Abstract: A method of manufacturing an electrode plate for a battery of the present disclosure includes: a step (A) of forming a through hole (20) in a strip-shaped electrode plate (10); and a step (B) of cutting the strip-shaped electrode plate along a width direction. In the step (A), the through hole is formed at a position on a cutting line (21) which extends in the width direction of the strip-shaped electrode plate, in the step (B), cutting of the strip-shaped electrode plate is performed by multiple cutting blades (30A, 30B) disposed along the cutting line, and at least one cutting blade of the multiple cutting blades is disposed at the position of the through hole.

Abstract: A machine tool for machining planar workpieces includes an upper tool, a lower tool, a machine frame, and a controller. The upper tool is movable with a stroke movement along a stroke axis by a stroke drive device in a direction towards a workpiece and in the opposite direction and positionable with an upper traversing movement along an upper positioning axis by a motor drive assembly. The lower tool is aligned with the upper tool and is positionable with a lower traversing movement along a lower positioning axis by a motor drive assembly. The upper and lower tools are movable in a frame interior of the machine frame. The motor drive assemblies can be controlled by the controller. The upper and lower traversing movements can be controllable independently of each other. The upper tool can be controlled with the upper traversing movement and the stroke movement in a superposed manner.

Abstract: A nibbling tool (11) adapted to incrementally remove material from an edge of sheet material (96). The nibbling tool (11) comprising a punch (71) adapted to reciprocate within a die (81). The punch (71) is configured to define a substantially radial contact surface (78) having a peripheral edge (79). The die (81) comprises an elongate guide for guiding reciprocation of the punch (71). The die (81) has a slot (87) which is adapted in use to receive said edge of the sheet material (96) and which is so positioned that the radial contact surface (78) on the punch (71) is caused to reciprocate across the slot (87). The slot (87) comprises a support surface (88) adapted to provide support to the sheet material (96) such that in use the peripheral edge of the contact surface (78) is caused to engage the sheet material (96) and cause it to be pressed against said support surface (88) to cause the incremental removal of material from the sheet (96).

Abstract: A cast-cutter for use in removing a cast from a patient comprises a body (20), cutting means (18, 148, 230) supported by the body (20), and a protection member (16, 204, 206, 236, 244) supported by the body (20) and adapted to be positioned between the cutting means (18, 148, 230) and the patient, to protect the skin of the patient. In one disclosed embodiment the cutting means cuts a cast by a shearing action. In another disclosed embodiment the cutting means cuts a cast by an abrading action.

Abstract: A cutting die head assembly for nibbler tools which enables the die head to be independently rotatably manipulated by the user's hand independent of its axial connection with the die body to provide for angular and/or circular cuts in areas of limited space use and thus avoiding the necessity of moving the nibbler body and attached drill in a similar path.

Abstract: A blade or punch assembly for double-ended nibbler tools which affords easier removal by in part providing a blade having central portions of a single diameter equal to or slightly less than the composite bore through which it is adapted to extend.

Abstract: An apparatus for cutting and nibbling a sheet metal (3) in coil form comprises pulling devices for pulling the sheet metal, which is delivered from a delivery bobbin or coil, and are driven by a pair of overlapping rollers (12), the sheet metal being adapted to intermittently advance, stop and move backward, the sheet metal being processed by machining heads (15,16), which are arranged at the top and bottom portions of the sheet metal and are designed for transversely move with respect to the sheet metal feeding direction.

Abstract: A blade or punch assembly for double-ended nibbler tools which affords easier removal by in part providing a blade having central portions of a single diameter equal to or slightly less than the composite bore through which it is adapted to extend.

