Patent Publication Number: US-2015083752-A1

Title: Dental compound gun

Description:
CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2013-0114099, filed on Sep. 25, 2013, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to dental compound guns and, more particularly, to a dental compound gun which can easily melt a solid compound material stick to be used to manufacture a denture, thus simplifying a denture manufacturing process, and markedly reducing the manufacturing time period compared to the conventional technique which has been conducted manually, and which is able to prevent a negligent accident such as a fire which may be caused during the denture manufacturing process and is configured such that it is convenient to place the dental compound gun on a support surface in an upright state, thus facilitating use and storage thereof 
     2. Description of the Related Art 
     Generally, dentures refer to dental prosthetic components to substitute for natural teeth when at least one natural tooth is damaged or lost. In order to manufacture such a denture, a wax denture is first manufactured and then temporarily installed in the mouth of a patient to check the functionality and esthetics. If there are no problems, remnants other than an artificial tooth which is in a wax denture state are manufactured by polymerizing resin into an acryl resin base. 
     Here, wax dentures are a kind of temporary prosthetic which are manufactured with the purpose of trail installation in the mouth of a patient to check factors such as esthetics, occlusion, pronunciation, etc. before completing a final partial denture or total denture prosthetic component. Typically, artificial teeth are arranged on a base plate, and a denture base is manufactured by carving wax. Therefore, such temporary dentures are called wax dentures. 
     To manufacture a final denture using such a wax denture, the wax denture is first placed in a flask. The flask is immersed in hot water, and heat is applied to the water, thus softening the wax. Subsequently, upper and lower bodies of the flask are separated from each other, a resin separating agent is applied to the flask, and then the upper and lower bodies of the flask are assembled with each other again. Thereafter, resin of different colors in a sufficiently melted liquid phase is injected into the flask. After the flask is sufficiently cooled, a denture formed of resin is extracted from the flask. Thereafter, final finishing and polishing are conducted, thus completing the manufacture of the final denture. 
     Meanwhile, to manufacture such a denture, various kinds of materials for dental impressions are used. To date, a material stick called a dental impression compound or a dental mold compound has been used in such a way that a user manually melts the material stick with a flame. 
     However, the conventional manufacturing method cannot be precisely conducted. Also, there is the possibility of loss of a material compound that has been stored after being used. Furthermore, the manual denture manufacturing process requires high precision. It is therefore difficult for a non-expert to perform such a denture manufacturing process. Furthermore, because the user must directly handle a device for producing a flame, there is likelihood of a negligent accident such as a fire being caused by an inexperienced manufacturing technician. 
     SUMMARY 
     Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a dental compound gun which can easily melt a solid compound material stick to be used to manufacture a denture, thus simplifying a denture manufacturing process, and markedly reducing the manufacturing time period compared to the conventional technique which has been conducted manually, and which is able to prevent a negligent accident such as a fire which may be caused during the denture manufacturing process and is configured such that it is convenient to place the dental compound gun on a support surface in an upright state, thus facilitating use and storage thereof. 
     In order to accomplish the above object, the present invention provides a dental compound gun, including: a body unit having a gun shape, with an insert hole formed in a first end of the body unit so that a compound material stick is inserted into the body unit through the insert hole; a feeding unit transferring the compound material stick inserted into the insert hole to a second end of the body unit; a melting unit heating the compound material stick transferred thereinto by the feeding unit, melting the compound material stick, and discharging melted compound material out of the body unit; a drive unit comprising a trigger for driving the feeding unit, and a motor provided to be operated by operation of the trigger; a control unit receiving an operation signal of the trigger and controlling power to be supplied to the motor; and a support unit coupled to a lower end of the body unit, the support unit being supported on a support surface so that the body unit is placed upright on the support surface, wherein the control unit controls the motor in such a way that when the operation signal of the trigger is generated, the motor is forwardly rotated, and when the operation signal of the trigger is interrupted, the motor is reversely rotated. 
