lamination of the insert is exposed. 
     Another object of the invention is to provide a golf putter head including a body having in the front face thereof a front recess which holds the front lamination of a laminated insert, and a pocket rearward of the recess which encloses and secures the rear potion of the laminated insert, the material properties of the front lamination and rear portion of the insert providing in combination with the body desired composite hardness and weight characteristics. 
     Another object of the invention is to provide a golf putter head having in the front face thereof a recess which receives a selected one of a plurality of laminated inserts secured to the head by fastening means, each insert having an exposed outer lamination of a fixed thickness and backed by one or more inner laminations enclosed with a pocket inward the recess. 
     Another object of the invention is to provide a golf putter head including a body having in the front face thereof an interchangeable laminated impact control insert in which only the front lamination thereof is exposed, thereby providing a single interfacial joint between the insert and the upper and lower surfaces of the putter head. 
     Various other objects and advantages of the present invention, and its most novel features, will become apparent to those skilled in the art by perusing the accompanying specification, drawings and claims. 
     It is to be understood that although the invention disclosed herein is fully capable of achieving the objects and providing the advantages described, the characteristics of the invention described herein are merely illustrative of the preferred embodiments. Accordingly, I do not intend that the scope of my exclusive rights and privileges in the invention be limited to details of the embodiments described. I do intend that equivalents, adaptations and modifications of the invention reasonably inferable from the description contained herein be included within the scope of the invention as defined by the appended claims. 
     SUMMARY OF THE INVENTION 
     Briefly stated, the present invention comprehends an improved golf putter in which the head of the putter is of a novel construction and receives a ball-impacting insert of improved design. 
     According to the present invention, a putter head is provided in which the front face thereof has a cutout portion that includes a recess having a uniform transverse cross section, the recess extending perpendicularly rearwardly or inwardly from the front ball-impacting face of the head. The recess is located at the intended ball-impacting region of the club head face, and is adapted to conformally receive the front or outer portion of an insert having the same outline shape as that of the recess. Rearward of the recess is located a shallow, trough-shaped pocket having a pair of laterally opposed side walls coextensive with the side walls of the recess. The pocket is of the same width as the recess, having laterally opposed side walls which are coplanar, inward extensions of the recess side walls. However, the height of the pocket is less than that of club head face and recess. Thus, a pair of horizontally disposed, rectangular cross section upper and lower ribs running between the lateral side walls of the recess comprise the upper and lower side walls of the pocket. The upper and lower surfaces of the upper and lower ribs, respectively, are co-extensive with the respective upper and lower surfaces of the club head. Thus constructed, the cutout portion of the front face of the putter head is adapted to receive an insert having a front portion or lamination of a fixed thickness which fits conformally within the recess portion of the cutout, with the lower or inner surface of the front lamination of the insert resting on the ribs, and the front surface of the lamination flush with the uncut portion of the club head face adjacent the recess. The insert has a rear portion consisting of an inner lamination or backing plate of smaller vertical extent than the front lamination of the insert, the rear portion being received in the pocket rearward of the recess. The insert is secured to the putter head by fastening means attached to the backing plate. In a preferred embodiment, the backing plate is releasably fastened to the putter head by a pair of screws which protrude forward through holes extending forward from the rear wall of the head through the bottom wall of the pocket, the screws being tightened into a pair of laterally opposed threaded holes provided in the rear surface of the backing plate. 
     The combination of the novel insert with the complementarily-shaped cutout in the putter head face provides an insert putter head construction in which only the front portion of an insert is exposed, allowing the rear portion or backing plate of the insert structure to be made of different materials and shapes, without altering the appearance of the putter. Moreover, containing the interface plane between the front lamination and backing plate within the pocket, rather than exposing the interface, minimizes the likelihood of delaminating the insert by accidental impact, and affords an aerodynamically smooth construction. 
