BACKGROUND ART A quartz oscillator is an element having a quartz plate (hereinafter, referred to as 'blank') in which a quartz crystal cut to have certain tilt and thickness is coated with film electrodes on both sides, and a base combined to the quartz plate. The quartz oscillator is broadly used in various communication equipments which require a stable oscillating circuit since it has very small temperature coefficients.

To make such a quartz oscillator, silver liquid 3 is generally coated on both ends of a blank 1, which is subsequently seated on an elastic support 2b installed at the top of a lead 2a of a base 2. The quartz oscillator fabricated as above, through a so-called'a blank mounting process', has a configuration as shown in FIG. 1.

In the conventional blank mounting process, an absorber absorbs a specific blank from a blank pallet, and a dispenser which moves independent from the absorber is then transferred toward the blank to coat silver liquid. After that, the absorber is again transferred toward the pallet and seats the blank on a specific base.

Such a process however needs much working time since the absorber and the

dispenser move independently. In addition, since the dispenser should moves a long distance relative to the absorber, there is increased a spatial error between the dispenser and the absorber, which is apt to cause inferiority at a position where the silver liquid is coated.

Furthermore, there is also frequently used a method for subsequently transferring not only the absorber but also the blank pallet and the base pallet so that the absorber may select a blank and a base in order. This method is useful only when blanks or bases are arranged regularly on the pallet, thereby causing the inconvenience that it is required to set positions of blanks or bases in advance.

DISCLOSURE OF INVENTION The present invention is designed to solve such problems of the prior art, therefore an object of the invention is to provide a blank mounting apparatus in which a blank absorbing unit and a dispenser unit are integrally configured to move together, thereby improving a working speed and preventing an inferiority of silver plate coating.

In order to accomplish the above object, there is provided a blank mounting apparatus which includes a robot body moving above a blank pallet and a base pallet, an absorption pin mounted to the robot body to be vertically movable, the absorption pin absorbing a blank on the blank pallet, transferring the blank upon the base pallet along with the robot body and then seating the blank on a selected base on the base pallet, and dispenser units installed to the robot body adjacently to both sides of the absorption so as to coat silver liquid at both ends of the blank absorbed at an end of the absorption pin.

Preferably, the robot body moves in two-dimension above the blank pallet and

the base pallet along an X-axis rail and a Y-axis rail, and the apparatus further comprises a controller for controlling the two-dimensional motion of the robot body according to an established working point coordinates.

In addition, the blank mounting apparatus may further include arrangement fingers mounted near both sides of the absorption pin respectively so as to pick the blank and arrange a position of the blank absorbed by the absorption pin, and a finger adjustment hand mounted to the robot body so that an end having a tapered portion is positioned between nippers at an upper portion of the arrangement finger, whereby the finger adjustment hand adjusts a distance of the nippers of the arrangement finger during rotation.

Additionally, the blank mounting apparatus may further includes a hinge for rotating to open or close the dispenser unit relative to the robot body so that a discharge hole of a nozzle equipped to the dispenser unit is exposed.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of preferred embodiments of the present invention will be more fully described in the following detailed description, taken accompanying drawings. In the drawings: FIG. 1 shows a conventional quartz oscillator fabricated by a blank mounting process; FIG. 2 is a perspective view showing an appearance of a blank mounting apparatus according to a preferred embodiment of the present invention; FIG. 3 is an enlarged view showing an absorption pin shown in FIG. 2; FIG. 4 shows a curved portion formed on a lower end of the absorption pin

according to the present invention; FIG. 5 is a front view of FIG. 4; FIG. 6 shows a concave groove formed on an end of an arrangement finger according to the present invention; FIG. 7 is an enlarged view showing a dispenser unit shown in FIG. 2; FIG. 8 is a perspective view exemplarily showing a dispenser gasket provided in accordance with the present invention; and FIG. 9 is a flow chart for illustrating the operation of the blank mounting apparatus according to a preferred embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

At first, FIG. 2 shows an appearance of a blank mounting apparatus according to a preferred embodiment of the present invention. As shown in FIG. 2, the blank mounting apparatus of the present invention includes an absorption pin 11 for absorption and seating of a blank 1, a dispenser unit 13 for coating silver liquid on the blank 1, and a robot body 10 moving above a blank pallet 4 and a base pallet 5 with supporting the absorption pin 11 and the dispenser unit 13 together.

