Abstract:
The invention is a dental model cutter for trimming the base of a dental model in a precise pre-determined manner where the dental model is precisely secured and positioned under a cutting guide and can be hand sawed or cut, thus eliminating the need of a conventional dental model grinder.

Description:
FIELD OF INVENTION  
         [0001]    The present invention is directed to a dental model trimming device for precisely cutting the base of a dental model without the creation of model dust, thus eliminating the requirement of running water with drainage or a high volume vacuum.  
         BACKGROUND OF THE INVENTION  
         [0002]    Dental models are made of a patient&#39;s teeth for such reasons as: the construction of crowns, partial dentures, retainers, removable orthodontic appliances, and study models. Dental stone or plaster is poured into an impression of the patient&#39;s teeth which then hardens. The hardened model then has to be trimmed for its variety of uses. The model trimming is done with a machine called a model trimmer which consists of a motor powered flat abrasive wheel flushed with running water to remove the grindings.  
           [0003]    The grindings are flushed into a drain which requires a plaster trap to preventing blockage of the drain lines. The water also has the disadvantage of removing a slight amount of the model surface which decreases the model accuracy.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention is directed towards a dental model cutter which allows a dental model to be precisely trimmed without the need of a conventional model trimmer, running water, any kind of drainage system, or a high powered air vacuum system. The dental model cutter holds a dental model in a firm position in relation to a slot guide for a hand or power saw which cuts the dental model.  
           [0005]    The model cutter is comprised of a rectangular box approximately 6″×12″ with ½″ thick walls. The rectangular box has opposing vertical sides and opposing vertical longitudinal ends. The bottom of the box is open and the middle ⅓ of the upper part of the box is open. The remaining two thirds of the upper part of the box is covered with left and right  1 ″ thick horizontal plates, each plate with an upper central T-slot groove which runs in the direction of the length of the box and is open to the top of the horizontal plate. A left and right horizontal sliding plate ½″ thick sits upon the respective upper surface of each horizontal plate, each containing a male T-track extending from its lower side which runs in the same direction and fits within the female T-slot of the respective left and right horizontal T-slot, allowing the horizontal sliding plates to move to back and forth on the horizontal plates. A horizontal screw within each horizontal plate engages the lower part of each male T-track which is each threaded to fit its respective screw, rotation of the screws move the sliding plates back and forth on the horizontal plates. A left and right vertical metal plate, each with a cushion pad facing the open area of the box is adhered to each sliding plate for securing the dental model. A vertical C-shaped saw guide is mounted centrally to the longitudinal sides of the rectangular box to guide a means for cutting the dental model, such as a hand saw. The dental model is positioned between the left and right vertical plates and the sliding plates are moved using the horizontal screws until the dental model is positioned appropriately below the cutting guide wherein the dental model is then cut.  
           [0006]    In one embodiment of the present invention a horizontal adjustable handle is mounted to the center of the left vertical plate with the handle to the left. The shaft of the handle passes through the vertical plate and is attached with a ball socket joined to a second free vertical plate with a foam pad on the opposite side. The movement of the free vertical plate enhances the fit to an irregular model base. The adjustable handle provides a quicker more finite method of adjusting the tension on the model and provides an easy method of clamping to successive dental models without adjustment of the sliding plates.  