     The support unit may include: a power connector for supplying external power to the control unit; and a thermostat for controlling a heating temperature of the melting unit, wherein the control unit may control an rpm of the motor in response to a temperature set by the thermostat, thus controlling a rate at which the compound material stick is transferred. 
     The feeding unit may include: a worm shaft connected to an output shaft of the motor so that the worm shaft is rotated by the motor; and at least one roller connected to the worm shaft by a gear, the roller coming into rolling contact with the compound material stick and rotating to transfer the compound material stick. 
     The feeding unit may further include a stick holder guiding insertion of the compound material stick into the melting unit. The stick holder may include: a tubular body made of elastic rubber; and a tapered surface disposed between the melting unit and the roller, the tapered surface being inclined inwards from an inlet of the stick holder such that an end of the compound material stick is frictionally guided by the tapered surface. 
     The feeding unit may further include a wobbling prevention member protruding towards the inlet of the stick holder and supporting an outer circumferential surface of the compound material stick inserted into the stick holder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view illustrating a dental compound gun according to an embodiment of the present invention; 
         FIG. 2  is a sectional view illustrating the dental compound gun according to the embodiment of the present invention; 
         FIG. 3  is a partially broken perspective view illustrating the internal construction of a body unit of the dental compound gun according to the embodiment of the present invention; and 
         FIG. 4  is a block diagram showing the construction of the dental compound gun according to the embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a dental compound gun according to an embodiment of the present invention will be described in detail with reference to the attached drawings. 
       FIG. 1  is a perspective view illustrating the dental compound gun according to the embodiment of the present invention.  FIG. 2  is a side view illustrating the dental compound gun according to the embodiment of the present invention.  FIG. 3  is a partially broken perspective view illustrating the internal construction of a body unit of the dental compound gun according to the embodiment of the present invention.  FIG. 4  is a block diagram showing the construction of the dental compound gun according to the embodiment of the present invention. 
     Referring to the drawings, the dental compound gun according to the embodiment of the present invention includes a body unit  10 , a feeding unit  20 , a melting unit  30 , a drive unit  40 , a control unit  50  and a support unit  60 . 
     The body unit  10  includes a main body  10   a  and a handle  10   b  which define therein a space for receiving the feeding unit  20 , the melting unit  30  and the drive unit  40 . The main body  10   a  and the handle  10   b  form a gun shape to facilitate use thereof. 
     The body unit  10  has an insert hole  11  in a first side, in detail, a rear end, of the main body  10   a  so that a compound material stick  2  is inserted into the main body  10   a  through the insert hole  11 . The compound material stick  2  which has been inserted into the insert hole  11  is transferred by the feeding unit  20  to a second side, that is, a front end, of the main body  10   a.    
     The feeding unit  20  has the construction to transfer the compound material stick  2  from the insert hole  11  to the front end of the body unit  10 . 
     The feeding unit  20  includes a guide  20   a  which has a longitudinal depression extending from the insert hole  11  towards the interior of the main body  10   a  in the longitudinal direction. The compound material stick  2  which is inserted into the insert hole  11  is guided by the guide  20   a  and moved therealong. 
     The melting unit  30  melts the compound material stick  2  that is transferred from the feeding unit  20  and discharges melted compound material out of the body unit  10 . 
     The melting unit  30  includes: a nozzle  31  which has an outlet hole  31   a  in the second side of the body unit  10 , in other words, in the front end of the main body  10   a , so that melted compound material is discharged out of the main body  10   a  through the outlet hole  31   a ; and a heating wire  32  which is wound around the nozzle  31 . 
     The nozzle  31  has therein a hollow space through which the compound material stick  2  transmitted from the guide  20   a  of the feeding unit  20  passes. The compound material stick  2  is melted by the heating wire  32 . Preferably, the nozzle  31  is made of aluminum which is light and has a high heat transfer coefficient. Melted compound material is smoothly discharged through the outlet hole  31   a.    
