Abstract:
A variable cutting angle hand plane is provided. The variable cutting hand plan has a base unit configured for holding an iron, wherein the base unit has a sole and a throat extending through the base unit to the sole. The base unit has an adjustable frog for supporting the iron at multiple angles with respect to the sole. A means for engaging the iron is used for holding the iron against the adjustable frog. The hand plane may have an adjustable throat. There may be a means for indicating the approximate angle of the adjustable frog.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to woodworking tools. Specifically, this invention relates to a variable cutting angle hand plane. 
   Hand planes have been used for hundreds of years to smooth the surface of wood. A hand plane works when a woodworker pushes or pulls the plane across the surface of the wood which allows the sharp blade of the plane iron to engage the wood and shear off a thin layer of wood, thereby smoothing the wood surface. 
     FIG. 1  shows an expanded view of a prior art hand plane. The hand plane assembly  10  has a base unit  12 , in which the bottom of the base unit  12  is the sole  14 . In addition, the base unit  12  has an opening in the sole  14  which is called the throat  16 . Attached to the base unit  12  is at least one handle or tote  18 . A device called a frog  20  extends upward from the inside of the base unit  12 . The frog  20  rigidly screws to the base unit  12  with two mounting screws  21 . The frog  20  holds the blade or cutter which is known as the iron  28  at a preset angle (approximately 45°) with respect to the sole  14 . 
   The user can turn the depth adjuster  22  which allows the iron  28  to extend farther through the throat  16 . Adjustment of the iron  28  depth allows the iron  28  to engage a deeper or shallower cut in the wood being planed. The lateral adjuster  24  allows the user to adjust the iron  28  into a left or right position. This in turn, allows for deeper cuts on one side of the plane or the other. A bolt inserted near the center of the frog  20  is called the fulcrum stud  26 . This stud  26  allows the iron  28  to be fastened securely to the frog  20 , so as to make a secure, tight fit which holds the iron  28  in place during use. 
   In order for the iron  28  to be of use, it must be sharpened. The sharpened area on an iron  28  is called the bevel  29 . Most prior art hand planes are designed in one of two ways. They either have the iron bevel-up, or the bevel-down in relation to the sole  14  of the plane. Typically planes that have a down bevel are similar to the design shown in the hand plane assembly of  FIG. 1 . These planes are most common and generally best for planning along the grain of the surface being planed. On the other hand, common bevel-up irons are used in a different style of hand plane (not shown) which do not have the frog. Instead, the iron  28  lays on a fixed angle inclined surface on the inside of the base unit  12  without the aid of the frog  20 . This allows a bevel-up iron  28  to lie at a much more reclined angle inside the base unit  12  of the plane. 
   A cap iron  30  is commonly used in conjunction with the iron  28  on bevel-down type planes. The cap iron  30  is secured to the iron  28  by the use of a cap iron screw  36 . This cap iron  30  acts as a chip breaker which helps to curl the cuttings cut by the iron  28  before they have a chance to split away from the larger working piece of wood. The end result is that the chip breaker part  38  on forward end of the cap iron  30  as seen in  FIG. 1 , which is the rounded-out bottom portion of the cap iron  30 , is desirable in bevel-down type irons  28 . Overall, the chip breaker contributes for much smoother cutting on the work surface of the wood. The iron  28  and the cap iron  30  when bolted together by the use of the cap iron screw  36  become one piece, which is held onto the frog  20  by the use of the lever cap  32 . This lever cap has a lever  34  with a cam on the end which applies pressure against the cap iron  30  to hold the cap iron  30  and the iron  28  assembly in place on top of the frog  20 . The cam on the bottom of the lever  34  causes the lever cap  32  to pivot around the fulcrum stud  26  and remain tight on the cap iron  30  and iron  28  assembly. 
