Abstract: Included herein is a circuit comprising resistors, capacitors, relays, diode bridges, TRIACs, and DIACs mounted to a substrate. The circuit may be electrically connected to a user device containing a wide range of types and specifications of AC induction motors. The circuit may be installed “plug-and-play” onto a user device, without the need for tools, custom installation or deconstruction of a user device. Upon user direction or automatically, the circuit may inject DC current into the user tool which generates a stationary magnetic field inside the AC induction motor causing deceleration/arrestment of the AC induction motor's rotor. The circuit may prevent unintended acceleration of the rotor upon powering on the user device. Also included is a method for prevention of unintended acceleration of the rotor upon powering on the user device. Also included is a method for decelerating/arresting an AC induction motor.

Abstract: An electric power tool includes an output shaft, drivable by an associated drive motor, and a brake apparatus for braking the output shaft rotating in the unpowered state of the associated drive motor. The output shaft is mounted in a rotatable manner in an associated housing and the brake apparatus has a magnetic-field brake unit with at least one first and one second brake element. The first brake element is arranged radially with respect to the output shaft in a rotationally fixed manner in the associated housing and includes at least one first and one second magnetic pole configured to generate a magnetic field that alternates in the circumferential direction of the output shaft. The second brake element is magnetically conductive and rotationally connected to the output shaft via an activatable coupling device.

Abstract: The present disclosure relates to a saw, comprising a drive, a first blade configured to oscillate about an axis perpendicular to a plane defined by a surface of the first blade, a second blade configured to oscillate about an axis perpendicular to the plane in a direction opposite to that of the first blade, and wherein gearing is provided between the drive and the first and second blades to reduce the speed transmitted from the drive to the blades. A saw blade, a connection mechanism for connecting a blade to a saw and associated methods are also provided.

Abstract: A rasp for shaping a bone is provided. The rasp includes a housing, a driving mechanism, a first gear assembly, two linkage units and two blades. The housing has a channel along a first axis. The driving mechanism has an output gear rotating about the first axis. The first gear assembly rotates about a second axis and is driven by the output gear. The first gear assembly has a first and a second rotation surfaces. A first and a second connection points are respectively located on the first and the second rotation surfaces. The linkage units slidably pass through the channel. The first end of each of the linkage units is pivotally connected to the corresponding connection point, such that the second ends move along the first axis in a reciprocating manner. The blades are respectively and detachably connected to the second ends.

Abstract: A driving tool with a housing, a motor received in the housing, a control unit and a trigger. The housing defines a handle. The control unit is configured to operate the motor and has a microswitch, an actuator arm and a spring. The actuator arm is biased by the spring toward the microswitch. The spring is configured to move the actuator arm against the microswitch to cause the microswitch to operate in an actuated switch state. The trigger is coupled to the handle and is movable between a first trigger position and a second trigger position. The trigger has a switch arm that cooperates with the actuator arm to form a lost-motion coupling that permits a predetermined amount of movement of the trigger from the first trigger position to the second trigger position before coupling the switch arm to the actuator arm. The actuator member does not contact the microswitch when the trigger is in the second trigger position so that the microswitch operates in a nominal switch state.

Abstract: This invention discloses methods and devices using ultrasound energy for resecting bone tissue during surgical procedures. The disclosure describes the use of ultrasound surgical saw consisting of an ultrasound generator, ultrasound transducer and ultrasound horn including a cutting blade to resect bone tissue without excessive temperature rise during typical surgical procedures. The cutting blade provides a self-clearing design that includes at least two teeth disposed to prevent accumulation of bone chips within the proximity of the teeth. The design of the cutting blade allows the mechanical motion of the blade and the emission of the ultrasound energy to remove accumulated bone chips and prevent excessive temperature rise.