Abstract: A cutting device has a body, a driving device, a moving base, a head and a cutting rod. The driving device is mounted on the body to actuate the moving base to move relative to the body. The head extends from the body and has a central hole defined through the head. A notch and an exhaust hole are defined in the bottom of the head and communicate with the central hole. The cutting rod is moveably received in the central hole in the head and is attached to the moving base. The cutting rod has a cutting recess defined around the cutting rod. Accordingly, the metal waste generated during the cutting process is kept from flying about and injuring the user, so the safety of using the cutting device is improved. In addition, the cut metal sheet can be kept from shake or vibration.

Abstract: A cutting die head assembly for nibbler tools which enables the die head to be independently rotatably manipulated by the user's hand independent of its axial connection with the die body to provide for angular and/or circular cuts in areas of limited space use and thus avoiding the necessity of moving the nibbler body and attached drill in a similar path.

Abstract: A punching unit for punching holes of a selected geometry in a wall of a component. The punching unit has a frame for supporting the component and the tool and die assembly releaseably securable to the frame. Tool and die assembly has a punch operatively coupled to a mandrel and a male die member and a female die member cooperating to form the hole in the wall. A portion of the tool and die assembly is interchangeable to provide a selected one of a plurality of predetermined hole geometries for the component.

Abstract: A depaneling system having multiple router stations. A feeder station in the dual routing station receives a panel from a feeder station. The feeder station then selectively delivers the panel to one of the router stations. The router station then severs all of the connections between the panel and the PC boards. The multiple router stations can also share a common router that is used by each station to sever the connections. In order to use a common router the router station have a movable receiving base which moves along a first axis. The router then moves along the second axis. The router and receiving base are then moved along the first and second axises independently to sever the connections.

Abstract: A machine for punching sheet metal, and having a worktable beneath which are located two stores for storing blank and machined sheets. Over each store, the worktable has a respective opening, which is closed selectively by a respective movable closing device, which, in the closed position, defines a portion of the worktable. Over one of the two stores, a handling device is provided for partly lifting a blank sheet from the store and over the worktable; and, over the other of the two stores, a movable stop element is provided for retaining the machined sheet over the respective opening as the respective movable closing device is moved.

Abstract: A slotting tool to slot a workpiece and cut off a slotted scrap from the workpiece comprising a punch having a toe portion and a heel portion located higher than the toe portion and a slotting portion located between the toe portion and the heel portion; a die having a starting blade to punch out a tip portion of the slotted scrap from the workpiece by cooperating with the toe portion to shear the workpiece; side blades to slot the workpiece by cooperating with the slotting portion to slot the workpiece; a terminating blade to cut off the slotted scrap by cooperating with the heel portion; a scrap cutting blade mounted to the die, the scrap cutting blade located below the starting blade for cooperating with the toe portion to cut off a tip portion of the slotted scrap; and a scrap path formed in the die, the scrap path locating under the starting blade to receive the tip portion of the slotted scrap.

Abstract: A process and apparatus for cutting up an element used in the construction of a nuclear installation for dismantling. The element is placed on a support and pushed toward a shearing tool having a blade pitch angle of 30.degree.. As the element is pushed, the blade performs a first shearing operation. Then a releasing stop controlled by a jack releases the element from the blade. Operation continues until the element is cut up.

Abstract: In a follow-up slotting tool for continuously punching workpiece (W) fed between a punch (3) and a die unit (5) at a predetermined pitch, the punch (3) is formed with a shear angle (.alpha.) at a lower end surface thereof in such a way that a front end of the punch is cut into the workpiece but a rear end thereof is not cut into the workpiece when lowered at a predetermined downward stroke; and the die unit (5) is provided with a counter member (15) for raising a residue (W.sub.A) partially cut away from the workpiece, after the punch has been lowered at the predetermined downward stroke, and with a cutting edge (21) for cutting off the partially cutaway residue (W.sub.A) raised by the counter member in cooperation with the punch, when the punch is lowered at the succeeding predetermined downward stroke.