     The drive unit  40  drives the feeding unit  20  such that the compound material stick  2  inserted into the body unit  10  is transferred by the feeding unit  20 . The drive unit  40  includes a trigger  41  which is provided to protrude from a front surface of the handle  10   b  of the body unit  10 , and a motor  42  which is provided in the handle  10   b  and is rotated in response to an operation signal of the trigger  41 . 
     The trigger  41  is provided in the gun-shaped body unit  10  to function as a switch for driving the feeding unit  20 . The trigger  41  is elastically supported on one end of the motor  42  by a spring and is electrically connected to the control unit  50  to apply power to the motor  42  or interrupt the supply of the power depending on the manipulation of the user. 
     When power is supplied to the motor  42  under control of the control unit  50  which will be explained later, the motor  42  is rotated, thus driving the feeding unit  20 . 
     The control unit  50  controls the operation of the feeding unit  20 , the melting unit  30  and the drive unit  40 . For this, the control unit  50  receives an operation signal of the trigger  41  and controls power to be supplied to the motor  42 . 
     As stated above, this embodiment is configured such that melted compound material is discharged by the nozzle  31  of the melting unit  30 . Here, when power is turned off to interrupt the discharge of the melted compound material, liquefied compound material which remains around the outlet hole  31   a  of the nozzle  31  may undesirably flow down. 
     In consideration of the above problem, the present invention is characterized by the structure capable of preventing residual compound material, after some compound material has been melted by the heating wire  32  in the nozzle  31  of the melting unit  30  and discharged through the outlet hole  31   a , from undesirably flowing down from the outlet hole  31   a.    
     For this, in the dental compound gun  1  according to the present invention, the control unit  50  controls the motor  42  in such a way that when an operation signal of the trigger  41  is applied to the motor  42 , the motor  42  is forwardly rotated for a preset time period, and when the operation signal of the trigger  41  is interrupted, the motor  42  is reversely rotated for a preset time period. 
     As shown in  FIG. 2 , the above-mentioned operation can be embodied by a motor relay  43  which is installed in the handle  10   b  of the body unit  10  or may be installed on a circuit board of the control unit  50 . The motor relay  43  is connected to the control unit  50  and configured such that, in response to an operation signal of the trigger  41 , when the forward rotating signal is interrupted, the motor  42  is reversely rotated for a preset time period. 
     Alternatively, a separate switch may be installed on an outer surface of the body unit  10  so that the motor  42  can be reversely rotated. As a further alternative, the trigger  41  may have a connection structure such that a reverse rotation signal can be created. 
     For example, the circuit of the control unit  50  may be designed such when the trigger  41  is pressed one time, the motor  42  is forwardly rotated, and when the trigger  41  is pressed one more, the motor  42  is reversely rotated. 
     The support unit  60  provides space to receive the control unit  50  therein. Further, the support unit  60  is coupled to a lower end of the body unit  10  so that the body unit  10  can stand on the support unit  60  placed on a support surface. 
     The support unit  60  has a planar casing shape having a bottom surface of a predetermined width to enable the body unit  10  to be stably placed. 
     The support unit  60  includes on a predetermined portion of a rear end thereof a power connector  61  for supplying external power to the control unit  50 . 
     The dental compound gun  1  according to the present invention having the above-mentioned construction can facilitate a denture manufacturing process. In addition, compared to the conventional method, the manufacturing process can be more precisely conducted. Furthermore, because the dental compound gun  1  is configured such that when the operation signal of the trigger  41  is interrupted to stop the discharge of melted compound material, the compound material that remains in the nozzle  31  can be prevented from flowing down through the outlet hole  31   a , thus the manufacturing process can be conducted conveniently and cleanly. 
     In the dental compound gun  1  according to the embodiment of the present invention, the feeding unit  20  includes a worm shaft  21  and a roller  22 . 
     The worm shaft  21  is connected to an output shaft of the motor  42  to provide rotational power to the roller  22 . 
     The roller  22  is provided in the main body  10   a  of the body unit  10  to transfer the compound material stick  2 . For this, at least one roller  22  is connected to the worm shaft  21  by gears and is brought into rolling contact with the compound material stick  2 . 