Abstract: An electro-hydraulic actuator has a master cylinder, an electric motor and an electro-mechanical brake. The master cylinder has a hydraulic cylinder and an actuation piston slidably received within the hydraulic cylinder to vary pressure within a hydraulic circuit. The electric motor is adapted to drive the actuation piston into the hydraulic cylinder. The motor has a stator and a rotor. The electro-mechanical brake is arranged to selectively and releasably hold the rotor with respect to the stator to prevent relative rotational motion there between.

Abstract: A lubrication structure for a working machine is provided. A driven gear that engages with a driving gear connected to a driving source and rotates, is accommodated in a chamber in a case. An eccentric cam is provided on a surface of the driven gear, and connected to a coupling pin in a blade through a crank member. A fitting ring part is provided in one end of the crank member, and the eccentric cam is inserted into the fitting ring part so as to rotate relative to the fitting ring part. An annular groove is formed on the inner surface of the fitting ring part which faces the outer surface of the eccentric cam. The annular groove communicates with a first chamber via a first lubricating passageway and also communicates with a second chamber via a second lubricating passageway.

Abstract: A reciprocating saw and one or more blades for cutting material. The reciprocating saw includes a drive system and a gear arrangement that is designed to cause first and second reciprocating saw blades to partially or fully reciprocate in opposite directions. The two reciprocating saw blades can include a tooth configuration that facilitates in maintaining the blades together during the cutting of material.

Abstract: An electric tool, particularly a saw, has a connecting region and an actuating handle. The actuating handle is pivotally arranged on the connecting region, wherein the actuating handle can be pivoted into a number of pivoted positions and the actuating handle has at least one actuating switch for the electrical actuation of the electric tool. An uncomfortable position of the hand during actuation of the actuating handle is avoided and a high degree of comfort is achieved by the connecting region and the actuating handle being connected to each other by way of an articulated connection and by the articulated connection having a bearing lug and a handle pivot pin in engagement with the bearing lug.

Abstract: An oscillating multi-tool for cutting, scraping, sanding, or grinding of material. The oscillating multi-tool includes a body, a drive system and a gear arrangement. The drive system and the gear arrangement are designed to cause first and second tool attachments to partially or fully oscillate in opposite directions. The gear arrangement is connected or interconnected to first and second tool connectors. The first tool attachment is connected to the first tool connector and the second tool attachment is connected to the second tool connector. The gear arrangement causes the first and second tool connectors to move when the drive system is activated to thereby cause the first and second tool attachments to partially or fully oscillate in opposite directions relative to one another.

Abstract: The invention relates to an eccentric gear arrangement of a motor-driven, hand-guided hedge trimmer (1). The eccentric gear arrangement includes two shearing blades (2, 3) driven in mutually opposite directions over a displacement path (a). Each shearing blade has a connecting link (4, 5) as well as an eccentric wheel (6) having a drive wheel (7) and two eccentrics (8, 9). The eccentric wheel (6) rotates about a rotational axis (10). The two connecting links (4, 5) lie directly above one another. The two eccentrics (8, 9) are arranged on the same side of the drive wheel (7) and engage each in one of the two connecting links (4, 5). The two shearing blades (2, 3) have contact pressure surfaces (11, 12) in the region of their two connecting links (4, 5) and are offset with respect to each other in such a manner that they are exposed at least over a portion of the displacement path (a). Two downholders (13, 14) are provided which act each on one of the assigned contact pressure surfaces (11, 12).

Abstract: A reciprocating saw for cutting material. The reciprocating saw includes a drive system and a gear arrangement that is designed to cause first and second reciprocating saw blades to partially or fully reciprocate in opposite directions. The gear arrangement is connected or interconnected to first and second blade carrying arms. The first reciprocating saw blade is connected to the first blade carrying arm and the second reciprocating saw blade is connected to the second blade carrying arm. The gear arrangement causes the first and second blade carrying arms to move when the drive system is activated to thereby cause the first and second reciprocating saw blades to partially or fully reciprocate in opposite directions relative to one another. The gear arrangement is designed to enable a stroke length of the first and second reciprocating saw blades to be changed.

