The present invention relates to saws and, more particularly, to hand saws configured for making “flush cuts” and starter saws configured for starting cuts from within a plane of the material being cut.
Saws capable of making “flush cuts” are known in the art. Such saws are capable of cutting through a protrusion that is perpendicular to a surface in manner so that the cut is “flush” to the surface. These saws are also useful for making cuts in locations having limited clearance, such as at a corner where the planes of two surfaces meet at a 90 degree angle. Some amount of clearance is needed for the saw handle and the user's hand, which makes flush cuts of this kind difficult with a conventional saw. Therefore, many saws designed for making flush cuts include saw blades that are of sufficient flexibility to permit the blade to be “flexed” so that a portion of the blade is parallel to and flush against a surface adjacent to the material being cut. These blades also typically have little or no lateral inclination to the saw teeth, so as to avoid marring the adjacent surface. Without sufficient flexibility of the blade, clearance needed for the saw handle or user's hand may not permit a sufficiently flush cut. Known prior art flush-cutting blades have a generally straight cutting edge that is not suitable for starting cuts from within the plane of the material being cut. The distal tip of the blade may be used to start a cut from within the plane of the material, but this is an awkward and difficult exercise and also results in premature wear of the teeth at end of the blade. Known prior art flush-cutting saws also lack appropriate adjustability of the blades relative to the handles to allow access in tight locations.
Starter saws capable of starting cuts from within the plane of the material being cut (i.e, not starting from an edge of the material) are also known in the art. Some of these saws include a convex cutting edge that allows the cut to be started from within the plane of the material being cut. However, such saws typically include some set or lateral inclination to the teeth, which makes them undesirable for use in a flush cutting operation. Such saws also lack any means for accurately controlling the depth of the cut.
In general, a saw of the present invention comprises a generally planar saw blade, a handle, and a depth control guide. The saw blade has a proximal end and a distal end. The blade has an arcuate cutting edge extending along at least a portion of the saw blade between its proximal end and distal end. The blade has a shank portion adjacent its proximal end. The handle is adapted for hand-engagement by a user. The shank portion of the saw blade is pivotally connected to the handle in a manner to permit pivoting movement of the saw blade relative to the handle in a plane of the saw blade. The depth control guide comprises an arcuate depth control surface. The arcuate depth control surface is adapted for engagement with a surface of material being cut by the saw in a manner to control cutting depth. The arcuate depth control surface has a curvature that approximates a curvature of the arcuate cutting edge of the saw blade. The depth control guide is adjustably connected to the saw blade in a manner so that the distance between the arcuate depth control surface and the arcuate cutting edge of the blade can be selectively adjusted to achieve a desired cutting depth.
In another aspect of the invention, a saw comprises a generally planar saw blade and a depth control guide. The saw blade has an arcuate cutting edge with a fixed radius of curvature. The depth control guide comprises an arcuate depth control surface that is configured for engagement with a surface of material being cut in a manner to control cutting depth. The depth control guide is movably connected to the saw blade in a manner so that a distance between the arcuate depth control surface and the arcuate cutting edge of the saw blade can be selectively adjusted to achieve a desired cutting depth. The arcuate depth control surface has an adjustable radius of curvature.
In still another aspect of the invention, a saw comprises a generally planar saw blade and a depth control guide. The saw blade is formed of a ferromagnetic material and has a cutting edge. The depth control guide has a depth control surface that is adapted for engagement with a surface of material being cut in a manner to control cutting depth. The depth control guide has at least one magnet. The depth control guide is adjustably connected to the saw blade via the magnet in a manner so that a distance between the depth control surface and the cutting edge of the saw blade can be selectively adjusted to achieve a desired cutting depth.
In a further embodiment of the present invention, a saw comprises a generally planar saw blade and a depth control guide. The saw blade has an arcuate cutting edge. The depth control guide comprises an arcuate depth control surface that is configured for engagement with a surface of material being cut in a manner to control cutting depth. The arcuate depth control surface has a curvature that approximates a curvature of the arcuate cutting edge of the saw blade. The depth control guide is adjustably connected to the saw blade in a manner so that a distance between the arcuate depth control surface and the arcuate cutting edge of the saw blade can be selectively adjusted to achieve a desired cutting depth.
Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
Reference characters used in these Figures correspond to reference characters used throughout the following detailed description of the preferred embodiments.
A saw of the present invention is represented in its entirety in
As shown in the Figures, the handle 14 resembles a clevis with a slot dimensioned to receive the shank portion 24 of the blade 12 therein. A pivot pin 32 engages both the handle 14 and the shank portion 24 in a manner to permit pivoting movement of the blade 12 relative to the handle 14 in a plane of the blade 12. Preferably, the saw 10 further comprises a locking mechanism 34 including a hand-operable locking member 36 that is operatively connected to the handle 14 in manner so that the relative positions of the saw blade 12 and handle 14 can be locked and unlocked by rotating the locking member 36 relative to the handle 14 about a locking pin 38. The pivot pin 32 includes a hole 40 (see
As best shown in
Preferably, the saw blade 12 is of a flexible material, e.g., relatively thin gauge steel, that permits flexion of the blade 12 in a plane that is generally perpendicular to the plane of the saw blade and that is also generally parallel to at least a portion of the cutting edge (i.e., side to side relative to the line of cut). Again, this flexibility permits flush cutting operations. Preferably, there is little or no lateral inclination to the cutting teeth so as to avoid marring the adjacent surface during a flush cutting operation.
