Patent Publication Number: US-7585035-B2

Title: Marking device and method for golf ball

Description:
This application claims priority on Patent Application No. 2004-260455 filed in JAPAN on Sep. 8, 2004, the entire contents of which are hereby incorporated by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a suitable device for printing a mark on a golf ball. More particularly, the present invention relates to a device using an ink jet printer utilizing an on-demand system. 
   2. Description of the Related Art 
   A golf ball manufacturer prints a mark on the surface of a golf ball and ships the golf ball. The mark includes characters, graphics, a combination of the characters and the graphics, and the like. Typically, the trademark of the golf ball is printed. The mark representing the trademark is referred to as a main mark. A user specifies the kind of the golf ball by taking the main mark as a clue. In some cases, a mark corresponding to the user is also printed on the golf ball. The mark is referred to as an own name mark. Specific examples of the own name mark include the name of a user, a company name, a company badge and a catchphrase. A lot in the case in which the own name mark is printed is much smaller than a lot in the case in which the main mark is printed. A method of printing a mark on a golf ball includes a type printing system, a transfer film system and a pad system. 
   For the type printing system, a type and a color film are used. In the printing, it is necessary to prepare the type in advance. For this reason, a long period is required from an order to a print. In the type printing system, it is impossible to print a fine line. In addition, in the type printing system, it is hard to carry out printing on the surface of a dimple. In recent years, the printing has rarely been carried out by using the type printing system. 
   In the transfer film system, a transfer film obtained by intaglio printing is used. The transfer film is expensive. In the intaglio printing, a large number of transfer films are manufactured at a time. Therefore, the transfer film system is not suitable for printing the own name mark in a small lot. In the transfer film system, furthermore, it is impossible to print a mark having a large size. 
   In the pad system, it is necessary to prepare the same number of inks and intaglios as the number of the colors of a mark. In the pad system, a great deal of time and labor is required for manufacturing the intaglio and toning the ink. Since a potlife of the ink is short, it is necessary to often exchange the ink in the pad system. In addition, in the pad system, a great deal of time and labor is required for washing an intaglio, a pad and an ink tray. 
   Japanese Laid-Open Patent Publication No. 2002-337329 has disclosed a method of printing a mark on a golf ball by an ink jet printer. In this method, it is possible to print a fine line. The ink jet printer is also suitable for printing an own name mark in a small lot. In the ink jet printer, the toning and the washing are not required. In the ink jet printer, it is not necessary to prepare a form plate. 
   The ink jet printer includes a continuous system and an on-demand system. In the ink jet printer using the continuous system, an ink is always discharged from a nozzle and an electric charge is added if necessary so that the ink is moved toward an object to be printed (typically, a paper). The ink jet printer using the continuous system is mainly utilized in commercial printing. In the ink jet printer using the on-demand system, an ink is discharged from a nozzle only if necessary. The printing is often carried out over a golf ball in a small lot. Therefore, the ink jet printer using the on-demand system is suitable for the printing. 
   The golf ball has a large number of dimples on a surface thereof. In the case in which the printing is carried out over the golf ball by the ink jet printer, a turbulent flow is generated by the dimples in the discharge of an ink. Due to the turbulent flow, the ink sticks to the nozzle. In the ink jet printer using the on-demand system, the discharge of the ink is temporarily stopped. In some cases, therefore, the ink sticking to the nozzle is dried to block the nozzle. Moreover, the turbulent flow causes a mark to be blurred. In some cases, furthermore, the amount of the ink sticking to the edge of the dimple becomes insufficient due to the turbulent flow. 
   In the printing for the golf ball, a ground is a cover or a coated layer formed on the surface of the cover. Both the cover and the coated layer are formed of a polymer such as a synthetic resin. The ground absorbs a water content with difficulty. An oil-based ink and an ultraviolet setting type ink are suitable for the printing over the golf ball. In the case in which the oil-based ink or the ultraviolet setting type ink is used, a nozzle is often clogged with the ink. The clogging of the nozzle deteriorates a productivity. 
   It is an object of the present invention to provide a marking device for a golf ball in which a clear mark can be obtained efficiently. 
