Abstract:
A dental saw blade is provided and includes a body having a first face and an opposing second face and a cutting edge and a central opening for receiving a drive component for rotating the blade. The blade has a region of abrasive material disposed on each of the first and second faces to define a cutting zone at an outer section of the face and further has a means for stiffening the body and reducing binding of the blade during a cutting operation. The means is disposed between the cutting zone and the central opening and includes features that are formed on each of the first and second faces.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates generally to dental tools and more particularly, to a dental saw blade for use with a motorized dental saw and having a more robust construction that permits deeper cuts without warping and/or binding of the blade.  
         BACKGROUND  
         [0002]    Dental work often requires different types of workpieces be to fabricated and then cut to form by making intricate cuts in the material that forms the workpiece. For example, in dental work involving fixed crown and bridge work, a dental cast of the patient&#39;s dental features (i.e., the dental arch) is made and the teeth to which the crown or bridge work is to be fitted are then sectioned and sawed from the dental arch for easy work. It will be appreciated that dental casts are made for a number of different reasons and also other dental materials are used for other applications that require the operation of a dental saw to make some type of cut to tailor the shape of the dental material to fit a particular patient.  
           [0003]    While hand-operated coping saws have been used to perform this particular task, there are several drawbacks to using such saws, namely that because the sawing action is done by hand, the saw cannot cut very quickly and the person operating the saw can become tires and therefore have difficulty keeping the saw on the correct path. Over time, motorized, handheld saws become the preferred type of saw to cut dental casts and the like. A motorized saw includes a drive mechanism that drives a dental saw blade at a prescribed speed (RPM).  
           [0004]    [0004]FIG. 1 is side elevational view of a conventional dental saw blade  10  for use in a motorized dental saw. The dental saw blade  10  typically has an annular shape and more specifically, is ring-shaped. The dental saw blade  10  has an opening  20  (e.g., circular opening) formed in an inner section  12  thereof to receive a component (e.g., a hub or drive shaft) of the drive mechanism to effectuate rotation of the dental saw blade  10 . The dental saw blade  10  also includes a circumferential outer edge  14  that represents the edge of the dental saw blade  10  that makes contact with and cuts the workpiece.  
           [0005]    The dental saw blade  10  has a cutting section (or zone)  30  of a predetermined width that extends around the entire circumference of the dental saw blade  10 . The cutting section  30  includes the outer edge  14  and extends inwardly toward the opening  20  and thus has a ring-shape. It will be appreciated that the cutting section  30  is formed on both the first face  16  and the opposing second face  18  of the dental saw blade  10 . An intermediate section  40  is formed between the cutting section  30  and the opening  20 . Because the cutting section  30  serves as the surface of the blade  10  (besides the outer edge itself) that contacts the dental material during a cutting operation, an abrasive material  50  is disposed within the cutting section  30  to enhance the cutting capabilities of the blade  10 .  
           [0006]    The dental saw blade  10  is typically formed of a metal material; however, the dental saw blade  10  is quite flexible due to the reduced thickness thereof. More specifically, one type of material to form the dental saw blade  10  is a hardened stainless steel and the blade  10  has a thickness of about 0.003 inch or greater, with a diameter being about 1.5 inch or greater. Any number of abrasive materials  50  can be used with diamond particles being one preferred material due to its physical properties, i.e., hardness.  
           [0007]    While the dental saw blade  10  is satisfactory for its intended use, there are a number of disadvantages that are associated with the use of the dental saw blade  10 . First, the cutting section  30  only has a width of about ¼ inch and this results in the dentist experiencing difficulties during the cutting operation due to the thickness of the blade  10  itself. More specifically, the thickness of the blade  10  is only about 0.005 inch and therefore, the blade  10  is very flexible and can easily bend during a cutting operation. As a result, when a cut is made into the dental material and the blade  10  is advanced further into the dental material, there is a tendency for the dental saw blade  10  to bind, causing the cut of the dental material to not be straight. Second, when the user needs to make a deep cut, the dental saw blade  10  binds with the dental material when the blade  10  passes the cutting section  30 . Since the cuts that are being made are very intricate and have small dimensions, such binding, warping and bending of the blade  10  results in the cut being oversized. This spoils the dental material and the dental saw blade  10  since both will then need to be discarded.  
           [0008]    What has heretofore not been available is a dental saw blade that includes stiffening and anti-binding features that overcome the deficiencies associated with conventional dental saw blades.  
         SUMMARY  
         [0009]    A dental saw blade is provided and includes a body having a first face and an opposing second face and a cutting edge that extends around a perimeter edge of the body. Typically, the body has a circular shape and further has an opening formed in the center thereof for receiving a driving component to cause rotation of the dental saw blade when the saw is actuated.  
