Abstract:
This invention relates to an extraction device for removing a stuck cast part from a stationary mold of a casting apparatus. The extraction member is disposed in the stationary mold section during the casting of a cast part and is disposed adjacent a part shape cavity. The extraction device is moveable between a first position, wherein the extraction member cooperates with the mold sections of the casting apparatus to form a part of the part shape cavity, and a second position, wherein said extraction member is operative to engage and eject the stuck cast part from the part shape cavity.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates in general to a casting apparatus and in particular to an extraction device for removing a stuck cast part from a stationary mold of such a casting apparatus. 
     A conventional casting apparatus can include a stationary mold member and a moveable mold member. The stationary mold member is typically a lower mold member and the moveable mold member is typically an upper mold member. The upper mold member is moved downwardly into contact with the lower mold member so as to define an internal mold cavity. Casting material is then introduced into the mold cavity to produce a cast part. After adequate cooling, the upper mold member is moved upwardly to enable the cast part to be removed or extracted from the mold cavity. 
     Sometimes the cast part remains “stuck” in the lower mold after the upper mold is moved away therefrom. In order to remove the cast part from the lower mold, it is known to manually deform the cast part in the lower mold. Then, the upper mold is moved downwardly into contact with the lower mold so as to forcefully contact the “deformed” portion of the stuck cast part to cause it to wedge within the upper mold and become more stuck in the upper mold than in the lower mold. The upper mold is then moved upwardly away from the lower mold so that the cast part can be removed from the upper mold using a conventional ejection system. Unfortunately, having to remove the stuck cast part from the lower mold in this manner usually damages the cast part and makes the part unfit for use. Also, considerable time is wasted in freeing the stuck cast part from the lower mold. In addition, damage to one or both of the lower and upper molds can occur when attempting to remove the cast part in this manner. Thus, it would be desirable to provide an apparatus to be used in a casting apparatus which is able to remove or extract a stuck cast part from the lower mold which was simple, reliable and which reduces the risk of damaging or destroying the cast part and/or which eliminates or reduces the risk of damaging the lower mold, the upper mold or both the upper and lower molds. 
     SUMMARY OF THE INVENTION 
     This invention relates to an extraction device for removing a stuck cast part from a stationary mold of a casting apparatus. The extraction member is disposed in the stationary mold section during the casting of a cast part and is disposed adjacent a part shape cavity. The extraction device is moveable between a first position, wherein the extraction member cooperates with the mold sections of the casting apparatus to form a part of the part shape cavity, and a second position, wherein said extraction member is operative to engage and eject the stuck cast part from the part shape cavity. 
     Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial sectional view of a casting apparatus including an extraction device in accordance with the present invention. 
         FIG. 2  is a sectional view similar to  FIG. 1  showing the first step of the use of the extraction device to extract a stuck cast part from the lower mold of the casting apparatus in accordance with the present invention. 
         FIG. 3  is a sectional view showing the second step of the use of the extraction device to extract a stuck cast part from the lower mold of the casting apparatus in accordance with the present invention. 
         FIG. 4  is a sectional view showing the third step of the use of the extraction device to extract a stuck cast part from the lower mold of the casting apparatus in accordance with the present invention. 
         FIG. 5  is a sectional view showing the fourth step of the use of the extraction device to extract a stuck cast part from the lower mold of the casting apparatus in accordance with the present invention. 
         FIG. 6  is a sectional view showing the final step of the use of the extraction device to extract a stuck cast part from the lower mold of the casting apparatus in accordance with the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings,  FIG. 1  illustrates a portion of a casting apparatus, indicated generally at  10 , including an extraction device  30  in accordance with the present invention. The general structure and operation of the casting apparatus  10  is conventional in the art. Thus, only those portions of the casting apparatus  10  which are necessary for a full understanding of this invention will be explained and illustrated in detail. Although this invention will be described and illustrated in conjunction with the particular casting apparatus  10  disclosed herein, it will be appreciated that this invention may be used in conjunction with other casting apparatuses. 
     As shown therein, the casting apparatus  10  includes a lower mold section  12  and an upper mold section  14 . In the illustrated embodiment, the lower mold section  12  is a stationary mold section and the upper mold section  14  is a moveable mold section. As shown in  FIG. 1 , when the upper mold section  14  is in a closed, lowered position and in contact with the lower mold section  12 , a part shape/gating cavity  16  is defined between the two mold sections. As will be discussed below, a suitable molten material is supplied to the cavity  16  to produce a cast part (a portion of the cast part being shown in  FIGS. 2–6  by reference number  60 ). Suitable means (not shown) are provided for moving the upper mold section  14  from the closed, lowered position shown in  FIG. 1  to a raised, open position (not shown). 
     In the illustrated embodiment, the lower mold section  12  is preferably provided with a cavity or pocket  18 , a first opening  20 , a second opening  22 , and a shoulder  24  for accommodating the extraction device  30 . In the illustrated embodiment, the first opening  20  is a non-threaded opening and the second opening  22  is a threaded opening. The upper mold section  14  is provided with a first opening  26  and second opening  28  for accommodating the extraction device  30 . Alternatively, the construction of the lower mold section  12 , the upper mold section  14  or both can be other than illustrated if so desired. 
