Abstract:
The method and apparatus for creating elevator buckets decreases the number of molds required to create a wide variety of dimensional configurations of such buckets by dividing the configurations into families, each of which has at least one dimension in common while each member of a family varies from other members thereof by at least one dimension, the method and apparatus being used to create all members of one family and enables changes to produce different bucket sizes within the same family without removing the mold base used in creating the family from the apparatus.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a Continuation in Part of U.S. Application No. 29/196,048, filed Dec. 22, 2003, entitled Stackable Elevator Bucket, now U.S. Design Pat. No. D496,052. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a method and apparatus for making elevator buckets. More specifically, the method and apparatus create families of buckets having at least one dimension in common while having another dimension vary, the buckets belonging to one family being created with a single mold. 
   2. Prior Art 
   Heretofore methods and apparatus have been proposed for producing or creating elevator buckets of various sizes. 
   In one older embodiment, each dimensional configuration for such bucket has required its own mold. Thus, as an example, if there were thirty-five desired configurations, thirty-five individual molds, each at a cost of over $20,000, have been required. 
   As an example, such thirty-five desired configurations, using the method and apparatus of the invention could be created using only seven molds instead of thirty-five. 
   In another older embodiment, a family of buckets has been proposed to be created using a mold base wherein a center portion core has been replaceable to accommodate varying bucket length. This has required disassembling and reassembling of the apparatus for every dimensional change, such reconfiguring of the apparatus often producing apparatus downtime of many hours per reconfiguration. 
   As will be described in greater detail hereinafter, the method and apparatus of the present invention provide for ease in reconfiguration of a mold base without requiring complete disassembly and reassembly of the entire apparatus, and thus decreasing reconfiguration time significantly, decreasing cost and labor and inherently increasing productivity. 
   SUMMARY OF THE INVENTION 
   According to the invention there is provided an apparatus for use in creating a family of elevator bucket configurations, each family having at least one dimension in common; with each bucket configuration within each family having at least one dimension which varies from other bucket configurations within the family; the apparatus comprising a mold base having a bucket interior forming portion and a bucket exterior forming portion, the bucket exterior forming portion having a cavity therein configured to be larger than the largest desired bucket configuration within the family and having an outer core oriented therein which is configured to be smaller than the smallest desired bucket configuration within the family; the bucket interior forming portion having a cavity therein which is smaller than the cavity in the exterior forming portion and also having an inner core oriented therein which is configured to be smaller than the smallest desired bucket configuration within the family; the outer core having one surface which aligns with an opposing surface of the inner core but being spaced a predetermined distance therefrom; the apparatus further including a plurality of pairs of outer surface inserts with each pair of inserts engaging about the outer core and extending along a height of the core to define an exterior surface of a bucket of a desired dimensional configuration, each pair of outer surface inserts being of differing dimensions corresponding to a particular desired outer configuration for one bucket of the family; and a plurality of pairs of inner surface inserts with each pair of inserts engaging about the inner core and extending along a height of the core to define an interior surface of a bucket of desired dimensional configuration, each pair of inner surface inserts being of differing dimensions corresponding to a particular desired inner configuration for one bucket of the family, each inner surface insert having at least one surface which align with an opposing surface of a corresponding outer surface insert and being spaced a predetermined distance therefrom. 
   Further, according to the invention there is provided a method for creating any elevator bucket of a family of elevator bucket configurations, each family having at least one dimension in common; with each bucket configuration within each family having at least one dimension which varies from other bucket configurations within the family: the method comprising the steps of: selecting the desired dimensional configuration for an elevator bucket to be molded; determining the family to which the bucket belongs; selecting the mold base corresponding to the family to which the bucket belongs; selecting the appropriate inner and outer inserts necessary to produce the desired dimensional configuration for the bucket and placing same into the corresponding forming portion about the core thereof; bringing the forming portions together; injecting material from which the bucket is to be formed; allowing the material to cool; separating the forming portions; ejecting the formed bucket; and, if desired, creating another bucket by repeating the steps of the method. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a lateral cross sectional view of the apparatus used with the method of the present invention 
       FIG. 2  is an end cross sectional view of the apparatus used with the method of the present invention 
       FIG. 3  is a table showing thirty-five exemplary dimensional configurations for a elevator bucket divided into 7 families as well as providing further characteristics for each bucket. 
