Abstract:
A mold, a molding apparatus embodying said mold, and a method of use thereof. The mold has a moveable mold core and a multi-part mold base having at least a fixed mold base and at least one moveable or slideable mold base slideable from an adjacent to an adjoining position with regard to said fixed mold base. When the moveable mold core is in its closed position the slideable mold portions are adjoining the fixed mold portion to define a mold cavity. The mold base may be shaped so as to aid in forming a part, or to hold a sheet of material onto which molding material is to be deposited so as to encapsulate the part on one or more edges or surface regions.

Description:
RELATED APPLICATIONS 
     The present application is a continuation-in-part of United States Letters Patent Application Ser. No. 08/898,207 entitled MOLDING METHOD AND APPARATUS AND PART PRODUCED THEREBY, filed Jul. 22, 1997, now U.S. Pat. No. 6,123,535, which claims the benefit of prior provisional patent application No. 60/023,007, filed Aug. 2, 1996. The priority of application Ser. No. 08/898,207 is specifically, claimed, and the specification of the application is incorporated by reference. The priority of prior copending provisional patent application No. 60/023,007 is also specifically claimed, and the specification of Ser. No. 60/023,007 is also incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method and apparatus for molding. More particularly, the present invention relates to a method and apparatus for molding onto or encapsulating all or a portion of a sheet of material. Most particularly, the present invention relates to a method and apparatus for encapsulating all or part of a glass sheet for use as an automotive glazing on a single side only. The scope of the present invention will be understood to cover the products made by the disclosed method and apparatus, as well as the particular mold structure and apparatus described herein. 
     2. Discussion of the Related Art 
     In the preferred embodiments of the present invention, the molding apparatus disclosed is of the type used to mold onto or encapsulate glass sheets of the type which are commonly employed as glazed enclosures in present day vehicles, such as automobiles and the like. In addition to such glass sheets being made to precisely defined curvatures dictated by the configuration and size of the openings in the vehicle body, in order to meet strict quality standards of manufacturers, it is necessary to mold onto or encapsulate the sheet of material, such as with a gasket around a predetermined portion of the sheet of material. 
     U.S. Pat. No. 4,561,625 discloses a mold structure for forming a polymeric gasket around a predetermined portion of a sheet of transparent material such as glass. The mold structure includes two cooperating mold sections for defining a chamber for receiving the transparent sheet. A seal is positioned about the periphery of the chamber and is utilized to resiliently support the sheet within the chamber. Also, the seal cooperates with a predetermined portion of the transparent sheet for defining a gasket cavity having a configuration corresponding to the gasket to be formed on the sheet of transparent material. 
     U.S. Pat. No. 4,762,481 discloses a mold for forming a window assembly which includes a transparent glass sheet and gaskets formed by curing a polymeric gasket material in situ on the glass sheet to encapsulate a marginal peripheral edge portion thereof. A glass sheet to be utilized in a vehicle has a front edge, rear edge, and a lower edge, to each of which is adhered such a gasket. In addition, a bracket means for attachment to a scissor linkage for raising and lowering the window can be secured to the lower edge of the window. 
     U.S. Pat. No. 4,584,155 discloses a method for molding surface structure onto the surface of the glass sheet. 
     U.S. Pat. No. 5,108,687 discloses a device for at least partially encapsulating a border of a substantially sheet shaped element. The device contains a cavity formed by an elastically deformable member having a profile which extends along an encapsulation border line of the element, and which is adapted to be elastically deformed while maintaining a tight contact along the encapsulation border line when pressure is applied thereon, in order to follow irregularities in the element along the border line. 
     The co-pending application of applicant&#39;s assignee, Ser. No. 08/898,207, filed Jul. 22, 1997 and entitled “Molding Method and Apparatus and Part Produced Thereby” shows a molding apparatus having a mold base and at least one moveable mold core rotatable into and out of a facing relationship with the mold base. When the moveable mold core is in its closed position, it cooperates with the mold base to define a mold cavity. The mold base may be shaped so as to aid in forming a part, or to hold.the sheet of material onto which molding material is to be deposited so as to encapsulate the part on one or more edges or surface regions. Structure may also be encapsulated onto the surface of the material during the molding operation. 