           [0010]    The blade has a cutting zone formed on each of the first and second faces with the cutting zone extending around a peripheral area of the respective face. The cutting zone has an abrasive material disposed therein and in an exemplary embodiment, the cutting zone is ring shaped with its outer edge being the cutting edge of the blade. One preferred abrasive material is diamond particles.  
           [0011]    The blade body also has a plurality of spokes formed on each of the first and second faces. Each spoke is formed of an abrasive material and is arranged radially relative to the cutting zone. More specifically, one end of the spoke intersects the cutting zone so as to form a seamless transition from the cutting zone to the spoke and the other end of the spoke extends inwardly towards but is spaced slightly from the central opening formed in the blade body. The spokes can be formed to have any number of shapes and sizes and preferably, there are more than two spokes formed on each face. The spokes are also preferably formed such that the spokes formed on the first face do not overlie the spokes formed on the second face. In other words, the spokes formed on the second face are formed such that they are disposed in spaces between adjacent spokes formed on the first face.  
           [0012]    The spokes on each face are also formed of an abrasive material; however, the abrasive material of the spokes does not have to be the same abrasive material that is used to form the cutting zone. Thus, for ease of manufacturing, the same abrasive material can be used to form the spokes and the cutting zone or a different abrasive material can be used.  
           [0013]    The inclusion of spokes provides a number of advantages that permits the present dental saw blade to overcome the disadvantages associated with conventional dental saw blades. First, the spokes act as a means for stiffening the blade body and therefore reduce the likelihood that the blade will warp or otherwise bend during normal cutting operations. Second, the spokes also act as anti-binding features since once the dental blade extends beyond the cutting zone during a deep cut, the material (i.e., dental material) is still cut by the spokes since there is a seamless transition from the cutting zone to the spokes and due to the spokes being formed of an abrasive material. Thus, the dental blade does not bind during deep cuts when the blade extends beyond the cutting zone.  
           [0014]    Other features and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0015]    The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings of illustrative embodiments of the invention in which:  
         [0016]    [0016]FIG. 1 is a side elevational view of a conventional dental saw blade having an abrasive region extending along an outer circumferential section of the blade;  
         [0017]    [0017]FIG. 2 is a side elevational view of a dental saw blade according to a first embodiment; and  
         [0018]    [0018]FIG. 3 is a side elevational view of a partial section of dental saw blade according to a second embodiment. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0019]    Referring first to FIG. 2 in which an exemplary dental saw blade  100  according to a first embodiment is illustrated. The blade  100  is of an annular construction in that it has a circular shape and includes a circumferential outer edge  102 . The blade  100  has a first face  110  and an opposing second face  120  and is formed of any number of materials that are suitable for the intended use, such as a metal. For example, one exemplary metal is hardened stainless steel and another exemplary metal is spring steel that has been hardened, ground and tempered.  
         [0020]    The blade  100  has an opening  130  formed in a central portion thereof for receiving a drive component, such as a drive shaft or hub, in a coupling relationship so as to cause rotation of the blade when the drive component is actuated, e.g., when the motorized saw is started. In the illustrated embodiment, the opening  130  has a circular shape which is the most common shape as a result of most drive components also having a circular shape.  
         [0021]    In order to enhance the cutting capabilities of the dental saw blade  100 , a cutting zone  140  is formed on each of the first face  110  and the second face  120 . Preferably, the cutting zone  140  has a ring-like shape in that the cutting zone extends from the outer edge  102  inwardly to an inner edge  142 . The inner edge  142  of the cutting zone  140  is thus spaced inwardly from the outer edge  102  and the cutting zone  140  thus has a width that is defined as the distance from the outer edge  102  to the inner edge  142 . The width of the cutting zone  140  is preferably uniform around the circumference of the dental saw blade  100  and therefore, the cutting zone  140  has an annular shape.  
         [0022]    The cutting zone  140  of the dental saw blade  100  has a material  150  disposed thereon which is different from the material that forms the blade  100  itself. Preferably, the material  150  that is disposed throughout the cutting zone  140  is an abrasive material which forms a cutting surface for cutting the dental material by the blade  100 . For example, the material  150  can be any number of abrasive or superabrasive materials that are commercially available including but not limited to diamond, cubic boron nitride (CBN), aluminum oxide, silicon carbide, tungsten carbide grit, boron carbide or other abrasive grit. The size of the abrasive material  150  can vary depending upon the particular application; however, exemplary abrasive materials have grit sizes from about 60 mesh to about 600 mesh. One preferred material  150  is diamond particles that are securely disposed on and held to the blade material defining the cutting zone  140  on both the first and second faces  110 ,  120 . Any number of conventional methods can be used to securely bind the abrasive material  150  to the blade material, including but not limited to impregnating the blade material within these regions during the fabrication of the blade  100 . Other fusing/bonding techniques can be used to effectively embed/anchor the abrasive material  150  within the blade material so that a portion of the abrasive material  150  protrudes above the surface of the blade material, thereby creating an abrasive, roughened surface.  
