CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and benefits of Chinese Patent Application Serial No. 201110421420.3, filed with the State Intellectual Property Office (SIPO) of P. R. China on December 15 ^th , 2011, the entire contents of which are incorporated herein by reference.

FIELD

The present disclosure relates to the field of amorphous alloy, more particularly to a die casting device and a die casting process for amorphous alloy.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Amorphous alloy materials are also termed as metallic glass. Due to special structure of atoms constituting the alloy, the amorphous alloy may possess excellent physical and chemical properties, such as high yield strength, high hardness, super-elasticity, high erosion resistance and high anti-corrosive performance etc., different from conventional crystalline metal material.

Meanwhile, the amorphous alloy also possess excellent die casting performance due to the special structure and chemical property. Because amorphous structure has to be formed during molding, heterogeneous nucleation has to be prevented from happening for the amorphous alloy. Because the amorphous alloy normally contains active elements such as zirconium, aluminum, magnesium, titanium, rare earths etc., the active elements may be reactive with nonmetallic gas elements to form the nucleus of heterogeneous nucleation, which may hinder the forming of the amorphous structure or decrease the critical size of the amorphous alloy tremendously.

U.S. Pat. No. 6,021,840 presents a vacuum die casting technology, which may prevent molten amorphous alloy and alloy elements during molding from oxidization by forming vacuum. However, with the use of vacuum technology, especially with the formation of high leveled vacuum as proposed, for example, in U.S. Pat. No. 6,021,840, up to lOOOum Hg, costs relating thereto is increased and the die casting period for the amorphous alloy is extended, which may decrease manufacturing efficiency. Meanwhile, the vacuum system has to be maintained with a sealing system which may tremendously impact the continuity and convenience of operators and increase complexity of manufacture.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The present disclosure is aimed to solve at least one of the problems existing in the art. In viewing thereof, a die casting apparatus for an amorphous alloy may need to be provided, which may have a simplified structure using positive pressure protecting gas without the need to form high degree vacuum, thus reducing manufacturing and maintenance costs.

In addition, a die casting method for an amorphous alloy may need to be provided, which may have a simplified operating process with lowered cost in addition to increased efficiency and shortened manufacturing period.

According to an embodiment of the present disclosure, a die casting apparatus for an amorphous alloy may comprise: a stationary die and a movable die defining a die chamber when mated with each other; a sealed cabin defining a sealing chamber, the sealing chamber having a feeding port; a protecting gas supplying device connected with the sealed cabin for supplying the protecting gas into the sealing chamber so that the protecting gas inside the sealing chamber has a positive pressure; a melting device disposed within the sealed cabin for receiving and melting amorphous alloy fed from the feeding port; a feed sleeve communicated with the die chamber having a molten material inlet, with a plunger positioned therein for injecting the molten amorphous alloy from the melting device into the die chamber via the molten material inlet; a driving device connected with the plunger for driving the plunger in the feed sleeve; and a gas purifying device communicated with the sealed cabin for purifying the gas from the sealed cabin.

According to another embodiment of the present disclosure, a method of die casting an amorphous alloy may comprise the steps of: purifying a sealing chamber defined in a sealed cabin; supplying protecting gas into the sealing chamber to maintain the protecting gas in the sealing chamber to a positive pressure; feeding amorphous alloy into a melting device disposed inside the sealing chamber to obtain the molten amorphous alloy while the protecting gas filled within the sealing chamber overflowing outside; feeding the molten amorphous alloy into a die chamber defined by a mated stationary die and a movable die via a feed sleeve with a plunger positioned therein; and opening the mated stationary and movable dies to extract at least a component formed at least partially of the amorphous alloy from inside the die chamber while the protecting gas filled within the sealing chamber overflowing outside.

According to embodiments of the present disclosure, the sealing chamber may be purified first and then filled with protecting gas having positive pressure, so that no external gas may be entered therein during material feeding or component exporting, which may effectively isolate the molten amorphous alloy from contacting with the air. Thus, heterogeneous nucleation may be prevented and the critical size of the amorphous alloy may be increased tremendously. In addition, vacuum suction may not be needed, which may reduce manufacturing and maintenance costs accordingly.