     The co-pending provisional application of applicants&#39; assignee, Ser. No. 60/111,467, filed Dec. 9, 1998 shows a compact molding press which may hold the mold shown in the present invention. 
     The above-mentioned patents show various window assemblies and methods to make the same. The apparatus to make the devices shown often involve complicated molding presses dedicated to making a single part, whereby the molding presses can not accept other molds, and the molds in said molding presses can not be installed on other molding presses. This results in increased expense in the molding process. 
     Thus, those skilled in the art continued to search for a molding method and apparatus which could easily be used in a wide variety of molding presses, thus, eliminating the need for costly and specialized machinery. 
     SUMMARY OF THE INVENTION 
     The aforementioned problems are addressed in accordance with the present invention by the utilization of a novel molding method and apparatus not hereto found in the prior art. In its broadest form, the mold of the present invention may be used in a wide variety of commercially available molding presses, thus eliminating the need for dedicated and/or complicated molding presses, and thereby reducing expenses. 
     In one embodiment of the present invention, a mold for molding a part is provided. The mold includes a multi-part mold base having a mold base plate, at least one fixed mold base on said mold base plate, and at least one slidable mold base on said mold base plate. The slidable mold base is adjacent to the fixed mold base of the mold in its open position, and moves into and out of an adjoining position with respect to fixed mold base. The multi-part mold base is used in combination with a mold core having at least a portion of a mold cavity formed therein. The mold core is moveable between an open position in a facing relationship with said multi-part mold base, and a closed position in an adjoining relationship with the multi-part mold base. When the mold core is in its closed position there is at least a portion of a mold cavity adjacent the multi-part mold base, and at least one slidable mold base adjoining the fixed mold base. 
     In another embodiment of the invention a mold for encapsulating a sheet of material is shown. The mold includes a multi-part mold base in which a sheet of material to be encapsulated is supported. The multi-part mold base includes a mold base plate, at least one fixed mold base on said mold base plate, and at least one slidable mold base on said mold base plate. The slidable mold base is adjacent to the fixed mold base in its open position, and moves into and out of an adjoining position with respect to fixed mold base. The multi-part mold base is used in combination with a mold core having at least a portion of a mold cavity formed therein. The mold core is moveable between an open position in a facing relationship with said multi-part mold base, and a closed position in an adjoining relationship with the multi-part mold base. When the mold core is in its closed position there is at least a portion of a mold cavity adjacent the multi-part mold base, and at least one slidable mold base adjoining the fixed mold base. 
     In a further embodiment of the present invention a mold for encapsulating a sheet of glass on a single side is shown. The mold includes a multi-part mold base in which the sheet of glass to be encapsulated is supported. The multi-part mold base includes a mold base plate, at least one fixed mold base on said mold base plate, and at least one slidable mold base on said mold base plate. The slidable mold base is adjacent to the fixed mold base in its open position, and moves into and out of an adjoining position with respect to fixed mold base. The multi-part mold base is used in combination with a mold core having at least a portion of a mold cavity formed therein. The mold core is moveable between an open position in a facing relationship with said multi-part mold base, and a closed position in an adjoining relationship with the multi-part mold base. When the mold core is in its closed position there is at least a portion of a mold cavity adjacent the multi-part mold base, and at least one slidable mold base adjoining the fixed mold base portion. 
     In a still further embodiment of the invention, an apparatus is shown for encapsulating a sheet of glass on one surface only. A multi-part mold base will have a mold base plate, and fixed mold base mounted on said mold base plate. The mold will further include a plurality of slidable mold bases mounted on said mold base plate adjacent to the fixed mold base. Each of the plurality of slidable mold bases may be in a normally open position adjacent the fixed mold base, and can be moveable into and out of an adjoining position with respect to said fixed mold base. A sheet of glass will be placed in position in the fixed mold base. Each of said plurality of slidable mold bases may be closed. A seal carried by the plurality of slidable mold base portions of the fixed mold base will seal the edge region of the glass to prevent material from molding onto or encapsulating the edge region. Cooperating with the multi-part mold base is a moveable mold core having at least a portion of a mold cavity formed therein. The mold core is moveable between an open position in a facing relationship with the multi-part mold base, and a closed position in an adjoining relationship with the multi-part mold base. At least a portion of a mold cavity is formed in said mold core and is adjacent the multi-part mold base when said moveable mold core is its closed position. Once the sheet of glass to be encapsulated is placed in the fixed mold base, the moveable mold core will move to its closed position, at least some of said plurality of slideable mold bases will close, and molding material will be introduced into a mold cavity formed by the glass sheet the mold core, the fixed mold base, and the slideable mold bases. After the molding process, the glass sheet will be removed, and will have encapsulation on one side or surface only. 
