Abstract: A composite utility knife blade and method of making such a blade involves butt joining a tool steel wire to a front edge of an alloy steel backing strip. The wire is electron beam welded to the backing strip to form a composite strip defining a first metal portion formed by the alloy steel backing strip, a second metal portion formed by the tool steel wire, and a weld region joining the first and second metal portions. The composite strip is then annealed, and the annealed strip is straightened to eliminate any camber therein. The annealed composite strip is then hardened such that the first metal portion defines a surface hardness within the range of approximately 38 Rc to approximately 52 Rc, and the second metal portion defines a surface hardness within the range of approximately 60 Rc to approximately 57 Rc.

Abstract: A composite utility knife blade and method of making such a blade involves butt joining a tool steel wire to a front edge of an alloy steel backing strip. The wire is electron beam welded to the backing strip to form a composite strip defining a first metal portion formed by the alloy steel backing strip, a second metal portion formed by the tool steel wire, and a weld region joining the first and second metal portions. The composite strip is then annealed, and the annealed strip is straightened to eliminate any camber therein. The annealed composite strip is then hardened such that the first metal portion defines a surface hardness within the range of approximately 38 Rc to approximately 52 Rc, and the second metal portion defines a surface hardness within the range of approximately 60 Rc to approximately 57 Rc.

Abstract: In a saw blade having a cutting edge defined by a plurality of teeth disposed along the blade, each tooth includes a tip, a rake face, and a curvilinear base surface. The tip of each tooth and the tip of the next consecutively disposed tooth cooperate to define a pitch distance therebetween, with the curvilinear base surface and the tip of each tooth cooperating to define a maximum gullet depth. In addition, the rake face and the curvilinear base surface of each tooth define an effective gullet radius greater than about 25% of the pitch distance, and also greater than about 55% of the maximum gullet depth.

Abstract: A variable pitch band saw is provided which has a toothed edge comprising a plurality of recurrent groups of teeth. Each group includes an unset leading tooth and a plurality of teeth that are alternately set laterally to opposite sides of the saw. Each tooth has a cutting edge disposed in a predetermined cutting plane and an accumulated pitch distance between it and the next preceding saw tooth having a cutting edge coplanar with said predetermined plane. The size of gullet area of each tooth is made directly proportional to the accumulated pitch distance of that tooth so that the size of the gullet areas are the same for all teeth having the same accumulated pitch. Each of the tooth groups may include teeth of varying height and degrees of lateral set, some of the teeth of each group having a different pitch, measured from the tip of one of said teeth to the tip of a tooth adjacent the one, to avoid uniform tooth spacing between all the teeth to the group.

Abstract: An arbor for a hole saw includes a shaft and a plurality of pins having either bearing surfaces, drive portions or both for engaging the hole saw. The arbor further includes a fixed position flange and a locking plate located above the flange, to which the pins are connected. The saw is mounted to the arbor and has a cylindrical body portion having a closed end defined by a drive plate and an opposite end defining a cutting edge for performing sawing operations on a work piece. The drive plate includes apertures for receiving the drive portions of the pins which pass through holes in the flange. When assembled the drive ends of the pins extend through the holes in the flange and into the mating drive plate apertures such that the bearing surfaces on the pins engage and support the drive plate of the hole saw.

Abstract: An improved hole saw for cutting holes having a cylindrical shape that includes, along its cutting edge, a plurality of repetitive groups of saw teeth having at least four radially displaced trailing teeth. The displacement of each trailing tooth is such that it has a substantially greater displacement than for any other tooth of said group preceding said trailing tooth. The displacement of each tooth being such that the cutting edge thereof is characterized as being movable along a cutting path different from the cutting paths of the other teeth of the group as the hole saw is rotated whereby each tooth cuts chips of uniform size. Each group of teeth may include a raker tooth having no substantial displacement with respect to the side surfaces of the hole saw. The raker tooth may be the same height or of greater height than the trailing teeth.

Abstract: A bimetallic band saw blade has a high speed cutting edge welded to a backing band of a steel alloy containing the following elements percentages by weight:Cr - 0.5% to no more than 1.5%V - 0.10% to 0.75%Mo - 1.5% to 2.5%wherein said backing band comprises a substantially lesser amount by weight of Chromium than Molybdenum the alloy also contains C, Si, Mn, Nb and/or Ni and Al in such varying amounts that the total alloy content, except for Fe and inevitable impurities, is in the range of 3.12% to 8.48%.

Abstract: An improved saw blade includes groups of saw teeth disposed along the cutting edge of the blade. Each group of teeth includes, in relation to the cutting direction of the blade, an unset leading tooth followed by two pairs of trailing teeth alternately set in opposite lateral directions outwardly of the centerline of the blade. The first pair of trailing teeth are generally of the same height as the leading tooth and the second pair of trailing teeth are shorter and have a substantially wider set than the first pair. The pair of trailing teeth that are shorter and wider set are disposed in consecutively and interposed relation between the first pair of trailing teeth. The set distance of the first pair of trailing teeth is approximately 50% of the set distance of the second pair of trailing teeth.