Abstract: A method of side-cutting by a turret punch press for improving working efficiency to a large extent. The method comprises a step in which a selected one (5.sub.1) of a plurality of punch chips (5.sub.1 to 5.sub.4) arranged so as to be selectively hit in a punch assembly (1) provided on the upper turret (2) is used for side-cutting a workpiece (6) and the other step in which one end of a part to be cut into a punching piece with the side cutting is cut off by another punch chip (5.sub.2).

Abstract: The invention provides a punch press and shearing tool which operate to provide a series of cuts linked end-to-end for severing a work piece such as a piece of sheet metal. The shearing tool includes first and second elongated, cooperating cutting blades. Each of the blades has a pair of slidably related faces that slide against one another in a plane of reciprocation. The cutting edges are oriented at a small angle, e.g. 2.degree. to 6.degree., relative to one another to sever a piece of sheet stock progressively along a line with a scissor action. An intermittent work piece advancing motor shifts the work piece toward the cutting blades and parallel to the cut when the blades are apart. Gripping members can be yieldably mounted adjacent the cutting blades to grasp and forcefully hold the work piece in place as one blade moves toward the other. Yieldable stripper members on opposite sides of the second blade engage and independently deal with the stock on opposite sides of the cut.

Abstract: A hand held nibbling machine has a manipulatable housing with a drive head in which there is a downwardly opening passage. A tool assembly has an upper portion extending into the passage of the drive head, a lower portion for supporting a die, and a neck portion therebetween providing a throat portion between the upper and lower portions and into which a workpiece may extend. The upper portion of the tool assembly is releasably engaged in the passage of the drive head by interengaging surfaces about a portion of the outer surface of the upper portion of the tool assembly and about a portion of the wall of the drive head defining the passage, and these surfaces are disengageable by rotation of the tool assembly within the passage to move the interengaging surfaces out of alignment. A releasable fastener in the drive head is engageable with the upper portion of the tool assembly to secure the tool assembly in a rotated position in which the surfaces are interengaged.

Abstract: The machining system (10) disclosed here is particularly well-suited for automatically machining flat parts from individual sheets of aluminum. The system (10) includes a machining table defined by a pair of spaced-apart, parallely-extending table beams (18, 20). Clamping rails (192) mounted to each beam (18, 20) grip opposite side edges of an individual sheet (11) of aluminum, in a manner such that the sheet spans the distance between the beams (18, 20). The clamp rails are driven linearly relative to the beams, in order to move the sheet back and forth therebetween. Upper and lower carriage beams (14, 16) also extend transversely across the table beams (18, 20), one above the sheet (11), and the other below. The upper carriage beam (14) carries both a spindle carriage (28) and an upper clamp carriage (30). The spindle carriage (28) moves a cutting tool back and forth sideways relative to the sheet (11), and vertically up and down, for cutting parts from the sheet (11).

Abstract: In a punching unit for punching apparatus having a punch removably mounted on the upper half side of a support section formed nearly in a channel-shape such that the punch will face a die mounted on the lower half side of the support section, and a lifting mechanism for vertically moving the punch, a flat force-cutting blade is attached at the bottom end of the punch rotatably mounted on the support section, and a lifting mechanism is provided in the support section to turn the punch through an angle of 90 degrees.

Abstract: An apparatus for edge notching moving webs (10) comprises a reciprocating punch (82) and die (64) which are rotated on a turntable (56) at a tangential speed matching the web speed and are actuated by a fixed cam (100) and a moving follower (94,96) connected to the punch. A related method is disclosed.

Abstract: A punch press, of the type capable of producing a piece from a sheet of material, the piece being attached to the sheet by a tab, is provided with a separation assembly that fits into a standard tool station. The invention provides for parting of the piece from the sheet, and automatic transport of the parted piece to a position overlying a hinged drop door provided as part of a removal assembly. The invention eliminates the need for manual parting and removal of the piece from the punch press.