     The front or outer lamination of the insert structure according to the present invention is made of a first material which provides desired ball-impacting properties. Thus, the outer lamination is preferably made of a material of a hardness that provides a desired feel when a golf ball is impacted by the club. According to the present invention, the rear portion or backing plate of the insert structure may have a shape and material composition different than that of the front lamination, to provide a desired weight distribution which depends mainly upon the characteristics of the rear portion of the insert rather than the front lamination. Thus, the insert structure preferably has a rear lamination or backing plate which fits into the pocket rearward of the recess, and which is made of a material which may be lighter or heavier than the front lamination of the insert structure Although the backing plate is preferably made of a material such as a metal which is harder and more rigid than the front lamination, it may also be made of other materials to provide a different head weight distribution, weight, or tactile response. Also, the rear portion or backing plate of the insert structure may have a non-homogeneous structure, as long as it fits in the pocket. Thus, the rear backing portion, backing plate or lamination of the insert may have center or outer portions of different densities or weights than other portions of the rear lamination. Moreover, the rear backing plate may have a heterogeneous structure, consisting of laminations made of different materials and/or shapes, to achieve a desired weight distribution and other ballimpacting characteristics. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an upper perspective view of a golf club putter head having a laminated face insert with single exposed lamination according to the present invention. 
     FIG. 2 is an exploded front perspective view of the putter head of FIG.  1 . 
     FIG. 3 is a right side elevation view of the putter head of FIG.  1 . 
     FIG. 4 is a fragmentary front plan view of the club head of FIG. 2, showing the insert thereof removed. 
     FIG. 5 is a transverse sectional view of the head of FIG. 4, taken along line  5 — 5 . 
     FIG. 6 is a rear elevation view of the putter head of FIG.  1 . 
     FIG. 7 is a bottom plan view of the putter head of FIG.  1 . 
     FIG. 8 is a rear elevation view of a laminated face insert comprising part of the golf club putter head of FIG.  1 . 
     FIG. 9 is a side elevation view of the insert of FIG.  8 . 
     FIG. 10 is a rear elevation view of a first modification of the insert of FIG.  8 . 
     FIG. 11 is an upper elevation view of the modified insert of FIG.  10 . 
     FIG. 12 is a rear elevation view of a second modification of the insert of FIG.  8 . 
     FIG. 13 is an upper elevation view of the modified insert of FIG.  12 . 
     FIG. 14 is a transverse sectional view of a modification of the putter head of FIG. 5, in which the weight of the head is concentrated near the lower portion thereof. 
     FIG. 15 is a transverse sectional view of another modification of the putter head of FIG. 5, in which the weight of the head is concentrated near the upper portion thereof. 
     FIG. 16 is a front elevation view of additional modifications of the putter head of FIG. 1, in which the shape and location of the insert and recess thereof are varied. 
     FIG. 17 is a transverse sectional view of the modified putter heads of FIG.  16 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-12 illustrate golf club putter heads having a laminated face insert with single exposed lamination according to the present invention. 
     Referring now to FIG. 1, a golf club putter head  20  according to the present invention is shown. Putter head  20  may be attached to shaft A, shown fragmentarily in FIG. 1, by conventional means to comprise a complete golf putter. 
     As shown in FIG. 1, golf club putter head  20  according to the present invention includes a horizontally elongated body  21  having a generally flat, generally vertically disposed front face  22  adapted to impact a golf ball. Putter head body  21  has an elongated, generally cylindrically-shaped shank or hosel  23  that protrudes upward  14  from the upper wall  24  of the body. As shown in FIG. 1, shank  23  joins upper wall  24  of body  21  at a location offset laterally outwards from the center of front head face  22 , near the angled right-hand side wall  25  of the body. As is also shown in FIG. 1, in front elevation view, shank  23  has a lower portion  23 A that protrudes generally vertically upward  14  from upper wall  24  of body  21 , and intermediate and upper portions  23 B and  23 C, respectively, that angle laterally away from a vertical center line through the body. 
     As may be seen best by referring to FIG. 3, in side elevation view, lower portion  23 A of shank  23  angles sinuously forward of front face  22  of putter head body  21 , while intermediate portion  23 B of the shank bends rearward to join upper portion  23 C, the latter two portions lying in a laterally disposed vertical plane. 
     As shown in FIGS. 1 and 3, upper portion  23 C of shank  23  has a circular cross section which is adapted to be invertably received within the bore of tubular putter shaft A. Preferably, upper cylindrical portions  23 C of shank  23  is of smaller diameter than the adjacent part of intermediate portion  23 B of the shank, and is joined thereto by an annular shoulder  23 D. Shoulder  23 D provides a seating surface for the lower annular wall surface B of putter shaft A. 