Abstract: There is provided a replaceable drywall saw blade capable of reciprocating in-line when mounted to a hand held reciprocating power saw. The blade includes a generally planar body member having a generally linear top edge and a generally parallel opposed bottom edge. The blade further includes a generally linear upper piercing edge angularly offset downwardly from the top edge. The blade additionally includes a generally linear lower piercing edge angularly offset upwardly from the bottom edge. The upper piercing edge and lower piercing edge intersect to form a forward point on said blade. A mounting aperture is also formed on the blade for releasably securing the blade to the hand held reciprocating power saw.

Abstract: An electric saw device includes a first saw blade and a second saw blade. The first and the second saw blades are respectively driven by a small transmission shaft and a large transmission shaft to rotate in opposite directions. A round rib is disposed on an inner end surface of the first saw blade, and at least three recessed holes are arranged in a top end surface of the round rib at equal angle intervals. A steel ball is accommodated in each of the recessed holes, and protrudes out of the recessed hole. Protruding ends of the steel balls urge against an inner surface of the second saw blade, so as to limit a distance between the first saw blade and the second saw blade, and form a rolling friction when the first and the second saw blade rotate in the opposite directions.

Abstract: An improvement for a reciprocal saw is disclosed, the saw being of the type having an oscillating drive shaft and a counter weight that oscillates in opposing phase to the drive shaft for the purpose of reducing vibration. The improvement comprises a lateral extension arm fixed to the counter weight and projecting generally towards the drive shaft. The extension arm is connected to a mounting plate that projects generally parallel to the drive shaft towards the distal end of the drive shaft, such that when the saw is activated the drive shaft oscillates oppositely, but in parallel, to the mounting plate. A mounting cover is fixed to the mounting plate with a fastener and includes a channel therein formed generally longitudinally parallel to the drive shaft and adapted to capture both a first saw blade slidably therein and a second saw blade fixedly therein.

Abstract: A battery-powered carving knife is shown having a housing and a switch, which connects and disconnects a battery to a motor. A drive mechanism including a worm gear together with a cam member causes reciprocation of reciprocating blade mounts to reciprocate back and forth in an out of phase fashion. The motor is positioned forward within the housing in motor receiving section, with the drive shaft of the motor facing rearwardly. The blade mounts are driven by the motor, and reciprocate in a position below the motor. The motor and blade mounts are positioned in front of a handgrip section, thereby improving the ergonomics of the device. Alternatively, the drive shaft can be positioned facing forward.

Abstract: A cutting tool which has a first cutting blade which is mounted in a scissors arrangement with a second cutting blade. The first cutting blade has formed at one end thereof a first cutting element and at the opposite end thereof a second cutting element. The second cutting blade has formed thereon a third cutting element at one end thereof and at the opposite end thereof a fourth cutting element. The cutting blades are pivotally connected intermediate their ends by the inner end by a pair of handle members with the cutting blades being captured between the handle members. The handle members are to be pivotable between a first position and a second position. When in the first position, the first cutting element and third cutting element are extended and capable of performing a cutting operation on an exterior structure.

Abstract: In the case of a sawing tool for a circular power saw having two coaxial saw blades (11, 11′) capable of being driven in opposite directions and rotating directly past each other, the anterior—relative to the direction of rotation—cutting edge (161, 161′) of each active cutting edge (16, 16′) is situated in a plane extending through the saw blade axis (18, 18′) to produce, using a simple design, an axial force on each saw blade (11, 11′) that counteracts the forcing apart of the saw blades (11, 11′) during the cutting process, and the active cutting edges (16, 16′) are sloped in the direction of the saw blade axes (18, 18′) in such a fashion that they incline downward from the facing sides of the saw blades (11, 11′) toward the sides of the blades facing away from each other (FIG. 5).

