Abstract:
An injection mold for forming a pattern for use in investment casting having mold sections carrying two pattern-forming surfaces and a translatable third pattern-forming element movable on a mold section. The mold also includes an inner core. Parting lines are located at inconspicuous locations by sizing and shaping the mold sections. The method of use of the injection mold includes employing an arrangement for facilitating lower mold section and for raising the inner core to facilitate its removal.

Description:
RELATED APPLICATIONS 
     This application is a divisional of an application filed Sep. 16, 1997 entitled “Injection Mold For Producing A Pattern And Method of Mold Use” Ser. No. 08/931,773 which U.S. Pat. No. 5,908,643 which application in turn was a continuation-in-part of an application filed Jul. 10, 1997 having the same title, Ser. No. 08/891,435 which in turn was a continuation of U.S. application Ser. No. 08/662,900 filed Jun. 12, 1996, also of the same title both are abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     Aluminum molds for making wax patterns have been in use for years. Combination aluminum and epoxy molds have also been used. Epoxy mold parts have the drawback of wearing after repeated use and of being easily damaged during the handling required to carry out repeated molding operations. Additionally, it is well known that aluminum molds have superior heat transfer relative to epoxy molds, thereby reducing dwell time for wax pattern production and overall cycle time. 
     Where molded parts have included an intricate interior cavity, a plurality of mold sections and cores have been required. The mold parts and cores require handling to accomplish assembly and disassembly. Further, in the molding of demanding shapes such as golf club heads parting lines have presented problems requiring trimming and reworking wax patterns. Prior wax patterns for making golf club heads are disclosed in U.S. Pat. Nos. 5,204,046 and 5,417,559. 
     SUMMARY OF THE INVENTION 
     In summary, the present invention comprises a multi-section mold including an inner cluster core which novel mold is shaped and proportioned to facilitate handling during molding operation. Mold manipulation by hand is limited to sliding and translating of mold sections and the removal and replacement of the cluster core. 
     Preferably, the mold is connected to and operated with a mold press which includes a work station and a preparation station into which a lower mold portion is slidably mounted with inner cluster core in place and the upper mold section is lowered against the lower section. After injection of wax and cooling, the upper section is raised, the lower section is slidably moved out of the work station to the preparation station and a third mold portion is translated in its open position. Finally, the cluster core is removed. 
     As a feature, it is contemplated that, as the lower section is moved out of the work station, the core along with the wax pattern may be automatically raised to facilitate pattern and core removal. The mold is made of aluminum. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of the upper and lower mold portions assembled with a removable core cluster; 
     FIG. 2 is a perspective view of the upper and lower portions separated with the core cluster removed; 
     FIG. 3 is a perspective view of the lower mold portion showing the lower mold cavity and slidable third mold portion in its closed position; 
     FIGS. 3A and 3B are views similar to FIG. 3 with the third mold portion slid open; 
     FIG. 4 is a perspective view of the upper mold portion; 
     FIG. 5 is a plan view of the pattern mold with parting lines and with the cluster of cores therein and with the wax pattern, not shown, surrounding the core cluster; 
     FIG. 6 is a front elevational view of the pattern mold including parting lines with the wax pattern not shown; 
     FIG. 7 is an expanded perspective view of the core cluster and mount ring; 
     FIG. 8 is a front elevational view of the press and mold apparatus with the lower mold in its injection position; and 
     FIG. 9 is a view similar to FIG. 8 with the lower mold in its assembly preparation station; 
     FIG. 10 is a front elevational perspective view of an alternative embodiment of the mold apparatus of the invention including the upper mold, the lower mold and the lower mold guide track; 
     FIG. 11 is a side elevational view partially broken away showing the apparatus assembled and one of the track&#39;s slotted rails; 
     FIG. 12 is a view similar to FIG. 11 in which the upper mold has been raised and the lower mold partially moved along the track; 
