Abstract:
A lightweight spray device with spray body that is suitable for precision cast molding, solving general casting problems, such as shrinkage and bubbling; and a process for manufacturing the same. The spray device is one with magnesium spray body provided with a spray part and a handle part, characterized in that the magnesium spray body is one formed with the use of a mold for magnesium spray body wherein a first slide pin is provided at a region where the spray part and the handle part cross each other and wherein around the first slide pin, there is provided a product melt orifice.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/441,339, entitled “SPRAY DEVICE AND PROCESS FOR MANUFACTURING THE SAME”, filed Mar. 13, 2009, which is herein incorporated by reference PCT Application No. PCT/JP2007/067953 entitled “SPRAY DEVICE AND METHOD OF MANUFACTURING THE SAME”, filed on Sep. 14, 2007, which is herein incorporated by reference in its entirety, and which claims priority to Japanese Patent Application No. 2006-249703, entitled “SPRAY DEVICE AND METHOD OF MANUFACTURING THE SAME”, filed on Sep. 14, 2006, which is herein incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to a spray device used to spray paint onto a target object and a method of manufacturing the same. More particularly, the present invention relates to a lightweight spray device easy to clean that is suitable for sprinkling liquid like not only paint but also water, adhesives, anti-corrosives, resists, coating liquids, chemicals, or the like, or that is suitable for spraying any of them onto a target object. 
       BRIEF DESCRIPTION 
       [0003]    A lightweight spray device with spray body that is suitable for precision cast molding, solving general casting problems, such as shrinkage and bubbling; and a process for manufacturing the same. The spray device is one with magnesium spray body provided with a spray part and a handle part, characterized in that the magnesium spray body is one formed with the use of a mold for magnesium spray body wherein a first slide pin is provided at a region where the spray part and the handle part cross each other and wherein around the first slide pin, there is provided a product melt orifice. 
     
    
     
       DRAWINGS 
         [0004]    These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
           [0005]      FIG. 1  is a right side view illustrating an exemplary embodiment of a paint spray device according to the present invention; 
           [0006]      FIG. 2  is a sectional view taken along the line II-II of  FIG. 1 ; 
           [0007]      FIG. 3  is a front view illustrating the exemplary embodiment of the paint spray device according to the present invention; 
           [0008]      FIG. 4  is a right side view illustrating the molding that is to be a cast spray body of the paint spray device in  FIG. 1 ; 
           [0009]      FIG. 5  is a rear view illustrating the molding that is to be the cast spray body of the paint spray device in  FIG. 1 ; 
           [0010]      FIG. 6  is a right side view illustrating the molding that has its catch basins and burrs eliminated so as to finish it into the cast spray body of the paint spray device in  FIG. 1 ; 
           [0011]      FIG. 7  is a right side view illustrating a previous rotary spray device that has its trigger lever pulled to half of its full back stroke; 
           [0012]      FIG. 8  is a right side view illustrating the rotary spray device in  FIG. 7  that has its trigger lever fully pulled proximally; 
           [0013]      FIG. 9  is a right side view illustrating the rotary spray device in  FIG. 7  that has its trigger lever released; and 
           [0014]      FIG. 10  is a vertical sectional view illustrating a handle and a adjusting unit of the rotary spray device in  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    One or more specific embodiments of the present invention will be described below. These described embodiments are only exemplary of the present invention. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
       Context 
       [0016]    Prior to discussing embodiments of the invention, the following discussion will begin with an introduction of various aspects of spray devices that may be related to embodiments of the present invention. Some of the spray devices will now be described in conjunction with the accompanying drawings, namely,  FIGS. 7 to 10 , giving a typical example of rotary atomizing spray device (see Patent Document 1 listed below). This discussion is believed to be helpful in providing the reader with context to facilitate a better understanding of the various embodiments of the present invention. Accordingly, it should be understood that statements pertaining to  FIGS. 7 to 10  are to be read in this light, and not as admissions of prior art. 
         [0017]    A rotary atomizer  101  is, as shown in  FIG. 7 , provided with a handle  110 , an adjusting unit  112  above the handle  110 , and a spray nozzle  114  at a distal end ahead of the adjusting unit  112 . The handle  110  includes a grip  120  at the bottom of which there are provided an air pipe connector  124  coupling the handle with a high-pressure air pipe  122  conducting to a compressor (not shown), and an air-adjustor thumb screw  126  adjusting pressure of pressurized air supplied to the rotary atomizer  101 . As depicted in  FIG. 10 , the air-adjustor thumb screw  126  displaces a 1st-valve regulator  129  of a first valve  128  to regulate the opening/closing of the first valve  128  that is positioned in a pressurized air duct  127  in communication with the air pipe connector  124 . 