Preferably, the robot body 10 is transferred along an X-axis rail 10a and a Y-axis rail 10b so as to move in two-dimension above the blank pallet 4 and the base pallet 5.

In addition, the robot body 10 is transferred according to working point coordinates previously established by a user by control of a controller (not shown) such

as a PLC (Programmable Logic Controller). Thus, it is possible to install a plurality of blank pallets 4 and base pallets 5 and then control the robot body 10 to be operated for a desired pallet. Therefore, the conventional inconvenience that the pallet should be changed may be solved.

The absorption pin 11 mounted to and driven by the robot body 10 for vertical movement receives an absorbing force from a pump (not shown) to absorb a blank 1 arranged on the blank pallet 4.

FIG. 3 shows the absorption pin 11 and its surroundings in more detail. In the figure, a lower end (hereinafter, referred to as'a nozzle 11 a') of the absorption pin 11 may be made of stainless steel having sufficient durability. For example, the nozzle 11 a may be made of a shock-absorbing material such as Teflon or urethane in order to prevent the blank 1 from being damaged.

The absorption pin 11 may be integrally configured. However, it is also possible that the nozzle 11 a is detachably combined to a body of the absorption pin 11 so that the nozzle 1 la may be changed as desired when its end portion is worn.

The lower end of the absorption pin 11 is preferably formed concave upward to configure a curved surface 1 lob having a predetermined radius of curvature, as shown in FIG. 4 in more detail. This may minimize a contact area between the lower surface of the absorption pin 11 and the upper surface of the blank 1, thereby preventing damages, for example scratch, which may occur on the surface of the blank 1.

Referring to FIG. 5, the radius of curvature of the curved surface lib is preferably set in a range of 3mm-5mm so that a sufficient area of the upper surface of the blank 1 is spaced apart from the curved surface llb, in consideration that a standardized pallet 1 has a width of 1. 8mm-2. 2mm.

The blank 1 absorbed at the lower end of the absorption pin 11 is arranged to a correct position by means of arrangement fingers 12 so that the blank 1 is accurately coated with the silver liquid and seated. At this time, each of the arrangement fingers 12 is mounted near both sides of the absorption pin 11 so as to pick a blank 1 and then arrange the blank 1.

For this purpose, the arrangement finger 12 preferably has an'L'shape so that an end of a horizontal portion of the'L'shape comes in contact with an edge of the blank 1 while arranging the blank 1.

The arrangement finger 12 preferably has a shock-absorbing portion 12a made of urethane or Teflon at a portion directly contacted with the blank 1, or a portion elongated from the contact portion, in order to prevent the blank 1 from being damaged injured when the arrangement fingers 12 pick both sides of the blank 1. The shock-absorbing portion 12a may be configured using various materials having shock-absorbing property and impact resistance, not limited to the above cases.

On the other hand, in case the nozzle 1 la of the absorption pin 11 has a width (a) greater than a width of the blank 1 and the nozzle 1 la of the absorption pin 11 has a length (b) greater than a length of the blank 1 as shown in FIG. 4, a concave groove 12b is formed on the end of the horizontal portion of the arrangement finger 12 so as to prevent the nozzle 11 a of the absorption pin 11 from contacting with the end of the arrangement finger 12 while arranging the blank 1.

In other words, as shown in FIG. 6 in more detail, the concave groove 12b is formed so that the end of the horizontal portion of the arrangement finger 12 has a'E' shape, seen from above. Thus, the arrangement fingers 12 may arrange the blank 1 in

contact with both side ends of the blank 1 without contacting with the nozzle 11 a.

Preferably, a finger adjustment hand 14 is installed to an upper portion of the arrangement finger 12 in order to control a distance between nippers. In other words, the finger adjustment hand 14 has a tapered end, which becomes thinner downward and is positioned between nippers 12c at an upper portion of each arrangement finger 12.