     In the dental compound gun  1  according to the embodiment of the present invention, the feeding unit  20  further includes a stick holder  24  which guides the compound material stick  2  into the melting unit  30 . 
     The stick holder  24  is installed between the melting unit  30  and the roller  22  and is preferably made of elastic rubber. The stick holder  24  is a tubular body having the same inner diameter as that of the nozzle  31 . A first end of the stick holder  24  is fastened to an outer circumferential surface of a rear end of the nozzle  31  by a snap ring, and the compound material stick  2  is inserted into an holder inlet, formed in a second end of the stick holder  24 , and is guided into the nozzle  31  by the stick holder  24 . 
     Meanwhile, in the present invention, the compound material stick  2  is transferred from the insert hole  11  formed in the rear end of the body unit  10  to the melting unit  30  through the guide  20   a . Here, due to the problem of the compound material stick  2  being undesirably moved in the front-rear direction, the compound material stick  2  may not be correctly inserted into the melting unit  30 . 
     To avoid the above-mentioned problem, as shown in  FIG. 2 , the stick holder  24  is connected to the rear end of the nozzle  31 , thus functioning to extend the inlet of the nozzle  31  of the melting unit  30  to an area around the roller  22 . Further, the stick holder  24  is made of elastic rubber so that frictional force between it and the compound material stick  2  made of resin can be enhanced, thus preventing the compound material stick  2  that is being transferred by the roller  22  from being undesirably pushed or moved in the front-rear direction. 
     A tapered surface  24   a  which is inclined inwards is provided in the inlet formed in the second end of the stick holder  24  so that an end of the compound material stick  2  can be effectively guided into the stick holder  24  with friction. An internal protrusion  24   b  protrudes inwards from an inner circumferential surface of a portion of the stick holder  24  that makes contact with the rear end of the nozzle  31 . 
     The compound material stick  2  which has been inserted into the insert hole  11  of the body unit  10  and is being transferred by the feeding unit  20  is pushed by the stick holder  224  into the melting unit  30 , in detail, into the nozzle  31 . During a process of transferring the compound material stick  2  towards the nozzle  31  using the drive force of the roller  22 , the outer circumferential surface of the compound material stick  2  is elastically compressed by the tapered surface  24   a , and the compound material stick  2  is pushed into the stick holder  24 . Here, when the compound material stick  2  reaches the inlet  31   b  formed in the rear end of the nozzle  31 , the compound material stick  2  is compressed and supported by the internal protrusion  24   b  so that it can be reliably transferred into the nozzle  31 . 
     When the roller  22  is forwardly or reversely rotated, the tapered surface  24   a  and the internal protrusion  24   b  function to guide the compound material stick  2  so that the compound material stick  2  can be easily inserted into the melting unit  30  and, simultaneously, function to prevent the compound material stick  2  from being undesirably moved in the front-rear direction. 
     In addition, as shown in  FIG. 3 , the tapered surface  24   a  and the internal protrusion  24   b  protrude inwards with respect to the radial direction, thus preventing melted compound material from flowing down from the nozzle  31  into the interior of the body unit  10 . 
     Meanwhile, in the dental compound gun  1  according to the embodiment of the present invention, the roller  22  includes a lower roller  221  and an upper roller  222 . 
     The lower roller  221  includes a first roller  221   a  and a second roller  221   b . The first roller  221   a  is connected to the worm shaft  21  by gears and rotated by it. The second roller  221   b  is disposed ahead of the first roller  221   a  at a position spaced apart therefrom by a predetermined distance. The second roller  221   b  supports a lower portion of the compound material stick  2  and guides the compound material stick  2  towards the inlet of the stick holder  24 . 