     As may be seen best by referring to FIG. 1, body  21  of putter head  20  has a flattened, convexly curved lower wall surface  27 . As shown in FIG. 1, putter head body  21  has an upper laterally disposed rectangular transverse cross section rib portion  28  that protrudes downwards from upper wall surface  24  of the body. Also, the rear portion of body  21  includes a trapezoidal transverse cross section portion  29  having an angled wall surface  30  that intersects rear wall  28 B of rib portion  28  below upper surface  24 , the angled wall sloping downwards and rearwards to intersect back vertical wall surface  31  of the body. As may be seen best by referring to FIGS. 1 and 6, a laterally, medial portion of trapezoidal portion  29  of putter head body  21  is cut downwards from angled wall  30  to form a notch  32 . The lower wall surface  33  of notch  32 , which forms with lower wall surface  27  of body  21  a thick web, preferably has marked thereon a longitudinally disposed indicator or index line  34 . Index line  34  is parallel to and midway between right and left side walls  25  and  26  of body  21 . Thus, index line  34  signifies to a golfer the ideal spatial orientation of the putter head velocity vector with respect to a golf ball impacted by the head. 
     Referring now primarily to FIGS. 1 and 2, but also to FIGS. 3-9, the novel construction and function of putter head  20 , which incorporates a laminated face insert having a single exposed lamination, will now be described in detail. 
     As shown in FIGS. 1 and 2, front face  22  of putter head body  21  has formed therein a notched or cutout portion that includes recess  35  which extends perpendicularly inwards or rearwards into the body. Recess  35  has a uniform transverse cross section, shaped like a wedge or trapezoid. Thus, recess  35  has angled straight right and left side walls  36  and  37  which penetrate lower wall surface  27  of club head body  21 , forming a thin, laterally elongated rectangularly-shaped opening  44  in the lower wall surface. Side walls  36  and  37  of recess  35  angle inwards towards a vertical center line of the recess, and extend upwardly towards upper wall surface  24  of body  21 . Side walls  36  and  37  penetrate upper wall surface  24 , forming therein a thin, laterally elongated rectangularly-shaped opening  45 . As shown in FIGS. 1 and 2, right and left side walls  36  and  37  of recess  35 , in combination with those portions of upper wall  24  and convexly curved lower wall  27  that are pierced by the recess, form a generally trapezoidal shape, modified by a convexly curved base. As may be seen best by referring to FIGS. 1 and 4, side walls  36  and  37  of trapezoidally-shaped recess  35  are spaced equidistant from a vertical longitudinally disposed center plane passing through index line  34  in rear notch  32  of body  21 . Recess  35  is adapted to receive and hold the front lamination  39  of an insert  38 , as will be described below. 
     Referring now to FIGS. 2-5, it may be seen that putter body  21  includes a shallow trough-shaped pocket  60  which is located inwardly or rearward of recess  35 . Pocket  60  has a pair of laterally opposed right and left side walls  36 A,  37 A which are coextensive with the inner ends of recess side walls  36  and  37 . Therefore, the lateral extent or width of pocket  60  is the same as that of recess  35 . However, the height of pocket  60  is less than that of recess  35 , as will now be explained. 
     As may be seen best by referring to FIGS. 4 and 5, a pair of laterally disposed upper and lower ribs  61  and  62 , respectively, limit the vertical span of pocket  60  so that the pocket does not penetrate either upper side wall  24  or lower side wall  27  of putter head body  21 . Ribs  61  and  62  are generally straight and of rectangular cross section, and are disposed between side walls  36  and  37  of recess  35 . As shown in FIGS. 4 and 5, the upper surface of upper rib  61  is coextensive with upper wall surface  24  of putter head body  21 , and the lower surface of lower rib  62  is coextensive with lower wall surface  27  of the putter head body. Ribs  61  and  62  have coplanar outer surfaces  63  and  64 , respectively, which lie in a vertical plane parallel to in and inward of front face  22  of putter head body  21 . As shown in the figures, pocket  60  preferably has a generally flat inner wall surface  65  which is also parallel to front face  22  of putter head body  21 . However, inner wall surface  65  could be contoured to conformally receive contoured parts of a rear portion of insert  38 , if desired. 
     Referring now to FIGS. 2,  8  and  9 , it may be seen that the cutout portion of putter head body is constructed to conformally receive a face insert  38  having a flat front portion  39  and rear portion  50  of smaller vertical extent. As shown in the figures, front portion  39  of insert  38  has a plan view shape complementary to that of recess  35 . Thus, front portion  39  of insert  38  has a horizontally disposed, slightly convexly curved lower base wall  40  and straight right and left side walls  41  and  42  which angle inwardly and extend upwards to a straight, horizontally disposed upper edge wall  43 . 
