Abstract: A press that includes a pair of die sections and a ram for propelling one of the die sections against the other to form a workpiece positioned therebetween. A die cushion is coupled to one of the die sections for cushioning force of engagement of the die sections, and includes at least one gas cylinder and a manifold for feeding gas under pressure to the cylinder. A pressure monitor includes a pressure sensor coupled to the manifold for supplying an electrical pressure signal as a function of gas pressure in the manifold. The pressure signal as compared to a predetermined threshold for supplying an alarm signal when gas pressure in the manifold is less than such threshold, and ram operation is stopped when the manifold gas pressure is less than the preset threshold.

Abstract: In a method and apparatus of forming a flat metal strip into a tube having generally flat side walls connected by bight portions along their opposite longitudinal edge portions comprising the steps of directing the strip between a pair of form rolls to bend the opposite longitudinal edge portions of the strip into similar generally upwardly curved edge portions; then directing the strip between a second set of rolls which engage the upwardly curved edge portions to center the strip laterally relative to the rolls and bend the strip along its longitudinal center line to form an upwardly rounded bend therealong while maintaining the portions of the strip on the opposite sides of the center bend relatively flat whereby to impart to the strip a V-shaped cross section having a central apex and oppositely upwardly inclined flat legs, each terminating in a laterally inwardly curved edge; directing the V-shaped strip between one or more additional sets of form rolls to increase the circumferential extend of said apex

Abstract: A machine for corrugating lengths of continuous strip stock that includes first and second sets of corrugation-forming rollers for receiving strip stock from associated coil rolls and feeding corrugating stock to vertically spaced slots in a shared cutting station. Running length of each corrugated strip is measured and the cutting station is controlled so as to obtain severed stock sections of predetermined lengths, which may be variably programmed in a predetermined sequence. The cutting station includes a stationary plate having vertically spaced strip-receiving slots, and a pair of shear blades integrally formed on a shear plate selectively driven by the machine controller through a cycloidal drive mechanism.

Abstract: A cut-off machine for cutting off predetermined lengths from a moving length of roll form material such as tubing adapted to be positioned downstream from a source such as a tube mill for receiving a moving length from the mill and severing plural predetermined lengths from the moving length. The machine comprises a plurality of cut-off assemblies which are reciprocated longitudinally of the moving length of material formed by the mill and operated during the movement to sever plural predetermined lengths. The reciprocating and cutting movements are mechanically derived from a motor driven in synchronism with the speed of movement of the moving length. The apparatus includes mechanisms that permit the length of the tubes to be changed while the machine is operating.

Abstract: A die stamping system includes opposed die members which clamp a metal workpiece to be shaped, cut or pierced after which the die members are moved away from one another and a part is subsequently ejected wherein the ejector is controlled for a selected delay time by a plurality of cylinder assemblies mounted in a manifold so that they are connected to a source of inert gas such as nitrogen under high pressure and to a source of hydraulic pressure. Each cylinder assembly includes a piston associated with and exposed to the nitrogen in the manifold. The cylinder assemblies are connected to a single hydraulic valve which has associated therewith an accumulator and which is operated simultaneously to actuate the cylinders. The hydraulic lines to the cylinders are provided in the manifold.

Abstract: A corrugating web forming apparatus for receiving selectively a plurality of webs of flat material and slitting each of said webs to form two strips which are thereafter shaped to form corrugations and severed to form shaped portions having predetermined lengths, predetermined height and predetermined spacing between the corrugations which comprises a slitting station including at least two sets of slitting rolls adapted to be used selectively for slitting a respective web, a forming station including at least two sets of forming rolls for transversely corrugating two strips severed from a web simultaneously, a plurality of longitudinally roll pack stations comprising at least two sets of forming rolls for controlling the longitudinally spacing between the corrugations on the strips, a web control station including at least two sets of rolls for engaging and intermittently interrupting the movement of the corrugated strips, and a cutting station for cutting predetermined lengths from said corrugated strips.