Abstract: Quick-release arbor for hole saws has a generally cylindrical shaft with a threaded end portion for a screw-fitted connection to the threaded bore of a hole saw. A collar is disposed about the shaft, includes a shank, at one end, adapted for connection to a power driven chuck and, at its other end, a pair of diametrically spaced-apart drive-pins. The collar and shaft are characterized, respectively, by inner and outer diameters which provide a clearance therebetween so that the collar and the shaft are both axially movable and rotatable relative to each other. A retainer carried by the collar and another retainer carrier by the shaft for interengagement with the one retainer.

Abstract: Quick-release arbor for hole saws has a generally cylindrical shaft with a threaded end portion for a screw-fitted connection to the threaded bore of a hole saw. A collar is disposed about the shaft, includes a shank, at one end, adapted for connection to a power driven chuck and, at its other end, a pair of diametrically spaced-apart drive-pins. The collar and shaft are characterized, respectively, by inner and outer diameters which provide a clearance therebetween so that the collar and the shaft are both axially movable and rotatable relative to each other. A retainer carried by the collar and another retainer carried by the shaft for interengagement with the one retainer.

Abstract: Segmental grinding wheel for forming the tip of intersecting surfaces on tools includes an array of peripherally extending and circumferentially, spaced segments. Each segment includes first and second grit-coated angularly oriented grinding surfaces. Another array includes similar grinding segments which are interdigitated in alternating sequence with the segments of the first array. The segments of the two arrays are concentric and partially coextensive in the axial direction of the wheel so that the plane of rotation of the first grinding surface of each segment in one array intersects the plane of rotation of the second grinding surface of an adjacent segment in the other array along a line which represents the tip of the intersecting surfaces.

Abstract: A foldable pocket saw has a handle with a mounting head extending from one end thereof. A blade mounting member is rotatably disposed on the mounting head with a saw blade removably attached thereto. A detent mechanism has a spring loaded pawl actuated by a button radially movable into and out of engagement with one of a plurality of circumferentially spaced, radially extending notches provided in the periphery of the rotatable blade mounting member for releasably locking the saw blade in any one of a plurality of positions relative to the handle.

Abstract: Reciprocal furnace for heating metallic parts to a predetermined temperature has a horizontally reciprocal hearth. The hearth includes a multi-layer firebrick base on which is carried a ceramic fixture adapted to receive the metal parts to be heated in the furnace. The ceramic fixture has a plurality of parallel slots which are longitudinally spaced apart in a direction corresponding to the reciprocal movement of the hearth. The hearth is supported at its underside by a reciprocal drive mechanism and is moved incrementally by a drive motor to advance each slot of the fixture in sequence to a predetermined position at which a part is inserted therein by the reciprocal feed mechanism. After all the slots have been sequentially loaded, the hearth is retracted by the reciprocal drive mechanism to its initial position at which the part, first inserted, is removed and another part is inserted in the same slot. The loading and unloading cycle is repeated continuously.

Abstract: A cutting device for cutting the shield of an armored cable has three mutually hinged members. One member is interposed between the other two and has a channel opening on one side for receiving the shielded cable therein. The second member is pivotable at one end of the first member and has a rotatable, circular cutter. The upper wall of the channel includes an axial slot to provide an access opening for the circular cutter. The upper wall of the channel member is generally in wedge shape construction for engagement with the upper surface of the shielded cable. The third member is pivotable to the one member at the same end as the second member and includes at its outer end a cable holding plate which extends upwardly from the outer end of the third member. A slot disposed in the lower wall portion of the channel member provides access for movement of the cable holding plate therethrough.

Abstract: Flash-butt welder in which the piston rod of a pneumatic cylinder is connected to one end of a pivotable lever arm. A pneumatic system sequentially supplies air at two different pressures to the cylinder. Fixed and movable platens, each with a work piece clamping jaw, are fitted onto a unitary shaft which is mounted in laterally spaced and generally parallel relationship with the pneumatic cylinder. The movable platen is moved by the opposite end of the lever arm along the shaft toward the fixed platen. The movable platen includes a laterally extending arm portion for angular orientation of the platen on the shaft. A switch is disposed to be actuated by the lever arm as it advances to a predetermined position which energizes a solenoid valve to supply substantially higher pressure air to the cylinder. An hydraulic cylinder, disposed in spaced parallel relation to the shaft, includes a piston rod engaged with a pivotable linkage carried by the arm portion of the movable platen.

Abstract: Drill bit for drilling holes of different diameters which has a series of cylindrical outer surfaces of increasing diameter from the outer to the inner end of the drill bit. A beveled conical surface interconnects each adjacent pair of cylindrical surfaces. At least two flutes are machined at two circumferentially spaced locations to provide two cutting edges on each diameter of the drill. At each cutting edge the cylindrical surfaces are relieved radially and the conical surface is relieved axially over an acute circumferential angle. The major peripheral portions of the cylindrical and conical surfaces for each diameter are respectively concentric to the axis of the drill and of zero pitch angle.