Additional aspects and advantages of the embodiments of the present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of the disclosure will become apparent and more readily appreciated from the following descriptions taken in conjunction with the drawings in which:

Fig. 1 is a schematic view of a vertical type die casting apparatus for an amorphous alloy according to an embodiment of the present disclosure;

Fig. 2 is a schematic view of a horizontal type die casting apparatus for an amorphous alloy according to an embodiment of the present disclosure; and

Fig. 3 is schematic diagram of a method of die casting an amorphous alloy according to a third embodiment of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail in the following descriptions, examples of which are shown in the accompanying drawings, in which the same or similar elements and elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein with reference to the accompanying drawings are explanatory and illustrative, which are used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure.

Various embodiments and examples are provided in the following description to implement different structures of the present disclosure. In order to simplify the present disclosure, certain elements and settings will be described. However, these elements and settings are only examples and are not intend to limit the present disclosure. In addition, reference numerals may be repeated in different examples in the disclosure. This repeating is for the purpose of simplification and clarity and does not refer to relations between different embodiments and/or settings. Furthermore, examples of different processes and materials are provided in the present disclosure. However, it is appreciated for those skilled in the art to understand that other processes and/or materials may be also applied.

Moreover, a structure in which a first feature is "on" a second feature may include an embodiment in which the first feature directly contacts the second feature and may include an embodiment in which an additional feature is prepared between the first feature and the second feature so that the first feature does not directly contact the second feature. In the following, a die casting apparatus 100 for an amorphous alloy may be explained in detail with reference to accompanying figures, where Fig. 1 shows a schematic view of a vertical type, and Fig. 2 shows a horizontal type. It should be noted that the die casting apparatus 100 may be used for die casting other active metals with similar properties to the amorphous alloy, such as titanium alloy, or magnesium alloy etc.

As shown in Fig. 1, the die casting apparatus 100 may comprise a stationary die 1, a movable die 2, a sealed cabin 4, a protecting gas supplying device (not shown), a melting device 5, a feed sleeve 6, a driving device 8 and a purifying device 10.

To be specific, the stationary die 1 and the movable die 2 may be closed or opened, and define a die chamber when the stationary die 1 and the movable die 2 may be mated with each other. A sealing chamber 40 may be defined in the sealed cabin 4 and the sealed cabin 4 may have a feeding port 41 to feed the amorphous alloy inside the sealing chamber 40. The protecting gas supplying device may be connected with the sealed cabin 4 to supply the protecting gas to the sealing chamber 40, and the protecting gas inside the sealing chamber 40 may have a positive pressure, which may effectively prevent external harmful gases from entering into the sealing chamber 40. Alternatively, the protecting gas may be at least one of inert gases, such as helium, neon, argon, krypton, xenon, radon or the combination thereof.

In one embodiment, the melting device 5 may be disposed in the sealed cabin 4 for receiving and melting the amorphous alloy fed from the feeding port 41. The feed sleeve 6 may be communicated with the die chamber 3, and the feed sleeve 6 may be formed with a molten material inlet 60, and a plunger 7 for injecting the molten amorphous alloy into the die chamber 3. The driving device 8 may be connected with the plunger 7 for moving thereof inside the feed sleeve 6, so that the molten amorphous alloy may be injected from the feed sleeve 6 to the die chamber 3 for die casting. The purifying device 10 may be connected with the sealed cabin 4 for purifying the harmful gases inside the sealing chamber

40. And the gas inside the sealing chamber 40 may contain harmful gases such as N ₂ , 0 ₂ ,

H ₂ 0, C0 ₂ or the combination thereof. In one embodiment, the die casting apparatus 100 may be formed with an output port 13 for outputting or exporting the amorphous alloy after die casting. It should be noted that the output port 13 may be formed on the sealed cabin 4 when the die casting apparatus 100 is a vertical type as shown in Fig. 1, and the output port 13 may be formed on the stationary die 1 and/or the movable die when the die casting apparatus 100 is a horizontal one, as shown in Fig. 2. The details thereof will be described in detail hereinafter.