       FIG. 4  is a side view of an exemplary bucket made with the method and apparatus of the present invention. 
       FIG. 5  is a perspective view of the bucket of  FIG. 4 . 
       FIG. 6  is an exploded perspective view of the apparatus 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings in greater detail, there is illustrated therein one apparatus  10  used in creating one family  11  of elevator buckets  12 . 
   Deferring to  FIG. 3 , it will be understood that each family  11  of elevator buckets  12  has at least one dimension in common. In the preferred embodiment, one common dimension selected is bucket projection  68 , or width across the top of the bucket  12 , from front  14  to back  16  but could also be depth  22 . Thus the preferred choice is not to be construed as limiting. Also, it will be seen that the buckets  12  belonging to a particular family  11  in the preferred embodiment have a common front depth  20 , back depth  22  and thickness  24 , though this should not be construed as limiting. The variable dimension within each family  11  is the lateral extent  26  or length  26  of the bucket  12 , which variability in length  26  is easily accommodated by the method and apparatus  10  such that, in the exemplary families  11  defined in  FIG. 3 , the described thirty five bucket  12  embodiments, rather than requiring thirty five individual molds can be created with only seven mold base embodiments  30 , as will be described in greater detail hereinbelow. 
   For the sake of brevity, only one mold base  30  embodiment will be described in detail, inasmuch as those skilled in the art will easily comprehend, without undue experimentation, how a mold base  30  for another family  11  of buckets  12  can be formed and used in the method from the following description of the one mold base  30 . 
   As will be understood from a concurrent perusal of the remaining Figures, the mold base  30  comprises two mold portions, a bucket  12  exterior forming portion  40  and a bucket  12  interior forming portion  60 . 
   Beginning with a perusal of the exterior forming portion  40 , it will be seen to incorporate a cavity  42  therein which is configured to be larger than the largest desired bucket  12  configuration within one family  11  of buckets  12 . 
   The cavity  42  incorporates an outer core  44  therein which extends into the cavity  42  toward the interior forming portion  60  a predetermined distance, which in the preferred embodiment terminates at a predetermined point which will eventually define a portion of an outer bottom surface  46  of any bucket  12  of the family  11 . It will further be seen that the gate  48  through which a suitable material from which the buckets  12  are created extends downwardly through this core  44 , emptying at a feed port  50  in a surface  52  which is oriented at the predetermined point of termination of the core  44 . 
   A plurality of pairs  53  of inserts  54  are provided which engage within the cavity  42  and extend laterally from and about the core  44 , each pair  53  of inserts  54  being of differing dimensions whereby each pair  53  of inserts  54  defines an outer surface configuration for a bucket  12  of a different lateral or widthwise extent, from a smallest desired lateral extent  26  to a largest desired lateral extent. 
   The exterior forming mold portion  40 , it will be understood, must cooperate with the interior forming mold portion  60  to create a bucket  12  having a desired three dimensional configuration, as well as at least a desired wall thickness  24 , and accommodating a desired front depth  20 , back depth  22  and projection  68  for each family  11  of buckets  12 , as well as accommodating a variable desired lateral extent  26  for each bucket  12  within a family  11 . 
   Turning now to a perusal of the interior forming portion  60 , it will also be seen to incorporate a cavity  70  therein which is configured to be of a predetermined smaller size than the cavity  42  in the exterior forming mold portion  40 . 