   SUMMARY OF THE INVENTION 
   A marking device for a golf ball according to the present invention comprises an ink jet head using an on-demand system and a stand for setting the golf ball thereto. The shortest distance between the tip of the nozzle of the ink jet head and the golf ball set into the stand is equal to or greater than 0.5 mm. 
   By the marking device, a clear mark can be obtained efficiently at a low cost. The marking device is particularly suitable for printing over a golf ball in a small lot. 
   It is preferable that an oil-based ink or an ultraviolet setting type ink should be used in the marking device. It is preferable that the marking device should further comprise a vessel filled with an ink, a tube for supplying an ink from the vessel to the ink jet head, and an elastic member for changing a position of the vessel corresponding to a residual amount of the ink. It is preferable that the marking device should further comprise a rest in which the nozzle is positioned when the ink jet head is stopped, a vessel filled with a solvent, and supply means for forcibly supplying the solvent from the vessel to the rest. 
   A golf ball marking method according to the present invention comprises the steps of:
         printing a mark on the golf ball by means of an ink jet head using an on-demand system including a nozzle in which the shortest distance from the golf ball is equal to or greater than 0.5 mm; and       

   applying a clear paint on the mark by using a pad and an intaglio subjected to shading. 
   It is preferable that the marking method should further comprise the steps of: 
   relatively changing a position to the intaglio in the golf ball to which the clear paint is applied; and 
   applying the clear paint again by using the pad and the intaglio. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a conceptual view showing a marking device for a golf ball according to an embodiment of the present invention, 
       FIG. 2  is a plan view showing an ink jet printer in the marking device of  FIG. 1 , 
       FIG. 3  is a right side view showing the ink jet printer in the marking device of  FIG. 1 , 
       FIG. 4  is an enlarged view showing a part of a head in the ink jet printer of  FIG. 2 , 
       FIG. 5(   a ) is a plan view showing the intaglio of a pad printing machine in  FIG. 1 , and 
       FIG. 5(   b ) is a front view showing the intaglio in  FIG. 5(   a ). 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention will be described below in detail based on a preferred embodiment with reference to the drawings. 
   A marking device  2  shown in  FIG. 1  comprises a personal computer  4 , an ink jet printer  6  and a pad printing machine  8 . The computer  4  and the printer  6  are connected to each other through a cable  10 . The pad printing machine  8  includes an intaglio  12 , a pad  14  and a cup  16 . The well-known pad printing machine  8  can be used in the marking device  2 . 
     FIG. 2  is a plan view showing the ink jet printer  6  of the marking device  2  in  FIG. 1  and  FIG. 3  is a right side view showing the same. The printer  6  includes a body  18 , a guide rail  20 , an ink jet head  22 , a slide table  24 , a tray  26 , four ink vessels  28 , a solvent vessel  30 , a pump  32 , a rest  34  and a waste liquid vessel  36 . The slide table  24  and the tray  26  constitute a stand. The printer  6  also includes a coil spring  38  to be an elastic member. 
   The body  18  includes a left wall  40  and a right wall  42 . The guide rail  20  is stretched between the left wall  40  and the right wall  42 . The head  22  is coupled to the guide rail  20 . The head  22  is guided by the guide rail  20 , and at the same time, is moved in a transverse direction in  FIG. 2 . 
   The slide table  24  is positioned below the head  22 . The slide table  24  can be moved in a vertical direction in  FIG. 2 . The tray  26  is mounted on the slide table  24 . A large number of openings  44  are formed on the tray  26 . In the example of  FIG. 2 , 12 openings  44  are provided on the tray  26 . A golf ball  46  is set into the opening  44 . 
   The ink vessel  28  is filled with an ink. The ink vessel  28  is filled with each of magenta, yellow, cyan and black inks. One of the ends of a tube  48  is connected to the ink vessel  28 . The other end of the tube  48  reaches the head  22 . The ink is supplied from the ink vessel  28  toward the head  22  through the tube  48 . 