Abstract: An apparatus and a method are disclosed, in which a shear and die set is adapted to be used in a numerically-controlled turret punch press for separating adjacent portions of a workpiece along predetermined parting lines, the shear and die set having a lower shearing or cutting edge on a vertical side of the shear portion of said set which is reciprocated vertically in shearing proximity to an upper cutting or shearing edge of a vertical wall of the die portion of said set, so that only a partial shear is effected for any reciprocation, and advancing the workpiece during the reciprocation so that a stepwise cut is effected along the entire length of said predetermined parting line and separation of the workpiece along said predetermined parting line is obtained.

Abstract: So that the path (BB, V1 to V7) for a rotable polygonal punching tool (WZ) can be determined easily, the workpiece contour (K), the dimension of the tool (x, y), the position of the axis of rotation (x/2, y/2) and the sense of direction of the machining are set by the operator into a numerical control (ST). An equidistant track (BB) is therefrom determined by the control (ST), such as is customary for milling operations. This track (BB), however, is corrected in the vicinity of corner of the workpiece contour (K) by the control (ST) in such a manner that punching optimized with respect to distance and time and with high contour fidelity is made possible.

Abstract: A punch press has a ram assembly with a lower portion which is rotatable and reciprocatable about a vertical axis and, a die holder which is rotatable about the same axis. A gear mechanism is coupled between a drive motor and the lower portion of the ram assembly and the die holder to effect simultaneous rotation thereof, which effects reorientation of the tooling relative to the X and Y axes of the punch press. In this fashion, rotation of the tooling will enable a single set of tooling to effect cutouts of different orientation in a workpiece relative to the X and Y axes, and movement of the sheet material along the X and Y axes together with such rotation of the tooling enables complex configurations to be nibbled or cutout with a limited number of sets of tools.

Abstract: A method for dimple free guillotine cutting of multiple wall tube which involves first cutting a transverse notch substantially completely through the outermost tube wall and secondly cutting a notch through the path of the first notch but of greater depth to extend partially through the innermost tube wall. The cutoff function is then finalized by means of a guillotine blade which enters through the coextensive notches. Both pull-across and thrust blades for carrying out the method are disclosed.

Abstract: To eliminate defects such as burr, rollover, sags, scar, etc. from cut-off surfaces of a workpiece in a turret punch press, for instance, a novel height-different punch formed with a lower front edge, an upper rear edge, and an intermediate edge extending between the two edges is used for the punch press. While feeding the workpiece on a horizontal plane in a predetermined direction, the punch is struck by a striker at a first stroke so that the lower front edge thereof cuts off the workpiece partially in cooperation with a die; at the succeeding strokes so that the intermediate edge thereof cuts off the workpiece mincingly and curls refuse within a recess of the die; and at the last stroke so that the upper rear edge thereof cuts curled refuse away from the workpiece to complete a multistroke punching operation.

Abstract: A method for shearing a plate-like workpiece using a punch press includes providing a punch having two adjacent blades disposed at a specified angle with respect to one another and a die having two blades corresponding to the blades of the punch. The punch and die are adjusted so that one of the blades on one of the punch and die will not mate with the corresponding blade on the other of the punch and die, and the other blade on one of the punch and die will mate with the corresponding blade of the other of the punch and die. The punch and die are brought together to shear the workpiece between the mating, corresponding blades of the punch and die. In one embodiment the blades of the punch are fixed on the base of the punch so as to be fixed with respect to one another. In a second embodiment, the punch is divided into two parts by a sliding surface which bisects the specified angle between the blades of the punch, so that the blades of the punch are longitudinally slidable with respect to one another.

Abstract: A punch press has a punch support and die support which are rotatable about a common vertical axis, and a drive mechanism for rotating and effecting the reorientation of the tooling relative to the X and Y axes of the punch press. In this fashion, rotation of the tooling will enable reorientation of single cutting surface, and location of various of the differently contoured cutting surfaces at the desired cutting position to effect cutouts of different contours or angular orientation in a workpiece relative to the X and Y axes. The punch has a cutting portion which is of a cross section providing at least one arcuate cutting surface A.sup.1 defined by the radius R.sup.1 and at least one rectilinear cutting surface A.sup.2. In accordance with one embodiment, the punch tooling is desirably of elongated cross section with a length L in its elongated axis and a width W in its transverse axis which is less than 1/2 L.

