BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of the components of a prior art metal plane.
FIG. 1A is an enlarged perspective view of the cutting blade and cap iron of the plane shown in FIG. 1.
FIG. 2 is a perspective view of a prior art wood block plane.
FIG. 3 is a perspective view of the improved hand plane of the present invention.
FIG. 4 is another perspective view from the front of the plane of the present invention.
FIG. 5 is a sectional view of the plane taken along lines 5-5 of FIG. 3.
FIG. 6 is a bottom plan view of the plane.
FIG. 7 is an exploded perspective view of the frog assembly of the improved hand plane of the present invention.
FIG. 8 is a side view of one of the frog shafts.
FIG. 9 is an exploded view of the lock bolt assembly for the frog.
FIG. 10 is a side elevation view of a scraping frog according to the present invention.
FIG. 11 is a bottom plan view of the scraping frog.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the improved hand plane of the present invention is shown in FIGS. 3-6. The improved hand plane 60 includes a base 62 with a bottom surface or sole 64 and a throat 66 which extends through the base 62 so as to define a mouth 67 on the sole 64. A rear tote or handle 68 is provided adjacent a rearward end of the plane 60, while a front handle or knob 69 is provided adjacent the front end of the plane 60.
A frog 70 is mounted in the throat 66 in a reverse angle, as compared to the prior art frog 20 shown in FIG. 1. The frog 70 extends upwardly and forwardly, as best seen in FIG. 5. A cutting blade or iron 72 is mounted on the bottom of the frog 70, and sandwiched between the frog 70 and a backup iron 74. A plurality of screws 76 extend through holes in the backup iron 74 and through slots in the blade 72 for threaded receipt in the bottom of the frog 70. Thus, when it is time t0 sharpen or dispose of the blade 72, the screw 76 need only be loosened slightly so that the blade can be slid out from between the frog 70 and the back iron 74.
The frog 70 is mounted in the throat 66 by a lock bolt 78 extending through the base 62, as best seen in FIG. 5. The rear face of the frog 70 includes a keyed slot 80 adapted to receive a head on the forward end of the lock bolt 78. The rear end of the lock bolt 78 includes a kipp-type locking lever 82 for tightening the lock bolt 78 such that the frog 70 is solidly seated against the back wall of the throat 66. Two throat adjusting screws 84 also extend through the base 62, as seen in FIGS. 4 and 5. Screws 84 are adjusted by hand and provide a solid seating against the back of the frog 7. In so doing the frog 70 can be moved fore and aft to close or open the mouth opening 67. The lock bolt 78 and the screws 84 provide a 3-point bearing for the frog 70.
A pair of threaded shafts 86 have a lower end with a dowel or head 88 received in keyed openings 90 in the frog 70, and an upper end extending upwardly through the base 62 with a knurled adjusting nut 92 which can be turned to adjust the depth and lateral position of the blade 72 relative to the mouth 67 of the throat 66. A metal plate 94 is provided on the upper surface of the base 62 beneath the knurled nuts 92, with a snap ring 96 residing below the metal plate 94 on each of the shafts 86. Because the two adjusting screws or shafts 86 operate independently at the outer sides of the frog 70, adjustment of the depth of the blade 72 also adjusts the lateral position of the blade, thereby eliminating any separate lateral adjustment component. Thus, the positioning of the blade is a quick and precise process. The throat adjusting screws 84 can be turned by a user's finger and thumb, without the use of a tool, such as a screwdriver, as in the prior art. Turning of the screws 84 allows the frog 70 to be moved forwardly and rearwardly at the bottom so as to open and close the mouth 67 of the throat 66. Under normal planing conditions, the lock bolt 78 holds the frog 70 in position within the throat, but is not so tight as to preclude depth and lateral adjustment by the adjusting screws 86.
As seen in FIG. 8, the head 88 of each shaft 86 includes a keyway-type slot 89. A pin 91 pivotally mounts the shaft 86 to the head 88, so that the frog 70 can pivot fore and aft at the bottom to narrow and widen the mouth opening 67.