   In respect of the strength of the mark, a cold setting type or hot setting type oil-based ink or an ultraviolet setting type ink is preferable. In respect of a reduction in the size and cost of the device, the cold setting type oil-based ink and the hot setting type oil-based ink are preferable, and the cold setting type oil-based ink is particularly preferable. In respect of the strength and productivity of the mark, the ultraviolet setting type ink is preferable and the ultraviolet setting type oil-based ink is particularly preferable. 
   The solvent vessel  30  is filled with an organic solvent. A tube  50  extended from the solvent vessel  30  reaches the rest  34  through the pump  32 . A tube  52  extended from the rest  34  reaches the waste liquid vessel  36 . 
   As shown in  FIG. 3 , a plate  54  is attached to the upper end of the coil spring  38 . The ink vessel  28  is mounted on the plate  54 . The coil spring  38  is a compression spring. The coil spring  38  presses the plate  54  upward. The loads of the ink vessel  28 , the ink and the plate  54  are applied to the coil spring  38 . When the load to be applied to the coil spring  38  is reduced due to a decrease in the ink, the coil spring  38  moves the ink vessel  28  upward. By this movement, the height of a liquid level  56  of the ink is maintained to be substantially constant so that the amount of the ink to be discharged is maintained to be constant. 
     FIG. 4  is an enlarged view showing a part of the head  22  in the ink jet printer  6  of  FIG. 2 .  FIG. 4  also shows a part of the golf ball  46 . The golf ball  46  has a large number of dimples  58  on a surface thereof. In  FIG. 4 , a virtual sphere is shown in a two-dotted chain line  60 . The virtual sphere  60  represents the surface of the golf ball  46  in the case in which it is assumed that the dimple  58  is not present. The head  22  has a nozzle  62 . The tip of the nozzle  62  is coincident with a nozzle surface  64 . In  FIG. 4 , an arrow L indicates the shortest distance between the tip of the nozzle  62  and the golf ball  46 . The head  22  employs an on-demand system. The ink is discharged as a very small droplet from the nozzle  62  by means of a piezoelectric element, a heater or the like which is provided in the head  22 . 
     FIG. 5(   a ) is a plan view showing the intaglio  12  of the pad printing machine  8  in  FIG. 1 , and  FIG. 5(   b ) is a front view showing the same. The intaglio  12  has an engraved portion  66 . The planar shape of the engraved portion  66  is usually a circle. It is preferable that the engraved portion  66  should have a diameter D which is sufficiently larger than a mark to be formed. The diameter D is preferably equal to or larger than 12 mm, is more preferably equal to or larger than 16 mm and is particularly preferably equal to or larger than 20 mm. The diameter D is usually equal to or smaller than 30 mm. The engraved portion  66  is subjected to shading. It is preferable that the area rate of a concave portion which is generated by the shading should be equal to or higher than 90% and be equal to or lower than 98%. 
   In order to form a mark by the marking device  2 , first of all, the specification of the mark is determined by using the computer  4 . For example, a character or a graphic is input from input means such as a keyboard or a mouse to determine the specification of the mark. Based on image data stored in a storage device (typically, a hard disk), the specification of the mark may be determined. The specification of the mark may be transmitted to the computer  4  through a communication line (typically, internet) connected to the computer  4 . Based on an image read by a scanner, the specification of the mark may be determined. Based on an image photographed by a digital camera, the specification of the mark may be determined. 
   When the specification of the mark is determined, data on the specification are transmitted to the printer  6  through the cable  10 . The data include information about the position and color of the mark. Upon receipt of the data, the printer  6  starts printing. In the printing, first of all, the slide table  24  is moved gradually upward in  FIG. 2 . At the same time, the head  22  is moved in a transverse direction. When the nozzle  62  and the golf ball  46  reach a predetermined positional relationship, the ink is discharged from the nozzle  62 . The ink is moved to the golf ball  46  so that the mark is formed. If an oil-based ink is used, liquid drops are generated after the movement with difficulty. 
