Patent GB-234451-A (GB)
Title: Improved method of and apparatus for making fin tube heat exchangers
IPC: B21D53/08
Filed: 1925-03-03
Abstract: 234,451. Griscom-Russell Co., (Assignees of Dewald, E. A.). May 24, 1924, [Convention date]. Radiators. - Finned tube-elements for heat exchangers of the type described in Specification 217,564, [Class 64 (ii), Surface apparatus &c.], are made by stamping the individual fins from a strip or ribbon of brass &c., collecting the fins in spaced relation as they are stamped out, and then threading them as a unit upon the tubes. A strip 9 of width equal to the length of a fin is fed step by step by corrugated rolls 17 operated by a press. The press-head has punches 12 for forming two or more shaped holes 5, Fig. 3, in the strip, punches 15 with reduced extensions for bending over the portions 6 at the edges of the holes so as to enlarge the holes to the diameter of the tubes and to furnish an increased heat-transferring path between the fin and the tube, and a shearing-knife 16. The punches 12 engage the strips and the extensions pass through the shaped holes in advance of the shear blade and thus hold the strip rigidly on the base during shearing. The fins 3 as formed. slide down the shoot 19 against a stop 22 and drop on to pairs of rods 20 carried on bases 21, which are removably mounted on a rotary carrier provided with ratchet teeth 28, Fig. 2. The fins may be prevented from dropping until the required time by levers 25, Fig. 1<a>, which are held together by a spring and are opened by a lever 24 operated by the press-head. The carrier is rotated when one pair of rods is full, either by hand or by a worm gear 32, 30 and chain gear 31 from the press-head, the worm wheel carrying a projection 33 which retracts the plunger 34 on which the pawl 29 is mounted and then releases it so as to allow the spring 35 to operate the pawl. The rods carrying the fins may then be placed in a spacing apparatus, Fig. 9, or may be transferred to similar rods 39 thereon. The spacing apparatus consists of a frame 36 with parallel tapered side walls 43 having internal horizontal grooves 37 corresponding to the required spacing. The rods 39 are carried by a base 40 and are slid along by a handle 41 to the position shown at 42, the fins being spaced in succession by engaging the grooves 37. The fins are received in a similarly grooved channelshaped holder 44, which is then removed and placed over similarly spaced grooves formed by laminations on a table 46, Fig. 14. The fins are pushed into the table grooves by a tool having two extensions passing through the holes in the fins. The tool is then removed. After the desired number of fins have been arranged on the table, the tube element, which consists of a pair of tubes 49 connected at one end by a chamber 50, Fig. 21, is then pushed through the holes in the fins by a chain 52 engaging lugs on an apertured member 53 detachably fitted on an extension 51 of the chamber 50. The finned tube-element is then secured in pairs of jaws 68 suspended by hangers 67 from a motor-driven derrick travelling on rails 65. It is dipped first in an acid bath 65, then in a solder bath 57, and then in a cooling bath 59. After each of the fluxing and soldering operations the hangers 67 are shaken by cams 70, Fig. 25, to remove excess of liquid. The cam; are mounted on a shaft driven through gearing from a second motor provided with a controller, which is operated so that the cams first lower and then raise the hangers, and are then oscillated to shake them, the cams having depressions in their upper edges for the last purpose. Each finned tubeelement is arranged between a partitioned header 2 and support 63 in a plane inclined at an angle of 45‹, the extensions 51 on the chamber ends of the elements engaging holes in the support 63.