Abstract: In a chain saw having a sprocket (11), which is supported in rotary fashion in a housing (10) and is for a saw chain (12) guided on a guide (13), and having a chain tension device (14) for longitudinally moving the blade (13), which device has a cam (15) that moves the guide (13) and a rotating member (17) for rotating the cam (15), in order to preset a chain tension that is optimal for operation and is independent of the user, the rotary connection between the rotating member (17) and cam (15) is embodied as a detent overload clutch (18), whose detent overload force is set in accordance with the required chain tension (FIG. 2).

Abstract: A rotary mechanism for cutting and/or sealing a web has a pair of counter-rotating rotors mounted on parallel axes and having radially projecting arms between which the web is momentarily gripped for cutting and/or sealing. Sealing is performed by heated pressure outer faces on the rotor arms. Cutting is performed by cutter and anvil bars on the opposed arms engaging the web. Bearer faces on the arms beyond the pressure faces set a gap between the pressure faces and a rectangular-section tongue and groove in mating contact faces one side of the pressure faces locate the pressure faces laterally. The cutting means are adjusted by a wedge bar bearing on the inner face of the cutter bar or anvil. The wedge bar is movable in the direction of rotation and has an outer face inclined in the same direction. Means accessible from the leading and/or trailing faces of the rotor arms are provided for adjusting the wedge bar and clamping the cutter and anvil bars.

Abstract: This invention is a tool for plunge cutting comprising a motor, a transmission connected to the motor and a blade assembly connected to the transmission, wherein the blades move in an oppositely reciprocating and sliding manner to provide plunge cuts of variable depth with closed ends and a continuous perimeter. The tool of the invention may be held and operated with one hand.

Abstract: The invention relates to a handheld surgical power saw intended to be an integrated surgical tool or an attachment to a motorized surgical tool. The tool consists of two arms that reciprocate in opposite directions at all times. Attached to each arm is a set of cam followers and a saw blade. The arms are driven by a cam with outer surfaces that smoothly undulate between the two sets of cam followers.

Abstract: My interest was aroused by the lack of any power tool to help the electrical contractor cutting rectangular holes through walls for his wall boxes for switches and receptacles. I started making a model in 1992 only to find out there was no parameters to follow for the specifications the thrust needed. To push four saw blades were one problem to solve. The fact that the unit would require a rigid attachment to the wall was another problem to solve. The small rectangular hole gave little room to work. The last problem to solve was about 12 inches of simultaneously sawing. By Thanksgiving time of 1996 my fourth model was finished. I had the surprise to discover that I was able to saw a rectangular hole of two inches by four inches in 1/2 inch plasterboard in about ten seconds and in plywood, less than one minute|This could be an excellent item for the mobile home builder to cut the holes in the walls. He would welcome this saw.

Abstract: A hand machine tool operated with two hands has a machine housing composed of insulating synthetic plastic shells, a fixed, web-shaped main handle formed as a part of the machine housing, an auxiliary handle, a drive including a motor and a transmission, at least one inner housing accommodating the motor and the transmission and surrounded by the synthetic plastic shells, and a tool driven by the drive. The handles, the machine housing, the inner housing and the tool are arranged so that forces applied to at least one of the handles are withdrawn from the machine housing by transferring the forces by the main handle directly to the inner housing without deforming the machine housing and then transferring the forces from the inner housing to the tool.

Abstract: A power-operated sword saw comprises a plate-shaped sword having a lower region with a guiding groove, two saw blades reciprocatingly movable in opposite directions parallel to one another and each having a front saw blade tip and an opposite clamping end. The saw blades have a toothed side provided with a plurality of teeth and an opposite saw blade back guided in the guiding groove of the sword. A drive is coupled with the clamping ends of the saw blades through a clamping unit. The saw blades are jointly coupled with the clamping unit and released from the clamping unit by a blocking element which blocks the clamping ends in a coupling position and release the clamping ends in a contact-free manner.