     In a further embodiment of the present invention an apparatus is provided which incorporates a mold of the foregoing nature. 
     In another embodiment of the present invention, a method of encapsulating a sheet of glass on one edge only, in accordance with-the above description, is provided. 
     Thus, one of the objectives of the present invention is to provide a novel mold for molding a part. 
     Another object of the present invention is to provide a novel mold for encapsulating a sheet of material. Another object of the present invention is to provide a novel mold structure for encapsulating a sheet of glass on a single side. 
     A still further object of the present invention is to provide a novel molding method for encapsulating a sheet of glass on a single side. 
     A still further object of the present invention is to provide an apparatus for holding the novel mold structure of the present invention. 
    
    
     Further objects and advantages of this invention will be apparent from the following description and dependent claims, reference being made to the accompanying drawings forming a part of the specification, wherein like reference characters designate corresponding parts in the several views. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which: 
     FIG. 1 is an elevational view of an apparatus embodying the construction of the present invention; 
     FIG. 2 is a perspective view of a part which may be manufactured according to the method of the present invention; 
     FIG. 3 is a sectional view, taken in the direction of the arrows, along the section line of  3 — 3  of FIG. 2; 
     FIG. 4 is a sectional view, taken in the direction of the arrows, along the section line  4 — 4  of FIG. 1; 
     FIG. 5 is a sectional view, taken in the direction of the arrows, along the section line  5 — 5  of FIG. 1; 
     FIG. 6 is an enlarged view of the area indicated by the view circle  6  in FIG. 4; 
     FIG. 7 is a sectional view, taken in the direction of the arrows, along the section line  7 — 7  of FIG. 6; 
     FIG. 8 is a view similar in large part to FIG. 7, but showing the mold core in its closed position; 
     FIG. 9 is a sectional view, taken in the direction of the arrows, along the section line  9 — 9  of FIG. 6; and 
     FIG. 10 is an enlarged view of the area shown within the view circle FIG. 10 in FIG.  8 . 
    
    
     It is to be understood that the present invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments, and of being practiced or carried out in various ways within the scope of the claims. Also it is to be understood that the phraseology and terminology employed herein is for the purpose of description, and not of limitation. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now in detail to the illustrative embodiment depicted in the accompanying drawings, there is shown in FIG. 1 a known horizontal molding press, generally designated by the numeral  20 , and including a frame  21 , a fixed lower mold platen  22 , and a moveable upper mold platen  23 . The moveable upper mold platen reciprocates on a plurality of tie bars  25 , and is powered for reciprocal movement by fluid cylinder  26 . Fluid cylinder  26 , together with well known fluid power components (not shown), comprise means to move the moveable upper mold platen  23  from its open position to its closed position, and vice versa, as desired. 
     Mounted in horizontal molding press  20  is mold  27 . Mold  27  consists of a multi-part mold base  29  fixedly, but removably, attached to fixed lower mold platen  22 , and a moveable mold core  30  fixedly, but removably, attached for reciprocating movement to moveable upper mold platen  23 . Injection port  32  provided in moveable upper mold platen  23 , and in fluid communication with moveable mold core  30 , allows for the injection of molding material into the mold  27 . 
     A sheet a of material to be encapsulated may be such as the automotive vehicle side light  35 , shown in FIG. 2 after the molding process. In the illustrated embodiment, the novel mold of the present invention is shown being used for single sided encapsulation. However, it should be understood that the present invention may a) mold a part, b) encapsulate a sheet of material, or c) encapsulate one or more sides of a sheet of glass, and be well within the scope of the present invention. 