Abstract: A die stamping system for use in a fine blanking apparatus that includes opposed die members which clamp a metal workpiece to be cut and pierced after which the die members are moved away from one another and the slugs pierced from the blank and the cut blanks are subsequently ejected wherein the ejector is controlled for a selected delay time by a plurality of cylinder assemblies mounted in a manifold so that they are connected to a source of inert gas such as nitrogen under high pressure. Each cylinder assembly includes a first piston associated with and exposed to the nitrogen in the manifold and a second piston engaged by the first piston and urged outwardly into engagement with a punch base.

Abstract: In a machine for corrugating a continuous length of strip stock fed between a pair of corrugation rollers, apparatus controls height of corrugations formed by the rollers by selectively varying tension on the strip stock fed between the rollers. Such apparatus includes a sensor for measuring actual height of corrugations formed by the rollers, and a clutch for applying tension to the strip stock upstream of the rollers, with the height of corrugations varying as a direct function of tension applied to the strip stock. A tension sensor is positioned between the clutch and the forming rollers for measuring tension applied to the strip stock and controlling the clutch accordingly.

Abstract: For use in a system comprising a source of pressurized fluid and a plurality of lines extending to a plurality of gas springs, a gas spring comprising a cylindrical body with a bore, a piston rod positioned in the body and having an end projecting beyond one end of the body, a base closing the other end of the body, the cylindrical body and piston rod interengaging one another to limit relative outward movement of the piston rod with respect to the body. The gas spring includes a radial inlet through the wall of the cylindrical body into the base. A one-way valve is positioned in the base within the inlet and an axial inlet pressure passage extends from the outlet end of the valve to the interior of the cylinder. A radial bore is provided in the base and communicates at one end through an axial pressure relief passage to the interior of the cylinder.

Abstract: A self contained gas spring interchangeable with a coil spring comprising a cylindrical body having a constant diameter external cylindrical surface, the cylindrical body having open ends and a piston within said cylindrical body and having one end projecting through one of the openings of the cylindrical body. The piston and the cylindrical body have interengaging flanges that limit the outward movement of the piston relative to the cylindrical body. A plug is positioned in the other end of the cylindrical body to close the opening of the cylindrical body. A charging valve is positioned in the plug for charging the interior of the gas spring. The piston has a hollow inner end with an inner surface tapering outwardly and axially toward the plug. The plug has a generally complementary surface such that the piston can move downwardly about a portion of the plug thereby substantially reducing the height of the gas spring.

Abstract: In an apparatus for rolling metal ribbon stock into convoluted fin strip for use in heat exchangers, an uncoiler apparatus comprising a base, a pair of coil supports for supporting a pair of coils of sheet metal ribbon stock. The coil supports are mounted on a plate which is rotatable about a vertical axis so that when the plate is rotated, one coil support is moved into driving engagement with the motor and the other coil support is moved out of driving engagement with the motor. A control system interconnects the drive of the motor on the uncoiler apparatus with the drive of the remainder of the corrugated fin rolling machine for positively driving the uncoiler as a function of machine speed.

Abstract: A transfer apparatus operable in connection with the reciprocating movement of a press to grasp and successively hold and move workpieces operated upon by the press comprising a plurality of opposed longitudinally spaced gripping members mounted to move transversely for gripping a plurality of workpieces, moving the workpieces longitudinally and thereafter releasing the workpieces so that the gripping member can be returned for successive cycles. Each of the movements is controlled by a vertically movable cam and a cam follower urged against its respective cam and interconnected by mechanical linkage to cause the gripping members to move inwardly to engage workpieces, longitudinally to move the workpieces, and outwardly to disengage the workpieces.