         [0023]    The dental saw blade  100  can come in a number of different dimensions depending upon the precise application and in general, the present blade  100  can be formed to have dimensions that are typically found in conventional dental saw blades. For example and according to one exemplary embodiment, the dental saw blade  100  has a diameter from about 1.5 inch to about 7.5 inch and the diameter of the opening  130  is from about ¾ inch to about 1.5 inch. The thickness of the dental saw blade  100  is from about 0.003 inch to about 0.045 inch. The cutting zone  140  has a width of about ⅛ inch to about ½ inch; however, these dimensions can vary depending upon the dimensions of the blade  100  itself.  
         [0024]    The dental saw blade  100  includes a plurality of features  200  that increases the robustness of the blade  100  and improves the overall cutting performance and life span of the dental saw blade  100 . The plurality of features  200  is in the form of a predetermined number of spokes that are formed radially around the inner opening  130  with each spoke  200  having a first end  202  that intersects the inner edge  142  of the cutting zone  140  and an opposing second end  204  that is closer to and spaced from the inner opening  130 . In the illustrated embodiment, each spoke  200  has a generally rectangular shape; however, it will be appreciated that the shape of the spoke  200  is not critical and therefore, the spoke  200  can be formed in any number of different shapes. Because the first end  202  joins the spoke  200  to the cutting zone  140 , the first end  202  will not be linear but will be slightly arcuate in shape, while the second end  204  can have a linear construction. The spoke  200  also has side edges  206 ,  208  that are parallel to one another when the spoke  200  has a rectangular shape.  
         [0025]    The spokes  200  are preferably formed on both the first face  110  and the second face  120  in an off set manner, as illustrated in FIG. 2. In other words, none of the spokes  200  formed on the first face  110  overlies one of the spokes  200  formed on the opposite second face  120 . The predetermined number of spokes  200  that are formed on each face  110 ,  120  varies on several factors, including the dimensions of each spoke  200  to be formed and according to the overall dimensions of the blade  100 . Preferably, two or more spokes  200  are formed on each of face  110 ,  120 . For example, either 2, 3, 4, 5 or 6 spokes can be formed on each face  110 ,  120  in an arrangement such that none of the spokes  200  on the first face  110  overlies one of the spokes  200  formed on the second face  120 . FIG. 2 illustrates an embodiment where three spokes  200  are formed on each face  110 ,  120  with the three spokes  200  being evenly spaced apart from one another and arranged so that the three spokes  200  on the first face  110  are disposed in spaces formed between the three spokes  200  formed on the second face  120  if the spokes  200  were translated to the second face  120 . In other words and as illustrated in FIG. 2, the spokes  200  are not formed in an overlying relationship.  
         [0026]    According to one exemplary embodiment, the width of one spoke  200  is from about ¼ inch to about ¾ inch (depending upon the number of spokes and dimensions of the blade) and a distance from the second end  204  to the outer edge  102  is from about ¾ inch to about 1.5 inch.  
         [0027]    The second end  204  of the spoke  200  is spaced slightly away from the opening  130  to permit a flange or other part of the drive component (e.g., drive shaft) to seat against the face of the blade  100  in an area free of spokes  200 . It is not desired for the drive component to seat against the abrasive material of the spokes  200  when the blade  100  is disposed on and locked to the drive component.  
         [0028]    Preferably, the lengths of each spoke  200  are the same. In the illustrated embodiment, the spokes  200  are arranged so that each spoke  200  on the first face  110  has a complementary spoke  200  on the second face  110  that is about 180° from the spoke  200  formed on the first face  110 .  
         [0029]    It will be appreciated that cutting zone  140  and the spokes  200  do not necessarily have to be formed of the same material. However, the cutting zone  140  and spokes  200  should both be formed of abrasive materials that can facilitate the cutting action of the blade  100 . In other words, two different types of abrasive materials can be used with one being used for the cutting zone  140  and the other being used for the spokes  200 . For ease of manufacturing, the material that is used to form the spokes  200  is preferably the same material as the abrasive material  150  that is used to form the cutting zones  140 . In other words, the spokes  200  are formed at the same time that the cutting zones  140  are formed.  
         [0030]    As previously mentioned, several disadvantages of the conventional saw blade  10  of FIG. 1 include that the thinness of the blade  10  causes the blade  10  to be very flexible and therefore easily bends during normal cutting operations. In addition, when it is necessary for the dental saw to make a deep cut, the dental saw blade  10  can easily bind with the dental material when the blade  10  passes the cutting zone  30 . The bending and binding actions cause the blade  10  to warp which results in the cuts being oversized and requires the cut dental material and the blade  10  itself to have to be rejected.  