During die casting, firstly, the stationary die 1 and the movable die 2 are mated with each other to form the die chamber 3, and the purifying device 10 may purify the harmful gases in the sealing chamber 40 so that the harmful gases in the sealing chamber 40 may have a concentration lower than a predetermined value. Then, the protecting gas supplying device may supply the protecting gas to the sealing chamber 40 until the protecting gas inside the sealing chamber 40 may have a positive pressure, which may mean that the pressure inside the sealing chamber 40 is higher than environmental pressure. And the amorphous alloy may be sent to the melting device 5 from the feeding port 41. Then, the feeding port 41 is closed, and the amorphous alloy is melted in the melting device 5 to be sent to the feed sleeve 6 via the molten material inlet 60, and the driving device 8 may drive the plunger 7 to inject the molten amorphous alloy into the die chamber 3, and the molten amorphous alloy may be shaped inside the die chamber 3. And finally the stationary die 1 and the movable die 2 may be opened, and the amorphous alloy after die casting may be extracted from the output port 13.

According to an embodiment of the present disclosure, by providing the protecting gas supplying device and the purifying device 10 and when the harmful gases inside the sealing chamber 40 are purified by the purifying device 10, the protecting gas supplying device may supply the protecting gas to the sealing chamber 40 and the protecting gas may maintain the positive pressure so that the amorphous alloy may be effectively prevented from contacting with the environmental air when the amorphous alloy is fed to the melting device 5 via the feeding port 41 or when the amorphous alloy after die casting is extracted via the output port

13, thus nucleus of heterogeneous nucleation formed by the reaction between the molten amorphous alloy and the harmful gases may be prevented, and the critical size of the amorphous alloy may be greatly increased. In addition, the sealing chamber 40 may not need to be performed with vacuum suction repeatedly, thus shortening manufacturing period, achieving continuous production and enhancing manufacturing efficiency. In addition, the die casting apparatus 100 has a simplified structure. By using the protecting gas with positive pressure, high-level vacuum suction may not be needed, thus further reducing manufacturing and maintenance costs accordingly.

As shown in the embodiments shown in Figs. 1 and 2, the purifying device 10 may be a vacuum suction device 101, a gas purifier 102 or the combination thereof. In the embodiment shown in Fig. 1, the purifying device 10 may be the combination of the vacuum suction device 101 and the gas purifier 102. At this time, when the harmful gases in the sealing chamber 40 may be purified, the sealing chamber 40 may be vacuum suctioned and the protecting gas may be filled in the sealing chamber 40 by the protecting gas supplying device, and the residual harmful gases in the sealing chamber 40 are repeatedly processed by the gas purifier 102 to control the harmful gases to a concentration satisfying process requirement, thus greatly decreasing the demands of the protecting gas, reducing costs while increasing lifespan of the purifying device 10.

However, the present disclosure is not limited hereto. The purifying device 10 may be the vacuum suction device 101. At this time, the sealed chamber 40 may be performed with vacuum suction and then filled with protecting gas, so that the concentration of the harmful gases in the sealing chamber 40 may be maintained to minimum. And in one embodiment, the purifying device 10 may be the gas purifier 102 only, and the protecting gas may be filled in the sealing chamber 40 after the harmful gases in the sealing chamber 40 are purified by the gas purifier 102 to reduce the concentration of the harmful gases in the sealing chamber 40.

As shown in Fig. 2, in one embodiment, the die casting apparatus 100 may be configured as a horizontal one where the stationary die 1 and the movable die 2 are disposed outside the sealing cabin 4.

As shown in Fig. 2, the stationary die 1 and the movable die 2 may be disposed at the left side of the sealed cabin 4 and deployed in a direction for the left to right. And the feed sleeve 6 may be disposed at the right side of the stationary die 1. And the right end of the feed sleeve 6 may be disposed inside the sealing chamber 40, and the left end thereof may be projected out of the sealing chamber 40 to be communicated with the die chamber 3. And the plunger 7 may be reciprocally moved in the feed sleeve 6 to inject the molten amorphous alloy into the die chamber 3. And the output port 13 may be disposed on the movable die 2 facing the left end of the feed sleeve 6. When the component(s) at least partially made of the amorphous alloy is extracted from the die chamber 3, the protecting gas may be partially overflown from the output port 13 by gravity, and the environmental air may not be entered inside the sealing chamber 40.