This finger adjustment hand 14 is also vertically movable by means of rotation in order to adjust a distance between the nippers 12c. Here, the finger adjustment hand 14 may be modified in various ways, of course. For example, the finger adjustment hand 14 may be tapered so as to become thinner upward.

The dispenser units 13 for coating silver liquid on the blank 1 are mounted adjacent to both sides of the absorption pin 11. At this time, each dispenser unit 13 is preferably hinged to the robot body 10 by means of a hinge 15 for the purpose of rotational open or close. In other words, the dispenser units 13 are hinged so that they are pulled to opposite directions on the center of the absorption pin 11, thereby exposing their ends toward a user. This helps the user to clean the discharge hole easier.

FIG. 7 shows the dispenser unit 13 in more detail. As shown in FIG. 7, the dispenser unit 13 is equipped with a nozzle 13a having a discharge hole 13b for discharging silver liquid received in a cylinder 13c.

At this time, the discharge hole 13b preferably has a rectangular section in order to enlarge a silver liquid adhering area between the blank 1 and an elastic support 2b (see FIG. 1), compared with the conventional circular discharge hole. This improves an adhesive force of the silver liquid. In addition, the silver liquid may be coated in a regular adhering area for each product, thus it is possible to reduce an error of a natural

frequency of the same kind of products.

There may be adopted many methods to make the discharge hole 13b have a rectangular section. As an example, a dispenser gasket 16 is preferably mounted to the nozzle 13a to make a rectangular discharge hole 13b. In other words, the dispenser gasket 16 having a sleeve as shown in FIG. 8 is mounted to the nozzle 13a to make the rectangular discharge hole 13b at its end.

Now, an operation of the blank mounting apparatus according to the present invention constructed as above is described with reference to FIG. 9.

At first, a user establishes and inputs working point coordinates on the blank pallet 4 and the base pallet 5. After that, if driving the apparatus of the present invention, the robot body 10 to which the absorption pin 11 is mounted is transferred to a corresponding point along the X-axis rail 10a and the Y-axis rail lOb, and the absorption pin 11 descends, absorbs a specific blank 1 and then ascends (step S 10).

Subsequently, the arrangement finger 12 is operated to pick both sides of the absorbed blank 1 and then arranges the blank 1 (step S15). After that, the absorption pin 11 and the dispenser unit 13 are transferred to a specific base 2 by support of the robot body 10 (step S20). Then, the dispenser unit 13 is driven to coal silver liquid on both ends of the blank 1 (step S25). At this time, the above procedure may be changed.

For example, the silver liquid coating process (step S25) may be advanced before the robot body 10 moves toward the base 2 (step S20).

If the silver liquid is coated on the blank 1, the absorption pin 11 descends and then seats the blank 1 on the base 2 (step S30).

The blank mounting apparatus of the present invention therefore performs the absorbing, silver liquid coating and seating processes automatically with transferring

the absorption pin 11 and the dispenser unit 13 together, by using the above-mentioned components and operation.

INDUSTRIAL APPLICABILITY According to the present invention, the blank mounting apparatus may improve a working speed and prevent errors in silver liquid coating positions since the absorption pin for absorbing a blank and the dispenser unit for coating silver liquid are integrally installed and transferred.

In addition, since the absorption pin and the dispenser unit move in two-dimension along the X-axis rail and the Y-axis rail by support of the robot body, a work initiating time and a work completing time may be established as desired.

The blank mounting apparatus of the present invention may also prevent the blank from being damaged since the absorption pin and the arrangement finger directly contacted with the blank are made of shock-absorbing materials.

Moreover, since the dispenser unit is hinged to the robot body, the cleaning process of the dispenser unit is more conveniently and easily conducted.

In particularly, since the discharge hole formed in the nozzle of the dispenser unit has a rectangular section by means of the gasket, an adhering area between the blank and the elastic support becomes broader even though the same amount of silver liquid as the conventional one is discharged. Thus, the adhesive force between the blank and the elastic support is increased with a constant adhering area, thereby reducing an error of a natural frequency.

The present invention has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.