Abstract:
A mold cooling system is disclosed for the blank mold halves of an I.S. machine. The mold halves are supported at their bottom by a lower hanger assembly which includes a discrete plenum for each of the mold halves. Each plenum is isolated and has its own air supply which includes an adjustable flow control. This provides complete control of the mold cooling process.

Description:
This invention relates to a mold mechanism at a blank station of an I.S. type glassware forming machine. 
   BACKGROUND OF THE INVENTION 
   In the production of glass containers by the press and blow method on the well known I S type machine, a gob of glass is provided to a blank or parison mold comprising two mold members or halves which are supported by a mold mechanism at a blank station of the machine, which mold members can be closed to form a mold cavity_ The glass in the mold cavity is pressed into the required shape of a parison by a plunger moving upwardly into the mold cavity, a lower portion of the glass being forced into a neck ring of the mold. The plunger is then withdrawn and the parison is carried by the neck ring away from the blank station and is transferred to a blow mold station where it is blown to the required shape. In the blow and blow method a gob of glass is provided to the parison mold and is then blown into the required shape of a parison. The shaped parison is again carried by a neckring away from the blank station to a blow mold station. 
   It is necessary to cool the parison mold and this is commonly done by providing the mold members with cooling passages extending axially therethrough from a lower end face to an upper end face of the mold member. Commonly, for reasons of space, the cooling air has been provided to the upper ends of these cooling passages, and has passed downwardly through the mold members, but this does impede access to the blank mold mechanism. 
   In I S machines as employed at present, the cooling applied to the two blank molds in a double gob machine does not differentiate between the two blank molds. This is in fact disadvantageous, as the two blank molds heat up to different extents and as a result the two parisons delivered to the blow molds are not in the same temperature condition as each other, which can lead to the formation of unsatisfactory containers. 
   GB 2151608 describes an arrangement for cooling the blank mold members at the blank station of a double gob IS machine in which air is supplied to a plenum chamber which is positioned over the upper portion of two adjacent blank mold members and from which air is supplied at substantially uniform pressure to upper ends of cooling passages extending axially through the two blank mold members. This arrangement has been successful in operation, particularly because the uniformity of the pressure of the air supplied to the axial cooling passages enables calculation of the cooling effect of the air, but as one plenum chamber supplies one mold member of each blank mold it is not possible to differentiate between the cooling of the two molds. 
   U.S. Pat. No. 4,388,099 describes an arrangement for cooling the blank mold members at the blank station of a double gob IS machine in which air is supplied through a series of throttle valves to a number of chambers each arranged to supply air to some of a number of cranked cooling passages which extend partially obliquely and partially axially through the two blank mold members. The cooling effect of the air in this arrangement is not readily calculable not only because adjustment of the throttle valves alters the air flow unpredictably, but also because air flow in such cranked passages is also irregular, and the success of the cooling system depends on ad hoc adjustments of the various throttle valves. 
   OBJECT OF THE INVENTION 
   It is accordingly an object of the present invention to provide a cooling system for the blank s of an I.S. machine which will allow individual control of each of the blank mold halves. 
   BRIEF DESCRIPTION OF THE DRAWNGS 
   In the accompanying drawings: 
     FIG. 1  shows a mold mechanism at a blank station of a double gob glassware forming machine with some parts omitted and with a pair of mold halves in the mechanism; 
     FIG. 2  shows a view similar to  FIG. 1  but viewed from the other side of the mold mechanism; 
     FIG. 3  shows a view of an upper portion of an air chamber member; and 
     FIG. 4  shows a view of a lower portion of an air chamber member. 

