Black Decker Inc.

John E Dibbern, Jr

Daniel L Krout

Gregory E Moores

William D Sauerwein

Frank J O'Hara

Robert P Welsh

Robert G Moores, Jr

Daniel H Montague

William R Stumpf

Lynn E Lentino

Robert I Somers

Dale Kenneth Wheeler

Friedrich J Katz

Richard A Schafebook

Steve A Weber

Richard L Mitchell

An improved chop saw may include a base assembly, a blade assembly including a blade having a center and a motor for driving the blade, an arm pivotally attached to the base assembly and carrying the blade assembly, the blade assembly being movable between a lower position for engaging and cutting a workpiece disposed on the base, and an upper position not engaging the workpiece. The chop saw further includes a vise for holding the workpiece in place, the vise including a vise screw, a latch support supporting the vise screw, and a vise jaw disposed at the end of the vise screw. Preferably, the maximum distance between the vise jaw and the latch support is about equal or shorter than the distance between the blade center and the latch support, when the blade assembly is at the lower position. Further the chop saw includes a substantially horizontal handle connected to the blade assembly. Preferably, the handle is slightly curved, with the centerpoint of the curvature being disposed below the handle and towards the base.

Chop saw

A power tool includes a motor, an arbor driven by the motor, a rotatable cutting tool disposed on the arbor and having a rotational axis, the cutting tool further having a hole, first and second clamps connected to the arbor and clamping the blade, wherein one of the cutting tool and at least one of the first and second clamps and arbor have a first drive surface for contacting a second drive surface on the other of the cutting tool and the at least one of the first and second clamps and arbor, the second drive surface being movable between a first position contacting the first drive surface and a second position bypassing the first drive surface. The second drive surface is resiliently connected to the other of the cutting tool and the at least one of the first and second clamps and arbor. At least one metal strip connects the second drive surface to the other of the blade and the at least one of the first and second clamps and arbor.

Clutch mechanism

Surfaces for a cutting tool hole

Mounting device for a cutting tool

Cutting tool hole

Rotatable cutting tool

An apparatus for limiting deflection of the armature shaft 38, 38', 103 of an electrically powered tool, such as a hand held saw 10 or drill 91. In saw 10, the armature shaft 38, 38'extends as a cantilever from the motor 14 and has a geared connection 58, 60 to an arbor 44 for driving the saw blade 18. An arrangement for limiting the deflection of the armature shaft 38, 38' comprises a pilot member 72, 84 and a socket 68, 82 associated, respectively, with one and the other of the armature shaft and a motor housing supported wall. The socket 68, 82 is larger in cross-section than that of the pilot member 72, 84 and limits transverse deflection of the armature shaft 38, 38' away from its axis of rotation A. If the saw 10 stalls in the material being cut, force is transmitted from the geared connection 58, 60 to the armature shaft 38, 38'. The socket 68, 82 and pilot member 72, 84 permit the armature shaft 38, 38' to deflect a predetermined amount to counteract torques resulting from the geared connection 58, 60. In one embodiment, the pilot 72 extends from the armature shaft 38 to be received in an aperture 68 formed in the housing wall 66. In another embodiment, the pilot 84 extends from the housing wall 66' to be received in a bore 82 formed in the armature shaft 38'. According to a third embodiment, in drill 91, the shaft deflection limiter is constituted by an armature shaft pilot 111 disposed in a roller bearing aperture 117.

Armature shaft deflection limiter

An apparatus for limiting deflection of the armature shaft 38, 38', 103 of an electrically powered tool, such as a hand held saw 10 or drill 91. In saw 10, the armature shaft 38, 38' extends as a cantilever from the motor 14 and has a geared connection 58, 60 to an arbor 44 for driving the saw blade 18. An arrangement for limiting the deflection of the armature shaft 38, 38' comprises a pilot member 72, 84 and a socket 68, 82 associated, respectively, with one and the other of the armature shaft and a motor housing supported wall. The socket 68, 82 is larger in cross-section than that of the pilot member 72, 84 and limits transverse deflection of the armature shaft 38, 38' away from its axis of rotation A. If the saw 10 stalls in the material being cut, force is transmitted from the geared connection 58, 60 to the armature shaft 38, 38'. The socket 68, 82 and pilot member 72, 84 permit the armature shaft 38, 38' to deflect a predetermined amount to counteract torques resulting from the geared connection 58, 60. In one embodiment, the pilot 72 extends from the armature shaft 38 to be received in an aperture 68 formed in the housing wall 66. In another embodiment, the pilot 84 extends from the housing wall 66' to be received in a bore 82 formed in the armature shaft 38'. According to a third embodiment, in drill 91, the shaft deflection limiter is constituted by an armature shaft pilot 111 disposed in a roller bearing aperture 117.

A hammer drill may be set for operation in a hammer mode or a drill mode through a mode selector 41. In the drill mode, output shaft 25 is locked in a forwardly biased position and is rotatably driven through spur gears 29, 31. In the hammer drill mode, output spindle 25 is rotatably driven by spur gears 29, 31 and is axially reciprocated by hammer clutch 55. An output clutch plate 57 of clutch 55 is axially and rotatably fixed to spindle 25 and has a first annular tooth array 63 on rear face 61. An input clutch plate 59 of clutch 55 is axially and nonrotatably fixed in tool housing 15 and has a second annular tooth array 67 on a forwardly inclined front face 65. Tooth arrays 63, 67 are engageable in the hammer mode. Output clutch plate 57 is shiftable in use in the hammer mode to position the rear face 61 generally parallel to the front face 65. The forward inclination of input clutch front face 65 compensates for the movement of output clutch rear face 61 from a no-load to a load position so that the faces 65, 61 are generally parallel in use. By ensuring parallelism of the clutch faces 65, 61 in use, clutch 55 has a significantly improved life.

Hammer drill with inclined clutch plate

A field subassembly is assembled by positioning two coil supports adjacent respective core end faces of a ferromagnetic core. The core-engaging surfaces of the coil supports and the core end faces have respective surfaces which are uninterrupted by projections. During the assembly of the field, fasteners are pushed into the respective coil supports and the core such that the fasteners engage mounting holes in the coil support with a press-fit. After the field is wound, a brush holder subassembly is also pressed onto the fasteners and the resultant core subassembly is connected to a field housing by driving the fasteners in a conventional fashion. In the preferred embodiment, the fasteners provide a three-point contact with mounting holes formed in the coil supports and the brush holder subassembly. This enables the fasteners to maintain the coil supports and the brush holder subassembly in alignment with the core while shearing a minimum of material from the coil supports and brush holder subassembly when the fasteners are pushed into their respective mounting holes. Then, the same fasteners remain with the subassembly to connect the field subassembly to the field housing.

Method of making a field subassembly

A contact includes an arcuately-shaped member having opposite end portions which are joined by an intermediate U-shaped portion. The end portions are slotted to form bifurcations which include contact-engaging surfaces. A contact element includes elongated first and second portions which are joined by an intermediate portion. A lanced-out tab is formed in, and forms an acute angle with, the first portion with the tab opening toward the intermediate portion.

Electrical contacts for a switch

Methods of assembling field subassemblies

Growing community of inventors

Street, MD, United States of America

John E Dibbern, Jr