     The finished automotive side light  35  has a plain front surface  36 , and a rear surface  37  having a ceramic enamel band  38  applied thereto for distance X before insertion into the mold  27 . 
     After the molding process takes place, in a manner to be described in detail below, the entire perimeter of the rear surface  37  of the automotive side light  35  is encapsulated for a distance Y with a gasket  39  applied over the ceramic enamel band  38 . The front surface  36  is completely free of molding material, as is the edge  40  of the side light  35 . 
     Referring now to FIGS.  1  and  4 - 10  the present invention is described in more detail. Referring specifically to FIG. 4, there is shown multi-part mold base  29  fixedly, but removably, attached by means well known in the art to the fixed lower mold platen  22 . The multi-part mold base  29  may include such as a mold base plate  40  to which is fixedly attached a fixed mold base  41 . Surrounding the fixed mold base portion  41  is a plurality of slidable mold bases  42 . In FIG. 4 the slidable mold bases  42  are shown in their normally open position adjacent the fixed mold base  41 . The slidable mold bases  42  are biased away from the fixed mold base  41  by springs  44  in a manner to be described in more detail herein. Each of said plurality of slidable mold bases  42  has at least one flange  46  (FIG. 9) which is engaged by complimentary shaped retainer  47 . In the preferred embodiment illustrated there is a flange  46  at each end of each slidable mold base  42 . Each flange  46  is engaged by a complimentary shaped retainer  47  in a manner which provides for reciprocating movement of the slidable mold bases  42 . The slidable mold bases  42  reciprocate between a closed adjoining (touching) relationship with the fixed mold base  41 , and an adjacent, open, relationship, as determined by the adjustable stops  50 . 
     Referring to FIG. 7, each adjustable stop  50  is fixedly attached to the mold base plate  40  by any of many ways well known in the art. A plurality of springs  44 , carried by an equal plurality of base spring pockets  52  and slidable spring pockets  53  keep the slidable bases  42  in an open, biased away from, or adjacent (non-touching) relationship with the fixed mold base  41 . The amount of travel permitted the slidable mold bases  42  is limited by the adjustable stops  50 . Each adjustable stop  50  has a threaded aperture  55  in a stop block  56 . A threaded stud  57  is threaded into the aperture  55  to the extent desired, and a lock nut  58  is threaded onto the threaded stud  57  and tightened to maintain the position of the stud once adjusted. Loosening the adjustable lock nut  58  permits the threaded stud  57  to be adjusted as desired. 
     Another function of the adjustable stops  50  is to keep the cam follower  60 , which may be mounted on each of the plurality of the slideable mold bases  42  in proper position to be acted on by cams  61  mounted on the moveable mold core  30 . It can be understood that as the moveable mold core  30  moves between its opened and closed position by reciprocation on the tie bars  25 , cams  61  will operate on cam followers  60  to move the slidable mold bases  42  between their open or adjacent position with respect to the fixed mold base  41 , and their closed or adjoining position with respect thereto. 
     To increase the wear properties of the mold  27 , a cam follower wear plate  60 A is provided or interposed between each cam follower  60  and its respective slidable mold base  42 . Likewise, a slide wear plate  62  may be provided or interposed between each slidable mold base  42 , and the mold base plate  40 . 
     Referring now to FIG. 5 the moveable mold core  29  is shown in more detail. Moveable mold core  29  is fixedly mounted to the moveable upper mold platen  23 . Moveable upper mold platen  23  reciprocates on tie bars  25  with the aid of bearings  64 . Proximate each corner of the moveable mold core  30  may be mounted a locating pin cavity  66  to accept a complimentary shaped locating pin  67  (FIG. 6) mounted proximate each corner of the multi-part mold base  29 , adjacent the complimentary shaped retainers  47 . 
     Recesses  70  (FIGS.  5 , 7 ) may be provided in moveable mold core  30  to provide clearance for the multi-part mold base  29 , and more specifically for the slidable mold bases  42 . Cams  61  are shown mounted in, or adjacent, the recesses  70 , but may be mounted in any desired position depending on the application. 