   The golf ball  46  is taken out and is then mounted on the cup  16  in the pad printing machine  8  automatically or manually. Next, a clear paint is supplied onto the intaglio  12 . The clear paint is colorless and transparent. A typical clear paint contains polyurethane as a base material. The clear paint on the intaglio  12  is scraped away by means of a doctor blade which is not shown. By the scraping operation, the clear paint present on a portion other than the engraved portion  66  is removed from the intaglio  12 . The engraved portion  66  is subjected to the shading. For this reason, the clear paint in the engraved portion  66  is not scraped away by means of the doctor blade. Next, the pad  14  is moved downward and abuts on the intaglio  12 . By the abutment, the clear paint is moved from the intaglio  12  to the pad  14 . Then, the pad  14  is lifted and is moved to a portion placed just above the golf ball  46 . Thereafter, the pad  14  is moved downward and abuts on the golf ball  46 . By the abutment, the clear paint is moved from the pad  14  to the golf ball  46 . Subsequently, the pad  14  is lifted. Thus, the clear paint is applied completely. The clear paint is dried so that a coated film is formed. The coated film protects the mark. 
   It is preferable that the golf ball  46  should be rotated finely in the cup  16  after the application of the clear paint and the clear paint should be applied again. The golf ball  46  is rotated so that the position of the golf ball  46  to the intaglio  12  is changed. By the change, the whole surface of the mark is surely coated with the clear paint irrespective of the engraved portion  66  which is subjected to the shading. 
   The shortest distance L (see  FIG. 4 ) between the tip of the nozzle  62  and the golf ball  46  is equal to or greater than 0.5 mm. The distance L is longer than a distance in a general ink jet printer using an on-demand system. The golf ball  46  has the dimple  58  on the surface thereof. When the distance L is set to be equal to or longer than 0.5 mm, a turbulent flow is suppressed. By the suppression of the turbulent flow, the ink can be prevented from sticking to the nozzle surface  64 . In the ink jet printer  6  using the on-demand system, the discharge of the ink is stopped temporarily. However, the ink can be prevented from sticking to the nozzle  62 . Consequently, the nozzle  62  can be prevented from being clogged due to the dryness of the ink. In the marking device  2 , the nozzle  62  is clogged with difficulty also in the case in which an oil-based ink or an ultraviolet setting type ink is used. The marking device  2  is particularly suitable for the print of an own name mark in which the discharge of the ink is often stopped. By the suppression of the turbulent flow, the color unevenness of the mark is also prevented. In respect of the suppression of the turbulent flow, the distance L is preferably equal to or longer than 0.6 mm and is more preferably equal to or longer than 0.7 mm. When the distance L is excessively long, the edge of the mark is blurred. In addition, when the distance L is excessively long, a high output device is required. From these viewpoints, the distance L is preferably equal to or shorter than 5.0 mm, is more preferably equal to or shorter than 3.0 mm, and is particularly preferably equal to or shorter than 2.0 mm. As is apparent from  FIG. 4 , the distance L is measured based on the virtual sphere  60 . 
   When the ink jet printer  6  is stopped, the head  22  is moved to a rightmost part. At this time, the nozzle  62  is positioned just above the rest  34 . The nozzle surface  64  (that is, the tip of the nozzle  62 ) is immersed in a solvent (alcohol such as ethanol) filled in the rest  34 . Consequently, the nozzle  62  can be prevented from being clogged due to the dryness of the ink. 
   The pump  32  is formed of a rubber or a synthetic resin. The pump  32  is spherical and hollow. The pump  32  is filled with the solvent. A check valve (not shown) is provided on the upstream and downstream of the pump  32 . When an operator contracts the pump  32 , the solvent in the pump  32  is forcibly transmitted to the rest  34  through the tube  50 . When the pump  32  is restored, it is filled up with the solvent from the solvent vessel  30  through the tube  50 . The pump  32  and the tube  50  constitute supply means. In the case in which the ink jet printer  6  is stopped for a long period (which is equal to or more than a half day, for example), a large amount of the solvent is supplied to the rest  34  by the contraction of the pump  32 . Consequently, the nozzle  62  can be prevented from being clogged due to the shortage of the solvent. The solvent contaminated with the ink is fed to the waste liquid vessel  36  through the tube  52 . 
   The marking device according to the present invention is suitable for printing an own name mark. The marking device can also be used for printing a main mark. The above description is only illustrative and various changes can be made without departing from the scope of the present invention.