         [0018]    The adjusting unit  112  is provided, at its center, with a gun body  130 , a trigger lever  134  of which rotary shaft links it to a cam lever  132 , a hook  136 , and a paint pipe connector  140  that is to couple a paint supply pipe  138  conducting to a paint tank (not shown). A spring member  133  urges the cam lever  132  to rotate in clockwise direction in  FIG. 7 . 
         [0019]    The trigger lever  134  is, as can be seen in  FIG. 10 , pivotally connected to the gun body  130  by means of a trigger-lever rocking member  135 . A second valve  137 , which is located on the downstream side of the first valve  128  in the context of air flow through the pressurized air duct  127 , has its coupling member  150  abutting against the trigger lever  134  at its middle segment. The second valve  137  has a compression spring  139  that urges the trigger lever  134  to pivot forward. A 2nd-valve regulator  151  of the second valve  137  is displaced by the coupling member  150  so as to regulate the opening/closing of the second valve  137 . 
         [0020]    With the trigger lever  134  being pulled to at the least half of its full back stroke as depicted in  FIG. 7 , the pressurized air is supplied to an air motor (not shown) to force a bell  206  to revolve. The trigger lever  134  is able to be locked in such a half a back stroke position or ½ back stroke position by engagement of a middle step  148  of a cam  132 C in the cam lever  132  with a cam pin  149  that is fixed with the gun body  130 . 
         [0021]    With the trigger lever  134  being pulled to its full back stroke as depicted in  FIG. 8 , the pressurized air is further supplied to force the bell  206  revolve and to permit paint to be supplied and atomized, so that the atomized paint can be sprayed through the bell  206 . The trigger lever  134  is also able to be locked in such a full back-stroke position by pulling the trigger lever  134  further proximally so as to overcome the repulsive force from the second valve coupling member  150  till the cam pin  149  is engaged with a front end  152  of the cam  132 C. In this way, adjusting a position of the cam pin  149  between the middle step  148  and the front end  152  to fix the position in either of them permits the paint to be sprayed with a controlled rate as desired. 
         [0022]    In order to release the trigger lever  134 , namely, to return it to its home position to bring the spraying to rest, an operator may simply use his or her thumb and press a projection  160  of the trigger lever  134  kept in its ½ back-stroke position as in  FIG. 7  so as to rotate the cam lever  132  in the clockwise direction. This allows the cam pin  149  to move from the middle step  162  to the a rear end  164  of the cam  132 C, and the trigger lever  134  released from confinement by the cam lever  132  becomes free to retrace its way as shown in  FIG. 9 . 
         [0023]    The adjusting unit  112  is provided, at its upper rear segment, with a sprayed-paint adjustor thumb screw  170  and a shaping-air adjustor thumb screw  172 . As shown in  FIG. 10 , the sprayed-paint adjustor thumb screw  170  alters a relative position of a 3rd-valve regulator  178  of a third valve  176  to the trigger lever  134  where the third valve is located in a paint duct  174  conducting to the paint pipe connector  140 . Thus, turning the sprayed-paint adjustor thumb screw  170  permits the paint to be supplied or sprayed with a controlled rate as desired while the trigger lever  134  is being pulled. 
         [0024]    The shaping-air adjustor thumb screw  172  displaces a 4th-valve regulator  182  of a fourth valve  180  on the downstream side of the second valve  137  in the pressurized air duct  127 , so as to regulate the opening/closing of the fourth valve  180 . 
         [0025]    The handle  110 , generally consisting of the grip  120  and the gun body  130 , is fabricated by means of the aluminum die casting, and alternatively, it may be made of die cast aluminum and rigid plastic (see Patent Documents 2 and 3 listed below). The gun body may be molded and/or machined of steels, steel alloys, and/or other substances of tough compositions (see Patent Document 4 listed below). Alternative embodiments have been disclosed like the gun body that is molded of composite resin, as a whole (see Patent Documents 5 and 6), or the one that is made of electrically insulating material suitable for a use of the rotary atomizing and electrostatic coating (see Patent Document 7). 
         [0026]    A further alternative embodiment has been disclosed which has an aluminum die cast spray gun body coated with fluorocarbon resin (see Patent Document 8). 