Abstract: A power saw has a sword having side walls which form a groove-shaped guide, and two parallel oppositely reciprocable saw blades having one longitudinal side provided with saw teeth and another longitudinal side provided with backs which are guided in the groove-shaped guide. The groove-shaped guide is interrupted by a plurality of recesses.

Abstract: A saw blade for a two-blade, contra-reciprocating saw has two strips spot welded together. Teeth are formed by scallops cut along an edge of each strip with lands between these scallops. Abrasive grit, such as tungsten carbide chips, is brazed on the teeth except on the sides of the teeth which rub against each other as the blades reciprocate. The main cutting surfaces are the lands which are longer on one strip than the other. The arrangement is useful for cutting masonry and metal products and reduces stresses on the blade.

Abstract: A reciprocating saw-blade device includes: a case; a main spindle rotatably supported by the case; bearings respectively arranged in front and rear end sections of the case; upper and lower saw blades protruding forward beyond the case and supported by the bearings in such a manner as to be slidable in the longitudinal direction thereof; eccentric cams formed on the main spindle such as to be axially spaced away from and 180.degree. out-of-phase with respect to each other; connecting rods respectively having big end portions pivotably connected with the eccentric cams and small end portions extending along the saw blades toward the rear end section of the case, where they are pivotably connected with the saw blades; and laterally-curved portions formed on the blades and extending in the longitudinal direction on one side of a middle section of the main spindle.

Abstract: A power saw has two oppositely reciprocating saw blades guided and supported in a receiving slot in a support plate. The blades are supported during sawing along shoulders on their outside by lower edges of support sections of the support plate. The arrangement is such that forces generated in operation during cutting press the saw blades together in the area of their teeth. This prevents saw dust, chippings etc. penetrating between the two saw blades. Preferably, the thickness of the saw blade shoulders are not greater than half the thickness of the saw blades, and preferably no greater than the thickness of the support section edges. The teeth of the saw blades may be so ground and arranged that the resultant force on the teeth during cutting also forces the saw blades together at their teeth.

Abstract: A saw blade comprises a support member having at least one edge, and, spaced along that edge, a series of slots in each of which is secured a saw tooth and in which a portion of the tooth is located within the slot and a further portion extends beyond the slot to overlie a portion of a surface of the support member.Part of the slot and a part of the tooth may be sector-shaped, each slot may include an entry portion with side edges and a base edge or edges, and the tip of the sector-shaped part is located centrally of the base edge, the sector-shaped part communicating with the entry portion via an opening in the base edge whose sides are rounded and which are a tight fit with a mating portion of a tooth, the remainder of a tooth fitting into the slot with some clearance.The invention also extends to a tooth for the saw blade, the tooth having a cutting portion and a body portion to locate in said slot.

Abstract: A sawing apparatus includes a guide and a pair of oppositely reciprocable saw blades mounted in a groove of the guide. Mounting portions of the saw blades disposed within the groove slidingly engage one another within an interface plane. Each saw blade includes a cutting portion disposed outside of the groove and carrying outwardly set teeth and inwardly set teeth. The inwardly set teeth extend toward and beyond the interface plane. Feed forces can be applied from the guide to the saw blades by inclined end edges of plates which form the guide. The end edges are inclined obliquely so as to face away from the interface plane and engage correspondingly inclined surfaces of the saw blades. Alternatively, feed forces can be applied to back shoulders of the mounting portions of the saw blades by a member which extends between the guide plates within the groove.

Abstract: A power saw has two oppositely reciprocating saw blades guided and supported in a receiving slot in a support plate. The blades are supported during sawing along shoulders on their outside by lower edges of support sections of the support plate. The arrangement is such that forces generated in operation during cutting press the saw blades together in the area of their teeth. This prevents saw dust, chippings etc. penetrating between the two saw blades. Preferably, the thickness of the saw blade shoulders are not greater than half the thickness of the saw blades, and preferably no greater than the thickness of the support section edges. The teeth of the saw blades may be so ground and arranged that the resultant force on the teeth during cutting also forces the saw blades together at their teeth.