Abstract: A die clamp arrangement for a press has a clamping lever that is shifted horizontally by a dog between an extended and a retracted position and rotated in a vertical plane between a clamping position and a released position. The cam and dog are interconnected for rotation in unison by a single shaft. In the retracted position the clamping lever is adapted to permit vertical movement of a die into and out of a press. Means are provided for actuating the clamps at the rear and at each side of the die from the front side of the press. The clamps at the front and/or the rear sides of the press are arranged to be pivoted from an operative position downwardly to an out-of the-way position below the top face of the press bolster.

Abstract: A nitrogen die piston-cylinder unit has a central post threaded at one end into a nitrogen manifold. The piston has an axial bore therethrough. A sleeve closed at one end is telescoped over the free end of the post and is vertically slideable thereon. The upper end of the post has an annular seal thereon in sliding sealed engagement with the bore of the sleeve. A key and keyway formed on the inside of the sleeve and the outside of the post are arranged to interengage when the sleeve is fully telescoped over the post to prevent relative rotation therebetween. The exposed end face of the sleeve is formed with recesses adapted to be engaged by a spanner wrench to enable the unit to be removed from the threaded port of the manifold when the key is engaged with the keyway.

Abstract: A die is clamped to the bolster plate of a press by means of clamps around the sides of the die. Each clamp is operated by a rotatable shaft which extends from the clamp to the front side of the press. The operating shafts for the clamps at the rear side of the die are disposed below the die.

Abstract: A tube mill for forming heat exchanger coolant tubes has a series of form rolls for rolling flat strip stock into a flat-sided tube with rounded longitudinal free edge portions. After rolling, the free edge portions are heated to a fusion temperature and pressed together between a pair of squeeze rolls to form a weld seam therebetween. The heating is performed by a high frequency induction coil which encircles both the tube and a guide for the free edge portions. The guide is located immediately upstream from the squeeze rolls.

Abstract: A die clamp adapted to be firmly mounted in a press has a body on which a clamping lever is rockably supported. The lever is rocked to and from a die clamping position by a rotatable cam. A screw connected to the cam by a link is shifted axially by rotating a nut on the clamp to rotate the clamp and thereby rock the lever to and from its clamping position.

Abstract: There is disclosed a piston-cylinder assembly for use as a die spring wherein one end of the cylinder is connected to the source of nitrogen at high pressure to bias the piston outwardly through the opposite open end of the cylinder. The open end of the cylinder is provided with a high pressure seal and the opposite end of the piston is likewise provided with a high pressure seal. An annular chamber of relatively small cross sectional area is provided between the piston and the cylinder. A valve stem on the piston controls a passageway communicating with the annular chamber. Axial pressure is applied to the seal on the cylinder to produce firm sealing engagement with the piston by pressurizing the annular chamber or by arranging a compression spring between the seal and a shoulder on the cylinder.

Abstract: A piston-cylinder unit for use in a die is threaded into a port of a nitrogen manifold. The piston has a seal thereon slideably engaging the cylinder bore and has a rod projecting out one end of the cylinder, the rod being biased by the gas pressure at the threaded end of the cylinder into engagement with a die member reciprocated in response to reciprocation of the ram of the press in which the die is mounted. The portion of the cylinder threaded into the manifold has a bleed passageway therethrough which communicates with the interior of the cylinder below the seal on the rod when the press ram is at bottom dead center position and with the interior of the cylinder above the seal on the piston when the piston rod is fully retracted.

Abstract: The punch retainer mounted on a die shoe has a body with a backing plate fastened to the top face thereof. The body is formed with a first bore for retaining a punch, the inner end of which abuts the backing plate. A first dowel projecting from the mounting face of the die shoe extends into the backing plate in axial alignment with the central axis of the first bore. Second and third bores in the body register with second and third holes in the backing plate. Tubular dowels engage in the registering bores and holes to align the backing plate on the body. The retainer is mounted on a die shoe by holding screws which extend through the tubular dowels and thread into the die shoe. The backing plate is aligned on the die shoe by either a separate fourth dowel in the backing plate spaced remotely from the first dowel or by extending one of the tubular dowels beyond the backing plate for engagement with a registering opening in the die shoe.