         [0027]    Patent Document 1: Japanese Patent Preliminary Publication of Unexamined Application No. 2004-321844 
         [0028]    Patent Document 2: Japanese Patent Preliminary Publication of Unexamined Application No. H6-190310 
         [0029]    Patent Document 3: Japanese Patent Preliminary Publication of Unexamined Application No. H7-275749 
         [0030]    Patent Document 4: Japanese Patent Preliminary Publication of Unexamined Application No. H9-511687 
         [0031]    Patent Document 5: Japanese Patent Preliminary Publication of Unexamined Application No. 2006-43593 
         [0032]    Patent Document 6: Japanese Patent Preliminary Publication of Unexamined Application No. 2002-523214 
         [0033]    Patent Document 7: Japanese Patent Preliminary Publication of Unexamined Application No. H7-70557 
         [0034]    Patent Document 8: Japanese Patent Preliminary Publication of Unexamined Application No. H7-275747 
       Problems to be Solved 
       [0035]    Even if replaced with a die cast aluminum body, the aforementioned previous handheld spray devices still have a considerable weight and are significantly heavy for the operator to have to bear so much burden, and there arises a problem that it is hard to continue precision spraying for a long time, which is why a more weight-reduced spray device has been wanted. On the other hand, although the spray device with the body of composite resin is advantageous because it is lightweight, its chemical and mechanical durability is degraded and unsatisfactory for a long-term use under severe conditions and/or as an industrial instrument that is to undergo repetitive washing/cleaning. 
         [0036]    In addition, in the case where the spray device employs the previous design of the aluminum spray body, a process such as the buffing after molded by the die casting, necessary to have its surface polishes the body. Such a polishing process is prone to cause the molded body to have its corners rounded, and this results in the finished surface of the molded body being undesirable in design; in other words, resulting in the reduced freedom of esthetical design. 
       Aspects of the Invention 
       [0037]    The present invention is made to overcome the aforementioned disadvantages in the previous spray devices, and accordingly, it is an aspect of the present invention to provide a lightweight spray device with a spray body that can be molded by means of precision casting without common problems during the casting procedures such as shrinkage and bubbling, and a method of manufacturing the same. 
         [0038]    It is another aspect of the present invention to provide a spray device that has the enhanced chemical and mechanical durability and that facilitates washing/cleaning so as to enable the device to keep the optimum conditions for the extended-term use, and a method of manufacturing the same. 
         [0039]    It is still another aspect of the present invention to provide a spray device and a method of manufacturing the same that permit the greater freedom of design from both the technological and esthetical viewpoints, that, unlike the previous aluminum die cast spray bodies, eliminate the necessity of having the molding polished by a process such as the buffing, and that allow the molding to undergo processes such as the embossing, the finishing to provide sharpened corners, or the like. 
       Means for Solving the Aforementioned Problems 
       [0040]    An embodiment of the present invention is first directed to a spray device that has a magnesium spray body comprised of a spray nozzle and a handle, and the spray device is characterized in that a die used to cast the magnesium spray body has a first slide pin located at an intersection of the spray nozzle and the handle, and a die in-gate through which fused magnesium is injected is defined, surrounding the first slide pin. 
         [0041]    In an aspect of the present invention, an embodiment of the spray device can be implemented as follows: 
         [0042]    The magnesium spray body has its surface anodized to form anodic oxide coating and then covered with primer coating, and the resultant surface is further covered with fluorocarbon coating. 
         [0043]    The die used to cast the magnesium spray body has a second slide pin, and a catch basin is defined, surrounding at least part of the second slide pin. 
         [0044]    The magnesium spray body has at least a surface of its handle embossed. 
         [0045]    The die used to cast the magnesium spray body has a vacuum chamber conducting to free ends of the spray nozzle and the handle. 
         [0046]    An embodiment of the present invention is also directed to a method of manufacturing a spray device that has a magnesium spray body comprised of a spray nozzle and a handle. The method is characterized in that a die used to cast the magnesium spray body has a first slide pin located at an intersection of the spray nozzle and the handle, and a die in-gate through which fused magnesium is injected is defined, surrounding the first slide pin. 
         [0047]    In another aspect of the present invention, an embodiment of the method of manufacturing a spray device can be implemented as follows: 
         [0048]    The magnesium spray body has its surface anodized to form anodic oxide coating and then covered with primer coating, and the resultant surface is further covered with fluorocarbon coating. 
         [0049]    The die used to cast the magnesium spray body has an additional slide pin, and a catch basin is defined, surrounding at least part of the additional slide pin. 
         [0050]    The magnesium spray body has at least a surface of its handle embossed. 
         [0051]    The die used to cast the magnesium spray body has a vacuum chamber conducting to free ends of the spray nozzle and the handle. 
