Abstract: A furnace heat exchanger tube cleaning apparatus is described. The furnace comprises a combustion chamber for generating heated gases including combustion products, a water jacket containing a liquid to be heated and including heat exchanger tubes passing therethrough and a flue for discharge of the combustion products. In operation, the heated gases including combustion products flow from the combustion chamber along the heat exchanger tubes to the flue. As the heated gases pass along the heat exchanger tubes, heat from the heated gases is transferred to the liquid in the container, thereby heating the liquid. The efficiency of heat transfer is increased by helical flights arranged to depend downward into the respective heat exchanger tubes from a support structure. Specifically, the flights create turbulence in the flow of the heated gases, thereby improving heat transfer.

Abstract: A one shot firing circuit for electrically powered tools is described which includes a manually operable normally open trigger switch connected electrically in series with a solenoid coil and an AC power source for controlling the supply of electrical power to both the firing circuit and the solenoid, such that when the trigger switch is open, the path of current flow to the solenoid coil is physically interrupted. The firing circuit also includes an SCR connected electrically in series with the trigger switch, the solenoid coil and the AC power source, for controlling the flow of current through the solenoid coil after the trigger switch has been closed.

Abstract: An improved rotary power shear that includes an electric motor which drives, through a reduction gear assembly, a rotary shear assembly comprised of a driving shear wheel which rotates against a cooperating driven shear wheel. The design of the tool is characterized by a handle that extends above the motor housing and gear casing, and which supports the tool at one end from the gear casing and at the other end from the rear of the motor housing. In this manner the tool is balanced when held by the handle as the weight of the gear casing and cutting assembly at the forward end of the tool offsets the weight of the motor at the rearward end of the tool. In addition, the design of the tool is facilitated by the provision of a single bracket member that serves the multiple functions of supporting and biasing together the rotary shear wheels, providing a cover for the gear casing, and also providing a support for the stub shafts on which the gears are journalled.

Abstract: A portable electric router including a housing enclosing an electric motor, and having a router bit extending from one end of the housing and driven by the motor. A router base assembly includes handles and a flat base plate and is adjustably fixed to the housing. The flat plate supports the router for movement along a work surface and is provided with a central opening through which the router bit extends to engage and penetrate the work surface. The other end of the housing has a support surface upon which the router can rest when the router is temporarily put down during use and when it is stored, or while the bit is changed, or while the base assembly is adjusted relative to the housing for depth adjustment of the bit. A switch is provided on the housing for turning the router motor "on" and "off", and is controlled by a switch operator having a portion which extends through an opening in the router housing support surface.

Abstract: A vise having jaw gripping members supported by a body having a bowl shaped body member is described. The body member is positioned in a cavity of a base member and a means is provided including a lock body positioned within the bowl member for selectively restraining the support body at a plurality of different orientations.

Abstract: A portable, electrically energized, cordless grass trimmer device is disclosed having a rotatable hub which is adapted to alternatively mount, for substantially balanced rotation therewith, a flexible cutter strip and a line cutter and mechanical counterbalance.

Abstract: The invention is directed to a foldable, portable workbench having a work table and a support structure for supporting the work table. The support structure includes a pair of mutually spaced leg assemblies and each of these leg assemblies, in turn, includes a pair of legs pivotally connected at one end thereof to the work table. Articulated linkages pivotally interconnect, respectively, the two legs of each pair of legs to each other and at least one of the legs to the work table. The articulating linkages are connected so that the work table and leg structures are stacked in juxtaposition to each other when the workbench is in its folded position and, so that the other ends of the leg structures are spread apart from each other with the work table substantially transverse to the leg structures when the workbench is in the erected position.

Abstract: A portable workbench has a supporting structure defining a supporting surface. The supporting structure includes a collapsible leg assembly for supporting the supporting surface above a floor surface. A first top member having an upper surface is supported by the supporting structure on the supporting surface. A second top member likewise has an upper surface and the upper surfaces lie in a substantially horizontal plane. The top members also have respective mutually adjacent side walls defining clamping surfaces. A guiding structure is provided for guiding the second top member relative to the supporting structure. The second top member can be moved along the guiding structure so as to adjust the position of the second top member with respect to the first top member.

Abstract: The invention is directed to a power operated jig-saw which includes a housing and an elongated saw-blade holder for holding a saw-blade. A first bearing pivotally mounts the elongated saw-blade holder in the housing. A drive imparts a reciprocating up and down movement to the elongated saw-blade holder. A cam arrangement imparts a reciprocating movement to the elongated saw-blade holder and includes a body rotatably mounted in the housing and operatively connected to the drive. The rotating body has formed thereon a continuous cam surface extending about the axis of rotation thereof. The cam arrangement also includes a carrier and a resilient member. The carrier is mounted in the housing so as to be reciprocally movable in a direction transverse to the elongated saw-blade holder and carries a bearing for slideably holding the saw-blade holder.

Abstract: The invention is directed to a gear transmission for an angle tool such as a grinder, polisher, sander, angle screwdriver or the like having a drive motor for driving an output spindle shaft. The motor has a drive shaft defining a longitudinal axis transverse to the output spindle shaft. The gear transmission connects the drive shaft of the motor to the output spindle shaft and includes a first stop and a second stop on one of the shafts. A first gear is mounted on the one shaft so as to abut against the first stop and a second gear mounted on the other one of the shafts. A resilient annular bearing is tightly held between the second stop and the first gear; and, a cut-shaped retainer is disposed on the one shaft for containing the resilient annular bearing.