In one embodiment, as shown in Fig. 1, the die casting apparatus 100 may be configured into a vertical one with the stationary die 1 and the movable die 2 being disposed inside the sealed cabin 4.

As shown in Fig. 1, the stationary die 1 and the movable die 2 may be vertically provided in the sealing chamber 4 in a direction from bottom to upward. And the feed sleeve 6 may be provided at the lower side of the stationary die 1 and communicated with the die chamber 3. The feed sleeve 7 may be moved in the vertical direction in the feed sleeve 6 to inject the molten amorphous alloy into the die chamber 3. The output port 13 may be disposed at the upper right portion of the sealing chamber 40. However, the present disclosure is not limited hereto. The output port 13 may be disposed at a top left portion or top portion of the sealing chamber 40. At this time, the gravity of the protecting gas may effectively prevent the environmental air from entering into the sealing chamber 40.

In one embodiment, as shown in Fig. 2, a vacuum sealing member 11 may be disposed between the stationary die 1 and the movable die 2 to further increase the sealing performance of the die chamber 3.

In one embodiment, the feed sleeve 6 may be communicated with the die chamber 3 via a communicating passage (not shown) formed in the stationary die 1. Therefore, the simplified structure may avoid the molten amorphous alloy from being exposed when transporting from the feed sleeve 6 to the die chamber 3.

In one embodiment, the protecting gas in the sealing chamber 40 may have a pressure between 1 atmospheric pressure (atm) and 1.1 atmospheric pressure, so that the amorphous alloy may be effectively prevented from contacting with the air when the amorphous alloy is fed to the melting device 5 via the feeding port 41 or when the amorphous alloy after die casting is extracted from the output port 13. In one embodiment, the protecting gas may have a density not less than that of the environmental air, so that the environmental gas may not be introduced into the sealing chamber 40 due to gravity when the amorphous alloy is fed to the melting device 5 via the feeding port 41 or when the amorphous alloy after die casting is extracted from the output port 13, and the protecting gas may not overflow outside easily, thus effectively preventing the protecting gas from being polluted by the environmental air.

In one embodiment, as shown in Figs. 1 and 2, the melting device 5 may comprise a crucible 50 and a heating device 51 for heating the crucible 50. To be specific, the heating device 51 may be an induction heating device, an electric arc heating device or a resistor heating device.

In one embodiment, the die casting apparatus 100 may further comprise a die chamber vacuum suction device 12 communicated with the die chamber 3 for performing vacuum suction to the die chamber 3, which may further decrease the concentration of the harmful gases and enhance discharging efficiency during die casting. And the contact of the molten amorphous alloy with the air may be isolated, avoiding the nucleus of heterogeneous nucleation formed by the reaction of the molten amorphous alloy with the harmful gases which may hardly form the amorphous alloy or greatly reduce the critical size of the amorphous alloy. In addition, the porosity of the die casted component of amorphous alloy may be decreased, which may enhance the die casting quality.

In the following, a method of die casting an amorphous alloy may be described with reference to Figs. 1-3. It should be noted that the method may be implemented by the die casting apparatus shown in Fig. 1 as well as the die casting apparatus shown in Fig. 2. In one embodiment, the method may comprise the following steps. Firstly, the sealing chamber 40 in the sealed cabin 4 of the die casting apparatus 100 may be purified, so that the harmful gases in the sealing chamber 40 may have a concentration less than a predetermined value (step SI 00). Then, the protecting gas may be supplied into the sealing chamber 40 to maintain the protecting gas in the sealing chamber 40 to a positive pressure (step S200). Next, the amorphous alloy may be fed into the melting device 5 disposed inside the sealing chamber 40 via the feeding port 41 formed on the sealing chamber 40 to obtain the molten amorphous alloy while the protecting gas filled within the sealing chamber 40 at least partially overflowing outside, so that the environmental air may not enter into the sealing chamber 40 (step S300). Then, the molten amorphous alloy may be fed into the die chamber 3 defined by the mated stationary die 1 and the movable die 2 via the feed sleeve 6 with the plunger 7 positioned therein (step S400). The plunger 7 may inject the molten amorphous alloy into the die chamber 3. Finally, the mated stationary and movable dies 1 and 2 may be opened to extract at least a component (not shown) formed at least partially of the amorphous alloy from inside the die chamber 3 while the protecting gas filled within the sealing chamber 40 overflowing outside via the output port 13 (step S500).