   The cavity  70  also has core  72  therein having a central decreased in diameter elevated portion  74  having top surface  75  dimensions which substantially correspond to the dimensions of the surface  52  of the core  44  of the exterior forming portion  40 , to which the top surface  75  thereof is subjacent and from which it is separated a predetermined distance of separation, substantially defining the wall thickness  24  of the bucket  12 . The cavity  70  is actually an inward continuation of cavity  42  and cavity  42  is thus a common cavity  42 , but is now defined by the open configuration of core  44  and inserts  54 . 
   The interior forming mold portion  60  also has associated therewith a plurality of pairs  76  of inserts  78  which engage about and extend in a lateral extent from the core  72  a predetermined distance so as to cooperate with the pairs  53  of inserts  54  in the exterior forming portion  40  in such a manner as to be spaced from the inserts  54  of the exterior forming portion  40  by the same predetermined distance between the inner and outer cores  72  and  44 , respectively, thus defining the thickness  24  of the buckets  12  by the dimension of the gap  80  between the cooperating exterior forming mold section  40  and the interior forming mold section  60 . 
   Thus it will be understood that by use of corresponding pairs  53  and  76  of the plurality of available exterior or outer inserts  54  and interior or inner inserts  78  in a corresponding mold base  30 , a plurality of buckets  12  having the same wall thickness  24 , front depth  20 , back depth  22  and projection  68  but having a different lateral extent  26  or dimension, defining members of one family  11  of buckets  12 , can be created using a single mold base  30  rather than requiring a separate and distinct mold base  30  for each desired bucket  12  in a family  11  of buckets  12 , as defined above. 
   Ease in reconfiguring the mold sections  40  and  60  is produced by the novel manner in which the inserts  54  and  78  are engaged to the mold base  30 , eliminating the need to remove the mold base  30  from the apparatus  10  during the process of reconfiguration. 
   In this respect, it will be seen that bolts  94  are used to secure the plurality of inserts  54  and  78  to the mold base  30 . The bolts  94  pass through each insert  54  and  78 , and terminate within an opening  96  in the respective cooperating area of the mold base  30 . The configuration of each opening  98  in each insert  54  and  78  is such that a head  100  of each bolt  94  is countersunk into an expanded are  102  of each opening  98  such that the head  100  of each bolt  94  does not interfere with required abutment of cooperating inserts  54  and  78  when the apparatus  10  is assembled for use. 
   Thus, the head  100  of each bolt  94  is readily accessible for changing of inserts  54  and  78  when the mold portions  40  and  60  are separated. 
   The method for using the apparatus  10  is relatively straightforward. 
   First, the family  11  to which a desired bucket  12  belongs is determined so that the appropriate mold base  30  is selected. 
   The desired lateral extent  26  for the bucket  12  is next determined and each appropriate pair  53  and  76  of cooperating inserts  54  and  78  is positioned within an appropriate cavity  42  and  70 . 
   The interior forming mold section  60  and the exterior forming mold section  40  are next pressed together, in known manner, and the desired material from which the bucket  12  is to be created is fed in a melted condition, through the gate  48  in the core  44  of the exterior forming portion  40  and fills the gap  80 . Cooling is next desired and water is fed through a water path system  82  positioned in locations most conducive to quick cooling, as is known in the art of injection molding. 
   After cooling, the sections  40  and  60  of the mold base  30  are separated and an ejector bar assembly  90  is used to release the cooled, formed bucket  12  from within the section  60 , in known manner. 
   It will be clear to those skilled in the art that the method is repeated using the same mold base  30  for all members of a family  11  of buckets  12 , while selecting and using a different mold base  30  when the dimensional configuration of a further bucket  12  to be made shows the desired bucket  12  to belong to a different family  11 . 
   As described above the method and apparatus of the preferred invention provides a number of advantages, some of which have been described above and others of which are inherent in the invention. 
   Also, modifications may be proposed without departing from the teachings herein. Accordingly the scope of the invention is only to be limited as necessitated by the accompanying claims.