     FIG. 12 a  is an enlarged side elevational view of the track rail of FIG. 12; 
     FIG. 13 is a top view of the lower mold; 
     FIG. 14 is a bottom view of the lower mold; 
     FIG. 15 is a bottom view of the upper mold; 
     FIG. 16 is a side view of the lower mold; 
     FIG. 17 is a perspective view of the portable core cluster stand with upstanding pins; 
     FIG. 18 is a perspective view of the stand with the cluster mounted thereon; 
     FIG. 19 is a perspective view of the stand with the cluster mounted thereon and the crank operated to lower the center core unit; 
     FIG. 20 is a perspective view of the center core unit; and 
     FIG. 20 a  is the side elevational view of the center core unit including its prong slot with the crank pin in engagement with the prong slot. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the Figures, pattern forming mold unit  10  functions to mold a wax molded pattern P having an exterior surface  11   e  and an interior surface  111  (see FIG. 5) which pattern P is used in investment casting of a metal part such as a portion of golf club head (see FIGS. 1,  5  and  6 ). Mold  10  includes four (4) pattern-shape determining portions which create mold cavity C: The first portion is upper mold portion  12 ; the second is lower mold portion  13 ; and the third is a slidable mold portion  16  mounted for horizontal slidable movement on lower portion  13  and the fourth portion is the core cluster  23  (see FIGS. 1,  3 ,  3 A and  4 ). Upper mold portion  12  includes cavity surface  18  which defines upper surface  11   u  of molded pattern P (not shown) (see FIG.  5 ). The lower mold portion  13  includes a cavity surface  19  which defines a portion  111  of the lower surface of the molded pattern P. Finally, face surface  21  of slidable mold portion  16  defines the remainder of the exterior surface of pattern P. Face surface  21  includes groove forming stand ups  21   g.    
     Mold  10  also includes a core cluster  23  which is composed of six (6) core sections  26   a-f  with core section  26   f  being the center core section (see FIG.  5 ). Each core section  26   a-f  has receiving pins  27   a-f  respectively (FIGS. 1,  5  and  7 ). The core cluster  23  is positioned in mount ring  29  having holes  31   a-f  for receiving pins  27   a-f . Attached to ring  29  and extending from it is locator prong  32  which fits into mold slot recess  33  to locate core cluster  23 . 
     Referring now to FIGS. 2,  3  and  4 , the size and shape of pattern P is defined by upper mold portion cavity surface  18 , lower mold portion cavity surface  19  and face surface  21   g  of slidable mold portion  16 . The parting lines created by mating of cavities  18 ,  19  and face surface  21  are crown periphery parting line  36  (see FIG. 5) and face periphery parting line  37  (see FIG.  6 ). These parting lines  36 ,  37  are located on pattern P such that they are inconspicuous and therefore little or no reworking of molded pattern P is necessary to assure that the mold product made using pattern P has no conspicuous imperfections. Also shown is wax injection port  20 . 
     Turning to FIGS. 8 and 9, mold  10  portions  12  and  13  are positioned for use in a mold press  40  having reciprocating platen  41  movable up and down. Upper mold portion  12  is attached to platen  41 . Below reciprocating platen  41  press base  42  supports lower mold portion  13  shown resting in its injection position in FIG.  8  and in its assembly position in FIG.  9 ). 
     Lower mold portion  13  is mounted on guide rails (not shown) for ease of horizontal translation on base  42  from its injection station (IS) to its assembly preparation station (PS). 
     In the operation of mold press  40 , lower mold portion  13  is translated horizontally by an operator to preparation station (PS) where the slidable mold portion  16  is moved away from mold surface  19 . Cluster of cores  23  are placed in mount ring  29  which ring  29  is mounted and located by insertion of prong  32  in recess  33  in lower mold portion  13 . Next, slide mold portion  16  is moved to its injection position. Lower mold portion  13  is translated to its injection station (IS). 
     Reciprocal platen  41  carrying upper mold portion  12  is then lowered to engage with lower mold portion  13 . Alignment pins  24 ,  25  on upper portion  12  enter alignment holes  34 ,  35 . of lower portion  13 . The hosel hole core pin (not shown) is inserted in cavity C to form hosel opening  38  (FIG.  4 ). Pressure is exerted to hold the mold portions  12 ,  13  together as wax is injected in the pattern forming cavity C. 
