AT LEAST TWO DISPARATELY-COLORED GOBS

5

BACKGROUND

The formation of glass into useful and artistic objects dates to at least the 4 ^,h

10 Century BCE. Among the established techniques for forming glass are flow-molding, press-molding and hand-blowing. Hand-blown glass objects are admired for the artistry and skill required to produce them, and the uniqueness of each piece so produced. In hand-blowing glass, a skilled artisan gathers a gob of molten glass about the distal end of a gathering implement. The gathering implement is typically i s hollow so that, as the artisan manipulates the implement to shape the gob, he can blow air into the gob to create a cavity within the work piece. In this general manner, a glassblower is able to create vessels such as cups, bowls and bottles.

As glass is hand-blown, the artisan might add unique features to the work piece. For example, color might be added by incorporating certain metals or minerals

20 into the glass as it is reheated and worked. The inclusion of such features signifies artistry, skill and uniqueness. However, the very nature of the hand-blowing process renders hand-blown pieces expensive and impractical for use as containers for all but the highest-end products such as fine perfumes and select alcoholic beverages.

Contrasting with the artistry associated with hand-blown glass objects is the

25 rapid mass production of strictly utilitarian objects such as window panes and beverage bottles. Among the goals of manufacturing vessels such as drinking glasses and beverage bottles are rapid reproducibility and uniformity of appearance among units. Of particular importance is uniformity among units in physical dimensions such as opening shape and size in order to facilitate the use of

30 standardized lids, plugs or caps as closures. Accordingly, in the modern era, glass vessels are largely produced by strictly-controlled automated hot pressing and blowing processes. Such processes have the advantage of being relatively inexpensive and invariant, but result in products lacking uniqueness and artistry.

A process for producing a multi-tone glass vessel from at least two disparately-

35 colored molten-glass gobs yields vessels combining the artistry and uniqueness traditionally resulting from hand-blowing with the dimensional reproducibility required for mass production. SUMMARY

Implementations of the present invention are generally directed to a method of mass-producing consistently-dimensioned, multi-tone (e.g., two-tone) glass vessels 5 from at least two disparately-colored molten-glass gobs while maintaining structural integrity. For purposes of conceptualizing the desired color contrast, it is to be understood that "transparent" or "clear" is regarded as a color throughout the present description and the claims appended hereto. Accordingly, one glass might be transparent, while another at least partially opaque. Although not so limited in scope,

10 among the glass vessels of particular interest are drinking glasses, cups, bowls, decanters, vases, and selectively closeable bottles intended for the containment of products such as perfume and alcoholic beverages, by way of non-limiting example.

In accordance with an illustratively implemented method of making a two-tone vessel of predetermined shape, an "initial" or "first" gob of molten glass of a first color i s is gathered. In a typical version, the molten-glass first gob is removed from a glass furnace by gathering it about a distal end of an elongated gathering implement such as a rod, tube or gathering iron, by way of example. The first gob is introduced into a pre-form mold into which - in one implementation - an initial quantity of gas, such as air, by way of non-limiting example, is injected in order to form the initial gob into a

20 rudimentary pre-form vessel. The pre-from mold is vertically oriented such that molten glass is introduced through an open upper end thereof and the gas is introduced through an opening at a lower end opposite the upper end. In this manner, the injection of an initial quantity of gas through the lower end of the pre-form mold forms a cavity within the first gob that fills with gas and causes the first gob to expand and

25 rise toward the open upper end of the pre-form mold. It will be appreciated that the end of the "partially-inflated" first gob that is nearest the upper end of the pre-form mold corresponds to what will become the lower end of a finished vessel, while the end of the first gob through which the gas is blown corresponds to what will become an opening in the finished vessel.

30 Once the partially-inflated first gob has assumed a predetermined shape and size, a molten-glass second gob of a second color, contrasting in color with the first color, is introduced into the pre-form mold over the partially-inflated first gob. Steps are taken to ensure that the glass is acceptably distributed within the pre-from mold. With the second gob disposed on top of the partially-inflated first gob, additional gas is introduced into the pre-form mold in order to form the first and second gobs into a single pre-form vessel having at least one pre-form vessel wall defining a pre-form vessel exterior surface and a pre-form vessel interior surface defining a pre-form 5 vessel cavity. The quantity of gas blown into the pre-form mold depends, in part, on the desired wall and base thicknesses of the vessel being formed.

In one version, when the pre-form vessel is sufficiently cool and "self- supporting" to retain its basic shape, it is removed, while still hot, from the pre-form mold, and introduced into a finish mold. If required, the pre-form vessel is heated

10 sufficiently to allow final shaping prior to introduction into the finish mold, while care is taken not to deform the pre-from vessel to such an extent that it cannot be processed in the finish mold. With the pre-form vessel disposed within the finish mold, a quantity of gas is injected into the pre-form vessel cavity in order to form the pre-form vessel into a finished vessel having at least one finished vessel wall defining finished vessel i s exterior and interior surfaces, the later surface further defining a finished-vessel storage cavity.