FIG. 9 shows an exploded view of the lock bolt assembly. The bolt 78 includes a head 120 at its lower end and external threads 122 at its upper end. The upper end of the bolt 78 also includes a threaded bore 124. A locking nut 126 is received on the threads 122 of the bolt 78, and is received in a mating recess 83 in the locking lever 82. A shoulder screw 128 extends through the locking lever 82 and has a threaded lower end 130 for receipt in the threaded bore 124 of the bolt 78. A spring 132 on the screw 128 applies sufficient force so as to prevent the screw 128 from unintentionally becoming unthreaded from the bolt 78.
In use, the depth and lateral position of the blade 72 of the hand plane 60 is adjusted by the knurled nuts 92, which move the frog 70 upwardly and downwardly within the throat 66. The reverse angle of the frog 70 causes the frog to act as chip breaker for the blade or iron 72 as the blade cuts shavings from the wood being smoothed. The curved or concave front face 98 of the frog 70 directs the shavings up and out of the throat 66. The bottom surface 100 of the frog 70 is ground at an angle that will place the blade 72 at the desired angle for the primary work of the plane 60. This angle may be from 20°-60° in relation to the sole 64 of the plane 60. The frog 70 may be seated 95°-120° in relation of the sole 64. Because of the reverse angle of the frog 70, and a corresponding angle at the front of the mouth 67, when the sole 64 wears or is reduced by truing, the mouth 67 will stay constant for the life of the sole 64. The reverse angle of the frog 70 also provides the benefit of allowing the rear handle or tote 68 to be gripped in a more ergonomically proper manner, without interference from the frog 70 or the blade 72.
The blade 72 is disposable or resharpenable. The rigid backup iron 74 prevents flexing of the blade 72. The backup iron 74 is ground so as to have a minimum clearance angle and therefore maximum support for the thin blade 72. The bevel 73 of the blade 72 is very short due to the thin profile of the blade, and therefore the cantilever of the unsupported portion of the blade 72 is very short. The assembly of the frog 70, the blade 72, and the backup iron 74 provides for rigidity for the blade 72, thereby reducing chatter and flex so that the plane 60 will more easily cut obstinate grain with reduced tear-out.
The screws 76 which mount the blade 72 and backup iron 74 to the frog 70, are accessible through the mouth 67 in the sole 64 of the plane 60. In order to change or sharpen the blade 72, the frog 70 need only be lowered a small amount through the sole 64, and the screws 76, such that the blade 72 can be removed via the slots 102, as best shown in FIG. 7. If the blade 72 is disposable, it may be double sided, with holes, rather than slots, for the fixing screws 76, which then need to be fully removed to replace the disposable blade.
The assembly of the frog 70, blade 72, and backup iron 74 may be replaced with a second assembly, shown in FIGS. 10 and 11. The scraper assembly includes a frog 104 with a scraper blade 106 secured to the front face of the frog 104 by a lock bolt 108. The lock bolt 108 is retained by an elongated lock screw 110 accessible through the bottom of the frog 104. The frog also includes a rearwardly extending slot 112 to receive a bowing pin 114. The position of the bowing pin 114 is controlled by a bowing screw 116 accessible through the bottom of the frog 104. The pin 114 and screw 116 have tapered mating surfaces which allow the pin 114 to be advanced or retracted within the slot 112. When the screw 114 is threaded deeper into the slot 112, the pin 114 is forced forwardly slightly so as to engage the blade 106, and bow the blade a small degree. The lock screws 110 and the bowing screw 116 are accessible through the mouth 67 of the base 62. The pin 114 applies tension to the blade 106, and thereby keeps the corners of the blade from digging in during the scraping process. Thus, that the improved hand plane 60 of the present invention can be used for both smoothing wood and scraping wood, with interchangeable frog and blade assemblies to accommodate the different functions and different wood characteristics.
It is further understood that the first frog assembly 70, 72, 74 can be interchanged with yet another frog assembly having a different angle of attack. For example, one frog assembly may have an angle of attack of 40°-50°, while another frog assembly may have an angle of attack of 55°-60° to accommodate wild grain.
The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives.
Patent Application
20080052924