     Furthermore, each of the first and second rollers  221   a  and  221   b  includes two rollers which are provided on a horizontal shaft at positions spaced apart from each other by a predetermined distance. Inner surfaces of the two rollers gently protrude in a symmetric shape, thus making contact between them and the outer circumferential surface of the compound material stick  2  smoother. Thus, the compound material stick is supported between the first rollers  221   a  and between the second rollers  221   b  in such a way that the compound material stick comes into rolling contact with the inner surfaces of the first and second rollers that are disposed at both sides. Furthermore, the compound material stick can be transferred by rotation of the first rollers  221   a.    
     Of the first rollers  221   a  including the two rollers, a roller disposed at one side is directly connected by gears to the worm shaft  21  which is rotated by the motor  42 . The second rollers  221   b  function not only to prevent the front end of the compound material stick  2  that is being transferred by the rotation of the first rollers  221   a  from being drooping but also to guide the compound material stick  2  such that it is brought into contact with the inlet of the stick holder  24 , that is, into the tapered surface  24   a  when entering the stick holder  24 . 
     The upper roller  222  includes third rollers  222   a  and fourth rollers  222   b . The third rollers  222   a  are provided above the first rollers  221   a  and connected to the first rollers  221   a  by gears to be rotated in a direction opposite to the direction of the rotation of the first rollers  221   a . The fourth rollers  222   b  are disposed ahead of the third rollers  222   a  at positions spaced apart therefrom by a predetermined distance. In addition, the fourth rollers  222   b  are located above the second rollers  221   b  and are connected to the second rollers  221   b  by gears, thus supporting an upper portion of the compound material stick  2 . 
     Referring to  FIG. 3 , the third and fourth rollers  222   a  and  222   b  of the upper roller  222  are rotated corresponding to the associated first and second rollers  221   a  and  221   b  that are connected to the third and fourth rollers  222   a  and  222   b  by gears so that the upper and lower portions of the compound material stick  2  which are transferred towards the melting unit  30  can be reliably supported by the upper and lower rollers  222  and  221 . In the same manner as those of the first and second rollers  221   a  and  221   b , the third rollers  222   a  include two third rollers, and the fourth rollers  222   b  include two fourth rollers. The two rollers of each of the third and fourth rollers  222   a  and  222   b  have inner surfaces which gently protrude inwards in a symmetric shape so that the rollers can smoothly make contact with the outer circumferential surface of the compound material stick  2 . 
     Therefore, when the compound material stick  2  moves forwards or backwards through the stick holder  24  made of elastic rubber, the compound material stick  2  can be reliably moved forwards or backwards while overcoming frictional resistance of the tapered surface  24   a.    
     Referring to  FIG. 3 , the upper roller  222  is installed in a rotational bracket  23 , which is connected at one end thereof to the body unit  10  by a hinge shaft and is rotated around the hinge shaft to be opened or closed with respect to the body unit  10 . Therefore, the space between the lower roller  221  and the upper roller  222 , which are connected to each other by gears, can be opened and the compound material stick  2  which is transferred in the body unit  10  can be exposed to the outside. 
     Furthermore, to facilitate an operation of extracting the compound material stick  2  from the body unit  10  when the worm shaft  21 , the roller  22  or the motor  42  malfunctions, an upper cover  12  is openably provided on the upper surface of the body unit  10 . An open button  13  is provided on the body unit  10  so that when the open button  13  is pressed, one end of the upper cover  12  which has been locked to the inner surface of the body unit  10  can be released therefrom. 
     In the dental compound gun  1  according to the present invention having the above-mentioned construction, the above-stated operational effect is exerted by organic mechanical solidarity among the elements. Particularly, by virtue of the construction including the roller  22  and the stick holder  24 , the compound material stick  2  can be prevented from being undesirably moved, and it can be reliably supplied into the melting unit  30 . Further, even when the dental compound gun  1  malfunctions, because the roller  22  can be easily removed from the compound material stick  2 , it is convenient to use, and structural stability of the device can be ensured. Moreover, maintenance and repair can be facilitated. 
     Meanwhile, the dental compound gun  1  according to the embodiment of the present invention further includes a thermostat which is provided in the support unit  60  to control the heating temperature of the melting unit  30 . 