In some implementations, the pre-form and finish molds are actually the same physical mold which, when used in a "pre-forming" step is referred to as a "pre-form mold" and, when used in a "finish-molding" step is referred to as a "finish mold." In

20 fabricating a more complex glass vessel, such as a bottle including a neck, the use of physically distinct pre-form and finish molds facilitates intermediate shaping, thereby obviating logistical difficulties and diminished quality attendant to the use of a single mold at two different stages of the process in order to form the first and second gobs into the final shape desired. Although the summation of the process to this point has

25 implied molding in two stages, it will be generally appreciated that implementations prescribing more than two molding steps are also within the scope of the invention as defined in the claims. More specifically, even in implementations involving three or more molding steps, at least one such step (e.g., the first molding step) is regarded as a pre-forming step involving a pre-form mold, while at least one other step (i.e., the

30 final molding step) is regarded as a finish molding step involving a finish mold.

In alternative implementations, apparatus controlled by a programmable computer are variously utilized in the performance one or more steps. For instance, the use of a computer-controlled pneumatic injector is particularly useful in ensuring that the quantity and pressure of gas injected into the mold is appropriate, precise and selectively tunable. Additionally, at least one multi-piece mold can be opened and closed by computer-controlled pneumatics, hydraulics or motor-actuated linkages. While human involvement is integral to the implementation of some versions, particularly at the gob-gathering and mold-filling stages - where an artisan's vision and skill might be desired - in alternative versions, even one or more of the steps prior to introduction of the gob into either the pre-form mold, or the introduction of the pre-form vessel into the finish mold, is performed by computer-controlled apparatus.

Representative, non-limiting implementations are more completely described and depicted in the following detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a molten-glass first gob being extracted from a glass furnace; FIG. 2 shows the molten-glass first gob of FIG. 1 being deposited into an open- top vessel-defining pre-form mold;

FIG. 3 depicts the partial inflation, and upward expansion, of the first gob of FIG. 2 as a gas is introduced into a lower end of the pre-form mold;

FIG. 4 illustrates the deposition of a molten-glass second gob, contrasting in color with the first gob of FIGS. 1-3, on top of the partially-inflated first gob within the pre-form mold of FIGS. 1 and 2;

FIG. 5A depicts the open pre-form mold and the injection of gas to force the molten gob to assume a non-final shape defined by the pre-form mold, although the pre-form mold would not be open when gas is injected;

FIG. 5B shows a non-finally-shaped pre-form vessel after removal from the pre- form mold;

FIG. 5C depicts the non-finally-shaped pre-form vessel of FIGS. 5A and 5B situated in an open finish mold;

FIG. 6 shows the finish mold of FIG. 5C in a closed position so that gas can be introduced to finalize the basic shape of the pre-form vessel of FIGS. 5A-5C; and

FIG. 7 illustrates the feeding into an annealer a finished vessel resulting from the molding step associated with FIG. 6.

DETAILED DESCRIPTION

The following description of methods of fabricating a multi-tone glass vessel is demonstrative in nature and is not intended to limit the invention or its application of 5 uses. The various implementations, aspects, versions and embodiments described in the summary and detailed description are in the nature of non-limiting examples falling within the scope of the appended claims and do not serve to maximally define the scope of the claims.

In conjunction with FIGS. 1 through 7, there are described alternative 10 illustrative methods of fabricating a multi-tone glass vessel from at least two disparately-colored molten-glass gobs. With initial reference to FIG. 1 , a molten-glass first gob 20a of first glass Gi of a first color Ci is gathered around the distal end 12 of an elongated gathering implement 10 and extracted from a furnace 15. The gathering implement 10 is manipulated in order to give the first gob 20a a generally ellipsoidal i s shape.

The illustrative implementations described with reference to FIGS. 1 through 7 prescribe multi-stage molding processes, each of which includes, as shown in FIG. 2, the introduction of the molten-glass first gob 20a into a pre-form mold 30. With temporary additional reference to FIG. 5A, the illustrative pre-form mold 30 first shown

20 in FIG. 2 includes first and second mold portions 32 and 36 with, respectively, first and second interior walls 33 and 37. When the first and second mold portions 32 and 36 - which are hingedly joined in the example depicted -- are brought into mutual contact, the first and second interior walls 33 and 37 define an internal pre-shaping cavity 38. In the illustrative version depicted, the pre-shaping cavity 38 is configured to define a

25 pre-form vessel 50.

With continued reference to FIGS. 2, and additional reference to FIG. 3, with the molten-glass first gob 20a deposited in the pre-form mold 30, a pneumatic injector 200 injects an initial quantity of gas 210 into the pre-form mold 30 through an opening 39. The pre-from mold 30 is vertically oriented such that molten glass is introduced

30 through an open upper end 31u thereof and the opening 39 through which the gas 210 is introduced is at a lower end 31 _L opposite the upper end 31 u- The injection of an initial quantity of gas 210 through the opening 39 in the lower end 31 _L forms a gob cavity 25 within the first gob 20a. Filling the gob cavity 25 with gas 210 causes the first gob 20a to inflate and rise toward the open upper end31u of the pre-form mold 30.