It should be noted that the die casting process may be continuous, for example, the amorphous alloy may be fed into the melting device 5 while the molten amorphous alloy may be injected into the die chamber 3.

According to the method of die casting amorphous alloy of an embodiment of the present disclosure, after the sealing chamber 40 may be purified and the protecting gas may be supplied into the sealing chamber 40 to maintain the protecting gas within the sealing chamber to the positive pressure, the harmful gases may have a concentration less than a predetermined value, and a part of the protecting gas may overflow outside when the amorphous alloy is fed to the melting device 5 via the feeding port 41 or when the amorphous alloy after die casting is extracted via the output port 13, so that the environmental air may not enter into the sealing chamber 40, thus nucleus of heterogeneous nucleation formed by the reaction between the molten amorphous alloy and the harmful gases may be prevented, and the critical size of the amorphous alloy may be greatly increased. In addition, the sealing chamber 40 may not need to be performed with vacuum suction repeatedly, since the protecting gas in the sealing chamber 40 may maintain the positive pressure, thus shortening manufacturing period, achieving continuous production and enhancing die casting efficiency. Further, the feeding port may be opened or closed at any time, thus further enhancing manufacturing efficiency and lowering costs accordingly.

In one embodiment, the purifying device 10 may be a vacuum suction device 101, a gas purifier 102 or the combination thereof. As shown in the embodiments shown in Figs. 1 and 2, when the harmful gases in the sealing chamber 40 may be purified, the sealing chamber 40 may be vacuum suctioned so that the harmful gases in the sealing chamber 40 may have a concentration lower than a predetermined value, then the protecting gas is filled in the sealing chamber 40, and the residual harmful gases in the sealing chamber 40 are repeatedly processed by the gas purifier 102, to control the harmful gases to a concentration satisfying process requirement, thus greatly decreasing the demands of the protecting gas.

In one embodiment, the protecting gas in the sealing chamber 40 may have a positive pressure between 1 atmospheric pressure (atm) and 1.1 atmospheric pressure, so that the amorphous alloy may be effectively prevented from contacting with the environmental air when the amorphous alloy is fed to the melting device 5 via the feeding port 41 or when the amorphous alloy after die casting is extracted from the output port 13. In addition, because the protecting gas in the sealing chamber 40 may have the positive pressure, the sealing chamber 40 may not need to be repeatedly vacuum suctioned, thus saving time. Further, the melting step may be synchronized with other steps, thus saving the waiting time for the melting of the amorphous alloy. In the embodiments shown in Figs. 1 and 2, the manufacturing period has been shortened to about 20 seconds. Comparing with the conventional vacuum negative pressure die casting, the manufacturing period is about 120 seconds since the sealing chamber has to be performed with vacuum suction and the melting steps cannot be synchronized with other steps. Thus, the method according to an embodiment of the present disclosure may have shortened the die casting period, thus enhancing production efficiency and decreasing manufacturing costs.

In one embodiment, the protecting gas may be at least one of the inert gases, thus avoiding the reaction of the molten amorphous alloy with the harmful gases. In one embodiment, the protecting gas may have a density not less than that of the air, so that environmental gas may not be introduced into the sealing chamber 40 due to gravity when the amorphous alloy is fed to the melting device 5 via the feeding port 41 or when the amorphous alloy after die casting is extracted from the output port 13, and the protecting gas may not overflow outside easily, thus effectively preventing the protecting gas from being polluted by the environmental air.

In one embodiment, the amorphous alloy may be Zr _a AlbCu _c Md, where M is at least one selected from a group consisting of Nb, Sc, Ta, Ni, Co, Y, Ag, Fe, Sn, Hf, Ti, Be and rare earths, and a, b, and c are atomic percentage, and 30<a<70, 5<b<35, 5<c<40, and 5<d<30. Further, there are impurity elements contained in the amorphous alloy which are less than 5% in atomic percentage. And the impurities may be Si, P, Be, Mg, B, O etc. And the amorphous alloy may possess properties which are resistant to the harmful gases so that cast may be obtained with high quality.