   A low angle bevel-up type iron plane which is not shown, is commonly known to one skilled in the art. A low angle iron allows a user with the much more reclined angle on the iron (approximately 37°) to use the plane in softer types of wood or the end grain of wood. The sharper attack angle allows the plane to cut harder woods or those with more difficult grain. Additionally, planes with a high cutting angle (approximately 90°), such as scraper planes (not shown), generally are used for scraping the top surface off the surface to be planed, such as scraping a finish or paint off the surface being planed. Thus, each type of plane, low angle, medium angle, or high angle scraper has its own specific purpose. 
   One problem in the prior art is that for every type of job, one needs separate hand planes to properly do the job. Therefore, it would be desirable to have one hand plane that can perform the jobs of multiple hand planes. Therefore, the primary feature or advantage of the current invention is to provide an improved variable cutting angle hand plane. 
   Another feature or advantage of the current invention is a hand plane suitable for using either bevel-up or bevel-down plane irons. 
   Another feature or advantage of the current invention is to provide a hand plane which can be used as a low angle plane, medium angle plane, and a high angle plane. 
   Another feature or advantage of the current invention is a hand plane which allows the throat to adjust for optimizing cutting. 
   A further feature or advantage is the provision of a variable cutting angle hand plane which is economical to manufacture, durable in use, and efficient in operation. 
   One or more of these and/or other features or advantages of the invention will be apparent from the specification and claims that follow. 
   SUMMARY OF THE INVENTION 
   One or more of the foregoing features or advantages may be achieved by a hand plane having a base unit configured for holding an iron, wherein the base unit has a sole and a throat extending through the base unit to the sole, the iron having a beveled edge for cutting the wood and further configured for the beveled edge of the iron to extend through the throat of the base unit, an adjustable frog operatively connected to the base unit that supports the iron at multiple angles with respect to the sole and, a means for engaging the iron and holding the iron against the frog. The means for engaging the iron may be an iron cap. The iron cap may pivot with respect to the base unit. The iron cap may have an articulating chip breaker which engages the iron. 
   Another aspect of the current invention is a hand plane with an adjustable frog which is pivotally mounted to a base unit. The adjustable frog can be supported with a moveable frog stop assembly which slides along the base unit. 
   Another aspect of the present invention is a hand plane having an angle indicator that approximately indicates the angle of an adjustable frog with respect to the sole. 
   Yet another aspect of the present invention is a hand plane having one or more adjustable throat plate(s) which allow the throat to adjust in size and location so that a user may optimize the throat as the angle of the adjustable frog changes and the protrusion of the iron through the throat changes. 
   A further aspect of the present invention is a hand plane with an adjustable frog which additionally comprises a depth adjuster for adjusting depth of the plane iron through the throat of the plane in the base unit. 
   A word that needs defined is iron. Iron does not refer to the type of material or element in which the current invention is made of. Rather, iron is a term commonly known in the art for the blade or the cutting device which actually cuts the wood for a hand plane. Therefore, a cap iron (or iron cap) is a cap that simply goes over the top of the iron, which can be made of many different materials including steel, cast iron, brass, or other similar metals. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an expanded view of a typical hand plane in the prior art. 
       FIG. 2  shows an isometric view of one embodiment of the current invention used in a hand plane. 
       FIG. 3  shows the embodiment of the invention shown in  FIG. 2  with a side of the base unit removed. 
       FIG. 4  shows a sectional view of one embodiment of the invention taken along lines  4 - 4  of  FIG. 3 . 
       FIG. 5  shows a sectional view of one embodiment of the invention taken along lines  5 - 5  of  FIG. 3 . 
       FIG. 6A  shows an exploded view of the top of one embodiment of an adjustable frog assembly. 
       FIG. 6B  shows an isometric bottom view of the adjustable frog assembly of  FIG. 6A . 
       FIG. 6C  shows one embodiment of a frog stop assembly. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The invention is an improved hand plane. One embodiment of the invention is shown in  FIGS. 2-6 . This embodiment incorporates an adjustable variable angle frog assembly  86 . 