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A multi gob glassware forming machine, specifically a double gob machine comprises a mold mechanism,  FIGS. 1 &amp; 2 , mounted on a table  3  of the machine at a blank station of the machine. The mold mechanism comprises a pivot  2  fixed in the machine and two mold arms  4 , 6 , mounted on the pivot  2  and adapted to support two blank molds, only one,  8 , of which is shown in an open condition in  FIG. 1 . The blank mold  8  comprises two mold members  10 , 12 , which are generally cylindrical in shape and each of which has straight cooling passages  14  extending axially through the mold member from a lower end face  16 , 18  to an upper end face  20 ,  22  of the mold members. It can be seen that the lower end faces  16 ,  18  bound a recess  17 ,  19  extending round an outer face of a lower end portion of the mold members, and the cooling passages  14  open into the recesses  17 ,  19  when the mold members are in position. It will be understood that the mechanism illustrated is adapted to have two blank molds, i.e. four mold members, and that the mold members are all similar as are the means for supporting the mold members in the mold mechanism. While the open and close mechanism is illustrated in the double gob configuration, it could also be single or double gob. 
   The mold arm  4  supports, on a generally vertical support rod  23 , an upper mold support  24 , and a spacer  26  which determines the height of the upper mold support  24  with respect to the mold arm  4 . The upper mold support  24  comprises two curved ridges  28 , only one of which can be seen in  FIG. 1 . The corresponding hook or curved ridge  30  on the member will be located behind the curved ridge when the mold is in place. A block  32  secured to the support  24  engages with a corresponding slot (shown at  34  on the mold member  12 ) in the mold member  10  accurately to locate the mold member  10  in position on the support  24 . 
   The mold arm  4  also supports on the rod  23  a lower mold support  36  and a spacer  38  between the mold support  36  and the arm  4  which determines the height of the lower mold support  36  with respect to the mold arm  4 . The lower mold support  36  defines an air plenum chamber  39  for the supported mold halves and serves not only to supply cooling air to the mold supported mold half but also to vertically locate the lower end portion of the mold member. The air chamber member  39  comprises an upper member  46  and a lower member  50  secured together by bolts  58  through holes  52  in the member  46  and  54  in the member  50 . The lower member  50  is recessed and comprises two air inlets  60  and  62 . The inlet  60  leads into a recess  64 , the inlet  62  leads into a recess  66  separated from the recess  64  by a wall  68 . The two members  46  and  50  when secured together provide two plenum chambers. In a plenum chamber, the entry to the chamber is sufficiently spaced from the exits to the chamber that a substantially uniform pressure is provided at the exits. The upper member  46  comprises two generally semicircular vertical surfaces  40  which are to be proximate the side wall of a supported mold. These vertical surfaces  40  are adjacent two horizontal supporting surfaces  42 . The surfaces  42  are flat and generally semicircular in plan and have a series of curved apertures  44  formed in them which open into the plenum chambers formed by the recesses  64  and  66  and which are adapted to correspond with the cooling passages of the mold members, i.e. the passages  14  of the mold member  10  opening into the end face  16 . The chamber member  39  enters the recess  17 , the bottom surface or face  16  engages the horizontal support surface  42 , and the vertical surfaces  40  engage the outer circumference of the mold member. The apertures  44  are positioned so that they will be in communication with the lower ends of the cooling passages in the mold member. The mold is supported vertically at the bottom of the mold where the horizontal bottom surface of the mold  16  rests on the horizontal supporting surface of the upper portion  46  of the lower support. 
   The upper member  46  has an aperture  70  which meets a corresponding aperture  72  in the lower member  50 , and the support rod  23  passes through the apertures  70  and  72  to support the chamber member  39  against the spacer  38 . The inlets  60 , 62  to each plenum chamber are connected by flexible air supply tubes  74  to air control cylinders  76 . Another air control cylinder  76  (not clearly shown) also support a manifold  78  which is also connected to a neck-ring cooling head  80  which directs cooling air onto a neck-ring mechanism  82  of the parison forming mechanism (only shown diagrammatically.) 
   The mechanism according to the invention offers improved control over mold cooling. An independently adjustable air control cylinder  76  (the control cylinder has a settable valve) controls the supply of cooling air to the neck-ring cooling and to each of the plenum chambers independently. 
   Each air control cylinder has a settable valve (either manually or electronically operable) and accordingly, each control valve is independently adjustable.