     After a suitable cooling period for the wax to solidify, the hosel core pin is retracted and then the reciprocal platen  41  carrying the upper mold portion  12  is raised and the lower mold portion  13  is translated from the injection station (IS) to the preparation station (PS). As the lower mold section is retracted toward the operator, the core cluster is moved automatically upward about one-half an inch by means of a wedge or cam device not shown, thereby improved ease of core cluster disassembly. Slide  16  is moved away from both cluster  23  and pattern P. The mount ring  29  including pattern P is then grasped by operator, lifted out of the mold  13  and placed on a stand (not shown). A second mount ring and core cluster unit are placed in lower mold portion  13 , mold portion  16  is moved into molding position, lower mold portion  13  translated back to its injection station (IS) and the press mold  40  is ready for the next cycle. The operator holds the wax pattern in one hand and lifts out the core cluster pieces  26   a-f , then the core cluster  23  is reassembled for use in the next injection cycle. 
     An identification piece with marking on it may be placed in mold cavity C causing corresponding markings to appear on the wax pattern P. 
     Turning to FIGS. 10 to  1 . 2 , mold press apparatus  50  operates to position mold sections described above for injection, for disassembly and reassembly which mold press  50  apparatus has an upper vertically reciprocal platen  51  to which the upper mold section  52  with beak section  52   a  is attached. Mold press apparatus  50  further includes a lower mold section  53  which is reciprocal in guide track  55  once separated from its upper mold section  52  from an injection position to a retracted position for disassembly and assembly. Movement of lower mold section  53  away from its upper mold section  52 ′, as guided by track  55 , is limited by stop piece  65 . Pin hosel  58 , which extends during operation into and occupies opening  54  (FIG. 15) to create a cylindrical void in the pattern being formed, is attached to a double acting air cylinder piston unit  67 . Cylinder-piston unit  67  is mounted on platen  51 . Track  55  includes spaced-apart guide left rail  56  and right rail  57  (as viewed in FIG. 10) with each rail  56 ,  57  including guide slots  68   a ,  68   b  forward upper guide slots  69   a ,  69   b , forward lower guide slots  71   a ,  71   b  and spring-loaded ramp  56   a  (FIG. 12 a ). Spring-loaded ramp  56   a  having slot  79   a  is swingable in rail pocket  72   a.    
     Lower mold section cross bar  59  positioned in opening  62  lower mold section  53  (FIG. 16) has cross bar  59  with right stud end  60  and left stud end  61  (not shown) which ends  60 ,  61  ride in guide slots  68   a ,  68   b  and  71   a ,  71   b  (FIG. 12 a ). Turning back to FIG. 12 a , bar stud end  60  rides in a path indicated by arrows A during lower mold  53  movement toward stop piece  65  in guide slot  68   a  until it enters slot  79   a  of ramp  56   a  causing stud end  60  to be raised up into upper guide slot  69   a  and as it continues forward to pass into guide slot recess areas  87   a ,  87   b . Stud end  60 , under spring urging, then drops down into lower slot  71   a  for return. As stud end  60  engages ramp lower surface  56   s  of ramp  56   a  during such return it raises ramp  56   a  and continues rearward through slot  68   a.    
     Turning further to FIG. 16 lower mold section opening  62  houses support plate  63  which rides up and down on vertical rods  64   a  and  64   b  (not shown). Springs  65   a ,  65   b  urge plate  63  downwardly. Plate  63  engages and causes upward movement of center core unit  88  during the withdrawal of lower mold section  53  to its disassembly/assembly station adjacent stop piece  65  and simultaneously shears injection sprue. Plate  53  is raised by bar stud ends  60 ,  61  travelling in guide slots as described above. The raising and lowering of plate  63  under action of cross bar  59  with its ends  60 ,  61  is accomplished by the inclined groove system of FIG. 12 a  serving stud end  60  and a similar groove system in rail  56  serving stud end  61 , all as explained above. Turning now to FIGS. 13-16, lower mold section  53  includes air cylinder stand-off portion  53   s , a slide mold section  70  riding in slide pocket  70   p  having face  70   f  and core  73 . When upper mold section  53  is raised its beak section  52   a  releases slide mold section  70  allowing it to move away from pattern (P) under force of a spring element (not shown). Lower mold section  53  further includes bottom surface  74  with a plurality of air (or other fluid) exit holes  76  arranged in rows  77   a-e . Air exit holes  76  may be arranged in rows or any other pattern. Air exit holes  76  are connected to an air manifold (not shown). 