     Referring still to FIGS. 2,  8  and  9 , it may be seen that insert  38  includes a rear portion  50  which has a smaller vertical extent than that of front portion  39  of the insert, thus allowing the rear portion to be received in pocket  60 . As shown in FIGS. 1 and 5, this construction allows insert  38  to be installed in putter head body  21  with front portion  39  of the insert fitting conformally within recess  35 , with rear surface  46  of the front insert portion seated on outer surfaces  63  and  64  of upper and lower ribs  61  and  62 , respectively, and with rear portion  50  of the insert fitting within pocket  60 . This novel design permits front end rear portions  39  and  50  of insert  38  to be made of different materials, and have different shapes, while exposing only surfaces of outer portion  39  of the insert. Thus, front portion  39  of insert  38  may have material properties chosen to produce a desired tactile response upon impacting the golf ball, while rear portion  50  may have a shape and composition different from those of the front portion, to permit independent variability of other characteristics affecting the trajectory of an impacted golf ball, such as weight distribution and/or rebound factor of the putter. 
     In preferred embodiments of golf putter heads according to the present invention, insert  38  has a laminated construction, in which front portion  39  of the insert is fabricated as a thin pad or lamination of the proper size and thickness to fit conformally within recess  35 , while rear portion  50  of the insert consists of lamination which has different material properties than the front lamination, the rear lamination incorporating means for fastening the insert to putter head body  21 . Thus, as shown in FIGS. 2,  8  and  9 , insert  38  preferably has a trapezoidally-shaped front lamination or face pad  39  of generally uniform thickness adapted to fit conformally within putter head face recess  35 . Front lamination  39  of insert  38  has a horizontally disposed, slightly convexly curved base wall  40 , and straight right and left side walls  41  and  42  which angle inwardly and extend upwardly to a straight, horizontally disposed upper edge wall  43 . Front lamination  39  of insert  38  is fabricated from a material which provides a desired tactile response feedback to the golfer upon impacting a golf ball. To achieve this response, the material from which front lamination  39  is fabricated may be selected from a wide variety of materials to suit the wishes of a particular golfer. Such materials include metals, woods, and other natural and synthetic materials including polymers such as polyurethane, balata and epoxy, as well as composites of the aforementioned materials, to yield desired ball traction, feel, and launching properties. 
     As shown in FIGS. 2,  8  and  9 , insert  38  also includes a rear lamination  50  of uniform thickness which is shaped like a trapezoid of less height than that of front lamination  39 , thus adapting the rear lamination to fit conformally within pocket  60  located inwardly or rearwardly of the outer faces of ribs  61  and  62  which form the inner or rear seating plane of recess  35  for front lamination  39 . Rear insert lamination  50  has a thickness no greater than the depth of pocket  60 , so that it may fit all the way rearward into the pocket. As shown in FIGS. 2,  8  and  9 , rear lamination  50  has formed through its thickness dimension a pair of laterally spaced apart, threaded screw holes  52 A for fastening the rear lamination to putter head body  21 , in a manner which will be described below. 
     Rear lamination  50  is preferably made of a rigid material, including metals, such as steel, zinc or brass. In a preferred embodiment of insert  38 , front lamination  39  of insert  38  is secured to rear lamination  50  by an adhesive layer  47  between inner, or rear flat wall surface  46  of the front lamination and front wall surface  48  of the rear lamination. In example embodiments of insert  38 , adhesive layer  47  consisted of a double-sided adhesive tape strip, coated on both sides with a pressure sensitive adhesive. In this embodiment, adhesive layer strip  47  is sandwiched between front lamination  39  and rear lamination  50 , and the sandwich squeezed to adhere the front and rear laminations together. 
     As may be seen best by referring to FIGS. 1,  2  and  6 , insert  38  is releasably secured to putter head body  21  by a pair of headed screws  52  inserted through a pair of longitudinally disposed, laterally spaced apart holes  53  which extend through rib section  28  of putter head body  21 . Screws  52  are threadingly secured by and tightened into threaded backing plate holes  52 A, thereby securing insert  38  in recess  35  of putter head  20 . With this construction, putter head  20  may be constructed to receive an interchangeable insert  38  having particular rebound, hardness, weight distribution and tactile response characteristics, and may be replaced by another insert having different desired characteristics by simply loosening screws  52 , removing the insert, and replacing it with a different insert. 