Abstract: A rotary type nibbler comprising a spindle having a helical groove, the spindle being rotatable in a body which terminates in a flat workpiece engagement face which is at an angle with respect to the axis of rotation approximating the helix angle of the groove so that the edge of a workpiece when urged into engagement with the root of the groove will have cut from it a crescent shaped slug.

Abstract: A punch press has a punch support and die support which are rotatable about a common vertical axis, and a drive mechanism for rotating and effecting the reorientation of the tooling relative to the X and Y axes of the punch press. In this fashion, rotation of the tooling will enable reorientation of a single cutting surface, and location of various of the distinctly contoured cutting surfaces, at the desired cutting position to effect cutouts of different contour or angular orientation in a workpiece relative to the X and Y axes. The punch has a cutting portion which is of a cross section providing at least two cutting surfaces of different contours with at least at least two arcuate cutting surfaces. In accordance with one embodiment, the punch is desirably of elongated cross section with a length L along its elongated axis and a width W in its transverse axis which is less than 1/2 L.

Abstract: An apparatus and method for cutting a pipe into a multiplicity of small pieces are provided wherein the pipe is fed by rotating the pipe about its longitudinal axis and simultaneously moving the pipe in a direction generally parallel to the longitudinal axis of the pipe, and wherein individual pieces are sequentially cut from an end of the pipe as it is being fed.

Abstract: A notcher includes a die having a die bore and a notching cutter received in the die bore. The die bore is connected to a suction device, and the notching cutter is formed with an air hole which opens to the atmospheric air and is communicated with the die bore. Accordingly, notching chips are smoothly discharged.

Abstract: A motor driven portable machine tool has a drive motor and a first gear mechanism which is driven thereby. Spaced from the first gear mechanism is a second gear mechanism, and it is drivingly engageable therewith through a disengageable coupling including a pair of coupling elements, a coiled spring disposed thereabout, and a clutch member rotatably disposed about the coil spring and adapted to tightly coil it about the coupling elements to effect driving engagement therebetween. A latch member is engageable with the clutch member to prevent its rotation, and a stop mechanism is operatively connected to the latch member to engage the latch member with the clutch member after one complete stroke of the tool which is being driven thereby. The stop mechanism may include a cam follower, and a cam surface on one of the gears, so that, upon a single revolution of that gear, the stop mechanism will effect the relatching of the clutch member to terminate the transmission of the power through the clutch.

Abstract: A rotary type nibbler comprising a spindle having a helical groove, the spindle being rotatable in a bearing sleeve which terminates in a flat workpiece engagement face which is at an angle with respect to the axis of rotation approximating the helix angle of the groove so that the edge of a workpiece when urged into engagement with the root of the groove will have cut from it a crescent shaped slug.

Abstract: A stamping or nibbling machine for cutting pieces off a metal workpiece comprises a hollow punch adapted to be driven against the workpiece to win small pieces thereof. A die having an opening therethrough is adapted to be located in alignment with the punch and on the other side of the workpiece. A centering pin has one end projecting into the interior of the punch and an opposite end extending out of the punch and adapted to engage into the opening beyond the position of the workpiece and a displacing mechanism for the pin is carried within the hollow punch and is advantageously in the form of a coil spring located between a collar at the inner end of the punch and the inner wall of the hollow workpiece which moves the outer end of the centering pin into association with a centering pin mounted within the die below the opening thereof.

Abstract: A method of manufacturing a configured cut-out in a sheet of material by arranging a pair of dies to support a sheet of material therebetween, pushing a punch shaft through one die, then through the sheet of material and then through the other die, then retracting the punch shaft to effectuate initiation of a nibbling operation to produce a cut-out in the sheet of material to correspond to a cut-out in a template, which template is traced by a pilot finger during common motion of the template and the sheet of material.