           [0007]    In another embodiment of the invention the right vertical plate is hinged to the sliding plate and has an adjustment bar for altering the position of the model allowing for a more precise cut of the dental model. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]    [0008]FIG. 1 is a perspective view of the left sliding plate;  
         [0009]    [0009]FIG. 2 is a perspective view of the right sliding plate;  
         [0010]    [0010]FIG. 3 is an end view of a sliding plate;  
         [0011]    [0011]FIG. 4 is an end view of the vertical saw guide;  
         [0012]    [0012]FIG. 5 is a perspective view of the vertical saw guide;  
         [0013]    [0013]FIG. 6 is a perspective view of the right end plate with right horizontal screw, C-clamps, and handle;  
         [0014]    [0014]FIG. 7 is a perspective exploded view of the horizontal screw handle;  
         [0015]    [0015]FIG. 8 is a perspective view of the left end plate and left horizontal screw with handle;  
         [0016]    [0016]FIG. 9 is a perspective view of the rectangular box with left and right horizontal plates; and  
         [0017]    [0017]FIG. 10 is a perspective view of the dental model cutter on a box base. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    Referring to FIGS. 9 and 10 the dental model cutter has a longitudinal rectangular box  42  as a base. The outer dimension of the rectangular box is  6 ″× 12 ″. The walls are composed of opposing sides and opposing longitudinal right end  48  and left end  49 . The walls of the rectangular box are ½″ thick and 1″ high. The rectangular box  42  has an open top  46  and an open bottom  47 . Attached horizontally to the top [46]of the rectangular box  42  are a left horizontal plate  42 A and a right horizontal plate  41 B, one at each end of the rectangular box  42  and each 6″×4″×1″, the 4″ dimension in the same longitudinal direction as the rectangular box  42 . As shown in FIG. 9, with the left horizontal plate  41 A and the right horizontal plate  41 B attached to the upper surface of the rectangular box  42  the rectangular box has an open upper center  46  between the left horizontal plate  41 A and right horizontal  41 B. In FIG. 9 on the upper surface of the left horizontal plate  41 A is a left central female T-slot  9 C and in the right horizontal longitudinal plate  41 B is a right central female T-slot  9 D in the longitudinal direction of the length of the rectangular box  42 . Referring to FIGS. 10 and 11 and a left horizontal male screw  31 A is enclosed within a left cylindrical longitudinal bore  30 A and a right horizontal male screw  31 B is enclosed within a right cylindrical longitudinal bore  30 B. It is important the left longitudinal bore  30 A and the right longitudinal bore  30 B are_not threaded which assures the left horizontal male screw  31 A stays in the same position in the left longitudinal bore  30 A and the right horizontal male screw  30 B stays in the same position within the right cylindrical longitudinal bore  30 B. In FIG. 9 the upper part of the left longitudinal bore  30 A is open to lower part of the left central female T-slot  9 A and the upper part of the right longitudinal bore  30 B is open to the lower part of the right central female T-slot  9 B.  
         [0019]    Referring to FIGS. 1, 2,  3 ,  10 ,  11  and  12  the dental model cutter has a left sliding plate  4 A and a right sliding plate  4 B, each 4″×6″, the 4″ dimension in the longitudinal axis of the rectangular box  42 .  
         [0020]    The left and right sliding plates  4 A and  4 B each have a longitudinal axis the same as the rectangular box  42 . The left sliding [plates] plate  4 A sits horizontally on top of the left horizontal plate  41 A and the right sliding plate  4 B sits horizontally on the top of the right horizontal plate  41 B and each have the same rectangular dimension as the horizontal plates  41 A and  41 B and are ⅛″ thick. Referring to FIGS. 1, 2 and  3  a left male T-track  9 A is integral and runs longitudinal in the center of the lower part of the left horizontal sliding plate  41 A and a right male T-track  9 B runs longitudinally in the center of the lower part of the right horizontal sliding plate  4 B. Referring to FIG. 3 the lower surface  30 A of the left male T-track  9 A and the lower surface  30 B of the right male T-track  9 B are [is] grooved and threaded to match the threads of the left horizontal screw  31 A and the right horizontal screw  31 B. The left horizontal sliding plate  4 A is attached to the left horizontal plate  41 A by placing the left male T-track  9 A into the left central female T-slot  9 C and the right horizontal sliding plate  4 B is attached to the right horizontal plate  41 B by placing the right male T-track  9 B into the right central female T-slot  9 D. The left horizontal screw  31 A is placed within the left horizontal female bore  30 A wherein the left horizontal screw  31 A engages the threaded portion  30 A of the left male T-track  9 A. The right horizontal screw  31 B is placed within the right horizontal female bore  30 B wherein the right horizontal screw  31 B engages the threaded portion  30 B of the right male T-track  9 B. The right sliding plate  4 B is assembled with the right horizontal screw  31 B and right horizontal plate  41 B. As in FIGS. 6, 7,  8  and  10  a left end plate  60 A with an inner and outer surface is attached to the outer longitudinal end of the left horizontal plate  41 A to secure the horizontal position of the left horizontal male screw  31 A and a right end plate with an inner and outer surface is attached to the outer longitudinal end of the right horizontal plate  60 B to secure and maintain the horizontal position of the left horizontal screw  31 A and the right horizontal screw  31 B. In FIGS. 6 and 7 the left horizontal screw  31 A and the right horizontal screw  31 B each have circumferential grooves  68  corresponding to the inner and outer surfaces of the left end plate  60 A and the right end plate  60 B. Inside C-clamps  63  and outside C-clamps  64  are placed in the circumferential grooves  68  which secure the left horizontal screw  31 A and the right horizontal screw  31 B in their horizontal positions wherein turning of the left horizontal screw  31 A moves the left sliding plate  4 A turning of the right horizontal screw  31 B moves the right sliding plate  4 B. Rotation of the left horizontal screw  31 A moves the left sliding plate  4 A along the left horizontal plate  41 A and rotation of the right horizontal screw  31 B moves the right sliding plate  4 B along the right horizontal plate  41 B.  