     With reference to FIGS. 8 and 10, the details of the mold cavity C being used to produce the side light  35  can be clearly seen. The shape and extent of the mold cavity C, into which molding material  71  is introduced, is defined by the shape of the frangible sheet A, which may include enamel band  38 , moveable mold core  30 , slidable mold bases  42 , and fixed mold base  41 . 
     More particularly, the fixed mold base  41  of mold  27  has a slanted surface  74  extending about an inner perimetrical portion thereof. Inwardly of the slanted surface  74  are mounted one or more vacuum heads  75 . A horizontal portion  76  has a first portion  76 A, and a second portion  76 B, separated by a support gasket groove  78 . A support gasket  79  is mounted in support gasket groove  78 . 
     A slideable mold base  42 , shown in its closed, adjoining, position in FIGS. 8 and 10, has a side seal groove  80  in which is carried a side seal  81 . Slideable mold base  42  also carries a material shaping surface  82 . 
     Moveable mold core  30  has a cavity seal groove  85 , which may be of the same shape as support gasket groove  78 , and be in a 180° opposed position, or mirror image, if desired. Carried in cavity seal groove  85  is cavity seal  86 . Moveable mold core  30  additionally has a complemental material shaping surface  87 , a substantially V shaped recess  88 , a dome shaped recess  89 , second material shaping surface  90 , and third material shaping surface  91 . 
     The frangible sheet a, such as side light  35 , is supported in the fixed mold base  41  by the vacuum heads  75  and the support gaskets  79 . Referring to FIGS. 4,  8 , and  10 , as the slideable mold bases  42  are closed by the action of the cams  61  on the cam followers  60 , the side seal gaskets  81  come into contact with edge  40  of side light  35  about the entire edge  40  of the side light  35 . 
     With the mold core  30  in its closed position, it can be seen that the mold cavity C is defined by the various shapes of the mold previously described, as well as the enameled band  38  on the side light  35 . More specifically, in the embodiment illustrated, the mold cavity is formed by the cavity seal groove  85 , the ceramic enameled band  38 , a portion of the side seal  81 , the material shaping surface  82 , the complemental material shaping surface  87 , the substantially shaped V-shaped recess  88 , the second material shaping surface  90 , dome shaped recess  89 , and the small third material shaping surface  91 . 
     According to the method of the present invention the moveable mold core  30  will be in its spaced apart, open, facing position with multiple part mold base  29 . Each of the plurality of the slideable mold bases  42  of the multi-part mold base  29  will be in their normally open, adjacent, position with respect to the fixed mold base  41 . A sheet of glass  5  will be loaded into the fixed mold base  41  and supported therein by the vacuum heads  75  and the support gasket  79 . Means will known in the art will control and supply vacuum to vacuum heads  75 . 
     Suitable control means and fluid power sources, also well known in the art, will be used to lower moveable mold core  30  into a facing, adjacent, or adjoining, position with the fixed mold base  41 . This causes the slideable mold bases  42  to come into an adjoining relationship with the fixed mold base  41 , and the side seal gasket  81  to seal against the edge  40  of the side light  35 . 
     At this point, mold  27  is completely closed, as shown in FIG.  10 . The cavity seal groove  85 , ceramic enamel band  38 , side seal  81 , material shaping surface  82 , complemental material shaping surface  87 , substantially V-shaped recess  88 , second material shaping surface  90 , dome shaped recess  89 , and third material shaping surface  91  form the mold cavity c. A molding material  71  will be introduced to the mold cavity C through the mold sprue or opening  32  (FIG.  1 ). The mold  27  will remain closed for a suitable curing or cooling time, after which the moveable mold core  30  will be opened, allowing the slideable mold bases  42  to move away from the fixed mold base  41  by virtue of the action of the springs  44 . The vacuum will be released from the vacuum heads  75 , and the sheet of glass i, such as the side light  35 , will be removed from the mold. 
     An apparatus for practice of the present invention may be the horizontal mold press  20  shown in FIG. 1, in which the mold  27  is mounted. It can be understood from the foregoing description that the mold  27  is easily used in a variety of known molding presses, all of which are well within the scope of the present invention. Thus, by carefully analyzing problems present in the molding art, a novel mold has been produced, as well as a novel method and apparatus for use with the mold. The product made by the method or process disclosed in the present application is also well within the scope of the present invention. 
     In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.