     In example embodiments of insert  38 , front lamination  39  had a thickness of about one-eighth (⅛) inch, while rear lamination  50  had a thickness of about three thirty-seconds ({fraction (3/32)}) inch. Front lamination  39  of insert  38  is preferably constructed of a material that has a hardness less than that of the remainder of club head body  21 , which is typically made of cast metal or hard, dense wood. Since the size, shape, material composition, and weight distribution of rear lamination  50  may be significantly different than the corresponding characteristics of front lamination  39 , the feel and ball handling characteristics of putter  20  may be varied over a much larger range than achievable with prior art putters provided with multi-lamination inserts. Moreover, this large range of variability is achieved without exposing the interface between the front face insert lamination with the rear lamination. From an aesthetic standpoint, this novel construction results in a pleasing appearance, with a single face insert lamination exposed to view. Moreover, the absence of any exposed joints between laminations of insert  38  according to the present invention minimizes the likelihood of accidently nicking or partially de-laminating the insert. 
     FIGS. 10 and 11 illustrate a first modification of insert  38 . As shown in FIGS. 10 and 11, modified insert  68  has a front lamination  69  substantially similar to front lamination  39  of insert  38  shown in FIGS. 1-9 and described above. Modified insert  68  also has a rear lamination  70  similar in construction to rear lamination  50  of insert  38 . However, modified rear insert lamination  70  has a laterally centrally located section of reduced thickness. Modified rear insert lamination  70  has formed in the rear wall surface  71  thereof a rectangular cross section groove or notch  72  which spans the height of the insert. Thus constructed, rear insert lamination  70  has a centrally located, relatively thin, plate-like rectangular portion  73 , joined at opposite lateral sides thereof by relatively thicker trapezoidally-shaped boss sections  74  in which are formed threaded fastening holes  81 . This construction of modified rear insert lamination  70  results in the weight of the central portion of insert  68  being less than outer portions, as desired by some golfers. In addition to providing a modified weight distribution, the central lateral portion  73  may be made sufficiently thin to allow it to flex elastically. By this means, the rebound factor of insert  68  may be varied over a relatively wide range, and independently of the characteristics of front insert lamination  69 . 
     FIGS. 12 and 13 illustrate another modification of insert  38 . As shown in FIGS. 12 and 13, modified insert  88  includes a front lamination  89  and a rear lamination  90  which has a laterally centrally located section of greater thickness than the outer lateral portions of the insert lamination. Thus, as shown in FIGS. 12 and 13, rear lamination  90  of modified insert  88  has a relatively thick, rectangularly-shaped central portion  93  which protrudes rearwardly from the rear surface  91  defined by the front surfaces of laterally adjacent mounting tab sections  94  in which are formed threaded fastening holes  101 . This construction causes the weight distribution of modified insert  88  to be concentrated near the lateral center line of the insert, as desired by some golfers. 
     FIGS. 14 and 15 illustrate two other modifications  100  and  120  of golf putter head  20 , in which the weight distribution of inserts  138 L,  138 U is concentrated near the lower and upper portions of the head  121 L,  121 U, respectively, to suit the desires of some golfers. 
     FIGS. 16 and 17 are front elevation and transverse sectional views, respectively, of other modifications of putter head  20 . Thus, FIGS. 16A and 17A illustrate a modified putter head  20 A according to the present invention, in which the front portion of the insert  38 A thereof is fitted in modified recess  35 A and pocket  60 A, and penetrates only the upper wall surface of the putter head body. Similarly, FIGS. 16B and 17B illustrate a modified putter head  20 B in which the front portion of the insert penetrates only the lower surface of the putter head body. FIGS. 16C and 17C illustrate a modified putter head  20 C in which only the front face of the insert is exposed. FIGS. 16D and 17D illustrate a modification of putter head  20 C, in which the pocket thereof has sloping side walls, rather than being of uniform transverse cross section. Of course, the previously described embodiments and modifications thereof may optionally also employ a pocket having inwardly or outwardly diverging side walls, to impart different desired weight distribution and ball impacting properties to a putter head according to the present invention. FIG. 16E illustrates a modified putter head  20 E having an insert  38 E with parallel vertical side walls.