   This embodiment of the invention is constructed with a base unit  12  in which the underside of the base unit  12  is called the sole  14 . An opening through the sole  14 , is a throat  16 . The throat  16  can be configured as an adjustable throat, as is common in the art. Attached to the base unit  12  is preferably one or more totes or handles  18 . The totes  18  allow the user to grip the plane so they can push or pull the plane over the wood surface to be planed. The iron  28  rests on the adjustable frog  88  and extends through the throat  16 . The iron  28  is held to the frog assembly  88  by an articulated iron cap assembly. The articulated iron cap assembly is constructed with an iron cap main body  64  which pivotally mounts to the base unit  12  by the iron cap assembly main pivots  74 . These iron cap assembly main pivots  74  allow the articulated iron cap assembly to pivot back and forth along the iron cap assembly main pivot  74  axis. 
   When the tensioning bolt  62  is screwed into the iron cap main body  64 , it applies pressure to the iron  28 , which is supported by the adjustable frog  88 . The articulating chip breaker  66 , which is pivotally attached to the iron cap main body  64 , then moves downward after the articulated iron cap assembly pivots about the iron cap assembly main pivot  74 . Preferably, attached to the articulating chip breaker is a nose piece  68 , which may or may not be extendable. If extendable, a retainer ring  78  can be used to keep the nose piece  68  from separating from the chip breaker  66 . As the tensioning bolt  62  is screwed tighter into the iron cap main body  64 , the nose piece  68  engages the iron  28 . The tighter the tensioning bolt  62  is tightened, the tighter the pressure that is held on the iron  28 . This pressure or loading allows the articulated iron cap assembly  60 A to hold the iron  28  into the base unit  12  of the plane. However, other types of iron caps are contemplated and other devices for holding the plane iron  28  to the frog  88  are contemplated. 
   As seen in  FIGS. 2-4 , the adjustable frog  88  pivots within the base unit  12  by adjustable frog pivot pins  89 . Preferably, there is one adjustable pivot pin  89  which extends out of each side of the adjustable frog  88  and engages corresponding holes within the sides of the base unit  12 . In this manner, the adjustable frog  88  is allowed to pivot through a range of angles relative to the sole  14 . As the iron  28  engages or rests on the frog  88 , the iron  28  correspondingly changes angles with the adjustable frog  88 . 
   Supporting the adjustable frog  88  is a frog stop assembly  90 . The frog stop assembly  90  can be constructed in any manner which will allow the adjustable frog  88  to pivot within the base unit  12 , but then support the adjustable frog  88  when the iron  28  is tightened down to the adjustable frog  88 . One embodiment of the frog stop assembly  90  is shown in  FIGS. 2-6 . The frog stop body  92  slides axially along the base unit  12 . The front assembly  90  tightens to the base unit when a dovetail nut  97  slides within the adjustable frogs slide groove  96  and receives a threaded stud  95 , which passes through the frog stop body  92  and tightens with an adjustable frog tightening nut  94 . A washer  110  may be placed between the adjustable frog tightening nut  94  and the adjustable frog stop body  92 . The dovetail nut  97  has angled sides which slide along corresponding angled sides in the frog slide groove  96 . In this way, when the adjustable frog tightening nut  94  is tightened onto the threaded stud  95 , the dovetail nut  97  tightens, but cannot pull through the adjustable frog slide groove  96 . This allows the frog stop assembly  90  to support the adjustable frog  88  in the desired position. Other designs of an adjustable frog stop  90  are contemplated for supporting the adjustable frog  88 . 
   To keep the adjustable frog stop assembly  90  properly aligned with respect to the adjustable frog  88 , an angle indicator groove  99  within the frog stop body  92  rides along a raised member which can be used as an angle indicator  98 . The angle indicator  98  preferably has graduations which, when aligned with the back end of the frog stop body  92  indicate the approximate angle of the adjustable frog  88  with respect to the sole  14 . Other methods of aligning the adjustable frog stop assembly  90  and other methods of indicating approximate angle of the adjustable frog  88  are contemplated with this invention. 
