This invention relates to metal-body woodworking planes.
Low angle jack planes have long been used in woodworking, and planes having adjustable mouths have also long been used. Adjustability of the mouth (through which the plane blade projects) is desirable because it usually is preferable to use as narrow a mouth as possible for the depth of cut (or thickness of shaving produced), but depth of cut must be adjustable, with the result that the thickness of the shaving produced changes. Thicker shavings require a larger mouth opening. Adjustable mouths can be provided by making the frog to which the plane blade is secured repositionable so that the blade can be differently positioned relative to the leading edge of the mouth in the plane sole. A particularly desirable structure for providing both an adjustable mouth and support for the cutter or blade is disclosed in U.S. Pat. No. 6,615,497 for a Bench Plane, which is incorporated herein by reference. However, production of a plane with an extremely low bed angle makes it difficult to use movable frog structures.
Adjustable mouths have long been achieved in low angle planes by providing an adjustable toe ahead of the plane blade. Such a toe has a bottom coplanar with the plane body sole and can slide forward and backward to make the mouth opening ahead of the blade smaller or larger. Such a toe is usually secured to the plane body by rotating the front knob on the plane around a threaded stud that projects from the toe through a hole in the plane body until the knob (acting as a “nut” on the threaded stud) contacts the plane body, thereby securing the toe to the underside of the plane body.
One drawback associated with use of an adjustable toe is that the toe can slide backward, for instance, if it strikes a protrusion from the work-piece or a benchstop, and contact and damage the cutting edge of the plane blade. It can also be difficult to adjust the position of the toe by the small increments often necessary in order to position the toe precisely where desired to achieve a particular mouth opening ahead of the plane blade.
Another difficulty associated with adjustable mouth planes is that smaller mouth openings create a greater tendency for the mouth to become clogged with shavings, which requires interruption of use of the plane in order to clear the mouth.
This invention is a plane having an adjustable toe that cannot inadvertently slide backwards in the plane body so that it contacts and possibly damages the plane blade. Moreover, this plane permits the mouth to be easily and quickly opened to clear shavings and then easily and quickly closed to the previously selected mouth opening size. The toe slides in the plane body forward and rearward. Rearward travel can be stopped by threaded stop screw mounted in the plane to bear against the toe, thereby establishing the point to which the toe can slide back in the plane body. Rotation of the threaded stop moves the end of the stop by small, easily controlled increments, making it easy to change and establish the width of the mouth while preventing contact between the toe and the plane blade. Because the threaded stop prevents only rearward travel beyond the position at which the toe contacts the stop, the knob securing the toe in the plane can be rotated to permit the toe to slide, and it can be easily and quickly slid forward to open the mouth and permit clearance of shavings. The toe can likewise be easily and quickly returned to precisely the same mouth opening position and the knob rotated to lock the toe in that position. This rapid operation involves grasping the handle or plane body, rotating the knob in a first rotational direction to loosen the knob until the toe can slide in the plane body, simultaneously applying force on the knob and handle or body in opposite directions away from each other until the toe slides forward in the body, thereby opening the mouth, removing the shavings from the mouth, simultaneously applying force on the knob and handle or body in opposite directions toward each other until the toe slides reward in the body and the boss contacts the screw, and rotating the knob in the opposite rotational direction to tighten the knob.
The low angle jack plane 10 of this invention has a plane body 12 to which an adjustable toe 14 attaches on the underside at the front. Attached to the body 12 are a rear handle or tote 16, front knob 18 and a blade assembly 20 that includes a blade 22, lever cap 24 and blade adjustment mechanism 26.
Toe 14 is secured to the plane body 12 by a threaded stud 28 that is threaded into a hole 30 in toe 14 or otherwise secured to toe 14. Stud 28 passes through oval hole 32 in body 12, washer 34, and into knob 18. Stud 28 is preferably received in a metal threaded insert 36 that has been installed in knob 18 if knob 18 is not itself metal or another material appropriately itself threaded. Rotation of knob 18 will either tighten or loosen engagement between toe 14 and plane body 12 in order to secure toe in a selected position or (by loosening knob 18) permit toe 14 to be moved within body 12.
The region 38 of body 12 behind hole 32 is somewhat thickened, as can be seen in
Also significantly, the mouth 48 can be quickly opened to facilitate removing shavings lodged in the mouth during use and then quickly closed to its previous size by rotating knob 18 enough to loosen the toe 14, pushing knob 18 and toe 14 forward to open the mouth 48, and then sliding knob 18 and 14 backward until toe 14 encounters the end of stop screw 42.
As will be appreciated by those skilled in the art, the exact structure described above and shown in the figures is not necessary to practice this invention. The benefits of mouth adjustability and blade damage prevention of this invention can be achieved with other structures. For instance, a stud, screw or other similar fitting can be positioned in the toe 14 for contact with a portion of the plane body 12. Additionally, the body region 38 through which stud 42 is threaded could be shaped differently, as could the protrusion or boss 46. Indeed, stud 42 could contact a recess or other structure on toe 14 rather than a protruding boss 46. In another variation, a position adjusting screw could be threaded into toe 14 and positioned to contact structure on the plane body 12. Structures other than threaded stud 42 could also be used, such as a movable wedge, but threaded members do provide highly functional adjustability in small increments.
The toe travel limiting and position adjusting structures of this invention could also be utilized in a variety of planes having moveable toes other than low angle jack planes, including bench planes of various sizes and configurations and block planes.
Accordingly, as will be understood by those skilled in the art, numerous configurations of the toe stop and adjustment mechanisms of this invention can be practiced within the scope and spirit of this invention and the following claims in addition to the embodiments described above and illustrated in the drawings.
This application claims priority to provisional application No. 60/538,987 filed Jan. 23, 2004 and is a continuation-in-part of application Ser. No. 10/914,677, filed Aug. 9, 2004.
Number | Date | Country | |
---|---|---|---|
60538987 | Jan 2004 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10914677 | Aug 2004 | US |
Child | 11041466 | Jan 2005 | US |