         [0031]    The present Applicant has discovered that by adding the spokes  200  to each of the faces  110 ,  120 , the stiffness of the blade  100  is advantageously increased since the spokes  200  serve to increase the robustness of the blade  100  due to the spokes  200  acting as structural enhancing features. By arranging the spokes  200  on the two faces  110 ,  120  such that the spokes  200  do not overlie one another, the stiffness of the entire blade  100  is increased since most regions of the blade  100  have a spoke  200  formed thereon, whether the spoke  200  is formed on the first face  110  or on the second face  120 . Because the stiffness of the blade  100  is increased as a result of the formation of the spokes  200 , the flexibility of the blade  100  is decreased and accordingly, the blade  100  does not excessively bend during normal cutting actions. As a result, the blade  100  maintains a cut that has a width that is equal to the thickness of the blade  100 . In other words, the cut is not oversized due to warping of the blade as is the case with conventional blades.  
         [0032]    Moreover, the blade  100  also provides a dental saw blade that can make a deep cut beyond the boundary of the cutting zone  140  without the blade  100  binding with the dental material due to the spokes  200  being formed of an abrasive material (just as the cutting zone  140 ). Once the blade  100  advances beyond the cutting zone  140  during a cutting action, the blade  100  can continue to cut without binding because the spokes  200  selectively contact the dental material as the blade  100  rotates. Thus, the dental material remains in contact with an abrasive material that can facilitate cutting of the dental material. The blade  100  can therefore continue to cut the dental material as it is advanced into the dental material so long as the dental material is in contact with either the cutting zone  140  or the spokes  200 .  
         [0033]    The arrangement of the spokes  200  creates spaces  260  on each face between the spokes  200  which are free of any abrasive material and therefore have a slightly reduced thickness. During the cutting of the dental material, the cutting action produces dust particles which tend to deposit on the faces of the blade  100 . By forming spaces  260 , an area is provided for the dust particles to accumulate instead of the cutting surfaces themselves (i.e., the cutting zone and the spokes). By getting the dust particles away from the cutting surfaces, it is less likely that binding of the blade will result. More specifically, one of the reasons that binding of the blade  100  occurs is due to a build-up of dust particles on the cutting surfaces. By providing a non-cutting surface area for the dust particles to accumulate, the blade  100  further reduces the chance that binding will occur during normal cutting applications.  
         [0034]    [0034]FIG. 3 illustrates a partial section of a blade  300  according to another embodiment. Blade  300  is very similar to the blade  100  in that the blade  300  includes cutting zone  140  and spokes  300  formed radially around each of the blade faces  110 ,  120 . The only difference between the blade  300  and the blade  100  is that the cutting zone  140  in this embodiment has a number of slots  310  formed circumferentially around the outer edge  102 . The number, shapes and dimensions of the slots  310  vary depending upon on a number of factors, including design choice. In the illustrated embodiment, each slot  310  has a U-shape with the open end being formed along the outer edge  102  and the inner arcuate portion of the slot  310  being spaced inwardly from the outer edge  102  but still within the cutting zone  140 . Between the U-shaped slots  310 , the outer edge  102  defines an arcuate edge that comprises a cutting edge when the blade  300  contacts the dental material.  
         [0035]    As previously-mentioned, when the saw is used to cut a workpiece (i.e., dental material), it produces dust particles which tend to deposit on the faces of the blade. However, with slots  310  being formed in the cutting zone  140  and more particularly, at the cutting edge, any dust generated during cutting tends to concentrate in the slots  310  (e.g., on a trailing edge of the slot  310 ) rather than on the faces of the blade  300 , thereby keeping the effective thickness of the blade thin and accordingly keeping the cut thin as it is supposed to be, as opposed to an oversized cut being formed due to excessive build-up.  
         [0036]    The following example is provided to be illustrative of the present blade and is not to be construed as being limiting.  
       EXAMPLE  
       [0037]    A dental saw blade in the form of the blade  100  illustrated in FIG. 2 was produced and used repeatedly in typical dental applications to cut dental materials. The dental saw blade  100  was used over 400 times and did not show signs of excessive wear and importantly, the blade  100  did not bind and warp during deep cuts. In contrast, the conventional device  10  excessively warped and binded during the same applications and after  30  or so cutting applications, the blade  10  had to be discarded.  
         [0038]    It is preferred that the spokes  200  have ends that intimately join the cutting zone  140  to form a continuous, uninterrupted transition between the two because as the user makes a deep cut and extends beyond the cutting zone  140 , the spokes  200  act as cutting surfaces and therefore, the transition should be seamless so as to create a nice smooth cutting action. This also reduces the chances that binding or warping will occur.  
         [0039]    While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the invention.