         [0021]    In FIGS. 1 and 12 a left vertical plate  3  is mounted to the upper surface of the left horizontal sliding plate  4 A 1″ from the left end of the left horizontal sliding plate  4 A at a right angle to the longitudinal axis of the dental model cutter. The left vertical plate  3  is ⅛″ thick, 4″ in width and 4″ tall. In an embodiment of the dental model cutter, FIGS. 11 and 12, the left free vertical plate  3  is positioned ¾″ from the right horizontal end of the left sliding plate  4 A wherein a left cushion pad  6  is placed is placed on the right flat surface of the left free vertical plate  5  placing the flat open surface of the left cushion pad  6  at the right longitudinal end of the left horizontal sliding plate  4 A. In FIG. 1 the center of the left vertical plate  3  has a threaded hole  2  in its center which receives a 4″ long adjustable screw  1 A with a handle  1 D mounted at the left end and a ball  1 C at the right end. The adjustable screw  1 A attaches to the left vertical plate  3  threaded center hole  2 , extends horizontally where its ball end  1 C fits into a socket  8 B in the center of a free vertical plate  5  which is the same dimension as the left vertical plate  3 . In FIG. 10 the free vertical plate  5  is ¾″ from the right longitudinal end of the left sliding plate  4 A and the cushion pad  6  is attached to the right surface of the free vertical plate  5  which places the free surface of the left cushion pad  6  even with the right end of the left sliding plate  4 A.  
         [0022]    In FIG. 2 a right vertical plate  22  is mounted to the top of the right sliding plate  4 B 1″ from the left longitudinal end, a right cushion pad  20  is attached on the open flat surface of the right vertical plate  22 .  
         [0023]    As shown in FIG. 9 the right cushion pad  20  has a thickness as such that leaves a 4-8 mm. of the right horizontal sliding plate  4 A open at its left top surface to allow the heel of a dental model to sit on the right sliding plate  4 A top surface.  
         [0024]    As shown in FIGS. 2, 9,  10  and  11  the right vertical plate  22 ,  4 ″× 6 ″×{fraction ( 1 / 8 )}″, is swivel mounted to the upper surface of the right sliding plate  4 B ¾″ from the left end of the right sliding plate  4 B allowing an open surface on the right sliding plate  4 B top surface for the heal of the dental model to vertically rest as shown in FIG. 12. An adjustable arm  24  is mounted from the upper center, right, surface of the right vertical plate  22  to the upper surface of the right sliding plate  4 B. The adjustment arm  24  is comprised of two pieces, one sliding over the other with a locking nut and bolt  25  which locks the adjustable arm  24  in a chosen position. The adjustable arm  24  allows the vertical angle of the right vertical plate  22  to be changed which affects the cut of the dental model in relation to the position of the teeth. In FIGS. 10, 11 and  12  the right cushion pad  20 , ½″×4″×4″, is adhesively attached to the left surface of the right vertical plate  22 .  
         [0025]    In FIGS. 4, 5 and  9  the dental model cutter also has a vertical C-shaped saw guide  50  fitted centrally in the rectangular box  42  comprising lower T-shaped male ends  53  which are fitted into vertical T-slots  43  located in the center of the opposing sides of the rectangular box  42 . Each male T-shaped end  53  is connected by a pivoting pin  52  to a 1″ horizontal section  59  of the saw guide  50 . The horizontal section  59  is solid and ½″ wide. Attached to the inner end of each horizontal section  59  is a vertical C-shaped saw guide  50  which extends 4″ vertically and 4″ across the top. The vertical C-shaped guide  50  has a center slot  57  2-4 mm. wide to allow for a saw blade width. It is important the horizontal width of the C-shaped saw guide is 4″ which allows for the back and forth sawing motion of a short-bladed saw such as a jewelers saw.  
         [0026]    The invention has been discussed with specific embodiments. The purpose of the dental model cutter is to provide a way to trim the base of a dental model by cutting the model, not grinding it. The model cutter holds the model precisely in relation to a cutting guide. The cutting means is not intended to be limited to a saw blade; the invention is intended to include any means, such as a laser, that would cut a dental model.