Referring to FIG. 4, when the partially-inflated first gob 20a has assumed a predetermined shape and size, as in FIG. 3, for example, a molten-glass second gob 20b of a second glass G2 and second color C ₂ , disparate from the first color Ci, is deposited into the pre-form mold 30 over the partially-inflated first gob 20a. With the second gob 20b disposed on top of the first, partially-inflated gob 20a, an additional, second quantity of gas 210 is introduced into the pre-form mold 30. The internal gas pressure is elevated sufficiently to form the gobs 20a and 20b into a single pre-form vessel 50. While the formation of the gobs 20a and 20b into a pre-form vessel 50 is shown in FIG. 5A with the pre-form mold 30 depicted in an open position, this is only to facilitate explanation; it is to be understood that the introduction of additional gas 210 into the pre-form mold 30 actually occurs while the first and second mold portions 32 and 36 are in mutual contact (i.e., while the pre-form mold 30 is closed), as in FIG. 3.

When the pre-form vessel 50 is sufficiently cool and "self-supporting" to retain its basic shape, the pre-form mold 30 is opened and the non-finally-shaped pre-form vessel 50 is removed, as shown in, respectively, FIGS. 5A and 5B. The illustrative pre-form vessel 50 of FIG. 5B has a pre-form vessel wall 52 defining a pre-form vessel exterior surface 54 and a pre-form vessel interior surface 56 defining a pre-form vessel cavity 57. Moreover, the disparately-colored first and second glasses Gi and G ₂ have been mutually fused into a unity structure (the pre-form vessel 50). In the illustrative implementation under consideration, the heated pre-form vessel 50 of FIG. 5B is transferred from the pre-form mold 30 to a finish mold 70. The illustrative finish mold 70 of FIG. 5C includes first and second mold pieces 72 and 76 having, respectively, first and second inside walls 73 and 77. When the first and second mold pieces 72 and 76 are urged into mutual contact to seal the finish mold 70, the first and second inside walls 73 and 77 define an internal finish-shaping cavity 78.

As shown in FIG. 6, in a manner analogous to that associated with shaping in the pre-form mold 30, a quantity of gas 210 is injected into the closed finish mold 70, and into the pre-form vessel cavity 57, through a pneumatic injector 200 in order to impart to the pre-form vessel 50 its final shape and form it into what is subsequently regarded as a finished vessel 80. After shaping in the finish mold 70, the finish mold 70 is opened in the general manner shown in FIG. 5C, and the finished vessel 80 is removed.

As shown in FIG. 7, an illustrative finished vessel 80 is being fed through an annealer 300 in order to cool the glass in a controlled manner and prevent internal stresses that might cause the glass to crack if it is allowed to cool too quickly. The finished vessel 80 has at least one vessel wall 82 defining finished vessel exterior and interior surfaces 84 and 86. As with the pre-form vessel 50 shown in FIG. 5B, the finished vessel 80 exhibits a two-tone pattern including the mutually fused first and second glasses Gi and G ₂ of, respectively, first and second colors Ci and C ₂ . It should be noted that, while the delineation between the first and second glasses Gi and G2 is depicted as relatively even and "clean" for illustrative purposes, in various implementations, the delineation is actually somewhat unpredictably "smeared," thereby imparting to each finished vessel 80 unique attributes by which it can be distinguished from other vessels 80 produced in accordance with the same general process in the same molds.

As previously explained, alternative implementations involve the use of either (i) a single mold in temporarily separate "pre-forming" and "finish-molding" steps or (ii) two or more physically distinct molds in "pre-forming" and "finish-molding" steps. As a general observation, more intricate final products call for molding in at least two stages with at least two physically distinct molds. For instance, while the formation of a vessel such as a drinking cup might be pre-formed and finish molded in a single physical mold, and perhaps even in a single molding step, a vessel such as a bottle might call for physically distinct pre-form and a finish molds.

The particular illustrative finished vessel 80 of FIG. 7 is a bottle 90 which has a main body 92 defining an internal storage cavity 94 and a neck 96 depending from the body 92. The neck 96 is narrow relative to the main body 92 and has a neck opening 98 (or channel) extending therethrough that renders the storage cavity 94 in fluid communication with the exterior of the bottle 90. It will be appreciated that the formation of a relatively narrow neck 96 might best be performed in a multi-stage molding process with at least two physically distinct molds. This is particularly true when the neck 96 and the neck opening 98 must be fabricated within "tight" or relatively unforgiving tolerances, as when the bottles 90 being produced are to be sealed by standardized closures such as caps or plugs (not shown).

The foregoing is considered to be illustrative of the principles of the invention. Furthermore, since modifications and changes to various aspects and implementations will occur to those skilled in the art without departing from the scope and spirit of the invention, it is to be understood that the foregoing does not limit the invention as expressed in the appended claims to the exact constructions, implementations and versions shown and described.