     As shown in  FIG. 1 , the extraction device  30  includes a lever  32 , a lock  34 , a plate  36  a pin  38 , a first threaded fastener  40 , and a second threaded fastener  42 . The lever  32  includes a first opening  42  and a second opening  44  formed therethrough. In the illustrated embodiment, the first and second openings  42  and  44  are non-threaded openings. The lock  34  includes a first opening  48  and a second opening  50  formed therethrough. In the illustrated embodiment, the first opening  48  is a elongated slotted opening have a generally U-shape and the second opening  50  is a threaded opening. The plate  36  is provided with a first opening  52  and a second opening  54  formed therethrough. In the illustrated embodiment, the first opening  52  is a non-threaded opening and the second opening  54  is a threaded opening. Alternatively, the construction of one or more of the openings  42 ,  44 ,  48 ,  50 ,  52  and  54  can be other than illustrated if so desired. 
     As shown in  FIG. 1 , when the extraction device  30  is installed in the lower mold cavity  18  and the mold section  12  and  14  are in the closed position, the threaded fastener  40  functions as a hold down fastener to secure the extraction device  30  in the casting apparatus  10 . To accomplish this, an enlarged head  60  of the fastener  40  is disposed in the opening  26  of the upper mold  14  and a lower end of the head  60  rests against an upper surface of the plate  36 . An upper non-threaded body portion  62  of the fastener  40  extends through the non-threaded opening  44  of the lever  32 , and a threaded body portion  64  of the fastener  40  passes through the U-shaped opening  48  of the lock  34  and is threadably received in the threaded opening  22  of the lower mold section  12 . Also, the pin  38  is disposed in the non-threaded openings  42  and  20  of the lever  32  and the lower mold section  12 , respectively, in a slight interference fit therewith. The pin  38  also passes through the U-shaped opening  48  of the lock  34  but does not contact any surface thereof. The fastener  42  includes an enlarged head  70  which is disposed in the opening  28  of the upper mold  14 . A lower end of the head  60  of the fastener  42  rests against an upper surface of the plate  36 . The fastener  42  includes a threaded body portion  72  which is threadably disposed in the threaded opening  54  of the plate  36 . 
     Turning now to  FIGS. 2–6 , the operation of the extraction device  30  will be discussed when the upper mold section  14  (not shown) has been moved to opened position and the cast part  60  has remained stuck in the lower mold section  12 . As shown in  FIG. 2 , hold down fastener  40  is unscrewed and removed from the extraction device  30  and the fastener  42  is unscrewed but not removed from the plate  36 . 
     Next, as shown in  FIG. 3 , the fastener  42  is used to rotate or pivot the plate  36  in the direction of the arrow A so as not to damage the cast part  60  during the removal of the plate  36  from the lower mold section  12 . Following this, the fastener  42  is completely removed from the plate  36 , screwed into the threaded opening  50  of the lock  34 , and used to remove the lock  34  from the lower mold section  12  as shown in  FIG. 4 . 
     The fastener  40  is then installed into a threaded opening  74  provided in the pin  38  as shown in  FIG. 5  and used to remove the pin  38  from the lever  32  and the lower mold section  12 . Following this, a suitable tool member  76  is used to apply a force in the direction of arrow B against an upper right hand end portion  78  of the lever  32  in  FIG. 6  to move the portion  78  downwardly into the cavity until it contacts the associated cavity wall. Such movement causes the lever  32  to pivot about a point  80  causing a left hand end portion  82  of the lever  32  to pivot or move upwardly to raise and eject the stuck cast part  60  from the mold cavity  16 . 
     Although the illustrated embodiment of the casting apparatus  10  is shown to include a single extraction device  30 , it is contemplated that a plurality of extraction devices  30  located at predetermined locations within the casting apparatus  10  may be used to insure the application of a uniform extraction force by the devices  30  to the stuck cast part  60  during the ejection of the part  60  from the lower mold section  12 . Some of the many factors that may determine the number of devices  30  that are needed can include the shape of the particular cast part  60  and the configuration of the mold sections  12  and  14 . Also, the construction of one or more of the lever  32 , the lock  34 , the plate  36 , the pin  38 , and the fasteners  40  and  42  can be other than illustrated if so desired. In addition, while the heads  60  and  70  of the fasteners  40  and  42 , respectively, are not shown as being recessed into the plate  36 , the heads  60  and  70  could be recessed if so desired. However, to facilitate flash clean up, the heads  60  and  70  are preferably not recessed as shown in the illustrated embodiment. Also, while the plate  36  is preferably disposed on the shoulder  24  of the lower mold section  12  to prevent or reduce flash into the pocket  18 , the lower mold section  12  could not be provided with the shoulder  24 . 
     In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been described and illustrated in its preferred embodiment. However, it must be understood that the invention may be practiced otherwise than as specifically explained and illustrated without departing from the scope or spirit of the attached claims.