Abstract: A method of manufacturing a heat exchanger coil, the method comprising the steps of reconfiguring the cross-sectional shape of an elongate tube from a substantially round cross-sectional shape having a first outer circumference to a reduced or corrugated cross-sectional shape having a second outer circumference which is less than the first outer circumference, forming a plurality of u-shaped hairpin tubes from the elongate tube, the u-shaped hairpin tubes each having a pair of parallel legs, inserting each of the parallel legs of the hairpin tube through a predetermined opening in at least one fin plate, attaching a plurality of return bends to the u-shaped hairpin tubes to form a predetermined circuitry and then incrementally applying fluid pressure from a fluid pressure source to an internal channel of the circuitry to incrementally expand the circuitry to form a tight heat transfer bond between the circuitry and at least one wall of the predetermined opening.

Abstract: Method and apparatus is disclosed for severing flat tubing. A length of tubing is gripped at longitudinally spaced apart locations and the tubing is deeply scored by rapidly rotating circular cutters which are moved across the faces of the tubing at a predetermined linear velocity. The angular velocity of the circular cutters greatly exceeds the linear velocity of traversal. An axial force is applied to separate the tubing.

Abstract: Method and apparatus for separating thin-walled flat metal tubing are disclosed. The tubing has flat upper and lower walls joined by end walls. The tubing is partially severed by providing relative movement between the tubing and opposed cutting blades having straight or slightly curved cutting edges. The relative movement is transverse to the longitudinal axis of the tubing, and the straight slicing edges, or the chords of curved slicing blades, form a small acute angle with respect to the flat faces of the tubing. The tubing is completely severed by applying an axial force to the tubing. Pressing heads follow the slicing blades to press any burrs back into the tubing.

Abstract: Method and apparatus for separating thin-walled flat metal tubing are disclosed. The tubing has flat upper and lower walls joined by end walls. The tubing is partially severed by providing relative movement between the tubing and opposed cutting blades having straight cutting edges. The relative movement is transverse to the longitudinal axis of the tubing, and the straight cutting edges of the blades form a small acute angle with respect to the flat faces of the tubing. The tubing is completely severed by applying an axial force to the tubing.

Abstract: Method and apparatus is disclosed for severing flat tubing. The method involves the steps of clamping a length of tubing, deeply scoring the tubing on opposite sides and applying a high impact axial force to sever the tube.

Abstract: An improved tube and fin heat exchanger and a method and apparatus for making the same is disclosed. The heat exchanger includes spaced end sheets and a stack of plate fins positioned therebetween. Hairpin tubes extend through the end plates and the stack of fins. The tubes are initially sized to loosely fit through the end sheets and fins and are expanded into tight heat exchange engagement therewith during manufacture. The end sheets are accurately positioned a fixed distance apart by a method and apparatus in which the end sheets are held a fixed distance apart during the expansion of the tubes. The bent ends of the hairpin tubes are moved upwardly through the adjacent end sheet and the fins ahead of the expansion bullets to compensate for the shortening of the tubes created by the expansion operation.

Abstract: An improved tube and fin heat exchanger and a method and apparatus for making the same is disclosed. The head exchanger includes spaced end sheets and a stack of plate fins positioned therebetween. Hairpin tubes extend through the end plates and the stack of fins. The tubes are initially sized to loosely fit through the end sheets and fins and are expanded into tight heat exchange engagement therewith during manufacture. The end sheets are accurately positioned a fixed distance apart by a method and apparatus in which the end sheets are held a fixed distance apart during the expansion of the tubes. The bent ends of the hairpin tubes are moved upwardly through the adjacent end sheet and the fins ahead of the expansion bullets to compensate for the shortening of the tubes created by the expansion operation.

Abstract: A rod mounting system for mounting expander rods in tube expander machines is disclosed. The mounting structure includes an opening in a header sized to receive the end of a mounting rod. A key extends into the opening from one side thereof. The rod end is provided with two longitudinally extending keyways and a peripheral groove. The first keyway extends from the end of the rod to an end face aligned with the peripheral groove. The second keyway extends from a location spaced from the end of the rod in both directions beyond the peripheral groove. The rod is installed in the header by longitudinal movement in an installation and removal orientation in which the key is aligned with the first keyway. When the rod engages the inner end of the first keyway, it is rotated to position the second keyway and the key in alignment. In such orientation, the rod is locked within the header for movement between two limits of longitudinal movement.

Abstract: An apparatus for cutting metallic tubing into predetermined lengths has a stationary supporting frame on which is mounted a feeding mechanism for moving a straight length of tubing unidirectionally intermittently along a straight path in alignment with the longitudinal axis of the tubing. A cutoff device driven by a motor having a hollow shaft for receiving the tubing is also mounted on the frame. The feeding mechanism is in two sections each being individually reciprocable but controlled to operate oppositely and alternately to feed tubing in predetermined lengths to the cutoff device. The cutoff device is operated to cut off the tubing while it is stationary between feeding movements of the feeding mechanism.

Abstract: An apparatus for cutting metallic tubing into predetermined lengths has a stationary supporting frame on which is mounted a feeding mechanism for moving a straight length of tubing unidirectionally intermittently along a straight path in alignment with the longitudinal axis of the tubing. A cutoff device driven by a motor having a hollow shaft for receiving the tubing is also mounted on the frame. The feeding mechanism is in two sections each being individually reciprocable but controlled to operate oppositely and alternately to feed tubing in predetermined lengths to the cutoff device. The cutoff device is operated to cut off the tubing while it is stationary between feeding movements of the feeding mechanism.

Abstract: A power driven dereeling apparatus comprising a supporting frame which carries for rotation thereon a table adapted to carry a reel of strand material coiled thereon. An electric motor is connected to rotate the table. A device is provided for sensing the tension of a strand being drawn off the reel, this device being fixedly disposed relative to the frame. The device further includes a cam roller engageable by a strand being drawn off the reel, the roller being movable between first and second positions in response to a predetermined change in tension of such strand. An electrical switch is disposed to be responsive to movement of said cam roller to said first position due to an increase in tension for energizing the aforesaid motor. This in turn causes rotation of the table and reel mounted in a direction to pay strand material off the reel.

Abstract: An apparatus for manufacturing sheathed heating elements, including means for supporting a plurality of sheaths to be filled with a particulate material, means for positioning a plurality of resistive elements individually within the sheaths, a plurality of sets of inner and outer concentric filling tubes defining an annular filler passage therebetween for the material, means for positioning the plurality of sets of concentric filling tubes within the sheaths in surrounding relationship to the resistance elements, means for feeding the material through the passage as the tubes are withdrawn from the sheath so as to concentrically position each resistance element within its respective sheath and to fill the sheath from the bottom thereof with the material, and valve means for controlling the feeding of the material through the passage.

Abstract: A tube cutoff device which includes a rotatable cutter head for radially slidably supporting a cutter and a pair of support rollers in circumferentially spaced relationship. A stationary tubular guide extends through the cutter head for permitting a tube to be fed therethrough and positioned between the cutter and the support rollers. A cam is rotatably supported on the cutter head and cooperates with the cutter and rollers for displacing same radially inwardly into engagement with the tube which is to be cut. The cutter head and the cam are rotatably drivably connected to first and second power trains, respectively, which cause the cam and cutter head to normally rotate at the same rotational speed.