       Effects of the Invention 
       [0052]    In accordance with embodiments of the present invention, there can be obtained a lightweight spray device with a spray body that can be molded by means of precision casting without common problems during the casting procedures such as shrinkage and bubbling, and a method of manufacturing such a spray device can also be attained. It has been observed that for similar handheld spray devices of substantially the same arrangements where one has its body made of aluminum and the other of magnesium, the one with the aluminum body is 295 grams in weight while the other with the magnesium body is 245 grams. 
         [0053]    The spray device of the disclosed embodiments or such a spray device obtained by the manufacturing method of the disclosed embodiments has the enhanced chemical and mechanical durability and facilitates washing/cleaning so as to enable the device to keep the optimum conditions for the extended-term use. 
         [0054]    The disclosed embodiments are furthermore advantageous in that they permit the greater freedom of design from both the technological and esthetical viewpoints, and, unlike the previous aluminum die cast spray bodies, eliminate the necessity of having the molding polished by a process such as the buffing, and thus, it allows the molding to undergo processes such as the embossing, the finishing to provide sharpened corners, or the like. 
       BEST MODE OF THE INVENTION 
       [0055]    Exemplary embodiments of a paint spray device and a method of manufacturing the same according to the present invention will now be described with reference to the accompanying drawings. 
         [0056]    An exemplary embodiment of a paint spray device according to the present technique is, as illustrated in  FIG. 1 , provided with a generally L-shaped spray body  10 , a head  12  at a front or distal end of the spray body  10 , a trigger lever  14  pivotally attached to the middle of the spray body  10 , a divergent spray pattern adjustor knob  16  and a sprayed-paint adjustor knob  18  both of which are attached to the middle of the spray body  10 , and a pressurized air adjustor knob  20  and a pressurized air supply aperture  22  both of which are disposed at the rear or proximal bottom of the spray body  10 . Also, as can be seen in  FIG. 2 , the spray body  10  has a paint supply aperture  24  along a distal left side. The spray body  10  is provided with a hook  26  at the distal top by which the paint spray device hangs, and a grip  28  at the lower half and a recess  30  in the grip  28  that the trigger lever  14  works in during its back stroke. 
         [0057]    The head  12  is, when viewed facing the front as shown in  FIG. 3 , provided with a paint ejecting aperture  40  at its center, and two opposite pairs of atomized air blowing apertures  42 ,  43 ,  44 ,  45  outside it, and two additional opposite pairs of divergent spray patterning air apertures  50 ,  51 ,  52 ,  53  further outside of them. 
         [0058]    Pressurized air sent through the pressurized air supply aperture  22  has its flow rate appropriately adjusted by the pressurized air adjustor knob  20  and then jetted out through the atomized air blowing apertures  42 ,  43 ,  44 ,  45  and the divergent spray patterning air apertures  50 ,  51 ,  52 ,  53 . The divergent spray pattern adjustor knob  16  regulates flow rate and pressure of the pressurized air supplied from the pressurized air supply aperture  22  and jetted out through the divergent spray patterning air apertures  50 ,  51 ,  52 ,  53  so as to control divergence of the spray pattern. The trigger lever  14  cooperative with the sprayed-paint adjustor knob  18  adjusts an amount of the paint sent through the paint supply aperture  24  and interrupts paint supply. 
         [0059]    The spray body  10  is fabricated by means of the magnesium die casting or the magnesium alloy die casting. The spray body  10  is cast in a die (not shown) that fits the contours of a green spray body  10 C associated with a die in-gate  60  into which fused magnesium is injected, a vacuum chamber  62  urging the fused magnesium to flow through minute clearances of the die, a catch basin  64  for the head  12  that compensates for “shrinkage” due to adverse debris and/or voids developed in the die, a catch basin  65  for the divergent spray pattern adjustor knob  16 , a catch basin  66  for the pressurized air supply aperture  22 , and a catch basin  67  for the hook  26 . 
         [0060]    The vacuum chamber  62  leads to a slide-pin hole  70  in the head, a slide-pin hole  73  in the pressurized air adjustor knob, a slide-pin hole  74  in the pressurized air supply aperture, and a projection  77  located at the bottom of the recess  30  in the grip, respectively. 
         [0061]    In  FIG. 4 , for clarifying illustrations of the slide-pin holes  70 ,  73 , and  74 , embossed surfaces in the grip  28 , the hook  26 , and the remaining approximately planar lateral portions of the device, which will be all detailed later, are omitted. 