The arcuate cutting edge 22 of the blade 12 will have a fixed radius of curvature R1. Again, the arcuate depth control surface 30 of the depth control guide 16 is adapted for abutting engagement with a surface of the material being cut in a manner to control cutting depth, and the depth control guide 16 is preferably adjustable relative to the blade 12 so that the distance between the arcuate depth control surface 30 and the arcuate cutting edge 22 of the blade 12 can be selectively adjusted to achieve a desired cutting depth. As best shown in
In the preferred embodiment of the invention, at least a portion of the depth control guide 16 is of a flexible and resilient material (e.g., molded Nylon) that permits flexion of the arcuate depth control surface 30 in a plane that is generally parallel to a plane of the saw blade (i.e., side to side relative to the line of cut). Thus, the depth control guide 16 will flex along with the blade 12 even when the blade 12 is flexed substantially during a flush cutting operation.
Preferably, the arcuate depth control surface 30 of the depth control guide 16 has an adjustable radius of curvature R2. As explained below, the depth control guide 16 is preferably configured in a manner so that the radius of curvature R2 of the arcuate depth control surface 30 decreases as the depth control guide 16 is moved relative to the saw blade 12 in a direction (upwardly as viewed in
Again, at least a portion of the depth control guide 16 is of a flexible and resilient material (e.g., molded Nylon) that permits flexion of the arcuate depth control surface 30 in a plane that is generally parallel to a plane of the saw blade. This material also preferably permits some degree of flexion and resilience with a plane of the depth control guide 16, generally parallel to the blade. Preferably, the depth control guide 16 is molded in a manner so that the arcuate depth control surface 30 has a nominal radius of curvature (i.e., a radius of curvature at equilibrium, when not undergoing any elastic deformation) that approximates the radius of curvature R1 of the arcuate cutting edge 22 of the saw blade 12. Thus, preferably, movement of the depth control guide 16 in a direction (upwardly as viewed in
Preferably, the saw blade 12 is of a ferromagnetic material (e.g. steel) and the depth control guide 16 includes at least one magnet 50 for connecting the depth control guide 16 to the saw blade 12. More preferably, the depth control guide 16 includes a plurality of such magnets 50 and the depth control guide 16 is connected to the saw blade 12 only via the magnets 50. As shown in
In the preferred embodiment of the invention, the magnets comprise rare earth magnets (e.g., Alnico, Neodymium or Samarian Cobalt). Rare earth magnets are preferred because of their significant magnetic strength relative to their size and weight. However, other types of magnetic materials or non-magnetic fasteners could be used without departing from the scope of the invention as claimed hereinafter. Preferably, the magnets 50 are of sufficient strength to resist movement of the depth control guide 16 relative to the arcuate cutting edge 22 of the saw blade 12 when the depth control guide 16 is subjected to external normal forces exerted on the arcuate depth control surface 30 by a surface of material being cut during a normal cutting operation. This, coupled with the internal restoring forces of the depth control guide 16 caused by the elastic deformation of the depth control guide 16, will preferably be sufficient to prevent unwanted movement of the depth control guide 16 relative to the arcuate cutting edge 22 during a normal cutting operation.
As best shown in the exploded view of
Preferably, the slots 60 are located along the saw blade 12 in a generally symmetrical manner and the magnets 50 are located along the depth control guide 16 in a correspondingly generally symmetrical manner (i.e., the magnets are positioned along the depth control guide 16 in a manner so that the spacings between the magnets is generally even) so that the depth control guide 16 may be used on either side of the saw blade 12. This will allow the blade 12 to be used for a flush cutting operation on either side.
As best shown in
Preferably, the slots 60 are oriented at an angle relative to the arcuate cutting edge 22 so that external normal forces exerted on the depth control guide 16 by the work piece during cutting are not acting parallel to the slot. Ideally, the slots 60 are oriented at an angle that will result in the external normal forces acting in a direction that is generally perpendicular to the slots 60. The orientation of the slots 60 shown in the Figures is intended for blade teeth that are set to cut on a pull stroke. As the saw blade 12 is pulled (generally to the right as viewed in
Thus, in the preferred embodiment of the invention shown in the Figures, the strength of the magnets 50, the internal restoring forces caused by the elastic deformation of the depth control guide 16, and the angled orientation of the slots 60, will together resist unwanted movement of the depth control guide 16 relative to the arcuate cutting edge 22 during a normal cutting operation.
In an alternative embodiment of the invention shown in
While the present invention has been described by reference to specific embodiments and specific uses, it should be understood that other configurations and arrangements could be constructed, and different uses could be made, without departing from the scope of the invention as set forth in the following claims.