Abstract: Disclosed herein is a method and apparatus for producing a barrel-shaped coil spring, by forming a coil spring having a first pig tail at one end, with a second pig tail at the other end. The method comprises providing a winding jig having a spiral stepped portion suited for forming a desired second pit tail; inserting the winding jig into the other end of the coil spring; and providing a rotary spindle for modifying the other end of the coil spring axially and radially relative to the winding jig, thereby winding the other end of the coil spring around the winding jig to form the desired second pig tail. Apparatus for performing the method is disclosed which comprises a winding jig and a cooperative rotary spindle to provide the second pig tail on the coil spring.

Abstract: In the production of metal- and other strip materials in continuous lengths and in several operations or processing facilities, such strip is wound into coils of finite length after each operation, then transported to the next operation and again welded into one continuous web, coil after coil.In order to avoid this wasteful practice a method and apparatus is disclosed which consists in feeding said strip emerging from one operation, without cutting it, directly into a variable capacity accumulator and feeding it out again from said accumulator into the apparatus of the following operation at the speed that such operation requires.

Abstract: A method of manufacturing a spiral tube including the steps of positioning an elongated mandrel within a tube, grasping the ends of the tube, forming a point of reduced resistance to torsional force in the wall of the tube, rotating one end of the tube while the other end is held stationary to cause the formation of a spiral groove in the tube, the mandrel defining the minimum interior diameter of the spiral tube so formed, and advancing the means grasping the tube towards each other to compensate for the reduction of length of the tube as the spiral groove therein is formed, and maintaining at least the area of the tube at which the spiral groove is being formed at an elevated temperature.

Abstract: A compact multiple coil heat exchanger having a high heat transfer density is provided to include at least an inner coil formed from a continuous tube into a plurality of contiguous turns about a common axis in a spiral arrangement and having a pitch in one direction and an outer coil formed from the continuous tube into a plurality of overlapping turns concentrically about the inner coil in a spiral arrangement having an opposite pitch. Further, a coil-forming apparatus and continuous coil-forming method is directed to form a multiple coil heat exchanger from a continuous tube using a coil-forming die rotatably mounted on a support frame. The coil-forming die includes a continuous spiral thread constructed to receive and laterally support the continuous tube while fabricating the multiple coil heat exchanger according to the continuous coil-forming method of this invention.

Abstract: An automated apparatus for forming helical corrugations in a cylindrical tube and comprising a tail stock movable in alternate forward and reverse directions, a head stock disposed in spaced relation with respect to the tail stock whereby the tube may be supported therebetween in a manner for rotating one end of the tube about its own longitudinal axis while holding the opposite end against rotation for twisting the wall of the tube to form the corrugations, a sensor device for detecting the progression of the corrugations along the length of the tube whereby forward movement of the tail stock and forward rotation of the head stock is stopped in accordance with a predetermined position in the twisting operation and the tail stock and head stock are actuated in reverse directions for a controlled unwinding and stretching of the twisted tube, a first sensor device responsive to the reverse movement of the tail stock for releasing the engagement of the twisted tube for permitting removal of the tube from the app

Abstract: A tensioned helical wire for use as a displacement sensor. The sensor made of high strength piano wire is attached at its ends to two anchors which in turn are attached to or are a part of the object or objects to be tested. In the preferred embodiment the sensor has straight ends which are attached to two small anchor blocks. These blocks are then attached to the test object. The displacement range and sensitivity of the sensor can be controlled by the initial geometry selected. If an initial tension applied is small, the sensor has a very large response range that is about fifty times that of a straight wire sensor. If a large initial tension is applied, the helical shape approaches that of a straight sensor and has a displacement range only a few times that of a straight wire sensor. If the sensor has a large displacement range, the sensitivity is much less than that of a straight wire sensor and if the sensor has a small range the sensitivity is comparable to that of the straight wire sensor.

Abstract: The method and device for the manufacture of helical rotor blanks for helical gear machines by moving a straight cylindrical shaft in a direction along the shaft axis while rotating it around the shaft axis by means of passing the shaft between at least three bending rollers, and the opposite end of the shaft held by a rotatable clamping chuck geared for infinitely variable timed relative movement with a bending roller. A first bending roller has a ring groove with a circular arc profile and a second bending roller ring groove has an elliptical profile with the second ring groove either laterally displaced or of greater width than the ring groove in the first bending roller.

Abstract: Metal stock is forged into a blank consisting of a rod-like shank joined at one end to the inner ends of a pair of forks having enlarged flattened outer ends projecting laterally of the forks in the same direction and provided with pin-receiving openings. One fork is aligned with the shank and the other fork extends laterally away from the shank and then outwardly, with its enlarged end projecting toward the other fork. Both forks are then twisted in the same direction to turn their flattened ends approximately 45.degree. into spaced parallel planes, and the longer fork is bent to move its flattened end into a position in which its opening is axially aligned with the opening in the other enlarged end.

Abstract: Metal stock is forged into a blank consisting of a rod-like shank joined at one end to the inner ends of a pair of substantially parallel forks having enlarged flattened outer ends projecting laterally away from each other in a common plane and provided with pin-receiving openings with parallel axes. The forging operation provides each fork with the appearance of a 90.degree. twist. After the blank is formed the forks are twisted on their axes in directions that will substantially eliminate their twisted appearance and will turn their enlarged ends into spaced parallel planes with their pin-receiving openings in axial alignment.