         [0062]    The green spray body  10 C cast in the die has the slide-pin hole  70  defined by using a slide pin (not shown) in an area that is to be the head  12 . Similarly, the slide-pin hole  71  is defined in an area where the divergent spray pattern adjustor knob  16  is to be located. Also similarly, the slide-pin hole  72  is defined in an area where the sprayed-paint adjustor knob  18  is to be inserted. The slide-pin hole  73  is similarly defined in an area where the pressurized air adjustor knob  20  is inserted. The slide-pin hole  74  is also formed in an area that is to be the pressurized air supply aperture  22 . The slide pins (not shown) used as part of the die to give shape to the slide-pin holes  70 ,  71 ,  72 ,  73 ,  74  in the pre-formation areas respectively corresponding to the head, the divergent spray pattern adjustor knob, the sprayed-paint adjustor knob, the pressurized air adjustor knob, and the pressurized air supply aperture are slid in parallel with the sheet dimensions of  FIG. 4 , or perpendicular to the sheet dimensions of  FIG. 5 . 
         [0063]    As depicted in  FIG. 4 , an in-gate  80 , which is conducted to the die in-gate  60  by a filling duct  61 , surrounds the entire circumference of the slide-pin hole  72  for the sprayed-paint adjustor knob, so as to completely open into the slide-pin hole. Alternatively, the in-gate  80  in communication with the die in-gate  60  via the filling duct  61  does not have to extend along the perfectly entire circumference of the slide-pin hole  72 , and instead, it may surround and open into only half a circular extension or any other appropriate arcuate extensions. 
         [0064]    The vacuum chamber  62  is in connection with the slide-pin holes  70 ,  71 , and  73  at only the left half of their respective circumferences. These connection areas should not be precisely limited to the left half of the circumferences of the slide-pin holes, and alternatively, the vacuum chamber  62  may be conducting to any other arcuate extensions around the slide-pin holes, allowing for manufacturing costs for the die and/or other factors. 
         [0065]    The catch basins  64 ,  65 ,  66  respectively shaped in pre-formation areas that are to be the head, the divergent spray pattern adjustor knob, and the pressurized air supply aperture are in connection with the slide-pin holes  70 ,  71 ,  74  at the left half of their respective circumferences. A catch basin  67  is in connection with a pre-formation point that is to be the top of the hook  26 . The connection areas of the catch basins  64 ,  65 ,  66  to the corresponding slide-pin holes  70 ,  71 ,  74  respectively shaped in pre-formation areas that are to be the head, the divergent spray pattern adjustor knob, and the pressurized air supply aperture should not be precisely limited to the left half of their respective circumferences, and instead, they may be conducting to any other arcuate extensions around the slide-pin holes, depending on manufacturing costs for the die and/or other factors. 
         [0066]    The grip  28 , the hook  26 , and the remaining approximately planar lateral portions of the device have their respective major surfaces embossed. 
         [0067]    As illustrated in  FIG. 6 , the spray body  10 C, after cast and removed from the die, has its die in-gate  60 , vacuum chamber  62 , and catch basins  64 ,  65 ,  66 ,  67  all cut off. After that, the green spray body  10 C has its entire surface polished by means of the buffing, and thus, it is finished in the spray body  10 . 
         [0068]    Moreover, the spray body  10  further undergoes the anodizing treatment to form anodic oxide coating thereover, and after the primer coating to form undercoat substrate, it is further coated with fluorocarbon. The primer coating enhances bonding effects of the fluorocarbon coating applied thereon. Since magnesium is salt aversive and cannot be plated, the anodic oxidation treatment on the magnesium surface is useful to protect magnesium. One typical example of such an anodic oxidation treatment is non-chrome anode oxidation processing available from Hori Metal Finishing Ind., Ltd. under the trademark ANOMAG. The ANOMAG non-chrome anode oxidation processing effectuates tight bonding with paint, enhances anti-corrosion and insulation properties, and enlarges the possibility to recycle magnesium because of heavy-metal free treatment. The above mentioned primer coating is 10 to 15 micrometers in thickness while the fluorocarbon coating is 30 5 micrometers. 
       APPLICABILITY IN THE INDUSTRY 
       [0069]    The spray device according to the disclosed embodiments is advantageous for a use as a lightweight and easy-to-clean spray device that is suitable for sprinkling liquid like not only paint but also water, adhesives, anti-corrosives, resists, coating liquids, chemicals, or the like, or that is suitable for spraying any of them onto a target object. The spray device of the disclosed embodiments also has applications as a static nozzle paint atomizing/coating device and a rotary atomizing/coating device. 
         [0070]    While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.