   The adjustable frog stop assembly  90  preferably has a frog stop roller  100  which engages the back side of the adjustable frog  88  for supporting the adjustable frog  88 . The frog stop roller  100  is preferred to have a flat support surface  104  which contacts the back side of the adjustable frog  88 . The frog stop roller  100  has frog stop roller pivots  102  which allow the frog stop roller  100  to adjust to the proper angle so that the support surface  104  can rest flatly against the back side of the adjustable frog  88  as the angle of the adjustable frog  88  changes. 
   Adjustment of the frog  88  changes the location where the iron  28  extends through the throat  16  of the base unit  12 . Therefore, this plane is preferred to have an adjustable throat  16 . One method of accomplishing this is shown with both a front adjustable throat plate  106  and a back adjustable throat plate  108 . These plates  106 ,  108  preferably slide linearly along the sole  14  of the base unit  12 . Therefore, the adjustable throat plates  106 ,  108  can be moved to the desired distance from the iron  28  in both the front and back of the iron  28 . The adjustable throat plates  106 ,  108  in this embodiment are held in the proper places in the base unit  12  by one or more throat plate tightening screws  114  which each tighten a dovetail nut  112 . The dovetail nuts are preferably constructed with angles which match corresponding angles within a groove on the bottom of the base unit  12 . Thus, as the tightening screws  114  tighten to the dovetail nuts  112 , the dovetail nuts  112  tighten within the groove in the base unit and prevent further sliding of the adjustable throat plate  106 ,  108 . This can be seen in  FIG. 5 . 
   Refer now to  FIGS. 6A and 6B  wherein one embodiment of the adjustable frog assembly  86  is shown.  FIG. 6A  shows the front side which engages the iron  28 .  FIG. 6B  shows the back side. The adjustable frog  88  preferably has a depth adjuster  22 . The depth adjuster  22  is threaded on one end and rotates within the adjustable frog  88 . The threaded end causes a pin to travel linearly on the threads of the adjuster  22  when the adjuster  22  is rotated. As this pin travels up and down, it preferably corresponds with a hole or aperture in the iron  28  and causes the iron  28  to travel along the front surface of the adjustable frog  88 . With this motion, the iron  28  can be properly positioned to the desired depth through the throat  16  for obtaining a proper thickness of cut. Although preferred, a depth adjuster  22  is not necessary for the current invention. 
   To allow the adjustable frog  88  to pivot in the base unit  12 , the adjustable frog assembly  86  preferably has adjustable frog pivot pins  89  which enter holes on opposite sides of the adjustable frog  88 . The pivot pins  89  fit into corresponding holes within the sides of the base unit  12 . The pivot pins  89  are held apart and tightly into the holes on the base unit  12  by a spring  24  which pushes apart the pivot pins  89 . To insert the adjustable frog assembly  86  into the base unit  12 , the pivot pins  89  are configured with a pivot pin groove  120  which can be accessed with a tool, such as needle nose pliers, through the access slots  126  on the adjustable frog  88 . The use of the tool allows one to squeeze the pivot pins  89  together, align the pins with the corresponding holes on the sides of the base unit and then release the pivot pins  89  to extend into the holes on the sides of the base unit  12 . Thus, the adjustable frog assembly  86  can pivot. The adjustable frog assembly  86  can be aligned with the frog stop assembly  90  by having a frog stop alignment guide  103  on the frog stop roller  100 . The frog stop alignment guide  103  aligns with a frog alignment groove  116  on the back side of the adjustable frog  88 . Thus, this helps to keep the adjustable frog assembly  86  aligned within the base unit  12 . 
   In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstance may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims. For example, the present invention contemplates variations in structure of the iron, the iron cap, the adjustable frog, the frog stop, the depth adjuster, the totes, the throat, and etc. These and other variations are within the spirit and scope of the invention.