     Referring to  FIGS. 2 and 3 , the thermostat  70  includes a touch switch  71  which is provided on an upper surface of a front portion of the support unit  60 , and a temperature indicator  72  which indicates a temperature control phase in response to the operation of the touch switch  71 . 
     The control unit  50  controls the rpm of the motor  42  in response to a temperature range determined by manipulating the thermostat  70 , that is, the touch switch  71 , thus controlling the speed at which the compound material stick  2  is transferred. 
     The reason why the control unit  50  controls the rpm of the motor  42  is due to the fact that if the temperature set by the thermostat  70  is comparatively high, because a melting rate of the compound material stick  2  is increased and a rate at which compound material is discharged through the nozzle  31  is increased, the feed rate of the compound material stick  2  must be reduced and, contrary to this, if the temperature set by the thermostat  70  is comparatively low, because a melting rate of the compound material stick  2  is slow, the feed rate of the compound material stick  2  must be increased in order to increase a rate at which melted compound material is discharged through the nozzle  31 . 
     In the dental compound gun  1  according to the present invention having the above-mentioned construction, when a denture is manufactured, the user can conveniently control a melting rate of the compound material stick  2  while the discharge rate of the compound material that is markedly varied depending on the melting rate can be stabilized. 
     Meanwhile, the feeding unit  20  further includes a wobbling prevention member  25  which is installed to be protruded towards the inlet of the stick holder  24  so as to guide and support the outer circumferential surface of the compound material stick  2  that is inserted into the stick holder  24 . 
     Referring to  FIGS. 2 and 3 , the wobbling prevention member  25  includes a pair of support members which have support surfaces that respectively protrude from upper and lower portions of the inlet of the stick holder  24 , in other words, upper and lower portions of the tapered surface  24   a  of the stick holder  24 , in order to support the compound material stick  2 . 
     The wobbling prevention member  25  is disposed in a shape in which the support members enclose the outer surfaces of the upper and lower portions of the stick holder  24 . In addition, each support surface has a shape similar to a portion of an arc. Therefore, the wobbling prevention member  25  can reliably support the outer circumferential surface of the compound material stick  2 . 
     That is, the wobbling prevention member  25  functions to reliably support the compound material stick  2  that has entered the stick holder  24  so that the compound material stick  2  can be prevented from wobbling. 
     After the compound material stick  2  is inserted into the body unit  10  through the insert hole  11 , the front end of the compound material stick  2  is inserted into the nozzle  31  of the melting unit  30  by the roller  22 , and it is melted by the heating wire  32 . As the melting process is conducted, the compound material stick  2  gradually becomes smaller and forms into a small compound material block. Ultimately, the rear end of the compound material stick  2  that has become small into a piece shape is removed from the roller  22 . Here, the small compound material block may undesirably wobble in an up-down or left-right direction by frictional force in the stick holder  24  made of elastic material while the operation for moving the compound material stick  2  forwards or backwards is conducted. 
     The small compound material block is pushed by a new compound material stick  2  that is inserted into the insert hole  11 . Here, if the above-stated wobbling phenomenon is caused, the compound material stick piece may be tilted, rather than being correctly pushed, and be caught in the roller  22 , thus making forward or backward movement impossible. 
     To prevent the above problem, in the dental compound gun  1  according to the present invention, the feeding unit  20  includes not only the stick holder  24  for guiding insertion of the compound material stick  2  into the nozzle but also the wobbling prevention member  25 . As a result, the forward and backward movement of the compound material stick  2  can be reliably performed. 
     As described above, the present invention provides a dental compound gun which can easily melt a solid compound material stick to be used to manufacture a denture and facilitate use of a melted compound material, thus simplifying a denture manufacturing process, and markedly reducing the manufacturing time period compared to the conventional technique which has been conducted manually. Furthermore, a negligent accident such as a fire which may be caused during the denture manufacturing process can be prevented. In addition, it is convenient to place the dental compound gun on a support surface in an upright state, thus facilitating use and storage thereof. 
     Although the preferred embodiment of the dental compound gun according to the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.