Abstract: Helically corrugated tubing with corrugations of variable depth is manufactured in a twisting machine by rotating one end of a deformable tube relative to the opposite end and simultaneously applying axially directed forces to the tube to progressively develop the helical corrugations in the tube wall. The depth of the corrugations is varied by means of a tapered mandrel which is located within the tube while the corrugations are being formed. Tubing sections with variable depth corrugations define flow paths in which the effective cross sectional area varies correspondingly, and such sections are useful in various heat exchangers.

Abstract: A corrugated elliptical waveguide comprises a unitary, fluid-impervious, corrugated metallic tube with a substantially elliptical cross section. The corrugated tube is permanently twisted about its longitudinal axis for connecting two terminals having their E planes out of register with each other. The twist is uniformly distributed along a predetermined length of the corrugated tube. The twist is formed by twisting a corrugated circular waveguide about its longitudinal axis and simultaneously converting the circular cross section to an elliptical cross section, thereby causing the twist to be set in the elliptical waveguide.

Abstract: A part such as a long concrete drill provided initially with rectilinear splines is heated in successive zones while producing a controlled increase in the distance between the two extremities. The part to be formed is thus subjected to controlled plastic elongation while the two extremities are driven in rotation at different speeds in order to subject the splined portion to a twisting effort and thus to convert the rectilinear splines to helical splines.

Abstract: Helically corrugated tubing with corrugations that have a gradually changing pitch from one end to the other is manufactured in a twisting machine by rotating one end of a deformable tube about the tube axis relative to the opposite end and simultaneously applying axially directed forces to the tube to progressively develop helical corrugations along the tube wall. The ratio of the torque and the axially directed forces applied to the tube is continuously varied to produce corresponding variations in the pitch of the corrugations. Tubing sections in which the pitch of the corrugations increases gradually from one end to the other are used in shell-and-tube or tube-in-tube heat exchangers and define flow paths having cross sectional areas which increase correspondingly.

Abstract: The constructional parts have walls formed of elongated elements, such as res or tubes, wound spirally in juxtaposition about the axis of symmetry of the part and connected to each other. The elongated elements are bent to shape utilizing a bending device having at least one bending groove conformable to the predetermined three-dimensional geometry of the part to be manufactured. One end of each wire or tube is fixed to the bending device and the other end is engaged in a clamping and adjusting device designed as a combined Cardan swivel joint which, during the bending, it utilized to continuously control the adjustment parameters of the wire or tube, about three mutually intersecting axes, in conformity with such predetermined three-dimensional geometry of the part.

Abstract: An elongated unhardened blank is passed between a first pair of rollers where it is conductively heated by supplying current to one of the rollers. Thereafter, the blank is further heated by induction and then passed between a second pair of rollers where it is shaped so as to impart thereto a predetermined cross-sectional configuration. The rollers of the second pair are profiled and the blank is maintained at an elevated temperature by supplying current to one of the rollers. After shaping, the blank is passed between a third pair of rollers. Current is again supplied to one of these rollers. The other roller is of a diameter corresponding to that desired for the finished annular articles and the blank is coiled about this roller. This latter roller is partially immersed in a quenching medium so that the blank is quenched and thereby hardened as it is being coiled. Coiling is continued until the number of convolutions corresponds to the number of annular articles which are to be produced.

Abstract: A method and apparatus for cold working steel lengths on a continuous basis so as to impart the cold working properties to the steel. The steel is twisted and immediately untwisted so as to impart torsional force into the steel. Tensile forces are also imparted simultaneously into the steel.

Abstract: Helical corrugations are formed in a tube having a cylindrical wall by generating pressure radially of the unsupported tube wall at localized areas distributed around the tube circumference. While the radial pressure is being generated, twisting of the tube about its own axis is initiated and as a result, radial deformation of the unsupported tube wall takes place. By controlling the axial length of the tube while it is twisted, the radial deformations develop into flutes which grow axially along a selected helical path in the tube wall.

Abstract: A machine bed supports stationary and rotary fixing means that are aligned for receiving bar stock therebetween. Electrical or electromechanical control means are provided for selecting and effecting, via a motor-driven step-down gear, exactly a predetermined amount of rotation of the rotary fixing means. Various detachable matching pieces hold opposite portions of the bar stock within the stationary and rotary fixing means, respectively, while the material is worked. Openings in the matching pieces positively fit the bar stock. The outer contour of the matching pieces permits insertion in the stationary and rotary fixing means for positive fit therein. A preferred embodiment of the apparatus serves the purpose of cold twisting square steel bars either singly or, for obtaining volutes, in bunches. Removal of worked bar stock is facilitated by a handwheel enabling the operator to manually counter-rotate the rotary fixing means by a selected small angle.

Abstract: A low cost, lightweight, helically preformed line tie is disclosed which is configured for yieldably securing an elongated conductor or the like to various standard sizes of conventional, grooved insulative supports without the need for specialized ties by provision of a unitary, substantially shape-retaining resilient metallic wire tie which includes a central, generally U-shaped, line-receiving bight and a pair of legs extending therefrom which have intermediate sections adjacent the bight and helically formed line-gripping terminal sections; in preferred forms, the intermediate sections include a pair of interconnected, generally straight segments disposed at an angle relative to each other, and the intermediate sections are wrapped under tension about the support body with the helical leg sections secured about the line for yieldably securing the latter to the support without creation of localized, rigidly held stress areas at the line support points which can lead to premature line failure by virtue of b