Abstract: A machine for manufacturing a templet for edge grinding a spectacle lens according to the shape of an opening in a spectacle frame designed to hold the lens, comprises a spectacle frame holder supported on a housing. A copying sensor is mounted on the housing for rotation about the axis of the opening and for rectilinear displacement, the sensor sensing the shape of the opening upon rotation thereof. A blank holder is rotatable synchronously with the sensor and a sliding carriage is mounted on the housing for rectilinear displacement with respect to the blank holder, the sliding carriage carrying a cutting tool for cutting the blank to provide said templet. A plunger is rectilinearly displaceable with the copying sensor and synchronously controls the rectilinear displacement of the sliding carriage and cutting tool, the plunger having an axis extending in the direction of the axis of the spectacle frame opening.

Abstract: A machine for punching and nibbling a piece of sheet material, preferably metal, for subsequent manufacture into a pallet, said machine comprising a pair of dies disposable on each side of the sheet material, a punch shaft being pushable through one die, then through the sheet material, then through the other die, which punch shaft also begins a nibbling operation on the return stroke, because of a shoulder cut into the shaft itself. The punch shaft is empowered by a pressurizable cylinder and an electric motor on the initial punch stroke, and just the electric motor during the reciprocable nibbling function.

Abstract: A nibbling tool for sheet material e.g. metal or plastics material and attachment to a power tool e.g. air or electric drill or air motor is disclosed. The structure of the tool permits a positive and easy change to be effected in respect of the cutting direction e.g. from the axial direction of the tool (for planar sheet) to a lateral direction for corrugated or contoured sheet. This change is effected by releasing a locking member externally of the housing and does not entail stripping down the tool. Likewise provision is made for a simple adjustment to optimize the stroke of the punch relative to the die.

Abstract: A circuit or control arrangement for an adjusting drive of a press ram of a high-speed cutting press which includes top and bottom dies respectively attached to the press ram and a platen of the press with the top die being adapted to dip or penetrate during a cutting process into the bottom die. An arrangement is provided for maintaining the depth of penetration of the upper die means into the lower die means to a constant value in dependence upon an operating condition of the high-speed cutting press. The maintaining arrangement may include at least one limit switch operatively connected with an oscillator stage which provides adjusting signals to the drive motor. In lieu of a limit switch, a cutting force measuring sensor member may be interconnected with an evaluator circuit and the oscillator means so as to control the drive motor.

Abstract: A punch press (10) having a punching head (30) which includes a large eccentric crankshaft (42) for operating selected punches (32). The large eccentric crankshaft (42) withdraws the punch (32) into an upper tool support (92) for a relatively large portion of the crankshaft rotation. The crankshaft (42) is connected to a selected punch (32) by a suitable mechanical interposer. The upper tool support (92) is provided to hold a variety of punches (32) and is movable to bring a selected punch (32) into position for being operated by the punching head (30). A mechanism is provided for relative positioning of a workpiece and the punching head (30). Since the punch (32) is withdrawn within the upper tool support (92) for a relatively large portion of the crankshaft (42) rotation the movement of the workpiece can take place while the selected punch is moving but withdrawn within the upper tool support (92).

Abstract: A device for cutting an edge of a workpiece comprising, a drive head having a carrier, a support bracket connected to the drive head for fixing the drive head with respect to the working piece edge, a tool holder reciprocately movable in and by the drive head, an impact cutting tool connected to the tool holder for cutting the workpiece edge, and a guide sleeve rotatably mounted but fixable in position in the carrier for guiding the motion of the cutting tool. The guide sleeve is rotatable to rotate the cutting tool and bring different edges thereof into a cutting position. Depending on the shape of the cutting tool, a plurality of edges are provided which can be changed as they become dull by rotating the guide sleeve. The axis of a cutting end of the impact tool can also be offset from an axis of the sleeve and an axis of a clamping end of the cutting tool connected to the tool holder to vary the depth at which the edge of the workpiece is cut.