Abstract: A portable electric drill is disclosed which includes a loss-proof chuck key. The drill includes a cord set and the chuck key includes a simple, rod-like handle which is shaped to form a closed loop. The loop is slightly larger than the diameter of the cord set but sufficiently smaller than the cross sectional dimensions of the plug so that the key cannot be slipped off over the plug. In a preferred embodiment, the key comprises a triangular handle to provide a good gripping surface for the user. Other accessory hand tools for use with electric or pneumatic power tools attached to the power tool in a similar manner are also disclosed.

Abstract: A nozzle assembly has a body with an axially closed end, and a radially apertured cup-like discharge chamber on the outside of the closed end, and a nozzle cap carried on the outside of the body, and having an annular seat surrounding its discharge opening, the seat being engageable with the body around the discharge chamber. The assembly is adapted to be non-threadedly secured to a source of liquid pressure, there being an extension which can be disposed between such source of liquid pressure and the body. The spray nozzle and spray nozzle extension are adapted to be connected to the discharge of a pump by which the pump is converted into a sprayer.

Abstract: A hammer tool such as a rotary hammer, hammer drill or the like includes a motor housing and a gear case secured to the motor housing forwardly of the motor housing. A motor in the motor housing has a shaft projecting into the gear case and a pinion formed on the end of the motor shaft. A first set of ratcheting teeth is formed on a body rotatably journaled in the gear case. An output spindle for holding a tool bit is provided and has a longitudinal axis. The output spindle is rotatably journalled in the gear case so as to be also slideable in the direction of said longitudinal axis. A second set of ratcheting teeth is mounted on the output spindle so as to be in confronting relation to the first set of ratcheting teeth. A spring provides a resilient force for holding the first and second sets of ratcheting teeth in spaced apart relation to each other.

Abstract: The invention is directed to a clamp for holding a workpiece to a work surface having an aperture formed therein. The clamp includes the main support arm having one end portion adapted for insertion into the aperture in the work surface. A clamping arm is pivotally connected to the main support arm above the above-mentioned end portion and the clamping arm defines a clamping surface for engaging the workpiece placed on the work surface. A first lever arm is pivotally connected to the main support arm and a second lever arm has one end pivotally connected to the first lever arm and another end pivotally connected to the clamping arm.

Abstract: A clamp arrangement for clamping saw blades to the blade holder of a power driven saw includes a seating surface formed on the end portion of a blade holder of the power driven saw for receiving the saw blade thereon. A collar surrounds the end portion of the blade holder and the shank portion of the saw blade. A threaded annular member threadably engages the collar and presses the saw blade against the seating surface and the end portion of the blade holder is, in turn, pressed against the inside wall surface of the collar. A clear passage through the annular member facilitates access to the shank portion of the saw blade held between the annular member and the seating surface whereby the shank portion can be easily removed from between the annular member and the receiving surface with the aid of an instrument passed through the clear passage in the event the blade should break off at the shank.

Abstract: The invention is directed to a portable workbench which includes a foldable support stand and a workpiece supporting and clamping assembly supported thereon. The workpiece supporting and clamping assembly has a base frame and a pair of elongated top members located on the base frame and defining upper work supporting surfaces lying generally in a common plane and having opposed side portions defining clamping surfaces. A clamping arrangement is operatively connected between the base frame and one of the top members for moving the latter toward and away from the other top member to provide for the clamping of workpieces between the top members. The support stand includes a pair of generally rigid frames, with each frame having spaced apart upper and lower longitudinally extending generally horizontal members.

Abstract: A field subassembly for a dynamo electric machine comprises a plurality of laminations secured together to form a stack, the stack having at least two spaced pole pieces and a pair of coil slots per pole piece, a field coil in each one of the pairs of slots, apertures in said stack, each aperture being located in one of the regions between adjacent pole pieces, and electrically-insulating terminal blocks mounted on the stack, each of said blocks being associated with one of the apertures, and each of the blocks having an external configuration corresponding to the region between said pole pieces and such that the blocks do not extend either externally of the stack in a radial direction or within the stack.

Abstract: The invention is directed to an arrangement for cutting contours in a workpiece with a router and includes a supporting structure and a pair of elongated vise members mounted on the supporting structure. The vise members are disposed in side by side relation to each other with at least one of the vise members defining a substantially smooth upper surface upon which the workpiece can be placed. At least one of the vise members is mounted on the supporting structure so as to be movable relative to the other one of the vise members. An elongated fence member adapted for insertion between the vise members is also provided. A clamping arrangement is included for adjusting the vise members with respect to each other to clamp the fence member therebetween. A mounting structure accommodates a router and is mounted on the fence member so that the mounting plate, the fence member and the upper surface of the workbench conjointly define a path for passing the workpiece therealong.

Abstract: A cordless twin blade electric lawnmower having substantially improved performance and efficiency is disclosed. The lawnmower includes a pair of spaced counter-rotating cutting blades, a pair of motors driving each of the respective blades and a battery for energizing the motor under the control of a switch. The housing of the lawnmower is supported on wheels and provides a passageway comprising a helical convolute for each of the respective blades. The two convolutes join in the center of the mower and provide a continuing passageway into a rear mounted bag. The front of the bag is partially closed by a chute which, when the bag is not present, automatically falls into a guard position wherein all air flow, objects and grass are directed downwardly at the rear of the motor. The guard also provides, in this position, for distribution of the grass across the width of the mower span.