Abstract: Sawblade for a powered saw with of the type in which two of the sawblades reciprocate side-by-side in a groove on the underside of the guidebar. A downward force from the guidebar is transmitted to a plurality of short longitudinally spaced ledge section projecting from the outer side faces of the sawblade. The ledges are formed by outwardly bent portions of the sawblade. The ledges can be slightly convex as viewed from the side.

Abstract: Sawblades for cutting materials containing abrasive grains or fibers with a power saw utilizing two reciprocating sawblades in contact with each other guided by a groove in a guidebar, all teeth on one blade pointing forwards and all teeth on the other blade pointing backwards. The teeth are located with unequal distances chosen so that two teeth on the first blade will not simultaneously be opposite two teeth on the other blade with the same distance as the teeth on the first blade.

Abstract: A hand-held power tool, for example a reciprocating saw, a chain saw, or a hedge trimmer, has a rear handle and a T-shaped forward handle formed by a forwardly directed strut with a crossbar. Looped side handles are detachably mounted on each side of the tool. Upper legs of the side handles are detachably connected to opposite ends of the forward handle crossbar. Lower legs of the side handles are detachably connected to bosses on opposite sides of the tool's housing adjacent its bottom. The side handles can be mounted with screws, or interlocking elements, or a combination of both. Preferably the forward handle is integrally formed with an upper part of the tool's housing. Both side handles may be omitted and the tool held by the forward and rear handles, this reducing the width of the tool.

Abstract: A saw blade, for a power saw having two such blades arranged adjacent and parallel to each other and reciprocating in opposite directions, comprises an elongate blade member having teeth along a bottom edge. The teeth comprise at least three types, a first type being at an outer surface of the blade member, a third type being at the inner surface, and the second type being therebetween. The first type are shaped to produce on the blade's bottom edge an outward force away from the inner surface while cutting a workpiece, and the second and third types are shaped to produce on the blade's bottom edge an inward force, the resultant force on the teeth while cutting urging the teeth in an inward direction away from the outer surface towards the inner surface. When the power saw is operating with a pair of these blades, the blades are urged together at their teeth by the cutting action so effectively eliminating penetration of sawdust and cuttings between the pair of blades.

Abstract: A sawing method involving in one direction continuously driven saw blades (1, 2) or saw wheels, according to which two saw blades (1, 2) or saw wheels are arranged in an adjacent position to each other, with associated saw teeths extending in an opposed relationship to each other. The saw blades (1, 2) or the saw wheels are thereafter caused to perform a continuous movement in opposite directions to each other in the operative direction for each saw blade (1, 2) or saw wheel, whereby same in a common and co-acting operation take up a saw cut in a workpiece. In order to maintain the saw teeths of the saw blades (1, 2) or the saw wheels separated from each other during a sawing operation, a pneumatical or hydraulical medium under pressure is advantageously supplied against the adjacently located surfaces of the saw blades (1, 2) or the saw wheels during the sawing operation.

Abstract: This invention relates to the counter-reciprocating double blade saws including a pair of the saw blades disposed in side by side relationship, one extremity of each of the two saw blades is connected to two counter-reciprocating holders driven by a power source, respectively, which arrangement is for the counter-reciprocating double blade saw of the saber saw type. The other extremities of the two saw blades connected to two reciprocating saw blade holders at their one extremities are connected to a pair of the idler counter-reciprocating saw blade holders supported by the common frame that also supports the drive counter-reciprocating saw blade holders in the construction of the counter-reciprocating double blade saw of the bow saw or butcher saw type. The counter-reciprocating double blade saw of the two-man type saw is constructed when said common frame is removed in the counter-reciprocating double blade saw of the bow or butcher saw type and a pair of handles are added to two opposite extremities.