In one embodiment, the gas in the sealing chamber 40 may contain the harmful gases, for example, at least one of N ₂ , 0 ₂ , H ₂ 0 and C0 ₂ , that may have a concentration less than 10000 ppm. In one embodiment, the harmful gases may have a concentration less than lOOOppm.

Alternatively, the method may further comprise a step of performing vacuum suction to the die chamber 3 before the molten amorphous alloy may be injected into the die chamber

3, which may further decrease the concentrations of the harmful gases in the die chamber 3 and enhance discharging efficiency during die casting. And the contact of the molten amorphous alloy with the air may be isolated, avoiding the nucleus of heterogeneous nucleation formed by the reaction of the molten amorphous alloy with the harmful gases which may hardly form the amorphous alloy or greatly reduce the critical size of the amorphous alloy. In addition, the porosity of the die casted component of amorphous alloy may be decreased, which may enhance the die casting quality.

In one embodiment, the output port 13 and the feeding port 41 may be alternately opened, so that the environmental air may not enter into the sealing chamber 40 caused by convection of the protecting gas in the sealing chamber 40 with the environmental air.

In the following, the operating process of the die casting apparatus 100 and the method of die casting the amorphous alloy may be described with reference to Figs. 1-3, and the horizontal type die casting apparatus 100 will be illustrated herein for explanation purpose only.

Firstly, the stationery die 1 and the movable die 2 may be mated with each other to form the die chamber 3. And the sealing chamber 40 of the sealed cabin 4 may be performed with vacuum suction so that the harmful gases in the sealing chamber 40 may have a concentration less than a predetermined value. Then, the protecting gas supplying device supplies the protecting gas into the sealing chamber 40 so that the protecting gas may have a positive pressure between 1 atm and 1.1 atm, and the gas purifier 102 may repeatedly process the residual harmful gases in the sealing chamber 40.

Then, the feeding port 41 is opened to send the amorphous alloy into the melting device 5. And this time, because the protecting gas has a pressure larger than the atmospheric pressure, a part of the protecting gas overflows outside the sealing chamber 40 through the feeding port 41, to avoid the environmental air from entering into the sealing chamber 40. The amorphous alloy is heated in the crucible 50 to melt the amorphous alloy by the heating device 51. And the molten amorphous alloy is sent to the feed sleeve 6 from the molten material inlet 60. At this time, in one embodiment, the die chamber 3 may be performed with vacuum suction by the die chamber vacuum suction device 12. And the plunger 7 injects the molten amorphous alloy in the feed sleeve 6 under the driving of the driving device 8, so that the amorphous alloy may be die casted in the die chamber 3 after vacuum suction.

After the die casting, the plunger 7 remains in the feed sleeve 6. And the stationary die

1 and the movable die 2 are opened. And the die casted amorphous alloy is extracted from the die chamber 3. At this time, a part of the protecting gas overflows through the output port 13. Then, the stationary die 1 and the movable die 2 are closed, and the plunger 7 returns to an initial position under the action of the driving device 8 to complete a whole manufacturing cycle. Then, the next cycle similar to this described hereinabove is started. Because the protecting gas in the sealing chamber 40 has a positive pressure without need to repeated vacuum suction, the costs and complexity relating thereto are reduced accordingly. And the feeding port 41 may be opened for feeding the amorphous alloy at any steps, then the amorphous alloy is melted in the crucible 50 by the heating device 51, so that the molten amorphous alloy may be injected into the feed sleeve 6 via the molten material inlet 60 at any time.

The feeding port 41 and the output port 13 may be alternately opened, which may effectively prevent environmental air from entering into the sealing chamber 40 by the convection of the protecting gas in the sealing chamber 40 with the environmental air. In one embodiment, under given outputting and feeding conditions, the smaller the passages communicating the feeding port 41 and the output port 13, the better for the maintaining of the pressure of the protecting gas in the sealing chamber 40.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that changes, alternatives, and modifications all falling into the scope of the claims and their equivalents may be made in the embodiments without departing from spirit and principles of the disclosure.