Abstract: The coordinate slides of a computer controlled punching and nibbling machine are coupled by resilient elements with respective nuts engaging screws driven by motors controlled by computer programming. The resilient coupling between the slides and the respective nuts permits the motors to run and thereby drive the nuts during periods when the slides are held stationary by engagement of the punching and nibbling tool with a workpiece mounted on the upper slide. As soon as the tool is disengaged from the workpiece, the workpiece is quickly moved to the next position by energy stored in the resilient elements. A sensor between each of the slides and the respective nut senses the displacement of the nut relative to the slide and transmits this information to the computer.

Abstract: A machine and a tool for cutting material such as wood and plastics. The tool includes a shank adapted to be fastened to and rotated by a power driven spindle. The tool further includes a cutting part having at least one spiral rib on its outer periphery. The outer periphery of the rib is sharpened on its edge which is adjacent the shank, and the spiral rib has a pitch in the range of approximately 5.degree. to 15.degree.. The machine includes the tool, a drive motor and the spindle, and a support table for supporting a workpiece. The table has an opening formed in it and the tool extends through the opening. The sharpened edge of the rib is adjacent the table.

Abstract: A generally portable sheet material cutting tool comprising apparatus having a substantially stationary sleeve member with a free end and a cutting tool reciprocable within the sleeve member, the cutting tool having both a transverse cutting edge formed along its length cooperable with the free end of the sleeve member and an initial hole forming means extending beyond the free end of the sleeve member. The reciprocation of the cutting tool is effected by cam means acting in response to rotary motion supplied by a hand held drill unit or by a rotary drive motor, the cam means being capable of being disengaged by axial pressure applied to the initial hole forming means. In one form of the apparatus the transverse cutting edge is given both a reciprocating and a rotating component of motion, and in a modified form of the apparatus the transverse cutting edge is restrained for reciprocating movement only.

Abstract: A cutting tool arrangement for a nibbler, wherein a support shaft with a cutting head is arranged for reciprocating movement relatively to a die, has the support shaft including an elongated portion, a narrowing portion and an end portion. The cutting head formed as a sleeve-shaped element surrounds the end portion of the shaft and a lower part of the narrowing portion of the shaft and is soldered thereto to prevent fatigue concentration stresses in a transition zone between the narrowing portion of the shaft and the cutting head.

Abstract: A hand-held nibbling tool for sheet metal or other thin material is provided with a reciprocating punch which on its upward stroke moves the metal to be chipped against a readily replaceable cutting die positioned in a die holder attached to the lower end of the tool. The tool is provided with a conventional reciprocating mechanism driven in a known manner by a conventional air or electric motor. The reciprocating punch is connected to the reciprocating mechanism by a piston rod supported for a substantial part of its length in a sleeve within the die holder. The said die holder, moreover, is provided with one or more passages extending upwardly from the die and outwardly of the die holder so as to permit the chips thrown upwardly by the action of the punch against the die to be removed from the nibbling area. The die itself has an internal opening cooperating with the aforesaid passages.

Abstract: To eliminate defects such as burr, rollover, sags, scar, etc. from cut-off surfaces of a workpiece in a turret punch press, for instance, a novel height-different punch formed with a lower front edge, an upper rear edge, and an intermediate edge extending between the two edges is used for the punch press. While feeding the workpiece on a horizontal plane in a predetermined direction, the punch is struck by a striker at a first stroke so that the lower front edge thereof cuts off the workpiece partially in cooperation with a die; at the succeeding strokes so that the intermediate edge thereof cuts off the workpiece mincingly and curls refuse within a recess of the die; and at the last stroke so that the upper rear edge thereof cuts curled refuse away from the workpiece to complete a multistroke punching operation.