     When the core  73  is placed in lower mold section  13 , six (6) rare earth magnets  98  (FIG.  13 ), aligned with core pins  95   a-f , magnetically attract pins  95   a-f  in assuring the pins  95   a-f  are properly seated in lower mold section  53  against plate  63  (FIG.  16 ). 
     In FIGS. 17 and 18, a portable core cluster handling device  82  normally positioned on surface S of mold apparatus  50  (FIG. 10) includes body  83  with front panel  83   f  and top surface  83   t . Upstanding pins  85  are mounted on top surface  83   t  and there is an opening  83   o  in top surface  83   t  to receive central core prong  86  of central core unit  88  (see FIG.  20 ). Device  82  has a crank  81  pivoted on pin  80  in front panel  83   f . Crank  81  carries projecting cam pin  78  which projects through front face slot  75  into prong slot  86   s . Pattern (P) is positioned on core cluster  73 . Core  73  includes central core unit  88  which in turn also includes ring body  89  and central core  91 . Ring body  89  includes holes  90  for receiving the pins  95   a-f  of core sections  94   a-c  (see FIGS. 18,  19  and also FIGS.  5  and  7 ). 
     In the operation of mold apparatus  50  and portable associated device  83 , upon wax or other mold material injection into engaged mold sections  52 ,  53  through sprue hole (not shown) together with core pin  58  in place, pin  58  is withdrawn and upper platen  51  with its attached mold section  52 , after a proper time delay, are raised. Preferably, this step of mold apparatus  50  and subsequent steps are automatically operated in a computer programmed control sequence. As upper mold section  52  moves up and away from lower mold slide section  70 , mold slide section  70  is free under spring urging to move away from the molded pattern (P). Next, the operator grasps handle  53   h  and at the same time opens air handle valve  53   v  (FIG. 10) causing air to flow out lower mold bottom holes  76  providing an air cushion between the lower mold bottom surface  74  and the press table surface (S). 
     Lower mold section  53  is then pulled with ease on air cushion by the operator in direction D (FIG.  10 ). As lower mold section  53  moves toward stop piece  65 , lower mold plate  63  is lifted due to the camming action of cross bar  59  with its stud ends  60 ,  61  as such stud ends  60 , 61  are cammed upwardly in guide slots  68 ,  68   b ,  69   a ,  69   b  and  71   a ,  71   b  causing core unit  88  to rise up (FIG. 12 a ). The sprue (not shown) is severed as core unit  88  rises. When stud ends  60 ,  61  reach the ends of slots  69   a ,  69   b  they drop down through recesses  87   a ,  87   b  under action of spring-loaded plate  63 . Stud ends  60 , 61  are then free to move under slots  71   a ,  71   b  as mold section  53  is pushed by the operator back to its position for mating with upper mold  52 . Core unit  88 , having been raised by plate  63 , is then readily grasped by the operator for removal. As core unit  88  is extracted the injection sprue is sheared off. Lubricant or cold air may be sprayed on the hosel pin  58  to reduce sticking. 
     The operator then places the wax pattern (P) with  15  the internal core cluster  73  on core cluster mount device  82 . The center core  88  is extracted by operating crank  81 . The projection pin  78  of crank  81  engages slot  86   s  of prong  86  to cause prong  86  to move downwardly as crank  81  is pushed down. As prong  86  is lowered by crank action, ring holes go accommodate upstanding pins  85  permitting downward movement until ring center cluster  89  is seated on device top surface  83   f . Center core  88  is thereby separated from pattern (P) without the operator grasping pattern (P) which could cause its deformation. The remaining core sections are then readily removed by hand and places them on a pedestal for assembly.